Vehicle dynamics

Introduction

The Texas Instruments C28x family of processors has been designed to implement control applications, for example digital motor control and un-interruptible power supplies. We shall start here with a simple application. In this Laboratory, you will build a simulation model of a vehicle dynamics using Simulink, and then emulate it using the eZDSP-F2812 board.

Related files

• Powerpoint Presentation - VehicleDynamics.ppt
• Simulink Model for PC Simulation - VehicleDynamics.mdl
• Simulink Model for Simulation with DSKF2812 - VehicleDynamicsF2812Simulation.mdl
• Simulink Model for Real-Time - VehicleDynamicsDSKF2812.mdl

Objectives

• Design a Simulink model of the motion of a vehicle.
• Run the model using Simulink on a PC.
• Modify the model for use with the Texas Instruments C28x Digital Signal Processor.
• Run the modified model on the Texas Instruments F2812 ezDSP.

Level

Beginner; This is intended as the first complete project using Matlab and Simulink.

It is suitable for students who have only limited exposure to Texas Instruments DSPs before.

Requirements

In developing this Laboratory, the following hardware and software were used:

• Matlab R2006b with Embedded Target for TI C2000.
• Code Composer Studio (CCS) 3.1.
• Spectrum Digital ezDSP F2812 Hardware
• Some external electronic components costing about $2.

Simulation

Running the vehicle dynamics simulation

Open VehicleDynamics.mdl .

Run the Model.

The input to the model is a ramp generator, which simulates smooth acceleration.

You will see the graphs of Horsepower and Vehicle Speed.

Changing the vehicle mass

Double click on the “Vehicle Dynamics” block. This models the equation of motion using Simulink Blocks.

At present, the vehicle mass is 8000 kg.

We will now simulate a small compact car. Change the 1/m gain block to 1/1000 and change the b/m block to 2/1000.

Run the model again and notice the effect on maximum vehicle speed and how long it takes to reach maximum vehicle speed

You might also like to simulate a 35,000 kg lorry. Change the 1/m block to 1/35000 and b/m to 10/35000.

Changing the engine power profile

Double click on the “Engine Management” block. This models the gas in – horsepower out function of the engine.

Double-click on the Power Transfer Function

Change the shape of the Power Transfer Function. You may wish to change the gradient or make the plateau wider. Run the model.

Other modifications to the model

Go to the Website of an automobile manufacture, and obtain the actual engine power transfer function for a real car. Run this in the model.