Steering wheel angle measurement method and steering wheel angle sensor

The embodiment of the invention provides a steering wheel angle measurement method and a steering wheel angle sensor. The method comprises the following steps of: calculating a change rate k of a steering wheel angle theta along a reading difference value delta of a first angle sensor and a second angle sensor; determining the change period number of the reading difference value delta in a steering wheel angle measurement range; determining a steering wheel angle minimum and a steering wheel angle maximum, which correspond to each change period; and constructing a piecewise linear function of the steering wheel angle theta and the reading difference value delta, and thus obtaining a current steering wheel angle by calculation, wherein the piecewise function quantity of the piecewise linear function is in accordance with the change period number. Compared with the conventional method for measuring a steering wheel angle by a binary indefinite equation, the steering wheel angle sensor has the advantages that by constructing the piecewise linear function and performing simple arithmetic operation, the current steering wheel angle can be obtained; and a measurement algorithm of the current steering wheel angle is simplified.