Design of Torque Balancing Mechanisms

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Design of a miniaturized work-cell for micro-manipulation

The paper describes the design and development of a miniaturised workcell devoted to the robotized micro manipulation and assembly of extremely small components, jointly carried out by the University of Brescia, University of Bergamo, University of Ancona and the Institute of Industrial Technologies and Automation of the Italian National Research Council in the framework of the project PRIN2009 MM&A, funded by MIUR. Besides analyzing theoretical and practical aspects related to the design of the work cell components (positioning and orienting devices, grippers, vision and control systems), an automated test bed for the assembly of micro pieces whose typical dimension belongs to the submillimeter scale range has been implemented. The perspective is to contribute to the realization of general automatic production systems at the moment absent for objects of these dimensions

Design of a miniaturized work-cell for micro-manipulation

The paper describes the design and development of a miniaturised workcell devoted to the robotized micro manipulation and assembly of extremely small components, jointly carried out by the University of Brescia, University of Bergamo, University of Ancona and the Institute of Industrial Technologies and Automation of the Italian National Research Council in the framework of the project PRIN2009 MM&A, funded by MIUR. Besides analyzing theoretical and practical aspects related to the design of the work cell components (positioning and orienting devices, grippers, vision and control systems), an automated test bed for the assembly of micro pieces whose typical dimension belongs to the submillimeter scale range has been implemented. The perspective is to contribute to the realization of general automatic production systems at the moment absent for objects of these dimensions

Mechatronic approach to the design of am machines

Any manufacturing process which allows to create a product in its finished form without the need for other machining operations belongs to Net Shape Forming family. Additive Manufacturing (AM) is a part of NSF family; it allows to build 3D objects by adding layer-upon-layer of material (polymers, metals, ceramics) and includes different manufacturing techniques as stated by ISO/ASTM Standard. In order to get good results by the application of these manufacturing techniques, some technological problems has to be faced and solved. They mainly concern: temperature control of the material to be processed, characteristics of the energy source for material transition, control of the power transferred to the material, scanning system’s head control, 3D model’s layer definition, generation of the laser point’s trajectories. All of these aspects have the same importance to guarantee the quality of the product and they are sinergically linked each other. As an example, the power of the energy source and the temperature of the material are strongly related; the power transferred to the material is related to the trajectories running speed; the 3D model’s layer definition influences the resolution of the positioning system; on the performances and control of the scanning head, depends the accuracy of the trajectories. The quality of the product strongly depends on all these aspects as well as on the technical solution to realize them. In other words, the machine implementing the AM technological process is crucial for the product’s manufacturing. From the early stages of machine’s concept, a multidisciplinary and synergic approach which allows to take into account all the different aspects involved in the process must be followed. This is the typical approach followed by Mechatronics; as a matter of fact, Mechatronics concerns the the synergistic application of mechanics, electronics, controls and computer engineering in the development of product and systems through an integrated design approach. In this paper, the fundamental aspects that must be taken into account in the design process of an AM machine are highlighted, and the used design approach is discussed

Driving Technologies for the Design of Additive Manufacturing Systems

In recent years, the Additive Manufacturing (AM) technology, belonging to the most comprehensive Net Shape Forming family, has shown a growing trend due to the increasing quality of the built product. These results may open the application of the AM to the industrial field, moving the application from laboratories to the plant floor. This step requires machines capable of executing the technology process of AM with the requirements of the industrial environment, concerning, for example, production speed, reliability, robustness, and process stability. The design of such a type of machinery requires a systematic and multidisciplinary approach to reach these industrial targets. Indeed, the AM process involves several design technological issues, like temperature control of the material to be processed, characteristics of the energy source for material transition, control of the power transferred to the material, scanning system’s head control, 3D model’s layer definition, and generation of the laser point’s trajectories. The final product’s quality strongly depends on all these aspects, which are synergically linked to each other, as well as on the technical solutions to realize them. The paper presents an interdisciplinary approach to the design of machines for AM, based on the Powder Bed Fusion process and targeted at the industrial field. The technological platforms discussed in the paper are essential for such types of machines. The strategy proposed constitutes a base reference point for the definition of a methodological approach to the design of AM machinery. Doi: 10.28991/HIJ-2021-02-01-03 Full Text: PD

An Optimal Redundancy Coordination Method for an Haptic Interface

In this work an optimal method for the solution of the inverse kinematics of a redundant haptic interface is shown. Methods that act on three different spaces are analyzed: at displacements, at velocities and at accelerations levels. For the first two levels features of different criterions for the redundancy coordination, based on kinematic performance indexes will be briefly presented. At the accelerations level it will be presented an original method based on the working frequency of the device. This algorithm automatically switches between two different approaches: at low working frequencies it is preferred a solution that optimizes the dexterity feature of the system, whereas at high frequencies a method that reduces the required motor torques

Sliding Contact between Freeform Surfaces

This paper deals with the sliding-contact constraint equations describing the relative motion of two freeform surfaces, assuming that the surfaces can have arbitrary curvature in threedimensional space. The sliding-contact equations are developed either for the non-penetration condition and for the surface-tangency condition. Both are differentiated twice in time in order to allow a straightforward application to dynamic and kinematic multibody simulation within the context of an augmented Lagrangian approach. This formulation represents the contact constraint by means of a sliding tangent plane, hence exploiting the advantageous optimizations of the so called lock formulation

Una metodologia numerica per la progettazione aerodinamica di ali per vetture da competizione

Nell’ambito del presente lavoro è stata sviluppata una metodologia numerica volta alla progettazione aerodinamica di ali per autovetture da competizione. La procedura in oggetto si basa su un approccio numerico che consente sia la definizione parametrica di profili alari specifici per applicazioni automobilistiche, sia l’ottimizzazione 3D dell’ala attraverso l’implementazione di un’opportuna soluzione numerica, concettualmente fondata sulla teoria non lineare dell’ala finita (numerical lifting line theory). Una favorevole caratteristica del metodo proposto riguarda l’elevata rapidità di impostazione ed esecuzione del calcolo rispetto ad un caso di simulazione CFD tridimensionale. E’ pertanto possibile affrontare efficacemente e velocemente problemi inerenti la definizione dei profili, della forma in pianta nonché dello svergolamento in direzione dell’apertura alare relativamente a molteplici varianti geometriche. Nel lavoro saranno presentati gli aspetti relativi all’implementazione della metodologia proposta, unitamente al confronto fra corrispondenti soluzioni ottenute sia con codici di calcolo CFD commerciali, sia con la procedura sviluppata.The paper reports a numerical procedure developed by the authors in order to design wings for racing cars. The mentioned procedure is based on a numerical approach to define specific airfoils sections to be used on cars. On the other hand it is possible to optimize the 3D shape of the resulting wing using the numerical lifting line theory. A positive characteristic of the method developed could be seen in terms of speed: the method is very rapid compared to a 3D CFD simulation. For this reason many different airfoils and 3D shapes of the wing (or different airfoil twist along the wing span) can be evaluated to find the best solution