A method for kinematic calibration is presented, which directly estimates the Jacobian matrix from measurements and extracts the kinematic parameters from the Jacobian exactly and without iteration. Two different experimental approaches are presented for measuring the Jacobian. In the first approach, a six degree-of-freedom manipulator is rigidly attached to the environmental at its endpoint, in one pose only. Joint torques are systematically exerted and the resulting endpoint forces and torques are measured. In the second approach, a manipulator attains different motions through the same endpoint location, and the joint velocities are related to measured endpoint linear and angular velocities. Simulations are presented to verify the method.>

The authors present a kinematic calibration method that does not require endpoint measurements or precision points. By forming manipulators into mobile closed kinematic chains, it is shown that consistency conditions in the kinematic loop closure equations are adequate to calibrate the manipulator from joint angle readings alone. This closed-loop kinematic calibration method is an adaptation of an iterative least-squares algorithm used in calibrating open-chain manipulators. Example tasks include a fixed endpoint (zero-degree-of-freedom (DOF) task), the opening of a door (one-DOF task), and point contact (three-DOF task).>

An approach to identifying the kinematic models of manipulators and their task geometry is presented. Starting with the observation that in many tasks manipulators naturally form mobile closed kinematic chains, it is shown that these closed loops can be identified by an iterative least-squares algorithm similar to that used in calibrating open chain manipulators. By merely using joint angle readings and self motions, consistency conditions can be utilized to identify the kinematic parameters. While the task of a robot opening a door is studied in detail, the method readily generalizes to a large class of robot tasks. Simulations are presented to accompany the analysis.>