基于刚度控制的六轴工业机器人零力跟踪模型

Force-free Control Model for Six Axis Industrial Robot Based on Stiffness Control

针对传统的通过操作示教盒移动六轴工业机器人到达指定位置效率低、过程复杂的问题,以Ethernet作为通信总线,将嵌入式系统引入六轴工业机器人的顺应性跟踪控制(零力跟踪)中,提出了一种基于刚度控制的六轴工业机器人零力跟踪模型.在该模型中,将六维力传感器上的力信号进行解耦与坐标变换,从而获得机器人末端的6个力的大小信息.通过刚度矩阵计算出输入位置控制器的偏移量,同时设计了一种轨迹预测算法来确定6个力的信息及下一个目标点的方向.最后,机器人根据运动学方程的逆解,调整相应的位姿.实验结果表明:该机器人末端分别在3个不同方向的牵引力的作用下,能平滑而快速地经过预定的轨迹,为直接示教系统中的顺应性跟踪控制提供了方法.

To solve problems of the efficiency-low and process-complex of the traditional operation by operating the teaching box to move the six axis industrial robot to the specified location. EtherNet was taken as the communication bus,an embedded system was introduced into the compliant tracking control （ force- free tracking） of a six axis industrial robot and a force-free tracking model based on stiffness control of the six axis industrial robot was proposed. In the model,in order to get the size information of six-dimensional force of the robotic end, the force signal of the six-dimensional force sensor was decoupled and its coordinate was transformed. Meanwhile a trajectory prediction algorithm was designed to confirm the information of the six-dimensional and the direction of the next target by the offset of the input position controller which was calculated by the stiffness matrix. Finally,the robot adjusted its position and attitude according to the inverse solution of kinematics equation. The experimental results show that the robotic end can pass the scheduled orbit smoothly and quickly under the action of three differently directional tractions, provided a method for compliant tracking control of direct teaching system.