Experimental results for expanding the dynamic range of a Shack-Hartmann sensor using astigmatic microlenses

2002 ◽  
Vol 41 (2) ◽  
pp. 529 ◽  
Author(s):  
Norbert Lindlein
Keyword(s):  
Dynamic Range ◽  
Experimental Results

scholarly journals Universal Filter Based on Compact CMOS Structure of VDDDA

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1683
Author(s):  
Winai Jaikla ◽  
Fabian Khateb ◽  
Tomasz Kulej ◽  
Koson Pitaksuttayaprot
Keyword(s):  
Metal Oxide ◽  
Dynamic Range ◽  
Complementary Metal Oxide Semiconductor ◽  
Metal Oxide Semiconductor ◽  
Experimental Results ◽  
Oxide Semiconductor ◽  
Cmos Process ◽  
Voltage Gain ◽  
Universal Filter ◽  
Mos Transistor

This paper proposes the simulated and experimental results of a universal filter using the voltage differencing differential difference amplifier (VDDDA). Unlike the previous complementary metal oxide semiconductor (CMOS) structures of VDDDA that is present in the literature, the present one is compact and simple, owing to the employment of the multiple-input metal oxide semiconductor (MOS) transistor technique. The presented filter employs two VDDDAs, one resistor and two grounded capacitors, and it offers low-pass: LP, band-pass: BP, band-reject: BR, high-pass: HP and all-pass: AP responses with a unity passband voltage gain. The proposed universal voltage mode filter has high input impedances and low output impedance. The natural frequency and bandwidth are orthogonally controlled by using separated transconductance without affecting the passband voltage gain. For a BP filter, the root mean square (RMS) of the equivalent output noise is 46 µV, and the third intermodulation distortion (IMD3) is −49.5 dB for an input signal with a peak-to peak of 600 mV, which results in a dynamic range (DR) of 73.2 dB. The filter was designed and simulated in the Cadence environment using a 0.18-µm CMOS process from Taiwan semiconductor manufacturing company (TSMC). In addition, the experimental results were obtained by using the available commercial components LM13700 and AD830. The simulation results are in agreement with the experimental one that confirmed the advantages of the filter.

Tracking control of a flexible-link manipulator using neural networks: experimental results

Robotica ◽  
2002 ◽  
Vol 20 (4) ◽  
pp. 417-427 ◽  
Author(s):  
H.A. Talebi ◽  
K. Khorasani ◽  
R. V. Patel
Keyword(s):  
Neural Network ◽  
Tracking Control ◽  
Dynamic Range ◽  
Experimental Results ◽  
Flexible Manipulator ◽  
System Response ◽  
Position Tracking ◽  
Pd Controller ◽  
Flexible Link ◽  
Tracking Controller

In this paper, the problem of tip position tracking control of a flexible-link manipulator is considered. Two neural network schemes are presented. In the first scheme, the controller is composed of a stabilizing joint PD controller and a neural network tracking controller. The objective is to simultaneously achieve hub-position tracking and control of the elastic deflections at the tip. In the second scheme, tracking control of a point along the arm is considered to avoid difficulties associated with the output feedback control of a non-minimum phase flexible manipulator. A separate neural network is employed for determining an appropriate output to be used for feedback. The controller is also composed of a neural network tracking controller and a stabilizing joint PD controller. Experimental results on a single-link flexible manipulator show that the proposed networks result in significant improvements in the system response with an increase in controller dynamic range despite changes in the desired trajectory.

Development and Performance Test of a Micromachined Resonant Accelerometer

2004 ◽  
Vol 261-263 ◽  
pp. 1575-1580
Author(s):  
Tae Sam Kang ◽  
Sang Kyung Sung ◽  
Chul Hyun ◽  
Byeung Leul Lee ◽  
Jang Gyu Lee ◽  
...  
Keyword(s):  
Performance Test ◽  
Dynamic Range ◽  
Fabrication Process ◽  
Experimental Results ◽  
Experimental Result ◽  
Bias Stability ◽  
Bonding Area ◽  
And Performance ◽  
Resonant Accelerometer ◽  
Structural Layer

In this paper, presented are design, analysis, and experimental result of a tunable surface micromachined resonant accelerometer, ACRC-RXL. Also fabrication process of mechanical structure is illustrated. We used 40[μm] thick epitaxially grown polysilicon as structural layer and sealing area. With the exception of the CMP process, for smoothing the bonding area, the fabrication processes are simple as the conventional surface micromachining process. Experimental results show that the developed accelerometer has a performance of bias stability about 0.5mg and dynamic range over 10g.

