【作者】 武曲；

【导师】 刘亚秋；

【作者基本信息】 东北林业大学 ， 林业信息工程， 2013， 博士

【摘要】 在中密度纤维板(MDF)连续平压过程中,板厚控制始终决定产品最终质量,板厚纠偏控制是板厚控制的重要组成部分。MDF连续平压由液压缸阵列驱动热压板产生位移和压力,对板坯进行热压、定厚或纠偏处理。液压缸阵列是一类群集系统,具有“个体自治、局部信息交换、整体运行一致性”等特点。本学位论文结合教育部高等学校博士点专项基金“MDF连续平压板形自动纠偏协同控制关键技术研究”(20120062110012),针对液压缸阵列控制问题,从群集控制角度研究多执行器基于行为的协同控制方法,形成MDF连续平压板厚纠偏协同控制机制,主要完成了以下创新工作：提出并建立多动力终端(即液压缸阵列)的协同控制递阶结构,即“协同核-控制中介-动力终端”结构。基于该结构,自底向上研究液压缸阵列协同控制方法,形成MDF连续平压板厚自动纠偏协同控制机制。建立单终端位移控制系统模型和静载压力控制系统模型,并设计相应的协同控制器。所建立的系统朗之万方程考虑了板坯粘弹性作用。分别推导位移控制系统和静载压力控制系统的序参量方程,求得协同控制律(即系统运行涨落力)表达式。对位移控制系统和静载压力控制系统进行仿真分析,结果表明,协同控制方法实现了单终端对位移和压力的无超调输出,适用于MDF连续平压这一必须严格避免输出超调的应用领域。定义热压工艺模式,提出多终端层次协同方案。针对多终端同步输出控制问题,研究控制中介对多终端的校正方法,形成层次协同方案。基于等状态耦合结构,推导自协同同步控制系统的序参量方程,采用协同控制方法校正自协同动力单元中两个终端的输出；引入干扰补偿器增强系统稳定性；基于模糊理论对跟踪控制器进行改进,改善自协同系统全压力输出时的稳态性能；基于主从校正结构和协同控制方法,解决互协同的个终端同步输出控制问题；分别对自协同、互协同的多终端系统进行仿真,结果表明,协同同步校正方法能有效消除自协同、互协同同步系统的输出误差。定义板厚偏差阈值,进行偏差等级划分,制定协同核板厚纠偏决策规则。研制MDF连续平压板厚纠偏系统,对研究形成的板厚纠偏协同控制机制进行测试。通过对模拟数据和实验用板坯厚度纠偏处理测试,验证协同控制机制的有效性。液压缸阵列位移输出与压力输出的动态曲面表明：根据板厚纠偏要求,各终端输出的位移或压力与板厚纠偏决策相吻合,协同核能够根据各终端作用处的板坯特性做出相应决策切换。综上,本文通过研究基于行为的液压缸阵列协同控制方法,最终形成MDF连续平压板厚自动纠偏协同控制机制,实现在MDF连续平压中对板厚偏差的无超调、动态调节,液压缸阵列整体输出具有良好一致性,方法可行且有效。所得到的结论对MDF连续平压板厚控制研究具有一定参考价值。更多还原

【Abstract】 In process control of medium density fiberboard(MDF) continuous press, slab thickness control is an important part which has a critical effect on final quality of the product. The thickness deviation rectification control to slab is a key point of slab thickness control. In the production line, press plate outputs displacement or pressure. It is driven by hydraulic cylinder-array and executes hot-pressing and thickness setting. The cylinder-array is an individual autonomy system which contains local information exchanging and output consistently overall. From the point of flocking control, behavior-based synergetic control for multi actuators is researched in this dissertation, which concludes thickness deviation rectification synergetic control mechanism for MDF continuous press, and is funded by the Specialized Research Fund for the Doctoral Program of Higher Education of China-Key Techniques of Synergetic Control for Flatness Deviation Auto-Rectification of MDF Continuous Press-(20120062110012). The main contents of this dissertation are as follows:Firstly, a hierarchical synergetic control structure is proposed for cylinder-array. It is Synergy Nuclear-Control Agent-Motion Terminal structure. Synergetic control method for cylinder-array is researched and thickness deviation rectification synergetic control mechanism for MDF continuous press is concluded based on the structure.Secondly, hydraulic displacement control system and static pressure load control system with single terminal are modeled, and the synergetic controllers are designed. The established Langevin’s equations have taken the viscoelastie of the slab. The order-parameter equations of the two kinds of system are derived. And synergetic control rule, which is also called fluctuating force of system, is formulated. To simulate the two kinds of system, the results demonstrate that synergetic control method enables the motion terminal to output without overshoot. It is suitable for application of continuous press which should avoid overshoot strictly.Thirdly, hot pressing process modes are defined. And hierarchical synergetic correction solution for multi terminals is proposed. For multi terminals synchronized output, study on the correction method of control agent and form the hierarchical synergy correction solution. Synergetic correction controller based on equal statue structure is employed to eliminate synchronized error for self-synergy terminals. Disturbance compensator is introduced into the system to enhance stability. And tracking controller is improved based on fuzzy theory so as to overcome dependence of synergetic controller on system’s precise mathematical model. Synergetic correction controller based on primary-minor structure is employed to eliminate synchronized error for inter-synergy terminals. To simulate self-synergy and inter-synergy terminals, the results demonstrate that synergetic synchronized correction method is effective to eliminate errors in self-synergy and inter-synergy synchronized system.Fourthly, slab thickness deviation thresholds are defined so as to make a distinction among thickness deviation levels. And thickness deviation rectification decision rules of synergy nuclear are formulated. Slab thickness deviation rectification system of MDF continuous press is developed. To test the established thickness deviation rectification synergetic control mechanism by the system, let the simulated data and slab for experiment be detected. The dynamic surfaces of displacement output and pressure output of slab thickness deviation rectification system demonstrate that the hydraulic cylinder-array’s outputs are consistent with slab deviation rectification decision. Synergy nuclear could shift decision rules according to slab features under each hydraulic cylinder.In summary, this dissertation mainly researches on behavior-based synergetic control method for cylinder-array, and finally formulates thickness deviation rectification synergetic control mechanism for MDF continuous press. It achieves slab thickness deviation dynamic rectifying for MDF continuous press without overshoot. The outputs of cylinder-array are consistent overall. The conclusions are meaningful for MDF continuous slab thickness control research.更多还原