Estimation of steering wheel angle

摘要

A control system (9) and a method for detecting an absolute steering wheel angle ´ in a steering wheel system for a vehicle. A first angle sensor (15) is positioned in connection to a steering shaft (2) and a second angle sensor (16) is positioned in the steering wheel system for direct or indirect detection of movement of a steering rack (6) upon rotation of the steering wheel (1). The control system (9) is arranged to store a predetermined transfer ratio C 2 /C 1 between a value C 2 representing the gain of the second angle sensor (16) and C 1 representing the gain of the first angle sensor (15). The transfer ratio C 2 /C 1 is dependent on that there can be only one unique pair n 1,2 of number of revolutions n 1,2 of the first angle sensor and the second sensor respectively that satisfy a number of criteria.