A system for a machine, in particular an automated production machine, has a large number of proximity sensors. Each proximity sensor has at least one secondary winding that is suitable for drawing power from a medium-frequency magnetic field. At least one primary winding, which is fed from a medium-frequency oscillator, is provided for supplying the proximity sensors with electrical power without using wires. Each proximity sensor is equipped with a transmitting device that emits radio signals, which contain sensor information of interest, to a central receiving device that is connected to a process computer for the machine. A proximity sensor and a primary winding for this purpose are also proposed.

The invention relates to a system for a machine having a large number of proximity sensors, as well as to a proximity sensor, and a primary winding for this purpose. The invention can be used for supplying electrical power to proximity sensors that are mounted on moving machine components (e.g. industrial robots, automatic production machines, and automated production machines).
A decentralized supply for a large number of transmitters utilizing inductive power transmission is known from Schoener J et al.: xe2x80x9cDezentrale Versorgung aktiver Geberxe2x80x9d [Decentralized supply of active transmitters], Radio Fernsehen Elektronik, DE, VEB Verlag Technik, Berlin, Volume 41, No. 9, Sep. 1, 1992 (1992-09-01), pages 627-630, in conjunction with a system for position detection. A constant-frequency alternator that is installed on a crane operates at a fixed frequency of 100 to 130 kHz or more acting on a frame antenna that is tuned to resonance and transmits AC power to the compact assemblies installed in the transmitters, and which are likewise equipped with a frame antenna tuned to resonance. The induced voltage is rectified and feeds the compact assembly. The distance to be bridged is 150 mm. A power level of approximately 100 mW must be transmitted for one compact assembly.
German published, non-prosecuted patent application DE 44 42 677 A1 discloses a method and a configuration for supplying an electrical load with an electrical supply voltage or an electrical supply current. The configuration supplies the voltage or current via radio waves from a radio transmitter to a radio receiver that is electrically connected to the load. The radio receiver converts the radio waves to the electrical supply voltage or the electrical supply current. The radio waves can come from the electromagnetic high frequency range (radio waves) or also from the microwave range. The electrical loads can be, for example, power or voltage sensors.
It is accordingly an object of the invention to provide a system for a machine having a large number of proximity sensors, as well as a proximity sensor, and a primary winding for this purpose that overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type and that specifies a cost-effective and reliable system for a machine having a large number of proximity sensors, which ensures that electrical power can be supplied to the proximity sensors without using wires. Furthermore, a proximity sensor that is suitable for this purpose will be proposed. In addition, a primary winding that is suitable for this purpose will be proposed.
With regard to the system, the object is achieved by a system for a machine, in particular an automated production machine, having a large number of proximity sensors. Each proximity sensor has at least one secondary winding that is suitable for drawing power from a medium-frequency magnetic field, with at least one primary winding that is fed from a medium-frequency oscillator being provided for supplying the proximity sensors with electrical power without using wires. Each proximity sensor is equipped with a transmitting device that emits radio signals, which contain sensor information of interest, to a central receiving device that is connected to a process computer for the machine.
With the foregoing and other objects in view, there is provided, in accordance with the invention, a system for a machine. The system includes a proximity sensor generating sensor information. A transmitting device transmits the sensor information from the proximity sensor and emitting radio signals containing the sensor information to a central receiving device connected to a process computer for the machine. A secondary winding connects to the proximity sensor for drawing power from a medium-frequency magnetic field. A primary winding is fed from a medium-frequency oscillator. The primary winding is provided for supplying the proximity sensor with electrical power without requiring wires.
With the objects of the invention in view, there is also provided a primary winding including a connection element and a plurality of parallel conductors. The plurality of parallel conductors forms a plurality of separate winding sections, the plurality of separate winding sections are mechanically and electrically connected to one another via the connection element.
With the objects of the invention in view, there is also provided a primary winding. The primary winding includes a number of parallel conductors forming a flexible cable with two cable ends being offset with respect to one another. A connection element electrically and mechanically connecting the two cable ends to one another. Connection lines are connected to the cable ends via the connection element and forming two free winding ends.
With regard to the proximity sensor, the object is achieved by a proximity sensor having a number of secondary windings that are suitable for drawing power from a medium-frequency magnetic field.
The medium-frequency oscillations that are of interest in this context are understood to be those in the range from about 15 kHz to about 15 MHz.
With regard to the primary winding, the object is achieved by a primary winding including a number of separate winding sections. Each of the winding sections is formed from a number of parallel conductors. The individual winding sections are mechanically and electrically connected to one another via connection elements. If one connection element electrically connects two winding sections to one another, the two winding sections are offset with respect to one another, thus forming two free winding ends that are suitable for connection of connection lines to a generator or oscillator.
An alternative embodiment of the primary winding achieves the object by including a primary winding having a flexible cable formed from a number of parallel conductors and a connection element that electrically and mechanically connects the two cable ends to one another. The parallel conductors are offset with respect to one another. Thus, two free winding ends are formed that are suitable for connection of connection lines to a generator or oscillator.
The invention achieves the following advantages. Compared to conventional solutions with a cable connection for supplying electrical power to the proximity sensors, the invention avoids the relatively high cost factor resulting from planning, material, installation, documentation, and maintenance, for a cable connection. In addition, no failures can occur due to cable breaks or poor contacts, for example corroded contacts.
Compared to batteries for supplying power to proximity sensors, no maintenance effort or cost is lost for replacing the batteries. Sometimes, the costs are exacerbated when the batteries are in poorly accessible locations.
In the stated medium-frequency range (from about 15 kHz to about 15 MHz), the disadvantages that result from skin effects, for example the losses that occur, are still manageable. No electromagnetic waves are emitted, because the primary windings are too small in comparison to the wavelengths that occur. Therefore, the primary windings do not act as antennas. This allows the configurations to be constructed in a simple manner. There is no need to conduct EMC measurements on any radiated interference. A further advantageous factor is that medium-frequency magnetic fields are shielded only to a minor extent by metallic machine components so that a magnetic field that is sufficiently powerful to supply power is advantageously produced even at inaccessible points in a machine.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a system for a machine having a large number of proximity sensors, as well as a proximity sensor, and a primary winding for this purpose, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

System for a machine having a large number of proximity sensors, as well as a proximity sensor, and a primary winding for this purpose


Layout generation for location-tracking sensors is disclosed herein. An example method in a computing device includes: receiving a map defining a set of features of a facility; obtaining layout data corresponding to the facility, the layout data defining, for each of a plurality of location tracking sensors, a location in a facility coordinate system; in response to deployment of the location tracking sensors in the facility according to the layout data, obtaining a performance metric for each of the location tracking sensors; and updating a primary layout generator according to the map, the layout data, and the performance metrics.

