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This paper presents method and result of analysis on the multivariate mutual information of an interferometric radar altimeter (IRA) for an application to the terrain-referenced navigation (TRN). As an effort to improve the performance of the IRA-based TRN, we have proposed a novel measurement model which utilizes three measurements. This paper addresses the preliminary study to quantify the effect...
This paper presents a method of improving the attitude determination accuracy for nanosatellites with the aid of the camera sensor. In typical mission, the star tracker is usually used as an optical sensor for the precise attitude pointing for the nanosatellite. However, mostly, the star tracker cannot be affordable for most of the missions because of its cost. Instead of using the star tracker, the...
This paper addresses the particle filters to deal with the measurement ambiguity. In terrain referenced navigation, the ambiguous measurement update due to the similar terrain profiles causes the performance degradation and it can be the primary reason of divergence in the worst case. We proposed a method to cope with terrain ambiguity that utilizes a solution to the out-of-sequence measurement(OOSM)...
This paper proposes a novel method of grafting one of the measurements of interferometric radar altimeter (IRA) onto particle filter that uses sequential importance resampling (SIR) to enhance the performance of terrain referenced navigation (TRN). IRA which is a terrain sensor that measures slant range, slant angle and look angle to the closest terrain point from the aircraft is introduced. The procedure...
This paper describes vision-based target state estimation approaches for autonomous landing on a moving ground target. The state of moving ground target is estimated by using vision information from a gimbaled camera on an Unmanned Aerial Vehicle (UAV). Using the information from vision system, the UAV estimates the state of a moving target on the ground using the Unscented Kalman Filter (UKF). In...
In this paper, the hybrid fuzzy-PID controller for a coaxial rotor helicopter is developed as a supplement to the conventional PID controller. The coaxial rotor helicopter uses one motor and two swash plates linked to each other. The helicopter system is modeled by nonlinear dynamics. The PID control system works well with a moderate velocity change. However, it provides unsatisfactory performance...
A decentralized controller for target tracking and obstacle avoidance for a multi-agent system is proposed. The controller is based on a navigation function which is composed of a goal function, as the D-optimality criterion of the Fisher information matrix, and a constraint function, which generates repulsive force to the agents near the obstacle. The multi-agent system is modeled as a graph and...
This paper presents results of developing and operating a team of multiple unmanned aircraft system. It is a challenging task since the system complexity increases as the number of the unmanned aircraft increases. Given the autonomy of each vehicle in navigation, guidance, control, and vision-based missions, a system of multiple unmanned aircraft is constructed which is expected to be applied to complicated...
This paper proposed a framework for airborne multisensor management for multitarget tracking, considering each of multiple unmanned aircraft as a sensor. The purpose of the algorithm is to quantify the performance of the multitarget tracking and to determine the time and location of the sensor deployment. Utilizing the posterior Cramer-Rao lower bound, the inverse of the Fisher information matrix,...
An approach to vision-based navigation system for autonomous navigation of unmanned aircraft with use of terrain elevation map is addressed. We considered simultaneous localization and mapping (SLAM) algorithm to be the system to which the digital terrain elevation data (DTED) is merged. The proposed algorithm acquires range measurement by line-of-sight (LOS) intersection and provides it to the SLAM...
This paper addresses a method to implement an ad-hoc network for inter-vehicle communication of multiple UAVs. During cooperative missions, it is essential to share information between different UAVs. The ad-hoc network provides greater autonomy to the team of UAVs because it is free of intervention of ground stations. The challenges we consider for implementing inter-vehicle communication are including...
Sports paradigm shift gave an opportunity to transform into transform into production-oriented industry activities creating high value-added. Sports industrial cluster, organic union of qualitative industries producing and distributing of various sports derivative products, is necessary system in these sports paradigm shift. This study is intended to suggest the construction and direction for future...
This research analyzed the current status concerning pro games in order to identify the level of vitalization for the e-sports in Korea with the goal of increasing qualitative growth. Along with current status analysis, this research examined socio-cultural significance of e-sports. As such, the purpose of this research is to provide implications so that the e-sports can be established properly and...
Path tracking algorithms applicable to various agricultural operations, such as tillage, planting, and spraying, are needed to generate steering angles for an auto-guidance tractor to track waypoints that define the desired trajectory. An optimal coverage path planning can enable the tractor to effectively travel an entire field along a path, with parallel paths at a fixed spacing. This paper reports...
Reliability of safety critical systems such as nuclear power plants and automobiles has become a significant issue to our society. As more computing systems are utilized in these safety critical systems, there are high demands for verification and validation (V&V) techniques to assure the reliability of such complex computing systems. However, as the complexity of computing systems increases,...
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