基于干扰观测器的柔性关节空间机器人退步自适应控制

研究了载体位置、姿态均不受控的情况下,系统参数不确定的柔性关节空间机器人轨迹跟踪的控制问题.结合系统动量、动量矩守恒关系,利用拉格朗日法推导出系统的动力学模型.为减小系统柔性关节对系统控制精度的影响,采用关节柔性补偿器来等效降低系统关节的柔性.再借助奇异摄动法,针对系统参数不确定的情况,设计了柔性关节空间机器人基于干扰观测器的退步自适应滑模控制方案.该方案不需要对系统惯性参数进行线性化处理,控制器结构简单,且实现了空间机器人期望轨迹的精确跟踪控制.通过平面两杆空间机器人的数值仿真证明了该方法的有效性.

ADAPTIVE BACK-STEPPING CONTROL BASED ON DISTURBANCE OBSERVER FOR SPACE ROBOT WITH FLEXIBLE JOINT

The trajectory tracking control of a space robot system with flexible joints in the joint space with uncontrolled base and uncertain parameters is discussed. From the conservations of the linear and angular momentum, the dynamic equations of the system are derived by the Lagrange method. A joint flexible com-pensation is used to reduce the system’s joint flexibility in order to reduce the effect of the flexible joints on the system’s control precision. As for the uncertain parameters, the singular perturbation method is used to design an adaptive back-stepping sliding mode control with the disturbance observation to track the desired trajectory in the joint space. With the proposed scheme, it is not required to linearly parameterize the dynamic equation of the system, and the controller is simple and achieves the accurate tracking control of the space robot joint movement. A planar space robot with two links is simulated to verity the feasibility of the proposed control scheme.