Various facilities, such as retail facilities containing various items for purchase, transport and logistics facilities such as warehouses storing items for shipment, and the like, may deploy inventory tracking systems. Such systems may, for example, track the locations of items to which radio frequency identification (RFID) tags are affixed. To implement location tracking, location sensors such as RFID readers may be installed throughout the facility. Data captured by the RFID readers (e.g. tag responses to scans emitted by the readers) can be employed to determine locations for the RFID-tagged items. However, determining where to place location sensors throughout a facility, e.g. in order to achieve adequate coverage of the facility, may be a time-consuming task performed by expert staff.


A sensor apparatus includes a sensor assembly for maintaining multiple and varying sensor components, wherein the sensor assembly comprises a molded sensor head configured to include a first cavity and a second cavity. A first sensor of a first sensor type can be located and maintained within the first cavity. A second sensor of a second sensor type is generally located and maintained within the second cavity, wherein the first sensor type is different from the second sensor type. The first sensor and the second sensor are respectively packaged into the separate first and second cavities within the molded sensor head of the sensor assembly to provide a sensor apparatus that provides for multiple and varying sensor capabilities.

Many automotive and other vehicles are equipped with electronic control systems that regulate various components of the vehicle, such as speed and temperature. These electronic control systems are utilized to control the components based on information represented by output signals from various sensors for detecting operating conditions. A vehicle speed sensor, for example, is a device, which is generally utilized in an automobile to sense vehicle speed and send this information to the vehicle's onboard computer. In order to control engine performance electronically, it is often necessary to provide a variety of signals to the engine control module. These signals indicate the status of the parameter being detected and to which the control must respond. Among status signals necessary is a signal that is indicative of the vehicle speed.
Temperatures sensors are also important in a number of applications, not merely automotive or vehicle applications. Temperature sensors that are used in conjunction with high-temperature applications, for example, typically comprise a metallic tube in which a temperature sensitive element is disposed inside one end with conductive wires extending within the tube from the temperature sensitive element to an opening at the other end of the tube. The metallic tube is inserted through a wall of the high-temperature application or environment to permit the temperature sensitive element to be placed in thermal communication with an internal cavity of the high-temperature application. Temperature sensors are utilized for a variety of applications, including low-temperature applications and applications that require ambient air temperature information, such as that required in modern aircraft.
A continuing need exists for sensor devices that can detect both temperature and speed. One of the problems with conventional methodologies and systems for combining speed and temperature sensor devices into a single package is that they are inflexible and subject to environmental conditions. Additionally, it is difficult to package such sensor devices into small compact packages without suffering a loss in the quality of the resulting detection data.

Speed and temperature sensing in separate cavities in a single sensing head


A camera is disclosed which includes: at least two image sensors, an image sensor selector, a multiplexer and an image processor. The at least two image sensors are configured to synchronously output successive pixels of image data. The image sensor selector is responsive to a pan and/or tilt signal input associated with a target view of the image data provided by the at least two image sensors, to output a select signal indicating for each synchronous output of pixels from the at least two image sensors a selected one of the at least two image sensors delivering a pixel within the target view. The multiplexer has inputs, an output, and a control input. The multiplexer inputs are each coupled to a corresponding one of the at least two image sensors to receive the successive pixels of image data there from. The multiplexer is responsive to the select signal from the image sensor selector at the control input to output the selected one of the pixels at the input which is within the target view during each pixel clock cycle. The image processor has an input coupled to the output of the multiplexer for processing the pixels within the target view.

1. Field of the Invention
The present invention relates to a camera having panning and/or tilting functionality and a method for such a camera.
2. Description of the Related Art
Cameras are widely used in order to make it possible to see or study remote sites. For example, cameras are used in surveillance systems and for presenting specific objects or surroundings to persons having access to such a camera via a network. For the reason of extending the area that may be viewed via a camera, or for other reasons, different types of pan/tilt solutions has been used in the past.
The most common solutions has been to provide the camera with a motor driven mechanism for turning the camera in the horizontal direction, i.e. panning, in the vertical direction, i.e. tilting, or in both the horizontal and vertical direction, i.e. panning and tilting, in order to scan a greater area than is possible with a stationary camera. Other implementations of the pan and/or tilt functionality have also been presented. One such implementation is to turn only the objective of the camera and another is to position a turning mirror in front of the camera.
All these solutions involves mechanical turning of devices of the camera or in the near proximity of the camera in order to achieve pan and/or tilt functionality. As commonly known, such turning of devices inevitably results in mechanical deterioration of at least the components involved in the turning. Thus, the cameras equipped with the above mentioned implementations of pan tilt functionality have to be serviced frequently, which results in extra work and, if the cameras are not maintained regularly, in the loss of pan tilt functionality until the camera is properly maintained. Further, cameras having pan tilt functionality implemented according to the above mentioned tends to be much more expensive than a camera having a fixed view. Accordingly, the present arrangements for providing a camera with pan and/or tilt functionality are unsatisfactory.

Method and apparatus for panning and tilting a camera


Disclosed is a device for automatically removing burrs from a riser of an aluminum alloy wheel. The device is composed of a frame, a clamping gear rack structure, a support plate, a servo motor and the like. When a clamping cylinder drives a first sliding plate to move, clamping wheels are controlled to center and clamp the wheel, and the servo motor controls the rotation of the clamping wheels, so that the wheel may rotate while being clamped. When a distance adjusting cylinder drives a second sliding block to move, a first sliding block and the second sliding block move synchronously under the action of a feed gear rack structure, so that a first deburring tool and a second deburring tool move synchronously to adjust the distance between them according to the diameter of a cap slot.

The machining accuracy and machining quality of a wheel riser directly affect the installation of a buckle cap. After the wheel is machined, the edge of the riser is synthesized by casting and machining surfaces, so a circle of burrs remain. Currently, the burrs here on the edge of the riser are removed manually, and the effect is not ideal. In addition, the front casting deformation of the riser increases the difficulty of removal, and the deep or shallow groove and the large or small force will cause the burrs at the edge of the riser not to be removed smoothly, so that the customer will complain poor product consistency. Moreover, when the burrs are removed manually, some of the burrs may be missing when removing so that the burrs remain, resulting in the unqualified appearance after coating and the corrosion caused by the incomplete coverage of a paint film. Based on the current situation, this application provides a device for automatically removing burrs from a wheel riser.

