Virtual Calibration: What It Is and How It Helps Your Development Process
Common Calibration Challenges
Powertrain testing and calibration is an essential part of the product development process, but it often takes years and costs millions of dollars to complete. The list of internal and external requirements for these powertrains has grown significantly over time due to regulatory (OBD/emissions), customer (efficiency), and manufacturer (reliability) demands. To meet these requirements, testing and calibration is performed via in-house tests, on-vehicle tests, trips to locations with extreme weather conditions, or specialized test benches.
Many unanticipated events happen during these tests such as destroyed prototype parts and delayed test trips that cause teams to miss the target weather conditions when a winter trip turns into a spring trip. It is very clear that doing 100% of powertrain tests with physical tests is inefficient and comes with risks.
There are many iterative engineering tasks (calibration/controls development) that are well-suited for a virtual or simulation environment. This greatly reduces the costs and time associated with traditional physical tests, while also incorporating those physical tests into the process.
Virtual calibration is defined as the act of performing traditional calibration/controls development tasks upfront in a simulation environment. It offers a solution to perform the same tasks quickly and at a lower cost.
Virtual powertrain calibration is a method that is actively being performed at many automotive and commercial vehicle (on/off-highway) companies. The value in virtual calibration is to let simulation perform most of the upfront work (baseline calibration, controls development, etc.) and let expensive and time-consuming testing perform the validation and refinement. Basically, sparingly use the expensive resource (testing) while taking care of the brunt of the work with the low-cost resource (simulation).
There are several benefits that come immediately to mind in Virtual Calibration (I am sure you are already thinking of some):
- Simulation has a lower cost to enter than test equipment.
- When the virtual calibration is performed it can be automated and does not require as much supervision.
- Enables full design space exploration at low cost/time.
- Virtual environment allows for any ambient boundary conditions to be created at minimal extra cost.
- Avoid expensive damage to prototype hardware during calibration.
- Many OEMs/Suppliers already have the framework in place to perform virtual calibration.
In my experience all OEMs and Manufacturers perform some form of powertrain simulation and could easily implement a virtual calibration workflow. This offers a great benefit to the engineering process and enables more efficient use of engineering time.
Virtual calibration is a way for the industry to respond to quicker development cycles with tighter regulatory requirements and increased customer expectations. As I mentioned earlier, virtual calibration is not meant to make testing obsolete, but to supplement testing and create a more efficient engineering process.
This blog is just the first in a series of blogs on virtual calibration that will be published in the coming weeks. Check back for future blogs that explain the different types of virtual calibration (open-loop and closed-loop). If you are interested in discussing virtual calibration or would like more details please reach out and contact us.
Written By: Michael Bambula