In Situ Identification of Natural Frequency Branches in Gyroscopic Systems via Autoresonance and Phase-Locked Loop

2019 ◽  
Vol 142 (1) ◽  
Author(s):  
Solomon Davis ◽  
Shachar Tresser ◽  
Netanel Ariel ◽  
Alex Ferdinskoif ◽  
Izhak Bucher
Keyword(s):  
Rotation Speed ◽  
Frequency Control ◽  
Phase Locked Loop ◽  
Campbell Diagram ◽  
Modal Frequency ◽  
At Resonance ◽  
Bending Mode ◽  
Run Up ◽  
Feedback Algorithm ◽  
The Individual

Abstract The methods described allow one to directly measure the individual branches of the Campbell diagram of a physical gyroscopic system at any rotation speed. Typically, such data are acquired by exciting the vibration modes through naturally occurring unbalance forces. During run-up, these forces expose some of the Campbell diagram, but mainly the forward whirling branches, leaving the backward whirling branches mostly hidden. Furthermore, good modal frequency data are only acquired at critical speeds. The methods proposed here allow one to excite either a forward or backward whirling mode at any rotation speed in a precisely controlled manner, greatly improving the quality of an acquired Campbell diagram. The technique employs an external excitation device that automatically produces oscillating forces at a chosen modal frequency. Control is based on the autoresonance feedback algorithm, which can excite a mechanical system at resonance effectively. It will also be shown that with two actuators and two sensors, one can choose which bending mode to excite at resonance in either the forward or backward whirling direction. As the rotation speed is then gradually increased, one can measure the speed dependence of the resonance frequency. Furthermore, when combining autoresonance with a phase-locked loop, one can acquire very clean measurements by removing most of the noise generated by the unbalance and other sources. The technique is demonstrated analytically, numerically, and experimentally.

scholarly journals Optimization Technique Inspired Load Frequency Controller for Multi Area Power System with Renewable Energy Source

2021 ◽  
Vol 850 (1) ◽  
pp. 012017
Author(s):  
J Shri Saranyaa ◽  
A Peer Fathima ◽  
Asutosh Mishra ◽  
Rushali Ghosh ◽  
Shalmali Das
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Control Method ◽  
Frequency Control ◽  
Renewable Energy Sources ◽  
Optimization Technique ◽  
Optimization Method ◽  
Load Frequency Control ◽  
Load Frequency ◽  
The Individual

Abstract Modern day scenario has an increasing power demand due to the growing development which indeed increases the load on the generation which might cause turbulence in the system and may bounce out of stability. The governor itself can’t handle such frequent load changes and adjust the generation amount to keep the frequency between the margins. This paper proposes an approach towards such predicament to incorporate an optimization method in order to ensure stability of the system despite the drastic changes in demand. Load frequency control is a control method for maintaining the frequency of the system during the change in demand. Use of controllers has proven to be effective in controlling the frequency deviations in the power systems and the response of the controller is further improved using optimization technique for better stability. The PID controller tuned by Particle Swarm Optimization is employed in multi-area system which reduces the time response by a considerable amount and the deviation settles much quicker despite the rapid load changes. The proposed controller is executed further for renewable energy sources connected to the individual areas and demonstration proves that the optimized controller is efficient enough in handling the frequency deviations when wind and solar with sunlight penetration is incorporated.

MAKING AN ALGORITHM FOR CONTROLLING THE INDIVIDUAL DRIVE OF THE DRIVING WHEELS OF A TRANSPORT AND TECHNOLOGICAL MODULE

2020 ◽  
pp. 10-15
Author(s):  
SHUTENKO VLADIMIR V. ◽  
Keyword(s):  
Power Distribution ◽  
Rotation Speed ◽  
Traction Force ◽  
Microprocessor System ◽  
Movement Trajectory ◽  
Microprocessor Control ◽  
Microprocessor Control System ◽  
The Individual ◽  
Mathematical Relationships ◽  
Technological Module

Improving the traction properties of mobile power tools is one of the most important tasks of modern tractor construction. The use of transport-technological modules (TTM) helps to solve this problem, but to ensure the best indicators of fuel economy and stabilization of a machine-and-tractor unit (MTU), the TTM driving wheels should be driven individually, which can be ensured by a microprocessor control system. Therefore, the study goal is to make an algorithm for controlling the driving wheels of the TTM, which will ensure the best characteristics of a MTU. To achieve this goal, the authors used mathematical modeling and graph-analytical methods. They are necessary for stating the main relationships and setting algorithm conditions that will optimize a tractor’s traction force and power consumption, as well as stabilize its movement trajectory. The operation of the microprocessor system consists in obtaining data from external sensors and determining the actual speed, skidding and direction of travel. The microprocessor system compares these parameters with ideal conditions, described with mathematical relationships, and based on the developed algorithm, corrects the rotation speed and power distribution between the driving wheels of a TTM.

