Toda Construction deploys autonomous drone in tunnels, cuts face inspection time to 17 minutes
Japan’s Toda Construction said its AI-powered drone system cut tunnel face inspection time from about two hours to 17 minutes.
Toda developed the system with Spiral and GreenBee to analyze newly excavated tunnel faces, a task that is typically handled by teams of engineers through a slow, labor-intensive process. The company said the aim is to reduce the need for personnel at the inspection site while speeding up surveys, improving project management and helping shorten schedules on major underground infrastructure jobs.
The setup includes a dust-proof charging canopy for the drone, designed for debris-filled mountain tunnels, and custom software intended to make operations autonomous and easier to deploy on site. The drone uses obstacle avoidance when flying to photograph the rock face, allowing it to steer clear of construction vehicles, workers and debris. Toda said tests confirmed flight stability, image capture performance and AI-based evaluation. The company also said the AI can select suitable images from hundreds of tunnel face photographs, while the drone can autonomously take off from its charging port, avoid obstacles, collect images in the tunnel and return to the correct position for landing and recharging.
The result points to a broader role for UAVs in underground construction, where access is difficult and safety demands are high. If adopted at scale, the system could reduce worker exposure in active tunnel zones, cut inspection delays and make drone-based surveys a practical tool for faster delivery of subterranean infrastructure projects.