A Rotation-Speed Measurement System Based on Magneto-Inductive Effect

2020 ◽  
Vol 18 (4) ◽  
pp. 299-303
Author(s):  
Tao Wang ◽  
Bicong Wang ◽  
Yuyi Chen ◽  
Yufeng Luo
Keyword(s):  
Direct Current ◽  
Measurement System ◽  
Rotational Speed ◽  
Inductive Effect ◽  
Rotation Speed ◽  
Rotating Shaft ◽  
High Rotational Speed ◽  
Sensing System ◽  
Dc Motors ◽  
Speed Measurement

There are few reports on high rotational speed measurement of brushless direct current (DC) motors based on giant magneto-inductive effect. In this study, a rotational speed measurement system based on giant magneto-inductive effect is established for measuring the rotational speeds of DC motors. Successive sawtooth waves are found when rotating shaft is close to the GMI sensor. Through using the magneto-inductive sensing system, different high rotational speeds (1500∼24000 r/min) of the motor are accurately measured. Therefore, this giant magneto-inductive sensor may be used for high rotational speed measurement of motors.

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.

scholarly journals Video-Tachometer Methodology for Wind Turbine Rotor Speed Measurement

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7314
Author(s):  
Francesco Natili ◽  
Francesco Castellani ◽  
Davide Astolfi ◽  
Matteo Becchetti
Keyword(s):  
Wind Turbine ◽  
Rotational Speed ◽  
Wind Farm ◽  
Turbine Rotor ◽  
Rotating Machinery ◽  
Speed Estimation ◽  
Rotor Speed ◽  
High Rotational Speed ◽  
Speed Measurement ◽  
Wind Turbine Rotor

The measurement of the rotational speed of rotating machinery is typically performed based on mechanical adherence; for example, in encoders. Nevertheless, it can be of interest in various types of applications to develop contactless vision-based methodologies to measure the speed of rotating machinery. In particular, contactless rotor speed measurement methods have several potential applications for wind turbine technology, in the context of non-intrusive condition monitoring approaches. The present study is devoted exactly to this problem: a ground level video-tachometer measurement technique and an image analysis algorithm for wind turbine rotor speed estimation are proposed. The methodology is based on the comparison between a reference frame and each frame of the video through the covariance matrix: a covariance time series is thus obtained, from which the rotational speed is estimated by passing to the frequency domain through the spectrogram. This procedure guarantees the robustness of the rotational speed estimation, despite the intrinsic non-stationarity of the system and the possible signal disturbances. The method is tested and discussed based on two experimental environments with different characteristics: the former is a small wind turbine model (with a 0.45 m rotor diameter) in the wind tunnel facility of the University of Perugia, whose critical aspect is the high rotational speed (up to the order of 1500 RPM). The latter test case is a wind turbine with a 44 m rotor diameter which is part of an industrial wind farm: in this case, the critical point regards the fact that measurements are acquired in uncontrolled conditions. It is shown that the method is robust enough to overcome the critical aspects of both test cases and to provide reliable rotational speed estimates.

Design of Surface Finish Using Compound Processes of Grinding and Electrochemical Finishing Following Turning

2008 ◽  
Vol 373-374 ◽  
pp. 782-785 ◽  
Author(s):  
Pai Shan Pa
Keyword(s):  
Direct Current ◽  
Feed Rate ◽  
Rotational Speed ◽  
Low Cost ◽  
Electrical Current ◽  
High Rotational Speed ◽  
Factors Affecting ◽  
Grinding Tool ◽  
Pulsed Direct Current ◽  
Electrochemical Finishing

A new finish method uses an effective electrode connecting with a nonconductive grinding tool to execute the design of compound processes of electrochemical finishing and grinding following turning is investigated. The submitted processes can be used for various turning operations. Through simple equipment attachment, electrochemical finishing and grinding can follow to execute the finishing process on the same machine. Among the factors affecting electrochemical finishing the performance of grinding combined with electrochemical finishing is primarily discussed. In the experiment, the electrode is used with continuous and pulsed direct current. The grinding tool moves following the electrode and grinds the workpiece surface. The experimental parameters are electrical current rating, feed rate of electrode and grinding tool, rotational speed of workpiecel, pulsed period, and geometry of finish-tool. The results show that pulsed direct current with longer off-time can slightly improve the finish effect for its dregs discharge mobility. Using an adequate rotational speed of workpiece with high rotational speed is advantageous to the finish effect. A thinner plate-form electrode with a smaller end radius is associated with larger discharge space and produces higher current density and provides faster feed rate and a better finish effect. The grinding can effectively increase the finish effect. An effective and a low-cost finish process through the design electrode and using the grinding assistance in the electrochemical finishing after turning process make the surface of workpiece smooth and bright.

