Range anxiety

Using ETAS calibration tools to ease range anxiety

Many automotive calibration engineers face a similar challenge – maximizing the range on their EV calibration projects. The concern about the effects of falling temperatures and how the upcoming, unforgiving winter will impact an EV project’s range is real – as is the struggle to limit range loss while keeping a comfortable cabin temperature.

A heat exchanger or heat pump design may address the issue. The Design for Six Sigma (DFSS) tools may indicate everything is covered. But is it really that simple?

Can the DFSS Tool do it alone? Questions and considerations

Will the design be effective during calibration trips to the desert – keeping the cabin, batteries, motors cool?  What about driving style in desert and/or cold climates – will the design address those? For example, will an aggressive driver make the trek in Alaska from Juneau and Fairbanks with two to three or four to eight charging stops?

In the end, there are a lot of questions, use cases, and non-linear and non-homogeneous variables to consider that may go beyond the scope of the DFSS tool. To ease their “range anxiety,” calibration engineers need to be fully confident in their models. And that’s where ETAS solutions can help.

ETAS solution, part 1: Create a comprehensive experiment with ETAS INCA

With ETAS INCA, engineers can quickly create a massive, multi-layered sledgehammer experiment with every imaginable input. The 64-bit application (when operating with Windows 10) provides full memory access, so the experiment will not compromise laptop functionality.

In addition, INCA provides:

  • Functional enhancements to address future calibration challenges, including improved hardware configuration and MatLab integration, as well as automotive Ethernet, AUTOSAR support and ADAS calibration.
  • The ability to load multiple data sets in the calibration data manager (CDM) without functionality issues.
  • Enhanced data buffering eliminates any chance of data buffer overflows.
  • Improved hardware configuration, allowing up to 4 CAN/CAN-FD description files on one CAN/CAN-FD node. And it’s ok to mix .dbc (database configuration) with AUTOSAR files.

ETAS INCA hardware configuration

ETAS solution, part 2: Obtain full statistical confidence with ETAS ASCMO

The ETAS ASCMO product family (Advanced Simulation for Calibration, Modeling and Optimization) offers a wide range of solutions for data-based system modeling and optimization. It is a powerful statistical tool that has a wide range of applications for nonlinear systems.

ASCMO-MOCA (MOdel CAlibration) optimizes parameters in physics-based models, including those used in ECU and simulation environments. Various plant models and controller models can be loaded, connected or modeled. In addition, measurement data can be loaded, model parameters can be imported and exported, and optimization tasks can be defined. ASCMO-MOCA provides a variety of functions and options for visualizing and analyzing data and models used – it’s like doing rocket science without having to be a rocket scientist.

With the ASCMO Static’s (AS) Design of Experiments creator, engineers can input that list of variables keeping them up at night, including:

  • Driver demand
  • Ambient temperature
  • Cabin comfort level
  • Manual control
  • Auto control
  • State of Change (SOC)
  • State of Health (SOH)

From there, they can use AS’s Convex Hull Compression tool, which reduces the design of experiments (DoE) size with low error, to begin gathering data and create custom response models.

ETAS ASCMO

If they already have data or a virtual model of the EV HVAC system and battery management system (BMS) (e.g., a Simulink model, FMU, c-code), it can be directly imported into MOCA through a user-friendly optimization tool. Once imported, optimization of all calibration variables is done simultaneously to achieve maximum range under certain cabin comfort and driving style constraints.

ASCMO-MOCA accurately reflects reality
In ASCMO-MOCA model data (blue line) can be adapted to real systems (black line) to reflect reality as accurately as possible

What does all this mean, especially looking at the software-defined vehicle of the near future? ASCMO-MOCA can continuously optimize in real time as drivers travel from point A to point B. No need to stop for vehicle updates at a dealership – it just happens along the journey. Cool stuff.

ETAS calibration tools help engineers maximize range and alleviate range anxiety with affordable, user-friendly solutions for all EV HVAC scenarios.

Contact us to learn more about ETAS INCA and ETAS ASCMO, and to see how our tools and solutions can help you get the most out of your calibration activities.

Also see our earlier blogpost on Calibrating electric motors with ETAS ASCMO.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.