基于力觉伺服轨迹规划的磨抛工业机器人曲面跟踪控制研究

Research on Surface Tracking Control of Grinding and Polishing Robot Based on Force Sense Servo Trajectory Planning

为进一步提升工业机器人磨抛自由曲面时的轨迹跟踪控制技术,设计一种自由曲面磨抛轨迹自动生成方法。生成工件的STL模型,利用Bezier三角曲面拟合方法得到工件的拟合曲面,基于螺旋式磨抛轨迹实现自由曲面轨迹规划;利用等参数法和轨迹偏置的方法生成全部的轨迹,根据曲线路径曲率的变化,自适应调节控制点的间距,避免了曲线偏置时的干涉问题;在工业机器人腕处安装6D力传感器,利用力/位置混合控制方法对工业机器人进行运动轨迹跟踪控制。通过实验平台测试,验证该方法能够有效地进行曲面跟踪控制。

To upgrade the surface tracking control technology of grinding and polishing robot,an automatic generation method of grinding and polishing trajectory of free-form surface is proposed.The STL model of the workpiece is generated,and Bezier triangle surface fitting method is applied to abtain the fitting surface of the workpiece.Based on spiral grinding and polishing trajectory,free suface trajectory planning is realized.All the trajectories are generated by Isoparameter method and trajectory offset method.According to the variations of curve path rates,adaptive adjustment on control point spacing is made to avoid interferences during curve offset.By installing a 6D force sensor at the wrist of the industrial robot,the motion control of the robot is carried out in combination with a force/position hybrid control method.The results from the experimental platform verify the effectiveness of the proposed method in surface tracking control.