Adaptive Fuzzy Slide Mode Control Design with Asymptotic Sliding Surface for MEMS Vibrational Gyroscope System in the Presence of Uncertaint

Electromechanical Gyroscopes are based on vibrational systems. To control the driving mode of such small vibrational system is of pivotal importance for researchers. A sliding-mode control system is proposed for MEMS gyroscopes. At first, for decreasing the uncertainties existed in dynamical equations, utilizing the Inverse Dynamics method known dynamics of the gyroscope system are eliminated. To make the controller robust against the remaining uncertainties, sliding-mode control is applied. Sliding mode control will add undesired chattering on the control input, which result in a reduction in driving mode actuator's lifetime. In order to preclude the chattering problem in the control input, two approaches are presented. In the first approach, an adaptive fuzzy approximator is used to estimate the uncertainty bound in dynamical equations. The application of proposed adaptive fuzzy sliding mode control in reducing the undesirable chattering in the control input is impressive. In the second approach, by adjusting the Adaptive fuzzy sliding mode control designing process, a new variable is presented, which finally leads to designing the control input derivative. The mathematical proof shows that the proposed control method will cause the sliding surface to converge to zero asymptotically in the presence of uncertainties. Since it is imperative for implementation purposes to take integral from the control input, the chattering phenomenon will disappear completely in practice. To demonstrate the function of the proposed controllers, four simulation steps have been implemented on MEMS gyroscopes. Simulation results indicate desired operation of adaptive fuzzy sliding mode control with the asymptotical sliding surface.