Smart controller design of air to fuel ratio (AFR) and brake control system on gasoline engine

Development of internal combustion engine control system is currently oriented on exhaust emissions, performance and fuel efficiency. This is caused by fuel prices rising which led to a crisis on the transport sector; therefore it is crucial to develop a fuel-efficient vehicles technology. Gasoline engine fuel efficiency can be improved by several methods such as by controlling the air-to-fuel ratio (AFR). AFR technology currently still has many problems due to its difficulty setting characteristic since AFR control is usually as internally engine control. Fuel efficiency can be improved by influence of external engine system. Brake control system is an external engine system that used in this research. The purpose of this research is to design and implement the AFR and brake control system in a vehicle to improve fuel efficiency of gasoline engines along braking period. The basic idea is the controller has to reduce the consumption of fuel injection along braking period. The applied control system on vehicle works using smart controller, such as Fuzzy Logic Controller (FLC). When the vehicle brakes, fuel injection is controlled by the ECU brake control system. This control system works in parallel with the vehicle control system default. The results show, when the engine speed exceeds 2500 rpm, AFR value increased infinitely, so that maximum efficiency is achieved. At engine speed less than 2500 rpm, AFR value reaches a value of 22. The fuel measurement has been able to show a decrease in fuel consumption of 6 liters to 4 liters within the distance of 50.7 km. Improvement of fuel efficiency can be achieved by approximately of 33.3%

Genset Optimization for Biomass Syngas Operation

Although biomass is underrepresented in current methods for power generation, it has great potential to help meet the growing need for clean energy. This chapter details the modification of a gasoline-powered two-stroke genset for operation on syngas from a woodchip-powered gasifier. Generator and engine modifications along with a flexible air/fuel control system are described. Results from genset operation indicate a sustainable power output of 360 W with a biomass consumption rate of approximately 6 kg/hour. Optimum power production was achieved at an air/fuel ratio close to 1. After several hours of operation the engine was disassembled and inspected, revealing significant deposits on the piston and crank case parts, indicating that the engine would require weekly maintenance under such operating conditions

HOMOGENEOUS CHARGE COMPRESSION IGNITION COMBUSTION CONTROL BY CNG DIRECT INJECTION

Homogenous Charge Compression Ignition (HCCI) is a combustion process that emits very low nitrogen oxides and has high thermal efficiency. It is one of the few solutions on hand that looks very promising to address the issues on the atmospheric air pollution and depleting fossil fuel resources exacerbated by increasing energy consumption of the world. However, currently there is no established means for HCCI combustion control and it has high HC and CO emissions. In this project, CNG direct injection was proposed as a tool for HCCI combustion control. Proportion of gasoline and CNG flow rates and degree of stratification of CNG were identified as potential parameters for HCCI combustion control. Role of CNG direct injection on HCCI combustion control and corresponding effects on performance and emission characteristics were experimentally investigated. The studies were carried out on a single cylinder, CNG direct injection (CNG DI) research engine. A gasoline fuel injection system and an intake air heater were fitted to the engine to operate the engine with dual fuels and in HCCI mode. Compression ignition combustion of homogeneously premixed charge of gasoline was achieved by heating the intake air and CNG was directly injected. CNG stratification was achieved by direct injection on a specially designed piston with a groove on its crown. The degree of stratification was varied by changing the start of CNG injection. Early injection (300° BTDC) created homogeneous mixtures and stratified mixtures were obtained by retarding the injection timing. High degrees of stratification were obtained by injecting at 80° and 120° BTDC, that is, after the closure of intake valves (132° BTDC). To study the effect of fuel proportions, CNG injection rate was varied at constant equivalence ratio of gasoline (φg) at 0.20 to 0.26. The effects of CNG stratification were studied by changing the injection timing form 300° to 80° BTDC and all experiments were repeated at different engine speeds ranging from 1200 to 2100 rpm. It was observed that heat released by gasoline HCCI combustion resulted in the subsequent combustion of CNG and the engine load could be increased by varying the CNG injection rate. Proportions of gasoline and CNG and degree of stratification of CNG were found to be effective means of combustion control within certain limits of engine load and HC and CO emissions could be significantly reduced

Air-Fuel Ratio Control of Spark Ignition Engines With Unknown System Dynamics Estimator: Theory and Experiments

