Dynamic Model Design and Controller Development of Lower Limb Prosthesis Through Matlab Simscape Multibody Toolbox

Abstract

Indeed, humans have achieved remarkable feats. Even so, some people lose parts of their bodies due to accidents, disease, or any other reason. Among them, lower limb amputation is the worst. Thus, prosthesis provides an appropriate solution to assist amputees in reintegration into society. Unfortunately, the user of several prostheses feels like a robot when using the prostheses with a traditional controller. Therefore, several efforts have been made to convey the amputee's brain instructions to the prosthesis using electromyography (EMG) sensors attached to the patient's residual muscles. This study aims to derive and realize the model of the lower limb prosthesis using the MATLAB Simscape Multibody library. The simulation model has been created by importing the essential structure from the CAD software. The model simulates the above-knee prosthesis with a single degree of freedom by allowing the knee joint to revolute voluntarily to create flexion and extension movements. A wireless EMG circuit board has been designed and evaluated to collect the amputee's residual muscle electricity. Subsequently, a novel combination between the traditional PID and Adaptive Neuro Fuzzy Inference System (ANFIS) controllers is designed to control, with a high percent of stability, the simulated prosthesis and overcome the oscillation of EMG signals. The movement of the simulated lower limb prosthesis is calibrated to the healthy leg of an 11-year-old child. The evaluation experimental tests have been accomplished by involving a healthy participant to compare his normal leg with the simulated controllable robotic prosthesis. The experimental results proved the functionality of the designed model to track the movement of the healthy lower limb. In addition, the effectiveness of the suggested controller to manipulate the prosthesis knee joint is proven. Fabricating the designed lower limb prosthetic and integrating it with the combination controllers proposed in this work is a continuation of this study in the future.