DeepX has developed a system called ‘GeoViz’, which visualizes the site in real-time three dimensions in a digital twin format. In 2022, together with Oriental Shiraishi Corporation, DeepX demonstrated this system at a site which use the pneumatic caisson method.

About Pneumatic caisson method

The term “Pneumatic caisson method” refers to a technique where ‘pneumatic’ means air and ‘caisson’ means box.
It is widely used for the foundations of bridges and buildings, as well as for sewage pumping stations, underground adjustment tanks, shield tunnel shafts, and the main structures of subways and road tunnels.
A reinforced concrete box (body) is constructed above ground, a workspace is set up underneath it, and excavation machinery and earth buckets for soil removal are installed.
By repeating the process of excavation, soil removal, and sinking of the body, it is advanced vertically.
A characteristic of this method is that compressed air, commensurate with the groundwater pressure, is introduced to prevent groundwater from entering the workspace.
Due to the high air pressure in the workspace, remote construction is the standard.
The caisson shovel targeted in this demonstration refers to the excavation machinery used in the pneumatic caisson method.

Challenges of remote construction

In recent years, in the pneumatic caisson method, operators have been performing construction by remotely operating the caisson shovel based on the information from the camera for remote operation.
However, there are challenges such as it being difficult for the site supervisor to accurately grasp the overall situation inside the workspace, and the operators not being able to grasp the distance to the ground, resulting in decreased work efficiency.
At the end of the day, workers are still required to enter the workspace and measure directly.

The actual situation at the site seen in the camera footage used by the operator.
It is difficult to accurately grasp the overall situation inside the workspace at a glance, and it requires skilled expertise to operate the machinery while accurately understanding the sense of distance to the ground and the shape.

Demonstrated on-site the ability to visualize construction machinery and terrain in real time

In this demonstration, we confirmed that by visualizing the site of the pneumatic caisson method in real-time using digital twins, we could assist in the operator’s operation and site management.

A. Technical verification

A-1. Perception and 3D visualization of construction machine and the terrain

We have confirmed that the positions and postures of the two caisson excavators, as well as the shape and height of the ground, can be perceived and visualized in 3D.
In particular, we confirmed that we can automatically calculate the open ratio, which is an indicator that shows the operational situation that is characteristic and important for the pneumatic caisson method.

A-2. Real-time performance

We have confirmed that the positions and postures of the two caisson excavators, as well as the shape and height of the ground, can be perceived and visualized in 3D.
In particular, we confirmed that we can automatically calculate the open ratio, which is an indicator that shows the operational situation that is characteristic and important for the pneumatic caisson method.

A-3. Stability of the system

This system is used to support operators or for automated driving on actual sites, so it is important that the system continues to operate stably and continuously. In this verification, we confirmed that the system can operate continuously for a long period without the intervention of engineers.

A-4. Rollback of operation history

This system can digitize the site’s situation in real time and save the ever-changing site’s situation as a log. By reading the saved log data with this system, we confirmed that it is possible to reproduce the state of the site at any past timing in a video.

B. Expected effects

The following three effects are expected from the perspective of on-site support.

• As the measurement results of the workspace can always be checked from the remote control room, there is no need for site supervisors to enter the workspace daily, improving safety.
• Operators can oversee the relationship between the construction machinery and the ground, improving the efficiency of machine operation.
• Supporting and automating report creation for site supervisors, and preventing communication errors with construction personnel improves management efficiency.

 

DeepX has constructed a visualization system based on ROS2

We took on primarily the development and provision of software, as well as integration work on site using these software. For the software, we developed a robot system that forms the basis, along with algorithms for perception, and a simulator for development verification.Oriental Shiraishi handled other demonstration sites and hardware arrangements.

A. The main software we developed

A-1. Robotic system

We developed a robot system based on ROS2. In this demonstration, we had in mind the development of an autonomous driving system after the demonstration, and therefore, we particularly emphasized the robustness and extensibility of the system during development.

A-2. Terrain perception

An algorithm that calculates the shape of the terrain in real time from point cloud data from multiple LiDARs.
It processes point cloud data obtained from several LiDARs on site in real time, estimating the three-dimensional shape of the constantly changing terrain.

B. Development Organization

In this demonstration, a solution team closely collaborated with customers to facilitate requirements definition and verification, while a software engineering team developed the visualization system. The software development and verification were carried out through the collaboration of these teams. Notably, the software engineering team comprised members from various nationalities, forming a global team.

A scene where a member from Oriental Shiraishi explain the history of the Pneumatic caisson method and the importance of autonomous driving.

The members of the solution team and the software engineering team involved in this project.

Pneumatic caisson method and Remote, Automated, and Autonomous operations

The pneumatic caisson method was the first construction method to be remotely executed in Japan.
Because the air pressure in the work space is high and remote construction is standard in many cases, sensors and actuators have been digitalized, providing a basis for automation.
Also, since people do not usually enter the work area, the safety requirements for autonomous operation are lower compared to general earthworks, and there are fewer restrictions from Industrial Safety and Health Act, which prohibit people from entering the working radius of industrial machinery.
Lastly, the work primarily involves repeated excavation and transportation of the earth.
Therefore, this method is considered to have favorable conditions for demonstrating and advancing automation and autonomous technology.
The site visualization system developed this time not only supports the site operatoin through visualization but also serves as the basis for an autonomous driving system.

Future outlook

Based on the software developed in this project, we plan to move towards the developement and verification of autonomous operation in actual construction sites.
We will continue to pioneer the frontier of construction machinery autonomous driving for practical implementation in the future.