Patent ID: 8290664

Claim:
Method of measuring the angular position, between two steering locks, of a steering wheel of a vehicle, comprising steps of: equipping said vehicle with a gearing, termed main gearing, composed of a first gearwheel ( 4 ; 4 â€²), which is coupled in rotation to the steering wheel, and of a second gearwheel ( 5 ; 5 â€²), and in measuring the angular position of the second gearwheel by means of a first angular sensor ( 15 ; 15 â€²) having a given measurement range, said first sensor, associated with the second gearwheel ( 5 ; 5 â€²), being designed, upon a movement of the second gearwheel ( 5 ; 5 â€²) within the measurement range of this first sensor ( 15 ; 15 â€²), to calculate values representative of the angular positions of this gearwheel within said measurement range, and at the ends of the measurement range, to positively or negatively increment a counter for storing the number of revolutions made; and equipping the vehicle with a second gearing, termed auxiliary gearing, composed of one of the gearwheels ( 5 ; 4 â€²) of the main gearing, of a third gearwheel ( 8 ; 9 â€²), and of intermediate means ( 6 , 7 , 9 - 11 ; 20 - 23 ) for sequentially driving the third gearwheel ( 8 ; 9 â€²) and rotating the third gearwheel stepwise in increments of a predetermined angular value (Î±) upon each complete rotation of the associated gearwheel ( 5 ; 4 â€²) of the main gearing, where (Î±) is such that, in the course of a rotational travel of the steering wheel between the two steering locks, the total angular travel of the third gearwheel ( 8 ; 9 â€²) is less than or equal to 360Â°; measuring the angular position of the third gearwheel ( 8 ; 9 â€²) by means of a second angular sensor ( 16 ; 16 â€²) associated with said third gearwheel; and managing the data provided by the first and second angular sensors in such a way that once the vehicle has started, in an â€œactiveâ€ mode thereof, the absolute angular position of the steering wheel is calculated from the angular values and from the values of the counter obtained by means of the first angular sensor ( 15 ; 15 â€²), and upon starting of the vehicle, in a â€œwakeâ€ mode, the absolute angular position of the steering wheel is calculated from the value representative of the angular position of the second gearwheel ( 5 ; 5 â€²) obtained by means of the first angular sensor ( 15 ; 15 â€²), and from the value of the angular position of the third gearwheel ( 8 ; 9 â€²) obtained by means of the second angular sensor ( 16 ; 16 â€²) and representative of the number of revolutions made by the steering wheel.