• Journal of Korean Society on Water Environment
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• v.28 no.2
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• pp.300-304
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• 2012

It has a limitation to satisfy the phosphorus effluent criteria of 0.2 mg/L which will be reinforced from 2012 with the Biological Nutrient Removal (BNR) process. The chemical coagulation process has been operated in parallel with the biological treatment process for advanced treatment of phosphorous in the developed countries including Europe. However, the coagulation process has some disadvantages such as the desired goal may not be achieved without injecting the optimum dosage of the coagulant. This study developed the automatic control system to inject the optimum dosage of phosphorous coagulant into the coagulation process. The adopted coagulant was 10% Poly Aluminum Chloride (PAC) in this study. The automatic control system developed in this study was adopted for the treatment of the phosphorus from the effluent in SBR process. The automatic control system was composed of the data receiving part, the optimum coagulant dosage control part and the data transmit part. The result of the phosphorous advanced treatment of the SBR effluent using the automatic control system showed the removing efficiency over 95% consistently with the phosphorous concentration under 0.02 ~ 0.15 mg/L. The reproducibility analysis for checking the safety of automatic control system showed more than 95% correlation.

• International Journal of Contents
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• v.11 no.4
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• pp.70-76
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• 2015

The development of technology provides and increases security as well as convenience for humans. The development of new technology directly affects the standard of life thanks to smart home automatic control systems. This paper describes a door control, automatic curtain, home security (CCTV, fire, gas, safe, etc.), home control (energy, light, ventilation, etc.) and web-based smart home automatic controller. It also describes the use of ARM (Advanced RISC Machines) for automatic control of home equipment, a Multi-Axes Servo Controller using FPGA (Field Programmable Gate Array) and PLC (programmable logic controller). Additionally, it describes the development of a HTML editor using web auto control software. The tab loading time (7 seconds) is faster when using ARM-based web browser software instead of Chrome and Firefox is used because the browser has a small memory footprint (300M). This system is realized by web auto controller language which controls and uses PLCs that are easier than existing devices. This smart home automatic control technology can control smart home equipment anywhere and anytime and provides a remote interface through mobile equipment.

• Journal of the Korean Society for Marine Environment & Energy
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• v.2 no.1
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• pp.90-101
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• 1999

This paper is concerned with the design of automatic ship maneuvering system including automatic path tracking controller and automatic berthing controller. The optimal control technique is employed to design the automatic path tracking controller, which is based on the linearized equations of ship motion. The numerical example shows that the automatic path tracking controller is capable of tracking the line between way points which are determined by pilot a priori. The decentralized control technique is employed to design the automatic berthing controller. In addition to the automatic path tracking controller, the fuzzy logic controller is used to control the forward speed. The numerical example shows that the automatic berthing controller can be successfully implemented.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.541-545
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• 1996

In this paper, The performance and functions of automatic flatness control system installed on the 4 hi-reversing mill and has been investigated under actualconditions. A new automatic flatness control system incorporates a measuring roll for measurement and correction calculations, hydraulic roll benders, selective roll cooling, and a programmable controller for interface and data logging. The test results are as following. The more the exit steel strip thickness is thick, the smaller the I value, and the more it is thin, the larger the I value. And, a complex distribution of strip tension was controlled, for example, not only a quarter buckle but also a simple center wave and edge wave. Because the tension deviation is larger at acceleration speed and deceleration speed than steady speed, so automatic flatness control system of contact type is better to adopt over 450 m/min, automatic flatness control system reduces rapidly large flatness deviation. The maximum I value of strip has been decreased to 13 I, and defects caused by poor flatness have been drastically decreased. And coolant temperature for work roll cooling system on the automatic flatness control system is better to adopt about 50-55 .deg. C.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.3
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• pp.49-55
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• 1996

