A wheel loader includes a forward clutch, an accelerator pedal, a brake pedal, and a controller configured to control hydraulic pressure of hydraulic oil supplied to the forward clutch. The controller performs clutch hydraulic pressure control for reducing the hydraulic pressure of the hydraulic oil supplied to the forward clutch according to an operation amount of the brake pedal on condition that at least the brake pedal is operated while the accelerator pedal is being operated. The controller continues the clutch hydraulic pressure control even after the clutch shifts from a complete engagement state to a semi-engagement state by the clutch hydraulic pressure control.

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 power transmission device for a hybrid vehicle with a first clutch (1a) and a second clutch (1b). The first clutch (1a) is capable of transmitting or cutting off driving power of an engine (E) to driving wheels (D). The second clutch (1b) is capable of transmitting or cutting off power of a motor (M) to the driving wheels (D). The power transmission device is capable of appropriately operating the first clutch (1a) and the second clutch (1b) in accordance with driving conditions of the vehicle. When the engine (E) is started by transmitting power from the motor (M) to the engine (E), via the first clutch (1a) and the second clutch (1b), the power transmission device slip-controls the first clutch (1a) and the second clutch (1b).

A vehicle drive device includes: a rotating electrical machine; a speed change mechanism including an input member and an output member drivingly connected to wheels, and configured to change a speed ratio between the input member and the output member; a friction engagement device interposed between the rotating electrical machine and the input member and including a friction engagement element configured to connect and disconnect power transmission between the rotating electrical machine and the input member as an engagement pressure is supplied and discharged; and a control device that controls the rotating electrical machine and the friction engagement device. The control device performs learning control when the input member is held stationary and non-rotatable, the learning control being control in which the control device drives the rotating electrical machine while controlling the engagement pressure to an engagement start pressure at which the friction engagement element starts to engage, and learns the engagement start pressure based on a change in driving state of the rotating electrical machine at the time the friction engagement element starts to engage.

In a case where a predetermined switching operation to a state in which a traveling position is selected from a state in which another shift position of a mechanical transmission device is selected is performed by a driver, a quick engagement command to quickly engage a predetermined engagement device is performed in a state in which output of a predetermined torque is stopped, and then a rapid garage control of increasing a rotation speed of an electric motor at a rotation speed equal to or higher than a predetermined rotation speed is executed. The rapid garage control is executed in a case where a predetermined start condition is established.

Methods and systems for operating a clutch of an axle are provided. In one example, the clutch may be characterized in static or dynamic conditions. The clutch characterization may be a basis for subsequently operating the clutch during gearbox shifting. In particular, an amount of torque that is transferred via the clutch may be controlled or adjusted according to the clutch characterization.

Methods and systems for operating a clutch of an axle are provided. In one example, the clutch may be characterized in static or dynamic conditions. The clutch characterization may be a basis for subsequently operating the clutch during gearbox shifting. In particular, an amount of torque that is transferred via the clutch may be controlled or adjusted according to the clutch characterization.

A vehicle traction control system for a vehicle, in which the vehicle has a prime mover, at least one wheel for providing tractive effort on a support surface, and a transmission having an input side operably coupled to the prime mover and an output side operably coupled to the at least one wheel, and in which the transmission has a controllable clutch pressure between the input side and the output side, includes a controller operable to monitor wheel slip of the at least one wheel. When wheel slip is detected the controller is operable to control the clutch pressure for modulating an output torque of the transmission for reducing the wheel slip. The clutch pressure can be controlled as a function of clutch slip.

A low-voltage hybrid powertrain system for a vehicle includes an engine that is coupled via an engine disconnect clutch to an input member of the transmission, and a low-voltage electric machine is coupled to the transmission. The powertrain system operates in an electric vehicle (EV) mode with the engine in an OFF state and with the engine disconnect clutch in an open/deactivated state. When an output torque request indicates a command for vehicle acceleration, the electric machine is controlled to generate torque in response to the output torque request and the engine is simultaneously cranked and started. Upon starting, the engine operates in a speed control mode to activate the engine disconnect clutch. The engine and the low-voltage electric machine are controlled to generate torque in response to the output torque request when the engine disconnect clutch is activated.

A method for operating a drive device for a motor vehicle with an internal combustion engine and a dual clutch transmission. In a starting operation of the drive device directed at a startup of the motor vehicle, an electric machine coupled to a first input shaft is used, when the first shift clutch is at least partially engaged and the first sub-transmission is disengaged and when the second shift clutch is at least partially engaged and the second sub-transmission is engaged, for providing at the output shaft a starting torque used for starting the internal combustion engine and a drive torque directed at the startup of the motor vehicle, and/or in that, in the starting operation, the internal combustion engine is operated, when the second shift clutch is at least partially engaged and the second sub-transmission is engaged.