Speech extraction with RGB-intensity gradient on rolling-shutter video

2021 ◽  
Vol 263 (5) ◽  
pp. 1095-1106
Author(s):  
Tsubasa Yoshizawa ◽  
Atsushi Yoshida ◽  
Kenta Iwai ◽  
Takanobu Nishiura
Keyword(s):  
Conventional Method ◽  
Extraction Method ◽  
Dynamic Range ◽  
Experimental Results ◽  
Sound Waves ◽  
Intensity Gradient ◽  
Equipment Cost ◽  
Single Lens ◽  
Phase Images ◽  
Speech Extraction

Recent studies have been proposed to extract speech from the captured video of objects vibrating by sound waves. Among them, from the viewpoint of equipment cost, the method of extracting speech from the video captured by rolling-shutter cameras, which are widely used in consumer digital single-lens reflex cameras, has been attracting attention. The conventional method with the rolling-shutter video uses a grayscale video for processing based on phase images. However, a grayscale video has a smaller dynamic range than an RGB video, and thus the speech extraction accuracy of the conventional method degrades. Therefore, this paper proposes a speech extraction method based on RGB-intensity gradients on an RGB video to improve speech extraction accuracy. The proposed method extracts the speech by calculating the similarity of R, G, and B intensity gradients, and using these three intensity gradients expands the dynamic range. The experimental results on the quality and intelligibility of the extracted speech show our proposed method outperforms the conventional method.

Application of Magnetic Garnet Films for Magnetooptical Imaging of Magnetic Field Distributions

2004 ◽  
Vol 834 ◽  
Author(s):  
H. Dötsch ◽  
C. Holthaus ◽  
A. Trifonov ◽  
M. Klank ◽  
O. Hagedorn ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Faraday Rotation ◽  
Dynamic Range ◽  
Uniaxial Anisotropy ◽  
High Sensitivity ◽  
Bias Field ◽  
Film Plane ◽  
Easy Plane ◽  
Experimental Results ◽  
Garnet Films

ABSTRACTRare-earth iron garnet films of high quality can be grown by liquid phase epitaxy on paramagnetic substrates of gadolinium galliumgarnet. Such films are currently used for imaging of the spatial distribution of magnetic fields. This application is based on the Faraday rotation which can strongly be enhanced by bismuth incorporation.The physical properties of the films can be controlled by the chemical composition, the growth conditions and the crystallographic orientation. The sensor properties like sensitivity, dynamic range, signal linearity and unambiguity must be optimized according to the application desired. These properties, however, are not independent of each other. In addition, they strongly depend on the optical wavelength. Thus, it is necessary to find compromises.The influence of Faraday rotation, Faraday ellipticity, optical absorption, magnetic anisotropies and film thickness on the performance of a magnetooptical indicator film is investigated. Based on the swing of the photoresponse, a new optimization process is introduced. The process is experimentally verified and application examples are demonstrated.Furthermore, two methods are presented to enhance the sensitivity of magnetooptical sensors. Using specific crystallographic orientations, an easy plane of magnetization can be induced which is inclined with respect to the film plane. If the magnetization lies in this plane a very high sensitivity is achieved. The dependence of the geometrical orientation of the easy plane on the growth direction is calculated and the sensitivity and dynamic range are derived. Experimental results of a [112] oriented garnet film are in good agreement with calculations.Garnet films which are magnetized along the film normal due to a strong induced uniaxial anisotropy support magnetic domains. If the collapse field perpendicular to the film plane is small, such films can be used as very sensitive indicator films. Such films are easier to prepare than sensitive in-plane films. However, the spatial resolution is limited by the size of the domains. This disadvantage can be avoided by applying a bias field in the film plane. Directly at the in-plane collapse field the sensor film is in-plane magnetized yielding high spatial resolution at still high sensitivity. The variation of magnetooptical images with in-plane induction is demonstrated. Experimental results are in agreement with calculations.

