Issue 41 Unmanned Systems Technology December/January 2022 PteroDynamics X-P4 l Sense & avoid l 4Front Robotics Cricket l Autonomous transport l NWFC-1500 fuel cell l DroneX report l OceanScout I Composites I DSEI 2021 report

59 Autonomous transport | Insight to a wide range of hardware stores to obtain a replacement deep-cycle battery if one breaks down, but you can’t get lithium-ion battery packs anywhere near that easily,” Vikram notes. “And while all marinas have infrastructure for overnight charging, the monocrystalline solar panels from Renogy extend our range by providing up to 2 kW of continuous power. They also act as a source of back-up power so that the Greycrafts can call for help if a battery should break down in operation.” Main forward propulsion comes from a Torqeedo thruster, with two additional side-oriented thrusters to enable sideways movement – helpful when trying to dock a boat tightly between others. Autonomous SLAM navigation is achieved by the company’s AutoMate suite, which combines GNSS-INS for route planning with a real-time Lidar-generated 3D map of the boat’s surroundings. Weather sensors and radar are also used to inform about interference by traffic, wind and other environmental disturbances, with sensor inputs and timing and velocity information all fused via Buffalo’s proprietary AI processing stack. “We can also use pan/tilt EO and IR cameras for added awareness, with neural networks developed around recognising different kinds of objects and adjusting the vehicle’s behaviour according to the kinds of objects that appear within the map it’s generating as it moves,” Vikram adds. Also making waves in the Netherlands is the Amsterdam-based Roboat, a joint project by the Massachusetts Institute of Technology and the Amsterdam Institute for Metropolitan Solutions Institute, who we spoke to in UST 31 (April/May 2020) to learn about the small-scale versions of its autonomous transport systems, initially for waterborne logistics but also for passenger and other applications. Two full-scale Roboat prototypes are now complete and operating with a 10 hour endurance between charges and a typical operating speed of 6 kph. “Places like Amsterdam have too much congestion clogging up roadways, and emissions and traffic are at unsustainable levels, but small autonomous boats are highly convenient for on-demand transport, not to mention scalable to meet demand,” says Ynse Deinema, project coordinator for the Roboat. “Each prototype is a 4 x 2 m electric craft. One is a passenger taxi and the other is a household waste collector. Each passenger Roboat has enough seating for six people or so, while the logistics unit can carry up to 1500 kg. The lower halves of the boats are identical, only the top deck is changed and swappable depending on the application the operator or owner wants to put them to. And the underlying autonomous technology can be applied to any type of vessel.” Localisation and navigation are performed using an RTK-GNSS receiver (and dual RTK-GNSS antennas for heading information) with an IMU for helping with navigation under bridges and in urban canyons. A 128-beam Lidar and a number of 6.3 MP cameras with 19 fps enhance navigational precision and enable real- time object detection and avoidance, with the Lidar at the front and the cameras providing 360° awareness. Installing a Doppler velocity log is also in the pipeline to provide an added data stream for speed and distance over the canal bed. “At the highest abstraction level, we have our environmental perception layer, fed by the sensors, and then we have our navigation layer which calculates the best free path based on processed scans of the surrounding space and objects,” Deinema explains. “Below that is our control layer, which translates the navigational calculations into waypoints and outputs for the thrusters to follow. “Now that we’ve set the boat’s navigation foundations, we’re testing full-scale versions at Marineterrein Amsterdam, our home base in the centre of the city. The next step for the Roboat will be to trial commercial use-cases on public waters.” The full-scale boats are built and developed in the Netherlands, and can be wirelessly charged when they are moored in a dedicated docking station. The Roboats can dock autonomously, using a latching mechanism that allows them to connect to the docking station or a different Roboat. “That mechanism consists of two robotic arms that are installed in the bumper of the Roboat on either side,” Deinema says. “When the boat approaches a docking station, the arms grab onto the underside of the docking steps, below where the passengers Unmanned Systems Technology | December/January 2022 Roboat has begun tests of its full-size prototype craft, which can navigate and recharge with full autonomy throughout Amsterdam’s waterways (Courtesy of Roboat)