Method for the determination of a voltage limit of a clutch actuating motor

1. A method for the determination of a motor voltage limit, wherein a clutch actuator of an automated shift transmission remains motionless, comprising the steps:

(a) raising or lowering a withstand voltage by an increment ΔU, starting from a current withstand voltage (U curr ); and,

(b) determining whether the clutch actuator moves under the changed withstand voltage.

2. The method recited in claim 1 , wherein the current withstand voltage is adapted as the withstand voltage limiting value when there is movement of the clutch actuator.

3. The method recited in claim 1 , wherein steps (a) and (b) are repeated until the clutch actuator moves.

4. The method recited in claim 1 wherein a movement of the clutch actuator is only detected as a movement in step (b) if the clutch actuator moves more than a predetermined minimum distance ΔX min .

5. The method recited in claim 1 wherein, after raising or lowering the withstand voltage, the procedure waits for a predetermined time Δt before finally determining in step (b) whether the clutch actuator moves.

6. The method recited in claim 1 wherein the current withstand voltage U curr is measured with the clutch actuator motionless.

7. The method recited in claim 6 wherein a determination is made in advance as to whether an upper or a lower withstand voltage limit is to be determined, and wherein, if an upper withstand voltage limit is to be determined, then the current withstand voltage U curr is raised by the increment ΔU in step (a), and wherein, if a lower withstand voltage limit is to be determined, then the current withstand voltage U curr is lowered by the increment ΔU in step (a), and wherein steps (a) and (b) are carried out until the actuator moves.

8. The method recited in claim 1 wherein in step (a) the current withstand voltage U curr is set as a known upper withstand voltage limit U up or as a known lower withstand voltage limit U dn , the current withstand voltage U akt is raised by the increment ΔU in step (a) if an upper withstand voltage limit U up is to be determined, and the current withstand voltage U curr is lowered by the increment ΔU in step (a) if a lower withstand voltage limit U dn is to be determined.

9. The method recited in claim 8 wherein the upper withstand voltage limit U up is raised by a value U inc or the lower withstand voltage limit U dn is lowered by a value U inc , if no movement is detected in step (b), and the upper withstand voltage limit U up is lowered by a value U inc or the lower withstand voltage limit U dn is raised by a value U inc , if a movement is detected in step (b).

10. A device for determining a motor voltage limit, where a clutch actuator of an automated shift transmission remains motionless, having a control system that is adapted to carry out a method for the determination of a motor voltage limit, wherein a clutch actuator of an automated shift transmission remains motionless, said device comprising:

(a) a means for raising or lowering a withstand voltage by an increment ΔU, starting from a current withstand voltage (U curr ); and,

(b) a means for determining whether the clutch actuator moves under the changed withstand voltage.