• Journal of the Korean Society for Precision Engineering
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• v.28 no.8
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• pp.951-958
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• 2011

In this paper, the purpose is to investigate the vibration characteristics and the design of resonance avoidance of the unmanned helicopter master. Based on the Euler-Bernoulli beam theory for helicopter master, the equation of motion is derived by using extended Hamilton's principle. It was studied about the natural frequency of helicopter master as the design variances(tip mass, length and diameter of master). Also, it was compared the theoretical results for natural frequency with the results of FE analysis. The results of this study showed the vibration characteristics of helicopter master for the design of resonance avoidance.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.8
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• pp.731-738
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• 2015

The rapid prototyping process and development tool which enable the control law evaluation efficiently are needed to minimize the development cycle, cost and risk of aircraft flight control system. This paper describes a development process that integrates the designed control law into HETLAS to evaluate simulation effectively using nonlinear mathematical models. The desktop engineering simulator was developed using HETLAS for the piloted simulation evaluation of a various control modes and the procedure was developed, which quickly integrates the HETLAS into HQS(Handling Quality Simulator) and HILS(Hardware In the Loop Simulation) environments. This paper presents a rapid prototyping process using HETLAS that significantly shortens the integration process of the control law into the nonlinear math model, HETLAS, and allows the control law designs to be quickly tested in the piloted simulation and HILS environments.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.1
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• pp.71-78
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• 2017

The electrical power system of Korean Utility Helicopter(KUH) is designed as a dual control system to enhance the system safety of aircraft and each system is installed separately at left and right of the aircraft. The system is composed of 2 AC generators, 1 APU generator, 2 Transformer Rectifier Units(TRU), AC/DC Electrical Master Box(AC/DC EMB). The AC/DC EMB, consists of 2 AC EMB and 2 DC EMB, is essential equipment which supply and distribute electric power to the aviation electronics and electrical equipment of KUH. There were defects caused by internal short circuit in AC EMB during the first production phase of the KUH. This paper describes the analysis of the defects, troubleshooting process, root cause, and the solution by design change.