Improving the angle measurement accuracy of circular grating

2020 ◽  
Vol 91 (6) ◽  
pp. 065108 ◽  
Author(s):  
Gang Chen
Keyword(s):  
Measurement Accuracy ◽  
Angle Measurement ◽  
Circular Grating

scholarly journals Modifying Kinect placement to improve upper limb joint angle measurement accuracy

2016 ◽  
Vol 29 (4) ◽  
pp. 465-473 ◽  
Author(s):  
Na Jin Seo ◽  
Mojtaba F. Fathi ◽  
Pilwon Hur ◽  
Vincent Crocher
Keyword(s):  
Upper Limb ◽  
Measurement Accuracy ◽  
Joint Angle ◽  
Angle Measurement

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 RESEARCH ON THE ACCURACY OF ANGLE MEASUREMENT / KAMPŲ MATAVIMO TIKSLUMO TYRIMAS

2012 ◽  
Vol 3 (6) ◽  
pp. 15-18 ◽  
Author(s):  
Artūras Prielaidas ◽  
Rimas Lazdinas
Keyword(s):  
Main Part ◽  
Measurement Accuracy ◽  
Angle Measurement ◽  
Rotary Disk

Rotary encoders are the main devices in industrial angle measurement. Accuracy is very important and is assured by the technology of manufacture. The main part (rotary disk) is under examination, and therefore a number of its characteristics are established and a comparison with the assembled encoder is presented. In conclusion, an error in the angle of the rotary disk makes a possibility of forecasting an error in the assembled encoder angle. Santrauka Nagrinėjamas limbų paklaidų matavimas, jų vertinimas, fotoelektrinių matavimų keitiklių paklaidų matavimas, bandoma nustatyti keitiklio paklaidų priklausomybę nuo limbo paklaidų. Pateikta limbų, keitiklių apžvalga, analizė, pagrindinės schemos. Atlikta limbų ir keitiklių paklaidų aproksimacija parametrinėmis funkcijomis. Apibendrinti visų matavimų rezultatai – kas būdinga paklaidų kreivėms, kokie dydžiai, jų aproksimacijos parametrinėmis funkcijomis rezultatai, formulės, analizė. Atlikti koreliacijos tarp limbo ir matavimo keitiklio paklaidų tyrimai.

scholarly journals A Novel Vision-Based Pose Measurement Method Considering the Refraction of Light

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4348 ◽  
Author(s):  
Wei Liu ◽  
Xin Ma ◽  
Xiao Li ◽  
Yi Pan ◽  
Fuji Wang ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
High Speed ◽  
Measurement Accuracy ◽  
Performance Testing ◽  
Angle Measurement ◽  
Normal Vector ◽  
Calibration Model ◽  
Linear Calibration ◽  
Observation Window ◽  
Vision Measurement

Nowadays, due to the advantages of non-contact and high-speed, vision-based pose measurements have been widely used for aircraft performance testing in a wind tunnel. However, usually glass ports are used to protect cameras against the high-speed airflow influence, which will lead to a big measurement error. In this paper, to further improve the vision-based pose measurement accuracy, an imaging model which considers the refraction light of the observation window was proposed. In this method, a nonlinear camera calibration model considering the refraction brought by the wind tunnel observation window, was established first. What’s more, a new method for the linear calibration of the normal vector of the glass observation window was presented. Then, combining with the proposed matching method based on coplanarity constraint, the six pose parameters of the falling target could be calculated. Finally, the experimental setup was established to conduct the pose measurement study in the laboratory, and the results satisfied the application requirements. Besides, experiments for verifying the vision measurement accuracy were also performed, and the results indicated that the displacement and angle measurement accuracy approximately increased by 57% and 33.6%, respectively, which showed the high accuracy of the proposed method.

Signal Sampling and Accuracy Analysis of Large Gear’s Angular Displacement Measuring its Deviation On-Machine

2011 ◽  
Vol 189-193 ◽  
pp. 4201-4204
Author(s):  
Jia Qi Jin ◽  
Hui Li
Keyword(s):  
Measurement Accuracy ◽  
Angular Displacement ◽  
Total Error ◽  
Measuring Method ◽  
Displacement Measurement ◽  
Signal Acquisition ◽  
Accuracy Analysis ◽  
Friction Disc ◽  
Large Gear ◽  
Circular Grating

To solve the critical problem of large gear deviation on-machine: angle displacement measurement that is how to get signal acquisition and accuracy analysis of angle displacement. A new measuring method is proposed, which applies the dividing mechanism (it is composed of friction disc and circular grating) to ensure index and pick up signal of gear corner correctly and strictly according to the principle of angular displacement measurement. Furthermore, the main error which affects measurement accuracy is analyzed, and accuracy is analyzed with geometrical theory such as Fourier series and error synthesis principle etc. The experimental results indicate that angel dividing and signal samplings are easier and more efficient by the dividing mechanism, furthermore, the accuracy is in the range of total error that is permitted by verification, and the mechanism can also meet the requirement of high accuracy, so the method is significance that assessing transmission accuracy of involutes gear.

scholarly journals Improvement of the Angle of Arrival Measurement Accuracy for Indoor UWB Localization

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
N. Awarkeh ◽  
J.-C. Cousin ◽  
M. Muller ◽  
N. Samama
Keyword(s):  
Measurement Accuracy ◽  
Continuous Wave ◽  
Energy Detection ◽  
Angle Measurement ◽  
Phase Correlation ◽  
Ultra Wideband ◽  
Line Of Sight ◽  
Angle Of Arrival ◽  
Localization System ◽  
Classical Energy

This paper shows that the accuracy of azimuth angle measurement for an interferometric localization system used to locate tags in its Line-of-Sight (LoS) can be improved by exploiting Impulse Radio-Ultra WideBand (IR-UWB) signals and without increasing the frequency bandwidth. This solution uses a Phase Correlation (PC) method, initially applied for Continuous Wave (CW) signals, adapted for Ultra WideBand (UWB) pulse signals. The obtained results are compared to those computed by a classical Energy Detection (ED) method where it becomes impossible to estimate azimuth angles for tag positions close to the orthogonal centered axis of the localization system baseline.

Measurement accuracy of articulated arm CMMs with circular grating eccentricity errors

2016 ◽  
Vol 27 (11) ◽  
pp. 115011 ◽  
Author(s):  
Dateng Zheng ◽  
Sanfeng Yin ◽  
Zhiyang Luo ◽  
Jing Zhang ◽  
Taiping Zhou
Keyword(s):  
Measurement Accuracy ◽  
Circular Grating

Assumptions of Centering – Leveling Device Application in Mechatronic Angle Measuring System

2015 ◽  
Vol 220-221 ◽  
pp. 391-395
Author(s):  
Lauryna Šiaudinytė ◽  
Deividas Sabaitis ◽  
Mindaugas Rybokas ◽  
Domantas Bručas
Keyword(s):  
Measurement Accuracy ◽  
Angle Measurement ◽  
Measuring System ◽  
Measuring Systems ◽  
Measured Object ◽  
Preliminary Results ◽  
Device Application ◽  
Angle Measuring ◽  
Slight Movement ◽  
Further Development

This paper deals with the presentation of the new centering – leveling device developed in Vilnius Gediminas Technical University. Precision angle measuring systems are always combined of many mechanisms and devices which influence angle measurement accuracy. Therefore, every one of them has to be investigated separately. This device can be used as a separate device to perform a slight movement of measured object or it can be used as a part of mechatronic angle measuring system. This paper presents preliminary results of centering – leveling device minimum pitch determination and analysis of further development of this device as a part of mechatronic angle measuring system.

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