Tension system control device and method of sheet extruding unit

Abstract

The invention provides a tension system control device and method of a sheet extruding unit. The device comprises a cold aid roll control system, a pinch roll control system with a tension roll and a tension detector, and a winding roll control system with a winding system tension roll and a winding system tension detector, which are connected with a control chip and sequentially arranged along the winding direction of sheets. The method comprises a control method of the cold aid roll control system, a control method of the pinch roll control system and a control method of the winding roll control system, which are sequentially executed and adopt adaptive fuzzy PID (proportion integration differentiation) control algorithms, wherein the control methods of the cold aid roll control system and the pinch roll control system adopt speed control modes to perform control, and the control method of the winding roll control system adopts a torque mode of a winding serve motor to perform control. The tension system control device is mainly applied to a high-precision tension closed-loop control system of the sheet extruding unit, and aims to improve the operation stability of the system, the tension control precision and the sheet quality.

Description

technical field [0001] The invention belongs to the field of tension detection and control, and in particular relates to a tension system control device and a control method of a sheet extruding unit. Background technique [0002] The tension system of the sheet extruder is mainly composed of three parts: auxiliary cooling roller, pinch roller and winding roller. After the molten raw material flows out of the die, it is extruded by the extrusion roller, and then needs to be cooled by the auxiliary cooling roller, cut and surface treated, and then sent to the winding roller for winding through the pinch roller. During this process, tension fluctuations in each roller have a certain impact on sheet quality, including sheet surface quality, dimensional accuracy, sheet strength, etc. For example, in the cooling roller system, irregular lines may appear on the surface of the sheet, and the sheet may be deformed during the cooling process; in the pinch roller system, the sheet ma...

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Problems solved by technology

However, the traditional PID control algorithm relies on an accurate mathematical model, and it is difficult to keep the tension constant; and in the actual process, due to fluctuations in the tension on the sheet caused by temperature, speed fluctuations, changes in resistance torque, tension feedback and position feedback systems The time lag and other uncertain factors will affect the accuracy of the mathematical model, so high-performance control cannot be achieved; while fuzzy control does not require high model accuracy and has good adaptability, it is not easy to eliminate steady-state errors ( Jiang Sheng, Liu Huikang, Application of Fuzzy Adaptive PID Controller in Tension Control [J], Microcomputer Information, Volume 22, Issue 8-1, 2006, Page 32-34)

In terms of control methods, the current tension control system of the sheet extrusion unit does not have a direct tension feedback control system, and most of them are open-loop or semi-closed-loop control: the tension of the sheet is controlled indirectly through speed synchronization between multiple rollers; for large speed fluctuations For the rewinding roller, the tension is controlled by the hydraulic device, or the closed-loop feedback control of the tension is carried out by the hydraulic device; because it is not a closed-loop direct tension feedback control, the tension control accuracy is not high, and it is difficult to obtain better sheet quality (Li Minghui, Liu Xianbao, Zhang Hongxing, Design and Implementation of Paper Machine Web Tension Control System [J], Packaging Engineering, 2013, Vol. 34, No. 3, pp. 49-54)

The current tension control system of the sheet extruder unit mostly improves the sheet quality through on-site observation and adjustment based on experience, and the degree of automation is low. Most of the control accuracy is improved by purchasing foreign high-end PLC controllers and high-precision AC servo motors (Liu Chen, based on fuzzy Research on PID coiling tension control system [D], Xi'an University of Architecture and Technology, 2011)

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