In EMC testing, 3D electromagnetic field data often needs to be visually analysed by an expert in order to detect product defects or unwanted interference between multiple devices. In this sense, the present work proposes the use of data visualization techniques allied to an Augmented Reality user interface to provide information that helps professionals to analyse the same data, however spatially situated where it was first measured. Apart from visualizing it, users may also interact with the data to narrow down their search by switching the attributes being displayed, combining them together, applying filters or changing the formatting in which data is presented. The approaches being proposed in this work will ultimately be tested against each other in comparable 2D and 3D interactive visualizations of the same data in a series of usability assessments with users to validate the solutions. The goal is to ultimately expose whether AR can help users to make more accurate decisions, particularly in EMC related tasks.
In electrical engineering, it is known that activity of electronic and
electrical devices can be highly affected by the frequency
components of electromagnetic waves emitted from external sources, such
as natural lightning, fluorescent lights, digital computers and even
other similar devices [
EMC testing measures the amount of EMI both radiated and
conducted by electronic devices. This kind of procedure ensures
whether or not the criteria mentioned above are being obeyed. In
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his book, [
It is possible to redress this sort of problem through a data
visualization that presents visual and interactive information situated
in the actual space they are relevant in. Augmented Reality (AR)
arguably has the potential of significantly increasing the possibilities
of problem assessment by making data spatially context-aware and
reducing user effort [
In a 2018 study, Sato et al. [
In a related work of the same year, Isrie et al. [
Among the most relevant works in the area, a 2019 study by
Rioult et al. [
As to address the disadvantages mentioned, the current work
intends on exposing EMC data in a more continuous and precise
manner, preserving the 3D topology of fields, as well as spatially
situating them where they were measured, in relation to the device
being analysed, supporting the Situated Visualization paradigm. In
recent works, different researchers compared the efficiency of data
perception and analysis in SV against traditional 2D manual and
interactive interfaces in different applications. These works exposed
a few advantages in tasks performed in the AR approach, including
gains in accuracy [
Much like in these works, our data will be displayed in an AR HMD with spatial mapping capabilities, allowing for a more realistic and precise location of virtual objects, as well as presenting them in an egocentric view, freeing the user’s hands to interact with the data. The work will focus both on readings of small device emission fields (desk-scale), as well as bigger ones (room-scale). 3
In order to expose the adaptability of SV and the proposed methods, a few use case scenarios will be designed and tested. These are meant to be applications of the visualization methods in real commercial, academic or day-to-day problems. Specifically aimed at EMC testing, the following two preliminary use cases are proposed. 3.1
Nowadays, the testing of small components is usually done with EMC scanners, such as the Detectus RSE 6421, which is able to measure the EMI in a high range of frequencies. Since the spectrum analysis of this sort of scanner is done with a near field probe attached to a X-Y-Z robot, it is able to render a three-dimensional graphical visualization of the data read, much like can be seen in Fig. 3. This kind of visualization enables experts to detect potential emission problems before they become integrated into a final product, also exposing what component is causing it, based on the data position.
We propose to implement a framework which will provide users with an Augmented Reality visualization of EMC scanned data, superimposing the actual scanned components or devices, much like
the mock-ups available in Fig. 3. Since the scanner is able to generate field plots in a wide band span, it will be possible to compare visualizations of multiple frequencies, either by overlapping them or interacting with the system to change the current one. Another intention is to render the EMC data from multiple components at the same time, allowing users to understand how they will interfere with each other once they are placed in the same system. For this purpose, we intend on using the Vuforia Engine2, which is capable of using 3D scans of real objects as markers, making it possible for the application to track the actual devices in real time. 3.2
Regarding larger devices in their integrity, entire rooms may be
required for testing. In conducting this sort of experiment, it is
recommended to isolate the test space from the outside
electromagnetic environment. According to [
Having access to one of these anechoic chambers, fully equipped for radiated emissions and immunity testing, our proposal is to render these room-scale EMC readings in 3D, in order to build an AR situated visualization of the test results. Much like the aforementioned proposal, however in a larger scale, these readings are meant for users to detect any EMI that may cause the equipment to malfunction or affect other systems. The main advantage of such an application is to spatially expose exactly where the interference is being propagated from and into what other components. In a situated view, it will be possible to perceive the influence of multiple devices on each other in loco, either inside the anechoic chamber or anywhere else these devices will be located at. 4
In a preliminary attempt to demonstrate the proposal, an application prototype was developed where the real 2D (planar) and 3D EMC data read from a sample antenna (seen in Fig. 4) emission was parsed, converted from spherical to cartesian coordinates and 2https://developer.vuforia.com/ rendered situated inside the anechoic chamber environment. For this, the physical room was scanned into a three-dimensional mesh, with its points in space being used as anchors for the data to be placed upon. Then, by loading this environment, with the data already being displayed in the right place according to the virtual mesh of the chamber, into an AR HMD with spatial tracking capabilities, the mesh can be matched with the real architecture of the area the user is located at. For the current project, the Microsoft HoloLens (1st generation)3 was used both to scan the room and to display the data to users.
As can be seen in Fig. 5, the virtual field is superimposed in the real environment the user is seeing. This arguably allows for a less cognitive demanding analysis of the data, since the proposed egocentric view of the surroundings does not require the mental translation from a 2D screen into the 3D surrounding space necessary in the allocentric task that is performed nowadays in the EMC industry. This argument, however, will be put into test in a future user experiment, where decision-making tasks will be performed and their performances evaluated.
In a quick demonstration made to three experts in the EMC testing area, feedback was outright positive. Users commended the visualization presented as being highly useful for analysing real data, even at a commercial level. As to work in a spiral model of software development, this demonstration served as a first prototype in order to verify and validate the concept, as well as using the feedback from the community as to understand their needs and fulfill those in upcoming projects. 5
As to properly evaluate the use of SV in the EMC field, formal user
tests are required. The next step in the current project is to test
the proposed visualizations with experts with EMC backgrounds.
Inspired by User Testing guidelines by Nielsen [
This work presented a proposal for an augmented situated visualization method for aiding decision-making in an EMC testing context.
The use case application is intended for helping expert users to analyse electromagnetic fields and EMC data in general. Using an AR HMD, users are able to visualize the spatial data read by high level industry standard equipment, such as an EMC scanner and an antenna inside an anechoic chamber.
This approach presents a highly compelling visualization for the state-of-the-art both in augmented reality and EMC testing, since new AR platforms are expected to emerge with less intrusive and cumbersome devices, supplying users with a more detailed and thorough field of view. Furthermore, this work will proceed with a comparison in user performance of tasks common to the EMC area, with the intention of assessing whether and how SV may offer advantages to this sort of activity.
This study was partly funded by the Coordenac¸a˜o de Aperfeic¸oamento de Pessoal de N´ıvel Superior - Brasil (CAPES) - Finance Code 001, partly by CNPq and partly by the Swedish Council for Higher Education (UHR). We also acknowledge FAPERGS (project 17/2551-0001192-9), CNPq-Brazil (project 311353/2017-7) and a Linnaeus-Palme grant within the partnership (3.3.1.34.11116-2019) between the School of Information Technology at Halmstad University and the Institute of Informatics at UFRGS for their financial support.