Multi UAVs Cooperated With 3D Printing To Build A House, And Research Was Put On The Cover Of Nature

Would you like to leave the construction to drones and let them perform 3D printing?

We can often see bees, ants and other animals busy nesting. After natural selection, their work efficiency is amazing.

The division and cooperation ability of these animals has been "passed on" to UAVs. A study from Imperial College of Technology shows us the future direction, as follows:

3D graying of UAV:

This research was published on the cover of Nature on Wednesday.

Address: https://www.nature.com/articles/s41586-022-04988-4

To demonstrate the UAV's capability, researchers used foam and a special lightweight cement material to build structures ranging in height from 0.18m to 2.05m. Compared with the original blueprint, the error is less than 5mm.

To prove that the system can handle more complex UAV formation, the team created a light trail delay sequence using the lights on the UAV to simulate a high dome structure.

Mirko Kovac, leader of the research and director of the Aerial Robotics Laboratory at Imperial College, said: This method can be used to build buildings in the Arctic or even on Mars, or help repair high-rise buildings that usually require expensive scaffolding.

However, at present, this technology is still subject to some restrictions, because UAVs are difficult to carry heavy objects, need to be charged regularly, and still need manual supervision. However, the researchers said that they hoped to alleviate some of these problems by automatically charging the UAV during the project study.

How is UAV 3D printing realized? In this regard, researchers have built a sophisticated system.

Research introduction

In order to improve productivity and safety, robot based construction technology is proposed for assembly of building components and free form continuous additive manufacturing (AM). Compared with the method based on assembly, free form continuous AM can flexibly produce geometric variable design, which is characterized by high efficiency and low cost. However, these large-scale systems need to be connected to the power supply. It is inconvenient to inspect, maintain and repair them, and it is difficult to manufacture them in harsh environments.

As an alternative to large single robot systems, small mobile robots can provide greater flexibility and scalability. However, the research on building with robot formation is still in the early exploration stage of development. In addition, the operating height of multi robot is limited at present, and it will not work if it exceeds a certain range. The figure below shows the comparison between SOTA robot platforms developed for AM in the construction industry.

Compared with the current robot system and its inherent limitations, natural builders have shown greater adaptability in building, and many use flight and additive construction methods to achieve this. For example, swallows can fly 1200 times between the material source and the building site to gradually complete the nest. Social insects such as termites and wasps show a greater degree of adaptability and scalability: aerial construction conducted by social wasps shows efficient and direct path optimization, reducing the navigation demand in the whole building process.

These natural systems inspire the method of collective construction using multi-agent, which needs to solve the coordination problem of multi-agent beyond the current available technology. In addition to the collective interaction method of multi robot systems, material design and use and environmental manipulation mechanisms must be integrated and jointly developed to achieve cooperative construction.

The system proposed by Imperial College is called Aerial AM, which combines biological cooperation mechanism with engineering principles and is realized by multiple UAVs.

To achieve autonomous additive manufacturing, UAV teams need to develop a number of key technologies in parallel, including: 1) aerial robots capable of high-precision material deposition and print quality, and real-time qualitative evaluation; 2) Aerial robot teams can broadcast their own activities to each other, share data wirelessly, and do not interfere with each other; 3) The autonomous navigation and task planning system, combined with the printing path strategy, adaptively determines and distributes manufacturing tasks; 4) Design or select material plans, especially lightweight and printable cement mixtures, suitable for aerial additive manufacturing methods without the need for formwork or temporary scaffolding.

Aerial AM uses two types of aerial robot platforms, called BuilDrone and ScanDrone respectively. BuilDrone is used to stack physical materials, and ScanDrone is used to perform incremental aerial scanning and verification observation after each layer of materials is deposited. The two robot platforms are coordinated on their respective workflows through distributed multi-agent methods. The construction cycle includes the in-flight printing performance characterization of BuilDrones and ScanDrone, the real-time trajectory adaptation and material printing of BuilDrones, and the verification of printing effect by ScanDrone and human supervisors.

Figure 2. Aerial AM framework for unrestricted and unbounded AM.

The multi-agent Aerial AM framework proposed by the new research consists of two cycles, which run on the planned slow time scale and the real-time operation fast time scale respectively for manufacturing and progress observation. In the proof of concept, the researchers used the scandrone airborne vision system to conduct 3D scanning to map the progress, and used expanded foam materials to build a large cylinder.

Figure 3. Aerial AM BuilDrone printed 2.05 m high cylindrical geometry, including 72 material deposition trips, and ScanDrone performed real-time printing evaluation.

Figure 4. Two BuilDrones use error compensation delta manipulators to 3D print thin-walled cylinders to deposit cementitious materials.

Figure 5. Aerial AM multi robot track virtual printing dome shaped rotating surface. a. C is the flight path, b and d are the top view and perspective view. F shows the simulation results of using 15 robots to print enlarged geometry, with a bottom diameter of 15 m.

Through the material deposition of BuilDrone and the real-time qualitative evaluation of the printing structure by ScanDrone, researchers successfully printed a cylinder up to 2.05 meters high, proving the ability of Aerial AM method to manufacture large geometric objects. The manufacturing experiment of cement thin wall cylinder proves that the coupling of self-aligning parallel delta manipulator and BuilDrone allows materials to be deposited with high accuracy (maximum 5 mm position error) in the horizontal and vertical directions, which is within the allowable range of British architectural requirements.

The virtual track AM and simulation results show that the Aerial AM framework can effectively print various geometric shapes through parallel multi robot manufacturing, solve congestion, and complete adaptation under abnormal conditions.

Although these experiments have successfully verified the feasibility of Aerial AM, they are only the first step to explore the potential of using aerial robots for building. The researchers said that in order to realize the 3D printing house building of UAV, significant progress needs to be made in robot technology and material science, especially in the frontier fields such as the deposition of support materials, curing of active materials and task sharing among multiple robots.

For the UAV itself, in order to make the research results go out of the laboratory, researchers are planning to implement a multi-sensor simultaneous positioning and mapping (SLAM) system with differential global positioning system (GPS) to provide sufficient outdoor positioning.

After being put into practice, Aerial AM may provide an alternative way to support housing and important infrastructure construction in remote areas.

Reference link:

https://www.nature.com/articles/s41586-022-04988-4

https://www.technologyreview.com/2022/09/21/1059864/drones-3d-print-tower/

Original title: Building a House with Multi UAV Collaborative 3D Printing and Research on the Cover of Nature