Cycle-to-Cycle Control of HCCI Engines

2003 ◽  
Author(s):  
Gregory M. Shaver ◽  
J. Christian Gerdes
Keyword(s):  
Fuel Injection ◽  
Molar Ratio ◽  
Exhaust Gas ◽  
Cylinder Pressure ◽  
Isentropic Compression ◽  
Detailed Model ◽  
Loop Control ◽  
Modeling And Control ◽  
Control Approach ◽  
Variable Valve Actuation

With stated benefits ranging from increased thermal efficiency to significantly reduced NOx emissions, Homogeneous Charge Compression Ignition (HCCI) represents a promising combustion strategy for future engines. When achieved by reinducting exhaust gas with a variable valve actuation (VVA) system, however, HCCI possesses nonlinear cycle-to-cycle coupling through the exhaust gas and lacks an easily identified trigger comparable to spark or fuel injection. This makes closed-loop control decidedly nontrivial. To develop a controller for HCCI, the engine cycle is partitioned into five stages: adiabatic, constant pressure induction of re-inducted product and reactant charge; isentropic compression to the point just prior to combustion initiation; constant volume combustion; isentropic expansion of product gases; isentropic exhaust of product gases. Using this framework, a nonlinear low-order model of HCCI combustion is formulated, where the input is the molar ratio of reinducted products to fresh reactants and the output is the peak in-cylinder pressure. Comparison with experimental in-cylinder pressure data shows that the model, while simple, offers reasonable fidelity. Using the nonlinear model, a linearized model and an accompanying LQR controller are formulated and implemented on a more detailed model presented in previous work. Results from these simulations show that the modeling and control approach is indeed successful at tracking a varying desired work output while maintaining a constant desired combustion phasing.

Cylinder Pressure Information-Based Postinjection Timing Control for Aftertreatment System Regeneration in a Diesel Engine—Part II: Active Diesel Particulate Filter Regeneration

2016 ◽  
Vol 138 (8) ◽  
Author(s):  
Hyunjun Lee ◽  
Jaesik Shin ◽  
Manbae Han ◽  
Myoungho Sunwoo
Keyword(s):  
Diesel Particulate Filter ◽  
Fuel Injection ◽  
Control Method ◽  
Particulate Filter ◽  
Exhaust Gas ◽  
Cylinder Pressure ◽  
Gas Temperature ◽  
Diesel Particulate ◽  
Dpf Regeneration ◽  
Exhaust Gas Temperature

The successful utilization of a diesel particulate filter (DPF) to reduce particulate matter (PM) in a passenger car diesel engine necessitates a periodic regeneration of the DPF catalyst without deterioration of the drivability and emission control performance. For successful active DPF regeneration, the exhaust gas temperature should be over 500 °C to oxidize the soot loaded in the DPF. Previous research increased the exhaust gas temperature by applying early and late post fuel injection with a look-up table (LUT) based feedforward control implemented into the engine management system (EMS). However, this method requires enormous calibration work to find the optimal timing and quantity of the main, early, and late post fuel injection with less certainty of accurate torque control. To address this issue, we propose a cylinder pressure based multiple fuel injection (MFI) control method for active DPF regeneration. The feedback control of the indicated mean effective pressure (IMEP), lambda, and DPF upstream temperature was applied to precisely control the injection quantity of the main, early, and late post fuel injection. To determine their fuel injection timings, a mass fraction burned 60% after location of the rate of heat release maximum (MFB60aLoROHRmax) was proposed based on the cylinder pressure information. The proposed control method was implemented in an in-house EMS and validated at several engine operating conditions. During the regeneration period, the exhaust gas temperature tracked the desired temperature, and the engine torque fluctuation was minimized with minimal PM and NOx emissions.

Multi-Input–Multi-Output Control of a Utility-Scale, Shaftless Energy Storage Flywheel With a Five-Degrees-of-Freedom Combination Magnetic Bearing

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Xiaojun Li ◽  
Alan Palazzolo
Keyword(s):  
Energy Storage ◽  
Degrees Of Freedom ◽  
Magnetic Levitation ◽  
High Strength ◽  
Magnetic Bearing ◽  
Detailed Model ◽  
Loop Control ◽  
Modeling And Control ◽  
Power Capability ◽  
Utility Scale

The modeling and control of a recently developed utility-scale, shaftless, hubless, high strength steel energy storage flywheel system (SHFES) are presented. The novel flywheel is designed with an energy/power capability of 100 kWh/100 kW and has the potential of a doubled energy density when compared to conventional technologies. In addition, it includes a unique combination magnetic bearing (CAMB) capable of providing five-degrees-of-freedom (5DOF) magnetic levitation. Initial test results show that the CAMB, which weighs 544 kg, can provide a stable lift-up and levitation control for the 5543 kg flywheel. The object of this paper is to formulate and synthesize a detailed model as well as to design and simulate a closed-loop control system for the proposed flywheel system. To this end, the CAMB supporting structures are considered flexible and modeled by finite element modeling. The magnetic bearing is characterized experimentally by static and frequency-dependent coefficients, the latter of which are caused by eddy current effects and presents a challenge to the levitation control. Sensor-runout disturbances are also measured and included. System nonlinearities in power amplifiers and the controller are considered as well. Even though the flywheel has a large ratio of the primary-to-transversal moment of inertias, multi-input–multi-output (MIMO) feedback control demonstrates its effectiveness in canceling gyroscopic toques at the designed operational spinning speed. Various stages of proportional and derivative (PD) controllers, lead/lag compensators, and notch filters are implemented to suppress the high-frequency sensor disturbances, structural vibrations, and rotor imbalance effects.

