[Tanaka, Hirose]
This is continued from klog37279.
While locked at DRMI 1f, we measured the sensing matrix for the 3f sensors.
The sensing matrix is as follows in Table 1. (Values marked with an asterisk (*) have a coherence below 0.85.) We excited the PRM, BS, and SRM of the PRCL, SRCL, and MICH actuators, respectively, at 150.125 Hz. (Figures 1, 2, and 3)
| Table1: Sensing matrix | /(PRCL1_IN1) | /(SRCL1_IN1) | /(MICH1_IN1) |
| RF135I | -2.294 | -0.254 | -2.74275 |
| RF135Q | 0.063 | 0.053 | 0.1170 |
| RF51I | -0.4016 | -0.3244 | -0.06095* |
| RF51Q | -0.4177 | -0.012* | -0.2417 |
We normalized the results in the table below so that the reference value for the degree of freedom is 1 for each sensor. (Table 2)
| Table 2 | PRCL | SRCL | MICH |
| RF135I | 1.000 | 0.111 | 1.196 |
| RF135Q | 0.5385 | 0.4530 | 1.000 |
| RF51I | 1.237 | 1.000 | 0.188* |
| RF51Q | 1.727 | 0.050* | 1.000 |
Based on the measurement results above(Table 2), we considered the sensor coefficients(Table 4) to achieve the signal response shown in the table below(Table 3).
Table 3 is based on the equations in Fig. 4.
| Table 3 | PRCL | SRCL | MICH |
| PRCL ERROR | 1 | 0 | 0.5 |
| SRCL ERROR | 0 | 1 | 0.5 |
| MICH ERROR | 0 | 0 | 1 |
Table 4 shows the sensor coefficients. The error signal for each degree of freedom is obtained by multiplying each sensor signal by its coefficient and summing the results. These coefficients will be used in the Input Matrix on the MEDM screen.
| Table 4: Input matrix | RF135I | RF135Q | RF51I | RF51Q | |
| 1 | -0.111 | -4.421 | PRCL ERR | ||
| 2.1663 | 1 | -1.9706 | SRCL ERR | ||
| -2.0019 | 0.2222 | 1 | MICH ERR |
Table 5 summarizes the calculated coupling of each degree of freedom in the error signals obtained using the sensor coefficients in Table 4. The calculated coupling ratios are close to the ideal values shown in Table 3.
| Table 5 : Signal Response | PRCL | SRCL | MICH |
| PRCL ERR | −6.773 | 0.000 | −3.225 |
| SRCL ERR | 0.000074 | 1.24046 | 0.62029 |
| MICH ERR | 0.000 | 0.000 | -1.394 |
Next time, we'll insert in this coefficient and try 3f lock.
