Hostname: page-component-77c89778f8-cnmwb Total loading time: 0 Render date: 2024-07-24T20:57:17.688Z Has data issue: false hasContentIssue false

Contact mechanics for soft robotic fingers: modeling and experimentation

Published online by Cambridge University Press:  31 October 2012

Sadeq H. Bakhy
Affiliation:
Department of Machines and Equipments Engineering, University of Technology, Baghdad, Iraq
Shaker S. Hassan
Affiliation:
Department of Machines and Equipments Engineering, University of Technology, Baghdad, Iraq
Somer M. Nacy*
Affiliation:
Department of Manufacturing Operations Engineering, Al-Khwarizmi College of Engineering, Baghdad, Iraq
K. Dermitzakis
Affiliation:
Artificial Intelligence Laboratory, Department of Informatics, University of Zurich, Zurich, Switzerland
Alejandro Hernandez Arieta
Affiliation:
Artificial Intelligence Laboratory, Department of Informatics, University of Zurich, Zurich, Switzerland
*
*Corresponding author. E-mail: somernacy@gmail.com

Summary

Human fingers possess mechanical characteristics, which enable them to manipulate objects. In robotics, the study of soft fingertip materials for manipulation has been going on for a while; however, almost all previous researches have been carried on hemispherical shapes whereas this study concentrates on the use of hemicylindrical shapes. These shapes were found to be more resistant to elastic deformations for the same materials. The purpose of this work is to generate a modified nonlinear contact-mechanics theory for modeling soft fingertips, which is proposed as a power-law equation. The contact area of a hemicylindrical soft fingertip is proportional to the normal force raised to the power of γcy, which ranges from 0 to 1/2. Subsuming the Timoshenko and Goodier (S. P. Timoshenko and J. N. Goodier, Theory of Elasticity, 3rd ed. (McGraw-Hill, New York, 1970) pp. 414–420) linear contact theory for cylinders confirms the proposed power equation. We applied a weighted least-squares curve fitting to analyze the experimental data for different types of silicone (RTV 23, RTV 1701, and RTV 240). Our experimental results supported the proposed theoretical prediction. Results for human fingers and hemispherical soft fingers were also compared.

Type
Articles
Copyright
Copyright © Cambridge University Press 2012 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1.Mason, M. T. and Salisbury, J. K., Robot Hands and the Mechanics of Manipulation (MIT Press, Cambridge, MA, 1985).Google Scholar
2.Hertz, H., “On the Contact of Rigid Elastic Solids and on Hardness,” Chapter 6, In: Assorted Papers (New York, Macmillan, 1882) [Quoted in K. L. Johnson, Contact Mechanics (Cambridge University Press, Cambridge, UK, 1985)].Google Scholar
3.Timoshenko, S. P. and Goodier, J. N., Theory of Elasticity, 3rd ed. (McGraw-Hill, New York, 1970) pp. 414420.Google Scholar
4.Schallamach, A., “The load dependence of rubber friction,” Proc. Physical Soc. 65 (9), 657661 (1969).CrossRefGoogle Scholar
5.Cutkosky, M. R., Jordain, J. M. and Wright, P. K., “Skin Materials for Robotic Fingers,” In: Proceedings of the 1987 IEEE International Conference on Robot and Automat, Los Alamitos, CA (1987) pp. 16491654.CrossRefGoogle Scholar
6.Han, H.-Y., Shimada, A. and Kawamura, S.Analysis of Friction on Human Fingers and Design of Artificial Finger,” In: Proceedings of the 1996 IEEE International Conference on Robot and Automat, Washington, DC (1996), pp. 30613066.Google Scholar
7.Xydas, N. and Kao, I., “Modeling of Contact Mechanics with Experimental Results for Soft Fingers,” In: Proceedings of the 1998 IEEE/RSJ International Conference on Intelligent Robots and Systems, Victoria, BC, Canada (Oct. 1998) pp. 488493.Google Scholar
8.Xydas, N. and Kao, I., “Modeling of contact mechanics and friction limit surface for soft fingers with experimental results,” Int. J. Robot, Res. 18 (9), 941950 (Sep. 1999).CrossRefGoogle Scholar
9.Kao, I. and Yang, F., “Stiffness and contact mechanics for soft fingers in grasping and manipulation,” IEEE Trans. Robot. Autom. 20 (1) (Feb. 2004) pp. 132135.CrossRefGoogle Scholar
10.Park, K.-H., Kim, B.-H. and Hirai, S., “Development of a Soft-Fingertip and Its Modeling Based on Force Distribution,” In: Proceedings of the 2003 IEEE.International Conference on Robotics & Automation, Taipei, Taiwan (Sep. 14–19, 2003) pp. 1419.Google Scholar
11.Inoue, T. and Hirai, S., “Elastic model of deformable fingertip for soft-fingered manipulation,” IEEE Trans. Robot. 22 (6), 12731279 (Dec. 2006).CrossRefGoogle Scholar
12.Hosoda, K., Tadaa, Y. and Asada, M., “Anthropomorphic robotic soft fingertip with randomly distributed receptors,” Robot. Auton. Syst. 54, 104109 (2006).CrossRefGoogle Scholar
13.Ficuciello, F., “Modelling and Control for Soft Finger Manipulation and Human-Robot Interaction,” Ph.D. Thesis (Faculty of Engineering, University of Naples Federico II, Italy, 2010).Google Scholar
14.Ho, V. A. and Hirai, S., “Understanding Slip Perception of Soft Fingertips by Modeling and Simulating Stick-Slip Phenomenon,” In: Proceedings of the Robotics: Science and Systems VII Conference, University of Southern California, LA, USA (2011), available at: http://robotics.usc.edu/rss2011/.Google Scholar
15.Hutchinson, J. W., “Fundamentals of the phenomenological theory of nonlinear fracture mechanics,” Trans. ASME, J. Appl. Mech. 50, 10421051 (1983).CrossRefGoogle Scholar
16.Suter-Kunststoffeag, Manual of Swiss-Composite Group. www.swiss-compsite.ch 2009.Google Scholar
17.Manual of Zwick Tensile Tester, EGR 281 (winter 2007), available at: http://www.zwick.co.uk/en.html.Google Scholar
18.Yang, W. Y., Cao, W., Chung, T. S. and Morris, J., Applied Numerical Methods Using Matlab (John Wiley, Hoboken, NJ, 2005).CrossRefGoogle Scholar
19.Lin, Q., Burdick, J. W. and Rimon, E., “A stiffness-based quality measure for compliant grasps and fixtures,” IEEE Trans. Robot. Automat. 16, 675688 (Dec. 2000).Google Scholar
20.Kinoshita, H., Backstrom, L., Flanagan, J. R. and Johansson, R.Tangential torque effects on the control of grip forces when holding objects with precision grip,” J. Neurophys. 78 (3), 16191630 (1997).CrossRefGoogle ScholarPubMed
21.Fung, Y. C.Biomechanics, Medical Properties of Living Tissues, 2nd ed. (Springer-Verlag, New York, 1993).Google Scholar
22.Schallamach, A., “The load dependence of rubber friction,” Proc. Physical Soc. 65 (9), 657661 (1969).CrossRefGoogle Scholar