• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.9
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• pp.883-888
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• 2011

The UAV tracking antenna system based on GPS has a characteristic of update of position information which can occurs a position error. To reduce the position error, UAV tracking antenna system separates period of GPS update-rate and predicts the position of UAV using divided time points. These process improves the tracking performance of UAV. To predict the position of UAV by divided time points, we used a linear kalman filter based on the velocity and acceleration. Using this system, we measured velocity and acceleration according to the change of position. Finally, we can predict the change of position on divided time points.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.10
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• pp.833-841
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• 2014

This paper proposes an algorithm to estimate the wind velocity by tracking free flying balloons. Balloons used in this method are expendable but inexpensive, which increases the usefulness of the method. Also we can obtain accurate 3D information by using multiple cameras and estimate the wind velocity of the local field. The proposed system consists of aerodynamic modeling of the balloon, a tracking algorithm using image processing, and the velocity estimation algorithm. We performed unit tests of each algorithm for the verification. The method is validated using a system simulation and sources of error case identified.

• Journal of the Korean Society for Precision Engineering
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• v.32 no.8
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• pp.719-726
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• 2015

This paper presents a velocity-synchronizing control for the multiple axes of an injection unit; based on MBS, a virtual design model has been developed for the multiple-axes servomechanism. Prior to the design of the controller, a linear plant model was derived via open-loop response simulations. To synchronize the motions of the multiple axes, a cross-type synchronizing controller was designed and combined with the PID control to accommodate any parameter mismatches among the multiple axes. From the tracking control simulations, a significant reduction of both velocity-tracking and position-tracking errors was achieved through the use of the proposed control scheme.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.783-786
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• 1991

Generally, The position of mobile robot moving on the plane is measured by the method of dead reckoning, using the encoder system coupled on a wheel axis. But it is noted that the encoder system cannot check the slip of a wheel, often occurring in tracking of the mobile robot. In this study, using velocity angular velocity sensor with a tuning fork vibration system, the system is developed which can measure the directional angle of positional variables on the mobile robot. By measuring the variations of tracking direction mobile robot equipped with this system, following result is found; In spite of the slip at a wheel when measuring the tracking directional angle, the error occurs in the range of .+-. 1 (degree).

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.4
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• pp.317-324
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• 2004

The ink jet printer media advance system is required to be exactly driven to the target position via tracking the reference velocity profile to obtain the high quality print image. A single gain PID controller is not sufficient to fulfill the control objectives, the exact velocity tracking and the accurate positioning, at the same time. A dual PID controller and its switching strategy are presented in this paper to achieve the control objectives. The media advance system is controlled by two separate PID controllers, one of which is for velocity control, and the other is for position control. A PID controller controls the velocity of the media advance system until it reaches the predetermined switching position. When the media advance system passes the predetermined position, the controller is switched to the other PID controller which is more profitable for exact positioning. The switching position is determined by the estimated stop distance. The simulation and experimental results are presented to show the validity and effectiveness of the proposed controller.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.6
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• pp.874-887
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• 1998

A 2-frame PTV (particle tracking velocimetry) system using the concept of match probability between two consequent image frames has been developed to obtain instantaneous velocity fields. The overall 2-frame PTV system including image pre-processing, tracking algorithm and post-processing routine was implemented to apply to real flows. The developed 2-frame PTV system has several advantages such as high recovery ratio of velocity vectors, low error ratio and small computational time compared with the conventional 4-frame PTV and the FFT-based cross-correlation PIV technique. The 2-frame PTV system was applied to a turbulent channel flow over a rectangular block to check its reliability and usefulness. Total 96 sequential image frames have been captured and processed to get both mean and fluctuating velocity vector fields over the recirculating region. The mean velocity and turbulent intensity profiles were well agreed with hte LDV measurements in the separated region behind the block. Time-averaged reattachment length is about 6.3 times of the block height.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.53 no.11
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• pp.664-670
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• 2004

This paper presents a new velocity estimation strategy of a non-salient permanent magnet synchronous motor (PMSM) drive without high frequency signal injection or special PWM pattern. This approach is based on the d-axis current regulator output voltage of the drive system that has the information of rotor position error. The rotor velocity can be estimated through a rotor position tracking PI controller that controls the position error to zero. For zero and low speed operation, PI controller gains of rotor position tracking controller have a variable structure according to the estimated rotor velocity. In order to boost the bandwidth of PI controller around zero speed, a loop recovery technique is applied to the control system. The proposed method only requires the flux linkage of permanent magnet and is insensitive to the parameter estimation error and variation. The designers can easily determine the possible operating range with a desired bandwidth and perform the vector control even at low speeds. The experimental results show the satisfactory operation of the proposed sensorless algorithm under rated load conditions.

• Journal of Advanced Marine Engineering and Technology
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• v.17 no.5
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• pp.44-53
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• 1993

In this paper, we discuss on the control algorithm to make the wheeled inverse pendulum type mobile robot move in two dimensional plane. The robot considered in this paper has two independently driven wheels in same axel which suport and move it-self, and is assumed to have the fyro type sensor to know the inclination algle of the body and rotary encoders to know wheel's rotation angular velocity. The control algorithm is divided into three parts. The first part is for the posture and velocity control for forward-backward direction, the second is the steering control, and the last part is for the control of total system to track the given trajectory. We handle the running velocity control of the robot as part of the posture control to keep the balance because the posture relates deeply with the velocity and can be controlled by the velocities of the wheels. The control problem is analyzed as the tracking control, and the controller is realized with the state feedback and feed-forward of the reference velocity. Constructing the control system which contained one intergrator in forward path, we also realized the control system without observer for the estimation of the accumulated errors in the inclination angle of the body. To prevent the robot from being unstable state by sudden variation of the reference velocity when it starts and stops, or changes velocity, the reference velocity of which acceleration is slowly changing, is ordered to the robot. To control its steering, we give the different reference velocities for both wheels which are calculated from the desired angular velocity of the body. Finally, we presents the experimental results of the experimental robot Yamabico Kurara in which the proposed control algorithm had been implemented.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.189-192
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• 2021

This study applies a deep learning-based long short-term memory(LSTM) model to track tracking technology. In the case of existing track tracking technology, the weight of constant velocity, constant acceleration, stiff turn, and circular(3D) flight is automatically changed when tracking track in real time using LMIPDA based on Kalman filter according to flight characteristics of an aircraft such as constant velocity, constant acceleration, stiff turn, and circular(3D) flight. In this process, it is necessary to improve performance of changing flight characteristic weight, because changing flight characteristics such as stiff turn flight during constant velocity flight could incur the loss of track and decreasing of the tracking performance. This study is for improving track tracking performance by predicting the change of flight characteristics in advance and changing flight characteristic weigh rapidly. To get this result, this study makes deep learning-based Long Short-Term Memory(LSTM) model study the plot and target of simulator applied with radar error model, and compares the flight tracking results of using Kalman filter with those of deep learning-based Long Short-Term memory(LSTM) model.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.1
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• pp.147-153
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• 2001

This paper proposes a shaker system design for acceleration test of gimbal. Main reason of shaker system design is to give acceleration to the gimbal, which is moving and tracking the target on the tracking test equipment. The shaker system is mounted on the tracking test equipment. It uses the scotch yoke mechanism to have the constant movement in return. The Scotch yoke mechanism changes the rotational movement of constant velocity to simple harmonic motion.