Walking Controller for Musculoskeletal Human Model

Biped Control is Difficult Balance, Robustness, Looking natural Various stylistic gaits ASIMO Honda HUBO KAIST PETMAN Boston Dynamics

Biped Control is Difficult? Wang et al. 2009 Yin et al. 2007 da Silva et al. 2008a,b Muico et al. 2009 Sok et al. 2007

Biped Control is Difficult? Wang et al. 2009 Yin et al. 2007 da Silva et al. 2008a,b Muico et al. 2009 Sok et al. 2007 Lee et al. 2010 Coros et al. 2010 Lasa et al. 2010 Wu et al. 2010 Liu et al. 2010

Musculoskeletal Model In biomechanics, musculoskeletal model have been used to analyze, simulate human movement More similar to human : investigate “how real human moves” Medical application : orthopedics surgery

Goal Controller for musculoskeletal model Reasonable computation time Responding to perturbation Reasonable computation time

Related Work Biomechanical model Deformable foot model Torso [Zordan 2004], neck [Lee 2006], hand [Tsang 2005], face [Sifakis 2005] Deformable foot model [Jain 2011], [Pauly 2004] Musculoskeletal simulation [Thelen 2003;2006] [Lee 2006;2009] [Tsang 2005] [Sifakis 2005] [Komura 2000]

Hill-Type Muscle Model Serial element : tendon Contractile element Parallel element pennation angle α

Hill-Type Muscle Model Force-length relation of tendon Active force-length relation of muscle Passive force-length relation of muscle Force-velocity relation of muscle

Activation / Excitation Activation : level of activation of muscle fiber (contractile element) Excitation : electrical stimulus (neural signal)

Dynamics of Musculoskeletal System Activation dynamics

Dynamics of Musculoskeletal System Activation dynamics Contraction dynamics

Dynamics of Musculoskeletal System Activation dynamics Contraction dynamics Forward dynamics (equations of motion)

Our Model 23 degrees of freedom 66 muscles Joint limit force Use OpenSim for musculoskeletal dynamics and Hill-type muscle model

Computing Muscle Force : joint torques, n : # of dof : muscle forces, m : # of muscle : moment arm matrix Resolve redundancy of muscle force Minimum norm solution by pseudo inverse f_min < f < f_max Optimization

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