text:
US Patent for Systems and methods for diagnosing a vehicle humidity sensor Patent (Patent # 10,197,000 issued February 5, 2019) - Justia Patents Search
Justia Patents With Fuel Injection ControlUS Patent for Systems and methods for diagnosing a vehicle humidity sensor Patent (Patent # 10,197,000)
Jul 26, 2017 - Ford
Methods and systems are provided for diagnosing a humidity sensor positioned in an intake system of a vehicle engine system. In one example, a method comprises rotating an engine unfueled in reverse and injecting a fluid into an exhaust system of the engine system, to draw the fluid into the intake system, where a humidity sensor output signal greater than a baseline output signal by a predetermined threshold is indicative of a humidity sensor that is functioning as desired. In this way, a humidity sensor may be periodically rationalized which may prolong engine lifetime by ensuring the engine is operating at optimal parameters.
The present description relates generally to methods and systems for rationalizing a humidity sensor positioned in an intake system of a vehicle.
Engine systems may be configured with exhaust gas recirculation (EGR) systems via which at least a portion of the exhaust gas is recirculated to the engine intake. Various sensors may be coupled in the engine system to estimate the amount of EGR being delivered to the engine. These may include, for example, various temperature, pressure, oxygen, and humidity sensors. Since the accuracy of the EGR estimation relies on the correct functioning of the various sensors, periodic sensor diagnostics are used. Further, engines with or without EGR need an estimate of air dilution to optimally set the ignition timing, among other controls. Combustion air dilution may be determined based on humidity measurements using humidity sensors, for example.
One example approach for diagnosing a humidity sensor is illustrated by Xiao et al. in U.S. Pat. No. 7,715,976. Therein, humidity sensor degradation is determined based on a comparison of an intake humidity estimated by a first humidity sensor in the intake manifold with an exhaust humidity estimated by a second humidity sensor in the exhaust manifold and an ambient humidity estimated by a third humidity sensor located outside of the engine. The sensor readings are compared during conditions when all the sensor readings are expected to be substantially equal, such as during engine non-fueling conditions in which the EGR valve is closed. If the readings of the three humidity sensors differ by more than a threshold, humidity sensor degradation may be determined.
However, the inventors herein have identified a potential issue with such an approach. The accuracy of determining degradation of any one humidity sensor may depend on the proper functioning of the other humidity sensors. Further, multiple humidity sensors may not be needed for engine control, and thus additional humidity sensors may not be available for comparison.
Another example approach for diagnosing a humidity sensor is illustrated by Pursifull et al. in U.S. Pat. No. 9,482,172. Therein, humidity sensor degradation is indicated based on a comparison of a response of the humidity sensor to a first gas flow and a second gas flow having a known humidity, or at least where the second gas flow is known to have a significantly different humidity than the first gas flow. The second gas flow may include intake manifold air, EGR, exhaust gas, and/or crankcase gas, for example. If the humidity sensor output is different than an expected output when the sensor is exposed to the second gas flow, degradation of the humidity sensor may be indicated.
However, the inventors herein have identified a potential issue with such an approach. For example, such an approach may be susceptible to false indications of degraded humidity sensor(s) if a difference in humidity of the first gas and the second gas is not enough to trigger a significant response in the humidity sensor during the second gas flow as compared to the first. Furthermore, such an approach may rely on engine operation, which may be limited in the case of hybrid electric vehicles (HEVs), start/stop (S/S) vehicles, etc., thus decreasing opportunities for humidity sensor diagnostic tests.
Thus, the inventors herein have developed systems and methods to at least partially address the above-mentioned issues. In one example, a method is provided comprising obtaining a baseline humidity measurement via a humidity sensor positioned in an intake system of an engine, while rotating the engine unfueled in a reverse direction, injecting a fluid into an exhaust system coupled to the engine which is drawn by the engine into the intake system, and rationalizing the humidity sensor as a function of a humidity measurement of the injected fluid by the humidity sensor and the baseline humidity measurement. In this way, the humidity sensor may be rationalized while the engine is not being fueled, which may improve fuel economy and may result in an increased lifetime of the engine.
In one example, the fluid comprises diesel exhaust fluid.
In an example, obtaining the baseline humidity measurement comprises commanding a throttle positioned in the intake system to a predetermined open position to couple the intake system and humidity sensor to atmosphere just prior to rotating the engine unfueled in the reverse direction. In such an example, obtaining the baseline humidity measurement and rationalizing the humidity sensor via rotating the engine unfueled in reverse and injecting the fluid into the exhaust may be commenced responsive to a predetermined duration of time elapsing since a vehicle-off event, where rationalizing the humidity sensor is requested during the vehicle-off event.
In some examples, rotating the engine in reverse is conducted at a predetermined engine speed, and may further include rotating the engine in reverse for a predetermined duration which comprises an amount of time where a response from the humidity sensor is expected provided that the humidity sensor is functioning as desired, without routing the fluid to atmosphere.
In another example, rationalizing the humidity sensor further comprises indicating that the humidity sensor is functioning as desired responsive to the humidity sensor outputting a signal that is greater than a threshold amount above the baseline humidity measurement, and indicating that the humidity sensor is not functioning as desired responsive to the humidity sensor outputting a signal that is lower than the threshold amount above the baseline humidity measurement.
In still another example, such a method may further include responsive to rationalizing the humidity sensor, rotating the engine unfueled in a forward direction, to route the fluid from the intake system back into the exhaust system.
FIGS. 3A-3B schematically shows an example H-bridge circuit which may be used to rotate a vehicle engine in a forward or reverse direction.
FIG. 4 shows a high-level flowchart for conducting a humidity sensor diagnostic and for loading an SCR catalyst.
FIG. 5 shows an example timeline for conducting a humidity sensor diagnostic and for loading an SCR catalyst, according to the method of FIG. 4.
The following description relates to systems and methods for conducting a humidity sensor diagnostic, in order to rationalize a humidity sensor positioned in an intake system of a vehicle. Such a humidity sensor diagnostic may comprise obtaining a baseline humidity sensor value or measurement, and then obtaining a test humidity measurement subsequent to obtaining the baseline humidity measurement. The test humidity measurement may be carried out under conditions where humidity in the vicinity of the humidity sensor may be expected to change. More specifically, to obtain the test humidity measurement, a solution of diesel exhaust fluid (DEF) may be injected into an exhaust system upstream of an SCR catalyst, and the engine may be rotated or spun unfueled in a reverse orientation in order to route the DEF (which contains water) to the intake system in order to rationalize the humidity sensor. Such a method may be carried out in a hybrid vehicle capable of rotating the engine unfueled via a motor, such as the hybrid vehicle depicted at FIG. 1. The humidity sensor may be positioned in an intake system of an engine, where a DEF injector may enable DEF to be injected upstream of the SCR catalyst, as illustrated in FIG. 2. An H-bridge circuit may be utilized to enable the engine to be rotated in the forward or reverse direction, illustrated at FIGS. 3A-3B. A method for conducting the humidity sensor diagnostic, is illustrated at FIG. 4. Subsequent to rationalizing the humidity sensor by rotating the engine in reverse, the engine may be rotated in the forward direction, to route the DEF in the intake system back to the exhaust system. The DEF being routed to the exhaust system may serve to populate or load the SCR catalyst with ammonia, such that the SCR catalyst is loaded and ready for a subsequent engine start event (e.g. engine cold start), which may reduce undesired emissions (e.g. NOx). An example timeline for conducting the humidity sensor diagnostic and for loading the SCR catalyst using DEF injected for the purpose of conducting the humidity sensor diagnostic, is illustrated at FIG. 5.
In still other examples, which will be discussed in further detail below, motor 120 may be configured to rotate engine unfueled in a forward (e.g. default orientation) or reverse orientation, using energy provided via energy storage device 150, exemplified by arrow 186.
Control system 190 may communicate with one or more of engine 110, motor 120, fuel system 140, energy storage device 150, and generator 160. Control system 190 may receive sensory feedback information from one or more of engine 110, motor 120, fuel system 140, energy storage device 150, and generator 160. Further, control system 190 may send control signals to one or more of engine 110, motor 120, fuel system 140, energy storage device 150, and generator 160 responsive to this sensory feedback. Control system 190 may receive an indication of an operator requested output of the vehicle propulsion system from a vehicle operator 102. For example, control system 190 may receive sensory feedback from pedal position sensor 194 which communicates with pedal 192. Pedal 192 may refer schematically to a brake pedal and/or an accelerator pedal. Furthermore, in some examples control system 190 may be in communication with a remote engine start receiver 195 (or transceiver) that receives wireless signals 106 from a key fob 104 having a remote start button 105. In other examples (not shown), a remote engine start may be initiated via a cellular telephone, or smartphone based system where a user's cellular telephone sends data to a server and the server communicates with the vehicle to start the engine.
The vehicle propulsion system 100 may also include an ambient temperature/humidity sensor 198, and a roll stability control sensor, such as a lateral and/or longitudinal and/or yaw rate sensor(s) 199. The vehicle instrument panel 196 may include indicator light(s) and/or a text-based display in which messages are displayed to an operator. The vehicle instrument panel 196 may also include various input portions for receiving an operator input, such as buttons, touch screens, voice input/recognition, etc. For example, the vehicle instrument panel 196 may include a refueling button 197 which may be manually actuated or pressed by a vehicle operator to initiate refueling. For example, as described in more detail below, in response to the vehicle operator actuating refueling button 197, a fuel tank in the vehicle may be depressurized so that refueling may be performed.
