Optimal Control of a Variable Geometry Turbocharged Diesel Engine Using Neural Networks: Applications on the ETC Test Cycle

Abstract

Modern diesel engines are typically equipped with variable geometry turbo-compressor, exhaust gas recirculation (EGR) system, common rail injection system, and post-treatment devices in order to increase their power while respecting the emissions standards. Consequently, the control of diesel engines has become a difficult task involving five to ten control variables that interact with each other and that are highly nonlinear. Actually, the control schemes of the engines are all based on static lookup tables identified on test-benches; the values of the control variables are interpolated using these tables and then, they are corrected, online, by using the control techniques in order to obtain better engine's response under dynamic conditions. In this paper, we are interested in developing a mathematical optimization process that search for the optimal control schemes of the diesel engines under static and dynamic conditions. First, we suggest modeling a turbocharged diesel engine and its opacity using the mean value model which requires limited experiments; the model's simulations are in excellent agreement with the experimental data. Then the created model is integrated in a dynamic optimization process based on the Broyden-Fletcher-Goldfarb-Shanno (BFGS) algorithm. The optimization results show the reduction of the opacity while enhancing the engine's effective power. Finally, we proposed a practical control technique based on the neural networks in order to apply these control schemes online to the engine. The neural controller is integrated into the engine's simulations and is used to control the engine in real time on the European transient cycle (ETC). The results confirm the validity of the neural controller.Index Terms-Diesel engines, dynamic optimization process, mean value model, optimal control and neural networks.

Dynamic Mapping of Diesel Engine through System Identification

“…A number of approaches to model MIMO, nonlinear dynamics of the diesel engine presented in the literature use neural networks [2,10,8]. In contrast to these works, the procedure presented here produces models on state-space form including noise models that fits directly into the framework of common control design methodologies such as MPC and LQG.…”

“…EGR and variable geometry turbine (VGT) valve positions [9,8], fuel injection parameters [2], variable valve actuation [15], or some combination of these [5]. In this paper, the combined effect of the most significant diesel engine actuators (EGR, VGT, injection timing, and injection duration) is examined.…”

Optimal Control of Electrified Powertrains

“…In [10] sequential quadratic programming (SQP) together with single shooting is used to minimize pollutants during different load steps at constant speed. [60,61] uses a quasi-Newton algorithm to minimize a trade-off between smoke and produced power for a VGT diesel engine over a specified torque and speed trajectory. In [44,46] the torque and speed responses of VGT-EGR diesel engines are studied.…”

A surge and choke capable compressor flow model—Validation and extrapolation capability

“…The control system, in turn, relies on good control oriented models for numerous applications e.g. observer design (Höckerdal, Frisk, & Eriksson, 2011), control (García-Nieto, Martínez, Blasco, & Sanchis, 2008Moulin & Chauvin, 2011;Omran, Younes, & Champoussin, 2009;Shehata, Abdullah, & Areed, 2009), and diagnosis (Kimmich, Schwarte, & Isermann, 2005;Nyberg & Stutte, 2004). The aim of this paper is to collect the state of the art in compressor knowledge and develops a control oriented compressor model, that is directly useful in control, estimation and diagnosis applications.…”