Abstract
As an advanced optical precision ranging method, FMCW (frequency-modulated continuous-wave) laser interferometric ranging technology can achieve a large-scale and high-precision absolute distance measurement, so it has high research and application value in the field of coordinate measurement in large space. How to improve the resolution and stability of laser interferometry is a research difficulty in this technology. Based on FMCW laser interferometry relative distance technology, a method for achieving absolute distance measurement through phase comparison after repeated sampling is proposed. Using the FMCW laser distance measuring system, two interference optical paths of measuring interferometer and auxiliary interferometer are constructed, respectively. Synchronous sampling is performed on two interference signals, and the phase ratio of the two interference signals is obtained through the extracted frequency information. The optical path difference of the unknown measurement interferometer is derived from the known auxiliary interferometer information. This method uses a triangular wave modulation laser to reduce the influence of Doppler frequency shift and eliminate quantization errors. By using the fixed-point repeated sampling, the optical path difference information is quickly extracted, and the nonlinear error of laser interference frequency modulation is effectively reduced.
1 Introduction
Since the birth of laser, it has played an important role in the field of distance measurement with its unique multiple characteristics such as high collimation, high coherence, and modulability [1,2]. Frequency-modulated continuous-wave (FMCW) laser interferometric ranging is derived from light detection and ranging technology. This method has the advantages of large ranging range, high accuracy, searchability, and stability and reliability and has been widely applied in the fields of ultra-precision manufacturing and large-scale detection [3,4,5]. The basic principle of FMCW is to implement periodic continuous frequency modulation on the laser, and the modulated laser first loads the ranging information in the optical path system and then combines the beam to form interference. When the optical paths corresponding to the reference and signal optical paths of the interference system are not equal, there is a certain frequency difference between the combined two FMCW lasers, resulting in a dynamic beat frequency interference signal. By demodulating the initial phase change of the beat signal, the change of the measured light path difference can be obtained [6,7]. FMCW laser interferometry technology produces a dynamic beat interference signal, and it is easy to extract the phase subdivision, phase-moving direction resolution, and interference period count in the signal. Since the extracted phase can subdivide the wavelength of a laser, the FMCW laser interferometry technology can achieve high-precision distance measurement [8,9].
The measurement system uses a distributed feedback laser (DFB) semiconductor laser as the light source. The laser is equipped with an fiber grating filter, which ensures a stable output wavelength, extremely narrow linewidth, and excellent edge mode suppression ratio. Due to its small size and convenient installation, this device has been widely used. However, as a semiconductor device, it has defects such as poor temperature characteristics and easy noise generation [10,11,12]. In actual measurement, the laser is affected by factors such as modulation nonlinearity error, system calibration error, and Doppler frequency shift. These factors all greatly affect the ranging accuracy and stability of the FMCW ranging system, making it difficult to achieve stable and reliable engineering applications.
In order to solve the aforementioned problems, many scholars have put forward a lot of very effective methods, which mainly include early active compensation and late fitting treatment. Active compensation methods include pre-correction compensation and feedback frequency modulation technology and electro-optic phase-locked loop feedback correction technology [13,14,15]. Post-processing methods include signal frequency reference correction, optical frequency comb correction, and multi-optical path correction [16,17]. Naresh built an FMCW laser ranging optical path and designed a semiconductor laser source feedback control system with a ranging resolution of 1.5 mm [18]. Satyan et al. used a single-mode vertical cavity surface emitting laser to build a ranging system with a spatial ranging resolution of 250 μm and a range of 1 m [19]. Iiyama et al. improved the light source system using fiber optic self-mixing technology and measured targets at a distance of 1.5 m, achieving a ranging resolution of 31 μm [20]. Baumann used a frequency comb to correct the optical frequency of the laser, increasing the ranging resolution to 130 μm and the repetition accuracy to 6 nm [16]. The aforementioned method optimizes the signal extraction method and improves the measurement accuracy to a certain extent. However, the Doppler phase shift and nonlinear error caused by the large-scale laser frequency dynamic modulation are still a difficult problem that seriously affects the measurement accuracy and stability and has not been completely solved.
