Abstract: A hybrid vehicle propulsion system including, an internal combustion engine coupled to an input of the fixed-ratio transmission is disclosed. In one example, a torque differential across a torque converter is reduced to assist torque converter clutch lockup. The system can improve shift feel during at least some conditions.

Abstract: A vehicle includes a motor/generator, a disconnect clutch disposed between the engine and the motor/generator, and a transmission disposed between the motor/generator and the vehicle drive wheels. The transmission includes an input clutch which is selectively engagable for facilitating torque transfer between the motor/generator and the vehicle drive wheels. When an engine start is requested, the motor/generator is operated, and a start mode for the engine is determined based on a number of vehicle parameters. The transmission input clutch is partially disengaged to at least partially isolate the vehicle drive wheels from engine torque disturbances when the engine is started. The disconnect clutch is engaged, and the engine is fueled, thereby facilitating torque production by the engine.

Abstract: A method for improving hybrid vehicle is disclosed. In one embodiment, a torque differential across a transmission is controlled while torque is provided to the vehicle driveline/wheels to meet driver demand. The method may improve transmission shifting by allowing earlier shifts, for example.

Abstract: A hybrid vehicle propulsion system including, an internal combustion engine, a torque converter including a lockup clutch the torque converter having an input and an output, the input coupled to the internal combustion engine, an electric energy conversion device coupled downstream of the torque converter output, and a control system for adjusting torque output of the hybrid propulsion system, the control system adjusting the torque output of the electric energy conversion device during a torque converter lockup clutch engagement transition event.

Abstract: A hybrid vehicle propulsion system including, an internal combustion engine, a torque converter including a lockup clutch, the torque converter receiving torque from at least the internal combustion engine, a multiple fixed-ratio transmission having an input and an output, the input coupled to the torque converter, a electric energy conversion device coupled downstream of the multiple fixed-ratio transmission output, and a control system for adjusting torque output of the hybrid propulsion system, the control system adjusting torque output of the electric energy conversion device to reduce a transmission output torque load and adjusting the multiple fixed ratio transmission to cause a transition in torque transfer responsive to adjusted torque output of the electric energy conversion device.

Abstract: A hybrid vehicle propulsion system including, an internal combustion engine coupled to an input of the fixed-ratio transmission, an electric motor coupled to the output of the multiple fixed-ratio transmission and powered at least by a battery, and a controller for adjusting the torque output of the hybrid propulsion system, the controller adjusting the multiple fixed-ratio transmission to shift from a current gear ratio to a different gear ratio upon a first condition during a first battery state of charge, and adjusting the multiple fixed-ratio transmission to shift from the current gear ratio to the different gear ratio upon a second condition during a second battery state of charge, where the second battery state of charge is lower than the first battery state of charge and the second condition is different from the first condition.

Abstract: A hybrid vehicle propulsion system including, an internal combustion engine, a torque converter including a lockup clutch the torque converter having an input and an output, the input coupled to the internal combustion engine, an electric energy conversion device coupled downstream of the torque converter output, and a control system for adjusting torque output of the hybrid propulsion system, the control system adjusting the torque output of the electric energy conversion device during a torque converter lockup clutch engagement transition event.

Abstract: A vehicle and a method for starting an engine in a vehicle are provided. The vehicle has a motor/generator, a disconnect clutch disposed between the engine and the motor/generator, and a transmission disposed between the motor/generator and the vehicle drive wheels. The transmission includes an input clutch which is selectively engagable for facilitating torque transfer between the motor/generator and the vehicle drive wheels. When an engine start is requested, the motor/generator is operated, and a start mode for the engine is determined based on a number of vehicle parameters. The transmission input clutch is partially disengaged to at least partially isolate the vehicle drive wheels from engine torque disturbances when the engine is started. The disconnect clutch is engaged, and the engine is fueled, thereby facilitating torque production by the engine.

Abstract: A vehicle includes a motor/generator, a disconnect clutch disposed between the engine and the motor/generator, and a transmission disposed between the motor/generator and the vehicle drive wheels. The transmission includes an input clutch which is selectively engagable for facilitating torque transfer between the motor/generator and the vehicle drive wheels. When an engine start is requested, the motor/generator is operated, and a start mode for the engine is determined based on a number of vehicle parameters. The transmission input clutch is partially disengaged to at least partially isolate the vehicle drive wheels from engine torque disturbances when the engine is started. The disconnect clutch is engaged, and the engine is fueled, thereby facilitating torque production by the engine.

Abstract: A vehicle and a method for starting an engine in a vehicle are provided. The vehicle has a motor/generator, a disconnect clutch disposed between the engine and the motor/generator, and a transmission disposed between the motor/generator and the vehicle drive wheels. The transmission includes an input clutch which is selectively engagable for facilitating torque transfer between the motor/generator and the vehicle drive wheels. When an engine start is requested, the motor/generator is operated, and a start mode for the engine is determined based on a number of vehicle parameters. The transmission input clutch is partially disengaged to at least partially isolate the vehicle drive wheels from engine torque disturbances when the engine is started. The disconnect clutch is engaged, and the engine is fueled, thereby facilitating torque production by the engine.