Abstract: Methods and system are described for changing a driveline gear range from a higher gear range to a lower gear range. The driveline may include two electric machines and four clutches in a four wheel drive configuration. The methods and systems permit a driveline to change from a higher gear range to a lower gear range without stopping a vehicle.

Abstract: A vehicle electric torque vectoring system includes a traction motor, a vectoring motor, gears, and a controller. The gears transfer torque from the propulsion and vectoring motors to wheels. The controller, responsive to a step change in an unmodified torque request for the vectoring motor and a predicted torque response of the vectoring motor being greater than the unmodified torque request, commands the vectoring motor to generate torque with a modified torque request less than the unmodified torque request. The controller further, responsive to the predicted torque response becoming less than the unmodified torque request, commands the vectoring motor to generate torque with the unmodified torque request.

Abstract: Systems and methods for operating a driveline of a vehicle that includes an automatic transmission and a torque converter are described. In one example, vehicle launch is controlled according to a linear quadratic regulator that provides feedback control according to torque converter slip error and vehicle speed error. The vehicle launch is also controlled according to feed forward control that is based on requested torque converter slip and requested vehicle speed.

Abstract: A method of operating a vehicle includes, responsive to a command to launch the vehicle and while the vehicle is in a first gear, determining, at a controller, a feedforward component including a target engine torque and a target bypass clutch torque, and a feedback component that is based on an error between the target converter slip and a measured converter slip and between the target wheel torque and a measured wheel torque. The method further includes changing a commanded engine torque and a commanded bypass clutch torque based on the feedforward component and the feedback component.

Abstract: A method of operating a vehicle includes, responsive to a command to launch the vehicle and while the vehicle is in a first gear, determining, at a controller, a feedforward component including a target engine torque and a target bypass clutch torque, and a feedback component that is based on an error between the target converter slip and a measured converter slip and between the target wheel torque and a measured wheel torque. The method further includes changing a commanded engine torque and a commanded bypass clutch torque based on the feedforward component and the feedback component.

Abstract: Systems and methods for operating a driveline of a hybrid vehicle are described. In one example, vehicle launch is controlled according to a linear quadratic regulator that provides feedback control according to torque converter slip error and vehicle speed error. The vehicle launch is also controlled according to feed forward control that is based on requested torque converter slip and requested vehicle speed.

Abstract: Systems and methods for de-identification of medical images can be applied to medical images acquired using various techniques. A 3D medical image can be analyzed to generate an image mask that partitions the image into a foreground region and a background region. From the image mask, a “skin surface” can be reconstructed based on the boundary between the foreground region and the background region. The image mask can be modified, e.g., by moving a randomly-selected subset of the voxels from the foreground region to the background region so that the shape of the skin surface is altered, thus obscuring patient-identifying features. The original medical image can be modified by changing the intensity of voxels in the background region while preserving the original intensity of voxels in the foreground region.

Abstract: Separation of fat and water signals in MRI images can be achieved by a technique that includes using a spin-lock RF pulse sequence that incorporates adiabatic pulses and using Dixon methods for water/fat separation. The spin-lock RF pulse sequence can be, for example, an adiabatic continuous-wave constant-amplitude spin-lock (ACCSL) pulse sequence. Data acquisition can use any acquisition method compatible with Dixon methods. Following data acquisition, a source image can be generated and analyzed (e.g., using Dixon methods) to generate separate water and fat images. A spatial distribution of a spin-lock based imaging biomarker (e.g., T1rho) can be determined from the water image and/or the fat image.

Abstract: Methods and systems are provided for operating a vehicle that includes a torque vectoring electric machine. In one example, torque output of a torque vectoring electric machine is adjusted to reduce driveline torque disturbances when the torque vectoring electric machine is activated. The torque output is adjusted in response to a speed difference between a wheel speed and a speed of the torque vectoring electric machine.

Abstract: Pulse sequences for an MRI apparatus can provide improved quantitative relaxometry in liver and other tissues. Relaxation parameters such as T1rho or T2 (or both at once) can be measured. The pulse sequence can include a magnetization preparation pulse sequence and an acquisition pulse sequence including a fast spin echo (FSE) pulse sequence. Flip angles and echo time for the FSE pulse sequence can be chosen to optimize image quality without affecting the quantification of a relaxation parameter. Additional pulse sequences, e.g., for enhanced blood suppression and/or fat suppression can be incorporated. The acquisition pulse sequence can have a duration that allows data for a single slice image to be acquired during a breath-hold.

Abstract: Powertrains may include a spring damper between the engine crankshaft and transmission input shaft. In some circumstances, an oscillation known as shuffle may occur in such powertrains. Active adjustment of engine torque is substantially more effective at mitigating shuffle oscillations if the engine torque includes a p-term proportional to displacement of the damper spring in addition to a d-term proportional to the speed difference across the damper. For various reasons, the spring displacement is difficult to measure directly. An observer algorithm is utilized to calculate a current estimated spring displacement based on a crankshaft speed sensor, a transmission input speed sensor, a wheel speed sensor, and past engine torques, using a dynamic model of the powertrain.

