A force/moment direction sensor and its use for human-robot interface in robot teaching

The teach pendant is the most widely used means of robot teaching at present. Despite the difficulties of using the motion command buttons on the teach pendant, it is an economical, robust and effective device for robot teaching tasks. This paper presents the development of a force/moment direction sensor named COSMO (COntact Sensor MOdule) that can improve teach pendant-based robot teaching. An intuitive robot teaching experiment with a six-axis commercial robot using the sensor is described, where the operator holds the sensor in his hand, and moves the robot by pushing, pulling and hoisting the sensor in the direction of the desired motion. No prior knowledge of the tool or world coordinate system is required. The function of the COSMO sensor is to detect the presence of forces and moments about the principal axes of the sensor coordinate system. The transducer used in the sensor is a micro-switch, and this intuitive robot teaching method can be implemented at very low cost