VHDL-AMS based genetic optimisation of fuzzy logic controllers

• Main Authors: Wang, Leran (Author), Kazmierski, Tom (Author)
• Format: Article
• Language: English
• Published: 2007-01.
• Subjects: Article
• Online Access: Get fulltext

 Purpose - This paper presents a VHDL-AMS based genetic optimisation methodology for fuzzy logic controllers (FLCs) used in complex automotive systems and modelled in mixed physical domains. A case study applying this novel method to an active suspension system has been investigated to obtain a new type of fuzzy logic membership function with irregular shapes optimised for best performance. Design/methodology/approach - The geometrical shapes of the fuzzy logic membership functions are irregular and optimised using a genetic algorithm (GA). In this optimisation technique, VHDL-AMS is used not only for the modelling and simulation of the FLC and its underlying active suspension system but also for the implementation of a parallel GA directly in the system testbench. Findings - Simulation results show that the proposed FLC has superior performance in all test cases to that of existing FLCs that use regular-shape, triangular or trapezoidal membership functions. Research limitations - The test of the FLC has only been done in the simulation stage, no physical prototype has been made. Originality/value - This paper proposes a novel way of improving the FLC's performance and a new application area for VHDL-AMS.