新型工业机器人结构设计及其全域刚度预估方法

Structure Design and Global Stiffness Prediction Method of a Novel Industrial Robot

设计了一种新型5自由度无间隙传动工业机器人结构,机器人机械臂采用平行四边形框架及电动缸对角驱动的桁架式结构,有利于提升机器人的综合刚度.腰部和腕部采用双电机驱动主从消隙控制消除传动间隙,臂部电动缸的滚珠丝杠副通过双丝母预紧消除反向间隙,实现机器人无间隙传动.根据机器人外部载荷和基于能量法计算的机器人末端变形建立机器人全域工作空间刚度预估模型,通过机器人的整机刚度有限元仿真结果及原理样机的实验结果验证了刚度预估模型的有效性.最后,分析了机器人的刚度分布特性并与Fanuc S900iB/400工业机器人进行了刚度比较,结果表明了本文机器人结构的刚性优势.

A novel non-backlash industrial robot with 5 degrees of freedom is designed, and the truss structure that has a parallelogram frame and an electric cylinder driven in the diagonal direction is adopted for robotic arms, which is beneficial to improve the comprehensive stiffness of the robot. In addition, the master-slave anti-backlash control method is applied to the waist and the wrist in order to eliminate the transmission backlash, and the double nuts with preload are used in the electric cylinders for the both arms in order to eliminate the reverse backlash, which makes the robot achieve non-backlash driving. A stiffness prediction model is established according to the external load and the deformations calculated based on the strain energy to estimate the robot stiffness in the global workspace, and the effectiveness of the prediction model is verified through the integral stiffness results calculated by the finite element analysis and the experiment results of the robot prototype. Finally, the stiffness distribution characteristics of the robot are analyzed, and the rigidity advantage of the robot is demonstrated by comparing the stiffness with the Fanuc S900iB/400 industrial robot.