• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.2
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• pp.117-122
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• 2014

A novel method to reduce the vibration of drum type washing machine is proposed. Recently, as the capacity of the drum-type washing machine gets expanded and its washing performance is improved, its market share is increasing in the whole world. But, the capacity of washing machine is limited because of door size and built-in washing machine size. The vibration of washing machine is caused by unbalanced cloths in high spining drum, and the displacement of tub is maximized at transient range about 3 Hz(180 rpm). Previous researches were concerned about steady-state vibration in spinning. In this study, concerned about transient vibration and the displacement of tub is decreased by using gyroscope system. Mutibody dynamic model of washing machine include gyroscope is designed and the vibration of tub have been reduced by 44.7 % over original.

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.3
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• pp.311-317
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• 1997

DTG(dynamically tuned gyroscope) is a sensor detecting disturbance in angle velocity control loop of EOTS(electro optical tracking system), which is used for the stabilization of gimbal. DTG is classified into rate mode or rate integrated mode according to operating mode. In this paper, basic principles and characteristics of DTG, depending on to operating mode, are compared and the model of rate integrated mode DTG is proposed. Also, the validity of the presented model is verified by computer simulations and experiments.

• Korean Journal of Applied Biomechanics
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• v.21 no.4
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• pp.495-501
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• 2011

The purpose of this study was to develop the inertial sensor module system to detect gait event using single angular rate sensor(gyroscope), and evaluate the accuracy of this system. This sensor module is attached at the heel and gait events such as heel strike, foot flat, heel off, toe off are detected by using proposed automatic event detection algorithm. The developed algorithm detect characteristics of pitch data of the gyroscope to find gait event. To evaluate the accuracy of system, 3D motion capture system was used and synchronized with sensor module system for comparison of gait event timings. In experiment, 6 subjects performed 5 trials level walking with 3 different conditions such as slow, preferred and fast. Results showed that gait event timings by sensor module system are similar to that by kinematic data, because maximum absolute errors were under 37.4msec regardless of gait velocity. Therefore, this system can be used to detect gait events. Although this system has advantages of small, light weight, long-term monitoring and high accuracy, it is necessary to improve the system to get other gait information such as gait velocity, stride length, step width and joint angles.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.2
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• pp.168-172
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• 2015

In general, open-loop fiber-optic gyroscopes (FOG) are less stable than closed-loop FOGs but they offer simpler implementation. The typical operation time of line-of-sight (LOS) stabilization systems is a few seconds to one hour. In this paper, a open-loop fiber optic gyroscope (FOG) for LOS applications is designed and implemented. The design goal is aimed at implementing a low cost, compact FOG with low Angle Random Walk (ARW) (< $0.03deg/\sqrt{h}$) and bias instability (< 0.25deg/h). The FOG uses an open-loop all-fiber configuration with 100M PM fiber wound on a small diameter spool. In order to get the design goal, digital signal processing techniques for signal detection, modulation control and compensation are designed and implemented in FPGA.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.8
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• pp.1075-1079
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• 2014

In this paper, we describe the analysis and the compensation method of the g-sensitivity error for MEMS vibratory gyroscopes. Usually, the g-sensitivity error has been ignored in the commercial MEMS gyroscope, but it deserves our attention to apply for the missile application as a tactical grade performance. Thus, it is necessary to compensate for the g-sensitivity error to reach a tactical grade performance. Generally, the g-sensitivity error seems intuitively to be a gyroscope bias error proportional to the linear acceleration. However, we assert that the g-sensitivity error mainly causes not a bias error but a scale-factor error. And we verify that the g-sensitivity scale-factor error occurs due to the non-linearity of parallel plate electrodes. Therefore, we propose the compensation method to remove the g-sensitivity scale-factor error. The experimental result showed that a proposed compensation method improved successfully the performance of the MEMS vibratory gyroscope.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.39.3-39
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• 2002

In this paper, presented is a feedback control loop, for an in-plane gimbaled micro gyroscope based on methodology and state weighted model reduction technique. The micro gyroscope is the basic inertial sensors. To improve the performances such as stability, wide dynamic range, bandwidth and especially robustness, it is necessary to design a feedback control loop, which must be robust, because the manufacturing process errors can be large. Especially, to obtain wide bandwidth, the feedback controller is indispensable, because the gyroscope is high Q factor system and has small open loop bandwidth. Moreover, the feedback controller reduces the effect...

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.3
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• pp.187-192
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• 2005

This paper presents the design of the Automatic Gain Control (AGC) system for the drive axis of a electro-magnetic driven cylinder gyroscope. The simulation and experimental results show that the designed AGC excites the cylinder at its natural frequency and maintains a specified amplitude of oscillations, and also track the natural frequency shifts due to temperature variations. The sensing performance of the AGC driven gyroscope is shown to be greatly improved compared to that of the open-loop driven one.

• Journal of Electrical Engineering and Technology
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• v.12 no.1
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• pp.385-395
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• 2017

A new digitized decoupled dual-axis micro dynamically tuned gyroscope with three equilibrium rings (TMDTG) is proposed which can eliminate the constant torque disturbance (CTD) caused by the double rotation frequency of a driving shaft with a micro dynamically tuned gyroscope with one equilibrium ring (MDTG). A mechanical and kinematic model of the TMDTG is theoretically analyzed and the structure parameters are optimized in ANSYS to demonstrate reliability. By adjusting the thickness of each equilibrium ring, the CTD can be eliminated. The digitized model of the TMDTG system is then simulated and examined using MATLAB. Finally, a digitized prototype based on FPGA is created. The gyroscope can be dynamically tuned by adjusting feedback voltage. Experimental results show the TMDTG has good performance with a scale factor of $283LSB/^{\circ}/s$ in X-axis and $220LSB/^{\circ}/s$ in Y-axis, respectively. The scale factor non-linearity is 0.09% in X-axis and 0.13% in Y-axis. Results from analytical models, simulations, and experiments demonstrate the feasibility of the proposed TMDTG.

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

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.7
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• pp.632-637
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• 2012

This paper introduces a simple and efficient calibration method for three-axis accelerometers and three-axis gyroscopes using three-axis motion rate table. Usually, the performance of low cost MEMS-based inertial sensors is affected by scale and bias errors significantly. The calibration of these errors is a bothersome problem, but the previous calibration methods cannot propose simple and efficient method to calibrate the errors of three-axis inertial sensors. This paper introduces a new simple and efficient method for the calibration of accelerometer and gyroscope. By using a three-axis motion rate table, this method can calibrate the accelerometer and gyroscope simultaneously and simply. Experimental results confirm the performance of the proposed method.