The stability analysis of control system of aerostatic worktable based on square box

In order to further study the matching stability of aerostatic guide rail support and linear motor drive, a two-dimensional aerostatic worktable based on square box was designed and developed. Taking square box as the mechanism design and assembly reference could effectively improve the bearing performance and motion accuracy of the two-dimensional aerostatic worktable. However, the stability of the control system of the whole aerostatic worktable was difference, due to the small friction damping and large load inertia. Therefore, the stability of the system needed to be analyzed and the improvement measures were proposed. In this essay, the mathematical model of the linear motor was established based on the aerostatic worktable, and the transfer function of the control system was derived. The Bode diagram was calculated and the stability margin was analyzed by Matlab, and an experimental platform was built for verification. The results showed that the phase margin of the current loop, the velocity loop and the position loop in the two axial directions of the aerostatic worktable were greater than 60° and the amplitude margin was greater than 10 dB, which met the requirements of the system stability margin and ensured the good stability of the control system. The experimental results were in good agreement with the simulation results, which verifies the stability of the control system of the aerostatic worktable.