Reducing time cost of polishing process is a major issue in metallic mold manufacturing. The feed rate, i.e., tangential velocity, of a polishing robot is generally limited to maintain stable contact with workpieces having a large curvature. We propose a feed rate generator using fuzzy reasoning for polishing robots that regulates the feed rate along free-formed surfaces appropriately. The smaller the curvature of the model designed by a 3D CAD, the larger the distance between two adjacent cutter location data (CL data) steps generated by the main processor of CAM. Therefore, given curvature results in acquiring the distance between two adjacent steps of CL data. We also propose a hybrid position/force controller with the feed rate generator enabling the robot to conduct polishing efficiently. Experiments show promising results.

1. [1] F. Nagata, K. Watanabe, and K. Izumi, “Furniture Polishing Robot Using a Trajectory Generator Based on Cutter Location Data,” Procs. of IEEE International Conference on Robotics and Automation, pp. 319-324, 2001.
2. [2] F. Nagata, K. Watanabe, Y. Fujimoto et al., “3D Machining and Finishing System for New Designed Furniture,” Procs. of the 2002 Japan-USA Symposium on Flexible Automation, pp. 1239-1245, 2002.
3. [3] F. Ozaki, M. Jinno, T. Yoshimi et al., “Force Controlled Finishing Robot System with a Task-Directed Robot Language,” Journal of Robotics and Mechatronics, Vol.7, No.5, pp. 383-388, 1995.
4. [4] D. M. Gorinevsky, A. M. Formalsky, and A. YU. Schneider, “Force Control of Robotics Systems,” CRC Press, 1997.
5. [5] F. Pfeiffer, H. Bremer, and J. Figueiredo, “Surface Polishing with Flexible Link Manipulators,” European Journal of Mechanics, A/Solids, 15, 1, pp. 137-153, 1996.
6. [6] Y. Takeuchi, D. Ge, and N. Asakawa, “Automated Polishing Process with a Human-like Dexterous Robot,” Procs. of IEEE International Conference Robotics and Automation, pp. 950-956, 1993.
7. [7] P. R. Pagilla, and B. Yu, “Robotic Surface Finishing Processes: Modeling, Control, and Experiments,” ASME Journal of Dynamic Systems, Measurement, and Control, 123, pp. 93-102, 2001.
8. [8] F. Nagata, Y. Kusumoto, K. Watanabe et al., “Development of a Hybrid Motion/Force Control Strategy for Ball End Abrasive Tools and Its Application to Polishing Robots for PET Bottle Molds,” Journal of the Japan Society for Precision Engineering, 70, 1, pp. 59-64, 2004 (in Japanese).
9. [9] F. Nagata, K. Watanabe, Y. Kusumoto et al., “Generation of Normalized Tool Vector from 3-Axis CL Data and Its Application to a Mold Polishing Robot,” Procs. of IEEE/RSJ International Conference on Intelligent Robots and Systems, pp. 3971-3976, 2004.
10. [10] J. J. Craig, “Introduction to ROBOTICS –Mechanics and Control Second Edition–,” Addison Wesley Publishing Co., 1989.