Device for removing burrs from riser of aluminum alloy wheel


An improved high-power resistor comprising a housing which can be or is traversed by a cooling medium and in which one or more resistance elements are provided.

High-power resistors are used in particular for braking electric motors, particularly in thyristor drives, especially high-frequency thyristor drives, but also for many other applications in the field of the control of electric drives. High-power resistors are also required especially in automotive engineering.
Known high-power resistors comprise a wire of a material having an electric resistance, which is wound around a core, the core generally being able to withstand high temperatures. There are also known high-power resistors made of a spiral wire which is not wound around a core. The wire is provided with an electric insulation. It is disposed in a thermally conductive material surrounded by a metallic housing which acts as heat exchanger.
In the known high-power resistors problems arise in particular when the operating frequency is high, for instance higher than 1 kHz, and/or when it is important to maintain the wave shape of the current. In the known power resistors the problems arise in particular as a result of the fact that they have a certain capacity and/or inductance by virtue of their construction, by which the shape and the format of the voltage signal and/or the current signal, which can for instance be rectangular or sinusoidal, can be impaired in an undesirable way.
It is an object of the present invention to provide an improved high-power resistor.
In accordance with the present invention, this object is solved by the features of claims 1 and 10. The high-power resistor comprises a housing which can be or is traversed by a cooling medium and in which a resistance element is provided. The cooling medium can be liquid or gaseous. Preferably, the cooling medium is liquid.
Advantageous embodiments are described in the dependent claims.
Preferably, the resistance element is planiform.
In the housing, a plurality of resistance elements, preferably three, can be provided. The resistance elements can be connected in parallel or in series. It is particularly advantageous when a plurality of planiform resistance elements are provided, which are arranged parallel to each other.
Preferably, separators are provided between the resistance elements. By means of the separators, the resistance elements can be isolated from each other. Furthermore, the separators can serve as conducting devices for the cooling medium. A particularly simple solution is obtained when planiform resistance elements are separated from each other by planiform separators.
Another advantageous embodiment is characterized in that the housing is made of plastic material, preferably of thermoplastic material. Such housing can be manufactured at low cost.
At the housing, connections can be provided, in particular tube connections for supplying and discharging the cooling medium.
Preferably, a terminal box is provided at the housing. The terminal box can include electric contacts for connecting electric lines.
Another advantageous embodiment is characterized by sealed connections for connecting the resistance element with the terminal box.
The present invention furthermore relates to a resistance unit which consists of a plurality of high-power resistors.
According to the embodiments described in the present application, a cooling-medium-cooled, in particular liquid-cooled high-power resistor is created. It provides for realizing a resistor with high performance values and in particular with low impedance and low induction. Particularly advantageously, the high-power resistor can be used for braking electric motors, in particular in high-frequency thyristor drives, but also in many other applications in the field of electric drive engineering, in particular the control of electric drives. Another important field of application is automotive engineering.
In particular in fields of application in which a low weight and/or a high packing density of the electric and/or electronic components is decisive, especially in the automotive industry, it is desirable to achieve a rather high power dissipation. This is required in particular during hard braking operations. At the same time, the required space should be minimized. The embodiments of the present invention provide for solving these problems.


A spoke of a bicycle rim has a spoke body having a connecting end and a threaded segment formed on the connecting end. The threaded segment has multiple first thread sections and at least one second thread section. The first thread sections have a major radius, a minor radius and a pitch. The at least one second thread section is formed between the first thread sections to form at least one loosen-proofing section between the first thread sections and has a major radius, a minor radius and a pitch. The major radius of the second thread section is smaller than the major radius of the first thread sections. The minor radius of the second thread section is larger than the minor radius of the first thread sections. The pitch of the second thread section is the same as that of the first thread sections.

1. Field of the Invention
The present invention relates to a spoke, and more particularly to a spoke of a bicycle wheel to enhance the combination between a nut and a threaded segment of the spoke to prevent the nut from loosening from the threaded segment.
2. Description of Related Art
A wheel of a bicycle substantially comprises a rim, a hub and multiple spokes. Each spoke has a mounting end connected securely with the hub and a connecting end. The connecting end is threaded and is connected securely with the rim with a nut. Accordingly, the spokes can provide an excellent supporting effect to the rim and transmits driving power from the hub to the rim to make the wheel rotating and driving the bicycle to move. To keep the safety of riding the bicycle, the wheel has to be an excellent circular condition. However, the nuts of the conventional spokes on a bicycle wheel will be loosened from the treaded connecting ends of the spokes to cause the wheel not kept at the excellent circular condition due to the shock or vibration generated during the riding of the bicycle. Accordingly, the stabilization and safety of riding the bicycle will be badly influenced.
With reference to FIG. 5, a conventional spoke 30 having a loosen-proofing effect comprises a spoke body 31, a mounting head 32 connected with a hub and a threaded segment 33. The threaded segment 33 is connected with a rim with a nut and has a non-threaded buffering section 34 formed between two thread sections including a first thread section and a second thread section adjacent to the spoke body 31. The second thread section has a length longer than that of the first thread section and has a pitch different from that of the first thread section. When the nut is screwed onto and engages the thread sections of the threaded segment 33 of the spoke 30, the non-threaded buffering section 34 will be expanded, shortened or twisted due to the difference between the pitches of the thread sections. Therefore, the threaded segment 33 of the spoke 30 will be deformed due to the elastic stress and torque caused by the deformation of the buffering section 34. The deformation of the threaded segment 33 will make the secure combination between the threaded segment 33 and the nut to provide a loosen-proofing effect, but this also easily cause break or damage to the buffering section 34 due to the stress and torque. When the buffering section 34 is broken or damaged, a new spoke is needed to replace a damaged one, and this is uneconomic and not environment friendly.
To overcome the shortcomings, the present invention tends to provide a spoke to mitigate or obviate the aforementioned problems.


A water heater comprising a tank defining a water chamber, a combustion chamber for heating water in the water chamber, and a combustion air inlet pipe including an outlet end communicating with the combustion chamber. The inlet pipe also includes an inlet end having a longitudinal axis, and a plate in the combustion air inlet pipe adjacent the inlet end, which plate extends outwardly of the inlet end along the longitudinal axis.

The invention relates to water heaters, and more particularly to water heaters having a combustion chamber and an air inlet pipe communicating with the combustion chamber.
It is known to provide an air scoop at the inlet end of an air inlet pipe to direct air into the inlet pipe. It is also known to provide a directionally adjustable ventilated cover at the inlet end to prevent the introduction of water or other unwanted debris into the inlet pipe.

