The potentiality of the Fused Deposition Modeling (FDM) process for multi-material printing has not yet been thoroughly explored in the literature. That is a limitation considering the wide diffusion ...of dual extruders printers and the possibility of increasing the number of these extruders. An exploratory study, based on tensile tests and performed on double-material butt-joined bars, was thus conceived; the aim was to explore how the adhesion strength between 3 pairs of filaments (TPU-PLA, PLA-CPE, CPE-TPU) is influenced by the material printing order, the type of slicing pattern used for the layers at the interface, and the infill density of the layers below the interface. Results confirm the effectiveness of mechanical interlocking strategies in increasing the adhesion strength even when thermodynamic and diffusion mechanisms of adhesion are not robust enough. Besides, thermal aspects also demonstrated to play a relevant role in influencing the performance of the interface.
The paper deals with prototyping strategies aimed at supporting engineers in the design of the multisensory experience of products. It is widely recognised that the most effective strategy to design ...it is to create working prototypes and analyse user’s reactions when interacting with them. Starting from this consciousness, we will discuss of how virtual reality (VR) technologies can support engineers to build prototypes suitable to this aim. Furthermore we will demonstrate how VR-based prototypes do not only represent a valid alternative to physical prototypes, but also a step forward thanks to the possibility of simulating and rendering multisensory and real-time modifiable interactions between the user and the prototype. These characteristics of VR-based prototypes enable engineers to rapidly test with users different variants and to optimise the multisensory experience perceived by them during the interaction. The discussion is supported both by examples available in literature and by case studies we have developed over the years on this topic. Specifically, in our research we have concentrated on what happens in the physical contact between the user and the product. Such contact strongly influences the user’s impression about the product.
In Mass Customisation (
MC
), products are intrinsically variable, because they aim at satisfying end-users’ requests. Modular design and flexible manufacturing technologies are useful strategies to ...guarantee a wide product variability. However, in the eyewear field, the current strategies are not easily implementable, due to some eyewear peculiarities (e.g., the large variability of the frame geometry and material, and the necessity to use specific manufacturing phases). For example, acetate spectacle-frames are bent through a thermoforming process. This particular phase requires dedicated moulds, whose geometry strictly depends on the frame model to be bent; consequently, changes of the frame geometry continuously require new moulds, which have to be designed, manufactured, used, and finally stored. The purpose of this paper is to propose a new strategy to transform a dedicated tool (i.e., a thermoforming mould) into a reconfigurable one, to optimise the tool design, manufacturing and use. First, how the frame features influence the mould geometry has been investigated, creating a map of relations. On the basis of this map, the conventional monolithic-metallic mould was divided into “standard” (re-usable) and “special” (ad-hoc) modules, where the “special” ones are in charge of managing the variability of the product geometry. The mapped relations were formalised as mathematical equations and then, implemented into a Knowledge Based Engineering (
KBE
) system, to automatically design the “special” modules and guarantee the mould assemblability. This paper provides an original example of how a reconfigurable thermoforming mould can be conceived and how a
KBE
system can be used to this aim.
This paper describes the design and preliminary test of a virtual reality driving simulator capable of conveying haptic and visual messages to promote eco-sustainable driving behavior. The driving ...simulator was implemented through the Unity game engine; a large street environment, including high-speed and urban sections, was created to examine different driving behaviors. The hardware setup included a gaming driving seat, equipped with a steering wheel and pedals; the virtual scenarios were displayed through an Oculus Rift headset to guarantee an immersive experience. Haptic stimulation (i.e., vibrations) was delivered to the driver through the accelerator pedal, while visual stimuli (i.e., icons and colors) were shown on a virtual head-up display. The sensory feedbacks were presented both alone and in combination, providing information about excessive acceleration and speed. Four different virtual scenarios, each one including a distracting element (i.e., navigator, rain, call, and traffic), were also created. Ten participants tested the simulator. Fuel consumption was evaluated by calculating a mean power index (MPI) in reference to the sensory feedback presentation; physiological reactions and responses to a usability survey were also collected. The results revealed that the haptic and visuo-haptic feedback were responsible for an MPI reduction, respectively, for 14% and 11% compared with a condition of no feedback presentation; while visual feedback alone resulted in an MPI increase of 11%. The efficacy of haptic feedback was also accompanied by a more relaxing physiological state of the users, compared with the visual stimulation. The system’s usability was adequate, although haptic stimuli were rated slightly more intrusive than the visual ones. Overall, these preliminary results highlight how promising the use of the haptic channel can be in communicating and guiding the driver toward a more eco-sustainable behavior.
