scholarly journals Recursive of Least Square Based Online Calibration Method in Geomagnetic Detection

2018 ◽  
Vol 232 ◽  
pp. 04087
Author(s):  
Long Li ◽  
Jiacai Huang
Keyword(s):  
Detection System ◽  
Calibration Method ◽  
Least Square ◽  
Correction Coefficient ◽  
Attitude Measurement ◽  
Online Calibration ◽  
Geomagnetic Survey ◽  
Geomagnetic Measurement ◽  
Attitude Detection ◽  
Error Ellipsoid

With the problem of attitude measurement accuracy is susceptible to various errors of geomagnetic survey, this paper establishes geomagnetic measurement error ellipsoid model by analysis of on the environment and own errors, uses the maximum likelihood algorithm for solving the static error correction coefficient. The experimental results show that, the maximum of attitude angle errors is less than 5° near blind direction, online combination correction can ensure the accuracy of attitude detection system under different shooting conditions.

An Online Calibration Method for Manipulator with Joint Clearance

ROBOT ◽  
2013 ◽  
Vol 35 (5) ◽  
pp. 521
Author(s):  
Feng WANG ◽  
Kai CHEN ◽  
Xiaoping CHEN
Keyword(s):  
Calibration Method ◽  
Joint Clearance ◽  
Online Calibration

scholarly journals Gait Phase Detection Based on Muscle Deformation with Static Standing-Based Calibration

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1081
Author(s):  
Tamon Miyake ◽  
Shintaro Yamamoto ◽  
Satoshi Hosono ◽  
Satoshi Funabashi ◽  
Zhengxue Cheng ◽  
...  
Keyword(s):  
Learning Algorithm ◽  
Detection System ◽  
Calibration Method ◽  
Detection Algorithm ◽  
Video Data ◽  
Detection Accuracy ◽  
Phase Detection ◽  
Gait Phase ◽  
Logistic Regression Algorithm ◽  
Short Time

Gait phase detection, which detects foot-contact and foot-off states during walking, is important for various applications, such as synchronous robotic assistance and health monitoring. Gait phase detection systems have been proposed with various wearable devices, sensing inertial, electromyography, or force myography information. In this paper, we present a novel gait phase detection system with static standing-based calibration using muscle deformation information. The gait phase detection algorithm can be calibrated within a short time using muscle deformation data by standing in several postures; it is not necessary to collect data while walking for calibration. A logistic regression algorithm is used as the machine learning algorithm, and the probability output is adjusted based on the angular velocity of the sensor. An experiment is performed with 10 subjects, and the detection accuracy of foot-contact and foot-off states is evaluated using video data for each subject. The median accuracy is approximately 90% during walking based on calibration for 60 s, which shows the feasibility of the static standing-based calibration method using muscle deformation information for foot-contact and foot-off state detection.

Research on Calibration Method of Tire Dynamic Balance Detection System

2012 ◽  
Vol 542-543 ◽  
pp. 828-832 ◽  
Author(s):  
Jing Fang Yang ◽  
Xian Ying Feng ◽  
Hong Jun Fu ◽  
Lian Fang Zhao
Keyword(s):  
High Speed ◽  
Detection System ◽  
Dynamic Balance ◽  
Calibration Method ◽  
Engineering Practice ◽  
Influence Coefficient ◽  
Quality Factors ◽  
High Speed Rotation ◽  
Speed Rotation ◽  
Upper Rim

Tire dynamic balance detection plays an important part in tire quality detection area. This paper uses the two-sided balance method to obtain the unbalance of the tire. According to the engineering practice, builds kinetic model and then introduces the calculating principle and operating procedures. In order to accurately determine the influence coefficient, a calibration method without tire is put forward. Further more, this new method is able to eliminate the unbalance caused by non-quality factors to some extent. But this method is presented based on the relative position invariance of the upper rim and lower rim, even both of them are under high-speed rotation situation. Finally, the experimental data acquired from both of the two methods are compared. The calibration method without tire is proved to be more feasible, efficient and accurate.

scholarly journals A Fast Calibration and Compensation Method for Magnetometers in Strap-Down Spinning Projectiles

