Mechanism and implementation of error suppression in MEMS inertial navigation system via rotational modulation and array

Abstract To enhance the accuracy of micro-electro-mechanical system (MEMS) inertial navigation systems (INSs) without using additional sensors, we propose a rotational and arrayed INS (RAINS) that compensates for both stochastic and deterministic MEMS inertial measurement unit (MIMU) errors through sensor array configuration and rotary modulation techniques. In this paper, the RAINS’s suppression effects of MIMU’s deterministic error and stochastic errors are analyzed. According to the mechanism analysis, the fusion method of MIMU array based on the minimum norm quadratic unbiased estimation method and error similarity degree is adopted, which improves the fusion accuracy and stability of the MIMU array. Furthermore, an optimization scheme for rotational modulation is proposed, which further improves the accuracy of the MEMS INS. In this paper, a prototype of RAINS was developed and experiments were carried out. The test results show that the developed RAINS improves the horizontal positioning accuracy by more than 70% compared with the MEMS INS. This proves that the RAINS, fusion method and modulation scheme proposed in this paper can effectively suppress the error of MEMS INS.