Abstract
Keywords: Hardware-in-the-Loop simulation, power steering systems, fuel consumption, energy management, driving cycles
This paper describes the application of Hardware-in-the-Loop simulation (HIL/S) in power steering systems of passenger cars, along with the procedure for determining the fuel consumption in customer-oriented driving cycles.
HIL/S integrates actual power steering systems with the vehicle model, forming a closed loop to be simulated in real time. It makes possible the identical test procedures that are difficult or even impossible to achieve in actual driving tests. Provided that the test procedures (i.e. driver input, vehicle parameters and road conditions) are identical, an objective comparison of the influence of power steering systems on the vehicle fuel consumption and energy management can be made. The results of the HIL/S have better credibility than that from pure numerical simulation.
The HIL test system has been built at the Lehrstuhl für Fahrzeugtechnik of the Technische Universität München. The modular design of the HIL test system allows integrating various power steering systems such as for conventional hydraulic power steering, electro-hydraulic power steering and electric power steering. The efficiency analysis and comparison is based on driving cycles which synthesise various day-to-day driving patterns with steering actions (urban, road, motorway). Data is provided which demonstrates the total sum of fuel savings through power-on-demand systems.