This manuscript proposes a method of fixed-point repeated sampling and phase comparison based on the correction technique of two optical paths to eliminate the nonlinear effects caused by laser modulation. The fixed-point repeated sampling algorithm is derived in detail. The correctness of the formula is verified by simulation analysis, and the corresponding auxiliary measurement optical path based on optical fiber is built by combining the algorithm. The experimental results show that the system can calculate the accuracy and reliability of the optical path difference and realize the high-precision and large-size measurement engineering application of FMCW laser interferometry absolute ranging.
2 FMCW ranging principle
As shown in Figure 1, the FMCW laser is collimated by a collimating lens and then divided by a coupler. The optical path where the fixed reflector is located is the reference beam, and the OPD (optical path difference) will not change. The optical path where the movable reflector is located is a signal beam. When the reflected beam from the movable reflector and the fixed reflector meets at the coupler, the two beams will interfere to generate a dynamic interference signal. The displacement of the movable reflector is calculated by the frequency and phase of the interference signal.

FMCW optical system diagram.
When these two waves interfere, the interference signal light intensity, the OPD between the reference wave and the signal wave in one modulation period, is as follows:
where
Then, the absolute ranging based on frequency is as follows:
3 Resampling phase comparison method for absolute ranging
In order to improve the accuracy of absolute distance measurement in large range and eliminate the quantization error caused by nonlinear frequency modulation and experimental calibration, a dual-optical path-measuring device based on a single-mode fiber is proposed. As shown in Figure 2, the basic structure of the dual optical path-ranging system is mainly composed of two parallel interference devices: one is the measuring interference device and the other is the auxiliary interference device. The DFB laser emits a triangular wave signal with the wavelength of 1,550 nm, which is divided into two parts according to the ratio of 1:1 by the coupler. The emitted light entering the measuring interference device is emitted through the circulator and collimating lens. The light reflected by the measuring target mirror and the light reflected by the half lens of the collimator form Michelson interference in the loop. The beat frequency signal formed by the interference is collected by photoelectric detector 1 through circulator 3. The laser entering the auxiliary interference device is divided into two parts by the coupler, enters the optical fiber with different optical path difference, and then combines the beams to form the Mach–Zehnder interferometer. The interference signal is collected by photodetector 2.

Schematic diagram of light path.
Analyzing the characteristics of measurement systems using frequency characteristics and decoupling important information hidden in physical phenomena is one of the important methods in signal processing technology [21–23]. In order to explain in detail, the working principle of resampling phase comparison absolute ranging, the acquisition method, is mathematically deduced. When the modulation frequency of the laser signal is
Auxiliary interferometer distance:
Measuring interferometer distance:
Then,
The absolute ranging calculation method based on beat frequency is adopted. Obviously, the measurement accuracy is restricted by frequency. Since the phase can subdivide the beat frequency signal frequency and improve the measurement accuracy, the absolute ranging calculation can be realized based on the sum of phases within the time window
Auxiliary interferometer distance:
Measuring interferometer distance:
Then, there is:
It can be seen from the aforementioned formula that if the optical path difference of the auxiliary interferometer is known in advance and the interference signals of the two interferometers are sampled synchronously, the optical path difference of the measuring interferometer can be obtained only by determining the ratio of the phase changes of the two interference signals in the same time period.
4 Experimental verification and analysis
In order to verify the correctness of the aforementioned methods, an absolute ranging experiment with a length of 2 m was designed in the standard vertebra laboratory environment. As shown in Figure 3, the distance between the precision electric drive guide rail and the collimating lens is 2 m on the Thorlabs optical platform. The measuring target mirror is installed on the electric driver, and the movable range is 0–1 m. The measuring beam is emitted from the collimator and reflected by the measuring target mirror and then combined with the half lens in the collimator to form the beat frequency signal of the measurement interferometer. Through channel 1 of the lower machine, the measurement signal is collected by the processor, and the moving distance of the target mirror is modulated and demodulated. It can be seen from the figure that the self-made auxiliary interferometer has a fixed cavity length, and the stable beat signal is collected and processed by channel 2 of the lower machine. The notebook computer is used as the host computer to collect two interferometer signals processed by the lower computer, and the results are statistically analyzed.

Measurement experiment.
