RAARA - Residential Area Augmented Reality Acoustics

Status

completed

Starting point, contents and results

Noise causes stress and thus triggers reactions such as cardiovascular diseases, sleep and concentration disorders to mental illnesses and has an influence on social behaviour (aggression). Especially in urban areas, people are very much affected by noise pollution. In addition to traffic and commercial noise, devices for heating or cooling are of great importance. Air conditioning systems, outdoor heat pump units (source) or noisy control cabinets repeatedly lead to conflicts between operators and residents. In general, noise pollution has increased again in recent years. Already 40% of Austrians feel affected by it. From the point of view of the steady expansion of renewable energies for heat and the rapidly growing demand for air conditioning units in the future, air heat pumps and air conditioning systems in urban areas in particular will increase sharply. Nowadays, their sound emissions are usually determined from a single number, the location-independent sound power level, and converted into a location-dependent sound pressure level using simple mathematical methods. Neither the frequency dependence, directional dependence, operating state nor the influence of the environment are taken into account. There is therefore an urgent need to develop a more intuitive, simpler but at the same time more precise approach to sound in order to provide cities with 100% renewable heating and cooling while reducing noise levels. This access is via augmented reality (AR) and represents a unique approach to date.

The aim of the RAARA – Residential Area Augmented Reality Acoustics project is to make sound emissions from noise sources visible and audible on site in real time before their installation by means of "augmented reality", depending on frequency, direction, operating status and environment. Noise sources such as, e.g. dry coolers, evaporators, fans, etc. in/on/around buildings, as well as noise insulation measures should be able to be placed virtually ON SITE before the devices are installed. Their sound emissions are visually displayed in real time on the surrounding surfaces or made acoustically perceptible. For the calculations, the automatically detected environment is taken into account acoustically. With the unique methodology developed in the project, various installation sites can be tested, taking into account noise-insulating measures and facades that have not yet been built, and thus the noise level of the heating and cooling devices to be installed in the future can be virtually optimized even before the devices have been ordered.
Project results include methods for:

• Conversion of noise source measurements into suitable sound profiles
• Automatic sound physical detection of the environment (near and far range)
• Ability to position additional virtual walls with selectable material properties
• Integration of external geometries via GPS and GIS
• Calculation of sound propagation based on sound profiles and environmental data
• Interactive visual and acoustic representation of calculations using AR (virtual noise source with virtual sound in real environments)

In the course of the project, both the smartphone prototype and a version for the Microsoft HoloLens were developed. Both applications have the same functionality, only the representation of the objects and the user interface differ.

The application allows automatic discovery of the environment and the creation of a virtual environment whose elements can be scaled, moved and rotated to reflect reality. Users can add manual walls and add different materials to the environment. Several heat pumps can be placed on the floor to indicate the directional sound power of the unit with bar graphs and color-coded cubes. The visualization of the sound pressure in the room is done by placing spheres at different positions in the room. The application also offers the possibility to add measuring points to perform a simplified sound simulation that depends on the distance between the sound source and the measuring point. A connection to the Internet enables a more sophisticated sound simulation through communication with a server application, which can be used for the final design of the heat pump systems due to the high precision of the results.

For automatic environment detection, horizontal and vertical flat surfaces are detected and displayed in the immediate vicinity of the user using a software library. Since this method allows at most the detection of objects within a radius of about 5 to a maximum of 12 meters, an image recognition algorithm had to be developed for the detection of more distant objects – such as building facades.

Within the framework of the RAARA project, the essential foundations were created to calculate sound events of virtual sound sources in a real environment using advanced methods and to visualize them using augmented reality. In addition, a first application was developed to demonstrate the possibilities considered to a broad audience and to significantly increase awareness of the noise issue, especially for heat pumps.

Since the prototype was able to prove the basic functionality of the envisaged application, it is planned to refine this program in further projects. The interest of the audience is very high and the next steps were discussed in numerous discussions at conferences and trade fairs.
The new IEA HPT Annex 63 "Placement Impact on Heat Pump Acoustics" focuses, among other topics, on the internationalization and expansion of available virtual tools for the calculation and visualization of sound pressure levels of heat pumps. This international project is also supported by a national Austrian consortium.

Project management

AIT Austrian Institute of Technology GmbH

Project or cooperation partners

ÖAW - Österreichische Akademie der Wissenschaften als Subauftragnehmer

AIT Austrian Institute of Technology GmbH
Christoph Reichl, Gerwin Drexler-Schmid
Giefinggasse 2
A-1210 Vienna
Tel.: +43 50550 6605
Fax: +43 50550 6679
E-mail: christoph.reichl@ait.ac.at, gerwin.drexler-schmid@ait.ac.at
Web: www.ait.ac.at