Pressure Casting Control System Design And Control Method

On the basis of brief introduction about the technics procedure of adjustable pressure casting, this paper puts forwards a scheme on TY-1 adjustable pressure casting control system. Referring to the manual control system, there are a lot of information on its circuit design in detail, including the design of electromagnetic valve control circuit, analog output circuit, expecting pressure curve circuit and so on. it also elaborates the programming on GAL chip. With regard to the distributed computer control system, the paper gives a minute description on the hardware structure of the control computer, What's more, it provides a full and accurate supplement about the software design of the control computer system: data acquisition program, asynchronous serial communication program, command processing program, DA output program etc. In addition, according to the standard of RS232, it works out and realizes a convenient protocol which suits the asynchronous serial communication between the acquisition computer and the control computer.After acquires the model of system by analyzing the work principle, it transforms the system into two SISO systems through the decoulped control at first, and eliminates the influence from delay among the plant by applying Smith estimator. Secondly, it adopts the method of pole assignment to design regular PID controller for each system. Finally, the author proposes a new design method of PID controller with the change of parameters in plant, the simulation result shows that this proposal produces a remarkable effect.