scholarly journals Flat Cross-Shaped Piezoelectric Rotary Motor

2020 ◽  
Vol 10 (14) ◽  
pp. 5022
Author(s):  
Andrius Čeponis ◽  
Dalius Mažeika ◽  
Piotr Vasiljev
Keyword(s):  
Experimental Investigation ◽  
Printed Circuit Board ◽  
Rotation Speed ◽  
Circuit Board ◽  
Geometrical Parameters ◽  
Printed Circuit ◽  
Harmonic Signals ◽  
Bending Mode ◽  
The Cross ◽  
Rotary Motor

A numerical and experimental investigation of a flat, cross-shaped piezoelectric rotary motor is presented. The design and configuration of the motor allow it to be mounted directly to the printed circuit board or integrated into the other system where mounting space is limited. The design of the motor is based on the cross-shaped stator with 16 piezo ceramic plates, which are glued on it. The rotor is placed at the center of the stator and consists of two hemispheres, a shaft, and a preloading spring. Special clamping of the stator was developed as well. It consists of four V-shaped beam structures that allow it to rigidly clamp the stator with reduced damping effect to vibrations. The operation principle of the motor is based on the first in-plane bending mode of the cross-shaped stator. The motor excitation is performed through four harmonic signals, which have a phase difference of π/2. A numerical investigation of the motor was conducted to optimize the geometrical parameters of the stator and to analyze the displacement characteristics of the contacting point. The prototype of the motor was made, and the electrical, as well as rotation speed characteristics of the motor, were measured. The results of the experimental investigation showed that the motor is able to provide a maximum rotation speed of 972.62 RPM at 200 Vp-p when the preload force of 22.65 mN was applied.

Anticipatory judgements associated with vision of an opponent’s end-effector: An approach by motion perturbation and spatial occlusion

2018 ◽  
Vol 72 (5) ◽  
pp. 1131-1140
Author(s):  
Hirofumi Ida ◽  
Kazunobu Fukuhara ◽  
Motonobu Ishii ◽  
Tetsuri Inoue
Keyword(s):  
Visual Analogue Scale ◽  
Visual Information ◽  
Analogue Scale ◽  
Rotation Speed ◽  
Elbow Extension ◽  
End Effector ◽  
Tennis Players ◽  
Occlusion Model ◽  
Tennis Serve ◽  
The Individual

This study was aimed at determining how the visual information of an end-effector (racket) and the intermediate extremity (arm) of a tennis server contribute to the receiver’s anticipatory judgement of ball direction. In all, 15 experienced tennis players and 15 novice counterparts viewed a spatially occluded computer graphics animation of a tennis serve (no-occlusion, racket-occlusion, and body-occlusion) and made anticipatory judgements of ball direction on a visual analogue scale (VAS). The patterns of the serve motions were generated by a simulation technique that computationally perturbs the rotation speed of the selected racket-arm joint (forearm pronation and elbow extension) on a captured serve motion. The results suggested that the anticipatory judgements were monotonically attuned with the perturbation rate of the forearm pronation speed excepting under the conditions of the racket-occlusion model. Although such attunements were not observed in the elbow perturbation conditions, the results of correlation analysis indicated that the residual information in the spatially occluded models had a similar effect to the no-occlusion model within the individual experienced participants. The findings support the notion that end-effector (racket) provides deterministic cues for anticipation, as well as imply that players are able to benefit from the relative motion of an intermediate extremity (elbow extension).

