Development of HIL test system for system optimization
For a client in the automotive industry, Infotiv Test & Development, together with the client, developed a system for testing and optimizing a complete system with engine, exhaust aftertreatment and control units. The assignment was an important part of the clients goals to move 20 percent of testing in a physical test cell to virtual testing in HIL (Hardware-In-the-Loop) test system. Infotiv delivered a total of four test systems to the client.
The system consists of simulation models for engine and exhaust aftertreatment that are connected to a physical engine control unit through the HIL system. The simulation models calculate a large amount of measurement parameters for the system, including temperatures, pressures, fuel consumption, and emissions. Simulation models of several types are integrated into Simulink and then connected to a real-time system that simulates the sensors (analog voltages and pulse trains) and data buses (CAN) that are needed to test the complete system. In this way, it is possible to run test cycles on the simulated system and to optimize the control system.
Infotiv chose to base the real-time system on the National Instruments PXI platform. Modules for analog inputs and outputs, as well as CAN are used. To control and configure the system, the Veristand software by National Instruments is used.
When Infotiv’s first concept system proved successful, Infotiv also received the assignment to design and deliver several test rigs to meet the clients increased test needs. The concept was adapted to the clients needs and focused on only implementing the test functionalities that were most valuable. To mention one, existing hardware was used for the components that did not need to be simulated. Thus, giving the customer the possibility to quickly begin using the system, but also to avoid unnecessary costs and complexity. The delivery could quickly generate value to the product development projects that were supported, in terms of e.g. calibration of new diagnostic functions.