Suspension settings for optimal ride comfort of off-road vehicles travelling on roads with different roughness and speeds
Loading...
Date
Authors
Uys, Petro E.
Els, Pieter Schalk
Thoresson, Michael John
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
This paper reports on an investigation to determine the spring and damper settings that will ensure optimal ride comfort of an off-road vehicle, on different road profiles and at different speeds. These settings are required for the design of a four stage semi-active hydro-pneumatic spring damper suspension system (4S4). Spring and damper settings in the 4S4 can be set either to the ride mode or the handling mode and therefore a compromise ride-handling suspension is avoided. The extent to which the ride comfort optimal suspension settings vary for roads of different roughness and varying speeds and the levels of ride comfort that can be achieved, are addressed. The issues of the best objective function to be used when optimising and if a single road profile and speed can be used as representative conditions for ride comfort optimisation of semi-active suspensions, are dealt with. Optimisation is performed with the Dynamic-Q algorithm on a Land Rover Defender 110 modelled in MSC.ADAMS software for speeds ranging from 10 to 50 km/h. It is found that optimising for a combined driver plus rear passenger seat weighted root mean square vertical acceleration rather than using driver or passenger values only, returns the best results. Results indicate that optimisation of suspension settings using one road and speed will improve ride comfort on the same road at different speeds. These settings will also improve ride comfort for other roads at the optimisation speed and other speeds, although not as much as when optimisation has been done for the particular road. For improved ride comfort damping generally has to be lower than the standard (compromised) setting, the rear spring as soft as possible and the front spring ranging from as soft as possible to stiffer depending on road and speed conditions. Ride comfort is most sensitive to a change in rear spring stiffness.
Description
Keywords
Ride comfort, Optimization techniques, Rough roads, Four stage semi-active suspension system, Suspension of automobiles
Sustainable Development Goals
Citation
Uys, PE, Els, PS & Thoresson, M 2007, ‘Suspension settings for optimal ride comfort of off-road vehicles travelling on roads with different roughness and speeds’, Journal of Terramechanics, vol.44, issue 2, pp. 163-175.[http://www.sciencedirect.com/science/journal/00224898]