Succeeded in remote underwater inspection of bridge piers using a combined hydro-air drone - Achieving DX of safety management work for aging bridge facilities -

New model of water-air combination drone

KDDI Smart Drone Co., Ltd. (Headquarters: Minato-ku, Tokyo, President and CEO: Masafumi Hirono, hereinafter referred to as KDDI Smart Drone), KDDI Research Institute, Inc. (Headquarters: Fujimino City, Saitama Prefecture, Representative Director and Director: Hajime Nakamura, hereinafter referred to as KDDI Research Institute), Prodrone Co., Ltd. (Headquarters: Nagoya City, Aichi Prefecture, President and Representative Director: Shunsuke Totani, hereinafter referred to as KDDI Research Institute) On March 5, 2024, Prodrone (Prodrone) successfully conducted a remote underwater inspection of the bridge piers at Chubo Bridge in Tokyo Bay using mobile communications as part of the Tokyo Bay eSG Project, which aims to create a sustainable city of the future, using a new jointly developed water-air combination drone.

The water-air combination drone is the world's first (Note 1) drone that combines an aerial drone and an underwater drone and can fly in the sky and dive under water using remote control via mobile communications. The acoustic positioning device allows you to determine the drone's location even underwater, where satellite-based positioning systems (GPS) cannot be used.

The new model is an underwater drone developed by Pro Drone, which allows for customization such as underwater maintenance functions, and an improved acoustic positioning device that allows inspections to be performed while stably grasping the underwater position even in actual sea areas with shaking and currents. In addition, it is now possible to check images and information from aerial, water, and underwater cameras using a single tablet, and inspections can now be carried out more efficiently with a smaller number of people.

There are 730,000 bridge piers nationwide, and by 2030, 55% of them will be over 50 years old, making inspection efficiency a major issue. In particular, inspections of the underwater parts of bridge piers require a ship to be sent out and a diver to inspect them, which has a low inspection implementation rate, and there is a need for safer and more efficient inspection methods.

In this demonstration, we were able to confirm that it is possible to remotely inspect the underwater part of a bridge pier from land using a combined water-air drone, without having to take out a ship. In 2024, we will conduct practical demonstrations for social implementation in the Tokyo Bay eSG Project, aimed at DX of sustainable social infrastructure management.■About water-air combination drone pier underwater inspection demonstration1. Implementation overviewWhen inspecting bridge piers, it is necessary to check (1) deformation in the upper part of the water, (2) deformation in the underwater part, and (3) scour conditions at the base. In this demonstration, we demonstrated whether it is possible to remotely photograph these deterioration conditions using a water-space drone.
[Date] March 5, 2024
[Location] Tokyo Bay Chubo Bridge

Water-air combined drone pier underwater inspection demonstration inspection details

2. Demonstration resultsIn the demonstration, ① above-water deformations were photographed using an aerial drone camera, and ②-③ deformations in the underwater part were photographed using an underwater drone camera. As a result of determining the degree of deterioration based on the Fisheries Infrastructure Facility Inspection Standards, we found no damage such as extensive exposure of reinforcing steel or spillage of filler material, confirming that there were no problems.

3. Demonstration systemSponsored by: Tokyo Metropolitan Government “Tokyo Bay eSG Project”
Smart Drone Platform: KDDI Smart Drone
Acoustic positioning technology: KDDI Research Institute
Aircraft production: Prodrone■About the new water-space combination drone1. Aircraft overviewBy combining aerial and underwater drones, it is possible to fly in the sky and dive underwater.
Underwater turbines allow it to move on the water, and information from GPS or GNSS allows it to maintain its position on the water without being blown away by ocean currents or winds. In addition, the new aircraft has a larger float to improve movement performance on water.

[Basic specifications]

・Size: 1670mm x 1670mm x 665mm
・Weight: 31kg
・Wind resistance: ~10m/s
・Water resistance: IP55
・Tidal current resistance: ~1m/s
・Flight time: ~15 minutes
・Dive time: Approximately 1 hour (depending on ocean currents)
・Cable: 70m2. Underwater drone and acoustic positioning deviceAhead of future autonomous underwater navigation, Prodawn has developed an underwater drone that is equipped with a function to maintain its underwater position based on acoustic positioning information and can be customized in both hardware and software.
Additionally, we have developed a new acoustic positioning device (sound generator/acoustic receiver) that increases the positioning frequency from 1 to 5 times per second and has sophisticated vibration correction, improving positioning accuracy in real environments. By making it even smaller, we have made it easier to mount it on underwater drones.

Underwater drone that can be customized with both hardware and software

New type of acoustic positioning device with improved positioning accuracy and smaller size

3. Water-space combined drone integrated management appAerial, above-water, and underwater images and information, which had been managed separately until now, will be aggregated on a smart drone platform (Note 2) and integrated into a tablet app. You can now operate the underwater drone while viewing its image and position on your tablet.

4. Usage purposeSince it is possible to check underwater conditions from the coast without having to take a boat out, it is expected to be useful in a variety of applications, including fisheries monitoring, where fish farms and fixed nets are routinely checked by boat, underwater infrastructure inspections such as offshore wind power, dams, and bridge piers, and blue carbon measurements.

■About KDDI smart droneKDDI Smart Drone is building a service that enables safe remote and long-distance flights by controlling drones using mobile communications. We are working to realize new businesses using drones and provide flexible services that meet customer needs in various fields such as inspection, logistics, monitoring, agriculture, and surveying. We also operate the KDDI Smart Drone Academy, a drone school that operates unmanned aircraft operator qualification courses that correspond to national drone qualifications, as well as specialist courses specializing in solutions, at more than 10 locations in Japan.
For details, see the KDDI Smart Drone homepage ( https://kddi.smartdrone.co.jp/ )Please see.■About ProdroneWith the vision of "becoming the most trusted drone company in the region," we aim to build a drone ecosystem in the Chubu region. We provide a one-stop service for everything from development to production of industrial drones, including the PD6B-Type3 multicopter, which has started mass production with a maximum recommended payload of 20kg, and the PDH-GS120 helicopter, which can fly for two hours and has excellent weather resistance.■About Tokyo “Tokyo Bay eSG Project”The "Tokyo Bay eSG Project" (Version 1.0) is a project that envisions urban development with an eye toward the future 50 to 100 years, set in the Bay Area.
This demonstration project was selected and implemented as a pioneering project that utilizes the vast central breakwater area to implement cutting-edge technology, with the aim of creating a sustainable city that combines nature and convenience.
・Tokyo Metropolitan Government “Tokyo Bay eSG Project” homepage ( https://www.tokyobayesg.metro.tokyo.lg.jp/ )

(Note 1) Three companies developed the world's first drone on May 31, 2021 as a combination of an aerial drone and an underwater drone that can fly in the sky and dive under water using remote control via mobile communication.
(Note 2) The smart drone platform is a platform that realizes autonomous flight beyond visual line of sight and remote monitoring and control using mobile communication.
*Smart drone is a drone compatible with KDDI's mobile communication network and is a registered trademark of KDDI.