Abstract:
Methods and systems are provided for adjusting noise, vibration, and harshness (NVH) limits for a vehicle based on an occupancy level of the vehicle. The occupancy level is inferred based on a number of occupants and their position within a vehicle, and further based on a degree of interaction of a primary occupant with vehicle controls. As the occupancy level decreases, NVH constraints for operating the vehicle are reduced and one or more vehicle operating parameters nay be based on the reduced NVH constraints.
Abstract:
A vehicle includes a powertrain and at least one controller programmed to, in response to a brake request and a shaft speed associated with a speed of the vehicle achieving a starting speed that is defined by a torque of the powertrain that changes with brake demand at a given shaft speed, reduce a regenerative torque limit that constrains regenerative braking torque over a blend-out duration based on the shaft speed.
Abstract:
Methods and systems are provided for adjusting noise, vibration, and harshness (NVH) limits for a vehicle based on an occupancy level of the vehicle. The occupancy level is inferred based on a number of occupants and their position within a vehicle, and further based on a degree of interaction of a primary occupant with vehicle controls. As the occupancy level decreases, NVH constraints for operating the vehicle are reduced and one or more vehicle operating parameters nay be based on the reduced NVH constraints.
Abstract:
Systems and methods for operating a transmission of a hybrid vehicle's driveline are presented. In one example, the systems and methods estimate a driveline disconnect clutch stroke pressure and gain via extending a line from a non-zero driveline disconnect clutch torque capacity to a zero driveline disconnect clutch torque capacity.
Abstract:
Systems and methods for operating a transmission of a hybrid vehicle's driveline are presented. In one example, the systems and methods estimate a driveline disconnect clutch stroke pressure and gain via extending a line from a non-zero driveline disconnect clutch torque capacity to a zero driveline disconnect clutch torque capacity.
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 hybrid vehicle includes an engine, an electric machine, a transmission, and a controller. The transmission is configured to alter clutch pressures in preparation for an upcoming shift between discrete gear ratios (e.g., input-to-output ratio). For example, the clutch pressures may spike to a heightened magnitude to prepare for the upcoming shift. The electric machine is configured to selectively propel the vehicle and perform regenerative braking. If regenerative braking demands occur during the clutch pressures being heightened during shift preparation, the controller is programmed to stop the preparing of the clutches. This can be done by reducing the clutch pressures back to their pre-preparation magnitude. The upcoming shift can be cancelled or delayed.
Abstract:
A manual transmission is partially automated by utilizing a controller to regulate the torque capacity of the clutch. Under most circumstances, the controller manipulates the clutch according to driver manipulation of a clutch pedal to simulate a non-automated manual transmission. However, to save fuel, the controller may enter a sailing mode in which the clutch is disengaged without the driver depressing the clutch pedal. The controller exits sailing mode in response to the vehicle speed decreasing below a threshold which is a function of the currently selected gear ratio. The threshold is selected such that the engine will not stall and will be able to generate sufficient power for acceleration when the clutch is re-engaged to exit sailing mode. In order to extend the use of sailing mode, the controller may activate a downshift indicator at a slightly higher speed threshold to encourage the driver to downshift.
Abstract:
Systems and methods for shifting a transmission of a hybrid driveline that include a torque converter with a lockup clutch are presented. The systems and methods may adjust a feedforward motor torque command to match application of motor torque to a time that a gear clutch closes so that shifting may be improved and so that driveline torque disturbances may be less noticeable.