1.) Reducing test time and costs
Experiments with real-world test systems are usually very time-consuming and can require high costs. Therefore, before beginning the actual test, it makes sense to realize the optimum functions with the help of a simulation. Parts of the system or the environment can be simulated using models. This allows, for example, the brake system of a vehicle to be tested ahead of time on a test stand, without using a vehicle.
2.) Preliminary testing
In the development of new systems, there is often times not a finished product available for testing. Nevertheless, in order to examine early models or components of the system, the missing parts and/or environmental conditions can be simulated. Thus, for example, in ECU development, there is often no target hardware available. In order to optimize regulation and control algorithms, the target hardware can be simulated using HiL. The exchange of information is generally via bus systems, and is therefore referred to as a bus simulation.
3.) Reproducibility and variability of tests
In order to draw comparisons between components or systems, an exact reproducibility of the experiments is required. When systems are tested in real-world environments, e.g., a vehicle in a driving test, many external factors such as weather, driving style, route details, etc., affect the comparability of test results. Therefore, exact reproducibility and systematic variability is only possible if the external factors are simulated.
HiL simulation allows tests to be carried out safely in an environment that could otherwise be dangerous. For example, when testing a vehicle, the driver/pilot could be exposed to potentially high risks. Likewise, a battery being tested could also be exposed to unnecessary dangers that could lead to distress. Hil simulation protects personnel and materials from this.