Methods for hierarchical hole-filling and depth adaptive hierarchical hole-filling and error correcting in 2D images, 3D images, and 3D wrapped images are provided. Hierarchical hole-filling can comprise reducing an image that contains holes, expanding the reduced image, and filling the holes in the image with data obtained from the expanded image. Depth adaptive hierarchical hole-filling can comprise preprocessing the depth map of a 3D wrapped image that contains holes, reducing the preprocessed image, expanding the reduced image, and filling the holes in the 3D wrapped image with data obtained from the expanded image. These methods are can efficiently reduce errors in images and produce 3D images from a 2D images and/or depth map information.

Embodiments of the present invention relate generally to three-dimensional images, and more specifically to improved three-dimensional image synthesizing using depth image-based rendering (DIBR) and hierarchical hole-filling.
An increasing number of movies and TV programs are being produced and/or presented in stereoscopic 3D format. This trend is being driven, at least in part, by noticeable advances in stereoscopic display technologies. Three dimensional television (3DTV) and 3D mobile TV are widely considered to be the future of multimedia broadcasting. 3DTV and other technologies can bring a more life-like and visually immersive experience to viewers.
In the future, viewers may have, for example, the freedom to navigate through a scene and choose multiple viewpoints. This is known as free-viewpoint TV (FTV). This technology can also be desirable and applicable to, for example and not limitation, movie theaters, presentations, still pictures, computer generated images (CGI), and animation, where viewers view 3D printed or projected image or motion picture.
Producing an FTV image can be complex. To produce stereoscopic 3D videos, for example, each individual viewpoint requires two videos corresponding to the left and right camera views. In addition, true multi-viewpoint video, such as true FTV, for example, can require up to 32 viewpoints (or possibly more). Consequently, capturing and broadcasting arbitrary viewpoints for FTV can require an unrealistically high number of cameras, extremely complex coding, and expensive processors. In addition, advances in 3D display technologies, such as autostereoscopic displays, require flexibility in the number of views and/or the ability to resize each view to match the display resolution. Hence, generating FTV from the multi-camera capture of a large number of views can be cumbersome and expensive.
One alternative is to generate, or synthesize, the intermediate views using view synthesis. One method of view synthesis is the aforementioned DIBR. In DIBR, two or more views for 3D display can be generated from a single 2D image and a corresponding depth map (i.e., an image or image data that contains information relating to the distance of the surfaces in a scene from a particular viewpoint).
DIBR has several advantages including, but not limited to, high bandwidth-efficiency, interactivity, easy 2D to 3D switching, and high computational and cost efficiency. These advantages make it possible for a TV, or other multimedia display device, to receive a 2D image and a depth map, and to convert the 2D image and depth map into a 3D image. In addition, through DIBR, a TV or other multimedia display device can receive a series of 2D images and depth maps, and convert the 2D images and depth maps into 3D images, which can be shown in succession to form 3D video.
In addition, DIBR can be accomplished using one or two cameras (less than would be required if each viewpoint was captured by its own camera or set of cameras). DIBR also eliminates photometric asymmetries between the left and right views because both views are generated from and based on the same original image. The inherent advantages of DIBR have lead the Motion Pictures Expert Group ("MPEG") to include it in their standard for coding video plus depth format, which is known as MPEG-C part 3. As shown in FIG. 1, the process of producing 3D images from captured content (with a 3DTV system, for example) can comprise six main steps: 3D video capturing and depth content generation 101; 3D content video coding 102; transmission 103; decoding the received sequences 104; generating virtual views 105; and displaying the stereoscopic images on the screen 106.
With DIBR, virtual views can be generated from the reference image and the corresponding depth map using a process known as 3D wrapping. The 3D wrapping technique allows mapping of a pixel at a reference view to a corresponding pixel at a virtual view at a desired location. This can be accomplished by first projecting the pixels at the reference view into world coordinates using explicit geometric information from the depth map and camera parameters. The pixels in the world coordinates can then be projected into the estimated virtual image coordinates to yield a 3D wrapped image.
To better understand DIBR, consider a reference camera Cr and a virtual camera Cv, as shown in FIG. 2. Further consider that Fr and Fv are the focal lengths of the reference and the virtual cameras, respectively (for simplicity, Fr and Fv are assumed to be equal, but do not have to be). Additionally, B is the baseline distance that separates the two cameras, and Zc is the convergence distance of the two cameras axis. The horizontal coordinates vector Xv of the virtual camera as a function of the horizontal coordinate vector Xr of the reference camera is given by:
            X      _        v    =                    X        _            r        +          s                                          F            v                              B                          Z          _                      +    h  where s=−1 when the estimated view is to the left of the reference view and s=+1 when the estimated view is to the right of the reference view, Z is a vector of the depth values at pixel location (xr, yr), and h is the horizontal shift in the camera axis which can be estimated as:
  h  =            -      s                                                F            v                              B                          Z          c                    .      In some applications the depth value is presented in terms of disparity maps. In such cases, the depth vector Z at a certain pixel location can be obtained from disparity vector D as:
      Z    _    =                    F        r                  b              D      _      where b is the original baseline distance of the stereo camera pair used in the disparity calculation. Finally, the wrapping equation can be expressed in terms of disparity as:
      x    v    =            x      r        +          s                                          F            c                              B                                D            _                                                F            r                              b                      -          s                                          F            v                              B                          Z          c
3D wrapping does not always result in a perfect image. Synthesized views using 3D wrapping may contain holes for a variety of reasons. Often, the holes are caused by disocclusion, which is primarily caused by two factors. Disocclusion can be caused, for example, by uniform sampling in the reference image becoming non-uniform in the desired image due to the virtual viewing angle. In other cases, holes can be caused simply because formerly occluded areas in the reference image becoming visible in the virtual image. In other words, as the image is manipulated, features come into, and go out of, view. Holes can also be the result of, for example and not limitation, inaccurate depth maps, errors in transmission, or noise in the depth map or image signal. FIGS. 3a-3c show several examples of synthesized images immediately after 3D wrapping. The holes in these figures tend to appear as black areas and/or black lines.
The presence of holes as the result of DIBR is a challenging problem because there is little or no information that can be derived from the depth map or the reference camera about disoccluded areas. One method that has been used to attempt to cure this problem is Gaussian filtering of the depth map, which is generally exemplified in FIG. 4. In this method, a Gaussian filter smoothes sharp transitions in the depth map thereby reducing the size of holes in the 3D wrapped image. The smaller holes can then be filled using an average filter. A problem with this approach is that processing the depth map through smoothing results in geometric distortions, as can be seen in the imperfections in FIGS. 5a and 5b.
To remedy these distortions; Zhang et al. proposed using a symmetric Gaussian filter followed by an average filtering of the image. L. Zhang & W. J. Tam, Stereoscopic Image Generation Based On Depth Images For 3DTV, IEEE TRANS. ON BROADCASTING, vol. 51, no. 2, pp. 191-199 (June 2005). One drawback of this approach is that it changes the original depth values resulting in a loss of depth cues after wrapping. This loss tends to lead to image distortion.
Criminisi et al. developed an inpainting technique for hole-filling in DIBR. A. Criminisi et al., Object Removal by Exemplar-Based Inpainting, IEEE TRANSACTIONS ON IMAGE PROCESSING, p. 13 (2004). Criminisi's method fills the holes by using a texture synthesis algorithm that gives higher weights to linear structures in an attempt to reduce image distortion. Unfortunately, the subjective results from Criminisi's technique have shown only a very slight improvement over the quality obtained by other methods and the resulting videos tend to suffer from severe flicker as a result of temporal inconsistencies.
Vazquez et al. developed a technique of horizontal interpolation to reduce holes. C. Vazquez et al., Stereoscopic Imaging: Filling Disoccluded Areas in Depth Image-Based Rendering, Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, vol. 6392 (October 2006). However, this method tends to cause severe and undesirable distortion to the texture of the background.
Thus, there is a need to produce high quality 3D images in a manner that is computationally efficient and requires reduced bandwidth. There is also a need for a method of removing holes from a view synthesized by DIBR that does not distort the image, does not lead to flickering, and results in a high quality image. There is also a need for a method of removing holes from a view synthesized by DIBR when the image is distorted or corrupted due transmission errors and/or distorted or corrupted signals. It is to these issues that embodiments of the present invention are primarily directed.

