Schwab Nottingham

Recent Developments in Passive Dynamic Walking Robots: 

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

Acknowledgement: 

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

Contents: 

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

Walking Robots: 

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

Passive Dynamic Walking: 

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

Simplest Walking Model: 

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

Walking Motion: 

Walking Motion Walking Motion in Phase Plane Cyclic Motion if

Family of Stable Cyclic Solutions: 

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

Basin of Attraction of Cyclic Motion: 

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

Basin of Attraction (Cont’d): 

Basin of Attraction (Cont’d) Basin of Attraction: askew & enlarged

A few steps into the Basin of Attraction: 

A few steps into the Basin of Attraction x = Cyclic Motion 1 = Start

Effect of the Slope on the BOA: 

Effect of the Slope on the BOA

Simplest Walking Robot: 

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

Bob: a Bipedal Robot based on Simulations: 

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

Robot with Knees, Round Feet, and Actuation: 

Robot with Knees, Round Feet, and Actuation Mike (2002)

For-Aft Stability or How to Keep from Falling Forward: 

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 Swing Leg Control

Adding an Upper Body: 

Adding an Upper Body Max (2003) Bisecting Hip Mechanism

Adding an Upper Body: 

Adding an Upper Body Max 2003 On Level Ground Self-Starting

Going into 3D: 

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

Going into 3D: 

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

Going into 3D: Denise: 

Going into 3D: Denise Bisecting Hip Mechanism Tilted Ankle Joint Lean-to-yaw Coupling Upper Body

Going into 3D: Denise: 

Going into 3D: Denise

Conclusions: 

Conclusions Passive Dynamic Robots: use less control and less energy walk more naturally. help understand human walking.