• Title/Summary/Keyword: angular acceleration

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Flexure Error Analysis of RLG based INS (링레이저 자이로 관성항법시스템의 편향 오차 해석)

  • Kim Kwang-Jin;Yu Myeong-Jong;Park Chan-Gook
    • Journal of Institute of Control, Robotics and Systems
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    • v.12 no.6
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    • pp.608-613
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    • 2006
  • Any input acceleration that bends RLG dithering axis causes flexure error, which is a source of the noncommutative error that can not be compensated by simply using integrated gyro sensor output. This paper introduces noncommutative error equations that define attitude errors caused by flexure errors. In this paper, flexure error is classified as sensor level error if the sensing axis coincides with the dithering axis and as system level error if the two axes do not coincide. The relationship between gyro output and the rotation vector is introduced and is used to define the coordinate transformation matrix and angular motion. Equations are derived for both sensor level and system level flexure error analysis. These equations show that RLG based INS attitude error caused by flexure is directly proportional to time, amount of input acceleration and the dynamic frequency of the vehicle.

AUTOMATION OF ASTRONOMICAL TELESCOPE: II. DEVELOPMENT OF TECHNIQUES, EQUIPMENTS AND SOFTWARES FOR REMOTE CONTROL OF TELESCOPE (천체 망원경의 자동화: II. 망원경 원격 조종 기술, 장비 및 소프트웨어의 개발)

  • Kang, Yong-Woo;Lee, Hyeong-Mok
    • Publications of The Korean Astronomical Society
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    • v.11 no.1
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    • pp.57-73
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    • 1996
  • As a continuing effort to develop an automatic control system for small telescope, we developed the software for telescope control and CCD observations under DOS operating system. For accurate pointing of the telescope in short amount of time, we modelled the angular speed of the telescope by aquadratic function of time (constant acceleration) for the first 15 second and then linear function of time (zero acceleration) aftwewards. By changing the telescope speed from 'slew' to 'fine' before the telescope reaches the desired position, we could achieve the accuracy of a few arcsecond. The CCD control software was written for model CCD-10 of CCD Technology. This CCD can be used for guiding purposes. We also conducted the study for remote control of the telescope using telephone line. Although it cannot be used for real observations at the present form, we succeded in remotely pointing the telescope to desired direction. As faster communication technologies become widely available, simple observations can be made remotely in the near future. Finally we report some observational results made with the present control system.

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Development of the Off-vertical Rotary Chair and Visual Stimulation system for Evaluation of the Vestibular Function (전정기능 평가를 위한 탈수직축 회전자극 시스템 및 HMD 시스템의 개발)

  • Kim Gyu-Gyeom;Ko Jong-Sun;Park Byung-Rim
    • Proceedings of the KIPE Conference
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    • 2001.07a
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    • pp.377-380
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    • 2001
  • The vestibular system located in the inner ear controls reflex body posture and movement. It has the semicircular canals sensing an angular acceleration and the otolith organs sensing a linear acceleration. With this organic signal, medical doctor decide if a person has disease or not. To obtain this data, a precision stimular system is considered. Robust control is needed to obtain eye signals induced by off-vertical axis rotation because of an unbalanced load produced by tilting the axis of the system upto 30 degrees. In this study, off-vertical axis rotatory system with visual stimulation system are developed. This system is consisted of head mounted display for generating horizontal, vertical, and three dimensional stimulus patterns. Furthermore wireless recording system using RF modem is considered for noiseless data transmission.

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Design of Trajectory Generator for Performance Evaluation of Navigation Systems

  • Jae Hoon Son;Sang Heon Oh;Dong-Hwan Hwang
    • Journal of Positioning, Navigation, and Timing
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    • v.12 no.4
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    • pp.409-421
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    • 2023
  • In order to develop navigation systems, simulators that provide navigation sensors data are required. A trajectory generator that simulates vehicle motion is needed to generate navigation sensors data in the simulator. In this paper, a trajectory generator for evaluating navigation system performance is proposed. The proposed trajectory generator consists of two parts. The first part obtains parameters from the motion scenario file whereas the second part generates position, velocity, and attitude from the parameters. In the proposed trajectory generator six degrees of freedom, halt, climb, turn, accel turn, spiral, combined, and waypoint motions are given as basic motions with parameters. These motions can be combined to generate complex trajectories of the vehicle. Maximum acceleration and jerk for linear motion and maximum angular acceleration and velocity for rotational motion are considered to generate trajectories. In order to show the usefulness of the proposed trajectory generator, trajectories were generated from motion scenario files and the results were observed. The results show that the proposed trajectory generator can accurately simulate complex vehicle motions that can be used to evaluate navigation system performance.

Biased PNG for Approximate Target Adaptive Guidance

  • Song chanho;Kim, philsung;Jun byungeul
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.141.2-141
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    • 2001
  • An approximate target adaptive guidance algorithm(TAG) is proposed on the basis of the assumption that angular acceleration of missile to target line-of-sight and start time for TAG can be obtained by IR seeker. The algorithm does not use any target state estimator. Instead, it avoids the problem of determining target attitude by using the observation that the missile using LOS rate guidance is nearly on the collision course in the later point of engagement. Computer simulation results show that the proposed algorithm can effectively perform target adaptive guidance.

