Computationally inexpensive methods of ion current signal manipulation for predicting the characteristics of engine in-cylinder pressure

Recent research on the use of ion current has focused on matching the characteristics of the in-cylinder pressure, thus avoiding the use of a pressure transducer. This paper explores techniques of calculating these pressure characteristics through the use of simple and computationally inexpensive artificial neural networks. Two neural networks are presented to deduce the in-cylinder pressure from ion current measurements, where one is used to predict the characteristics directly and the other is used to calculate the in-cylinder pressure curve. Experimental results show that both networks give satisfactory results for different purposes. Some engineering implementation issues and the further improvement of the developed techniques are discussed

Using in-cylinder gas internal energy balance to calibrate cylinder pressure data and estimate residual gas amount in gasoline homogeneous charge compression ignition combustion

Data established from pressure measurements in HCCI operation can prove problematic to calibrate due to the presence of TRG, pegging, and thermal shock issues. This article presents an algorithm aimed at using the measurements available on a typical research engine to overcome these issues, yielding properly calibrated results for both averaged and individual cycles

The advance combustion control in a hybrid SI/HCCI engine by using ion current sensing

In a future ‘hybrid mode’ SI/HCCI engine transition between these modes, over the operating map, will play a crucial role. The engine management system must provide a fast and smooth transition between these two modes, hence a new combustion feedback based control system is needed. The aim of this paper is to investigate the use of an ion-current sensor in SI/HCCI engine for direct combustion feedback control. The experimental results obtained, at different speed and loads, show that the estimation of cylinder pressure, through the ion signal, can be performed with high accuracy, and that ion-current has the potential to be a cost effective solution for direct combustion control

Political travel across the ‘Iron Curtain’ and Communist youth identities in West Germany and Greece in the 1970s and 1980s

This article explores tours through the Iron Curtain arranged by West German and Greek pro-Soviet Communist youth groups, in an attempt to shed light on the transformation of European youth cultures beyond the ‘Americanisation’ story. It argues that the concept of the ‘black box’, employed by Rob Kroes to describe the influence of American cultural patterns on Western European youth, also applies to the reception of Eastern Bloc policies and norms by the Communists under study. Such selective reception was part of these groups’ efforts to devise a modernity alternative to the ‘capitalist’ one, an alternative modernity which tours across the Iron Curtain would help establish. Nevertheless, the organisers did not wish such travel to help eliminate American/Western influences on youth lifestyles entirely: the article analyses the excursions’ aims with regard to two core components of youth lifestyles in Western Europe since the 1960s, which have been affected by intra-Western flows, the spirit of ‘doing one’s own thing’ and transformations of sexual practices. The article also addresses the experience of the travellers in question, showing that they felt an unresolved tension: the tours neither served as a means of Sovietisation nor as an impulse to develop an openly anti-Soviet stance.PostprintPeer reviewe

Using ion-current sensing to interpret gasoline HCCI combustion processes

Homogeneous charge compression ignition (HCCI), combustion has the potential to be highly efficient and to produce low NOx, carbon dioxide and particulate matter emissions, but experiences problems with cold start, running at idle and producing high power density. A solution to these is to operate the engine in a ‘hybrid mode’, where the engine operates in spark ignition mode at cold start, idle and high loads and HCCI mode elsewhere during the drive cycle, demanding a seamless transition between the two modes of combustion through spark assisted controlled auto ignition. Moreover; HCCI requires considerable control to maintain consistent start of combustion and heat release rate, which has thus far limited HCCI’s practical application. In order to provide a suitable control method, a feedback signal is required. This paper will investigate the use of an ion-current sensor in HCCI combustion in order to extract and quantify combustion measurants, with particular reference to control applications. A presentation of results of ion-current sensing for monitoring combustion under steady state operation, over a variety of speeds and trapped residual gas amounts is made. The results show that estimation of cylinder pressure parameters through the ion signal with promising accuracy is shown, and ion-current is proven to be a cost effective and adequately informative feedback signal for both SI and HCCI engine control