John E. W. Poxon

Development of a driver model to study the effects of real-world driver behaviour on the fuel consumption

The real-world fuel economy of vehicles is becoming increasingly important to manufacturers and customers. One of the major influences in this is driver behaviour, but it is difficult to study in a controlled and repeatable manner. An assessment of driver models for studying real-world driver behaviour has been carried out. It has been found that none of the currently existing driver models has sufficient fidelity for studying the effects of real-world driver behaviour on the fuel economy of the individual vehicle. A decision-making process has been proposed which allows a driver model with a range of driving tasks to be developed. This paper reports the initial results of a driver model as applied to the conceptually straightforward scenario of high-speed cruising. Data for the driver model have been obtained through real-world data logging. It has been shown that the simulation driver model can provide a good representation of real-world driving behaviour in terms of the vehicle speed, and this is compared with a number of logged driver speed traces. A comparison of the modelled fuel economy for logged and driver model real-world drivers shows good agreement.

Determining a suitable all electric range for a light weight plug-in hybrid electric vehicle

With the increasing awareness and adoption of eco-friendly vehicle technologies such as hybrid electric vehicles (HEVs); most if not all major worldwide vehicle manufacturers have released an eco-friendly vehicle or have announced a future release (e.g. concept demonstrator vehicles). Such vehicles can meet current legislative emissions standards (with comparatively lower CO2 tailpipe emissions compared to conventional combustion engine vehicle equivalents), yet performance in the real world is often far worse than quoted test figures (e.g. fuel economy). In order to maintain and grow customer acceptance of such vehicle technologies it is important that real world usage is considered during the design and development processes. This paper describes the method of selecting a suitable all electric range (AER) to meet both legislative emissions and real world usage demands and demonstrates its use through a case study of a lightweight plug-in hybrid electric vehicle (PHEV).