Our prototype is consist of the IR emitter and receivers, a wood base, wood towers for the IR sensors, an electromagnet, an Arduino Mega, an amplifier and power supplies.
The IR sensors were bought at Radio Shack and placed on the wood towers. The sensors were placed 2 inches apart from each other as seen on the pictures above. The wood towers and base were made from flat wooden panels and the laser cutter in the Autolab machine shop was used to cut the parts. The base is made of two flat wooden panels that sandwich the bottom plate of the electromagnet. By this way, the electromagnets are secured to the instrument and more professional look was achieved. Furthermore, in order to enhance the overall ergonomics of the playing drum, the base is tilted so that it faces the user. Lastly, the switch for selecting different instruments was attached to the base. The pictures below show the CAD drawing for the laser cut parts.
The electromagnet was made from a spool of insulated magnet wire. The entire spool was used as the core of the electromagnet and we used a circular pipe and a thin iron plate to minimize the magnetic field loss.
We are using one Arduino Mega board for data acquisition and control signal generation and the code is shown on another thread. The Arduino board sends out a PWM signal to drive the electromagnet and the signal is amplified by AMC 12A8 motor controller. The amplifier receives the power from four 25 V power supplies. The power supplies are connected in series and parallel to achieve both high voltage and current. Two power supplies are connected in series and so are the other two. And then the two groups of power supplies are connected in parallel. This gave us approximately 50 V to operate the amplifier and high current so that the electromagnet could generate the strong magnetic field.
The IR sensors were bought at Radio Shack and placed on the wood towers. The sensors were placed 2 inches apart from each other as seen on the pictures above. The wood towers and base were made from flat wooden panels and the laser cutter in the Autolab machine shop was used to cut the parts. The base is made of two flat wooden panels that sandwich the bottom plate of the electromagnet. By this way, the electromagnets are secured to the instrument and more professional look was achieved. Furthermore, in order to enhance the overall ergonomics of the playing drum, the base is tilted so that it faces the user. Lastly, the switch for selecting different instruments was attached to the base. The pictures below show the CAD drawing for the laser cut parts.
The electromagnet was made from a spool of insulated magnet wire. The entire spool was used as the core of the electromagnet and we used a circular pipe and a thin iron plate to minimize the magnetic field loss.
We are using one Arduino Mega board for data acquisition and control signal generation and the code is shown on another thread. The Arduino board sends out a PWM signal to drive the electromagnet and the signal is amplified by AMC 12A8 motor controller. The amplifier receives the power from four 25 V power supplies. The power supplies are connected in series and parallel to achieve both high voltage and current. Two power supplies are connected in series and so are the other two. And then the two groups of power supplies are connected in parallel. This gave us approximately 50 V to operate the amplifier and high current so that the electromagnet could generate the strong magnetic field.
Creative idea and really good construction. The final project looked pretty professional and operated well (for the most part). I was shocked and how much power you guys were able to push through the coil generate the magnetic force feedback. But it did feel amazing when it was working properly. It would have been nice to have a larger range for the drum stick but given the time and materials you guys did an excellent job.
ReplyDeleteActually we melted wires connecting the amplifier and the coil on the day of demonstration while we were setting things up. After the melting, we softened the force feedback. If we were able to supply more current safely, the feedback could have been better. Our product could only work when people were gentle with the drum stick.
ReplyDeleteI think the greatest achievement for your instrument is that you have made force sensible and correlated to the producing of sound. The idea of using sensors at different positions to detect strength and speed of the drum sticks was quite impressive for me. I think a successful force feedback has been established in your system while I was playing the drum.
ReplyDeleteI think your design is very robust. The overly large power supply next to it actually made it looked "stronger" too. The looks aside, I think strong magnetic field can interfere with other electronic devices. So, there might be a limitation on how much current you can supply. Anyway, I really liked the design.
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