Haptic Display Device John MacDuffie Woodburn Michael Vitale Thomas Santoro – Team Leader Villanova University

Agenda Purpose Theory Design Testing Results Conclusions Acknowledgements Questions

Purpose Medical Field Console Games Visually Handicapped

Virtual Reality Block Diagram

Theory, Active vs Passive Active Haptic Devices utilize actuators forces are actively generated by actuators Phantom Haptic Device

Theory, Active vs Passive Passive Haptic Devices the user has to apply forces to feel any resistances Programmable Tactile Array (TiNi Alloy)

Theory Magnetorheological (MR) fluids Composed of micron-sized, magnetizable particles immersed in water or different synthetic oils (Lord Corporation)

Theory Magnetorheological (MR) fluids when a magnetic field is applied (Lord Corporation)

Theory Magnetorheological (MR) fluids Exposure to an external magnetic field, induces in the fluid, a change in rheological behavior (Lord Corporation)

Theory Device is similar to a damper Cylinder is used as a core for the coil of the electromagnet Electrical current is applied to the coil An electromagnet changes the density of the MR fluid Stiffening of the fluid changes the resistance felt by the user as he/she.

Design Requirements and limitations: Heat generation by the electromagnet Creating an electromagnet that will affect the viscosity of the MR fluid Simple Design for manufacturing

Preliminary Designs

Preliminary Designs

Equilibrium State of Design Final Design Equilibrium State of Design Inside View Outside View

Final Design Design Compressed Inside View Outside View

Final Design Schematic of a single unit Schematic of an array of pins

Final Device

Device Working As weight is applied the pin moves down with no applied current As weight is applied it is harder to move the pin down as the applied current is increased

Testing Achieve a characterization that will give the input-output relationship from the current/voltage to the resistance offered. This information can be used for resistance generation to provide haptic interactions.

Testing Testing Apparatus Rotational Displacement Sensor Force Sensor Haptic Device Power Source Movable Platform

Testing Procedure Tested the device at increments of 0.25 volts ranging from 0 to 5.0 volts. For the first run at 0 volts Applied 0 volts to the coil Started the Data Studio Program Gradual raised the device up into the force sensor Stopped the Data Studio Program Repeat in increments of 0.25 volts till 5.0 volts

Testing Procedure Collected the data into three graphs for each increment of voltage Applied Force versus Time Applied Voltage versus Time Applied Force versus Applied Voltage Based upon Applied Force versus Applied Voltage, can find the resistive force Each increment of applied voltage will characterize the resistive force

Testing Parameters Need to measure the applied force to the pin for a constant applied voltage, Fv Need to measure the displacement of the pin for a constant applied voltage, Dv Need to record the applied voltage for each trial

Data Y=0.7936x3-2.0838x2+2.9265x+0.5551

Data Y=-9.4759x3+31.597x2-15.525x+1.038

Data

Results Y=0.0625x3-0.2698x2+0.8014x+0.1248 Applied Voltage (Volts) Applied Force (Newtons) 0.01 0.25 0.46 0.5 0.48 0.75 0.63 1 0.7 1.25 0.77 1.5 1.75 0.92 2 1.35 2.25 1.03 2.5 1.41 2.75 1.46 3 1.95 3.25 2.14 3.5 2.47 3.75 2.56 4 2.69 4.25 3.62 Y=0.0625x3-0.2698x2+0.8014x+0.1248

Conclusion Accomplished our goals Able to Characterize the MR fluid for the use of Haptic Display Device Simple part design for mass production

Acknowledgements Professor Dougherty - Advisor Professor Rungun Rama Nathan Professor Kroos Chris Townend and Zack Nowosad Art Viescas and Professor Vassiliou

Thank you for your time and have a good day Questions? Thank you for your time and have a good day