Lyapunov-Based Nonlinear Feedback Control Design for Exhaust Gas Recirculation Loop of Gasoline Engines

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Weihai Jiang ◽  
Tielong Shen
Keyword(s):  
Dynamical Behavior ◽  
Control Design ◽  
Exhaust Gas Recirculation ◽  
Feedback Stabilization ◽  
Design Stage ◽  
Exhaust Gas ◽  
Exhaust Manifold ◽  
Challenging Issue ◽  
Gas Recirculation ◽  
Recirculation Loop

For gasoline engine with an exhaust gas recirculation loop, a challenging issue is how to achieve maximum brake efficiency while providing the desired torque. This paper presents a solution to this challenging issue via dynamical control approach which consists of two phases: optimal equilibrium point generation and feedback regulation of the optimized operating mode. First, a mean-value model is developed to represent the dynamical behavior of the intake manifold and exhaust manifold focused on gas mass flows. Then, the control scheme is constructed based on the control-oriented model. Mainly, the optimal set-points are designed by solving the optimal programming problem of maximizing the brake efficiency under demand torque constraint which is the first control design stage, and the dynamical model to the feedback stabilization regulation control for improving transient performance is at the second stage. Lyapunov-based design is used for the derivation of the state feedback law. Furthermore, the proposed exhaust manifold pressure estimator is also coupled into the controller to replace the cost prohibitive exhaust pressure sensor. Finally, experimental validations on the test bench are provided to evaluate the proposed controller.

Strategies for using valvetrain flexibility instead of exhaust manifold pressure modulation for diesel engine gas exchange and thermal management control

2019 ◽  
pp. 146808741988063 ◽  
Author(s):  
Kalen R Vos ◽  
Gregory M Shaver ◽  
Mrunal C Joshi ◽  
Aswin K Ramesh ◽  
James McCarthy
Keyword(s):  
Thermal Management ◽  
Pressure Control ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Valve Closure ◽  
Exhaust Manifold ◽  
Intake Valve ◽  
Cylinder Deactivation ◽  
Valve Opening ◽  
Gas Recirculation

At low-to-moderate loads, modern diesel engines manipulate exhaust manifold pressure to drive exhaust gas recirculation and thermally manage the aftertreatment. In these engines, exhaust manifold pressure control is typically achieved via either a valve after the turbine, a variable geometry turbine, or wastegating. The study described here demonstrates how valvetrain flexibility enables engine operation without requiring exhaust manifold pressure control. Specifically, intake valve closure modulation and cylinder deactivation at elevated engine speeds, along with exhaust valve opening modulation at low engine speeds, can match, or improve, efficiency and thermal management compared to a stock thermal calibration that requires exhaust manifold pressure control. During low-speed, low-load operation, the stock engine uses elevated exhaust manifold pressures to increase the required fueling (for thermal management) and to drive exhaust gas recirculation. Exhaust valve opening modulation can instead be implemented to enable similar aftertreatment warm-up, while cylinder deactivation allows aftertreatment temperature maintenance with a 40% reduction in fuel consumption. During high-speed, low-to-moderate loads, the stock engine implements thermal management operation by decreasing exhaust manifold pressure. Intake valve closure modulation together with cylinder deactivation can instead be implemented to enable fuel-efficient thermal management improvements via charge flow control.

Location Isolability of Intake and Exhaust Manifold Leaks in a Turbocharged Diesel Engine With Exhaust Gas Recirculation

2014 ◽  
Author(s):  
Michael J. Hand ◽  
Anna Stefanopoulou
Keyword(s):  
Exhaust Gas Recirculation ◽  
Fault Detection And Isolation ◽  
Exhaust Gas ◽  
Exhaust Manifold ◽  
Heavy Duty ◽  
Turbocharged Diesel Engine ◽  
Heavy Duty Diesel ◽  
Gas Recirculation ◽  
Operating Points ◽  
Multiple Operating Points

An investigation into the isolability of the location of intake and exhaust manifold leaks in heavy duty diesel engines is presented. In particular, established fault detection and isolation (FDI) methods are explored to assess their utility in successfully determining the location of a leak within the air path of an engine equipped with exhaust gas recirculation and an asymmetric twin-scroll turbine. It is further shown how consideration of the system’s variation across multiple operating points can lead to improved ability to isolate the location of leaks in the intake and exhaust manifolds.

