An optimal H ₂ controller based on vibration energy minimization for a horizontal vibration isolator supported by air bearings

To suppress various interferences in the active vibration control process simultaneously, an optimal H₂ control method based on vibration energy minimization is proposed in this paper. The interference sources mainly include floor vibration interference, direct interference, and sensor noise as well as electrical noise and quantization noise of the analog to digital and digital to analog converters. The interferences are modeled by weighting filters and the load vibration is weighted by a scaling filter, both of which are introduced into the design of the system’s H₂ controller. Thus, the load vibration energy is equivalent to the H₂ norm of the system. This method can minimize the total impact of external interferences and improve the vibration isolation performance of the system. Compared with the traditional proportional integral derivative control method, it significantly reduces the root-mean-square value of the load vibration. Simulation and experimental results verify the effectiveness of the proposed control method.