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The role of walking surface in enhancing the stability of the simplest passive dynamic biped

Published online by Cambridge University Press:  27 February 2014

Ali Tehrani Safa  and
Mahyar Naraghi
Ali Tehrani Safa
Affiliation:
Mechanical Engineering Department, Amirkabir University of Technology, No. 424, Hafez Avenue, Tehran 15914, Iran
Mahyar Naraghi*
Affiliation:
Mechanical Engineering Department, Amirkabir University of Technology, No. 424, Hafez Avenue, Tehran 15914, Iran
*
*Corresponding author. E-mail: naraghi@aut.ac.ir
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Summary

Employing passive dynamics of the simplest point-foot walker, we have shown that the walking surface could have a great role in promoting the gait stability. In this regard, the stabilization of the simplest walking model,3 between the range of slopes greater than 0.0151 rad. and less than 0.26 rad., has been achieved. The walker like other passive dynamic walking models has no open or closed-loop control system; so, is only actuated by the gravity field. Moreover, no damper or spring is used. Obviously, according to the model's unstable behavior, it is unable to walk on an even flat ramp between the mentioned intervals.3 Here, instead of restraining the model, we let it explore other smooth surfaces, walking on which, will end in an equally inclined surface. To reach the objective, we employ a parallel series of fixed straight lines (local slopes) passing through contact points of an unstable cycling gait, which is generated by an ordinary ramp. To categorize, we have nicknamed those local slopes that guide the biped to a stable cyclic walking, “Ground Attractors,” and the other, leading it to a fall, “Repulsive Directions.” Our results reveal that for the slope <0.26 rad., a closed interval of ground attractors could be found. Stabilization of those unstable limit cycles by this technique makes obvious the key role of walking surface on bipedal gait. Furthermore, following our previous work,13 the results confirm that the two thoroughly similar walking trajectories can have different stability. All of these results strongly demonstrate that without considering the effects of a walking surface, we cannot establish any explicit relationship between the walker's speed and its stability.

Keywords

Passive dynamic walkingStabilityGround attractorsRepulsive directions
Type
Articles
Information
Robotica , Volume 33 , Issue 1 , January 2015 , pp. 195 - 207
Copyright
Copyright © Cambridge University Press 2014 

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References

1.Borzova, E. and Hurmuzlu, Y., “Passively walking five-link robot,” Automatica 40 (4), 621–629 (2004).Google Scholar
2.Byl, K. and Tedrake, R., “Stability of passive dynamic walking on uneven terrain,” Proceedings of the Dynamic Walking, Ann Arbor, MI (2006).Google Scholar
3.Garcia, M., Chatterjee, A., Ruina, A. and Coleman, M., “The simplest walking model: Stability, complexity, and scaling,” ASME J. Biomech. Eng. 120 (2), 281–288 (1998).Google Scholar
4.Goswami, A., Thuilot, B. and Espiau, B., “A study of the passive gait of a compass-like biped robot: Symmetry and chaos,” Int. J. Robot. Res. 17 (12), 1282–1301 (1998).CrossRefGoogle Scholar
5.Hass, J., Herrmann, J. M. and Geisel, T., “Optimal mass distribution for passivity-based bipedal robots,” Int. J. Robot. Res. 25 (11), 1087–1098 (2006).Google Scholar
6.Hobbelen, D. G. E. and Wisse, M., “Swing-leg retraction for limit cycle walkers improves disturbance rejection,” IEEE Trans. Robot. 24 (2), 377–389 (2008).CrossRefGoogle Scholar
7.Kuo, A. D., “A simple model of bipedal walking predicts the preferred speed-step length relation,” ASME J. Biomech. Eng. 123 (3), 264–269 (2001).Google Scholar
8.Kuo, A. D., “The six determinants of gait and the inverted pendulum analogy: A dynamic walking perspective,” Hum. Mov. Sci. 26 (4), 617–656 (2007).CrossRefGoogle ScholarPubMed
9.Kuo, A. D., Donelan, J. M. and Ruina, A., “Energetic consequences of walking like an inverted pendulum: Step-to-step transitions,” Exercise Sport Sci. Rev. 33 (2), 88–97 (2005).Google Scholar
10.McGeer, T., “Passive dynamic walking,” Int. J. Robot. Res. 9 (2), 62–82 (1990).CrossRefGoogle Scholar
11.McGeer, T., “Passive Walking With Knees,” Proceedings IEEE International Robotics & Automation Conference, IEEE Computer Society, Los Alamitos, CA (1990) pp. 1640–1645.CrossRefGoogle Scholar
12.Ning, L., Junfeng, L. and Tianshu, W., “The effects of parameter variation on the gaits of passive walking models: Simulations and experiments,” Robotica 27 (4), 511–528 (2008).Google Scholar
13.Safa, A. T., Saadat, M. Ghaffari and Naraghi, M., “Passive dynamic of the simplest walking model: Replacing ramps with stairs,” Mech. Mach. Theory 42 (10), 1314–1325 (2007).CrossRefGoogle Scholar
14.Schwab, A. L. and Wisse, M., “Basin of attraction of the simplest walking model,” Proceedings of the ASME Design Engineering Technical Conferences, Pennsylvania, Paper number DETC2001/VIB-21363 (2001).Google Scholar
15.Seyfarth, A., Geyer, H. and Herr, H., “Swing-leg retraction: A simple control model for stable running,” J. Exp. Biol. 206 (15), 2547–2555 (2003).CrossRefGoogle ScholarPubMed
16.Su, J. L. and Dingwell, J. B., “Dynamic stability of passive dynamic walking on an irregular surface,” ASME J. Biomech. Eng. 129 (6), 802–810 (2007).Google Scholar
17.Wisse, M., Atkeson, C. G. and Kloimwieder, D. K., “Swing Leg Retraction Helps Biped Walking Stability,” Proceedings of the IEEE-RAS International Conferences on Humanoid Robots, Tsukuba, Japan (2005) pp. 295–300.Google Scholar
18.Wisse, M., Schwab, A. L. and Helm, F. C. T. Vander, “Passive dynamic walking model with upper body,” Robotica 22 (6), 681–688 (2004).CrossRefGoogle Scholar