Rolling mill hydraulic AGC system and control method thereof

Abstract

The invention discloses a hydraulic AGC system of a rolling mill, and a control method thereof, and the system is connected to be formed in a manner of double closed loop of an inner-outer loop that is combined by an outer closed loop and an inner single closed loop. A thickness measuring device is taken as a feedback element, a deviation signal of the feedback value of the thickness measuring device and a given thickness value is firstly input into a PID controller which is based on Smith predictor function and then is input into the PID controller in the inner single closed loop, the deviation signals of a position sensor, a pressure sensor, a tension sensor and the feedback value of an speed measuring device are input into the PID controller; the PID controller processes the signals by a control module, and a touch screen HMI device is used for setting and displaying the parameters of the system and operating and monitoring all the steps. As the strategy of the PID controller based on Smith predictor function is introduced in the invention, the feedback and response speed is fast, thus improving the control precision and stability of the system obviously. The system and the method have the advantages of simple installation and debugging, convenient operation and reliable running.

Description

technical field [0001] The invention relates to a metal rolling technology, in particular to a rolling mill hydraulic automatic control (AGC) system for rolling plates and a control method thereof. Background technique [0002] With the continuous improvement of the quality requirements of users for cold-rolled strips, the precision of the hydraulic control system of the rolling mill also needs to be improved. Finished product accuracy plays a vital role. The current rolling mill hydraulic AGC system includes an amplifier, a servo valve and a hydraulic cylinder connected in series; it also includes a position sensor, a pressure sensor, a tension sensor and a tachometer connected in parallel, and the thickness gauge behind the stand is used for feedback. The disadvantage of this control method is that the hysteresis is very large. Especially in low-speed rolling, it often takes hundreds of milliseconds to run from the outlet of the deformation zone to the thickness gauge. T...

AI Technical Summary

Problems solved by technology

The disadvantage of this control method is: the lag is very large

Especially in low-speed rolling, it often takes hundreds of milliseconds to run from the exit of the deformation zone to the thickness gauge. The feedback with a large lag is likely to make the system unstable and also affect the control accuracy. Therefore, in the process of rolling plates, how to eliminate the The impact of system time lag is an urgent problem to be solved, and the effective solution of this problem is especially important for improving rolling productivity and ensuring plate quality

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