scholarly journals Digital Approach to Rotational Speed Measurement Using an Electrostatic Sensor

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2540 ◽  
Author(s):  
Lin Li ◽  
Hongli Hu ◽  
Yong Qin ◽  
Kaihao Tang
Keyword(s):  
Rotational Speed ◽  
Sampling Rate ◽  
Correlation Method ◽  
Response Speed ◽  
Square Wave ◽  
Signal Conversion ◽  
Speed Measurement ◽  
Auto Correlation ◽  
Relative Errors ◽  
A Charge

In industrial production processes, rotational speed is a key parameter for equipment condition monitoring and fault diagnosis. To achieve rotational speed measurement of rotational equipment under a condition of high temperature and heavy dust, this article proposes a digital approach using an electrostatic sensor. The proposed method utilizes a strip of a predetermined material stuck on the rotational shaft which will accumulate a charge because of the relative motion with the air. Then an electrostatic sensor mounted near the strip is employed to obtain the fluctuating signal related to the rotation of the charged strip. Via a signal conversion circuit, a square wave, the frequency of which equals that of the rotation shaft can be obtained. Having the square wave, the M/T method and T method are adopted to work out the rotational speed. Experiments were conducted on a laboratory-scale test rig to compare the proposed method with the auto-correlation method. The largest relative errors of the auto-correlation method with the sampling rate of 2 ksps, 5 ksps are 3.2% and 1.3%, respectively. The relative errors using digital approaches are both within ±4‰. The linearity of the digital approach combined with the M/T method or T method is also superior to that of the auto-correlation method. The performance of the standard deviations and response speed was also compared and analyzed to show the priority of the digital approach.

scholarly journals Wireless Passive High-Temperature Sensor Readout System for Rotational-Speed Measurement

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yingping Hong ◽  
Pengyu Jia ◽  
Xihao Guan ◽  
Jijun Xiong ◽  
Wenyi Liu ◽  
...  
Keyword(s):  
High Temperature ◽  
Rotational Speed ◽  
Maximum Temperature ◽  
Readout System ◽  
Passive Measurement ◽  
Signal Conversion ◽  
Speed Measurement ◽  
Signal Demodulation ◽  
Characteristic Signal ◽  
Frequency Demodulation

Rotational-speed measurement in harsh environments is an important topic. However, the high rotation results in rapid frequency variations in the signals of a sensor and changes in physical properties under extreme thermal circumstances cause significant difficulties in reading signals. To address this problem, we adopt wireless passive measurement methods to design a special characteristic signal circuit module that achieves precise measurement of rotational speed at high temperatures. The sensor and the readout system include a variable frequency source, a readout antenna, and a radio frequency demodulation circuit. Herein, a demodulation detector of the signal conversion circuit is designed and used in the envelope detection module of the single sideband demodulation method. In addition, a conversion circuit test platform for high-temperature environment sensor signal is developed. From the testing, the output signal demodulation of the sensor was observed under a maximum temperature of 700°C with error less than 0.12%. The new sensor and measurement method do not require physical leads and achieve wireless noncontact accurate measurement of rotational speed at high temperature.

A Study On Methods for Determining Phase Space Reconstruction Parameters

2021 ◽  
Author(s):  
Shihui Lang ◽  
Zhu Hua ◽  
Guodong Sun ◽  
Yu Jiang ◽  
Chunling Wei
Keyword(s):  
Time Delay ◽  
Phase Space ◽  
Correlation Dimension ◽  
Nearest Neighbor ◽  
Correlation Method ◽  
Phase Space Reconstruction ◽  
Lorenz Attractor ◽  
Embedding Dimension ◽  
Phase Trajectories ◽  
Auto Correlation

