Design And Research Of Electro-hydraulic Servo System In Mold Oscillation Of Casting

Mold oscillation is the key equipment in the casting,the form of its vibration and control,online monitoring and adjustment have an important impact on the quality of the casting.Therefore,it has practical significance in researching the mold oscillation and its control technology.This paper studied the one iron-steel company's slab casting,derived the mathematical expression of non-sinusoidal waveform,analyzed its dynamic performance,and gave their quantitative selection criteria of the basic parameters and technical parameters.According to the best match principle of the load power,this paper calculated the parameters of the servo-cylinder and servo-valve,and selected the standard models of servo-cylinder and the servo-valve in accordance with the parameters.The principle schematic of hydraulic servo system was made according to the mold oscillation's function.Base on the valve control asymmetric cylinder system characteristics,this paper set up the flow equation of hydraulic control valve,the flow continuity equation of hydraulic cylinder and force balance equation of cylinder and force,and Laplace transform them,obtained the transfer function of cylinder valve.By electro-hydraulic position servo control theory,derived the transfer function of the various links,and calculated the specific values of the parameters,derived the system transfer function.The error transfer function was also given and analyzed its.In order to improve the control system performance,PID controller was taken in this paper.Tuned PID control parameters based on the Ziegler-Nichols method, analyzed the effect of various parameters change to system performance,and gave the best parameters combination which fit this system.Used MATLAB / Simulink to simulate the PID controller system and done the comparative analysis.In this paper, used incremental PID control algorithm,combined with BP neural network which has self-learning and self-adaptive ability,tuned the PID control parameters using combination BP neural network and PID controller.The simulation results showed that the use of BP neural network PID control system,the system control performance could be significantly improved and had a high reality application value.