Direct teaching on industrial robot without force sensor

In order to improve the efficiency of robot teach, this paper presents a direct teaching control strategy for industrial robot with no need for multidimensional force/torque sensor. The kinematics and statics of a specific six-DOF robot are analyzed, and the joints' torque is educed. In the direct teaching process, the servo motors of the robot joints operate in torque/position hybrid mode. Each joint is in dynamic balance status under the corporate impacts of inaccurate motor torque, virtual friction, viscous damping, robot weight, tool weight, and manual drag force. The operator drags the robot/joints easily, and high efficient teach is achieved.