Uncrewed Systems Technology 049 - April/May 2023

54 Digest | Ottonomy Ottobot Ottonomy provides that using its in- house developed High Information Maps (HIMs), which it intends as an improvement on the HD Maps system used by many autonomous cars. “A lot of the time the Ottobots will use geometric and semantic data inputs to stamp objects like doors, street lamps, pillars and so on with numbers, to keep the density of data easy to handle for the edge hardware,” Vijay says. “They will also record some information on what’s happening around those objects.” Korupolu adds that despite this keeping themaps lightweight, they retain enough information for the UGVs to localise without needing GNSS. In a new operating environment, a first version of the HIMs is typically created by Ottonomy’s engineers driving the robots around the serviceable areas and pathways of potential delivery routes and customers. “As they do so, the Ottobot builds its own maps with the fused point cloud and vision data, and these are uploaded to the cloud for the entire fleet to use,” Korupolu says. “With our real-time AI, we detect but also remove objects dynamically, as contextually we can understand that things like people, bikes, vehicles, chairs or tables go missing in streets or building interiors, and the UGV doesn’t get confused by that.” Vijay adds, “GNSS is used mainly for georeferencing of the customer’s location, but we don’t use it very deeply in our navigation. Nonetheless, we have tested and used various companies’ GNSS to identify which companies could give us a consistent and reliable performance as well as supply.” Path planning and dynamic avoidance Localisation within the HIMs is essentially what enables the Ottobots to operate indoors as well as outdoors without relying on GNSS, with the camera and Lidar data and semantics being key to the UGVs understanding where they are without GNSS information playing a fundamental role in the process. That hugely diminishes the likelihood of errors occurring due to multi-pathing or outages of GNSS signals that could occur when the Ottobots are navigating between tall buildings or through crowds of people. As Korupolu explains, “At any given time, the Ottobot is calculating seven to 10 possible trajectories, and selects what it determines as the most cost-effective route. With the swerve capability from our 4WD, we can achieve precise, smart and safe turning radii, as well as sidestepping where necessary; the path-planning algorithm takes that into account.” As the Ottobot executes its preferred routes, fused information from the cameras and Lidars as well as the ultrasonic sensors and cliff detectors helps inform the main computer how to dynamically recalculate routes and actuator commands to ensure it avoids objects, people and precipices during movement. Depending on the modular configuration chosen, 12-16 ultrasonic sensors could be installed about the Ottobot, as each one has a much narrower FoV than the cameras and is more prone to performance losses owing to noise from other near-band frequencies, particularly other ultrasonic sensors, such as those from parked cars. “The probability of interference was actually quite high, somore than 4months of r&d went into testing and selecting the most robust ultrasonic sensors we could find,” Vijay says. “They’re not COTS or standardised components.” The cliff detection sensor meanwhile is an IR-filtered camera at the robot’s front that points downwards, at an angle that prevents it being affected by ambient light. It has a very short range, as its role is to scan the floor for anything that might indicate a precipice. “Among our AI algorithms, we also have a safety algorithm that automatically overrides the robot’s movements and forces a stop if anything comes too close,” Korupolu notes. “It is also what limits the speed to 6 kph, and it checks and validates every command the main autonomy software puts out.” April/May 2023 | Uncrewed Systems Technology After navigating to a customer, the displays on the Ottobot’s front help with identifying and confirming an order