• Journal of Advanced Research in Ocean Engineering
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• v.1 no.2
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• pp.134-147
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• 2015

This study proposes a method to determine the effective angular velocity of each motor of a specific four-rows tracked vehicle (FRTV) in order to follow a given turning radius. The configuration of the four-rows tracked vehicle is introduced, and its dynamics analysis model is built using the DAFUL commercial software. The soil has been assumed to be hard ground, and the friction force between the ground and the tracked links is calculated using the Coulomb friction model. This paper uses a simulation to show that the error in the position increased with respect to the angle of the curvatures, so a method is proposed to compensate for the error in the motion of the motors. Various simulations are then carried out to verify the proposed formulation. The effects of the soil characteristics and the driving velocity will be further investigated in future studies.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.29-33
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• 1993

This paper suggests Kalman filter formulation using by precision GINS output angle for SDINS initial transfer alignment of missile. The Kalman filter model was derived from quaternion parameters and the transfer alignment system by angle matching method satisfies azimuth observability in horizontal angular motion. The estimated error of SDINS attitude settles to less 3mrad(1.sigma.) in 200 seconds at proper sea state.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.6
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• pp.438-445
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• 2019

In this paper, we present a new approach to extract the g-sensitivity scale-factor error for a MEMS gyroscope. MEMS gyroscopes, based on the use of both angular momentum and the Coriolis effect, have a g-sensitivity error due to mass unbalance. Generally, the g-sensitivity error is not considered in general use of gyroscopes, but it deserves our attention if we are to develop for tactical class performance and reliability. The g-sensitivity error during vehicle flight increases navigation error; so it must be analyzed and compensated for the use of MEMS IMU for high dynamics vehicle systems. Therefore, we analyzed how to extract the g-sensitivity scale-factor error from the inertial sensor error model. Furthermore we propose a new method to extract the g-sensitivity error using flight motion simulator. We verified our proposed method with experimental results.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.7
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• pp.1354-1360
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• 2001

Calculated velocity distribution was used to visual information by image that is obtained from camera. The visual velocity of object that is obtained from this visual information were fused and experimented. That is, need motion of eye that motion of head that happen by external disturbance or move of camera itself to get stable image in environment that receive external disturbance can be compensated. In this treatise, algorithm that control gaze which vision and sense of equilibrium are fused in environment with external disturbance proposed, and thing that compare with that it controls gaze only that control gaze which vision and sense of equilibrium are fused in the experiment result and position deflection is few confirmed. This was because action of camera prop is effect that record conclusion error of the speed because the appearance speed is decreased being compensated by angular velocity sensor.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.1
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• pp.43-48
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• 2012

This paper proposes a practical linear recursive robust motion deblurring filter using the inertial sensor measurements for strapdown image seekers. The angular rate information obtained from the gyro mounted on the missile is used to define the PSF(point spread function). Since the gyro output contains a unknown but bounded bias error. the motion blur image model can be expressed as the linear uncertain system. In consequence, the motion deblurring problem can be cast into the robust Kalman filtering which provides reliable state estimates even in the presence of the parametric uncertainty due to the gyro bias. Through the computer simulations using the actual IR scenes, it is verified that the proposed algorithm guarantees the robust motion deblurring performance.

• Physical Therapy Korea
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• v.10 no.3
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• pp.63-70
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• 2003

The purpose of this study was to compare the difference of joint position sense between measurements. Fourteen healthy male subjects were recruited for this study. The elbow joint position senses were measured using angle reproduction test. The elbow joint position sense was assessed with three experimental conditions: ipsilateral reproduction test in open-chain condition, contralateral reproduction test in open-chain condition, ipsilateral reproduction test with weight in open-chain condition and ipsilateral reproduction test in closed-chain condition. The angular difference between stimulus position and the reproduced position (angular error) was calculated in all testing conditions to examine the accuracy of the joint position sense. One way ANOVA was used to compare the error angles in all experimental conditions. The error angles between measurements were significantly different in elbow joint. The error angles was smallest in ipsilateral reproduction test with weight in open-chain condition and was greatest in the contralateral reproduction test in open-chain condition. Findings of this study indicate that testing methods, types of task, existence of resistance should be considered in clinical assessment for the joint position sense.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.1
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• pp.65-70
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• 2002

An analysis method for calculating motion accuarcy of double sides hydrostatic table is proposed in this paper. In this method, profiles of each rails are assumed as periodic function, therefore it is represented as the sum of spacial frequencies. Bearing clearance at any position rail is depended on the variation of linear, angular motion error of table and the form errors of both sides of a rail. Finite element method is applied to calculate pressure distributions in bearing clearance. In order to simplify the analyzing process, double sides table model is converted into equivalent single side table model. Results calculated by the proposed modeling method agree well with the results directly caculated by double sides modeling method, and also agree well with experimental results. From the theoretical and experimental analysis, it is verified that the proposed analysis method is very effective to analyze the motion accuracy of double sides hydrostatic table.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.65-69
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• 2002

In order to practicalize high precision centerless grinder for machining the ferrule, its feeding system is designed and tested. For satisfying the desired diametric tolerance and cylindricity of the ferrule, the feeding system is designed to have relatively high axial stiffness of 600 N/$\mu\textrm{m}$, high angular motion accuracy of 0.5 arcsec/mm in yaw direction and minimum resolution of 0.05 $\mu\textrm{m}$. A prototype of feeding system is built up with hydrostatic guideway and ballscrew. A linear scale with 0.05 $\mu\textrm{m}$ of resolution is used for position feedback. Experimental results show that the feeding system has the infinity of axial stiffness within the range of 1000 N and 0.3 arcsec/mm of yawing error. Also the feeding system shows obvious step response against 0.05 $\mu\textrm{m}$/step command without the lost motion or backlash. Although the vertical stiffness is reduced to 440 N/$\mu\textrm{m}$ by the elastic deformation of rail, it is good enough to use for machining the ferrule. From above, it is confirmed that the feeding system is applicable to centerless grinder for machining the ferrule.

• Nuclear Engineering and Technology
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• v.53 no.7
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• pp.2251-2260
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• 2021

The motion control of the divertor maintenance system of the China Fusion Engineering Test Reactor (CFETR) was studied in this paper, in which CFETR Multi-Functional Maintenance Platform (MFMP) was simplified as a parallel robot for the convenience of theoretical analysis. In order to design the motion controller of parallel robot, the kinematics analysis of parallel robot was carried out. After that, the dynamic modeling of the hydraulic system was built. As the large variation of heavy payload on MFMP and highly nonlinearity of the system, A Fuzzy-PID controller was built for self-tuning PID controller parameters by using Fuzzy system to achieve better performance. In order to test the feasibility of the Fuzzy-PID controller, the simulation model of the system was built in Simulink. The results have showed that Fuzzy-PID controller can significantly reduce the angular error of the moving platform and provide the stable motion for transferring the divertor.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.38 no.3
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• pp.243-248
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• 2010

This study addresses spacecraft moment of inertial estimation approach using Modified Rodrigues Parameters(MRP). The MRP offer advantage by avoiding singularity in Kalman Filter design for attitude determination caused by the norm constraint of quaternion parameters. Meanwhile, MRP may suffer singularity for large angular displacement, so that we designed appropriate reference attitude motion for accurate estimation. The proposed approach is expected to provide stable error covariance update with accurate spacecraft mass property estimation results.