Методика построения гибридной нейросистемы реального времени для решения обратной задачи кинематики избыточного манипулятора

Abstract

Solution of the inverse kinematics (IK) problem with the aid of neural networks is considered. The control system for a multi-link redundant manipulator is synthesized. The configuration of a control system on the basis of servo drives is presented. The proposed control system is based on an algorithm involving a new hybrid method for solving the IK problem. This method combines the ANFIS adaptive neural fuzzy inference network and an iterative refinement algorithm (according to the Newton-Raphson method). Thus, the proposed algorithm combines the advantages of the neural network and iterative approaches, namely, high precision and high response speed. The required coordinates (link rotation angles) for the inverse problem are calculated in the neural network (ANFIS), after which they are refined by the iteration method. Hence, a much fewer number of iterations have to be carried out in the numerical method, and, accordingly, much shorter time is taken to execute the algorithm. The developed algorithm ensures a controlled accuracy of calculations with due regard of its application in real-time control systems. The developed control system is universal in nature and can be used for manipulators having different design parameters. For investigating the control system synthesized proceeding from the developed method for solving the IK problem, a three-link manipulator design was considered. The mathematical description used for constructing the manipulator’s operating space and for training the control system neural network is presented. The results from experimental investigations of applying the hybrid algorithm for calculating the link and actuator coordinates are given. The method was investigated in the Matlab environment. The results of the performed experiments allowed a conclusion to be drawn about the possibility of using the developed method in real-time control systems. To solve the problem of shaping the operating spaces of certain types of manipulators, a graphical interface was developed using the Matlab GUI. The application includes features for adjusting the design parameters (the mechanical structure and accuracy). As an example, the workspaces of both planar and spatial manipulator designs with the specified parameters are taken.