A Genetic Algorithm for Determining Cylinder Pressure in Internal Combustion Engines

Abstract

In this paper, a genetic-algorithm- (GA-) based method has been developed to determine the instantaneous pressure in cylinders of internal combustion engines. Some parameters associated with a pressure curve in each cylinder are optimized from two validated submodels which reproduce the engine behavior using a genetic algorithm. In this process, the profile of both measured and modeled instantaneous angular speeds of the engine are compared. According to a typical design of a genetic algorithm, different operators, such as the selection process, crossover, and mutation, have been evaluated and applied over theoretical data. The best results define the adopted GA structure, and it is applied to three different engines: single-cylinder diesel engine(DE), three-cylinder spark ignition engine, and a 16-cylinder vee power plant diesel engine. This algorithm makes it possible to estimate a good quality pressure profile in cylinders for any kind of engine (operation basis and the number and disposition of cylinders), using indirect measurements and low-cost equipment.

Fast on-line identification of instantaneous mechanical losses in internal combustion engines

“…A first approach could be distributing the mean torque losses T fM between cylinders. On the other hand, for flexible crankshaft and driveline considerations (even for single-cylinder engines), there are several applications where an iterating procedure must be established, such as the indirect determination of in-cylinder pressure profile from the angular speed measurement [2,14,15]. Thus, the solution can be obtained by solving Eqs.…”

“…Second, for multi-cylinder engines, overlapping between torque profiles associated to the different cylinders makes it difficult to evaluate those coefficients. Finally, pressure acts as an unknown quantity when the inverse problem is applied; that is, pressure profile is determined from angular speed measurements by an indirect method [14,15]. In these conditions, a non-linear identification procedure is required.…”

Genetic algorithm optimization applied to the fuel supply parameters of diesel engines working at plateau

“…In Ref. [10], a GA based method has been developed to estimate the instantaneous pressure in cylinders. Some parameters associated with a pressure curve are optimized from two validated sub-models which reproduce the engine behavior via GA.…”

Influence of a Combustion Parametric Model on the Cyclic Angular Speed of Internal Combustion Engines. Part II: Statistical Sensitivity Assessment Results

“…Although these relations are obvious, this study proposes a scientific methodology to evaluate their interactions. In a previous study, it was demonstrated that both terms φ and θ i (or θ j ) could be fairly well estimated by an indirect identification procedure (IMV). , Nevertheless, the third parameter (m p ) is directly related to the rest of terms, thus providing a good agreement with the pressure profile, but showing higher differences in relation with DM identification. It means that the number of input parameters initially considered as independent terms in the Wiebe’s function must be reduced, in order to ensure an adequate identification of this parameter.…”

“…To improve the exhaust emissions and performance of internal combustion engines, the influence of the design parameters over the engine behavior must be identified . Depending on the purpose (design, control, or diagnosis), pressure cycle measurements and modeling may be required. − Among the different procedures to model the combustion process into a combustion chamber, − the Wiebe’s parametric model that provides the mass burned fraction (MBF) corresponds to one of the most internationally extended . In this sense, many studies predict the correlations between some of the previous parameters. , …”