Modeling and Control of a Novel Design of Series Elastic Actuator for Upper Limb Rehabilitation

Abstract

The field of rehabilitation robotics for upper limb assistance has grown rapidly in the past few years. Rehabilitation robots have direct contact with human joints, which presents a serious safety concern. In this paper, a novel design for a series elastic actuator (SEA) is presented for upper limb rehabilitation of sensorimotor dysfunctions. The proposed SEA ensures safety and robust torque control under various disturbances. The proposed SEA is modeled and simulated using MATLAB Simulink to obtain Input/Output driven data. For the proposed system, two modeling approaches, ARMAX and NN, are used along with comparative analysis for each model fitting. After SEA dynamic modeling, the PSO-tuned LQR controller is designed and implemented. Comparison parameters are then chosen to test the controller behavior during different applied disturbances. The chosen controller showed optimum set-point tracking performance, which is equivalent to upper limb movement. This research can be extended to develop and implement a test bench for upper limb rehabilitation.