Research On Automatic Temperature Control System Of Drying Room Of Cathode Electrophoresis Coating Line Based On Fuzzy PID Control

With Chinese auto market is in a stage of rapid development, huge market demand has led to major car manufacturers have the equipment for expansion and upgrading. The government advocates an energy saving, environmental protection and efficient lean production model, allowing companies to upgrade existing obsolete equipments to meet the requirements of low carbon emissions. Since the optimization process and using environmentally friendly lead-free paints, the temperature control system of drying room must be optimized.The systematic fuzzy PID temperature control technology is used in the temperature control system of drying room of the cathode electrophoresis line for the first time. Compared with the function and feature of the traditional PID technology and fuzzy PID control technology in the automatic control system, combined with configuration software and I/O communications technology, the automatic temperature control system of drying room of the cathode electrophoresis coating line comes true. This technology resolves some problems, such as the big overshoot, the worse dynamic characteristics, and the temperature oscillation and so on. It can find a new way to control temperature in drying room of the cathode electrophoresis coating line.In the design of control methods, the paper deeply studys the different physical phenomena and chemical phenomena of the baking process of the cathode electrophoresis line. On this basis, the temperature of drying room is the controlled object and the different parameters and rules of fuzzy PID controller are analyzed. The simulation model of drying room structure is built on the computer and the fuzzy controller by MATLAB R2008a software. PID controller and fuzzy PID controller are simulated separately. Simulation results show that: Fuzzy PID controller is better than PID controller, with a short settling time, a small overshoot, a better robustness, and a small steady-state error.In the design of hardware circuits, Honeywell's UDC2500 PID temperature controller is used as the controller, mainly collecting temperature measurements, transmission control signals to the actuators, and communication with the host computer. In the design of PC, the touch screen of Jobwell is used as the control center, mainly completing the basic parameters of temperature display and settings, and rules of fuzzy PID algorithm. In the design of burner, the Eclipse's gas burner and Siemens's LFL1.335 program controller are used, mainly completing the inspection before ignition and implementation of the ignition, and in the combustion process, dealing with the emergence of high temperature. In the design of actuator, Honeywell's M941D actuator is used, mainly debugging air pressure and gas pressure and completing the appropriate action.In the design of software, Likong's Forcecontrol configuration software is used as the temperature control system development and application platform. It mainly shows the basic parameters, the temperature history curve, the PID control parameters and alarm information, through the Modbus communication protocol, the host computer sends the information to the temperature controller. It also uses DDE (dynamic data exchange), to complete fuzzy PID controller's action. The temperature control system software mainly completes many actions, such as system initialization, the temperature acquisition, data processing, the temperature curve, the adjustment of the actuator, over-temperature alarm system management tasks and so on.