Research ArticleParameter estimation and interval type-2 fuzzy sliding mode control of a z-axis MEMS gyroscope

•Complete dynamics of z-axis MEMS gyroscope is derived.•Normalized gradient algorithm is used to estimate the unknown parameters.•Time varying angular rate is estimated consistently via the identifier.•Type-2 fuzzy sliding mode control is exploited to minimize the effect of noise.•The controller regulates the amplitude and frequency of vibrations.

This paper reports a hybrid intelligent controller for application in single axis MEMS vibratory gyroscopes. First, unknown parameters of a micro gyroscope including unknown time varying angular velocity are estimated online via normalized continuous time least mean squares algorithm. Then, an additional interval type-2 fuzzy sliding mode control is incorporated in order to match the resonant frequencies and to compensate for undesired mechanical couplings. The main advantage of this control strategy is its robustness to parameters uncertainty, external disturbance and measurement noise. Consistent estimation of parameters is guaranteed and stability of the closed-loop system is proved via the Lyapunov stability theorem. Finally, numerical simulation is done in order to validate the effectiveness of the proposed method, both for a constant and time-varying angular rate.