scholarly journals A Parallel-Phase Demodulation-Based Distance-Measurement Method Using Dual-Frequency Modulation

2019 ◽  
Vol 10 (1) ◽  
pp. 293
Author(s):  
In-Gyu Jang ◽  
Sung-Hyun Lee ◽  
Yong-Hwa Park
Keyword(s):  
Frequency Modulation ◽  
Measurement Method ◽  
Continuous Wave ◽  
Measurement Range ◽  
Distance Measurement ◽  
Measurement Technology ◽  
Dual Frequency ◽  
Distance Measurements ◽  
Time Required ◽  
Phase Demodulation

Time-of-flight (ToF) measurement technology based on the amplitude-modulated continuous-wave (AMCW) model has emerged as a state-of-the-art distance-measurement method for various engineering applications. However, many of the ToF cameras employing the AMCW process phase demodulation sequentially, which requires time latency for a single distance measurement. This can result in significant distance errors, especially in non-static environments (e.g., robots and vehicles) such as those containing objects moving relatively to the sensors. To reduce the measurement time required for a distance measurement, this paper proposes a novel, parallel-phase demodulation method. The proposed method processes phase demodulation of signal in parallel rather than sequentially. Based on the parallel phase demodulation, 2π ambiguity problem is also solved in this work by adopting dual frequency modulation to increase the maximum range while maintaining the accuracy. The performance of proposed method was verified through distance measurements under various conditions. The improved distance measurement accuracy was demonstrated throughout an extended measurement range (1–10 m).

scholarly journals A Novel Three-Head Ultrasonic System for Distance Measurements Based on the Correlation Method

2014 ◽  
Vol 14 (6) ◽  
pp. 331-336 ◽  
Author(s):  
Krzysztof Gądek ◽  
Marek Dudzik ◽  
Anna Stręk
Keyword(s):  
Standard Deviation ◽  
Present Article ◽  
Experimental Research ◽  
Measurement Method ◽  
Correlation Method ◽  
Distance Measurement ◽  
Distance Measurements ◽  
Mechanical Interference ◽  
Measurement Signal

Abstract A novel double-emitter ultrasonic system for distance measurements based on the correlation method is presented. The proposed distance measurement method may be particularly useful in difficult conditions, e.g. for media parameters undergoing fast changes or in cases when obstacles and mechanical interference produce false reflections. The system is a development of a previously studied single-head idea. The present article covers a comparison of the two systems in terms of efficiency and precision. Experimental research described in this paper indicated that adding the second head improved the measurement exactness – standard deviation decreased by 40%. The correlation method is also described in detail, also giving the criterion for the quality of the measurement signal.

scholarly journals EXAMINATION METHOD OF THE EFFECT OF THE INCIDENCE ANGLE OF LASER BEAM ON DISTANCE MEASUREMENT ACCURACY TO SURFACES WITH DIFFERENT COLOUR AND ROUGHNESS

2016 ◽  
Vol 22 (3) ◽  
pp. 420-436 ◽  
Author(s):  
Karol Daliga ◽  
Zygmunt Kurałowicz
Keyword(s):  
Laser Beam ◽  
Measurement Method ◽  
Measurement Accuracy ◽  
Incidence Angle ◽  
Distance Measurement ◽  
Distance Measurements ◽  
Total Station ◽  
Examination Method ◽  
Critical Incidence ◽  
Reflective Foil

Interest in the influence of the incidence angle of a laser beam to distance measurements can be seen in many areas of science and technology: geodesy, glaciology, archaeology, machine automation, and others. This paper presents results of measurements of the effect of the incidence angle of a laser beam to distance measurements to the surfaces of different colour and roughness by Topcon's electro-optical total station with an accuracy of 3 mm. Measurement method and the method of elimination of test stand errors are presented. The results of measurements have been analysed and the influence of selected factors (surface colour and roughness, lack of instrument rectification) on the distance measurement have been discussed. It is also shown the critical incidence angle above which it can be impossible to measure distances to reflective foil with tested total station

scholarly journals RSHL: a Ranging and Speed Measurement Method by Jointing Hyperbolic Frequency Modulation and Linear Frequency Modulation

2021 ◽  
Author(s):  
Peng Liu ◽  
Caixia Song
Keyword(s):  
Frequency Band ◽  
Frequency Modulation ◽  
Pulse Width ◽  
Measurement Method ◽  
Distance Measurement ◽  
Linear Frequency Modulation ◽  
Matched Filtering ◽  
Linear Frequency ◽  
Speed Measurement ◽  
Ranging Error

