Proceedings of the
9th International Conference of Asian Society for Precision Engineering and Nanotechnology (ASPEN2022)
15 – 18 November 2022, Singapore

An Add-On Pose Measurement Device for Rapid Robot Teaching

Wei Lin1,a, Ngoc Chi Nam Doan1, Haiyue Zhu1 and Xiong Li2

1Singapore Institute of Manufacturing Technology, Agency for Science, Technology and Research, Singapore 638075

2Tencent Robotics X Lab, Tencent Technology (Shenzhen) Co. Ltd, Shenzhen, China


Recent advancement of collaborative robotics has broadened the applications of robots in manufacturing and service sectors. Apart from the fact that collaborative robots allow the operator to share their workspace without fences, the ease of robot teaching using walk-through method is a big draw. However, the walk-through method has several weaknesses. The major one is that the power-assistive motion control limits the speed of the robot during teaching. As a result, such teaching method is too slow for the robots to be used in high-mix and low-volume production. This paper presents a novel robot path teaching method that can acquire the robot tool paths quickly. Using a device called Robot Teach Handle (RTH) attached at the robot wrist, operator holds the device and moves its end-effector along a desired path without moving the robot itself. The device is a serial linkage system with 7 passive rotary joints that connect a probe and a base with lightweight links. The base can be rigidly attached to the link of a typical industrial robot. The pose of the probe is obtained from the joint angles of the RTH using forward kinematics. It is then transformed to the robot base coordinate system providing the desired robot end-effector pose for precision process automation. The major advantage of the robot teaching method is that the robot path teaching time is much shorter than the comparable method of walk-through teaching. In realizing new teaching method, we have developed several key capabilities. They include the error compensation for 7- joints serial-linked mechanism, calibration algorithm for localization of the RTH mounted on the host robot and high-precision serial mechanism in particular the rotary joints. In this paper we will present the methods for achieving high accuracy pose measurements of the RTH probe, in terms of the applications of precision machine design principles and the methods for reducing the systematic errors in the joints and overall linkage system.

Keywords: Industrial robots programming, Manipulator calibration, Precision machine design

PDF Download