Index / Work / N° 05
Project N°05 of 24
CategorySimulation · Robotics
Year2025

Biomechanical Simulation & Exoskeleton Optimization

Simulated human gait dynamics within OpenSim to evaluate and optimize the assistive force of a powered ankle exoskeleton, aiming to minimize the wearer's metabolic cost of locomotion.

Key Engineering Contributions

  1. 01
    Musculoskeletal Modeling: Conducted Inverse Dynamics (ID) analysis on a 10-DOF, 18-muscle human gait model to calculate lower-limb joint torques and establish baseline metabolic costs for key muscles (e.g., soleus, tibialis anterior).
  2. 02
    Wearable Device Integration: Simulated the integration of both passive (spring-damper) and active (PlantarFlexAssist) assistive devices directly into the human gait model to observe their impact on joint kinematics and muscle exertion.
  3. 03
    Metabolic Cost Reduction: Iteratively tuned the active actuator's optimal force scaling, successfully reducing the integrated metabolic cost of the soleus muscle to a highly efficient target of ~15 J over a single gait cycle.

Visual Documentation

OpenSim Musculoskeletal Model: 10-DOF, 18-muscle lower limb model utilized for i
Figure 1
01.png
OpenSim Musculoskeletal Model: 10-DOF, 18-muscle lower limb model utilized for inverse dynamics and gait simulation
OpenSim Musculoskeletal Model: 10-DOF, 18-muscle lower limb model utilized for inverse dynamics and gait simulation
Plot of right ankle torque profile over time during unassisted walking
Figure 2
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Plot of right ankle torque profile over time during unassisted walking
Plot of right ankle torque profile over time during unassisted walking
Plot of right ankle torque profile over time while walking with a passive spring
Figure 3
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Plot of right ankle torque profile over time while walking with a passive spring. Parameters of the biarticular spring damper are a resting-length of 0.4 m, stiffness of 10000.0 N/m and dissipation of
Plot of right ankle torque profile over time while walking with a passive spring. Parameters of the biarticular spring damper are a resting-length of 0.4 m, stiffness of 10000.0 N/m and dissipation of 0.01 s/m. Lower maximum peaks may be observed relative to its unassisted counterpart.
Plot of integrated metabolic cost of right gastrocnemius, soleus, and tibialis a
Figure 4
04.png
Plot of integrated metabolic cost of right gastrocnemius, soleus, and tibialis anterior muscles during unassisted walking
Plot of integrated metabolic cost of right gastrocnemius, soleus, and tibialis anterior muscles during unassisted walking
Plot of integrated metabolic cost of right gastrocnemius, soleus, and tibialis a
Figure 5
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Plot of integrated metabolic cost of right gastrocnemius, soleus, and tibialis anterior muscles during spring-assisted walking. The tibialis anterior experiences more metabolic cost while the gastroc
Plot of integrated metabolic cost of right gastrocnemius, soleus, and tibialis anterior muscles during spring-assisted walking. The tibialis anterior experiences more metabolic cost while the gastrocnemius and soleus muscles experience less metabolic cost relative to their unassisted counterparts.
Plot of integrated metabolic cost of right gastrocnemius, soleus, and tibialis a
Figure 6
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Plot of integrated metabolic cost of right gastrocnemius, soleus, and tibialis anterior muscles during active-assisted walking. The tibialis anterior muscle experiences much higher metabolic cost and
Plot of integrated metabolic cost of right gastrocnemius, soleus, and tibialis anterior muscles during active-assisted walking. The tibialis anterior muscle experiences much higher metabolic cost and the soleus muscle experiences lower metabolic cost.