16.423J/HST515J Aerospace Biomedical Engineering and Life Support Prof. Newman
Robot / Human Comparisons (how inhumane)
Table I presents some of the elements of robotic and animal movement systems
neatly compared for your viewing pleasure.
Table I. Comparison of Movement Control Systems in the Robot and Human
Communication
Speed
Control System
Effectors
Effector Directionality
Transmission
Degree of Freedom
Control Design
Transducers
ROBOT
wires
3 x 10
8
m/sec
computer
motors (linear)
push or pull
gears/linkages
(precise geometry
<10
closed loop
position
velocity
acceleration
HUMAN
10
5
-10
6
axons
10-100 m/sec
brain/spinal cord
400
+
muscles (non-linear)
pull only
joints/tendons
(nightmare geometry
~100
closed loop
position (Muscle spindle)
velocity (Muscle spindle)
force (Golgi Tendon
Organ)
Table II Motor Unit Properties (adapted from Henneman, 1980).
Red Muscle Fibers White Muscle Fibers
Number of motor units many few
Number of muscle fibers few many
per motor unit
Axon diameter small large
Tetanic tension small larg
Contraction speed slow rapid
Fatigue slow rapid
Metabolism aerobic anaerobic
Blood supply rich sparse