Base frame calibration for coordinated industrial robots

To solve the problem of base frame calibration for coordinated multi-robot system, a new method is proposed in this paper. It is carried out through a series of ‘‘handclasp’’ manipulations between two coordinated robots, then a preliminary result can be reached by the calibrating equation. After that, in order tomake sure that the calibrated rotationmatrix is orthonormal, an optimal estimation of the relative rotation between the base frames of coordinatedmanipulators is solved out under the criterion of optimal Frobenius norm approximation. By the quaternion representation for rotation matrix and the Lagrange Multiplier method, an orthonormal matrix can be reached which is just the unknown calibrating result for base frames of the coordinated robots. Simulation and experiment results have verified the validity and effectiveness of the proposed method. © 2011 Elsevier B.V. All rights reserved.