Chapter 1

Introduction

DefinitionChassis: All vehicle

structures except body and engine

Chassis Components:1. Chassis Beam2. Steering System3. Braking System4. Suspension System5. Tire and Wheel6. Driveline (gearbox,

propeller shaft, drive shaft)

Basic Vehicle Motions

6 Basic Motions of a Vehicle:

1. Roll Motion

2. Pitch Motion

3. Vertical Motion

4. Yaw Motion

5. Lateral Motion

6. Longitudinal Motion

Vehicle Roll

- Steering input from the driver or asymmetric road profile between left and right tires can cause the vehicle to roll

-Excessive roll angle can cause the vehicle to rollover

- Disadvantages of vehicle roll: reduces stability and safety, driver can loss control of the vehicle; and reduces passenger comfort

Vehicle Pitch

- Braking/throttle inputs from the driver or asymmetric road profile between front and rear tires can cause the vehicle to pitch

- Disadvantages of vehicle pitch: reduces stability and safety, driver can loss control of the vehicle; and reduces passenger comfort

Vehicle Yaw

Yaw angle: the difference between the direction of vehicle forward speed with the direction of travel

Steering input from the driver, side wind force, asymmetric road friction can cause the vehicle to yaw

Vehicle Lateral Motion

- Vehicle will move laterally under steering input from the driver

- Lateral Maneuvers: lane change, cornering, collision avoidance, etc.

Longitudinal Motion

- Throttle or braking inputs from the driver can cause the vehicle to move longitudinally

- Longitudinal maneuver: accelerating or decelerating

Vertical Motion

- Vertical motion of the vehicle reduces vehicle comfort level

- Road input, steering input, brake input and throttle input can cause the vehicle to move vertically

Body Center of Gravity

How to determine the location of the body center of gravity of a vehicle???