|Analysis of fuzzy systems : a describing function approach
Hong Kong Polytechnic University -- Dissertations
|v, 97 leaves : ill. ; 30 cm
|Fuzzy logic controllers have been found to be applicable to many disciplines during the past two decades. To make the fuzzy logic controlled system to be more economical and to shorten the development time for a product, some signal processors with the built-in fuzzy rule inference mechanism are provided by different semiconductor manufacturers recently. These processors are designed so sophisticated that they can be programmed to meet the requirement of different applications. However, the problem is that the performance of the tuned processors cannot be visualized until they are implemented with the plant. As the behavior of the controller can be observed from its control surface, we suggest an approach to analyze this surface in this dissertation. A demonstration on our approach is presented in order to show that it can provide a set of meaningful data about the controller. Before introducing a controller to a system, we must ensure that the new system is stable. Since the fuzzy logic controller behaves as a nonlinear controller, it is difficult for us to study the stability of the system with the techniques which have been found to be useful for a linear system. In this dissertation, the describing function method is used to find the stability of a fuzzy logic controlled system. We select the describing function method because of its low computation complexity and the ability of providing graphical insight of the system performance. The result indicates that the use of the describing function method to analyze the stability of a fuzzy logic controlled system is possible.
|All rights reserved
Files in This Item:
|For All Users (off-campus access for PolyU Staff & Students only)
As a bona fide Library user, I declare that:
- I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
- I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
- I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.
By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.
Please use this identifier to cite or link to this item: