A Composite Adaptive Controller Design for 3-DOF MEMS Vibratory Gyroscopes Capable of Measuring Angular Velocity

Abstract

In this paper, a contributive just schematic design of a 3-DOF MEMS (Micro Electro Mechanical System) vibratory gyroscope is presented. Not only does the conceptual design have the advantage of being manipulated by balanced force actuation mechanism, but also it benefits providing a differential capacitive one. The three sets operate along drive and sense axes since both displacement and velocity states are required to be observed in order to control the device. In addition and more importantly, a composite adaptive controller is proposed to compensate for quadrature error and make the sense mode oscillator generate sinusoidal oscillation along the sense axes with desired amplitudes and frequencies. The designed composite scheme owns capability of estimating the rotation rate realizing persistently excitation condition as well as benefits of fast tunable estimation, landmark identification accuracy and an intrinsic tunable structural robustness in comparison with adaptive sliding mode controller. The simulation results bring about a hint of consent. It should be reminded that major malfunctioning effects like quadrature error and uncertainty inevitably transpire in fabrication process and awfully distorts sense mode response of the gyroscope. They chiefly emanate from abnormal geometries which bring about aniso-damping and aniso-elasticity and also from accuracy–deficiency in modeling and fabrication procedure, making design of a suitable controller integral and controversial to exploit the device. Weakness of the pole placement state-feedback controller in tracking desired trajectory and its incapability of estimating angular velocity mandate considering other modern controllers like adaptive ones.