Sliding modes control of active suspensions

2009

SIMULATION

This paper presents a VHDL-AMS based genetic optimization methodology suitable for performance improvement of hardware systems in automotive applications. Models of such systems are mixedsignal (analog and digital) in which the analog parts cover mixed physical domains. A case study applying this novel method to the fuzzy logic controller (FLC) optimization in an automotive active suspension system (AASS) has been investigated. A new type of fuzzy logic membership functions with variable geometrical shapes has been proposed and optimized. In this optimization technique, VHDL-AMS is used not only for the modeling and simulation of the FLC and its underlying AASS but also for the implementation of a parallel genetic algorithm (GA). This has resulted in an integrated performance optimization system wholly implemented in the hardware description language (HDL). Results show that the proposed FLC has superior performance to that of existing FLCs that use fixed-shape membership functions.

Section: Introductionmentioning

confidence: 99%

VHDL-AMS Based Genetic Optimization of Mixed-Physical-Domain Systems in Automotive Applications

2009

SIMULATION

“…However, the design of a suitable active suspension controller, which determines the value of the actuator force according to the dynamic motions of the sprung and/or unsprung mass, is difficult and still attracts researchers' interest. A number of different control algorithms have been established (Alleyne and Hedrick, 1995;Yagiz et al, 1997;Sam et al, 2000;Chantranuwathana and Peng, 2004). Accurate performance analysis and optimisation of such systems is difficult since the input to an AASS (i.e.…”

Section: Introductionmentioning

confidence: 99%

VHDL‐AMS based genetic optimisation of fuzzy logic controllers

COMPEL - The International Journal for Computation and Mathematics in Electrical and Electronic Engineering

2007

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.

“…However, the design of a suitable active suspension controller, which determines the value of the actuator force according to the dynamic motions of the sprung and/or unsprung mass, is difficult and still attracts researchers' interest. A number of different control algorithms have been established [15,11,2]. Generally speaking, an accurate model of the system is difficult to identify since the input to an active suspension system (i.e.…”

Section: Introductionmentioning

confidence: 99%

VHDL-AMS based genetic optimization of a fuzzy logic controller for automotive active suspension systems

BMAS 2005. Proceedings of the 2005 IEEE International Behavioral Modeling and Simulation Workshop, 2005.

This paper presents a new type of fuzzy logic controller (FLC) membership functions for automotive active suspension systems. The shapes of the membership functions are irregular and optimized using a genetic algorithm (GA). In this optimization technique, VHDL-AMS is used not only for the modeling and simulation of the fuzzy logic controller and its underlying active suspension system but also for the implementation of a parallel GA. Simulation results show that the proposed FLC has superior performance to that of existing FLCs that use triangular or trapezoidal membership functions.