Study on Harmonic Analysis and Error Correction in Synchro to Digital Conversion

2011 ◽  
Vol 225-226 ◽  
pp. 334-337 ◽  
Author(s):  
Yan Liu ◽  
Ze Gang Ye
Keyword(s):  
Harmonic Analysis ◽  
Error Correction ◽  
Measurement Method ◽  
Angle Measurement ◽  
Conversion Process ◽  
Matlab Simulation ◽  
Angle Error ◽  
Digital Conversion ◽  
Current Implementation ◽  
Improve Accuracy

The current implementation of the synchro to digital conversion (SDC) can not directly detect harmonic which can cause the problem of low precision angle measurement. To improve accuracy of angle, harmonic interference was analyzed and summarized in the axis-angle to digital conversion process. Through detailed research, a new angle measurement formula is proposed in this paper, this formula can be very good for angle error correction and compensation. In order to meet the practical requirements, a software measurement method based on FFT algorithm of harmonic analysis and error correction is put forward. Matlab simulation shows that the formula and method is effective and feasible.

scholarly journals An Angle Error Compensation Method Based on Harmonic Analysis for Integrated Joint Modules

Sensors ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 1715
Author(s):  
Yi Hu ◽  
Yuyi Zhan ◽  
Liang Han ◽  
Penghao Hu ◽  
Bing Ye ◽  
...  
Keyword(s):  
Harmonic Analysis ◽  
Coordinate Measuring Machine ◽  
Angle Measurement ◽  
Error Model ◽  
The Self ◽  
Model Parameters ◽  
Angle Error ◽  
Positioning Accuracy ◽  
Measuring Machine ◽  
High Repeatability

Nowadays, integrated joint modules are increasingly adopted in manipulators for their advantages of high integration, miniaturization and high repeatability positioning accuracy. The problem of generally low absolute positioning accuracy (namely angle measurement accuracy) must be solved before they can be introduced into the self-driven articulated arm coordinate measuring machine which is under study in our laboratory. In this study, the sources of joint module’s angle error were analyzed and the error model based on harmonic analysis was established. Two integrated joint modules were calibrated on the self-designed calibration platform and the model parameters were deduced, respectively. The angle error was then compensated in the experiments and the results demonstrated that the angle error of the joint modules was reduced by 82.03% on average. The established angle error model can be effectively applied into the self-driven articulated arm coordinated measuring machine.

scholarly journals Fast 10-Point DFT Algorithm for Power System Harmonic Analysis

2021 ◽  
Vol 11 (15) ◽  
pp. 7007
Author(s):  
Janusz P. Paplinski ◽  
Aleksandr Cariow
Keyword(s):  
Computational Complexity ◽  
Power System ◽  
Harmonic Analysis ◽  
Efficient Algorithm ◽  
System Analysis ◽  
Spectral Leakage ◽  
Power System Analysis ◽  
Improve Accuracy ◽  
The Cost ◽  
Harmonic Power

This article presents an efficient algorithm for computing a 10-point DFT. The proposed algorithm reduces the number of multiplications at the cost of a slight increase in the number of additions in comparison with the known algorithms. Using a 10-point DFT for harmonic power system analysis can improve accuracy and reduce errors caused by spectral leakage. This paper compares the computational complexity for an L×10M-point DFT with a 2M-point DFT.

scholarly journals An Optical Frequency Domain Angle Measurement Method Based on Second Harmonic Generation

Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 670
Author(s):  
Wijayanti Dwi Astuti ◽  
Hiraku Matsukuma ◽  
Masaru Nakao ◽  
Kuangyi Li ◽  
Yuki Shimizu ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Second Harmonic Generation ◽  
Frequency Domain ◽  
Harmonic Generation ◽  
Measurement Method ◽  
Second Harmonic ◽  
Angle Measurement ◽  
Laser Source ◽  
Optical Frequency ◽  
Measurable Range

This paper proposes a new optical angle measurement method in the optical frequency domain based on second harmonic generation with a mode-locked femtosecond laser source by making use of the unique characteristic of the high peak power and wide spectral range of the femtosecond laser pulses. To get a wide measurable range of angle measurement, a theoretical calculation for several nonlinear optical crystals is performed. As a result, LiNbO3 crystal is employed in the proposed method. In the experiment, the validity of the use of a parabolic mirror is also demonstrated, where the chromatic aberration of the focusing beam caused the localization of second harmonic generation in our previous research. Moreover, an experimental demonstration is also carried out for the proposed angle measurement method. The measurable range of 10,000 arc-seconds is achieved.