Control system 190 may be communicatively coupled to other vehicles or infrastructures using appropriate communications technology, as is known in the art. For example, control system 190 may be coupled to other vehicles or infrastructures via a wireless network 131, which may comprise Wi-Fi, Bluetooth, a type of cellular service, a wireless data transfer protocol, and so on. Control system 190 may broadcast (and receive) information regarding vehicle data, vehicle diagnostics, traffic conditions, vehicle location information, vehicle operating procedures, etc., via vehicle-to-vehicle (V2V), vehicle-to-infrastructure-to-vehicle (V2I2V), and/or vehicle-to-infrastructure (V2I or V2X) technology. The communication and the information exchanged between vehicles can be either direct between vehicles, or can be multi-hop. In some examples, longer range communications (e.g. WiMax) may be used in place of, or in conjunction with, V2V, or V2I2V, to extend the coverage area by a few miles. In still other examples, vehicle control system 190 may be communicatively coupled to other vehicles or infrastructures via a wireless network 131 and the internet (e.g. cloud), as is commonly known in the art.
FIG. 2 shows a schematic depiction of a vehicle system 206. It may be understood that vehicle system 206 may comprise the same vehicle system as vehicle system 100 depicted at FIG. 1. The vehicle system 206 includes an engine system 208 coupled to an emissions control system 251 and a fuel system 218. It may be understood that fuel system 218 may comprise the same fuel system as fuel system 140 depicted at FIG. 1. Emission control system 251 includes a fuel vapor container or canister 222 which may be used to capture and store fuel vapors. The engine system 208 may include an engine 110 having a plurality of cylinders 230. The engine 110 includes an engine air intake system 223 and an engine exhaust system 225. The engine air intake 223 includes a throttle 262 in fluidic communication with engine intake manifold 244 via an intake passage 242. Further, engine air intake 223 may include an air box and filter (not shown) positioned upstream of throttle 262. The engine exhaust system 225 includes an exhaust manifold 248 leading to an exhaust passage 235 that routes exhaust gas to the atmosphere. The exhaust passage may lead to one or more exhaust after-treatment devices (e.g. 226, 229, 236), as well as a reductant delivery and storage system, such as diesel exhaust fluid (DEF) system 238.
The exhaust after-treatment devices may be disposed in various orders and/or combinations along exhaust passage 235. For example, a diesel oxidation catalyst (DOC) 226 may be followed downstream by a selective catalytic reduction (SCR) catalyst 229. SCR catalyst 229 may be followed downstream by a diesel particulate filter (DPF) 236. It should be understood that the emissions control devices of the exhaust system 225 shown in FIG. 2 are exemplary in nature. Various other emission control devices and configurations may be included in engine exhaust system 225. For example, exhaust system 225 may include an SCR catalyst followed by a DPF only. In another example, the exhaust system 225 may only include an SCR catalyst. In still another example, a DPF may be located upstream of the SCR catalyst, or a combined DPF/SCR catalyst may be used.
The engine exhaust system 225 may further include a reductant delivery and/or storage system, such as DEF system 238. The DEF may be a liquid reductant, such as a urea and water mixture, stored in a storage vessel, such as a storage tank. In one example, the DEF system 238 may include DEF tank 239 for onboard DEF storage, a DEF delivery line 240 that couples the DEF tank 239 to exhaust passage 235 via an injector at or upstream of SCR catalyst 229. The DEF tank 239 may be of various forms, and may include a filler neck 241 and corresponding cap and/or cover door in the vehicle body. Filler neck 241 may be configured to receive a nozzle for replenishing DEF.
DEF system 238 may also include a DEF injector 243 in line 240 which injects DEF into the exhaust upstream of the SCR catalyst 229. DEF injector 243 may be used to control the timing and amount of DEF injections, via control system 214. DEF system 238 may further include DEF pump 246. DEF pump 246 may be used to pressurize and deliver DEF into line 240. DEF system 238 may further include a DEF line heater 247 which heats DEF line 240. For example, the DEF line heater 247 may warm the DEF fluid on the way to the DEF pump at low temperatures in order to maintain a DEF fluid viscosity. DEF line heater 247 may be a resistive heater, or various other configurations. DEF line heater 247 may be coupled to energy storage device 150, which may include a battery, and may be enabled and controlled via control system 214, for example.
It will be appreciated that other components may be included in the engine such as a variety of valves and sensors. For example, a barometric pressure sensor 213 may be included in the engine intake. In one example, barometric pressure sensor 213 may be a manifold air pressure (MAP) sensor and may be coupled to the engine intake downstream of throttle 262. Barometric pressure sensor 213 may rely on part throttle or full or wide open throttle conditions, e.g., when an opening amount of throttle 262 is greater than a threshold, in order accurately determine BP.
A humidity sensor 258 may be positioned in the engine air intake, downstream of throttle 262. The humidity sensor may be positioned to determine the humidity of intake air flowing through intake passage 242, for example. In an example, humidity sensor 258 may measure the relative humidity and temperature of gas that the sensor is exposed to. Based on the relative humidity and temperature, the specific humidity of the gas may be determined (e.g. the amount of water per unit mass of gas flow). To measure the relative humidity, a dew point sensor (using a chilled mirror, for example) or a wet bulb/dry bulb sensor may be used. In other examples, the absolute humidity may be measured by a capacitance sensor, and the temperature and/or pressure of the air may be estimated or measured in order to calculate the relative and/or specific humidity.
In particular, engine control systems tend to want to know the specific humidity, for example the humidity ratio of the air. In other words, the engine control system wants to know how much of the air is water vapor (or some other diluent). Some engine humidity sensors measure the absolute humidity, for example the mass of water in a volume of air. In many cases, a humidity sensor may measure absolute humidity, convert it to relative humidity via selected measurements and assumptions, send the relative humidity data to the controller 212 which reconverts to absolute humidity, and then converts to specific humidity. To make such conversions, both pressure and temperature at the point of measurement may be measured or inferred. Accordingly, in some examples, barometric pressure sensor 213 and temperature sensor 260 may be included in close proximity to humidity sensor 258.
The humidity sensor is used inside the engine intake system for engine control purposes. Thus, to ensure that the humidity sensor is functioning as desired, such a sensor may be rationalized via a humidity sensor diagnostic. In some examples, a humidity sensor may be rationalized or diagnosed by comparing its response to that of another downstream humidity sensor, or an oxygen sensor downstream of the humidity sensor. However, such diagnostic strategies may be problematic in that humidity may differ between two or more sensors. For example, humidity may exist in the intake manifold, while not necessarily in the exhaust manifold.
Furthermore, there may be many noise factors that may result in such a diagnostic being challenging to interpret. Examples include incomplete combustion, exhaust temperature, presence of degradation stemming from the intake manifold, exhaust manifold, etc. Other attempts, such as rationalizing the humidity sensor via weather cloud data also poses challenges to interpretation, as humidity may be local and weather map data may be insufficient for such a diagnostic.
Still further, some vehicles such as HEVs, PHEVs, S/S, etc., may have limited engine run time, and thus attempting to utilize downstream exhaust gas sensors or other methods may be futile without significant engine run time. Thus, a more robust humidity sensor test diagnostic is desired, which is the focus of this application, and which will be discussed in further detail below and with regard to FIGS. 4-5.
Engine system 208 may also include an exhaust gas recirculation (EGR) system 249 that receives a portion of an exhaust gas stream exiting engine 110 and returns the exhaust gas to engine intake manifold 244 downstream of throttle 262. Under some conditions, EGR system 249 may be used to regulate the temperature and/or dilution of the air and fuel mixture within the combustion chamber, thus providing a method of controlling the timing of ignition during some combustion modes. Further, during some conditions, a portion of combustion gases may be retained or trapped in the combustion chamber by controlling exhaust valve timing. EGR system 249 is shown forming a common EGR passage 250 from exhaust passage 235 to intake passage 242.
In some examples, exhaust system 225 may also include a turbocharger (not shown) comprising a turbine and a compressor coupled on a common shaft. The turbine may be coupled within exhaust passage 235, while the compressor may be coupled within intake passage 242. Blades of the turbine may be caused to rotate about the common shaft as a portion of the exhaust gas stream discharged from the engine 110 impinges upon the blades of the turbine. The compressor may be coupled to the turbine such that the compressor may be actuated when the blades of the turbine are caused to rotate. When actuated, the compressor may then direct pressurized fresh air to air intake manifold 244 where it may then be directed to engine 110. In systems where EGR passage 250 is coupled to engine exhaust 225 upstream of the turbine and coupled to intake passage 242 downstream of the compressor, the EGR system may be considered a high pressure EGR system. The EGR passage may alternatively be coupled downstream of the turbine and upstream of the compressor (low pressure EGR system).
An EGR valve 253 may be coupled within EGR passage 250. EGR valve 253 may be configured as an active solenoid valve that may be actuated to allow exhaust gas flow into intake manifold 244. The portion of the exhaust gas flow discharged by engine 110 that is allowed to pass through EGR system 249 and return to engine 110 may be metered by the measured actuation of EGR valve 253, which may be regulated by controller 212. The actuation of EGR valve 253 may be based on various vehicle operating parameters and a calculated overall EGR flow rate.
One or more EGR coolers 254 may be coupled within EGR passage 250. EGR cooler 254 may act to lower the overall temperature of the EGR flow stream before passing the stream on to intake manifold 244 where it may be combined with fresh air and directed to engine 110. EGR passage 250 may include one or more flow restriction regions 255. One or more pressure sensors 256 may be coupled at or near flow restriction region 255. The diameter of the flow restriction region ma thus be used to determine an overall volumetric flow rate through EGR passage 250.
An air intake system hydrocarbon trap (AIS HC) 257 may be placed in the intake manifold of engine 110 to adsorb fuel vapors emanating from unburned fuel in the intake manifold, puddled fuel from degraded fuel injectors and/or fuel vapors in crankcase ventilation emissions during engine-off periods. The AIS HC may include a stack of consecutively layered polymeric sheets impregnated with HC vapor adsorption/desorption material. Alternately, the adsorption/desorption material may be filled in the area between the layers of polymeric sheets. The adsorption/desorption material may include one or more of carbon, activated carbon, zeolites, or any other HC adsorbing/desorbing materials. When the engine is operational causing an intake manifold vacuum and a resulting airflow across the AIS HC 257, the trapped vapors may be passively desorbed from the AIS HC and combusted in the engine 110. Thus, during engine operation, intake fuel vapors are stored and desorbed from AIS HC 257. In addition, fuel vapors stored during an engine shutdown can also be desorbed from the AIS HC during engine operation. In this way, AIS HC 257 may be continually loaded and purged, and the trap may reduce evaporative emissions from the intake passage even when engine 110 is shut down.
