Main Papers by Antonio E. Uva
IEEE Computer Graphics and Applications (Volume 35, Issue 2, 1 March 2015, Article number 7064667, Pages 52-61), 2015
In the Industrie 4.0 vision, the creation of leading-edge options for interaction between people ... more In the Industrie 4.0 vision, the creation of leading-edge options for interaction between people and technology occupies a key role. In this context, augmented reality (AR) is one of the most suitable solutions. However, it is still not ready to be effectively used in industry. A crucial problem is the legibility of text seen through AR head-worn displays (HWDs). AR interface designers have no standard guidelines to follow, especially for these devices. Literature and anecdotal evidence suggest that legibility depends mainly on background, display technology (that is, see-through optical or video HWDs), and text style (for example, plain text, outline, or billboard). Furthermore, there are constraints to consider in industrial environments, such as standard color-coding practices and workplace lighting. The authors examine aspects affecting text legibility with an emphasis on deriving guidelines to support AR interface designers. Their results suggest that enhancing text contrast via software, along with using the outline or billboard style, is an effective practice to improve legibility in many situations. If one text style is needed for both types of HWD, their results suggest that colored billboards (with neutral white text) are effective. When color coding is not mandatory, white text and blue billboard are more effective than other styles tested.
IEEE Transactions on Visualization and Computer Graphics (Volume 21, Issue 5, 1 May 2015, Article number 6994851, Pages 638-651), 2015
Text readability with augmented reality head-worn displays is critical and at present time, there... more Text readability with augmented reality head-worn displays is critical and at present time, there are no standard guidelines to follow. The readability depends mainly on background lighting, display technology (i.e., OST: optical see-through or VST: video see-through), and text style (e.g., plain text, outline or billboard). In this work, we addressed the readability limits for industrial activities. We experimented the effects of two background illuminances levels (1,000 lx for very fine basic industrial tasks and 4,000 lx for fine machining), two commercially available head-worn display technologies, variable outline widths and contrast polarity of text. We analyzed the performance of 12 subjects by collecting about 3,400 measurements using a specific test application and followed by qualitative interviews. With high illuminances, VST performed better than OST, regardless of contrast polarity and outline width. We found that negative contrast polarity is preferable with VST, and that just a minimum outline (1 px) around black text is optimal. On the contrary, positive contrast polarity should be used with OST and outline is not effective. Therefore, we evaluated the usage limits of the OST by sampling its contrast sensitivity function.
Computers in Industry (Volume 70, 1 June 2015, Pages 70-78), Jun 1, 2015
Augmented Reality is a promising technology for the product lifecycle development, but it is stil... more Augmented Reality is a promising technology for the product lifecycle development, but it is still not established in industrial facilities. The most relevant issues to be addressed relate to the ergonomics: avoid the discomfort of Head-Worn Displays, allow the operators to have free hands and improve data visualization. In this work we study the possibility to use projection-based Augmented Reality (projected AR), as optimal solution for technical visualization on industrial workbenches. In particular, text legibility in projected AR is difficult to optimize since it is affected by many parameters: environment conditions, text style, material and shape of the target surface. This problem is poorly addressed in literature and in the specific industrial field. We analyze the legibility of a set of colors prescribed by international standards for the industrial environments, on six widely used industrial workbenches surfaces. We compared the performance of 14 subjects using projected AR, with that using a traditional LCD monitor. We collected about 2500 measurements (times and errors) through the use of a test application, followed by qualitative interviews. The results showed that, as regards legibility, projected AR can be used in place of traditional monitors in most of the cases. Another not trivial finding is that the influence on legibility of surface irregularities (e.g., grooves, prominences) is more important than that of surface texturization. A possible limitation for the use of projected AR is given by the blue color, whose performance turned out to be lower than that of other colors with every workbench surface.
Computer-Aided Design and Applications, 2014
The paper describes an interactive Finite Elements Analysis (FEA) tool that aims to improve the l... more The paper describes an interactive Finite Elements Analysis (FEA) tool that aims to improve the learning of mechanical behavior of materials in industrial engineering schools. We implemented a "user in the loop" approach where students can explore the mechanical behavior of virtual specimens selected from a library of standard elements (cantilever beam, IPE beams etc.). The users can apply forces or displacements interactively by mouse or haptic device, and visualize and "feel" the structures stress configurations. We extended our previous work and compared this novel approach with respect to traditional FEA learning techniques. A test with twenty engineering students showed that learners following the interactive approach are faster in completing the given assignment showing a reduced error rate.
