The system is based on two main components:
1. The TC software, which is in charge of the management of the farming job.
2. The wireless sensors infrastructure to gather information from the environment.
The TC software will be developed to be compliant with the ISO 11783 part 10 standard. This device will serve as a gateway between the FMIS and all the ECU connected to the ISOBUS implement bus. It receives the directions on how to perform some cultivation tasks from the FMIS and gives the appropriate commands to the ECUs connected to the implement bus to get the tasks accomplished. In the perspective of the STRATOS project, the task controller can use the data coming from the sensors to dynamically adjust some task parameters, e.g. the application rate of some products. This functionality can be enabled through the modification of the farm management software, which in first instance should be made aware of the existence of these additional data sources. Afterwards, the task planning logics should be upgraded in order to permit the user the exploitation of the new data as control variables for the single task. Then, original control algorithms for the task controller software should be designed and implemented, with the purpose of modifying the automated system behaviour on the basis of the sensed data. Aiming to develop an open and safe control architecture, the most recent standard will be used, like UML (unified Modelling Language,
http://www.uml.org) to model the software development and standard ISO 25119 (Safety-related parts of control systems), for the safety rules compliance.
The wireless sensor infrastructure will be formed by a network of sensors deployed in the farming field and by sensors on board the tractor or the implements. The general architecture of the sensor node is comprised of four subsystems: (1) an energy harvesting module, (2) a set of sensible element, (3) a processing unit and (4) a radio transceiver. Each subsystem will be customized depending on the type of sensor. The energy harvesting module varies according to the place where the node operates: if it is on board the tractor or an implement, the vibrations of the vehicle can be exploited to power the node, otherwise the energy provided by solar irradiance and temperature gradients can be used. The wireless sensor nodes communicate (directly or in a multi-hop fashion) with a wireless gateway, using a protocol designed for low power and short range devices like ZigBee. This gateway collects the data transmitted by the wireless nodes and generates appropriate ISOBUS messages to communicate these information to other ISOBUS devices (e.g. the TC, tractor or implement ECUs). To support this operational mode, methodologies to develop ISOBUS infrastructure for the heterogeneous, clustered WSN will be investigated within STRATOS. During all the engineering phases, it will be adopted engineering procedures for system modelling and simulation. Laboratory experiments will be conducted to assess correctness of the developed system, and, finally the hardware-software infrastructure will be tested in a dedicated facility to verify functional completeness and quantify the system performance. Tests will be performed in cooperation with farmers and/or of agricultural machines vendor to permit tests on real agricultural machines and agricultural.
