Leg Function in Humans & Humanoids Outline Human Gait Humanoid Gait Model Gait Comparison 2 Leg function What is a good model? 3 Leg function in robots Scout II iSprawl EduBot (based on Rhex) Kenken Review: Zhou & Bi (2012) Bioinspir & Biomimetics 4 Human leg function Video: Sten Grimmer 5 Level of Complexity 2012-02-10 | PAK 146, Köln | TU Darmstadt AG Lauflabor | Seyfarth | 6 6 Global Leg Function RLF Radial Leg Function RTF Tangential Leg Function 7 Christian Rode 7 Radial Leg Function in human walking and running speed Radial Leg Force Leg Length Kovac 2010 Force- Length Function Susanne Lipfert 8 Self-stable locomotion? Hip spring Dai Owaki et al. (2008) ICRA RUN Leg spring ) hip k WALK Hip stiffness ( Hip stiffness Leg stiffness (kleg) 9 Passive Dynamic Runner Dai Owaki et al. Dynamic Walking 2009 ) RENNEN hip k Hip stiffness ( Hip stiffness GEHEN Leg stiffness (kleg) 10 Passive Dynamic Runner Dai Owaki et al. 2009 Dynamic Walking 11 Model for stable walking and running Geyer et al. (2006) Proc Roy Soc Lond B 12 Bipedal Spring-Mass Model (BSLIP) Hartmut Geyer WALK RUN GRF = " vertical GRF vertical GRF ground reaction force Geyer et al. (2006) Proc Roy Soc Lond B 13 Spring-Mass Model = spring-loaded inverted pendulum (SLIP) What does this model assume? COM • Forces are pointing to center of mass (COM) • Forces are proportional to leg compression • Fixed foot point (FP) at ground Model validation • Comparison with experimental data FP Trunk Body Segments Leg segments Extensions of the model 3D Locomotion Muscle arrangement Neuromuscular mechanisms Geyer et al. (2006) Proc Roy Soc Lond B 14 Spring-like leg operation in walking and running? Spring-like leg function? Rennen Gehen Susanne Lipfert (2009) Dissertation Spring-like leg function? Running Walking TD TD TD = touch down, TO = take off, c = contralateral leg Susanne Lipfert (2009) Dissertation Elastic leg function in a segmented leg SE1042/6 BioBiped Project (with SIM group, Prof. von Stryk) 18 Elastic leg function in a segmented leg Alternating hopping (contacts: left-right-left) SE1042/6 BioBiped Project (with SIM group, Oskar von Stryk) 19 Global leg function Body alignment POSTURE Spring-like leg Leg alignment BOUNCE SWING Seyfarth et al., 2012 AT 20 Body posture Virtual Pivot Point VPP concept Maus et al. (2010) Nature Communications 22 Hip torques Leg spring Maus et al. (2010) Nature Communications 23 Virtual Pivot Point VPP model Idea: hip torque aligns " leg force towards VPP Maus et al. (2010) Nature Communications 24 Virtual Pivot Point VPP in humans, animals and machines Maus et al. (2010) Nature Communications 25 Virtual Pivot Point VPP model Maus et al. (2008) CLAWAR 26 Segmented Legs Two-joint Leg Muscles VPP# Christian Rode 28 Walking with Segmented Legs VPP by two-joint thigh muscles VPP# Rode & Seyfarth Dynamic Walking 2013 Christian Rode 29 Standing with Segmented Legs VPP by two-joint thigh muscles Christian Rode 30 Templates and Anchors Full, R. J. and Koditschek (1999) J. Exp. Biol. Mechanical template models BOUNCE POSTURE SWING ✔ ✔ ✗ enhance model complexity Neuro-muscular representations BOUNCE ✔ POSTURE ✗ SWING ✗ 31 Thank you! www.biobiped.de .