Hierarchical hole-filling for depth-based view synthesis in FTV and 3D video


A disc type determining apparatus in a disc recording and reproducing apparatus in which vibrations generated by rotations of a disc occur in a focus and tracking control actuator includes an error gain adjusting unit, which adjusts an amplitude of a focus and tracking error in order to maintain a constant amplitude of the focus and tracking error; a loop gain adjusting unit which compares the closed loop phase of the focus and tracking control loop and a predetermined reference closed loop phase, and maintains a constant gain of the focus and tracking control loop; a vibration measuring unit which measures vibrations using the adjusted error and the output of a controller; and a disc type determining unit which extracts a predetermined signal to determine the type of a disc using the measured vibrations, measures the deflection, eccentricity, and mass eccentricity of a disc using the extracted signal.

1. Field of the Invention
The present invention relates to an apparatus and method for optical disc drive operations, and more particularly, to a disc type determining apparatus and method in which vibrations generated in a drive by a disc are measured, and then, using the measured vibrations, determining whether the disc is a deflected disc, an eccentric disc, or a mass eccentric disc, and based on this determination, setting the transfer rate of the determined disc.
2. Description of the Related Art
Discs having a deflection, an eccentricity, and a mass eccentricity larger than those of a normal disc are referred to as a deflection disc, an eccentricity disc, and a mass eccentricity disc, respectively. In these special discs, disturbances occur caused by vibrations not damped by a servo in a focus and tracking control loop. Therefore, in a disc drive, it should be determined whether a received disc is a special disc. If the results indicate that the disc is a special disc, the transfer rate of the disc should be limited such that a normal drive operation is performed according to the deflection, eccentricity, and mass eccentricity.
If the deflection, eccentricity, and mass eccentricity of the disc increase, disturbances increase for which a focus and tracking control loop should compensate. Moreover, if the transfer rate of the disc increases, the rate of change of the disturbances increases and all servo operations become unstable. In particular, after a search or a layer jump operation, a focus and tracking control cannot start in a stable mode. Therefore, only when the speed of a spindle motor is limited to a predetermined value at which a normal servo operation is performed in accordance with the deflection, eccentricity, and mass eccentricity of the special disc can data be stably recorded on and reproduced from the special disc.
In order to limit the speed, an algorithm is used to determine whether a received disc is either a deflection disc, an eccentric disc, or a mass eccentric disc. However, according to algorithms used conventionally, the result of the determination varies according to a state of the servo. Also, since there is no algorithm appropriate to determine if the special disc is the disc deflection, there are many disc drive models which do not determine or recognize whether the disc is a deflection disc.
FIG. 1A shows a focus error signal used in measuring the deflection of a disc. The amplitude of this focus error signal is then used as data to determine whether the disc is the deflection disc. FIGS. 1B and 1C are, respectively, a waveform diagram of a tracking error signal used to generate a tracking zero cross (TZC) used in measuring disc eccentricity, and a TZC signal generating block. The tracking error signal of FIG. 1B is compared with a reference value in a comparison unit 10 of the TZC signal generating block of FIG. 1C. The result of the comparison is compensated in a compensation unit 11 so as to generate the TZC signal. Since the TZC signal is output as a sequence of pulses whenever a pickup (not shown) passes through one track, the number of this TZC pulses is calculated and used as data for determining whether the disc is the deflection disc.
Conventionally, determining whether a disc is the deflection disc, the eccentric disc, or the mass eccentric disc is performed in an initial lead-in operation. A microcomputer (not shown) normally drives a drive with automatic adjustment, and then determines the disc type by the following methods.
Deflection Disc:
For a constant focus control loop gain, a disc having a great deflection has a great focus disturbance, a deflection component which is not controlled is great, and the amplitude of the sine wave appearing in the focus error signal of FIG. 1A increases. Therefore, by measuring the amplitude of the focus error, it can be determined if the disc has a large deflection.
In order to increase the measuring resolution, the focus loop gain is reduced and the output of the focus error signal is increased.
In the prior art, the focus error signal is read by a microcomputer (not shown). If the obtained amplitude of the signal is greater than a predetermined value, it is determined that the received disc is the deflection disc. The greater the amplitude of the focus error signal, the greater deflection of the received disc, and therefore the maximum transfer rate of the disc is reduced. However, if the focus error signal is used to determine the disc deflection, the measuring reliability is degraded because the signal is greatly affected by noise. Therefore, in most disc drive models, this method is not used. Even when this method is used, the importance of the determining the disc deflection is minimized.
Eccentric Disc:
In a state where only focus control is performed, a track transverse signal as shown in FIG. 1B is a tracking error. Since the number of sine waves output during one disc rotation cycle varies with respect to the eccentricity of the disc, the eccentricity of the disc can be calculated by counting the number of pulses of the sine waves output during one disc rotation cycle. For this, the TZC signal, used to find the number of tracks passed in searching, is employed.
The eccentricity of the disc is obtained by multiplying the number of pulses of the sine wave output during one disc rotation cycle by (track pitch/2). Using the calculated eccentricity, it is determined whether the disc is the eccentric disc, and the speed of a spindle motor is limited according to the eccentricity. The prior art method for measuring disc eccentricity is widely used for many drives because it is more reliable than the method for measuring disc deflection.
Mass Eccentric Disc:
The mass eccentric disc presents a small eccentricity for a low transfer rate, but the eccentricity increases for a high transfer rate. Accordingly, when an algorithm for measuring disc eccentricity is used, if the number of pulses of the sine wave output during one disc rotation cycle at the low transfer rate is almost the same as that at the high transfer rate, the received disc is not the mass eccentric disc. If the difference in the number of pulses is great, the received disc is a mass eccentric disc. Here, according to the difference of the number of pulses, the maximum transfer rate is limited.
As described above, in the prior art, the disc deflection, the disc eccentricity, and the disc mass eccentricity are not directly measured. Instead, an algorithm is used which utilizes general characteristics. For instance, the general characteristics include that if the deflection, the eccentricity, and the mass eccentricity increase, the amplitude of the focus error increases, or the number of pulses of the sine waves increases during the output of a disc rotation frequency. The eccentricity algorithm has a relatively high accuracy and is used in most disc drive models, while the deflection algorithm has a low accuracy and a high probability of erroneous determination, and is rarely used. If the type of the special disc is not distinguished and the transfer rate is not appropriately lowered, the focus and tracking control loop becomes unstable and the performance of the disc drive degrades.

This patent is subject to a terminal disclaimer.

