Isokinetic Training Control Method of Scaled-type Pneumatic Wrist Exoskeleton Based on EMG Supervision

Conventional isokinetic wrist training devices are often constrained by high costs, single application scenario, and limited patient engagement. This paper presents a portable, low-cost scale-like pneumatic wrist exoskeleton and an EMG (electromyogram) supervised isokinetic control strategy designed to facilitate active rehabilitation. Firstly, a reconfigurable soft pneumatic actuator is designed based on a multi-chamber scale-like airbag array, which is integrated into a flexible wearable wrist exoskeleton tailored to wrist kinematics. Secondly, an EMG-supervised chain impedance control method is proposed, which maps EMG-weighted neural activation dynamically to actuation stiffness. Finally, a prototype of scale-like pneumatic actuator is developed for mechanical testing. By integrating the actuator and the hardware system, an isokinetic wrist training prototype is developed for the experiment of active engagement evaluations. Experimental results confirm that the drive model accurately characterizes output force, and the motion range of the exoskeleton meets functional requirements of wrist training. In the experiment of active engagement evaluations, the voluntary force generation is enhanced by 30% through EMG supervision, demonstrating the effectiveness of the proposed method.