Kinematic model and metrology system for modular robot calibration

In this paper, a metrology method is presented to calibrate modular robots. It is to perform metrology at the modular level and measure the kinematic parameters of each module so that the acquired information may be used for obtaining an "as built" model every time either a modular robot is reconfigured or maintenance has been made. Based on the product-of-exponentials formula and the modified dyad kinematics, two calibration models with or without the interface error compensation are proposed. The success of this method is based on two key technologies; the first key is an accurate and interchangeable standardized interface and the second key is to develop a state-of-the-art 3-D metrology system which is accurate, flexible, and easy to use. This paper presents these topics with kinematic models for modular robot calibration.