In the last years, interactive exhibitions based on digital technologies have become widely common, thanks to their flexibility and effectiveness in engaging visitors and creating memorable ...experiences. One of the topics in which digital technologies can be particularly effective is the communication of abstract concepts that are difficult for the human mind to imagine. An emblematic example is the astronomy discipline, which requires us to imagine and understand phenomena far away from our everyday life. In this paper, the authors present a research project, MARSS, in which digital technologies are used effectively to enhance the Users’ Experience of the Museo Astronomico di Brera located in Milan. Specifically, the MARSS project aims at designing and developing a new digital journey inside the museum to allow different categories of visitors to enjoy the exhibition in an engaging and interactive way. The paper presents the design and development phases of the experience and its evaluation with users. The results of the evaluation indicate that the digital interactive experience is appreciated by users and is successful in translating the content of high scientific value into more engaging and easily understandable elements.
The need for companies to improve their competitiveness may lead to innovation and the reconceptualization of traditional products and processes, with companies making an effort to enhance product ...elements related to functionality, attractiveness, technology and sustainability, and implementing mass-customisation concepts. Mass-customised products are developed to satisfy specific customer needs, in line with increasing demand for product variety and customisation. The analysis of what customers really want, capturing the Voice of the Customer (VOC), is one of the strategies used to establish effective product development processes. Using a VOC survey, it is possible to transform customer needs into the functional and psychological requirements of the product. This paper presents a methodology based on Virtual Reality (VR) technologies to support the capturing of the VOC in regard to the visual, haptic and auditory characteristics of products. This method can be applied to the beginning of the product development process, to allow companies to deduce from the data the requirements of new industrial customised products. A flexible and interactive Virtual Prototype (VP) of a product category is then developed as a product platform in a draft version by designers and configured according to customer needs, using an immersive VR environment. This method, based on the use of VP, reduces the number of physical prototypes that need to be manufactured during the product development process, thus reducing overall costs. In addition, the VP based method supports the mass-customisation process of products through the real-time integration and collection of data for product configuration preferences, involving as many users as possible representative of the target users of the new products. To demonstrate this process a case study concerning the development of the VP for a washing machine, a summary of test sessions with users and results are presented. Specifically, the results presented in this paper are related to improvements in capturing the VOC and reductions in Virtual Prototyping cost and time.
The performance of 2D digital imaging systems depends on several factors related with both optical and electronic processing. These concepts have originated standards, which have been conceived for ...photographic equipment and bi-dimensional scanning systems, and which have been aimed at estimating different parameters such as resolution, noise or dynamic range. Conversely, no standard test protocols currently exist for evaluating the corresponding performances of 3D imaging systems such as laser scanners or pattern projection range cameras. This paper is focused on investigating experimental processes for evaluating some critical parameters of 3D equipment, by extending the concepts defined by the ISO standards to the 3D domain. The experimental part of this work concerns the characterization of different range sensors through the extraction of their resolution, accuracy and uncertainty from sets of 3D data acquisitions of specifically designed test objects whose geometrical characteristics are known in advance. The major objective of this contribution is to suggest an easy characterization process for generating a reliable comparison between the performances of different range sensors and to check if a specific piece of equipment is compliant with the expected characteristics.
In this article, we present an approach that uses both two force sensitive handles (FSH) and a flexible capacitive touch sensor (FCTS) to drive a haptic-based immersive system. The immersive system ...has been developed as part of a multimodal interface for product design. The haptic interface consists of a strip that can be used by product designers to evaluate the quality of a 3D virtual shape by using touch, vision and hearing and, also, to interactively change the shape of the virtual object. Specifically, the user interacts with the FSH to move the virtual object and to appropriately position the haptic interface for retrieving the six degrees of freedom required for both manipulation and modification modalities. The FCTS allows the system to track the movement and position of the user's fingers on the strip, which is used for rendering visual and sound feedback. Two evaluation experiments are described, which involve both the evaluation and the modification of a 3D shape. Results show that the use of the haptic strip for the evaluation of aesthetic shapes is effective and supports product designers in the appreciation of the aesthetic qualities of the shape.
PDF