Controller 212 may comprise a portion of a control system 214. In some examples, control system 214 may be the same as control system 190, illustrated in FIG. 1. Control system 214 is shown receiving information from a plurality of sensors 216 (various examples of which are described herein) and sending control signals to a plurality of actuators 281 (various examples of which are described herein). As one example, sensors 216 may include exhaust gas sensor 237 located upstream of the emission control device 270, temperature sensor 233, pressure sensor 291, pressure sensor 282, and canister temperature sensor 232. Other sensors such as pressure, temperature, air/fuel ratio, and composition sensors may be coupled to various locations in the vehicle system 206. As another example, the actuators may include throttle 262, fuel tank isolation valve 252, canister purge valve 261, and canister vent valve 297. The control system 214 may include a controller 212. The controller may receive input data from the various sensors, process the input data, and trigger the actuators in response to the processed input data based on instruction or code programmed therein corresponding to one or more routines. Example control routines are described herein with regard to FIG. 4.
In some examples, the controller may be placed in a reduced power mode or sleep mode, wherein the controller maintains essential functions only, and operates with a lower battery consumption than in a corresponding awake mode. For example, the controller may be placed in a sleep mode following a vehicle-off event in order to perform a diagnostic routine at a duration after the vehicle-off event. The controller may have a wake input that allows the controller to be returned to an awake mode based on an input received from one or more sensors. For example, the opening of a vehicle door may trigger a return to an awake mode. In other examples, the controller may need to be awake in order to conduct such methods. In such an example, the controller may stay awake for a duration referred to as a time period where the controller is maintained awake to perform extended shutdown functions, such that the controller may be awake to conduct diagnostic routines. In another example, a wakeup capability may enable a circuit to wake the controller when a diagnostic is requested (e.g. when a humidity sensor diagnostic is requested, or when conditions are met for conducting such a diagnostic).
When the engine is spun in the default direction, a vacuum is generated in the intake manifold, while a pressure is generated in the exhaust system. However, if the engine is spun in reverse, a vacuum is generated in the exhaust system, while a pressure is generated in the intake manifold. More specifically, as the engine spins in reverse, the opening of a cylinder exhaust valve (not shown) brings fresh air (and exhaust gas if present) into the cylinder, and a subsequent opening of the cylinder intake valve (not shown) evacuates the cylinder to the intake manifold.
A vehicle such as the vehicle propulsion system 100 described above comprises a hybrid electric vehicle, and as such, the vehicle motor (e.g. 120) may be utilized to spin or rotate the engine unfueled using power supplied via the energy storage device (e.g. 150), such as a battery. In some examples, which will be discussed in further detail below, it may be desired to spin the engine in a reverse orientation (opposite that of the default direction). For example, in order to rationalize the humidity sensor (e.g. 258), DEF may be injected into the exhaust manifold, where spinning the engine in reverse may draw the DEF into the intake, in the direction illustrated by arrow 263, where the humidity sensor may respond due to the DEF comprising a 32.5% UREA and 67.5% deionized water. More specifically, the water content in the injected DEF may result in a response in the humidity sensor (e.g. 258), under conditions where the humidity sensor is functioning as desired.
Subsequent to routing the DEF into the intake manifold, the engine may be spun or rotated unfueled in the forward, or default, direction for a predetermined duration. While the engine is being rotated in the forward direction, the DEF that was routed to the intake manifold may be re-rerouted back to the exhaust system, exemplified by arrow 264. As will be discussed in further detail below, routing DEF back into the exhaust system may serve to populate the SCR catalyst (e.g. 229) with ammonia. In this way, the injected DEF may ensure that the SCR catalyst is primed for an engine start event, such that undesired emissions may be reduced or avoided. In some examples, depending on a loading state and a desired loading state of the SCR catalyst as indicated via a model, one or more additional injections of DEF may be conducted during the rotating the engine unfueled in the forward direction. A method for conducting such a humidity sensor diagnostic will be discussed in detail below with regard to FIG. 4.
FIGS. 3A and 3B show an example circuit 300 that may be used for reversing a spin orientation of an electric motor. Circuit 300 schematically depicts an H-Bridge circuit that may be used to run a motor 310 in a first (forward) direction and alternately in a second (reverse) direction. Circuit 300 comprises a first (LO) side 320 and a second (HI) side 330. Side 320 includes transistors 321 and 322, while side 330 includes transistors 331 and 332. Circuit 300 further includes a power source 340.
In FIG. 3A, transistors 321 and 332 are activated (energized), while transistors 322 and 331 are off. In this confirmation, the left lead 351 of motor 310 is connected to power source 340, and the right lead 352 of motor 310 is connected to ground. In this way, motor 300 may run in a forward direction. When operating the engine in a forward direction via the motor, the engine may be in a cranking mode for initial combustion commencement. Additionally and/or alternatively, when operating the engine in a forward direction via the motor, the engine (and motor or another motor) may be in a drive mode to drive the vehicle. It may be understood that in some examples, the engine may be spun in the forward (e.g. default) direction under conditions where the vehicle is stationary and it is desired only for the engine to be spun or rotated in the forward direction, without combustion.
In FIG. 3B, transistors 322 and 331 are activated (energized), while transistors 321 and 332 are off. In this confirmation, the right lead 352 of motor 310 is connected to power source 340, and the left lead 351 of motor 310 is connected to ground. In this way, motor 310 may run in a reverse direction.
Thus, a system for a vehicle may comprise an engine system including an intake system, exhaust system, and engine, a diesel exhaust fluid injection system configured to inject a diesel exhaust fluid into the exhaust system upstream of a selective catalytic reduction catalyst, a motor configured to at least rotate the engine unfueled via power from a battery, a humidity sensor positioned in the intake system, and a controller storing instructions in non-transitory memory that, when executed, cause the controller to: responsive to conditions being met for conducting a humidity sensor diagnostic test, rotate the engine unfueled in reverse at a predetermined engine speed for a predetermined duration via the motor, inject a predetermined amount of diesel exhaust fluid into the exhaust system where the rotating the engine unfueled in reverse draws the diesel exhaust fluid into the intake system to rationalize the humidity sensor. Such a system may further include additional instructions to, subsequent to rotating the engine unfueled in reverse for the predetermined duration, stop the rotating the engine unfueled in reverse and commence rotating the engine unfueled in a forward direction for a predetermined duration via the motor, to route the diesel exhaust fluid back to the exhaust system in order to load the selective catalytic reduction catalyst with ammonia, and where conditions being met include at least a predetermined vehicle-off duration.
Such a system may further comprise a throttle positioned in the intake system upstream of the humidity sensor, and wherein the controller stores additional instructions to obtain a baseline humidity measurement from the humidity sensor just prior to rotating the engine unfueled in reverse by commanding the throttle to a predetermined open position to couple the intake system to atmosphere. The system may maintain the throttle at the predetermined open position or a fully open position during the rotating the engine unfueled in reverse, and may command or maintain the throttle to the fully open position just prior to rotating the engine unfueled in the forward direction, where rationalizing the humidity sensor includes indicating that the humidity sensor is functioning as desired responsive to a humidity measurement during the rotating the engine unfueled in reverse being greater than the baseline humidity measurement by at least a threshold amount.
For such a system, the diesel exhaust fluid may comprise a mixture of urea and water, where the water may stimulate the humidity sensor to rationalize the humidity sensor, and where the urea may be converted to ammonia at the selective catalytic reduction catalyst.
Such a system may further comprise an exhaust gas recirculation system selectively coupled to the engine system via an exhaust gas recirculation valve, an evaporative emissions system selectively coupled to the engine system via a canister purge valve, and the controller may store additional instructions to command both the exhaust gas recirculation valve and the canister purge valve to closed positions during the rotating the engine unfueled in both the forward and reverse directions.
Turning now to FIG. 4, a high-level example method 400 for conducting a humidity sensor diagnostic on a humidity sensor positioned in an engine intake system of a vehicle, is shown. More specifically, method 400 may include injection of a diesel exhaust fluid (DEF) into an exhaust system upstream of an SCR catalyst, and may further include rotating or spinning an engine in a reverse orientation (compared to a default, or forward direction) in order to route the DEF into the intake system of the engine. In cases where the humidity sensor is functioning as desired, the humidity sensor may output a response greater than a threshold response over a baseline humidity measurement. However, if the humidity sensor is not functioning as desired, the humidity sensor may not respond, or any response may be below the threshold response over the baseline humidity measurement. Subsequent to assessing the functionality of the humidity sensor, the engine may be spun or rotated in the forward direction, to direct the DEF back into the exhaust system, where it may serve to populate the SCR catalyst with ammonia, for subsequent engine startup event. In this way, a vehicle intake humidity sensor may be diagnosed via the water content of the DEF, as one commonly used DEF comprises 32.5% UREA and 67.5% deionized water, and furthermore the injection of DEF may additionally populate the SCR catalyst in the exhaust system, subsequent to diagnosing the humidity sensor.
Method 400 will be described with reference to the systems described herein and shown in FIGS. 1-2, though it should be understood that similar methods may be applied to other systems without departing from the scope of this disclosure. Method 400 may be carried out by a controller, such as controller 212 in FIG. 2, and may be stored at the controller as executable instructions in non-transitory memory. Instructions for carrying out method 400 and the rest of the methods included herein may be executed by the controller based on instructions stored on a memory of the controller and in conjunction with signals received from sensors of the engine system, such as the sensors described above with reference to FIGS. 1-2. The controller may employ engine system actuators, such as motor (e.g. 120), throttle (e.g. 262), canister purge valve (e.g. 261), EGR valve (e.g. 253), DEF injector (e.g. 243), DEF pump (e.g. 246), DEF heater (e.g. 247), etc., according to the method below.
