Title :
A polynomial H∞-controller for muscle moment control
Author :
Jaime, R.-P. ; Hunt, K.J. ; Gollee, H.
Author_Institution :
Dept. of Mech. Eng., Univ. of Glasgow, Glasgow, UK
fDate :
Aug. 31 1999-Sept. 3 1999
Abstract :
The paper deals with the application of H∞-design of a moment controller for the plantarflexor muscle group. This is part of a programme of work in rehabilitation engineering which aims to provide control of unsupported standing in paraplegia. A very popular model of iso-metrically contracting muscle follows the Hammerstein hypothesis. The Hammerstein hypothesis means that the muscle can be modelled by a static nonlinear recruitment curve followed by an LTI-transfer function. But this assumption inadequately reflects the physiological conditions. The first section describes the motivation to apply an H∞-design; this is due to the existence of motor units with varying dynamic properties. In the second section the polynomial approach to H∞-design is summarized, following the work of Kwakernaak [7, 8, 9]. The third section contains experimental results of a complete laboratory session including muscle identification, controller design and controller tests.
Keywords :
H∞ control; control system synthesis; medical control systems; muscle; nonlinear control systems; patient rehabilitation; spatial variables control; H∞-design; Hammerstein hypothesis; LTI-transfer function; controller design; controller tests; dynamic properties; iso-metrically contracting muscle; muscle identification; muscle moment control; paraplegia; plantarflexor muscle group; polynomial H∞-controller; rehabilitation engineering; static nonlinear recruitment curve; unsupported standing control; Frequency control; Muscles; Physiology; Polynomials; Recruitment; Sensitivity; Transfer functions; Η∞-Control; Functional Electrical Stimulation; Mixed-Sensitivity-Problem; Polynomial Equation Approach;
Conference_Titel :
Control Conference (ECC), 1999 European
Conference_Location :
Karlsruhe
Print_ISBN :
978-3-9524173-5-5
