In today’s blog post I am happy to introduce Ed Marquez Brunal, a first-time guest in this blog. This is a holistic summary of our project on modeling vehicles. Find 4 videos and 2 MATLAB Central File Exchange submissions, including anything you may need to get started, linked in the article.
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If you are part of an automotive competition these days, you’ve probably heard about “vehicle modeling”. But before I tell you more about vehicle modeling and its advantages, let’s briefly see how the term “model” has evolved since the adoption of Model-Based Design in the automotive industry.
When people said “vehicle model” in the early 90’s, what came to mind was most likely a car prototype that was very expensive, highly complex, and hard to build. Engineers had to drive, and sometimes break, the so called “vehicle model” of the early 90’s to gather data. Just imagine the pain of these engineers spending tons of time and money building a prototype that they had to break to figure out what was wrong with it!
Today, most people would associate the term “vehicle model” with a computer representation that can be simulated under certain scenarios. Now you may be wondering, why did automotive engineers and students go from building prototypes to working on a computer? Well, it is fun to build the better product that meet specs, and saving time and money is the added benefit.
Faster, Better, and Cheaper
That’s right! Some advantages of vehicle modeling are that the final product can be built faster, it can be better (in terms of engineering requirements), and all while reducing cost. Sounds too good to be true? Let me explain.
Building and simulating a vehicle model enables the engineers to analyze several powertrain configurations and determine if requirements are met for each design. If engineering requirements are not met by a powertrain configuration, it is much easier to change a parameter in a computer model than it is to make a change to a vehicle prototype that is already built. For example, it is easy to change the power rating of an electric motor in a computer model, but we know it can be challenging to swap motors in a real vehicle.
Another advantage of vehicle modeling is that the engineers can study the performance and energy consumptions aspects of a powertrain configuration from a vehicle model. Finally, let’s not forget that running computer simulation is faster and more cost effective than building and driving an actual vehicle prototype (90’s model).
If you are interested in seeing some student success stories, be sure to check out the series page: Formula Student Teams Share Their Keys to Success.
Alright, this vehicle modeling stuff sounds great! But, how can you get started?
Vehicle Modeling Tools
We have created instructional videos, vehicle models, and guidelines for when to use each tool. There is no right or wrong choice here. In fact, you can combine these tools in your models to get the best out of all worlds. However, a clever way to proceed is to think about what tool will fit your needs best before you build your model. For instance: if you are in initial stages of you design, consider Simulink or Simscape. Conversely, consider an alternative like Powertrain Blockset for fine-tuning of your model. An important consideration is that Simulink serves as the foundational platform for all the tools we will cover below.
Simulink is a graphical programming environment for modeling, simulating, and analyzing dynamic systems. Consider Simulink for vehicle modeling if you:
- Want to get started with vehicle modeling
- Seek simplicity and speed for your models
- Have equations describing a system
If you are interested in doing some hardware testing and deployment at later stages of your development process, you can leverage the automated code generation capabilities that Simulink provides. Yes, you can go from a Simulink model to C/C++ code that can be executed by hardware platforms and/or simulators. In fact, all products that we cover in this section support code generation with the appropriate settings. For more details, please refer to Jose’s blog post. For demos and more information on Simulink, please see Part 1 of our 4-video series on vehicle modeling.
Powertrain Blockset is an add-on that expands Simulink capabilities for vehicle modeling, and it is great for parameterizing plant models using test data.
Powertrain Blockset implements a data-driven approach. Consider Powertrain Blockset if you:
- Want well-documented, open, and reconfigurable models
- Have access to vehicle parameters and test data
- Seek to maintain or increase model fidelity with fewer blocks (compared to Simulink)
For details and demos on Powertrain Blockset, please check out Part 2 of our 4-video series on vehicle modeling.
Simscape is the MathWorks language of physical modeling. This tool provides the ability to model multidomain systems. An important aspect of Simscape is that the connections between components are bidirectional, and these physical connections also have units.
Consider Simscape for vehicle modeling if you:
- Use blocks that implement system equations for you
- Reduce visual complexity of a Simulink model
- Model and integrate different domains in a system
For demos and more details on Simscape, please see Part 3 of our 4-video series on vehicle modeling. Also, if you want to use Simscape, I recommend our Student Competition Training on physical modeling as a prerequisite.
Simscape Multibody allows to simulate 3D rigid body dynamics of a system, while providing a 3D animation of the system response. In vehicle modeling, the power of Simscape Multibody can be leveraged to simulate and visualize system dynamics. It can also be used to optimize a design, like a suspension – check the episode on Design Optimization for more details. Last but not least, Simscape Multibody is helpful for modeling wheel-to-ground contact, see racing lounge blog post “Introduction to Contact Modeling“.
Consider Simscape Multibody for vehicle modeling if you:
- Need to model a mechanical system in 3D
- Need a 3D visualization of the system response
- Need to perform system-level analysis
- Need to model wheel-to-ground contact
For your convenience, we put together a 3D vehicle model demo using Simscape Multibody. For more details on the demo, be sure to download the MATLAB Central File Exchange entry (link in introduction). For more details on the demo interface and Simscape Multibody, please check our Part 4 or our 4-video series on vehicle modeling.
If there is one thing to remember from today’s blog is that computational vehicle modeling offers the potential to produce a better final product in a faster and more cost-effective manner. This is possible because of the benefits that computer models and simulations offer over physical prototypes. Some of these benefits include:Conclusion
- Ability to analyze several powertrain configurations
- Ability to determine if requirements are met for each design
- Flexibility to quickly change design parameters in a computer model
- Faster computer simulations vs actual track tests
- Cost effective simulations vs expensive prototype tests
We also introduced four powerful MathWorks products to model vehicle systems. Namely, these products are: Simulink®, Powertrain Blockset™, Simscape™, and Simscape Multibody™. An important idea to remember is that there is no right or wrong choice here. You can combine these tools in your models to get the best of all worlds, but be wise and thoughtful when choosing how to develop your models. To make this easier for you, we also provided some guidelines for when to use what product.
Now that you know the advantages of vehicle modeling with MathWorks tools, and you also know the available options to create your models, it is time to get started and have fun! Let us know how things are going as well as your questions.