惯性参数不确定的自由漂浮空间机器人自适应控制研究

针对自由漂浮空间机器人系统惯性参数不确定问题,提出一种笛卡儿空间内的自适应轨迹跟踪控制方法。采用扩展机械臂模型建立了自由漂浮空间机器人关节空间动力学方程,进而推导笛卡儿空间中的自由漂浮空间机器人动力学方程。在基于逆动力学法的自由漂浮空间机器人自适应控制器设计中,利用标称控制器离线固定控制参数与补偿控制器在线补偿方法,既可以保证惯量矩阵可逆,又可以使控制参数实时估计。采用Lyapunov方法的稳定性分析表明系统是稳定且渐进收敛的。最后,应用该控制方法对两杆平面自由漂浮空间机器人进行了仿真研究。仿真结果显示自由漂浮空间机器人末端执行器在笛卡儿空间具有良好的轨迹跟踪能力。

Adaptive Control of Free-floating Space Robot with Inertia Parameter Uncertainties

In order to cope with the inertia parameter uncertainty of a free-floating space robot system, an adaptive trajectory tracking control method is proposed in Cartesian space. Dynamic equations in the joint space of the free-floating space robot system are formulated using the extended manipulator model, and then the dynamic equations in Cartesian space of the free-floating space robot system are derived. During the design of the adaptive controller for the free-floating space robot based on inverse dynamics, a nominal controller with fixed parameters offline and a compensative controller online are proposed to ensure invertibility of the inertial matrix of the dynamics model and real-time estimation of the parameters. The closed-loop system is proved to be stable and convergent by Lyapunov methods. Finally, numerical simulations of a two-link planar free-floating space robot are given using the proposed control method, which demonstrate good trajectory tracking performance of the end-effector of the free-floating space robot in Cartesian space.