Method 400 begins at 405, and may include indicating whether conditions are met for conducting a humidity sensor diagnostic. Conditions being met for conducting the humidity sensor diagnostic may include a predetermined amount of time elapsing since a prior humidity sensor diagnostic, in one example. The predetermined amount of time may include less than two days, two days, three days, greater than three days but less than 8 days, greater than 8 days but less than 12 days, etc.
In some examples conditions being met at 405 may additionally or alternatively include an indication that the humidity sensor (e.g. 258) is not functioning as desired. Examples may include a situation where the vehicle controller (e.g. 212) may monitor variation in an output signal from the humidity sensor during a transient time period such as an engine cold start, to indicate if the sensor is outputting a changing humidity as expected. In some examples, the controller may additionally or alternatively compare humidity sensor output signals and measurements across a number of prior drive cycles and different days of operation of the vehicle in order to indicate with a certain probability that the humidity sensor may not be functioning as desired. Other examples may include the vehicle controller comparing output signals from the humidity sensor to humidity readings obtained from a source external to the vehicle, such as regional or local weather reports (obtained via communication with the internet, for example) or forecast from a satellite of other weather broadcast. Still other examples may include comparison of the vehicle's humidity sensor output with one or more other vehicle or infrastructure humidity sensors, where such data may be acquired via V2V (vehicle-to-vehicle) or V2X (vehicle-to-infrastructure) communications, etc. In such examples, the humidity external to the vehicle may comprise a humidity that may be indicative of the humidity as sensed by the vehicle humidity sensor (e.g. 258), for example. Thus, such comparisons of vehicle humidity sensor measurements with an external humidity sensor may be restricted to external humidity sensor measurements within a predetermined radius or specified distance from the vehicle.
In still further examples, conditions being met at 405 may additionally or alternatively include an indication that a soak-time, or vehicle-off duration of time since a key-off event, is greater than a threshold soak-time duration. For examples, such a threshold soak-time duration may comprise 2 hours, between 2 hours and 4 hours, between 4 hours and 8 hours, etc. In some examples, the soak-time threshold may be a function of an amount of time for exhaust temperatures, engine heat from combustion during a previous drive cycle, etc., to reach a point where such factors may not adversely affect the outcome of the humidity sensor diagnostic.
In still further examples, conditions being met at 405 may additionally or alternatively include an indication that an amount of DEF stored in the DEF tank (e.g. 239) is greater than a threshold amount, such that DEF may be reliably injected into the exhaust system, as will be described in further detail below.
In yet another example, conditions being met at 405 may additionally or alternatively include an indication that there is not degradation in the intake system, exhaust system, or engine which would adversely affect the outcome of the humidity sensor diagnostic.
If, at 405, it is indicated that conditions are not met for conducting the humidity sensor diagnostic, method 400 may proceed to 410. At 410, method 400 may include maintaining current vehicle operating parameters. Maintaining current vehicle operating parameters at 410 may include maintaining engine operation if the vehicle is being propelled at least in part, via the engine. Other examples may include maintaining operation of a motor (e.g. 120) to propel the vehicle, if the vehicle is being propelled at least in part, via the motor. In still other examples, if the vehicle is not in operation, but conditions are not yet indicated to be met for conducting the humidity sensor diagnostic, method 400 may include maintaining relevant components of the vehicle system in their current states. Method 400 may then end.
Alternatively, if, at 405, it is indicated that conditions are met for conducting the humidity sensor diagnostic, method 400 may proceed to 415. At 415, method 400 may include waking the vehicle controller, such that the diagnostic may be conducted. As an example, one or more of the above-mentioned conditions may be indicated to be met for conducting the humidity sensor diagnostic at a key-off event, where the vehicle system is shut down. However, for conditions to be fully met for conducting the humidity sensor diagnostic, the vehicle system may need to soak for the threshold soak-time duration. Thus, at the key-off event the vehicle controller may request a humidity sensor diagnostic, or humidity sensor rationalization, to be conducted during the vehicle-off condition, and may thus set a timer that may be coupled to a circuit that may enable the circuit to wake the controller in response to the timer duration expiring.
Responsive to waking the controller at 415, method 400 may proceed to 420. At 420, method 400 may include commanding or maintaining a throttle (e.g. 262) to a predetermined open position. In some examples, the predetermined open position may comprise a position greater than closed but not fully open, or fully open. By commanding or maintaining the throttle at the predetermined open position, the humidity sensor (e.g. 258) positioned in the intake system may sense a similar humidity as that of air external to the vehicle (e.g. in a vicinity immediately surrounding the vehicle). Furthermore, at 420, method 400 may include commanding or maintaining both a CPV (e.g. 261) and an EGR valve (e.g. 253) in their respective closed configurations.
With the throttle commanded to the predetermined open position, and with the CPV and EGR valve closed, method 400 may proceed to 425 and may include obtaining baseline humidity data. For example, because the humidity sensor may sense a similar environment as that immediately surrounding the vehicle, due to the throttle being in the predetermined open position, it may be understood that the baseline humidity data obtained at 425 may represent humidity of the air in the vicinity immediately surrounding the vehicle.
Baseline humidity data may be retrieved via the controller after a predetermined duration subsequent to commanding the throttle to the predetermined open position. The predetermined duration may comprise a duration where it is expected that the air in the intake system is substantially equivalent to the air immediately surrounding the vehicle. In other words, the predetermined duration may comprise a duration where air immediately external to the vehicle may sufficiently mix with air in the intake system of the vehicle, until the air in the intake system is substantially equivalent to the air immediately external to the vehicle. Thus, the humidity sensor readings during the obtaining the baseline data may represent humidity substantially equivalent to humidity immediately surrounding the vehicle. In examples where the throttle is already at the predetermined open position, then baseline data may be obtained immediately at 425, as the air in the intake system would already be expected to be substantially equivalent to air immediately surrounding the vehicle.
Baseline humidity data may be obtained via one or more readings or output signals sent from the humidity sensor to the controller. In a case where a plurality of readings are obtained, the readings may be averaged or otherwise processed to obtain a high confidence baseline humidity measurement. The baseline humidity sensor data may be stored at the controller.
Proceeding to 430, method 400 may include injecting a predetermined amount of DEF into the vehicle exhaust system upstream of the SCR catalyst. The predetermined amount may comprise an amount of DEF that is likely to result in the humidity sensor outputting a response greater than a threshold response over the baseline humidity measurement under conditions where the humidity sensor is functioning as desired. As will be discussed below, in some examples, the predetermined amount of DEF injected may further be a function of a current level of ammonia stored at the SCR catalyst compared to a desired level. For example, more DEF may in some examples be injected if the current level of ammonia stored at the SCR catalyst is lower, as compared to a situation where the current level of ammonia stored at the SCR catalyst is higher. In a case where more DEF is injected based on the current level of ammonia stored at the SCR catalyst, any thresholds (discussed below) related to the rationalizing of the humidity sensor may be adjusted accordingly. For example, a threshold for indicating the humidity sensor is functioning as desired may be raised under conditions where more DEF is injected than usual.
At 430, method 400 may further include rotating the engine in reverse unfueled. As mentioned above, rotating the engine in reverse may be conducted via a motor (e.g. 120), via power from an onboard energy storage device (e.g. 150). In some examples, the engine may be rotated for a predetermined duration at a predetermined speed prior to the injection of the DEF into the exhaust system. By rotating the engine prior to DEF injection, the DEF injection may be more likely to vaporize and easily be drawn into the intake manifold where the water content may excite the humidity sensor.
As mentioned, the engine may be rotated in reverse in some examples prior to injection of DEF into the exhaust system. In some examples, the predetermined duration and predetermined speed of engine rotation in reverse may comprise a predetermined duration and predetermined speed such that a predetermined temperature may be reached in the exhaust system/engine. The predetermined temperature may comprise a temperature that encourages vaporization of the DEF, such that it may be readily drawn into the intake system via the engine spinning in reverse.
In some examples, the speed at which the engine is rotated in reverse prior to the DEF injection may be the same or substantially equivalent speed at which the engine is rotated after the DEF injection. However, in other examples, the speed may not be the same, and the engine speed subsequent to the DEF injection may be either less than, or greater than engine speed just prior to the DEF injection.
Subsequent to the DEF injection, the engine may be spun for (another) predetermined duration in reverse, where such a predetermined duration may comprise an amount of time where it is expected that the DEF would be routed to the intake system to excite the humidity sensor, but not routed past the throttle and to atmosphere. In other words, the duration of engine spinning in reverse may comprise a duration whereby the humidity sensor may be excited via the water content of the DEF, but where duration is not sufficient to route the DEF out of the intake system to atmosphere.
Proceeding to 435, method 400 may include indicating whether the humidity sensor response during the spinning the engine unfueled in reverse (subsequent to the injection of DEF into the exhaust system) is greater than the baseline humidity data obtained at step 425 by the threshold amount. If the response is indicated to not be greater than the threshold amount subsequent to the predetermined duration of engine spinning in reverse after injection of DEF into the exhaust system, method 400 may proceed to 440. At 440, method 400 may include indicating that the humidity sensor is degraded, or is not functioning as desired. Proceeding to 445, method 400 may include updating vehicle operating parameters to reflect the degraded humidity sensor. In some examples, updating vehicle operating parameters at 445 may include the vehicle controller commanding an electric-only mode of vehicle operation as frequently as possible, to mitigate any issues with engine operation stemming from an inaccurate humidity measurement. In other examples, humidity may be estimated or approximated via sources external to the vehicle. For example, humidity estimations may be retrieved via V2V or V2X communications, where the vehicle controller initiates communication with one or more other vehicles or infrastructures within a predetermined threshold radius or other distance of the vehicle, in order to retrieve reasonable estimates of humidity in close proximity to the vehicle. In other examples, humidity measurements may be retrieved via GPS or other onboard navigation system, and may include cross-referencing humidity data with humidity data retrieved from the internet, for example. In still other examples, humidity may be estimated via other sensors positioned in the vehicle, if the vehicle is equipped with such sensors. In some examples, such a humidity estimate may be retrieved from one or more sensors that may reflect a similar humidity as that in the intake system of the vehicle.
