Study And Development Of A Building Fire Simulated Experimental Intelligent Measurement And Control System

The damage to the human lives and properties of fire especially building fire is obvious to all. In order to study the happening, developing as well as the destruction mechanism of building fire, it is necessary to establish a set of building fire simulated experiment system, which can simulated test the mechanics performance change of each kind of building component under the action of flame. It must be according to the international standard ISO834 for the system to add fire load to building component in the heating process. Particular theoretic and experiment research tasks are carried on the study and development of a building fire simulated experimental intelligent measurement and control system in this dissertation. The primary research work include:(1) A buildings fire simulated experimental system including a vertical furnace, a horizontal furnace, a set of liquefied petroleum gas system and a device to add pressure to experiment building component is designed. There are two innovation characteristics: on the one hand, using liquefied petroleum gas to furthest simulate the flame heating process of building fire; and on the other hand, the measurement and control system can satisfy the flexible, comprehensive and reliable test speciality of building fire simulation test, which requires to the multi-types building component.(2) A soft measurement modeling based on principal component analysis and RBF neural network is introduced, which adapts the furnace temperature estimate of fire simulated experiment system and can solve this puzzle in fire simulated experimental. For the collected 119 groups 18 loops data, 80 groups are used in PCA and RBF neural network preliminary discipline to determinate appropriate center distance, weight and hidden layer. The other 39 groups data are used to test the disciplined soft measurement model to complete an on-line furnace temperature estimate model. The comparison result of this model with the weight average method illuminates that the model has obvious advantages in the precision and stability of furnace temperature estimate.(3) A new multi intelligent controller based on Fuzzy expert PID control is presented. The relation between 3 PID controller parameters (K_p, K_I, K_D) and the dynamic or stability characteristic of PID controller is thoroughly studied, and a method to intelligent on-line adjust K_p, K_I, K_D is developed in the dissertation. After the comparsion experiment between Fuzzy expert PID and general PID, 5 curves are shown in different time of the heating process, which indicate that the Fuzzy expert PID has obvious advantages in control precision,stability and so on comparing with general PID At last, 5 comparison curves of furnace temperature measured in real time to the standard value are given, and these curves indicate that the control result for fumace temperature is completely according with the demand of the international standard ISO834, and what is more, the performance index such as control precision, stability error and so on are much more excellent than the design request.(4) A data collection stytem with virtual instrument constructure is introduced, which include different type temperature sensors such as thermocouple, thermal resistance and DS18B20 digital thermometer. 54 channel temperature collecting and processing system is developed, and a particular measurement and control hardware constructure is designed, which contain a RS-485 serial interface for MCUs communicating and a EPP parallel interface between MCU and IPC.(5) The software system is developed by a multi-platform tool including Visual Basic 6.0, MCU assemble language, FRANKLIN C and MATLAB. The system is consist of a furnace temperature data collecting software, a communication software, a soft measurement software, a neural network training software based on MATLAB, a Fuzzy expert PID controller software and an experiment process management software.(6) A novel experiment method is put forward by comparing embedding temperature sensors into test object to measure temperature with temperature field calculationan. The temperature field distribution of building component in the fire simulated experiment furnace is analyzed both from theoretic and experiment aspects. As a result, curves of all measuring data comparing with analysis and calculation data are given. The result proves that the building fire simulated experiment system developed by the author have availability, practicability and advancement in building component anti-fire performance test.