Research on Three-Position Calibration Method for the Installation Error of Inclinometer with Two-Axis Gravity Accelerometer

2014 ◽  
Vol 1030-1032 ◽  
pp. 1237-1241
Author(s):  
Jiang Hong Deng ◽  
Xin Yuan Chen ◽  
Liang Cai Zeng
Keyword(s):  
Output Voltage ◽  
Calibration Method ◽  
Calibration Error ◽  
Error Angle ◽  
Iterative Calculation ◽  
Attitude Angle ◽  
Drilling Tools ◽  
Error Calibration ◽  
Position Calibration

At present,The installation error calibration of gravity accelerometer for the automatic vertical drilling tools is complex and difficult . For this,the paper presents three-position calibration method for the installation error of inclinometer with two-axis gravity accelerometer. The method is based on the equation about actual attitude angle of the inclinometer, installation error angular of two-axis gravity accelerometer and output voltage. The voltage value of the three position is measured, and iterative calculation with MATLAB is used to obtain the installation error angle. The results of simulation prove that this method can meet the requirements of installation error angle calibration of drilling tools , the calibration error is less than 1.5%.

scholarly journals A New Norm-Observed Calibration Method Based on Improved Differential Evolution Algorithm for SINS

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yang Liu ◽  
Gongliu Yang ◽  
Qingzhong Cai ◽  
Lifen Wang
Keyword(s):  
Angular Velocity ◽  
Parameter Identification ◽  
Differential Evolution Algorithm ◽  
Calibration Method ◽  
Calibration Error ◽  
Differential Evolutionary Algorithm ◽  
Optimization Function ◽  
Position Calibration ◽  
Mutation Strategies ◽  
Improved Differential Evolution Algorithm

It is vital for a strapdown inertial navigation system (SINS) to be calibrated before normal use. In this paper, a new kind of norm-observed calibration method is proposed. Considering that the norm of the output of accelerometers and gyroscopes can be exactly the norm of local acceleration of gravity and Earth rotation angular velocity, respectively, optimization function about all-parameter calibration and the corresponding 24-position calibration path is established. Differential evolutionary algorithm (DE) is supposed to be the best option in parameter identification due to its strong search and fast convergence abilities. However, the high-dimensional individual vector from calibration error equations restrains the algorithm’s optimum speed and accuracy. To overcome this drawback, improved DE (IDE) optimization is specially designed: First, current “DE/rand/1” and “DE/current-to-best/1” mutation strategies are combined as one with complementary advantages and overall balance during the whole optimization process. Next, with the increase of the evolutionary generation, the mutation factor can adjust itself according to the convergence situation. Multiple identification tests prove that our IDE optimization has rapid convergence and high repeatability. Besides, certain motivation of external angular velocity is added to the gyroscope calibration, and a series of dynamic observation paths is formed, further improving the optimization accuracy. The final static navigation experiment shows that SINS with calibration parameters solved by IDE has better performance over other identification methods, which further explains that our novel method is more accurate and reliable in parameter identification.

scholarly journals HPR AND OPK ANGLE ELEMENT CONVERSION METHOD BASED ON AIRBORNE LIDAR ALIGNMENT AXIS ERROR CALIBRATION

2020 ◽  
Vol XLII-3/W10 ◽  
pp. 71-75
Author(s):  
Y. X. Mu ◽  
G. Q. Zhou ◽  
X. Zhou ◽  
J. Gao ◽  
X. Y. Peng
Keyword(s):  
Calibration Method ◽  
Airborne Lidar ◽  
Calibration Model ◽  
Control Points ◽  
Angle Error ◽  
Error Angle ◽  
Coincidence Effect ◽  
Error Calibration ◽  
Foot Position ◽  
Efficiency And Reliability

