| Thermal Gradient Chemical Vapor Infiltration (TCVI) process based on the CVI process is a new technique to manufacture C/C composites. When the TCVI stove is heating up, there will be thermal gradient in the initial fibre preform. The precursor gas will diffuse under pressure and react at the depositing temperature in the initial fiber preform to obtain C/C composites. The TCVI technique avoids the weakness of isothermal-isobaric CVI and isothermal forced-flow CVI due to the shorter processing time and the higher quality of the products. Therefore TCVI technics is a potential attractive method for prepare C/C composites.In this thesis, according to the problem of TCVI equipment and controlling process parameters difficultily, we studied the autocontrol of depositing temperature under existing conditions in order to realize the autocontrol of TCVI technics, and make it on stream.Due to the high power needed in this process, the depositing temperature was controlled by controlling transformer and thyristors. Based on fuzzy control theory and controllers' experience, the fuzzy control system was developed using Sugeno model of Matlab fuzzy logical toolbox to change the fuzzy rule easily. As a result, the autocontrol of transformer was realized successfully.Using least-square algorithm and least-square linear indentifying to compute parameters, the mathematical model of autocontrol method of deposition temperature was studied as well. So the parameters of PID can be computed and the direct digital control system will be established, which can reduce the damage of the rectifier.Applying hybrid program technology, the process control software was developed by integrating Kingview6.5 and VisualBasic6.0. Characterized by good human-computer interaction, easy application and good practicability, the software can complete data acquisition and control, FP93 programmable PID controller controll, long-distance control, and so on.
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