1. Haptic displays and virtual mechanisms

2. Haptic Displays Man-machine interfaces, capable of reproducing forces as user’s hand; Accurately On an extended frequency range A couple of devices developed, in collaboration with the Biorobotics Lab. – UW Direct drive motors Optical analog position sensing to enhance resolution

3. Haptic displays PantoMouse Panto-Mouse 3D

4. Haptic Displays in rehabilitation Interaction with virtual objects User-designed environments Training, games, virtual mechanisms

5. Rehabilitation Rehabilitation systems Evaluation of patient’s recovery on tailored exercises

6. Virtual Mechanism   F=kx x k x I=K p x F’= K f I If K f K p =k  F=F’ Same perceived force!! Virtual mechanisms haptic displays devoted to the reproduction of the touch feedback that a user would experience when interacting with a actual mechanism Inertia, viscous friction, elasticity can be easily simulated

7. Mikey Project When playing a musical instrument, a player perceives not only the sound generated, but also the haptic interaction arising during the contact between player and instrument. The tight correspondence between acoustic response and touch response is lost in electronic instruments, in which the sound generation is related only to the speed of the key. Mikey (Multi-Instrument Keyboard) project: Virtual mechanisms to simulate three different key- operated musical instruments: Grand piano, hammond organ, harpsichord

8. Grand Piano Mechanism composed of a dozen of parts Hard to simulate in real time Different “states” of the mechanism to be modeled in the dynamic simulator Escapement Hammer flight Strimg-hammer impacts

9. Experimental Setup Keys are driven by rotational voice coils motors (low-cost, from Hard Disk Drives) Weights are added to account for lowest inertial term (flying hammer condition)

10. Experimental Setup D/A, 16 bits 44.1 kHz VCM Key A/D, 16 bits 44.1 kHz Position sensor DSP board Transcond. Amplifier Each key has a reflective position sensor, read by a 44.1 kHz, 16 bits A/D The low-cost fixed point DSP sends a current command to the motor, using a 16 bits D/A and a low-cost power amplifier

11. Dynamic simulator The dynamic simulator computes hammer position and the force to be applied to the key The first goes to the synthesizer, the second to the motor