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Force control for walking on soft terrains

Published online by Cambridge University Press:  09 March 2009

Hannu Lehtinen
Affiliation:
VTT Automation, P.O. Box 13022, FIN-02044 VTT (Finland)

Summary

Force control of walking machines is essential in a natural soft and uneven terrain. A load adaptive PI force control method for the hydraulic actuation system of MECANT I has been developed. The I term of the controller is changed according to the desired load. Force control satisfies the support requirement also when a leg penetrates the terrain. A method to distribute support forces in an optimal manner has been developed. A rule based altitude controller and a dead-zone and saturation based attitude controller calculates the desired body forces. Walking tests on uneven wet sand fields show the useful applicability of the method.

Type
Article
Copyright
Copyright © Cambridge University Press 1996

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References

1.Hartikainen, K.K., Halme, A.J., Lehtinen, H. & Koskinen, K.O., 1992. “MECANT I: A six legged walking machine for research purposes in outdoor environment” IEEE Int. Conf. on Robotics and Automation Proceedings, vol. 1,Nice(12–16, May 1992) pp. 157163.Google Scholar
2.Pugh, D.R., Ribble, E.A., Vohnout, V.J., Bihari, T.E., Walliser, T.M., Patterson, M.R. & Waldron, K.J., “Technical Description of the Adaptive Suspension VehicleInt.J.of Robotics Research 9, No. 2, 2442 (1990).CrossRefGoogle Scholar
3.Gardner, J.F., “Efficient Computation of Force Distributions for Walking Machines on Rough TerrainRobotica 10, Part 5, 427433 (1992).CrossRefGoogle Scholar
4.Kumar, V. & Waldron, K.J., “Sub-optimal Algorithms for Force Distribution in Multifingered Grippers” IEEE Int.Conf. on Robotics and Automation Proceedings, Raleigh,Washington D.C.:(31 March-3 April, 1987) pp. 252257.Google Scholar
5.Nahon, M.A. & Angeles, J., “Real-time Force Optimization in Parallel Kinematic Chains under Inequality ConstraintsIEEE Trans, on Robotics and Automation 8, No. 4,439450 (1992).CrossRefGoogle Scholar
6.Viersma, T.J., Analysis, Synthesis and Design of Hydraulic Servosystems and Pipelines (Amsterdam-Oxford-New York, Elsevier Scientific Publishing Co., 1980).Google Scholar
7.Nevala, K., “Improving the Accuracy of Winding Arm Motion and Nip Load Control on a Paper Center Winder,” Ph.D. Thesis (Technical Research Centre of Finland, Espoo, 1993).Google Scholar
8.Lehtinen, H., “Force Based Motion Control of a Walking Machine”, 1994, Espoo: Technical Research Centre of Finalnd, 150 p.+ app. 8 p, (VTT Publications 179), (Doctor's Thesis). Ph.D. Thesis (Technical Research Centre of Finland, Espoo, 1994).Google Scholar
9.Halme, A., Hartikainen, K. & Karkkainen, K., “Terrain Adaptive Motion and Free Gait of a Six-legged Walking Machine” Preprints of the 1st IF AC Int. Workshop in Intelligent Autonomous Vehicles, Hampshire, Pergamon Press, Oxford (04, 1993) pp. 17.Google Scholar