UST030

96 “If we tell each sprayer to cover four rows per refill, for example, it will spray four rows,” Thompson says. “Then, when it makes its turn into row five it will automatically stop and idle down, and then the nurse truck will pull up and fill it. That takes about two-and-a- half minutes, then you hit Resume and it starts driving and spraying again.” Knowing when and where each spray vehicle will stop for a refill, a nurse truck’s driver can anticipate that and be waiting for the sprayer in the right place, saving time. Individual routes The third set-up step is to build routes for individual sprayers using a tool in the interface. The operator selects the first and last rows on the route, then decides whether to spray every row or every other row, and so on. With its tight turning circle, the GUSS is capable of spraying every row in turn, unlike many tractor-trailer set-ups. The operator then clicks Enter and the software builds the route. Next, the operator assigns a route to each sprayer, clicks Go, and each vehicle drives to the entrance to its first row, turns in and starts spraying. Once the GUSS vehicles are spraying, the operator’s job becomes purely one of monitoring and supervision, and if any of them has a problem it sends an alert that is displayed on the laptop screen, along with a warning sound. The severity of the problem is indicated by the colour in which the map icon for the affected vehicle flashes – either red or yellow. “Let’s say that if the pump pressure is down, or the flow rate of the material falls off, it’s going to highlight it in red,” Thompson explains. “Then the operator can either stop the machine where it’s at or let it get to the end of the row and stop it, then go check it. “There’s also a chance that some nozzles become plugged or a filter is blocked. The operator can take care of the problem and send the vehicle on its way again.” Should the comms fail, the vehicle will simply continue operating until it reaches its next programmed refill point, where it will stop and wait. Its mission plan and all its safety systems remain operational, Thompson says. Using the caution markers on the map, the supervisor can anticipate when any of the vehicles will encounter an obstacle February/March 2020 | Unmanned Systems Technology Among the GUSS’s safety systems is its front bumper, which will shut the engine down if it comes into contact with any obstacle, independently of the automation software Four-wheel hydraulic steering enables the GUSS to make tight turns at the row ends, an improvement on conventional tractor-trailer set-ups that often have to skip rows because of their larger turning circles If pump pressure is down, say, the operator can stop the machine where it’s at or let it reach the end of the row, stop it and then check it