【作者】 胡如龙；

【导师】 孟志强；

【作者基本信息】 湖南大学 ， 控制理论与控制工程， 2008， 硕士

【摘要】 在橡胶工业中,硫化工艺是最后一个工艺过程,也是最为关键的一个环节。作为橡胶硫化主要设备的平板硫化机必须具备控制硫化条件(硫化温度、硫化时间和硫化压力)的能力,其控制的精度将直接影响橡胶硫化制品的质量好坏。通过分析可知,平板硫化机系统的温度是一种不确定、大惯性、非线性严重的控制对象,在实际生产中,普遍存在温度控制精度不高,达不到国家硫化标准的问题。因此实现平板硫化机高精度的温度控制以提高橡胶制品质量对橡胶工业生产具有重大的现实意义;硫化压力通常不是硫化化学反应的必要条件,但却是绝大多数橡胶制品硫化的必要条件,因此实现平板硫化机高精度的压力控制也是提高橡胶制品质量的必要因素;硫化时间也是硫化化学反应必要的条件,其控制精度的高低关系到硫化结果的成败。本文的研究目的是在改造原有的平板硫化机控制系统的基础上,开发出一个控制精确、价格适宜、稳定可靠的平板硫化机控制系统,以实现对硫化条件的精确控制。本文在分析国内外平板硫化机控制系统发展现状的基础上,对PID控制的基本原理和模糊控制的基本原理作了简单介绍和对比。根据硫化过程中温度存在的非线性、大滞后和大干扰的实际情况,为解决PID参数难以整定以及减小未建模、动态工况和模型误差对控制效果产生的影响,本文探讨了模糊自适应PID算法在平板硫化机温度控制中的应用。通过对常规PID和模糊自适应PID的仿真结果进行分析对比,证明模糊自适应PID控制方法具有较小的超调量和较短的调节时间,良好的动、静态特性,以及更好的适应性和鲁棒性,优于常规的PID控制。本文结合目前所具备的实验条件,并根据用户的要求,研究与设计了采用高性能的AVR单片机作主控制器,利用PT100铂电阻温度传感器组成的电桥电路检测系统温度,采用全周波双向可控硅过零调功电路实现温度调节控制的平板硫化机自动控制系统。该控制系统配备了掉电实时数据保存电路、功率MOS管开关量输出电路、YXD-19264AG图形点阵液晶显示电路、基于Modbus协议的RS-485串行通讯接口电路等一系列外围电路,使单片微型计算机的硬件和软件资源的功效得到了充分发挥。最后,针对平板硫化机的控制要求高、工作环境恶劣等情况,介绍了常用的抗干扰措施,特别是本文设计中用到的具体的硬件和软件抗干扰措施。设计的样机运行测试结果表明本文研究的方法和设计有效,达到了设计目标。更多还原

【Abstract】 In the rubber processing, the vulcanization is the last phase as well as the most important one. As the primary machine of the vulcanization,the flat vulcanization machine should have the ability of controlling the vulcanization’s condition,such as:vulcanization temperature、time and pressure. The control precision will impair rubber product’s quality directly.By analyzing, the control temperature of the flat vulcanization machine is an uncertainty, big, inertia and serious non-linearity object. In actual producing medium, the control precision of temperature is not accurate enough, which can not reach the national standard. So, designing the flat vulcanization machine with high precision tempreture--control to improve the quality of rubber products is of great significance of rubber industry. Usually, the vulcanized stress is not a necessary condition for the vulcanization chemical reaction, but for vast majority of robber products. So, to achieve high precision control pressure is also a necessary factor of the flat vulcanization. Meantime, the vulcanization time is a necessary condition for the vulcanization chemical reaction as well, the control precesion level of which is related to the success or failure of vulcanization. This study is on the basis of remaking the original control system of flat vulcanization and aimed at developing a control system which is of reliable, stable, precise control and reasonable price to achieve precise control of vulcanization condition.The text analysis on the basis of both domestic and international development status of the flat vulcanization machine’s temperature control system, then, we made a simple introduction and contract with PID control of the basic tenets and the fuzzy’s. In order to solve the difficulty that the PID parameter is hard to find the suitable one, and the influence on the control effect which is from reducing the unmodelled, dynamic status and model error.Meantime, In the vulcanization process, according to actual situation, that the vulcanization temperature is nonlinear,hysteresis/delay and big interference. This paper discusses the adaptive fuzzy PID’s algorithm, which used in the application of temperature control of flat vulcanization. By comparing the simulation results of conventional PID with fuzzy adaptive PID, which proves that the control method of fuzzy adaptive PID is of shorter overshoot and regulation time, good dynamic and static properties, as well as a better adaptability and rubustness, which is superior to the conventional control. With the current experimental conditions, and in accordancing with the user’s requirements, in this paper, the design of flat vulcanization control system is based on the high-performance AVR single-chip computer system, and using bridge circuit that makes up of PT100 platinum resistance sensor, and regulate the power at the zero-crossing of the two-way thyristor with the full sine wave circuit to achieve control of temperature. The control system equipped with the real-time date retention circuit when the power cut off, the switching output circuit of the MOS, XYD-19264AG graphic dot-matrix LCD circuit, and a series of external circuits, such as RS-485 serial communication interface circuit based on the MODBUS agreement. These make the effectivenees of single-chip microcomputer’s hardware and software resources be fully played.Finally, base on the plat vulcanization machine’s high control requirements and poor working environment,the paper introduced the popular anti-disturbance measures, particular the design of specific hardware and software anti-disturbance measures used in this paper. The specimen testing results show that the methods and the design is effective,and meets the design request.更多还原