HIL is a testing and simulation technique where a physical system or component is connected to a simulation environment through hardware, creating a closed-loop system. This setup allows for the testing and evaluation of the real-world performance of the hardware under various conditions.
By adding hardware-in-the-loop (HIL) testing, engineers can get more out of unit 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 does HIL Work?
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. 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.
The results generated by a Hardware-in-the-Loop (HIL) system typically comprise data, measurements, and feedback obtained throughout the testing and simulation procedures. These results play a crucial role in evaluating the performance and operational capabilities of a physical system across diverse simulated conditions. Although the precise output may differ based on the tested system type, it commonly encompasses outcomes like sensor readings, actuator responses, metrics reflecting system behavior, and other pertinent performance indicators. The primary objective is to authenticate and confirm the hardware’s functionality by simulating real-world scenarios within a controlled environment.
Take the case of HIL testing for automotive or e vehicles, a steering is mounted on the test bed and simulated with real-world scenarios. Wheel direction, angular rotations, and other parameters are evaluated. Similar to Steering HIL the, ECU, Suspension control module (SCM ), Battery management system (BMS), Airbag control module (ACU), and Climate control unit (CCU) HIL systems are developed.
HIL Testing in 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 modules and devices from third parties and provide the freedom to adapt to the changes in signal lists and I/O specifications. HIL systems can be best used during verification and validation on a standard test architecture.
TMCS Offerings -HIL Systems:
With years of experience, the TMCS team is equipped to deliver challenging HIL systems like Transmission Control Module (TCM), Brake Control Module (BCM), Central Control Module (CCM), Central Timing Module (CTM), General Electronic Module (GEM), Body Control Module (BCM),
Hardware-in-the-loop (HIL) testing facilitates a thorough evaluation of a system’s behavior and performance, offering valuable insights to developers, engineers, and stakeholders. The observations gleaned from this testing process serve as a guide for making refinements and optimizations, thereby playing a pivotal role in the overall success of hardware integration and development projects. By leveraging the outcomes of HIL testing, teams can make informed decisions, address potential issues early in the development cycle, and ensure the seamless integration of hardware components. This approach enhances the reliability, efficiency, and functionality of the system, ultimately contributing to the successful realization of the project goals.
Key Benefits Of HIL Testing:
- 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.
- Repeatability, Flexibility of the system
- HIL offers 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 ( here I mean company development teams, accelerating the development process.
Key Features of HIL Testing:
Efficiency in Scenario Testing:
HIL testing allows developers to navigate through hundreds of scenarios, all without the time and cost constraints associated with traditional physical road tests. This capability enables exhaustive scenario testing in a controlled and replicable environment.
Some scenarios in automotive testing are inherently dangerous or impractical to replicate on the road. HIL testing steps in as a safer alternative, providing a controlled environment to test edge cases, emergencies, and other scenarios that would be risky or infeasible in real-world conditions.
Automation and Multithreading for Speedy Development:
The HIL testing process is highly automated, embracing the power of automation to execute tests seamlessly enabling the simultaneous execution of multiple tests. This parallel testing capability significantly accelerates the development process, allowing for faster iterations and quicker identification of issues.
Timely Flaw Identification:
While HIL testing occurs later in the development process compared to Software-in-Loop (SIL) testing, it still takes place within the CI/CD/CT parameters. This positioning enables developers to catch potential flaws, ensuring a more reliable and refined final product.
Enhanced Collaboration and Information Sharing:
HIL test results are not confined within the development team’s silo. Instead, they can be easily shared with development teams from OEMs and third parties. This open exchange of information accelerates the development cycle, contributes to the overall quality, reliability, and safety of the product, and fosters collaboration in the industry.