Testing hydraulic actuator for steering rear wheels of motor vehicle - controlling operation of two two-way valves dependent upon sensor signal indicating actual adjustment path

摘要

Dependent upon the adjustment direction, a first valve is used as inlet valve and a second valve as outlet valve. With an actually determined adjustment path as reference actual path in a first step, a first valve (15,16) is opened as inlet valve and the second valve (16,15) is closed. In a second step, the second valve (16,15) is opened as an inlet valve and the first valve (15,16) is closed. After the first and second steps, the adjustment actual path is determined and a faulty second valve (16,15) is detected if after the first step a new adjustment actual path is measured which deviates from the reference actual path. A faulty first valve (15,16) is detected is after the second step a new adjustment actual path which deviates from the reference actual path is measured. USE - Vehicle with four-wheel steering.