ABSTRACT
Robot accuracy compensation is a process by which robot pose errors are compensated through corrections to the joint variables, based on the kinematic parameter errors that have been identified during the kinematic identification phase of a robot calibration procedure. Techniques for robot accuracy compensation can be classified into two basic categories: model-based and interpolation methods. In a model-based method, a robot kinematic model is used to describe robot pose errors, assuming that the dominant error sources are geometric errors such as joint axis misalignments and joint offsets. Calibration involves the fitting of robot model parameters to measured pose errors. Among model-based techniques, one of the simplest is the so-called Pose Redefinition method, utilizing the nominal inverse kinematic solution applied to properly redefined world coordinates of each task point. A suitable interpolation technique is applied to fit joint command correction according to positioning errors throughout a region of interest within the robot workspace.
