Valve positioner control based on active disturbance rejection control technology

Abstract The pneumatic regulating valve is a commonly used actuator in industrial settings. The smart valve positioner, acting as the “brain” of the pneumatic regulating valve, dictates the control performance of the regulating valve, primarily relying on control algorithms. However, the valve positioner is a typical nonlinear system, making it difficult to establish an accurate mathematical model that can reflect the system’s nonlinear characteristics. Furthermore, due to variations in valves, installations, and processes, the model parameters differ significantly, making it challenging to self-adjust the parameters. Additionally, various disturbances in process control will affect the positioner’s control performance. Currently, commonly used control algorithms rely on precise mathematical models, resulting in poor control performance and robustness. Therefore, this article proposes a smart valve positioner control algorithm based on self-disturbance control. Initially, a steady-state model and system identification of the valve positioner system are obtained through open-loop testing, resulting in a simplified second-order system model. Based on the simplified second-order model, a second-order self-disturbance control algorithm is designed. Finally, a test platform based on the rapid control prototype (RCP) controller is established to verify that the introduction of the self-disturbance control algorithm can effectively enhance the control performance and robustness of the smart valve positioner.