Review of Research on Improved PID Control in Electro-hydraulic Servo System

Background: Proportional-integral-differential (PID) controller is widely used in the engineering field because of its simple structure, high control accuracy, and easy operation. Different patented PID control technologies have their own advantages, disadvantages, and application scenarios. Objective: By analyzing and discussing the improved PID control techniques in the electrohydraulic servo system, some valuable conclusions have been drawn to predict the future research and development of PID control techniques. Methods: The improved PID control techniques applied to electro-hydraulic servo systems are classified into three categories: PID parameter tuning technology, PID parameter online adjustment strategy and compound control strategy combined with PID algorithm. Results: By comparing the principles and characteristics of the above techniques, the advantages, disadvantages and application scenarios of each are analyzed, and the further development of PID control technology is discussed. Conclusion: Based on the characteristics of electro-hydraulic servo systems, the further combination of the three types of technology can make up for the shortcomings of PID algorithms to form a control strategy with high control accuracy, high robustness, and fast response speed.