muri fabrication biomimetic robots - onr site visit - august 9, 2000 h. kazerooni human engineering...
Post on 22-Dec-2015
214 views
TRANSCRIPT
MURI
Fabrication
Biomimetic Robots - ONR Site Visit - August 9, 2000
H. Kazerooni
Human Engineering Laboratory (HEL)
University of California at Berkeley
ONR Site VisitAugust 9, 2000
MURI
Fabrication
Biomimetic Robots - ONR Site Visit - August 9, 2000
Topics
1. Ground Reaction Force Control2. Frequency Matching Control
EXAMPLE
a
b c
d
f
g
Path Generation
MURI
Fabrication
Biomimetic Robots - ONR Site Visit - August 9, 2000
Power Terrain
• One motor powers all legs
MURI
Fabrication
Biomimetic Robots - ONR Site Visit - August 9, 2000
Flexible Feet Construction
• Shape Deposition Modeling (SDM)
• Simple Spring Legs Control system is embedded in hardware (Elasticity, Damping, and Mass of Legs)
2
34
1
2
3
4
1 2
3
4
MURI
Fabrication
Biomimetic Robots - ONR Site Visit - August 9, 2000
Frequency Matching
• Inverse Pendulum Model• Frequency of Walking (pendulum) α
Natural Frequency of Leg (spring)• In fact, for cockroach,
Freq. of Walking ≈ fn of 3 legs / 3 ≈ 14Hz
Trajectory of center of mass
MURI
Fabrication
Biomimetic Robots - ONR Site Visit - August 9, 2000
Mechanical Walker
MURI
Fabrication
Biomimetic Robots - ONR Site Visit - August 9, 2000
MURI
Fabrication
Biomimetic Robots - ONR Site Visit - August 9, 2000
MURI
Fabrication
Biomimetic Robots - ONR Site Visit - August 9, 2000
MURI
Fabrication
Biomimetic Robots - ONR Site Visit - August 9, 2000
Ground Reaction Force Control
The only external force on a walking machine is imparted by the ground.
Large Ground Reaction Forces lead to large acceleration and large speed
Considering Newtonian Mechanics, zero Ground Reaction Forces lead to zero motion (f = m α)
MURI
Fabrication
Biomimetic Robots - ONR Site Visit - August 9, 2000
Infinitely Rigid GroundGround Reaction forces = f (T1, T2)
A leg during stance phase
MURI
Fabrication
Biomimetic Robots - ONR Site Visit - August 9, 2000
Zero Stiffness GroundGround Reaction forces = 0
A leg during swing phase
A leg during swing phase does not contribute to motion of the machine.
MURI
Fabrication
Biomimetic Robots - ONR Site Visit - August 9, 2000
Actual GroundGround Reaction Forces = f ( T1, T2 and K)
A leg during stance phase
The fundamental method of creating locomotion for the
walking machine is the generation of appropriate
ground reaction forces on the machine leg that is in contact with the ground, not the leg
which is swinging; in fact, the leg during the swing phase
should not be powered to save
energy.
MURI
Fabrication
Biomimetic Robots - ONR Site Visit - August 9, 2000
The Ground Reaction Forces are the “Actuators” of a Walking Machine
MURI
Fabrication
Biomimetic Robots - ONR Site Visit - August 9, 2000
MURI
Fabrication
Biomimetic Robots - ONR Site Visit - August 9, 2000
MURI
Fabrication
Biomimetic Robots - ONR Site Visit - August 9, 2000
W
ηW
The Horizontal Ground Reaction Forces are controlled to be larger than ηW
MURI
Fabrication
Biomimetic Robots - ONR Site Visit - August 9, 2000
MURI
Fabrication
Biomimetic Robots - ONR Site Visit - August 9, 2000
Electronic Schematic
MURI
Fabrication
Biomimetic Robots - ONR Site Visit - August 9, 2000
ηW C
os () +
W Sin (
)
The Ground Reaction Forces must be controlled
to be larger than ηW Cos () +W Sin ()
Inclined Maneuvers
MURI
Fabrication
Biomimetic Robots - ONR Site Visit - August 9, 2000