This brief addresses the emission reduction of spark ignition engines by proposing a new control to regulate the air-fuel ratio (AFR) around the ideal value. After revisiting the engine dynamics, the AFR regulation is represented as a tracking control of the injected fuel amount. This allows to take the fuel film dynamics into consideration and simplify the control design. The lumped unknown engine dynamics in the new formulation are online estimated by suggesting a new effective unknown system dynamics estimator. The estimated variable can be superimposed on a commercially configured, well-calibrated gain scheduling like proportional-integral-differential (PID) control to achieve a better AFR response. The salient feature of this proposed control scheme lies in its simplicity and the small number of required measurements, that is, only the air mass flow rate, the pressure and temperature in the intake manifold, and the measured AFR value are used. Practical experiments on a Tata Motors Limited two-cylinder gasoline engine are carried out under a realistic driving cycle. The comparative results show that the proposed control can achieve an improved AFR control response and reduced emissions

Fuel-to-air ratio control under short-circuit conditions through UEGO sensor signal analysis

[EN] The impact of short-circuit pulses on the after-treatment system of a spark-ignited engine must be taken into account to keep the fuel-to-air equivalence ratio within the three-way catalyst window, thereby reducing pollutant emissions. The fuel-to-air equivalence ratio overestimation that suffers the wide-range ¿-sensor upstream three-way catalyst in the presence of short circuit is especially relevant. In this study, a novel approach to deal with the fuel-to-air equivalence ratio control under short-circuit conditions is introduced. Under this scope, this work proposes a strategy for the on-board correction of the aforementioned fuel-to-air equivalence ratio overestimation, by means of the information regarding short-circuit level that provides the frequency content of the ¿-sensor at the engine frequency. Finally, the potential of this approach to minimize pollutant emissions, in particular the NOx penalty arisen as a consequence of running the engine under leaner conditions than expected, is assessed through experimental tests.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The authors acknowledge the support of Spanish Ministerio de Economia, Industria y Competitividad through project TRA2016-78717-RGuardiola, C.; Pla Moreno, B.; Real, M.; Travaillard, C.; Dambricourt, F. (2020). Fuel-to-air ratio control under short-circuit conditions through UEGO sensor signal analysis. International Journal of Engine Research. 21(9):1577-1583. https://doi.org/10.1177/1468087418820747S15771583219Pagot, A., Duparchy, A., Gautrot, X., Leduc, P., & Monnier, G. (2006). Combustion Approach for Downsizing: the IFP Concept. Oil & Gas Science and Technology, 61(1), 139-153. doi:10.2516/ogst:2006009xLeduc, P., Dubar, B., Ranini, A., & Monnier, G. (2003). Downsizing of Gasoline Engine: an Efficient Way to Reduce CO2 Emissions. Oil & Gas Science and Technology, 58(1), 115-127. doi:10.2516/ogst:2003008Observer-based air fuel ratio control. (1998). IEEE Control Systems, 18(5), 72-83. doi:10.1109/37.722254Takiyama, T. (2001). Airâ fuel ratio control system using pulse width and amplitude modulation at transient state. JSAE Review, 22(4), 537-544. doi:10.1016/s0389-4304(01)00135-7Chen-Fang Chang, Fekete, N. P., Amstutz, A., & Powell, J. D. (1995). Air-fuel ratio control in spark-ignition engines using estimation theory. IEEE Transactions on Control Systems Technology, 3(1), 22-31. doi:10.1109/87.370706Shafai, E., Roduner, C., & Geering, H. P. (1996). Indirect Adaptive Control of a Three-Way Catalyst. SAE Technical Paper Series. doi:10.4271/961038Yildiz, Y., Annaswamy, A. M., Yanakiev, D., & Kolmanovsky, I. (2010). Spark ignition engine fuel-to-air ratio control: An adaptive control approach. Control Engineering Practice, 18(12), 1369-1378. doi:10.1016/j.conengprac.2010.06.011Germann, H., Taglaiferri, S., & Geering, H. P. (1996). Differences in Pre- and Post-Converter Lambda Sensor Characteristics. SAE Technical Paper Series. doi:10.4271/960335Olsen, D. B., Hutcherson, G. C., Willson, B. D., & Mitchell, C. E. (2002). Development of the Tracer Gas Method for Large Bore Natural Gas Engines—Part I: Method Validation. Journal of Engineering for Gas Turbines and Power, 124(3), 678-685. doi:10.1115/1.1454116Macian, V., Lujan, J. M., Guardiola, C., & Yuste, P. (2006). DFT-based controller for fuel injection unevenness correction in turbocharged diesel engines. IEEE Transactions on Control Systems Technology, 14(5), 819-827. doi:10.1109/tcst.2006.876924Macián, V., Galindo, J., Luján, J. M., & Guardiola, C. (2005). Detection and Correction of injection failures in diesel engines on the basis of turbocharger instantaneous speed frequency analysis. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, 219(5), 691-701. doi:10.1243/095440705x2831

