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- 摘要
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- 实验方案
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Absolute distance measurement based on spectral interferometry using femtosecond optical frequency comb
摘要： We demonstrated an absolute distance measurement method based on the frequency folding e?ect using the spectral interferometry of femtosecond optical frequency comb. And the investigation was carried out on the ranging accuracy in?uence of the phase noise in the traditional complicated phase unwrapping method via band-pass ?lter and Fourier Transform. To reduce the e?ects of the phase noise, we proposed the non-?ltered and di?erential envelop phase demodulation method, and its robustness was illustrated with a standard deviation of 75 nm for the stability of single point measurements. Further, through the extension of the non-ambiguity range, we achieved a resolution of better than 30 ??m in a long distance measurements range of 70 m, yielding a relative precision of 3.1 × 10 ? 7.
关键词： Spectral interferometry,Optical frequency comb,Absolute distance measurement
更新于2025-11-28 14:23:57
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Recovering distance information in spectral domain interferometry
摘要： This work evaluates the performance of the Complex Master Slave (CMS) method, that processes the spectra at the interferometer output of a spectral domain interferometry device without involving Fourier transforms (FT) after data acquisition. Reliability and performance of CMS are compared side by side with the conventional method based on FT, phase calibration with dispersion compensation (PCDC). We demonstrate that both methods provide similar results in terms of resolution and sensitivity drop-off. The mathematical operations required to produce CMS results are highly parallelizable, allowing real-time, simultaneous delivery of data from several points of different optical path differences in the interferometer, not possible via PCDC.
关键词： distance measurement,spectral domain interferometry,optical coherence tomography,dispersion compensation,phase calibration,Complex Master Slave,Fourier transforms
更新于2025-09-23 15:23:52
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Laser distance measurement by triangular-wave amplitude modulation based on the least squares
摘要： Phase ranging method of distance measurement usually sacri?ces the simplicity of the ranging system by adding complex circuit and multi-frequency ruler to achieve high accuracy. Laser pulse ranging has the counting error of the number of round-trip pulses which a?ects the accuracy of ?ight time calculation. Hence a novel method to measure a distance by triangular-wave amplitude modulation laser based on the least squares is proposed in this article. The triangular-wave is adopted to modulate the laser amplitude linearly, which improves the signal to noise ratio (SNR) of the ranging system e?ectively. The proposed system designs two identical channels for referenced and measured signals with certain length of optical distance. Their return signals are ?tted with improved straight-line ?tting algorithm based on the least square. Then a series of ?tting parameters and singular characteristic points of triangular wave were obtained. The detection distance is calculated with the proposed theoretical algorithm based on the relationship between the two signals and the time shift information of the characteristic point. The average measuring error of this laser ranging system is maintained within 2.8 mm with the detection distance in 10 m according to experimental results.
关键词： Time shift,Least-square ?tting approach,Distance measurement,Triangular wave modulation,Characteristic point detection
更新于2025-09-23 15:19:57
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Numerical study of comb-based high-accuracy distance measurement utilizing VIPA interferometry
摘要： The ultrahigh-precision distance measurement based on a single laser frequency comb as the multi-wavelength source together with an ultra-high-resolution dispersive spectrometer utilizing a virtually imaged phase array (VIPA) was studied numerically. The simulations provide the component parameter optimization and the comb spectral images on a CCD camera. An ameliorated scheme was proposed through achieving real-time comparisons between the reference and interference signals captured on a camera simultaneously to improve both the measurement accuracy and the precision signi?cantly. With the optimized data processing, the proposed approach is especially suitable for serving as a ultra-high precision relative distance measurement, and the measurement resolution can reach picometer scale in the optimal cases.
关键词： Ultra-high precision distance measurement,Ultra-high resolution spectroscopy,Laser frequency comb,Virtually imaged phase array interferometry
更新于2025-09-19 17:15:36
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Robot Operating System (ROS) Compatible Low Cost Rotating Light Detection and Ranging (Lidar) Design
摘要： Robot Operating system (ROS) is collection of software frameworks for robot software development. Researchers that work with ROS will have an opportunity to use or to be exact to reuse any software framework from another researcher as long as they use a similar robot platform, or similar device that has been include in the ROS. This paper present a design for a low cost rotating Lidar that compatible with ROS. As all we know distance measurement is the basic for building an autonomous capability for robots. Rotating lidar is among one the most popular device used to acquire this kind of information. However most of them are not suitable for low budget project because of their high cost. The design presented here tries to build a low cost rotating lidar based on Lidar Lite device with the compatibility with the ROS. The design incorporate a control board based on a microcontroller.
关键词： rotating,distance measurement,low cost,ROS,Lidar
更新于2025-09-09 09:28:46
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[IEEE 2018 International Conference on Indoor Positioning and Indoor Navigation (IPIN) - Nantes, France (2018.9.24-2018.9.27)] 2018 International Conference on Indoor Positioning and Indoor Navigation (IPIN) - Moving Object Tracking Based on High Precision Opto-Acoustic BPSK-CDMA Distance Measurement
摘要： Opto-acoustic indoor localization systems based on ultrasound and infrared allow the tracking of tools and hand movements in complex manual industrial assembly and handling processes, e. g. the application of glue or adhesive sealing material. However, this requires a localization system that is able to track the position of multiple objects simultaneously during movement when the system is affected by Doppler effects and noise. The amplitude shift keying (ASK) modulation method within the code division multiple access (CDMA) environment using Gold codes is focused in previous publications for unilateral distance measurement of non-moving objects. The novelty of this contribution is the implementation of the binary phase shift keying (BPSK) modulation method and the consideration of moving objects with a Doppler effect mitigation algorithm. This algorithm can be performed in real time with an acquisition and a tracking step. Moreover, BPSK provides a permanently available phase information that can be used for exact positioning of multiple moving transmitters and ensures more robustness to modeling errors and noise. In this publication unilateral distance measurement results for up to four moving objects simultaneously with various speeds up to 0.54 m/s are presented showing the superiority of BPSK-CDMA with Doppler effect mitigation (mean errors below 6.9 mm) compared to ASK-CDMA and BPSK-CDMA without Doppler effect consideration.
关键词： Doppler effect,time-of-flight,distance measurement,BPSK,ultrasound,Localization,CDMA,indoor positioning
更新于2025-09-09 09:28:46