BMW engineers have submitted a new patent that pursues an unusual approach for a rather uncomplicated problem: how to make electric cars so blunt so that pedestrians can hear them. Most EVS and hybrids currently use external speakers to emit noises at low speeds that are often required by law to prevent silent vehicles from being surprising. But BMW’s patent suggests deleting these speakers completely.
The idea: make noises with what is already there
Instead of adding speakers, the patent describes a method for using existing electric motors in the car – such as those that supply their windows, windshield wipers or tailgers with electricity – to create sound. By pulsating these engines in a certain way, they were able to produce audible tones. BMW even suggests combining the operation of several engines to create layered or directed noises that can then be reinforced with special housings or resonators.
In theory, it is a clever problem bypass. The speakers take up space, add a little weight and require cabling and assembly points. If you can use the hardware already installed, this is less complexity in the system.
The catch: it’s a bit of a distance
This idea falls apart in the practical problems. First, most of these accessory engines seem to be buried deep in doors or hatches – no ideal places for the projective sound. Second, they were not designed so that they primarily make noises. Therefore, they require that they require additional housings or resonators loudly (and in the correct frequencies) to compensate for space or weight savings.
Compared to the implementations of others, the idea of BMW goes one step further by using actual work components to do the job. But instead of expanding the driving experience, the goal here is strictly functional: to warn others that a vehicle is nearby.
Just because a patent was filled does not mean that BMW will decide this implementation. Let us take this for the time being with a grain of salt.
[Source: WIPO.int via CarBuzz]
