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

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.