基于准连续高阶滑模的可重复使用运载器再入姿态控制

针对可重复使用运载器再入段的姿态控制问题，提出一种基于准连续高阶滑模的控制方法。将姿态控制系统分为两个回路，分别为角度控制回路与角速度控制回路。角度回路作为外回路产生角速度指令，角速度回路作为内回路跟踪外回路产生的角速度控制指令。为了提高系统的鲁棒性，对两个回路分别设计滑模控制器。外回路中设计基于低通滤波的终端滑模控制方法，以获得平滑的控制量作为角速度指令。内回路设计增加系统相对阶的准连续高阶滑模方法，使控制律中不直接含有符号函数项，保证系统稳定的同时减弱控制器抖振。在具有外界干扰与参数不确定的情况下，使用本文提出的方法进行仿真试验，仿真结果证明了所提出方法的有效性。

Attitude Control of Reentry Reusable Launch Vehicle Based on Quasi-continuous High Order Sliding Mode

For the attitude control problem of reusable vehicles in reentry stage, a control method based on quasi-continuous high order sliding mode is proposed. The attitude control system is divided into two loops, one is the angle control loop and the other is the angular velocity control loop. The angle control loop generates the angular velocity command signals, and the angular velocity loop as the inner loop is responsible for tracking the command signals generated by the angle control loop. In order to improve the robustness of the system, the sliding mode controller is designed for each of the two loops. The outer loop uses the terminal sliding mode control method based on low-pass filtering to obtain smooth control commands. In order to reduce the chattering of the sliding mode controller, a quasi-continuous high-order sliding mode method by increasing the relative order of the system is proposed, so that the control law does not contain sign function. The simulation experiment is carried out using the method proposed with external disturbances and parameter uncertainties. The simulation results prove the effectiveness of the method proposed.