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
groundreactionforce
forceexerted byleg
groundreactionforce
shor
teni
ng
body
Force sensor
Forcing the issue
Ground reaction forces vary with time.
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
sarcomere
Muscles are more than motors
strain
stre
ss
strain(length/length)
stress(force/area)
stim
extensor
flexor
3) measureforce
2) stimulateIn phase
1) oscillatemuscle
Muscles are more than motors
activatehere
strain
stre
ssslope = stiffness
changingactivation
phase
Muscle do not have to work as motors to function.
Muscles are more than motors
Muscles are more than motors
Physeter macrocephalus (Sperm Whale)largest toothed whale
20 meters long50,000 Kilograms70 year lifespan
pan-global distribution200,000 population
Central Nervous System
Central Nervous System
Central Pattern Generator
motornerve
sensorynervedorsal
ventral
Musculoskeletal System
sarcomere
Musculoskeletal System
myosin power stroke = 10 x 10-9 Mwhale length = 60 M
~1010 ratio
Musculoskeletal System
Musculoskeletal System
Musculoskeletal System
Musculoskeletal System
myoglobin
Musculoskeletal System
Indohyus, 48 mya
Musculoskeletal System
Musculoskeletal System
Musculoskeletal System
HydrodynamicForce
Velocity, U
Force = ½ C S U2 C = force coefficient of flukeS = Surface area of flukeU = velocity = density of sea water
Hydrodynamics
path of fluke
thrust
+lift
thrust
-lift
Hydrodynamics
thrust
+lift
Emits sound at 230 decibels!
Sensory Systems
Can dive to 3 Kilometers
Higher Order Locomotion
Lecture 1: Overview on Animal Locomotion