In this project we implemented a real-time, high-performance hardware-in-the-loop software framework in LabVIEW. The distinguishing features of the framework are flexibility through a generic API for the specification and debugging of test sequences, easy deployment in hybrid (real-time/desktop) environments, and a heavily optimized execution engine for high test throughput.
Airmatic Ltd. is an SME from Kecskemét, Hungary, building test benches for configuration and functional testing of their customers' product/assembly lines, mainly for the transportation domain (such as railway and heavy goods vehicles). Airmatic test benches are equipped with a complex software system to support the specification, execution and display of test sequences. This project was about designing and implementing a future version of this software system, also called Airstudio. One of the main challenges for Airstudio lies in the ability to execute tests in a real-time manner, which poses special requirements against the software and hardware environment. A second, but just as important challenge is performance throughput, i.e. the number of test commands executed per time unit. Real-time guarantees and high execution performance are usually contradicting requirements that call for a compromise.
First, to help Airmatic assess the risks, we started with careful requirement analysis and a comprehensive study. It was determined that off-the-shelf solutions, such as Veristand, do offer real-time guarantees but lack flexibility with respect to how the real-time core can interact with the user interface, which results in limited applicability. Therefore, it was concluded that no viable existing solution exists in the LabVIEW ecosystem, and thus custom development is the best way to go forward. Hence, Airmatic and IncQuery Labs have agreed on collaboratively developing a novel solution, in the framework of a 6-month project. The goal was to realize a feature-complete prototype of Airstudio, a new test sequence editor and execution software platform, featuring a real-time capable high-performance test execution engine and a flexible user interface. The project plan specified that the development of the engine itself and the corresponding programming interfaces, most notably for human-machine interactions and debugging purposes, was to be developed exclusively by IncQuery Labs, while the complete user interface and experience were the responsibility of Airmatic.
Despite its complexity, the project has been delivered as specified and on time. Alongside the real-time execution engine, IncQuery Labs have also developed a flexible application programming interface (API) for editing and debugging domain-specific test sequences. Based on this API, Airmatic successfully realized a visual interactive development and debugging environment (IDE), so that their users can create custom test sequences too. The validation of Airstudio was carried out using a complex real-time reference test sequence, as well as an actual device under test: a valve used in automotive braking systems. The final tests also successfully demonstrated the minimum required performance of Airstudio, i.e., the throughput of test sequences. In fact, the actual throughput exceeded the required number by more than one order of magnitude. This enables Airmatic’s customers to execute test sequences much faster, allowing for faster development cycles and shorter time-to-market. As IncQuery Labs was also responsible for the project management and coordination, we have customized and documented a new agile R&D process as an enhancement of standard software practices. This allowed the joint team to deliver very complex results without delays. Additionally, we have also modernized the customer’s software development toolchain, including version control and continuous integration.