โดย นายธนะธร พ่อค้า 457 03433 21 อาจารย์ที่ปรึกษา ดร. อรรถวิทย์ สุดแสง

1. Regrasp Planning for a 4-Fingered Hand Manipulating a Polygonการวางแผนการจับด้วยมือที่มี 4 นิ้วเพื่อทำการจัดการกับวัตถุหลายด้าน โดย นายธนะธร พ่อค้า 457 03433 21 อาจารย์ที่ปรึกษา ดร. อรรถวิทย์ สุดแสง

2. Outline • Introduction • Related works • Background • Thesis

3. Introduction • Why regrasp?

4. Introduction • Properties for stable grasp Equilibrium Force closure

5. Introduction • Computing a sequence of finger repositioning • Problem definition • Polygonal object • 4-fingered hand

6. 3 1 4 2 2 Introduction Finger switching Finger aligning

7. Introduction • New approach • Switching graph • Graph search FC grasps Finger switching FC grasps Finger switching FC grasps Finger switching FC grasps Finger switching FC grasps FC grasps Finger switching

8. Related works • Dexterous manipulation • Task planning • Grasp positions • Dynamics, kinematics, force

9. Related works • Robot hands • S. Jacobsen, E. Iversen, D. Knutti, R. Johnson, and K. Bigger. Design of the Utah/MIT Dextrous Hand. IEEE Int. Conf. on Robotics and Automation, pp. 96-102, 1986. • J. Butterfass, M. Grebenstein, H. Liu, and G. Hirzinger. DLR-Hand II: Next Generation of a Dextrous Robot Hand.IEEE Int. Conf. on Robotics and Automation, Seoul, 2001. • C.S. Lovchik and M.A. Diftler. 1999. The Robonaut hand: a dexterous robot hand for space.IEEE Int. Conf. on Robotics and Automation, pp. 907-912, 1999. • I. Yamano, K. Takemura, and T. Maeno. Development of a Robot Finger for Five-fingered Hand using Ultrasonic Motors. IEEE/RSJ Int. Conf. on Intelligent Robots and Systems,2003.

11. Related works • Grasping • V-D. Nguyen. Construction force-closure grasps, 1988. • 2-fingered force closure grasp • Independent contact region • J. Ponce and B. Faverjon. On computing three-finger force-closure grasps of polygonal objects, 1995. • 2 and 3-fingered force closure grasp • Independent contact region

12. Related works • Dexterous manipulation & regrasping • J.W. Hong, G. Lafferriere, B. Mishra, and X.L. Tang. Fine manipulation with multifinger hand,1990. • Regrasping with 3 and 4 fingers • Finger gaiting • Curved object • L. Han and J.C. Trinkle. Dextrous manipulation by rolling and finger gaiting, 1998. • General framework for dexterous manipulation • Finger rolling and gaiting • Spherical object

13. Related works • Dexterous manipulation & regrasping • T. Omata and K. Nagata. Planning reorientation of an object with a multifingered hand, 1994. • 4-fingered hand • Polygonal object • Search tree • Linear and non-linear programming

14. Grasping Stable grasp Finger & contact Equilibrium Force closure Friction cone 3-Fingered grasp Necessary & sufficient Positively span  - Positively span Sufficient Concurrent grasp

15. ftx ftx fn fn fn mz fty Grasp and friction • Hard fingers • Coulomb friction at contact points (b) (c) (a)

16. Grasp and friction • f < |n| •  = tan-1 () • Force at contact points lie in friction cone n 

17. Equilibrium and force closure Equilibrium grasp Force closure grasp ? Equilibrium grasp Force closure grasp

18. Condition for grasping • A set of vectors positively span nif any vector in n can be written as a positive combination of the given vectors. u1 u3 u2

19. Condition of grasping • Necessary and sufficient condition u2 u1 u3  u1 u2 u3 three-finger equilibrium grasp

20. Condition for grasping • - positively span 2 • LetCi(i = 1,2,3) be the cones centered onaiwith half-angle. We say that the three vectors ai (i = 1,2,3)  - positively span 2when any triple of vectorsviCi(i = 1,2,3) positively span2. a1 C1   a2 C3 C2 a3

21. Condition for grasping • Sufficient condition a1 C1   a3  a1 a2 a2 C3 C2 a3 “concurrent grasp” three-finger equilibrium grasp

22. Thesis • New approach • Switching graph • Finger switching • Finger aligning

23. Regrasping Finger aligning Finger switching Switching graph Node Edge Set of concurrent grasp “Focus cell” Overlapping Focus cell Represent a set of grasps by a point in the plane

24. Switching graph • Point in the plan can represent a set of grasps. • Independent contact region Ec Eb Ec Ec Eb Eb xc xb . x0 x0 Ea xa Ea Ea (a) (b)

25. Eb Ec Ea Switching graph • Focus cell Ea

26. b c a d Switching graph a,b,c a,b,d

27. Scope • Regrasp Planning for a 4-Fingered Hand Manipulating a Polygon • Concurrent grasp • Switching graph • Optional scope • Two-finger force closure grasp • Parallel grasp

28. Completed works • Study works in grasping and regrasping. • Switching graph for concurrent grasp. • Implement in C++ with LEDA.

29. Completed works • Publication • A. Sudsang and T. Phoka. Regrasp planning for a 4-fingered hand manipulating a polygon. IEEE Int. Conf. on Robotics and Automation,pp. 2671 – 2676. Taipei, 2003. • T. Phoka and A. Sudsang. Regrasp planning for a 5-fingered hand manipulating a polyhedron. IEEE/RSJ Int. Conf. on Intelligent Robots and Systems, pp. 3674 – 3679. Las Vegas, 2003.

30. Ongoing works • Design the switching grasp • Two-finger force closure grasp • Parallel grasp • Experiment • Writing a thesis

31. Benefit • New approach for regrasping

32. Thank you