【作者】 苗虎；

【导师】 周玉成；

【作者基本信息】 中国林业科学研究院 ， 木基复合材料科学与工程， 2014， 博士

【摘要】 干燥设备是木材干燥作业的基础条件，其性能优劣对木材干燥质量有着直接的影响。在其控制系统的设计过程中，采用合理的控制策略可以使干燥设备发挥最优性能，从而缩短干燥时间，降低能耗，提高木材的干燥质量，增加企业的经济效益。因此，将智能控制算法应用到木材除湿干燥控制系统的设计中具有一定的实用意义。本研究在分析典型木材除湿干燥设备总体结构和工作原理的基础上，设计了一种基于模糊解耦理论的木材除湿干燥控制系统，能够根据干燥窑内温度、相对湿度的变化，动态的调节除湿机的开启比例，给出一个控制周期T内最佳的除湿机开启与停止时间，从而精确控制干燥窑内的温度、相对湿度，满足木材干燥基准的要求。主要研究结果如下：（1）基于模糊解耦理论，设计了用于木材除湿干燥过程控制的多变量模糊解耦控制器。在设计过程中，对多变量系统进行模糊解耦分析，将其分解为温度-除湿机开启比例的温度模糊控制器，相对湿度-除湿机开启比例的相对湿度模糊控制器两个SISO系统；然后对两个SISO系统进行模糊控制器的设计，其模糊控制规则是在对北京凯明提琴有限公司多年使用木材除湿干燥设备积累的控制经验进行总结、分析后得到的，并以此作为模糊推理的依据，分别得到两个SISO系统的控制输出查询表；最后将2个SISO系统的控制输出按照“取小法”的合成法则进行合成，得到多变量系统的解耦控制输出。（2）针对除湿机不能频繁开启、停止，且开启、停止之间需要一定的时间间隔的工作特点，提出控制周期T的概念，可以根据所处干燥阶段的不同，设定不同的控制周期T，对除湿机进行控制。这样在保证对干燥窑内温度、相对湿度的精准控制的基础上，可以减轻设备磨损，延长设备寿命，同时对干燥质量也有一定的提高。（3）根据辅助电加热器在木材除湿过程不同阶段的作用和功能，提出其在干燥预热阶段、干燥阶段的控制思想，保证在不影响除湿机本身的供热能力的基础上，能够精确地补充干燥窑内湿空气所需的热量。（4）搭建了木材除湿干燥控制系统的硬件平台，并对其控制软件进行了设计。控制系统采用ATmega1280单片机作为控制器，以DWIN智能触摸屏为人机交互方式，选用合理的温湿度传感器和数据存储芯片，编制相应的控制程序，完成木材除湿干燥过程的精准控制和可视化操作。（5）对北京凯明提琴有限公司的木材除湿干燥设备在仪表控制和模糊解耦控制两种方式下的实际运行情况进行总结分析，结果表明：相比仪表控制方式，本研究设计的控制系统能够在保证干燥质量的前提下，缩短干燥周期，由原来的30天减为23天；降低能耗，节能17%左右，同时除湿机的工作时间减少157小时，减轻了设备磨损，延长设备寿命。本研究第一次将模糊解耦理论应用到木材除湿干燥过程的控制中，并设计了相应的控制系统，经过两年多的实际生产使用，取得了很好的应用结果，干燥木材的合格率在95%以上。该研究成果可为同类型的木材除湿干燥设备的设计与应用提供参考，具有良好的应用前景。更多还原

【Abstract】 Drying equipment is a key part in wood drying process, and its performance greatlyaffects the drying quality. In the design of control system for drying equipment, reasonablecontrol strategies could maximize the performance of drying equipment, thus shortening thedrying time, reducing energy consumption, improving the drying quality and increasingeconomic efficiency of enterprises. So it would be practically significant to introduce theintelligent control algorithm into the design of the control system of dehumidification drying.Analyzed with the overall structure and working principle of dehumidification dryingequipment, in this study, a kind of intelligent control system was designed on the basis of fuzzydecoupling theory. The control system could dynamically adjust the run-time proportion ofdehumidifier according to the changes of temperature and relative humidity in the drying kiln,then calculate turn-on time and stop time of dehumidifier in one control cycle T, so as toexactly control the drying process to meet the wood drying schedule. Main results for thisstudy are as follows:(1) Based on the fuzzy decoupling theory, a multivariable fuzzy decoupling controller wasdesigned for the process control of dehumidification drying. During the design process, it wasdivided into two SISO systems: temperature--the run-time proportion of dehumidifier andrelative humidity--the run-time proportion of dehumidifier; then the fuzzy controllers for twoSISO systems were designed respectively, their fuzzy control rules were established afteranalyzing and summarizing the control experiences which was accumulated from the long-termuse process of dehumidification drying equipment in Beijing Kaiming fiddle CO., LTD. Next,fuzzy reasoning was calculated on the basis of the fuzzy control rules so as to get the fuzzycontrol query tables of two SISO systems respectively. In the end the control output of MISOsystem was gotten from the synthesis calculation conducted between the control outputs of twoSISO systems in accordance with “min” criterion. (2) The dehumidifier cannot frequently open and shut down, and it requires a certain timeinterval between the opening and closing. For these working characteristics, the concept ofcontrol cycle T was proposed. According to the different drying stage, it can be configured todifferent values to control dehumidifier. This method could not only ensure the precise controlof temperature and relative humidity in the drying kiln, but also reduce device wearing toprolong the life cycle of the device, and improve the drying quality to some extent.(3) Considering the functions of auxiliary electric heater at different stages ofdehumidification drying, different control ideas for drying preheating stage and drying stagewere put forward. It could accurately supply the required heat in the drying kiln withoutaffecting the heating capacity of dehumidifier itself.(4) The hardware platform of control system for dehumidification drying was built andcontrol software was designed. Control system chosen ATmega1280single chip asmicrocontroller and adopt DWIN intelligent touch screen as the man-machine interactive way.Then suitable temperature&relative humidity sensor and data storage chip were selected.Finally the corresponding control programs were established to realize the precise control andvisual operation of dehumidification drying.(5) The actual use of dehumidification drying equipment under instrument control andfuzzy decoupling control were analyzed and summarized respectively in Beijing Kaimingfiddle CO., LTD. The results indicated that compared with instrument control, the controlsystem designed in this study could shorten the drying time, from30daysto23days; reducethe energy consumption and the energy-saving ratio is17%on the premise of good dryingquality. At the same time, the running time of dehumidifier decreased by157hours, so thedevice wear was reduced to extend the life of equipment.The research used fuzzy decoupling theory in the process control of dehumidificationdrying for the first time. The corresponding control system was designed. It has been used inthe actual production for over two years and obtained a good application result. The qualifiedrate of wood after drying in the equipment is over95%. The study can provide a reference for the design and application of the same type of dehumidification drying equipment. It has agood application prospect.更多还原