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Instantaneous rotation speed measurement and error analysis for variable speed hydraulic system 被引量:1
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作者 杨彬 谷立臣 +1 位作者 刘永 王平 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2015年第4期315-321,共7页
In order to monitor the working state of piston motor and measure its instantaneous rotation speed accurately, the measuring principle and method of instantaneous rotation speed based on industrial personal computer a... In order to monitor the working state of piston motor and measure its instantaneous rotation speed accurately, the measuring principle and method of instantaneous rotation speed based on industrial personal computer and data acquisition card are introduced, and the major error source, influence mechanism and processing method of data quantization error are dis- cussed. By means of hybrid programming approach of LabVIEW and MATLAB, the instantaneous rotation speed measurement system for the piston motor in variable speed hydraulic system is designed. The simulation and experimental results show that the designed instantaneous speed measurement system is feasible. Furthermore, the sampling frequency has an important influ- ence on the instantaneous rotation speed measurement of piston motor and higher sampling frequency can lower quantization er- ror and improve measurement accuracy. 展开更多
关键词 variable speed hydraulic system instantaneous rotation speed measurement error analysis hybrid programming
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Speed Measurement Feasibility by Eddy Current Effect in the High-Speed MFL Testing
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作者 Zhaoting Liu Jianbo Wu +4 位作者 Sha He Xin Rao Shiqiang Wang Shen Wang Wei Wei 《Structural Durability & Health Monitoring》 EI 2023年第4期299-314,共16页
It is known that eddy current effect has a great influence on magnetic flux leakage testing(MFL).Usually,contacttype encoder wheels are used to measure MFL testing speed to evaluate the effect and further compensate t... It is known that eddy current effect has a great influence on magnetic flux leakage testing(MFL).Usually,contacttype encoder wheels are used to measure MFL testing speed to evaluate the effect and further compensate testing signals.This speed measurement method is complicated,and inevitable abrasion and occasional slippage will reduce the measurement accuracy.In order to solve this problem,based on eddy current effect due to the relative movement,a speed measurement method is proposed,which is contactless and simple.In the high-speed MFL testing,eddy current induced in the specimen will cause an obvious modification to the applied field.This modified field,which is measured by Hall sensor,can be utilized to reflect the moving speed.Firstly,the measurement principle is illustrated based on Faraday’s law.Then,dynamic finite element simulations are conducted to investigate the modified magnetic field distribution.Finally,laboratory experiments are performed to validate the feasibility of the proposed method.The results show that Bmz(r1)and Bmx(r2)have a linear relation with moving speed,which could be used as an alternative measurement parameter. 展开更多
关键词 Magnetic flux leakage testing(MFL) speed measurement eddy current effect modified magnetic field
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A new method for high precsion instantaneous speedmeasurement of hydraulic system 被引量:1
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作者 LIU Jia-min GU Li-chen SUN Yu 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2019年第4期307-314,共8页
The instantaneous speed of a hydraulic system contains a wealth of operational information,and its accurate extraction is the basis for condition monitoring and fault diagnosis.In order to solve the problem of high ha... The instantaneous speed of a hydraulic system contains a wealth of operational information,and its accurate extraction is the basis for condition monitoring and fault diagnosis.In order to solve the problem of high hardware requirement for instantaneous speed measurement based on data acquisition card,a new method of high precision measurement is proposed.In this method,the time-displacement information of each tooth is obtained from the pulsed square wave signal of the gear disk collected by magnetoelectric sensors.The time-displacement curve is interpolated by the cubic spline interpolation method,and then the instantaneous speed is calculated by the five-point digital differential formula.The experimental results show that the method improves the speed measurement resolution and reduces the quantization error.The high precision instantaneous speed signal can also be acquired by hardware devices with less teeth and low sampling frequency.The related research results provide a theoretical basis and a method for improving the accuracy of instantaneous speed measurement. 展开更多
