• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2004.11a
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• pp.543-547
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• 2004

Visualization of construction process simulation and physical modeling were considered to overcome the limitations of current graphical simulation. The output of discrete-event simulation programs which are the most common mathematical statistical simulation tool for construction processes were analyzed for the visualization of earthmoving process that dealing with objects without fixed. Object-oriented models for equipment, material and work environments were devised to effectively visualize the numerical simulation results of the working time, the queuing time as well as the amount resources etc. The oscillation of the crane's cable and the lifted material that should be considered to rationally modeled and simulated by construction graphical simulation. The derived equation of motion was solved by numerical analysis procedure. Then obtained results was used for physical modeling.

• Composites Research
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• v.33 no.1
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• pp.13-18
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• 2020

Recently, the fire rescue truck in problem proceed research it for the fast works action and for pass the small road. So we were research for weight reduction. In this study, the (NO. 5) fifth boom of the fire rescue truck have 288 mm(W) × 299 mm(D) × 3,691 mm(L) with a maximum load of 876 kg and the thickness of 3 mm of the Steel Boom. This changing of Steel (STRENX960) to CFRP was weave Carbon Fiber NCF (±45°, 2axis) and then it make the NCF Prepreg. This process was designed based on structural analysis, the effects of NCF Prepreg (±45°) on torsion were identified, and the optimal design was made with Stacking Pattern (b). Stack patterns were optimized for levels equal or higher than existing Steel Boom and CFRP Boom stacked in the UD direction, and finally, the lightening effect on weight of approximately 49.6% of the steel was identified.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• v.10 no.2
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• pp.32-35
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• 2005

밭고랑 옆의 해가림시설 지주목에 파이프라인을 설치하고 방제장치를 탑재한 주행장치가 자동으로 파이프를 추적하면서 농약을 살포 할 수 있는 방제기를 개발하여 인삼재배포장에서 성능시험을 실시하였다. 그 결과를 요약하면다음과 같다. 가. 인삼재배용 방제기의 주행장치는 동력원으로 축전지를 사용하는 DC모터에 의한 4륜 구동형으로 제작하였고, 방제장치는 수직 붐노즐 방식으로 쌍선형 노즐을 좌우에 3개씩 부착하고 살포각도를 조절할 수 있도록 제작하였으며, 인력으로 골간 이동시키는 방식이다 나. 성능시험결과 주행속도는 0.3m/s이고, 장애물이나 요철부의 통과 가능높이는 4cm였고, 작업성능은 38분/10a로 나타났다. 다. 방제성능은 피복면적비를 측정한 결과 인삼 잎 앞면은 100%, 뒷면은 40%이상으로 분무입자의 부착률이 양호한 것으로 나타났다.

• Journal of the Korean Society of Safety
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• v.8 no.4
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• pp.213-222
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• 1993

This paper is concerned with automation of tower cranes in view of the robust control of tower crane during take-off, load hoisting, load lowering and landing. The model equation of the tower crane is induced by using Lagrange's equation and it is linearized at equillibrium point. The control is realized by adopting the optimal regulator method. The effectiveness is proved through the experimental results for the oscillation control of cargo rope and the position controls of trolley and boom by the implementation of digital control using 16 bits microcomputer for the designed optimal control law.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.1
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• pp.122-128
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• 2016

The purpose of this study was to develop improved strength of an arm and a boom on over-load environment, which causes damage in the initial design statement. To develop improved strength of an excavator front group, we calculated load conditions using the MATLAB program, and using these conditions, we performed a structural analysis of an excavator front group for the maximum digging force condition. Finally we performed a topology optimization to reduce weights of an arm and a boom, and we re-modeled an arm and a boom based on the topology design results and re-performed the structural analysis. The strength of the re-design is higher than the initial design but its weight is almost the same as the initial design.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.3
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• pp.283-288
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• 2010

Mobile harbor is characterized by the lightweight compact structure when compared to the conventional above-ground port container crane. A new concept RORI crane system, which was devised for mobile harbor to satisfy the compactness and light weightness, not only can load/unload containers with high speed on sea but can be completely folded at maneuvering mode. This study is concerned with the tip deflection of the horizontal boom of mobile harbor at container loading operation. Both the theoretical method utilizing the Castigliano's theorem and the numerical approach by finite element method are employed, and the reliability of the latter approach is verified through the comparison with the theoretical results. And then, the effect of the initial cable tension on the tip deflection is parametrically examined by the finite element analysis.

• Korean Journal of Construction Engineering and Management
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• v.7 no.1 s.29
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• pp.80-88
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• 2006

Construction graphical simulations usually do not reflect physical properties of construction equipment and material because there are restricted to the geometric model. The complete description of construction operations is difficult for graphical simulation without a physical modeling. The object of this research is to enhance the functionality of restricted simulation system to geometric model. And research is conducted to overcome the limitation of current construction graphical simulation system through the connection geometric model and physical model with the physical properties of construction equipment and material such as crane's cable oscillation. The motion equations for the oscillation of crane cable as a result of the trolley's movement and the boom's rotation were derived. The equations were solved through numerical analysis and the results were simulated visually. The realistic description with physical modeling of construction operations will contribute for ensuring preliminary against risks and improving constructability as well as the application of various fields.

• Journal of the Korea Society for Simulation
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• v.15 no.1
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• pp.51-58
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• 2006

Virtual Manufacturing is a powerful methodology for developing a new product, new equipment and new production system. It enables the checking errors in design before production. This paper is a case study of virtual manufacturing in an excavator factory. The final welding operations of the boom and the rotating table of upper body are selected for application. 3D models of parts and fixtures are developed with $CATIA^{(R)}$ and 3D simulation models are developed with $IGRIP^{(R)}$. These models are used for verifying the design of fixture and for the motion design of robot. As a result, the manual welding systems are replaced by automatic systems and many design errors are corrected in the design phase, which reduces the developing cost and time.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.3
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• pp.229-238
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• 2015

This study was conducted to develop electronic control system of weeding implement that can operated at various areas such as slope land and inclined road side. The weeding implement consists of five main parts; the electronic control system, the hydraulic system, the main frame, the boom and arm mechanism, and the rotary type weeder. And the weeding implement was developed to be attached by three-point hitch of tractor considering the use of electronic control system. As a result, the electronic control test was conducted with the weeding implement attached to tractor in slope land. The results of the electronic control system test showed satisfactory weeding performance.

• Korean Journal of Construction Engineering and Management
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• v.17 no.3
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• pp.143-155
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• 2016

Recently, the interest on applying AVM(Around View Monitoring) systems in construction equipments have been increasing due to the demand for better control, work efficiency and safety. Most of the existing AVM systems have been developed focusing on the application in automobiles and only several AVM systems have been developed for construction equipments. However, the original technology of AVM remained the same as in the automobiles that failed to consider the main properties of construction equipments and suggest appropriate range of AVM display (Top-view). Therefore, the purpose of this study is to suggest a pilot type of AVM system for construction equipment. Accordingly, literature review, deduction of main consideration factors, selection of sensors, system design, algorithm development of a pilot type of AVM system for construction equipment have been conducted. A laboratory experiment has also been conducted for the deduction of further improvements. As a result, a minimum image refresh rate of 20 fps has been achieved that clearly reflects the actual situation of the equipment and also, the actual motions of Boom, Arm, Bucket have been displayed appropriately on the AVM system based on the angle data collected by sensors. However, the experiment results have also shown that the following tasks still remain for future work: 1)Improvement of AVM image interpolation, 2)Development of calibration module for variety construction equipment.