Hybrid Simulation of a Variable Transport Lag

SIMULATION ◽  
1969 ◽  
Vol 12 (2) ◽  
pp. 65-70
Author(s):  
R.N. Nilsen
Keyword(s):  
Time Delay ◽  
Execution Time ◽  
Digital Computer ◽  
Dynamic Range ◽  
Random Noise ◽  
Sampling Rate ◽  
Memory Capacity ◽  
Experimental Results ◽  
Variable Time Delay ◽  
Hybrid Solution

The object of this paper is to present a hybrid solution to the problem of simulating an ideal transport lag hav ing a variable time delay. The dynamic range over which the allowable time delay may be realized by this tech nique is limited on the low end by the sampling rate and execution time of the digital computer, and on the high end by the memory capacity of the digital computer. Experimental results using signals consisting of either sinusoidal waveforms or random noise are presented.

scholarly journals Lock-in amplifier with a high common-mode rejection ratio in the range of 0.02 to 100 kHz

ACTA IMEKO ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 103
Author(s):  
Pavel Baranov ◽  
Valeriy Borikov ◽  
Veronica Ivanova ◽  
Bien Bui Duc ◽  
Sergey Uchaikin ◽  
...  
Keyword(s):  
Metrological Characteristic ◽  
Dynamic Range ◽  
Experimental Results ◽  
Frequency Range ◽  
Common Mode ◽  
Common Mode Rejection Ratio ◽  
Differential Input ◽  
Rejection Ratio ◽  
Lock In

<span lang="EN-US">The paper presents a new lock-in amplifier with a differential input. The lock-in amplifier has a high common-mode rejection ratio of 200 dB at 1 kHz and 160 dB in the frequency range of 20 Hz to 100 kHz. A method for extending the dynamic range of comparing signals is suggested. The experimental results of metrological characteristic tests are discussed.</span>

scholarly journals SFCW Radar with an Integrated Static Target Echo Cancellation System

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5829
Author(s):  
Danijel Šipoš ◽  
Dušan Gleich
Keyword(s):  
Continuous Wave ◽  
Dynamic Range ◽  
Automatic Gain Control ◽  
High Energy ◽  
Integrated System ◽  
Experimental Results ◽  
Echo Cancellation ◽  
Stationary Target ◽  
Minimal Impact ◽  
Static Target

Continuous Wave (CW) radars systems, especially air-coupled Ground-Penetrating Radar (GPR) or Through-Wall Imaging Radar (TWIR) systems, echo signals reflected from a stationary target with high energy, which may cause receiver saturation. Another effect caused by reflection of stationary targets is noticeable as background within a radargram. Nowadays, radar systems use automatic gain control to prevent receiver saturation. This paper proposes a method to remove stationary targets automatically from the received signal. The method was designed for a radar system with a moving platform, with an assumption that the distance between the surface and target is constant. The design is proposed of an SFCW radar with an integrated system for real-time multiple static target Echo Cancellation (EC). The proposed EC system removes the static target using active Integrated Circuit (IC) components, which generate the corresponding EC signal for each frequency step of the SFCW radar and sum it with the received echo signal. This has the main advantage of removing even multiple echoes at any distance, and excludes the need for a high-dynamic-range receiver. Additionally, the proposed system has minimal impact on the radar size and power consumption. Besides static target removal, the antenna coupling can be removed if the signal appears to be constant. The operating frequency was selected between 500 MHz and 2.5 GHz, due to the limitation of the used electronic components. The experimental results show that the simulated target’s echo using a cable with a known length could be suppressed to up to 38 dB. Experimental results using a moving radar platform and the real environment scenario with static and dynamic targets, show that the proposed EC system could achieve up to 20 dB attenuation of the static target. The system does not affect any other target of interest, which can even move at any distance during the measurement. Therefore, this could be a promising method for further compact implementation into SFCW radars, or any other radar type that generates CW single frequencies.

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