Calibration Method for Optical Axis Perpendicular Error of Laser Sensor

Lens distortion is closely related to the spatial position of depth of field (DoF), especially in close-range photography. The accurate characterization and precise calibration of DoF-dependent distortion are very important to improve the accuracy of close-range vision measurements. In this paper, to meet the need of short-distance and small-focal-length photography, a DoF-dependent and equal-partition based lens distortion modeling and calibration method is proposed. Firstly, considering the direction along the optical axis, a DoF-dependent yet focusing-state-independent distortion model is proposed. By this method, manual adjustment of the focus and zoom rings is avoided, thus eliminating human errors. Secondly, considering the direction perpendicular to the optical axis, to solve the problem of insufficient distortion representations caused by using only one set of coefficients, a 2D-to-3D equal-increment partitioning method for lens distortion is proposed. Accurate characterization of DoF-dependent distortion is thus realized by fusing the distortion partitioning method and the DoF distortion model. Lastly, a calibration control field is designed. After extracting line segments within a partition, the de-coupling calibration of distortion parameters and other camera model parameters is realized. Experiment results shows that the maximum/average projection and angular reconstruction errors of equal-increment partition based DoF distortion model are 0.11 pixels/0.05 pixels and 0.013°/0.011°, respectively. This demonstrates the validity of the lens distortion model and calibration method proposed in this paper.

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High-precision Calibration Method for Three-dimensional Measurement of a Mirror-based High-speed Optical Axis Controller

The Journal of The Institute of Image Information and Television Engineers ◽

10.3169/itej.71.j162 ◽

2017 ◽

Vol 71 (5) ◽

pp. J162-J171

Author(s):

Tomohiro Sueishi ◽

Hiromasa Oku ◽

Masatoshi Ishikawa

Keyword(s):

High Precision ◽

High Speed ◽

Optical Axis ◽

Three Dimensional ◽

Calibration Method ◽

Dimensional Measurement ◽

Three Dimensional Measurement

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LOW FREQUENCY ERROR ANALYSIS AND CALIBRATION FOR HIGH-RESOLUTION OPTICAL SATELLITE’S UNCONTROLLED GEOMETRIC POSITIONING

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprsarchives-xli-b1-395-2016 ◽

2016 ◽

Vol XLI-B1 ◽

pp. 395-399

Author(s):

Mi Wang ◽

Chengcheng Fang ◽

Bo Yang ◽

Yufeng Cheng

Keyword(s):

High Resolution ◽

Information Fusion ◽

Optical Axis ◽

Low Frequency ◽

Calibration Method ◽

Error Model ◽

Model Construction ◽

Frequency Error ◽

Star Sensor ◽

Geometric Calibration

The low frequency error is a key factor which has affected uncontrolled geometry processing accuracy of the high-resolution optical image. To guarantee the geometric quality of imagery, this paper presents an on-orbit calibration method for the low frequency error based on geometric calibration field. Firstly, we introduce the overall flow of low frequency error on-orbit analysis and calibration, which includes optical axis angle variation detection of star sensor, relative calibration among star sensors, multi-star sensor information fusion, low frequency error model construction and verification. Secondly, we use optical axis angle change detection method to analyze the law of low frequency error variation. Thirdly, we respectively use the method of relative calibration and information fusion among star sensors to realize the datum unity and high precision attitude output. Finally, we realize the low frequency error model construction and optimal estimation of model parameters based on DEM/DOM of geometric calibration field. To evaluate the performance of the proposed calibration method, a certain type satellite’s real data is used. Test results demonstrate that the calibration model in this paper can well describe the law of the low frequency error variation. The uncontrolled geometric positioning accuracy of the high-resolution optical image in the WGS-84 Coordinate Systems is obviously improved after the step-wise calibration.

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A Novel Calibration Method of Articulated Laser Sensor for Trans-Scale 3D Measurement

Sensors ◽

10.3390/s19051083 ◽

2019 ◽

Vol 19 (5) ◽

pp. 1083 ◽

Cited By ~ 2

Author(s):

Jiehu Kang ◽

Bin Wu ◽

Xiaodeng Duan ◽

Ting Xue

Keyword(s):

