A method for operating a vehicle that includes a driveline disconnect clutch is described. In one example, the method adjusts torque of an electric machine in response to a estimated torque capacity of the driveline disconnect clutch. The estimated torque capacity of the driveline disconnect clutch is based on a combined inertia of a dual mass flywheel and the driveline disconnect clutch.

An electrified vehicle torque transfer system includes, among other things, an engine having an engine shaft, an electric machine having an electric machine shaft, a first clutch that is selectively engaged to rotatably couple together the engine shaft and the electric machine shaft such that the engine can drive rotation of the electric machine, and a second clutch that is selectively engaged to rotatably couple together the engine shaft and the electric machine shaft such that the electric machine can drive rotation of the engine.

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.

Systems and methods for operating a vehicle that includes an engine and an electric machine are described. In one example, an actual total number of transmission gear downshifts are counted to determine whether or not a transmission clutch characterization is immature. The transmission clutch characterization may be adjusted if it is determined to be immature.

A clutch control method for a hybrid vehicle with a DCT of the present invention is provided. The method includes checking whether a current shift range is a D-range and determining a gradient of a current driving road and driver's vehicle stop requirement. In response to determining that the current shift range is the D-range, the gradient of the road is not a gradient that requires uphill driving, and there is driver's vehicle stop requirement, a controller reduces an operation current supplied to a clutch actuator of a clutch for transmitting power to a first gear to a regulation current. The regulation current is set based on an operation of the vehicle by the driver when the vehicle is restarted after the current reduction.

A launch control method is provided for a vehicle having an accelerator, a brake and a continuously variable transmission (CVT). The method comprises determining: (i) a braking torque set by a vehicle operator by pressing a brake pedal of the vehicle; and (ii) a holding torque required to hold the vehicle in a stationary position. The method also determines that the operator has released the brake pedal. The brake is released whilst engaging a launch clutch of the CVT, wherein the launch clutch is engaged by increasing a clutch engagement pressure at a first pressure ramp rate, such that the sum of the braking torque and a clutch torque of the clutch remains equal to the holding torque. An acceleration torque requested by the operator via the accelerator is determined. The clutch engagement pressure is increased at a second pressure ramp rate when it is determined that the braking torque is substantially zero, such that the clutch torque is increased by the acceleration torque. A fixed minimum pressure ramp rate is stored, wherein the minimum pressure ramp rate increases the clutch engagement pressure towards a maximum engagement pressure. The current pressure ramp rate is compared with the minimum pressure ramp rate, and the clutch engagement pressure is switched to the minimum pressure ramp rate if the current pressure ramp rate is less than the minimum pressure ramp rate.

A hybrid vehicle controller is configured to: upon receiving a predetermined mode switching request, bring a clutch into a half-clutch state to start an engine using rotation of a transmission shaft; and upon determining that the engine has started, shift the clutch from the half-clutch state to a stand-by state and subsequently shift the clutch to an engaged state, the stand-by state being a state which is intermediate between the half-clutch state and a disengaged state and in which drive power of the engine is not transmitted to the transmission shaft.

A control device of a hybrid vehicle of the disclosure includes a clutch controller configured to perform slip control of a hydraulic clutch in response to satisfaction of a start condition of an engine and to perform pressure increase control of increasing a hydraulic pressure to the hydraulic clutch with elapse of time after a rotation speed difference between the engine and a motor enters a predetermined range; and an engine controller configured to start fuel injection and ignition of the engine before the rotation speed difference enters the predetermined range, to control the engine such that the rotation speed of the engine becomes equal to a target rotation speed after the start of the fuel injection and the ignition, and to increase the target rotation speed of the engine as an angular acceleration of the motor becomes larger during execution of the pressure increase control.

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 a differential gear that transmits rotation of a propeller shaft to an axle. A differential lock switches the differential gear between a locked state and an unlocked state. A clutch is provided in a power transmission path between a prime mover and wheels of the vehicle. A controller controls an engaging force of the clutch during a moving start of the vehicle in accordance with which of the locked state and the unlocked state is selected by the differential gear.