• 유공압시스템학회:학술대회논문집
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• 2010.06a
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• pp.62-65
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• 2010

Field robot represented by excavator can be applied for various working in manufacturing, construction, agriculture etc. Because of the flexibility of its multi-joint mechanism and the high power of hydraulic actuators. Since the excavator operates in the hazardous working circumstance, operators exposed in harmful environment. Therefore, automation system has been investigated to protect from the harmful environment. In this paper, the method to construct the remote control system is proposed. The remote control system is consisted of a manual and auto mode. Manual mode controls a hydraulic cylinder as open loop control. and auto mode controls the end effecter of excavator using tracking control system. The efficiency of remote control system was evaluated through the field test.

• Korean Journal of Construction Engineering and Management
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• v.5 no.4 s.20
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• pp.139-146
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• 2004

Resent removal work for road signs has been labor intensive and required times since it has been done manually using shaving type equipment. While traditional process is conducting, there are traffic jams caused by the passing control, and happened unexpected accidents to workers working at dangerous road circumstance. Besides, in current shaving method, there are high potentialities on the air pollution as well as the explosive accident occurred by using a propane gas. So, as an alternative, we have studied to develop the automatic erasing equipment made up with a high pressure water-jet system and automatic control system, mobile system; Wate-rjet system consists of an intensifier and nozzles to give a high pressure and spray on the sign, and automatic control system is composed of one axis robot using a hydraulic servo actuator controlled by a lever, And as a mobile system, a truck plays an important role for the transport of equipment and the forward movement in a removal process. In this paper, we have analyzed the characteristics of road signs and have investigated current erasing methods in the field. And we have organized and designed automatic erasing equipment, and we have made a basic experiment to find out the optimal spray condition as like the spray distance, spray angle and injection pressure.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.469-474
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• 2002

The Field Robot means the machinery applied for outdoor tasks in construction, agriculture and undersea etc. In this study, to field-robotize a hydraulic excavator that is mostly used in construction working, we have developed an automatic excavation system and adaptive control system. A model- reference adaptive controller has been designed on the model that is obtained through off-line System Identification. It is illustrated by computer simulations that the proposed control system gives good performances in the trajectory tracking control and adaptation to parameter variation.

• Transactions of The Korea Fluid Power Systems Society
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• v.6 no.4
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• pp.9-15
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• 2009

Hydraulic excavators are the representative of field robot and have been used in various fields of construction. Since the excavator operates in the hazardous working environment, operators of excavator are exposed in harmful environment. Therefore, the hydraulic excavator automation and remote operation system has been investigated to protect from the hazardous working environment. In this paper, remote operation excavator system is developed using the mini hydraulic excavator and the tracking control system of each links of excavator is designed. To apply the tracking control system, the adaptive sliding mode control algorithm is proposed. It is found that the performance of the proposed control system is improved through experimental results of using the remote operation excavator system.

• Journal of the Korea Institute of Building Construction
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• v.13 no.2
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• pp.159-168
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• 2013

Construction projects have become increasingly complex in recent years, resulting in substantial safety hazards and frequent fall accidents. In an attempt to prevent fall accidents, various safety management systems have been developed. These systems have mainly been evaluated qualitatively and subjectively by practitioners or supervisors, and there are few tools that can be used to quantitatively evaluate the performance of safety management systems. We propose an expertise-based safety performance evaluation model (EXSPEM), which integrates a fuzzy approach-based analytic hierarchy process and a regression approach. The proposed model uses S-shaped curves to represent the degree of contribution by subjective expertise and is verified by a genetic algorithm. To illustrate its practical application, EXSPEM was applied to evaluate the safety performance of a newly developed real-time mobile detector monitoring system. It is expected that this model will be a helpful tool for systematically evaluating the application of a robust safety control and management system in a complex construction environment.

• Korean Journal of Construction Engineering and Management
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• v.5 no.2 s.18
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• pp.153-161
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• 2004

The systematic material and labor management planning should be established on accomplished EVM data. The matrix method of integrated cost and schedule was used with common category concept according to the construction project control system. The construction project control system was suggested through analyzing process and data modeling based on integrated cost, schedule and material. Information of construction project can be developed the relationship between the field data and the integrated cost, schedule database. Process and data modelling is provide a standard data format which are related to the material, labor management based on integrated cost, schedule database.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.288-293
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• 1987

This study presents the methodology for the hierachical construction of digital control system which can be of practical value to a wide application of sequence control. Optimization of digital control system, programming of the system by micropascal, and simulation of a model program under test are discussed.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.227-228
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• 2012

In contemporary architectural practice, flat sections and plan drawings are no longer a primary means of representation and communication with participants. A typical building design has an ornamental exterior wall system and a roof system that should have water-proof quality and drainage function. By comparison, distinction between exterior wall and roof are unclear in freeform buildings, and they are integrated into a concept of a building envelope. This study is to propose 3D coordinate control technology for freeform structure by CNC curved tube method in order to develop a BIM-based envelope design and construction method for freeform building. Because a much wider freeform building construction can be achieved with correct 3D data and easy-to-implement in construction field, the proposed 3D coordinate control technology is highly recommended for practical use instead of the conventional CAD system.

• 제어로봇시스템학회:학술대회논문집
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• 1999.10a
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• pp.73-78
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• 1999

This paper presents an effective construction method of adaptive multiple control systems utilizing some knowledge upon the plants. The adaptive multiple control system operates plants un-der widely changing environmental conditions. The adaptive multiple control system is composed of a family of candidate controllers together with a supervisor. The system does not require any identification schemes of environmental conditions. Monitoring outputs of the plant, the supervisor switches from one candidate controller to another, The basic ideas of adaptation are as follows: (1)each candidate controller is prepared for each environmental condition in advance; (2)the supervise. applies a sequence of speculative controls to the plant with candidate controllers just after the start of control or just after the detection of a change in the environmental condition. Each candidate controller can keep the system stable during one-step period of the speculative control and the most appropriate candidate controller for the environmental condition to which the system is exposed can be selected before the last trial of speculative control step comes to an end. We proposed a construction method of adaptive multiple control system without any knowledge of plant dynamics and applied the method to a cart-pole balancing problem and a vehicle anti skid braking system. In real applications, as we can often easily obtain a piece of knowledge upon plant dynamics beforehand, we intend to extend the method such that multiple control systems can be efficiently designed using the knowledge. We apply the new idea to the cart-pole balancing problem with variable length of the pole. The simulation experiments lead us to the conclusion that the new attempt can reduce the manpower to design the candidate controllers for adaptive multiple control systems.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1053-1059
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• 2009

Construction system modeling can enhance work performance by following the behaviors of a system. System behaviors may originate from physical aspects of a system, namely operation level variables, or from non-physical aspects of a system known as context level variables. However, construction system modelers usually focus on only one type of system variable (i.e., operation level or context level) which can lead to less accurate results. Hybrid modeling with System Dynamics (SD) and Discrete Event Simulation (DES) is one of the approaches that has been utilized to address this issue. In this research, an SD-DES hybrid model of a steel fabrication shop is developed, and the benefits of capturing context level variables together with operation level variables in the model are discussed.