scholarly journals Lightweight Thermal Compensation Technique for MEMS Capacitive Accelerometer Oriented to Quasi-Static Measurements

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3117
Author(s):  
Javier Martínez ◽  
David Asiain ◽  
José Ramón Beltrán
Keyword(s):  
Computational Cost ◽  
Calibration Method ◽  
Scale Factor ◽  
Thermal Drift ◽  
Thermal Compensation ◽  
Characteristic Parameters ◽  
Thermal Dependence ◽  
Temperature Drift ◽  
Capacitive Accelerometer ◽  
Average Improvement

The application of MEMS capacitive accelerometers isimited by its thermal dependence, and each accelerometer must be individually calibrated to improve its performance. In this work, aight calibration method based on theoretical studies is proposed to obtain two characteristic parameters of the sensor’s operation: the temperature drift of bias and the temperature drift of scale factor. This method requiresess data to obtain the characteristic parameters, allowing a faster calibration. Furthermore, using an equation with fewer parameters reduces the computational cost of compensation. After studying six accelerometers, modelIS3DSH, their characteristic parameters are obtained in a temperature range between 15 ∘C and 55 ∘C. It is observed that the Temperature Drift of Bias (TDB) is the parameter with the greatest influence on thermal drift, reaching 1.3 mg/∘C. The Temperature Drift of Scale Factor (TDSF) is always negative and ranges between 0 and −400 ppm/∘C. With these parameters, the thermal drifts are compensated in tests with 20 ∘C of thermal variation. An average improvement of 47% was observed. In the axes where the thermal drift was greater than 1 mg/∘C, the improvement was greater than 80%. Other sensor behaviors have also been analyzed, such as temporal drift (up to 1 mg/h for three hours) and self-heating (2–3 ∘C in the first hours with the corresponding drift). Thermal compensation has been found to reduce the effect of theatter in the first hours after power-up of the sensor by 43%.

Multi-Position Self-Calibration Method of Inertial Navigation System

2012 ◽  
Vol 580 ◽  
pp. 146-150
Author(s):  
Ji Wei Zhang ◽  
Xiao Dong Xu ◽  
Bo Wang
Keyword(s):  
Navigation System ◽  
Horizontal Plane ◽  
Inertial Navigation System ◽  
Inertial Navigation ◽  
Calibration Method ◽  
Scale Factor ◽  
Self Calibration ◽  
Attitude Angle ◽  
On Line

In order to solve the problem that in the dual axle rotating modulation inertial navigation system the angle between the horizon roller of the system and horizontal plane can't be removed, this paper provides an on-line self calibration method based on inertial navigation system, and this method realized the on-line self calibration of the inertial navigation system by calculating bias and scale factor both of the gyroscope and accelerometer, solving the problem that in the dual axle rotating modulation inertial navigation system the angle between the horizon roller of the system and horizontal plane can't be removed, providing an calculable basis for the prediction of attitude angle and realizing on-line autonomous self-calibration.

scholarly journals Thermal Drift Investigation of an SOI-Based MEMS Capacitive Sensor with an Asymmetric Structure

Sensors ◽  
2019 ◽  
Vol 19 (16) ◽  
pp. 3522 ◽  
Author(s):  
Haiwang Li ◽  
Yanxin Zhai ◽  
Zhi Tao ◽  
Yingxuan Gui ◽  
Xiao Tan
Keyword(s):  
Structural Parameters ◽  
Weighted Average ◽  
Capacitive Sensor ◽  
Expansion Ratio ◽  
Asymmetric Structure ◽  
Temperature Sensitive ◽  
Navigation Systems ◽  
Temperature Drift ◽  
Capacitive Accelerometer ◽  
Symmetric Structure

High-precision, low-temperature-sensitive microelectromechanical system (MEMS) capacitive accelerometers are widely used in aerospace, automotive, and navigation systems. An analytical study of the temperature drift of bias (TDB) and temperature drift of scale factor (TDSF) for an asymmetric comb capacitive accelerometer is presented in this paper. A five-layer model is established for the equivalent expansion ratio in the TDB and TDSF formulas, and the results calculated by the weighted average of thickness and elasticity modulus method are closest to the results of the numerical simulation. The analytical formulas of TDB and TDSF for an asymmetric structure are obtained. For an asymmetric structure, TDB is only related to thermal deformation and fabrication error. Additionally, half of the fixed electrode distance is not included in the expressions of Δ d and Δ D for asymmetric structures, thus resulting in the TDSF of the asymmetric structure being smaller compared to a symmetric structure with the same structural parameters. The TDSF of the symmetric structure is [−200.2 ppm/°C, −261.6 ppm/°C], while the results of the asymmetric structure are [−11.004 ppm/°C, −72.404 ppm/°C] under the same set of parameters. The parameters of the optimal asymmetric structure are obtained for fabrication guidance using numerical methods. In the experiment, the TDSF and TDB of the packaged structure and the non-packaged structure are compared, and a significant effect of the package on the signal output is found. The TDB is reduced from 3000 to 60 μg/°C, while the TDSF is reduced from 3000 to 140 ppm/°C.

