Fig 1.
Parameters of (a) SLIP and (b) PMB model in stance phase.
Fig 2.
The conceptual circle trajectory and initial velocity vector for stance phase.
Fig 3.
Free body diagram of PMB on circular-arc trajectory.
Fig 4.
(a) SLIP model trajectory for one complete step of periodic running, (b) Horizontal and vertical components of toe force profiles.
Fig 5.
The desired and actual arc trajectories in stance phase.
Table 1.
Running gait parameters for various trajectories in stance phase.
Fig 6.
PMB trajectory in one complete step of periodic running with arc trajectory in stance phase.
Fig 7.
COM horizontal speeds during stance phase for SLIP and PMB models.
Fig 8.
Generated polynomial trajectories of degrees 2, 4 and 6 with two parameters in stance phase.
Fig 9.
PMB model trajectory in one complete step of periodic running with tuned degree-4 polynomial trajectory in stance phase.
Fig 10.
Horizontal and vertical components of toe force profiles for SLIP model and PMB model with tuned degree-4 trajectory in stance phase.
Fig 11.
Comparison of various generated trajectories for SLIP and PMB models in stance and flight phases.
Fig 12.
Needed leg force profiles vs time for various trajectories in stance phase.
Fig 13.
Degree 6 polynomial trajectories in stance phase with various coefficient 'a'.
Fig 14.
Needed leg force profiles vs time for degree 6 polynomial trajectories in stance phase with various values of coefficient 'a'.
Fig 15.
Variation of max leg force of stance phase vs. coefficient 'a' for degree 6 polynomial trajectories.
Fig 16.
State variables of PMB in stance phase.
Fig 17.
(a) Contour plot and (b) 3D plot of COT variation relative to θ0 and β0.
Fig 18.
(a) Contour plot and (b) 3D plot of maximum leg force variation relative to θ0 and β0.
Table 2.
Optimal values of stance initial condition.
Fig 19.
Horizontal and vertical components of toe force profiles with optimal values of stance initial condition.