Adaptive Sliding Mode Control of a Three-DOF MEMS Vibratory Tri-axial Gyroscope with the Capability of Angular Velocity Estimation

in this paper, structure and fundamentals of a three-DOF Micro Electro Mechanical System (MEMS) tri-axial vibratory gyroscope gets described and its dynamics is reviewed first. Reduction of performance, caused by imperfections in fabrication procedures, is debated and the more accurate model is put forth. The open-loop scheme deficiencies, particularly on the ground of quadrature error, also get conversed and proved via simulation. Quadrature error unavoidably comes up in fabrication and ruins sense mode responses. It originates from abnormal geometries which results in anisoelasticity and anisodamping. Secondly, an adaptive control system is designed to compensate for malfunctioning impact of the error of the quadrature and have the sense mode accelerometers produce sinusoidal oscillations along three orthogonal directions with the desiderated amplitudes and frequencies in spite of the parametric uncertainties and exogenous disturbance in the gyroscope. The designed system can estimate three corresponding orthogonal revolving rates due to the persistently excitation condition. The simulation results are very promising.