Figure 6
Encoder alignment measurements taken using the capacitive sensor: (a) an example of angular displacement measured by the capacitive sensor, showing that the long-range linearity of the axes is excellent; (b) the difference between the read-back values and fit to the measured data after the alignment process. The individual encoder data are shifted vertically for clarity. The presence of the interpolation (20000-line oscillations) errors is evident, with each encoder having a different amplitude and phase. |