Vermelding onderdeel organisatie

1

Recent Developments in Passive Dynamic Walking Robots

Seminar

May 13, 2005 University of Nottingham, UK

Laboratory for Engineering MechanicsFaculty of Mechanical Engineering

Arend L. SchwabGoogle: Arend Schwab [I’m Feeling Lucky]

May 13, 2005 2

Acknowledgement

TUdelft:Martijn WisseJan van FrankenhuyzenRichard van der LindeFrans van der HelmJaap Meijaard… MSc students

Cornell University:Andy RuinaMariano Garcia

Mike Coleman

Insitu Group: Tad Mc Geer

Collins, S., Ruina, A., Tedrake, R. and Wisse, M., 2005. ``Efficient Bipeal Robots Based on Passive-Dynamic Walkers’’, Science 307: 1082-1085

May 13, 2005 3

Contents

• Passive Dynamic Walkers• Passive Dynamic Robots• The Simplest Walker• Cyclic Motion; Stability & Basin of Attraction• Stability: Fore-Aft and Sideways• Conclusions

May 13, 2005 4

Walking Robots

-Anthropomorphic Design-Energy Efficient Ct=(energy used)/(weight*distance)=0.2

Museon 2001 Mike 2002 Max 2003 Denise 2004

Stappo 1995 Bob 2000 Baps 2001

May 13, 2005 5

Passive Dynamic Walking

Wire Walker by G. T. Fallis Patented in 1888.

Wire Walker, Model 2002

May 13, 2005 6

Simplest Walking Model

Scaling with: M, l and g and limit case: m/M -> 0

Leaves one free parameter:

May 13, 2005 7

Walking Motion

Walking Motion in Phase Plane

nn

1

Cyclic Motion if

May 13, 2005 8

Family of Stable Cyclic Solutions

Stability of Cyclic Motion Determined by Characteristic Multipliers ||<1 But How Stable?

May 13, 2005 9

Basin of Attraction of Cyclic Motion

Cyclic Motion (Fixed Point) : )1561.0,1534.0(),(

Poincare Section

with basin of Attractionand failure modes:-falling Forward-falling Backward-Running

May 13, 2005 10

Basin of Attraction (Cont’d)

Basin of Attraction: askew & enlarged

May 13, 2005 11

A few steps into the Basin of Attraction

x = Cyclic Motion

1 = Start

May 13, 2005 12

Effect of the Slope on the BOA

May 13, 2005 13

Simplest Walking Robot

Simplest Walker (1999): 2D, straight legs and point feetwalking down a shallow slope.(copy of the 1988 Tad McGeer walker)

May 13, 2005 14

Bob: a Bipedal Robot based on Simulations

Bob (2000): 3D, Flat Feet, Knees and Ankle Actuation

May 13, 2005 15

Robot with Knees, Round Feet, and Actuation

Mike (2002)

May 13, 2005 16

For-Aft Stability or How to Keep from Falling ForwardSwing Leg Control:’’You will never fall forward if you put your swing leg fast enough

in front of your stance leg’’

Uncontrolled Swing Leg Control

May 13, 2005 17

Adding an Upper Body

Max (2003) Bisecting Hip Mechanism

May 13, 2005 18

Adding an Upper Body

Max 2003 On Level Ground Self-Starting

May 13, 2005 19

Going into 3D

Sideway Stability by means of Lean-to-yaw Coupling

As in a Skateboard:

Velocity dependent Stability

May 13, 2005 20

Going into 3D

Sideway Stability by means of Lean-to-yaw Coupling

Or as in a Bicycle:

Velocity dependent Stability

May 13, 2005 21

Going into 3D: Denise

Bisecting Hip Mechanism

Tilted Ankle Joint

Lean-to-yaw Coupling

Upper Body

May 13, 2005 22

Going into 3D: Denise

May 13, 2005 23

Conclusions

Passive Dynamic Robots:

- use less control and less energy - walk more naturally.- help understand human walking.