איך מיצרים רכב שקט?עם רעש מהרמקולים

[LotusElise]

http://www.channel4.com/apps26/4car/jsp/main.jsp?lnk=211&id=6192

 

A new 3.0-litre V6, fitted to the Accord-based Honda Inspire for the Japanese domestic market, features the anti-noise control pioneered by Lotus in the 1980s. It's one of the first production uses of the technology that Lotus sold to Japan, which has lain largely hidden ever since.

 

The Inspire's V6 engine switches to a three-cylinder mode when idling or under light load, achieved by deactivating the valves of the other three cylinders. This reduces pumping losses, by making fewer cylinders work harder, and thus improves fuel efficiency.

 

Trouble is, a three-cylinder half-a-V6 produces vibrations not fitting for an engine that's meant to be refined. Honda uses two solutions: an 'active engine mount', designed to compress and extend in concert with the engine's movements thus ensuring that these movements are absorbed before they can excite the Inspire's structure, and 'active noise control'.

 

This system works out what noise frequency needs to be attenuated by monitoring the engine speed and resultant noise pulses. It then feeds that frequency through the car's front and rear loudspeakers but in the opposite wave-form phase, thus cancelling the noise. Two microphones, one in the front of the cabin and one in the back, monitor the cabin noise levels and instantly update then out-of-phase signal as required to keep the cabin quiet.

 

4CAR has sampled the system, and can confirm that it works. The Inspire is indeed an eerily quiet car, and its occupants are entirely unaware that sometimes the engine is using just half its cylinders.

[תומR]

wow.

 

that was very interesting.

 

now i can sleep tight,knowing about this silent engine.

 

 

 

 

zzzzzzz.............

[nirtal]

שיתקינו את זה במכוניות החדשות של אלפא-רומיאו ופרארי.

יש תלונות של לקוחות על כך שהמכוניות האלו תמיד היו נורא רועשות

ויש להן צליל מעצבן

אגב, זה ממש לא חדש. דווח על הפטנט הזה כבר לפני כמה שנים.

וכנראה לא היו לו דורשים.

[LotusElise]

http://www.channel4.com/apps26/4car/jsp/main.jsp?lnk=211&id=6192

 

features the anti-noise control pioneered by Lotus in the 1980s. It's one of the first production uses of the technology that Lotus sold to Japan, which has lain largely hidden ever since.

 

 

nirtal

כתוב פה שלוטוס מכרו את הפטנט ליפנים בשנות השמונים.