PID–PFC control of continuous rotary electro-hydraulic servo motor applied to flight simulator

Abstract

Due to the uncertainties caused by high non-linearity, friction, leakage and other external factors existing in the flight simulator with continuous rotary electro-hydraulic servo motor and the traditional control strategies discontenting with the high-performance requirements, the mathematical model of continuous rotary electro-hydraulic position servo system is established and the compound control theory combining proportional-integral-derivative (PID) and the predictive function control (PFC) method is proposed. In order to enable the servo system to estimate the influence of uncertainties and correct it by repeating online optimisation continuously, PID–PFC compound controller basing on the structure of internal model control is designed and then applied to continuous rotary electro hydraulic servo system. The simulation results show that compared with the traditional PID, PFC controller, PID–PFC compound control can effectively inhibit the interferences of the electro-hydraulic servo system, and greatly improve the response speed and tracking performances and expanding the system frequency band width. The accurate control of motor's position can be realised by applying PID–PFC compound control, which can make the servo system has stronger robustness.

Keywords

• three-term control
• servomotors
• position control
• predictive control
• electrohydraulic control equipment
• aircraft control
• uncertain systems
• optimisation
• motor position control
• response tracking
• system frequency band width
• response speed
• online optimisation
• proportional-integral-derivative method
• continuous rotary electrohydraulic position servo system
• continuous rotary electrohydraulic servo motor
• traditional control strategies
• leakage
• flight simulator
• internal model control
• PID–PFC compound controller
• predictive function control method
• compound control theory