Lab meeting update
description
Transcript of Lab meeting update
Lab meeting update
Samson Phan Sept 24, 2010
In the beginning…
Conclusions
• HIC numbers associated with collisions are insufficient to cause concussions– HIC & concussions: are they really a good
measure?
• Automotive Laceration scales are too insensitive.
• Automotive based injury indices insufficient for robot human collisions
So we built a model…
02
46
810
0
0.05
0.110
4
106
108
1010
velocityrobot radii
Ma
teri
al p
rop
ert
y fu
nct
ion Wassink et al
µ = 0.4
µ = 0.8
Bruise Volumes
And a sensor…
Sensor ResultsNormal 30 degrees
68.2 68.25 68.3 68.35 68.4 68.45 68.5 68.55
0
50
100
150
200
250
300
350
400
450
data1
data2
data3
data4
146.05 146.1 146.15 146.2 146.25 146.3 146.35
0
200
400
600
800
1000
data1
data2
data3
data4
Why similar patterns?Sensors are spaced too far?Sensors are not being sampled quickly enough?
Capacitance Leakage?
225 230 235 240 245 250
-100
-50
0
50
100
150
200
250
300
Capacitance Leakage?Sensor # No touch
Freq (KHz)Finger TouchFreq (KHz)
Pen TouchFreq (KHz)
Delta between Finger and Pen
1 640 507 480 27
2 663 542 490 52
3
4 809 700 580 120
5 720 600 500 100
6 960 740 730 10
7 760 645 600 45
8 865 680 640 40
Inertia Coupling
Frequency Stiffnes Experimental (by Sami Haddadin)
Theory
High High Ilower Ilower+xIupper
High Low Ilower Ilower
Low High Ilower+Iupper Ilower+Iupper
Low Low Ilower+xIupper Ilower+xIupper
0<x<1
Questions
• Why the difference between theory and experiment (if it really exists)– Zero Order Hold? Backlash?– Is there a response rate threshold that is deleterious?– What happens when reaction time is less than collision
time?• Does the source of stiffness matter?
– Preliminary results suggests so– How do hydraulics/pneumatics (PAMS) behave?
(0<x<1)• Initial operating pressure variations
Future Work
• Conduct Collision Tests with Adept Setup to see varying effects of stiffness on Inertia coupling
• Use HSR arm setup to explore stiffness source effects. – Pneumatics, electromagnetic
motors
Experimental Setup
Adept Setup HSR Setup
How does stiffness affect collision?
Want to know more?HSR meeting @4 pm in Gates
GOOD LUCK SAL!