Combustion air inlet diverter plate for a water heater


The present invention relates to a positive working photosensitive composition having an improved sensitivity due to the use of a sensitizer and having an excellent incandescent light safety. This composition comprises at least 1 molar % of a structural unit derived from at least one of monomers having the following general formulae: ##STR1## wherein: R.sub.1 represents a hydrogen atom, an alkyl group or a substituted alkyl group,. R.sub.2 represents a divalent alkylene group or a substituted divalent alkylene group, PA0 R.sub.3, R.sub.4 and R.sub.5 may be the same as or different from each other and each represents an alkyl group, a substituted alkyl group, an aryl group or a substituted aryl group, PA0 R.sub.6 and R.sub.7 may be the same as or different from each other and each represents a hydrogen atom, an alkyl group, a substituted alkyl group, an aryl group or a substituted aryl group, PA0 Ar.sub.1 represents a single bond or Ar.sub.2, and PA0 Ar.sub.2 represents a divalent arylene group or a substituted divalent arylene group.

1. Field of the Invention
The present invention relates to a new positive working photosensitive composition suitable for production of lithographic printing plates, proofs or multicolor printings, drawings for an overhead projector, integrated circuits, and photomasks.
2. Description of the Prior Art
o-Quinone diazide compounds have been known as so-called positive working photosensitive materials which are solubilized by activating rays. They have been widely used for lithographic printing plates, photoresists, etc. These o-quinone diazide compounds are described in many publications, for example, U.S. Pat. Nos. 2,766,118, 2,767,092, 2,772,972, 2,859,112, 2,907,665, 3,046,110, 3,046,111, 3,046,115, 3,046,118, 3,046,119, 3,046,120, 3,046,121, 3,046,122, 3,046,123, 3,061,430, 3,102,809, 3,106,465, 3,635,709 and 3,647,443.
The o-quinone diazide compounds are decomposed by irradiation with activating rays to become a five-membered carboxylic acid which is soluble in an alkali. However, they have a defect that their photosensitivity is yet insufficient, because the photochemical sensitization of them is difficult and their quantum yield does not essentially exceed 1. Further, the wave length for the sensitization usable is limited and, therefore, usable light sources are limited, namely the acceptability of light sources is much limited. Accordingly, it is difficult to use them in the light of an incandescent lamp for a long period of time (incandescent light safty lacks). Another problem is that their absorbance of a deep UV region of about 200 to 300 nm is high and therefore they are unsuitable when they are used to improve their resolving power with a light or low wave length.
Although various processes have been tried for improving the photosensitivity of a photosensitive composition containing an o-quinone diazide compound under these circumstances, it has been very difficult to improve the photosensitivity while the developability is kept good. These processes are described in, for example, Japanese Patent Publication for Opposition Purpose (hereinafter referred to as `J. P. KOKOKU`) No. 48-12242, Japanese Patent Unexamined Published Application (hereinafter referred to as `J. P. KOKAI`) No. 52-40125 and U.S. Pat. No. 4,307,173.
Recently, several positive working photosensitive compositions free of o-quinone diazide compounds have been proposed. Among them, proposed was a polymer compound having an o-nitrocarbinol ester group described in, for example, J. P. KOKOKU No. 56-2696. However, its photosensitivity is also yet insufficient for the same reasons as those of the o-quinone diazide compounds. Also, proposed is a compound which becomes sulfonic acid upon exposure as described in J. P. KOKAI Nos. 60-260947 and 62-36404. However, these compounds were not able to be easily produced.

Positive working photosensitive composition


A method for controlling a motor vehicle includes detecting a first predefined trajectory, determining a region across which the first trajectory leads, determining a second trajectory that has a different extension in the determined region than the first trajectory, detecting a driver-controlled selection of one of the trajectories, and autonomously controlling the motor vehicle in such a way that it follows the selected trajectory.

A motor vehicle includes a driver-assistance function which is meant to make the guidance of the motor vehicle less stressful for the driver. For example, the motor vehicle can be guided along a predefined trajectory in an either partially or completely automated manner for the purpose of carrying out a parking or unparking operation.
DE 10 2015 205 142 A1 relates to a method for the driver-controlled teaching of a trajectory in order to later automatically guide a motor vehicle along the trajectory.
Prior to guiding the motor vehicle along the trajectory, the trajectory can be presented to a person who then decides whether or not the trajectory is to be used for a partially or fully automatic control. For example, if the person deems a safety distance from an object along the trajectory to be insufficient, then the trajectory might not be used. As a rule, the trajectory is graphically displayed to the person from a bird's eye view. This may be perceived as confusing, and a safety distance to an object that is at a vertical offset from the motor vehicle may be difficult to judge.

Trajectory-based guidance of a motor vehicle


A low-power, fully self-contained fingerprint capture, enrollment and verification method and device (100). The device includes a logic unit (110), a memory (120), a fingerprint sensor (130) and an interface (150) to an external unit (140). Included in the memory is a program (126) that includes a sensor data capture module (200), an image processing module (202), a minutia extraction module (204), a template creation module (206), a template compare module (208), and a database (210). The processes for capturing, enrolling and verifying a fingerprint are designed to be minimally computationally intensive. This allows implementation of these processes in a portable, battery-powered unit using hardware with limited memory and computing capability, or implementation in a PC with substantial performance advantages relative to known fingerprint capture, enrollment and verification processes and devices. Fingerprint verification is performed using fingerprint templates storing information as to location and type of minutia point, and direction of fingerprint ridge leading to the minutia point, rather than full image-to-image comparison.

