A Sonic Distance Measurement Approach Using Linear Frequency Modulated Signal

2013 ◽  
Vol 427-429 ◽  
pp. 2018-2021
Author(s):  
Ting Lan ◽  
Jian Jun Xie ◽  
Yang Bo Wu
Keyword(s):  
Measurement System ◽  
Measurement Range ◽  
Distance Measurement ◽  
Chirp Signal ◽  
Echo Signal ◽  
Linear Frequency ◽  
Alternative Approach ◽  
Correlation Result ◽  
Linear Frequency Modulated Signal ◽  
Measurement Approach

This paper deals with the development of an alternative approach for sonic distance measurement. A linear frequency modulated signal (chirp signal) is regarded as a template signal. The sonic distance measurement system transmits the template signal and receives the echo signal, then calculate the correlation between template and echo signal. The time of flight is determined according to the position of the peak in the correlation result, then the distance is calculated. The major advantage of this approach is that it can detect weak echo signals among noises and increase measurement range significantly.

A 60 GHz Six-Port Distance Measurement System With Sub-Millimeter Accuracy

2009 ◽  
Vol 19 (10) ◽  
pp. 644-646 ◽  
Author(s):  
K. Haddadi ◽  
M.M. Wang ◽  
D. Glay ◽  
T. Lasri
Keyword(s):  
Measurement System ◽  
Distance Measurement ◽  
60 Ghz

scholarly journals Validation of a new automated chemiluminescent anti-SARS-CoV-2 IgM and IgG antibody assay system detecting both N and S proteins in Japan

2020 ◽  
Author(s):  
RIn Yokoyama ◽  
Makoto Kurano ◽  
Yoshifumi Morita ◽  
Takuya Shimura ◽  
Yuki Nakano ◽  
...  
Keyword(s):  
Measurement System ◽  
False Positive ◽  
Laboratory Testing ◽  
Antibody Test ◽  
Measurement Range ◽  
Antibody Assay ◽  
Serum Samples ◽  
Igg Antibody ◽  
Antibody Titers ◽  
Pcr Test

PCR methods are presently the standard for the diagnosis of Coronavirus disease 2019 (COVID-19), but additional methodologies are needed to complement PCR methods, which have some limitations. Here, we validated and investigated the usefulness of measuring serum antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using the iFlash3000 CLIA analyzer. We measured IgM and IgG titers against SARS-CoV-2 in sera collected from 26 PCR-positive COVID-19 patients, 53 COVID-19-suspected but PCR-negative patients, and 20 and 100 randomly selected non-COVID-19 patients who visited our hospital in 2020 and 2017, respectively. The within-day and between-day precisions were regarded as good, since the coefficient variations were below 5%. Linearity was also considered good between 0.6 AU/mL and 112.7 AU/mL for SARS-CoV-2 IgM and between 3.2 AU/mL and 55.3 AU/mL for SARS-CoV-2 IgG, while the linearity curves plateaued above the upper measurement range. We also confirmed that the seroconversion and no-antibody titers were over the cutoff values in all 100 serum samples collected in 2017. These results indicate that this measurement system successfully detects SARS-CoV-2 IgM/IgG. We observed four false-positive cases in the IgM assay and no false-positive cases in the IgG assay when 111 serum samples known to contain autoantibodies were evaluated. The concordance rates of the antibody test with the PCR test were 98.1% for SARS-CoV-2 IgM and 100% for IgG among PCR-negative cases and 30.8% for SARS-CoV-2 IgM and 73.1% for SARS-CoV-2 IgG among PCR-positive cases. In conclusion, the performance of this measurement system is sufficient for use in laboratory testing.

All Polarization Maintaining Fiber Based Dual-Comb High Precision Absolute Distance Measurement System

2015 ◽  
Vol 35 (s2) ◽  
pp. s212001
Author(s):  
许立明 Xu Liming ◽  
宋有建 Song Youjian ◽  
梁飞 Liang Fei ◽  
师浩森 Shi Haosen ◽  
胡明列 Hu Minglie ◽  
...  
Keyword(s):  
High Precision ◽  
Measurement System ◽  
Distance Measurement ◽  
Absolute Distance ◽  
Polarization Maintaining Fiber ◽  
Polarization Maintaining

scholarly journals Gear Shape Parameter Measurement Using a Model-Based Scanning Multi-Distance Measurement Approach

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 3910
Author(s):  
Marc Pillarz ◽  
Axel von Freyberg ◽  
Andreas Fischer
Keyword(s):  
Shape Parameter ◽  
Spur Gear ◽  
Distance Measurement ◽  
Measuring Instruments ◽  
Single Digit ◽  
Promising Alternative ◽  
Model Based ◽  
Base Circle ◽  
The Mean ◽  
Measurement Approach

To reduce wind turbine failures by defective drive trains, deviations in the geometry of large gears (diameter ≳ 1 m) must be extensively determined with single-digit micrometer uncertainties. Fixed measuring volumes limit standard measuring methods like coordinate and gear measuring instruments for large gear measurements. Therefore, a model-based scanning multi-distance measurement approach for gear shape parameters is presented. The measurement approach has a scalable design and consists of a confocal-chromatic sensor, rotary table as a scanning unit and model-based signal processing. A preliminary study on a midsize spur gear demonstrates the general feasibility of the model-based scanning multi-distance measurement approach. As a result, the mean base circle radius as the fundamental gear shape parameter is determined with an uncertainty of <5 μm. The calibration and adjustment of the sensor arrangement were performed with a known calibration gear. Scalability is not experimentally validated in this article. However, simulations verify the scalability of the measurement approach in a first step. For gears with 1 m in diameter and varying tooth flank geometries, the estimated achievable uncertainty of the mean base circle radius is still <5 μm. Therefore, the model-based scanning multi-distance measurement approach is a promising alternative for gear inspection.

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).

Sign in / Sign up

Export Citation Format

Share Document