Supervisory Framework and Model-based Control of Engine and Exhaust Aftertreatment System

In this article, a modular control framework for integrated engine and exhaust aftertreatment management is proposed. The framework includes a supervisory controller which has three function blocks: engine setpoint generator, exhaust aftertreatment system (EATS) setpoint generator and emission limits generator. The focus of the article is on development and evaluation of a model based optimal control strategy for the engine setpoint generator. The control objectives of this block and the framework, in general, are to improve the fuel economy while fulfilling emission legislation. The framework is proposed for heavy duty diesel engines, and the strategy for the engine setpoint generator is evaluated using a high-fidelity simulation platform where a validated GT-POWER model of a 13L turbo compound diesel engine and first principles model of an EATS are used. The developed engine setpoint generator-a first step towards a complete implementation of the proposed framework-has reduced complexity compared to a standard controller used in industry consisting of feedforward maps and feedback control. Simulation results show 0.5% decrease in fuel consumption, compared to the standard controller, while maintaining NO_x emissions under the legislative limit.