Hostname: page-component-586b7cd67f-2brh9 Total loading time: 0 Render date: 2024-11-22T08:33:44.775Z Has data issue: false hasContentIssue false

Effect of compliance location in series elastic actuators

Published online by Cambridge University Press:  07 June 2013

Jonathon W. Sensinger*
Affiliation:
Rehabilitation Institute of Chicago, Center for Bionic Medicine, Chicago, Illinois, USA Physical Medicine and Rehabilitation/Mechanical Engineering, Northwestern University, Chicago, Illinois, USA
Lawrence E. Burkart
Affiliation:
Kyocera, San Diego, California, USA
Gill A. Pratt
Affiliation:
Franklin W. Olin College of Engineering, Needham, Massachusetts, USA Defense Advanced Research Projects Agency, Arlington, Virginia, USA
Richard F. ff. Weir
Affiliation:
Department of Bioengineering, University of Colorado, Denver, Colorado, USA VA Eastern Colorado Health Care System, Aurora, Colorado, USA
*
*Corresponding author. E-mail: [email protected]

Summary

Series elastic actuators have beneficial properties for some robot applications. Several recent implementations contain alternative placements of the compliant element to improve instrumentation design. We use a class 1 versus class 2 lever model and energy-port methods to demonstrate in this paper that these alternative placements should still be classified as series elastic actuators. We also note that the compliance of proximal series elastic actuators is reflected by an augmented gear ratio dependent on the nominal gear ratio, which is significant for small gear ratios and approaches unity for large gear ratios. This reflected compliance is shown to differ depending on the sign of the gear ratio. We demonstrate that although the reflected compliance is only marginally influenced by the magnitude of the gear ratio, there are several notable differences, particularly for small gear ratios.

Type
Articles
Copyright
Copyright © Cambridge University Press 2013 

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.Pratt, G. A., Williamson, M. M., Dillworth, P., Pratt, J. E., Ulland, K. and Wright, A., “Stiffness Isn't Everything,” In: Proceedings of the 4th International Symposium on Experimental Robotics, Stanford, NJ, USA (1995) pp. 253262.Google Scholar
2.Pratt, G. A. and Williamson, M. M., “Series Elastic Actuators,” In: Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems, Pittsburgh, PA, USA (1995) pp. 399406.Google Scholar
3.Van Ham, R., Sugar, T. G., Vanderborght, B., Hollander, K. W. and Lefeber, D., “Compliant actuator designs review of actuators with passive adjustable compliance/controllable stiffness for robotic applications,” IEEE Robot. Autom. Mag. 16 (3), 8194 (2009).Google Scholar
4.Sensinger, J. W. and Weir, R. F. ff., “Improvements to Series Elastic Actuators,” In: Proceedings of the IEEE/ASME International Conference on Mechatronic and Embedded Systems and Applications, Beijing, China (2006) pp. 160166.Google Scholar
5.Whitney, D. E., “Force feedback control of manipulator fine motions,” J. Dyn. Syst. Meas. Control 99 (2), 9197 (1977).CrossRefGoogle Scholar
6.Albu-Schaffer, A., Eiberger, O., Grebenstein, M., Haddadin, S., Ott, C., Wimbock, T., Wolf, S. and Hirzinger, G., “Soft robotics: From torque feedback-controlled lightweight robots to intrinsically compliant systems,” IEEE Robot. Autom. Mag. 15 (3), 2030 (2008).CrossRefGoogle Scholar
7.Paluska, D. and Herr, H., “The effect of series elasticity on actuator power and work output: Implications for robotic and prosthetic joint design,” Robot. Auton. Syst. 54 (8), 667673 (2006).CrossRefGoogle Scholar
8.Zinn, M., Khatib, O., Roth, B. and Salisbury, J. K., “Playing it safe,” IEEE Robot. Autom. Mag. 11 (2), 1221 (2004).CrossRefGoogle Scholar
9.Au, S. K., Weber, J. and Herr, H., “Powered ankle–foot prosthesis improves walking metabolic economy,” IEEE Trans. Robot. 25 (1), 5166 (2009).CrossRefGoogle Scholar
10.Hitt, J. K., Sugar, T. G., Holgate, M. and Bellman, R., “An active foot–ankle prosthesis with biomechanical energy regeneration,” J. Med. Devices 4 (1), 011003 (2010).CrossRefGoogle Scholar
11.Sensinger, J. W. and Weir, R. E. F., “User-modulated impedance control of a prosthetic elbow in unconstrained, perturbed motion,” IEEE Trans. Biomed. Eng. 55 (3), 10431055 (2008).CrossRefGoogle ScholarPubMed
12.Sulzer, J., Peshkin, M. and Patton, J., “Pulling your strings: Cable moment arm manipulation as a method of joint actuation,” IEEE Robot. Autom. Mag. 15 (3), 7078 (2008).CrossRefGoogle Scholar
13.Veneman, J. F., Kruidhof, R., Hekman, E. E. G., Ekkelenkamp, R., Van Asseldonk, E. H. F. and der Kooij, H. Van, “Design and evaluation of the LOPES exoskeleton robot for interactive gait rehabilitation,” IEEE Trans. Neural Syst. Rehabil. Eng. 15 (3), 379386 (2007).CrossRefGoogle ScholarPubMed
14.Laura, M., Legault, M.-A., Lavoie, M.-A., Michaud, F., “Differential Elastic Actuator for Robotic Interaction Tasks,” In: Proceedings of the IEEE International Conference on Robotics and Automation, Pasadena, CA, USA (2008) pp. 36063611.Google Scholar
15.Petit, F., Chalon, M., Friedl, W., Grebenstein, M. and Albu-sch, A., “Bidirectional Antagonistic Variable Stiffness Actuation: Analysis, Design and Implementation,” In: IEEE International Conference on Robotics and Automation (ICRA), Anchorage, AK, USA (2010) pp. 41894196.Google Scholar
16.Kim, B. S., Song, J. B. and Park, J. J., “A serial-type dual actuator unit with planetary gear train: basic design and applications,” IEEE-ASME Trans. Mechatronics 15 (1), 108116 (2010).Google Scholar
17.Sensinger, J. W. and Weir, R. F. F., “Modeling and preliminary testing socket–residual limb interface stiffness of above-elbow prostheses,” IEEE Trans. Neural Syst. Rehabil. Eng. 16 (2), 184190 (2008).CrossRefGoogle ScholarPubMed