A novel inspection system combining drones and artificial intelligence is revolutionizing construction of the Chengdu-Deyang intercity railway in Sichuan province, marking a pioneering integration of technology and industry in China's rail transit sector.

The system integrates autonomous drone patrols, AI-powered hazard detection, real-time 3D modeling and instant warning responses, according to Chen Longhua, an on-site engineer with Sichuan Chengdu-Deyang Rail Transit Co.

"These drones have not only wings and eyes, but also a smart AI brain," Chen said.

Operating without hands-on human guidance, the drones take off from charging stations, patrol the construction site, return to recharge when battery runs low and resume their missions automatically, Chen said.

At the Tianxun intelligent command center, a large screen displays real-time footage transmitted by the drones, offering a comprehensive view of every segment of the elevated sections. The system automatically analyzes images to identify potential safety hazards such as deep foundation pit risks and smoke spots.

"When a hazard is detected, the drone can immediately broadcast warnings to alert workers on-site while simultaneously sending the information to managers' mobile phones," Chen said.

The drone-mounted AI model, trained on vast amounts of construction site data, can identify subtle hazards that human eyes might miss, including missing protective barriers and improper hoisting operations, he added.

The system also generates 3D models of the construction site using real-time dynamic positioning modules, enabling precise tracking of progress for every pier column and beam, Chen said.

"The elevated section in Chengdu alone stretches 18 kilometers — a distance that previously required hundreds of workers for around-the-clock inspections during peak construction," said Xia Bangjun, deputy manager of the Chengdu-Deyang line command center at China Railway City Development and Investment Group.

"Now, just two drones can complete a patrol in 30 minutes, improving efficiency by more than 80 percent."

According to Chen, the system was developed from the railway project's inception and has recently been deployed in key areas including elevated sections and underground tunnel sections.

"As application scenarios expand, its AI brain will become increasingly intelligent and accurate," he said.