关键词 instantaneous speed measurement variable speed hydraulic system cubic spline interpolation five-point digital differentiation
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APPROACH OF IMPROVING PRECISION IN ULTRASONIC DOPPLER BLOODSTREAM SPEED MEASUREMENT BY CHAOS-BASED FREQUENCY DETECTING 被引量:3
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作者 Zhang Shuqing Jin Shijiu +2 位作者 Lv Jiangtao Zhang Liguo Li Jun 《Journal of Electronics(China)》 2006年第3期457-460,共4页
It is critical for cerebral vascular disease diagnosis through Doppler to detect the maximum and the minimum of the carotid blood flow speed accurately. A kind of Duffing system under an external periodic power with d... It is critical for cerebral vascular disease diagnosis through Doppler to detect the maximum and the minimum of the carotid blood flow speed accurately. A kind of Duffing system under an external periodic power with dump is introduced in the letter, numerical analysis is carried out by four-order Runge-Kutta method. An oscillator array is designed according to the frequency of the ultrasonic wave. When the external signals are inputted, computational algorithm is used to scan the array in turn and analyze the result, and the frequency can be determined. Based on the methods above, detecting the carotid blood flow speed accurately is realized. The Signal-to-Noise Ratio (SNR) of-20.23dB is obtained by the result of experiments. In conclusion, the SNR has been improved and the precision of the measured bloodstream speed has been increased, which can be 0.069% to 0.13%. 展开更多
关键词 CHAOS Frequency detecting Bloodstream speed measuring Ultrasonic Doppler Signal-to-Noise Ratio (SNR) Measuring precision
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Research on the measurement of belt speed by video in coal mine based on improved template matching algorithm 被引量:1
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作者 ZHU Ai-chun HUA Wei +1 位作者 WANG Chun WANG Yong-xing 《Journal of Coal Science & Engineering(China)》 2011年第4期469-474,共6页
In order to improve the intelligence of video monitoring system of belt and make up the deficiency of higher failure rate and bad real-time performance in the traditional systems of measurement of belt speed, accordin... In order to improve the intelligence of video monitoring system of belt and make up the deficiency of higher failure rate and bad real-time performance in the traditional systems of measurement of belt speed, according to the fact that the light of coal mine is uneven, the strength of light changes greatly, the direction of belt movement is constant, and the position of camera was fixed, various algorithms of speed measurement by video were studied, and algorithm for template matching based on sum of absolute differences (SAD) and correlation coefficient was proposed and improved, besides, the tracking of feature regions was realized. Then, a camera calibration method using the invariance of the cross-ratio was adopted and the real-time measurement of belt speed by the hardware platform based on DM642 was realized. Finally, experiment results show that this method not only has advantages of high precision and strong anti-jamming capability but also can real-time reflect the changes of belt speed, so it has a comprehensive applicability. 展开更多
关键词 speed measurement by video template matching algorithm DM642 invariance of cross-ratio
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Information fusion of train speed and distance measurements based on fuzzy adaptive Kalman filter algorithm 被引量:1
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作者 FAN Ze yuan DONG Yu 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2018年第3期286-292,共7页
The measurement accuracy of speed and distance in high speed train directly affects the control precision and driving efficiency of train control system. To improve the capability of train self control, a combined spe... The measurement accuracy of speed and distance in high speed train directly affects the control precision and driving efficiency of train control system. To improve the capability of train self control, a combined speed measurement and positioning method based on speed sensor and radar which is assisted by global positioning system(GPS) is proposed to improve the accuracy of measurement and reduce the dependence on the ground equipment. In consideration of the fact that the filtering precision of Kalman filter will decrease when the statistical characteristics are changing, this paper uses fuzzy comprehensive evaluation method to evaluate the sub filter, and information distribution coefficients are dynamically adjusted according to filtering reliability, which can improve the fusion accuracy and fault tolerance of the system. The sub filter is required to carry on the covariance shaping adaptive filtering when it is in the suboptimal state. The adjustment factor of error covariance is obtained according to the minimized cost function, which can improve the matching degree between the measured residual variance and the system recursive residual. The simulation results show that the improved filter algorithm can track the changes of the system effectively, enhance the filtering accuracy significantly, and improve the measurement accuracies of train speed and distance. 展开更多
