On the Autonomous Gain and Phase Tailoring Transfer Functions of Symmetrically Distributed Piezoelectric Sensors

A new design concept for a distributed sensor, which was developed based on the principle that the strain distribution of an arbitrary finite plate structure can be expressed as the superposition of even and odd strain functions, is presented. The distributed sensors adopt a symmetric weighting electrode to match the symmetric distribution of the even parts of the strain in order to introduce a no-phase delay low-pass filter to tailor the sensor transfer function. Both the design concept and the experimental results are detailed herein.

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Disturbance Elimination of Buck-Converter with Resonant LPF via ILQ Servo-System

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.492.493 ◽

2014 ◽

Vol 492 ◽

pp. 493-498

Author(s):

Shuhei Shiina ◽

Sidshchadhaa Aumted ◽

Hiroshi Takami

Keyword(s):

Transfer Functions ◽

Design Method ◽

Servo System ◽

State Equation ◽

Buck Converter ◽

Linear Quadratic ◽

Pass Filter ◽

Low Pass Filter ◽

Low Pass ◽

The Stability

The proposed optimal control on the basis of both current and voltage of the buck-converter is designed to be based on Inverse Linear Quadratic (ILQ) design method with the resonant low pass filter, which eliminates the disturbance by appended disturbance compensator. The designed scheme is composed of the state equation, an optimal ILQ solution, the ILQ servo-system with the disturbance elimination, the optimal basic gain, the optimal condition, the transfer functions and the disturbance compensator. Our results show the proposed strategy is the stability and robust control and has been made to improve ILQ control for the disturbance elimination of the output response, which guarantees the optimal gains on the basis of polynomial pole assignment.

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The Design of Ideal Positioning Servo System

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.816.132 ◽

2015 ◽

Vol 816 ◽

pp. 132-139

Author(s):

Ľubica Miková ◽

Alexander Gmiterko ◽

Michal Kelemen

Keyword(s):

Frequency Characteristic ◽

Pid Controller ◽

Transfer Functions ◽

Servo System ◽

Second Order ◽

Pass Filter ◽

Low Pass Filter ◽

Low Pass ◽

Degree Of Stability

The paper deals with the design of an ideal positioning servo system. To achieve this aim, we will derive transfer functions of the PID controller and the second-order low-pass filter while using typical fault frequencies for PID controller with a low pass filter. Consequently, an overall frequency characteristic of the open servo system will be depicted. This characteristic will be further used to determine the amplitude and phase safety, which determine the degree of stability system.

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Band-Stop Filter Algorithm Research Based on Nano-Displacement Positioning System

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.380-384.697 ◽

2013 ◽

Vol 380-384 ◽

pp. 697-700 ◽

Cited By ~ 1

Author(s):

Yue Zhou ◽

Xiao Xiao Yao ◽

Jin Xiang Pian ◽

Yan Qiang Su

Keyword(s):

Transfer Functions ◽

Experimental Simulation ◽

Infinite Impulse Response ◽

Positioning System ◽

Pass Filter ◽

Low Pass Filter ◽

Control Precision ◽

Band Stop Filter ◽

Low Pass ◽

Inherent Frequency

This paper proposed the algorithms of infinite impulse response (IIR) band-stop filter and all-pass filter to eliminate the inherent frequency for piezoelectric ceramics and improve the control precision for nanodisplacement positioning system. The IIR algorithm was composed of five steps (such as the determination of normalized frequency, filter orders and transfer functions of analog low-pass filter, analog band-stop filter and digital band-stop filter). Based on the experimental simulation results on the nanodisplacement positioning platform, the butterworth band-stop filter algorithm can achieve the requested filtering effects within 10 orders .

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Transfer function analysis of vagal control of heart rate during synchronized vagal stimulation

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1995.269.6.h1931 ◽

1995 ◽

Vol 269 (6) ◽

pp. H1931-H1940 ◽

Cited By ~ 6

Author(s):

A. Mokrane ◽

A. R. LeBlanc ◽

R. Nadeau

Keyword(s):

