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.

This clutch control apparatus includes: a clutch device that connects and disconnects a power transmission between an engine and a drive wheel; a clutch actuator that drives the clutch device and changes a clutch capacity; a driven mechanism that is arranged between the clutch actuator and the clutch device, is operated by a drive of the clutch actuator, and operates the clutch device; a control part that calculates a control target value of the clutch capacity; and a temperature sensor that measures a temperature of the driven mechanism, wherein the control part corrects the control target value based on the temperature measured by the temperature sensor.

A hydraulic actuation device for a motor vehicle friction clutch has a manually actuatable master cylinder, that has a master pressure chamber which, in a rest position, is fluidically connected to a reservoir. The master cylinder is connected to a slave arrangement that is functionally connected to the motor vehicle friction clutch. A pressure line connects the master pressure chamber to the slave arrangement and in which incorporates an electrically actuatable valve arrangement with an electrically actuatable proportional valve and, connected in parallel, a first check valve which blocks in the direction of the master pressure chamber. A motor pump is connected, on the input side, to the reservoir and can be connected, on the output side, to the pressure line between the valve arrangement and the slave pressure chamber through a second check valve that blocks in the direction of the motor pump.

A clutch cylinder in a hydraulic pressure system can be charged with a controlled rotational speed of a pump to deliver hydraulic fluid into the clutch cylinder until a biting point of the clutch is reached and exceeded and a motor current of the pump has attained a predetermined minimum value. On the basis of a profile of the controlled rotational speed, a first volume of the hydraulic fluid delivered into the clutch cylinder by the pump up is determined until the minimum value is attained. The value of the first volume can be reduced by a predetermined amount to a second volume, which can be used for clutch processes during vehicle operation, wherein the second volume is delivered into the clutch cylinder, with a high rotational speed of the pump, such that the clutch is filled such that the biting point of the clutch is not quite reached.

Actual pressure of a hydraulic clutch of a motor vehicle can be regulated by: a) providing a value for a desired pressure to be present in a clutch cylinder; b) filling the clutch cylinder with hydraulic fluid to achieve the desired pressure; c) wherein, if the desired pressure lies between 0 and 7 bar, the actual pressure in the clutch cylinder is adjusted by regulating a rotational speed of the pump of the electric motor, and if the desired pressure is greater than 7 bar, the actual pressure in the clutch cylinder is adjusted by regulating a motor current of the electric motor; d) regulating the actual pressure until the desired pressure is achieved.

This clutch control apparatus includes: a clutch device that connects and disconnects a power transmission between an engine and a drive wheel; a clutch actuator that drives the clutch device and changes a clutch capacity; a driven mechanism that is arranged between the clutch actuator and the clutch device, is operated by a drive of the clutch actuator, and operates the clutch device; a control part that calculates a control target value of the clutch capacity; and a temperature sensor that measures a temperature of the driven mechanism, wherein the control part corrects the control target value based on the temperature measured by the temperature sensor.

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 method for determining an actuator path of a hydraulic clutch actuator, includes measuring a first temperature of the hydraulic clutch actuator with a first temperature sensor, measuring a second temperature of the hydraulic clutch actuator with a second temperature sensor, calculating a first temperature difference between the first temperature and the second temperature, using the first temperature or the second temperature as a clutch actuator temperature to determine a compensation value of the actuator path when the first temperature difference is less than a threshold value, and modifying the actuator path using the compensation value. In an example embodiment, the first temperature sensor measures a one of a circuit board temperature, an angle sensor temperature or a pressure sensor temperature, and the second temperature sensor measures another one of the circuit board temperature, the angle sensor temperature or the pressure sensor temperature.

A hydraulic clutch system that enables automatic emergency braking (AEB) and remote start of a manual transmission vehicle. The hydraulic clutch system includes a piston-operated hydraulic cylinder or other accumulator to store a charge of hydraulic fluid that can be selectively routed to the clutch and discharged under electronic control to thereby disengage the clutch independently of any operator input via the clutch pedal. By doing so, the system can provide an improved AEB response that slows or stops the vehicle without stalling the engine. The system may also be used to provide remote start capability to the vehicle by automatically disengaging the clutch as part of a remote start sequence of operations.

A method for determining an actuator path of a hydraulic clutch actuator, includes measuring a first temperature of the hydraulic clutch actuator with a first temperature sensor, measuring a second temperature of the hydraulic clutch actuator with a second temperature sensor, calculating a first temperature difference between the first temperature and the second temperature, using the first temperature or the second temperature as a clutch actuator temperature to determine a compensation value of the actuator path when the first temperature difference is less than a threshold value, and modifying the actuator path using the compensation value. In an example embodiment, the first temperature sensor measures a one of a circuit board temperature, an angle sensor temperature or a pressure sensor temperature, and the second temperature sensor measures another one of the circuit board temperature, the angle sensor temperature or the pressure sensor temperature.