The Simulation And Applied Study On Straightening Machine Hydraulic Press Servo System Based On The Expert Control System

In modern manufacturing industry, the requirement for shaft parts is increasingly getting higher and higher, and this proposes new requirements for precise straightening machine, as an advanced shaft parts manufacturing equipment, which is widely used in machinery, automobile, engineering machinery and other types of machinery manufacturing industry. Hydraulic servo body is the main part of precise straightening machine parts, which directly determines the work piece machining accuracy. However, because this body is a non-linear time-varying system, and this system is comparatively dependent on the environment, such as temperature height, operating time length, viscosity of hydraulic oil and so on. These factors can affect the hydraulic pressure position server's work precision, making its control certain difficult. In such cases, it is necessary to conduct the analytical study to its hydraulic position servo system analysis in order to find a more precise way to control this system.This thesis, by inferring its transfer function through the study of valve controlling cylinder, carry on the research based on the two load conditions of no-load pressure and the pressure head press down the work piece to analyze the corresponding mathematical model established by the analysis. Then, the hydraulic servo system control method is improved. Because the traditional PID control cannot overcome the influence of the factor of the load, the wide range change of the model parameter and the misalignment effectively, so this paper introduces the indirect expert controller, one kind of new controller which unifies the expert control system and the traditional PID control system forms. This kind of controller revises the PID parameter by using the expert system knowledge library, thus changes the PID control mode to achieve the best PID control effect. Finally, this paper comes to the conclusion that this controller is more appropriate for a certain type straightening machine by the application of the effect of this control through the Matlab simulation.