A new efficient free-rolling tyre-testing procedure for the parameterisation of vehicle dynamics tyre models

Abstract

This paper describes an efficient tyre test procedure that can be used to gather the data required to parameterise empirical tyre models used in the computer simulation of vehicle dynamics. The new GS2MF FreeRolling test procedure builds on established methodologies, such as the TIME and MICH2MF methods developed as alternatives to traditional square matrix testing. The new process is designed to reduce the number of expensive tyre tests without compromising the accuracy of the generated tyre model parameters. The process is demonstrated by a programme of tyre testing carried out using the Calspan flat-belt tyre testing facility in the USA and it is shown here how the GS2MF test procedure can be used more efficiently to parameterise the pure lateral and self-aligning moment components for the well-known Magic Formula tyre model. This is achieved using a 'cruise' type procedure which is more representative of conditions existing while driving a real vehicle. During the test, a novel automated logic approach is also proposed to manage the tyre temperature. Finally, graph sweeps are introduced at the start and end of the test, allowing a judgement to be made as to the influence of tyre wear on data obtained throughout the test. The development of accurate and representative tyre models remains a significant challenge as vehicle manufacturers target increased use of virtual prototypes and simulation. This work contributes to this challenge by improving the efficiency of the expensive testing process needed to parameterise the models. KeywordsTyre testing, GS2MF, free rolling tyre test, tyre modelling, Magic Formula, vehicle dynamics 1 Tyre CAE and Modelling Consultants, Banbury, Oxfordshire, UK 2 Mobility and Transport Research Centre, Coventry University, U.K. Corresponding author:Gregory Smith, Tyre CAE and Modelling Consultants, Lawn Hill Cottage, Appletree, Oxfordshire. OX17 1ET Email: gregorysmithuk@gmail.com IntroductionThe use of computer models and virtual simulation in vehicle development has grown significantly within all areas of the automotive industry. The overall impetus for this is driven by the requirements to reduce cost, improve repeatability and avoid, where possible, the necessity to conduct dangerous manoeuvres at the proving ground. This overall area of activity is recognised as critical in the drive towards the more extended use of virtual prototypes and the ambition to enable total virtual sign-off of new vehicle designs. In some areas the methodologies applied to the modelling of vehicle systems and components are well established. In other areas further development is needed. Of these, the modelling of the pneumatic tyre to support the simulation of vehicle dynamics studies into ride and handling [1, 2] remains one of the most challenging and is the subject of advanced and specialist research. Studies for example into areas such as braking [3] or anti-lock braking systems [4] will require an understanding of the longitudinal force in the tyre as it varies with slip ratio while for v...

The testing of pneumatic tyres for the interpretation of tyre behaviour for road/rail vehicles when operating on rails

“…As such, research has been carried out that has led to more efficient tyre test procedures such as the GS2MF method that reduces the amount of testing. 16 To test the RRV tyres acting on the rail-head it was also necessary to plan an efficient test programme that would provide sufficient information to inform the development of a new tyre model and provide numerical data for the model parameters.…”

“…This has led to additional research to find more efficient ways to carry out a tyre test programme, without compromising the quality of the generated tyre model parameters. One such study 16 led to a new tyre testing methodology known as GS2MF. Whichever testing approach is taken, the idea is to carry out a range of tests that map out and capture the expected scenarios the tyre will experience while driving.…”

“…This has led to additional research to find more efficient ways to carry out a tyre test programme, without compromising the quality of the generated tyre model parameters. One such study 16 led to a new tyre testing methodology known as GS2MF.…”

Predicting Tyre Behaviour on Different Road Surfaces

“…By repeating friction experiments at different temperatures (-40°C to +50°C), the measurements allow for the construction of a friction master curve, see section 3. Measurements were focused on the sandpaper surface used on the Calspan flat-track test rig (see section 5) [6].…”

Identification of Tire Transient Parameters from Vehicle Onboard Sensors Data

“…These quantities can be directly measured on a rolling tire with traditional methods like a test bench [2] or on a vehicle, using a rim mounted camera and markers on the tire inner liner like it is done in [3].…”