Table 3.
Pearson’s correlation between sensor error and robot angle or time (series).
| Calculation Method | With Reference to the Earth Gravity Vector (Flexion and Abduction) |
With Reference to the Sensor’s Orientation in the Starting Position (Internal/External Rotation) |
||||
|---|---|---|---|---|---|---|
| Axis (Calibration Method) |
Roll (acc) |
Roll (acc + gyro) |
Pitch (acc) |
Pitch (acc + gyro) |
Roll (acc) |
Roll (acc + gyro) |
| Robot angle vs. sensor error | ||||||
| p | <0.001 | <0.001 | <0.001 | <0.001 | <0.001 | <0.001 |
| r | −0.030 | 0.579 | 0.338 | 0.726 | −0.030 | 0.576 |
| (95% CI) | (−0.033;−0.027) | (0.577;0.581) | (0.336;0.34) | (0.725;0.728) | (−0.033;−0.027) | (0.574;0.578) |
| Series vs. sensor error | ||||||
| p | <0.0001 | <0.0001 | <0.0001 | <0.0001 | <0.0001 | <0.0001 |
| r | 0.351 | 0.125 | 0.507 | 0.116 | 0.352 | 0.125 |
| (95% CI) | (0.348;0.353) | (0.123;0.128) | (0.505;0.509) | (0.113;0.119) | (0.349;0.354) | (0.122;0.128) |