A New Mechanical Resonance Suppression Method for Large Optical Telescope by Using Nonlinear Active Disturbance Rejection Control

Abstract

Aiming at solving the problem of the multi-low-frequency mechanical resonances appearing in the large optical telescope control system, this paper proposes a novel control method based on nonlinear active disturbance rejection control (NADRC) and proportional-integral (PI) control. In the proposed control framework, a nonlinear tracking differentiator (NTD)-based feedforward control is designed to improve the tracking performance of the system. Then, the principle of suppression of mechanical resonance of this method is analyzed. Compared with the most commonly used acceleration feedback control (AFC) method, the theoretical analysis shows that the proposed method is more effective for suppressing the low-frequency mechanical resonance. Finally, the proposed method is applied to a large optical telescope, and the experimental results show that the proposed method is better than AFC.

Keywords

• Mechanical resonance suppression
• active disturbance rejection control (ADRC)
• acceleration feedback control (AFC)
• nonlinear tracking differentiator (NTD)
• optical telescope