November 11, 2019
Hyundai Motor Develops World’s First Road Noise Active Noise Control Technology
Hyundai Motor today announced the development of the world’s first Road Noise Active Noise Control (RANC) system. The first-ever system dramatically reduces noise within the cabin of a vehicle. RANC builds on Hyundai’s current Active Noise Control (ANC) technology, actively reduces noise by emitting soundwaves inverted to incoming noise. ANC is a software-driven technology that analyses the in-cabin sound to decrease engine and road noise, versus than the passive method of blocking noise through sound insulation. The existing noise insulation method involved sound insulations and dynamic dampers, which not only increased weight but also failed to block the buzzing infrasound completely.
In contrast, ANC utilizes much lighter parts like microphones and controllers to control the noise and reduces infrasound more efficiently. The technology is already available in some Hyundai Motor Group vehicles.Using an acceleration sensor, RANC calculates the vibration from the road to the car and 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.
Based on tests evaluating road surface, vehicle speed, and different seating positions, RANC was able to reduce in-cabin noise by 3dB. That 3dB level is roughly half the noise level as compared without RANC. Hyundai Motor Group went through six years of research and development for the mass production of RANC. Hyundai Motor Group has completed domestic and American patent application about the location of sensors and signal selection method, the core technology of RANC.The technology will begin to be applied to an upcoming Genesis model.