A universal and flexible theodolite-camera system for making accurate measurements over large volumes

Zhang, Xiaohu; Zhu, Zhaokun; Yuan, Yun; Li, Lichun; Sun, Xiangyi; Yu, Qifeng; Ou, Jianliang

doi:10.1016/j.optlaseng.2012.05.009

Cited by 43 publications

(10 citation statements)

References 25 publications

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“…Finally, the main advantage of QDaedalus versus other similar developed techniques combining theodolites with camera (Zhang et al, 2012;Wu and Wang, 2013) is that the CCD sensor is adjusted directly on the telescope of the Total Station making known the exact position and orientation of the captured images. The latter simplifies the technique by avoiding the calibration of the camera with respect to the position of the theodolite/total station and by limiting the potential errors, which may be introduced during the transformations of the measurements in the common coordinate system.…”

Section: Qdaedalus Versus Video-recording Systemsmentioning

confidence: 99%

Measuring sub-mm structural displacements using QDaedalus: a digital clip-on measuring system developed for total stations

et al. 2014

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Section: Qdaedalus Versus Video-recording Systemsmentioning

confidence: 99%

Measuring sub-mm structural displacements using QDaedalus: a digital clip-on measuring system developed for total stations

et al. 2014

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“…For instance, Zhang Zuxun et al [19,20] designed a measuring system named Photo Total Station System (PTSS), within which a metric camera with known internal parameters was rigidly installed on the telescope of the total station to extend the FOV and improve the accuracy. Zhang et al [21] designed a theodolite-camera (TC) measurement system consisting of a theodolite and a camera for precise measurement at large viewing angles. The total station or theodolite can provide the spatial coordinates of the control points, which can be used to establish the relationship of the camera while rotating.…”

Section: Introductionmentioning

confidence: 99%

Alignment Method of an Axis Based on Camera Calibration in a Rotating Optical Measurement System

Hou

Chen

2020

Applied Sciences

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The alignment problem of a rotating optical measurement system composed of a charge-coupled device (CCD) camera and a turntable is discussed. The motion trajectory model of the optical center (or projection center in the computer vision) of a camera rotating with the rotating device is established. A method based on camera calibration with a two-dimensional target is proposed to calculate the positions of the optical center when the camera is rotated by the turntable. An auxiliary coordinate system is introduced to adjust the external parameter matrix of the camera to map the optical centers on a special fictitious plane. The center of the turntable and the distance between the optical center and the rotation center can be accurately calculated by the least square planar circle fitting method. Lastly, the coordinates of the rotation center and the optical centers are used to provide guidance for the installation of a camera in a rotation measurement system. Simulations and experiments verify the feasibility of the proposed method.

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“…Compared with the centralized measurement system, the distributed system has advantages of measurement range scalability, which is very practical in large-scale metrology. There have been several distributed measurement systems provided for large-scale measurement, including theodolite networks [5,6], digital photogrammetry [7] and laser trackers. However, the theodolite networks cannot measure automatically in real time, the digital photogrammetry has a limited field of view and the laser tracker is unable to measure more than one point concurrently.…”

Section: Introductionmentioning

confidence: 99%

A Sub-Regional Calibration Method That Can Accomplish Error Compensation for Photoelectric Scanning Measurement Network

Zhang

Ren

Yang

et al. 2019

Sensors

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In the measurement process of photoelectric scanning measurement network, the laser surface edge area has lower measurement accuracy than the middle area due to the geometrical distortions of the laser surface of the transmitter. This paper presents a sub-regional calibration method that can accomplish error compensation for the measurement system. Unlike the camera sub-regional calibration, the regional division and identification of the laser surface are more difficult. In this paper, the pitch angle in the transmitter coordinate frame of the spatial point was used as the basis for the division and identification of the laser surface. In the calibration process, the laser surface of the transmitter was divided into different regions and each region was calibrated independently, so that an intrinsic parameters database containing the intrinsic parameters of different regions could be established. Based on the database, the region identification and error compensation algorithm were designed, and comparison experiments were carried out. With the novel calibration method, the measurement accuracy of the system had an obvious upgrade, especially at the edges of the laser surface within a certain measurement area, which could enlarge the effective measurement area of the transmitter and would broaden and deepen the application fields of photoelectric scanning measurement network.

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A universal and flexible theodolite-camera system for making accurate measurements over large volumes

Cited by 43 publications

References 25 publications

Measuring sub-mm structural displacements using QDaedalus: a digital clip-on measuring system developed for total stations

Measuring sub-mm structural displacements using QDaedalus: a digital clip-on measuring system developed for total stations

Alignment Method of an Axis Based on Camera Calibration in a Rotating Optical Measurement System

A Sub-Regional Calibration Method That Can Accomplish Error Compensation for Photoelectric Scanning Measurement Network

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