Computers in Industry 65 (2), 270-278, 2014
We present an empirical study that evaluates the effectiveness of technical maintenance assisted ... more We present an empirical study that evaluates the effectiveness of technical maintenance assisted with interactive augmented reality instructions. Our approach consists in an augmented visualization on a large screen and a combination of multiple fixed and mobile cameras. We used commercial available solutions. In our test, 14 participants completed a set of 4 maintenance tasks based on the inspection manual of a motorbike engine. Tool selection, bolts removal, part dis\assembly are supported by visual labels, 3D virtual models and 3D animations. All participants executed similar operations in two modalities: paper manuals and augmented instructions. Statistical analysis proved that the augmented instructions reduced significatively participants’ overall execution time and error rate.
Presence: Teleoperators and Virtual Environments, 2013
The application of augmented reality in industrial environments requires an effective visualizati... more The application of augmented reality in industrial environments requires an effective visualization of text on a see-through head-mounted display (HMD). The main contribution of this work is an empirical study of text styles as viewed through a monocular optical see-through display on three real workshop backgrounds, examining four colors and four different text styles. We ran 2,520 test trials with 14 participants using a mixed design and evaluated completion time and error rates. We found that both presentation mode and background influence the readability of text, but there is no interaction effect between these two variables. Another interesting aspect is that the presentation mode differentially influences completion time and error rate. The present study allows us to draw some guidelines for an effective use of AR text visualization in industrial environments. We suggest maximum contrast when reading time is important, and the use of colors to reduce errors. We also recommend a colored billboard with transparent text where colors have a specific meaning.
IEEE Transactions on Visualization and Computer Graphics, 2013
Efficient text visualization in head-worn Augmented Reality displays is critical because it is se... more Efficient text visualization in head-worn Augmented Reality displays is critical because it is sensitive to display technology, text style and color, ambient illumination, etc.. The main problem for the developer is to know the optimal text style for the specific display and for applications where color coding must be strictly followed because it is regulated by laws or internal practices. In this work we experimented the effects on readability of two head worn devices (optical and video see-through), two backgrounds (light and dark), five colors (white, black, red, green, and blue) and two text styles (plain text and billboarded text). Font type and size were kept constant. We measured the performance of 15 subjects by collecting about 5000 measurements using a specific test application and followed by qualitative interviews. Readability turned out to be quicker on the optical see-through device. For the video see-through device, background affects readability only in case of text without billboard. Finally our tests suggest that a good combination for indoor augmented reality applications, regardless of device and background, could be white text and blue billboard, while a mandatory color should be displayed as billboard with a white text message.
Journal of Computer Science and Information Systems, 2013
We developed a wearable device to improve lower limb sport training. The presented system consist... more We developed a wearable device to improve lower limb sport training. The presented system consists of a pair of spandex shorts which embed a processor unit, 2 accelerometers and 2 vibro motors. The accelerometers are located in proximity to the knees and measure tri-axial accelerations. We present a novel method to compute and correct asymmetry of lower limbs during training. The user performs an initial calibration phase which sets the accelerometer reference frames. While running, the system continuously refines the calibration using principal component analysis to take in account occasional shorts assessments. The system activates a corrective vibro feedback on the specific leg according to an asymmetry metric based on: (i) foot ground impact, (ii) phase error between legs, (iii) transversal knee movements. User tests demonstrated that the device is ergonomic to wear, easy to use and the corrective vibro feedback is appreciated during the training.
International Journal on Interactive Design and Manufacturing, 2013
The interaction metaphor, based on mouse, monitor and keyboard, presents evident limits in the en... more The interaction metaphor, based on mouse, monitor and keyboard, presents evident limits in the engineering design review activities, when real and virtual models must be explored and compared, and also in "outside-the-office" environments, where the desk is not available. The presented research aims to explore a new generation of gesture-based interfaces, called "natural interfaces", which promise an intuitive control using free hands and without the desk support. We present a novel natural design review workspace which acquires user motion using a combination of video and depth cameras and visualizes the CAD models using monitor-based augmented reality. We implemented a bimanual egocentric pointer paradigm by a virtual active surface in front of the user. We used a XML configurable approach to explore bimanual gesture commands to browse, select, dis/assembly and explode 3D complex models imported in standard STEP format. Our experiments demonstrated that the virtual active surface is able to effectively trigger a set of CAD specific commands and to improve technical navigation in non-desktop environments: e.g. shop floor maintenance, on site quality control, etc. We evaluated the feasibility and robustness of the interface and reported a high degree of acceptance from the users who preferred the presented interface to a unconstrained 3D manipulation.