During the measurement, the modulation frequency of DFB laser is 100Hz, the amplitude of modulation voltage is 1.23 V, and the modulation current range is 39.9–83.1 mA. The average change rate of laser output light frequency with current is about 0.4 Ghz/mA, and the frequency modulation range (bandwidth) is about 18 GHz. During the experiment, the micro-displacement platform was controlled to drive the measurement target mirror to move at a uniform speed, and the position of the guide rail and the measurement results of the interferometer were recorded every 100 mm (1,000,000 μm). In the experiment, ten measurements were taken within the range of 1–2 m, using the position of the guide rail as a reference. The results recorded and obtained are shown in the measurement error curve of the laser interferometer as shown in Figure 6. It can be seen from Figure 4. that the error is ≤10 μm.

Linear error curve of interferometer.
In a laboratory environment, adjust the range of the distance between the collimator and the measurement target mirror to be 1.3 m, and continuously collect 17,000 data in a static state. The stability scatter diagram is shown in Figure 5. Perform normal distribution processing on the scatter plot; as shown in Figure 6, within the 95% confidence interval, the maximum standard deviation is 2.656 μm.

Scatter diagram of interferometer stability.

Normal distribution.
It can be seen through experiments that this method can eliminate the influence of the quantization error substituted by the experimental calibration and realize the ranging resolution of 1 nm, and the measurement standard deviation exceeds 3 μm, which proves that the method has a high resolution and measurement repeatability. However, because the system has not been accurately calibrated, there are still systematic errors in the ranging results. Since the distance measurement experiment is implemented on a vibration isolation optical platform, external vibration and temperature changes have little effect on the experimental results. However, the system is more sensitive to vibration and temperature, and the impact of vibration and temperature must be considered in actual measurement, and vibration isolation design and temperature control are required.
5 Conclusion
FMCW laser interferometry ranging technology is to linearly modulate the frequency of the emitted laser, and the local oscillator signal interferes with the echo signal to form a beat frequency signal. The measurement distance is calculated by extracting the frequency information of the beat frequency signal. In the actual measurement, the laser has the problem of modulation nonlinearity, which causes the spectrum broadening of the measured signal seriously, which limits the ranging accuracy of the FMCW ranging system. In order to solve these problems, this study proposes an absolute ranging method based on the resampling phase comparison. Two signals of measuring interferometer and auxiliary interferometer are constructed by using dual optical path FMCW laser-ranging system. If two interferometers are sampled synchronously, the optical path difference can be obtained only by calculating the phase ratio of the two interferometers. The experimental results show that the nonlinear frequency modulation error of the laser is reduced by using fixed-point sampling because the quantization error caused by experimental calibration is eliminated, and this method effectively improves the accuracy and stability of measurement.
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Funding information: This work was supported by the National Natural Science Foundation of China (No. 62263028) and Shaanxi Natural Science Foundation of China (No. 2023-JC-YB-592/2023-JC-QN-0633).
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Author contributions: All authors have accepted responsibility for the entire content of this manuscript and approved its submission.
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Conflict of interest: The authors state no conflict of interest.
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Data availability statement: The data used to support the findings of this study are available from the corresponding author upon request.
