针对具有非最小相位特性的升力式再入飞行器的姿态控制问题,设计了一种基于干扰观测器的动态逆预测级联姿态控制器。提出了“外界输入控制外部状态,外部状态偏差控制内部状态”的级联控制策略。在内部状态回路中,利用模型预测控制器的最优性,以较小的控制量镇定内部状态到有界范围;在外部状态回路中,采用动态逆控制器将输出偏差镇定在内回路所需控制量上,并加入干扰观测器来消除再入过程中的建模不确定性,进而实现飞行器姿态的稳定跟踪输出。数值仿真结果表明,该级联控制策略能够有效地解决具有非最小相位特性的模型指令跟踪问题。Monte Carlo数值仿真结果表明,在建模不确定性存在的情况下,该级联姿态控制器具有良好的鲁棒性。
This paper proposes a cascade attitude controller combining the dynamics inverse control based on disturbance observer and model predictive control, for studying the lifting reentry vehicles with nonminimum phase characteristic. To solve the output tracking problem of these lifting reentry vehicles, a cascade control strategy is developed in which the external inputs control the external states and the external state deviations control the internal states. In the internal state loop, a model predictive controller with optimality is used to stabilize the internal dynamics via a smaller control quantity; in the external state loop, a dynamics inverse controller is used to keep the external dynamics deviation to the control quantity that the inner loop needs, and a disturbance observer is added to eliminate the modeling uncertainty in the reentry phase, so that the vehicle attitude can track the output command stably. Simulation results show that this cascade controller can solve the attitude tracking problem of the nonminimum phase system. Monte Carlo results show that this cascade controller is of good robustness in the case of modeling uncertainty.