Cooperative teleoperation systems

This thesis deals with the studies on the Cooperative Teleoperation Systems. The literature on cooperative teleoperation did not take into account control architectures composed of pairs of wave-based bilateral teleoperators operating in a shared environment. In this work The author two cooperative control schemes based on wave variables by considering two pairs of single-master/single-slave devices collaborating to carry out operations in a shared remote environment are proposed. Such architectures have been validated both with simulations and experimental tests. Ch. 2 introduces a description of the two control architectures proposed and presents some simulation results where the cooperative teleoperation systems evolve in free space and in contact with a stiff wall. In the Ch. 3 some experimental results which confirm the positive results of the control schemes are illustred. Such results have been achieved by using a prototype custom built at Laboratory of Automaiton and Robotics of University of Bologna, which is also illustrated in this chapter. In Ch. 4 the problem of defining proper tools and procedures for an analysis, and possibly a comparison, of the performances of cooperative teleoperation systems is addressed. In particular, a novel generalization of criteria adopted for classical (i.e. one master-one slave) teleoperators is presented and illustrated on the basis of the force-position and the position-position cooperative control schemes proposed in Ch. 2, both from a transparency and stability point of view, and by assuming a null time delay in the communication channel.

Le aziende vitivinicole: da “machines à produire” a elementi di attrazione nel paesaggio. Proposte e criteri progettuali per l’efficienza funzionale e la qualità architettonica ed ambientale delle strutture ed infrastrutture della trasformazione enologica.

La ricerca ha per oggetto la messa a punto e applicazione di un approccio metaprogettuale finalizzato alla definizione di criteri di qualità architettonica e paesaggistica nella progettazione di aziende vitivinicole medio-piccole, che effettuano la trasformazione della materia prima, prevalentemente di propria produzione. L’analisi della filiera vitivinicola, della letteratura scientifica, della normativa di settore, di esempi di “architetture del vino eccellenti” hanno esplicitato come prevalentemente vengano indagate cantine industriali ed aspetti connessi con l'innovazione tecnologica delle attrezzature. Soluzioni costruttive e tecnologiche finalizzate alla qualità architettonica ed ambientale, attuali dinamiche riguardanti il turismo enogastronomico, nuove funzionalità aziendali, problematiche legate alla sostenibilità dell’intervento risultano ancora poco esplorate, specialmente con riferimento a piccole e medie aziende vitivinicole. Assunto a riferimento il territorio ed il sistema costruito del Nuovo Circondario Imolese (areale rappresentativo per vocazione ed espressione produttiva del comparto vitivinicolo emiliano-romagnolo) è stato identificato un campione di aziende con produzioni annue non superiori ai 5000 hl. Le analisi svolte sul campione hanno permesso di determinare: modalità di aggregazione funzionale degli spazi costruiti, relazioni esistenti con il paesaggio, aspetti distributivi e materico-costruttivi, dimensioni di massima dei locali funzionali alla produzione. Il caso studio relativo alla riqualificazione di un’azienda rappresentativa del comparto è stato utilizzato per la messa a punto e sperimentazione di criteri di progettazione guidati da valutazioni relative alle prestazioni energetiche, alla qualità architettonica e alla sostenibilità ambientale, economica e paesaggistica. L'analisi costi-benefici (pur non considerando le ricadute positive in termini di benessere degli occupanti ed il guadagno della collettività in termini di danni collegati all’inquinamento che vengono evitati in architetture progettate per garantire qualità ambientale interna ed efficienza energetica) ha esplicitato il ritorno in pochi anni dell’investimento proposto, nonostante gli ancora elevati costi di materiali di qualità e dei componenti per il corretto controllo climatico delle costruzioni.

