Vehicle Dynamics

A central page to host all of my posts around the subject of vehicle dynamics.

Ackermann Angle – The toe-out or toe-in of a vehicle with Ackermann steering when the wheels are positioned straight ahead.

Ackermann Deviation – The difference between the calculated ideal Ackermann angle and the actual outside wheel angle.

Ackermann steering

Ackermann Steering – A double-pivoting steering system where the outer ends of the steering arms are bent slightly inward so that when the vehicle is making a turn, the inside wheel will turn more sharply than the outer wheel.

Gross Vehicle Weight (GVW) – The maximum loaded weight, including the vehicle itself, passengers, and cargo, for which a vehicle is designed and as specified by the manufacturer. Often used as a criterion of vehicle size for the purpose of legislation.

Independent Suspension – A suspension system that allows each wheel on a vehicle to move up and down independently of the other wheels. Allows a vehicle to provide a more level and stable ride.

Roll Axis – Longitudinal line around which a vehicle rolls (joins front and rear roll centres).

Roll Centre – Invisible moving point around which a vehicle is considered to rotate in a corner. This is the only point on the vehicle centreline that does not move up or down during a turn.

CAD image of a shock absorber

Shock Absorber – A mechanical device designed to smooth out or dampen a sudden shock impulse and dissipate kinetic energy. The shock absorber turns kinetic energy into thermal energy within the working fluids of system.

Sprung Weight – The weight supported by the suspension, including a proportion of the suspension arms.

Unladen Weight – The actual weight of a vehicle or combination with no payload.

Unsprung Weight – All parts of the vehicle that are not supported by the suspension system, wheels, tyres, brakes, etc

Wheel Hop – The vertical oscillatory movement of a wheel between the road surface and the sprung mass of the vehicle.