Temperature Control System Of Medical Thermotank

Temperature is an important factor in medical medicinal inspection, if the temperature is too high or too low, the final result is seriously affected. Therefore, it is necessary to reach some desired temperature points quickly and exactly in medical inspection. Presently, the control theory which mostly used in temperature control is classical PID control theory. It is difficult to determine classical PID parameters, usually need to try may different parameters on line, and the inaccuracy of mathematical modeling of the plants usually degrades the performance of the controller, especially for nonlinear and complex control problems.In this thesis the temperature control system of medical thermotank is discussed and researched. Thermotank is a typical first integral inertial object with time delay, there are many disturbances in it and it is difficult to built its actual model, thus classical control method can not fulfill the requirement.In order to solve this problem, in this thesis self-tuning PID controller based on flexible neural networks and temperature dynamic matrix controller are brought forward, and we make the simulations that the two method are used in thermotank temperature controlling. The simulation results indicate that the new control methods can improve the control property greatly.Except theory studies we design the hardware and software of the control system. The hardware is centred by an AT89S52 microcomputer, four controlled IGBTs drive two pletiers to heating or cooling the thermotank. The hardware consist of control circuit, drive circuit, power converter, temperature sample circuit, communication circuit; the software consist of main program, interrupt program, temperature sample program, data manage program, etc.