• Journal of Advanced Navigation Technology
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• v.22 no.5
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• pp.367-374
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• 2018

A trajectory-based scheduling system is proposed for air traffic management using next generation aviation data communication link. Based on the service concept of 4-dimensional trajectory data link (4DTRAD) using air traffic serveices (ATS) datalink Baseline 2, a procedure for trajectory-based operation of an en-route flight is established and described in detail. To mitigate air traffic controllers' workload which might be caused by various and complicated data utilization, a prototype of the scheduling system, which predicts the aircraft trajectory based on the flight intents received by air traffic service system and provides advisory information for air traffic control, was developed. The simulation environment for trajectory based operation was built to validate the scheduling functionality of the prototype.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.5128-5134
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• 2011

This paper investigates the dq current trajectory for maximum torque per ampere(MTPA) operation of an interior PM synchronous motor for HEV(Hybrid Electric Vehicle). Based on the dq current trajectory for the MTPA operation derived from the motor parameters, the change of the MTPA operating point for the variation of the motor parameters including the magnet flux and the dq inductances is considered. The dq current trajectory for MTPA operation is verified through the experiment.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.147-148
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• 2022

Recently, as a number of accidents occur while berthing ships, the need for safety measures for ship operation in ports is emphasized. In order to quantitatively analyze the contents of safety measures in Busan New Port, this study collected ship trajectory data,, and based on this data, applied a maritime artificial intelligence algorithm to analyze the trajectory pattern. As a result, the waypoint of the ship arriving and departing Busan New Port was derived and the operation pattern of the ship's speed and course was proposed.

• International Journal of Aeronautical and Space Sciences
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• v.13 no.3
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• pp.377-385
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• 2012

The Automatic Dependent Surveillance Broadcast (ADS-B) system is a key component of CNS/ATM recommended by the International Civil Aviation Organization (ICAO) as the next generation air traffic control system. ADS-B broadcasts identification, positional data, and operation information of an aircraft to other aircraft, ground vehicles and ground stations in the nearby region. This paper explores the ADS-B based trajectory prediction and the conflict detection algorithm. The multiple-model based trajectory prediction algorithm leads accurate predicted conflict probability at a future forecast time. We propose an efficient and accurate algorithm to calculate conflict probability based on approximation of the conflict zone by a set of blocks. The performance of proposed algorithms is demonstrated by a numerical simulation of two aircraft encounter scenarios.

• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.5
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• pp.463-469
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• 2014

This paper proposes a maximum torque operation strategy for the direct torque control of a surface-mounted permanent-magnet synchronous motor (SPMSM). The proposed method analyzes the available operation region of the stator flux of the SPMSM under voltage and current constraints. Based on this analysis, the optimal stator flux trajectory that yields the maximum torque is obtained across the entire operation region, including constant torque and constant power regions. The proposed strategy is also applicable in the flux-weakening region II operation of the SPMSM, which has no speed limit. The validity of the proposed method is verified through experiments conducted on an 800 W SPMSM drive system.

• Journal of Convergence for Information Technology
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• v.8 no.5
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• pp.77-83
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• 2018

A modular robot that memorizes motion can be easily created and operated because it expresses by hand. However, since there is not enough storage space in the module to store the user-created operation, it is impossible to reuse the created operation, and when the modular robot again memorizes the operation, it changes to another operation. There is no main controller capable of operating a plurality of modular robots at the same time, and thus there is a disadvantage that the user must input directly to the modular robot. To overcome these disadvantages, a remote controller has been proposed that can be operated in the surrounding smart devices by designing web server and component based software using wired and wireless network. In the proposed method, various types of structures are created by connecting to a modular robot, and the reconstructed operation is performed again after storing, and the usefulness is confirmed by regenerating the stored operation effectively. In addition, the reliability of the downloaded trajectory data is verified by analyzing the difference between the trajectory data and the actual trajectory. In the future, the trajectory stored in the remote controller will be standardized using the artificial intelligence technique, so that the operation of the modular robot will be easily implemented.

• International Journal of Aeronautical and Space Sciences
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• v.10 no.1
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• pp.112-121
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• 2009

This paper deals with supersonic air-breathing missile system. A supersonic air-breathing missile system has very complicated and incoherent thrust characteristics with respect to outer and inner environment during operation. For this reason, the missile system has many maneuver constraints and is allowed to operate within narrow flight envelope. In this paper, trajectory optimization of the missile is accomplished. The trajectory optimization problem is formulated as a discrete parameter optimization problem. For this formulation, Legendre Pseudo-Spectral method is introduced. This method is based on calculating the state and control variables on Legendre-Gauss-Lobatto (LGL) points. This approach helps to find approximated derivative and integration quantities simply. It is shown that, for this trajectory optimization, trend analysis is performed from thrust characteristics on various conditions so that the trajectory optimization is accomplished with fine initial guess with these results.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.8
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• pp.969-976
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• 1999

This paper is concerned with the generation of a balancing trajectory for improving the walking performance. The balancing motion has been determined by solving a second -order differential equation. However, this method caused some difficulties in linearizing and approximating the equation and had restrictions on using various balancing trajectories. The proposed difficulties in linearizing and approximating the equation and had restrictions on using various balancing trajectories. The proposed method i this paper is based on the genetic algorithm for minimizing the motins of balancing joints, whose trajectories are generated by the fifth-order polynomial interpolation after planning leg trajectories. The real walking experiments are made on the biped robot IWR-III, developed by our Automatic Control Laboratory. The system has 8 degrees of freedom and the structure of three pitches in each leg, and one roll and one prismatic joint in the balancing joints. The experimental result shows the validity and applicability of the new proposed algorithm.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.5B
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• pp.913-924
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• 2000

This paper proposes an efficient descriptor for objects motion trajectory and a video retrieval algorithm based on objects motion trajectory. The algorithm describes parameters with coefficients of 2-order polynomial for objects motion trajectory after segmentation of the object from the scene. The algorithm also identifies types, intervals, and magnitude of global motion caused by camera motion and indexes them with 6-affine parameters. This paper implements content-based video retrieval using similarity-match between indexed parameters and queried ones for objects motion trajectory. The proposed algorithm will support not only faster retrieval for general videos but efficient operation for unmanned video surveillance system.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.5
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• pp.402-409
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• 2018

In this paper, we propose a lunar landing scenario of a robotic lunar landing mission and implements an optimal landing trajectory at the powered descent phase based on the proposed scenario. The change of attitude of the lunar lander in the power descent phase affects not only the amount of fuel used but also sensor operation of image based navigation. Therefore, the attitude angular velocity is included in the cost function of the optimal control problem to minimize the unnecessary attitude change when the optimal landing trajectory generates at powered descent phase of the lunar landing. The influence of the change of attitude angular velocity on the optimal landing trajectory are analyzed by adjusting the weight of the attitude angular velocity. Based on the results, we suggest the proper weight to generate the optimal landing trajectory in order to minimize the influence of the attitude angular velocity.