A vehicle control device disengages a clutch provided between an engine and a driving wheel at a brake-off and an accelerator-off during traveling of the vehicle, and stops the engine and carries out inertia traveling. The vehicle control device starts the engine by the push-start by engaging the clutch and by transmitting the power of the driving wheel to the engine, if it is determined that a brake pedal has been depressed during the inertia traveling.

A method of operating a drive-train with an automated transmission and a drive aggregate and the automated transmission provides at least two starting gears for the forward driving direction, and with a transmission-internal or transmission-external starting clutch. The method of operating the drive-train, during crawling at a crawling speed in the forward driving direction, such that for crawling in a starting gear engaged in the transmission for forward driving and with the starting clutch engaged without slip, the drive aggregate is operated in a rotational speed regulated manner so that a crawling speed is obtained, which depends on the rotational speed of the drive aggregate and the gear ratio of the starting gear engaged in the transmission. Based on actuation of an operating element of a speed regulating unit, at least one appropriate starting gear for crawling is determined and automatically engaged in the transmission.

Systems and methods are shown for meeting wheel torque demand in a hybrid vehicle with an engine, a dual clutch transmission coupled to a driveline of the vehicle downstream of the engine, and an electric machine coupled to the driveline downstream of the dual clutch transmission. In one example, a method comprises transferring transmission input torque through a clutch of the dual clutch transmission controlled to a first capacity, and in response to a desired transmission input torque exceeding the capacity, increasing torque output of the electric machine coupled downstream of the dual clutch transmission to assist in meeting a wheel torque demand. In this way, a driver-requested increase in acceleration may be met under conditions where transmission input torque is limited by clutch capacity.

A method for operating a drive device for a motor vehicle, which has an internal combustion engine and an electric motor. A drive shaft of the internal combustion engine can be coupled to a motor shaft of the electric motor by a shift clutch. The shift clutch is adjusted to a desired clutch torque over a dragging period for startup of the internal combustion engine. Prior to the startup, a quantity of heat that is expected to accrue in the shift clutch during the startup is predicted and, when the predicted quantity of heat exceeds a limit value, at least one operating parameter of the drive device that influences the startup is chosen in such a way that the quantity of heat expected to accrue is reduced.

A method of controlling a mode transition of a hybrid vehicle includes determining whether a mode transition from a first mode to a second mode is required based on a first torque, the first torque being a current required torque. A second torque, which is a required torque expected to be generated at a near-future time from a current time, is also determined. A predicted gear shift time point and a predicted engagement time point of an engine clutch are determined based on the second torque. The mode transition to the second mode is performed when it is determined that the mode transition to the second mode is required and the predicted engagement time point is earlier than the predicted gear shift time point.

A control apparatus for a power transmission system is provided. The control apparatus includes an electronic control unit. The electronic control unit is configured to, when a discharge flow rate of a mechanical oil pump is smaller than a predetermined flow rate and an electric oil pump is being driven while a vehicle is traveling, determine whether a decrease in the operating hydraulic pressure has occurred. The electronic control unit is configured to, when a first engagement device is controlled from a released state toward an engaged state, control a first control pressure such that the first control pressure in a case where a decrease in a operating hydraulic pressure has occurred is lower than the first control pressure in a case where a decrease in the operating hydraulic pressure does not occur.

A method and device for controlling an engine clutch of a hybrid vehicle are provided. The method includes setting a target speed of an engine to change a driving mode of the hybrid vehicle from an EV mode to an HEV mode and operating a HSG to adjust an engine speed to reach the target speed. An engine clutch that connects the engine with a driving motor or disconnects the engine from the driving motor is engaged to start when the speed of the engine is maintained at the target speed. A kiss point generated when the engine clutch is in a slip state is detected to learn the kiss point of the engine clutch and an output of the engine is increased based on a driver required torque when the speed of the engine and a speed of the driving motor are synchronized after the kiss point is learned.

A control system of a vehicle includes a driving source configured to generate a driving force of the vehicle and transmit the driving force to driving wheels, without intervention of a torque converter, a transmission provided between the driving source and the driving wheels, a friction engagement element used for starting the vehicle, the friction engagement element being provided between the driving source and the driving wheels so as to be engageable and disengageable, and a controller configured to control an engaging force of the friction engagement element to adjust the driving force transmitted from the driving source to the driving wheels. The controller sets a target acceleration of the vehicle based on a rotational speed difference between an input rotational speed and an output rotational speed of the transmission, and controls the engaging force based on the target acceleration.

Systems and methods for improving operation of a driveline disconnect clutch for a hybrid vehicle shifting are presented. In one example, pressure of a working fluid supplied to the driveline disconnect clutch is adjusted in response to a rate of change in accelerator pedal position. Further, pressure of the working fluid may be decreased responsive to selected operating conditions.

A vehicle includes an engine, a first motor generator, a second motor generator, a transmission, a differential device, and an electronic control unit. The transmission includes an input shaft, an output shaft, and a clutch. The electronic control unit is configured to detect a rotation speed difference between the input shaft and the output shaft when the clutch is controlled so as to be brought into a power transmission shut-off state. The electronic control unit is configured to, when the rotation speed difference detected by the electronic control unit is smaller than a target rotation speed difference between the input shaft and the output shaft that occurs in a case where the power transmission shut-off state of the clutch is established, suppress cranking of the engine by the first motor generator.