Skip to main navigation Skip to main content
  • E-Submission

JKSPE : Journal of the Korean Society for Precision Engineering

OPEN ACCESS
ABOUT
BROWSE ARTICLES
EDITORIAL POLICIES
FOR CONTRIBUTORS

Page Path

4
results for

"Jehun Hahm"

Article category

Keywords

Publication year

Authors

"Jehun Hahm"

Articles
A Study on Controlling Arrival Velocity of Pneumatic Tube Carriers Using Counterpressure
Sung-Ho Hong, Jae Youl Lee, Jonghwan Baek, Sang Ho Kim, Jehun Hahm, Jin-Ho Suh
J. Korean Soc. Precis. Eng. 2023;40(2):149-155.
Published online February 1, 2023
DOI: https://doi.org/10.7736/JKSPE.022.095
A pneumatic tube system is a system that transmits and receives objects quickly inside pipes and is used in urgent situations or when transferring or returning objects. It is mainly used in hospitals, large marts, and automation systems. For long-distance transportation (up to 10 km) high pressure is used at industrial plant industrial sites. A large amount of flow rate and high pressure are used to generate instantaneous pressure and flow to the opposite side, where the transport target is stored in a separately manufactured carrier and transported. Specially manufactured carriers considering significant frictional force in the straight, curved, rising, and lower sections during long-distance transport are employed. The other party experimentally generates reverse pressure to lower the care speed inside the transfer pipe that arrives at a high speed and operates the worker valve to reduce the speed, but the valve must be operated every time according to pressure and distance changes. In the present work, a method of arriving at a carrier in a stable pipe through speed reduction by controlling the flow rate and reverse pressure depending on the distance from the transmission unit and calculating the reverse pressure compared to the teleportation speed is presented.
  • 5 View
  • 0 Download
A Study on Improving the Sensitivity of High-Precision Real-Time Location Receive based on UWB Radar Communication for Precise Landing of a Drone Station
Sung-Ho Hong, Jae-Youl Lee, Dong Ho Shin, Jehun Hahm, Kap-Ho Seo, Jin-Ho Suh
J. Korean Soc. Precis. Eng. 2022;39(5):323-330.
Published online May 1, 2022
DOI: https://doi.org/10.7736/JKSPE.022.014
Drone stations are increasingly being applied to enhance the mission capabilities of drones. The drone’s station landing occurs in a limited space. A relative position communication signal between the drone and the station is required. Strong, precise control over communication signal interference is required. In this paper, we describe a filter processing method for position signal processing. In consideration of the anchor position and installation angle of the UWB module of the drone station, nine performance test cases were proposed. As a result of the performance test, high position accuracy output was confirmed when considering the result of minimizing signal shading and beam pattern direction with excellent reception sensitivity. A performance test was conducted using the developed drone station, and the landing performance was confirmed with a precision of within 20 cm.
  • 7 View
  • 0 Download
Evaluation of Structural Integrity for Lifting-and-Lowering-Type Drone Station Using Fluid-Structure Interaction Analysis
Sang Ho Kim, Jae Youl Lee, Sung-Ho Hong, Jehun Hahm, Kap-Ho Seo, Jin-Ho Suh, Young Sik Joung, Se Hoon Jeung
J. Korean Soc. Precis. Eng. 2021;38(11):841-849.
Published online November 1, 2021
DOI: https://doi.org/10.7736/JKSPE.021.045
An elevating drone station is very useful when lifting and lowering the battery charging station for safe installation, maintenance, and energy efficiency of a drone operation. When drone station modules rise above the average roof level of neighboring structures they may receive a strong wind force; thus, understanding the physical phenomena of both the structures and fluid is important to understand the structure"s reaction to the wind force. However, most studies in the field of drone stations did not perform a structural safety evaluation under wind loadings. Therefore, in this paper, we carried out a fluid-structure interaction analysis to verify the design of the lifting-and-lowering-type drone station.
  • 5 View
  • 0 Download
Multibody Dynamic Analysis for the Lifting-and-Lowering-Type Drone Station including Cable-Pulley Systems
Sang Ho Kim, Jae Youl Lee, Sung-Ho Hong, Jehun Hahm, Kap-Ho Seo, Jin-Ho Suh, Young Sik Joung
J. Korean Soc. Precis. Eng. 2021;38(10):785-792.
Published online October 1, 2021
DOI: https://doi.org/10.7736/JKSPE.021.069
The lifting-and-lowering type drone station is very useful when lifting and lowering the battery charging station for safe installation, maintenance, and energy efficiency of drone operation. Therefore, understanding the coupling motion between cable and pulley is important for evaluating characteristics like safety and dynamic stability of the lifting-and-lowering type drone station. Although multibody dynamics (MBD) is widely used for numerically analyzing the dynamic behavior of interconnected bodies, attempts to analyze the coupling motion between cable and pulley have been made only recently, within the last decade. Therefore, this paper attempts to develop the MBD model for the lifting-and-lowering type drone station, including cables, pulleys, and winches using MotionSolve (Altair). The results of the winch torque obtained analytically and numerically were compared to verify the effectiveness of the proposed MBD model.

Citations

Citations to this article as recorded by  Crossref logo
  • A Study on Improving the Sensitivity of High-Precision Real-Time Location Receive based on UWB Radar Communication for Precise Landing of a Drone Station
    Sung-Ho Hong, Jae-Youl Lee, Dong Ho Shin, Jehun Hahm, Kap-Ho Seo, Jin-Ho Suh
    Journal of the Korean Society for Precision Engineering.2022; 39(5): 323.     CrossRef
  • 9 View
  • 0 Download
  • Crossref