Janus‐configured all fibre laser Doppler velocimetry

Fan, Zhen; Sun, Qizhen; Du, Lei; Bai, Jie

doi:10.1049/iet-opt.2017.0047

Cited by 4 publications

(3 citation statements)

References 20 publications

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“…The simulated speed error component ∆V 2 in the stability aspect can be evaluated by the frequency stability of the Doppler shift generated by the moving target simulator. According to the recommended testing method in [23], a total of 101 consecutive measured values of Doppler shift frequency generated by the moving target simulator are required to calculate the frequency stability σ, where the frequency measurement gate-time of the dual-channel universal frequency counter is set to 1 s. The frequency stability σ can be calculated by Equation (12) [23]:…”

Section: Stabilitymentioning

confidence: 99%

“…With the advantage of high-accuracy, wide-range, long-lifetime, stability, and reliability [6][7][8][9], the 24 GHz continuous wave (CW) Doppler radar sensor (DRS) has been widely used in high-speed and urban rail trains, working together with some of the other conventional wheel speed sensors to directly measure the instantaneous speed of trains in real time by using a non-contact approach, which is not affected by wheel slip and spin. Unlike the dual-sided symmetrical structure of vehicle-borne dual-channel DRS with the Janus configuration, which is used as a mobile standard speed-measuring instrument for the field verification of traffic speed meters in road traffic [10][11][12], train-borne dual-channel DRSs usually adopt a single-sided asymmetric structure, which is a more common and complicated configuration than the Janus configuration used in vehicle-borne dual-channel DRSs and seeks no approximation methods for the solution on train speed calculation [10]. Additionally, the train-borne single-channel DRS is still widely used for speed measurements of freight trains in railway freight dedicated lines because of its low-cost, long-lifetime, and stability [1].…”

Section: Introductionmentioning

confidence: 99%

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Speed Calibration and Traceability for Train-Borne 24 GHz Continuous-Wave Doppler Radar Sensor

Sun

Bai

et al. 2020

Sensors

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The 24 GHz continuous-wave (CW) Doppler radar sensor (DRS) is widely used for measuring the instantaneous speed of moving objects by using a non-contact approach, and has begun to be used in train-borne movable speed measurements in recent years in China because of its advanced performance. The architecture and working principle of train-borne DRSs with different structures including single-channel DRSs used for freight train speed measurements in railway freight dedicated lines and dual-channel DRSs used for speed measurements of high-speed and urban rail trains in railway passenger dedicated lines, are first introduced. Then, the disadvantages of two traditional speed calibration methods for train-borne DRS are described, and a new speed calibration method based on the Doppler shift signal simulation by imposing a signal modulation on the incident CW microwave signal is proposed. A 24 GHz CW radar target simulation system for a train-borne DRS was specifically realized to verify the proposed speed calibration method for a train-borne DRS, and traceability and performance evaluation on simulated speed were taken into account. The simulated speed range of the simulation system was up to (5~500) km/h when the simulated incident angle range was within the range of (45 ± 8)°, and the maximum permissible error (MPE) of the simulated speed was ±0.05 km/h. Finally, the calibration and uncertainty evaluation results of two typical train-borne dual-channel DRS samples validated the effectiveness and feasibility of the proposed speed calibration approach for a train-borne DRS with full range in the laboratory as well as in the field.

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Section: Stabilitymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Speed Calibration and Traceability for Train-Borne 24 GHz Continuous-Wave Doppler Radar Sensor

Sun

Bai

et al. 2020

Sensors

Self Cite

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“…However, the measuring equipment easily interferes with the flow rate of the point to be measured. Laser Doppler velocimetry (LDV) is a noninvasive technique for measuring the speed of moving solid-state surfaces or particle velocity in a fluid by laser interferometry [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Researchers continuously develop and design LDV devices suitable for different applications [15][16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Laser Velocimetry for the In Situ Sensing of Deep-Sea Hydrothermal Flow Velocity

Sun,

Zhang,

et al. 2023

Sensors

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Laser Doppler velocimetry (LDV) based on a differential laser Doppler system has been widely used in fluid mechanics to measure particle velocity. However, the two outgoing lights must intersect strictly at the measurement position. In cross-interface applications, due to interface effects, two beams of light become easily disjointed. To address the issue, we present a laser velocimeter in a coaxial arrangement consisting of the following components: a single-frequency laser (wavelength λ = 532 nm) and a Twyman–Green interferometer. In contrast to previous LDV systems, a laser velocimeter based on the Twyman–Green interferometer has the advantage of realizing cross-interface measurement. At the same time, the sensitive direction of the instrument can be changed according to the direction of the measured speed. We have developed a 4000 m level laser hydrothermal flow velocity measurement prototype suitable for deep-sea in situ measurement. The system underwent a withstand voltage test at the Qingdao Deep Sea Base, and the signal obtained was normal under a high pressure of 40 MPa. The velocity contrast measurement was carried out at the China Institute of Water Resources and Hydropower Research. The maximum relative error of the measurement was 8.82% when compared with the acoustic Doppler velocimeter at the low-speed range of 0.1–1 m/s. The maximum relative error of the measurement was 1.98% when compared with the nozzle standard velocity system at the high-speed range of 1–7 m/s. Finally, the prototype system was successfully evaluated in the shallow sea in Lingshui, Hainan, with it demonstrating great potential for the in situ measurement of fluid velocity at marine hydrothermal vents.

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Comparison study of laser vibration measurement and quantum vibration measurement

Zhang

Yang

Wang

et al. 2021

2021 13th International Conference on Wireless Communications and Signal Processing (WCSP)

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Janus‐configured all fibre laser Doppler velocimetry

Cited by 4 publications

References 20 publications

Speed Calibration and Traceability for Train-Borne 24 GHz Continuous-Wave Doppler Radar Sensor

Speed Calibration and Traceability for Train-Borne 24 GHz Continuous-Wave Doppler Radar Sensor

Laser Velocimetry for the In Situ Sensing of Deep-Sea Hydrothermal Flow Velocity

Comparison study of laser vibration measurement and quantum vibration measurement

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