Characteristic Model-Based Adaptive Discrete-Time Sliding Mode Control for the Swing Arm in a Fourier Transform Spectrometer

This paper aims to guarantee high-precision tracking of the desired optical path difference velocity for a Fourier transform spectrometer (FTS) in a space exploration system with time-varying parameters and nonlinear dynamics. A novel characteristic model-based adaptive discrete-time sliding mode control (ADSMC) scheme is proposed. The design of the ADSMC includes characteristic modeling, characteristic model-based discrete-time sliding mode control, and the estimator of the uncertain coefficients. The stability analysis of the ADSMC is also given in this paper. Simulation and experimental results demonstrate that the proposed characteristic model-based ADSMC can achieve high-precision control over a Michelson interferometer-based FTS. The significant advantages of the proposed ADSMC are its robustness and better control performance over the external disturbance and internal parameter uncertainty of the system.