【作者】 刘鑫钰；

【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， 2013， 博士

【摘要】 大气候室法能够模拟实际室内环境，对人造板及其制品进行整体的甲醛释放量检测，测试结果能够反映室内环境中甲醛释放的实际情况，具有较高的可信度。但是大气候室造价高，检测周期长，导致甲醛检测成本过高，影响了大气候室在国内的应用。另外，大气候室的温度和相对湿度属于非线性、强耦合、大滞后的控制对象，常规的PID控制很难获得良好的控制效果。本文针对上述两个问题开展研究，开发出以微处理器为核心控制器的30m3甲醛检测大气候室，应用模糊滑模变结构控制算法，通过理论推导、仿真实验和实际运行，研究模糊滑模变结构对大气候室的控制效果。主要研究结果如下：（1）开发了模拟居住环境的30m3大气候室设备，将其用于人造板及其制品的甲醛释放量检测。大气候室的控制系统以ATmega2560微处理器为核心，系统程序设计成功能单一、结构清晰的模块，方便编译、维护和修改，模块化的设计容易实现系统移植，加快了软件的开发进程。与PLC控制系统相比，成本仅为其1/3左右。（2）建立大气候室温、湿度数学模型，并采用局部线性化方法对系统数学模型进行简化，对大气候室温度和相对湿度之间存在的耦合效应进行前馈解耦，将双输入双输出系统分解成两个单输入单输出系统，以方便模型求解。（3）分别研究了模糊控制和滑模控制对大气候室系统模型的控制效果，分析了这两种控制方式的控制特点，为了发扬不同控制方式的优点，克服其缺点，将两种控制方式相结合，设计出模糊滑模控制器。以切换函数s作为模糊输入变量，以改进型指数趋近律的系数ε和k为模糊输出变量，优化系统的趋近过程，削弱控制输入的抖振现象。仿真结果表明模糊滑模控制器对大气候室这种非线性系统控制效果良好，与传统的PID控制相比，具有响应速度快、超调小等优势。（4）首次将模糊滑模控制算法应用到甲醛检测大气候室的温、湿度控制上来。系统运行测试结果表明，室外环境温度为9℃时，大气候室的温度和相对湿度约7h后达到稳定状态，超调很小，控制精度分别为±0.3℃和±1%。（5）使用模糊滑模变结构控制实现了动态条件下产生饱和湿空气的约束技术，整个检测过程中，检测室内没有出现雾与结露，保证了检测过程的准确性。更多还原

【Abstract】 Climate chamber method can simulate actual indoor environment, evaluate formaldehyderelease of artificial board and its products. The testing results has a high credibility since theyreflects the actual situation of formaldehyde release indoor.Due to high cost of climate chamber equipment and a longer testing cycle, themeasurement of formaldehyde release cost a lot, which results in climate chamber method cannot be widely used in domestic. In addition, climate chamber temperature and relative humidityare nonlinear controll objects with the properties of strong coupling and large lag. Therefore, itis hard to to obtain good control using the conventional PID control. In order to solve abovetwo problems, this study is aiming at developing a30m3formaldehyde test climate chamberwith the core of microprocessor. Fuzzy sliding mode variable structure arithmetic is applied toclimate chamber control. Through theoretical derivation, simulation experiment and actualmotion, the control effectiveness of fuzzy sliding mode variable structure on control of climatechamber are assessed. The specific conclusions are given as follows:(1) A new climate chamber equipment has been developed to simulate a livingenvironment with a volume of30m3. It can be used to examine the formaldehyde release ofwood-based panels and wood products. ATmega2560microprocessor is applied as the core ofcontrol system. The main features of system programs are single function and clear structure,which lead to easily compile, maintain, modify, and easy to transplant the syste, accordinglyspeed up software development. In comparison to the cost of PLC system, the cost ofmicroprocessor control system is reduced by one third.(2) Mathematical models between temperature and relative humidity of climate chamberhas been established. The mathematical models are simplified based on local linearization andfeedforward decoupling. Meanwhile, the double input and double output system is decomposedinto two single input single output system, in order to slove this model easily. (3) Control effect of fuzzy control and sliding mode control on system model of climatechamber are studied respectively in this research. In order to combine the advantages of twodifferent control strategies, a fuzzy sliding mode controller has been designed. In this newcontroller, switch function S is used as fuzzy input variable and improved exponential reachinglaw coefficient k and ε as fuzzy output variable. In this way, the approach process is optimizedand chattering phenomenon is alleviated. Simulations results show that fuzzy sliding modecontroller has a good control on climate chamber nonlinear system. Compared to PID control,it has faster response speed and smaller overshoot, et.al advantages.(4) For the first time, fuzzy sliding mode control algorithm was applied to temperatureand relative humidity control of the formaldehyde test climate chamber. The test results showthat when outdoor environment temperature is9℃, it takes about7h to reach steady statebetween climate chamber temperature and relative humidity. It also shows that the accuracyfor temperature and relative humidity can achieve±0.3℃and±1%respectively, with a slightovershoot.(5) Fuzzy sliding mode variable structure control makes constraint technology ofgenerating saturated moist air in dynamic environment come true. There is no fog and dewgenerated through whole detecting process, which ensures the accuracy of the inspectionprocess.更多还原