I learned a new term today—hardware-in-the-loop simulation. Raise your hand if you’ve heard of this before. Yeah, I thought so. For those of you with your hands down, hardware in the loop simulation, or HIL simulation, is a technique that allows devices to be tested in real-time thereby increasing the efficiency of those tests.

You’re likely aware that safety, availability, and cost considerations can make performing thorough tests of embedded control devices using the complete system impractical. During the HIL test, the physical system that interfaces to an embedded control device is simulated on real-time hardware, and the outputs of the simulator mimic the actual output of the physical system. Hence, the embedded controller thinks that it’s in a real system. The simulation tests all embedded control devices in a virtual environment before moving on to perform real-world tests of the complete system.

Even you’re looking for more information on how this works, National Instruments has written an app note, Key Considerations for Powertrain HIL Test, that goes through it in detail. Note that the app note uses an automotive drive train as its real-world example.