A method for industrial robot calibration

Presents an approach to robot-tool calibration. It is a well-known fact that industrial robots are not very accurate. Two aspects of the accuracy should be taken into account: the ability of a robot manipulator to perform accurate positioning in the task space and the ability of a robot to follow straight-line and circular trajectories. Many of the calibration approaches deal with the accurate positioning which improves the robot's capability to follow straight or circular trajectories. However, there are drawbacks in these approaches: the need for expensive measurement devices and no guarantee that the calibration model will still be correct on the manufacturing floor. Our approach concentrates on the ability of a robot to follow the technological trajectories. The approach does not require any expensive measurement techniques. The criteria of equal distances between the points in the robot space and the task space is used. The approach is demonstrated by the results of the calibration of the GMFanuc S-10 robot. The error analysis and convergence rate for this robot are also presented. The calibration can be performed directly on the manufacturing floor where the robot is used. The advantages of the approach are simplicity of the measurement setup, fast data collection and high reliability of the kinematic parameters obtained.