1,720,999 research outputs found
Augmented Reality and Robotic Systems for Assistance in Percutaneous Nephrolithotomy Procedures: Recent Advances and Future Perspectives
Full text linkPercutaneous nephrolithotomy is the gold standard for the treatment of renal stones larger than 20 mm in diameter. The treatment outcomes of PCNL are highly dependent on the accuracy of the puncture step, in order to achieve a suitable renal access and reach the stone with a precise and direct path. Thus, performing the puncturing to get the renal access is the most crucial and challenging step of the procedure with the steepest learning curve. Many simulation methods and systems have been developed to help trainees achieve the requested competency level to achieve a suitable renal access. Simulators include human cadavers, animal tissues and virtual reality simulators to simulate human patients. On the other hand, the availability of pre-operative information (e.g., computed tomography or magnetic resonance imaging) and of intra-operative images (e.g., ultrasound images) has allowed the development of solutions involving augmented reality and robotic systems to assist the surgeon during the operation and to help a novel surgeon in strongly reducing the learning curve. In this context, the real-time awareness of the 3D position and orientation of the considered anatomical structures with reference to a common frame is fundamental. Such information must be accurately estimated by means of specific tracking systems that allow the reconstruction of the motion of the probe and of the tool. This review paper presents a survey on the leading literature on augmented reality and robotic assistance for PCNL, with a focus on existing methods for tracking the motion of the ultrasound probe and of the surgical needle
Complete and Consistent Payload Identification During Human-Robot Collaboration: A Safety-Oriented Procedure
No full textThe paper proposes a procedure to provide a complete and physically-consistent estimation of mass, center of mass and inertia tensor of the payload attached to the end-effector of an industrial manipulator equipped with a force/torque sensor. The procedure involves the generation of an artificial potential field that allows the proper excitation of the payload inertial parameters while avoiding static and dynamic obstacles, thus ensuring a safe and collaborative scenario. The adopted identification algorithm consists in the solution of a constrained non-linear optimization problem that guarantees the physical consistency of the inertial parameters. The proposed approach has been validated by simulating a typical collaborative workcell where a Franka-Emika Panda robot performs the procedure while avoiding dynamic obstacles
A Control Barrier Function Approach for Maximizing Performance while Fulfilling to ISO/TS 15066 Regulations
No full textISO/TS 15066 is globally recognized as the guideline for designing safe collaborative robotic cells, where human and robot collaborate in order to fulfill a common job. Current approaches for implementing the ISO/TS 15066 guidelines lead to a conservative behavior (e.g. low velocity) of the robot and, consequently, to poor performance of the collaborative cell. In this letter, we propose an approach based on control barrier functions that allows to maximize the performance of a robot acting in a collaborative cell while satisfying the ISO/TS 15066 regulations. The proposed approach has been successfully validated both in simulation and through experiments
Improving the Feasibility of DS-based Collision Avoidance Using Non-Linear Model Predictive Control
No full textIn this paper we present a novel strategy for reactive collision-free feasible motion planning for robotic manipulators operating inside an environment populated by moving obstacles. The proposed strategy embeds the Dynamical System (DS) based obstacle avoidance algorithm into a constrained non-linear optimization problem following the Model Predictive Control (MPC) approach. The solution of the problem allows the robot to avoid undesired collision with moving obstacles ensuring at the same time that its motion is feasible and does not overcome the designed constraints on velocity and acceleration. Simulations demonstrate that the introduction of the MPC prediction horizon helps the optimization solver in finding the solution leading to obstacle avoidance in situations where a non predictive implementation of the DS-based method would fail. Finally, the proposed strategy has been validated in an experimental work-cell using a Franka-Emika Panda robot
A study of fault diagnosis and recovery techniques for manufacturing systems
No full textThis chapter describes a framework for the development of a diagnosis methodology for industrial manufacturing systems. The aim of the project is to support technicians that supervise the manufacturing plant to identify the causes of faults and failures on the machine and, in particular, to indicate a procedure for the recovery of its working condition. The chapter presents a study as the first step of a design project whose objective is to realize a supervisory system with advanced features devoted to Faults Detection and Isolation (FDI) for the manufacturing industry, with an emphasis on its integration with Human-Machine Interfaces. The requirements described in the chapter are defined giving particular care to the peculiarities of the application domain to allow the design of a powerful, but easy to use for industrial technicians, diagnostic system. An example of a manufacturing machine quite common in the packaging industry is schematized in the chapter, which is analyzed to define the fault trees for the most critical failure modes. © 2007 Copyright © 2007 Elsevier Ltd All rights reserved
On the use of UML for modeling mechatronic systems
