Simplifying Control Through Active Tail Use · Simplifying Control Through Active Tail Use...
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x y ↵ SLIP-Model ' T x y y F ' H ' Template Model with Flywheel Agama Lizard & co. courtesy ciber.berkeley.edu Body-pitch righting Simplifying Control Through Active Tail Use Motivation • Aquatic vertebrates use tails for propulsion, but... • Most terrestrial vertebrates have repurposed their tails for roles other than locomotion. Why? Our Approach: Rebuild the solution! Mathematical Model: SLIP & Flywheel • There are some notable exceptions! Why do tails work for these animals? Through modeling, simulation and robots, we focus on the use of tails during steady-state locomotion in the sagittal plane. Cheetah courtesy CheetahsAlive.org Turning? Red Kangaroo courtesy http://www.hdNewWallpapers.com/ Steady-State Locomotion? Authors: Steve W. Heim Mostafa Ajallooeian Peter Eckert Massimo Vespignani Professor Auke Ijspeert Extended Model with Tail Coupled Control in a Nutshell Imagine you have a faucet and you want to control the water temperature as well as flow. These simple models reveal an important advantage: minimizing tail-mass greatly simplifies control and decouples body-pitch stabilization from energy-input. Our models are based on the spring-loaded inverted pendulum (SLIP) Model. We fully model body and leg dynamics, and add a joint for the tail. Our simplest model uses a flywheel centered at the body center of mass. Decoupled Control: Lifting the lever affects only flow, and turning the lever affects only temperature. Decoupled Control for the Template Model with Flywheel Control Matrix for the Flywheel model: Sparse! Control Inputs 0 B B B B B B @ ¨ x ¨ y ¨ ' ¨ y F ¨ ' H ¨ ' T 1 C C C C C C A = H (q, ˙ q ) + 0 B B B B B B B B @ sin(' H ) m s y F cos(' H ) J F +m S y 2 F 0 - cos(' H ) m s y F sin(' H ) J F +m S y 2 F 0 0 - 1 J S - 1 J S 1 m S 0 0 0 1 J F +m S y 2 F 0 0 0 1 J T 1 C C C C C C C C A 0 @ ⌧ F ⌧ H ⌧ T 1 A Accelerations Natural Dynamics Coupled Control: Turning either knob affects both the flow as well as temperature. courtesy heatAndPlumb.com
Transcript of Simplifying Control Through Active Tail Use · Simplifying Control Through Active Tail Use...
x
y↵
SLIP-Model
'T
x
yyF
'H
'
Template Model with Flywheel
Agama Lizard & co. courtesy ciber.berkeley.edu
Body-pitch righting
Simplifying Control Through Active Tail Use
Motivation • Aquatic vertebrates use tails for propulsion, but... • Most terrestrial vertebrates have repurposed their tails
for roles other than locomotion. Why?
Our Approach: Rebuild the solution!
Mathematical Model: SLIP & Flywheel
• There are some notable exceptions!Why do tails work for these animals?
Through modeling, simulation and robots, we focus on the use of tails during steady-state locomotion in the sagittal plane.
Cheetah courtesy CheetahsAlive.org
Turning?
Red Kangaroo courtesy http://www.hdNewWallpapers.com/
Steady-State Locomotion?
Authors:Steve W. Heim Mostafa Ajallooeian Peter Eckert Massimo Vespignani Professor Auke Ijspeert
Extended Model with Tail
Coupled Control in a Nutshell Imagine you have a faucet and you want to control the water temperature as well as flow.
These simple models reveal an important advantage: minimizing tail-mass greatly simplifies control and decouples body-pitch stabilization from energy-input.
Our models are based on the spring-loaded inverted pendulum (SLIP) Model. We fully model body and leg dynamics, and add a joint for the tail.Our simplest model uses a flywheel centered at the body center of mass.
Decoupled Control: Lifting the lever affects only flow, and turning the lever affects only temperature.
Decoupled Control for the Template Model with Flywheel
Control Matrix for the Flywheel model: Sparse!
ControlInputs
0
BBBBBB@
xy'yF'H
'T
1
CCCCCCA= H
(q,q) +
0
BBBBBBBB@
sin('H)
ms
yF cos('H)
JF+mSy2F
0
� cos('H)
ms
yF sin('H)
JF+mSy2F
0
0 � 1
JS� 1
JS1
mS0 0
0 1
JF+mSy2F
0
0 0 1
JT
1
CCCCCCCCA
0
@⌧F⌧H⌧T
1
A
Accelerations Natural Dynamics
Coupled Control:Turning either knob affects both the flow as well as temperature.
courtesy heatAndPlumb.com
