Optimization of suspension characteristics for increasing expected daily exposure durations in vehicles according to ISO 2631-1 standard using genetic algorithms

Human perception related vehicle comfort problems have been an important topic for researchers as evident from a large number of scientific papers available in the literature. Increasing duration of expected daily exposure in vehicles means that the vehicle is comfortably driven for longer periods of time. The aim of this study is to increase the comfortable driving time of a bus by optimizing the suspension system characteristics using genetic algorithm approach. Thus a full car model of the corresponding vehicle is built in order to improve its driving comfort. In the optimization procedure, maximum allowed vertical acceleration of the seat and suspension deflection parameters are used as the cost functions. Furthermore, genetic algorithm parameters and weighting factors are defined in accordance with the problem and applied to solve the optimization problem. Comparison between optimized and current suspension systems is made by using health guidance zones in the International Organization for Standardization 2631-1 to evaluate comfort. As a result, duration of the expected daily exposure time is increased for different types roads. This method can be applied to different types of vehicles and can be a guidance tool for vehicle manufacturers to produce comfortable vehicles.