In modern vehicles, a large number of electronic control units regulate important applications such as ABS or airbag deployment while driving. However, the complexity and interaction of different control systems must be tested in advance before the first prototype can leave the assembly line. The solution: simulations that can demonstrate a realistic check of the various features, such as braking behavior in slippery conditions. The automotive industry relies on so-called HiL (Hardware in the Loop) systems. The engineering company in-tech has developed its own modular orangeHiL system for complex simulation processes. With a real-time test and simulation environment, this system meets all the requirements of a fully-fledged HiL test bench. "With orangeHiL we simulate the conditions in the vehicle before the first prototype was ever built. This means that the vehicle electronics can be tested under real conditions very early in the development process," explains Managing Director Christian Wagner. A new load simulation component has recently been added to the system.

The orangeHiL system enables realistic testing of the functionality of ECUs outside their physical system environment. Individual control units, such as transmission control, stability control and the like, can be tested on the test bench independently of the vehicle. A real vehicle in a real environment is simulated for the control unit. To achieve this, the module to be tested receives a large number of signals from the orangeHiL system. In the example of stability control, these would include wheel speeds, lateral and longitudinal acceleration, road friction coefficient and much more. The output signals of the control unit to be tested are then read in again by the orangeHiL system. This makes it possible to test whether the control unit behaves correctly.

Just like in the vehicle later, the control unit is connected via buses such as CAN, LIN, Flexray and analog/digital/PWM interfaces for sensors and actuators. As a rule, testing is not performed manually, but by means of test automation programs. "Depending on the customer, individual applications can be connected here. The orangeHiL system is controlled and monitored either via a tablet or various PC applications," Wagner continues.

Wireless data transmission

The results can be accessed wirelessly using the orangeCtrl App developed by in-tech. The Android solution accesses the sensor data on the CAN bus and the HiL system and transmits the information to mobile devices via WLAN or Bluetooth. In addition, the user can also control the HiL system with the app. For example, start and stop processes are possible, as well as loading models and changing simulation parameters.

Modular design and automated test sequences

"The most innovative feature of the orangeHil system compared to other HiL systems is its modular and distributed design. Via the EtherCAT control bus used, the orangeHiL system can be constructed comparatively modularly, small and cost-efficiently. The system is connected via simple LAN cables. This allows battery test stands, for example, whose low-voltage and high-voltage components are spatially separated from each other, to be tested simply and distributed. As an option, it can also be operated as a classic 19-inch test stand," says the managing director. Together with the orangeSwitch (patent pending), the orangeHiL allows highly automated test sequences and optimum test stand utilisation. The system is also highly scalable and adaptable: customers can individually select their product from a Mini-HiL for desktop use to a full-size test bench.

Existing test platforms can be seamlessly expanded by integrating orangeHiL load simulation. The orangeHiL load simulation enables complete HiL tests on control units which, in addition to communication, sensors and actuators, also simulate electrical loads such as interior and exterior lights, window and windscreen wiper motors, seat heating and much more. "For simpler applications, such as the simulation of pure constant loads, we also offer stand-alone load boxes," adds Christian Wagner.