Subsequent to updating vehicle operating parameters at 445 in response to indicated degradation of the humidity sensor position in the vehicle intake system, method 400 may proceed to 450. At 450, method 400 may include stopping the engine spinning in reverse, and may include spinning the engine unfueled in the default, or forward, direction, for a predetermined duration. In such an example, an H-bridge, such as that depicted in FIGS. 3A-3B, may be utilized such that the vehicle controller may actuate the engine to rotate in the forward direction. As with the reverse engine spin, a default or forward engine spin may be carried out via the motor (e.g. 120), using power supplied via the onboard energy storage device (e.g. 150), which may comprise a battery, for example.
Spinning the engine unfueled in the forward direction may comprise spinning the engine unfueled in the forward direction for a predetermined duration. Spinning the engine unfueled in the forward direction may serve at least two purposes. First, spinning the engine in the forward direction may result in a vacuum in the intake system, which may thus route the injected DEF back to the exhaust system. Second, as discussed above, the exhaust system may include a selective catalytic reduction (SCR) catalyst. Thus, by spinning the engine unfueled in the forward direction, the DEF may be used to load the SCR. More specifically, as mentioned above, DEF comprises a mixture of water and urea. The urea from the injected DEF breaks down to form ammonia (NH3), which is the reductant utilized in reactions with oxides of nitrogen (NOx) from exhaust flow while the engine is in operation and is combusting fuel and air. Briefly, the ammonia is adsorbed onto the SCR catalyst, which is then utilized to convert NOx to nitrogen and water, with CO2 as a reaction product.
The complete decomposition of urea takes place in several steps when the vehicle engine is combusting air and fuel. The water in the solution is first evaporated, releasing the urea. The urea then decomposes to release one ammonia molecule and one isocyanic acid (HNCO) molecule. The next step is for the HNCO to decompose to release a second NH3 molecule, and one CO2. The two ammonia molecules may then be available for NOx reduction.
However, it is known that urea decomposition to two ammonia molecules does not reach completion in the gas phase at temperatures below about 300° C. More specifically, only about 20% of urea decomposes to HNCO and NH3 in the gas phase at 300° C., and HNCO has been shown to be very stable in the gas phase. Thus, during low temperature conditions such as when the engine is spun in the forward direction in the presence of DEF injected into the exhaust system upstream of the SCR catalyst, very nearly all of the urea decomposition may occur on the surfaces of the SCR catalyst. In this way, the SCR catalyst may be loaded with ammonia to be utilized in reactions with NOx at a next engine startup event, where such a startup event includes the engine combusting air and fuel. By pre-loading the SCR catalyst, injections of DEF may be delayed or otherwise altered as a function of the loading state of the SCR catalyst at a next engine startup event.
As mentioned, to route DEF from the intake system to the exhaust system, to populate the SCR catalyst with ammonia, the engine may be spun unfueled for the predetermined duration. The predetermined duration may thus include an amount of time expected for all of the DEF to be completely re-rerouted back to the exhaust system. In some examples, engine speed may comprise a same or substantially equivalent engine speed in the forward direction as the speed the engine was spun in the reverse direction. However, in other examples, engine speed may be differentially controlled when spinning the engine in the forward direction at step 450. For example, engine speed may be increased in some examples. In other examples, engine speed may be decreased in the forward direction as compared to when it was spun in the reverse direction. In still other examples, engine speed may be controlled to achieve a desired engine temperature. The desired temperature may in some examples comprise a temperature where it is likely that all the DEF is routed from the intake system to the exhaust system.
In some examples, the vehicle controller may include or employ an SCR catalyst model that may estimate an amount of ammonia that is loaded onto the SCR catalyst. Thus, a loading state of the SCR catalyst may be known or estimated via the vehicle controller, prior to conducting the humidity sensor diagnostic. Based on the amount injected, and current canister loading state, the vehicle controller may estimate an updated loading state of the SCR catalyst (where loading state refers to an amount of ammonia loaded onto the SCR catalyst). Accordingly, proceeding to 455, method 400 may include indicating an updated SCR catalyst loading state, after the engine has been spun unfueled in the forward direction for the predetermined duration. While not explicitly illustrated, in some examples, one or more additional DEF injections may be performed during the spinning the engine unfueled in the forward direction, as a function of SCR catalyst loading state. For example, if a current loading state (prior to conducting the humidity sensor diagnostic) is known, and it is inferred from the SCR catalyst model that one DEF injection would not sufficiently populate the SCR catalyst with a desired level (e.g. saturation level) of ammonia, then one or more additional injections of DEF may be conducted during the spinning the engine unfueled in the forward direction. The desired level of ammonia loaded onto the catalyst may comprise a level at which reductions in emissions may be accomplished during a subsequent cold-start of the engine, for example.
Subsequent to updating a loading state of the SCR catalyst at 455, method 400 may proceed to 460. At 460, method 400 may include stopping the spinning the engine in the forward direction, and may further include returning the throttle to the default configuration. In other examples, the throttle may be maintained in its current configuration. Stopping the engine may comprise the vehicle controller commanding the electric motor to slow the vehicle engine to a halt, or in other examples the motor may be shut off, and the engine may spin to a halt. Method 400 may then end.
Returning to 435, if the humidity sensor response is greater than the baseline data by the threshold amount subsequent to injecting the DEF into the exhaust system and rotating the engine unfueled in reverse, method 400 may proceed to 465. At 465, method 400 may include indicating that the humidity sensor is functioning as desired. For example, such an indication may be stored at the controller, indicating a time and date of the successful humidity sensor test diagnostic. Proceeding to 470, method 400 may include updating vehicle operation parameters. For example, since the outcome of the humidity sensor indicated that the humidity sensor is functioning as desired, vehicle operating parameters may be maintained at 470. Furthermore, a humidity sensor diagnostic test schedule may be updated, to reflect the recent results of the humidity sensor test diagnostic.
Continuing to 450, the rest of method 400 may be conducted in a substantially equivalent fashion as that described above. Briefly, the engine may be controlled via the vehicle controller to stop spinning in the reverse direction, and may be commanded to rotate in the forward direction for a predetermined duration, to populate or load the SCR catalyst with ammonia to prepare the vehicle for a subsequent start-up event. During the spinning the engine in the forward direction, one or more additional injections of DEF may be conducted, based on the model of the loading state of the SCR catalyst, and a desired loading state.
At 455, the loading state of the SCR catalyst may be updated as a function of the amount of DEF injected into the exhaust system. Such an updated loading state may be based on a model of SCR catalyst loading state, as discussed above. Subsequent to updating the loading state of the SCR catalyst, method 400 may proceed to 460, and may include stopping the engine spinning in reverse, and may include restoring the throttle to the default position, or maintaining the throttle in its current configuration. Method 400 may then end.
Thus, a method may include injecting a diesel exhaust fluid into an exhaust system of an engine of the vehicle, and rotating the engine unfueled in reverse to draw the diesel exhaust fluid into an intake system of the engine. The method may include rationalizing a humidity sensor positioned in the intake system subsequent to the injection of the diesel exhaust fluid into the exhaust system and the rotating the engine unfueled in reverse, and rotating the engine unfueled in a forward direction subsequent to rationalizing the humidity sensor, to route the diesel exhaust fluid back into the exhaust system.
In one example, the method may further comprise obtaining a baseline humidity sensor measurement from the humidity sensor positioned in the intake system just prior to injecting the diesel exhaust fluid into the exhaust system and rotating the engine unfueled in reverse, where obtaining the baseline humidity sensor measurement includes commanding an intake system throttle to a predetermined open position, to couple the intake system to atmosphere. In such a method, rationalizing the humidity sensor may include indicating that the humidity sensor is functioning as desired responsive to a humidity sensor test measurement during the drawing the diesel exhaust fluid into the intake system being greater than the baseline humidity sensor measurement by at least a threshold amount.
In another example, the method may further comprise maintaining a canister purge valve configured to couple an evaporative emissions system of the vehicle to an engine system, in a closed conformation, and maintaining an exhaust gas recirculation valve configured to enable exhaust gas to be routed back to the intake system, in a closed conformation during the rotating the engine unfueled in both the reverse direction and the forward direction.
In yet another example of the method, injecting the diesel exhaust fluid into the exhaust system may further comprise injecting the diesel exhaust fluid into the exhaust system upstream of a selective catalytic reduction catalyst, and wherein rotating the engine in the forward direction subsequent to rationalizing the humidity sensor routes the diesel exhaust fluid into the exhaust system in order to load the selective catalytic reduction catalyst with ammonia. In such an example, a controller of the vehicle may employ a model to infer a loading state of the selective catalytic reduction catalyst, where inferring the loading state involves determining an amount of ammonia loaded on the selective catalytic reduction catalyst. In some examples, such a method may further comprise injecting additional diesel exhaust fluid into the exhaust system during the rotating the engine in the forward direction, based on a desired loading amount of the selective catalytic reduction catalyst with ammonia. As an example, the diesel exhaust fluid may comprise a mixture of urea and water, and where the urea may react with the selective catalytic reduction catalyst to form ammonia.
In still another example of the method, injecting the diesel exhaust fluid into the exhaust system of the engine is commenced via a wake-up of the controller at a predetermined duration of time after a vehicle-off event, where a request to rationalize the humidity sensor is requested for the vehicle-off event.
