The systematic, thorough testing of today’s complex, safety-critical or reliability-critical embedded systems is a must. Because this, test environments have to meet a new, but increasingly important requirement. This requirement is, to test a device not only in static situations, but in dynamic ones. Furthermore, it’s important to simulate real world conditions, to ensure appropriate timing, to provide deterministic execution of tests, and to validate the behavior of the tested device. Due to these requirements, the application of a real-time test environment is needed.
The so-called Hardware-in-the-Loop (HIL) test method is used to test complex, real-time, embedded system. HIL testing provides a more effective way to filter errors. Due to this, development costs and time to market can be reduced. The goal of the HIL method is, to simulate how the environment around the tested controller unit behaves. A great advantage of this test method is that the virtual environment makes it possible to test part(s) of the system, without the availability of the complete system.
HIL testing can be used during the beginning of the development process, for example to test a microcontroller, but the method can be used to validate the functionality of a whole system. During the final tests of a controller unit, not only the proper functionality, but the effects of possible errors can be examined too. Using a simulated test environment makes possible to run tests without stopping, and the accurate reproducibility of processes, measurements is available too.
The topic of my thesis is the implementation of a HIL test environment, which is based on hardware and software solutions of National Instruments. The test environment is based on the NI VeriStand software environment. The main hardware unit of the test system is the PXI modular measurement and control device of NI.
The A variety of analog and digital signals is needed as stimulus for the tested embedded system. The HIL simulation is a powerful method to make testing of embedded control systems more efficiently. It can be included to the development process too, because HIL testing is available on parts of the system.
The task of this HIL test environment is, to validate a specific automotive controller.