Over the last 18 months Claytex have been working with Hyundai Kia Motor Company (HKMC) to develop a Virtual implementation of their Road Load Data Acquisition (RLDA). During this time, we had an engineer residing with us to co-develop, validate and learn how to use VeSyMA.
The goal of this project was creation and validation of the first stage of a simulation platform to generate road load data. This was a key step in reducing the cost, time and emissions that the durability department within HKMC require to test their vehicles.
Requirements From the Platform
There were several requirements that needed to be met to be a useful tool for the durability engineers. The primary and initial investigation focused on building the Ioniq 5 vehicle model, a couple of which I will expand on:
- Vehicle Controller
- Hydraulic Brake System (Mechanical / Thermal)
- Vehicle Dynamics (Ideal & Bushed Suspension)
- Motor (Electrical / Thermal for Standard & In Wheel Motor)
- Battery (Equivalent Circuit Models / Thermal Cell & Pack)
- Thermal Management (Entire Vehicle Circuit)
- Integrated Vehicle Model (Assembly)
- Durability Scenarios (Tyre / Driver / Road Models)
The scenarios covered several use cases, such as
- Surface events, such as cobblestones
- Powertrain events such as stop and go
- Longer field test from mountain roads
Building the Vehicle Models
With HKMC’s previous experience within VeSyMA, there had already been significant development using the libraries to create vehicles and tests successfully. But this project specifically focused on the idea of scaling a simulation ability, alongside the validation of a proof-of concept task to ensure that the data output is reliable.
To that end, one principal aim was the scalability of models, reducing the reliance on engineers to perform repetitive tasks for each new vehicle or sub-system. Therefore, suspension linkage models were parameterised and extended from VeSyMA – Suspensions models.
But the key ability was that they imported all the data from common excel spreadsheets that are the common dissemination method of suspension data within HKMC. This dependency meant that changing the spreadsheet chosen should be all that is needed to get a bushed suspension model for a different vehicle.
The rest of the components throughout the vehicle were parameterised in more conventional methods, as the data is less standardised. However, the level of detail of each sub-system was scaled to match the requirements for the experiment. For example, when the objective was to investigate the suspension system, higher fidelity suspension but lower fidelity motor models were used, and vice-versa when investigating motor temperature dynamics.
Powertrain and Brakes
The powertrain, brake and thermal models were developed to match the requirements of HKMC, but were all based on existing VeSyMA or supported library models, with the main aim, again, to be scalability and reusability.
Some key areas of investigation involved the In Wheel Motors and associated brake models, therefore particular effort was taken to develop bespoke thermal brake models based on the types of data provided by HKMC to achieve a high correlation when compared to test data.
Validation of the models
As previously mentioned, the key element required to ensure usefulness of the platform was that it produced valid results, and these all needed to be evaluated using test data. All test data was from an existing vehicle, being the Ioniq 5, that had a plethora of both type and quantity of data.
For each sub-system there was a physical vehicle test and subset of variables selected from measured data of that test that served as the goal to be compared against. A simulation was created that was the mimic of that test, either through recreation of the test on measured/representative surfaces or using other measured data as inputs.
Validation of front left suspension from Half-car rig simulation on Belgian Pave
Continuing Development
The relationship with HKMC is continuing and is building on the existing platform to incorporate more suspension types and able to cover a wider range of vehicle platforms. With expansion into covering concept vehicles, it is demonstrating the speed with which vehicles can be tested and evaluated.
For more information, the Modelica Conference paper CoWritten by HKMC and Claytex can be found in the 2025 Conference Proceedings.