Coding of reaching in 3-D space

Many psychophysical studies suggest that target depth and direction during reaches are processed independently, but the neurophysiological support to this view is so far limited. Here, we investigated the representation of reach depth and direction by single neurons in an area of the medial posterior parietal cortex (V6A). Single-unit activity was recorded from V6A in two Macaca fascicularis monkeys performing a fixation-to-reach task to targets at different depths and directions. We found that in a substantial percentage of V6A neurons depth and direction signals jointly influenced fixation, planning and arm movement-related activity in 3D space. While target depth and direction were equally encoded during fixation, depth tuning became stronger during arm movement planning, execution and target holding. The spatial tuning of fixation activity was often maintained across epochs, and this occurred more frequently in depth. These findings support for the first time the existence of a common neural substrate for the encoding of target depth and direction during reaching movements in the posterior parietal cortex. Present results also highlight the presence in V6A of several types of cells that process independently or jointly eye position and arm movement planning and execution signals in order to control reaches in 3D space. It is possible that depth and direction influence also the metrics of the reach action and that this effect on the reach kinematic variables can account for the spatial tuning we found in V6A neural activity. For this reason, we recorded and analyzed behavioral data when one monkey performed reaching movements in 3-D space. We evaluated how the target spatial position, in particular target depth and target direction, affected the kinematic parameters and trajectories describing the motor action properties.

Numerical and experimental analysis of 3D printed smart structures and systems

Three dimensional (3D) printers of continuous fiber reinforced composites, such as MarkTwo (MT) by Markforged, can be used to manufacture such structures. To date, research works devoted to the study and application of flexible elements and CMs realized with MT printer are only a few and very recent. A good numerical and/or analytical tool for the mechanical behavior analysis of the new composites is still missing. In addition, there is still a gap in obtaining the material properties used (e.g. elastic modulus) as it is usually unknown and sensitive to printing parameters used (e.g. infill density), making the numerical simulation inaccurate. Consequently, the aim of this thesis is to present several work developed. The first is a preliminary investigation on the tensile and flexural response of Straight Beam Flexures (SBF) realized with MT printer and featuring different interlayer fiber volume-fraction and orientation, as well as different laminate position within the sample. The second is to develop a numerical analysis within the Carrera' s Unified Formulation (CUF) framework, based on component-wise (CW) approach, including a novel preprocessing tool that has been developed to account all regions printed in an easy and time efficient way. Among its benefits, the CUF-CW approach enables building an accurate database for collecting first natural frequencies modes results, then predicting Young' s modulus based on an inverse problem formulation. To validate the tool, the numerical results are compared to the experimental natural frequencies evaluated using a digital image correlation method. Further, we take the CUF-CW model and use static condensation to analyze smart structures which can be decomposed into a large number of similar components. Third, the potentiality of MT in combination with topology optimization and compliant joints design (CJD) is investigated for the realization of automated machinery mechanisms subjected to inertial loads.

Hybrid ground-aerial mesh networks for IoT monitoring applications: network design and software platform development

The Internet of Things (IoT) has grown rapidly in recent years, leading to an increased need for efficient and secure communication between connected devices. Wireless Sensor Networks (WSNs) are composed of small, low-power devices that are capable of sensing and exchanging data, and are often used in IoT applications. In addition, Mesh WSNs involve intermediate nodes forwarding data to ensure more robust communication. The integration of Unmanned Aerial Vehicles (UAVs) in Mesh WSNs has emerged as a promising solution for increasing the effectiveness of data collection, as UAVs can act as mobile relays, providing extended communication range and reducing energy consumption. However, the integration of UAVs and Mesh WSNs still poses new challenges, such as the design of efficient control and communication strategies. This thesis explores the networking capabilities of WSNs and investigates how the integration of UAVs can enhance their performance. The research focuses on three main objectives: (1) Ground Wireless Mesh Sensor Networks, (2) Aerial Wireless Mesh Sensor Networks, and (3) Ground/Aerial WMSN integration. For the first objective, we investigate the use of the Bluetooth Mesh standard for IoT monitoring in different environments. The second objective focuses on deploying aerial nodes to maximize data collection effectiveness and QoS of UAV-to-UAV links while maintaining the aerial mesh connectivity. The third objective investigates hybrid WMSN scenarios with air-to-ground communication links. One of the main contribution of the thesis consists in the design and implementation of a software framework called "Uhura", which enables the creation of Hybrid Wireless Mesh Sensor Networks and abstracts and handles multiple M2M communication stacks on both ground and aerial links. The operations of Uhura have been validated through simulations and small-scale testbeds involving ground and aerial devices.