Abstract. This paper mainly uses manual calibration technology to check the elements Yaw, Pitch and Roll (YPR) in the LiDAR DGPS/IMU system and obtained the error value. Combined with the error angle, the external azimuth angle elements Kappa, Omega and Phi required by photogrammetry are obtained. The paper points out that the placement angle error will have a serious impact on the LiDAR foot position. Therefore, this paper puts forward a method to check the placement angle of the steeple roof and flat straight highway, and gives the design scheme of the optimized route to reduce the number of flights. This paper focuses on the specific process of YPR calibration, and gives a mathematical calibration model based on the influence of attitude angles Yaw, Pitch and Roll on the LiDAR foot during the flight. The placement angle error is obtained after the calibration, and the error angle matrix is used to convert the elements YPR and OPK. After checking and error correction, the point cloud obtained from adjacent airlines have achieved better coincidence effect. The experimental results show that the theory and method of YPR element calibration are correct and feasible, which simplifies the conversion process of YPR and OPK. Compared with the traditional calibration method that requires control points, this method can greatly improve the efficiency and reliability of the inspection.

scholarly journals Error Correction of Water Vapor Radiometers for VLBI Observations in Deep-Space Networks

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1601
Author(s):  
Houcai Chen ◽  
Junxiang Ge ◽  
Qingde Kong ◽  
Zhenwei Zhao ◽  
Qinglin Zhu
Keyword(s):  
Water Vapor ◽  
Measurement Errors ◽  
Measurement Accuracy ◽  
Calibration Method ◽  
Absolute Calibration ◽  
Calibration Error ◽  
Ambient Conditions ◽  
Gain Error ◽  
Error Calibration ◽  
Water Vapor Radiometer

In this paper, we present the design and implementation tests of a water vapor radiometer (WVR) suitable for very long baseline interferometry (VLBI) observation. We describe the calibration method with an analysis of the sources of measurement errors. The experimental results show that the long-term measurement accuracy of the brightness temperature of the water vapor radiometer can reach 0.2 K under arbitrary ambient conditions by absolute calibration, receiver gain error calibration, and antenna feeder system temperature noise error calibration. Furthermore, we present a method for measurements of the calibration error of the oblique path measurement. This results in an oblique path wet delay measurement accuracy of the water vapor radiometer reaching 20 mm (within one month).

scholarly journals An Automatic Offset Calibration Method for Differential Charge-Based Capacitance Measurement

2021 ◽  
Vol 11 (2) ◽  
pp. 22
Author(s):  
Umberto Ferlito ◽  
Alfio Dario Grasso ◽  
Michele Vaiana ◽  
Giuseppe Bruno
Keyword(s):  
Standard Deviation ◽  
Output Voltage ◽  
Process Variations ◽  
Calibration Method ◽  
Capacitance Measurement ◽  
Effective Technique ◽  
Fully Integrated ◽  
Front End ◽  
Novel Method ◽  
On Chip

Charge-Based Capacitance Measurement (CBCM) technique is a simple but effective technique for measuring capacitance values down to the attofarad level. However, when adopted for fully on-chip implementation, this technique suffers output offset caused by mismatches and process variations. This paper introduces a novel method that compensates the offset of a fully integrated differential CBCM electronic front-end. After a detailed theoretical analysis of the differential CBCM topology, we present and discuss a modified architecture that compensates mismatches and increases robustness against mismatches and process variations. The proposed circuit has been simulated using a standard 130-nm technology and shows a sensitivity of 1.3 mV/aF and a 20× reduction of the standard deviation of the differential output voltage as compared to the traditional solution.

scholarly journals A Nonlinear Calibration Method Based on Sinusoidal Excitation and DFT Transformation for High-Precision Power Analyzers

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Wenjian Zhou ◽  
Sheng Yang ◽  
Li Wang ◽  
Hanmin Sheng ◽  
Yang Deng
Keyword(s):  
High Precision ◽  
Interpolation Method ◽  
Spline Interpolation ◽  
Calibration Method ◽  
Calibration Error ◽  
Initial Moment ◽  
Calibration Process ◽  
Calibration Methods ◽  
Nonlinear Calibration ◽  
Sinusoidal Excitation

