Active control of low-frequency vibrations with parameter self-optimization for quantum sensing

In quantum precision measurement, vibration, especially low-frequency vibration, is a key factor which restricts the precision and sensitivity of instruments. Based on the demand for testing signals in different frequency bands, the need for broadband vibration suppression has been proposed. In the paper, the response characteristics of the comagnetometer as a typical quantum sensing device to linear vibration and angular vibration are analyzed and tested based on the experimental setup designed. In order to realize the wide-broadband requirements of the active vibration suppression, a parameter self-optimizing controller suitable for low-frequency active vibration isolation system is proposed. The primary vibration suppression frequency band can be configured to accommodate the specific vibration suppression requirements of various apparatus. Of particular significance is the embedding of a parameter self-optimizing component within the controller, allowing the controller parameters to be obtained by solving the optimization problem. The active vibration controller with optimized parameters achieves a balance between vibration suppression efficiency and stability, facilitating the potential for active isolation of substantial load. The effectiveness of the active vibration isolation controller with parameter self-optimization has been validated through a single-stage negative stiffness active vibration isolator under a substantial load of 400 kg. Vibration is experimentally verified to be effectively attenuated to within 1×10^-9m/s/Hz^1/2, under the specified frequency range of 0.8 Hz to 6 Hz, with a notable suppression to 5.6×10^-10m/s/Hz^1/2 which reducing ground vibrations by 98 % specifically at 1 Hz, marking the best performance observed with the substantial load mass.