Over recent decades, multiple iterations of emissions standards have drastically reduced the amount of polluting emissions permissible when operating commercial vehicles. Electrically controlled fuel injection systems have been crucial to achieving these standards. To be highly effective, each of the injector’s sub-systems must perform near optimally; but how can the highest standards of performance be maintained for an extended time in an aggressive, high-temperature, high-vibration, Diesel engine environment? One way might be to implicitly monitor valve condition. As a first step towards this aim, this paper discusses models of the interactions between the electrical drive and electro-hydraulic valve sub-systems of an injector developed using Matlab-Simulink®. This is a critical element in understanding how implicit sensing procedures might be developed that could provide robust, micro-second accurate injector performance across the unit’s 1 000 000 mile lifetime. Consideration is given to how the electronic controller generates drive current in the electro-magnetic sub-system and how this develops the Maxwell Pulling Force within the unit. The effect of this force on control valve pin displacement is then explored. To create a usefully representative model requires that feed-forward and feedback interactions between sub-systems are included. Various system models are described and demonstrated to be useful by comparison of their outputs to known data sets.
