Integral algorithm design in sliding mode controller of MEMS gyroscope

In order to remove the undesired DC offset of integral signal, a modified integral algorithm based on the Single Moving Average Method is proposed. In this algorithm, the N samples during one cycle are collected as a set, and the average value of them is calculated as the instantaneous DC offset. Therefore, a pure AC signal without any offset is obtained by subtracting the DC offset from the integral signal. On every rising edge of the clock, a new sampling point is added into the set and the oldest one should be removed. In this way, the length of the set remains constant and the DC offset can be updated in real time. Both the simulation and test results demonstrate the effectiveness of this integral algorithm. This algorithm has been successfully used in the sliding mode controller of a MEMS gyroscope. Compared with the existing integral algorithm, the proposed method is less complex, easier to be realized and can achieve better real time response.