Heart Rate ◽

Transfer Functions ◽

Vagal Stimulation ◽

Sinus Node ◽

Time Interval ◽

Pass Filter ◽

Dynamic Component ◽

Low Pass Filter ◽

Transfer Function Analysis ◽

Low Pass

Synchronized electrical stimulation was used to study the heart rate (HR) response to fluctuations in parasympathetic input to the sinus node in anesthetized dogs. This was obtained by varying the time interval (interpulse interval) between stimulatory vagal pulses. Spectral methods were used to estimate transfer functions between the excitatory signal and the resulting HR response for different intensities of vagal stimulation. The intensity of vagal stimulation was proportional to the number of pulses delivered in each cardiac cycle. From the estimated transfer functions, and based on a mathematical model of the time course of ACh concentration at the sinus node, filter models were derived by using a system identification approach. HR response was characterized by a combination of two different filter behaviors: a low-pass filter behavior of mean cut-off frequency of 0.065 Hz and an all-pass filter behavior. The magnitude of the low-pass filter gain decreased with increasing intensity of vagal stimulation. The magnitude of the all-pass filter gain increased and then decreased with increasing intensity of vagal stimulation. The all-pass filter characteristics of HR response during synchronized stimulation of the vagus nerves are specific to this mode of stimulation, because they were not observed in nonsynchronized modes of vagal stimulation. We can conclude that, during synchronized vagal stimulation, the HR response exhibits both a slow dynamic component and a fast component related to beat-to-beat variations.

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Temporal Modulation Transfer Functions in Cat Primary Auditory Cortex: Separating Stimulus Effects From Neural Mechanisms

Journal of Neurophysiology ◽

10.1152/jn.00490.2001 ◽

2002 ◽

Vol 87 (1) ◽

pp. 305-321 ◽

Cited By ~ 72

Author(s):

Jos J. Eggermont

Keyword(s):

Auditory Cortex ◽

Cortical Neurons ◽

Transfer Functions ◽

Frequency Tuning ◽

Primary Auditory Cortex ◽

Modulation Transfer ◽

Temporal Modulation ◽

Pass Filter ◽

Low Pass Filter ◽

Low Pass

We present here a comparison between the local field potentials (LFP) and multiunit (MU) responses, comprising 401 single units, in primary auditory cortex (AI) of 31 cats to periodic click trains, gamma-tone and time-reversed gamma-tone trains, AM noise, AM tones, and frequency-modulated (FM) tones. In a large number of cases, the response to all six stimuli was obtained for the same neurons. We investigate whether cortical neurons are likely to respond to all types of repetitive transients and modulated stimuli and whether a dependence on modulating waveform, or tone or noise carrier, exists. In 97% of the recordings, a temporal modulation transfer function (tMTF) for MU activity was obtained for gamma-tone trains, in 92% for periodic click trains, in 83% for time-reversed gamma-tone trains, in 82% for AM noise, in 71% for FM tones, and only in 53% for AM tones. In 31% of the cases, the units responded to all six stimuli in an envelope-following way. These particular units had significantly larger onset responses to each stimulus compared with all other units. The overall response distribution shows the preference of AI units for stimuli with short rise times such as clicks and gamma tones. It also shows a clear asymmetry in the ability to respond to AM noise and AM tones and points to a strong effect of the frequency content of the carrier on the subcortical processing of AM stimuli. Yet all temporal response properties were independent of characteristic frequency and frequency-tuning curve bandwidth. We show that the observed differences in the tMTFs for different stimuli are to a large extent produced by the different degree of phase locking of the neuronal firings to the envelope of the first stimulus in the train or first modulation period. A normalization procedure, based on these synchronization differences, unified the tMTFs for all stimuli except clicks and allowed the identification of a largely stimulus-invariant, low-pass temporal filter function that most likely reflects the properties of synaptic depression and facilitation. For nonclick stimuli, the low-pass filter has a cutoff frequency of ∼10 Hz and a slope of ∼6 dB/octave. For nonclick stimuli, there was a systematic difference between the vector strength for LFPs and MU activity that can likely be attributed to postactivation suppression mechanisms.

