Engine noise cancellation for cars implemented in software

October 18, 2013 // By Christoph Hammerschmidt
A silent car environment with no noise from engine and gearbox, allowing drivers and passengers to enjoy their music while on the road, is the objective of a software package from QNX.

With its noise cancelling approach, QNX addresses OEMs and suppliers, not end customers. QNX Acoustics for Active Noise Control is a purely software-based solution that runs on the car radio - that is, if this radio is implemented as a Software Defined Radio (SDR) and has an appropriate processor or DSP inside. As sensors and actuators, the system uses loudspeakers and hands-free microphones that are already available in the car. Since no additional hardware is required, manufacturers can implement this solution at significantly lower cost than hardware-based systems. QNX also claims that the results of their Acoustic for Active Noise Control are significantly better than with existing Active Noise Control solutions. In addition, a software-based solution enables much shorter design cycles - an argument that counts, in particular in the infotainment domain where a young clientele increasingly applies the same standards as for the consumer electronics in their living room - according to QNX.

The software becomes particularly relevant against the background of the recent measures from carmakers to increase engine efficiency and reduce fuel consumption: Engine downsizing is a widespread approach to make cars more "green" but the downside of downsizing is that the engine runs rougher and creates more undesired noise. Carmakers try to reduce this noise by increasing noise insulation. With the software, such costly measures become redundant, QNX claims.