H∞ robust control design for unsupported paraplegic standing: experimental evaluation

Holderbaum, W. ORCID: https://orcid.org/0000-0002-1677-9624, Hunt, K. J. and Gollee, H. (2002) H∞ robust control design for unsupported paraplegic standing: experimental evaluation. Control Engineering Practice, 10 (11). pp. 1211-1222. ISSN 0967-0661 doi: 10.1016/S0967-0661(02)00082-5

Abstract/Summary

This paper is concerned with the design of robust feedback H~-control systems for the control of the upright posture of paraplegic persons standing. While the subject stands in a special apparatus, stabilising torque at the ankle joint is generated by electrical stimulation of the paralyzed calf muscles. Since the muscles acting as actuators in this setup show a significant degree of nonlinearity, a robust H~-control design is used. The design approach is implemented in experiments with a paraplegic subject. The results demonstrate good performance and closed loop stability over the whole range of operation.