Document Type : Original article
Authors
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1. Master student in Mechanical Department., Faculty of Engineering, University of Isfahan. Isfahan. Iran
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2. Biomedical engineering PhD, Assistant Professor of Biomedical Engineering, Faculty of Engineering, University of Isfahan. Isfahan. Iran
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3. Electrical PhD, Associate Professor of Electrical Engineering, Electrical Engineering Department, University of Isfahan. Isfahan. Iran
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4. Master student in Mechanical Department, Faculty of Mechanical Engineering, Isfahan University of Technology.
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5. MD, Cardiolosist, Aadvanced (3D) Echocardiologist, Associate professor Of Isfahan University Of Medical Sciences of occupational therapy, Tehran University of Medical Sciences, Tehran, Iran
Abstract
Background and Aim: In many fields of rehabilitation robotics, desired torque would be obtained by considering dynamics of the actuators. Also, dynamic model of many actuators is hard to approach and it has been neglected in many researches that cause the considerable disadvantages in general results. . The aim of this study is to optimize the performance of gait rehabilitation robot.
Materials and Methods: Kinematic data obtained from 10 patients, including joint angles, angular velocity and angular acceleration that eighty data recorded in a walk cycle and applied as inputs to the neural network. Then, performance of a NARMA-L2 controller for actuators of the biped walking robot is shown. It is noticeable that the controller is learned by LM algorithm and three evolutionary algorithms; PSO, GA and ICA. For controlling the robot walking, two kinds of dc motors are used. These actuators improve control of the biped robot by tracking the required torques for a human walk cycle as a reference model by neural network in two ways; offline and online.
Results: In this research, gait recovery system is introduced that the dynamics of the actuators are considered. Finally, reducing dimensions of the neural network hardware and using the evolutionary algorithms, respectively, reduces costs and increases accuracy of the rehabilitation biped robot based on reducing the minimum mean square error of 20 times after learning of neural network.
Conclusion: This system would be effective in promoting gait recovery. Helping the recovery of patient using robotic system and muscle compensation was the predictive goals of manufacturing of the system. The simple structure of neural network, negligible tracking error and high speed system recognition are the factors that make it the best system recognition in this field.
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