How to Model a 3-Wheeled Vehicle Using the Vehicle Body 3DOF Dual Track Block in MATLAB R2024b?

In MATLAB R2024b, I am trying to model a three wheeled, two axis vehicle using the block "Vehicle Body 3DOF Dual Track", with external longitudinal forces and rear wheel steering. I want my model to represent a vehicle with two wheels on the front axis at the front corners of the vehicle, and one wheel in the center of the rear axis. Using this block, how can I accurately model my three wheeled vehicle?

Answer 1

[MathWorks Support Team]

This block, "Vehicle Body 3DOF Dual Track" can be used to approximate the response of a three wheeled vehicle. It is important to note that the input parameters on both axles (i.e. "WhlAngR", "FwR", "FwF") will always require a vector of length (2), regardless of how many wheels are on the axle. This is because the underlying equations for this block were established for a four wheel / two axle vehicle. Changing the number of wheels per axle will affect the scaling of force distribution, but not the underlying equations.

To simulate this 3 wheeled vehicle, set the following block parameters:

• "Number of wheels on rear axle, NR" - should be set to 1.
• "Track width, w" - the rear width should be set to zero. This variable accepts a 2 element vector in the form of [frontWidth, rearWidth]. The front track width should remain a positive, nonzero value, so this could look something like w = [1.4 0].
• "WhlAngR" - the angular position (in radians) of the rear wheel should contain the same value on both indices of "WhlAngR," the rear steer input signal
• "FwR" - the longitudinal force on the rear wheel should be averaged. For example, to simulate a force of 1000N on the back wheel, you should set "FwR" to [500 500].