scholarly journals Algorithm for Processing Signals of the Incremental Encoder for Calculating the Angles of Rotation of the Torsional Pendulum

2021 ◽  
Vol 19 (2) ◽  
pp. 25
Author(s):  
V V Tarasov ◽  
A V Churkin ◽  
V N Novikov ◽  
E A Kalentev ◽  
V F Lys ◽  
...  
Keyword(s):  
Torsional Pendulum ◽  
Incremental Encoder

В статье приведен алгоритм обработки сигналов инкрементного датчика для оценки свободных колебаний крутильного маятника при исследовании фрикционных характеристик смазочных материалов применительно к стальным канатам с использованием возможности ПО «PowerGraph». Стальной канат является сложной и гибкой стержневой системой, в которой проволоки имеют форму пространственной спирали (винтовой линии) или двойной спирали. При этом внутренние проволоки стальных канатов находятся внутри и недоступны для прямого исследования, измерения и контроля. Анализ фрикционных характеристик смазочных материалов, используемых в стальных канатах, усугубляется многокомпонентностью и сложной структурой объекта исследования. Экспериментальные методы исследования в этом случае представляют один из наиболее эффективных и достоверных способов оценки эксплуатационных свойств изделия в целом. В основу эксперимента положен процесс затухания вращательных колебаний тяжелого груза, висящего на исследуемом стальном канате. Используемый смазочный материал влияет на такой колебательный процесс, и характеристикой такого влияния является декремент затухания колебательного процесса. В качестве датчика угла использован инкрементный энкодер, установленный соосно исследуемому канату и обеспечивающий разрешение регистрации угла поворота до 0,18 градуса.

Improved ANFIS based MRAC observer for sensorless control of PMSM

2021 ◽  
pp. 1-13
Author(s):  
Suryakant ◽  
Mini Sreejeth ◽  
Madhusudan Singh
Keyword(s):  
Fuzzy Inference ◽  
Permanent Magnet Synchronous Motor ◽  
Torque Control ◽  
Control Algorithms ◽  
Motor Speed ◽  
Inference System ◽  
Rotor Position ◽  
Improved Performance ◽  
Incremental Encoder ◽  
Model Reference Adaptive

Detection of the rotor position is an important prerequisite for controlling the speed and developed torque in permanent magnet synchronous motor (PMSM). Even though use of incremental encoder and resolver is one of the popular schemes for sensing the rotor position in a PMSM drive, it increases the size and weight of the drive and reduces its reliability. Dynamic modeling of the motor and control algorithms are often used in sensor-less control of PMSM to estimate rotor position and motor speed. Most sensor-less control algorithms use machine parameters like torque constant, stator inductances and stator resistance for estimating the rotor position and speed. However, with accuracy of such estimation and the performance of the motor degrades with variation in motor parameters. Model reference adaptive control (MRAC) provides a simple solution to this issue. An improved Adaptive neuro-fuzzy inference system (ANFIS) based MRAC observer for speed control of PMSM drive is presented in this paper. In the proposed method adaptive model and adaptive mechanism are replaced by an improved ANFIS controller, which neutralize the effect of parametric variation and results in improved performance of the drive. The modeling equations of PMSM are used to estimate the rotor position for speed and torque control of the drive. Simulation studies have been carried out under various operating condition using MATLAB/Simulink. In addition, a comparative analysis of the conventional MRAC based observer and improved ANFIS based MRAC observer is carried out. It is observed that the proposed method results in better performance of the PMSM drive.

Stream Selector’s Control System Based on High-Precision Incremental Encoder

2013 ◽  
Vol 303-306 ◽  
pp. 1657-1660
Author(s):  
Zhi Guang Zhang ◽  
Wei Hu ◽  
Xiao Qiong Li ◽  
Xue Fei Lv ◽  
Min Ping Zhang ◽  
...  
Keyword(s):  
Control System ◽  
Power Consumption ◽  
High Precision ◽  
Position Control ◽  
High Reliability ◽  
Dc Motor ◽  
Step Motor ◽  
Low Power Consumption ◽  
Incremental Encoder ◽  
The One

