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Muscle-Reflex Model That Encodes Principles of Legged Mechanics Produces Human Walking Dynamics and Muscle Activities. 서울대학교 이경호 2012. 4. 06. Introduction. C entral Pattern Generator(CPG) complex network of neurons that controls legged locomotion of animals and humans. i n spinal cord.
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Muscle-Reflex Model That Encodes Principlesof Legged Mechanics Produces Human WalkingDynamics and Muscle Activities 서울대학교 이경호 2012. 4. 06
Introduction • Central Pattern Generator(CPG) • complex network of neurons that controls legged locomotion of animals and humans. • in spinal cord
Introduction • Principle of legged mechanics • it can largely simplify locomotion control • self-stability, compliant leg behavior • How these principles integrated into human motor control? • spinal reflexes • they can link sensory information into activation of the leg muscles
Human Model SOL : soleus VAS : vasti GAS : gastrocnemius TA : tibialis anterior GLU : gluteal muscles HFL : hip flexor muscles HAM : hamstring
Muscle Control • positive force feedback (F+) S : stimulation S0 : prestimulation G : Gain F : force △t : time delay
Muscle-tendon model A : muscle activation fl : force-length relationship fv : force-velocity relationship
Human Model SOL : soleus VAS : vasti GAS : gastrocnemius TA : tibialis anterior GLU : gluteal muscles HFL : hip flexor muscles HAM : hamstring
Muscle Control • positive length feedback (L+)
Human Model SOL : soleus VAS : vasti GAS : gastrocnemius TA : tibialis anterior GLU : gluteal muscles HFL : hip flexor muscles HAM : hamstring
Muscle Control • PD control kp, kd : gain : reference lean angle
Actual Leg Swing Phase During actual swing, we mainly rely on a leg’s ballistic motion. The distal leg muscles SOL, GAS, and VAS are silent in that phase. Only TA’s L+, remains active to provide foot clearance with the ground
Result • Walking Gait - Matlab SimMechanics GRF: ground reaction force
Result • Predict Motor Output
Result • Adaptation to Slopes
Discussion • Principles of legged mechanics explains the basic dynamics of human locomotion • encode several principles of legged mechanics with actuators and control, which turned into muscles and reflexes • Is it sufficient? • more principles of legged mechanics do certainly exist • level of detail
Discussion • CPG vs Reflex • Actual ratio of central and reflex inputs is remain uncelar