Active disturbance rejection control of test sample in electrostatic suspension system

The electrostatic suspension system is a contactless detective method to analyze the material properties of test sample. In this article, the characteristics about electric field force and electric image force of an electrostatic suspension system are analyzed, and the force analysis and dynamic functions of test sample in the electrostatic suspension system are developed. The suspension precision of test sample in vertical direction is sensitive to the gravity and the disturbances. Therefore, an active disturbance rejection control (ADRC) model including a displacement control loop and an acceleration control loop is designed to the suspension control of test sample. The simulation and experiment are conducted to validate the effectiveness of ADRC model when the random and impulse disturbances are imposed on the test sample in vertical direction, and results indicate that the ADRC model could improve the robust stability of test sample and reduce the oscillation amplitude of high voltage electrodes.