The super nose

Air freshening systems are an integral feature in luxury vehicles these days. But until now, the only tool available for developing unobtrusive fragrances for vehicles was the human nose. IAV’s new mobile “sniff lab” now enables objective, reproducible measurements in real time. And faster application.

Scents have an immediate effect on the brain. The direct neural connection between olfactory cells and the memory center means that odors bring past events immediately to mind. They also release neurochemical substances such as endorphins or serotonin. All this means it’s no wonder that medical professionals use fragrances for aromatherapy, or that some retailers use scents to boost sales or brand loyalty.

Vehicle manufacturers are also aware of the potent psychological effects of smells, which is why air freshening systems are already available as special features in luxury vehicles today. “These systems are supposed to enhance comfort, and the OEM can also use them to emphasize a vehicle’s value,” says Thomas Einzinger, who heads the Thermal Management department at IAV. He and his employees also work on the air inside the vehicle.

At Audi, for example, passengers can choose between “winter” and “summer” scents, with four levels of intensity: subtle, light, medium, and strong. The fragrances are located in two bottles under the steering wheel, and they are diffused in the vehicle’s interior through the vents. They were composed by world-renowned perfume specialists in the small town of Grasse, in the south of France, where various French perfume makers are based.

IAV has supported OEMs in developing these kinds of air freshening systems in the past. Before now, the only measurement instrument used in this application was engineers’ noses. They were the benchmark used to decide when a certain dosage was still considered “light” and when it should be considered “medium” instead. But this method is rather subjective, and it does not provide objective measurement values.

Precision down to the PPM range

With this in mind, Einzinger and his team set about developing a new measurement method for the application of air freshening systems. IAV’s mobile “sniff lab” is about the size of a desktop computer. It takes in air from the vent and sends its measurement results to a connected computer. In this way, the sensor inside can tell developers with pinpoint accuracy just how many fragrance molecules the interior air contains (expressed in ppm – parts per million).

«This makes the measurements quantifiable and reproducible. Our new measurement system also supplies all values in real time, which noticeably accelerates the application.»

Dominik Fellner — Team Manager of System Development at IAV

This means which fragrance concentration corresponds to the “light” or “medium” setting is no longer a matter for (just) the application engineers’ noses.

The ultra-sensitive mobile sniff lab was created in-house at IAV and has been available to use since April 2021. Einzinger and Fellner are silent on the details of the measurement method. All they will say is that the sensor is an ultra-sensitive measurement device from chemical lab operation and was integrated into an overall measurement concept that is optimally adapted to the requirements of vehicle development. Aside from that, the experts use the Design of Experiments (DoE) method to minimize the number of measurements needed.


Universally usable in all modes of transportation

In the future, air freshening systems could also be available as special features in vehicles below the premium class. And in combination with eye recognition, they could, for example, use fragrances deliberately to affect drivers’ mood. “But we also see possible uses in other areas, such as buses, trains, ships, and airplanes,” Einzinger says.

With an eye to the future, completely new approaches arise for autonomous driving in conjunction with ongoing position location and an AI methodology. A future system could be self-learning, adjusting the air freshening function automatically when there is a change of drivers or when the car enters an urban area with poor exterior air quality.

Appropriate natural scents could also be fed in during autonomous driving, for example through a forested area. It is also conceivable that a person will have the car drive them autonomously while watching a movie with the system adding appropriate scents for the action scenes, creating not a 2D or 3D experience, but a 4D driving experience.

«The USPs for the vehicles offered in the future will no longer be geared solely toward the quality and performance of the powertrain. Instead, they will focus on comfort or experience features during the time people spend in the vehicle. We want to contribute something there.»

Thomas Einziger — Head of the thermal management department at IAV

IAV’s “super nose” is ready and waiting for new use cases, at any rate.

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