Deployment of Vehicle Thermal Management analysis tools

FMI Add-in for Excel helps you deploy simulation models to the masses

Why deployment and what does it mean?

OEMs often face the problem of small groups of model developers, but large groups of model users.

For example, let’s think of a Vehicle Thermal Management analysis where the power train and thermal engineers seek to understand the effects of different system parameters, controller, and air conditioning settings on the fuel consumption and other engine details such as coolant temperatures, torque, etc. 

In this case the analysis engineers could use the detailed Modelica models developed by the model developer, but that would require that they are experts in Modelica, experts in the modeling tool (e.g. Dymola) and also have access to the modeling tool.

The solution we propose involves FMI Add-in for Excel (FMIE), a tool developed by Modelon, which allows you to work in the familiar environment of Excel® while still using detailed physical models.

We demonstrate this workflow below.

Four step workflow

1. The model developer annotates the key variables and parameters of interest for the analysis within the model itself.  The annotations follow a standard markup [1] that the simulation tool can interpret automatically.  The variables and parameters can be at any level within the model. 

When the model is ready, the developer then generates a co-simulation FMU from the test case model and shares that with you, the thermal management or power train engineer.

2. With FMIE installed, you then open the Excel workbook and can optionally automatically load the FMU (Functional Mock-up Unit [2]), or manually load a new FMU.

The annotated variables are automatically populated on an experiment sheet, as shown in the right column in the next figure.

The tool automatically simulates your application for the default parameter variant saved in the original model.

Once the simulation is complete, Excel® charts are automatically generated for all the annotated variables.  A subset of these figures is shown in the Plt_DriveCycleVTM worksheet below.  Up to this point, no interaction from you was needed beyond simply opening the workbook (and optionally locating the FMU).

3. Now it is very easy to create new experiments for custom studies.  Simply duplicate an existing worksheet and enable the test cases for the desired system parameter sensitivity studies - see sheet Exp_DriveCycleVTM(2) below.

4. Charts including all cases are automatically created. This simplifies the comparison of results across cases:

You can then calibrate and tune things like shift schedules and component sizing all while still capturing the effects on fuel economy and thermal management.

Run your system analysis while staying in Excel

We hope that this simple 4 step demo clarified how easy is to deploy models across an organization. That it showed how to enable analyses without requiring knowledge of specific modeling tools, by staying in the friendly and familiar environment of Excel.

If you are interested in achieving a seamless system analysis involving models from different groups in your organization, or if FMIE can be useful for you without being expert in specific simulation software, just drop us a line to ask. We will be happy to answer! 

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[1] Markup – a standard annotation format added to the variable descriptions in the native model to support automated deployment: https://github.com/xogeny/XenGen/wiki/Markup

[2] FMU – a binary simulation file containing the model exported from your modeling tool that supports FMI standards: https://www.fmi-standard.org


Jesse Gohl has been working in model based engineering since 2003. He holds a MSc in Mechanical Engineering from the University of Minnesota with a focus on controls.  At Modelon he supports customers adopt model based development strategies with both Modelica and FMI technology in a variety of fields. 

Adina Tunér is a Marketing Communications Manager at Modelon. With a keen interest in writing, a PhD in Mechanical Engineering from Romania, another one from Sweden, and with 17 years of engine research in her rucksack, Adina settled lately for the challenges of melting together innovative technologies with business and communication.

by Jesse Gohl and Adina Tunér