Towards quasi-static kinematic calibration of serial articulated industrial manipulators

Abstract

Research on kinematic calibration of industrial robots has focused on applying different measurement instruments into open- and closed-loop approaches and optimising calibration configurations through various cost functions. Such ways are either expensive or time-consuming. This work presents essential steps towards realising quasi-static kinematic calibration of industrial manipulators. This approach employs measurement data from a quasi-static measurement instead of a static one to identify the model parameters and has the potential of considerably reducing the measurement phase time during calibration. The focus lies on the technological challenges needed to achieve a successful quasi-static kinematic calibration, such as the trajectory generation, the measurement instrument and the controller data synchronisation. A case study assess the data obtained from a quasi-static kinematic measurement with a robot/tracker configuration of 100 mm/s and 100 Hz. The average positioning accuracy is similar for the static and the quasi-static measurement. The time for the quasi-static trajectory is reduced to almost one-third of the static trajectory time without considering the setup time.