• 제목/요약/키워드: Transmitted Velocity

검색결과 130건 처리시간 0.042초

무선 랜 통신을 이용한 이동 로봇의 곡선 추종 구현 (Design of Mobile Robot's Curve Following by Wireless LAN Communication)

  • 홍인택;김용택;김종수;전홍태
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 하계종합학술대회 논문집(3)
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    • pp.5-8
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    • 2002
  • In this paper, we propose the self-autonomous algorithm for mobile robot system. The proposed mobile robot system controlled by Personal Digital Assistant(PDA) can follow the target at regular intervals. The mobile robot can evaluate the distance between robot and target with ultrasonic sensors, transmits the distance to the PDA. The velocity and direction decided in PDA are transmitted to the mobile robot with wireless LAN communication. Considering the state, velocity-changing and distance-maintenance, of the mobile robot, driving velocity and direction are applied. For safety, the velocity of the mobile robot is changed step by step. As a result, we confirm the ability of following the target with proposed mobile robot.

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Early adjusting damping force for sloped rolling-type seismic isolators based on earthquake early warning information

  • Hsu, Ting-Yu;Huang, Chih-Hua;Wang, Shiang-Jung
    • Earthquakes and Structures
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    • 제20권1호
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    • pp.39-53
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    • 2021
  • By means of installing sloped rolling-type seismic isolators (SRI), the horizontal acceleration transmitted to the to-be-protected object above can be effectively and significantly reduced under external disturbance. To prevent the maximum horizontal displacement response of SRI from reaching a threshold, designing large and conservative damping force for SRI might be required, which will also enlarge the transmitted acceleration response. In a word, when adopting seismic isolation, minimizing acceleration or displacement responses is always a trade-off. Therefore, this paper proposes that by exploiting the possible information provided by an earthquake early warning system, the damping force applied to SRI which can better control both acceleration and displacement responses might be determined in advance and accordingly adjusted in a semi-active control manner. By using a large number of ground motion records with peak ground acceleration not less than 80 gal, the numerical results present that the maximum horizontal displacement response of SRI is highly correlated with and proportional to some important parameters of input excitations, the velocity pulse energy rate and peak velocity in particular. A control law employing the basic form of hyperbolic tangent function and two objective functions are considered in this study for conceptually developing suitable control algorithms. Compared with the numerical results of simply designing a constant, large damping factor to prevent SRI from pounding, adopting the recommended control algorithms can have more than 60% reduction of acceleration responses in average under the excitations. More importantly, it is effective in reducing acceleration responses under approximately 98% of the excitations.

유속 및 파이프 두께 측정 겸용 초음파 트랜스듀서 개선 (Improvement of an Ultrasonic Transducer for Measuring Both Flow Velocity and Pipe Thickness)

  • 김주완;김진오
    • 한국소음진동공학회논문집
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    • 제26권2호
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    • pp.148-156
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    • 2016
  • The paper deals with improvement of a piezoelectric ultrasonic transducer for measuring both pipe thickness and flow velocity. The transducer structure is based on the conventional transducers for measuring flow velocity by obliquely transmitting ultrasonic waves to the flow direction. The transducer invented earlier for measuring flow velocity and pipe thickness had an advantage of including only one piezoelectric disc, but for the thickness measurement the ultrasonic wave had to be reflected twice in a wedge material to be transmitted vertically to a pipe, and thus the wave signal was too weak. The transducer has been improved to transmit waves for thickness measurement vertically to a pipe without any prior reflection by electrically connecting two piezoelectric discs, one for flow velocity and the other for pipe thickness measurement. By comparing the measured results of specimen thickness with the improved transducer and conventional transducers, the accuracies of the improved one have been evaluated in the pipe thickness measurements.

마이크로 컴퓨터를 이용한 휴대용 부정맥 모니터의 개발(I)-하드웨어 설계를 중심으로- (Development of Portable Arrhythmia Moniter Using Microcomputer(I))

  • 이명호;안재봉
    • 대한의용생체공학회:의공학회지
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    • 제7권2호
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    • pp.169-182
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    • 1986
  • Pulsed ultrasonic Doppler system is a useful diagnostic instrument to measure blood-flow-velocity, velocity profile, and volume-blood-flow. This system is more powerful compare with 2-dimensional B-scan tissue image. A system has been deve- loped and ii being evaluated using TMS 32010 DSP. We use this DSP for the purpose of real-time spectrum analyzer to obtain spectrogram in singlegate pulsed Doppler system and for the serial comb filter to cancel clutter and zero crossing counter to estimate Doppler mean frequency in multigate pulsed Doppler system. The Doppler shift of the backscattered signals is sensed in a phase detector. This Doppler signal corresponds to the mean velocity over a some region in space defined by the ultrasonic beam dimensions, transmitted pulse duration, and transducer ban(iwidth. Multi- gate pulsed Doppler system enable the transcutaneous and simultaneous assessment of the velocities in a number of adjacent sample volumes as a continuous function of time. A multigate pulsed Doppler system processing the information originating from presented.

