M. Bidarvatan, M. Shahbakhti, S.a. Jazayeri,
Volume 1, Issue 3 (5-2011)
Abstract
Homogenous Charge Compression Ignition (HCCI) engines hold promise of high fuel efficiency and low emission levels for future green vehicles. But in contrast to gasoline and diesel engines, HCCI engines suffer from lack of having direct means to initiate combustion. A combustion timing controller with robust tracking performance is the key requirement to leverage HCCI application in production vehicles. In this paper, a two-state control-oriented model is developed to predict HCCI combustion timing for a range of engine operation. The experimental validation of the model confirms the accuracy of the model for HCCI control applications. An optimal integral state feedback controller is designed to control the combustion timing by modulating the ratio of two fuels. Optimization methods are used in order to determine the controller’s parameters. The results demonstrate the designed controller can reach optimal combustion timing within about two engine cycles, while showing good robustness to physical disturbances.
M.h. Shojaeefard, S. Ebrahimi Nejad, M. Masjedi,
Volume 6, Issue 1 (3-2016)
Abstract
In this article, vehicle cornering stability and brake stabilization via bifurcation analysis has been investigated. In order to extract the governing equations of motion, a nonlinear four-wheeled vehicle model with two degrees of freedom has been developed. Using the continuation software package MatCont a stability analysis based on phase plane analysis and bifurcation of equilibrium is performed and an optimal controller has been proposed. Finally, simulation has been done in Matlab-Simulink software considering a sine with dwell steering angle input, and the effectiveness of the proposed controller on the aforementioned model has been validated with Carsim model.
S. Ali Mirmohammadsadeghi, Dr. Kamyar Nikzadfar, Nima Bakhshinezhad, Dr. Alireza Fathi,
Volume 8, Issue 3 (9-2018)
Abstract
In order to lowering level of emissions of internal combustion engines (ICEs), they should be optimally controlled. However, ICEs operate under numerous operating conditions, which in turn makes it difficult to design controller for such nonlinear systems. In this article, a generalized unique controller for idle speed control under whole loading conditions is designed. In the current study, instead of tedious time-consuming trial-and-error based methods, soft computing techniques are employed to tune a proportional-integral-derivative (PID) controller which controls idle speed of engine. Since model based design technique is employed, a mean value model (MVM) is taken advantage due to its evidenced merits. Moreover, a brief introduction to the selected meta-heuristics is given followed by a flowchart to show how the engine model is linked to the optimization algorithms. A set point of 750 rpm is fed to the system, and the weighted sum of the three characteristics of mean squared error, control energy, and percent overshoot of the control system is set to the problem objective function to be minimized. It is evidenced that of all the examined meta-heuristics, Bees Algorithm (BA) converges to a better solution. Finally, to consider the effectiveness of the developed optimal controllers in disturbance rejection, they are implemented to the engine MVM model. The results of the research indicate, all the four optimally designed control systems, albeit the intermediate superiority, are of conspicuous success in compensating for the input disturbances of the load torque.
