Systems and methods for improving operation of a hybrid vehicle are presented. In one example, an engine is couple to a transmission in response to a transmission upshift to reduce transmission output shaft torque disturbances.

A hybrid electric vehicle includes an engine and an electric machine, both capable of providing torque to transmission gearing. A clutch is disposed between the engine and the electric machine and is configured to selectively couple the engine to the electric machine. At times in which control of the amount of engine torque transmitted to the gearing is desirable, a controller is programmed to slip the clutch. If the controller is able to determine the amount of torque transmitted through the slipping clutch, the controller alters an output of the electric machine based upon the torque through the clutch. If, however, the controller is unable to determine the amount of torque transmitted through the slipping clutch, the controller alters the output of the electric machine based upon an acceleration of the electric machine.

The power controller, when switching from the second power-source drive to the first power-source drive, determines a specified power of the second power-source based on a ratio of the target transmission capacity of a clutch to the target vehicle power, and controls the second power-source based on the specified power.

A method includes estimating a first pressure at a first location of a clutch based on a flow rate of a fluid in the clutch, computing a first torque lead value based on the first pressure, computing a second torque lead value based on a second pressure, computing a third torque lead value by combining the first torque lead value and the second torque lead value, and applying torque from a motor of the vehicle based on the third torque lead value.

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. The shift actuator is mounted on an exterior wall of a housing including the countershaft and the main shaft. A shift control circuit operates a shift actuator using a first opposing pulse command and a first actuating pulse command, and releases pressure with shift actuating and opposing volumes of the shift actuator upon determining a shift completion event.

Embodiments of the present invention provide a controller for a hybrid electric vehicle having a first actuator and a second actuator operable to drive a driveline of the vehicle, the vehicle having releasable torque transmitting means operable releasably to couple the first actuator to the driveline, the releasable torque transmitting means being operable between a first condition in which the first actuator is substantially disconnected from the driveline and a second condition in which the first actuator is substantially connected to the driveline, the controller being operable to control the vehicle to transition between a first mode in which the releasable torque transmitting means is in the first condition and a second mode in which the releasable torque transmitting means is in the second condition, when a transition from the first mode to the second mode is required the controller being arranged to provide a control signal to the first actuator to control the speed thereof, the control signal being responsive to the speed of the first actuator and the amount of torque transfer provided by the releasable torque transmitting means.

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. A controller controls the shift actuator utilizing an actuating pulse and an opposing pulse.

An engine clutch control apparatus of a hybrid vehicle is provided. The apparatus includes an engine clutch that is disposed between an engine and a drive motor to selectively connect the engine and the drive motor and an integrated starter-generator that is connected with the engine to start the engine or to generate electricity. A vehicle controller releases or couples the engine clutch to implement a driving mode and determines a chargeable torque and an engine target estimation torque based on a generator rotation speed of the integrated starter-generator. An engine target torque and a charge torque are set based on the chargeable torque and a clutch input torque is generated using at least one of the engine target torque, an engine friction torque, and the charge torque. The engine clutch is then released when the clutch input torque is less than a reference value.

A controller includes a control unit which is configured to execute a coast stop control. The coast stop control is configured to perform automatic stopping of the drive source while the vehicle is traveling, when a permitting condition is satisfied, the permitting condition including a condition that a speed ratio R of the variator is lower than a first threshold R1 while the lock-up clutch is in an engaged phase. The control unit is configured to prohibit execution of the coast stop control in a case in which an input-output rotation speed difference of the torque converter is equal to or more than a predetermined value when the lock-up clutch is in the engaged phase.

A method of controlling a hybrid vehicle is provided, which includes shifting a friction engagement element from a released state to a slipping or engaged state, and performing motor control where an engine is started using a motor in response to a startup demand of the stopped engine during vehicle traveling, applying as the motor control a first control in which a target speed to be set for the motor is instructed and feedback control of the motor is executed based on a speed detected by a motor speed sensor to be the target speed, determining whether a condition for switching the motor control from the first control to a second control in which a target torque to be outputted from the motor is instructed to cause the motor to output the target torque, is satisfied, and when determined to be satisfied, switching the motor control to the second control.