• Journal of Service Research and Studies
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• v.11 no.2
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• pp.118-130
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• 2021

This study designs and validates a greenhouse complex environmental control algorithm with a multi-phase processing scheme that can combine and control actuators according to the degree of change in the greenhouse environment. The composite environmental control system is a system in which the complex environmental controller analyzes the information detected by sensors and operates appropriately actuators to maintain the crop growth environment. A composite environmental controller directs control devices driving actuators through a composite environmental control algorithm, which calculates the values necessary for the operation of the control devices. Most existing algorithms carry out control procedures on a single phase by iteration cycle, which can cause abnormal changes in the greenhouse environment due to errors in output. The proposed algorithm distributes control procedures over multiple phases: environmental control, environmental control, and device operation, and every iteration cycle, detects environmental changes in the environmental control phase first, and then combines control devices that can control the environment in the environmental control phase, and finally, performs the controls to derive the actuators in the device operation phase. The proposed algorithm is designed based on the analysis of the relationship between greenhouse environmental elements and control devices deriving actuators. According to verification analysis, the multi-phase processing scheme provides room to modify or supplement the setting value and enables the control devices to reflect changes in the associated environmental components.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1034-1037
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• 2003

Recently in the field of precision positioning device, the contact-free actuators are gaining focuses with their outstanding performances by eliminating mechanical frictions. Th is paper is about the driving algorithm for contact-free linear actuator. The proposed driving algorithm has similar structure of drives of switched reluctance motor and reduces the normal forces and force ripple. The simulation and experiment are executed to verify the proposed method.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.1-8
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• 2017

This paper presents the development of an adaptive cruise control (ACC) system, which is one of the typical advanced driver assist systems, for 4-wheel drive hybrid in-wheel electric vehicles. The front wheels of the vehicle are driven by a combustion engine, while its rear wheels are driven by in-wheel motors. This paper proposes an adaptive cruise control system which takes advantage of the unique driveline configuration presented herein, while the proposed power distribution algorithm guarantees its tracking performance and fuel efficiency at the same time. With the proposed algorithm, the vehicle is driven only by the engine in normal situations, while the in-wheel motors are used to distribute the power to the rear wheels if the tracking performance decreases. This paper also presents the modeling of the in-wheel motors, hybrid in-wheel driveline, and integrated ACC control system based on a commercial high-precision vehicle dynamics model. The simulation results obtained with the model are presented to confirm the performance of the proposed algorithm.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.5
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• pp.598-603
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• 2004

An optical head actuator of an optical disk drive consists of two servo mechanisms for the focusing and the tracking to acquire data from disk. As the rotational speed of the disk grows, the utilized lag-lead-lead compensator has known to be above its ability for precisely controlling the optical head actuator. To overcome the difficulty, this paper propose a new controller design method for optical head actuator based fuzzy proportional-integral-derivative (PID) control and the genetic algorithm(GA). It employs a two-stage control structure with a fuzzy PI and a fuzzy PD control and is optimized by the GA to yield the suboptimal fuzzy PID control performance. It is shown the feasibility of the proposed method through a numerical tracking actuator simulation.

• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.4
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• pp.321-327
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• 2003

As the continuous casting process is to product slab with high temperature liquid steel, the main role of strand driven roll is to withdraw slab from mold as operator set up casting speed pattern. The strand driven roll in old cast machine is controlled casting speed only. Due to inaccuracies in drive setting up, varying roll diameters, bulging in the product, withdrawal force was distributed irregularly. As a result, because of horizontal crack in slab comer, high casting speed can't be achieved. In this paper, the correlation between the distribution of withdrawal force and slab quality is investigated and the new control algorithm which can be distributed regularly the withdrawal force of strand driven roll is proposed. The principle of proposed algorithm is not to control motor torque directly but to control motor speed reference according to sharing ratio of withdrawal force which is set up in high level controller. The proposed algorithm implemented in POSCO Kwangyang 1-4 continuous casting plant.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.761-765
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• 1995

The old Timing Controller for Control Element Drive Mechanism (CEDM) is designed as an open loop control system because it is difficult to mount sensors within the Control Element Drive Mechanism(CEDM) which is operating under the pressure boundary of the reactor vessel. In this work new method which can be used to detect the CEDM operational conditions without mounting sensors within the CEDM housing is developed in order to resolve problems of the old Timing Controller. By using the developed new method, the new Timing Controller for the CEDM is designed as a closed loop controller which has features of the control rod drop prevention, fine position control and the coil life time extension. The algorithm developed under closed loop control concept resolves most problems occurred in the old Timing Controller and improves the performance and reliability of the system. During designing and testing of the Timing Controller algorithm, the real time CEDM simulator developed here was used. And all functions of the developed algorithm were verified using CEDM simulator with the real data collected from the site. The results show that the Timing Controller performs its intended functions properly.

• Journal of the Korean Geographical Society
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• v.33 no.2
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• pp.293-308
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• 1998

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.5
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• pp.692-699
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• 2008

This paper describes optimal operation method using recognition of walker's will for a robotic walker. Recently, walking aid system has been required according to the increase of elder and handicapped person. However, most of walking aid system don't have actuator for its movement. Unfortunately, standard frames have weakness for the movement to upward/download direction of slope. So, active type walking aids are interested, but it is not easy to control. In this paper, we adapt user's will system that can recognize walking direction and speed. First, FSR(Force Sensing Register) is applied to measure user's will to walk. And then, fuzzy algorithm is used for determining optimal wheel velocity and direction of the walking aid. From the result, walking aid can move smoothly and safely following the user's will. The walking aid can help user to walk more optimally. Here, all the processes are verified experimentally in the real world.

• Journal of the Society of Naval Architects of Korea
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• v.32 no.4
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• pp.105-113
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• 1995

A mechanical actuator to generate adjustable force ants its active control algorithm to minimize ship structural vibration are developed. The algorithms comprise initial algorithm which determines optimal phase and force magnitude of the actuator using the variation of vibration response according to the phase difference between the main engine and the actuator, and regulating algorithm which performs continuous optimal control to track the change of the engine speed. This control system can be applied without any prior identification for the dynamic characteristics of the controlled structure. In the control experiments for the deckhouse structural vibration of a 300,000 DWT crude oil carrier and a 2,270 TEU container carrier, the developed system showed good performance to reduce the vibration levels to $1/2{\sim}1/6$ of the uncontrolled levels.

• Proceedings of the KIEE Conference
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• 2004.07d
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• pp.2221-2223
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• 2004

본 논문에서는 유전알고리즘을 기반으로 하여 설계된 광 디스크 드라이브의 광학헤드 구동기용 퍼지 PI/PD 제어기를 제안한다. 본 논문에서 제안하는 제어기는 광디스크 드라이브의 광학헤드용 구동기의 포커싱 서보계, 트랙킹 서보계를 제어할 수 있는 퍼지 제어기이며 유전알고리즘을 통해 최적의 퍼지 규칙을 도출한다. 그리고 이를 토대로 모의실험을 수행한다.