Method for determining a kisspoint of a clutch. A method is provided of determining a kisspoint of a clutch in a driveline of a vehicle comprising a. increasing a target clutch pressure of a clutch piston up to a first predetermined test target pressure, b. increasing the target clutch pressure up to an upper target pressure and subsequently keeping the target clutch pressure stable for a predetermined time interval, c. monitoring a parameter indicative for the filling of the clutch piston, e.g. the rotational speed of a pump, during the predetermined time interval, d. repeating steps a., b., and c. for at least one further predetermined test target pressure, and e. determining the kisspoint based on the monitored parameter indicative for the filling of the clutch piston.

A vehicle control apparatus output a packing hydraulic-pressure command value and a cranking hydraulic-pressure command value higher than the packing hydraulic-pressure command value. The packing hydraulic-pressure command value is outputted to place a clutch in a pack-clearance-elimination completion state in a process of switching of the clutch from a released state to an engaged state. The cranking hydraulic-pressure command value is outputted, after elapse of a predetermined time required to place the clutch in the pack-clearance-elimination completion state, to cause the clutch to transmit a cranking torque required by a cranking by which a rotational speed of an engine is increased. In a case in which it is determined that a request to increase a vehicle power performance during output of the packing hydraulic-pressure command value, the cranking hydraulic-pressure command value is outputted in place of the packing hydraulic-pressure command value even before the elapse of the predetermined time.

A work vehicle includes a rotary member, a support member, a sealing ring, a pressure controller, and a vehicle speed determination component. The rotary member has a first hydraulic fluid supply channel to supply the hydraulic fluid to the steering clutch, and is rotated by power from the transmission when the steering clutch is engaged. The sealing ring is disposed between the rotary member and the support member and is mounted adjacent to the connected part between the first hydraulic fluid supply channel and the second hydraulic fluid supply channel. The pressure controller controls the engagement pressure to be a specific first pressure when the vehicle speed is determined not to be equal to or greater than a specific speed, and controls the engagement pressure to decrease from the first pressure when the vehicle speed is determined to be equal to or greater than a specific speed.

A method for adapting a biting point filling time of a hydraulically actuated hybrid disengaging clutch is implemented step by step during driving of the motor vehicle via a plurality of selected engagement phases of the hybrid disengaging clutch with a manipulation of the customary rapid filling routine. Proceeding from an initially stored biting point filling time, a filling time which is shortened in comparison with this for a subsequent rapid filling routine is increased step by step, in each case by an increment. Here, an actual value which is set in each case for a test parameter, from which a change in the transmission of torque of the hybrid disengaging clutch can be derived, is detected until the actual value corresponds to a setpoint value.

A line pressure control method for a double clutch transmission (DCT) includes estimating a line pressure, which decreases with stoppage of an electric oil pump, based on a linear regression model using state variables of the DCT that are related to a line pressure change, and driving the electric oil pump when the line pressure estimated based on the linear regression model reaches a predetermined lower limit.

Methods and systems for a vehicle transmission are provided herein. The vehicle transmission includes an input interface configured to mechanically couple to a motive power source. The vehicle transmission further includes a first disconnect device releasably mechanically coupling a first output to a first drive axle and a second disconnect device releasably mechanically coupling a second output to a second drive axle.

A method for controlling a friction clutch actuated by an actuation system using an actuation pressure ambiguously applied along an actuation path includes providing the friction clutch and the actuation system, detecting a time curve of an actuation processes of the friction clutch, and comparing the time curve with the actuation pressure to ascertain an unambiguous friction clutch actuation path. The method may also include using the time curve to determine whether the friction clutch is in an opening state or a closing state and whether the actuation pressure is applied to an opened friction clutch actuation path or a closed friction clutch actuation path, and starting from a set actuation pressure, carrying out a directional control of the friction clutch by specifying the actuation pressure.

A method for automatically warming up a clutch actuator for a clutch of a transmission in a vehicle, wherein the clutch actuator is operable by use of pressurized fluid and configured to actuate the clutch from an engaged to a disengaged state, and/or vice versa, the method including: identifying if a temperature is below a predetermined temperature value and if the clutch actuator is leaking, and if it is identified that the temperature is below the predetermined temperature value and that the clutch actuator is leaking; then repeatedly pressurizing the clutch actuator by use of the pressurized fluid until a state is reached indicative of the clutch actuator being functional, or until a maximum run out state is reached indicative of a faulty clutch actuator.

A method for adapting a biting point filling time of a hydraulically actuated hybrid disengaging clutch is implemented step by step during driving of the motor vehicle via a plurality of selected engagement phases of the hybrid disengaging clutch with a manipulation of the customary rapid filling routine. Proceeding from an initially stored biting point filling time, a filling time which is shortened in comparison with this for a subsequent rapid filling routine is increased step by step, in each case by an increment. Here, an actual value which is set in each case for a test parameter, from which a change in the transmission of torque of the hybrid disengaging clutch can be derived, is detected until the actual value corresponds to a setpoint value.

A method of setting a clutch control reference value includes monitoring the pressure of a clutch while a controller applies test current having a predetermined amplitude and frequency to a solenoid valve in the manner of gradually reducing the magnitude of the test current from a predetermined entry value, applying, when the amplitude of the pressure of the clutch starts to change, predetermined checking current, the checking current vertically oscillating based on the magnitude of current when the amplitude of the pressure of the clutch starts to change as a central value, and determining a volumetric kiss point (VKP) by comparing the amplitude of the pressure of the clutch according to application of the checking current with a predetermined reference range.