scholarly journals Dynamic Properties of Orientation to a Visually Fixated Target by Walking Colorado Beetles

1991 ◽  
Vol 158 (1) ◽  
pp. 149-164 ◽  
Author(s):  
ULRICH LÖNNENDONKER
Keyword(s):  
Time Course ◽  
Closed Loop ◽  
Dynamic Properties ◽  
Visual Orientation ◽  
Optomotor Response ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Density Peaks ◽  
Low Pass ◽  
Fixation Reaction

The dynamic components of the fixation behaviour of walking Colorado beetles were examined. The beetles walked on top of a locomotion compensator under closed-loop conditions. The fixation target was a yellow disk with small black stripes (‘Colorado dummy’). The paths of beetles walking towards the stationary dummy were characterized by oscillations, and were investigated by applying a fast Fourier transform to the turning-velocity time course. The power density peaks near 0.3 Hz with varying amplitude. Films of the fixation reaction revealed that this frequency was much slower than the stepping-pattern frequency of the beetles. During orientation to other stimuli (wind or gravity), the oscillations were not present, showing that they were not an artefact of the motor output. However, they were present in other forms of visual orientation, such as the optomotor response and during positive phototaxis. A frequency-response curve (Bode diagram) under closed-loop conditions was obtained for the fixation reaction by changing the dummy position sinusoidally and measuring the phase and amplitude of the tracking response. A simple model of this behaviour, including a low-pass filter and an integrator, describes the reaction. Hence, the reaction can be understood as the simple resonance behaviour of an underdamped closed-position loop. The question of whether this can explain zigzagging paths in other species is discussed. Note: Present address: Universität Kaiserslautern, FB Biologie, Abteilung Allgemeine Zoologie, D-6750 Kaiserslautern, Germany.

Processing Load Signal on Wheel Loader Transmission

2011 ◽  
Vol 383-390 ◽  
pp. 4482-4485
Author(s):  
Li Sun ◽  
Yong Chen Liu
Keyword(s):  
Time Course ◽  
Load Spectrum ◽  
Processing Load ◽  
Random Load ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Wheel Loader ◽  
Virtual Test ◽  
Low Pass ◽  
Filter Frequency

To determine fatigue life of Loader transmission and to analyze machine power for different user, the torque loads of wheel loader transmission are tested and calibrated with the method of four sections per cycle. The disturbed signals are filtered by low-passed filter, and anomalous spikes are eliminated with the NSOFT. And contrastively analyzes the disposal effect of signal, then acquires pure random load-time course. It concludes that one Hz of the low-pass filter frequency is suitable, and the test signal is in line with the actual work of Loader. These provide the base for getting load spectrum and virtual test on wheel loader transmission.

The Design of the Single-Phase Inverter Based on DSP (TMS320F2812)

2014 ◽  
Vol 989-994 ◽  
pp. 3231-3235
Author(s):  
Zhao Xia Zhou ◽  
Jia En Huang
Keyword(s):  
Single Phase ◽  
Closed Loop ◽  
Optical Coupling ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Filter Output ◽  
Low Pass ◽  
Loop Feedback ◽  
Closed Loop Feedback ◽  
Single Phase Inverter

This paper designs a single-phase inverter.Battery as a 12V DC input, and output for the 24V,50 HZ standard AC wave. The load is resistive.The power supply adopts the Boost booster and two full-bridge inverter transform. For the control circuit, the preceding Boost converter using tl494 chip control closed-loop feedback and for the inverter part, adopting the 6N137 to finish the optical coupling isolation.Then,through the DSP (TMS320F2812) to complete the output of SPWM modulation.And the modulated SPWM signal can drive chip IR211 conducting the full bridge inverter. Finally, through a low-pass filter output the standard sine AC inverter power.

Decentralized Vibration and Shape Control of Structures With Colocated Sensors and Actuators

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
A. H. Ghasemi ◽  
Jesse B. Hoagg ◽  
T. M. Seigler
Keyword(s):  
Shape Control ◽  
Closed Loop ◽  
Controller Design ◽  
Cutoff Frequency ◽  
Sensors And Actuators ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Unknown Disturbances ◽  
Low Pass ◽  
Model Parameter Uncertainty

This paper introduces a decentralized shape and vibration controller for structures with large and potentially unknown system order, model-parameter uncertainty, and unknown disturbances. Controller implementation utilizes distributed, colocated, and independent actuator–sensor pairs. Controller design requires knowledge of the relative degrees of the actuator and sensor dynamics and upper bounds on the diagonal elements of system's high-frequency gain matrix. Closed-loop performance is determined by a parameter gain, which can be viewed as the cutoff frequency of a low-pass filter. For sufficiently large parameter gain, the closed-loop performance is arbitrarily small. Numerical examples are used to demonstrate the application and effectiveness of the decentralized controller, and we present experimental results for a setup consisting of a cantilever beam with piezoelectric actuators and strain-gauge sensors.

A Practical Fractional-Order Sinusoidal Oscillator Design and Implementation

2021 ◽  
pp. 2150231
Author(s):  
İbrahim Ethem Saçu
Keyword(s):  
Fractional Order ◽  
Closed Loop ◽  
Passive Components ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Design And Implementation ◽  
Sinusoidal Oscillator ◽  
Fractional Oscillator ◽  
Low Pass ◽  
Fractional Differentiator

In this study, a new sinusoidal fractional oscillator circuit in which the fractional low-pass filter and fractional differentiator form a closed loop has been introduced. The single series [Formula: see text] pair and Valsa method have been used to imitate the fractional-order capacitor. Two different sinusoidal signals with different phases are available at output ports. An integer version of the proposed oscillator is not possible, only the fractional version is valid, that is a noticeable feature. The introduced circuit has been simulated by employing SPICE software. The proposed fractional oscillator is also verified by implementing circuit with AD817ANs and passive components, experimentally.

The spatiotemporal transfer function of crayfish lamina monopolar neurons

1994 ◽  
Vol 71 (6) ◽  
pp. 2168-2182 ◽  
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.

scholarly journals Cascade-Type Pole-Zero Cancellation Output Voltage Regulator for DC/DC Boost Converters

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3824
Author(s):  
Sung Hyun You ◽  
Koo Bonn ◽  
Dong Soo Kim ◽  
Seok-Kyoon Kim
Keyword(s):  
Output Voltage ◽  
Closed Loop ◽  
Active Damping ◽  
Voltage Regulator ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Boost Converters ◽  
System A ◽  
Low Pass ◽  
Cascade Structure

This paper presents a novel output voltage regulator in the cascade structure under the consideration of both the parameter and load uncertainties. It leads to the first-order closed-loop inner and outer loop dynamics in the low-pass filter form by the pole-zero cancellation through the active damping injection, which is the main contribution of this study. Moreover, it is proved that the active damping injection level determines the disturbance rejection capability of the closed-loop system. A 3-kW DC/DC boost converter confirms the actual advantages from these two contributions.

Design of Programmable Wideband Low Pass Filter with Continuous-Time/Discrete-Time Hybrid Architecture

2017 ◽  
Vol E100.C (10) ◽  
pp. 858-865 ◽  
Author(s):  
Yohei MORISHITA ◽  
Koichi MIZUNO ◽  
Junji SATO ◽  
Koji TAKINAMI ◽  
Kazuaki TAKAHASHI
Keyword(s):  
Discrete Time ◽  
Continuous Time ◽  
Hybrid Architecture ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Low Pass
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