The University of Adelaide Copyright © September, 2005 Slide Number 1/43 Robotic Violin Player Project No. 395 Team Members: Boon Yao Hong, Joshua Chia, Chin Hooi Lee, Beinjy Lim Supervisor: Dr. Frank Wornle Mechatronics Honours Project 2006

The University of Adelaide Copyright © September, 2005Slide Number 2/43

The University of Adelaide Copyright © September, 2005Slide Number 3/43

The University of Adelaide Copyright © September, 2005Slide Number 4/43 Seminar Outline  Introduction  Background  Project Goals  Design overview  Bowing mechanism  Fingering mechanism  Control system overview  Summary  Conclusion  Questions

The University of Adelaide Copyright © September, 2005Slide Number 5/43 Background – The Violin  Smallest and highest pitch bowed string musical instrument  Four strings G, D, A, E  Right hand bowing  Left hand fingering  Human intelligence and expression  Various bowing styles  Vibrato – pitch of note varies in pulsating rhythm Audio sample of violin sound

The University of Adelaide Copyright © September, 2005Slide Number 6/43 Background – The Violin (Wikipedia 2006)

The University of Adelaide Copyright © September, 2005Slide Number 7/43 Background – The Violin (Menuhin et al. 1976)

The University of Adelaide Copyright © September, 2005Slide Number 8/43 Background  Gulbransen Virtuoso Violin (QRS Music Technologies 2005)  “KANSEI” violin playing robot by Shibuya Labs of Ryukoku University (Shibuya Lab. 2006)

The University of Adelaide Copyright © September, 2005Slide Number 9/43 Background (Beyond Tomorrow 2006)

The University of Adelaide Copyright © September, 2005Slide Number 10/43 Project Goals  Design and build a robotic system capable of playing the violin to a given set of musical notes.  Mechanical bowing system  Mechanical fingering system  Control system

The University of Adelaide Copyright © September, 2005Slide Number 11/43 Current Design

The University of Adelaide Copyright © September, 2005Slide Number 12/43 Mechanical design of bowing arm  Major aspects  Movements  Motors selection  Motors placement  Material used  Pulleys  Gears  Frame

The University of Adelaide Copyright © September, 2005Slide Number 13/43 3 degree of freedom required  Lifting motion (Rotational motion)  Tilting motion (Rotational motion)  Bowing motion (linear motion)

The University of Adelaide Copyright © September, 2005Slide Number 14/43 Lifting Motion

The University of Adelaide Copyright © September, 2005Slide Number 15/43 Tilting Motion

The University of Adelaide Copyright © September, 2005Slide Number 16/43 Bowing motion

The University of Adelaide Copyright © September, 2005Slide Number 17/43 Motors  DC motor (Bowing)  4.5V – 15V  Gearbox combination (50:1)  Torque – (mNm)  Speed – 252 (R.P.M)  Weight – 156 (g)  Size – 32.5 x 90 x 30 (mm³)  Required torque – 87.5 (mNm)  Required speed – 239 (R.P.M)

The University of Adelaide Copyright © September, 2005Slide Number 18/43 Motors  Servo Motor x2  4.8 – 6V  Torque – 1000(mNm)  Speed – 0.2sec / 60deg  Weight – 10 (g)  Size x 26.5 x 51.5mm (L x W x H) Required Torque – 700 (mNm) Required Speed – 0.63sec / 60deg

The University of Adelaide Copyright © September, 2005Slide Number 19/43 Motors placement  All motors are closely arranged.  Wiring  Ease of isolating noise  Motors are placed at one end of a pivot point  Reduce load of servo motor (lifting motion)

The University of Adelaide Copyright © September, 2005Slide Number 20/43 Pulley  Center of string is screwed onto the pulley to prevent slip while the pulley turns  String is spooled on in both clockwise and anti-clockwise direction.

The University of Adelaide Copyright © September, 2005Slide Number 21/43 Gears  Additional torque  Gear ratio – 1:3  Torque – 3 times larger  Provide clearance  Sufficient space to mount DC motor and Servo motor

The University of Adelaide Copyright © September, 2005Slide Number 22/43 Frame  Adjustable  Portable  Made of Aluminium

The University of Adelaide Copyright © September, 2005Slide Number 23/43 Mechanical design of fingering system  Overall function outlines  Analysis of design  Motor selection

The University of Adelaide Copyright © September, 2005Slide Number 24/43 Why 6 fingers?

