Jonny Gustafsson

Spatial augmented reality on industrial CNC-machines

In this work we present how Augmented Reality (AR) can be used to create an intimate integration of process data with the workspace of an industrial CNC (computer numerical control) machine. AR allows us to combine interactive computer graphics with real objects in a physical environment - in this case, the workspace of an industrial lathe. ASTOR is an autostereoscopic optical see-through spatial AR system, which provides real-time 3D visual feedback without the need for user-worn equipment, such as head-mounted displays or sensors for tracking. The use of a transparent holographic optical element, overlaid onto the safety glass, allows the system to simultaneously provide bright imagery and clear visibility of the tool and workpiece. The system makes it possible to enhance visibility of occluded tools as well as to visualize real-time data from the process in the 3D space. The graphics are geometrically registered with the workspace and provide an intuitive representation of the process, amplifying the users understanding and simplifying machine operation.

ASTOR: an autostereoscopic optical see-through augmented reality system

We present a novel autostereoscopic optical see-through system for augmented reality (AR). It uses a transparent holographic optical element (HOE) to separate the views produced by two, or more, digital projectors. It is a minimally intrusive AR system that does not require the user to wear special glasses or any other equipment, since the user would see different images depending on the point of view. The HOE itself is a thin glass plate or plastic film that can easily be incorporated into other surfaces, such as a window. The technology offers great flexibility, allowing the projectors to be placed where they are the least intrusive. ASTORs capability of sporadic AR visualization is currently ideal for smaller physical workspaces, such as our prototype setup in an industrial environment.

Development of a 3D interaction table

We have identified the need for, and started development of, a new tool we call an interaction table. In this paper the experiences with the first prototype are described. The interaction table presents a computer-generated, autostereoscopic, three-dimensional image that can be viewed and interacted with.

Practical system for time-resolved holographic interferometry

An easily implemented and easily manageable system for timeresolved holographic interferometry is presented. The system consists of a multiple-pulsed Q -switched ruby laser and a rotating disk having radial slits with a constant angular separation. The disk is used to scan the reference beam along a holographic plate, thereby achieving spatial multiplexing. Since the influence on the beam is negligible and a single slit is illuminated by every laser pulse, there is no need for synchronization. The interferometric pattern is achieved by removing the disk and exposing a reference image on the holographic plate. The system may serve as an excellent tool for full-field dynamic measurements. A simple experiment has been performed showing a sequence of momentary interference patterns on a vibrating plate.

Large Format 3D Interaction Table

This paper presents some aspects and applications of the Interaction Table, which is a tool for interactive communication around a virtual 3D model between a small number of people. Some issues with large format displays of this kind are discussed, as well as their image quality, especially the contrast. The demands of some engineering applications are also described.

Internet-based support for the production of holographic stereograms

Holographic hard-copy techniques suffers from a lack of availability for ordinary users of computer graphics. The production of holograms usually requires special skills as well as expensive equipment which means that the direct production cost will be high for an ordinary user with little or no knowledge in holography. Here it is shown how a system may be created in which the users of computer graphics can do all communication with a holography studio through a Java-based web browser. This system will facilitate for the user to understand the technique of holographic stereograms, make decisions about angles, views, lighting etc., previsualizing the end result, as well as automatically submit the 3D-data to the producer of the hologram. A prototype system has been built which uses internal scripting in VRML.

Method for fringe enhancement in holographic interferometry for measurement of in-plane displacements.

Theoretical background along with experimental results are given for a simple method for in-plane fringe enhancement in dual-beam illumination holographic interferometry. In this method, the fringes representing in-plane displacements arise as a moirépattern between two interferograms. To distinguish the in-plane displacement, a sequence of images is recorded while the reference mirror is continuously tilted at random. The in-plane fringes arethen found as the maximum contrast of the out-of-plane fringes in the image sequence. The resulting fringe quality is close to the quality of the out-of-plane fringes.

Model infrastructures and human interaction in a stereo table environment

The digital modelling of technical systems and physical phenomena and their environment forms the basis for design and development in the future. Based on models and visualisation technologies, the appearance and behaviour of a technical system can be studied, simulated and viewed for different purposes, in different disciplines, and at different detailing levels. It forms the base for human communication and interaction to meet the goals of all stakeholders in their study and development. Adding new technologies for man-model interaction and for the dynamic change of models and their viewing will further increase human possibilities for interaction and communication in the same co-located environment as well as in a virtual co-located environment. The paper will focus on a stereo interaction table environment as an important vehicle for integrated human-to-model and human-to-human interaction and some future possible developments.

Finding new wavelengths for pulsed holography

A short popular overview is given of the possibilities of finding new pulsed laser sources for making holograms. Special emphasis is made on wavelengths suitable for color holography.

Internet-based preproduction system for holographic stereograms

A system has been designed with the aim of helping the communication between a producer of holographic stereograms and users of three-dimensional (3D) computer graphics. The user of the system communicates with the producer through a small program, an applet, which is transferred over the Internet. In the applet the user makes all settings necessary for producing the hologram, and then sends the 3D file together with its settings to a holographic printer for production of the hologram. The system uses virtual reality modeling language as an interchangeable graphics format and Java as programming language. It is believed that the system will significantly improve the dissemination of holographic hard copies to ordinary users of computer graphics.