Simulatore di interfaccia uomo-macchina per i controllo di UAV

Recent statistics have demonstrated that two of the most important causes of failures of the UAVs (Uninhabited Aerial Vehicle) missions are related to the low level of decisional autonomy of vehicles and to the man machine interface. Therefore, a relevant issue is to design a display/controls architecture which allows the efficient interaction between the operator and the remote vehicle and to develop a level of automation which allows the vehicle the decision about change in mission. The research presented in this paper focuses on a modular man-machine interface simulator for the UAV control, which simulates UAV missions, developed to experiment solution to this problem. The main components of the simulator are an advanced interface and a block defined automation, which comprehend an algorithm that implements the level of automation of the system. The simulator has been designed and developed following a user-centred design approach in order to take into account the operator’s needs in the communication with the vehicle. The level of automation has been developed following the supervisory control theory which says that the human became a supervisor who sends high level commands, such as part of mission, target, constraints, in then-rule, while the vehicle receives, comprehends and translates such commands into detailed action such as routes or action on the control system. In order to allow the vehicle to calculate and recalculate the safe and efficient route, in term of distance, time and fuel a 3D planning algorithm has been developed. It is based on considering UASs representative of real world systems as objects moving in a virtual environment (terrain, obstacles, and no fly zones) which replicates the airspace. Original obstacle avoidance strategies have been conceived in order to generate mission planes which are consistent with flight rules and with the vehicle performance constraints. The interface is based on a touch screen, used to send high level commands to the vehicle, and a 3D Virtual Display which provides a stereoscopic and augmented visualization of the complex scenario in which the vehicle operates. Furthermore, it is provided with an audio feedback message generator. Simulation tests have been conducted with pilot trainers to evaluate the reliability of the algorithm and the effectiveness and efficiency of the interface in supporting the operator in the supervision of an UAV mission. Results have revealed that the planning algorithm calculate very efficient routes in few seconds, an adequate level of workload is required to command the vehicle and that the 3D based interface provides the operator with a good sense of presence and enhances his awareness of the mission scenario and of the vehicle under his control.

Indagine sulla presenza di Helicobacter pullorum in allevamenti avicoli italiani

From September 2005 to December 2006, in order to define the prevalence of Helicobacter pullorum in broiler chickens, laying hens and turkey, a total of 365 caecum contents of animals reared in 76 different farms were collected at the slaughterhouse. A caecum content of a ostrich was also sampled. In addition, with the aim of investigating the occurrence of H. pullorum in humans, 151 faeces were collected at the Sant’Orsola-Malpighi University Hospital of Bologna from patients suffering of gastroenteritis. A modified Steele–McDermott membrane filter method was used. Gram-negative curved rod bacteria were preliminary identified as H. pullorum by a PCR assay based on 16S rRNA, then subjected to a RFLP-PCR assay to distinguish between H. pullorum and H. canadensis. One isolate from each farm was randomly selected for phenotypic characterization by biochemical methods and 1D SDSPAGE analysis of whole cell proteins profiles. Minimum Inhibitory Concentration (MIC) for seven different antibiotics were also determined by agar dilution method. Moreover, to examine the intraspecific genomic variability, two strains isolated from 17 different farms were submitted to genotyping by Pulse-Field Gel Electrophoresis (PFGE). In order to assess the molecular basis of fluorquinolone resistance in H. pullorum, gyrA of H. pullorum CIP 104787T was sequenced and nucleotide sequences of the Quinolone Resistance Determining Region (QRDR) of a total of 18 poultry isolates, with different MIC values for ciprofloxacin and nalidixic acid, were compared. According to the PCR and PCR-RFLP results, 306 out of 366 animals examined were positive for H. pullorum (83,6%) and 96,1% of farms resulted infected. All positive samples showed a high number of colonies (>50) phenotipically consistent with H. pullorum on the first isolation media, which suggests that this microrganism, when present, colonizes the poultry caecum at an elevate load. No human sample resulted positive for H. pullorum. The 1D SDS-PAGE whole protein profile analysis showed high similarity among the 74 isolates tested and with the type strain H. pullorum CIP 104787T. Regarding the MIC values, a monomodal distribution was found for ampicillin, chloramphenicol, gentamicin and nalidixic acid, whereas a bimodal trend was noticed for erythromycin, ciprofloxacin and tetracycline (indicating an acquired resistance for these antibiotics). Applying the breakpoints indicated by the CSLI, we may assume that all the H. pullorum tested are sensitive only to gentamicin. The intraspecific genomic variability observed in this study confirm that this species don’t have a clonal population structure, as motioned by other autors. The 2490 bp gyrA gene of H. pullorum CIP104787T with an Open Reading Frame (ORF) encoding a polypeptide of 829 amino acids was for the first time sequenced and characterized. All ciprofloxacin resistant poultry isolates showed ACA®ATA (Thr®Ile) substitution at codon 84 of gyrA corresponding to codons of gyrA 86, 87 and 83 of the Campylobacter jejuni, H. pylori and Escherichia coli, respectively. This substitution was functionally confirmed to be associated with the ciprofloxacin resistant phenotype of poultry isolates. This is the first report of isolation of H. pullorum in turkey and in ostrich, indicating that poultry species are the reservoir of this potential zoonotic microorganisms. In order to understand the potential role as food-borne human pathogen of H. pullorum, further studies must be carried on.