• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.29 no.3
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• pp.175-179
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• 2023

This paper analyzes the vibration characteristics within the cargo compartment of a three-wheeled cargo bike when used on both regular roads and dedicated bicycle lanes. When cargo is loaded into the cargo compartment of a cargo bike and driven on the road, the shocks and vibrations transmitted from the ground can potentially affect the transported goods and even lead to product damage. As the vibration characteristics applied to the cargo compartment may vary depending on the condition of the road, vibration sensors were attached to the cargo bike's cargo compartment for data collection during operation on different road types. According to KS T ISO 13355 standards, the cargo bike can withstand vibrations within the range of 10 Hz to 60 Hz when operating on both bicycle lanes and regular roads. However, it is observed that there are peaks exceeding the profile in the frequency range of 3-6 Hz. In the 70-200 Hz range, the profile is exceeded on both regular roads and bicycle lanes, with a tendency for higher exceedance on bicycle lanes. The Grms value within the frequency range of KS T ISO 13355 is 5.926 m/s² (0.604 Grms). When operating on bicycle lanes with cargo, the Peak envelope optimization PSD value is 6.553 Grms, while on bicycle lanes, it is 7.708 Grms, indicating a difference of at least tenfold.

• Journal of the Korean Society for Railway
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• v.17 no.2
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• pp.133-139
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• 2014

Due to the absence of design guidelines for elevated light-rail structures in Korea, most elevated light-rail structures have been designed and constructed based on the design codes of conventional railway bridges and on the codes recommended by foreign vehicle manufacturers. This is the main reason why most elevated light-rail structures are massive or over-designed or poorly constructed economically. In this paper, the authors carried out field tests to analyze the braking forces caused by braking a train running at speeds of 50km/h, 60km/h, and 70km/h, acting on the elevated structures of rubber-wheeled Light Rail Transit (LRT) trains. The authors also briefly describe the analyzed results of the braking force acting on the substructures of elevated light-rail structures. The test-results presented here in this paper can be referenced when establishing design guidelines or standards for elevated structures of LRT systems.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.10a
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• pp.519-520
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• 2010

R-410A 냉매를 적용한 9,000 Btu 군용에어컨은 2 1/2톤 쉘터카고 차량에 탑재된 쉘터를 냉, 난방하기 위해 사용된다. 이 에어컨은 차량에 탑재된 쉘터의 벽면에 설치되기 때문에 차량 이동 중의 진동, 충격 환경에서 그 기능이 유지되어야 하며, 이에 대한 진동시험을 실시한다. 진동시험은 MIL-STD-810G, 514.5C-VII Composite Wheeled Vehicle 규격에 따라 수행하며, 동특성시험을 통해 확보된 입력 진동값을 진동 규격과 비교하여 적합성을 판단한다.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.713-716
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• 1991

This paper describes a methodology of mobile robot navigation which is designed to carry heavy payloads at high speeds to be used in FMS(Flexible Manufacturing System) without human control. Intelligent control scheme using fuzzy logic is applied to the navigation control. It analyzes sensor readings from multi-sensor system, which is composed of ultrasonic sensors, infrared sensors and odometer, for environment learning, planning, landmark detecting and system control. And it is implemented on a physical robot, AGV(Autonomous Guided Vehicle) which is a two-wheeled, indoor robot. An on-board control software is composed of two subsystems, i.e., AGV control subsystem and Sensor control subsystem. The results show that the navigation of the AGV is robust and flexible, and a real-time control is possible.

• The Journal of Korea Robotics Society
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• v.8 no.4
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• pp.229-237
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• 2013

In this paper, we report a self-balancing robot wheelchair which has the capability of keeping upright posture regardless of the terrain inclination in terms of the three dimensional balancing motion. It has the mobility of five degrees of freedom, where pitching, yawing, and forward motions are generated by the two-wheeled inverted pendulum mechanism and the rolling and vertical motions are implemented by the movement of the tilting mechanism. Several design considerations are suggested for the sliding type vehicle body, wheel actuator module, tilting actuator module, power and control system, and the riding module.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.108.3-108
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• 2001

In this work, we consider a real time optimal control problem of mechanical systems with restrictions for actuators i.e. input restrictions and constraints for the movable area i.e. state constraints. First, we formulate an optimal control problem which evaluates the cost function for a finite time horizon with input restrictions and state constraints of a wheeled vehicle as an example of mechanical systems. In this problem, the differentiability of the cost function is not required and this implies that the problem cannot be solved analytically. Therefore, in this work, we use an optimization method to solve the optimal control problem and a new real time optimization method is proposed to solve the problem. In this method, we provide a parameter that indicates the ...

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.9
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• pp.2339-2348
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• 1994

The objective of this paper is to develop a solution method for the differential-algebraic equation(DAE) derived from constrained muti-body dynamic systems. Mechanical systems are often modeled as bodies and joints. Differential equations of motion are formulated for bodies. Since the bodies are connected by joint, the differential variables must satisfy the kinematic constraint equations that come from the joints. Difficulties are arised due to drift of the differential variables off the constraint equations. An optimization method is adopted to correct the drift of the differential variables. To demonstrate the efficiency of the proposed method a slider-crank mechanism is analyzed dynamically. Identical results are obtained as these from the commercial program DADS. Dynamic analysis of a High Mobility Multi-purpose Wheeled. Vehicle(HMMWV) is carried out to show the practicalism of the proposed method.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.511-516
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• 2007

Rubber wheeled AGT(Automated Guide-way Transit) system is a prominence transportation system for urban area, because of its low construction cost and management, low noise and vibration and fine exterior view. AGT system uses concrete tracks. Concrete can be easily damaged by the impact, change of temperature and external loads. The fault of concrete track is harmful not only to riding quality but also to bridge. Therefore, in this study, the effects of railway prominence to the bridge are surveyed by experimental method. The experiment was executed for PSC bridge at AGT test line in Kyungsan. And the test results for 5mm, 10mm prominence and without prominence are compared and investigated, according to the vehicle speed.

• Journal of the Korea Institute of Military Science and Technology
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• v.19 no.5
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• pp.567-573
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• 2016

GMAW and GTAW processes have been used for welding of equipment mounting pads during decades. For improving the mobility and survivability of KWV(Korean Wheeled Vehicle), various types of equipment are required and numbers of pads for welding were increased. In this research, for improving productivity of mounting pads welding process, new technology of stud welding was studied. In this study, mechanical properties of stud weldment were investigated to compare with those of GMAW weldment. Also, research of stud weldment durability was carried out and proved its fatigue strength under the condition of KWV's 32,000 km load profile.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.1
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• pp.28-38
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• 2016

Cooperative-Intelligent Transport Systems (c-ITS) has emphasized a real-time traffic safety service in urgent situations among highway infrastructure and four-wheeled vehicles, while two-wheeled vehicles, e.g. bicycles and motorcycle, sharing highway space and endangering highway safety, have yet been out of its interest. This paper delivers the results of a study conducted to analyze the patterns of two-wheeled-vehicle traffic accidents experienced in the past, the last three years (2011~2013), and to propose the types of service enhancing the safety of the riders of those. It was found from the analysis of historical accident data that the side collision on a link section should be taken care of for further safety treatment, while the old female drivers need additional care to decrease their fatality rate. By combining the services proposed for bicycles and motorcycles, this paper proposes (1) eight different bicycle-to-everything (B2X) services which can be eventually provided in c-ITS and (2) three of those that would be available in the near future with the current communication technologies.