Measurement Instrument ◽

Calibration Method ◽

High Accuracy ◽

Industrial Applications ◽

Laser Beams ◽

Laser Sensor ◽

3D Measurement ◽

System Parameters ◽

Laser Sensing ◽

Processing Techniques

The articulated laser sensor is a new kind of trans-scale and non-contact measurement instrument in regular-size space and industrial applications. These sensors overcome many deficiencies and application limitations of traditional measurement methods. The articulated laser sensor consists of two articulated laser sensing modules, and each module is made up of two rotary tables and one collimated laser. The three axes represent a non-orthogonal shaft architecture. The calibration method of system parameters for traditional instruments is no longer suitable. A novel high-accuracy calibration method of an articulated laser sensor for trans-scale 3D measurement is proposed. Based on perspective projection models and image processing techniques, the calibration method of the laser beam is the key innovative aspect of this study and is introduced in detail. The experimental results show that a maximum distance error of 0.05 mm was detected with the articulated laser sensor. We demonstrate that the proposed high-accuracy calibration method is feasible and effective, particularly for the calibration of laser beams.

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LOW FREQUENCY ERROR ANALYSIS AND CALIBRATION FOR HIGH-RESOLUTION OPTICAL SATELLITE’S UNCONTROLLED GEOMETRIC POSITIONING

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xli-b1-395-2016 ◽

2016 ◽

Vol XLI-B1 ◽

pp. 395-399

Author(s):

Mi Wang ◽

Chengcheng Fang ◽

Bo Yang ◽

Yufeng Cheng

Keyword(s):

High Resolution ◽

Information Fusion ◽

Optical Axis ◽

Low Frequency ◽

Calibration Method ◽

Error Model ◽

Model Construction ◽

Frequency Error ◽

Star Sensor ◽

Geometric Calibration

The low frequency error is a key factor which has affected uncontrolled geometry processing accuracy of the high-resolution optical image. To guarantee the geometric quality of imagery, this paper presents an on-orbit calibration method for the low frequency error based on geometric calibration field. Firstly, we introduce the overall flow of low frequency error on-orbit analysis and calibration, which includes optical axis angle variation detection of star sensor, relative calibration among star sensors, multi-star sensor information fusion, low frequency error model construction and verification. Secondly, we use optical axis angle change detection method to analyze the law of low frequency error variation. Thirdly, we respectively use the method of relative calibration and information fusion among star sensors to realize the datum unity and high precision attitude output. Finally, we realize the low frequency error model construction and optimal estimation of model parameters based on DEM/DOM of geometric calibration field. To evaluate the performance of the proposed calibration method, a certain type satellite’s real data is used. Test results demonstrate that the calibration model in this paper can well describe the law of the low frequency error variation. The uncontrolled geometric positioning accuracy of the high-resolution optical image in the WGS-84 Coordinate Systems is obviously improved after the step-wise calibration.

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Research on Calibration Method of the Beam Direction the Point Laser Sensor Based on Standard Ball

Proceedings of the 2015 International Conference on Automation, Mechanical Control and Computational Engineering ◽

10.2991/amcce-15.2015.86 ◽

2015 ◽

Author(s):

Chengwei Li ◽

Jianguo Fang ◽

Jingliang Liu ◽

Fei Liu ◽

Di Li

Keyword(s):

Calibration Method ◽

Laser Sensor ◽

Beam Direction

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Automatic Calibration Method for Mounting Position of Protein Crystal Mounting Robot Based on Visual Positioning

10.21203/rs.3.rs-122417/v1 ◽

2020 ◽

Author(s):

Jiangping Qin ◽

Zhaolong Li ◽

Bo Sun ◽

Feng Yu ◽

Yi Liu ◽

...

Keyword(s):

Calibration Method ◽

Image Features ◽

Protein Crystal ◽

External Parameter ◽

Automatic Calibration ◽

Relationship Matrix ◽

Laser Sensor ◽

Circle Fitting ◽

Visual Positioning ◽

Fitting Algorithm

Abstract With the popularization of automounting robots in protein crystal diffraction experiment beamline stations, the coordinate calibration of the robot sample mounting position has become an inevitable task in the daily maintenance of the beamline station. In this method, the image features of the laser sensor spot and goniometer are extracted by color extraction and edge detection, respectively, and the noise is eliminated by median filtering. Then, after locating the pixel coordinates of the center of the circle through the Hough circle detection and the minimum closed circle fitting algorithm, the coordinates in the base coordinate system are obtained using the camera internal and external parameter matrices and the hand-eye relationship matrix. Finally, according to the deviation of the laser spot and the visual positioning coordinate of the goniometer, the position of the robot is compensated to improve the positioning accuracy, and the automatic calibration of the sample point is realized.

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