Experimental Proof-of-Concept of HiL Based Virtual Calibration for a Gasoline Engine with a Three-Way-Catalyst

The increasing complexity of modern combustion engines together with the substantial variability of hybrid electric powertrains, lead to new challenges in function development, system integration and vehicle calibration processes. Hardware-in-the-Loop (HiL) simulations have been introduced to front-load part of the testing and calibration tasks from the vehicle to a virtual environment. With this approach, the simulation quality and the cost-benefit ratio are strongly dependent on the accuracy of the plant modelling and the computational effort.

This paper introduces a novel HiL simulation platform for an engine control unit (ECU) with a crank-angle resolved real-time model (GT-Power) for a gasoline engine with direct fuel injection, single stage turbocharging and a three-way catalyst. By simplifying the fluid dynamics simulation model from the concept phase, a good compromise between model accuracy and computation speed can be achieved with relatively low effort. The coupling of the engine model and the hardware ECU has been implemented using a realtime workstation with a co-simulation platform (xMOD) coupled to a HiL-simulator with the necessary I/O boards (dSPACE). The closed-loop boost pressure and the air-fuel ratio control by the hardware ECU shows a system behaviour close to the real engine on a dynamometer test bench. The HiL setup can be used to investigate various real driving scenarios for calibration purposes.