Experimental assessment of the performance and emissions of a spark-ignition engine using waste-derived biofuels as additives

The use of biofuels for spark ignition engines is proposed to diversify fuel sources and reduce fossil fuel consumption, optimize engine performance, and reduce pollutant emissions. Additionally, when these biofuels are produced from low-grade wastes, they constitute valorisation pathways for these otherwise unprofitable wastes. In this study, ethanol and pyrolysis biogasoline made from low-grade wastes were evaluated as additives for commercial gasoline (RON95, RON98) in tests performed in a spark ignition engine. Binary fuel mixtures of ethanol + gasoline or biogasoline + gasoline with biofuel incorporation of 2% (w/w) to 10% (w/w) were evaluated and compared with ternary fuel mixtures of ethanol + biogasoline + gasoline with biofuel incorporation rates from 1% (w/w) to 5% (w/w). The fuel mix performance was assessed by determination of torque and power, fuel consumption and efficiency, and emissions (HC, CO, and NOx). An electronic control unit (ECU) was used to regulate the air–fuel ratio/lambda and the ignition advance for maximum brake torque (MBT), wide-open throttle (WOT)), and two torque loads for different engine speeds representative of typical driving. The additive incorporation up to 10% often improved efficiency and lowered emissions such as CO and HC relative to both straight gasolines, but NOx increased with the addition of a blend.This work was supported by FCT-Fundação para a Ciência e Tecnologia within the R&D Units, MEtRICs Project Scope: UIDP/04077/2020. Joaquim da Costa was supported through a PhD Grant from Fundo de Desenvolvimento Capital Humano of the Government of Timor Leste

Hydrogen SI and HCCI Combustion in a Direct-Injection Optical Engine

Hydrogen has been largely proposed as a possible alternative fuel for internal combustion engines. Its wide flammability range allows higher engine efficiency with leaner operation than conventional fuels, for both reduced toxic emissions and no CO2 gases. Independently, Homogenous Charge Compression Ignition (HCCI) also allows higher thermal efficiency and lower fuel consumption with reduced NOX emissions when compared to Spark-Ignition (SI) engine operation. For HCCI combustion, a mixture of air and fuel is supplied to the cylinder and autoignition occurs from compression; engine is operated throttle-less and load is controlled by the quality of the mixture, avoiding the large fluid-dynamic losses in the intake manifold of SI engines. HCCI can be induced and controlled by varying the mixture temperature, either by Exhaust Gas Recirculation (EGR) or intake air pre-heating. A combination of HCCI combustion with hydrogen fuelling has great potential for virtually zero CO2 and NOX emissions. Nevertheless, combustion on such a fast burning fuel with wide flammability limits and high octane number implies many disadvantages, such as control of backfiring and speed of autoignition and there is almost no literature on the subject, particularly in optical engines. Experiments were conducted in a single-cylinder research engine equipped with both Port Fuel Injection (PFI) and Direct Injection (DI) systems running at 1000 RPM. Optical access to in-cylinder phenomena was enabled through an extended piston and optical crown. Combustion images were acquired by a high-speed camera at 1°or 2°crank angle resolution for a series of engine cycles. Spark-ignition tests were initially carried out to benchmark the operation of the engine with hydrogen against gasoline. DI of hydrogen after intake valve closure was found to be preferable in order to overcome problems related to backfiring and air displacement from hydrogens low density. HCCI combustion of hydrogen was initially enabled by means of a pilot port injection of n-heptane preceding the main direct injection of hydrogen, along with intake air preheating. Sole hydrogen fuelling HCCI was finally achieved and made sustainable, even at the low compression ratio of the optical engine by means of closed-valve DI, in synergy with air-pre-heating and negative valve overlap to promote internal EGR. Various operating conditions were analysed, such as fuelling in the range of air excess ratio 1.2-3.0 and intake air temperatures of 200-400°C. Finally, both single and double injections per cycle were compared to identify their effects on combustion development. Copyright © 2009 SAE International

