The present invention relates to a method for controlling a clutch arrangement (102) of a vehicle transmission (100) arranged within a gearbox housing (104) of a vehicle, the clutch arrangement being connected to a pneumatically controlled actuator arrangement (106) for controllably arrange the clutch arrangement between a closed position and an open position, wherein the vehicle transmission further comprises at least one rotatable transmission component (108, 108′, 108″) configured to assume an engaged state, a disengaged state and an at least partially engaged state. By means of the method, the rotatable transmission component is arranged to be positioned in the at least partially engaged state for increasing the heat within the gearbox housing.

This clutch control device includes an engine (13), a transmission (21), a clutch device (26) configured to connect and disconnect motive power transmission between the engine (13) and the transmission (21), a clutch actuator (50) configured to drive the clutch device (26) and change a clutch capacity, and a control unit (60) configured to calculate a target value (Pt) of a control parameter (Ps) for the clutch capacity. When the target value (Pt) of the control parameter (Ps) immediately after system startup is defined as a first control target value (P1) and the target value (Pt) of the control parameter (Ps) during a clutch stroke at the time of the system startup is defined as a second control target value (P2), the control unit (60) is configured to set the first control target value (P1) to a value greater than the second control target value (P2).

The disclosure is concerned with control system and control method, for a vehicle including a driving power source, drive wheels, a first clutch, and a second clutch. An electronic control unit, which is included in the control system, places the first clutch in a half-engaged state with a predetermined clutch torque capacity, when the vehicle is started, performs start control in a first mode using the second clutch, by gradually increasing a clutch torque capacity of the second clutch from a released state, and switches the start control from the first mode using the second clutch to a second mode using the first clutch, when the increased clutch torque capacity of the second clutch reaches the clutch torque capacity of the first clutch.

A method for operating a vehicle that includes a driveline disconnect clutch is described. In one example, the method includes adjusting a pressure of the driveline disconnect clutch as a function of an engine pull-up torque minus a driver demand torque when the pressure of the driveline disconnect clutch is between a torque stroke pressure and a hydraulic stroke pressure.

A method for operating a hybrid drive train of a motor vehicle includes: starting the motor vehicle solely with the aid of an electric machine; engaging a torque converter lockup clutch for rotationally fixing an impeller of a torque converter to a turbine wheel of the torque converter, wherein the turbine wheel is rotationally fixed to the electric machine; and engaging a clutch in order to drivingly connect the impeller to a motor vehicle drive unit, in order to start the motor vehicle drive unit.

A power control system is provided for a work vehicle with an engine. A combination starter-generator device has an electric machine and a gear set configured to receive rotational input from the electric machine and the engine and to couple the electric machine and the engine in two power flow directions. The gear set operates in one of multiple relatively high-torque, low-speed start gear ratios in one direction, including a first start gear ratio corresponding to a cold engine start mode and a second start gear ratio corresponding to a warm engine start mode, and in a relatively low-torque, high-speed gear ratio in another direction corresponding to a generation mode. First and second clutch assemblies are selectively coupled to the gear set to effect the start gear ratios during the engine start modes. A control valve is fluidly coupled to selectively apply a fluid pressure to the clutch assemblies.

A power control system is provided for a work vehicle with an engine. A combination starter-generator device has an electric machine and a gear set configured to receive rotational input from the electric machine and the engine and to couple the electric machine and the engine in two power flow directions. The gear set operates in one of multiple relatively high-torque, low-speed start gear ratios in one direction, including a first start gear ratio corresponding to a cold engine start mode and a second start gear ratio corresponding to a warm engine start mode, and in a relatively low-torque, high-speed gear ratio in another direction corresponding to a generation mode. First and second clutch assemblies are selectively coupled to the gear set to effect the start gear ratios during the engine start modes. A control valve is fluidly coupled to selectively apply a fluid pressure to the clutch assemblies.

The present invention relates to a method for controlling a clutch arrangement (102) of a vehicle transmission (100) arranged within a gearbox housing (104) of a vehicle, the clutch arrangement being connected to a pneumatically controlled actuator arrangement (106) for controllably arrange the clutch arrangement between a closed position and an open position, wherein the vehicle transmission further comprises at least one rotatable transmission component (108, 108, 108) configured to assume an engaged state, a disengaged state and an at least partially engaged state. By means of the method, the rotatable transmission component is arranged to be positioned in the at least partially engaged state for increasing the heat within the gearbox housing.

In order to pre-stage a clutch piston in preparation for clutch engagement, a controller commands a high current to a Casting Integrated Direct Acting Solenoid (CIDAS) valve. This staging is performed in two distinct phases wherein the current is higher in the first phase than in the second phase. Staging the piston in this manner reduces the staging time and reduces the variability of the staging time. The duration of the first phase may be adjusted based on a number of parameters including, the length of a preceding engine off period, the number of clutch applications since the engine off period, a fluid temperature, and a length of time since a preceding engagement of the clutch.

In order to pre-stage a clutch piston in preparation for clutch engagement, a controller commands a high current to a Casting Integrated Direct Acting Solenoid (CIDAS) valve. This staging is performed in two distinct phases wherein the current is higher in the first phase than in the second phase. Staging the piston in this manner reduces the staging time and reduces the variability of the staging time. The duration of the first phase may be adjusted based on a number of parameters including, the length of a preceding engine off period, the number of clutch applications since the engine off period, a fluid temperature, and a length of time since a preceding engagement of the clutch.