The present invention relates to an electronic fingerprint identification device. More specifically, the present invention relates to a stand-alone, low-power, portable electronic fingerprint identification device featuring fingerprint identification algorithms that are designed to minimize the use of computationally intensive operations.
Biometric devices such as fingerprint identification devices have become increasingly popular in recent years, their most common uses being for security and access control. They are considered more secure than personal identification (PIN) numbers or cards because a fingerprint cannot be forged and possession of a fingerprint cannot be transferred.
There has also been a heightened demand among consumers for increased portability in computing, communications, and other devices for which access control is necessary or desirable. Among other developments there has been a proliferation of portable communication, computing and network interface devices such as personal digital assistants (xe2x80x9cPDAsxe2x80x9d), beepers, pages, information appliances, Internet access devices and the like. However, existing fingerprint identification devices are not generally designed to interface with such existing devices, and do not typically include the stand-alone, low-power capabilities desired for portable devices.
Existing fingerprint devices generally scan a fingerprint and transmit the image through a serial connection to a personal computer (PC). However, these devices require the use of software that is installed on PC having at least a PENTIUM(copyright) class microprocessor operating at 200 MHz or more in order to process the fingerprint image and perform enrollment, verification, and database functions. More particularly, known algorithms for performing such functions are sufficiently computationally intensive that only a relatively powerful microprocessor can perform the operations necessary to identify a fingerprint in a commercially reasonable period of time. For instance, known algorithms use functions such as Fourier transforms, and complete image-to-image comparisons, which require substantial computing power to execute in a reasonable period of time. Requiring a PC to process the fingerprint image adds to the expense of such devices makes them unusable by owners of portable computing, communication and other devices, and generally diminishes the applications in which they can be used.
Also known in the art are fingerprint identification devices that contain embedded or autonomous fingerprint capture and verification software and thus do not require a PC to process the fingerprint image, such as the Sony(copyright) FIU fingerprint identification unit. The power requirements of these devices are substantial and require an external power supply, which diminishes their portability and convenience and their usability with PDAs, cellular telephones, and other portable devices. As such, these devices cannot be considered to operate on a xe2x80x9cstandalonexe2x80x9d basis.
At least one attempt has been made to design a portable, battery powered, stand-alone biometric (including fingerprint) identification device, as described in International Application WO 99/56429, assigned to Identix Incorporated. Unfortunately, because of the RISC microprocessor, DRAM memory and A/D converter, the peak power consumption is estimated to be on the order of 4.3 Watts (xe2x80x9cWxe2x80x9d). This power consumption is substantially in excess of what is commercially acceptable for many applications. Indeed, for many applications it is essential the fingerprint identification device operate on low-cost batteries that can operate for extended periods of time, i.e., weeks to months, without replacement. To achieve this goal, and provide fingerprint identification with a high degree of accuracy, it is desirable that peak power consumption of portable, stand-alone fingerprint devices not exceed about 1 W. The computationally intensive nature of known fingerprint identification algorithms and the power consumption demands of existing memory and processor devices has, it is believed, made attainment of this objective an impossibility.
Thus, there exists a need in the art for a stand-alone, low-power, battery-operated, compact device that is capable of verifying and/or enrolling a fingerprint relative quickly and with a high degree of accuracy.
One aspect of the present invention is a biometric verification device for providing secure access to a unit connected to the device. The device includes a biometric sensor capable of sensing a biometric trait of a user that is unique to the user and providing a first signal containing information representing the biometric trait. The device also includes a processing unit connected to the biometric sensor so as to receive the first signal. The processing unit is adapted to compare the information with biometric data stored in the processing unit representing a biometric trait of an enrolled person, and provide a verification signal indicating whether or not the information corresponds sufficiently with the biometric data to verify the user is the enrolled person. The processing unit completes the comparison and generates the verification signal within 20 seconds of when the biometric sensor senses the biometric trait using no more than 1 W of peak power.
Another aspect of the present invention is a system for extracting fingerprint minutia points from a first monochrome image containing an x-y array of pixels, each representing either a fingerprint ridge or a fingerprint valley. The x-y array is divided into a plurality of contiguous local blocks, each having a predetermined number of the pixels arranged in rows and columns. Each minutia point is one of several types. The system includes a scanner module that scans lines of pixels in each local block to detect the position of segments of pixels in each local block representing a fingerprint ridge. Also included is a comparator module that compares each of the ridge segments detected by the scanner module in each local block with adjacent ridge segments to determine if a minutia point exists, and identifies its position and minutia point type. The system further includes a ridge direction module that determines direction of fingerprint ridges leading to each minutia point determined by the comparator module, and a minutia list module that saves the position and type of minutia points determined by the comparator module and fingerprint ridge directions determined by the ridge direction module.
Yet another aspect of the present invention is a fingerprint identification device that includes a sensor for providing an output signal containing information representing attributes of a user""s fingerprint positioned proximate the sensor that are unique to the user. The device also includes a memory for storing a first template containing attributes of a fingerprint of a first person that are unique to the first person and a logic unit connected to the memory. A program is stored in the memory that, in cooperation with the memory and logic unit: (i) creates the first template using the information in the output signal from the fingerprint sensor that represents unique attributes of the first person""s fingerprint positioned proximate the sensor; (ii) creates a second template using the information in the output signal from the fingerprint sensor that represents in less than 1 K bytes of data unique attributes of a user""s fingerprint positioned proximate the sensor; and (iii) verifies if the user is the first person by attempting to match the unique attributes in the first template with the unique attributes in the second template.
Still another aspect of the present invention is a method of creating a template containing attributes of a fingerprint unique to a first person, the fingerprint having a plurality of minutia points of one or more types and a ridge leading to each of the minutia points. The method comprises the steps of (a) identifying the location and type of a plurality of minutia points on the fingerprint, (b) identifying the direction of the ridge leading to each minutia point, and (c) using no more than 1 K bytes of data, storing the location and type of the minutia points identified in step a and the direction of the ridge leading to each minutia point identified in step b.

System and method for capturing, enrolling and verifying a fingerprint


Embodiments relate to providing a multi-cloud, multi-region, parallel file system cluster service with caching between file system storage nodes. In some embodiments, a first file system storage node of a file system storage cluster receives a request from a client device to access data of a first file system. In response to the request to access the data, a plurality of servers of the first file system storage node pulls, in parallel, the data and nearby data of the data from a second file system storage node of the file system storage cluster. The plurality of servers stores the data and nearby data in the first file system, and provide the data and nearby data to the client device.

This invention relates generally to file systems and specifically relates to a parallel file system cluster service.
A centralized file system can provide data to client devices over a network, such as the Internet, from a single location. However, this type of file system architecture creates difficulties when serving a large number of client devices in different geographical regions. For example, a slow network connection or large geographical distance can result in longer access times. In another example, a large number of connected client devices can cause network congestion or computing bottlenecks at the file system.


A multiple layer printed circuit board (PCB) in which the cores (or core layers) are removed and replaced with prepreg layers, which provide structure integrity for the PCB. Such a multi-layer PCB may include a plurality of layers that include a plurality of signal layers, a plurality of ground plane layers, a plurality of inner signal layers, and a single core substrate layer. Each layer in the plurality of layers may be separated from every other layer in the plurality of layers by at least one prepreg substrate layer.

