جستجوی مقالات مرتبط با کلیدواژه "ربات دو درجه آزادی" در نشریات گروه "برق"

The purpose of designing and manufacturing prosthetic organs is to create their maximum behavioral similarity to human organs. The aim of this paper is to improve the robotic arm control via Model Reference Adaptive System (MRAS) based on Lyapunov theory using EMG data classification. In this paper, human arm is modeled with a robot with two degrees of freedom. The proposed control method is MRAS. The outcome of this research is a robotic arm with MRAS, using the classification of electromyogram (EMG) data recorded from human arm movements, results in proper tracking of the reference signal, less overshoot and steady-state error compared to the conventional PI controller. For this purpose, using two electrodes, EMG data is collected from the anterior deltoid and middle deltoid muscles of the arm of five female athletes and by performing two movements of abduction and flexion of the arm. Then, after eliminating noise, integral of absolute value (IAV), zero crossing (ZC), variance (VAR) and median frequency (MF) are extracted. Then, classification is done by linear discriminant analysis (LDA) method to detect movements based on data characteristics. Finally, the proposed controller and model are designed according to the EMG characteristics to achieve the proper control response and the appropriate command signal is sent to the controller to perform the corresponding movement. The results and the values of the obtained errors show the conformity of the model and controller behavior with the predefined movement pattern.

Standard PID controllers are one of the most desirable controllers for industrial automation and the most widely used control in feedback systems. However, linear controllers have limitations that represent tation controllers can be used to overcome these limitations. In this paper, a robust reset control based on optimal output feedback to control a robot with two degrees of freedom. In general, the behavior of reset controllers is similar to that of linear controllers, in other words, they are easy to implement. In this regard, in this paper, by introducing a special combination control called robust reset output feedback control, the disadvantages of the linear controller are eliminated and its main purpose is to reduce overexposure and increase the response speed and better stability of the controlled system. Therefore, this paper introduces a systematic method for reset optimal output feedback controller. To do this, an optimal output feedback controller is first designed without the reset action, so that the poles of the closed-loop system are located in a predefined area. This area is selected to ensure the stability of the exponential and the arrival time of the closed loop in a finite time. Then, the reset value at reset times is designed to minimize a cost-effective function for better performance. In this paper, for the first time, the reset value is specified only with the system output information and then the stability of the system will be guaranteed. The robot used in this article is a practical and industrial example that has two arms and two joints with separate control capability. The position and behavior of the arms based on the governing equations and mathematical relations indicate its direct effect on each other. Finally, to prove the proposed design, numerical simulation will be performed using Matlab software and a comparison between the proposed controller and a similar controller will be performed.