Position synchronization control method of hydraulic servo system on two sides of rolling mill

Abstract

The invention belongs to the technical field of metallurgy machinery, automation and rolling, particularly relates to a position synchronization control method of a hydraulic servo system on the two sides of a rolling mill. The positions of the hydraulic cylinders on the two sides of the rolling mill are controlled by independent valve sets and hydraulic cylinders respectively, an algorithm for controlling the positions of the hydraulic cylinders on the two sides is a PI control algorithm; in the early-stage debugging process, an initial proportionality coefficient and an initial integral coefficient of the two side position control PI algorithm is determined; in the normal production process, the absolute value difference e<d> of the deviation of the two sides is compared, and accordingto the absolute value e<d> of the deviation of the two sides, the value of the speed selection switch w is determined, and the proportion coefficient and the integral coefficient of the two side position control PI algorithm during normal work is calculated, so that one side, where the closed-loop response is relatively fast, of the hydraulic cylinder position is enabled to follow the action of the relatively slow side, and the synchronous control of the positions of the hydraulic servo systems on the two sides of the rolling mill is realized while the stability is ensured.

Description

technical field [0001] The invention belongs to metallurgical machinery, automation, and rolling technology, and particularly relates to a position synchronization control method of a hydraulic servo system on both sides of a rolling mill. More specifically, the improved control method is applied to the roll gap control of a rolling mill so that the rolls on both sides The seam changes synchronously, thereby reducing the wedge shape of the strip. Background technique [0002] With the continuous improvement of the market's quality requirements for steel and other non-ferrous metal plates and strips, modern high-speed rolling has higher and higher requirements for control precision. The hydraulic servo position system occupies a very important position in the strip rolling control system. The response speed and tracking accuracy of the hydraulic servo position on the transmission side and the operation side directly affect the product quality. Due to differences in the insta...

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Problems solved by technology

"Two-stage two-way high-precision hydraulic synchronous control system" (Patent No. CN 103195764 A) proposes to use a hydraulic synchronous motor to distribute the oil entering the hydraulic cylinder in the first stage on the main oil circuit, and then use a proportional servo valve to distribute the hydraulic oil to the hydraulic synchronous motor. The second adjustment is made by dividing the flow, and the decoupling between the inflow and outflow of the oil cylinder is realized by connecting the remote ports of a group of pilot relief valves to the oil tank, so as to realize the two-way synchronization of the system. This method requires additional equipment to achieve synchronization; "an electric Hydraulic Proportional Valve Controlled Hydraulic Synchronization System” (Patent No. CN 205715021 U) proposes that the displacement deviation signals of the hydraulic cylinders on both sides are amplified and then act on the proportional valves to change the flow rate into the hydraulic cylinders to achieve synchronization. The displacement of the hydraulic cylinders on both sides calculated by this method The deviation acts on the control loops on both sides at the same time, which is easy to cause the oscillation of the hydraulic control loop; Wang Zhe from Beijing University of Science and Technology proposed in the paper "Active disturbance rejection synchronization control of hydraulic servo position system on both sides of the rolling mill" to use active disturbance rejection technology to realize hydraulic synchronization. The algorithm is relatively complicated, and the feedback curve cannot be accurately designed, and the actual application effect is not obvious; Zhang Zhiwei of Northeastern University proposed a proportional differential synchronous control algorithm in the paper "A Dual Hydraulic Cylinder Synchronous Control Method and Its Simulation Research". The value makes the slow system speed up and the fast system slows down, which reduces the hydraulic position synchronization error on both sides to a certain extent, but the displacement deviation of the hydraulic cylinders on both sides calculated by this method acts on the control loops on both sides at the same time, which is easy to cause the hydraulic control loop. At the same time, the actual on-site feedback signal has random interference, and the use of differential algorithms will make the system less stable; Fang Yiming of Yanshan University wrote in the paper "Robust Dynamic Output Feedback Synchronous Control "Robust dynamic feedback synchronous control is designed in this paper, so that the system can achieve fast synchronization in the case of uncertain parameters and external disturbances, and a good control effect has been achieved in the experiment. This method is computationally complex and difficult to apply; Xi'an Jiaotong University In his paper "Intelligent Control of Dual-cylinder Electro-hydraulic Position Servo Synchronous Control System", Deng Biao adopted a proportional-integral-differential iterative learning control algorithm, which improved the position synchronization accuracy on both sides to a certain extent by compensating the set value, but low precision

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