3D-printed autonomous boats could help ease congestion in busy cities
Image credit: MIT
Autonomous boats that offer high manoeuvrability and precise control could help to reduce congestion in cities that rely heavily on their waterways, such as Amsterdam and Bangkok.
MIT researchers have developed the boats which can be rapidly 3D printed using a low-cost printer, making mass manufacturing more feasible.
“Imagine shifting some infrastructure services that usually take place during the day on the road - deliveries, garbage management, waste management - to the middle of the night, on the water, using a fleet of autonomous boats,” said Daniela Rus who co-authored a paper on the technology.
The researchers even envisage that the boats could be programmed to self-assemble into floating bridges, concert stages, platforms for food markets and other structures in a matter of hours.
“Again, some of the activities that are usually taking place on land, and that cause disturbance in how the city moves, can be done on a temporary basis on the water,” Rus said.
The boats feature rectangular 4m x 2m hulls and are equipped with sensors, microcontrollers, GPS modules and other hardware.
The boats could also be equipped with environmental sensors to monitor a city’s waters and gain insight into urban and human health.
To make the boats, the researchers 3D printed a rectangular hull with a commercial printer, producing 16 separate sections that were spliced together. Printing took around 60 hours. The completed hull was then sealed with several layers of fiberglass.
Integrated onto the hull are a power supply, Wi-Fi antenna, GPS, a minicomputer and microcontroller.
For precise positioning, the researchers incorporated an indoor ultrasound beacon system and outdoor real-time kinematic GPS modules, which allow for centimetre-level localisation, as well as an inertial measurement unit (IMU) module that monitors the boat’s yaw and angular velocity, among other metrics.
The boat is a rectangular shape, instead of the traditional kayak or catamaran shapes, to allow the vessel to move sideways and to attach itself to other boats when assembling other structures.
Four thrusters are positioned in the centre of each side which can generate both forward and backward forces, making the boat more agile in tight spaces.
The team also developed an algorithm that enables the boat’s controller to track its position and orientation more quickly and accurately.
“The controller considers the boat dynamics, current state of the boat, thrust constraints, and reference position for the coming several seconds, to optimise how the boat drives on the path,” said the paper’s first author Wei Wang. “We can then find optimal force for the thrusters that can take the boat back to the path and minimise errors.”
A next step for the work is developing adaptive controllers to account for changes in mass and drag of the boat when transporting people and goods. The researchers are also refining the controller to account for wave disturbances and stronger currents.