Auto-Ignition Control in Spark-Ignition Engines Using Internal Model Control Structure

Abstract

This paper analyzes the feasibility of applying model predictive control strategies for mitigation of the auto-ignition phenomenon, which affects the performance of spark-ignition internal combustion engines. The first part of this paper shows the implementation and experimental validation of a two-dimensional model, based on thermodynamic equations, to simulate operating conditions in engines fueled with natural gas. Over this validated model, several control strategies are studied in order to evaluate, through simulation analysis, which of these offer the best handling capacity of the auto-ignition phenomenon. In order to achieve this goal, multivariate control strategies are implemented for a simultaneous manipulation of the fuel/air ratio, the crank angle at ignition, and the inlet pressure. The controlled variable in this research is the temperature at the ignition point. This temperature is obtained through an estimation based on pressure in the combustion chamber at that point, which is located toward the end zone of the compression stroke. If the ignition temperature of the fuel–air mixture is reached during the compression process, then auto-ignition takes place. Proposed control strategies consist of maintaining the temperature in the ignition point below the fuel–air mixture auto-ignition temperature. The results show that auto-ignition is difficult to avoid using a single input–single output (SISO) strategy. However, a multiple input–single output (MISO) approach avoids the influence of the phenomenon without a significant impact over the engine's performance. Among the developed strategies, an approach based on model predictive control and feedforward control strategy shows the best performance, measured through the integral absolute error (IAE) index. These results open the possibility of new ways for improving the control capacity of auto-ignition phenomenon in engines compared to currently available feedback control systems.

Combustion and Performance Evaluation of a Spark Ignition Engine Operating with Acetone–Butanol–Ethanol and Hydroxy

“…The investigation of Nithyanandan [12] leads to similar findings when implementing blends of ABE 20-40. In this sense, the integration of control strategies that facilitates spark timing could be a feasible solution to avoid the magnification of BSFC in dual-fuel operation [44,45].…”

Model Predictive Control Strategies Performance Evaluation over a Pipeline Transportation System

“…, where indicates the control horizon. These functions are known as discrete Laguerre functions, and its z-transform is shown in (11).…”

“…Only the first sample of the calculated trajectory is applied to the actuator, and the horizon window is moved one sample forward, and the optimization process is repeated using new measurement data. Most popular MPC strategies found in literature are DMC (Dynamic Matrix Control) [9], GPC (Generalized Predictive Control) [10], IMC (Internal Model Control) [11], RHC (Receding Horizon Control) [4], NMPC (Nonlinear Model Predictive Control) [12,13], among others [14].…”

Caracterización de un sistema de adquisición de datos para un banco de prueba de Motor Diésel Monocilíndrico

“…La gran evolución de los Motores de Combustión Interna (MCI) se atribuye a los diferentes estudios enfocados en el funcionamiento de estos. Diferentes trabajos, basados en la formulación de modelos termodinámicos para predecir la temperatura en el punto de ignición, la manipulación de la relación aire/combustible, ángulo del cigüeñal y presión de admisión, han permitido establecer estrategias de control para mejorar la operación en MCI [1], [2]. De igual manera, el uso de sistemas de Recirculación de Gases de Escape (EGR), la implementación de combustible gaseoso y el desarrollo de sistemas de postratamiento [3]- [6], han sido enfocados en disminuir la formación de contaminantes durante el proceso de combustión, aportando mejoras significativas al funcionamiento de estas máquinas.…”