关键词 information fusion federated Kalman filter fuzzy comprehensive evaluation train speed and distance measurements
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Application of Fiber in Blood Speed Measurement
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作者 SHANG Li-ping, ZHENG De-zhong, XIE Hua-bing, SHI Jin-shan (Yanshan University, Qinhuangdao 066004, CHN) 《Semiconductor Photonics and Technology》 CAS 2000年第2期126-128,共3页
There exist many methods to measure blood speed, all of which have some serious shortcomings. As fiber is characterized by tiny diameter, and low lost ratio of power and flexibility, it is suitable for measuring blood... There exist many methods to measure blood speed, all of which have some serious shortcomings. As fiber is characterized by tiny diameter, and low lost ratio of power and flexibility, it is suitable for measuring blood speed. It is proved that the speedometer has high space resolving power,high time resolving power, and outstanding capability of approaching target, etc. 展开更多
关键词 FIBER speed measurement Doppler frequency shifting
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Simultaneous measurement of distance and speed using frequency-modulated continuous-wave self-mixing interferometry and all-phase fast Fourier transform
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作者 Jinyuan Yuan Bin Liu 《Chinese Optics Letters》 SCIE EI CAS CSCD 2024年第7期29-34,共6页
In this work,we propose a method using frequency-modulated continuous-wave(FMCW)self-mixing interferometry(SMI)and all-phase fast Fourier transform(APFFT)for simultaneous measurement of speed and distance.APFFT offers... In this work,we propose a method using frequency-modulated continuous-wave(FMCW)self-mixing interferometry(SMI)and all-phase fast Fourier transform(APFFT)for simultaneous measurement of speed and distance.APFFT offers superior accuracy in frequency determination by mitigating issues like the fence effect and spectrum leakage,contributing to the high-accuracy measurement for speed and distance.Both simulations and experiments have demonstrated relative errors at the levels of 10^(−4) and 10^(−3) for distance and speed measurements,respectively.Furthermore,factors impacting measurement performance have been discussed.The proposed method provides a high-performance and cost-effective solution for distance and speed measurements,applicable across scientific research and various industrial domains. 展开更多
关键词 self-mixing interferometry frequency-modulated continuous-wave interferometry all-phase fast Fourier transform measurement of distance and speed
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Study on Integral Expression in Measurement of Average Ion Velocity by Multi-Grid Probe
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作者 宁中喜 于达仁 魏振磊 《Plasma Science and Technology》 SCIE EI CAS CSCD 2008年第4期471-475,共5页
In order to improve the interference rejection performance in the measurement of average ion velocity by multi-grid probe, an integral expression is proposed. The integral expression, differing from other expressions ... In order to improve the interference rejection performance in the measurement of average ion velocity by multi-grid probe, an integral expression is proposed. The integral expression, differing from other expressions for probe measurement, avoids the differential operation on the I-V characteristics of multi-grid probe measurement; and by this method, the ion average velocity can be figured out directly by the I-V characteristics of multi-grid probe measurement. 展开更多
关键词 multi-grid probe ion beam speed measurement
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Rotation speed measurement of moving particles in a CFB riser 被引量:3
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作者 Xuecheng Wu Qinhui Wang Zhongyang Luo Mengxiang Fang Kefa Cen 《Particuology》 SCIE EI CAS CSCD 2009年第4期238-244,共7页
This paper presents a study on measuring rotation speed of moving glass beads with an average diameter of 500 p.m in a pilot-scale circulating fluidized bed (CFB) riser with a high-speed digital imaging system. Two ... This paper presents a study on measuring rotation speed of moving glass beads with an average diameter of 500 p.m in a pilot-scale circulating fluidized bed (CFB) riser with a high-speed digital imaging system. Two methods have been developed to calculate particle rotation speed from the particle images. The first method consists of a fully automated algorithm based on cross-correlation of gray distribution of particle images for particles whose rotation axes are (nearly) perpendicular to the imaging plane, and the second method calculates the speed of particle rotation by identifying its rotation axis using two or more characteristic points on its surface. The reliability of the two methods is verified by using a small sphere with known speed and direction of rotation. The first method is shown to be capable of measuring accurately the rotation speed for the particle with a rotation axis (nearly) perpendicular to the imaging plane and filtering off other particles using an appropriate threshold of correlation coefficient. The second method is shown to be capable of yielding both the speed and direction of particle rotation, with a measurement error of less than 10%. Results of both methods on real glass beads in a CFB riser are compared against each other. 展开更多