References
[1] Lu C, Liu G, Liu B, Chen F, Gan Y. Absolute distance measurement system with micron-grade measurement uncertainty and 24 m range using frequency scanning interferometry with compensation of environmental vibration. Opt Exp. 2016;24(26):30215–24.10.1364/OE.24.030215Search in Google Scholar PubMed
[2] Liu G, Lu C, Liu B, Chen F, Gan Y. Combining sub-Nyquist sampling and chirp decomposition for a high-precision and speed absolute distance measurement method. Appl Opt. 2016;55(35):9974–7.10.1364/AO.55.009974Search in Google Scholar PubMed
[3] Wu H, Zhang F, Li J, Cao S, Meng X, Qu X. Intensity evaluation using a femtosecond pulse laser for absolute distance measurement. Appl Opt. 2015;54(17):5581–90.10.1364/AO.54.005581Search in Google Scholar PubMed
[4] Jin J, Kim YJ, Kim Y, Kim SW. Absolute distance measurements using the optical comb of a femtosecond pulse laser. Int J Precis Eng Manuf. 2010;8(4):22–6.Search in Google Scholar
[5] Wu H, Zhang F, Cao S, Xing S, Qu X. Absolute distance measurement by intensity detection using a mode-locked femtosecond pulse laser. Opt Exp. 2014;22(9):10380–97.10.1364/OE.22.010380Search in Google Scholar PubMed
[6] Zheng J. Reflectometric fiber optic frequency-modulated continuous-wave interferometric displacement senso. Opt Eng. 2005;44(12):124401–5.10.1117/1.2148939Search in Google Scholar
[7] Zheng J. Single-mode birefringent fiber frequency-modulated continuous- wave interferometric strain sensor. IEEE Sens J. 2009;10(2):281–5.10.1109/JSEN.2009.2032153Search in Google Scholar
[8] Yang J, Yang T, Wang Z, Jia D, Ge C. A novel method of measuring instantaneous frequency of an ultrafast frequency modulated continuous-wave laser. Sensors. 2020;20(14):3834.10.3390/s20143834Search in Google Scholar PubMed PubMed Central
[9] Zheng J. Optical frequency-modulated continuous-wave interferometers. Appl Opt. 2006;45(12):2723–30.10.1364/AO.45.002723Search in Google Scholar
[10] Mahdy AM, Lotfy K, El-Bary A, Sarhan HH. Effect of rotation and magnetic field on a numerical-refined heat conduction in a semiconductor medium during photo-excitation processes. Eur Phys J Plus. 2021;136:553.10.1140/epjp/s13360-021-01552-3Search in Google Scholar
[11] Khamis AK, Allah Nasr AM, El-Bary AA, Atef HM. The influence of variable thermal conductivity of semiconductor elastic medium during photothermal excitation subjected to thermal ramp type. Results Phys. 2019;25(12):4731–40.Search in Google Scholar
[12] Mahdy AM, Lotfy K, El-Bary A, Tayel IM. Variable thermal conductivity and hyperbolic two-temperature theory during magneto-photothermal theory of semiconductor induced by laser pulses . Eur Phys J Plus. 2021;136:651.10.1140/epjp/s13360-021-01633-3Search in Google Scholar
[13] Roos PA, Reibel RR, Berg T, Kaylor B, Barber ZW, Babbitt WR. Ultrabroadband optical chirp linearization for precision metrology applications. Opt Lett. 2009;34(23):3692–4.10.1364/OL.34.003692Search in Google Scholar PubMed
[14] Behroozpour B, Sandborn PAM, Quack N, Seok TJ, Matsui Y, Wu MC, et al. Electronic-photonic integrated circuit for 3D microimaging. IEEE J Solid-State Circuits. 2017;52(1):161–72.10.1109/JSSC.2016.2621755Search in Google Scholar
[15] Shi G, Zhang F, Qu X, Meng X. High-resolution frequency-modulated continuous-wave laser ranging for precision distance metrology applications. Opt Eng. 2014;53(12):122402.10.1117/1.OE.53.12.122402Search in Google Scholar
[16] Baumann E, Giorgetta FR, Coddington I, Sinclair LC, Knabe K, Swann WC, et al. Comb-calibrated frequency-modulated continuous-wave ladar for absolute distance measurements. Opt Lett. 2013;38(12):2026–8.10.1364/OL.38.002026Search in Google Scholar PubMed