Apparatus and method for determining disc type


A device having a thin ceramic layer therein, is made by preparing a mixture of ceramic particles, a binder, and a plasticizer, and forming the mixture into a ceramic layer. A second layer is placed adjacent to the ceramic layer to form a composite layered structure. The thickness of the composite layered structure is reduced, preferably by rolling, until the ceramic layer portion of the composite layered structure has a preselected small thickness. If desired, the thickness of the ceramic layer can be reduced to an arbitrarily small value by stacking the reduced composite layered structures (or one of the layered structures with another structure) and repeating the reducing operation on the stack. The ceramic layer having the preselected thickness is assembled into a device. Devices that can be prepared by this approach include, for example, multilayer capacitors, solid oxide fuel cells, and solid-electrolyte electrochemical storage cells.

This invention relates to the manufacture of devices that include a ceramic layer, and, more particularly, to a reliable, inexpensive approach for preparing such a device with a very thin ceramic layer.
Ceramics are used in a wide variety of devices because of their unique properties. For example, many ceramics have low electrical conductivity and are therefore useful as dielectric insulators in devices such as capacitors and microelectronic devices. Other ceramics having high ionic conductivity can act as solid electrolytes in applications such as fuel cells and electrochemical storage cells.
In such devices, the ceramic is generally present as a thin layer between or adjacent to electrical conductors or electrodes. The operating principles of such devices, as well as the general need in many devices to improve performance and reduce weight and space requirements, dictate that the ceramic layer should be made as thin as possible consistent with other physical requirements such as sufficient strength and an absence of defects such as pinholes through the ceramic layer.
There are two types of approaches for preparing thin ceramic layers for use in such devices, powder-based techniques and direct deposition techniques. In the powder-based approach, the ceramic is furnished as a powder which is suspended in a fluid or mixed with a binder and a plasticizer. The fluid or binder/plasticizer aid in the handling and forming of the ceramic particles. The flowable mixture is formed into the required shape, the fluid or binder/plasticizer is removed by heating, and the solid ceramic is sintered to its final density. At present, the powder-based techniques of this type have been used to produce layers of about 25 micrometers (0.001 inch) or more in thickness.
In the direct deposition approach, a layer of ceramic is deposited from a bulk or gaseous source onto a substrate by a transport process such as physical vapor deposition or chemical vapor deposition. These direct deposition techniques can produce arbitrarily thin ceramic layers, down to the atomic thickness range in some cases. However, they are usually slow and difficult to implement in many production operations because they require complex deposition apparatus and often require line-of-sight to the deposition region from the source of the ceramic. These techniques may also be limited as to the compositions and degrees of porosity that can be prepared.
A number of devices such as capacitors, solid oxide fuel cells, and solid electrolyte electrochemical storage cells are commonly manufactured using ceramic layers made by conventional powder-based techniques. In general, currently the thickness of the ceramic layers made by those techniques is about 25 micrometers. Direct deposition techniques are also used in some cases, but they are too slow and costly for most applications. Such devices would benefit from the ability to economically manufacture them with thinner ceramic layers, on the order of 10 micrometers in thickness or less. There is therefore a need for an improved approach by which devices having thin ceramic layers can be fabricated.

Preparation of devices that include a thin ceramic layer


Disclosed are systems and methods for improving wavelength control in tunable laser sources. Embodiments of the systems and methods include delivering a fraction of the light output from the laser to an optical filter subsystem. The optical filter subsystem is capable of outputting at least one filter response signal, and comprises 2 complementary optical etalon filters with nominally identical free spectral ranges but offset by nominally one third of the free spectral range. The filter response signal is processed in a control unit which executes a control algorithm to generate a tuning signal that is used to control the wavelength of the laser.

Diode lasers are important in a wide variety of applications in optical communications, science, biophotonics, and many other areas. In an increasing number of applications, it is important to know the laser frequency with high precision. These applications include dense wavelength-division multiplexed (DWDM) optical communications, where the optical frequency must be controlled to typical 1-2 GHz. Systems using coherent optical detection require two laser with frequencies matched to at least sub-GHz accuracy. A variety of techniques for generating high-frequency microwave or terahertz radiation involve mixing together two wavelength-controlled lasers, and the resulting frequency is only as accurate as the control of the optical frequencies. For these applications and more it is important to be able to control the absolute wavelength of a diode laser source with a precision in the order of less than 10 MHz.
Most of the important applications discussed herein require single-frequency (distributed feedback (DFB) or distributed Bragg reflector (DBR)) lasers, but the methods disclosed are applicable to all types of diode lasers. Wavelength generally must be controlled actively, since the laser wavelength depends on device temperature and output power (which is proportional to the injection current), and this dependence changes as the laser ages. Active control is accomplished by measuring the laser wavelength and adjusting the laser temperature by means of a thermoelectric cooler (TEC).
A variety of methods exist to measure the wavelength of a laser diode. Wavelength meters operate by counting fringes in an optical interferometer. While highly precise, these instruments require mechanical parts to scan the interference pattern; hence they are too large and expensive for many applications. A scanning Fabry-Perot (FP) interferometer is a common device used for accurate frequency measurement. However, these are expensive, difficult to align, and require careful calibration with a known frequency source to provide absolute frequency measurement. Fiber FPs have been developed to offset cost issues somewhat, but these still lack absolute wavelength measurement. We seek a low-cost solution with absolute measurement capability.
It is well known that a wide variety of optical filters with fully characterized transfer functions (transmission or reflection versus wavelength) can be used to provide absolute frequency measurement. A variety of slope filters have been manufactured using, for example, thin film multilayer coatings to provide an approximately linear transfer function over a targeted range of wavelengths. The output signal then corresponds to a unique input wavelength. Since these can be made from materials (e.g., fused silica) with low thermal dependence, they can provide good thermal stability and temperature dependence that can be corrected easily. However, the accuracy of the wavelength control depends on the slope of the transfer function relative to the noise (noise from optical detection and from digital sampling) in the output signal. For wavelength tuning over a wide range, this slope becomes small, and the accuracy of wavelength control is impaired. We require the maximum possible accuracy; therefore this limited slope is unacceptable. In addition, a different filter is required for each operating range. This complicates supply and inventory management, as many different parts must be ordered, and this increases cost.
In optical communications systems using dense wavelength-division multiplexing (DWDM) wavelengths must be controlled to align the standard ITU frequency plan. Channels by this plan are defined on a periodic frequency grid with 100, 50, or 25 GHz frequency spacing. A typical DFB laser can be temperature tuned typically over several channels. To lock a laser to the center wavelength of an ITU channel, wavelength lockers have been developed. These generally consist of a Fabry-Perot etalon, made using thin-film multilayer dielectric minors. The mirror reflectivities are designed to produce resonances with a reasonably sinusoidal transfer function. While the exact peak of the FP resonances is angle and temperature dependent, the desired periodicity (100, 50, or 25 GHz) can be fabricated with high precision. Wavelength control is accomplished by locking the laser to the steep slope of the transfer function, where the transmission is typically in the middle between the maximum and the minimum. This provides a low-cost and accurate method for locking to discrete, specific, and periodic channels. However, the periodicity of the etalon transfer function causes ambiguity in wavelength measurement. Also, the measurement accuracy is decreased as the optical wavelength under measurement falls within the range around the maxima and minima (tops and bottoms) of the transfer function where the slope is decreased. Additionally, the accuracy at the bottoms is degraded more than that at the tops due to lower signal-to-noise ratio around the minima. Thus the use of a single etalon is not a suitable technique for precise wavelength determination over a wide wavelength range.
The measurement ambiguity due to the periodic transfer function of an optical etalon can be circumvented by adding a coarse wavelength determination method, as long as this method has a wavelength resolution no larger than the FSR of the etalon. One approach uses a linear spectral filter for the wavelength band of interest [U.S. Pat. No. 7,505,137 B2]. Alternatively the output wavelength of a semiconductor laser can be approximated by laser operation characteristics, including current, temperature and power.
Many approaches for improving measurement sensitivity of single etalon transfer function utilize a second etalon transfer function have been proposed. In one previous work, two high finesse etalons with different FSR are used to measure the wavelength of a tunable laser. But the absolute wavelength of the tuning range is measured by a wavelength meter and the tuning range is limited by the larger FSR between two etalons. Also, the method does not allow real-time wavelength monitoring [S. Yoshida, Y. Tada, and K. Nosu, "High resolution optical spectrum analysis by coherent detection with multi-electrode DBR-LD's as local oscillators," in Conf. Proc. IMTC/94. IEEE Instrumentation Measurement Technology Conf., vol. 1, 1994, pp. 230-233].
Alternatively, the second periodic transfer function has same FSR as that of the first but with a phase shift of a fraction of FSR. Normally, two low finesse etalons with quadrature (90 degree) phase shift are used to mimic a pair of orthogonal sinusoidal response functions [U.S. Pat. No. 6,178,002 B1 and U.S. Pat. No. 7,420,686 B2]. In this method, the slope parts of one sinusoidal function cover the phase (optical wavelength or frequency) range where the other is at its maximum or minimum. The optical wavelength is then extracted from the pair of orthogonal signals. In U.S. Pat. No. 7,420,686 B2, the measurements at the maximum and minimum of the transfer functions (dead zones) are ignored. The finesse of two etalons has to be low (2 or less) to avoid dead zone overlapping and to make the etalon response relatively close to sinusoidal function. However, the very low finesse of an etalon gives a transfer function with a decreased contrast, which degrades the sensitivity due to decreased overall slope. Also, the quadrature phase shift is only optimal for a pair of etalons with this low finesse.
Furthermore, the binary method of deciding the validity of the measured signals in U.S. Pat. No. 7,420,686 B2 ignores the effect of the signal-to-noise ratio on the measurement accuracy. The accuracy is not only dependent on the slope of the etalon transfer function, but also sensitive to the noise in the signal output. The determination of the wavelength becomes less accurate when the input optical wavelength is close to the minimum of the transfer function due to both decreased slope and high relative noise. Therefore, generally, the measurement is more precise at a higher signal output (transmission or reflection) point than that of a low signal output even with a same function slope.
Accordingly, a method that optimizes the etalon finesse, relative phase shift, and wavelength algorithm based on detector sensitivity and signal-to-noise ratio so as to improve the performance of optical wavelength measurement and control is desired.