关键词 Rotation speed measurement Moving particles Gas-solid flow Circulating fluidized bed (CFB)
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Particle Filter and Its Application in the Integrated Train Speed Measurement 被引量:3
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作者 ZHANG Liang BAO Qilian +3 位作者 CUI Ke JIANG Yaodong XU Haigui DU Yuding 《Journal of Shanghai Jiaotong university(Science)》 EI 2019年第1期130-136,共7页
Particle filter(PF) can solve the problem of state estimation under strong non-linear non-Gaussian noise condition with respect to traditional Kalman filter(KF) and those improved KFs such as extended KF(EKF) and unsc... Particle filter(PF) can solve the problem of state estimation under strong non-linear non-Gaussian noise condition with respect to traditional Kalman filter(KF) and those improved KFs such as extended KF(EKF) and unscented KF(UKF). However, problems such as particle depletion and particle degradation affect the performance of PF. Optimizing the particle set to high likelihood region with intelligent optimization algorithm results in a more reasonable distribution of the sampling particles and more accurate state estimation. In this paper, a novel bird swarm algorithm based PF(BSAPF) is presented. Firstly, different behavior models are established by emulating the predation, flight, vigilance and follower behavior of the birds. Then, the observation information is introduced into the optimization process of the proposal distribution with the design of fitness function. In order to prevent particles from getting premature(being stuck into local optimum) and increase the diversity of particles, Lévy flight is designed to increase the randomness of particle's movement. Finally,the proposed algorithm is applied to estimate the speed of the train under the condition that the measurement noise of the wheel sensor is non-Gaussian distribution. Simulation study and experimental results both show that BSAPF is more accurate and has more effective particle number as compared with PF and UKF, demonstrating the promising performance of the method. 展开更多
关键词 particle filter(PF) bird swarm algorithm fitness function Lévy flight proposal distribution integrated train speed measurement
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A portable high precision three dimensional trace measuring system for underwater target with high speed 被引量:1
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作者 TIAN Tan, DING Yuzhong and YAO Lan (Harbin Shipbuilding Engineering Institute) 《Chinese Journal of Acoustics》 1991年第1期53-62,共10页
The paper describes a portable high precision three-dimensional trace measuring system for underwater target with high speed. The mathematical model for location, the main error sources, the calibration method for the... The paper describes a portable high precision three-dimensional trace measuring system for underwater target with high speed. The mathematical model for location, the main error sources, the calibration method for the underwater array and the way to correct its state are discussed. Problems about the distance ambiguity and multi-path interference are also analyzed. Part of experimental results on lake and at sea are given as well. 展开更多
关键词 A portable high precision three dimensional trace measuring system for underwater target with high speed HIGH
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Experimental Investigation of Electric Drive Dynamics
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作者 Sigitas Juraitis Roma Rinkevieiene Algirdas Smilgevicius 《Journal of Energy and Power Engineering》 2012年第7期1153-1157,共5页
Induction motor is used in many applications to drive an electromechanical system. Transients of the motor torque and speed are outlined by the inertia of rotating rotor. The paper deals with influence of rotor inerti... Induction motor is used in many applications to drive an electromechanical system. Transients of the motor torque and speed are outlined by the inertia of rotating rotor. The paper deals with influence of rotor inertia to transients of motor speed. The method of speed control measurement and experimental equipment is discussed. Simulation and experimental results are compared. 展开更多
关键词 Electromechanical system SIMULATION model of induction motor rotation speed measurement.
