Botha, Theunis R.Els, Pieter Schalk2016-03-112015-10Botha, TR & Els, PS 2015, 'Digital image correlation techniques for measuring tyre-road interface parameters : part 2 - longitudinal tyre slip ratio measurement', Journal of Terramechanics, vol. 61, pp. 101-112.0022-4898 (print)1879-1204 (online)10.1016/j.jterra.2015.05.003http://hdl.handle.net/2263/51789Measurement of tyre longitudinal slip-ratio is often estimated from three independent measurements devices namely wheel rotation speed, vehicle speed and tyre rolling radius. This produces an expensive measurement system to indirectly determine the slip-ratio. This paper presents a method by which the slip-ratio is determined from a video camera using digital image correlation techniques. The camera, mounted in such a way that the contact patch region is captured, enables the system to measure the tyre tread speed and ground speed at the contact patch. The slip-ratio is then determined from these two measurements.en© 2015 ISTVS. Published by Elsevier Ltd. All rights reserved. Notice : this is the author’s version of a work that was accepted for publication in Journal of Terramechanics. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Terramechanics, vol. 61, pp. 101-112, 2015. doi : 10.1016/j.jterra.2015.05.003.Longitudinal slipDigital image correlationCameraLongitudinal tyre forceContact patch velocityEngineering, built environment and information technology articles SDG-09SDG-09: Industry, innovation and infrastructureEngineering, built environment and information technology articles SDG-11SDG-11: Sustainable cities and communitiesPostprint Article