Transcript Forcing the issue

Lecture 1: Overview on Animal Locomotion
Control systems are closely coupled
(controller)
=
(plant)
Feedforward Control
Control systems are closely coupled
=
Control systems are closely coupled
Control systems are closely coupled
Feedback Control
Forcing the issue
body
ground
reaction
force
ground
reaction
force
force
exerted by
leg
Forcing the issue
Ground reaction forces
vary with time.
Force sensor
Forcing the issue
Forcing the issue
=
=
Forcing the issue
Forcing the issue
Leaving the straight and narrow
Leaving the straight and narrow
Leaving the straight and narrow
Muscles are more than motors
Muscles are more than motors
sarcomere
extensor
stress
Muscles are more than motors
activate
here
flexor
strain
3) measure
force
strain
(Dlength
/length)
stress
(force
/area)
stim
2) stimulate
In phase
1) oscillate
muscle
Muscles are more than motors
Muscle do not have to work as motors to function.
slope = stiffness
stress
changing
activation
phase
strain
Muscles are more than motors
Physeter macrocephalus (Sperm Whale)
largest toothed whale
20 meters long
50,000 Kilograms
70 year lifespan
pan-global distribution
200,000 population
Central Nervous System
Central Nervous System
dorsal
sensory
nerve
Central Pattern
Generator
ventral
motor
nerve
Musculoskeletal System
Musculoskeletal System
sarcomere
Musculoskeletal System
myosin power stroke = 10 x 10-9 M
whale length = 60 M
~1010 ratio
Musculoskeletal System
Musculoskeletal System
Musculoskeletal System
myoglobin
Musculoskeletal System
Musculoskeletal System
Indohyus, 48 mya
Musculoskeletal System
Musculoskeletal System
Hydrodynamics
Hydrodynamic
Force
Velocity, U
Force = ½ C S U2 r
C = force coefficient of fluke
S = Surface area of fluke
U = velocity
r = density of sea water
Hydrodynamics
+lift
path
of fluke
+lift
thrust
thrust
thrust
-lift
Sensory Systems
Emits sound at 230 decibels!
Higher Order Locomotion
Can dive to 3 Kilometers
Lecture 1: Overview on Animal Locomotion