[17] Mateo AB, Barber ZW. Precision and accuracy testing of FMCW ladar-based length metrology. Appl Opt. 2015;54(19):6019–24.10.1364/AO.54.006019Search in Google Scholar PubMed
[18] Barber ZW, Babbitt WR, Kaylor B, Reibel RR, Roos PA. Accuracy of active chirp linearization for broadband frequency modulated continuous wave ladar. Appl Opt. 2010;49(2):213–9.10.1364/AO.49.000213Search in Google Scholar PubMed
[19] Satyan N, Vasilyev A, Rakuljic G, Leyva V, Yariv A. Precise control of broadband frequency chirps using optoelectronic feedback. Opt Exp. 2009;17(18):15991–9.10.1364/OE.17.015991Search in Google Scholar PubMed
[20] Iiyama K, Matsui SI, Kobayashi T, Maruyama T. High-resolution FMCW reflectometry using a single-mode vertical-cavity surface-emitting laser. IEEE Photonics Technol Lett. 2011;23(11):703–5.10.1109/LPT.2011.2131124Search in Google Scholar
[21] Guariglia E, Guido RC. Chebyshev wavelet analysis. J Funct Spaces. 2022;(1):5542054.10.1155/2022/5542054Search in Google Scholar
[22] Guariglia E. Harmonic Sierpinski gasket and applications. Entropy. 2018;20(9):714.10.3390/e20090714Search in Google Scholar PubMed PubMed Central
[23] Zhang L, Liu ST, Yu C. Control effects of Morlet wavelet term on Weierstrass–Mandelbrot function model. Indian J Phys. 2014;88(8):867–74.10.1007/s12648-014-0497-3Search in Google Scholar
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- Analytical solutions of the extended Kadomtsev–Petviashvili equation in nonlinear media
- A novel compact highly sensitive non-invasive microwave antenna sensor for blood glucose monitoring
- Inspection of Couette and pressure-driven Poiseuille entropy-optimized dissipated flow in a suction/injection horizontal channel: Analytical solutions
- Conserved vectors and solutions of the two-dimensional potential KP equation
- The reciprocal linear effect, a new optical effect of the Sagnac type
- Optimal interatomic potentials using modified method of least squares: Optimal form of interatomic potentials
- The soliton solutions for stochastic Calogero–Bogoyavlenskii Schiff equation in plasma physics/fluid mechanics
- Research on absolute ranging technology of resampling phase comparison method based on FMCW
- Analysis of Cu and Zn contents in aluminum alloys by femtosecond laser-ablation spark-induced breakdown spectroscopy
- Nonsequential double ionization channels control of CO2 molecules with counter-rotating two-color circularly polarized laser field by laser wavelength
- Fractional-order modeling: Analysis of foam drainage and Fisher's equations
- Thermo-solutal Marangoni convective Darcy-Forchheimer bio-hybrid nanofluid flow over a permeable disk with activation energy: Analysis of interfacial nanolayer thickness
- Investigation on topology-optimized compressor piston by metal additive manufacturing technique: Analytical and numeric computational modeling using finite element analysis in ANSYS
- Breast cancer segmentation using a hybrid AttendSeg architecture combined with a gravitational clustering optimization algorithm using mathematical modelling
- On the localized and periodic solutions to the time-fractional Klein-Gordan equations: Optimal additive function method and new iterative method
- 3D thin-film nanofluid flow with heat transfer on an inclined disc by using HWCM
- Numerical study of static pressure on the sonochemistry characteristics of the gas bubble under acoustic excitation
- Optimal auxiliary function method for analyzing nonlinear system of coupled Schrödinger–KdV equation with Caputo operator
- Analysis of magnetized micropolar fluid subjected to generalized heat-mass transfer theories
- Does the Mott problem extend to Geiger counters?
