News & Analysis
Delphi offers sound generator for e-cars
Christoph Hammerschmidt
2/22/2011 1:38 PM EST
With the advent of e-cars the problem arises that approaching electric cars are not noticed by other traffic participants such as pedestrians and cyclists. Automotive tier one Delphi has developed a sound generator that facilitates the recognition.
According to Delphi, the generator is available in two different versions. Due to their programmability they can meet future legal requirements even though the related discussion has not been completed yet.
The generators automatically are activated when the vehicle's own noises fall below a certain level, for instance because of low speed. The two versions obtainable differentiate themselves through the way the electronic vibrations are transformed into audible noise; customers can choose between a piezo-based sound transducer and an electrodynamic one.
According to Delphi, the piezo-based version weighs only one third of a conventional multi-module system, and it consumes 90 percent less energy. Its audio spectrum covers the range from 500 Hz to 10 kHz. The electrodynamic version features a broader spectrum; its frequency range goes down to 150 Hz.
Both systems are programmable; customers can generate sound sequences indicating their brand identity. They consist of a 32-bit microprocessor with flash memory and a class-D amplifier. An interface connects them to the vehicle's internal data bus. The systems are designed for operation in rough environments, Delphi said.
This article originally appeared on EE Times Europe.
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selinz
2/22/2011 2:34 PM EST
This is really dumb, if you ask me (ya, I know. You didn't). People have headphones on, etc. Why pollute the environment with sound.
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Mark Wehrmeister
2/24/2011 10:46 PM EST
What a shame. The automotive industry has finally figured out how to make the ultimate quiet car and they have to increase the cost by adding a sound generator. Hopefully, it will work using a proximity sensor that will only enable the sound when something is near the vehicle.
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DrQuine
2/26/2011 2:13 PM EST
The elegant design would be to create just the necessary sound outside while using sound cancellation to spare the driver. [I also wonder how much of this is a red herring: while I've heard blind people curse the silent EV vehicles, many other vehicles are also functionally silent when they coast slowly. I suspect the real problem is backing up up from a stationary position. The driver often has poor real visibility and the reving engine of traditional vehicles warns nearby pedestrians.]
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dck
3/2/2011 6:28 AM EST
Agree with you Mark !. Its such a shame. The Automotive industry has been working now for decades together to reduce Noise & Vibrations in the vehicles. When there is a breakthrough solution achieved, technology is now being used to create something that was originally considered as the problem.
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