System and method for laser wavelength control


A vehicle control system has a controller comprising a first section for producing a control signal to control the rear wheel steer angle so that the rear wheel steer angle remains equal to a linear combination of a proportional term obtained by multiplying the front wheel steer angle by a proportional coefficient, and a negative derivative term obtained by multiplying the time rate of change of the front wheel steer angle by a derivative coefficient, and a second section which increases the rear wheel steering amount in the direction opposite to the front wheel steering direction by increasing the absolute value of the derivative coefficient with increase in the lateral acceleration of the vehicle or the front wheel steer angle, in order to improve the yawing characteristic of the vehicle in the high lateral acceleration range.

The present invention relates to a vehicle steering control system for controlling at least a rear wheel steer angle of a vehicle.
Japanese Patent Provisional Publication No. 60-229873 shows a rear wheel steer angle control system which steers rear wheels of a vehicle so that an actual rear wheel steer angle is given by; EQU .delta..sub.r =K.times..theta.-.tau..times..theta.
where .delta..sub.r is the rear wheel steer angle, .theta. is a steering angle of the vehicle, .theta. is a steering angular speed, K is a proportional constant (or coefficient), and .tau.(tau) is a derivate constant (coefficient). The derivative constant is positive.
Similar rear wheel steer angle control systems are disclosed also in many commonly-assigned, copending U.S. patent applications. Examples are Ser. No. 07/195,085 (, filed by F. SUGASAWA, on May 17, 1988, for "VEHICLE STEER ANGLE CONTROL SYSTEM"), Ser. No. 07/195,078 (, filed by K. MORI, on May 17, 1988, for "SYSTEM FOR CONTROLLING STEER ANGLE OF REAR WHEELS OF FOUR WHEEL STEERABLE MOTOR VEHICLE"), Ser. No. 07/275,061 (, filed by K. KAWAGOE, on Nov. 22, 1988, for "VEHICLE STEERING CONTROL SYSTEM WITH DERIVATIVE GAIN ADJUSTING CAPABILITY"), Ser. No. 07/277,745 (, filed by K. MORI et al., on Nov. 30, 1988, for "REAR WHEEL STEER ANGLE CONTROL SYSTEM FOR VEHICLE"), Ser. No. 07/277,744 (, filed by K. MORI et al., on Nov. 30, 1988, for "FOUR-WHEEL STEER CONTROL SYSTEM"), Ser. No. 07/269,698 (, filed by F. SUGASAWA et al. on Nov. 10, 1988, for "METHOD FOR STEERING VEHICLE"), Ser. No. 07/284,414 (, filed by T. EGUCHI et al., on Dec. 14, 1988, for "VEHICLE REAR WHEEL STEER ANGLE CONTROL SYSTEM") and Ser. No. 07/305,023 (filed by F. SUGASAWA, on Feb. 2, 1989, for "FAIL-SAFE STEER ANGLE CONTROL SYSTEM FOR VEHICLE").
The proportional coefficient K and the derivative coefficient tau assume different values in accordance with the make of the vehicle and the vehicle speed. The proportional coefficient K is generally positive. For example, K equals 0.38, and minus tau equals -0.049 when the mass M of the vehicle equals 160 kgS.sup.2 /m, the yawing moment of inertia I of the vehicle equals 252 kgmS.sup.2, the wheelbase 1 equals 2.48 m, and the vehicle speed V equals 120 km/h. However, K =0.33 and minus tau =-0.056 for the same vehicle speed, V =120 km/h if M =125 kgS.sup.2 /m, I =227 kgS.sup.2 and 1 =2.48 m.
When the steering wheel is turned speedily, the control system of this type steers the rear wheels so that the rear wheel steer angle remains for a limited time in an opposite phase side in which the rear wheels are steered in the opposite direction to the steering direction of the front wheels, and then changes to a same phase side in which the rear wheels are steered in the same direction as the front wheels (so-called phase inversion control).
However, this control system takes no account of the vehicle lateral acceration in determining a value of the derivative coefficient, so that it cannot improve the vehicle steering response of yawing motion satisfactorily.
In general, it is desired to improve the yawing characteristic of a vehicle in the low vehicle speed range. In the high vehicle speed range, it is desired to improve the stability of the vehicle. In the control system using the above-mentioned equation, the vehicle yawing characteristic is mainly determined by the derivative term .tau..theta. which is the product obtained by multiplying the steering speed .theta. by tau. This derivative term acts to increase the opposite phase steering amount through which the rear wheels are steered in the direction opposite to the steering direction of the front wheels, or to reduce the same phase steering amount through which the rear wheels are steered in the same direction as the front wheel steering direction. The derivative term .tau..theta. increases with increase in the steering speed .theta., provided that the derivative coefficient tau is fixed. On the other hand, the derivative term increases with increase in the derivative coefficient tau, provided that the steering speed .theta. is fixed. As the derivative term is increased, the opposite phase steering amount is increased, and accordingly the vehicle yawing characteristic is improved.
The yawing characteristic in the range of low lateral accelerations can be increased by increasing the derivative coefficient tau and thereby increasing the opposite phase steering amount. However, in this case, there appears a momentary lateral acceleration in the outward direction away from the center of the turning arc, which arouses unnatural feeling in the driver. Therefore, there is a limit to the increase of the derivative coefficient tau.
In a turn of a high lateral acceleration, provided that the steering conditions (the steering angle .theta. and the steering speed .theta. are the same), it is necessary to make the opposite phase steering amount higher than the level required in the low lateral G range, in order to obtain the yawing characteristic of the same rank. FIG. 4 shows a characteristic of a tire cornering force. When the vehicle is in a turn of a low lateral G or in a straight ahead operation (in a range A' in FIG. 4), the side slip angle is still small, and the rate of increase of the cornering force with respect to the side slip angle (the slope of a tangent line a shown in FIG. 4) is high. When the lateral G is medium (a range B'), the side slip angle becomes greater, but the rate of increase (the slope of a tangent line b) becomes lower than that of the low G turn. When the lateral G is high (a range C'), the side slip angle reaches its maximum and then decreases, and the rate of increase of the cornering force (the slope of a tangent line c) is further decreased. During a turn of a high lateral G, therefore, the vehicle slip angle is large, and the cornering force produced per unit steer angle is low. Therefore, in the high lateral G range, it is desired to improve the yawing characteristic by increasing the opposite phase steering amount beyond the level of the low lateral G range. However, the control system of the conventional example cannot satisfy both of the demand for improving the yawing characteristic in the low lateral G range, and the demand for improving the yawing characteristic in the high lateral G range.

