Recent Developments in Passive Dynamic Walking Robots Seminar

Recent Developments in Passive Dynamic Walking Robots Seminar Arend L. Schwab Google: Arend Schwab [I’m Feeling Lucky] May 13, 2005 University of Nottingham, UK 1 Laboratory for Engineering Mechanics Faculty of Mechanical Engineering

Acknowledgement TUdelft: Cornell University: Martijn Wisse Jan van Frankenhuyzen Richard van der Linde Frans van der Helm Jaap Meijaard … MSc students Andy Ruina Mariano 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 2

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 3

Walking Robots -Anthropomorphic Design -Energy Efficient Ct=(energy used)/(weight*distance)=0. 2 Museon 2001 May 13, 2005 Mike 2002 Stappo 1995 Bob 2000 Max 2003 Baps 2001 Denise 2004 4

Passive Dynamic Walking Wire Walker by G. T. Fallis Patented in 1888. May 13, 2005 Wire Walker, Model 2002 5

Simplest Walking Model Scaling with: M, l and g and limit case: m/M -> 0 Leaves one free parameter: g May 13, 2005 6

Walking Motion in Phase Plane Cyclic Motion if May 13, 2005 7

Family of Stable Cyclic Solutions Stability of Cyclic Motion Determined by Characteristic Multipliers |l|<1 But How Stable? May 13, 2005 8

Basin of Attraction of Cyclic Motion Poincare Section with basin of Attraction and failure modes: -falling Forward -falling Backward -Running Cyclic Motion (Fixed Point) : May 13, 2005 9

Basin of Attraction (Cont’d) Basin of Attraction: May 13, 2005 askew & enlarged 10

A few steps into the Basin of Attraction x = Cyclic Motion 1 = Start May 13, 2005 11

Effect of the Slope on the BOA May 13, 2005 12

Simplest Walking Robot Simplest Walker (1999): 2 D, straight legs and point feet walking down a shallow slope. (copy of the 1988 Tad Mc. Geer walker) May 13, 2005 13

Bob: a Bipedal Robot based on Simulations Bob (2000): 3 D, Flat Feet, Knees and Ankle Actuation May 13, 2005 14

Robot with Knees, Round Feet, and Actuation Mike (2002) May 13, 2005 15

For-Aft Stability or How to Keep from Falling Forward Swing Leg Control: ’’You will never fall forward if you put your swing leg fast enough in front of your stance leg’’ Uncontrolled May 13, 2005 Swing Leg Control 16

Adding an Upper Body Max (2003) May 13, 2005 Bisecting Hip Mechanism 17

Adding an Upper Body Max 2003 May 13, 2005 On Level Ground Self-Starting 18

Going into 3 D Sideway Stability by means of Lean-to-yaw Coupling As in a Skateboard: Velocity dependent Stability May 13, 2005 19

Going into 3 D Sideway Stability by means of Lean-to-yaw Coupling Or as in a Bicycle: Velocity dependent Stability May 13, 2005 20

Going into 3 D: Denise Lean-to-yaw Coupling Upper Body Tilted Ankle Joint Bisecting Hip Mechanism May 13, 2005 21

Going into 3 D: Denise May 13, 2005 22

Conclusions Passive Dynamic Robots: - use less control and less energy - walk more naturally. - help understand human walking. May 13, 2005 23