Offline motion planning and simulation of two-robot welding coordination

Abstract

This paper focuses on the two-robot welding coordination of complex curve seam which means one robot grasp the workpiece, the other hold the torch, the two robots work on the same workpiece simultaneously. This paper builds the dual-robot coordinate system at the beginning, and three point calibration method of two robots’ relative base coordinate system is presented. After that, the non master/slave scheme is chosen for the motion planning, the non master/slave scheme sets the poses versus time function of the point u on the workpiece, and calculates the two robot end effecter trajectories through the constrained relationship matrix automatically. Moreover, downhand welding is employed which can guarantee the torch and the seam keep in good contact condition all the time during the welding. Finally, a Solidworks-SimMechanics simulation platform is established, and a simulation of curved steel pipe welding is conducted. The results of the simulation illustrate the welding process can meet the requirements of downhand welding, the joint displacement curves are smooth and continuous and no joint velocities are out of working scope.

Key words： complex curve seam; two robots; coordinated welding; motion planning

Acknowledgements

This work was partly supported by the National High Technology Research and Development Key Program of China (No. 2009AA043901–3), Breakthrough Projects Focused on Key Areas of Hong Kong and Guangdong (No. 20090101-1), Science and Technology Planning Project of Guangdong Province (No. 2010B080703004) and Industry, University and Research Project of Guangdong Province (No. 2010B090400259).

References

1 Jouaneh M K, Wang Z, Dornfeld D A. Trajectory planning for coordinated motion of a robot and a positioning table. I. Path specification. IEEE Transactions on Robotics and Automation, 1990, 6(6): 735–745

2 Chien Y P, Xue Q, Chen Y. Configuration space model of tightly coordinated two robot manipulators operating in 3-dimensional workspace. IEEE International Conference on Systems, Man and Cybernetics, 1992, 2: 1110–1115

3 Lee B H, Lee C S G. Collision-free motion planning of two robots. IEEE Transactions on Systems, Man and Cybernetics, 1987, 17(1): 21–32

4 Chang C, Chung M J, Lee B H. Collision avoidance of two general robot manipulators by minimum delay time. IEEE Transactions on Systems, Man and Cybernetics, 1994, 24(3): 517–522

5 Bien Z, Lee J. A minimum-time trajectory planning method for two robots. IEEE Transactions on Robotics and Automation, 1992, 8(3): 414–418

6 Hwang K S, Ju M Y, Chen Y J. Speed alteration strategy for multijoint robots in co-working environment. IEEE Transactions on Industrial Electronics, 2003, 50(2): 385–393

7 Shin Y S, Bien Z. A novel method of collision-free trajectory planning for two robot arms. In: Proceedings of the 1988 IEEE International Conference on Systems, Man, and Cybernetics, 1988, 2: 791–794

8 Chiddarwar S S, Babu N R. Dynamic priority allocation for conflict free coordinated manipulation of multiple agents. IEEE International Conference on Automation Science and Engineering, 2009, 549–554

9 Yeo H J, Lee S J, Suh I H, Yi B J, Oh S R. External force control using cooperating two arms with general kinematic structures. 5th IEEE International Workshop on Robot and Human Communication, 1996, 388–394

10 Tao J M, Luh J Y S, Zheng Y F. Compliant coordination control of two moving industrial robots. IEEE Transactions on Robotics and Automation, 1990, 6(3): 322–330

11 Yeo H J, Suh II H, Yi B J, Oh S R. A single closed-loop kinematic chain approach for a hybrid control of two cooperating arms with a passive joint: an application to sawing task. IEEE Transactions on Robotics and Automation, 1999, 15(1): 141–151

12 Kraus W J, McCarragher B J. Hybrid position/force coordination for dual-arm manipulation of flexible materials. In: Proceedings of the 1997 IEEE/RSJ International Conference on Intelligent Robots and Systems, 1997, 1: 202–207

13 Cho H K, Kim J, Yea S H. Task-oriented path planning for the coordinated motion of two manipulators. In: Proceedings of the 6th IEEE International Workshop on Robot and Human Communication, 1997, 46–50

14 Kasagami F, Ishimatsu T, Watanabe S, Izawa A, Koujina Y. Coordinated motion of arc welding robots using parallel data processor. In: Proceedings of the 1992 International Conference on Power Electronics and Motion Control, 1992, 2: 656–663

15 Tang C Q, Meng Z D. Realization of coordinated motion of arc-robot and positioned. Industrial Control Computer, 2008, 21(1): 47–49 (in Chinese)

16 Craig J J. Introduction to Robotics: Mechanics and Control. 3rd ed. Saddle River: Prentice Hall, 2004

17 Wu L, Cui K, Chen S B. Redundancy coordination of multiple robotic devices for welding through genetic algorithm. Robotica, 2000, 18(6): 669–676

18 Fernandez K, Cook E. A generalized method for automatic downhand and wirefeed control of a welding robot and positioned. NASA technical paper 2807, 1988