When a brake is turned on during travel of a hybrid vehicle, a required braking force required for a drive shaft is set based on a brake depression amount, a base rotation speed of an engine is set based on the required braking force, a shift stage is set based on the base rotation speed and a vehicle speed, a target rotation speed of the engine is set based on the shift stage and the vehicle speed, and the engine, the first motor, and the second motor are controlled such that the engine operates at the target rotation speed and the required braking force acts on the drive shaft.

A hybrid drive system has a battery and a combustion engine for energy sources. The system has a traction motor, a generator, a variable voltage converter (VVC), a motor inverter, a generator inverter, a bus coupling the VVC to the inverters, and a controller. The controller regulates engine speed, motor torque, and generator torque. The engine speed is determined according to a driver torque demand. In normal conditions, 1) the controller regulates the engine speed by modifying a generator torque command, and 2) the bus voltage is regulated using the VVC and battery. When the controller detects a fault in which the battery and VVC become unavailable for regulating the bus voltage, then the controller regulates a motor inverter power output to match a sum of a generator inverter power output and an estimated power loss of the inverters in order to regulate the bus voltage.

A transmission includes an input shaft coupled to a prime mover, a countershaft, main shaft, and an output shaft, with gears between the countershaft and the main shaft. A shift actuator selectively couples the input shaft to the main shaft by rotatably coupling gears between the countershaft and the main shaft. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. An integrated actuator housing includes a single external power access for the shift actuator. A controller interprets a shaft displacement angle, determines if the transmission is in an imminent zero or zero torque region, and performs a transmission operation in response to the transmission in the imminent zero or zero torque region.

A transmission includes an input shaft coupled to a prime mover, a countershaft, main shaft, and an output shaft, with gears between the countershaft and the main shaft. A shift actuator selectively couples the input shaft to the main shaft by rotatably coupling gears between the countershaft and the main shaft. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. An integrated actuator housing includes a single external power access for the shift actuator. A controller interprets a shaft displacement angle, determines if the transmission is in an imminent zero or zero torque region, and performs a transmission operation in response to the transmission in the imminent zero or zero torque region.

A transmission is provided having a control module, an input member, an output member, four planetary gear sets, a plurality of interconnecting members, and a plurality of torque transmitting devices. Each of the planetary gear sets includes first, second and third members. The torque transmitting devices include clutches and brakes. The control module includes a control logic sequence for performing a coasting downshift of the transmission.

A transmission is provided having a control module, an input member, an output member, four planetary gear sets, a plurality of interconnecting members, and a plurality of torque transmitting devices. Each of the planetary gear sets includes first, second and third members. The torque transmitting devices include clutches and brakes. The control module includes a control logic sequence for performing a coasting downshift of the transmission.

A traction motor of a hybrid electric vehicle drives a primary pump to provide pressurized hydraulic fluid to engage a power flow path of a multi-ratio transmission. To reduce fuel consumption, the motor is maintained at zero speed until a shift lever is moved into a drive position. After a power flow path is established, the motor speed is again reduced to zero until a driver demands torque by pressing an accelerator pedal. While the traction motor is stationary, an auxiliary pump maintains the fluid pressure to keep the transmission power flow path engaged.

A traction motor of a hybrid electric vehicle drives a primary pump to provide pressurized hydraulic fluid to engage a power flow path of a multi-ratio transmission. To reduce fuel consumption, the motor is maintained at zero speed until a shift lever is moved into a drive position. After a power flow path is established, the motor speed is again reduced to zero until a driver demands torque by pressing an accelerator pedal. While the traction motor is stationary, an auxiliary pump maintains the fluid pressure to keep the transmission power flow path engaged.

Methods and systems are provided for a vehicle. In one example, a method for the vehicle includes adjusting an output torque of an electric machine to produce a desired vehicle speed and direction of propulsion while operating an auxiliary load powered via the transmission. The output torque may be adjusted while disengaging clutches of a transmission or a service brake to mechanically unlock an output shaft of the transmission. The first electric machine may be operated in a speed control to learn an amount to torque to hold the vehicle speed at zero and the amount of learned torque may be superimposed with an amount of requested torque upon vehicle launch.

A hybrid vehicle includes an engine, a first motor, a planetary gear mechanism, a second motor, a battery, and an electronic control unit. The electronic control unit is configured to: set a shift stage based on a depression amount of an accelerator and a vehicle speed or a driver's operation; set a base driving force based on the degree of the depression amount of the accelerator, the vehicle speed, and a target rotation speed; set a correction driving force such that the correction driving force increases with an increase in elapsed time after upshifting or an increase in the vehicle speed after upshifting when the shift stage upshifts; and control the engine, the first motor, and the second motor such that a driving force obtained by correcting the base driving force using the correction driving force is output to the drive shaft.