Patent ID: 8901921

Claim:
An angle measurement system for determining an angular position of a shaft, comprising: first and second magnets adapted to cooperatively rotate over different angular distances according to a predetermined relationship, where the first magnet consists of a single pole-pair which is radially disposed about an entire circumference of the shaft and which rotates with the shaft; first and second angle sensors located at different positions and adapted to measure magnetic field directionality due to the first and second magnets, where the first angle sensor includes a sensing element that is located over the first magnet and which is at least substantially centered between an inner radius of the first magnet and an outer radius of the first magnet and wherein the second angle sensor is located on a rotational axis of the second magnet; at least one redundant angle sensor over the second magnet, where the at least one redundant angle sensor is stacked over the second angle sensor and lies at least substantially on the rotational axis of the second magnet; and a controller adapted to determine the angular position of the shaft based on the magnetic field directionality measured by the first angle sensor and the second angle sensor.