Prevention of Dicing-Induced Damage in Semiconductor Wafers

2007 ◽  
Vol 345-346 ◽  
pp. 485-488
Author(s):  
Seong Min Lee
Keyword(s):  
Rotation Speed ◽  
Negative Impact ◽  
Mechanical Damage ◽  
Processing Method ◽  
Productivity Improvement ◽  
Active Device ◽  
Close Proximity ◽  
Saw Blade ◽  
The Individual ◽  
Sawing Process

Semiconductor devices are usually formed on a single silicon wafer during a batch processing method. Individual devices are separated from the wafer during the wafer sawing or dicing step. Subsequent packaging processes are then performed on the individual devices, whose edge portions are very susceptible to mechanical damage from the sawing process. Defects formed along device edges due to the dicing saw blade often provide potential sites for serious reliability problems. If the scribing area is reduced, the number of the separated devices from a single wafer increases, which results in productivity improvement. However, the closer the scribing position of the saw blade comes to the active device pattern, the greater possibility of sawing-induced damage to the active pattern is. Thus, this work shows methods to reduce the negative impact of the saw blade while maintaining close proximity of the scribe lines to the IC devices. In particular, this work suggests that a decrease in the size of the diamond particles embedded in the saw blade and in the rotation speed of the saw blade might contribute to the prevention of sawing-induced damage to device patterns.

scholarly journals VII. Mathematical contributions to the theory of evolution.— IV. On the probable errors of frequency constants and on the influence of random selection on variation and correlation

1898 ◽  
Vol 191 ◽  
pp. 229-311 ◽  
Keyword(s):  
General Theorem ◽  
Random Selection ◽  
Natural Order ◽  
Theory Of Evolution ◽  
Insignificant Difference ◽  
Normal Correlation ◽  
The Subject ◽  
The Difference ◽  
Run Up ◽  
The Individual

(1) In earlier memoirs by one of the present authors, methods have been discussed for the calculation of the constants ( a ) of variation, normal or skew, ( b ) of correla­tion, when normal. The subject of skew correlation would now naturally present itself, but although several important conclusions with regard to skew correlation have been worked out, there are still difficulties which impede the completion of the memoir on that topic. Meanwhile Mr. G. U. Yule has shown that the constants of normal correlation are significant, if not completely descriptive, even in the case of skew correlation. It seems desirable to take, some what out of its natural order, the subject of the present memoir, partly because the formulæ involved have been once or twice cited and several times used in memoirs by one of the present writers, and partly because the need of such formulæ seems to have been disregarded by various authors in some what too readily drawing conclusions from statistical data. Differences in the constants of variation or of correlation have been not infrequently asserted to be significant or non-significant of class or of type, or of race differences, without a due investigation of whether those differences are, from the standpoint of mathematical statistics, greater or less than the probable errors of the differences. Not withstanding that every artificial or even random selection of a group out of a community changes not only the amount of variation, but the amount of correlation of the organs of its members as com pared with those of the primitive group, it has been supposed that correlation might be a racial constant, and the approximate constancy of coefficients of correlation of the same organs in allied species has been used as a valid argument. In the like manner differences in variation have been used as an argument for the activity of natural selection without a discussion of the probable errors of those differences. In dealing with variation and correlation we find the distribution described by certain curves or surfaces fully determined when certain constants are known. These are the so-called constants of variation and correlation, the number of which may run up from two to a very considerable figure in the case of a complex of organs. If we deal with a complex of organs in two groups containing, say, n and n ' individuals, we can only ascertain whether there is a significant or insignificant difference between those groups by measuring the extent to which the differences of corresponding constants exceed the probable errors of those differences. The probable error of a difference can at once be found by taking the square root of the sum of the squares of the probable errors of the quantities forming the difference. Hence the first step towards determining the significance of a group difference— i. e ., towards ascertaining whether it is really a class, race, or type difference— is to calculate the probable errors of the constants of variation and correlation of the individual groups. This will be the object of our first general theorem.

Debugging Phase-Locked Loop Failures in Integrated Circuit Products

2014 ◽  
Author(s):  
S.H. Goh ◽  
Wendy Lau ◽  
B.L. Yeoh ◽  
H.W. Ho ◽  
G.F. You ◽  
...  
Keyword(s):  
Integrated Circuit ◽  
Frequency Control ◽  
Photon Emission ◽  
Building Blocks ◽  
Phase Locked Loop ◽  
Fault Isolation ◽  
Loop Control ◽  
Isolation Techniques ◽  
Loop Control System ◽  
Specific Frequency

Abstract A phase-locked loop (PLL) is commonly used in integrated circuit devices for frequency control. In a finished product, it comprises of sub-building blocks operating in a closed-loop control system which do not have register readback or test access points for easy debugging. Failure analysis becomes a challenge. This paper demonstrates the inherent limitation of relying only on dynamic fault isolation techniques, in specific frequency mapping for PLL failure debug. A systematic debug approach that combines volume failure characterization on test, additional characterization using dynamic photon emission and design simulation is then presented. Results are obtained on a 28 nm node device.

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