For the precision rotor position control of stream selector, a control system based on direct current motor (DC motor) has been constructed. The DC motor, with a high-precision incremental encoder used as the driving force, was assembled with the stream selector rotor through a shaft coupling. Following the motor rotation, the encoder generated two-channel quadrature pulses and one channel index pulses. An ultralow-power consumption microcontroller (msp430f2232) received theses pulses and calculated them. The position of the slot was determined by the number of pulses counted from the index pulse. Operator can set and monitored the slot positions of five stream selectors simultaneously through the program which was written with LabVIEW on the host computer. This module featured high reliability and low power consumption compared with the one driven by step motor. Beyond that, it was much smaller and lighter.

A Proposed Experiment Using a Sphere with an Eccentric Cavity for Hypothetical Long-Range Interactions

1997 ◽  
Vol 12 (08) ◽  
pp. 1465-1482 ◽  
Author(s):  
G. L. Klimchitskaya ◽  
V. M. Mostepanenko ◽  
C. Romero ◽  
Ye. P. Krivtsov ◽  
A. Ye. Sinelnikov
Keyword(s):  
Long Range ◽  
High Sensitivity ◽  
Experimental Setup ◽  
Interaction Range ◽  
Steel Sphere ◽  
Long Range Interactions ◽  
Torsional Pendulum ◽  
Additional Interaction ◽  
Homogeneous Gravitational Field ◽  
Degree Type

The constraints are examined which may be obtained for the parameters of long-range hypothetical interactions by the use of the precise experimental setup created originally for the calibration of accelerometers. This setup includes the large rotating steel sphere with a nonconcentric spherical cavity in which the strictly homogeneous gravitational field arises. The field of additional interaction produced by the atoms of the sphere, however, is not homogeneous. The essential features required of the detector of additional interaction which is the torsional pendulum of high sensitivity are discussed. Both the cases of the Yukawa-type and degree-type hypothetical interactions are investigated. It is shown that the known-to-date constraints for Yukawa-type interactions may be strengthened by a factor of 400 in the appropriate interaction range. For the degree-type hypothetical forces decreasing with distance as r-3, r-4 and r-5 correspondingly the known constraints may be strengthened by the factors of 90, 35 and 20. The conclusion is made that with the use of the specially created related setup it will be conceivable to strengthen the constraints for Yukawa-type interactions up to 4500 times over a wide interaction range.

Error Considerations for Turbine-Generator Torsional Vibration Monitoring

2020 ◽  
Author(s):  
Jindrich Liska ◽  
Jan Jakl ◽  
Sven Kunkel
Keyword(s):  
Power Systems ◽  
Torsional Vibration ◽  
Gas Turbines ◽  
Measurement Errors ◽  
Power Plants ◽  
Signal To Noise Ratio ◽  
Vibration Monitoring ◽  
Turbine Generator ◽  
Turbine Generators ◽  
Incremental Encoder

Abstract Turbine-generator torsional vibration is linked to electrical events in the power grid by the generator air-gap torque. Modern power systems are subject to gradual transformation by increasing flexibility demands and incorporation of renewable resources. As a result, electrical transient events are getting more frequent and thus torsional vibration is getting more and more attention. Especially in the case of large steam and gas turbines torsional vibration can cause material fatigue and present a hazard for safe machine operation. This paper freely builds on previous work, where a method for torsional vibration evaluation using an incremental encoder measurement was presented, in that it supplements error considerations to this methodology. Measurement errors such as precision of the rotor encoder manufacturing, choice of the proper sensor, its signal to noise ratio and the error of instantaneous velocity computation algorithm are analyzed. The knowledge of these errors is essential for torsional vibration as there is an indirect and relatively complicated path from the measurement to the final torsional vibration results compared to other kinds of vibration. The characteristics of particular errors of the processing chain are validated both on experimental data from a test rig as well as field data measured on turbine-generators in power plants.

scholarly journals Elastic constants of fused quartz. Change of young's modulus with temperature