Early diagnosis of lung tumors by genetically optimized 3D-metaball malignancy metric (2012) GECC... more Early diagnosis of lung tumors by genetically optimized 3D-metaball malignancy metric (2012) GECCO'12 -
Journal of Computing and Information Science in Engineering, 2012
Engineering 3D models become complex that paper drawings representation and monitor/mouse navigat... more Engineering 3D models become complex that paper drawings representation and monitor/mouse navigation on a computer-aided design (CAD) system is difficult and also frustrating. We present a novel interface paradigm for natural interactive visualization. It incorporates augmented reality enhanced engineering drawings and natural and tangible interfaces. We embedded ID markers on technical drawings to provide CAD data retrieval and tangible navigation. A user gets access to the CAD navigation functions using the drawing itself as a tangible device. In addition, CAD functions are triggered with gestures recognized by a video camera. We performed a pilot test assessment with industrial engineers. The results demonstrate the feasibility and the effectiveness of these techniques.
Please cite this article as:
Fiorentino, M.; Uva, A.; Monno, G. & Radkowski, R.
Augmented technical drawings: A novel technique for natural interactive visualization of computer-aided design models
Journal of Computing and Information Science in Engineering, 2012, 12. doi:10.1115/1.4006431.
ASME 2011 World Conference on Innovative Virtual Reality, WINVR , 2011
This work presents a novel Augmented Realty (AR) application to superimpose interactive Product M... more This work presents a novel Augmented Realty (AR) application to superimpose interactive Product Manufacturing Information (PMI) onto paper technical drawings. We augment drawings with contextual data and use a novel tangible interface to access the data in a natural way. We present an optimized PMI data visualization algorithm for CAD models in order to avoid model and annotation cluttering. Our algorithm ranks the model faces with technical annotations according to angle, distance, occlusion and area. The number of annotations visualized on 3D model is chosen following the cognitive perception theory to avoid information overload. We also extended the navigation metaphor adding the concept of tangible model navigation and flipping using the duplex drawing. As case studies we used annotated models from ASME standards. By using PC hardware and common paper drawings, this approach can be integrated at low-cost in existing industrial processes.
Control Engineering and Applied Informatics, 2011
We present a novel self-calibrating wearable device to improve running training by active vibro f... more We present a novel self-calibrating wearable device to improve running training by active vibro feedback. The system consists of a pair of spandex shorts embedding: a processor unit, 2 three-axial accelerometers, 2 vibro motors, a SD card reader\writer module and a real time clock. Two supplementary wireless accelerometers are located on the shoes. We present an algorithm to compute gait asymmetry from the four sensors data. The main novelty is the auto calibration algorithm which uses principal component analysis on each sensor based on kinematic assumptions. The system provides two important advantages: data logging and real time active correction. The active correction is performed sending signals to the user in real time via vibrations cells (rumble feedback). The vibration signals are sent to the specific leg and its intensity is proportional to the entity of required correction. This training system for running can be very useful to athletes and to sport medicine in order to improve speed, posture, fatigue and reduce joints osteoarthrotic problems.
… (MeMeA), 2011 IEEE …, Jan 1, 2011
The main objective of this works is to develop a wearable device to improve sport training in low... more The main objective of this works is to develop a wearable device to improve sport training in lower limb. The system consists of a pair of spandex shorts which embed a processor unit, 2 accelerometers, 2 vibro motors, a SD card readerwriter module and a real time clock. The accelerometers are located in proximity to the knees and are used to measure in real time the tri-axial accelerations for each leg. We present a novel algorithm to compute asymmetry from the 3 axial sensor data. We propose two applications of the system: for real time active correction and for data logging. In the correction mode, adjustment signal are sent to the user during the training by vibrations. The vibration signal is sent to the specific leg and its intensity is related to the entity of required correction. The second application of the system is as datalogger. The device stores all the training data in a SD card. Those log files can be processed using a dedicated application on a PC. This information can be very useful for long term analysis. This novel approach to sport training is very useful to athletes and sport medicine doctor in order to improve posture, efficiency and performance, but it can be also useful in other medical appliances such as rehabilitation.
Computer-aided Design, Jan 1, 2010
In this work we integrate augmented reality technology in a product development process using rea... more In this work we integrate augmented reality technology in a product development process using real technical drawings as a tangible interface for design review. We present an original collaborative framework for Augmented Design Review Over Network (ADRON). It provides the following features: augmented technical drawings, interactive FEM simulation, multimodal annotation and chat tools, web content integration and collaborative client/server architecture. Our framework is intended to use common hardware instead of expensive and complex virtual or augmented facilities. We designed the interface specifically for users with little or no augmented reality expertise proposing tangible interfaces for data review and visual editing for all the functions and configurations. Two case studies are presented and discussed: a real-time “touch and see” stress/strain simulation and a collaborative distributed design review session of an industrial component.
