HIL(hardware In Loop) - TMCS

Hardware-In-Loop (HIL) Testing System For Firmware Tests

The software industry uses continuous integration (CI) extensively. CI methods are used to test firmware and software on real hardware that is easy to adapt to electronic designs and simulations. A developer could go through and manually watch these signals while testing, but that would waste a lot of time. Instead, a developer can build in tools that use the HIL test system to automatically sample desirable states.


By adding hardware-in-the-loop (HIL) testing, developers can get more out of unit tests, regression tests, and functional tests. HIL testing can be very helpful for making sure that hardware accesses are working as expected and that all system outputs are also working as expected. When combined with HIL testing, continuous development (CD), continuous integration (CI), and continuous testing (CT) can speed up development, save money, and make the end product better.

How HIL Functions:


In HIL testing, a device and the environment are used to make the electronic control unit (ECU) feel like it is responding to real-world conditions. All the required electronic parts are present on the HIL test bench. In order to determine whether the system under test responds correctly to the inputs, a simulator exposes inputs to real systems, which then send signals to them.


Take the case of HIL testing for automobiles. A scenario where a car moving at 60 kmph around a bend in the rain runs into an unidentified object in the road or an approaching car veering across the center line can be created using HIL test scripts. The HIL test bench is equipped with cameras and radar that provide images to the ECU, which then uses that information to make decisions about what to do next.


Advantages of HIL:

For a number of reasons, HIL testing is an essential step in the modern software development process:

  • Without spending the time and money on physical testing, HIL testing may simulate hundreds or thousands of scenarios.

  • Situations that would be too risky or impractical to test in hazardous conditions can be accommodated by HIL testing.

  • The HIL tests can be repeated.

  • The HIL testing procedure is highly automated and supports multithreading, enabling numerous tests to run concurrently and accelerating the development process.

  • HIL offers a regular software release cycle with predictable system behavior.

  • Although HIL testing takes place after SIL testing, it still falls under the purview of the CI/CD/CT process and allows developers to find any issues before the product is released.

  • Results of HIL tests can be communicated to third parties and company development teams, accelerating the development process. Quality, dependability, and safety are all benefited from this.

HIL testing using NI:


HIL tests use simulation and modeling to evaluate embedded software on automotive ECUs. This cuts test times and increases coverage, especially for test cases that are hard to recreate in physical lab/track/field testing accurately. More than ever, HIL testing is required to guarantee the dependability of EV and ADAS/Active Safety systems that are developing quickly. As a test method, HIL is essential for figuring out how systems and vehicle domains are getting increasingly connected and dependent on each other as they work together to produce important vehicle qualities.


The NI HIL solutions are open and adaptable. They make it possible to add models and devices from third parties and give you the freedom to adapt to inevitable changes in signal lists and I/O specifications. Because NI gives you control over the system instead of the test vendor, you can use HIL systems best during verification and validation on a standard test architecture.