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In recent years, robotics and automation technology have spread significantly throughout the agricultural harvesting sector. The increased productivity and the high cost of labour are some of the main reasons for this phenomenon. However, the harvesting of some crops is still carried out manually. One such crop is radicchio, which ripens at various times, thus requiring selective harvesting. This paper presents the development of an innovative modular system which aims at automating the harvesting of radicchio. Each module adopts a mechanical sensor to recognize the ripening status of the plant, on the basis of the hardness/compliance of its core. The module contains a cutting system, made of pneumatically actuated blades, and a harvesting system, made of two electrically powered tape conveyors. The module is intended to be used for a single row of radicchio cultivations using a tractor to move it. In laboratory tests the module prototype was manually moved. For this reason, the prototype is equipped with a control panel for monitoring and commanding. The conceived design, technical specifications and the prototype of the module are presented in detail. In addition, performances and functional tests are discussed. Finally, the functionality of the whole system is validated.

In the last few years, robotics has been increasingly adopted in agriculture to improve productivity and efficiency. This paper presents recent and current work at the Politecnico of Bari in collaboration with the University of Lecce in the field of agriculture robotics. A cost effective robotic arm is introduced for the harvesting of radicchio, which employs visual localization of the plants in the field. The proposed harvester is composed of a double four bar linkage manipulator and a special gripper, which fulfills the requirement for a plant cut approximately 10 mm underground. Both manipulator and end-effector are pneumatically actuated and the gripper works with flexible pneumatic muscles. The system employs computer vision to localize the plants in the field based on intelligent color filtering and morphological operations; we call this algorithm the Radicchio Visual Localization (RVL). Details are provided for the functional and executive design of the robotic arm and its control system. Experimental results are discussed, obtained with a prototype operating in a laboratory testbed showing the feasibility of the system in localizing and harvesting radicchio plants. The performance of the RVL is analyzed in terms of accuracy, robustness to noises and variations in lighting, and is also validated in field experiments.