Printed circuit boards (PCBs) are the core of most electronics today, and one of the most important components in an electrical system not shown on schematics. PCBs are electrical systems with electrical properties and have discrete components and devices mounted to them. Generally, PCBs are made up of an insulator substrate material that has metal plating on one or both sides, typically copper. The PCB may also have portions of metal (typically copper) that is etched away to form conductive paths or to assist in mounting devices.
A PCB may be a single or multiple layer board design. Multi-layer PCBs include plated and etched substrates that are glued together in a stack with additional insulator substrates between the etched substrates. Holes may be drilled through the multilayer stack, and conductive plating may be applied to the holes to form conductive connections between the different layers of the etched copper.
Multi-layer PCBs are more complex than single layer PCB boards, but have many added advantages such as performance improvements like noise, stray capacitance and cross talk. Multi-layer PCBs also enable miniaturization of electronics.

Method and procedure for miniaturing a multi-layer PCB


A method of providing an on-chip high-speed time domain digital analyzer for the characterization and analysis of signals within an integrated circuit is provided. The method involves processing the signal being characterized/analyzed in the digital domain irrespective of it's starting format. The approach performs a voltage-to-time conversion using predetermined voltage thresholds, applying a time amplification to the digital time information, measuring the amplified time difference between events and converting the amplified time difference as required by the characterization/analysis. The method allows the capture of very high-speed signals with high resolution without the requirements of complex and high-speed electronics. As such the on-chip high-speed time domain digital analyzer can function as an oscilloscope, pulse width analyzer, rise time analyzer and even logic analyzer. Further the method allows the capture and analysis of single and non-repetitive signal events unlike prior art approaches to time domain oscilloscopes.

Design for Test (DFT) has gone in recent years from a somewhat beneficial feature to a necessity within integrated circuits. Originally focused on digital circuits with the inclusion of circuit elements for Built-In Self-Test (BIST), and subsequently expanding to Built-In Test Equipment (BITE), the DFT methodology has now penetrated all areas of electronics and IC design, but is especially important with increasing operational speeds and increased integration in analog and mixed signal circuits where demands for performance, reliability, and defectivity are increasing whilst customer continually demand decreasing costs and guaranteed supply.
The motivations to employ DFT strategies in IC design are not always obvious at the first glance. Implementing DFT into an IC typically results in add-on test circuitry, which does not improve the primary circuit functions. It does not make a circuit faster, it does not reduce the power consumption, and it does not make it more robust to variations of process or environmental parameters. Even worse, the circuitry for testing adds additional problems. Circuit performance may be degraded, if for example switching elements are added into signal paths. Chip complexity increases, and a particularly elegant circuit solution is often questionable after test circuitry has "ruined" the layout.
DFT strategies are not merely an add-on module to an existing, and working, circuit solution but dominantly shape the semiconductor circuit solution, by for example determining the module boundaries, bring limitations and restrictions to the freedom of the analog designer and of the circuit implementation, and require additional circuitry which increases the die area, therefore increasing the die manufacturing costs and increasing the probability of faults in the chip.
As such a driving force to utilize DFT for analog and mixed signal ICs comes from market demands identified previously. One main reason for DFT is to reduce the (final) costs of ICs through reducing testing time. Testing a mixed-signal chip after production is typically responsible for between 30% and 80% of the total cost, depending on chip system complexity, volume, and application demands. Furthermore, DFT increases the testability per definition and, therefore, increases the fault coverage, which in turn increases the reliability of a circuit in the field by reducing early life failures. This is particularly important where industry trends are to single figure part per million (ppm) failures.
Another main reason to employ DFT for ICs is the demands from safety critical, highly dependable, and high reliability applications. Complex solutions for the health, nuclear, or transportation industries including automotive, aerospace and public transportation applications demand high testability and on-line functional verification to allow safe, dependable and reliable operation. Furthermore, legislative requirements and demands from insurers in many cases necessitate proof of "completeness" in testing after manufacture and even continuing on-line verification capabilities for certain applications. As such DFT evolves from a mere idea to make the test engineers life easier to a concept which is paramount to successful IC design, production, marketing, and sales.
DFT techniques evolved primarily from the digital circuit domain, and the vast majority of DFT approaches exploit digital circuits to communicate with other circuitry, perform analysis, and are digital circuits themselves. However, with digital circuits routinely operating at 10 Gb/s and above in telecommunications and developments extending to 40 Gb/s and 100 Gb/s, the line between digital and analog signals is increasingly blurring. Analog signals are often considered to be continuous signals but today's systems can operate with multiple modulation formats, frequency agility, short aperiodic bursts and digital encoding. Hence, the original differentiations between analog and digital test equipment are disappearing and circuit designs at these high speeds and operating frequencies becoming more synergistic in building blocks, semiconductor technology and testing requirements.
Historically, the design of "analog" circuits has been one with significantly less design automation than digital circuits, and is further compounded by supporting multiple semiconductor technologies such as SiGe, GaAs, and InP rather than simply silicon. As such whilst an analog element of a mixed signal IC may take up only 5-10% of the die footprint it's design can take 80-90% of the development time and it's production testing a similar proportion of test time.
As a result there has been interest in expanding the overall embrace of DFT into circuits by expanding the BIST/BITE toolset with the inclusion of an on-chip oscilloscope function such that critical parameters such as rise-time, fall-time, eye-opening, jitter, and noise can be measured automatically in real-time within the circuit. Conventional automated test equipment (ATE) for high-speed characterization of signals has centered on digital oscilloscopes, and their closely related counterpart the logic analyzer. Prior art has addressed elements of reducing either the complexity or requirements of the ATE whilst beginning the first steps of integrating the required functionality into an IC.
Prior art has therefore tended to either mimic the design of conventional time-domain oscilloscopes or provide an interface to such conventional instruments. As such prior circuits providing the special focus on BITE have addressed the issue of sampling the high-speed signals with an integrated circuit block thereby allowing the signal integrity within a mixed signal IC to be evaluated. Such an approach was reported by Delmas Ben-Dhia et al; (S. Delmas Ben-Dhia et al, "On-Chip Sampling in CMOS Integrated Circuits" IEEE Trans. Of Elec. Comp. Vol. 41, No. 4, pp 403-406, November 1999), to evaluate CMOS circuits. This integrated sampling approach has been extended by Ho et al, (R. Ho et al; "Applications of On-Chip Samplers for Test and measurement of Integrated Circuits" Dig. IEEE Symposium of VLSI Circuits, pp 138-139, June 1998), where the sampling allowed the evaluation of the VLSI circuit with a lower speed external oscilloscope.
In fact, these prior art solutions sought to address the cost of automated test equipment by embedding the high speed sampling circuit within the VLSI IC, an SRAM in the case of Ho et al, and coupling this circuit block to conventional logic analyzer/oscilloscope units external to the IC. Digitization or analysis of the signal within the IC was performed externally to the IC in these prior art approaches. Typically, signal digitization in the prior art was undertaken using external analog buffers and analog-to-digital (ADC) circuits, generally within conventional laboratory test instruments.
A step further in integration from the sampling circuit is the provisioning of the measurement clock signals necessary to control the BITE circuitry. Such measurement clock signals having been at lower speeds than the IC clock signals in these prior art solutions which address repetitive high speed signals, but would need to be at higher speeds than the IC clock signals in real time, single shot characterization and evaluation circuits for DFT, especially in capturing error events and on-line real time analysis. Such on-chip clock generation was demonstrated in the prior art by Takamiya et al, (M. Takamiya et al, "An On-Chip 100 GHz Sampling Rate 8-Channel Sampling Oscilloscope with Embedded Sampling Clock Generator", Dig. IEEE ISSCC, Vol. 1, Session 11, Paper 11.2, February 2002), wherein the sampling clock generator was integrated with 8-sampling circuits such as typically implemented within a laboratory style logic analyzer. The approach is also outlined within Japanese Patent Application 2003/114253.
However, again only sampled signals were generated on-chip and digitization was again performed off-chip within conventional test instrumentation. Prior art digitization has been restricted to simple solutions, such as the single comparator approach of Roberts et al, (G. W. Roberts et al, "A 4-GHz Effective Sample Rate Integrated Test Core for Analog and Mixed Signal Circuits", IEEE JSSC, Vol. 37, No. 4, pp. 499-514, April 2002) wherein the functional integration was increased, or Roberts and Hafed, (M. M. Hafed and G. W. Roberts, "A 5-Channel Variable Resolution 10 GHz Sampling Rate Coherent Tester/Oscilloscope IC and Associated Test Vehicles", Proc. IEEE CICC, pp. 621-624, September 2003) where external clock circuits allowed for increased speed of operation.
By extending the circuit with voltage sweeping, the circuit could perform as an on-chip tester with minimum circuit overhead. The voltage sweeping resulting in multiple thresholds such that in conjunction with digital memory digital representations of the signal could be generated. However, common to such prior art comparator based approaches the simplicity was traded off against increased test time, due to requiring the reference voltage to be swept over all possible levels and settle for each "measurement".
A variation to this is the successive approximation approach to analog-to-digital conversion; see for example the prior art by Price and McIntosh, (C. Price and C. McIntosh, "Successive Approximation Analog-to-Digital Converter" U.S. Pat. No. 6,351,231). This form of ADC having been shown integrated with a sampling circuit by Shepherd and Zheng, (K. L. Shepherd and Y. Zheng, "On-Chip Oscilloscope for Non-Invasive Time-Domain Measurements of Waveforms in Digital Integrated Circuits", IEEE Trans. On VLSI Systems, Vol. 11, No. 3, pp. 336-344, June 2003).
In mimicking conventional instrumentation, and also simplifyng the BITE circuit block these prior art solutions have relied for the most part on under sampling, see for example FIG. 3 in "Measurement and Prediction of Electromagnetic Emissions from Integrated Circuits" by B. Vrignon et al in Proceedings of IEEE Conference of Electromagnetic Compatibility August 2004. Such under sampling allows the ATE to capture a repetitive high-speed signal with a resolution of a predetermined time interval, which is set by a delay circuit generator, at a relatively low capture rate. Using the multipass approach basically allows the use of the same comparator in many iterations (passes) while varying the DC reference voltage in every new iteration. Hardware complexity is decreased at the expense of increased test time due to the dual-loop system.
Importantly the under sampling approach does not allow the capture of single events, such as occur with one-off error events within ICs or systems measuring nuclear interactions, or even those operating in safety critical or high reliability situations where on-line functional verification is required. In these instances there is no repetition, and the prior art solutions could only provide a solution with the further integration of a recirculating delay line capable of providing the multiple repetitions of the signal being characterized.
It would be advantageous therefore to provide an on-chip high-speed time domain analyzer that supports requirements of DFT and BITE processes but also provides the capability to analyze and characterize signals in real time such as a single error event pass of a signal through the BITE circuit. It would be further advantageous for the solution not to require high speed digital or mixed signal circuits operating faster than the actual IC they are characterizing. Finally the solution should be implementable without significant manufacturing costs and technical requirements that offset the financial benefits of providing the functional analysis and characterization on-chip. Such an on-chip high-speed time domain digital analyzer could function as an oscilloscope, pulse width analyzer, rise time analyzer and even logic analyzer.

