In recent years agriculture has received the focus of different research groups that operate in the robotics and automation field. Moreover, electronics, informatics and automation solutions have been proposed as commercial products by most of agriculture machine and tools suppliers. Nevertheless, in-field fully autonomous operations yet have some barriers to overcome in order to become relatively common and cheap as well as reliable, in comparison to the great number of applications in the manufacturing industry.
The main reasons for this delay is due to the fact that agricultural tasks are carried out in an outdoor environment, often really unstructured, dynamic and most of the time heavily conditioned by water, mud, wind, light, dust, chemicals and so on. Moreover, the actual cost of a robotic system is usually too high with respect to the other production costs and with respect to the standard season operators’ salary. Despite these premises, different solutions exist for some specific agricultural operations. In [1
] a robotic system for vineyard and greenhouses operation, like transportation and spraying, is reported. Several other examples of robotic harvesting systems have been developed and reported in [3
]. However not so many commercial systems exist and most of these are simply research laboratory prototypes. In [6
], an interesting review on the fruit harvesting problem and the possible automatic solutions is reported. Among the harvesting robots that have been developed, it is possible to cite the Orange Picking Robots [7
] developed by the University of Catania, where a detailed study on the vision processing analysis was carried out and several testing of the picking mechanism were developed. In [8
], two in-depth reviews about artificial vision applications to the agricultural problem and useful algorithm are reported, while in [10
] a possible solution to the fruit detection problem has been implemented and tested. Another interesting research activity has been carried out by Wageningen University that performed several studies and field tests for a cucumber harvesting robot [11
]. As regard harvesting, many applications concentrated in greenhouse environment, where it is simpler to move the harvesting system and to locate vegetables, as in the case of strawberry harvesting [12
]. Only a few works concentrate on vegetable harvesting in outdoor fields, as in the case of radicchio harvesting [13
]. Other interesting applications of robotics in agriculture include precision spraying and precision fertilization [14
], inspection and treatment of plants [15
], selective herbicide application [16
], just to name a few.
As far as we know, there is only one example of a machine for artichoke harvesting. The aim of the BIOCARD EU FP6 STREP project [17
] was to demonstrate the economical and technical feasibility of a global process to improve annual lifecycle Cynara cardunculus exploitation for energy applications. Among the different activities of that project, the development of specific machinery able to harvest the capitula and separate directly in the field seeds from cynara biomass was addressed. Concerning automatic artichoke harvesting for fresh vegetable market, our research work represents a preliminary step toward the introduction of robotics into this specific field. In particular the main peculiarities of our approach are from one side the design and development of an automated robotic system for harvesting and on the other side the fact that the research was carried out working concurrently with the growers and with the experts in horticulture, to select suitable plants that could make the process of harvesting easier.