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
2019 ◽  
Vol 57 (11) ◽  
pp. 2449-2460 ◽  
Author(s):  
Mahdi Zabat ◽  
Amina Ababou ◽  
Noureddine Ababou ◽  
Raphaël Dumas

2015 ◽  
Vol 19 (2) ◽  
pp. 159-170 ◽  
Author(s):  
Diego Álvarez ◽  
Juan C. Alvarez ◽  
Rafael C. González ◽  
Antonio M. López

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Yuta Teruyama ◽  
Takashi Watanabe

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.


2012 ◽  
Vol 3 (6) ◽  
pp. 15-18 ◽  
Author(s):  
Artūras Prielaidas ◽  
Rimas Lazdinas

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.


Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4348 ◽  
Author(s):  
Wei Liu ◽  
Xin Ma ◽  
Xiao Li ◽  
Yi Pan ◽  
Fuji Wang ◽  
...  

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.


2021 ◽  
Author(s):  
Rongguo Song ◽  
Zelong Hu ◽  
Shaoqiu Jiang ◽  
Li Ma ◽  
Qingsong Ai ◽  
...  

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
N. Awarkeh ◽  
J.-C. Cousin ◽  
M. Muller ◽  
N. Samama

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.


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