Rear wheel steering control system for vehicle


The recoiling temperature of a metal strip from a continuous heat treatment line is controlled by continuously passing the metal strip through an accumulator system where it passes around spaced accumulator rolls. While travelling through the accumulator, the metal strip is subjected to ambient cooling air and the length of aluminum strip travelling through the accumulator determines the amount of cooling that takes place. The length of the metal strip in the accumulator is in turn controlled by varying spacing between the accumulator rolls around which the metal strip travels. The spacing is preferably controlled by a programmed controller in response to temperature signals.

The invention relates to a method and system for controlling the rewind temperature of strip metal, e.g. aluminum, in a continuous heat treatment line.
In the heat treatment of aluminum strip it is important to control the final temperature of the metal as it is rewound into coil form. This is because even at room temperature, the solutionized and quenched metal will undergo a process of microstructural transformation known as xe2x80x9cagingxe2x80x9d. Once rewound, due to the large mass of the coil and relatively small exposed surface area, the metal cools to room temperature over a period of many hours during which time the aging process continues. The aging will proceed to a greater or lesser extent depending on the initial temperature of the coil and the coil cooling rate. A certain amount of controlled aging is sometimes desirable and for that reason coils may be wound at a controlled temperature above room temperature to take advantage of this phenomenon.
Currently there is no active control of strip temperature after the furnace and quench section of a continuous heat treatment line. The rewind temperature control is dependent upon establishing a heat treatment and quench practice for each product giving a strip temperature upstream from the accumulator to achieve approximately the desired temperature at the rewind. This method is unreliable because conditions in the line affecting heat transfer, such as ambient air temperature, air circulation, metal width and roll temperatures can vary considerably resulting in rewind temperatures too high or too low. The only way to compensate for this has been to alter conditions upstream in the furnace or quench. This has the major disadvantages of providing very little ability to change conditions without potentially affecting the heat treatment of the metal, limited ability to predict or control the effect of the changes and slowness of response when furnace or cooler temperatures must be changed.
Johnson et al. U.S. Pat. No. 6,263,714, issued Jul. 24, 2001 describes a control system for a rolling mill in which metal strip is processed between an unwind reel and a rewind reel. It includes a programmed controller for controlling the system.
In Sellitto et al. U.S. Pat. No. 4,913,748, issued Apr. 3, 1990 an apparatus is described for the continuous annealing of strip metal. The rate at which the metal strip is fed through the system is regulated by a feed controller which includes a catenary loop of the metal strip. The size of the loop may be controlled such that a furnace may be operated concurrently to anneal the strip and function as an accumulator.
It is an object of the present invention to provide rapid and automated control of rewind temperature in a heat treatment line without affecting heat treatment or quench conditions upstream.
The present invention in one aspect relates to a method of controlling the recoil temperature of metal strip in a continuous heat treatment line. Hot, heat-treated metal strip is continuously passed through an accumulator system where it passes around at least two accumulator rolls in a spaced relationship. While travelling between the accumulator rolls, the metal strip is exposed to ambient cooling air. In order to control the amount of cooling, the length of metal strip exposed to the ambient cooling air is controlled. This exposed strip length is in turn controlled by varying the distance between the spaced accumulator rolls around which the strip travels. Thus for a greater amount of cooling, the spaced accumulator rolls are positioned further apart and for a lower degree of cooling the rolls are brought closer together.
Typically the invention uses an accumulator tower consisting of an upper and lower bank of rolls which banks of rolls can be brought together or moved apart to control the recoil temperature. The moving aluminum strip is passed alternately between the upper rolls and lower rolls to form a number of strands before passing out of the accumulator to the rewind reel or coiler.
The distance between the upper and lower roll sets and thus the length of metal strip subjected to ambient cooling air may conveniently be controlled by a programmed controller in response to a measured temperature of the metal strip at the rewind reel used as a feed back signal to the controller. As there may be some lag time between a change in conditions upstream, e.g. in the temperature of metal entering the accumulator, and the detection of the change of temperature at the rewind, it is preferable to also incorporate a feed forward signal to the controller. This may be accomplished by obtaining a strip temperature signal at some point prior to the accumulator and then by means of a mathematical model of the process calculate the required adjustment in strip length (accumulator spacing) to achieve the correct temperature at the rewind reel under the new conditions. The mathematical model may incorporate inputs of heat transfer coefficients, pressures and temperatures of the heat transfer media in each section of the line, as well as strip speed, thickness and width. Then using an appropriate algorithm in a programmable logic controller (PLC) a calculation is made as to the required accumulator spacing. The reference temperature for the feed forward signal may be the entry temperature to the line or a temperature taken at any other point in the line provided that a reasonably accurate model can be constructed to predict strip temperature from that point forward to the rewind reel.

Method of controlling metal strip temperature


A number of embodiments of induction systems for internal combustion engines wherein a control valve arrangement is provided in the induction passage for selectively generating either or both of tumble and/or swirl to the intake charge in response to varying running conditions. Various types of control valve arrangements are disclosed as are systems for cooling the control valves and augmenting the flow pattern caused by the control valve.

