空间双柔性机械臂刚-柔耦合建模及定标误差分析

Rigid-flexible coupling modeling and calibration error analysis of the space double flexible manipulators

为研究空间多自由度机械臂在作大范围运动时臂杆柔性和关节柔性对末端定标精度的影响,考虑柔性臂杆的横/侧向弯曲变形所引起轴向伸缩的二次耦合项,采用计入集中质量的转子扭簧模型描述关节的柔性效应;提出了基于臂杆柔性的D-H参数法,递推出空间机械臂的柔性机构运动方程;应用Hamilton原理建立了空间双柔机械臂的一次近似刚-柔耦合动力学方程。对空间六关节双柔机械臂末端定标误差进行仿真,结果表明:臂杆的柔性和关节的柔性在空间机械臂的大范围运动中是相互耦合的;在工程应用中,需要将抓取目标设定在机械臂定标误差较小的方向上,以提高抓捕和操作的成功性。

To study the impact of the arm and joint flexibility on the terminal calibration precision when the space multi-degrees of freedom manipulator did spatial motion in a large range,considering the secondary coupling term of axial stretching caused by the flexible arm horizontal/lateral bending deformation,a D-H method was proposed based on flexible arm by using a rotor torsion-spring model including lumped mass to describe the flexible effect of joints.The flexible mechanism movement equation of space manipulator was proposed.The first approximation rigid-flexible coupling dynamics equations of space double flexible manipulator was established by using the Hamilton principle.The simulation of the terminal calibration error of the space six joints double flexible manipulator was carried out.The results show that：arm and joint flexibility are coupled when the space manipulator is in a large range movement.To improve the success of the capture and operation,the fetchingtargets should be set in the direction with a smaller calibration error of manipulators in engineering applications.