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계단 주파수 레이더에서 이동표적의 고해상도 거리 추정을 위한 코히어런트 펄스열 기반의 속도 추정 및 보상 (Coherent Pulse Train Based Velocity Estimation and Compensation for High Resolution Range Profile of Moving Target in Stepped Frequency Radar)

  • 심재훈;배건성
    • 전기전자학회논문지
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    • 제22권2호
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    • pp.309-315
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    • 2018
  • 계단 주파수 레이더(Stepped Frequency Radar: SFR)는 송신 펄스의 주파수를 점진적으로 증가시켜 넓은 합성 대역폭을 만듦으로써 높은 거리 해상도를 얻는 방식이다. 그런데 이동표적의 경우 거리-도플러 결합(range-Doppler coupling) 현상으로 정확한 거리 추정을 할 수 없게 되므로 정확한 속도 추정을 통한 보상이 필요하다. 본 논문에서는 코히어런트 펄스열(Coherent Pulse Train: CPT)을 갖는 계단 주파수 레이더 파형을 제안하고, 이를 이용한 속도 추정 및 파라미터에 따른 결과를 기존의 VMD(Velocity Measurement Data) 방식과 시뮬레이션을 통해 비교하고 분석하였다.

가로 등방성 복합재료의 파동전파에 관한 연구 (The Wave Propagation in transversely isotropic composite laminates)

  • 김형원
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2005년도 제25회 추계학술대회논문집
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    • pp.422-425
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    • 2005
  • 가로 등방성 복합재료에서 반사되거나 굴절된 파동의 속도와 입자방향, 그리고 진폭을 운동방정식과 구성방정식 그리고 파동수와 진동수로 표현된 변위식을 사용하여 구하였다. Snell 법칙을 사용하여 Eigenvalue 문제를 풀어 파동속도를 구하였으며 그 결과는 T300 Carbon fiber/5208 Epoxy 재료 성질을 이용하여 검증하였다. 이러한 분석은 수분 침수 C-scan을 이용하여 가로등방성 복합재료의 결점을 찾아내는데 응용될 수 있다.

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Experimental Planning for Realistic Force Feedback in a Bicycle Simulator

  • Hun, Yang-Gi;Soo, Kwon-Dong
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.117.5-117
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    • 2001
  • This paper presents the key idea of handlebar reaction force and pedal resistance force generation in creating life-like feeling in KAIST bicycle simulator. Also, it provides methods to evaluate its reality level with given reaction force profile. In KAIST bicycle simulator, the pedal resistance force and the handlebar reaction force are calculated using the bicycle dynamic model. With the information handlebar angle, rider´s pedaling torque and road profile transmitted from the handlebar system, the pedal system and the visual part, the bicycle dynamics engine calculates the handlebar reaction force and the pedal velocity. The handlebar system and the pedal resistance system generate reaction force and resistance force transmitted from dynamics engine. However to make more realistic riding feeling ...

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가로 등방성 복합재료의 초음파에 관한 연구 (The Wave Propagation in Transversely Isotropic Composite Laminates)

  • 김형원
    • 한국추진공학회지
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    • 제10권2호
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    • pp.62-69
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    • 2006
  • 가로 등방성 복합재료에서 반사되거나 굴절된 파동의 속도와 입자방향, 그리고 진폭을 운동방정식과 구성방정식 그리고 파동수와 진동수로 표현된 변위식을 사용하여 구하였다. Snell 법칙을 사용하여 Eigenvalue 문제를 풀어 파동속도를 구하였으며 그 결과는 T300 Carbon fiber/5208 Epoxy 재료 성질을 이용하여 검증하였다. 이러한 분석은 수분 침수 C-scan을 이용하여 가로등방성 복합재료의 결점을 찾아내는데 응용될 수 있다.

탄소섬유강화 복합재 적층판의 충격파괴 특성에 관한 연구 (A Study on Characteristics of Impact Fracture in CFRP Laminate Plates)

  • 양인영;정종안
    • 한국자동차공학회논문집
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    • 제3권5호
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    • pp.38-46
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    • 1995
  • In this paper, an experimental study on the effects of the impact damage and the perforation characteristic of CFRP laminates with different fiber stacking orientation and ply number was done through an observation of interrelations between the impact energy vs. transmitted energy and the impact energy vs. absorbed energy per unit volume. The velocities of the ball before or after impact are measured by the high-speed camera. And when CFRP laminates are subjected to tranverse impact by a steel ball(${\phi}10$), the delamination shapes generated by impact damage are observed by using SAM (Scanning acoustic Microscope).

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초음파를 이용한 감자의 내부결함검사 (Ultrasonic Inspection of Internal Defects of Potatoes)

  • 김인훈;정규홍;장경영;서륜;김만수
    • 한국정밀공학회지
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    • 제20권3호
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    • pp.82-88
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    • 2003
  • The nondestructive internal quality evaluation of agricultural products has been strongly required from the needs for individual inspection. Recently, the ultrasonic wave has been considered as a solution fur this problem, and an ultrasonic system was constructed for the ultrasonic NDE of fruits and vegetables in our previous work. In this paper, the practical applicability of our ultrasonic system is tested fur the inspection of internal defects (central cavity) in Atlantic potato. Sound speed and RMS of transmitted ultrasonic wave signal were measured and classification algorithm using 2 dimensional stochastic analysis. was presented. Experimental results showed greater value of sound speed and RMS (root mean square) of transmitted signal in normal samples than in abnormal samples with cavity. Also a stochastic method to distinguish normal and abnormal showed fault detection rate less than 5%.