This invention relates to an induction system for an internal combustion engine and more particularly to a tumble control valve for the intake port of an internal combustion engine.
As is well known, most internal combustion engines are called upon, in their application, to operate over widely varying speed and load ranges. This is particularly true in connection with vehicular applications such as automobiles and motorcycles. As is also well known, because of this speed and load variation over which the engine is operated, there are many compromises in the design of the engine. This is particularly true in the area of the induction system.
It has been well known that combustion at low engine speeds and low engine loads can be significantly improved with attendant improvements in fuel economy and exhaust emission control if a high degree of turbulence is induced into the intake charge and in the combustion chamber. However, all turbulence increasing devices in the induction system tend to offer some flow resistance. Therefore, the use of turbulence increasing devices in the induction system reduces the maximum power output of the engine. Thus, most induction systems are designed as compromise between good low speed performance and good high speed performance.
One form of turbulence which is generated in the combustion chamber is characterized as "swirl". Swirl is a flow of the charge in the combustion chamber in a generally circumferential direction around the axis of the cylinder. Swirl is generally generated by use of swirl ports in the induction system. However, the generation of swirl can reduce the volumetric efficiency at high speed. This is because swirl ports have higher flow resistance than non-swirl ports. In addition, there are some phases of running of the engine when swirl is not desirable even though some form of motion of the charge in the chamber is desirable.
Another form of motion in the combustion chamber is called "tumble". Tumble is a swirling motion of the intake charge about an axis that generally extends transversely to the cylinder bore axis. With such a flow arrangement, the charge tends to flow across the cylinder head, down one side of the cylinder bore, back across the cylinder bore across the top of the head of the piston and then up the other side of the cylinder bore back to the cylinder head with this flow pattern repeating. This type of motion also requires the formation of a specially formed port which will provide flow resistance and reduce volumetric efficiency under high speed. Like swirl, tumble is more effective at some speed than other speeds.
Of course, even more turbulence may be generated in the intake charge if both swirl and tumble can be generated at the same time. However, generating both such motions through a single port configuration can further increase the flow resistance and reduce high speed performance.
It is, therefore, a principal object of this invention to provide and improved induction port system that will permit selective increase in turbulence in the combustion chamber under some running conditions and different flow patterns under other running conditions.
It is a further object of this invention to provide an arrangement for the induction system of internal combustion engines which permits the generation of both swirl and tumble.
It is a further object of this invention to provide an induction system for an internal combustion engine wherein swirl and tumble can be generated under some running conditions but avoided under other running conditions.
It is yet another object of the invention to provide an arrangement for the induction system of an engine which permits the generation of swirl and/or tumble, depending upon the running conditions.
One way in which the flow pattern in the combustion chamber can be varied under varying speed and load conditions is to provide a control valve in the induction passage that changes the effective configuration of the induction passage as the control valve is moved. The control valve can then be moved in response to varying speed and load conditions so as to provide the desired flow pattern. Such arrangements, however, as previously proposed have only permitted the establishment of either one type of swirling motion (either swirl or tumble) or substantially no turbulence.
It is, therefore, a further object of this invention to provide a single control valve arrangement that permits the generation of either swirl and/or tumble in the induction system and combustion chamber.
One technique for changing the flow pattern from an intake passage in an internal combustion engine employs an additional passage that intersects the main intake passage upstream of the valve seat and through which another higher velocity flow is established. However, like other flow altering devices, there are some running conditions when it is not desirable to have this small port be effective. This can be done through the provision of a control valve but if another control valve is also employed for changing the effective configuration of the port, then the engine becomes very complicated. Furthermore, it may be physically impossible to employ two such valves in the cylinder head of an engine, where the intake port is normally formed.
It is, therefore, a still further object of this invention to provide an improved control valve arrangement for an engine induction system wherein the flow through two ports terminating at a common valve seat may be controlled by a single valve element to alter the flow relationship of the charge entering the combustion chamber.
As has been noted, one way in which the flow patten within a combustion chamber may be altered is by providing a control valve that operates in the intake passage of the engine. However, where such a control valve is provided, even when the control valve is in a wide open position, some obstruction to the flow through the intake passage may occur. This can be either by direct flow resistance of the valve or a mounting portion of it extending into the induction passage even when the valve is fully opened. In addition, the control valve in its fully open position or some portion associated with it can give rise to a less than smooth intake passage which will induce turbulence within the intake passage itself and, accordingly, adversely effect volumetric efficiency.
It is, therefore, a still further object of this invention to provide an improved intake passage and control valve arrangement therefore wherein the effective cross sectional area of the intake passage may be changed but in its fully open position the control valve does not interfere in any way with the smooth transition of flow through the intake passage.
It is a further object of this invention to provide an improved intake passage and control valve arrangement for an internal combustion engine.
In connection with the control of the flow pattern of an intake charge into the combustion chamber from an intake port, there may some advantages in utilizing a rectifier plate in the intake port upstream of the valve seat so as to direct the flow. In addition, a control valve may be employed in conjunction with such a rectifier plate so as to not only control and direct the flow but change the velocity and direction.
It is, therefore, a still further object of this invention to provide an improved intake port and rectifier structure.
In connection with the use of such a rectifier plate in the intake passage, there is also a problem in actually forming such a plate in the cylinder head. If an attempt is made to cast the port directly into the cylinder head, this can greatly complicate the casting process and, in fact, may cause other problems. If a separate insert is employed, however, then there is a risk that the insert may become displaced, particularly during running of the engine.
It is, therefore, a still further object of this invention to provide an improved valve seat and rectifier plate formed as a unitary assembly.
In connection with the use of a control valve for controlling and altering the flow through an intake port, the control valve can be subject to heating during operation of the engine. If there are too large a temperature gradient created between the control valve and the supporting portion of the cylinder head, binding in the control valve operation may result.
It is, therefore, another still further object of this invention to provide an improved arrangement for cooling the control valve of an engine induction system.
It is a further object of this invention to provide an improved cooling arrangement for an intake port control valve that is mounted for rotation in the cylinder head of an engine.
There are a number of advantages to employing rotary control valves for the intake passage of an internal combustion engine. Where the engine has overhead valves, it is also desirable to have the rotational axis for the control valve extend transversely to the intake passage, and if multiple cylinders are employed, to extend along the length of the engine so all intake passages can be controlled by a single valve assembly. However, when this is done, the added components to the cylinder can present problems in connection with placement and operation.
It is, therefore, a still further object of this invention to provide an improved arrangement for affixing a cylinder head and cylinder block together and locating a control valve for the intake passages of the engine without interference from the fasteners.
The problems in placement of the control valves in the cylinder head are further magnified if the engine employs twin overhead camshafts, as is typical with high performance engines. That is, with normal camshaft placements the addition of a control valve for the intake port and the fastening arrangements can give rise to some problems.
It is a further object of this invention, therefore, to provide an improved control valve layout for the intake ports of a twin overhead camshaft internal combustion engine.


The present invention is designed to control transmission power properly even when communication is controlled based on shortened processing time. A user terminal communicates in a cell where a shortened TTI, having a transmission time interval (TTI) length shorter than 1 ms, is used, and/or in a cell where communication is controlled based on shortened processing time, which is shorter than in existing LTE systems, and this user terminal has a receiving section that receives a DL signal, a transmission section that transmits a UL signal in response to the DL signal, and a control section that controls transmission power of the UL signal based on a power control command contained in downlink control information transmitted in a predetermined transmission time interval in which the DL signal is transmitted, or in a transmission time interval located before the predetermined transmission time interval.