Applied Mechanics and Applied Technology in Fuel Injection Pump Bench Rotational Speed Measurement System Design Based on CPLD

2014 ◽  
Vol 910 ◽  
pp. 316-319
Author(s):  
Ji Chang Wang ◽  
Huan Huan Quan
Keyword(s):  
System Design ◽  
Measurement System ◽  
Rotational Speed ◽  
Fuel Injection ◽  
Test Bed ◽  
Injection Pump ◽  
Speed Measurement ◽  
Fuel Injection Pump ◽  
Pump Test ◽  
Hardware Description

In the article, proposing one kind of design plan about rotational speed measurement system design based CPLD. Various modules design has completed according to EDA tools and VHDL hardware description language. The feasibility of the speed measurement system design was verified based on the experiment. At present, the system has been successfully application in the fuel injection pump test-bed.

Equal Precision Rotation Speed Measurement System of Vichicle Transmission

2013 ◽  
Vol 765-767 ◽  
pp. 2153-2158
Author(s):  
Hong Tao Li
Keyword(s):  
Measurement System ◽  
Precision Measurement ◽  
Measurement Accuracy ◽  
Rotation Speed ◽  
Measurement Methods ◽  
Control Technology ◽  
Electronic Control ◽  
Power Train ◽  
Speed Measurement ◽  
Wide Range

The rev of vehicle transmission is an important parameter to reflect the performance of the power train, and the measurement accuracy will have an influence on the implement of electronic control technology in transmission system. Based on the analysis of common rev measurement methods, aiming at the feature of wide range of rev during HMCVT test, a method of rev equal precision measurement is been put forward.

The Rotational Speed Measurement of Brushless DC Motor Based on STM32 Microcontroller

2013 ◽  
Vol 760-762 ◽  
pp. 891-895
Author(s):  
Meng Bing ◽  
Fang Xiu Jia ◽  
Wen Jin Yao
Keyword(s):  
Real Time ◽  
Measurement System ◽  
Rotational Speed ◽  
Dc Motor ◽  
Brushless Dc Motor ◽  
Flip Flop ◽  
Brushless Dc ◽  
Speed Measurement ◽  
Trajectory Correction ◽  
Hall Sensors

The brushless DC motor applied on the electric steering gear of trajectory correction projectiles often requires getting real-time rotational speed value. The hall sensors output the hall signals for measurement, after the integration by the D-type flip-flop, an ideal pulse can be produced. Afterwards STM32F103ZE microcontroller is used to calculate the rotational speed value of the motor by the Improved M/T method. The resolution and precision can be analyzed after getting the result. This rotational speed measurement system has high precision and good real-time characteristics. It is significant for the meaning of the correction of the steering gear.

Transfer Function Modeling and Experimental Variation of Rotor System Considering Morton Effect Caused in Journal Bearing

2019 ◽  
Author(s):  
Shota Yabui ◽  
Jotaro Chiba ◽  
Takafumi Suzuki ◽  
Shigeyuki Tomimatsu ◽  
Tsuyoshi Inoue
Keyword(s):  
Experimental Data ◽  
Frequency Domain ◽  
Rotational Speed ◽  
Journal Bearing ◽  
Rotating Machinery ◽  
Rotating Shaft ◽  
High Rotational Speed ◽  
Proposed Model ◽  
Morton Effect ◽  
Unstable Vibration

Abstract In recent years, a rotating machinery are required to operate at high rotational speed for high efficiency. However, the rotating machinery may become unstable due to the increase of rotational speed. One cause of unstable vibration is the Morton Effect generated in a journal bearing. To avoid unstable vibration due to the Morton Effect, construction of a mathematical model for predicting it becomes an important subject. Many researches on the Morton Effect have been conducted previously. Conventional researches are mostly divided into two types. The first one is a study based on detailed numerical simulation using computational fluid dynamics (CFD), thermoshydrodynamics (THD) and so on. It tries to find solution of a differential equation which indicates the Morton Effect induced vibration for a specific machine or a test rig. Therefore, this approach has led not comprehensive model. The other one is a study expressed by a simple mathematical formula. However, modeling in the time domain has been mainly focused and modeling in the frequency domain has not been investigated in detail. In this research, a model based on the frequency response that can quantitatively evaluate the Morton Effect induced vibration in the rotating machinery supported by the journal bearing is developed. First, experimental data was collected for modeling by using an experimental rig. Using these experimental data of journal position in the journal bearing and temperature of journal, a model of the Morton Effect was constructed based on frequency responses. In the proposed method, the characteristic of the journal bearing was considered as a proportional differential controller from control engineering point of view. In addition, the proposed model considers the Morton Effect induced vibration as a new bending mode of a rotating shaft caused by thermal difference. Then, the developed model of the Morton Effect was evaluated in the frequency domain. The characteristics of vibration calculated by the proposed model indicated good correlation with that of the experimental data. Finally, the behavior of the rotating shaft at another rotational speed was predicted by using the proposed model. It was confirmed that the experimental data well agreed with the predicted results. These results show the usefulness of the proposed method of this research for predicting the Morton Effect.

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