Self-triggered output tracking model reference adaptive control for test mass suspension

In this paper, the high-precision test mass suspension control of the space inertia sensor is investigated by proposing an enhanced output tracking self-triggered model reference adaptive control (MRAC) scheme. Based on the proposed control scheme, the test masses are adaptively suspended by using reduced-ordered output. To suppress the disturbance due to the test mass suspension, we introduce a $\sigma$-modification approach to the adaptive controller with a bounded switching gain. Furthermore, to reduce the actuation consumption, a self-triggering mechanism (STM) is applied to determine the triggering instants using the current responses. An extended Lyapunov analysis based on Filippov solutions proves the boundedness of all closed-loop signals for the suspension system with switching adaptive gains. Numerical simulations are performed to verify the reduction of the actuation cost and the effectiveness of the proposed control scheme, under external disturbances, parameter uncertainties, input saturation, and hysteresis.