The University of Adelaide Copyright © September, 2005Slide Number 25/43 Overall function outlines  Distributes pressure evenly  Latch and release fingering actuation  Positioning of fingering  Control of system actuation

The University of Adelaide Copyright © September, 2005Slide Number 26/43 Analysis of design  Latch and release mechanism  Bracket supports the neck of the violin  Lever bar pushes the fingering bar vertically downwards  Spring returns the fingering bar to its initial position Rubber Lever Fingering bar Spring

The University of Adelaide Copyright © September, 2005Slide Number 27/43 Analysis of design  Positioning of the fingering mechanism  Guiding rods  Grub screws

The University of Adelaide Copyright © September, 2005Slide Number 28/43 Motor selection  Linear solenoid, pneumatic actuation solenoid and stepper motor are considered  M42SP-5 Stepper motors (18V)  Holding torque mNm  Step angle – 7.5º/step  Coil DC resistance - 100Ω/phase ±7%  Max pull-out pulse rate – 445pps  Max pull-in pulse rate – 435pps

The University of Adelaide Copyright © September, 2005Slide Number 29/43 Control System

The University of Adelaide Copyright © September, 2005Slide Number 30/43 Control System

The University of Adelaide Copyright © September, 2005Slide Number 31/43 Control System of the Bowing Motion  The bow should be able to follow prescribed velocity profiles thereby allowing the violin system to play at different timings, tempos and rests

The University of Adelaide Copyright © September, 2005Slide Number 32/43 Control System of the Tilting and Lifting Motion  Servo motors are controlled by Pulse-width Modulation (PWM)  Duty cycles correspond to the angle of the servo motor

The University of Adelaide Copyright © September, 2005Slide Number 33/43 Control System of the Fingering Motion  Stepper motor is programmed to turn in clockwise and anti-clockwise directions  Clockwise motion to press and latch the finger onto the strings  Anti-clockwise motion to release the finger to original position

The University of Adelaide Copyright © September, 2005Slide Number 34/43 Control System of the Fingering Motion PulsesGateDirection pin Trigger

The University of Adelaide Copyright © September, 2005Slide Number 35/43 Teaching the System to Play Music  Involves 2 steps 1.Find parameters of the bowing and fingering mechanism to play each music note 2.Assign those parameters to each music note e.g. C # =T36 L26 B2 F3 e.g. C # =T36 L26 B2 F3  T36 = tilting at the angle of 36 degrees  L26 = lifting at the angle of 26 degrees  B2 = bowing speed  F3 = finger No3 is activated

The University of Adelaide Copyright © September, 2005Slide Number 36/43 Teaching the system to play music

The University of Adelaide Copyright © September, 2005Slide Number 37/43 Playing the Music  Send a series of music notes to the micro controller  e.g C # DAGF #

The University of Adelaide Copyright © September, 2005Slide Number 38/43 Current Work  Successful in achieving:  Effective and cost efficient design  The parameters of the bowing mechanism to play each string Future Work  Aims yet to achieve:  Further programming for the fingering actuation  An algorithm that can read a series of musical notes and the robot could run accordingly

The University of Adelaide Copyright © September, 2005Slide Number 39/43 Extended goals  Digital signal processing  Generate vibrato  Expression and sensitivity

The University of Adelaide Copyright © September, 2005Slide Number 40/43 Conclusion  Robotic system capable of playing the violin  3 main systems  Achieve majority of fundamental goals for project

The University of Adelaide Copyright © September, 2005Slide Number 41/43 Acknowledgements  Dr. Frank Wornle  Project Supervisor  Mr. Silvio De Ieso  Electronics and Instrumentation  Mr. George Osborne  Mechanical Design

The University of Adelaide Copyright © September, 2005Slide Number 42/43 List of references  Beyond Tomorrow 2006, Pianola Violin, Australia, viewed 4 th September 2006,  Menuhin, Y, Primrose, W & Stevens, D 1976, Violin and Viola, MacDonald and Jane’s, London.  QRS Music 2005, The Virtuoso Violin, USA, viewed 4 th September 2006,  Shibuya Laboratory 2006, Violin Playing Robot, Japan, viewed 4 th September 2006,  Wikipedia Free Encyclopedia 2006, Violin, California, viewed 4 th September 2006,  Shibuya Laboratory 2006, Violin Playing Robot, Japan, viewed 4 th September 2006,

The University of Adelaide Copyright © September, 2005Slide Number 43/43 Questions?