Development of Innovative Fringe Locking Strategies for Vibration-Resistant White Light Vertical Scanning Interferometry (VSI)

2010 ◽  
Vol 437 ◽  
pp. 89-94 ◽  
Author(s):  
Liang Chia Chen ◽  
Abraham Mario Tapilouw ◽  
Sheng Lih Yeh ◽  
Shyh Tsong Lin ◽  
Jin Liang Chen ◽  
...  
Keyword(s):  
White Light ◽  
High Speed ◽  
Experimental Result ◽  
Band Pass Filter ◽  
Pass Filter ◽  
Nano Scale ◽  
Image Sensing ◽  
Vertical Range ◽  
Environmental Vibration ◽  
Vertical Scanning Interferometry

White light interferometry has become an important method for measuring micro surface profiles with a long vertical range and nano-scale resolution. However, environmental vibration encountered in in-field optical inspection is usually unavoidable and it affects measurement performance significantly. Isolating vibration sources from the measurement system sometimes is not completely effective, especially within complicated in-field fabrication environment. Therefore, in this research we aim to develop a novel method in achieving white-light fringe-locking condition during vertical scanning processes. The developed optical system consists of white light source, a Mirau objective, a PZT vertical scanner, an optical band-pass filter and two image sensing devices. The developed system generates a high and a low coherent interferograms, simultaneously captured by two charged coupled devices (CCDs). The high coherent interferogram is employed to detect high-speed nano-scale displacement and direction of the external vibration. An innovative real time fringe-locking operation is performed and a new vertical scanning technique is performed accordingly to isolate vertical scanning from environmental disturbances. The feasibility of the anti-vibration VSI system is verified by performing some of industrial in-field examples. Based on the experimental result, the fringe locking technique can improve the measurement result.

Imaging the Keyhole in PAW of Aluminum Alloys

1999 ◽  
Vol 121 (3) ◽  
pp. 372-377 ◽  
Author(s):  
B. Zheng ◽  
H. J. Wang ◽  
Q. L. Wang ◽  
R. Kovacevic
Keyword(s):  
Aluminum Alloys ◽  
Weld Pool ◽  
Image Sensor ◽  
Band Pass Filter ◽  
Concave Mirror ◽  
Pass Filter ◽  
Image Sensing ◽  
Bottom Width ◽  
Band Pass ◽  
Variable Polarity Plasma Arc

This paper presents a technique for front image sensing of the weld pool in variable polarity plasma arc welding of aluminum alloys, and describes the determination of the geometrical size of the keyhole for subsequent real-time feedback control of a full penetration weld. Image formation occurs when the arc light reflects off the concave mirror-like surface of the depressed keyhole weld pool, and passes through a band-pass filter onto the image sensor. The image of the visual keyhole (nominal keyhole) is a two-dimensional projected picture of the actual keyhole weld pool. The variation in area of the nominal keyhole is closely correlated with the variation of the bottom width of the weld bead.

scholarly journals Preparation of Nickel Nanoparticles by Direct Current Arc Discharge Method and Their Catalytic Application in Hybrid Na-Air Battery

Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 684 ◽  
Author(s):  
Fengmei Su ◽  
Xuechao Qiu ◽  
Feng Liang ◽  
Manabu Tanaka ◽  
Tao Qu ◽  
...  
Keyword(s):  
Direct Current ◽  
Composite Structures ◽  
High Speed ◽  
Large Scale ◽  
Nickel Nanoparticles ◽  
Arc Discharge ◽  
Band Pass Filter ◽  
Pass Filter ◽  
Air Battery ◽  
Discharge Method