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4157 ◽  
Author(s):  
Dafeng Long ◽  
Xiaoming Zhang ◽  
Xiaohui Wei ◽  
Zhongliang Luo ◽  
Jianzhong Cao
Keyword(s):  
Low Cost ◽  
Experimental System ◽  
Calibration Method ◽  
Attitude Estimation ◽  
Attitude Measurement ◽  
Angle Error ◽  
Estimation Errors ◽  
Zero Bias ◽  
Launch Site ◽  
Spinning Projectile

Attitude measurement is an essential technology in projectile trajectory correction. Magnetometers have been used for projectile attitude measurement systems as they are small in size, lightweight, and low cost. However, magnetometers are seriously disturbed by the artillery magnetic field during launch. Moreover, the error parameters of the magnetometers, which are calibrated in advance, usually change after extended storage. The changed parameters have negative effects on attitude estimation of the projectile. To improve the accuracy of attitude estimation, the magnetometers should be calibrated again before launch or during flight. This paper presents a fast calibration method specific for a spinning projectile. At the launch site, the tri-axial magnetometer is calibrated, the parameters of magnetometer are quickly obtained by optimal ellipsoid fitting based on a least squares criterion. Then, the calibration parameters are used to compensate for magnetometer outputs during flight. The numerical simulation results show that the proposed calibration method can effectively determine zero bias, scale factors, and alignment angle errors. Finally, a semi-physical experimental system was designed to further verify the performance of the calibration method. The results show that pitch angle error reduces from 3.52° to 0.58° after calibration. The roll angle error is reduced from 2.59° to 0.65°. Simulations and experimental results indicate that the accuracy of magnetometer in strap-down spinning projectile has been greatly enhanced, and the attitude estimation errors are reduced after calibration.

scholarly journals HYBRID ONLINE MOBILE LASER SCANNER CALIBRATION THROUGH IMAGE ALIGNMENT BY MUTUAL INFORMATION

2016 ◽  
Vol III-1 ◽  
pp. 25-31 ◽  
Author(s):  
Mourad Miled ◽  
Bahman Soheilian ◽  
Emmanuel Habets ◽  
Bruno Vallet
Keyword(s):  
Mutual Information ◽  
Imaging System ◽  
Laser Scanner ◽  
Point Clouds ◽  
Calibration Method ◽  
Online Calibration ◽  
Calibration Methods ◽  
Laser Calibration ◽  
Scanner Calibration

This paper proposes an hybrid online calibration method for a laser scanner mounted on a mobile platform also equipped with an imaging system. The method relies on finding the calibration parameters that best align the acquired points cloud to the images. The quality of this intermodal alignment is measured by Mutual information between image luminance and points reflectance. The main advantage and motivation is ensuring pixel accurate alignment of images and point clouds acquired simultaneously, but it is also much more flexible than traditional laser calibration methods.

A Rapid Field Calibrating Method for MIMU

2011 ◽  
Vol 80-81 ◽  
pp. 1140-1144
Author(s):  
Yu Bao Fan ◽  
Jie Li ◽  
Bo Wang ◽  
Xiao Chun Tian ◽  
Jun Liu
Keyword(s):  
Inertial Measurement Unit ◽  
Operation Time ◽  
Calibration Method ◽  
Least Square ◽  
Measurement Unit ◽  
Calibration Model ◽  
Time Saving ◽  
Inertial Measurement ◽  
Field Calibration ◽  
Calibration Program

When the Micro Inertial Measurement Unit is been placed randomly in the case of stationary, the sum vectors that measured by the inertial devices configured orthogonally along three axis, are constant vectors. In view of the above objective facts, a field calibration method of micro inertial measurement unit was proposed. On the base of the establishment and optimization of calibration model, all parameters to be calibrated can be obtained through the least square by the ellipsoid fitting, with the result of high-precision field calibration for micro inertial measurement unit. Finally, a filed calibration program for micro inertial measurement unit is scheduled reasonably. The experiment results show that the method has such characteristics such as easily-operation, time-saving, higher calibration accuracy, and not depending on the baseline direction and datum offered by precision instruments. Especially, it fits for inertial measurement systems which work short time and ask for high accuracy. In addition, it can also significantly increase the measurement accuracy of micro inertial measurement system in practical application.

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