Transcript Muscle Slideshow

The Muscle Low-Down
Needs
• Controllable
– React to output from software via controller
• Fast
– Respond and recover quickly
• Provide 180° of rotation
• Behave approximately like actual muscles
• Durable
– 106 + cycles
How much contraction?
Muscle length= 10 in.
Muscle+Tendon length= 14 in.
10 in
14 in
2in
Moment arm= 2in.
After rotation the muscle have to be 6 in. long
so that the muscle+tendon length is 10 in.
(10-6)/10=40% contraction
Changing to 1 inch moment arm with 4 inches
of tendon and a twelve inch upper arm
necessitates a 22% contraction.
Air Muscles
• Pros:
– Can contract by 25% easily
– Similar to muscles in appearance and action
– Quick
• Cons:
– Complex to control: electrically actuated
valves and such
– bulky
Nitinol Muslce Wire
• Pros:
– All electrical control
– Small form
– React quickly
• Cons:
– Slow cool down time
– Can not contract more than 5% repeatedly
Air Muscle Implementation Idea
Pressure Cylinder
3-way
valve
Pressurized air
Valve
+-
From
muscle
When the pressure is turned off, the muscle can
immediately relax.
Exhaust
Muslce Wire Implementation Idea
• Make the actual length
of the wire longer
somehow so that it
contracts a greater
distance.