Acta Optica Sinica, Volume. 42, Issue 15, 1512001(2022)
Rapid Position and Pose Measurement Method for Segment Girder Formwork in Precast Girder Yard
Figures & Tables(21)
Fig. 2. Checkerboard grid calibration plates for camera calibration in experiment
Table 1. Parameters of collecting device
View tableTable 1. Parameters of collecting device
Parameter Description Price of
equipment /yuan
4499（CNY） Weight of
equipment /g
Approximately 196（with battery） Rear main
camera /pixel
4 （f/1.8 aperture） Photo resolution Supporting up to 7296 pixel×5472 pixel，
3648 pixel×2736 pixel in regular mode
Table 2. Comparison of open source libraries for 3D reconstruction stage
View tableTable 2. Comparison of open source libraries for 3D reconstruction stage
Software Positioning Level of open source Cost Maintenance Documentation Visual SFM Enabling image-based 3D reconstruction Some modules open source Free for personal，non-commercial，academic applications Personal Less Bundler Enabling image-based 3D reconstruction Fully open source Free for non-commercial use Personal Less Open MVG Multi-view geometry library Fully open source Free for non-commercial use Groups Enrichment ContextCapture Bentley's software Not open source Business software Groups Enrichment
Table 3. Measurement accuracy under different illumination conditions
View tableTable 3. Measurement accuracy under different illumination conditions
Light intensity /lx Illumination condition MError /pixel 2500 Shady 0.357 15000 Shady 0.397 45000 Direct sunlight 0.171 80000 Direct sunlight 0.657
Table 4. Measurement accuracy under different background features
View tableTable 4. Measurement accuracy under different background features
Category Description /pixel Less feature plane in group 1 Number of images：6；
number of reconstructed point cloud points：849；
running time：1.52 min
Minimum value：1.609；
mean value：2.300；
maximum value：3.146
Multi-feature plane in group 1 Number of images：6；
number of reconstructed point cloud points：3851；
running time：2.83 min
Minimum value：0.202；
mean value：1.106；
maximum value：2.167
Less feature plane in group 2 Number of images：5；
number of reconstructed point cloud points：197；
running time：2.87 min
Minimum value：0.657；
mean value：0.784；
maximum value：0.883
Multi-feature plane in group 2 Number of images：4；
number of reconstructed point cloud points：19429；
running time：14.32 min
Minimum value：0.115；
mean value：0.277；
maximum value：0.392
Table 5. Measurement accuracy under different optical axis angles
View tableTable 5. Measurement accuracy under different optical axis angles
Group No. Angle of optical axis /（°） MError /pixel 1 Centre marker points：0-5；
inner circle marker points：5-15；
outer ring marker point：15-25
Mean value of centre marker points：1.783；
mean value of inner circle marker points：2.012；
mean value of outer ring marker point：2.477
2 Centre marker points：0-5；
inner circle marker points：5-15；
outer ring marker points：15-30
Mean value of centre marker points：0.902；
mean value of inner ring marker points：0.975；
mean value of outer ring marker points：1.168
Table 6. Results of measurement accuracy verification experiments
View tableTable 6. Results of measurement accuracy verification experiments
Point No. Actual 3D coordinates of marker point read by calibrator /mm 3D coordinates of marker points obtained by proposed method /mm Deviation /mm 1 （300.0，－240.0，0） （300.7，－240.8，－0.8） 1.3 2 （540.0，－240.0，60.0） （543.3，－241.7，58.7） 3.9 3 （540.0，60.0，0） （542.4，58.8，0） 2.6
Table 7. Results of precast girder yard validation experiments
View tableTable 7. Results of precast girder yard validation experiments
Point No. Group No. Actual 3D coordinates of marker point read by calibrator /mm 3D coordinates of marker point obtained by proposed method /mm Deviation /mm 1 1 （-207.0，-1076.0，-92.0） （-210.0，-1074.1，-91.9） 3.6 2 （-207.0，-1076.0，-92.0） （-207.2，-1075.6，-95.0） 3.0 2 1 （-458.0，-604.0，-92.0） （-461.1，-600.7，-92.7） 4.6 2 （-458.0，-604.0，-92.0） （-460.3，-600.3，-94.3） 5.0 3 1 （-545.0，-1259.0，-115.0） （-547.4，-1253.9，-109.6） 7.8 2 （-545.0，-1259.0，-115.0） （-549.3，-1254.3，-111.8） 7.1 4 1 （-800.0，-786.0，-115.0） （-802.1，-781.4，-116.5） 5.3 2 （-800.0，-786.0，-115.0） （-804.7，-782.2，-119.7） 7.7 5 1 （-448.0，211.0，48.0） （-444.9，208.2，47.4） 4.2 2 （-448.0，211.0，48.0） （-448.3，207.7，48.4） 3.3 6 1 （-738.0，316.0，119.0） （-735.0，315.4，114.9） 5.1 2 （-738.0，316.0，119.0） （-733.8，315.6，117.4） 4.5 7 1 （-762.0，40.0，46.0） （-758.8，39.1，43.6） 4.0 2 （-762.0，40.0，46.0） （-762.9，39.3，44.5） 1.9 8 1 （-1254.0，51.0，118.0） （-1250.6，52.2，114.0） 5.4 2 （-1254.0，51.0，118.0） （-1257.3，52.7，114.9） 4.9
Table 8. Performance comparison of common measurement methods
View tableTable 8. Performance comparison of common measurement methods
Parameter Proposed system Total station Laser scanning Instrument cost /yuan 15000（CNY） 50000（CNY） 300000（CNY） Instrument weight /kg 0.2 3.5 6.0 Indoor measurement accuracy /mm 5.0 5.0 1.0 Field measurement accuracy /mm 8.0 5.0 1.0 Measurement time /min 4.0 15.0 2.0 Calculation time /min 6.0 10.0 3.0 Multi-point measurement Support Unsupported Support Personnel requirement Single Double Single 3D coordinate measurement Support Support Support
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Zhiliang Ma, Yu Liu, Shilong Liu, Qingbo Shi, Zhibing Wang. Rapid Position and Pose Measurement Method for Segment Girder Formwork in Precast Girder Yard[J]. Acta Optica Sinica, 2022, 42(15): 1512001
Paper Information
Category: Instrumentation, Measurement and Metrology
Received: Jan. 18, 2022
Accepted: Feb. 28, 2022
Published Online: Aug. 4, 2022
The Author Email: Ma Zhiliang (mazl@mail.tsinghua.edu.cn)
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