Improve work efficiency of bridge and plant inspections!Two types of drones that realize plate thickness measurement and gas leak detection-Drone Journal

Kyushu, which is engaged in the plant engineering business, exhibited two types of drones for gas leak detection and plate thickness measurement at the International Drone Exhibition 2021. Nine is working on the development of safe and efficient inspection techniques using drones.

Regular plate thickness measurement is indispensable for maintenance management of bridges and plants. Most of the work is done by humans at high places, resulting in a large loss of cost and time associated with the installation and removal of the place. Therefore, if a drone is used, it is possible to improve work efficiency and reduce dangerous high-place work. As drone inspections that detect deterioration such as cracks are progressing, Kyukyu is developing drones with high workability such as plate thickness measurement.

Conventionally, some drones for measuring plate thickness have been developed, but the measured values ​​are inaccurate depending on the skill of the operator. Therefore, Kyukyu has developed a plate thickness measurement drone that can be measured evenly by anyone.

It seems that the demonstration verification was carried out on the bridge.

The plate thickness measurement drone has an arm attached to the Luce Search hexacopter, and is equipped with a 3-point plate thickness measuring probe (* 1) that also supports bending at the tip, and the probe is equipped with a probe for measuring plate thickness. Press and measure. It measures plate thickness using ultra-high waves and has been used as a handheld tool for inspectors. In order to measure with ultra-high waves, it was necessary to apply glycerin to the measuring part and wipe it off after the measurement. It is a mechanism to spray, so if it is water, there is no need to wipe it off and it will not damage the structure. In addition, it is possible to measure a structure with a coating film or a low degree of rust.

* 1 A sensor that incorporates a vibrating element that emits and receives ultra-high waves.

When the probe is brought close to the structure, water is ejected. Measure by pressing the probe against the measuring unit. The measured data can be checked manually. The image of the visible light camera is also projected on the upper right, and the table can be inspected at the same time.

In addition to the probe for measuring plate thickness, it is equipped with a visible light camera and can inspect rust at the same time. If the plate thickness cannot be measured due to rust bumps, the image data of the rusted part can be acquired with a visible light camera. In addition, it is not uncommon for rust deterioration to be misjudged if it is judged only by color. It is said that there are cases where it is judged that the part has deteriorated because the melted rust becomes rust juice and accumulates at the bottom. By inspecting in combination with a visible light camera, such mistakes can be prevented.

Next year, we are planning a demonstration experiment at a high temperature of around 100m at a chimney facility in Chiba prefecture. In the verification so far, it is known that the error of the measured value is suppressed to ± 0.2 mm, and it is said that the reliability will be further improved by repeating the verification. In addition, since the maneuvering is done by humans, it is difficult to determine which part was measured after the measurement. For this reason, we are also considering a function to mark the measurement points by providing a mechanism for stamping the probe.

Recently, the number of cases where drones are used for plant inspections has increased. In addition to the plate thickness measurement drone, Kyu has developed a gas detection drone that can visually inspect gas leaks.

A FLIR gas detection camera is mounted on a Luce Search multicopter.

Like the plate thickness measurement drone, the gas detection drone uses a drone made by Luce Search. The multicopter is equipped with a FLIR gas detection camera, which helps to detect gas leaks at an early stage. The magnification of the camera can be controlled from the transmitter of the drone, making it easier to catch abnormal parts even in inlaid structures.

A model that simulates a gas leak is used in the booth. Gas is leaking from the pipe connection, and the camera shows a smoky gas leak.

Gas leaks are difficult to distinguish from steam leaks, and visualization prevents misjudgment. If a large amount of gas leaks, it may explode, so it is important to deal with it as soon as possible. By using the gas detection drone on a daily basis, it is possible to detect minor abnormalities at an early stage, and it is possible to take measures such as releasing pressure and replacing packing.

The person in charge of developing the drone for measurement and inspection said, "In the past, inspectors climbed to high places and reported the inspection points through photography. However, the situation at the site can only be understood by the inspector in charge. There was no such thing. Therefore, if an inspection is performed based on the high-resolution images and videos of the drone, it will be possible for other specialists to judge whether it is good or bad. The drone can be used in a wide variety of ways, leading to a reduction in the number of drones and an improvement in operational efficiency. , The centralized management of the decay rate, repair history, etc. has also been realized. "