Periodic Disturbance Compensation Control of a Rope-Driven Lower Limb Rehabilitation Robot
| Autor: | Zhijun Wang, Mengxiang Li, Xiaotao Zhang |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2023 |
| Předmět: |
lower limb rehabilitation robot
compensation for external periodic disturbances repetitive learning control trajectory planning Stone–Weirstrass theorem Materials of engineering and construction. Mechanics of materials TA401-492 Production of electric energy or power. Powerplants. Central stations TK1001-1841 |
| Zdroj: | Actuators, Vol 12, Iss 7, p 284 (2023) |
| Druh dokumentu: | article |
| ISSN: | 2076-0825 |
| DOI: | 10.3390/act12070284 |
| Popis: | In order to solve the external periodic disturbance and unknown dynamics influence in the passive rehabilitation process of a rope-driven lower limb rehabilitation robot, a control method with periodic repeated learning was designed. In this control method, the closed-loop dynamics are divided into a periodic disturbance term, an unknown dynamics term, and a basic term, and the shape function is designed by using the Stone–Weirstrass theorem. In the process of periodic operation, the estimated value of the shape function coefficient is repeatedly learned to obtain the periodic disturbance term approximation and to realize the compensation in advance. Through the design of the impedance learning rate, the unknown dynamic term is periodically learned, and the unknown dynamics approximation is obtained. By combining the two approximations with the basic terms which can be solved directly, the external periodic disturbance is compensated for in advance and the control precision is improved. The control algorithm was verified by simulation, and the error fluctuation of the system gradually decreases and reaches the ideal value within several cycles. The performance of the control system is stable, and the problem of limb impedance caused by different patients is well solved. |
| Databáze: | Directory of Open Access Journals |
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