Nickel nanoparticles were prepared by the arc discharge method. Argon and argon/hydrogen mixtures were used as plasma gas; the evaporation of anode material chiefly resulted in the formation of different arc-anode attachments at different hydrogen concentrations. The concentration of hydrogen was fixed at 0, 30, and 50 vol% in argon arc, corresponding to diffuse, multiple, and constricted arc-anode attachments, respectively, which were observed by using a high-speed camera. The images of the cathode and anode jets were observed with a suitable band-pass filter. The relationship between the area change of the cathode/anode jet and the synchronous voltage/current waveform was studied. By investigating diverse arc-anode attachments, the effect of hydrogen concentration on the features of nickel nanoparticles were investigated, finding that 50 vol% H2 concentration has high productivity, fine crystallinity, and appropriate size distribution. The synthesized nickel nanoparticles were then used as catalysts in a hybrid sodium–air battery. Compared with commercial a silver nanoparticle catalyst and carbon black, nickel nanoparticles have better electrocatalytic performance. The promising electrocatalytic activity of nickel nanoparticles can be ascribed to their good crystallinity, effective activation sites, and Ni/NiO composite structures. Nickel nanoparticles prepared by the direct current (DC) arc discharge method have the potential to be applied as catalysts on a large scale.

scholarly journals Novel Microstrip Band Pass Filter for C- Band Wireless Applications

2018 ◽  
Vol 7 (4.6) ◽  
pp. 227
Author(s):  
Dr. S. Sreenath Kashyap ◽  
Kantipudi MVV Prasad ◽  
Dr. Vipul M Dabhi
Keyword(s):  
Dielectric Substrate ◽  
Experimental Result ◽  
Impedance Method ◽  
Band Pass Filter ◽  
Electrical Parameters ◽  
Pass Filter ◽  
Band Frequency ◽  
Wireless Applications ◽  
Novel Approach ◽  
Band Pass

In this paper, a novel approach for designing the parallel coupled microstrip bandpass filter operating at C-band frequency is numerically analyzed iteratively and simulated. The physical dimensions are being finalized using standard odd- even impedance method. Various electrical parameters such as insertion loss, reflection loss are being analyzed and practical results are being compared and found same as the predicted results. The proposed design is fabricated on FR4 dielectric substrate and the experimental result shows the scientifically acceptable for C-band Applications.  

The Transceiver Circuit Design of Digital Ultrasonic System

2013 ◽  
Vol 834-836 ◽  
pp. 968-973
Author(s):  
Xiao Feng Zhang ◽  
Fo Chang Xie ◽  
Guo Wei Yang ◽  
Wei Zhang
Keyword(s):  
Circuit Design ◽  
High Voltage ◽  
High Speed ◽  
Power Input ◽  
High Gain ◽  
Low Noise ◽  
Band Pass Filter ◽  
Echo Signal ◽  
Pass Filter ◽  
Input Use

This paper introduces the design process of the digital ultrasonic transmission circuit: echo receiving circuit and the echo signal regulate circuit. Among them, outside 500 V DC - DC module for high voltage power input, use non-tuned type circuit design ultrasonic transmission circuit ; Select high voltage fast recovery diode FR107 design echo receiving limiter circuit; Using ultra-high speed, low noise, low distortion of the integrated operational amplifier MAX4104ESA design preamplifier circuits and the band-pass filter circuits; Using linear decibels, low noise, wide bandwidth, high gain accuracy amplifier AD603 design echo amplifying circuit. The experimental results indicate that the basic realization of the ultrasonic transceiver circuit and echo signal conditioning functions.

Active Damping Stabilization for High-Speed BLDCM Drive System Based on Band-Pass Filter

2017 ◽  
Vol 32 (7) ◽  
pp. 5438-5449 ◽  
Author(s):  
Xinda Song ◽  
Shiqiang Zheng ◽  
Bangcheng Han ◽  
Cong Peng ◽  
Xinxiu Zhou
Keyword(s):  
High Speed ◽  
Active Damping ◽  
Drive System ◽  
Band Pass Filter ◽  
Pass Filter ◽  
Band Pass

scholarly journals Design and Implementation of a Long Range Indoor VLC System using PWM