Analisa Pengaruh Air-Fuel Ratio Kaya Terhadap Performa Internal Combustion Engine Bahan Bakar Bensin Satu Silinder 150 CC

This study was conducted to investigate the effect of variations in the rich air-fuel ratio (AFR) on the performance of a single-cylinder gasoline internal combustion engine. In injection motors or often called EFI, it is easy to make adjustmets to the desired performance. All parts of the machine are controlled electrically. The Electronic Control Unit is the main component that acts as a regulator of all functions in the motor engine. In this study, we take he rich AFR as a reference. Experimental method using a single cylinder gasoline engine 150 CC. The air-fuel ratio is varied by AFR 10:1, AFR 11:1, AFR 12:! At engine speed of 3000 to 9000 rpm with an interval 250 rpm. The result of the combustion engine test get the following torque data, at AFR 12:1 with a value 12,2 HP, AFR 11:1 with a value 11,9 HP, AFR 10:1 with a value 9,9. AFR 12:1 gets the highest Torque and Power. AFR 12 makes the best mix for fast engine speeds

Study Of Signal Processing Of Engine Knocking On Vehicle

An engine is a device or machine designed to convert one form of energy into another form which is from thermal energy to mechanical energy. However, while transforming energy from one form to another form, the efficiency of conversion plays an important role. From this, the air fuel ratio is the main factor where the efficiency of combustion is determined inside the engine. Engine knock has long been a well-recognized phenomenon in the automotive industry. Detecting engine knock opens up the possibility for an indirect feedback of the engine’s internal combustion without installing a pressure transducer inside the cylinder. Knock detection has mainly been used for spark advance control, making it possible to control the engine close to its knock limit in search for the optimal ignition timing. Detecting engine knock opens up the possibility for an indirect feedback of the engine’s internal combustion without installing a pressure transducer inside the cylinder. The research were done on the suitable using the knocking sensor in the exhaust stream after the combustion process. Using the standard Air/Fuel ratio of the gasoline engine, the program for controlling the fuel injection into the internal combustion engine is made using the Arduino controller. Then, the data is collected and will be analyses and also compared with other data. This thesis is submitted for the partial requirement of final year project named Study Signal Processing of Engine Knocking on Vehicle Using Closed Loop System. Gasoline and diesel engine are widely used in industry and agricultural field, and it has different performance, combustion and vibration characteristics in the internal combustion engine. This project will study based on signal processing of engine knocking for the gasoline engine. Engine knock has long been a well-recognized phenomenon in the automotive industry

Experimental investigation of gasoline – Dimethyl Ether dual fuel CAI combustion with internal EGR

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.A new dual fuel Controlled Auto-Ignition (CAI) combustion concept was proposed and researched for lower exhaust emissions and better fuel economy. The concept takes the advantage of the complementary physical and chemical properties of high octane number gasoline and high cetane number Di-Methyl Ether (DME) to organize the combustion process. Homogeneous gasoline/air mixture is utilized as the main combustible charge, which is realised by a low-cost Port Fuel Injection (PFI) system. Pressurised DME is directly injected into cylinder via a commercial Gasoline Direct Injection (GDI) injector. Flexible DME injection strategies are employed to realise the controlled auto ignition of the premixed charge. The engine is operated at Wide Open Throttle (WOT) in the entire operating region in order to minimize the intake pumping loss. Engine load is controlled by varing the amount of internal Exhaust Gas Recirculation (iEGR) which is achieved and adjusted by Positive Valve Overlap (PVO) and/or exhaust back pressure, and exhaust rebreathing method. The premixed mixture can be of either stoichiometric air/fuel ratio or fuel lean mixture and is heated and diluted by recycled exhaust gases. The use of internal EGR is considered as a very effective method to initiate CAI combustion due to its heating effect and moderation of the heat release rate by its dilution effect. In addition, the new combustion concept is compared to conventional SI combustion. The results indicate that the new combustion concept has potential for high efficiency, low emissions, enlargement of the engine operational region and flexible control of CAI combustion