自由漂浮空间机器人轨迹跟踪的模型预测控制

针对传统控制方法难以解决自由漂浮空间机器人(free-floating space robot, FFSR)轨迹跟踪过程中的各类约束的问题,采用模型预测控制对自由漂浮空间机器人的轨迹跟踪问题进行了研究.在自由漂浮空间机器人拉格朗日动力学模型的基础上,建立了系统伪线性化的扩展状态空间模型;在给定系统的性能指标和各类约束的情况下,基于拉盖尔模型设计相应的离散模型预测控制器,并证明控制器的稳定性,控制器中引入任务空间滑模变量实现了对末端期望位置和期望速度的同时跟踪;以平面二杆自由漂浮空间机器人为例,对无约束末端轨迹跟踪和有约束末端轨迹跟踪两种情况进行对比仿真验证.仿真结果表明,该模型预测控制器不仅可以实现对末端期望轨迹的有效跟踪,还能满足各类约束.

Model predictive control for trajectory tracking of free-floating space robot

Aiming at various constraints in the process of tracking control, a model predictive control method is developed for trajectory tracking of FFSR(free-floating space robot). Based on the Lagrange dynamic model of FFSR, the pseudo-linearized extended state space model of the system is established. A model predictive controller is designed based on the Laguerre model when the performance index and various constraints are given, in which a task space synovial variable is introduced to track end position and end velocity at the same time. The numerical simulation for a planar 2DOF FFSR is performed and the results show that the model predictive controller not only realizes effective trajectory tracking but also satisfies various constraints.