| Forging hydraulic press is one of the important equipments for national defense construction and infrastructure construction.It has a significant impact on the national economy.Improving the control performance of the hydraulic press control system is essential to improving the quality of forged products.This paper proposes the following research content for this issue.1.Aiming at the case that no displacement sensor is installed when the forging hydraulic press is modified,a solution based on machine vision detection is proposed.The camera uses the camera to track the markers on the hydraulic cylinder to obtain the real-time displacement of the hydraulic cylinder,instead of acting as a displacement sensor.The monocular and binocular detection displacement principle and feature point detection principle are introduced.The calibration data of the binocular module is obtained by using the Matlab calibration toolbox.The three-dimensional information is restored by using image matching with the markers.Tracking accuracy of binocular vision displacement detection system under different conditions.2.Aimed at the non-linear characteristics of the hydraulic press control system,a mathematical model was established,and an AMESim-Simulink simulation interface was created.The simulation verified the PID control algorithm and the fuzzy adaptive PID control algorithm.Compared with the PID control algorithm,the fuzzy adaptive PID control algorithm Better control performance.Aiming at the problems of huge flow and high position accuracy of the control system during rapid forging of the hydraulic press,a dual-valve control structure using a directional valve and a proportional valve in parallel was proposed.When the displacement value of the control cylinder is larger than the target displacement value,a low-frequency and large-flow reversing valve control is adopted to ensure the response speed.When it is close to the target value,a high-frequency and small-flow proportional valve control is used to ensure the position tracking accuracy..The simulation model of the hydraulic control system was established,and the effects of the response time of the switching valve and the dead zone of the proportional valve on the dynamic characteristics of the system were analyzed.The position tracking characteristics of the dual-valve parallel control and the control system using large flow proportional valve control were compared and analyzed.It is shown that the dual-valve parallel structure and corresponding strategies have smaller steady-state errors and longer response times,and provide an effective control method for high-performance control of forging hydraulic presses. |
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