Turning now to FIG. 5, an example timeline 500 is shown for conducting a humidity sensor diagnostic, according to the methods depicted herein and with reference to FIG. 4, and as applied to the systems depicted herein and with reference to FIGS. 1-2. Timeline 500 includes plot 505, indicating an engine speed, over time. Engine speed may represent speed of the engine while the engine is being spun, or rotated, in the forward or reverse direction. In such examples, an electric motor (e.g. 120) may be used to rotate the motor in the forward or reverse direction. Timeline 500 further includes plot 510, indicating whether fuel injection to one or more engine cylinders is on, or off, over time. Timeline 500 further includes plot 515, indicating a position of an intake throttle (e.g. 262), over time. Timeline 500 further includes plot 520, indicating whether a DEF injector (e.g. 243) is on (where DEF is injected) or off (where DEF injection is prevented), over time. While not explicitly illustrated, it may be understood that in order for DEF to be injected, a DEF pump (e.g. 246) may be activated to pressurize DEF to route it to the DEF injector.
Timeline 500 further includes plot 525, indicating an output signal from a humidity sensor (e.g. 258), over time, where the output signal corresponds to an estimated, inferred, or measured humidity in the vicinity of the humidity sensor. Line 526 represents a baseline humidity in an intake system of the vehicle. Line 527 represents a threshold humidity (humidity greater than the baseline humidity by a threshold amount), which, if reached or exceeded during a humidity sensor diagnostic, indicates that the humidity sensor is functioning as desired.
Timeline 500 further includes plot 530, indicating whether conditions are met (yes) or not (no) for conducting the humidity sensor diagnostic, discussed in detail above at step 405 of method 400. Timeline 500 further includes plot 535, indicating a loading state of an SCR catalyst, over time. Here, loading state may refer an amount of ammonia (NH3) loaded onto the SCR catalyst. Line 536 represents a desired SCR catalyst loading state. Timeline 500 further includes plot 540, indicating whether the humidity sensor is functioning as desired (yes) or not (no), over time.
At time t0, the engine is off (plot 505) and thus fuel injection (plot 510) to one or more engine cylinders is off. The intake throttle is in a default closed position (plot 515), and the DEF injector is off (plot 520). Conditions are not yet indicated to be met for conducting the humidity sensor diagnostic (plot 530). The SCR catalyst is populated with some ammonia (plot 535), but is not saturated, and there is no conclusive information indicating that the humidity sensor is not functioning as desired, and thus, the humidity sensor is indicated to be functioning as desired (plot 540).
Thus, it may be understood that at time t0 the vehicle is an off configuration. The controller may not be awake at time t0, thus the humidity sensor may not be actively monitoring/measuring humidity in the intake system. Accordingly, between time t0 and t1, plot 525 is indicated as a dashed line, representing an actual humidity in the intake system, for reference.
At time t1, conditions are indication to be met for conducting the humidity sensor diagnostic. As discussed above at step 405 of method 400, there may be a plurality of conditions that may be met prior to conducting the humidity sensor diagnostic. In this example timeline, it may be understood that at time t1, a soak-time, or vehicle-off duration since a key-off event is greater than a threshold soak-time duration. In other words, between time t0 and t1, a humidity sensor diagnostic is requested, however the soak-time duration is less than the threshold soak-time duration. Thus, between time t0 and t1, conditions are not indicated to be met for conducting the humidity sensor diagnostic, but at time t1 conditions are indicated to be met as the soak-time threshold duration is indicated.
Accordingly, at time t1, the throttle (e.g. 262) is controlled to a predetermined open position, as discussed above at step 420 of method 400. The predetermined open position may comprise a position such that the intake system is coupled to atmosphere, such that the intake system air may become substantially equivalent to external air immediately surrounding the vehicle.
With the throttle controlled to the predetermined open position, between time t1 and t2, one or more humidity sensor measurements are obtained via the vehicle controller. More specifically, the humidity sensor may output a signal which is a function of humidity, and such a signal may be communicated to the vehicle controller. As discussed, in some examples, a plurality of measurements may be obtained, and averaged or otherwise processed to obtain a high confidence humidity measurement. Such a measurement may comprise a baseline humidity measurement. Accordingly, by time t2, a baseline humidity measurement, indicated by line 526, is established and stored at the vehicle controller.
At time t2, subsequent to obtaining the baseline humidity sensor data, represented by line 526, the engine is initiated to rotate in reverse at a predetermined engine speed (RPM) for a predetermined duration. Rotating the engine in reverse may be carried out via a motor (e.g. 120). With the engine rotating in reverse, between time t2 and t3, a single injection of DEF is commanded via the vehicle controller, upstream of the SCR catalyst. With the engine rotating in reverse, and with DEF injected into the exhaust system, a vacuum may develop in the exhaust system which may route the injected DEF into the intake manifold of the vehicle, where the humidity sensor may respond if the humidity sensor is functioning as desired.
At time t3, the humidity sensor outputs a signal that is substantially equivalent to the threshold humidity (humidity greater than the baseline humidity by a threshold amount), and between time t3 and t4, the humidity sensor output signal exceeds the threshold. Accordingly, the humidity sensor is indicated to be functioning as desired (e.g. the diagnosis of the humidity sensor as functioning as desired remains unchanged).
At time t4, the predetermined duration of rotating the engine in reverse expires. Accordingly, between time t4 and t5, the engine is slowed to an off configuration, and then at time t5 the engine is again commenced rotating unfueled via the electric motor, yet this time the engine is rotated in the forward, or default, direction. Furthermore, responsive to rotating the engine in the forward direction, the throttle is commanded to a more open position than that during the rotating the engine unfueled in reverse. In this way, an amount of air flow through the intake system and into the exhaust system may be increased.
Between time t5 and t6, the engine is rotated in the forward direction, and two more injections of DEF are commanded via the vehicle controller. The injections may be based on a loading state of the SCR catalyst, which may be indicated via a model stored at the controller, for example. Such a model may be based on at least engine run time, DEF injection number and amount, etc. More specifically, the model may indicate current SCR catalyst loading state, and the model may further indicate a desired SCR catalyst loading state, indicated by line 536. The desired loading state may represent a loading state that may reduce undesired emissions at a subsequent engine cold-start event, for example.
With the engine rotating in the forward direction between time t5 and t6, and responsive to the additional injections of DEF into the exhaust system upstream of the SCR catalyst, SCR loading state rises until the desired SCR catalyst loading state is reached.
At time t6, the predetermined duration for rotating the engine in the forward direction expires. Thus, at time t6 it may be understood that the DEF that was routed to the intake system (e.g. the first injection between time t2 and t3) is now all re-rerouted out of the intake system and into the exhaust system, where it may populate the SCR catalyst with ammonia, along with the two DEF injections (between time t5 and t6) which may further serve to populate the SCR catalyst with ammonia.
Responsive to the predetermined duration for rotating the engine in the forward direction expiring, the engine may be controlled to an off configuration, and the throttle may be controlled to its default vehicle-off configuration.
In this way, a humidity sensor positioned in the intake system of a hybrid vehicle may be periodically rationalized, such that it may be indicated as to whether the humidity sensor is functioning as desired. Such a method utilizing DEF injection into the exhaust system and subsequent routing of the DEF to the intake system where it may interact with the humidity sensor, may enable humidity sensor rationalization in a vehicle where engine run time is limited, such as a hybrid electric vehicle (HEV), plug-in hybrid electric vehicle (PHEV), S/S/, etc. By using such a method, rationalizing the humidity sensor via other humidity sensors in the vehicle, temperature sensors, pressure sensors, oxygen sensors, etc., may be avoided, which may reduce uncertainty in the humidity estimations.
The technical effect is to recognize that DEF comprises a solution in which the water content of the DEF may be used to rationalize the humidity sensor, and that routing DEF to the intake humidity sensor may be accomplished via rotating the engine unfueled in reverse subsequent to a DEF injection into the exhaust system. A further technical effect is to recognize that the DEF injected into the exhaust system, and routed to the intake system, may further be routed back to the exhaust system subsequent to rationalization of the humidity sensor. In this way, the DEF may be purged from the intake system subsequent to the humidity sensor diagnostic. Thus, a still further technical effect is to recognize that the DEF being re-routed to the exhaust system may be utilized to load an SCR catalyst with ammonia, for use in a subsequent engine start event.
The systems described herein, and with reference to FIGS. 1-3B, along with the methods described herein, and with reference to FIG. 4, may enable one or more systems and one or more methods. In one example, a method comprises obtaining a baseline humidity measurement via a humidity sensor positioned in an intake system of an engine; while rotating the engine unfueled in a reverse direction, injecting a fluid into an exhaust system coupled to the engine which is drawn by the engine into the intake system; and rationalizing the humidity sensor as a function of a humidity measurement of the injected fluid by the humidity sensor and the baseline humidity measurement. In a first example of the method, the method may further include wherein the fluid comprises diesel exhaust fluid. A second example of the method optionally includes the first example, and further includes wherein obtaining the baseline humidity measurement comprises commanding a throttle positioned in the intake system to a predetermined open position to couple the intake system and humidity sensor to atmosphere just prior to rotating the engine unfueled in the reverse direction. A third example of the method optionally includes any one or more or each of the first and second examples, and further includes wherein obtaining the baseline humidity measurement and rationalizing the humidity sensor via rotating the engine unfueled in reverse and injecting the fluid into the exhaust is commenced responsive to a predetermined duration of time elapsing since a vehicle-off event, where rationalizing the humidity sensor is requested during the vehicle-off event. A fourth example of the method optionally includes any one or more or each of the first through third examples, and further comprising rotating the engine in reverse at a predetermined engine speed. A fifth example of the method optionally includes any one or more or each of the first through fourth examples, and further includes wherein rotating the engine in reverse is for a predetermined duration which comprises an amount of time where a response from the humidity sensor is expected provided that the humidity sensor is functioning as desired, without routing the fluid to atmosphere. A sixth example of the method optionally includes any one or more or each of the first through fifth examples, and further includes wherein rationalizing the humidity sensor further comprises indicating that the humidity sensor is functioning as desired responsive to the humidity sensor outputting a signal that is greater than a threshold amount above the baseline humidity measurement; and indicating that the humidity sensor is not functioning as desired responsive to the humidity sensor outputting a signal that is lower than the threshold amount above the baseline humidity measurement. A seventh example of the method optionally includes any one or more or each of the first through sixth examples, and further comprises responsive to rationalizing the humidity sensor, rotating the engine unfueled in a forward direction, to route the fluid from the intake system back into the exhaust system.
