Now showing 1 - 10 of 11
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    Low cost Engine Management System (EMS) for the cost sensitive two-wheeler application: Idle speed and A/F ratio control using PID and fuzzy logic control algorithms
    In this work an Engine Management System (EMS) using a low cost 8-bit microcontroller specifically for the cost sensitive small two-wheeler application was designed and developed. Only the Throttle Position Sensor (TPS) and the cam position sensor (also used for speed measurement) were used. A small capacity 125CC four stroke two-wheeler was converted into a Port Fuel Injected (PFI) engine and was coupled to a fully instrumented Eddy Current Dynamometer. Air-fuel ratio was controlled using the open loop, lookup-table [speed (N) and throttle (α)] based technique. Spark Time was controlled using a proportional / fuzzy logic based close loop control algorithm for the idle speed control to reduce fuel consumption and emissions. Test results show a significant improvement in engine performance over the original carbureted engine, in terms of fuel consumption, emissions and idle speed fluctuations. The Proportional controller resulted in significantly lower speed fluctuations and HC / CO emissions than the fuzzy logic controller. Though the fuzzy logic controller resulted in low cycle by cycle variations than the original carbureted engine, it leads to significantly higher HC levels. The performance fuzzy logic can be improved by modifying the membership function shapes with more engine test data. Copyright © 2007 by ASME.
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    Low cost engine management system with two degrees freedom air-fuel ratio controller for a small displacement port fuel injected SI engine
    (01-12-2012) ;
    Singaperumal, M.
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    A two-degree freedom air fuel ratio controller (Model based feed forward transient plus closed loop Proportional Integral-Derivative (PID) steady state controllers) developed for controlling the air fuel ratio of the charge in a small displacement (125 CC) SI engine is presented. The feed forward controller's airflow and injector models were developed after conducting extensive experiments on the engine modified for the Port Fuel Injection (PFI) operation. A dynamic air fuel ratio model obtained (air fuel ratio changes measured using an UEGO sensor) by injecting the Pseudo Random Binary Signal (PRBS) signal in addition to base line fuel injection pulse, was used for designing the PID controller. Optimal PID gain values were identified using Nelfer-Mead optimization technique. The control algorithms were implemented and optimized using SIMULINK blocks that are run under dSPACE on the MicroAuto box hardware. The optimized control algorithms were ported on the specially designed, in-house built, low cost engine management system (EMS) developed around an 8-bit microcontroller. The spark timing was also controlled simultaneously for knock free operation. The two-degree freedom air fuel ratio controller could maintain the air fuel ratio under steady and transient conditions closely. High thermal efficiency and low HC & NOx emissions were achieved using the developed EMS. At higher speed elevated NOx emission was observed, due to the use of leaner mixture. The improvements are expected to be higher if a suitable smaller injector is used. Copyright © 2012 by ASME.
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    Development of an idle speed engine model using in-cylinder pressure data and an idle speed controller for a small capacity port fuel injected SI engine
    (01-02-2011) ;
    Singaperumal, M.
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    An idle speed engine model has been proposed and applied for the development of an idle speed controller for a 125 cc two wheeler spark ignition engine. The procedure uses the measured Indicated Mean Effective Pressure (IMEP) at different speeds at a constant fuel rate and throttle position obtained by varying the spark timing. At idling conditions, IMEP corresponds to the friction mean effective pressure. A retardation test was conducted to determine the moment of inertia of the engine. Using these data, a model for simulating the idle speed fluctuations, when there are unknown torque disturbances, was developed. This model was successfully applied to the development of a closed loop idle speed controller based on spark timing. The controller was then implemented on a dSPACE Micro Autobox on the actual engine. The Proportional Derivative Integral (PID) controller parameters obtained from the model were found to match fairly well with the experimental values, indicating the usefulness of the developed idle speed model. Finally, the optimized idle speed control algorithm was embedded in and successfully demonstrated with an in-house built, low cost engine management system (EMS) specifically designed for two-wheeler applications. © 2011 The Korean Society of Automotive Engineers and Springer-Verlag Berlin Heidelberg.
