Indirect determination of control system supply and reference voltages for motor vehicle steering column e.g. for fault recognition - using coarse potentiometer working over whole rotation of shaft, and two fine potentiometers, and using max. signal to determine supply voltage and min. signal to determine reference voltage.

摘要

The method indirectly determines a reference voltage (UR) and a system supply voltage (UV) used in the evaluation of a steering column rotation from signals supplied by a composite sensor (10, 12) required by the computer-controller (14, 15). The sensor (10, 12) comprises a coarse (11) and two similar fine (10) reference potentiometers covering the full travel of the column and the signals (UGS, UFS1, UFS2) are derived from their respective sliding contacts. The values of the additionally required voltages (UR, UV) enabling error recognition are evaluated from the maximum and minimum voltages obtainable from the fine potentiometers (10) wrt a given coarse potentiometer setting (UGS). USE/ADVANTAGE - Enables reduction of six analogue inputs to computer three whilst retaining full error signal recognition, as consequence of internal evaluation of reference voltage and supply voltage by computer-controller.