Patent ID: 8474567
Filing Date: 2013-07-02
Classification: F16D

Abstract:
1. A method for calibrating an actuator of an all-wheel drive clutch of a motor vehicle having at least a part of a driving torque permanently transmitted to a primary axle and a part of the driving torque optionally transmitted to a secondary axle by the clutch, the method comprising: calculating a desired clutch torque (M determining a control signal for the actuator from the desired clutch torque in accordance with a preset desired clutch torque/control signal relationship; determining a clutch slip value (Δn) that corresponds to a difference between a speed of the primary axle and a speed of the secondary axle; determining a reference secondary axle torque (Mref comparing the clutch slip value (Δn) with a threshold value (Thresh) and comparing the desired clutch torque (M checking torque increase conditions by determining whether the clutch slip value (Δn) is larger than the threshold value (Thresh) and whether the desired clutch torque (M changing the desired clutch torque/control signal relationship in dependence on a result of the comparisons, wherein the desired clutch torque/control signal relationship is changed in the sense of an increase in the proportion of the driving torque transmitted to the secondary axle by the clutch if the torque increase conditions are satisfied; and using the changed desired clutch torque/control signal relationship to determine the control signal for the actuator upon subsequent actuation of the clutch.