• Journal of Korea Multimedia Society
• /
• v.23 no.11
• /
• pp.1372-1382
• /
• 2020

This paper proposes a core technology for a micro river monitoring terminal device suitable for flood monitoring in small rivers and valleys. Our proposed device is basically equipped with a 77GHz radar, gyro and accelerometer sensors. To measure the flow velocity and water level, we proposed a signal processing technique that extracts pure water energy components from the observed Doppler velocity and reflection intensity from the radar. And to determine the stability of the river structure equipped with our device, we constantly monitor the displacement of the measured values of the gyro and accelerometer sensors. Experimental result verified that our method detects pure water energy in various river environments and distinguishes between flow velocity and water level well. And we verified that vibration and position change of structures can be determined through a gyro sensor. In future research, we will work to build a secure digital twin river network by lowering the cost of supplying RF-WAV devices. Also we expect our device to contribute to securing a preventive golden time in rivers.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.21 no.4
• /
• pp.508-519
• /
• 2018

This paper concerns on stabilization control of a gyro-stabilized 2-axes gimbal system which is mounted on a moving vehicles such as automobiles, armored vehicles, ships, flying vehicles, etc. A target image acquisition system is attached on the inner gimbal, and the gimbal systems are required to retain high stabilization accuracy in the absolute coordinate in order to provide fine target image while vehicle is moving. The stabilization control performance is hardly depended upon disturbance rejection ability of control, and disturbance feedforward compensation is effective because feedforward compensation reduce the amount of disturbance before the disturbance disturbs the systems. This paper suggests an experimental method which can estimate system parameters and disturbance torques by using 3-axes accelerometer mounted on the inner gimbal. Furthermore, a simple disturbance identification method which can be applied to any slanted base conditions has been suggested to identify mass unbalance vector and friction torques of each gimbal simultaneously. By using the estimated parameters, a feedforward compensation has been applied to the gyro-stabilized 2-axes gimbal system. The experimental results showed that the feedforward compensation based on the identification method suggested is effective to improve stabilization performances.

• Journal of IKEEE
• /
• v.20 no.4
• /
• pp.420-423
• /
• 2016

In this paper, we proposed an implementation of panoramic image stitching that operates in real time at the embedded environment by applying ROI based PROSAC algorithm using the directionality of the image. The conventional panoramic image stitching applies SURF or SIFT algorithm which contains unnecessary computation and a lots of data to detect feature points. In this paper, we use the direction of the input image and we proposed the method of reducing the unnecessary computation by using ROI. We use a gyro sensor and an acceleration sensor. Output data from gyro and acceleration sensors can be calibrated by complementary filter. The calibration does not affect the operating time of the proposed image stitching algorithm in embedded environment. Therefore, it is possible to operate in real-time.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.12 no.4
• /
• pp.599-606
• /
• 2017

In this paper, the automatic control system of the stroller brake was designed and manufactured to reduce the safety accident of the stroller. The ultrasonic sensors are used to determine whether the handle of the driver's hand is touching or not, and the gyro sensor is designed to detect the current tilt of the baby carriage. If the next driver's hand is not recognized and the tilt exceeds a certain angle, the servo motor is activated and the hydraulic brake is operated to prevent the accident on the downhill road. Finally, in this paper, a smart phone-based application was developed to make the remote control of the brake possible.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.1488-1490
• /
• 2008

The gyroscope is the sensor for detecting the rotation in inertial reference frame and constitute the navigation system together an accelerometer. As the inertial reference equipment for attitude determination and control in the satellite, the mechanical gyroscope has been used but it bring the disturbance for mass unbalance so the disturbance give a bad influence to the observation satellite mission because the mechanical gyroscope has the rotation parts. During the launch, The mechanical gyroscope is weak in vibration, shock and has the defect of narrow operating temperature range so it need the special design in integration. Recently the low orbit observation satellite for seeking the high pointing accuracy of image camera payload accept the FOG(Fiber Optic Gyro) or RLG(Ring Laser Gyro) for the attitude determination and control. The Ring Laser Gyro makes use of the Sanac effect within a resonant ring cavity of a He-Ne laser and has more accuracy than the other gyros. It need the 1000V DC to create the He-Ne plasma in discharge tube. In this paper, the design process of the High Voltage Power Supply for RLG(Ring Laser Gyroscope) is described. The specification for High Voltage Power Supply(HVPS) is proposed. Also, The analysis of flyback converter topology is explained. The Design for the HVPS is composed of the inverter circuit, feedback control circuit, high frequency switching transformer design and voltage doubler circuit.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2013.05a
• /
• pp.919-922
• /
• 2013