1929 ◽  
Vol 122 (789) ◽  
pp. 274-282 ◽  
Keyword(s):  
Shear Modulus ◽  
Elastic Constants ◽  
Torsional Oscillation ◽  
Elastic Solids ◽  
Continuous Increase ◽  
Rate Of Increase ◽  
Fused Quartz ◽  
Torsional Pendulum ◽  
The Mean ◽  
Good Agreement

When fused quartz is heated, its elastic constants for stretch shear and bulk change all increase, a sharp distinction in behaviour from that of most other elastic solids. An elastically-stretched fibre becomes shorter upon heating, and a strained torsion member reduces its twist for a given twisting effort; and so forth. The changes of shear modulus with temperature have been studied in detail (22 to 98° C.) by Threlfall and later by Horton to about 1000° C., who used methods of experiment based upon the changes in period upon heating, of a torsional pendulum having fused quartz as the elastic member. The results of Horton's experiments showed a continuous increase in modulus up to about 880° C. beyond which temperature the modulus rapidly diminished. At 880° C. the modulus was 5·9 per cent, greater than at 15° C. and the mean rate of increase up to 500° C. was 0·85 × 10 -4 per degree Centigrade. The increase is more rapid at lower temperatures, thus, in the interval 20 to 100° C. mean rate of increase per degree Centigrade was found by Horton to be 1·25 × 10 -4 , which is in good agreement with the earlier determinations made by Threlfall. At still lower temperatures, and using the same method of torsional oscillation, Guye and Einhorn-Bodzechowski showed that the mean temperature coefficient in the interval —194° C. to 0° C. is 1·46 × 10 -4 per degree Centigrade, and that there is no major discontinuity in behaviour in this range.

scholarly journals On the compensation of incremental encoder imperfections for motion control: a DC motor case-study

2018 ◽  
Vol 51 (13) ◽  
pp. 627-632
Author(s):  
Missie Aguado-Rojas ◽  
William Pasillas-Lépine ◽  
Antonio Loría ◽  
Alexandre De Bernardinis
Keyword(s):  
Motion Control ◽  
Dc Motor ◽  
Incremental Encoder

scholarly journals Comparison of numerical integration methods in strapdown inertial navigation algorithm  

2011 ◽  
Vol 57 (Special Issue) ◽  
pp. S30-S34 ◽  
Author(s):  
V. Cviklovič ◽  
D. Hrubý ◽  
M. Olejár ◽  
O. Lukáč
Keyword(s):  
Numerical Integration ◽  
Mathematical Theory ◽  
Inertial Navigation ◽  
Trapezoidal Rule ◽  
Calculation Algorithm ◽  
Computing Power ◽  
Velocity Error ◽  
Sample Frequency ◽  
Incremental Encoder ◽  
Strapdown Inertial Navigation

The numerical mathematical theory provides a few ways of numerical integration with different errors. It is necessary to make use of the most exact method with respect to the computing power for a majority of microprocessors, because errors are integrated within them due to the algorithm. In our contribution, trapezoidal rule and Romberg&rsquo;s method of numerical integration are compared in the velocity calculation algorithm of the strapdown inertial navigation. The sample frequency of acceleration and angular velocity measurement was 816.6599 Hz. Inertial navigation velocity was compared with precise incremental encoder data. Trapezoidal method velocity error in this example was 1.23 &times; 10<sup>&ndash;3</sup> m/s in the fifteenth-second measurement. Romberg&rsquo;s method velocity error was 0.16 &times; 10<sup>&ndash;3 </sup>m/s for the same input data. The numerical mathematical theory provides a few ways of numerical integration with different errors. It is necessary to make use of the most exact method with respect to the computing power for a majority of microprocessors, because errors are integrated within them due to the algorithm. In our contribution, trapezoidal rule and Romberg&rsquo;s method of numerical integration are compared in the velocity calculation algorithm of the strapdown inertial navigation. The sample frequency of acceleration and angular velocity measurement was 816.6599 Hz. Inertial navigation velocity was compared with precise incremental encoder data. Trapezoidal method velocity error in this example was 1.23 &times; 10<sup>&ndash;3</sup> m/s in the fifteenth-second measurement. Romberg&rsquo;s method velocity error was 0.16 &times; 10<sup>&ndash;3 </sup>m/s for the same input data.

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