Toeards modelling and optimisation of semi-active suspension. Magnetorheological damper and magnetostrictive electric generator.

Abstract

Magnetorhelogical technology is a promising method for avoiding conflicts associated with optimisation of vehicle suspensions. With MR dampers, the damping coefficient can be varied by applying relatively small magnetic fields. Multi-criteria optimisation was conducted to investigate the potential performance improvements obtainable with this technology. Vehicle simulations were implemented in Matlab using a quarter car model, after which the results were verified in Adams. Apart from performance, the electric current necessary to sustain the system was estimated. Additionally, an attempt to convert mechanical into electric power was made using a magnetostrictive electric generator, or MEG. An adaptive structure consisting of a rack and pinion and a cam was designed to amplify the frequency of excitation, and thereby enhance the MEG s conversion efficiency. Finally, its effect on passenger comfort was investigated. The simulations showed that MR dampers can have a positive effect, particularly to counteract motion caused by load shifts. Installation of the harvesting device was found to have a negative influence on passenger comfort, and thus requires further development.