Rinaldo C. Michelini

Conceptual Design of an AUV Equipped with a Three Degrees of Freedom Vectored Thruster

The early stages of design and simulation of a new concept, autonomous underwater vehicle equipped with vectored thrusters is investigated. The opportunity to increase the research effort in innovative solutions for AUV propulsion and guidance systems is related to the state-of-the-art analysis. The dynamics of submersibles is briefly recalled, to justify the choice to equip the vehicle with a three degrees of freedom mechanism capable to orient both the propeller and the stabilising tail-fins. The vehicle presented has to be considered as a “concept submersible”, that needs further improvements and tuning to become a completely running test-bench for navigation system assessment. A tailored simulation package and results are also described, in order to perform a wide ranging numerical test campaign to foresee life cycle behaviour.

Constraint Singularities of Force Transmission in Nonredundant Parallel Robots With Less Than Six Degrees of Freedom

The analysis of the workspace singularities is one of the fundamental aspects in the design of parallel robots. The architecture singularities are generally studied analysing the local properties of the Jacobian matrix. Nevertheless, for limited-DOF parallel robots, there is a category of singularities (constraint or constructive singularities), relating to the constraint force transmission, which are not described by this matrix. This paper deals with a general approach to the analysis of these singularities, used in the synthesis of a Linear Delta robot to suitably modify its geometry, remarkably improving the structural behavior. Details and numerical results are provided.@DOI: 10.1115/1.1588343#

Integrated management of concurrent shopfloor operations

Abstract The problem of combining efficiency with flexibility is the basic challenge faced by the factories of the future. In this paper, the solution is investigated through expert governors that can manage the concurrency of manufacturing processes enabling efficient decentralized control for standard running conditions. Flexible adaptive control is possible when recovery intervention is requested as a result of unsteady occurrences. The presentation is carried out by programming facilities developed by the Industrial Robot Design Research Group of the University of Genova, Italy.

Information Infrastructures and Sustainability

Today sustainability is a basic demand. It often contradicts with the need of an affluent society. The life quality of industrial countries could never lower, if trading of extended artefacts (products-services) will be based on exchanging information-intensive deliveries. The wealth build-up will follow in the knowledge society, fostering eco-consistent behaviours by balancing tangibles decay by intangibles increase. The idea is described by the KILT model, which characterises by the TYPUS metrics. The paper discusses some topics of the prospected scenario, underlining supply chain issues, showing that the ICT options are critical aids to create the required information environment. Some basic trends are sketched, focusing on products-services trading, supplied by extended enterprises, under supervision of independent certifying bodies.

Humanitarian demining : path planning and remote robotic sweeping

Purpose – Humanitarian demining is addressed as an engineering‐driven duty, aiming at optimal price/effectiveness figures, joining low‐cost robotics and flexible automation. The mine sweeping is highly dangerous task, and safety is sought by automatic rigs, with remote steering and control. The small price is achieved with resort to locally available equipment, technology and know‐how.Design/methodology/approach – The robotic solutions are split at three levels: the mobility enabler, exploiting standard agricultural machinery; the demining outfits, specialising cheap end‐effectors; the robot path planner, exploring reliable remote govern options. The approach aims at the pace‐wise deployment of consistent rigs with assessed productivity and tiny investment.Findings – The paper explores basic ideas to modify common agricultural machines, placing in front proper effectors and specifying the guidelines needed to choose both carriers and suitable demining tools. The remote command logic of the suggested demin...

Development of CAD codes for the job integration of industrial robots

Abstract The work of the Industrial Robot Design Research Group working at the University of Genoa, Italy, is summarized. The reasons for developing special-purpose CAD codes are noted, together with a discussion of the approach that has been utilized. An example procedure concerning the selection of the controlling strategies is presented, with typical output results. The integration of the robotic devices into manufacturing lines is discussed with an indication of the computational codes presently under development.

Knowledge Organization And Govern For Flexibility In Manufacturing

In this paper, we investigate co-operative knowledge processing as an opportunity for increasing the capabilities of computer-integrated manufacturing in the presence of varying product-mixes. We achieve this goal by exploiting the flexible capacity of robot-assisted production facilities, developing design innovations iteratively, and using fabrication according to the requirements of market-driven manufacture — all according to the simultaneous engineering rules.

The govern-for-flexibility of manufacturing facilities: an explanatory example

Abstract Flexibility in manufacturing is a challenge: it potentially improves the exploitation of resources available, and expands the product mix; it is also puzzling for production engineers, since efficiency and performance depend heavily on the on-process availability of directed decision processes. Computer-integrated facilities are the reference technology, and the build-up of appropriate CAD/CAM instruments, based on broad expertise and extended experimentation of the govern-for-flexibility options, deserves particular interest. This paper discusses the problem, referring to an example plant and considering a simulated environment the XIM-SIFIP code, that fully describes the dynamic behaviour of multiprocess manufacturing, giving a powerful aid for collecting and comparing the capabilities added by adaptive scheduling.

Product Lifestyle Design: Innovation for Sustainability

The product lifestyle design is necessary sustainable growth accomplishment, enforced by the enacted eco-regulations. The paper discusses the incumbent restructuring of the manufacturing companies, recalling the innovation at the design phase, by effective product-process-environment-enterprise, 2P2E, integration, supported by suitably detailed modelling and simulation features, MS service dealers, for the extended enterprise added value operations; recovery rulers, for reverse logistics accomplishments and tasks overseeing. A short outlook of the topics is sketched, and, for explanatory purposes, example developments are recalled, referred to industrial situations emerging from the recent EU environmental policy.

Path Guidance and Attitude Control of a Vectored Thruster AUV

The study deals with developing small and cheap autonomous underwater vehicles, AUV, entrusted of extended manoeuvrability for surveying and docking missions, with accurate of path tracking and attitude keeping, capable of travelling at low speed, down to proper depth, to carry out the given tasks with proper autonomy and without relevant impact on the surroundings. The to day available AUVs, generally, make use of several propellers, distributed around the body, to achieve the desired mobility with full attitude control. The solution requires the closure of multiple loops between sensors and actuators, highly cross-coupled and dependent on dynamics non-linearity and marine surroundings disturbances. The prospected solution considers a properly shaped vehicle, to grant minimal drag for lowering power consumption. A single rear propeller has in charge propulsion and manoeuvring. The propeller can be oriented around two axes, say, pitch (for heaving) and yaw (for veering); the screw (hydrodynamic) torque is balanced by variable tilt fins, either, by counter-rotating vanes. A three degrees of freedom parallel kinematics robotic wrist provides joint path-and-attitude selection and twist compensation, by driving the propeller assembly through three independent actuations. The build-up makes use of a duct-restricted propeller, with externally driven pitch-and-yaw bending and twist to counteract the screw torque by reactive fins, either, continuous rotation. The balancing wile assures best performance, in the reactive mode, during steady surveying missions, while the local hover or docking is better accomplished by active counter-rotation. The paper discusses the basic design steps by example manoeuvres carried with virtual checks on a digital mock-up.Copyright