For most high-precision power analyzers, the measurement accuracy may be affected due to the nonlinear relationship between the input and output signal. Therefore, calibration before measurement is important to ensure accuracy. However, the traditional calibration methods usually have complicated structures, cumbersome calibration process, and difficult selection of calibration points, which is not suitable for situations with many measurement points. To solve these issues, a nonlinear calibration method based on sinusoidal excitation and DFT transformation is proposed in this paper. By obtaining the effective value data of the current sinusoidal excitation from the calibration source, the accurate calibration process can be done, and the calibration efficiency can be improved effectively. Firstly, through Fourier transform, the phase value at the initial moment of the fundamental frequency is calculated. Then, the mapping relationship between the sampling value and the theoretical calculation value is established according to the obtained theoretical discrete expression, and a cubic spline interpolation method is used to further reduce the calibration error. Simulations and experiments show that the calibration method presented in this paper achieves high calibration accuracy, and the results are compensation value after calibration with a deviation of ± 3 × 10 − 4 .

scholarly journals Global Calibration of Multi-Cameras Based on Refractive Projection and Ray Tracing

2017 ◽  
Author(s):  
Mingchi Feng ◽  
Xiang Jia ◽  
Jingshu Wang ◽  
Song Feng ◽  
Taixiong Zheng
Keyword(s):  
Ray Tracing ◽  
Real Data ◽  
Calibration Method ◽  
Calibration Error ◽  
Multiple Cameras ◽  
Projection Model ◽  
Vision Measurement ◽  
3D Computer Vision ◽  
Global Calibration ◽  
Calibration Methods

Multi-cameras system is widely applied in 3D computer vision especially when multiple cameras are distributed on both sides of the measured object. The calibration methods of multi-cameras system are critical to the accuracy of vision measurement and the key is to find an appropriate calibration target. In this paper, a high-precision camera calibration method for multi-cameras system based on transparent glass checkerboard and ray tracing is described, which is used to calibrate multiple cameras distributed on both sides of the glass checkerboard. Firstly, the intrinsic parameters of each camera is obtained by Zhang’s calibration method. Then, multiple cameras capture several images from the front and back of the glass checkerboard with different orientations, and all images contain distinct grid corners. As the cameras on one side are not affected by the refraction of glass checkerboard, extrinsic parameters can be directly calculated. However, the cameras on another side are influenced by the refraction of glass checkerboard, and the direct use of projection model will produce calibration error. A multi-cameras calibration method using refractive projection model and ray tracing is developed to eliminate this error. Furthermore, both synthetic and real data are employed to validate the proposed approach. The experimental results of refractive calibration show that the error of the 3D reconstruction is smaller than 0.2 mm, the relative errors of both rotation and translation are less than 0.014%, and the mean and standard deviation of reprojection error of 4-cameras system are 0.00007 and 0.4543 pixel. The proposed method is flexible, high accurate, and simple to carry out.

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.

Study of Split Capacitor DAC Mismatch and Calibration in SAR-ADC

2016 ◽  
Vol 26 (01) ◽  
pp. 1750003
Author(s):  
Yun Zhang ◽  
Yiqiang Zhao ◽  
Peng Dai
Keyword(s):  
Calibration Method ◽  
Sar Adc ◽  
Calibration Error ◽  
Cmos Process ◽  
Analog To Digital ◽  
Significant Performance ◽  
Performance Deterioration ◽  
Conventional Structure ◽  
Split Capacitor ◽  
Simulation Results

Mismatch and parasitic effects of bridge capacitors in successive-approximation-register analog-to-digital converter’s (SAR-ADC) split capacitor digital-to-analog conversion (DAC) cause a significant performance deterioration. This paper presents a nonlinearity analysis based on an analytical model, and a modified calibration method utilizing a pre-bias bridge capacitor is accordingly proposed. The proposed method, which uses three-segment split capacitor DAC structure, can effectively eliminate over-calibration error caused by conventional structure. To verify the technique, a 14-bit SAR-ADC has been designed in 0.35-[Formula: see text]m 2P4M CMOS process with the PIP capacitor, and the simulation results show the method can further improve ADC performance.

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