A drive system for a hybrid vehicle and a method of operation of the drive system are provided. The drive system includes an internal combustion engine having a shaft, a vehicle transmission having a transmission input shaft and an output shaft, a transmission clutch between the transmission input and output shafts, an inertia-mass drive unit arranged between the internal combustion engine shaft and the transmission input shaft, a first clutch between the internal combustion engine shaft and inertia-mass drive unit and a second clutch between the inertia-mass drive unit and the transmission input shaft; and an electrical machine torque-transmittingly connected to the transmission input shaft. The inertia-mass drive unit may include rotational oscillation reduction device. Operation of the first, second and transmission clutches in coordination with electric motor and engine operation provides multiple operating modes while minimizing operator disturbance during transitions between engine deactivated and activated states.

Systems and methods for launching a hybrid vehicle that includes a motor/generator and an automatic transmission with a torque converter are described. The systems and methods may permit improved vehicle acceleration to enhance hybrid vehicle performance during specific vehicle launch conditions. The launch conditions may be established based on brake pedal position and accelerator pedal position.

A vehicle includes an engine and an electric machine coupled to a gearbox through a torque converter. The vehicle includes a controller programmed to command an engine torque and an electric machine torque to achieve a predetermined positive torque at the input of the torque converter when a driver demand torque at the torque converter input decreases to fall within a range between the predetermined positive torque and a predetermined negative torque.

A method for obtaining gear shifting of a vehicle, where the vehicle has a planetary gearing in the drive train, a combustion engine with an output shaft connected to a rotor of a second electric machine and to a first component of the planetary gearing, a first electric machine with a rotor connected to a third component of the planetary gearing and an input shaft of a gearbox connected to a second component of the planetary gearing. The method is started with the components of the planetary gearing interlocked by a locking means, in which they are released during the gear shifting and interlocked again after the gear shifting has been carried out.

Methods and systems are provided for operating a driveline of a hybrid vehicle that includes an internal combustion engine, an electric machine, and a transmission are described. In one example, gears of a transmission may be unlocked from layshafts while an engine is stopped to conserve energy. Alternatively, the gears may be locked and unlocked from layshafts in response to vehicle operating conditions while the engine is stopped to improve driveline response.

A drive control apparatus for an electric vehicle includes a controller that controls an engine, a traveling motor, a transmission, and an output clutch. The controller estimates the rotation angle of the motor by a first estimation method and controls the motor on the basis of the estimated angle. The estimation method is executable when the rotation speed of the motor is a threshold or higher. When a rotation angle sensor for the motor is in an abnormal state and a specific driving state is present, the controller controls one or more of the engine, the transmission, and the output clutch differently from when the sensor is in a normal state, and thereby maintains the rotation speed at the threshold or higher. The specific driving state is a state in which the rotation speed is lower than the threshold under the control when the sensor is in the normal state.

Methods and systems are provided for operating a driveline of a hybrid vehicle that includes an internal combustion engine, an electric machine, and a transmission are described. In one example, gears of a transmission may be unlocked from layshafts while an engine is stopped to conserve energy. Alternatively, the gears may be locked and unlocked from layshafts in response to vehicle operating conditions while the engine is stopped to improve driveline response.

A hybrid vehicle includes an electronic control unit configured to, when the drive mode is changed from one of the series-parallel mode and the parallel mode to the other one of the series-parallel mode and the parallel mode and the speed stage is changed from one of the low speed stage and the high speed stage to the other one of the low speed stage and the high speed stage, selectively execute either one of a first control and a second control. The first control is control in which the drive mode and the speed stage are changed by passing through the series mode. The second control is control in which one of the drive mode and the speed stage is changed and then the other one of the drive mode and the speed stage is changed without passing through the series mode.

A vehicle regenerative speed control device is provided that includes a controller which performs a regenerative speed control for downshifting a belt-type continuously variable transmission to the low gear ratio side and increasing a rotational speed of a transmission input shaft to which a motor generator is connected when there is a request for an increase in the regeneration amount while decelerating. The controller also imposes the limitation of staying within a Pri end command rotational speed change rate for the Pri end command rotational speed when performing a regenerative speed control for increasing the Pri end command rotational speed based on a braking operation in a brake switching region for switching from regenerative braking to hydraulic braking due to a decrease in vehicle speed.

Methods and systems are provided for operating a driveline of a hybrid vehicle that includes an internal combustion engine, an electric machine, and a transmission, where the transmission is downstream of the engine, and where the electric machine is downstream of the transmission. In one example, while the vehicle is being propelled solely via the electric machine, one or more gears of the transmission may be pre-engaged or selected, to prepare the driveline for an engine start event. In this way, driveline torque disturbance and delays in torque requests may be reduced or avoided upon a request for an engine start event.