DEVELOPMENT OF AN ADAPTIVE ALGORITHM FOR FAULT-TOLERANT TRAJECTORY TRACKING CONTROL OF A LIFTING-BODY DESCENT VEHICLE

Wu Zhengjie, Liang Gaoyu

The article presents the development of an adaptive algorithm for a fault-tolerant automatic control system of a lifting-body descent vehicle's trajectory under conditions of partial or complete engine failure. The relevance of the research is driven by the lack of methods capable of simultaneously ensuring high control accuracy, stability in the event of a complete loss of thrust, and real-time operation on onboard computers. A hybrid approach based on a combination of a Linear-Quadratic Regulator (LQR) and a Genetic Algorithm (GA) is proposed, which automatically reconfigures the controller parameters when thrust changes, minimizing deviations from the reference trajectory. The mathematical model of the vehicle includes a system of nonlinear differential equations for center-of-mass motion, accounting for aerodynamic forces and engine failure factors. Taylor series expansion was used for model linearization, and the optimization of the LQR weight matrices was performed using the GA, achieving a balance between control accuracy and energy consumption. Simulation results in MATLAB showed that the proposed system reduces altitude deviation by 60% and pitch angle deviation by 85% compared to an open-loop control system. The practical value of the research is confirmed by the possibility of integrating the developed algorithm into existing control systems and enhancing the reliability of reusable spacecraft.

Keywords:fault-tolerant control, lifting-body descent vehicle, linear-quadratic regulator, genetic algorithm, engine failure