Error-based observer with dual compensations for disturbance rejection in electro-optical tracking system

Abstract

The electro-optical tracking system (ETS) on the motion platform can only acquire the system tracking error of the camera output. This poses a significant challenge to disturbance rejection. Existing error-based disturbance rejection methods have a limited disturbance rejection effect due to the filter bandwidth constraint. To address this problem, this paper proposes an error-based observer structure based on dual filters (DEBO) to suppress the contradiction between the disturbance rejection effect and the noise amplification. The dependence on the filter bandwidth is alleviated by the method of superposition processing for disturbance rejection. The stability of the proposed structure is also demonstrated using frequency domain analysis. Meanwhile, specific disturbance rejection experiments are designed to verify the effectiveness of the method and compared with the standard error-based observer (EBO). The results show that the DEBO structure effectively improves the disturbance rejection effect of the system and avoids the noise amplification. It provides a new idea for improving the design of disturbance rejection method in electro-optical tracking system.