scholarly journals Microphones and Knock Sensors for Feedback Control of HCCI Engines

2004 ◽  
Author(s):  
Jason S. Souder ◽  
J. Hunter Mack ◽  
J. Karl Hedrick ◽  
Robert W. Dibble
Keyword(s):  
Fuel Injection ◽  
Compression Ignition ◽  
Cylinder Pressure ◽  
Indirect Methods ◽  
Loop Control ◽  
Hcci Engine ◽  
Hcci Engines ◽  
Timing Data ◽  
Knock Sensor ◽  
Direct Fuel Injection

Homogeneous charge compression ignition (HCCI) engines lack direct in-cylinder mechanisms, such as spark plugs or direct fuel injection, for controlling the combustion timing. Many indirect methods have been used to control the combustion timing in a HCCI engine. With any indirect method, it is important to have a measure of the combustion timing so the control inputs can be adjusted for the next cycle. In this paper, it is shown that microphones and knock sensors can be used to detect combustion in HCCI engines. The output from various microphones and a knock sensor on an HCCI engine are measured at light and high loads. The combustion timing data obtained from the sensors are compared to the combustion timing data obtained from a piezoelectric cylinder pressure transducer. One of these sensors is selected and used for closed-loop control of the combustion timing in a single cylinder HCCI engine.

Air Fuel Ratio Estimation Using In-Cylinder Pressure Frequency Analysis

2003 ◽  
Vol 125 (3) ◽  
pp. 812-819 ◽  
Author(s):  
N. Cavina ◽  
F. Ponti
Keyword(s):  
Frequency Analysis ◽  
Closed Loop ◽  
Fuel Injection ◽  
Combustion Engine ◽  
Control Strategies ◽  
Feedback Signal ◽  
Exhaust Gas ◽  
Cylinder Pressure ◽  
Passenger Cars ◽  
Fuel Ratio

This paper presents an original approach to estimate the air-fuel ratio (AFR) of the mixture that burned inside a given cylinder of a spark-ignited (SI) internal combustion engine, using the information hidden in the corresponding in-cylinder pressure signal. In modern closed-loop fuel injection control strategies, the feedback signal is usually given by one (or more) heated exhaust gas oxygen (HEGO) sensor(s), mounted in the exhaust manifold(s). The information that such sensors give is related to the stoichiometry of the mixture that burned inside the cylinders. The HEGO sensor is not able to evaluate the AFR value precisely, being only able to determine whether the mixture was rich or lean. This information is sufficient to allow the implementation of a closed-loop strategy for injection time control. Generally speaking, such strategy could be improved in terms of readiness and precision by directly measuring (or by estimating) the actual AFR. Universal exhaust gas oxygen (UEGO) sensors are still considered expensive and their use is mostly limited to laboratory and racing applications, even if some automotive manufacturers have started installing such sensors on board passenger cars, as part of an effort to comply with ULEV (ultra low emission vehicles) regulations. For this reason the idea of estimating AFR values from other signals has received great attention in the past few years. A new approach based on in-cylinder pressure frequency analysis is presented here.

Engine Control Using Estimated Parameters From a Real Time Model of an Engine With Variable Valve Actuation

2005 ◽  
Author(s):  
John L. Lahti ◽  
John J. Moskwa
Keyword(s):  
Real Time ◽  
Mass Fraction ◽  
Fuel Injection ◽  
Exhaust System ◽  
Time Estimation ◽  
Exhaust Gas ◽  
Engine Control ◽  
Cylinder Pressure ◽  
Time Model ◽  
Residual Mass

A real time model of an engine was developed and integrated with engine control software to provide better engine control with less calibration effort. The model uses one-dimensional compressible gas wave equations for the intake and exhaust system along with a thermodynamic model of the cylinder to provide real time estimation of the cylinder air charge, exhaust gas residual mass fraction, cylinder pressure, cylinder temperature, and various other states along the intake and exhaust system. Information from the model is used to control the fuel injection, spark advance, valve timing, and throttle position on the actual engine. The system does not use any volumetric efficiency tables. Since the real time model responds like the actual engine there is no need for transient fuel or transient spark advance correction factors. The estimated cylinder pressure is used to calculate the instantaneous indicated engine torque and engine efficiency. Using the model it is possible to optimize efficiency, control the torque output, and regulate the exhaust gas residual mass fraction. The system offers many control advantages and is easy to calibrate.

