Modelling closed-loop mechanisms in robots for purposes of calibration

A method for modelling the significant parameters of closed-loop mechanisms in robots for purposes of calibration is presented. Non-linear kinematic and mechanical characteristics of the closed-loop mechanisms are modelled in such a way that they can be integrated into an open-loop manipulator model and identified. This integration is accomplished through a separation of the spatial open-loop manipulator (defining the kinematic model) and its joint-actuating mechanisms or actuator models which can be non-linear in case of closed-loop mechanisms. Identifiability of model parameters (including elasticity) is analysed and calibration results are presented.