Abstract: Systems and methods for de-identification of medical images can be applied to medical images acquired using various techniques. A 3D medical image can be analyzed to generate an image mask that partitions the image into a foreground region and a background region. From the image mask, a “skin surface” can be reconstructed based on the boundary between the foreground region and the background region. The image mask can be modified, e.g., by moving a randomly-selected subset of the voxels from the foreground region to the background region so that the shape of the skin surface is altered, thus obscuring patient-identifying features. The original medical image can be modified by changing the intensity of voxels in the background region while preserving the original intensity of voxels in the foreground region.

Abstract: Powertrains may include a spring damper between the engine crankshaft and transmission input shaft. In some circumstances, an oscillation known as shuffle may occur in such powertrains. Active adjustment of engine torque is substantially more effective at mitigating shuffle oscillations if the engine torque includes a p-term proportional to displacement of the damper spring in addition to a d-term proportional to the speed difference across the damper. For various reasons, the spring displacement is difficult to measure directly. An observer algorithm is utilized to calculate a current estimated spring displacement based on a crankshaft speed sensor, a transmission input speed sensor, a wheel speed sensor, and past engine torques, using a dynamic model of the powertrain.

Abstract: A vehicle includes an engine with an associated engine-speed sensor, and wheels each having a respective wheel-speed sensor. The vehicle also includes a continuously variable transmission (CVT) coupled to the engine and configured to operate at variable input-to-output ratios. At least one controller is programmed to reduce the operating ratio of the CVT in response to the engine-speed sensor indicating the engine is operating at idle speed and the wheel-speed sensor indicating the velocity is approximately zero. This provides less noise, vibration and harshness in the vehicle due to the reduced ratio that is possible during conditions in which a vehicle launch in that reduced ratio may not be acceptable.

Abstract: A vehicle includes an engine and driven wheels each having an associated friction brake. A brake pedal is operable to engage the friction brakes. The vehicle includes a transmission having an input shaft driveably connected to the engine, an output element driveably connected to the driven wheels, and a gear mechanism adapted to establish at least one torque flow path between the input shaft and the output element. The transmission further includes a shift element that interrupts the torque flow path when disengaged. A gear selector is disposed in the passenger cabin and includes at least one forward-drive position, a reverse position, and a neutral position. At least one vehicle controller is configured to, in response to the gear selector being in the forward-drive position, a speed of the vehicle being zero, the vehicle being within a first predefined distance of a stoplight, and the brake pedal being depressed, disengage the shift element to put the transmission in neutral idle.

Abstract: A vehicle includes an engine and driven wheels each having an associated friction brake. A brake pedal is operable to engage the friction brakes. The vehicle includes a transmission having an input shaft driveably connected to the engine, an output element driveably connected to the driven wheels, and a gear mechanism adapted to establish at least one torque flow path between the input shaft and the output element. The transmission further includes a shift element that interrupts the torque flow path when disengaged. A gear selector is disposed in the passenger cabin and includes at least one forward-drive position, a reverse position, and a neutral position. At least one vehicle controller is configured to, in response to the gear selector being in the forward-drive position, a speed of the vehicle being zero, the vehicle being within a first predefined distance of a stoplight, and the brake pedal being depressed, disengage the shift element to put the transmission in neutral idle.

Abstract: MRI techniques provide robust imaging in the presence of inhomogeneity in the B1 (RF) and/or B0 magnetic fields. The techniques include using a magnetization prep sequence that includes an adiabatic half passage (AHP) followed by a spin-lock pulse, followed by a reverse AHP, after which a data acquisition sequence can be applied. The AHP and reverse AHP can have amplitude and frequency modulated to sweep through a region of frequency space. The RF amplitude of the AHP and reverse AHP can be designed to be equal to the spin-lock amplitude. Quantification of a magnetization relaxation parameter (e.g., T1rho) can use a modified relaxation model that accounts for relaxation effects during the reverse AHP. A dual-acquisition technique in which the reverse AHP of the second magnetization prep sequence has opposite frequency modulation to the reverse AHP of the first magnetization prep sequence can also be used.

Abstract: A method of controlling a Continuously Variable Transmission (CVT) simulates a step-ratio transmission upshift. To simulate a step-ratio torque phase, the input torque is gradually reduced before beginning to change the variator ratio. Then, as the variator ratio is changed, the input torque is gradually increased to compensate for the decreasing torque ratio, simulating the relatively constant output torque of an inertia phase of a step-ratio upshift.

Abstract: Pulse sequences for an MRI apparatus can provide improved quantitative relaxometry in liver and other tissues. Relaxation parameters such as T1rho or T2 (or both at once) can be measured. The pulse sequence can include a magnetization preparation pulse sequence and an acquisition pulse sequence including a fast spin echo (FSE) pulse sequence. Flip angles and echo time for the FSE pulse sequence can be chosen to optimize image quality without affecting the quantification of a relaxation parameter. Additional pulse sequences, e.g., for enhanced blood suppression and/or fat suppression can be incorporated. The acquisition pulse sequence can have a duration that allows data for a single slice image to be acquired during a breath-hold.

Abstract: A method of controlling a Continuously Variable Transmission (CVT) simulates a step-ratio transmission upshift. To simulate a step-ratio torque phase, the input torque is gradually reduced before beginning to change the variator ratio. Then, as the variator ratio is changed, the input torque is gradually increased to compensate for the decreasing torque ratio, simulating the relatively constant output torque of an inertia phase of a step-ratio upshift.