Abstract
This article describes the design of a traction control system in an electric Formula Student vehicle. In many race applications the accelerator pedal is difficult to control for an in-experienced driver, especially in the case of electric vehicles, where a large torque is available from standstill. A 3-DOF driveline model is used in combination with a 7-DOF vehicle model and a non-linear tyre model based on 10 parameters. The driveline and tyre model are validated by measurements. These models are used to design a suitable traction control system. This system consists of an open-loop part, which uses the longitudinal and lateral acceleration to calculate a torque limit via a driver provided friction estimation. The feed-back part of the controller regulates the slip-ratio of the rear-wheels. The traction control system is first implemented in the vehicle model and later in an electric Formula Student vehicle. A comparison is made between the vehicle with and without traction control. The vehicle with traction control performs significantly better in terms of longitudinal acceleration and shows a better driveability in terms of lateral acceleration.
KEYWORDS – Traction-control, Longitudinal vehicle control, Powertrain control, Slip-ratio control, Driversupport