Portable Multimodal Vision-Based Device for Non-Destructive Evaluation of Rebar Welds

The quality of rebar welds directly impacts the overall service performance of highway infrastructure. However, current assessments of weld appearance quality primarily rely on traditional inspection methods such as manual visual inspection, which suffer from significant limitations in accuracy, reliability, and efficiency. Given the increasing demand for safety performance inspections of highway infrastructure in China, traditional methods struggle to meet modern rapid inspection requirements. Therefore, this study proposes the design of a portable, non-destructive inspection device for rebar weld appearance, utilizing visible light vision and line-structured light 3D scanning technology. The device is equipped with an STM32 master control chip to manage encoder reading, scanning laser control, ring fill light, industrial camera synchronization, image acquisition, and serial port command transmission. Additionally, a weld image processing and detection software system was developed to receive, store, and identify weld defects. A field inspection prototype was created and subjected to various defect weld detection experiments in a laboratory setting. Experimental results demonstrate that the device can accurately measure weld parameters by acquiring multimodal images, fulfilling defect detection requirements. The device features high detection accuracy, portability, and user-friendliness, making it significant for the objective inspection and evaluation of rebar weld appearance and welding quality.