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    Publication
    LOW COST ENGINE MANAGEMENT SYSTEM (EMS) FOR THE COST SENSITIVE TWO-WHEELER APPLICATION: IDLE SPEED AND A/F RATIO CONTROL USING PID AND FUZZY LOGIC CONTROL ALGORITHMS
    In this work an Engine Management System (EMS) using a low cost 8-bit microcontroller specifically for the cost sensitive small two-wheeler application was designed and developed. Only the Throttle Position Sensor (TPS) and the cam position sensor (also used for speed measurement) were used. A small capacity 125CC four stroke two-wheeler was converted into a Port Fuel Injected (PFI) engine and was coupled to a fully instrumented Eddy Current Dynamometer. Air-fuel ratio was controlled using the open loop, lookup-table [speed (N) and throttle (α)] based technique. Spark Time was controlled using a proportional / fuzzy logic based close loop control algorithm for the idle speed control to reduce fuel consumption and emissions. Test results show a significant improvement in engine performance over the original carbureted engine, in terms of fuel consumption, emissions and idle speed fluctuations. The Proportional controller resulted in significantly lower speed fluctuations and HC / CO emissions than the fuzzy logic controller. Though the fuzzy logic controller resulted in low cycle by cycle variations than the original carbureted engine, it leads to significantly higher HC levels. The performance fuzzy logic can be improved by modifying the membership function shapes with more engine test data.
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    A new method for measurement of air–fuel ratio based on the response time of binary-type exhaust gas oxygen (BEGO) sensor for application in small spark ignition (SI) engines
    (01-01-2014) ;
    Singaperumal, m.
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    A binary-type exhaust gas oxygen (BEGO) sensor that is usually used to maintain the air–fuel ratio (AFR) at stoichiometric conditions in current spark ignition (SI) engines is significantly lower in cost compared with the universal exhaust gas oxygen sensor. However, it can only switch from a high state (≈0.7 V) to a low state (≈0.1 V) when the mixture goes from richer to leaner than stoichiometric conditions or vice versa. Thus, it cannot indicate the actual AFR. A novel method of estimating the AFR of an SI engine using a BEGO sensor has been demonstrated in this work for leaner than stoichiometric mixtures. Experiments were conducted on a single-cylinder, manifold-injection SI engine. The air–fuel mixture was initially kept at a richer than stoichiometric level while the engine was maintained at constant speed and throttle. The mixture was suddenly changed to a leaner than stoichiometric level. The switching time of the BEGO sensor during this operation was noted. This was repeated for different initial and final AFRs. A relationship between the switching time and change in AFR was obtained for different initial AFRs. A look-up table to determine the AFR was made and used under test conditions. The error is less than 5% in the estimated AFR. The system was also incorporated on a low-cost microcontroller-based engine management system and tested under laboratory conditions. © 2013, SAGE Publications. All rights reserved.
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    Development of a system for control of Air Fuel ratio in a small two wheeler engine
    (09-01-2008) ;
    Paul, Ciju
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    In the case of small SI engines for two-wheelers emission reduction will preferably be achieved through the use of lean mixtures since catalytic converters will increase the cost. In such cases a very close control over the air fuel ratio will be needed. In this work a carbureted 125cc small capacity two-wheeler engine was modified to operate with Port Fuel Injection (PFI) for improved control over the air fuel ratio. A throttle body was specially made to house the injector and a position sensor. A cam position sensor, crank angle sensor, manifold air pressure (MAP) sensor, 60-2 toothed wheel for precise control of the events on the angle basis were used. Extensive tests were conducted with the throttle body and fuel injector to obtain the mathematical models for the inlet manifold and fuel injector. These were used to make the model based controller. The dSPACE - Micro Auto Box platform was used to develop and test the control algorithms. Software was written using SIMULINK. The closed loop PID algorithm was used for air-fuel ratio control and map based spark time control for steady state operation and model based control during the transient operation. The controller is able to maintain air fuel ratio as demanded in both steady and transient conditions in the test bed and there are significant improvements in CO, HC, NOX emissions and fuel consumption as compared to the carbureted operation.
