Early social reintegration of patients with disabilities of the wrist is possible with the help of dedicated rehabilitation equipment. Using such equipment reduces the duration of recovery and reduces significantly rehabilitation costs. Based on these considerations the paper puts forward a novel constructive solution of rehabilitation equipment that ensures the simultaneous passive mobilization of the radiocarpal, metacarpophalangeal, and interphalangeal joints. The novelty of this equipment consists in the bioinspired concept of the hand support based on the Fin-Ray effect and in driving it by means of a pneumatic muscle, an inherently compliant actuator. The paper places an emphasis on the compliant character of the rehabilitation equipment that is responsible for its adaptability to the concrete conditions of patient pain tolerability.
This paper presents a tracking control method for pneumatic muscle actuators (PMAs). Considering that the PMA platform only feedbacks position, and the velocity and disturbances cannot be observed directly, we use the extended-state-observer (ESO) for simultaneously estimating the system states and disturbances by using measurable variables. Integrated with the ESO, a super twisting controller (STC) is design based on estimated states to realize the high-precision tracking. According to the Lyapunov theorem, the stability of the closed-loop system is ensured. Simulation and experimental studies are conducted, and the results show the convergence of the ESO and the effectiveness of the proposed method.
In this work a novel pneumatic artificial muscle is fabricated using golden muga silk and silicon rubber. It is assumed that the muscle force is a quadratic function of pressure. Here a single degree of freedom system is considered where a mass is supported by a spring-damper-and pneumatically actuated muscle. While the spring-mass damper is a passive system, the addition of pneumatic muscle makes the system active. The dynamic analysis of this system is carried out by developing the equation of motion which contains multi-frequency excitations with both forced and parametric excitations. Using method of multiple scales the reduced equations are developed for simple and principal parametric resonance conditions. The time response obtained using method of multiple scales have been compared with those obtained by solving the original equation of motion numerically. Using both time response and phase portraits, variation of few systems parameters have been carried out. This work may find application in developing wearable device and robotic device for rehabilitation purpose.
Extended-State-Observer-Based Super Twisting Control for Pneumatic Muscle Actuators