Currently, society thinks human-health is very important. As a result, the number of individual bikes is increasing. And bicycle accident rate is increasing every year. We have developed the safety-equipment utilizing a smartphone. Because, in order to reduce the rate of bicycle accidents. The working principle is that the connection between the bicycle and safety equipment with built-in Bluetooth chip. Information of bike-driving Is measured using a smartphone with built-in gyro sensor. I made an algorithm for specifying a direction by using the values of the gyro sensor. With this algorithm, it is possible to reduce the accident rate of the bicycle.

• Journal of Electrical Engineering and Technology
• /
• v.9 no.1
• /
• pp.334-343
• /
• 2014

In this paper, we suggest a method to improve the fusion of an accelerometer and gyro sensor by using a Kalman filter to produce a more high-quality respiration signal to supplement the weakness of using a single accelerometer. To evaluate our proposed algorithm's performance, we developed a chest belt-type module. We performed experiments consisting of aerobic exercise and muscular exercises with 10 subjects. We compared the derived respiration signal from the accelerometer with that from our algorithm using the standard respiration signal from the piezoelectric sensor in the time and frequency domains during the aerobic and muscular exercises. We also analyzed the time delay to verify the synchronization between the output and standard signals. We confirmed that our algorithm improved the respiratory rate's detection accuracy by 4.6% and 9.54% for the treadmill and leg press, respectively, which are dynamic. We also confirmed a small time delay of about 0.638 s on average. We determined that real-time monitoring of the respiration signal is possible. In conclusion, our suggested algorithm can acquire a more high-quality respiration signal in a dynamic exercise environment away from a limited static environment to provide safer and more effective exercises and improve exercise sustainability.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 2000.11b
• /
• pp.333-343
• /
• 2000

An automatic guidance system for combine was designed to harvest paddy rice by following a predetermined path. The automatic guidance system consisted of DGPS to locate position of combine, a gyro sensor system to measure heading angle, ultrasonic sensors to detect obstacles, a hydraulic system, microcomputer as a controller, and I/O interface system. Hydraulic cylinders and valves were installed to control movement of the combine. The heading angle and the position of the combine, and ultrasonic measurements from edge were used as the inputs of the controller. The operating position of hydraulic cylinder was determined as output of the controller. The automatic guidance system was evaluated at the 45-m straight path by changing the posture of the combine. The average RMS errors were 14.0 cm without offset and 15.0 cm with 1-m offset. The DGPS provided accurate position information within the limited error to guide the combine in the field. The results showed that the automatic guidance system could guide the combine autonomously in the paddy field when the posture of the combine was changed.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.39 no.6
• /
• pp.543-552
• /
• 2011

Control Moment Gyro(CMG) is one of the most efficient momentum exchange devices for satellite attitude control and CMG is very essential device for agile satellite. In this study, the essential dynamic equation for the design of gimbal motor and wheel motor is summarized. The development process of SGCMG hardware for agile small satellite system, the description of developed hardware and its performance test results are presented. Test result shows that the developed hardware model can produce an output torque more than 1.2Nm as designed. Other test items are max. torque, gimbal bandwidth, minimum torque, torque error, gimbal rate error.

• Journal of Korea Society of Industrial Information Systems
• /
• v.21 no.4
• /
• pp.13-20
• /
• 2016

It is possible to implement an optical character recognition system using a high-resolution camera mounted on smart phones in the modern society. Further, characters extracted from the implemented application is possible to provide the voice service for the visually impaired person by using TTS. But, it is difficult for the visually impaired person to properly shoot the objects that character information are included, because it is very hard to accurately understand the current state of the object. In this paper, we propose a method of inducing an appropriate shooting for the visually impaired persons by using a smartphone gyro sensor. As a result of simulation using the implemented program, we were able to see that it is possible to recognize the more character from the same object using the proposed method.