Suspension simulation guide

Quarter car freebody diagram

This is general suspension simulation guide. The force of springs is F_s=-kx. The force of dampers is Fd=-cv. We will be using dot notion to represent derivatives. For example, if x denotes position of a object, ẋ (x-dot) is the velocity of the object, and ẍ (x-double-dot) is the acceleration of the object.

Quarter Car

The simplest form to explain the physics of suspension simulation is the quarter car. A quarter car model contains the sprung mass (chassis), coilover spring, the damper (dashpot), unsprung mass, and the tire spring. The tire spring exist because... the tire is a spring and has a stiffness. The sprung mass is supported by the coilover spring and the damper which are connected to the unsprung mass. The unsprung mass is supported by the tire spring.

Coding

All MATLAB files can be found on our Github under the vehicle_sim repository.

Go to Home -> Environment -> Add-Ons -> Get Add-Ons. Search for and install the following toolboxes:

• Control System Toolbox
• DSP System Toolbox
• Model Predictive Control Toolbox
• RF Toolbox
• Signal Processing Toolbox
• Communications Toolbox

We will first explore the quarter car code.