Abstract Several pairs of algorithms were used to determine the phase space reconstruction parameters to analyze the dynamic characteristics of chaotic time series. The reconstructed phase trajectories were compared with the original phase trajectories of the Lorenz attractor, Rössler attractor, and Chens attractor to obtain the optimum method for determining the phase space reconstruction parameters with high precision and efficiency. The research results show that the false nearest neighbor method and the complex auto-correlation method provided the best results. The saturated embedding dimension method based on the saturated correlation dimension method is proposed to calculate the time delay. Different time delays are obtained by changing the embedding dimension parameters of the complex auto-correlation method. The optimum time delay occurs at the point where the time delay is stable. The validity of the method is verified through combing the application of correlation dimension, showing that the proposed method is suitable for the effective determination of the phase space reconstruction parameters.

scholarly journals Ion Selective Electrodes for Flue Gas Desulfurization Wastewater Monitoring: Effects of Ionic Strength on Selective Ions

2019 ◽  
Vol 9 (15) ◽  
pp. 3085
Author(s):  
Kyle McGaughy ◽  
Jay P. Wilhelm ◽  
M. Toufiq Reza
Keyword(s):  
Ionic Strength ◽  
Flue Gas ◽  
Sampling Rate ◽  
Operating Conditions ◽  
Flue Gas Desulfurization ◽  
Ion Selective Electrodes ◽  
Wastewater Sample ◽  
Electrode Performance ◽  
Relative Errors ◽  
Nitrate And Nitrite

Ion selective electrodes (ISE) were evaluated for use in a flue gas desulfurization (FGD) wastewater monitoring system. Calcium, chloride, nitrate, and nitrite ISE’s were calibrated in a broad range of concentrations that were designed to model an actual FGD wastewater sample that was obtained from an industrial partner. Ideal Nernst, Modified Nernst, and a multiparameter regression analysis was performed for each electrode and evaluated on general fit and sensitivity at anticipated operating conditions. The Ideal Nernst equation, even with correction for ionic strength, was not able to properly model actual electrode performance. The multiparameter regression was able to model the electrode performance with relative errors of 10–25% when ionic strengths were below 0.1 M. Through the evaluation of real-time sensor usage at real conditions, a methodology of washing and sampling rate is suggested to minimize error in the readings.

Design of New Automobile Rotational Speed Measuring Device

2011 ◽  
Vol 383-390 ◽  
pp. 325-328
Author(s):  
Gui Yin Yu ◽  
Lu Zhang
Keyword(s):  
Rotational Speed ◽  
Phase Locked Loops ◽  
Frequency Division ◽  
Measurement Device ◽  
Measuring Device ◽  
Speed Measurement ◽  
Information Collecting

The automobile rotational speed measurement device, consisting of information collecting and processing, phase-locked loops, wave shaping, frequency division and display, can be applied for measurement of the rotational speed of automobiles with various cylinders.

A Research of High Precision Rotational Speed Measurement System Based on Infrared Sensor and Microcontroller

2013 ◽  
Vol 278-280 ◽  
pp. 680-683
Author(s):  
Zi Qin Ma ◽  
Ren Zhang ◽  
Da Li Kang ◽  
Wu Yang
Keyword(s):  
High Precision ◽  
Measurement System ◽  
Rotational Speed ◽  
Pulse Signal ◽  
Measuring Method ◽  
Infrared Light ◽  
Infrared Sensor ◽  
Flip Flop ◽  
Speed Measurement ◽  
Photoelectric Sensor

With the deep analysis on the rotational speed measurement and the error existed in the measurement process at present, this paper introduces a high precision rotational speed measurement system based on infrared sensor and microcontroller. This system combines with improved measuring method. The sensor is an infrared photoelectric sensor, and uses its characteristics of the autocollimator ensured accuracy of measurement. The photoelectric sensor outputs weak voltage pulse signal when it receives the reflected infrared light. And then the signal is processed by double-reversed amplification and twice pulse shaping circuit. The system uses the relevant logic functions of a D-type flip-flop to control two 16-bit microcontroller chip timing/counter turned on and off simultaneously, and calculates the rotation speed. At last, the result is displayed on LED by Microcontroller. This measurement system has high accuracy, fast sampling speed and wide measuring range.

Sign in / Sign up

Export Citation Format

Share Document