Embedded time domain analyzer for high speed circuits


A party production apparatus allows a party program to be stored in advance and automatically serves various dishes in accordance with the progress of the party to produce the party successfully. The party production apparatus comprises a kitchen counter, a table counter, and a controller. The kitchen counter includes cooking device. The table counter includes a frame, a table provided on the frame, a food displaying section formed on the table, a storage chamber provided in the frame for accommodating a plurality of dishes therein, and a transport apparatus for transporting a selected dish or dishes accommodated in the storage chamber to the food displaying section. The controller includes a register for storing therein a party program including a plurality of operations to be executed successively in a time series relationship and controls the transport apparatus in accordance with an order sequence stored in the register to transport the dish or dishes to the food displaying section.

This invention relates to a party production apparatus which prepares dishes in accordance with a party program based on a plurality of operations to be performed successively in a time series relationship to produce a party.
In recent years, as the development of the culture of food proceeds, parties outside and inside the home are produced actively. For example, a system including a cooking counter for preparing dishes and serving the prepared dished on a counter is disclosed in Japanese Laid-Open Patent Application No. 3-191906.
However, as means for producing such a party successfully, it is an essential factor not only to merely serve dishes and drinks but also to serve various cool dishes (dishes to be served cool) and warm dishes (dishes to be served warm) at good intervals in accordance with the procedure of the party.

Programmable apparatus for storing displaying and serving food and drink


A tamper-evident syringe tip cap is provided and includes an outer housing with an outer shell, and a tip cover secured to an upper end of the outer shell. An inner core has a female Luer lock fitting, a spindle projecting vertically from the fitting, and a sleeve matingly engaging the spindle and being constructed and arranged for releasably securing the outer housing to the inner core. The outer housing is movable relative to the inner core between a first, pre-activated position and a second, activated position.