Nonlinear observer-based exhaust manifold pressure estimation and fault detection for gasoline engines with exhaust gas recirculation

2019 ◽  
pp. 146808741988212
Author(s):  
Weihai Jiang ◽  
Tielong Shen
Keyword(s):  
Fault Detection ◽  
Exhaust Gas Recirculation ◽  
Nonlinear Observer ◽  
Exhaust Gas ◽  
Exhaust Manifold ◽  
Gasoline Engines ◽  
Recirculation System ◽  
Experimental Validations ◽  
Pressure Observer ◽  
Gas Recirculation

This article presents a nonlinear observer-based method to estimate the exhaust manifold pressure for the gasoline engines equipped with an exhaust gas recirculation system. A dynamic model is designed to estimate the exhaust manifold pressure, which includes both the intake manifold and exhaust manifold dynamics focusing on gas mass flows. Based on the developed model, a nonlinear exhaust manifold pressure observer is proposed to replace the exhaust manifold pressure sensor, and the global convergence is analyzed by a constructed Lyapunov function and the physical meaning of the time-varying parameters. The experimental validations show that the observer-based exhaust manifold pressure estimator is able to converge to the real value at arbitrary initial value and estimates the exhaust manifold pressure accurately during both the steady-state and transient conditions. Finally, the proposed exhaust manifold pressure observer is applied into the fault detection problem for the exhaust gas recirculation system. The experimental validations show that the observer is able to be used to estimate the exhaust gas recirculation ratio and as an extra signal to assist to detect the faults of the exhaust gas recirculation system accurately.

Evaluation of the main operating parameters of a homogeneous charge compression ignition engine for performance optimization

2016 ◽  
Vol 231 (8) ◽  
pp. 1001-1021 ◽  
Author(s):  
Mostafa Mohebbi ◽  
Azhar Abdul Aziz ◽  
Vahid Hosseini ◽  
Mostafa Ramzannezhad ◽  
Rouzbeh Shafaghat
Keyword(s):  
Thermodynamic Parameters ◽  
Homogeneous Charge Compression Ignition ◽  
Exhaust Gas Recirculation ◽  
Design Stage ◽  
System Response ◽  
Exhaust Gas ◽  
Compression Ignition ◽  
Reformer Gas ◽  
Gas Recirculation ◽  
Homogeneous Charge

Homogeneous charge compression ignition engines require a smart control system to regulate the input quantities of the engine in various operational conditions. Achieving an optimum combustion needs an appropriate system response for different engine loads and speeds according to the power acquired from the engine, as well as the amounts of emissions present in the exhaust. Therefore, performing a set of experimental tests together with numerical simulations in a wide range of conditions facilitates calibration of the input parameters of the engine. In this study, the effects of the thermodynamic parameters and the thermokinetic parameters on the engine output in the preliminary design stage were obtained at different speeds to determine the optimum exhaust emissions, the optimum combustion timing and the ranges of misfiring and knock, using multiple-zone thermodynamic modelling. On the assumption that the simulation cycle is closed, the probability density function was used to determine the initial conditions for the temperature and the residual gas from the previous cycle mass distribution in each area inside the cylinder. The results obtained proved that the kinetic properties of the mixture due to the effects of the the air-to-fuel ratio, the percentage of exhaust gas recirculation and the percentage of reformer gas have dominant effects on the output in comparison with the thermodynamic parameters such as the intake pressure and the intake temperature. At low speeds, exhaust gas recirculation retards combustion and delays engine knock. At higher engine speeds, the reformer gas advances combustion and improves misfiring.

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