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DVCC based (2+α) order low pass Bessel filter using optimization techniques

10.21203/rs.3.rs-362512/v1 ◽

2021 ◽

Author(s):

Ashu Soni ◽

Maneesha Gupta

Keyword(s):

Transfer Functions ◽

Search Algorithm ◽

Optimization Technique ◽

Optimization Techniques ◽

Least Square ◽

Current Conveyors ◽

Circuit Realization ◽

Pass Filter ◽

Low Pass Filter ◽

Low Pass

Abstract This paper proposes the design and analysis of (2+α) order low pass Bessel filter using different optimization techniques. The coefficients of the proposed filter are found out by minimizing the error between transfer functions of (2+α) order low pass filter and third-order Bessel approximation using simulated annealing (SA), interior search algorithm (ISA), and nonlinear least square (NLS) optimization techniques. The best optimization technique based on the error in gain, cut off frequency, roll-off, passband, stopband, and phase is chosen for designing the proposed filter. The stability analysis of the proposed filter has also been done in W-plane. The simulated responses of the best optimized proposed filter are obtained using the FOMCON toolbox of MATLAB and SPICE. The circuit realization of 2.5 order low pass Bessel filter is done using two DVCCs (differential voltage current conveyors), one generalized impedance converter (GIC) based inductor, and one fractional capacitor. The proposed filter is implemented for the cut off frequency of 10 kHz using a wideband fractional capacitor. Monte Carlo noise analyses are also performed for the proposed filter. The MATLAB and SPICE results are shown in good agreement.

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The spatiotemporal transfer function of crayfish lamina monopolar neurons

Journal of Neurophysiology ◽

10.1152/jn.1994.71.6.2168 ◽

1994 ◽

Vol 71 (6) ◽

pp. 2168-2182 ◽

Cited By ~ 10

Author(s):

R. M. Glantz ◽

A. Bartels

Keyword(s):

Time Course ◽

Transfer Functions ◽

Temporal Frequency ◽

Sine Wave ◽

Orientation Preference ◽

Pass Filter ◽

Low Pass Filter ◽

Low Pass ◽

Band Pass ◽

Sensitivity Profile

1. The graded, synaptic potentials of first-order visual interneurons (lamina monopolar cells) were examined with intracellular recordings. The spatiotemporal properties were characterized with drifting sine wave gratings and annuli. 2. Annulus-elicited inhibition is maximal for annulus-test pulse intervals of approximately 140 ms and declines exponentially. The inhibition declines with increasing annular internal radii (ri). 3. Grating responses were examined with respect to spatial and temporal frequency. The gratings elicit sinusoidal signals that are approximately linear with contrast. 4. Variations in spatial frequency produce response functions with a low-pass or modest band-pass characteristic, which are described by a difference of Gaussians sensitivity profile. The central Gaussian approximates the sensitivity profile of photoreceptors. The inhibitory Gaussian is similar to the inhibitory field estimated with annulus pulses. The peak of the inhibitory Gaussian is approximately 18% of the peak excitatory Gaussian. 5. Variations in temporal frequency generally produce transfer functions with a band-pass characteristic and a peak at 1.0 Hz. These data were described by a difference of exponentials function convolved with a low-pass filter that approximates the photoreceptor response. The inhibitory time course estimated from these data was similar to that of the annulus measurements. 6. The spatiotemporal properties of lateral inhibition are consistent with inhibitory action by the lamina amacrine neurons. The proposed model is spatiotemporally inseparable and nonrecurrent. 7. Eleven of 20 monopolar cells tested exhibited a strong orientation preference with a bias to the vertical. Photoreceptors exhibit little or no orientation preference.

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GRAVIMETER FILTERS

Geophysics ◽

10.1190/1.1440066 ◽

1969 ◽

Vol 34 (6) ◽

pp. 968-973 ◽

Cited By ~ 2

Author(s):

George F. Floyd

Keyword(s):

Optimization Problem ◽

Transfer Functions ◽

Tracking Errors ◽

Pass Filter ◽

Low Pass Filter ◽

Signal Tracking ◽

Signal Error ◽

Gravity Measurements ◽

Low Pass ◽

Error Constraint

In order to obtain accurate gravity measurements from ships or aircraft, it is necessary to remove the “noise” effects of platform accelerations by filtering. At the same time, the filter must track the changing gravitational field, the “signal,” or signal errors will result. Thus, there is the optimization problem of designing filters which maximize noise reduction without introducing signal tracking errors. The best class of filters for this purpose is defined in terms of what is called a zero signal‐error constraint, which specifies that the filter must track any parabolic input with no error except a known time delay. Since the noise to be eliminated is such that a low‐pass filter is required, study of the transfer functions was restricted to that type filter in light of this constraint. It was found that only the Butterworth filter with n⩾2 is satisfactory. The problem of physical realization of an optimum filter was investigated by setting appropriate constraints on attenuation at the cut‐off frequency and the envelope at the impulse response.

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