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    An Electronically Controlled System for Parametric Studies on Fuel Injection in an Automotive Gasoline Engine
    (22-08-2003)
    Sarkar, Sushantha Kumar
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    An electronic system was developed for the control of the injection timing and injected fuel quantity for studies on a passenger car engine. This system can be used to produce maps of these parameters for implementation in an electronic control unit. The complete electronic hardware which included the cam position sensor, pulse shaping, pulse delay and sequencing features was developed and tested. The system could control the injection pulse width for the different cylinders independent of each other. The developed system was used to conduct parametric studies. The results obtained were compared with that obtained from the base carbureted engine. There was a significant improvement in brake thermal efficiency and reduction in HC and CO emissions with the injection system. A retarded injection timing was needed at low loads. The volumetric efficiency of the injection system was much higher than the carbureted version. Since the system was tuned for lean mixtures the power output was lower.
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    Studies on An Electronic Governor with A Stepper Motor Actuator for A Diesel Engine
    (16-01-2004)
    Reddy, Boreddy Balakrishna
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    A personal computer (PC) based electronic governor was developed in this work for a diesel engine. A stepper motor was used to actuate the rack of the inline fuel pump of the engine with a bell crank lever. The digital output of the system was used to control the stepper motor using special hardware. This governor was tested under different steady and transient operating conditions. The electronic governor performed satisfactorily. In most cases the speed settled down in time duration comparable to that with the mechanical governor. The electronic governor could operate with no change in the mean speed with engine output. The performance was very sensitive to the P, I and D parameters of the control software. It was felt that the system could be improved with a stepper motor of finer steps and higher torque.
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    An ionization current based cylinder gas pressure estimation for knock detection and control in a single cylinder Si engine
    (01-01-2009)
    Kumar, Davinder
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    Babu, M. K.Gajendra
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    The ionization current across the spark plug gap is obtained by applying a constant voltage using DC power source across the spark gap after the high-voltage discharge. The methodology involves study and comparison of different knock detection methods (cylinder gas pressure, accelerometer and ion current) through literature survey, development of analytical models (ionization current, chemical equilibrium, kinetic Nitric Oxides) to estimate crank angle resolved cylinder gas pressure from the measured values of ionization current. Model refinements and validations, development of Ignition Coil integrated DC power source and ion current measurement circuit, Transistorized Coil Ignition and microcontroller based knock controller have been carried out. Experiments have been conducted to validate the model with the reference method (cylinder gas pressure). The ion current and cylinder gas pressure signals are measured during knocking conditions and it is shown that ion current signals can be used to detect knock. A circuit to detect ion current by using single spark plug has been developed and applied successfully. The nature of ion currents has been studied and a model has been developed to estimate cylinder gas pressure from this signal. This has been validated and applied to detect presence of knock. A microcontroller-based system with software has been developed to control the spark timing based on knock intensity. The purpose of this work is to implement it in a two wheeler small engine with a long term goal to increase compression ratio in lean burn engines with high likelihood of knock. Copyright © 2009 SAE International.
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    Investigations on performance and emissions of a two-stroke SI engine fitted with a manifold injection system
    (01-04-2006)
    Loganathan, M.
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    Simple and cost effective electronically controlled injection systems have to be developed to combat the problem of urban pollution. In this work an electronically controlled fuel injection system developed in the Internal Combustion Engine Laboratory of Indian Institute of Technology Madras has been tested in detail on a two-stroke SI engine. The system is fitted on the intake manifold of a single cylinder, air cooled two-stroke scooter engine. Tests have been done at 3000 rpm and 4000 rpm at different throttle positions. The optimum injector pulse widths for thermal efficiency, lowest HC emissions and highest power are all different. The maximum brake thermal efficiency values are 22.6% and 23% at 3000 and 4000 rpm respectively. At a power output of 3 kW and 4000 rpm the brake thermal efficiency is about 21% for the carbureted engine. It increases to 23% with the fuel injection system. HC emissions are considerably lower than the carbureted version at all operating conditions and speeds. The engine can work with leaner mixtures with the injection system in general as compared to the carburetor. The maximum power increases with the injection system. The developed system can be used for mapping the engine for the development of software for injection system control.