• Journal of Convergence for Information Technology
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• v.7 no.5
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• pp.137-148
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• 2017

Recently, researchers are actively addressed to utilize Unmanned Aerial Vehicles(UAV) for military and industry applications. One of these applications is to trace the preceding flight when it is necessary to track the route of the suspicious reconnaissance aircraft in secret, and it is necessary to estimate the attitude of the target flight such as Roll, Yaw, and Pitch angles in each instant. In this paper, we propose a method for estimating in real time the attitude of a target aircraft using the video information that is provide by an external camera of a following aircraft. Various image processing methods such as color space division, template matching, and statistical methods such as linear regression were applied to detect and estimate key points and Euler angles. As a result of comparing the X-plane flight data with the estimated flight data through the simulation experiment, it is shown that the proposed method can be an effective method to estimate the flight attitude information of the previous flight.

• Journal of Astronomy and Space Sciences
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• v.19 no.4
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• pp.351-366
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• 2002

In this study, we developed low cost INS and (D)GPS integration for continuous attitude and position and utilized it for the determination of exterior orientation parameters of image sensors which are equipped in 4S-Van. During initial alignment process, the heading information was extracted from twin GPS and fine alignment with Kalman filter was performed for the determination of roll and pitch. Simulation and van test were performed for the performance analysis. Based on simulation result, roll and pitch error is around 0.01-0.03 degrees and yaw error around 0.1 degrees. Based on van test, position error in linear road is around 10 cm and curve around 1 m. Using direct georeferencing method, the image sensor's orientation and position information can be acquired directly from (D)GPS/INS integration. 4S-Van achieved 3D spatial data using (D)GPS/INS and image data can be applied to the spatial data integration and application such as contemporary digital map update, road facility management and Video GIS DB.

• Journal of the Korea Society of Computer and Information
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• v.16 no.7
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• pp.157-163
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• 2011

In this paper, configuration control for the Horizontal Maintenance and driving of the mobile inverted pendulum robot has been studied using ARS(Attitude Refrence System). The inverted pendulum technique is getting attention and there have been many researches on the seg-way since the US. Using its 2 freedom, a mobile inverted pendulum robot can move in various modes and Our robot performs goal reaching ARS. Mobile inverted pendulum robot fall down to the forward or reverse direction to converge to the stable point. Kalman Filter is normally used for the algorithm and numerous research is progressing at the moment. To calculate the attitude in ARS using 2 axis gyro(roll, pitch) and 3 axis accelerometers (x, y, z). In this paper we present a two wheel robot system for an autonomous mobile robot. This paper realized the robot control method which is much simpler but able to get desired performance by using the IMU and PID control.

• Journal of IKEEE
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• v.23 no.4
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• pp.1236-1242
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• 2019

Recently, according to improvement of robot technology, research for mobile robot is increasing. Mobile robot having 2-wheels or 4-wheels is easy for straight driving but is difficult for direction change and rotation. So, ball robot having one contact point with base is interested by researchers. By characteristics of the one contact, ball robot is required the balancing and driving control. In this paper, smart phone application, which is usable for control by wireless communication, is proposed. The ball robot having the proposed smart phone application is designed and manufactured. Balancing and driving control by wireless communication is conducted. From the test, it is conformed that ball robot has the control performances as roll angle error is ±0.8deg, pitch angle error is ±0.7deg, x-axis position error is ±0.1m, and y-axis position error is ±0.08m for 1m driving control.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.6
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• pp.1886-1896
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• 1991

This paper presents a method to predict the flying height of the head slider in a hard disk drive. Quantitative predicts of the flying height according to the variations of the external load and the disk velocity have been done by numerical computation. In addition, the magnitude of the external load to keep flying height constant were also suggested. The Modified Reynolds' equation driven from hydrodynamic lubrication theory under slip flow condition was used to describe air-bearing system under the slider. To solve the equation, a Finite Volume Method (FVM) has been applied. To determine the final minimum flying height and pitch angle of the head slider, the Secant iteration method is used which update initial guess of the minimum flying height and pitch angle of the slider. In this study, the model head slider has been selected from a real hard disk drive which is equipped in many commercial personal computers. As a result, as the disk velocity increases at constant external load, the minimum flying height and the pitch angle increase due to the in crease of the air-bearing force at the bottom of slider.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.1
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• pp.42-47
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• 2010

This paper considers a fault tolerant control problem for a spacecraft using wheels which are momentum exchanging devices. The control of a satellite with only two healthy wheels has been studied and its result has been presented. Two different configurations have been considered. When the yaw rate cannot be controlled directly by any control input, the desired yaw rate can be obtained by using the roll rate as a pseudo control. As a result, all three angular speeds have been stabilized, and two attitude angles including pitch and yaw have been controlled to converge to the desired values.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.1
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• pp.82-87
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• 2002

The attitude determination in LEO Satellite like KOMPSAT is one of the most important issues for Sun-Acquisition. Particularly, in KOMPSAT, the roll axis direction can be determined since the sun sensor gives the information on the Euler angle for pitch and yaw axes in Sun-Acquisition mode. In other words, it is the problem to determine the two unknown axes direction with one axis knowledge. This paper proposes a new effective method for attitude determination of general LEO satellites when one axis information is avilable and proves its usefulness throughout the simulation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.2
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• pp.213-220
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• 2016

This research aims to develop core technologies for passive carrier (no power in carrier itself) transfer system. The technologies are passive levitation, propulsion, and guidance, which can be great benefits for semiconductor and display manufacturing industries. Passive maglev carrier is necessary to precise position control for quiet and stable transfer operation. However, the structural characteristics of carrier and the installation errors of gap sensors cause the pitch motion. Hence, the controller design in consideration of pitch motion is required. This study deals with the reduction control of carrier pitch motion. PDA controller and PDA controller with pitch control are proposed to compare the pitch angle analysis. The pitch angle and the levitation precision are measured by experiment. Finally, the optimized design of pitch controller is presented and the effects are discussed.

• The Journal of the Acoustical Society of Korea
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• v.19 no.4
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• pp.93-100
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• 2000

Target signal feature parameters are very important to classify target by active sonar. Two highly correlated broad band pulses separated by time T have a time separation pitch(TSP) of 1/T Hz which is equal to the trough-to-trough or peak-to-peak spacing of its spectrum. In this study, TSP informations which represent feature of each target signal were effectively extracted by the FFT. The extracted TSP feature parameters were also applied to the pattern recognition algorithm to classify target and to analyze their properties.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.1
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• pp.177-186
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• 2017

Recently, Autonomous vehicles are getting hot attention. Amazon, the biggest online shopping service provider is developing a delivery system that uses drones. This kinds of platforms are need accurate attitude information for navigation. In this paper, a structure design of AHRS using low-cost inertia sensor is proposed. To estimate attitudes a Kalman filter which uses a quaternion based dynamic model, bias-removed measurements from MEMS Gyro, raw measurements from MEMS accelerometer and magnetometer, is designed. To remove bias from MEMS Gyro, an additional Kalman filter which uses raw Gyro measurements and attitude estimates, is designed. The performance of implemented AHRS is compared with high price off-the-shelf 3DM-GX3-25 AHRS from Microstrain. The Gyro bias was estimated within 0.0001[deg/s]. And from the estimated attitude, roll and pitch angle error is smaller than 0.2 and 0.3 degree. Yaw angle error is smaller than 6 degree.