Abstract
For the virtual development of steering systems, especially those including electric power steering systems (EPS or EPAS), it is required to have a tyre model that accurately predicts the forces and moments at standstill and manoeuvring at low velocities. This means that the tyre model must be able to deal with combined slip situations of spin, sideslip and longitudinal slip, not only for steady-state, but also for transient behaviour.
Recently, TNO updated the turn slip theory originally developed by Pacejka in the latest MF-Swift 6.2 tyre model. Extensive validation with measurements has however been lacking, as suitable tyre test facilities are unavailable. Generally the ‘standard’ centre-point steering experiment is used for parameter identification and model validation. Drawback of this test approach is that only a limited operating range is considered and only a few parameters can be identified. In this study, the applicability of the turn slip model for realistic parking manoeuvres is assessed using vehicle measurements and simulations.
KEYWORDS – Tyre simulation model, parking manoeuvres, Magic Formula, SWIFT, turn slip