Another example of a method comprises injecting a diesel exhaust fluid into an exhaust system of an engine of the vehicle, and rotating the engine unfueled in reverse to draw the diesel exhaust fluid into an intake system of the engine; rationalizing a humidity sensor positioned in the intake system subsequent to the injection of the diesel exhaust fluid into the exhaust system and the rotating the engine unfueled in reverse; and rotating the engine unfueled in a forward direction subsequent to rationalizing the humidity sensor, to route the diesel exhaust fluid back into the exhaust system. In a first example of the method, the method further comprises obtaining a baseline humidity sensor measurement from the humidity sensor positioned in the intake system just prior to injecting the diesel exhaust fluid into the exhaust system and rotating the engine unfueled in reverse, where obtaining the baseline humidity sensor measurement includes commanding an intake system throttle to a predetermined open position, to couple the intake system to atmosphere; and wherein rationalizing the humidity sensor includes indicating that the humidity sensor is functioning as desired responsive to a humidity sensor test measurement during the drawing the diesel exhaust fluid into the intake system being greater than the baseline humidity sensor measurement by at least a threshold amount. A second example of the method optionally includes the first example, and further comprises maintaining a canister purge valve, configured to couple an evaporative emissions system of the vehicle to an engine system, in a closed conformation, and maintaining an exhaust gas recirculation valve configured to enable exhaust gas to be routed back to the intake system, in a closed conformation during the rotating the engine unfueled in both the reverse direction and the forward direction. A third example of the method optionally includes any one or more or each of the first and second examples, and further includes wherein injecting the diesel exhaust fluid into the exhaust system further comprises injecting the diesel exhaust fluid into the exhaust system upstream of a selective catalytic reduction catalyst; and wherein rotating the engine in the forward direction subsequent to rationalizing the humidity sensor routes the diesel exhaust fluid into the exhaust system in order to load the selective catalytic reduction catalyst with ammonia. A fourth example of the method optionally includes any one or more or each of the first through third examples, and further includes wherein a controller of the vehicle employs a model to infer a loading state of the selective catalytic reduction catalyst, where inferring the loading state involves determining an amount of ammonia loaded on the selective catalytic reduction catalyst. A fifth example of the method optionally includes any one or more or each of the first through fourth examples, and further comprises injecting additional diesel exhaust fluid into the exhaust system during the rotating the engine in the forward direction, based on a desired loading amount of the selective catalytic reduction catalyst with ammonia. A sixth example of the method optionally includes any one or more or each of the first through fifth examples, and further includes wherein the diesel exhaust fluid comprises a mixture of urea and water, and where the urea reacts with the selective catalytic reduction catalyst to form ammonia. A seventh example of the method optionally includes any one or more or each of the first through sixth examples, and further includes wherein the injecting the diesel exhaust fluid into the exhaust system of the engine is commenced via a wake-up of the controller at a predetermined duration of time after a vehicle-off event, where a request to rationalize the humidity sensor is requested for the vehicle-off event.
An example of a system for a vehicle comprises an engine system including an intake system, exhaust system, and engine; a diesel exhaust fluid injection system configured to inject a diesel exhaust fluid into the exhaust system upstream of a selective catalytic reduction catalyst; a motor configured to at least rotate the engine unfueled via power from a battery; a humidity sensor positioned in the intake system; and a controller storing instructions in non-transitory memory that, when executed, cause the controller to: responsive to conditions being met for conducting a humidity sensor diagnostic test, rotate the engine unfueled in reverse at a predetermined engine speed for a predetermined duration via the motor, inject a predetermined amount of diesel exhaust fluid into the exhaust system where the rotating the engine unfueled in reverse draws the diesel exhaust fluid into the intake system to rationalize the humidity sensor; and subsequent to rotating the engine unfueled in reverse for the predetermined duration, stop the rotating the engine unfueled in reverse and commence rotating the engine unfueled in a forward direction for a predetermined duration via the motor, to route the diesel exhaust fluid back to the exhaust system in order to load the selective catalytic reduction catalyst with ammonia, and where conditions being met include at least a predetermined vehicle-off duration. In a first example of the system, the system further comprises a throttle positioned in the intake system upstream of the humidity sensor, and wherein the controller stores additional instructions to: obtain a baseline humidity measurement from the humidity sensor just prior to rotating the engine unfueled in reverse by commanding the throttle to a predetermined open position to couple the intake system to atmosphere; maintain the throttle at the predetermined open position or a fully open position during the rotating the engine unfueled in reverse; and command or maintain the throttle to the fully open position just prior to rotating the engine unfueled in the forward direction, where rationalizing the humidity sensor includes indicating that the humidity sensor is functioning as desired responsive to a humidity measurement during the rotating the engine unfueled in reverse being greater than the baseline humidity measurement by at least a threshold amount. A second example of the system optionally includes the first example, and further includes wherein the diesel exhaust fluid comprises a mixture of urea and water, and where the water stimulates the humidity sensor to rationalize the humidity sensor, and where the urea is converted to ammonia at the selective catalytic reduction catalyst. A third example of the system optionally includes any one or more or each of the first and second examples, and further comprises an exhaust gas recirculation system selectively coupled to the engine system via an exhaust gas recirculation valve; an evaporative emissions system selectively coupled to the engine system via a canister purge valve; and wherein the controller stores additional instructions to command both the exhaust gas recirculation valve and the canister purge valve to closed positions during the rotating the engine unfueled in both the forward and reverse directions.
obtaining a baseline humidity measurement via a humidity sensor positioned in an intake system of an engine;
2. The method of claim 1, wherein the fluid comprises diesel exhaust fluid.
3. The method of claim 1, wherein obtaining the baseline humidity measurement comprises commanding a throttle positioned in the intake system to a predetermined open position to couple the intake system and humidity sensor to atmosphere just prior to rotating the engine unfueled in the reverse direction.
4. The method of claim 3, wherein obtaining the baseline humidity measurement and rationalizing the humidity sensor via rotating the engine unfueled in reverse and injecting the fluid into the exhaust is commenced responsive to a predetermined duration of time elapsing since a vehicle-off event, where rationalizing the humidity sensor is requested during the vehicle-off event.
5. The method of claim 1, further comprising, rotating the engine in reverse at a predetermined engine speed.
6. The method of claim 1, wherein rotating the engine in reverse is for a predetermined duration which comprises an amount of time where a response from the humidity sensor is expected provided that the humidity sensor is functioning as desired, without routing the fluid to atmosphere.
7. The method of claim 1, wherein rationalizing the humidity sensor further comprises indicating that the humidity sensor is functioning as desired responsive to the humidity sensor outputting a signal that is greater than a threshold amount above the baseline humidity measurement; and
indicating that the humidity sensor is not functioning as desired responsive to the humidity sensor outputting a signal that is lower than the threshold amount above the baseline humidity measurement.
8. The method of claim 1, further comprising responsive to rationalizing the humidity sensor, rotating the engine unfueled in a forward direction, to route the fluid from the intake system back into the exhaust system.
injecting a diesel exhaust fluid into an exhaust system of an engine of the vehicle, and rotating the engine unfueled in reverse to draw the diesel exhaust fluid into an intake system of the engine;
rationalizing a humidity sensor positioned in the intake system subsequent to the injection of the diesel exhaust fluid into the exhaust system and the rotating the engine unfueled in reverse; and
rotating the engine unfueled in a forward direction subsequent to rationalizing the humidity sensor, to route the diesel exhaust fluid back into the exhaust system.
10. The method of claim 9, further comprising obtaining a baseline humidity sensor measurement from the humidity sensor positioned in the intake system just prior to injecting the diesel exhaust fluid into the exhaust system and rotating the engine unfueled in reverse, where obtaining the baseline humidity sensor measurement includes commanding an intake system throttle to a predetermined open position, to couple the intake system to atmosphere; and
wherein rationalizing the humidity sensor includes indicating that the humidity sensor is functioning as desired responsive to a humidity sensor test measurement during the drawing the diesel exhaust fluid into the intake system being greater than the baseline humidity sensor measurement by at least a threshold amount.
11. The method of claim 9, further comprising maintaining a canister purge valve, configured to couple an evaporative emissions system of the vehicle to an engine system, in a closed conformation, and maintaining an exhaust gas recirculation valve configured to enable exhaust gas to be routed back to the intake system, in a closed conformation during the rotating the engine unfueled in both the reverse direction and the forward direction.
12. The method of claim 9, wherein injecting the diesel exhaust fluid into the exhaust system further comprises injecting the diesel exhaust fluid into the exhaust system upstream of a selective catalytic reduction catalyst; and
wherein rotating the engine in the forward direction subsequent to rationalizing the humidity sensor routes the diesel exhaust fluid into the exhaust system in order to load the selective catalytic reduction catalyst with ammonia.
13. The method of claim 12, wherein a controller of the vehicle employs a model to infer a loading state of the selective catalytic reduction catalyst, where inferring the loading state involves determining an amount of ammonia loaded on the selective catalytic reduction catalyst.
14. The method of claim 12, further comprising injecting additional diesel exhaust fluid into the exhaust system during the rotating the engine in the forward direction, based on a desired loading amount of the selective catalytic reduction catalyst with ammonia.
15. The method of claim 12, wherein the diesel exhaust fluid comprises a mixture of urea and water, and where the urea reacts with the selective catalytic reduction catalyst to form ammonia.
