A method for operating a hydraulic actuator for a prime mover or a drive device of a vehicle includes determining that the hydraulic actuator is to be actuated via an actuating system and detecting an operating variable influenced by a filling state of the hydraulic actuator indicative of pressure conditions in the hydraulic actuator, with the operating variable being separate from actuator operating variables of the hydraulic actuator and the actuating system. The method further includes pressurizing the actuator during a fast fill phase to one or more pressures over a fast fill time period in response to determining that the hydraulic actuator is to be actuated. The fast fill time period and the one or more pressures are adjusted as a function of the operating variable under certain operating conditions. Additionally, the method includes pressurizing the actuator during a pressure build-up phase after the fast fill phase.

A hydraulic control device for a vehicle is provided wherein a determination of “base neutral” is made when a difference between a command hydraulic pressure and an actual hydraulic pressure of a hydraulic clutch is within a predetermined minute value range, and when the difference is out of the minute value range, a determination of “base raising” is made if the command hydraulic pressure is larger than the actual hydraulic pressure, and a determination of “base lowering” is made if the command hydraulic pressure is smaller than the actual hydraulic pressure. The determination of “sub raising” is made when an inclination of command torque subjected to low-pass filter processing is positive for a predetermined time or more, and the determination of “sub lowering” is made when the inclination is negative for the predetermined time or more, whereby a rising or dropping tendency of the command torque is determined.

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.

The disclosure relates to a method for calibrating a drive system for an axle of a motor vehicle; wherein the drive system includes at least one electric machine as the drive unit, a drive shaft driven by the drive unit, a first output shaft and a second output shaft, as well as a first clutch connecting the drive shaft to the first output shaft and a second clutch connecting the drive shaft to the second output shaft.

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.

A hydrostatic actuator system includes an electric motor for delivering a hydraulic fluid via a piston unit. The actuator system is operating using a method in which a change in volume caused by a temperature change is sensed by a pressure measurement. The method reliably identifies a state of the transfer of the hydraulic fluid from a planetary roller transmission compartment into the master piston. The pressure measurement is continuously evaluated, and, in the event of a negative signal of the pressure measurement, suction of the hydraulic fluid by a planetary roller transmission lying in the hydraulic fluid between the electric motor and the piston unit into the piston unit is recognized and a fault signal is output.

A hybrid vehicle includes an electric motor and a combustion engine. A K0 clutch couples the combustion engine to a drivetrain of the vehicle. A control module of the vehicle calculates a torque to be applied by the motor to the K0 clutch when initiating engagement of the combustion engine to the drivetrain. The control module calculates two separate torque lead values by two separate methods and calculates the torque by combining the two torque lead values.

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.

Systems and methods of controlling a clutch in a vehicle are provided. With the goal of enabling autonomous/assisted control of the clutch by an electronic control unit while preserving the familiar mechanical feeling at the clutch pedal that driving enthusiasts prefer, embodiments of the disclosed technology use a shuttle valve to blend control of clutch engagement between a driver and an ECU. In these embodiments, a clutch pedal in the vehicle may be mechanically connected to a piston in a first hydraulic cylinder (just like in a traditional mechanical/hydraulic clutch actuation system), and an ECU may actuate a second hydraulic cylinder. Accordingly, a shuttle valve may be used to route the fluid coming from the cylinder with the greater pressure (i.e. the driver actuated cylinder or the ECU actuated cylinder), to a third hydraulic cylinder which adjusts engagement of a clutch by a mechanical linkage.