Engine performance monitoring using spark plug voltage analysis

Abstract

Spark plug based engine combustion diagnostics have the advantage of simplicity and easy access. Over the years there has been considerable interest in developing and applying spark plug ionization probes to monitor the in-cylinder combustion process. In this paper, alternative approaches are presented using the spark plug as the primary sensor. These methods are based on the analysis of the spark voltage and a secondary high-voltage discharge. A series of experiments have been conducted to evaluate their potential in the measurement of combustion quality and the detection of misfire. It is found that the spark voltage decay time is related to the initial flame kernel development and may be used to detect misfire and deteriorating combustion quality in the initial flame development. The results also show that the analysis of secondary voltage decay time could be an effective means of monitoring the combustion quality and detecting misfire during the main combustion period.

Development of vacuum-tube-based voltage and current probes for automotive ignition systems

“…Although the vacuum tube voltage probe can measure only a positive spark voltage, it can be applied to ignition systems with double-ended coils and to other systems equipped with multi-electrode-type spark plugs, which need the positive polarity of the central electrode. 7,20 An advantage is that the non-contact current probes are isolated from the ignition circuit. On the other hand, the ignition cable should pass through the hole in the current sensor.…”

“…Many researchers have proposed simulation models 3 and various spark energy estimation and measurement methods. [4][5][6][7][8][9] According to the publications, the spark energy can be characterized through voltage and current monitoring. High-voltage measurements are often performed using passive probes, e.g.…”

Overview of Electric Field Applications in Energy and Process Engineering

“…In particular, misfire and knock detection is of high relevance and currently ionization current measurement systems have been used as well for pre-ignition detection. Furthermore, it is applicable to study spark plug fouling and for assessment of the combustion quality [139][140][141]. Misfire is also an abnormal combustion phenomenon that can lead to high hydrocarbon emissions and deterioration of engine performance and catalyst function.…”

A transient virtual-AFR sensor using the in-cylinder ion current signal

“…Spark plug voltage analysis, more specifically, the voltage decay time can be used to study AFR [7]. The principle is that the spark discharge time is related to the number of ions in the flame and, hence, the quality of combustion.…”