MIT’s fleet of robotic boats has been updated with new capabilities to “shapeshift,” by autonomously disconnecting and reassembling into a variety of configurations, to form floating structures in Amsterdam’s many canals.
The autonomous boats are being developed as part of the ongoing “Roboat” project between MIT and the Amsterdam Institute for Advanced Metropolitan Solutions (AMS Institute).
In the future, Amsterdam wants the roboats to cruise its 165 winding canals, transporting goods and people, collecting trash, or self-assembling into “pop-up” platforms, like bridges and stages, in order to help relieve congestion on the city’s busy streets.
[smlsubform prepend=”GET THE SAFETY4SEA IN YOUR INBOX!” showname=false emailtxt=”” emailholder=”Enter your email address” showsubmit=true submittxt=”Submit” jsthanks=false thankyou=”Thank you for subscribing to our mailing list”]
In 2016, MIT researchers tested a roboat prototype that could move forward, backward, and laterally along a pre-programmed path in the canals. Last year, researchers designed low-cost, 3-D-printed, one-quarter scale versions of the boats, which were more efficient and agile, and came equipped with advanced trajectory-tracking algorithms.
During June, they created an autonomous latching mechanism that allows the boats target and clasp onto each other, and keep trying if they fail.
In a new paper presented at the last week’s IEEE International Symposium on Multi-Robot and Multi-Agent Systems, the researchers describe an algorithm that enables the roboats to smoothly reshape themselves as efficiently as possible.
Namely, in demonstrations in an MIT pool and in computer simulations, groups of linked roboat units rearranged themselves from straight lines or squares into other configurations, such as rectangles and “L” shapes. The experimental transformations only took a few minutes. More complex shapeshifts may take longer, depending on the number of moving units — which could be dozens — and differences between the two shapes.
For their work, the researchers had to address challenges with autonomous planning, tracking, and connecting groups of roboat units. Giving each unit unique capabilities to, for example, locate each other, agree on how to break apart and reform, and then move around freely, would need complex communication and control techniques that could make movement inefficient and slow.
During shape-shifting, all connected CVPs in a structure compare the geometric differences between its initial shape and new shape. Then, each CVP determines if it stays in the same spot and if it needs to move. Each moving CVP is then assigned a time to disassemble and a new position in the new shape.
Each CVP uses a custom trajectory-planning technique to compute a way to reach its target position without interruption, while optimizing the route for speed. To do so, each CVP analyzes all collision-free regions around the moving CVP as it rotates and moves away from a stationary one.
In about a year, the researchers want to use the roboats to create into a dynamic “bridge” across a 60-meter canal between the NEMO Science Museum in Amsterdam’s city center and an area that’s under development. The project, called RoundAround, will use roboats to sail in a continuous circle across the canal, picking up and dropping off passengers at docks and stopping or rerouting when they detect anything in the way.
Now, the researchers are further developing the roboats to make sure they can safely hold people, and are robust to all weather conditions, like heavy rain. They are also ensuring the roboats can effectively connect to the sides of the canals, which can vary greatly in structure and design.
