Calibration of parallel kinematic structures: Overview, classification and comparison

Kinematic calibration has been shown to be an efficient method to improve the absolute accuracy of industrial robots. Originally developed for serial manipulators a number of methods have been adopted to the class of parallel robots. The most common calibration techniques rely on external measurement systems, which are expensive, time consuming and require highly skilled operators. Newest developments focus on autonomous self-calibration techniques which allow for easy calibration if required, without particular knowledge about robot calibration. Some promising approaches exist, especially for parallel robots. This paper classifies the different robot calibration schemes, presents some innovative calibration ideas and compares them to existing strategies. Prospects as well as problems of the solutions are discussed.