An Improved Vision Method for Robust Monitoring of Multi-Point Dynamic Displacements with Smartphones in an Interference Environment

Current research on dynamic displacement measurement based on computer vision mostly requires professional high-speed cameras and an ideal shooting environment to ensure the performance and accuracy of the analysis. However, the high cost of the camera and strict requirements of sharp image contrast and stable environment during the shooting process limit the broad application of the technology. This paper proposes an improved vision method to implement multi-point dynamic displacement measurements with smartphones in an interference environment. A motion-enhanced spatio-temporal context (MSTC) algorithm is developed and applied together with the optical flow (OF) algorithm to realize a simultaneous tracking and dynamic displacement extraction of multiple points on a vibrating structure in the interference environment. Finally, a sine-sweep vibration experiment on a cantilever sphere model is presented to validate the feasibility of the proposed method in a wide-band frequency range. In the test, a smartphone was used to shoot the vibration process of the sine-sweep-excited sphere, and illumination change, fog interference, and camera jitter were artificially simulated to represent the interference environment. The results of the proposed method are compared to conventional displacement sensor data and current vision method results. It is demonstrated that, in an interference environment, (1) the OF method is prone to mismatch the feature points and leads to data deviated or lost; (2) the conventional STC method is sensitive to target selection and can effectively track those targets having a large proportion of pixels in the context with motion tendency similar to the target center; (3) the proposed MSTC method, however, can ease the sensitivity to target selection through in-depth processing of the information in the context and finally enhance the robustness of the target tracking. In addition, the MSTC method takes less than one second to track each target between adjacent frame images, implying a potential for online measurement.

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Wide band frequency and in situ characterization of high permittivity insulators (high-k) for high-speed integrated passives

Microelectronic Engineering ◽

10.1016/j.mee.2005.07.054 ◽

2005 ◽

Vol 82 (3-4) ◽

pp. 548-553 ◽

Cited By ~ 3

Author(s):

T. Lacrevaz ◽

B. Fléchet ◽

A. Farcy ◽

J. Torres ◽

M. Gros-Jean ◽

...

Keyword(s):

High Speed ◽

Wide Band ◽

In Situ Characterization ◽

High Permittivity ◽

Band Frequency ◽

Integrated Passives ◽

High K

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A Robust Vision-Based Method for Displacement Measurement under Adverse Environmental Factors Using Spatio-Temporal Context Learning and Taylor Approximation

Sensors ◽

10.3390/s19143197 ◽

2019 ◽

Vol 19 (14) ◽

pp. 3197 ◽

Cited By ~ 7

Author(s):

Chuan-Zhi Dong ◽

Ozan Celik ◽

F. Necati Catbas ◽

Eugene OBrien ◽

Su Taylor

Keyword(s):

Displacement Measurement ◽

Sensor Data ◽

Displacement Sensor ◽

Illumination Change ◽

Context Learning ◽

Illumination Changes ◽

Measurement Results ◽

Resolution Imaging ◽

Series Of Experiments ◽

Spatio Temporal

Currently, the majority of studies on vision-based measurement have been conducted under ideal environments so that an adequate measurement performance and accuracy is ensured. However, vision-based systems may face some adverse influencing factors such as illumination change and fog interference, which can affect measurement accuracy. This paper developed a robust vision-based displacement measurement method which can handle the two common and important adverse factors given above and achieve sensitivity at the subpixel level. The proposed method leverages the advantage of high-resolution imaging incorporating spatial and temporal contextual aspects. To validate the feasibility, stability, and robustness of the proposed method, a series of experiments was conducted on a two-span three-lane bridge in the laboratory. The illumination changes and fog interference were simulated experimentally in the laboratory. The results of the proposed method were compared to conventional displacement sensor data and current vision-based method results. It was demonstrated that the proposed method gave better measurement results than the current ones under illumination change and fog interference.

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A Robust Vision-based Method for Displacement Measurement under Adverse Environmental Factors using Spatio-Temporal Context Learning and Taylor Approximation

10.20944/preprints201906.0023.v1 ◽

2019 ◽

Cited By ~ 1

Author(s):

Chuan-zhi Dong ◽

Ozan Celik ◽

Fikret Catbas ◽

Eugene OBrien ◽

Su Taylor

Keyword(s):

Displacement Measurement ◽

Sensor Data ◽

Displacement Sensor ◽

Temporal Context ◽

Illumination Change ◽

Context Learning ◽

Measurement Results ◽

Resolution Imaging ◽

Series Of Experiments ◽

Spatio Temporal

Currently the majority of studies on vision-based measurement has been conducted under ideal environments so that an adequate measurement performance and accuracy is ensured. However, vision-based systems may face some adverse influencing factors such as illumination change and fog interference, which can affect the measurement accuracy. This paper develops a robust vision-based displacement measurement method which can handle the two common and important adverse factors given above and achieve sensitivity at the subpixel level. The proposed method leverages the advantage of high-resolution imaging incorporating spatial and temporal context aspects. To validate the feasibility, stability and robustness of the proposed method, a series of experiments was conducted on a two-span three-lane bridge in the laboratory. The illumination change and fog interference are simulated experimentally in the laboratory. The results of the proposed method are compared to conventional displacement sensor data and current vision-based method results. It is demonstrated that the proposed method gives better measurement results than the current ones under illumination change and fog interference.