In the UMTS (Universal Mobile Telecommunications System) network, the specifications of long-term evolution (LTE) have been drafted for the purpose of further increasing high speed data rates, providing lower latency and so on (see non-patent literature 1). In addition, successor systems of LTE are also under study for the purpose of achieving further broadbandization and increased speed beyond LTE (referred to as, for example, "LTE-A (LTE-Advanced)," "FRA (Future Radio Access)," "4G," "5G," "56+(plus)," "NR (New RAT)," "LTE Rel. 14," "LTE Rel. 15 (or later versions)," and/or the like).
In existing LTE systems (for example, LTE Rel. 8 to 13), downlink (DL) communication and/or uplink (UL) communication are carried out by using 1-ms transmission time intervals (TTIs) (also referred to as "subframes" and/or the like). This 1-ms TTI is the unit of time it takes to transmit one channel-encoded data packet, and is the processing unit in, for example, scheduling, link adaptation, retransmission control (HARQ (Hybrid Automatic Repeat reQuest)) and so on.
Also, in existing LTE systems (for example, LTE Rel. 8 to 13), frequency division duplex (FDD) and time division duplex (TDD) are supported as duplex schemes. FDD is a scheme to assign different frequencies to DL and UL, and is also referred to as "frame structure (FS) type 1 (FS 1)." TDD is a scheme to switch between DL and UL over time in the same frequency, and is also referred to as "frame structure type 2 (FS 2)." In TDD, communication is carried out based on UL/DL configurations, which define the formats of UL subframes and DL subframes in radio frames.
Also, in existing LTE systems (for example, LTE Rel. 8 to 13), the timing for transmitting retransmission control information (including, for example, ACK (ACKnowledgement) or NACK (Negative ACK), A/N, HARQ-ACK and so on, and these hereinafter will be collectively referred to as "A/N") in response to a DL shared channel (for example, a physical downlink shared channel, which hereinafter will be referred to as "PDSCH") (and this timing will be hereinafter also referred to as "DL HARQ timing" and so on) is controlled by taking into account the signal processing time and the like in user terminals and/or radio base stations, and on assumption that the reference value for the timing for transmission is fixed at 4 ms.
For example, in FDD in existing LTE systems (for example, LTE Rel. 8 to 13), when a PDSCH is received in subframe #n, an A/N is transmitted (as feedback) in response to this PDSCH in subframe #n+4, on assumption that the time it takes for a user terminal to process the PDSCH and/or others is 4 ms. Also, when, in TDD, a PDSCH is received in DL subframe #n, an A/N in response to this PDSCH is transmitted in subframe #n+4 or a later UL subframe on assumption that the processing time of the PDSCH and/others in the user terminal takes 4 ms.
Also, in existing LTE systems (for example, LTE Rel. 8 to 13), the timing for transmitting A/Ns in response to an uplink shared channel (for example, a physical uplink shared channel, which hereinafter will be referred to as "PDSCH") (this timing will be also referred to as "UL HARQ timing" and/and so on) is also controlled by using 4 ms as a fixed reference value for the timing for signal transmission in user terminals and/or radio base stations.

User terminal and radio communication method


Methods, systems and media for simulating or analyzing voltage drops in a power distribution network can use an iterative approach to define a portion of a design around a victim to capture a sufficient collection of aggressors that cause appreciable voltage drop on the victim. This approach can be both computationally efficient and accurate and can limit the size of the data used in simulating dynamic voltage drops in the power distribution network.

The field of this disclosure relates to systems for designing electrical circuits and more particularly to systems that use dynamic voltage drop (DVD) analysis to predict circuit behavior when designing electrical circuits. Dynamic voltage drop analysis is often done to simulate how a power grid or power distribution network in an integrated circuit will perform when data signals switch or toggle between voltage states, such as from high to low states, etc. Often, this switching can cause circuits to consume more power than when the circuit is idle (and therefore there is little switching). This increased power consumption can cause the power grid to deliver less than desired levels of voltage at one or more nodes or pins in the circuit, and this lowered level of voltage can affect the operation of logic circuits to the extent that the logic circuits may not operate correctly or as desired. Thus, circuit designers often use simulation software to perform dynamic voltage drop analysis before they finish the design of an electrical circuit. Dynamic voltage drop analysis typically involves simulating the repeated change over time of various data signals so that over time different data signals are repeatedly toggled to different voltage states to simulate normal operation of the circuit (in which it is expected that the various data signals will change over time due to the normal operation of the circuit). When performing dynamic voltage drop analysis, signals that are to be toggled are identified in a vector that can either be user provided or automatically constructed through a random approach. There are two commonly used approaches to choose signals that are toggled in approaches which use random selection of toggling. In one approach, a purely random selection of signals is used. This can be fast and easy and provide a reasonable representation for full system power. However, purely random selection can lead to toggle selections that would be impossible to occur in the actual design, such as by choosing to signals to toggle in the same direction that are connected by an inversion or that are mutually exclusive. In this situation, randomly selected vectors are pessimistic in that they cause higher dynamic voltage drop versus than what would be observed in the real design. In the other approach, randomly selected toggle values are used only for registers and then a timed logical propagation is used to determine which downstream signals will toggle. This alternative approach is very computationally expensive, and due to the nature of random inputs to combinational logic, typically causes the signal toggling to die down after a very limited number of propagation stages. While all such toggle patterns can actually be reproduced in the actual design, they failed to exercise enough of the reachable vector space, leading to this alternative approach as being optimistic versus what will normally be observed in a real design. One flaw that is common to both approaches is that both approaches, by relying on independent random choices for each signal, will fail to catch some very important conditions for dynamic voltage drop analysis, wherein all bits of a logical unit, such as a bus, toggle at once. Having many bits simultaneously toggle is extremely improbable to happen by random choice even though this scenario might be guaranteed to occur in normal operation of the design. Similarly, random choices will fail to account for logical excursions in the vector space, such as n-hot encoded buses or n-cold encoded buses.
Existing dynamic voltage drop simulations perform the voltage drop analysis across the entire integrated circuit (IC), and thus these simulations must be repeated for the entire IC when just a portion of the design has changed and thus any changes in the design will increase the time required to complete the design process by requiring a full dynamic voltage drop simulation again after the change. Moreover, it is not practical with existing software simulators to perform a DVD simulation with full coverage of all of the possible switching conditions affecting any particular instance in a design.

Voltage drop analysis using local circuit representation


When a roller holder attached to a floating chassis of the disk player rotates to raise a carrier roller from a disk non-carrying position to a disk carrying position, a convex portion of the roller holder is engaged with concave portions of the main chassis from above so as to fix the floating chassis to the main chassis in the back and forth directions as well as the right and left directions. The roller holder further rotates about a fulcrum to raise the floating chassis. As a result, the floating chassis is made to abut against another part of the main chassis from below to fix the floating chassis to the main chassis in the vertical direction.

