连续平压热压机电液伺服系统的设计与仿真研究

发布时间：2018-05-03 08:03

本文选题：连续平压热压机 + 伺服系统　；参考：《南京林业大学》2013年硕士论文

【摘要】：人造板生产规模主要决定于热压机，传统的间歇式压机已经不能满足人造板生产发展的需要，连续压机以其优良的性能逐步取而代之。面对国外技术封锁的阻碍，本研究将构建电液伺服系统，通过对连续平压过程中的各区段热压压力和板坯厚度的精确控制，为我国研发拥有自主知识产权的连续平压机发挥一定的作用。本研究首先介绍连续平压机的组成，分析其要完成的工艺任务和需控制的各项参数，确定了电液伺服系统的以油缸压力和油缸位移为控制对象，使用电液伺服阀进行调节的闭环控制方案，在此基础上设计连续平压机液压系统原理图。文中完成了泵站系统和机架油缸组控制系统各组成部分原理图的设计，实现了压力、流量控制，压板提升下降等功能。本研究以位置伺服系统为例，建立了位置伺服系统各环节的数学模型，以压制厚度为12mm的中密度纤维板为基础设计参数，得出了位置伺服系统的闭环传递函数。在数学模型的基础上进行系统性能分析和系统校正。文中使用PID控制器进行系统校正，分别使用稳定边界法、Ziegler-Nichols公式、Cohen-Coon公式和误差积分指标最优PID校正设计法对PID参数进行整定，最终得出使用时间绝对偏差乘积积分最优法整定PID参数后，系统的峰值时间tP0.01s，调节时间ts=0.03s，响应速度很快，短时间内进入稳态，稳态实际输出值与期望输出值一致，超调量s%=14%，满足控制要求。本研究最后使用AMESim软件进行计算机仿真分析，通过对不同负载情况下系统的仿真结果的分析，确定了压机二次加压区开始阶段和压机出口处的不同工艺控制方式。通过对同侧油缸控制仿真结果的分析，显示在二次加压开始段，一个伺服阀控制同侧多个油缸可以满足工艺要求，压机出口处的几个机架油缸组的尽量使用一个伺服阀控制一个油缸。通过对一个机架油缸组控制仿真结果的分析，在排气段，，可以中间油缸采用压力控制，左右两侧油缸采用位置控制，保证板坯横向厚度尺寸均匀稳定。
[Abstract]:The scale of wood-based panel production mainly depends on the hot press. The traditional intermittent press can not meet the needs of the development of wood-based panel production. The continuous press is gradually replaced by its excellent performance. In the face of foreign technical blockage, this study will construct an electro-hydraulic servo system, which can accurately control the hot pressing pressure and slab thickness of each section in the process of continuous flat pressing. For our research and development with independent intellectual property rights of continuous flat press play a certain role. In this study, the composition of the continuous flat press is introduced, and the process tasks and parameters to be controlled are analyzed. The control object of the electro-hydraulic servo system is the cylinder pressure and the displacement of the cylinder. On the basis of the closed-loop control scheme of electro-hydraulic servo valve, the principle diagram of hydraulic system of continuous flat press is designed. In this paper, the design of the schematic diagram of each component of the pump station system and the control system of the oil cylinder group of the frame is completed, and the functions of pressure, flow control and pressure plate lifting and lowering are realized. Taking the position servo system as an example, the mathematical model of each link of the position servo system is established. The closed-loop transfer function of the position servo system is obtained based on the design parameters of the medium density fiberboard (MDF) with the thickness of 12mm. System performance analysis and system correction are carried out on the basis of mathematical model. In this paper, the PID controller is used for system correction, and the stable boundary method is used to calibrate the PID parameters by using the stable boundary method and the Cohen-Coon formula and the optimal PID correction design method of the error integral index, respectively. Finally, after the PID parameters are adjusted by the time absolute deviation product integral optimization method, the peak time of the system is tP0.01s, the adjusting time is 0.03s, the response speed is fast, the steady-state output value is in steady state in a short time, and the actual output value of the steady-state system is in agreement with the expected output value. The overshoot is about 14 to meet the control requirements. At the end of this study, AMESim software is used for computer simulation analysis. Through the analysis of the simulation results of the system under different loads, the different process control methods in the initial stage of the secondary pressurization zone of the press and at the outlet of the press are determined. Through the analysis of the simulation results of the same side cylinder control, it is shown that at the beginning of secondary pressurization, one servo valve can control the same side multiple cylinders to meet the process requirements. Use a servo valve to control a cylinder as much as possible for several rack cylinders at the outlet of the press. Through the analysis of the simulation results of the control of a frame oil cylinder group, the pressure control can be adopted in the middle cylinder and the position control on the left and right sides of the oil cylinder in the exhaust section, which ensures the horizontal thickness of the slab to be uniform and stable.
【学位授予单位】：南京林业大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TS642

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