16. The method of claim 9, wherein the injecting the diesel exhaust fluid into the exhaust system of the engine is commenced via a wake-up of the controller at a predetermined duration of time after a vehicle-off event, where a request to rationalize the humidity sensor is requested for the vehicle-off event.
an engine system including an intake system, exhaust system, and engine;
a diesel exhaust fluid injection system configured to inject a diesel exhaust fluid into the exhaust system upstream of a selective catalytic reduction catalyst;
a motor configured to at least rotate the engine unfueled via power from a battery;
a humidity sensor positioned in the intake system; and
a controller storing instructions in non-transitory memory that, when executed, cause the controller to: responsive to conditions being met for conducting a humidity sensor diagnostic test, rotate the engine unfueled in reverse at a predetermined engine speed for a predetermined duration via the motor, inject a predetermined amount of diesel exhaust fluid into the exhaust system where the rotating the engine unfueled in reverse draws the diesel exhaust fluid into the intake system to rationalize the humidity sensor; and subsequent to rotating the engine unfueled in reverse for the predetermined duration, stop the rotating the engine unfueled in reverse and commence rotating the engine unfueled in a forward direction for a predetermined duration via the motor, to route the diesel exhaust fluid back to the exhaust system in order to load the selective catalytic reduction catalyst with ammonia, and where conditions being met include at least a predetermined vehicle-off duration.
18. The system of claim 17, further comprising a throttle positioned in the intake system upstream of the humidity sensor, and wherein the controller stores additional instructions to:
obtain a baseline humidity measurement from the humidity sensor just prior to rotating the engine unfueled in reverse by commanding the throttle to a predetermined open position to couple the intake system to atmosphere;
maintain the throttle at the predetermined open position or a fully open position during the rotating the engine unfueled in reverse; and
command or maintain the throttle to the fully open position just prior to rotating the engine unfueled in the forward direction, where rationalizing the humidity sensor includes indicating that the humidity sensor is functioning as desired responsive to a humidity measurement during the rotating the engine unfueled in reverse being greater than the baseline humidity measurement by at least a threshold amount.
19. The system of claim 17, wherein the diesel exhaust fluid comprises a mixture of urea and water, and where the water stimulates the humidity sensor to rationalize the humidity sensor, and where the urea is converted to ammonia at the selective catalytic reduction catalyst.
an exhaust gas recirculation system selectively coupled to the engine system via an exhaust gas recirculation valve;
an evaporative emissions system selectively coupled to the engine system via a canister purge valve; and
wherein the controller stores additional instructions to command both the exhaust gas recirculation valve and the canister purge valve to closed positions during the rotating the engine unfueled in both the forward and reverse directions.
6763298 July 13, 2004 Boggs et al.
7715976 May 11, 2010 Kiao et al.
8739766 June 3, 2014 Jentz et al.
9074548 July 7, 2015 Surnilla et al.
9249764 February 2, 2016 Wiggins et al.
9329160 May 3, 2016 Pursifull et al.
9382861 July 5, 2016 Jankovic et al.
9482172 November 1, 2016 Pursifull et al.
9828949 November 28, 2017 Surnilla
9879630 January 30, 2018 Guo
20040069273 April 15, 2004 Visser
20050072406 April 7, 2005 Cullen
Sluder, C. et al., “Low Temperature Urea Decomposition and SCR Performance,” Proceeding of the SAE 2005 World Congress and Exhibition, Apr. 11, 2005, Detroit, Michigan, 9 pages.
Dudar, A. “Systems and Methods for Indicating Canister Purge Valve Degradation,” U.S. Appl. No. 15/202,288, filed Jul. 5, 2016, 67 pages.
Dudar, A. “Method and System for a Humidity Sensor in a Vehicle Techncal Field,” U.S. Appl. No. 15/474,386, filed Mar. 30, 2017, 23 pages.
Inventor: Aed M. Dudar (Canton, MI)
Application Number: 15/660,015
Current U.S. Class: With Fuel Injection Control (123/406.47)
International Classification: F01N 3/10 (20060101); F01N 3/20 (20060101); F02D 41/00 (20060101); F02D 41/22 (20060101); F01N 9/00 (20060101); B01D 53/94 (20060101); F02N 11/00 (20060101);

type: global

value: Justia is an American website specializing in legal information retrieval. It was founded in 2003 by Tim Stanley, formerly of FindLaw, and is one of the largest online databases of legal cases.


text:
#47 of 89 Restaurants in Taos
All reviews sushi orange chicken chinese restaurant friendly service place to eat vegetables hunan spicy takeout

value: Tripadvisor, Inc. is an American online travel company that operates a website and mobile app with user-generated content and a comparison shopping website.


text:
Grilled Asian Chicken and Veggies | The BBQ World of mrdodd
← Building A UDS	Smoky Jalapeno Cornbread →	Grilled Asian Chicken and Veggies	23
One of my favorite things about Asian cooking is the multitude of flavors it offers. It’s ideal for summertime grilling, with all the fresh produce available. With recipes like this you can just let your imagination run wild, the more vegetables the better.
Marinate chicken and an array of veggies in an Asian marinade, then grill.
What you will need: Boneless (skinless if you choose) chicken breast
An Asian marinade of your choice (a recipe is provided below for one of our favorites)
1/2 lb fresh sugar peas
Let’s begin with the marinade.
1/2 cup Terriyaki
3 Tbls of chili paste (this was the driving force and inspiration behind this recipe)
3 tsp of fresh grated ginger (fresh ginger makes all the difference in the world)
5 or 6 roughly cut dried Arbol chilies (not pictured my imagination kicked in at this point)
5 or 6 more uncut Arbol chilies
Toss it all in and mix well in a bowl tasting and seasoning as you go (not much here so move along).
Simpy dice your veggies into a dice that you are comfortable with. However I will mention here if you don’t have a grill pan I’d recommend cutting them a little on the large size and using skewers so you can cook them kabob style.
Here we have our fresh veggies: yellow, red, and orange peppers, along with an onion (I prefer a red onion for this but I had a Spanish that needed using). We also found some really nice sugar peas we decided to toss in.
Now on to the chicken
We began with two bone in chicken breast. I chose “bone in” because I’m too cheap to spend an extra dollar a pound for someone else to remove the bone and skin. Boneless, skinless will work quite well here for this.
Start by rinsing them thourghly under cold running water. Then remove the rib bone. It’s rather simple, Cut the exposed meatless ribs off. A cleaver or heavy chef’s knife works well here. Sorry about the pictures being somewhat blurry, my wing man was taking them. He’s a wing man, he’s use to being tossed under the bus.
Then feel for the solid part of the rib and cut the meat away from it. I used a pairing knife for this, a fillet knife would of been preferable……. but I didn’t have one.
That’s it two simple steps, it should take you about ten minutes. Just clean them up a little and remove the skin if you want. I don’t see me buying “boneless, skinless” breast again anytime soon.
Time to combine and let set
Place the chicken breast and veggies into a gallon zip lock bag, along with your marinade, and let set up to 24 hours.
Important step, wash and BLEACH EVERYTHING that you may even think the chicken came in contact with. Yes, this includes the counters, and the sink you used to rinse the chicken off in. Time to fire up the grill
Begin by setting up your grill for direct grilling.
While the grill is coming up to temperature, drain your marinade off of your breast and veggies. We’re going to reserve this and use it as a sauce later.
Once your grill is up to temperature, we’re looking for about a medium heat here (a 5 second count with your hand over the grill before it gets too hot). Place your breast, veggies, and marinade on the grill. Note: either coat your sauce pan with oil or dish soap before placing on the grill, this will make your clean up much easier later.
Cook for about 30 minutes flipping twice, until you reach an internal temperature of 165f and the juices run clear for the chicken breast, tender crisp for the veggies, and a nice simmer on the sauce. The sauce can simmer for however long the chicken and veggies take.
All that’s left to do now is dice your chicken breast, and serve with that sauce that you simmered on the grill.
Now it’s time to set back and enjoy the complements.
Posted by mrdodd on June 23, 2013 in Uncategorized
Tags: Asian cooking, Asian grill, Asian marinade, bbq, charcoal, chicken, chili paste, cooking, dinner, kingsford, marinade, mrdodd, vegetables, veggies	← Building A UDS	Smoky Jalapeno Cornbread →	One response to “Grilled Asian Chicken and Veggies”	Greg	June 23, 2013 at 8:43 pm	Looks delicious!

value: WordPress (WP, WordPress.org) is a free and open-source content management system (CMS) written in PHP and paired with a MySQL or MariaDB database. Features include a plugin architecture and a template system, referred to within WordPress as Themes.


text:
Food & Lacquer Too: Day 1: Red
I usually can't stand to keep a design on my nails for longer than a day or two, but I'm really feeling this Flo-Jo design. I want to keep it at least for another day or two. Luckily I have two younger sisters who are willing to allow me to use their hands for this challenge.
So I painted Day 1's challenge on my youngest sister's nails...
I only have 10 reds so I just assigned one nail to each shade...
They all photograph pretty much the same.
I had a polish explosion where a white polish busted and spilled all over 75% of my other polishes. That's why some of the polishes are covered in white.
The shades (from left to right, top to bottom):
Sally Hansen-Wine Not!
Vernis Absolu-Royale
NYC-Madison Ave
Sinful-Bleeding Heart
Sally Hansen-Racey Rouge
Pure Ice-All Nighter
Wet N' Wild-Red Red
Santee-Garnet Red
Urban Decay-F Bomb
I will be dedicating the entire month of October to this challenge. Also, I'm going to try and think up another challenge for us lacquer lovers.
Peace ... And much lacquer to you.
Posted by RHOyal Fiasco at 10:51 PM

value: Blogger is an American online content management system (CMS) which enables multi-user blogs with time-stamped entries. Pyra Labs developed it before being acquired by Google in 2003.