A Quick-response and High-precision Dynamic Measuring Method with the Application on Small Angle Measurement

Author(s):  
Zichen Wang ◽  
Tao Huang ◽  
Yueting Kang ◽  
Zhihong Luo

Abstract Small angle measuring tools with pendulum mechanical structure has two major challenges. One is that it takes long time to wait for the pendulum structure to completely stop swinging, and the other is that the instrument has poor anti-interference ability. Inspired by the two challenges, this paper proposes a dynamical measuring method to achieve a fast and accurate measurement synchronously. Specially, a damped oscillation modeling of the pendulum with nonlinear least squares fitting is presented to estimate the model parameters which includes the angle of the oblique plane. Besides, it is proved that the minimum sample size required for data fitting is decided by one oscillation period, which guarantees the shortest measuring time within high precision. Moreover, this paper also presents the precision criterion of fitting parameters to judge whether the fitting results meet the requirements. This proposed method is applied to a developed small angle measuring tool. The error of the proposed measurement system is better than 3.25 '' and the uncertainty is 4.8 '' within the measurement angle of 2000 '', and the settling time is 0.45 s. The experimental results confirm that this method can not only greatly shorten the measuring time, but also enhance the anti-interference ability and realize high-precision measurement.

2014 ◽  
Vol 1022 ◽  
pp. 96-99 ◽  
Author(s):  
Le Ha ◽  
Li Jin Fang

In the project of testing platform, characteristics of the measured object are framework. In view of the difficulties of non-contact high-precision measurement of the planar motion objects, an innovative measuring method is proposed which is based on the combined using of high-precision laser distance sensors. This paper presents the structure of the new sensor and its measuring principle, and established a mathematical model of the measurement object and its error model by using differential method. We use the Monte Carlo method to random sample the random sampling of random variables of the error model; finally combining with the instance; we use the Monte Carlo method to get frequency distribution histogram of the measurement error. Through analysis and calculation of this paper, we prepare for theory for the practical application of this new type of sensor.


2017 ◽  
Vol 868 ◽  
pp. 99-104
Author(s):  
Wen Ying Zhang ◽  
Wei Hu Zhou ◽  
Da Bao Lao ◽  
Hao Ran Zhu

Cylindrical grating angle sensor is a common angle measuring device with high precision. Due to the reflecting arc surface of the cylindrical grating the effects of relative displacement of graduation line and gap variation will interact. Significant residual errors still exist even with high precision cylindrical grating and multiple reading heads around the scale disc .In this paper, based on the principle of circumference closure, the principle of self-calibration is deduced and analyzed in detail. The calibration curve is obtained by obtaining the deviation between the certain position and an ideal position of the graduation line position in real time. A simple self-calibration method of cylindrical grating is acquired. It can calibrate random errors and system errors with time and improve the angle measurement accuracy. The method has the advantages of simple structure and strong maneuverability, and provides technical means for the miniaturization and high precision of cylindrical grating.


2010 ◽  
Author(s):  
Jingang Zhong ◽  
Pan Qi ◽  
Chun Chen ◽  
Zhen Chen

1991 ◽  
Vol 1 (12) ◽  
pp. 1669-1673 ◽  
Author(s):  
Hans Gerd Evertz ◽  
Martin Hasenbusch ◽  
Mihail Marcu ◽  
Klaus Pinn ◽  
Sorin Solomon

Radiocarbon ◽  
2020 ◽  
pp. 1-13
Author(s):  
Alexandra Fogtmann-Schulz ◽  
Sabrina G K Kudsk ◽  
Florian Adolphi ◽  
Christoffer Karoff ◽  
Mads F Knudsen ◽  
...  

ABSTRACT We here present a comparison of methods for the pretreatment of a batch of tree rings for high-precision measurement of radiocarbon at the Aarhus AMS Centre (AARAMS), Aarhus University, Denmark. The aim was to develop an efficient and high-throughput method able to pretreat ca. 50 samples at a time. We tested two methods for extracting α-cellulose from wood to find the most optimal for our use. One method used acetic acid, the other used HCl acid for the delignification. The testing was conducted on background 14C samples, in order to assess the effect of the different pretreatment methods on low-activity samples. Furthermore, the extracted wood and cellulose fractions were analyzed using Fourier transform infrared (FTIR) spectroscopy, which showed a successful extraction of α-cellulose from the samples. Cellulose samples were pretreated at AARAMS, and the graphitization and radiocarbon analysis of these samples were done at both AARAMS and the radiocarbon dating laboratory at Lund University to compare the graphitization and AMS machine performance. No significant offset was found between the two sets of measurements. Based on these tests, the pretreatment of tree rings for high-precision radiocarbon analysis at AARAMS will henceforth use HCI for the delignification.


2012 ◽  
Vol 184-185 ◽  
pp. 789-792
Author(s):  
Bing Li ◽  
Yu Lan Wei ◽  
Meng Dan Jin ◽  
Ying Ying Fan

Put forward a method that use scatter points which got in different places to measure the involution cylindrical gears, give a mathematical model that use the discrete points to sure the total deviation of gear tooth profile. The experience results show that this way is of high precision in measurement points, measurement an error data processing less intervention, etc.


1995 ◽  
Vol 583 ◽  
pp. 263-267 ◽  
Author(s):  
A. Lépine-Szily ◽  
J.M. Casandjian ◽  
W. Mittig ◽  
A.C.C. Villari ◽  
R. Lichtenthäler Filho ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document