Recently, the necessity for more accurate automatic gauge control has increased of customers' requirement for cold rolled steel sheets with thinner gauge and better gauge quality. Therefore, many cold rolling mills replaced its electric screw down automatic gauge control system with a new hydraulic automatic gauge control system, to ensure closer gauge tolerance. In this paper, The performance of a hydraulic automatic gauge control system for cold rolling has been investigated under industrial conditions. It was investigated that variation of gauge deviation according to the final products thickness, cold rolling speed and pass number, in the actual rolling mill. As a result, it was found that the system enables strip thickness variation to be reduced substantially and caused by poor gauge deviation have been drastically decreased. The test results are as following. The more the exit steel strip thickness is thick, the smaller the aguge deviation rate is large, and the more it is thin, the large the gauge deviation rate is large. Because the gauge deviation is larger at accleration speed and deceleration speed than steady speed, so automatic gauge control system is better to adopt over 50m/min. automatic gauge control system reduces rapidly large thickness deviation.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.3
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• pp.38-47
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• 1995

A new automatic cardiac output control algorithm for the motor-driven electromechanical total artificial heart(TAH) was developed based on the motor current waveform analysis without using any extra transducer. The basic control requirements of artificial heart can be described in terms of three features : preload sensitivity, afterload insensitivity, and balanced ventricular outputs. In the previous studies, many transducers were utilized to obtain informations of hemodynamic states for the automatic cardiac output control, But such automatic control systems with sensors have had reliability problems. We proposed a new sensorless automatic cardiac output control algorithm providing adequate cardiac output to the time-varying physiological demand without causing right atrial collapse, which is one of the critical problem in an active-filling type device. In-vitro tests were performed on a mock circulation system to evaluate the performance of the developed algorithm and the results show that the new algorithm satisfied the basic control requirements on the cardiac output response and the possibility of application of the developed algorithm to in vivo experiments.

• Journal of Biosystems Engineering
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• v.19 no.2
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• pp.99-111
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• 1994

Automatic control system using microcomputer that have been studied in greenhouse, however, it was very difficult operation with success due to handicap for a various conditions and cultivated plants. This study was performed in order to develop of the basic program and hardware system for automatic control in greenhouse, such as automatic supplying of water, liquefied fertilizer solution and chemical solution. The results were summarized as follows. 1. The program for soil moisture control used by the switch type tensiometer was well operated. 2. The proximity switch was applied as well to water level control but it was very expensive, so low-priced sensor has to be developed. 3. The water meter was not excellent for mixing control of liquefied fertilizer, chemical and water, so water meter for only agricalture has to be developed. 4. Interface system for this study was suited to the developed controller. 5. Automatic control system to supply for water, liquefied fertilizer and chemical solution that was well operated as a fundamental study for product of controller.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.255-261
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• 1998

The train automatic operation control system is an on-board train control system that is widely adopted in modern rapid transit systems. The control system consists of TCMS(Train Control and Monitoring System), ATC(Automatic Train Control), ATO(Automatic Train Operation) and TWC(Train to wayside communication) in the train and wayside facilities. The functions of the system is to regulate train riding comfort, to service limited speed and smoothness during start, acceleration, constant speed travel, and fixed point parking under the corresponding commands. The paper describes the simulation model of the train automatic operation control of subway system, configuration of simulator hardware and software and operational algorithms.

• Journal of Institute of Control, Robotics and Systems
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• v.2 no.2
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• pp.81-87
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• 1996

Time delay control(TDC) law has been recently suggested as an effective control technique for nonlinear time-varying systems with uncertain dynamics and/or unpredictable disturbances. This paper focuses on the applications of the TDC algorithm to torque control of an engine system and speed control of an engine/automatic transmission system. Through the stability analysis of the engien system based on TDC, determination of the appropriate time delay and control factor is investigated. It was revealed that the size of time delay of the TDC law should be greater than that of transport delay of the system for both stability and better control performance. Simulation and experimental results for the engine torque control and engine/automatic transmission speed control systems show both relatively good command following and disturbance rejection properties. However, TDC controller shows rather slow responses when applied to the system with large transport delay.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.107-112
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• 2005

When it comes to automatic operation control of urban rail vehicle, a PID control makes it run between stations within the fixed time and stop exactly at the stop sign on the platform, satisfying jerk limit. An optimal control is applied to automatic operation performance control to minimize energy consumption while the urban rail vehicle satisfies automatic operation condition on this paper. The control performance in terms of energy minimization along with the constraint on precision stops is compared between the optimal control and PID control.