Brief paper: Adaptive inverse dynamics control of robots with uncertain kinematics and dynamics
Automatica (Journal of IFAC)
Robot calibration by observing a virtual fixed point
ROBIO'09 Proceedings of the 2009 international conference on Robotics and biomimetics
A novel XY-Theta precision table and a geometric procedure for its kinematic calibration
Robotics and Computer-Integrated Manufacturing
Online robot calibration based on vision measurement
Robotics and Computer-Integrated Manufacturing
| Hi-index | 0.00 |
This paper describes an industrial robot calibration algorithm called the virtual closed kinematic chain method. Current robot kinematic calibration methods use measurements of position and orientation of the end effector. The accuracy of these measurements is limited by the resolution of the measuring equipment. In the proposed method, a laser pointer tool, attached to the robot's end effector, aims at a constant but unknown location on a fixed object, effectively creating a virtual 7 DOFs closed kinematic chain. As a result, small variations in position and orientation of the end effector are magnified on the distant object. Hence, the resolution of observations is improved, increasing the accuracy of joint angle measurements that are required to calibrate the robot. The method is verified using both simulation and real experiments. It is also shown in simulation that the method can be automated by a feedback system that can be implemented in real time. The accuracy of the robot after using the proposed calibration procedure is measured by aiming at an arbitrary fixed point and measuring the mean and standard deviation of the radius of spread of the projected points. The mean and standard deviation of the radius of spread were improved from 5.64 and 1.89 mm to 1.05 and 0.587 mm, respectively.