2019 ◽  
Vol 3 (1) ◽  
pp. 20-27 ◽  
Author(s):  
Majed Basha ◽  
Martin J. Sibley ◽  
Peter J. Mather
Keyword(s):  
High Speed ◽  
Pulse Width Modulation ◽  
Low Cost ◽  
Transmission Range ◽  
Band Pass Filter ◽  
Ambient Light ◽  
Visible Light Communications ◽  
Pass Filter ◽  
Light Interference ◽  
Front End

Visible Light Communications (VLC) is currently considered one of the most promising Optical Wireless Communications (OWC) for commercial applications, due to the widespread deployment of Light Emitting Diodes (LEDs) for energy efficiency, durability and low cost. With the ability to provide several THz of bandwidth, VLC is expected to co-exist with legacy and future Radio Frequency (RF) media as a reliable solution to the rapid demand of high-speed wireless communication. VLC is challenged by two main drawbacks: ambient light interference and the transmission range. To overcome these drawbacks, we propose a tuned VLC Analog Front-End (AFE) using simple and low-cost electronic circuity. The proposed VLC receiver architecture consists of a transimpedance amplifier, a fourth order Multiple Feed Back (MFB) band pass filter and a comparator. Experimental results demonstrated that by employing the proposed front-end the VLC transmission range could be extended up to 4.7 m by using Pulse Width Modulation (PWM). Moreover, the proposed system showed robustness against ambient light interference under the indoor scenario.

One Abstraction Method for Displacement Response in the Sweep-Frequency Testing of Rotating Spindle

2016 ◽  
Vol 693 ◽  
pp. 1377-1384
Author(s):  
Yu Zhu Guo ◽  
Tian Ning Chen ◽  
Xiao Peng Wang ◽  
Yan Fei Xu
Keyword(s):  
Frequency Domain ◽  
High Speed ◽  
Measured Signal ◽  
Band Pass Filter ◽  
Shape Error ◽  
Cnc Milling ◽  
Sweep Frequency ◽  
Pass Filter ◽  
Time Frequency ◽  
Displacement Response

ion Method for Displacement Response in the Sweep-Frequency Testing of Rotating Spindle Guo Yuzhu1,a*, Chen Tianning1,b, Wang Xiaopeng1,c and Xu Yanfei11 State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi’an Jiaotong University, 710049 Xi’an, China [email protected], [email protected], [email protected] Keywords: Rotating spindle; Sweep-frequency measurement; Error separation. Abstract. In the measurement of motorized spindle dynamic performance, the non-contact sweep-frequency excitation is adopted to obtain the displacement response of spindle rotor under high speed rotating. Due to the shape error at measurement section, eccentric error and random vibration, the illusory signals is introduced to the practical measured signal, which makes it difficult to analyze the displacement response. To effectively separate the error, a new method combining template signal and slip filtering is presented. After analyzing the characteristics of displacement response and illusory signals in time-frequency domain, the template signal constructed by the non-superposing portions between response and error is employed to eliminate the error in superposing portions. And a band-pass filter which can slip in time-frequency domain is employed to eliminate the other error. A spindle of CNC milling machine is tested at 7000 r/min, and the analysis result shows that the displacement response can be abstracted successfully from the original signal measured by rotating spindle.

scholarly journals Improve Temporal Fourier Transform Profilometry for Complex Dynamic Three-Dimensional Shape Measurement

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 1808
Author(s):  
Yihang Liu ◽  
Qican Zhang ◽  
Haihua Zhang ◽  
Zhoujie Wu ◽  
Wenjing Chen
Keyword(s):  
Fourier Transform ◽  
High Speed ◽  
Three Dimensional ◽  
Reference Plane ◽  
Shape Measurement ◽  
Band Pass Filter ◽  
Pass Filter ◽  
Fourier Transform Profilometry ◽  
Sharp Edges ◽  
Band Pass

