【摘要】 针对火星着陆任务大气进入段的轨迹跟踪控制问题,给出了一种基于约束预测控制的跟踪策略。综合考虑大气进入段动力学模型的非线性、状态初值的不确定性、控制量限幅约束以及参数摄动,设计了基于线性化阶跃响应预测模型、反馈校正和含约束滚动优化的约束预测控制器,并通过数学仿真对该方法进行了数值验证,结果表明:约束预测控制较PID对参考指令跟踪精度更高,开伞点误差圆半径远小于PID方法;能得到控制量限幅约束条件下平稳的控制曲线。更多还原

【Abstract】 Aiming at tracking the vehicle’s entry optimized trajectory for Mars Landing,a new method based on constrained predictive control is proposed.The vehicle’s nonlinear dynamics,the initial state uncertainties,saturation limit of the control input and the parameter perturbation are taken into consideration synthetically.A constrained predictive control(CPC)is developed which consists of a linearized step-response predictive model,feedback correction and constrained rolling optimization.The simulation results indicate that:constrained predictive control has a more accurate guidance command tracking performance compared with the PID method,therefore its radius error at the parachute deploying point is far smaller than that of the PID method;a smooth control curve can be obtained under the saturation constraint of the control input.更多还原