1. . d31 - 274e-12 m/V
2. The series of experiments employing the nominal and off-nominal circuits is described in the next sections;The
3. In general, the closed loop results agreed well with the analytical predictions. The authority of the SRF was limited because of instability in either the second or fourth mode. Both the PPF and LQG compensators had their authority limited by unmodeled modes in the optical bench at 1.5 Hz and 5.5 Hz. A summary of the reduction in RMS tip displacement is given in Table 3. These values were calculated and measured from 10 Hz-1 kHz to minimize the effect of the low frequency unmodeled modes. The gain of the open loop model of the disturbance-performance transfer function was adjusted to match the low frequency gain of the measured transfer function. The analytical compensator was then applied to this system.fc101 " 110-200i
4. J04 Ex rimental
5. Off-nominal behavior may occur in many instances, including initial mismatch in circuit components, and change in component properties over time or with temperature. The temperature and amplitude sensitivity of the piezoelectric, as well as hysteretic nonlinearities , may also contribute to this error. The effect of mismatch on the zeros in the open loop case, and on the RMS performance in the closed loop case is described here. 104GlOI "-g·"'10-2C: bl).;