There will be three main components to our design: the electromagnetic drum, the drum stick with an embedded permanent magnet, and a sensor curtain. The electromagnetic drum will consist of a ferrous, non-permanent winding core surrounded by a back iron. The purpose of the winding core and back iron will be to minimize the air gap around the electromagnet, thereby increasing the strength of the magnetic field. A cylinder magnet will be embedded in the drum stick, with an isolated pole at the tip designed to experience repelling forces when placed near the "virtual drum face". The sensor curtain will be composed of infrared emitters and phototransistor detectors to determine the speed of the drumstick and location to correlate a proper impulse response to the drum.
When playing the instrument, the user will initially select what type of drum they would like to play, be that a snare or tom tom. This will tell the controller which type of impulse to send to the electromagnet. At wil the user can change the design, and sound, of the drum.
Concept Sketch:
This was awesome, I really liked its performance at the expo. And conceptually it seems pretty easy to implement. How did you guys change the tone between the snare mode and the tomtom mode in PD? I see you used two different channels. So did you use 2 different PD patches? And could you just post a screenshot of your PD patch file?
ReplyDeleteWe actually used a free MIDI synthesizer off of the internet instead of PD. It was called Power Sequencer Plus 3.
ReplyDelete-Jonathan
How much would a larger permanent magnet in the drum stick have helped the response of the system? It was really neat feeling the impulse when you tried to hit the drum head, but it seemed that you had to line your hit up perfectly.
ReplyDelete--Colin
We really liked the idea of simulating the feel of the drum sets by the use of the magnets. It was clever to have used the magnetic property to provide the force feedback. We're interested in knowing if the team used two different force profiles for the two different sounds it produced.
ReplyDeleteA larger magnet would have certainly improved the virtual drum face's effective area. If we had the time and resources to build our own coil, we would have made it a highly eccentric ellipse or a slender rectangle. This would give a wider, more uniform magnetic field.
ReplyDeleteI had a lot of fun playing your drum. I think my comments have been echoed elsewhere but being able to "hit" a drum without automatically creating external noise could be a very useful idea to pursue. I also liked how the system was based in a grounded platform, letting you use a normal stick with only a minor alteration. Now all you need is the velocity sensor and you'll have a marketable system.
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ReplyDeleteI really enjoyed your teams project. As a drummer myself, I thought the feeling of each strike was very similar to an actual drumhead response. I like how you can select different types of drums too. This could be used as a great teaching mechanism someday. Nice work.
ReplyDeleteThis drum was really fun to play and it is particularly interesting to get the force feedback from the magnet. It's definitely felt a lot different than the one our team made since we used mechanical force as our force feedback. Good job, guys.
ReplyDeleteYour drum felt pretty nice to play with. Although a few times I was able to cheat your optical sensors and generated beats without intending to hit the pad, but the feel was rewarding. The haptic feel of the impulse of the drum beats went pretty well.
ReplyDeleteCan you let me have a sense of the power consumption in your electromagnets?
Amit Ranjan