Innovative Control Strategies for the Diagnosis of Injector Performance in an Internal Combustion Engine via Turbocharger Speed

Abstract

In order to ensure a high level of performance and to comply with the increasingly severe limitations in terms of fuel consumption and pollution emissions, modern diesel engines need continuous monitoring of their operating conditions by their control units. With particular focus on turbocharged engines, which are presently the standard in a large number of applications, the use of the average and the instantaneous turbocharger speeds is thought to represent a valuable feedback of the engine behavior, especially for the identification of the cylinder-to-cylinder injection variations. The correct operation of the injectors and control of the injected fuel quantity allow the controller to ensure the right combustion process and maintain engine performance. In the present study, two different techniques are presented to fit this scope. The techniques are discussed and experimentally validated, leading to the definition of an integrated control strategy, which features the main benefits of the two, and is able to correctly detect the cylinder-to-cylinder injection variation and, consequently, properly correct the injection in each cylinder in order to balance the engine behavior. In addition, the possibility of detecting misfiring events was assessed.

Wrong Injection Detection in a Small Diesel Engine, a Machine Learning Approach

“…Each sample presents a certain num- ber of features (inputs to the model) and two labels (outputs of the model) referring respectively to a general anomaly (at least 1 out of 4 cylinders has a wrong injection) and to a localized anomaly (the 1 st cylinder presents a wrong injection). Data collection phase was not performed during this activity but was carried out previously; indeed the experimental setup, the sensors description and the engine features are extensively reported by Becciani et al in (Becciani et al, 2019). For a better understanding Figure 1 shows the matrix of tests performed during data collection; in particular it shows the normalized injected fuel quantity at three engine load levels by varying the engine speed from 1000 rpm to 3000 rpm by steps of 250 rpm.…”

Real Time Estimation of Combustion Indicators on a 4-Cylinder CI Turbocharged Engine Based on Instantaneous Engine Speed Measurement with Rapid Prototyping Implementation

“… engine block vibrations, [6][7][8];  acoustic emissions [9][10][11][12];  engine torque by means of torque sensors [13];  measurements through a load cell placed under the head studs, [14][15][16], correlating force to internal pressure;  the use of an instantaneous speed sensor of the turbocharger, [17][18], which allows to derive the thermodynamic cycle of the various cylinders through the analysis of the energy contained in the exhaust gases; However, all these technologies have the common downside of needing the installation of additional sensors on the engine. On the other hand, the use of instantaneous speed measurement, obtained from the engine's phonic wheel, allows to derive the in-cylinder pressure without the need of additional sensors, being this signal already acquired by the engine control unit [19][20][21][22][23][24].…”