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Adaptive Interval Type-2 Fuzzy Controller for Variable-speed Wind Turbine 被引量:1
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作者 Danyal Bustan Hoda Moodi 《Journal of Modern Power Systems and Clean Energy》 SCIE EI CSCD 2022年第2期524-530,共7页
In this paper,an adaptive interval type-2 fuzzy controller is proposed for variable-speed and variable-pitch wind turbines.Because of attractive features of the well-known wind turbine baseline controller,the proposed... In this paper,an adaptive interval type-2 fuzzy controller is proposed for variable-speed and variable-pitch wind turbines.Because of attractive features of the well-known wind turbine baseline controller,the proposed controller acts as an augmented controller and works in parallel to the baseline controller.As typical variable-speed wind turbines have different controllers for different operation regions,for each operation region,a dedicated interval tvpe-2 fuzzy controller is designed.Because of the uncertainty in wind speed measurement,modern control techniques try to estimate this value.However,in contrast to these modern control techniques,the proposed controller is independent of the wind speed estimation.Thus,there is a better saving in cost and computational burden.To evaluate the effectiveness of the proposed controller,simulations are conducted with wind profiles which span all operation regions.Results show that,compared with the baseline controller,the proposed controller enhances power generations and reduces mechanical loads concurrently. 展开更多
关键词 Interval type-2 fuzzy control baseline controller wind speed measurement wind turbine
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Epidemic modeling:Diffusion approximation vs.stochastic differential equations allowing reflection
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作者 Mohamed El Fatini Mohammed Louriki +1 位作者 Roger Pettersson Zarife Zararsiz 《International Journal of Biomathematics》 SCIE 2021年第5期273-293,共21页
A birth-death process is considered as an epidemic model with recovery and transmittance from outside.The fraction of infected individuals is for huge population sizes approximated by a solution of an ordinary differe... A birth-death process is considered as an epidemic model with recovery and transmittance from outside.The fraction of infected individuals is for huge population sizes approximated by a solution of an ordinary differential equation taking values in[0,1].For intermediate size or semilarge populations,the fraction of infected individuals is approximated by a diffusion formulated as a stochastic differential equation.That diffusion approximation however needs to be killed at the boundary{0}U{1}.An alternative stochastic differential equation model is investigated which instead allows a more natural reflection at the boundary. 展开更多
关键词 Epidemic models stochastic differential equations scale measure speed measure diffusion approximations reflecting boundaries killed processes
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Novel laser Doppler tachometer
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作者 Wentao Li Jian Zhou 《Chinese Optics Letters》 SCIE EI CAS CSCD 2021年第1期24-30,共7页
In order to improve the accuracy and universality of the rotational speed measurement,an instantaneous rotational speed measurement method based on laser Doppler technology is proposed.The composition and working prin... In order to improve the accuracy and universality of the rotational speed measurement,an instantaneous rotational speed measurement method based on laser Doppler technology is proposed.The composition and working principle of the new system are discussed in detail.Theoretical and experimental results show that the new rotational speed measurement system belongs to the non-contact method,which eliminates the quantization error of the contact method and greatly improves the applicability and accuracy.Compared to the commonly used method,the measurement accuracy of the new rotational speed measurement system will not be affected by the system’s installation angle deviation,and it does not need to measure the radius of the rotating body,so the influence of the radius fluctuation of the rotating body on the measurement accuracy can be avoided while outputting the rotational speed in real time.The relative error of the rotational speed measurement is less than 0.06%(1σ). 展开更多
关键词 laser Doppler technology rotational speed measurement NON-CONTACT real time
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