Backstepping Terminal Sliding Mode Control of FOG Inertial Platform Stability Loop Based on Extended State Observer

To realize the high-precision control of the inertial platform of fiber optic gyroscope (FOG) under the influence of multi-source nonlinear disturbance torques, a backstepping terminal sliding mode control method for the FOG inertial platform stability loop based on the extended state observer was proposed. Firstly, the mathematical model of velocity loop control and position loop control of the inertial platform stability loop was established by using FOG as the sensitive element. Secondly, the backstepping terminal sliding mode control law was designed, and the extended state observer was used to estimate the disturbances and unknown states of the velocity loop and position loop respectively. The chattering caused by the sliding mode control law was reduced. This method is compared with the traditional PID single-loop control method. Under the same disturbance, the results show that the maximum rotation angle of the platform body axis caused by step disturbance is reduced 12.6” and the amplitude of the rotation angle of the platform axis caused by sinusoidal disturbance is reduced 11.34”. The stability loop using the backstepping terminal sliding mode control law based on the extended state observer has high stability accuracy and strong anti-interference ability.