Car modelling and simulation of an electronic stability control.

Modern cars have a wide range of safety features to ensure that the driving is as safe as possible. One of these safety features is called electronic stability control, often abbreviated as E.S.C. The goal of the E.S.C. is to make sure that the car stays on the road even under dangerous circumstances such as a slippery road or the driver committing mistakes. During this project, a simulation program is made to help with the development of an E.S.C. for a new car. The purpose of this thesis work was to create a vehicle model and a simulation program that could be used to study a vehicle with and without electronic stability control. The program is made for the company Uniti Sweden AB that is currently developing an electric car. The goal is to give the user of the simulation program the ability to simulate a car making a turn under various driving conditions and to test an electronic stability control program while it’s under development. During the project a three degrees of freedom vehicle dynamics model is created together with two automatic control systems to represent E.S.C.s. and a simulation program in Scilab. The program is able to accurately describe the behaviour of the vehicle during various driving conditions and vehicle parameters. Of the two controllers one is a sliding mode controller and the other is an On/Off controller. Simulations are run to test the controllers and the car model to see how they behave under situations resulting in oversteer or understeer