An Efficient Approach for Modeling and Control of a Quadrotor

2016 ◽  
Vol 4 (2) ◽  
pp. 1-16
Author(s):  
Ahmed S. Khusheef
Keyword(s):  
Pid Control ◽  
Control Method ◽  
Mechanical Design ◽  
Loop Control ◽  
Modeling And Control ◽  
Loop Control System ◽  
And Control ◽  
Close Loop Control ◽  
Close Loop Control System ◽  
Made In

 A quadrotor is a four-rotor aircraft capable of vertical take-off and landing, hovering, forward flight, and having great maneuverability. Its platform can be made in a small size make it convenient for indoor applications as well as for outdoor uses. In model there are four input forces that are essentially the thrust provided by each propeller attached to each motor with a fixed angle. The quadrotor is basically considered an unstable system because of the aerodynamic effects; consequently, a close-loop control system is required to achieve stability and autonomy. Such system must enable the quadrotor to reach the desired attitude as fast as possible without any steady state error. In this paper, an optimal controller is designed based on a Proportional Integral Derivative (PID) control method to obtain stability in flying the quadrotor. The dynamic model of this vehicle will be also explained by using Euler-Newton method. The mechanical design was performed along with the design of the controlling algorithm. Matlab Simulink was used to test and analyze the performance of the proposed control strategy. The experimental results on the quadrotor demonstrated the effectiveness of the methodology used.

Implementing variable valve actuation on a diesel engine at high-speed idle operation for improved aftertreatment warm-up

2019 ◽  
Vol 21 (7) ◽  
pp. 1134-1146
Author(s):  
Kalen R Vos ◽  
Gregory M Shaver ◽  
Mrunal C Joshi ◽  
James McCarthy
Keyword(s):  
Particulate Matter ◽  
High Speed ◽  
Exhaust Valve ◽  
Exhaust Gas ◽  
Warm Up ◽  
Aftertreatment System ◽  
Idle Speed ◽  
Variable Valve Actuation ◽  
Brake Mean Effective Pressure ◽  
Valve Opening

Aftertreatment thermal management is critical for regulating emissions in modern diesel engines. Elevated engine-out temperatures and mass flows are effective at increasing the temperature of an aftertreatment system to enable efficient emission reduction. In this effort, experiments and analysis demonstrated that increasing the idle speed, while maintaining the same idle load, enables improved aftertreatment “warm-up” performance with engine-out NOx and particulate matter levels no higher than a state-of-the-art thermal calibration at conventional idle operation (800 rpm and 1.3 bar brake mean effective pressure). Elevated idle speeds of 1000 and 1200 rpm, compared to conventional idle at 800 rpm, realized 31%–51% increase in exhaust flow and 25 °C–40 °C increase in engine-out temperature, respectively. This study also demonstrated additional engine-out temperature benefits at all three idle speeds considered (800, 1000, and 1200 rpm, without compromising the exhaust flow rates or emissions, by modulating the exhaust valve opening timing. Early exhaust valve opening realizes up to ~51% increase in exhaust flow and 50 °C increase in engine-out temperature relative to conventional idle operation by forcing the engine to work harder via an early blowdown of the exhaust gas. This early blowdown of exhaust gas also reduces the time available for particulate matter oxidization, effectively limiting the ability to elevate engine-out temperatures for the early exhaust valve opening strategy. Alternatively, late exhaust valve opening realizes up to ~51% increase in exhaust flow and 91 °C increase in engine-out temperature relative to conventional idle operation by forcing the engine to work harder to pump in-cylinder gases across a smaller exhaust valve opening. In short, this study demonstrates how increased idle speeds, and exhaust valve opening modulation, individually or combined, can be used to significantly increase the “warm-up” rate of an aftertreatment system.

Effect of Injection Timing on Combustion Characteristics of a DI Diesel Engine Fuelled with Pistacia chinensis Bunge Seed Biodiesel

2012 ◽  
Vol 614-615 ◽  
pp. 337-342
Author(s):  
Li Luo ◽  
Bin Xu ◽  
Zhi Hao Ma ◽  
Jian Wu ◽  
Ming Li
Keyword(s):  
Combustion Temperature ◽  
Fuel Injection ◽  
Direct Injection ◽  
Combustion Characteristics ◽  
Injection Timing ◽  
Brake Specific Fuel Consumption ◽  
Cylinder Pressure ◽  
Combustion Duration ◽  
Di Diesel Engine ◽  
Maximum Combustion Temperature

In this study, the effect of injection timing on combustion characteristics of a direct injection, electronically controlled, high pressure, common rail, turbocharged and intercooled engine fuelled with different pistacia chinensis bunge seed biodiesel/diesel blends has been experimentally investigated. The results indicated that brake specific fuel consumption reduces with the increasing of fuel injection advance angle and enhances with the increasing of biodiesel content in the blends. The peak of cylinder pressure and maximum combustion temperature increase evidently with the increment of fuel injection advance angle. However, the combustion of biodiesel blends starts earlier than diesel at the same fuel injection advance angle. At both conditions, the combustion duration and the peak of heat release rate are insensitive to the changing of injection timing.

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