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William Schattevoet
David Duwaer
Eric Backx
Arjan de Visser


Main page

Working principle of the violin and predicting it’s behavior

Ways to exite the string

Hardware Design

Software Design (Quantifying the signal we want to see)

Realisation and Proof of concept

Patent Research

Background information: Interview with Hendrick Zick



This chapter is about the recommendations that we, as the First Viotar project Group have for the next Group that is going to work on this project. Since we already have almost 5 months of experience with the Viotar and know everything that happened during the design of the current Viotar, we thought it would be a good idea to give some recommendations for the next group.

First we will have to look at what the demands where, that we stated at the start of the project. From these demands and the progress that is already made, the next steps in designing the Viotar can be determined. The demands that where set are:

  • The sound had to be generated by the strings and after that it gets electronically processed.
  • All the strings can be excited in every combination ore at the same time.
  • The amplitude of the note can be varied from the minimum to the maximum during the excitation of the string. The minimum and maximum are set by the bowing pressure and force at which Helmholtz is reached.
  • The Viotar must be capable of playing 18 different notes each second on one string.
  • The Viotar must be capable of playing 18 different notes on different string separately.
  • The string is always excited in such way that Helmholtz occurs, regardless of the player’s skill.
  • The Viotar is also playable as a normal guitar. Therefore is must be possible to excite the string manually on the Viotar.
  • The Viotar’s tone reach has to be from base to soprano, the lowest note has to be lower than E4, and the highest note has to be higher than A5.

What we did achieve:

  • We made a Viotar, which has 2 strings that can already be bowed electrically. The Viotar we made can also be upgraded to 6 string fairly easy, this only takes some new money funds in order to pay for the parts.
  • All strings can be bowed simultaneously or in every combination.
  • The sound is generated by the strings and is afterwards electronically processed.

What we almost achieved.

  • The Viotar can still be played as a normal guitar, this is not as easy as it should be.
  • We do have a good system that can make sure that Helmholtz occurs, this doesn’t work on the Viotar though.
  • The tone reach can be achieved, in order to do so all the strings need to be placed and equipped with a bowing device.

What we cannot achieve:

  • We probably cannot bow 18 different notes in one second.

This gives us the following recommendations:

  • The Viotar, ore its replacer, should have 6 bowing devices and all its strings attached. We could have achieved this but we did not have enough cash funds to do so.
  • The actuators and electro motors need encoders in order to make sure that the bow speed and bow force stay constant.
  • The regulation program needs to be translated to c, or another language that cooperates with matlab, in order to make it work on the Viotar.
  • Test need to be done in order to check whether the Viotar can or cannot play 18 different notes in one second with the equipment it has now. The bowing belts also need to be tested, they are probably not very suitable for the job. If the Viotar, for some reason, would fail these test, a different design has to be made that passes the tests and meets the requirements.
  • A right hand interface has to be made.
  • A custom body needs to be designed in order to fit everything inside the body itself. And this body needs to ensure that the Viotar is playable as a guitar.