Thesis Type: Postgraduate
Institution Of The Thesis: Middle East Technical University, Faculty of Engineering, Department of Civil Engineering, Turkey
Approval Date: 2014
Thesis Language: English
Student: Muhammad Usman Hassan
Supervisor: ÖZGÜR KURÇ
Abstract:As-built information of reinforced sections is necessary to ascertain structural characteristics from load carrying capacity, serviceability, structural integrity and adherence to code perspective. The objective of this research is to develop a semi-automated structural information acquisition method that can be used to determine as-built information regarding rebar grids of reinforced concrete columns. The technique involves application of photogrammetry, image processing and computer vision knowledge to obtain structural information in 2D and 3D space. Method developed during the course of this research is divided into bar detection, bar diameter measurement, stirrup spacing, and 3D rebar location computation algorithms. Multi prong approach of color space and line detection is utilized to add robustness to the method. In order to improve automation of developed product a stereo matching algorithm is developed to match points between two images of symmetric and hollow rebar grids. Every step of the proposed method is tested on different rebar specimens with varying dimensions and complexity to adjudge its performance. Based on images acquired in ideal condition, the error in measurement of rebars diameters and stirrup spacing remained below 8.5%. For 3D measurement of rebar coordinates, error has increased up to 20%.