No full textThis paper describes a modeling language that aims to provide a unified framework for representing control systems, namely, physical plants coupled with computer-based control devices. The proposed modeling methodology is based on the cardinal principle of object orientation, which allows describing both control software and physical components using the same basic concepts, particularly those of capsules, ports, and protocols. Furthermore, it is illustrated how the well-known object-oriented specification language unified modeling language can be adopted, provided an adequate formalization of its semantics, to describe structural and behavioral aspects of control systems, related to both logical and physical parts. Note to Practitioners-The development of an automated system within an industrial setting is a complex task, whose successful result depends on the joint efforts of a team of designers with different scientific backgrounds and specialized knowledge. In fact, an automated system is typically composed of a mechanical assembly, which must be precisely designed and manufactured, and a set of sensors and actuators (e.g., electrical drives, pneumatic systems, etc.), which are, on their turn, controlled most of the time by means of digital processors. course, both electrical parts and control algorithms (e.g., proportional integral, and derivative (PID) regulators, logic and supervisory control, reference trajectories for mechanical motions, etc.) should be designed with the same care given to mechanical aspects. Moreover, it is undeniable that none of the various parts composing the automated system design specification can, on their own, allow engineers to understand the actual behavior of the whole system, especially without a common description language that is understandable for all of the designers. The present paper introduces a unified language which aims to support integrated design specifications of automated systems, including the dynamics of heterogeneous physical assemblies, the discrete-event behavior of distributed control software, and the specification of interface ports between the plant and the control system. With the proposed language, it is possible to obtain a complete picture of the automated system suitable for its simulation, documentation, and validation. The modeling language described in the paper supports the principles of object orientation. This choice moves in the direction of enhancing modularity and reusability properties of design specifications, which are aspects of great importance in the design practice. Moreover, the object-oriented approach to automated systems design proposed in the paper aims to introduce the concept of design by extension in the manufacturing industry. This means that the definition of specialization relationships between classes of components implies that those components should be designed in order to be substitutable with each other, especially from a dynamic point of view. This aspect will be the subject of further papers illustrating other practical insights on the use of object-oriented models for automated systems
Verification of Fault Tolerance of Discrete-Event Object-Oriented Models using Model Checking
No full textThe Object-Oriented (O-O) approach has been recently used in the industrialautomation to design logic control systems, thanks to the features of specification languages(e.g. UML) that can help to describe event-based behavioral requirements. In this paper, weaim to formalise an O-O framework for the design of modular logic controllers, in which faultsoccurring in the plant can alter the behavior of closed-loop system. Given the formal model ofthe system in terms of Kripke structures, it is possible to verify with model checking that evenin case of faults the system do not violate given safety and liveness properties. Moreover, we willconsider the case in which an O-O logic controller is refined applying the so-called “design-by-extension” mechanism, in which case it is important to verify that the fault tolerance propertyis inherited by the refined system
Behavioral inheritance in object-oriented models for mechatronic systems
No full textThis paper describes a formal framework for Object-Oriented (O-O) modelling of mechatronic systems, whose main contribution is, on the one hand, to unify the modelling approaches for dynamical systems and for industrial control software and, on the other hand, to provide a definition of inheritance, a cardinal concept in object-orientation, which emphasises the behavioural conformity of basic and derived classes of objects. The proposed framework exploits the coalgebraic description of software artefacts to provide a connection between the behavioural approach for modelling dynamical systems and the O-O approach for software modelling and design. In particular, our definition of inheritance aims to allow control engineers to apply the design by extension methodology, widely used in software engineering, to the development of mechatronic components for manufacturing systems
Unified Modeling and Verification of Logic Controllers for Physical Systems
No full textThe paper describes a modeling approach that aims to provide a unified framework for the specification and verification of logic controllers for multi-domain physical systems. The proposed modeling methodology is based on the cardinal principle of object orientation, which allows to describe both control software and physical components using the same basic concepts, like classes and interface ports, and the same modeling notation, based on the UML language. Thanks to this unified approach, it is possible to describe structural and behavioral aspects of any multi-domain system coupled with a logic control device. Moreover, the behavior of the closed-loop system can be analyzed with formal verification techniques for hybrid systems, in order to prove correctness properties otherwise difficult to verify considering only discrete-event models
UML come linguaggio di modellazione unificato per sistemi meccatronici
No full textNel presente articolo, viene proposto un linguaggio di modellazione il cui scopo è quello di fornire una lingua franca per tutti i progettisti coinvolti nello sviluppo di un sistema meccatronico. Al fine di raggiungere tale obiettivo, il linguaggio presentato unifica i concetti fondamentali dell’approccio orientato agli oggetti (Object-Oriented, O-O), tipico dei sistemi software rappresentati con modelli UML, ed i concetti fondamentali dei Bond Graphs, un linguaggio di modellazione per sistemi fisici di natura eterogenea basato sulle interazioni energetiche fra componenti basilari.L’articolo mostra come i concetti propri dei Bond Graphs ed, in particolare, della loro formalizzazione in termini di sistemi Port-Hamiltonian, possano essere incorporati nel linguaggio UML, adottandone il profilo definito originariamente per sistemi software distribuiti e Real-Time. In tal modo, sia le specifiche strutturali e di comportamento del software di controllo che le dinamiche continue del sistema fisico possono essere descritte in un unico modello, facilitando così la progettazione integrata dei sistemi meccatronici
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