The present invention relates to caps for syringes used in medical treatments and procedures, and more specifically to a tamper evident cap for such a syringe.
It is common for medical syringes to be pre-loaded with a medical solution, such as medicine, saline or a constituent of a medical treatment that is designed to be mixed with another constituent prior to administration to the patient. Medical practitioners including doctors, nurses and medical technicians are concerned that the contents of these syringes remain in the syringe prior to administration, and also that the contents remain sterile and unadulterated prior to their desired administration.
Thus, there is a need for a cap for a medical syringe that addresses these objectives.


Apparatus and method for at least partially fitting a medical implant system to a recipient is described. The medical implant system is configured to provide electrical stimulation and at least one other mode of stimulation to the recipient. These apparatuses and methods comprise executing a genetic algorithm to select a set of parameter values for the medical implant system. This genetic algorithm may comprise generating successive generations of child populations and then providing a determined set of parameter values to the medical implant system for use in providing stimulation to the recipient.

1. Field of the Invention
The present invention relates generally to stimulating medical devices, and more particularly, to fitting a stimulating medical device.
2. Related Art
Many medical devices have structural and/or functional features which are to be adjusted for an individual recipient. The process by which a medical device is tailored or customized for the specific needs of a recipient is commonly referred to as fitting. One type of medical device which is typically fitted to individual recipients is a cochlear implant system.
Cochlear implant systems provide the benefit of hearing to individuals suffering from severe to profound hearing loss. Hearing loss in such individuals is often due to the absence or destruction of the hair cells in the cochlea which transduce acoustic signals into nerve impulses. Cochlear implant systems essentially simulate the auditory nerves by directly delivering electrical stimulation to the auditory nerve fibers. This causes the brain to perceive a hearing sensation resembling the natural hearing sensation normally delivered by the auditory nerve.
Conventional cochlear implant systems commonly include an external assembly directly or indirectly attached to the body of the recipient (sometimes referred to herein as the recipient), and an internal assembly which is implanted in the recipient. The external assembly typically comprises one or more microphones for detecting sound, a speech processing unit that converts detected sound into an electrical coded signal, a power source, and an external transcutaneous transfer coil. The internal assembly typically comprises an internal transcutaneous transfer coil, a stimulator unit located within a recess of the temporal bone of the recipient, and an electrode array positioned in the recipient's cochlea. Completely implantable cochlear implant systems having functionally similar components are under development.
In addition to providing electrical stimulation, some cochlear implant systems also include a mechanical stimulation mode of operation. Such so called mixed-mode systems offer rehabilitation by mechanically stimulating a portion of a recipient's auditory pathway, either acoustically or physically. For example, there have been approaches to offer rehabilitation with conventional hearing aids via the application of an amplified acoustic signal to the external auditory canal, or by physically stimulating an ossicle of the middle ear or the inner ear via mechanical or hydromechanical stimulation.
Modern cochlear implant systems provide a wide variety of fitting options that can be customized for an individual recipient. Because recipients are heterogeneous, each recipient requires a different set of parameters to maximize speech reception and recipient satisfaction. The task of the clinical professional, usually an audiologist, is to select a set of parameters, commonly referred to as a parameter map or, more simply, a MAP, that will provide the best possible sound reception for an individual recipient. Because there may be thousands of possible parameter maps, it is impractical for a recipient to experience all of the alternatives and to evaluate the performance of each alternative. Nor is it possible to identify an optimal parameter map by prescription based on a limited set of measurements as is, for example, the case in fitting eyeglasses. Because parameters of cochlear implant systems often interact non-linearly and non-monotonically, it is also not feasible to sequentially optimize individual parameters, adjusting each in succession to its optimal value.
As a result, clinicians have adopted a variety of approaches for fitting the cochlear implant systems to recipients. Some simply set the parameters to default values regardless of the individual recipients. Others adopt preferred parameter maps, which they believe are good, if not best, for many or most recipients. The preferences may be based on personal experience, published performance data, or intuition. Some clinicians evaluate a limited set of alternatives adjusting individual parameters based upon measured perceptual limitations and inferred relationships among the parameters. These approaches are time consuming, costly, and unreliable, and typically fail to achieve the optimal outcome for individual recipients.

This patent is subject to a terminal disclaimer.

Using a genetic algorithm in mixed mode device


A feedback control numerical machine tool and a method thereof are provided. The machine tool includes at least two spindles, an acoustic frequency detecting module, at least two spindle position detecting modules, and a control module. The spindles machine a workpiece. The acoustic frequency detecting module detects an acoustic frequency of the spindles when machining the workpiece. The spindle position detecting modules detects position information of the spindles when machining the workpiece. The control module acquires the acoustic frequency and the position information of the spindles, monitors whether any of the spindles chatters according to the acoustic frequency of the spindles, and performs chattering avoidance to the spindle that chatters according to the position information of the spindles. As such, the present disclosure performs chattering monitoring to a plurality of spindles and avoids the chattering immediately.

1. Technical Field
The present disclosure relates to feedback control numerical machine tools and methods thereof, and, more particularly, to a feedback control numerical machine tool and method thereof capable of avoiding chattering.
2. Description of Related Art
The traditional feedback control numeric machine tool can only deal with chattering avoidance of spindles by an offline method with numeric control program. Although the machining quality or machining process of the spindle is globally optimized, it is still necessary to monitor all the time during the spindles machine a workpiece for handling the chattering of the spindle.
Moreover, the traditional art can only perform chattering avoidance to a single spindle or shut down the feedback control numeric machine tool once the spindle chatters. Therefore, it is difficult to employ the traditional art to a feedback control numeric machine tool having a plurality of spindles. Also, it is difficult for the traditional art to allow other spindles without chattering to continuously machine the workpiece when at least one of the spindles chatters.
Further, although some of the traditional arts employ a microphone or a microphone array, those are usually utilized to detect noise, and the microphone can only support or work on a single spindle.
If the microphone or microphone array is employed in plural spindles, once at least one of the spindles chatters, the only solution of the conventional art is to shut down the machine tool, and it takes considerable time to troubleshoot the chattering of the spindle. Accordingly, the chattering cannot be avoided immediately during the machining of the spindles, such that the machining process of the spindles to the workpiece cannot be effectively reduced.
From the foregoing, how to overcome abovementioned issues raised by the traditional arts becomes the objective being pursued by persons skilled in the art.

Feedback control numerical machine tool and method thereof

Industrial Technology Research Institute