| 摘要 |
An accelerometer system (FIG. 2) suitable for measuring low-frequency accelerations in inertial systems is also able to measure high-frequency vibrational accelerations which give rise to e.g. sculling effects in inertial platform arrangements employing three such accelerometer systems. The system comprises a low-frequency inertial quality force feedback accelerometer 10' and a high-frequency, e.g. piezo-electric, accelerometer 46. The output of h.f. accelerometer 46 is summed at 48 with the feedback signal from transducer 32' in the l.f. accelerometer feedback loop, the faster response of the h.f. accelerometer providing most of the feedback to balance the l.f. loop without significant displacement of mass 11'. Up to several hundred Hz the displacement of mass 11' and the feedback component from transducer 32' is only to overcome the error in the h.f. accelerometer signals and at higher frequencies the response of the h.f. accelerometer alone provides a measure of acceleration offering a wide system bandwidth. Because of the limited displacement of the proof mass the l.f. feedback loop may have a transfer function minimizing vibropendulous errors at lower frequencies. |
