Issue 39 Unmanned Systems Technology August/September 2021 Maritime Robotics Mariner l Simulation tools focus l MRS MR-10 and MR-20 l UAVs insight l HFE International GenPod l Exotec Skypod l Autopilots focus l Aquaai Mazu

78 In operation | Exotec Skypod U3DV than others to propel the robot up the racks. That could lead to spills or friction- induced damage and breakages. To compensate for that, the Skypods are fitted with gyroscopes at their corners in order to calculate their orientation and balance from the angular rate data coming in from each end of their bodies. Unlike the wheels, each corner’s climbing machine is driven by its own dedicated electric motor and ESC. If one corner is found to be leaning, the robot’s motion controller boosts the power at the corresponding motor to compensate for any weight imbalance and keep the robot level. “So, between the racks, picking stations and bin interface, there are not a lot of points of transition per order, where robots interact with people or shelves,” Lueg observes. “I used to write software for conveyor belts and robotic sorter arms, and eventually I’d find myself asking logistics managers how many points of transition were needed. That was because if there were 10 or more, it would take a huge amount of work to try to error-proof that system – every point of transition is a point where a container could get stuck or something similar.” Between deliveries By using the ASTAR software to track the locations of the Skypods, the WCS can also log the distances travelled and orders carried out, which helps determine when each one is likely to need routine maintenance checks or overhauls. Such usage data is transmitted back to on-site control rooms and Exotec’s headquarters, to inform service decisions and bulletins. ASTAR will also track the energy levels of each Skypod, sending them to recharge their batteries when necessary. For example, if a traffic build-up is detected near where a Skypod needs an item, and no other lines are urgently needed, the management software could determine that it ‘might as well’ go for a brief recharge. The robots will typically spend 10% of their lifetime being recharged, averaging 5-6 minutes per hour, in the dedicated charging areas of the warehouse, which are next to the picking stations. Typically, two contact-based charging pads are supplied at each pick station – regardless of the number of Skypods in the warehouse – making it convenient for a Skypod to drive up, touch two contacts on the back to two copper plates on the pad, and begin fast DC charging. “We’ve also written our own battery management system, based on recommendations from Tesla such as only charging up to 60-70% and never letting the energy drain to 5% or below, to keep battery capacity from diminishing too quickly,” Lueg says. “We don’t want to charge our customers too much for spare parts, and if they’re going through batteries too quickly their bill will get very large, so we’re motivated to make sure the batteries are being used wisely.” Exotec is now adding new customers to its existing ones. The latest is Decathlon North America, which operates partly independently from Decathlon in France and whose distribution centre in Montreal is expected to begin operating Skypods in December. “We’re not in the business of eliminating jobs, we want to make existing warehouse jobs more productive, and less strenuous and dangerous for the pickers,” Lueg says. “It’s hard enough for e-commerce groups to attract workers at the moment, so we like to think that working alongside robots and watching them zip about the aisles will make warehouse work a bit more fun for the people doing it.” August/September 2021 | Unmanned Systems Technology The autonomous Skypods enable more efficient use of human labour, and with greatly reduced risk of injury or damage compared with conventionally automated warehouse robots