Drivers will soon have a more quiet driving experience. Harman, an infotainment system vendor, recently succeeded in applying noise cancellation technology, hitherto known mostly from headphones, to the interior of cars.

The company's Road Noise Cancellation (RNC) noise management solution, jointly developed with the British sports cars legend Lotus Engineering, minimises noise generated by the contact of the tyres with the road surface.

RNC, currently on its way to market introduction, has a strong economic aspect: It enables carmakers to use lighter materials and improve fuel economy without compromising vehicle noise levels.

In pursuing ways to lessen the environmental impact of vehicles and raise fuel efficiency, car designers are reducing vehicle weight, often by using less noise-dampening insulation in the car's interior. The use of lighter materials, however, increases perceptible road noise inside the vehicle, which then penetrates the interior (and passenger ears) and compromises the audio experience of the onboard infotainment system. Traditional NVH (noise, vibration, and harshness) methods have difficulties mitigating these issues satisfactorily, and these technologies tend to add weight, which cancels out the fuel economy effect of using lighter materials.

With the latest Harman solution, drivers and passengers can soon look forward to a quieter ride. The Harman HALOsonic noise management suite comprises a Road Noise Cancellation (RNC) solution which detects and neutralizes unwanted road noise and thereby creates opportunities to improve vehicle weight and handling without impacting interior noise levels.

Being the first solution of its kind in the industry, RNC is based on the principle of using anti-noise to counteract road noise. To implement RNC, the chassis of the vehicle is fitted with accelerometers, which enable the system to measure the correlation of vibration coming from the road and the resulting noise inside the cabin. Subsequently, Harman's algorithm in the controller creates inverse sound waves through the car's audio system loudspeakers to cancel out the noise caused by the road-induced vibration. It is also able to cope with the broadband nature of road noise, with its wide range of frequencies. The solution at hand can reduce the peaks of the noise across the target frequency range, creating a quieter experience within the vehicle cabin.

HALOsonic consists of a suite of noise management technologies to improve noise levels and to enhance and contour sound inside and outside the vehicle. In addition to RNC, HALOsonic comprises Engine Order Cancelation (EOC) and internal as well as external Electronic Sound Synthesis. External ESS (eESS) generates sound primarily for hybrids and electric vehicles, creating the authentic sounds which drivers and pedestrians are familiar with from combustion engines, thereby increasing safety both for drivers and other road users. Internal ESS (iESS) serves to generate unique sound signatures for vehicles to contour and accentuate the engine sound.

By: DocMemory
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