The high-speed three-dimensional (3-D) shape measurement technique has become more and more popular recently, because of the strong demand for dynamic scene measurement. The single-shot nature of Fourier Transform Profilometry (FTP) makes it highly suitable for the 3-D shape measurement of dynamic scenes. However, due to the band-pass filter, FTP method has limitations for measuring objects with sharp edges, abrupt change or non-uniform reflectivity. In this paper, an improved Temporal Fourier Transform Profilometry (TFTP) algorithm combined with the 3-D phase unwrapping algorithm based on a reference plane is presented, and the measurement of one deformed fringe pattern producing a new 3-D shape of an isolated abrupt objects has been achieved. Improved TFTP method avoids band-pass filter in spatial domain and unwraps 3-D phase distribution along the temporal axis based on the reference plane. The high-frequency information of the measured object can be well preserved, and each pixel is processed separately. Experiments verify that our method can be well applied to a dynamic 3-D shape measurement with isolated, sharp edges or abrupt change. A high-speed and low-cost structured light pattern sequence projection has also been presented, it is capable of projection frequencies in the kHz level. Using the proposed 3-D shape measurement algorithm with the self-made mechanical projector, we demonstrated dynamic 3-D reconstruction with a rate of 297 Hz, which is mainly limited by the speed of the camera.

Voltage Waveform Control of Three-Phase PWM Inverter Based on the Output Harmonic Current Feed-Forward Compensation

2012 ◽  
Vol 229-231 ◽  
pp. 953-956
Author(s):  
Wang Tao ◽  
Amir M. Soomro ◽  
Xiao Zhong Liao
Keyword(s):  
Compensation Method ◽  
Experimental Result ◽  
Band Pass Filter ◽  
Harmonic Current ◽  
Nonlinear Load ◽  
Pass Filter ◽  
Feed Forward ◽  
Pwm Inverter ◽  
Three Phase ◽  
Control Scheme

A control scheme based on the load harmonic current feed-forward compensation for three-phase pulse width modulated (PWM) voltage source inverter is presented. This control scheme is designed to improve the quality of the three-phase inverter output voltage under nonlinear load. The model of the control system in the d-q coordinate system is established based on the traditional double loop control where the feed-forward current is taken from a band pass filter. In order to analyze this compensation method, the system is divided in to two subsystems and each subsystem is analyzed, and the structure of the output harmonic current feed-forward compensation channel is given. Simulation and experimental result validate that the proposed feed-forward compensation method has a good steady state performance and dynamic responses.

scholarly journals Real-Time Traffic Light Detection with Frequency Patterns Using a High-Speed Camera

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 4035 ◽  
Author(s):  
Kento Yabuuchi ◽  
Masahiro Hirano ◽  
Taku Senoo ◽  
Norimasa Kishi ◽  
Masatoshi Ishikawa
Keyword(s):  
Real Time ◽  
High Speed ◽  
Detection System ◽  
Band Pass Filter ◽  
High Speed Camera ◽  
Traffic Light ◽  
Pass Filter ◽  
Real Time Processing ◽  
Traffic Lights ◽  
Original Dataset

LEDs are widely employed as traffic lights. Because most LED traffic lights are driven by alternative power, they blink at high frequencies, even at twice their frequencies. We propose a method to detect a traffic light from images captured by a high-speed camera that can recognize a blinking traffic light. This technique is robust under various illuminations because it can detect traffic lights by extracting information from the blinking pixels at a specific frequency. The method is composed of six modules, which includes a band-pass filter and a Kalman filter. All the modules run simultaneously to achieve real-time processing and can run at 500 fps for images with a resolution of 800 × 600. This technique was verified on an original dataset captured by a high-speed camera under different illumination conditions such as a sunset or night scene. The recall and accuracy justify the generalization of the proposed detection system. In particular, it can detect traffic lights with a different appearance without tuning parameters and without datasets having to be learned.

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