A method controls a clutch actuator, comprising a clutch cylinder piston of a clutch cylinder, which clutch cylinder piston moves an actuation element of a friction clutch along an actuation path, and comprising a hydraulic pump, which actuates the clutch cylinder piston by means of a pressure medium pumped along a hydrostatic path and which is operated by means of an electric motor. In order to determine an actuation state of the friction clutch, the operating state along the actuation path is estimated by means of a pressure medium volumetric flow rate produced by the pump and by means of a leakage volumetric flow rate of the pump.

A clutch control device includes an ECU that controls a clutch actuator, the ECU sets a control target value of the clutch capacity according to the operation amount detected by the clutch operation amount sensor, and executes feedback control so that the control parameter which is detected by the control parameter sensor approaches the control target value, and changes a method of the feedback control when the control parameter reaches a predetermined control state change determination value during the feedback control.

A method determines the travel of a clutch in a hydraulic clutch-actuation system. A hydraulic signal which extends between a transmitting end and a receiving end is acted upon by an acoustic signal for the generation of a wave packet. The acoustic signal on the transmitting end of the clutch-actuation system is fed into the hydraulic fluid, a wave packet generated by the acoustic signal on the receiving end is reflected back to the transmitting end, a running time of the transmitted and reflected wave packet on the transmitting end is evaluated to determine the coupling travel.

There is provided a clutch control device which includes an electric oil pump, a clutch unit, and a pressure measurement unit, and which controls an operation of the electric oil pump so as to change a transmission state of the clutch unit. The device includes a pressure control valve that is located between an oil passage for connecting the electric oil pump and the clutch unit to each other and an oil pan for storing an unpressurized hydraulic oil, and that discharges the pressurized hydraulic oil from the oil passage to the oil pan, when pressure of the hydraulic oil exceeds valve opening pressure, and a pump drive control unit that controls hydraulic pressure by driving the electric oil pump, based on target pressure indicated by a change command of the transmission state of the clutch unit and the hydraulic pressure measured by the pressure measurement unit.

An angle-measuring device is provided for a rotationally-driven linear actuator, which can be implemented into a clutch actuator. A rotor element has an axis of rotation and rotates concentrically with a rotor of a rotary drive for an axially movable linear actuator element. A measurement magnet arrangement is fixed relative to the rotor element and has a polarization. The polarization is oriented in such a way that the magnetic field lines can change with a rotation of the rotor element so as to enable the angle to be precisely determined from at least one measurement position. At one location, a 360-degree sensor is provided for measuring angular positions based on the measurement magnet arrangement. At another location, a revolution-counting sensor is provided for counting a number of revolutions carried out based on the measurement magnet arrangement.

A method for adjusting an operating point of a hydraulic actuator arrangement, in which a volumetric flow source is connected to a hydraulic cylinder via a pressure line which is filled with a hydraulic fluid, wherein a volume of the hydraulic fluid is regulated via the volumetric flow source and the operating point corresponds to a position of the actuator arrangement for a predefined parameter of a device which is to be actuated by the actuator arrangement, wherein the volume of the hydraulic fluid which is required to adjust the operating point is derived from a rotational position of a volumetric flow source motor and/or the volumetric flow source. In a method which facilitates a reliable start of the volume determination, a volume determination is started by means of a rotary angle regulation at a predefined pressure, wherein the predefined pressure is lower than a system pressure.

The invention relates to a method for determining the absolute position of a component of an actuator rotating about a rotational axis, in particular a clutch actuator, wherein the component has a co-rotating magnetic element (18), and the absolute position of the magnetic element (18) is detected by way of a multi-turn sensor (16) located opposite the magnetic element (18), which is supplied with a voltage. In a method, in which the absolute position can be detected without great constructional effort, a position of the magnetic element (18) is monitored by a Wiegand wire unit (19), which detects a movement of the component when the actuator (3, 12, 13) is turned off, and if a movement is detected, transmits a voltage pulse to the multi-turn sensor (16) for measuring the current position of the component.

A method for controlling a hydraulic pressure refilling operation for an engine clutch of a vehicle includes determining whether the vehicle travels using power of a driving motor with an engine clutch maintained in a disengaged state, and upon determining that the vehicle travels using power of the driving motor with the engine clutch maintained in the disengaged state, determining whether loss of hydraulic pressure has occurred, and upon determining that loss of hydraulic pressure has occurred, controlling a hydraulic pressure refilling operation such that working fluid in a reservoir is supplied to the actuator with the engine clutch in an engaged state, and controlling the driving motor so that the driving motor outputs a compensated torque by compensating for an effect of a load torque, generated by a non-operating engine, on a torque of the driving motor.

A method for controlling a hydraulically actuated shift element of a vehicle transmission (G) includes determining a fill level of a pressure compensating cavity (2) associated with a pressure chamber (1) and controlling pressurizing of the pressure chamber (1) with hydraulic fluid based at least in part on the determined fill level of the pressure compensating cavity (2). The pressure chamber (1) is fillable with the hydraulic fluid by an electronically controlled hydraulic system in order to actuate the shift element.

A clutch connecting/disconnecting device comprises: a clutch pedal; a clutch cylinder; a depression force transmission mechanism; and an actuator. The depression force transmission mechanism is configured to include a cylinder device. The cylinder device includes an input piston, an output piston, a first oil chamber, and a second oil chamber. A pressure receiving area on the first oil chamber side of the output piston is male equal. to a pressure receiving area on the second oil chamber side of the output piston. The first oil chamber and the second oil chamber are connected via an electromagnetic valve connecting and disconnecting between the first oil chamber and the second oil chamber, and the actuator is connected to the output piston in a power transmitting manner.