scholarly journals An Improved Calibration Technique for MEMS Accelerometer-Based Inclinometers

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 452 ◽  
Author(s):  
Jiaxin Zhu ◽  
Weifeng Wang ◽  
Shiping Huang ◽  
Wei Ding

Micro-electro-mechanical system (MEMS) accelerometer-based inclinometers are widely used to measure deformations of civil structures. To further improve the measurement accuracy, a new calibration technique was proposed in this paper. First, a single-parameter calibration model was constructed to obtain accurate angles. Then, an image-processing-based method was designed to obtain the key parameter for the calibration model. An ADXL355 accelerometer-based inclinometer was calibrated to evaluate the feasibility of the technique. In this validation experiment, the technique was proven to be reliable and robust. Finally, to evaluate the performance of the technique, the calibrated MEMS inclinometer was used to measure the deflections of a scale beam model. The experimental results demonstrate that the proposed technique can yield accurate deformation measurements for MEMS inclinometers.

Abstract. Health monitoring systems are used to assess building damage immediately after an earthquake and have become widely utilized in Japan. For example, the system developed by the authors has been installed in more than 60 buildings since 2014. Such systems mostly rely on accelerometers to estimate the building performance. Recently, Micro electro mechanical system (MEMS) accelerometers have been increasingly applied for such uses due to their economic advantages. However, MEMS accelerometers are known to have relatively low measurement accuracy for certain frequency band excitations compared to servo type accelerometers. Past research has been undertaken to test their measurement accuracy, however, few studies review their performance under long period and large amplitude seismic motions. Evaluation of measurement accuracy in such conditions is essential since the system is also installed in tall buildings and isolated buildings with relatively long natural periods. Therefore, this study evaluates the measurement accuracy of the MEMS accelerometer under long period and large amplitude vibration based on the results of shake table testing.


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.


2008 ◽  
Vol 79 (10) ◽  
pp. 10F525 ◽  
Author(s):  
Carine Giroud ◽  
A. G. Meigs ◽  
C. R. Negus ◽  
K.-D. Zastrow ◽  
T. M. Biewer ◽  
...  

Robotica ◽  
2013 ◽  
Vol 32 (3) ◽  
pp. 447-466 ◽  
Author(s):  
Albert Nubiola ◽  
Mohamed Slamani ◽  
Ahmed Joubair ◽  
Ilian A. Bonev

SUMMARYThe absolute accuracy of a small industrial robot is improved using a 30-parameter calibration model. The error model takes into account a full kinematic calibration and five compliance parameters related to the stiffness in joints 2, 3, 4, 5, and 6. The linearization of the Jacobian is performed to iteratively find the modeled error parameters. Two coordinate measurement systems are used independently: a laser tracker and an optical CMM. An optimized end-effector is developed specifically for each measurement system. The robot is calibrated using fewer than 50 configurations and the calibration efficiency validated in 1000 configurations using either the laser tracker or the optical CMM. A telescopic ballbar is also used for validation. The results show that the optical CMM yields slightly better results, even when used with the simple triangular plate end-effector that was developed mainly for the laser tracker.


2020 ◽  
Vol 10 (22) ◽  
pp. 8295
Author(s):  
Wenhe Xing ◽  
Xueping Ju ◽  
Jian Bo ◽  
Changxiang Yan ◽  
Bin Yang ◽  
...  

The process of radiometric calibration would be coupled with the polarization properties of an optical system for spectropolarimetry, which would have significant influences on reconstructed Stokes parameters. In this paper, we propose a novel polarization radiometric calibration model that decouples the radiometric calibration coefficient and polarization properties of an optical system. The alignment errors of the polarization module and the variation of the retardations at different fields of view are considered and calibrated independently. According to these calibration results, the input Stokes parameters at different fields of view can be reconstructed accurately through the proposed model. Simulations are performed for the presented calibration and reconstruction methods, which indicate that the measurement accuracy of polarization information is improved compared with the traditional undecoupled calibration method.


2019 ◽  
Vol 9 (02) ◽  
pp. 63-67
Author(s):  
Indra Feriadi ◽  
Fajar Aswin ◽  
M Iqbal Nugraha

Vibration measurement technology using conventional sensors such as piezoelectric (PZT) Accelerometer is still expensive. Currently, many low-cost vibration measuring devices have been developed by using Micro Electro Mechanical System (MEMS) technology. This study aims to analyze the results of vibration measurement system MEMS Accelerometer ADXL345 with PZT Accelerometer. This research applies design and develop approach with comparative data analysis technique, that is comparing data of result of measurement of MEMS Accelerometer ADXL345 to PZT Accelerometer Vibroport80. The construction comprises the ADXL345 sensor connected to the Arduino Mega 2560 microcontroller operated by Widows operating system and programming language Arduino IDE 1.08. Testing of measurements at Bearing speeds of 500, 1000, and 1500 RPM with length of time measurements at 5, 10, and 20 seconds respectively. The analysis of the test results shows that the MEMS Accelerometer ADXL345 of vibration measurement system can measure, process and display vibration measurement data larger 3% than PZT Accelerometer and can provide the best measurement accuracy at 20 seconds measurement length of time.


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