US 12,436,048 B1
Bolt axial force measurement method, device, apparatus, and readable storage medium
Xiaoli Sun, Guangzhou (CN); Zhiguo Zhou, Guangzhou (CN); Jun Yang, Guangzhou (CN); Sijia Zhu, Guangzhou (CN); Linbin Wang, Guangzhou (CN); and Feng Li, Xinjiang (CN)
Assigned to GUANGZHOU MUNICIPAL ENGINEERING TESTING CO., LTD., Guangzhou (CN); and GUANGZHOU INSTITUTE OF BUILDING SCIENCE GROUP CO., LTD., Guangzhou (CN)
Filed by Guangzhou Municipal Engineering Testing Co., Ltd., Guangzhou (CN); and Guangzhou Institute of Building Science Group Co., Ltd., Guangzhou (CN)
Filed on May 20, 2025, as Appl. No. 19/213,462.
Claims priority of application No. 202410841159.X (CN), filed on Jun. 27, 2024.
Int. Cl. G01L 5/12 (2006.01); G01L 1/06 (2006.01); G01L 25/00 (2006.01)
CPC G01L 5/12 (2013.01) [G01L 1/06 (2013.01); G01L 25/00 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A bolt axial force measurement method, comprising steps of:
capturing an image of a bridge bolt by a movable imaging device;
identifying an outer edge of a nut, a centroid of the nut, and a circular position of a laser spot at a center of the bridge bolt in the captured image of the bridge bolt;
projecting a calibration laser spot onto a bolt plate and obtaining a current frame as a bolt-detection image when the outer edge of the nut, the centroid of the nut, and the circular position of the laser spot at the center of the bridge bolt in the captured image of the bridge bolt meet preset conditions;
performing dimensional calibration on the bolt-detection image based on a size of the calibration laser spot in the bolt-detection image and determining a displacement of pre-calibrated feature points on the bridge bolt in the bolt-detection image;
calculating a bolt axial force value based on the displacement of each of the pre-calibrated feature points on the bridge bolt in the bolt-detection image;
wherein the step of performing dimensional calibration on the bolt-detection image based on a size of the calibration laser spot in the bolt-detection image and determining a displacement of each of the pre-calibrated feature points on the bridge bolt in the bolt-detection image comprises:
determining an actual size of the calibration laser spot based on the size of the calibration laser spot in the bolt-detection image in connection with a corresponding dimensional calibration curve;
performing dimensional calibration in the bolt-detection image based on the actual size of the calibration laser spot;
reading a position of each of the pre-calibrated feature points on the bridge bolt in the bolt-detection image dimensionally calibrated; and
calculating the displacement of each of the pre-calibrated feature points on the bridge bolt in the bolt-detection image by establishing a position of the pre-calibrated feature point at the centroid of the nut of the bridge bolt in the bolt-detection image as an origin of a polar coordinate.