International Journal on Interactive Design and Manufacturing, 2009
We present a novel approach, called tangible digital master (TaDiMa), based on a flexible access ... more We present a novel approach, called tangible digital master (TaDiMa), based on a flexible access to Product Lifecycle Management (PLM) database using a tangible/graphical user interface and augmented reality. We developed and tested a technical drawing template with automatically embedded markers for augmentation. We embedded the Mozilla FireFox engine into our annotation system for the integration of web 2.0 applications in the AR environment. We also extended the concept of web feed to PLM for notification of technical contents. We implemented a dynamic labelling management with view-driven filtering and placement. We also present a tangible management for layers visualization and users access by marked tokens. We validated the TaDiMa approach in a selection of possible scenarios for different PLM applications. The main benefit of the TaDiMa system is the easy and low-cost integration in the product lifecycle process.
… MeMeA), 2011 IEEE …, Jan 1, 2011
Abstract We present a novel framework for computer aided measurements which supports physicians d... more Abstract We present a novel framework for computer aided measurements which supports physicians during 3D virtual colonoscopy. We propose a four steps methodology:(i) segment colon regions,(ii) search for colorectal polyps by means of a supervised neural network architecture,(iii) 3D reconstruction of polyp geometry using a synthetic model and (iv) qualitative and quantitative geometrical analysis. Doctor can graphically visualize and inspect the surface and search for irregularities. This qualitative visual support is extended ...
Journal of Computer Applications in Technology, Jan 1, 2008
Large stereo displays and 3D input devices have proved significant productivity benefits in CAD, ... more Large stereo displays and 3D input devices have proved significant productivity benefits in CAD, but they have also shown interaction weaknesses. Large displays interaction requires to consider also the user's viewpoint, differently from desktop interface. We present a novel user centred approach for pointing CAD entities with a 3D cursor on a wall like stereoscopic display. Firstly we proved that the user error is affected by anisotropy. To address this issue, we present an enhanced snap tool called eSnap. This tool uses an elliptic metric for 3D cursor proximity, which differs from previous approaches where 2-norm (sphere) or infinity norm (box) is used. Then we present a CAD test case to compare the eSnap with existing techniques. The provided results demonstrate a significant improvement in user performances and can be used as a guide for the development of user interfaces in emerging 3D displays.
Computer-aided Design, Jan 1, 2010
Part modelling in a CAD environment requires a bi-manual 3D input interface to fully exploit its ... more Part modelling in a CAD environment requires a bi-manual 3D input interface to fully exploit its potentialities. In this research we provide extensive user tests on bi-manual modelling using different devices to control 3D model’s rotation. Our results suggest that a simple trackball device is effective when the user task is mostly limited to rotation control (i.e. when modelling parts in a CAD environment). In our tests, performances are even better than those achieved with a specifically designed device. Since the task of rotating a CAD part often shows the need of flipping the controlled object, we introduce a non linear transfer function which combines the precision of a zero order control mode with the ability to recognise fast movements. This new modality shows a significant improvement in the user’s performances and candidates itself for integration in next generation CAD interfaces.
… of the 13th International Conference in …, Jan 1, 2005
We have developed a pen device for CAD applications in virtual reality which provides novel featu... more We have developed a pen device for CAD applications in virtual reality which provides novel features compared to existing systems. The SenStylus consists of a wireless pen designed to be ergonomically handled by the user for spatial interaction using a six degree of freedom optical tracking. In addition to the classic digital button(s) input, it provides analog multi-axial control, and a dual-rumble feedback output. We have integrated the device into an existing virtual reality CAD environment and extended the application functionalities with new devicespecific features. The SenStylus vibration feedback improves perception in the virtual world by controlling frequency, amplitude, and duration of the feedback, simulating a variety of responses during collisions and selection tasks. This capability enforces the visual depth sensitivity, which is critical when wo rking with complex CAD models. The multi-axial analog input provides a natural interaction paradigm to the user, thus simulating pen pressure and angle as in real world sketching and in real clay modeling. Dynamic tool-tip dimensioning and shaping are implemented as extra features. We present some applications to prove the added value of the SenStylus. The evaluation of the device received positive feedback by designers and engineers alike. The new features offered by this device can easily be extended to other VR applications using the API provided.
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Main Papers by Antonio E. Uva
Please cite this article as:
Fiorentino, M.; Uva, A.; Monno, G. & Radkowski, R.
Augmented technical drawings: A novel technique for natural interactive visualization of computer-aided design models
Journal of Computing and Information Science in Engineering, 2012, 12. doi:10.1115/1.4006431.
Please cite this article as:
Fiorentino, M.; Uva, A.; Monno, G. & Radkowski, R.
Augmented technical drawings: A novel technique for natural interactive visualization of computer-aided design models
Journal of Computing and Information Science in Engineering, 2012, 12. doi:10.1115/1.4006431.