Trumpet Playing Robot... how does it work?

[corrado33]

See this video...

(Edit, second video in series on this page, or youtube "trumpet playing robot")
http://www.wonderhowto.com/wonderment/merry-christmas-bots-play-you-a-song-0113713/

Actually it's the second video... don't know where the link for that one is, but it's right below this one, it's hard to miss, just click on it.  (Although the first one is robot related too!)

Anyway, how do these work.  If anyone has every played a brass instrument, you have to make your lips vibrate to make the instrument work.  (Yes yes kinda like a motor boat)  So, how do the robots achieve this?  It's just a regular trumpet, you can tell cause in other videos the bot actually brings the trumpet to it's mouth, and you can see the mouthpiece. 

Also, you can change the note by simply vibrating your lips differently, in fact that's what you have to do to get to different octaves.  I'm very intrigued...

So, any ideas for how that works?

[SmAsH]

I assume it has an air pump in there with a seal around the "mouth" of the robot and it blows through the
trumpet. That trumpet changes its notes using the "buttons" on it, there are three.
If you look closely you can see the robots hand playing it. Most noticeable at the start.

[corrado33]

Well yeah I knew it blew air into it..., and there are only a certain numbers of notes you can get from three buttons...  BUT if you simply blow into a trumpet nothing happens.  It just sounds like hissing air.  That's why  you have to vibrate your lips.  And that's what I'm wondering about.

[T0110100101101101K]

All they have to do is vibrate the air entering the trumpet at the frequency they want to influence the pitch.  Lips do this for humans, but my guess is that they used some sort of flapper inside the mouth of the robot.

Here is a better view of a couple Aerophone playing robots.  Toyota's Robot Quartet Band.  You can see there is nothing protruding from the mouth, and the orifice is smooth.

[TrmptPhysics]

Resurrecting a very old thread here, but I was researching this topic and have some new information.

It was said, "the lips vibrate/buzz to produce the sound, so how do the robots make sound?" There is a fundamental property of physics that must be understood to know HOW the lips vibrate. When a trumpet player plays a note, they DO NOT make their lips buzz. Their lips vibrate in sympathy with the motion of the air. Meaning that when air is passed through the lips and into the trumpet, a standing wave is created within the instrument, and the lips vibrate in sympathy with the motion of the air. In a standing wave, there are two points of maximum compression/tension created, and these are called nodes. The wave moves between these two point, and depending upon the length of that wave, you will get higher and lower notes. As the wave/air bounces back to the lip, they vibrate and make tone.

Now, a trumpet players lips vibrate faster or at a greater rate when the pitch is higher. This is actually a result of the air moving faster to create the higher tones. There is also an aperture in the lips through which the air moves, and this changes size in relation to the pitch and speed of the air. Basic take away, lower notes, slower air. Faster notes, faster air. Lower notes, a slower rate of sympathetic vibration in the lip and a more open aperture. Higher notes, a faster rate of sympathetic vibration and a smaller aperture.

The way this robot works; a synthetic mouth is created. Most likely using latex and a basic "dental structure." The mouthpiece is placed on these "lips," and internal air compressor moves air through the lips and into the trumpet and tones are produced. One of the most important things to remember is that the trumpet is a static instrument, it cannot produce sound with out air and sympathetic vibrations from the lips. If you were to take the instrument away from the robot's "mouth" and allow the air to continue moving through the robot's "lips," you'd simply hear a hissing sound. Again, the vibration is created in conjunction with the motion of the air and the standing wave within the instrument.

So, basically the robot "blows" air through the trumpet the same way a trumpet player does. The difference is there is no muscle structure or creative process in the "mind" of the robot, and therefore it cannot manipulate it's sound to produce anything beyond a very basic tone. I hope this helps those of you curious about the trumpet robot, and I'd love to know if there are more questions! If we really want to go down the rabbit hole, we can talk about the uproar this little guy created within the trumpet pedagogy community at the time of his release

[Filip]

Can you text to me I want to go down to the rabbit hole like you said

[piesobese]

All they have to do is vibrate the air entering the trumpet at the frequency they want to influence the pitch.  Lips do this for humans, but my guess is that they used some sort of flapper inside the mouth of the robot.

Here is a better view of a couple Aerophone playing robots.  Toyota's Robot Quartet Band.  You can see there is nothing protruding from the mouth, and the orifice is smooth.

I was truly enlightened with this new perspective.