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 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.

scholarly journals An Online Calibration Method for Microsoft HoloLens

IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 101795-101803 ◽  
Author(s):  
Na Guo ◽  
Tianmiao Wang ◽  
Biao Yang ◽  
Lei Hu ◽  
Hongsheng Liu ◽  
...  
Keyword(s):  
Calibration Method ◽  
Online Calibration ◽  
Microsoft Hololens

scholarly journals Online Calibration Method for Current Sensors Based on GPS

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1923
Author(s):  
Shuang Zhao ◽  
Jun Liu ◽  
Yansong Li
Keyword(s):  
Calibration Method ◽  
National Standard ◽  
Economic Losses ◽  
Current Sensor ◽  
Sensor Calibration ◽  
Gps Receiver ◽  
Angular Difference ◽  
Online Calibration ◽  
Calibration Methods ◽  
Current Sensors

At present, most sensor calibration methods are off-line calibration, which not only makes them time-consuming and laborious, but also causes considerable economic losses. Therefore, in this study, an online calibration method of current sensors is proposed to address the abovementioned issues. The principle and framework of online calibration are introduced. One of the calibration indexes is angular difference. In order to accurately verify it, data acquisition must be precisely synchronized. Therefore, a precise synchronous acquisition system based on GPS timing is proposed. The influence of ionosphere on the accuracy of GPS signal is analyzed and a new method for measuring the inherent delay of GPS receiver is proposed. The synchronous acquisition performance of the system is verified by inter-channel synchronization experiment, and the results show that the synchronization of the system is accurate. Lastly, we apply our online calibration method to the current sensor; the experimental results show that the angular difference and ratio difference meet the requirements of the national standard and the accuracy of the online calibration system can be achieved to 0.2 class, demonstrating the effectiveness of the proposed online calibration method.

Integrated Method for Online Calibration of Real-Time Traffic Network Management Systems

2015 ◽  
Vol 2528 (1) ◽  
pp. 106-115 ◽  
Author(s):  
Hossein Hashemi ◽  
Khaled Abdelghany
Keyword(s):  
Network Management ◽  
Real Time ◽  
Simulation Models ◽  
Calibration Method ◽  
Propagation Model ◽  
Traffic Network ◽  
Operational Conditions ◽  
Online Calibration ◽  
Integrated Method ◽  
Real Time Traffic

This paper presents an integrated method for online calibration of realtime traffic network simulation models. The method integrates a time-dependent demand adjustment module and a link-based traffic flow propagation model calibration module. These modules use available realtime traffic observations to minimize inconsistency between the model estimation results and real-world observations. The modules are integrated into a real-time traffic network management system that was developed for the US-75 corridor in Dallas, Texas. Results illustrate that the online calibration method is effective in enhancing the model's consistency in the different operational conditions.

scholarly journals An Online Calibration Method for a Galvanometric System Based on Wavelet Kernel ELM

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1353 ◽  
Author(s):  
Wugang Zhang ◽  
Wei Guo ◽  
Chuanwei Zhang ◽  
Shuanfeng Zhao
Keyword(s):  
Real Time ◽  
Calibration Method ◽  
System Structure ◽  
Data Sets ◽  
Position Measurement ◽  
Online Calibration ◽  
Time Performance ◽  
Calibration Methods ◽  
Testing Data ◽  
Mean Square Errors

The online calibration method of a two-dimensional (2D) galvanometer requires both high precision and better real-time performance to meet the needs of moving target position measurement, which presents some challenges for traditional calibration methods. In this paper, a new online calibration method is proposed using the wavelet kernel extreme learning machine (KELM). Firstly, a system structure is created and its experiment setup is established. The online calibration method is then analyzed based on a wavelet KELM algorithm. Finally, the acquisition methods of the training data are set, two groups of testing data sets are presented, and the verification method is described. The calibration effects of the existing methods and wavelet KELM methods are compared in terms of both accuracy and speed. The results show that, for the two testing data sets, the root mean square errors (RMSE) of the Mexican Hat wavelet KELM are reduced by 16.4% and 38.6%, respectively, which are smaller than that of the original ELM, and the standard deviations (Sd) are reduced by 19.2% and 36.6%, respectively, indicating the proposed method has better generalization and noise suppression performance for the nonlinear samples of the 2D galvanometer. Although the online operation time of KELM is longer than ELM, due to the complexity of the wavelet kernel, it still has better real-time performance.

scholarly journals A New Online Calibration Method Based on Lord’s Bias-Correction

2017 ◽  
Vol 41 (6) ◽  
pp. 456-471 ◽  
Author(s):  
Yinhong He ◽  
Ping Chen ◽  
Yong Li ◽  
Shumei Zhang
Keyword(s):  
Maximum Likelihood ◽  
Maximum Likelihood Estimation ◽  
Bias Correction ◽  
Likelihood Estimation ◽  
Calibration Method ◽  
New Method ◽  
Parameter Estimates ◽  
Item Calibration ◽  
Online Calibration ◽  
True Values

Online calibration technique has been widely employed to calibrate new items due to its advantages. Method A is the simplest online calibration method and has attracted many attentions from researchers recently. However, a key assumption of Method A is that it treats person-parameter estimates [Formula: see text] (obtained by maximum likelihood estimation [MLE]) as their true values [Formula: see text], thus the deviation of the estimated [Formula: see text] from their true values might yield inaccurate item calibration when the deviation is nonignorable. To improve the performance of Method A, a new method, MLE-LBCI-Method A, is proposed. This new method combines a modified Lord’s bias-correction method (named as maximum likelihood estimation-Lord’s bias-correction with iteration [MLE-LBCI]) with the original Method A in an effort to correct the deviation of [Formula: see text] which may adversely affect the item calibration precision. Two simulation studies were carried out to explore the performance of both MLE-LBCI and MLE-LBCI-Method A under several scenarios. Simulation results showed that MLE-LBCI could make a significant improvement over the ML ability estimates, and MLE-LBCI-Method A did outperform Method A in almost all experimental conditions.

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.

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