Speed Control for the Pitching Axis of a Remote Sensing Camera Using an Improved Active Disturbance Rejection Controller

Abstract

This paper proposes the theoretical framework and the experimental application of an improved active disturbance rejection controller (ADRC) to speed control for the pitching axis of a remote sensing camera. Mechanical model of the pitching axis, mechatronics model of the speed control system for the pitching axis, and speed algorithm model of a permanent magnet synchronous motor are established. Control rates of the extended state observer (ESO) and the nonlinear state error feedback (NSEF) of the traditional ADRC are improved using a new nonlinear function. The nonlinear dynamics, model uncertainty, and external disturbances of the speed control system are extended to a new state, and the improved ESO is implemented to observe this state. The overtime variation of the speed control system is predicted and compensated for in real time using the improved ESO. The nonlinear integration method is adopted to nonlinearly combine the differential and the error differential by the improved NSEF. Subsequently, high-quality control is provided to the system. Simulation and experimental verification for the speed control system for the pitching axis of a remote sensing camera are conducted. Results show the effectiveness of the proposed controller.