Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
The ride comfort versus handling decision for off-road vehicles
Dissertation (MEng (Mechanical Engineering))--University of Pretoria, 2007.
Saved in:
| Other Authors: | |
|---|---|
| Format: | Thesis |
| Published: |
University of Pretoria
2013
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613483508432896 |
|---|---|
| access_status_str | Open Access |
| author2 | Uys, Petro E. |
| author_browse | Uys, Petro E. |
| author_facet | Uys, Petro E. |
| collection | Thesis |
| dc_rights_str_mv | © 2007, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Dissertation (MEng (Mechanical Engineering))--University of Pretoria, 2007. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/29027 |
| institution | University of Pretoria (South Africa) |
| last_indexed | 2026-06-10T12:36:52.135Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2013 |
| publishDateRange | 2013 |
| publishDateSort | 2013 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/29027 The ride comfort versus handling decision for off-road vehicles Uys, Petro E. rbester23@gmail.com Bester, Rudolf Running root mean square (rrms) Vertical acceleration Quadratic discriminant Terrain classification Ride comfort Handling Semi-active suspension Vehicle dynamics Self-organising maps Lateral acceleration Road roughness. UCTD Dissertation (MEng (Mechanical Engineering))--University of Pretoria, 2007. Today, Sport Utility Vehicles are marketed as both on-road and off-road vehicles. This results in a compromise when designing the suspension of the vehicle. If the suspension characteristics are fixed, the vehicle cannot have good handling capabilities on highways and good ride comfort over rough terrain. The rollover propensity of this type of vehicle compared to normal cars is high because it has a combination of a high centre of gravity and a softer suspension. The 4 State Semi-active Suspension System (4S4) that can switch between two discrete spring characteristics as well as two discrete damper characteristics, has been proven to overcome this compromise. The soft suspension setting (soft spring and low damping) is used for ride comfort, while the hard suspension setting (stiff spring and high damping) is used for handling. The following question arises: when is which setting most appropriate? The two main contributing factors are the terrain profile and the driver’s actions. Ride comfort is primarily dependant on the terrain that the vehicle is travelling over. If the terrain can be identified, certain driving styles can be expected for that specific environment. The terrains range from rough and uncomfortable to smooth with high speed manoeuvring. Terrain classification methods are proposed and tested with measured data from the test vehicle on known terrain types. Good results were obtained from the terrain classification methods. Five terrain types were accurately identified from over an hour’s worth of vehicle testing. Handling manoeuvres happen unexpectedly, often to avoid an accident. To improve the handling and therefore safety of the vehicle, the 4S4 can be switched to the hard suspension setting, which results in a reduced body roll angle. This decision should be made quickly with the occupants’ safety as the priority. Methods were investigated that will determine when to switch the suspension to the handling mode based on the kinematics of the vehicle. The switching strategies proposed in this study have the potential, with a little refinement, to make the ride versus handling decision correctly. Copyright 2007, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: Bester, R 2007, The ride comfort versus handling decision for off-road vehicles, MEng dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-10252007-111611 / > Mechanical and Aeronautical Engineering unrestricted 2013-09-07T14:43:15Z 2007-11-26 2013-09-07T14:43:15Z 2007-04-20 2007-11-26 2007-10-25 Dissertation Bester, R 2007, The ride comfort versus handling decision for off-road vehicles, MEng dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://hdl.handle.net/2263/29027 > http://hdl.handle.net/2263/29027 http://upetd.up.ac.za/thesis/available/etd-10252007-111611/ © 2007, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | Running root mean square (rrms) Vertical acceleration Quadratic discriminant Terrain classification Ride comfort Handling Semi-active suspension Vehicle dynamics Self-organising maps Lateral acceleration Road roughness. UCTD The ride comfort versus handling decision for off-road vehicles |
| title | The ride comfort versus handling decision for off-road vehicles |
| title_full | The ride comfort versus handling decision for off-road vehicles |
| title_fullStr | The ride comfort versus handling decision for off-road vehicles |
| title_full_unstemmed | The ride comfort versus handling decision for off-road vehicles |
| title_short | The ride comfort versus handling decision for off-road vehicles |
| title_sort | ride comfort versus handling decision for off road vehicles |
| topic | Running root mean square (rrms) Vertical acceleration Quadratic discriminant Terrain classification Ride comfort Handling Semi-active suspension Vehicle dynamics Self-organising maps Lateral acceleration Road roughness. UCTD |
| url | http://hdl.handle.net/2263/29027 http://upetd.up.ac.za/thesis/available/etd-10252007-111611/ |