Adaptive Augmented Anti-Disturbance Load Relief Controller Design and Stability Analysis

This paper proposes an adaptive augmented anti-disturbance load relief control scheme for a solid launch vehicle. It can effectively satisfy the composite control requirements including high-precision attitude control, resistance to elastic frequency deviations, sudden wind disturbances, and active load relief. Firstly, the dynamic model of the elastic solid launch vehicle was established and subjected to small-perturbation linearization. Based on the state-space approach, the open-loop transfer function of the system was derived, and a basic PD controller with correction networks was presented. Subsequently, an adaptive augmented control law was designed to achieve adaptive variation in open-loop gain. Furthermore, a load relief control law was designed to address the launch vehicle’s need for load mitigation during the ascent phase through high-wind regions. Simultaneously, to further enhance disturbance rejection capability, a linear extended state observer was developed. Finally, frequency-domain methods and sinusoidal function analysis were applied to the four designed modules to evaluate the system’s stability margins, and the overall stability margin of the whole control system was calculated. Comprehensive time-domain simulation results and frequency-domain analysis examples demonstrate the effectiveness of the proposed method, which offers a novel solution for launch vehicle ascent control and facilitates meeting multi-constraint control requirements.