Design of a remotely operable sprayer for precision farming application

The aim of this research activity is to develop a modular, fully customizable and remotely operable sprayer. This kind of device can be installed on-board a standard farm tractor/support machine or to be integrated on-board the U-Go robot that is under development with a joined project between the DiGeSA and the DIEEI and co-founded by MIPAAF. The aim of the U-Go robot is to improve worker safety level during harmful operation inside greenhouses as chemicals distribution. The robot has autonomous navigation capabilities and the on-board computer can send command to the sprayer and receive information from the sprayer sensors. All the sprayer parameter can be accessed and modified during operation. These features are not very common in commercial computer controlled sprayer unit that normally use only a touch screen panel as user interface. The device is composed by a hydraulic subsystem and an electronic control unit. The hydraulic part of the sprayer is composed by a 130 l tank with 5 l hand-wash separated reservoir, an electrical actuated pump, a manual pressure regulator, an electric flux regulator, a pressure sensor, a flow rate meter and two electric on/off valves. These two valves can supply two vertical bar equipped with anti-drop, high pressure nozzles for spraying operation inside a standard tomato greenhouse. The pump has a nominal maximum pressure of 25 bar and a maximum flow of 20 l/m. The electronic control unit is composed by two digital/analog I/O modules with Ethernet interface that allows to remotely operate the different hydraulic component and read information from sensors and to manage other control unit parameter. The Ethernet interface will allows remote operation from the robot on-board computer as well as any other remote station with an internet connection using a suitable command set. The proposed architecture, being very modular, will allow component (sensor, actuators) to be added in an easy way. At this stage the sprayer unit is being mounted on-board the U-Go robot. In the meanwhile the electronic control unit is under development at DIEEI laboratory and preliminary functional test has been performed. In order to make totally transparent to a mid-level user all the lowlevel hardware behaviour, a suitable software server has been developed. In this way, user command can be sent as high-level string and sensor information can be received as numeric text string. As the whole system will be integrated, complete test will be performed.