1. Field of the Invention
The present invention relates to a disk player in which a floating chassis is fixed or unfixed with respect to a main chassis by the movement of a roller holder which supports a disk carrier roller.
2. Description of the Related Art
In a disk player mainly for vehicles, a pickup, a turntable, a clamper and the like are mounted on the floating chassis supported in the main chassis in the floating condition, so that those pickup, turn table, clamper and the like are not affected by external vibrations. When the disk player is not in use, the floating chassis is fixed to the main chassis so as to make it easy to insert or take out a disk. Various devices have heretofore been proposed as a device for fixing the floating chassis to the main chassis.
The rock mechanism of a disk player for vehicles described in Japanese Unexamined Patent Publication No. 2000-48445 utilizes the movement of a roller holder which supports a disk carrier roller to fix the floating chassis to the main chassis.
That is to say, an xe2x80x9carm memberxe2x80x9d is positively rotated by means of a rise of the roller holder, and the positive movement of the arm member advances a xe2x80x9cslide memberxe2x80x9d mounted on the main chassis so as to engage with the floating chassis. Due to this engagement, the floating chassis is fixed to the main chassis in the vertical direction. At this time, the slide member also engages with the roller holder, but since the roller holder is attached to the floating chassis, the floating chassis is fixed to the main chassis in the back and forth direction as well. Unfixing of the floating chassis from the main chassis is performed by the completely opposite movement.
With the above-described fixing device, the xe2x80x9caim memberxe2x80x9d is reciprocally rotated by making the roller holder move up and down, and the xe2x80x9cslide memberxe2x80x9d is advanced or retreated by means of the rotation of the arm member so that the floating chassis is fixed or unfixed with respect to the main chassis. Therefore, the arm member and the slide member are required in addition to the roller holder in order to fix or unfix the floating chassis, which increases the number of parts. Since these members have to be connected and interlocked to each other, the construction becomes complicated, so as to increase the production cost.
In view of the situation, it is an object of the present invention to provide a disk player in which a floating chassis is fixed or unfixed with respect to a main chassis by the movement of a roller holder which supports a disk carrier roller, so as to reduce the number of parts, to simplify the construction and to decrease the production cost.
A disk player comprises a disk carrier roller, a roller holder and a floating chassis equipped with a turntable and a clamper (supported in a main chassis in the floating condition). The right and left side plates of the roller holder are rotatably mounted between the right and left side plates of the floating chassis to rotatably support the opposite ends of the disk carrier roller by the roller holder, such that the disk carrier roller is moved between an upper disk carrying position and a lower disk non-carrying position by means of the rotation of the roller holder. When the roller holder rotates to raise the disk carrier roller from the disk non-carrying position to the disk carrying position, the right and left side plates of the roller holder are engaged with a part of the main chassis from above to fix the floating chassis to the main chassis in the front and back directions as well as the right and left directions, and the roller holder further rotates about a fulcrum to raise the floating chassis, which makes at least one of the floating chassis and an arm of the clamper attached thereto abut against another part of the main chassis from below, to thereby fix the floating chassis to the main chassis in the vertical direction.
The disk carrier roller is rotatably supported by the roller holder such that the opposite ends thereof move independently in the directions of approaching and separating from the disk. When the opposite ends are energized respectively by a spring in the direction approaching the disk, the disk can be carried without any problem even if the disk is eccentrically inserted.
The right and left side plates of the roller holder engage with the part of the main chassis by fitting a convex portion provided in one of the part and the plates and concave portions provided in the other one of the part and the plates, which makes the construction simpler.


Technologies for processing network packets by a network interface controller (NIC) of a computing device include a network interface, a packet processor, and a controller device of the NIC, each communicatively coupled to a memory fabric of the NIC. The packet processor is configured to receive an event message from the memory fabric and transmit a message to the controller device, wherein the message indicates the network packet has been received and includes the memory fabric location pointer. The controller device is configured to fetch at least a portion of the received network packet from the memory fabric, write an inbound descriptor usable by one or more on-die cores of the NIC to perform an operation on the fetched portion, and restructure the network packet as a function of an outbound descriptor written by the on-die cores subsequent to performing the operation. Other embodiments are described herein.

In present packet-switched network architectures, data is transmitted in the form of network packets between computing devices and/or device components at a rapid pace. At a high level, data is packetized into a network packet, which is transmitted by a network interface controller (NIC) of one network computing device and received by a NIC of another network computing device. Upon receipt, the network packet is typically processed, classified, etc., and the payload is typically written to memory (e.g., cache, main memory, etc.). Upon having written the network packet data to memory, the receiving NIC may then notify a host central processing unit (CPU) that the data is available for further processing. However, writing the contents of the network packet data from the NIC to memory for processing by a host CPU can be expensive and introduce latency, or otherwise have some other negative performance impact.

Technologies for processing network packets by an intelligent network interface controller


A method of controlling shifts in a vehicle transmission, for example a utility vehicle, having a transmission or partial transmission designed as a dual-clutch transmission that shifts as a without traction force interruption. The transmission comprises a dual clutch having a first clutch and a second clutch that are functionally connected to a drive engine, and a transmission or partial transmission comprises a main transmission that shifts with traction force interruption and is connected to a drive-train downstream from the dual-clutch transmission. During shifts in the main transmission that is connected downstream from the dual-clutch transmission, the dual clutch is operated, by pre-loading the two clutches, as a transmission brake and/or an engine brake for adapting the speed of components to be shifted so as to enable short shifting times and ensure comfortable and reliable driving operation.

For reasons of comfort and performance, powershift transmissions are increasingly used in utility vehicles. For this, dual clutch transmissions that can be shifted with no traction force interruption are particularly attractive. Transmission structures of dual-clutch transmissions for utility vehicles are known for example from DE 10 2005 033 027 A1 and DE 10 2006 054 281 A1. A method for controlling shift processes in a dual-clutch transmission is described for example in DE 10 2004 039 273 A1.
Such automated shift transmissions comprise an intermediate transmission or a number of intermediate transmission groups connected one after another, and if necessary also a downstream planetary transmission. The gears are divided into two groups, each group being associated with one clutch of the dual clutch system, by virtue of which a sequential shift sequence almost free from traction force interruptions can be carried out. In a conventional manner the force flow of the gears can pass via a drive input shaft and a drive output shaft, or it can meander through the transmission by way of repeatedly changing shafts. Compared with pure powershift automatic transmissions of planetary design, automated shift transmissions have efficiency and cost advantages. However, as the number of gears increases, so also do the overall size, the structural complexity and thus also the production costs.
Since as a rule, depending on their field of use, to obtain a particular transmission spread utility vehicle transmissions need a relatively large number of gears for efficient operation, it is expedient also to consider mixed forms, so-termed partial dual-clutch transmissions, in which, besides a powershift transmission or partial transmission with a dual clutch, there is provided a conventional transmission section, i.e. one that is shifted with traction force interruption, or a downstream transmission that shifts with traction force interruption.
In addition, partial dual-clutch transmissions can advantageously be combined by way of a transfer box or axle transmission with long gear ratios on the rear axle of utility vehicles, which enable fuel-saving and low-emission operation of the drive engine at relatively low rotation speeds. However, owing to the rather low torque reserve in such an operating range this tends to lead to a further increase of the in any case high shifting frequency in utility vehicle transmissions and hence also to a larger number of shift processes with traction force interruption in the conventional part of the transmission.
Upshift processes with traction force interruption are fundamentally always problematic since, to reduce the torque losses, the aim in modern internal combustion engines is to have speed reversion or speed reduction gradients which are as flat at possible. In upshift processes this leads either to more intensive slipping operation at the two clutches of the dual clutch, which translates into higher clutch wear particularly when shift processes are frequent as they are in utility vehicles, or to longer shifting times and hence to longer, unfavorable traction force interruptions since the synchronizing of the clutch in each case takes a longer time.
To accelerate the speed reversion of the internal combustion engine, although an existing engine brake of the utility vehicle can be activated during the shifts, this interferes with driving comfort because of clearly perceptible engagement and disengagement times and operating noise and also results in premature wear because of the large number of shift cycles. Thus, speeding up the speed adaptation during shift processes in the conventional transmission section of partial dual-clutch transmissions by means of the engine brake is rather problematic.
Synchronization, i.e. the speed adaptation of the components to be shifted during a shift process, can also be assisted by an existing transmission brake. In the case of unsynchronized claw-type shifting elements the synchronizing in upshifts can be done completely by means of the transmission brake. However, such an additional brake needs to be designed in accordance with its required power and shifting frequency, and can therefore occupy a relatively large amount of structural space and be correspondingly costly. Thus, speeding up the speed adaptation during shift processes in the conventional transmission section of the partial dual-clutch transmissions exclusively by means of a transmission brake is not optimal.

Method for controlling shifts in a vehicle transmission