Paper Reading #15 : Madgets: Actuating Widgets on Interactive Tabletops

Reference

Authors:

Malte Weiss, Florian Schwarz, Simon Jakubowski, Jan Borchers

Affiliation:

RWTH Aachen University

52056 Aachen, Germany

Presentation:

UIST’10, October 3–6, 2010, New York, New York, USA

Summary

Hypothesis

The paper presents a system for the actuation of tangible magnetic widgets (Madgets) on interactive tabletops. It combines electromagnetic actuation with fiber optic tracking to move and operate physical controls. The presented mechanism is hypothesized to support actuating complex tangibles that consist of multiple parts. They as well make use of new actuation dimensions, such as height, force feedback, and power transfer.

Contents

Madgets are low-cost, easy to prototype, and do not require any built- in electronics or power source for actuation or tracking.

Unlike previous works controls for this system are translucent tangible general-purpose widgets, such as sliders, knobs, and buttons, with attached magnets that can be actuated using an array of electromagnets.

The actuation algorithm ensures consistency between physical controls and their virtual counterparts. They also introduce a tracking algorithm that detects widgets even from highly subsampled input video.

Methods

The paper talks about the design of the Madgets and different constraints to be taken into consideration. The authors did not want to have too many electrical component to match their need of lightweight, flexible and easy to prototype system.They decided to make the controls out of acrylic so that they could change their appearance dynamically using LCD screens.

A 24” (52.2 cm × 29.3 cm) TFT panel (Figure 3b), detached from a Samsung SyncMaster 2494LW monitor, displays the user interface at a resolution of 1920 × 1080 pixels (93 dpi). An electroluminescent (EL) foil beneath the panel provides a uniform backlighting.The matrix consists of 19 × 12 electromagnets with a diameter of 19.5 mm and a length of 34.5 mm.An Arduino microcontroller board1 triggers the magnets via 10 custom made shields.The authors' actuation algorithm can apply different actuation forces to different permanent magnets on the widget. Tangential actuation is used to move magnets in the plane of the tabletop and normal actuation is used to apply force in the normal direction of the table top. To alleviate the heating problem,switching was allowed between electromagnets during use. In order to track the widgets, gradient fiducially were introduced to the widgets. One of the neat features introduced was the concept of moving widgets vertically.

Results

After designing the system, the authors were able to have the following functionalities 1)Persistence 2)Remote collaboration and 3)Ad-hoc use comparable to desktop applications and some sort of 3D interface. They were able to create a system that provides low-cost physical widgets and new actuation dimensions, such as height, force feedback, and power transfer.

Discussion

The paper was interesting to read from a design perspective but I would definitely want to know how it will work on real user testing. The lack of such valuable data and observance makes me kind of skeptical about the research. The design and the interface with actual objects to perform different tasks seems impressive.I cannot really tell how we can implement this system into mainstream use. I feel like if we can make everyday things like pens or phones with magnets like those widgets then we can have multiple functionality on what we are already using now.