Practical error compensation for use in off-line programming of robots

Off-line generated target poses used to direct the task of a robot result in position and orientation inaccuracies in the actual robot. These inaccuracies stem from dimensional differences between the robot-model used for programming and control, and the actual robot. Errors in the robot-model can be compensated using calibrated robot-model results which closely estimate actual kinematic and mechanical features of the robot. Presented in this paper is a practical error compensation procedure developed in combination with a tested robot calibration routine at the IPK. Using special measurement tools and mathematical procedures, robot parameters can be completely identified from the robot-base coordinate frame to a coordinate frame attached to the robot's tool-mounting flange. Error compensation occurs outside the robot controller so not to disturb control algorithms and parameters.