- Stability analysis, phase plane analysis, and isolated soliton solution to the LGH equation in mathematical physics
- Effects of Joule heating and reaction mechanisms on couple stress fluid flow with peristalsis in the presence of a porous material through an inclined channel
- Bayesian and E-Bayesian estimation based on constant-stress partially accelerated life testing for inverted Topp–Leone distribution
- Dynamical and physical characteristics of soliton solutions to the (2+1)-dimensional Konopelchenko–Dubrovsky system
- Study of fractional variable order COVID-19 environmental transformation model
- Sisko nanofluid flow through exponential stretching sheet with swimming of motile gyrotactic microorganisms: An application to nanoengineering
- Influence of the regularization scheme in the QCD phase diagram in the PNJL model
- Fixed-point theory and numerical analysis of an epidemic model with fractional calculus: Exploring dynamical behavior
- Computational analysis of reconstructing current and sag of three-phase overhead line based on the TMR sensor array
- Investigation of tripled sine-Gordon equation: Localized modes in multi-stacked long Josephson junctions
- High-sensitivity on-chip temperature sensor based on cascaded microring resonators
- Pathological study on uncertain numbers and proposed solutions for discrete fuzzy fractional order calculus
- Bifurcation, chaotic behavior, and traveling wave solution of stochastic coupled Konno–Oono equation with multiplicative noise in the Stratonovich sense
- Thermal radiation and heat generation on three-dimensional Casson fluid motion via porous stretching surface with variable thermal conductivity
- Numerical simulation and analysis of Airy's-type equation
- A homotopy perturbation method with Elzaki transformation for solving the fractional Biswas–Milovic model
- Heat transfer performance of magnetohydrodynamic multiphase nanofluid flow of Cu–Al2O3/H2O over a stretching cylinder
- ΛCDM and the principle of equivalence
- Axisymmetric stagnation-point flow of non-Newtonian nanomaterial and heat transport over a lubricated surface: Hybrid homotopy analysis method simulations
- HAM simulation for bioconvective magnetohydrodynamic flow of Walters-B fluid containing nanoparticles and microorganisms past a stretching sheet with velocity slip and convective conditions
- Coupled heat and mass transfer mathematical study for lubricated non-Newtonian nanomaterial conveying oblique stagnation point flow: A comparison of viscous and viscoelastic nanofluid model
- Power Topp–Leone exponential negative family of distributions with numerical illustrations to engineering and biological data
- Extracting solitary solutions of the nonlinear Kaup–Kupershmidt (KK) equation by analytical method
- A case study on the environmental and economic impact of photovoltaic systems in wastewater treatment plants
- Application of IoT network for marine wildlife surveillance
- Non-similar modeling and numerical simulations of microploar hybrid nanofluid adjacent to isothermal sphere
- Joint optimization of two-dimensional warranty period and maintenance strategy considering availability and cost constraints
- Numerical investigation of the flow characteristics involving dissipation and slip effects in a convectively nanofluid within a porous medium
- Spectral uncertainty analysis of grassland and its camouflage materials based on land-based hyperspectral images
- Application of low-altitude wind shear recognition algorithm and laser wind radar in aviation meteorological services
- Investigation of different structures of screw extruders on the flow in direct ink writing SiC slurry based on LBM
- Harmonic current suppression method of virtual DC motor based on fuzzy sliding mode
- Micropolar flow and heat transfer within a permeable channel using the successive linearization method
- Different lump k-soliton solutions to (2+1)-dimensional KdV system using Hirota binary Bell polynomials
- Investigation of nanomaterials in flow of non-Newtonian liquid toward a stretchable surface
- Weak beat frequency extraction method for photon Doppler signal with low signal-to-noise ratio
- Electrokinetic energy conversion of nanofluids in porous microtubes with Green’s function
- Examining the role of activation energy and convective boundary conditions in nanofluid behavior of Couette-Poiseuille flow
- Review Article
- Effects of stretching on phase transformation of PVDF and its copolymers: A review
- Special Issue on Transport phenomena and thermal analysis in micro/nano-scale structure surfaces - Part IV
- Prediction and monitoring model for farmland environmental system using soil sensor and neural network algorithm
- Special Issue on Advanced Topics on the Modelling and Assessment of Complicated Physical Phenomena - Part III
- Some standard and nonstandard finite difference schemes for a reaction–diffusion–chemotaxis model
- Special Issue on Advanced Energy Materials - Part II
- Rapid productivity prediction method for frac hits affected wells based on gas reservoir numerical simulation and probability method
- Special Issue on Novel Numerical and Analytical Techniques for Fractional Nonlinear Schrodinger Type - Part III
- Adomian decomposition method for solution of fourteenth order boundary value problems
- New soliton solutions of modified (3+1)-D Wazwaz–Benjamin–Bona–Mahony and (2+1)-D cubic Klein–Gordon equations using first integral method
- On traveling wave solutions to Manakov model with variable coefficients
- Rational approximation for solving Fredholm integro-differential equations by new algorithm
- Special Issue on Predicting pattern alterations in nature - Part I
- Modeling the monkeypox infection using the Mittag–Leffler kernel
- Spectral analysis of variable-order multi-terms fractional differential equations
- Special Issue on Nanomaterial utilization and structural optimization - Part I
- Heat treatment and tensile test of 3D-printed parts manufactured at different build orientations