Lab Presentation 12/10/2010

Safer Human Robot Interaction through Compliance in Design Compliance via pneumatic actuators – Inertia reduction – Inertia decoupling Compliance via soft covering – Peak force reduction – Capacitative sensing skin Research Goal – Investigate these effects on impact forces ->injury

Robot arm Target

System Equations of Motion VariableDefinition k int Interface stiffness kmkm Muscle stiffness f(pressure) kpkp Controller stiffness Ɵ1Ɵ1 Arm angle Ɵ2Ɵ2 Head mass angle L2L2 Pendulum length M head Target mass L link Length of arm link M arm Arm mass

Effect of Stiffness Source Stiffness sourceLow FreqMedium FreqHigh Freq Motor PAMS Springs (expected) 6 Hz30 Hz Test Conclusions Mini does not increase peak forces significantly while vastly improving performance Pressure has little effect on peak forces

Limitations Fragile One of kind Limited travel Limited end tip velocity (0.5 m/s)

Goals Does joint stiffness effect collision? Can skin sensor pick detect collision?

Distal link Torque spring JR3 sensor Piece of tape

Cushion layer shield Sensor strip

Preliminary Results 2 m/s, k = N mm/deg2 m/s, k = N mm/deg

JR3 Data 2 m/s, k = N mm/deg2 m/s, k = N mm/deg

To do: Find optimal frequency division – Noise vs response Improve experimental setup – Ensure configuration – Stiffen target – Find optimal skin thickness