• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.105-110
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• 2003

The hydraulic excavator has been a popular research object for automation because of its multi-workings and economic efficiency. When it works crane tasks, most of disasters happen. The objective of this paper is to design each components and to construct boom, arm, bucket circuit. These models modeled with AMESim show us change of variables and behavior of excavator. Simulation model will be used for simulator of excavator.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.693-697
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• 1990

A position control system is developed for an electro-hydraulic servo actuator with coaxial rotary spool, where the actuator is controlled by stepping motor. The position control system is utilized to develop the wireless remotely controlled crane system. And remote engine control system is also developed. Finally, to show the validity of this system, some experimental results and field test results am presented.

• Journal of Drive and Control
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• v.14 no.2
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• pp.23-29
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• 2017

In this study, a flexible multi-body dynamic simulation model of a knuckle boom crane is developed to evaluate the stress of spindle and rack gears under dynamic working conditions. It is difficult to predict potential critical damage to a knuckle boom crane if only the static condition is considered during the development process. To solve this issue, a severe working scenario (high speed with heavy load) was simulated as a boundary condition for testing the integrity of the dynamic simulation model. The crane gear model is defined as a flexible body so contact analysis was performed. The functional motion of a knuckle boom crane is generated by applying forces at each end of the rack gear, which was converted from hydraulic pressure measured for the experiment. The bending and contact stress of gears are theoretically calculated to validate the simulation model. In the simulation, the maximum stress of spindle and rack gears are observed when the crane abruptly stops. Peak impact force is produced at the contact interface between pinion and rack gears due to the inertia force of the boom. However, the maximum stress (bending/contact) of spindle and rack are under the yield stress, which is safe from damage. By using the developed simulation model, the experiment process is expected to be minimized.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.5
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• pp.367-374
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• 2017

The goal of this study was to develop control algorithms to improve the steering performance of a 120-ton all-terrain crane. To accomplish this, a hydraulic steering system for the crane was modeled using AMESim software, and a PID steering control algorithm was designed in the MATLAB/Simulink environment. The performance of the designed controller was verified through multiphysics co-simulations based on a real-time simulator.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.209-214
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• 2004

This paper deals with tipping over of hydraulic excavator's crane work. If excavator lift too heavy weight, excavator tipped up. This is 38% of whole excavator accidents. In this paper, tipping over load which is maximum load of excavator can lift with displacement of excavator links, real load and tipping over rate are calculated with Zero Moment Point. We designed the tipping-over stability criterion algorithm considering the dynamic characteristics to which ZMP theory is applied and discussed the usefulness of the proposed algorithm compared with the moment equilibrium equation through the simulation and the actual test.

• Journal of the Korean Society for Precision Engineering
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• v.27 no.11
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• pp.78-83
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• 2010

Since a tower crane is too high for a worker to ascend and by the wind in the high altitude, the possibility of a safety accident is very high, a lift assist is used. In this study, the hydraulic fall prevention device using the pressure generation device by Seok, et al. was developed. For this, the effects on the fall prevention performances of factors such as gear clearance, oil viscosity, rotative velocity and so on were evaluated by the analysis of fluid flow using FEM and the prototype was producted and a function test was performed.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.35 no.1
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• pp.65-76
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• 1999

Our status of off-shore stow-net fishery is in face with many difficult problems; the lack of fisherman by evading the 3-D occupation, the safety accident by unskilled crew and old type fishing system. In order to solve those problems, it is necessary to save the man power and ensure the safety of fishing work by the effective utilization of power and automatization of fishing gear system. This is consists of the side drum driven by main engine, the net hauler, the bow and stern capstan, jib crane etc. Therefore, we suggest the design on unification of power device of fishing gear system as follows; (1) fishing system by uni-hydraulic power and (2) fishing system by electric motor and electro-hydraulic power.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.1
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• pp.35-41
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• 2010

An overload limiter is used to prevent its overturning accident during an operation of a movable crane. Recently the indirect measuring method, which measures hoisting load and overturning moment of overload limiter, demands instead of the existing method, which measures only hoisting load. The indirectly measuring method is how to conduct the hoisting load and overturning moment as measuring the load of hydraulic cylinder for a luffing driving of boom. So we need to develop the multi-angular pin type load cell with the measuring angle of ${\pm}10$ degree instead of the existing load cell with the measuring angle of ${\pm}2$ degree. In this study the finite element analysis is conducted to evaluate the effect of the aspect ratio of measuring cross section on the measuring limit of the load cell to develop the many-angular pin type load cell. For this investigation, the aspect ratio of measuring cross section and load applying angle were adopted as design parameters and the stresses of measuring part were evaluated for each parameter.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.2
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• pp.89-94
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• 2016

Equipments to influence by external force have to take effect mechanical oscillation. These equipments regardless of the movement on the external force such as roll, pitch and heave etc, worked to keep the height of tote are required for activeness and needed a device as equipment's fluctuation for rapidly compensation. Because the actual development of these devices is difficult to cost-effectively, we were developed to compensation simulator scaled down 1/50. In this paper, we were studying kinematic characteristics, designed the simulator to grasp the point and manufactured. This paper was analyzed for confirming the superiority of compensation simulator and set up 50 ton crane in practice.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.04a
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• pp.153-159
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• 1997

This paper presents the swing motion analysis of the container crane headblock with the passive control device using hydraulic motors and anti-swing ropes. The device hauls at the headblock to opposite direction of its swing motion using the tension difference between anti-swing ropes connected to the headblock. To consider this control mechanism, the headblock is modelled as the rigid bar suspended by two hoist ropes at the overhead trolley and its non-linear equation of motion is derived using Lagrange's equation. Some numerical experiments using the equation are carried out to investigate the swing motion characteristics of the headblock under the variation of geometric relation among the cargo handling components and to evaluate the performance of the anti-swing device.