Background

After a brief hiatus from Baja SAE at UCLA, I returned by Summer 2023 to help design next year’s suspension.

In the previous year, I was not involved in the design process as much as I would have liked to be, and I decided to take it upon myself to make a greater contribution this year. Before, I helped with part designs and strength analysis (more details here), making instruments for data logging, and manufacturing parts. This year, I am making a lot more decisions in regard to suspension geometry and driving dynamics.

The suspension designers in our team usually stick to MATLAB and excel calculations and manual iterations to ultimately have a final design sketch in Solidworks.

This time, I wanted to implement a more comprehensive and powerful tool that will let us both visualize our suspension and optimize it to achieve the characteristics we desired.

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Enter Simscape Multibody (shown above). I created an intro video for future users in our suspension team as well as documentation on how to install it.

https://youtu.be/HO9Q_pYGx-0

Changes from the Previous Years

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Our 2022 Model BAJA car

For the past few years, UCLA Baja has used a double A-arm front and A-arm + “goofy arm” rear suspension setup. The rear setup essentially acted as a double A-arm suspension but it has had its fair share of issues that I will discuss. This year we decided to change to a 3-link trailing arm in the rear.

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3 link trailing arm. Picture courtesy of Univ. of Colorado Boulder

Issues with the “Goofy Arm”

<aside> 🚧 will add more here soon!

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How it works. The basics.

Let me note that making and trouble shooting this was a pain in the a**. But the good thing about this is that, once I make the system for a particular suspension system (e.g. front double A-arm, rear 3 link-trailing arm), future teams can simply tweak some of the numbers without having to dive deep into the simulink model itself in order to test their own suspension design.

Here is what the simulink/simscape model looks like: