Development of the end-effector measurement system for a 6-axis welding robot

We develop a new measurement system which can measure position and orientation of the end-effector of a six-axis welding robot. The developed measurement system consists of five digital probes. The measurement values from the digital probes are transformed into position and orientation of the end-effector with consideration of measurement system kinematics. Calibration procedure is applied to the probe system and accuracy of the system is measured. After the calibration, the positional accuracy is observed as 0.025mm, and the orientational accuracy is 0.075°, respectively. By using the developed measurement system, we present an experimental result for controller gain tuning about a welding robot. We used Taguchi method to find optimal gain set and succeeded to suppress the fluctuation of the end-effector. The fluctuation with high frequency can be reduced by 54% after gain tuning.

[1]  Huang Jin,et al.  Industry robot and external axle calibration using Particle Swarm Optimization Algorithm , 2008, 2008 6th IEEE International Conference on Industrial Informatics.

[2]  Sun Lei,et al.  Geometry-based robot calibration method , 2004, IEEE International Conference on Robotics and Automation, 2004. Proceedings. ICRA '04. 2004.

[3]  J. K. Mills,et al.  A new approach to the position and orientation calibration of robots , 1999, Proceedings of the 1999 IEEE International Symposium on Assembly and Task Planning (ISATP'99) (Cat. No.99TH8470).

[4]  Miguel Ayala Botto,et al.  Vibration control of a very flexible manipulator system , 2005 .

[5]  Roberto H. Tsunaki,et al.  Robot-based dedicated measuring system with data redundancy for profile inspection , 2005, 2005 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[6]  Nicolas Andreff,et al.  Simplifying the kinematic calibration of parallel mechanisms using vision-based metrology , 2006, IEEE Transactions on Robotics.

[7]  Kyu-Yeul Lee,et al.  Development and application of a novel rail runner mechanism for double hull structures of ships , 2008, 2008 IEEE International Conference on Robotics and Automation.

[8]  Jin-Hwan Borm.  An Efficient Calibration Procedure of Arc Welding Robots for Offline Programming Application , 1996 .

[9]  Timothy N. Chang,et al.  Vibration control of linear robots using a piezoelectric actuator , 2003 .

[10]  Xin-Jun Liu,et al.  Determination of the Link Lengths for a Spatial 3-DOF Parallel , 2006 .

[11]  François Pierrot,et al.  Optimal design of a 6-dof parallel measurement mechanism integrated in a 3-dof parallel machine-tool , 2008, 2008 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[12]  Chris Lightcap,et al.  Improved Positioning Accuracy of the PA10-6CE Robot with Geometric and Flexibility Calibration , 2008, IEEE Transactions on Robotics.

[13]  Jeong Wan Lee.  A Systematic Gain Tuning of PID Controller Based on the Concept of Time Delay Control , 2008 .

[14]  Suguru Arimoto,et al.  Approximate Jacobian control for robots with uncertain kinematics and dynamics , 2003, IEEE Trans. Robotics Autom..

[15]  Benedito Di Giacomo,et al.  Robot measuring form errors , 2009 .

[16]  M. Yamada,et al.  A Kinematic Calibration Method for Industrial Robots Using Autonomous Visual Measurement , 2006 .

[17]  Jongwon Kim,et al.  Controller gain tuning of a simultaneous multi-axis PID control system using the Taguchi method , 2000 .

[18]  M. Tomizuka,et al.  Sensor-based controller tuning of indirect drive trains , 2008, 2008 10th IEEE International Workshop on Advanced Motion Control.

[19]  Giovanni Legnani,et al.  Calibration of a measuring robot: Experimental results on a 5 DOF structure , 2001, J. Field Robotics.