scholarly journals Ultrasonic distance and velocity measurement by low-calculation-cost Doppler-shift compensation and high-resolution Doppler velocity estimation with wide measurement range

2009 ◽  
Vol 30 (3) ◽  
pp. 220-223 ◽  
Author(s):  
Shinnosuke Hirata ◽  
Minoru Kuribayashi Kurosawa ◽  
Takashi Katagiri
Keyword(s):  
High Resolution ◽  
Doppler Shift ◽  
Velocity Measurement ◽  
Measurement Range ◽  
Velocity Estimation ◽  
Doppler Velocity

Study on Doppler Velocity Measurement System

2012 ◽  
Vol 562-564 ◽  
pp. 1240-1243
Author(s):  
Jian Chao Li ◽  
Jun Hong Su ◽  
Ming Gao
Keyword(s):  
Measurement System ◽  
Velocity Measurement ◽  
High Speed ◽  
Processing System ◽  
Measurement Range ◽  
High Accuracy ◽  
Laser Doppler ◽  
Doppler Velocity ◽  
Dual Frequency ◽  
Frequency Laser

In order to satisfy the high accuracy velocity measurement requirement, using the improved dual-frequency laser Doppler velocity measurement principle, designed a set of laser Doppler velocity measurement system. System consists of two parts: optical system and signal acquisition and processing system. Through the establishment of dual-frequency laser Doppler velocity measurement experimental platform for testing, the result shows that the method can be carried on the high accuracy velocity measurement which in high speed move object. Measurement range from 0.1 m/s to 50 m/s, the error is less than 2 percent and it could increase the speed measurement range.

scholarly journals GNSS DOPPLER VELOCITY BASED ON ADAPTIVE ROBUST KALMAN FILTERING

2020 ◽  
Vol XLII-3/W10 ◽  
pp. 1005-1012
Author(s):  
H. Liu ◽  
M. Z. Xin ◽  
J. J. Wei ◽  
Y. K. Liang ◽  
F. L. Yang
Keyword(s):  
Kalman Filter ◽  
Kalman Filtering ◽  
Velocity Measurement ◽  
Measurement Errors ◽  
Threshold Value ◽  
Velocity Estimation ◽  
Least Square ◽  
Doppler Velocity ◽  
Factors Affecting ◽  
Robust Kalman Filter

Abstract. The main factors affecting the error of Doppler velocity measurement mainly come from the measurement errors of GNSS data, influence of different motion states on GNSS velocity measurement and the noise of different receiver types. To improve the precision of GNSS velocity estimation, an algorithm of adaptive robust Kalman filter based on the PDOP was put forward. PDOP value as well as the number of satellite in each epoch are used as a criterion in the velocity processing. While the PDOP value is greater than the threshold value, which means the observation accuracy is low, then the robust Kalman filter based on IGG – III scheme is introduced. While the PDOP value is between the threshold values, which means the observation precision is normal, adaptive factor could be determined normally, and the single-factor three-stage adaptive model is applied for Kalman filtering. If the above two conditions are not consistent, it indicates that the prediction accuracy of the local epoch satellite is high, and Kalman filtering can be directly used. Through the experiment of shipborne GNSS velocity measurement, it was proved that comparing with conventional least square, the algorithm based on the adaptive robust Kalman filtering can improve the accuracy and stability of the GNSS velocity determination.

HIGH‐RESOLUTION LASER DOPPLER VELOCITY MEASUREMENT OF BIDIRECTIONAL PULSATILE FLUID FLOW

1970 ◽  
Vol 17 (12) ◽  
pp. 523-525 ◽  
Author(s):  
Otto Lanz ◽  
Curtis C. Johnson ◽  
Satsuki Morikawa
Keyword(s):  
Fluid Flow ◽  
High Resolution ◽  
Velocity Measurement ◽  
Laser Doppler ◽  
Doppler Velocity

scholarly journals Measuring Current in a Power Converter Using Fuzzy Automatic Gain Control

2021 ◽  
Vol 11 (13) ◽  
pp. 5793
Author(s):  
Bartosz Dominikowski
Keyword(s):  
High Resolution ◽  
Fuzzy Controller ◽  
Automatic Gain Control ◽  
Gain Control ◽  
Measurement Range ◽  
Power Converter ◽  
Current Measurement ◽  
Dc Power ◽  
Programmable Gain ◽  
Electric Loads

The accuracy of current measurements can be increased by appropriate amplification of the signal to within the measurement range. Accurate current measurement is important for energy monitoring and in power converter control systems. Resistance and inductive current transducers are used to measure the major current in AC/DC power converters. The output value of the current transducer depends on the load motor, and changes across the whole measurement range. Modern current measurement circuits are equipped with operational amplifiers with constant or programmable gain. These circuits are not able to measure small input currents with high resolution. This article proposes a precise loop gain system that can be implemented with various algorithms. Computer analysis of various automatic gain control (AGC) systems proved the effectiveness of the Mamdani controller, which was implemented in an MCU (microprocessor). The proposed fuzzy controller continuously determines the value of the conversion factor. The system also enables high resolution measurements of the current emitted from small electric loads (≥1 A) when the electric motor is stationary.

scholarly journals Dynamic Optimization Method for Broadband ADCP Waveform with Environment Constraints

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3768
Author(s):  
Yongshou Yang ◽  
Shiliang Fang
Keyword(s):  
Distance Estimation ◽  
Acoustic Doppler Current Profiler ◽  
Optimization Method ◽  
Measurement Range ◽  
Velocity Estimation ◽  
Estimation Accuracy ◽  
Dynamic Configuration ◽  
Optimal Velocity ◽  
Flood Warning ◽  
The Impact

Broadband acoustic Doppler current profiler (ADCP) is widely used in agricultural water resource explorations, such as river discharge monitoring and flood warning. Improving the velocity estimation accuracy of broadband ADCP by adjusting the waveform parameters of a phase-encoded signal will reduce the velocity measurement range and water stratification accuracy, while the promotion of stratification accuracy will degrade the velocity estimation accuracy. In order to minimize the impact of these two problems on the measurement results, the ADCP waveform optimization problem that satisfies the environment constraints while keeping high velocity estimation accuracy or stratification accuracy is studied. Firstly, the relationship between velocity or distance estimation accuracy and signal waveform parameters is studied by using an ambiguity function. Secondly, the constraints of current velocity range, velocity distribution and other environmental characteristics on the waveform parameters are studied. For two common measurement applications, two dynamic configuration methods of waveform parameters with environmental adaptability and optimal velocity estimation accuracy or stratification accuracy are proposed based on the nonlinear programming principle. Experimental results show that compared with the existing methods, the velocity estimation accuracy of the proposed method is improved by more than 50%, and the stratification accuracy is improved by more than 22%.

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