Research On Electro-hydraulic Servo Control System For Heat Alternating Test

Heat alternating pressure fatigue test is an important test metod in testing the fatigue limits of products.Many products such as condensers,radiators,oil lines need to be tested their fatigue limits under hot and alterating pressure circumstance.Servo control alternating pressure test will be the trend of alternating pressure test in nation and abroad. The electro-hydraulic servo pressure conrol system is a key part.So the research is of great importance.Research on the experimental result of electro-hydraulic pressure control lsystem of heat alternating test following different types of pressure curves with different frequencies and amplitudes has been done and the pressure control process of system has been modeled and simulated by using AMESim simulation sofrware.The difficulties of system's pressure control has been pointed out by analyzing the experimental result.And together with analyzation of system simulation,the impact of load characteristic to hydraulic system's dynamic characteristic is researched on the emphasis,and the improvement way is also be pointed out.Because of the great elastance of load and deficiency of conventional PID control,variable coefficient PID control method is put forward to improve the pressure control precision of the hydraulic system.This control strategy is simple and effective and is fit for industry application.In chapter one.the background,actuality and development of the heat alternating test-bed is introduced ,and the content and the significant of the research is also pointed out.In chapter two,the work principle and the system conposation of heat alternating test-bed is introduced,containing its hydraulic control system,electrical control system and the structure of the load.In chapter three,mathematical model of the pressure alternating test-bed's electro-hydraulic servo pressure control system is done,and system's performance of...