Scale factor calibration method for integrating-bucket sinusoidal phase shifting interferometry

2020 ◽  
Vol 127 ◽  
pp. 106149
Author(s):  
Fajie Duan ◽  
Ruijia Bao ◽  
Tingting Huang ◽  
Xiao Fu ◽  
Cong Zhang
Keyword(s):  
Calibration Method ◽  
Scale Factor ◽  
Phase Shifting ◽  
Phase Shifting Interferometry

Automatic calibration of powder diffraction experiments using two-dimensional detectors

2007 ◽  
Vol 22 (1) ◽  
pp. 3-19 ◽  
Author(s):  
P. Rajiv ◽  
B. Hinrichsen ◽  
R. Dinnebier ◽  
M. Jansen ◽  
M. Joswig
Keyword(s):  
Powder Diffraction ◽  
Computational Cost ◽  
Nonlinear Least Squares ◽  
Calibration Method ◽  
High Signal ◽  
Automatic Calibration ◽  
Experimental Calibration ◽  
One Dimensional ◽  
Least Squares Fit ◽  
Image Artefacts

Calibration of powder diffraction experiments using area detectors is essential to extract high quality one-dimensional powder diffraction pattern. Precise calibration necessitates a sensible characterization of the Debye-Scherrer rings formed on the detector plane. An algorithm, designed and developed to automate this process, is described in this paper. All the parameters required for an experimental calibration are extracted using robust pattern recognition techniques. Several image preprocessing methods are employed, reducing the computational cost but retaining high signal quality. A modified version of a one-dimensional Hough transformation is used to determine the final parameters of the ellipses. After extraction, the parameters are optimized using nonlinear least squares fit. The presented algorithm is insensitive to image artefacts and was successfully applied to a large number of calibration images. The performance of the algorithm is demonstrated by the comparison of results obtained from the presented automatic calibration method and an existing manual method.

Calibration of Partial Safety Factors Through the Inverse FORM Method

2007 ◽  
Author(s):  
Francisco L. Silva-Gonza´lez
Keyword(s):  
Computational Cost ◽  
Calibration Method ◽  
Structural System ◽  
Safety Factors ◽  
Suction Caisson ◽  
Design Point ◽  
Inverse Form ◽  
Partial Safety Factors ◽  
Calibration Techniques ◽  
Form Approach

A calibration method which uses the so-called inverse FORM approach is proposed. The objective is to find the design point on a hypersphere in U-space, whose radius is the target reliability index, which maximizes the response that the structural system must withstand. Once the design point is determined, the safety factors can be calculated. It is demonstrated that the computational cost of the proposed method is less than the computational cost of traditional calibration techniques. The proposed method is illustrated by means of three examples: parabolic, Eurocode and suction caisson design equations.

scholarly journals Calibration Method of Accelerometer Based on Rotation Principle Using Double Turntable Centrifuge

Micromachines ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 62
Author(s):  
Xianshan Dong ◽  
Xinlong Huang ◽  
Guizhen Du ◽  
Qinwen Huang ◽  
Yixiong Huang ◽  
...  
Keyword(s):  
Calculation Method ◽  
Calibration Method ◽  
Calibration Procedure ◽  
Scale Factor ◽  
Centripetal Acceleration ◽  
Mems Accelerometer ◽  
Key Technology ◽  
Acceleration Vector ◽  
Back Calculation ◽  
Input Acceleration

For linear accelerometers, calibration with a precision centrifuge is a key technology, and the input acceleration imposed on the accelerometer should be accurately obtained in the calibration. However, there are often errors in the installation of sample that make the calibration inaccurate. To solve installation errors and obtain the input acceleration in the calibration of the accelerometer, a calibration method based on the rotation principle using a double turntable centrifuge is proposed in this work. The key operation is that the sub-turntable is rotated to make the input axis of the accelerometer perpendicular to the direction of the centripetal acceleration vector. Models of installation errors of angle and radius were built. Based on these models, the static radius and input acceleration can be obtained accurately, and the calibration of the scale factor, nonlinearity and asymmetry can be implemented. Using this method, measurements of the MEMS accelerometer with a range of ±30 g were carried out. The results show that the discrepancy of performance obtained from different installation positions was smaller than 100 ppm after calibrating the input acceleration. Moreover, the results using this method were consistent with those using the back-calculation method. These results demonstrate that the effectiveness of our proposed method was confirmed. This method can measure the static radius directly eliminating the installation errors of angle and radius, and it simplifies the accelerometer calibration procedure.

scholarly journals Automatic calibration of a functional-structural wheat model using an adaptive design and a metamodelling approach

2021 ◽  
Author(s):  
Emmanuelle Blanc ◽  
Jérôme Enjalbert ◽  
Pierre Barbillon
Keyword(s):  
Experimental Data ◽  
Gaussian Process ◽  
Adaptive Design ◽  
Computational Cost ◽  
Simulated Data ◽  
Calibration Method ◽  
Complex Models ◽  
Competition For Light ◽  
High Computational Cost

- Background and Aims Functional-structural plant models are increasingly being used by plant scientists to address a wide variety of questions. However, the calibration of these complex models is often challenging, mainly because of their high computational cost. In this paper, we applied an automatic method to the calibration of WALTer: a functional-structural wheat model that simulates the plasticity of tillering in response to competition for light. - Methods We used a Bayesian calibration method to estimate the values of 5 parameters of the WALTer model by fitting the model outputs to tillering dynamics data. The method presented in this paper is based on the Efficient Global Optimisation algorithm. It involves the use of Gaussian process metamodels to generate fast approximations of the model outputs. To account for the uncertainty associated with the metamodels approximations, an adaptive design was used. The efficacy of the method was first assessed using simulated data. The calibration was then applied to experimental data. - Key Results The method presented here performed well on both simulated and experimental data. In particular, the use of an adaptive design proved to be a very efficient method to improve the quality of the metamodels predictions, especially by reducing the uncertainty in areas of the parameter space that were of interest for the fitting. Moreover, we showed the necessity to have a diversity of field data in order to be able to calibrate the parameters. - Conclusions The method presented in this paper, based on an adaptive design and Gaussian process metamodels, is an efficient approach for the calibration of WALTer and could be of interest for the calibration of other functional-structural plant models .

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