The Hyundai Group is working on developing the world’s first Road Noise Active Noise Control system (RANC), which builds on the automaker’s existing Active Noise Control tech (ANC).
ANC actively reduces noise by emitting soundwaves inverted to incoming noise, and does this by analyzing the in-cabin sound to decrease engine and road noise, as opposed to simply blocking noise through sound insulation.
RANC on the other hand is able to analyze various types of noise in real-time and produce inverted soundwaves – for example, it can counteract the sounds created between tires and wheels or the rumble sounds coming from the road.
“RANC is a remarkable technology which takes existing NVH technology to the next level,” stated Gangdeok Lee, a researcher at NVH Research Lab. “We will continue to take the leading position of NVH technology and deliver the highest level of quietness to customers.”
The way RANC works is as follows: it uses an acceleration sensor to calculate the vibration from the road to the car, while the control computer analyzes road noise.
“As its computation and signal transfer speeds are optimized, it only takes 0.002 second to analyze the noise and produce an inverted soundwave, generated by the DSP (Digital Signal Processor). The microphone constantly monitors the road noise cancelation status, and sends the information to the DSP. RANC is able to conduct accurate noise analysis and rapid computation to combat road noise for the driver’s seat, the passenger seat and rear seats separately.”
According to Hyundai, RANC can reduce in-cabin noise by 3 db, which in turn means that the Group could potentially decrease the amount of unsprung weight in a car by using fewer sound-insulating parts and dampers.
This technology was developed with future vehicles in mind. As internal combustion models get phased out, vehicle noise will primarily come from three sources: powertrain, road and wind – but since electric and fuel cell vehicles make almost no powertrain noise, quieting road and wind noise will become imperative.