Table 1.
Mechanical work provided by the motor (nut output, positive + absolute of negative), the spring (positive) and the overall robotic ankle in J/(kg m)
| Nut | Spring | Robotic ankle | ||||
|---|---|---|---|---|---|---|
| Trial (m/s) | RA | Model | RA | Model | RA (tot/pos/neg) | Model (tot/pos/neg) |
| Running 4.0 | 0.12 | 0.22 | 0.17 | 0.31 | 0.29/0.2/0.09 | 0.49/0.35/0.14 |
| Running 2.6 | 0.21 | 0.23 | 0.23 | 0.25 | 0.44/0.32/0.12 | 0.51/0.36/0.15 |
| Walking 1.6 | 0.14 | 0.17 | 0.11 | 0.15 | 0.2/0.15/0.05 | 0.24/0.19/0.05 |
Model assumptions were made using the stiffness of the spring and the data from [24]. Lower model requirements are possible if the spring stiffness is optimal for each individual gait condition and the individual subject weight