Design of Master-slave velocity tracking Upper-limb Exoskeleton system and Feed-forward compensation control

Abstract

Abstract In this paper, we propose a design approach of mirror driving master-slave upper limb exoskeleton based on inertia measurement unit (IMU) system and ZigBee wireless network transmission system. By integrating two gyroscopes on the master side, we can conduct measurement of rotation velocity and acceleration signal and control over a larger range of motion (ROM) of the exoskeleton. The angular velocity information is transmitted to the controller on the paretic side through ZigBee wireless module. Applying the Lagrangian dynamic equation and Geometric projection method, the 3-axes angular velocity are converted into the reference angular velocity control signal of four joint motors of the rehabilitation upper limb exoskeleton. Moreover, a novel control scheme based on inertia moment and gravity moment feed-forward compensation is proposed. The simulation results demonstrate that the controller can enhance the performance according to the responding speed and stability. Experimental results show that the designed scheme of the mirror driving master-slave upper limb exoskeleton system is completely feasible and realizable.