1. Walking Controller for Musculoskeletal Human Model

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

3. 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

4. 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

5. 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

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

7. 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]

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

10. 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

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

12. Dynamics of Musculoskeletal System
Activation dynamics

13. Dynamics of Musculoskeletal System
Activation dynamics
Contraction dynamics

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

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

16. 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

17. Thank you