Lin, F.; Cheng, Y. and Zhang, J. (2026) Efficient rebar layout estimation enabled by a custom detection network and enhanced visual measurement. Journal of Construction Engineering and Management, 152(9): 04026152, ISSN 0733-9364
Abstract
Accurate detection of reserved rebar spacing in precast concrete structures is essential for ensuring proper component assembly and structural safety. However, conventional measurement methods are inefficient, error-prone, and involve potential safety risks. To address these issues, this paper investigates high-precision rebar spacing measurement from a single monocular image under wide-area and noncoplanar conditions. Accordingly, a vision-based single-image rebar spacing measurement method is proposed. The proposed method integrates a rebar section detection model with a multichessboard, height-adjusted planar calibration strategy. A task-aware image enhancement module is introduced to improve detection stability in complex construction environments. Multiple chessboards are used to construct a wide-area calibration plane, and a height compensation mechanism is employed to mitigate scale recovery errors caused by the noncoplanarity between the calibration plane and the measurement plane, enabling quantitative rebar spacing measurement from a single image. Compared with an structure from motion + multi-view stereo (SfM + MVS)-based 3D reconstruction measurement method, the proposed approach reduces the average measurement error by 76.8% and yields a more concentrated and stable error distribution. The proposed method provides a basis for further development of automated rebar adjustment devises with integrated visual feedback, enabling closed-loop automation from measurement to correction in construction.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | image quality improvement; precast concrete structures; rebar detection; rebar positioning; visual measurement |
| Index terms: | estimation, measurement method, recovery, precast concrete, compensation, image quality, module, rebar, reconstruction, strategy, automation, stability |
| Subjects: | computer vision, operations management, building construction, financial and cost management, structural engineering, architectural elements, management, dispute resolution, automation and robotics, building materials |
| Topics: | Cost Management, Design Practice, Engineering Principles, Business Strategy, Legal Issues, Project Management, Digital Applications, Construction Materials |
| Descriptive scope: | 2 PC |
N.B. Descriptive scope is a count of how many of the five facets of empirical research are indicated by the words used in title, abstract and keywords. It is not intended as a judgement on the research; merely a count of the kind of word we would expect to indicate Phenomenon, Concepts, Theoretical framing, Empirical techniques, Analytical techniques. If all five are present, then a code of “5 PCTEA” will indicate this. If you feel the coding for this record is questionable, we welcome discussion around the terms we matched or the way we categorized them. The facet you would expect may not be coded, or a facet may be coded inappropriately. This can also bear on a larger question, of which facets should be treated as defining in construction management research. Please get in touch, and we will look at it. More details here