提高机器人结构刚度及关节精度的方法

Approaches for Improving Structure Stiffness and Joint Accuracy of Robots

传统工业机器人具有工作空间大、结构紧凑、灵活性好等优势,已由早期的物料搬运、点焊、喷涂等操作逐渐应用于制孔、铣削、磨削等高精度金属切削加工领域。然而,工业机器人相比于机床刚性较弱,金属切削过程中的切削载荷使机器人末端刀具偏离期望的加工轨迹,外部激振力极易引发机器人颤振,影响机器人加工精度;此外,关节减速器内部齿隙也会严重影响机器人精度。对采用机器人刚度优化、机器人加工误差补偿、机器人传动间隙补偿、机器人加工振动抑制等提高机器人精度方法的研究现状做了总结,提出了两种提高机器人精度的机器人结构改进设计,分别为基于双电机驱动的无间隙传动机器人结构和基于四边形机构的高刚性机械臂结构,并对新型机器人的结构特点进行了阐述。

Traditional industrial robots have advantages of large workspace, compact structure, and good flexibility,and have been gradually used in the high precision metal cutting fields of drilling, milling and grinding instead of materialhandling, spot welding, spray painting and other operations. However, the stiffness of industrial robots is weak comparedwith metal cutting machine tools. The weak stiffness of the robot makes the tool deviate from the desired machining trajectory,and makes the robot easy to chatter when it is subjected to the external excitation force, which affects the machiningaccuracy of the robot; in addition, the internal backlash of the joint reducers is also one of the most important factorsaffecting the machining accuracy of the robot. The research status of robot stiffness optimization, robot machining errorcompensation, backlash compensation of the robot and vibration suppression of the robot are summarized. Two kinds ofrobot structure improvement design are proposed to increase the accuracy of the robot, the robot structure of non-backlashdriving based on dual-motor drive and the high stiffness robotic arm based on parallelogram mechanisms are respectivelydescribed. And the structural characteristics of the robot are elaborated.