Title: Fuzzy logic controller for a SCARA robot with synchronous network

Authors: Shiuh-Jer Huang, Daw-Ning Yang

Addresses: Department of Mechanical Engineering, National Taiwan Institute of Technology, No. 43, Keelung Road, Sec. 4, Taipei, Taiwan. ' Department of Mechanical Engineering, National Taiwan Institute of Technology, No. 43, Keelung Road, Sec. 4, Taipei, Taiwan

Abstract: A prototype SCARA robot with synchronous network control interface has been designed and constructed. This hardware structure can be employed and extended to simultaneously control multi-targets with a distributed local controller by the monitoring of a centralised controller through a synchronous network. Here a centralised controller is designed to control a SCARA robot without local controllers for each degree of freedom. Since the robotic manipulator has a complicated mathematical model, it is difficult to design a control system based on the multi-variable nonlinear coupling dynamic model. The model-free fuzzy logic control approach has gained much attention. The traditional fuzzy logic controller does not have a learning capability. It needs a lot of effort to search the optimal control rules and the shapes of membership functions. Due to the system|s time-varying behaviour, the required tracking accuracy is difficult to achieve by adjusting the fuzzy rules only. To simplify the implementation problems of fuzzy control, the concept of pre-correction of the system output deviation is added to the fuzzy control structure using a grey predictor. The experimental results show that this fuzzy controller has improved the trajectory tracking accuracy and simplified the searching effort of fuzzy rules and membership functions obviously.

Keywords: fuzzy logic; fuzzy control; controller design; industrial automation; SCARA robots; synchronous networks; multivariable nonlinear systems; fuzzy set theory; dynamic modelling; robot control.

DOI: 10.1504/IJCAT.1997.062237

International Journal of Computer Applications in Technology, 1997 Vol.10 No.1/2, pp.15 - 26

Published online: 02 Jun 2014 *

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