Adaptive global fast terminal sliding mode control of MEMS gyroscope

In this paper, an adaptive global fast terminal sliding mode control (GFTSM) is proposed for tracking control of Micro-Electro-Mechanical Systems (MEMS) vibratory gyroscopes under unknown model uncertainties and external disturbances. To improve the convergence rate of reaching the sliding surface, a global fast terminal sliding surface is employed which can integrate the advantages of traditional sliding mode control and terminal sliding mode control. It can be guaranteed that the designed control system can reach the sliding surface and equilibrium point in a shorter finite time from any initial state. In the presence of unknown upper bound of system nonlinearities, an adaptive global fast terminal sliding mode controller is derived to estimate this unknown upper bound. The closed-loop stability can be guaranteed with the proposed adaptive global fast terminal sliding mode control. Simulation results demonstrate that the tracking error can be attenuated efficiently and robustness of the control system can be improved.