The article discusses the method of evaluation of the fuel injector operation based on the observation of the electric current parameters, which were measured with a current transducer using the Hall effect, during the dosing process. This method relies on comparison of the electric current-related values of the examined injector with the model characteristics, which are representing the properly functioning injector. A model of the fuel injector in the form of the electric current waveform that describes the changes in the electric current and voltage during its work is presented in this article. Complex equations describing the fuel injector model under discussion account for the characteristics of the current variations, with no damage-induced modifications. Due to these, the modeled electric current/voltage waveform mirrors the real conditions. The use of a mathematical model describing the voltage–current phenomena occurring during the injector operation allows determining the actual beginning and duration of the injection. The model can also be used to develop new injector diagnostic methods that can be implemented in the engine controller (ECU).
This paper discusses a method of diagnosing electromagnetic valves of injection systems in combustion engines. Based on multiple analyses of electrical quantities occurring in the course of the electromagnetic injector work and physical relationships between them, the quantities have been demonstrated on which the fluctuation of the electromagnetic force in the injector depends. Moreover, the results of its fluctuations have been mapped to the electric quantities controlling the fuel injector’s work. The research has shown that the current and voltage waveforms contain information on electrical properties of the injector coil and its mechanical properties determining the injector’s technical health as well as that of the fuel system.
12 June 2020 in Eksploatacja i Niezawodność – Maintenance and Reliability
The aim of the work was to develop a method of real time diagnosing electromagnetic fuel injectors using the observation of electric current parameters available in the engine control unit. Performing this task required finding a precise criterion for assessing the correct operation of an...
This work discusses the proposition of the identification of electrical waveforms resulting from the executive systems’ operation, controlled by the vehicle electronic modules. This proposition results from the fact that the electric current powering the actuator has two functions: to supply and to control. Observation of such waveforms enables the ongoing control as well as the diagnostics of the state of the executive elements. This work focused on the fundamentals of the method implementation in the vehicle controller. The algorithm for detecting the model values of the waveform has been developed and described, allowing for an efficient control of the system. The algorithm, after being used in the memory of the control module and having the measuring subassemblies (gauging the voltage and electric current) added, will enable the automatic detection of the essential values. The developed code, after the optimization, can support the control performed by the ECU, which is damage-orientated. The paper presents examples of the operation of a computational program developed on the basis of the adopted algorithm. Tests were performed on an electromagnetic valve—fuel injector—of a spark-ignition engine for different cases of its operation. The effectiveness of the program was demonstrated when detecting changes occurring in the current signals of fuel injectors corresponding to different engine speeds (time of 4 and 8 ms) and different loads (pressure of 0.2 and 0.4 MPa).