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A study on the swing control using anti-swing orane (무진동 크레인을 이용한 흔들림 제어에 관한 연구)

  • 박병석;윤지섭;이재설
    • 제어로봇시스템학회:학술대회논문집
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    • 1990.10a
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    • pp.292-297
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    • 1990
  • An anti-swing controller for an overhead crane in the stop position is designed. The developed anti-swing controller improves on the poor damping characteristics of overhead crane by feeding back the crane acceleration as a function of swing angular speed. The experimental results show that this crane using the proposed controller yields small stop position error and rapid damping response characteristics.

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Anti-Swing Control Algorithm for the Automation of Overhead Crane (천정크레인 설비의 자동화를 위한 반진동 제어 알고리즘)

  • 배상욱;노철균;배영호;이득기
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.17 no.2
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    • pp.49-57
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    • 2003
  • In this paper, is proposed an anti-swing control algorithm for the automation of overhead crane. The algorithm consists of three parts, the FCL with compensatory FLC which generates acceleration, velocity and position reference to reduce swing angle and acceleration feedback controller which feedback control errors. Especially the algorithm dose not need angular sensor which detect swing angle of payload and requires high cost. By the simulation study and experiment with prototype crane, we showed the usefulness of the proposed algorithm.

Kinetic analysis of the elbow joint in human motion (인체운동에 있어서 주관절의 운동학적 분석)

  • Noh, Tae-Hwan;Kim, Sik-Hyun;Kim, Jae-Hun
    • PNF and Movement
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    • v.5 no.1
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    • pp.49-56
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    • 2007
  • Objectives : We find that the reaction force on the elbow joint during elbow flexion, extension with and without an object in the hand can be calculated the equations of motion that the sum of the torque and the sum of the force acting on the elbow joint must be zero and (moment of inertia x angular acceleration) and (mass x acceleration). Methods : we have calculated the equations of motion (${\Sigma}F=0$, ${\Sigma}{\tau}=0$, ${\Sigma}F=ma$, ${\Sigma}{\tau}=Ia$) to investigate the reaction force on the elbow joint during elbow flexion, extension by means of the simplified free-body technique for coplanar forces. Results : we found that the reaction force on the elbow joint during elbow flexion, extention as constant acceleration motion is more than constant velocity, static motion. Also, we found that the relation between during flexion and during extension like this ; $J_{flexion}$ < $J_{extension}$.

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Data Processing and Numerical Procedures Influencing on Occupant Risk Indices (탑승자 안전지수에 영향을 주는 데이터 처리과정과 수치절차)

  • Kim, Kee-Dong;Ko, Man-Gi;Nam, Min-Kyun
    • International Journal of Highway Engineering
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    • v.9 no.4
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    • pp.215-226
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    • 2007
  • To verify the performance of roadside barriers, occupant risk indices are calculated from acceleration and angular velocity data of vehicle crash tests. The occupant risk indices to be computed include THIV(Theoretical Head Impact Velocity), PHD(Post-impact Head Deceleration), ASI(Acceleration Severity Index), OIV(Occupant Impact Velocity) and ORA(Occupant Ridedown Acceleration). There is a confusion due to different values of occupant risk indices produced for the same test data because various computational procedures and data processing methods can be applied to compute them. To slove this problem the effects of various numerical procedures and data processing methods on occupant risk indices were investigated. If the sampling rate specified in the guidelines is used for full-scale vehicle crash tests, an interpolation of impact time and numerical integration methods do not result in an appreciable change of THIV and OIV. The way to determine 10msec moving average for PHD and zero offset of data processing should be specified in the guidelines because 10msec moving average and zero offset methods have a significant influence on occupant risk indices.

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Velocity Control of Magnet-Type Automatic Pipe Cutting Machine and Measurement of Slipping Using MEMS-Type Accelerometer (자석식 자동 파이프 절단기의 정속제어와 MEMS 형 가속도계를 이용한 미끄럼 측정)

  • 김국환;이성환;임성수;이순걸
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.475-478
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    • 2004
  • In this paper, a magnet-type automatic pipe cutting machine that binds itself to the surface of the pipe using magnetic force and executes unmanned cutting process is proposed. During pipe cutting process when the machine moves around the pipe laid vertical to the gravitational field, the gravity acting on the pipe cutting machine widely varies as the position of the machine varies. That is, with same driving force from the driving motor the cutting machine moves faster when it climbs down the surface of the pipe and moves slower when it climbs up to the top of the pipe. To maintain a constant velocity of the pipe cutting machine and improve the cutting quality, the authors adopted a conventional PID controller with a feedforward effort designed based on the encoder measurement of the driving motor. It is, however, impossible for the encoder at the motor to measure the absolute position and consequently the absolute velocity of the cutting machine in the case where the slip between the surface of the pipe and wheel of the cutting machine is not negligible. As an attempt to obtain a better estimation of the absolution angular position/velocity of the machine the authors proposes the use of the MEMS-type accelerometer which can measure static acceleration as well as dynamic acceleration. The estimated angular velocity of the cutting machine using the MEMS-type accelerometer measurement is experimentally obtained and it indicates the significant slipping of the machine during the cutting process.

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