This thesis describes an efficient tyre test procedure that can be used by automotive manufacturers to gather the data required to parameterise empirical tyre models used in the computer simulation of vehicle dynamics. The new test procedure builds on established methodologies developed as alternatives to traditional Square Matrix testing. The new process is designed to reduce the duration 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 major tyre testing facilities in the United Stated of America. Testing has been carried out at using the Calspan TIRF (TIre Research Facility) tyre testing rig in Buffalo, NY; as well as the SoVaMotion flat-trac facility in Alton, VA. It is shown here how the new test procedure can be used more efficiently to parameterise all components for the well-known Magic Formula tyre model, for load cases including free-rolling, longitudinal and combined slip conditions; as well as inflation pressure interpolation for both steady state and transient manoeuvres. This is achieved using a ‘cruise’ type procedure which is more representative of the loading conditions exerted on the tyre whilst driving a real vehicle. During the test, an innovative new sweep shape is used to minimise both mechanical hysteresis and temperature variation during each test sweep, while an automated logic approach is used to manage the tyre temperature throughout the procedures. 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. Finally, the new test procedure is compared with the more traditional Square Matrix style of testing and a 73% reduction in overall test duration is demonstrated. The development of accurate and representative tyre models remains a significant challenge as vehicle manufacturers target increased use of virtual prototypes and simulation. The presented work contributes to this by improving the efficiency of the expensive tyre testing required to parameterise the models. This has been achieved through the introduction of a novel tyre test process that has been developed and proven during this study.
|Date of Award||2018|
|Sponsors||Jaguar Land Rover|
|Supervisor||Mike Blundell (Supervisor)|