• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.8
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• pp.3103-3120
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• 2015

This paper presents a single-phase energy metering chip with built-in calibration function to measure electric power quantities. The entire chip consists of an analog front end, a filter block, a computation engine, a calibration engine, and an external interface block. The key design issues are how to reduce the implementation costs of the computation engine from repeatedly used arithmetic operations and how to simplify calibration procedure and reduce calibration time. The proposed energy metering chip simplifies the computation engine using time-division multiplexed arithmetic units. It also provides a simple and fast calibration scheme by using integrated digital calibration functionality. The chip is fabricated with 0.18-μm six-layer metal CMOS process and housed in a 32-pin quad-flat no-leads (QFN) package. It operates at a clock speed of 4096 kHz and consumes 9.84 mW in 3.3 V supply.

• Journal of the Korean Society of Propulsion Engineers
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• v.6 no.1
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• pp.39-46
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• 2002

It is very difficult to measure an exact thrust in liquid rocket engine compared to solid rocket motor, however it is very important to estimate a performance of engine for developing rockets. To get a good result, we have to concern about errors of measurement and find a method of calibration. In this research, we developed new thrust measurement system for liquid rocket engine.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.3
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• pp.319-329
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• 2016

Globally, many researchers have been trying to improve the fuel economy of a vehicle for satisfying future $CO_2$ regulation and minimizing air pollution problem. For the same background, diesel engine and vehicle system optimization using simulation models have been key technologies for the improvement of vehicle system efficiency. Therefore, in this study, calibration method for the air breathing system of a WGT diesel engine using mean value model has been composed for efficient engine and vehicle optimization simulation researches. And virtual WGT performances have been calculated for a 2 cylinder downsized diesel engine system. From these researches, the calibration method for the boost pressure and EGR rate of a virtual diesel engine related with WGT performances could be composed and some of technical issue related with downsized diesel engine could be investigated.

• Journal of ILASS-Korea
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• v.20 no.4
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• pp.247-253
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• 2015

Recently, the engine calibration technique has been much more complicated than that of the past engine case in order to satisfy the strict emission regulations. The current calibration method for the diesel engine which has an increasing market is both costly and time-consuming. New engine calibration method is required to develop for high-quality diesel engines with low cost and release it at the appropriate time. This study provides the optimal calibrating technique for complex engine systems using statistical modeling and numerical optimization. Firstly, it design a test plan based on Design of Experiments, a V-optimality methodology which is suitable looking for set-points, and determine the shape of test engine response. Secondly, it uses functions to make linear regression model for data analysis and optimization to fit the models of engines behavior. Finally, it generates the optimal calibrations obtained directly from empirical engine models using Grey Relational Analysis and compares the calibrations with data. This method can develop a process for systematically identifying the optimal balance of engine emissions.

• Aerospace Engineering and Technology
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• v.6 no.1
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• pp.120-127
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• 2007

Performance dispersion in the engine should be considered to predict the flight accuracy of a launch vehicle. A dispersion estimation method was presented with a LOx/Kerosene gas generator cycle engine. The orifices in the propellant supply lines in the engine were assumed to be used for calibration of the performance and the required pressure drops were acquired. The dispersions after calibration were quantified also.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.30B no.11
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• pp.84-92
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• 1993

Calibration of Engine models is a painstaking process but very important for successful application to automotive industry problems. A combined heuristic and machine learning approach has therefore been adopted to improve the efficiency of model calibration. We developed an intelligent calibration program called ICALIB. It has been used on a daily basis for engine model applications, and has reduced the time required for model calibrations from many hours to a few minutes on average. In this paper, we describe the heuristic control strategies employed in ICALIB such as a hill-climbing search based on a state distance estimation function, incremental problem solution refinement by using a dynamic tolerance window, and calibration target parameter ordering for guiding the search. In addition, we present the application of amachine learning program called GID3*for automatic acquisition of heuristic rules for ordering target parameters.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.1
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• pp.134-143
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• 2008

The hardware scatters as well as the engine parameters calibration have strong influences on exhaust emissions in recent diesel engines. In this research DoE(Design of Experiments) optimizations were done to study the possibility of minimizing the emission deviations caused by flow rate scatters of the injectors. It has been shown that the optimization of engine calibration, which minimizes the emission deviations, is feasible by establishing a target function representing the emission deviations for test results of maximum, mean and minimum flow rate injectors. It has also been shown that optimization of both emission deviations and emission level is possible by sequential DoE optimizations of the target functions representing the emission level and the emission deviations respectively with the appropriate boundary limits.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.6
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• pp.104-108
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• 2008

Recently, studies conducted by our research group, revealed the possibility for reducing BSFC, NOx and PM emissions to meet the Euro 4 & 5 legislations. The main objective of the present study is to get better fuel economy in commercial vehicles by considering real driving conditions. Firstly, in order to improve fuel economy on fields, specifically it is required to analyze the driving pattern and make the representative modes from real field data. Secondly, it is performed to make the engine dynometer test to optimize the fuel consumption by reflecting on the representative driving modes, based on the Korea 2008 emission legislation equal to the Euro 4. The engine components such as engine calibration, combustion chamber, turbocharger and ancilliaries were modified to optimize vehicle fuel economy over a typical customer drive cycle whilst still meeting the exhaust emission restrictions. Finally, these results were confirmed by field testing of vehicle equipped with the updated calibration engine. It was placed the two vehicles together traveling the same route and accomplishing the same amount of stops(back to back), in order to evaluate the fuel consumption in comparison to the current vehicle. Through several repeats such as the engine calibration and field test, we could get 3 % to 7.7 % vehicle fuel economy improvements compared to previous vehicle.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.5
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• pp.44-48
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• 2008

This paper describes on studies of the heavy duty engine calibration for better fuel economy based on real driving conditions. Using testbed validated software simulation of the engine and turbocharger system, an alternative turbocharger specification, with potential to improve fuel economy was identified. Secondly, the engine calibration was modified to optimize vehicle fuel economy over a typical customer drive cycle whilst still meeting the steady-state (testbed) emissions legislation. These results were confirmed by field testing of a vehicle equipped with the updated specifications. This study found good agreements between the prediction and the field test on the vehicle fuel economy improvements of the express bus with updated calibration and turbocharger.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.1
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• pp.71-76
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• 2014

This Research focuses on how to maximize fuel economy improvement of I.S.G. while keeping 12V system. With 12V system the maximum gain of fuel economy with I.S.G. is known to be about 3~5% in FTP-75 mode because engine stop is only conducted in standstill idle. But in this study deceleration engine stop (engine speed is zero) has been tried additionally and the optimum condition for deceleration engine stop was found to maximize fuel economy improvement in practical point of view, the result of which is about 8.8% in FTP-75.