Why VI-grade Opened Its Driving Simulation Technology to Modelica

Embed Modelica models into the VI-grade ecosystem so they are a part of your driving simulator experience.

VI-grade is continuing to open its driving simulator ecosystem to third-party technology. Historically, the company focused on installing turnkey simulator solutions that run on proprietary software.

David Ewbank, Technical Director UK at VI-grade, said, “that was quite a unique selling point for customers buying into the VI-DriveSim product, they got a complete system, and they could come to one place for support for any issues they had.”

VI-grade’s DiM400 DYNAMIC Simulator driving on the Portimao circuit. (Video courtesy of VI-grade).

The challenge with such a rigid ecosystem is that it’s difficult to interface with legacy software. Engineers use various software for vehicle development. They could be industry standards, your personal preferences, or in-house proprietary solutions. If that legacy software doesn’t work with the driving simulator your team is eyeing to purchase, the upper brass might be less inclined to get it.

“Retaining that sort of closed solution wasn’t really viable, for VI-grade, for developing business in the future,” said Ewbank. “So, we went back to what we had to work out a process where we can open that ecosystem up to enable customers to replace the VI-grade technology with their own chosen solution for a function.”

The latest tools to be added to the ecosystem are Modelica models. For decades, engineers have created, shared and used these models to simulate various vehicle dynamics. Now, you can embed them into the VI-grade ecosystem, so they become a part of your driving simulator experience.

A Simulation of a car using Modelon’s Modelica Vehicle Dynamics Library. (Image courtesy of Modelon.)

A Simulation of a car using Modelon’s Modelica Vehicle Dynamics Library. (Image courtesy of Modelon.)

John Griffin, technical specialist of Vehicle Dynamics at Modelon, said, “what VI-grade has done, by opening up their ecosystem and allowing you to plug in different things, like the vehicle model, is that you’re not in this box where you have to use VI-CarRealTime. If you’ve got something that you’re comfortable with, and that you’ve got a process built around, like Modelica, then you can come with that and you can still gain all the benefits of using a driving simulator.”

How Engineers Will Integrate Modelica Models into VI-grade Technology

To understand how engineers will integrate Modelica models into VI-DriveSim, it’s best to know how the ecosystem works. Ewbank explained that it is a modular ecosystem that consists of parts like:

  • Graphics engine
  • Physics engine
  • Vehicle model
  • Road model
  • Data logger interface
  • Simulator hardware

He said, “we’ve gone back to that and asked: ‘How can we replace each of those individual components with third-party products?’ From a user perspective, you want the transition to be pretty seamless so they can switch from using VI-CarRealTime vehicle dynamics models to similar-based Modelica models, or any one of the supported tools. But overall, it shouldn’t fundamentally change the way of working with the driving simulator.”

A VI-CarRealTime simulation. (Video courtesy of VI-grade).

Ewbank noted that SIMulation Workbench is used to interface with third-party vehicle models; it sits on top of the Concurrent Real-Time computer. With the Spectris acquisition of Concurrent Real-Time, he suspects that this workflow will become streamlined (more on that later). But presently, there are three different ways of doing it. Vendors can:

FMI is the current approach to interconnect Modelica-type solutions.

Griffin said, “an FMI block has inputs and outputs. The requirement is to have the proper
interface to route inputs from VI-DriveSim to the vehicle model and provide outputs from the model back to VI-DriveSim. Then, the chassis can be displayed and the motion platform can move properly. Basically, it was taking internal data, that we always generate from the vehicle model, connecting it up with the required interface, so that you can drop it into the VI-grade ecosystem.”

When you want to use a third-party model, instead of a VI-CarRealTime model, what limitations might you have to deal with? Well, here is a hint, it isn’t called “VI-CarRealTime” for nothing.

“Obviously, you can have an incredibly complex model in Modelica. You still have the requirement that that model has to run in real-time,” said Ewbank. “All of your functions, all of your processes must complete within 1000 microseconds, ready for the next step. So yes, you can have incredibly complex vehicle models in whichever package, but when they come onto the Concurrent Real-Time machine, they still have to be capable of processing that within that 1000 microsecond interval.”

VI-Certified Will Ensure the Functionality of an Expanding Driving Simulator Ecosystem

Modelica-based vehicle models aren’t the only third-party software engineers expect to integrate into the VI-grade ecosystem. At a recent event, it was announced that companies in process of getting VI-certified, include:

  • Dassault Systèmes
  • Hexagon’s MSC Software
  • Mechanical Simulation Corp.

“If you look at Dassault Systèmes, you’re talking about SIMPACK,” said Ewbank, “Typically, there you’re talking about full multibody dynamics models where you’re running the SIMPACK solver in a way that enables those models to run in real-time with little or no model reduction.”

An overview of VI-DriveSim’s open environment. (Image courtesy of VI-grade).

An overview of VI-DriveSim’s open environment. (Image courtesy of VI-grade).

He added, “I think the same applies there with MSC Adams Real Time. Again, they’re looking at taking the full multibody dynamics model and running that with little or no model reduction in real-time on the concurrent system.” Ewbank gave nearly the same response when it came to the models, engineers produce using CarSim from Mechanical Simulation Corp.

As to why these tools are being integrated into the ecosystem, again, it’s all about ensuring that engineers can use whatever tools they want, or need, at any given time.

“We’re talking about the vehicle manufacturers here, where they may have a very defined toolchain. If you take that out to the supplier level, Tier One suppliers, for example, might be working with many different vehicle manufacturers, all of whom have different toolchains in place,” said Ewbank. “They want to buy one driving simulator to evaluate tire performance on, but they also want to connect to every toolset that their customers use. There’s a very powerful reason for wanting an open architecture.”

As for the Spectris acquisition of Concurrent Real-Time, Ewbank notes that there is a lot in the mix. But he’s unable to give many specifics.

He said, “we are able to go through some planning at this stage. We are not able to share highly confidential information between the companies. But certainly, there’s a lot of product discussion and product planning taking place.”

As for what type of product enhancements could come from these discussions, Ewbank was uncertain. But he did note that in the future “I think the FMI is an area that will see some enhancements for driving simulator applications.”

For more on VI-grade, read Driving Simulators: Engineers Need Explorations into How Models Feel

Written by

Shawn Wasserman

For over 10 years, Shawn Wasserman has informed, inspired and engaged the engineering community through online content. As a senior writer at WTWH media, he produces branded content to help engineers streamline their operations via new tools, technologies and software. While a senior editor at Engineering.com, Shawn wrote stories about CAE, simulation, PLM, CAD, IoT, AI and more. During his time as the blog manager at Ansys, Shawn produced content featuring stories, tips, tricks and interesting use cases for CAE technologies. Shawn holds a master’s degree in Bioengineering from the University of Guelph and an undergraduate degree in Chemical Engineering from the University of Waterloo.