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DC feedback for wide band frequency fixed current source

Journal of Electrical Bioimpedance ◽

10.5617/jeb.294 ◽

2019 ◽

Vol 4 (1) ◽

pp. 33-37 ◽

Cited By ~ 1

Author(s):

Aoday H. Al-Rawi ◽

W. M. A. Ibrahim ◽

Eraj Humayun Mirza

Keyword(s):

High Speed ◽

Current Source ◽

Bioelectrical Impedance ◽

Wide Band ◽

Impedance Analysis ◽

Input Voltage ◽

Blood Analysis ◽

Composition Analysis ◽

Current Feedback ◽

Band Frequency

Abstract Alternating current sources are mainly used in bioelectrical impedance devices. Nowadays 50 – 100 kHz bioelectrical impedance devices are commonly used for body composition analysis. High frequency bioelectrical impedance analysis devices are mostly used in bioimpedance tomography and blood analysis. High speed op-amps and voltage comparators are used in this circuit. Direct current feedback is used to prevent delay. An N-Channel J-FET transistor was used to establish the voltage controlled gain amplifier (VCG). A sine wave signal has been applied as input voltage. The value of this signal should be constant in 170 mV rms to keep the output current in about 1 mA rms. Four frequencies; 100 kHz, 1 MHz, 2 MHz and 3.2 MHz were applied to the circuit and the current was measured for different load resistances. The results showed that the current was stable for changes in the resistor load, bouncing around an average point as a result of bouncing DC feedback.

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Three-Dimensional Spatio-Temporal Disturbance Flow Field Analysis of Particulate-Induced High-Speed Boundary-Layer Transition

AIAA Scitech 2021 Forum ◽

10.2514/6.2021-1657 ◽

2021 ◽

Author(s):

Sayed Mohammad Abdullah Al Hasnine ◽

Vincenzo Russo ◽

Anatoli Tumin ◽

Christoph Brehm

Keyword(s):

Boundary Layer ◽

Flow Field ◽

High Speed ◽

Three Dimensional ◽

Boundary Layer Transition ◽

Field Analysis ◽

Layer Transition ◽

Flow Field Analysis ◽

Spatio Temporal

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Wide-Band Input Buffer with Optimized Linearity For High-Speed High-Resolution ADCs

2020 IEEE 14th International Conference on Anti-counterfeiting, Security, and Identification (ASID) ◽

10.1109/asid50160.2020.9271786 ◽

2020 ◽

Author(s):

Ting Li ◽

Yong Zhang ◽

Yabo Ni ◽

Xingfa Huang

Keyword(s):

High Resolution ◽

High Speed ◽

Wide Band ◽

Input Buffer

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Design of a Compact Ultra Wide Band Frequency Selective Surfaces as a Reflector for Satellite Platforms

2019 9th International Conference on Recent Advances in Space Technologies (RAST) ◽

10.1109/rast.2019.8767873 ◽

2019 ◽

Author(s):

Emre Hanbay ◽

Fatih Goksel

Keyword(s):

Wide Band ◽

Ultra Wide Band ◽

Frequency Selective Surfaces ◽

Band Frequency ◽

Frequency Selective

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Based on FPGA Intelligent Physiological Parameters Acquisition

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.344.107 ◽

2013 ◽

Vol 344 ◽

pp. 107-110

Author(s):

Shun Ren Hu ◽

Ya Chen Gan ◽

Ming Bao ◽

Jing Wei Wang

Keyword(s):

High Speed ◽

Low Cost ◽

Physiological Parameters ◽

Sensor Data ◽

Low Power Consumption ◽

Physiological Signal ◽

Pulse Sensor ◽

Monitoring Applications ◽

Field Programmable ◽

Design Ideas

For the physiological signal monitoring applications, as a micro-controller based on field programmable gate array (FPGA) physiological parameters intelligent acquisition system is given, which has the advantages of low cost, high speed, low power consumption. FPGA is responsible for the completion of pulse sensor, the temperature sensor, acceleration sensor data acquisition and serial output and so on. Focuses on the design ideas and architecture of the various subsystems of the whole system, gives the internal FPGA circuit diagram of the entire system. The whole system is easy to implement and has a very good promotional value.

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