scholarly journals Effectiveness of Variable-Gain Kalman Filter Based on Angle Error Calculated from Acceleration Signals in Lower Limb Angle Measurement with Inertial Sensors

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Yuta Teruyama ◽  
Takashi Watanabe
Keyword(s):  
Kalman Filter ◽  
Lower Limb ◽  
Measurement Accuracy ◽  
Inertial Sensors ◽  
Angle Measurement ◽  
Angle Error ◽  
Variable Gain ◽  
Improve Measurement ◽  
Kalman Gain ◽  
Acceleration Signals

The wearable sensor system developed by our group, which measured lower limb angles using Kalman-filtering-based method, was suggested to be useful in evaluation of gait function for rehabilitation support. However, it was expected to reduce variations of measurement errors. In this paper, a variable-Kalman-gain method based on angle error that was calculated from acceleration signals was proposed to improve measurement accuracy. The proposed method was tested comparing to fixed-gain Kalman filter and a variable-Kalman-gain method that was based on acceleration magnitude used in previous studies. First, in angle measurement in treadmill walking, the proposed method measured lower limb angles with the highest measurement accuracy and improved significantly foot inclination angle measurement, while it improved slightly shank and thigh inclination angles. The variable-gain method based on acceleration magnitude was not effective for our Kalman filter system. Then, in angle measurement of a rigid body model, it was shown that the proposed method had measurement accuracy similar to or higher than results seen in other studies that used markers of camera-based motion measurement system fixing on a rigid plate together with a sensor or on the sensor directly. The proposed method was found to be effective in angle measurement with inertial sensors.

scholarly journals A radio navigation angle measurement method with entangled microwave signals

AIP Advances ◽  
2018 ◽  
Vol 8 (6) ◽  
pp. 065217 ◽  
Author(s):  
X. Li ◽  
D. W. Wu ◽  
T. L. Wei ◽  
Q. Miao ◽  
H. N. Zhu ◽  
...  
Keyword(s):  
Measurement Method ◽  
Angle Measurement ◽  
Radio Navigation ◽  
Microwave Signals

scholarly journals Dispersion measurement method with down conversion process

2018 ◽  
Vol 2 (6) ◽  
pp. 065014 ◽  
Author(s):  
Marta Misiaszek ◽  
Andrzej Gajewski ◽  
Piotr Kolenderski
Keyword(s):  
Measurement Method ◽  
Conversion Process ◽  
Dispersion Measurement ◽  
Down Conversion

A high-precision roll angle measurement method

Optik ◽  
2015 ◽  
Vol 126 (24) ◽  
pp. 4837-4840 ◽  
Author(s):  
Zhai Yusheng ◽  
Zhang Zhifeng ◽  
Su Yuling ◽  
Wang Xinjie ◽  
Feng Qibo
Keyword(s):  
High Precision ◽  
Measurement Method ◽  
Angle Measurement ◽  
Roll Angle

scholarly journals A Novel Technique for Resolver-to-Digital Conversion Using Principal Frequency Component S-Transform

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Like He ◽  
Jiliang Yi
Keyword(s):  
Frequency Conversion ◽  
Frequency Component ◽  
Sampling Point ◽  
Angle Error ◽  
Digital Conversion ◽  
Time Frequency ◽  
Novel Technique ◽  
Principal Frequency ◽  
S Transform ◽  
Maximum Angle

A novel technique for resolver-to-digital conversion (RDC) using principal frequency component S-transform (PFCST) is proposed in this paper. First, the mode envelope of two output signals of the resolver is extracted by PFCST. The envelope extracted by PFCST maintains the same time resolution as the original signal because it performs time-frequency conversion for each sampling point. Then, the quadrant of the resolver is determined by the judgment rule formed by the polarity of the optimum nonzero region of the signals, and the quadrant information is used to correct the arctangent to obtain the accurate rotor position. Finally, the simulations prove that the maximum angle error of the resolver estimated by this method occurs at the quadrant junction but does not exceed one deg., and the experiments are used to verify the effectiveness of the proposed method.

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