Abstract In the waveform design, the distance measurement and resolution are a pair of irreconcilable contradictions. Linear Frequency Modulation (LFM) can alleviate this contradiction. LFM is widely used in radar and sonar, however, its Doppler tolerance is not ideal. Hyperbolic Frequency Modulation (HFM) signal has a particularly strong tolerance towards Doppler frequency shift. However, when the unidirectionally modulated HFM signal is in distance measurement, the Doppler delay of the matched filtering output cannot be eliminated, and there is a ranging error. After the echo signal of the combined HFM+LFM signal is matched filtering, the Doppler-induced delay is the same but opposite in direction, and the delay is closely related to the frequency, bandwidth, and pulse width of the transmitted signal. By using the combined signals, the ranging error in the ranging of single modulated HFM signal or LFM signal can be eliminated. In this paper, a Ranging and Speed measurement method by jointing Hyperbolic frequency modulation and Linear frequency modulation (RSHL) is proposed, which employs the same frequency band of positive and negative frequency modulation signals for speed measurement and ranging. In RSHL method, the signal parameters of the combined LFM+HFM signal can be set independently and no longer depend on each other. Therefore, the pulse width and frequency band in the combined LFM+HFM signal can be controlled independently, which can optimize the transmission signal form, reduce the operation cost, improve the measurement accuracy, and make full use of frequency band resources or pulse width resources.

scholarly journals Distance Measurement Errors in Silent Fm-Cw Sonar with Matched Filtering

2012 ◽  
Vol 19 (2) ◽  
pp. 321-332 ◽  
Author(s):  
Jacek Marszal ◽  
Roman Salamon
Keyword(s):  
Frequency Modulation ◽  
Measurement Errors ◽  
Distance Measurement ◽  
Matched Filtering ◽  
Good Resolution ◽  
Target Movement ◽  
Distance Measurements ◽  
Range Resolution ◽  
Continuous Frequency ◽  
Frequency Modulations

Distance Measurement Errors in Silent Fm-Cw Sonar with Matched Filtering The secretiveness of sonar operation can be achieved by using continuous frequency-modulated sounding signals with reduced power and significantly prolonged repeat time. The application of matched filtration in the sonar receiver provides optimal conditions for detection against the background of white noise and reverberation, and a very good resolution of distance measurements of motionless targets. The article shows that target movement causes large range measurement errors when linear and hyperbolic frequency modulations are used. The formulas for the calculation of these errors are given. It is shown that for signals with linear frequency modulation the range resolution and detection conditions deteriorate. The use of hyperbolic frequency modulation largely eliminates these adverse effects.

Distance Measurement Technique of Large Bandwidth Laser Frequency Modulated Continuous Wave Under Sinusoid Frequency Modulation

2018 ◽  
Vol 45 (12) ◽  
pp. 1201002
Author(s):  
史春钊 Shi Chunzhao ◽  
张福民 Zhang Fumin ◽  
潘浩 Pan Hao ◽  
李雅婷 Li Yating ◽  
曲兴华 Qu Xinghua
Keyword(s):  
Measurement Technique ◽  
Frequency Modulation ◽  
Continuous Wave ◽  
Laser Frequency ◽  
Distance Measurement ◽  
Large Bandwidth

Applications of radar measurement technology using 24 GHz, 61 GHz, 80 GHz and 122 GHz FMCW radar sensors

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Akanksha Bhutani ◽  
Sören Marahrens ◽  
Marius Kretschmann ◽  
Serdal Ayhan ◽  
Steffen Scherr ◽  
...  
Keyword(s):  
Measurement Accuracy ◽  
Continuous Wave ◽  
Estimation Method ◽  
Signal Propagation ◽  
Distance Measurement ◽  
Radar Signal ◽  
Measurement Technology ◽  
Fmcw Radar ◽  
Radar Sensors ◽  
24 Ghz

Abstract This paper presents a review of radar applications in high-accuracy distance measurement of a target. The radars included in this review are frequency modulated continuous wave (FMCW) radar sensors operating in four different millimeter-wave frequency bands, namely 24 GHz, 61 GHz, 80 GHz and 122 GHz. The radar sensors are used to measure the distance of standard and complex targets in a short range of a few meters, thus indicating that the choice of target and the medium used for radar signal propagation also play a key role in determining the distance measurement accuracy of an FMCW radar. The standard target is a trihedral corner reflector in a laboratory-based free space measurement setup and the complex targets include a piston in an oil-filled hydraulic cylinder and a planar positioning stage used in micromachining. In each of these measurement scenarios, a distance measurement accuracy in micrometer range is achieved due to the use of a sophisticated signal processing algorithm that is based on a combined frequency and phase estimation method. The paper is concluded with a technical comparison of the accuracy achieved by the FMCW radars reviewed in this article with other related works.

Acoustic Distance Measurement Method Using 2ch Microphones Measurable from 0m Based on Phase Interference and Removal of DC Component

2015 ◽  
Vol 135 (11) ◽  
pp. 1349-1350
Author(s):  
Kazuhiro Suzuki ◽  
Noboru Nakasako ◽  
Masato Nakayama ◽  
Toshihiro Shinohara ◽  
Tetsuji Uebo
Keyword(s):  
Measurement Method ◽  
Distance Measurement ◽  
Phase Interference ◽  
Dc Component
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