Pressure Casting Control System Design And Realization

As one kind of advanced casting technology developed on the basis of counter pressure casting, adjustable pressure casting has higher filling capacity, better feeding capacity, and has vacuum metallurgy effect merit concurrently. On the foundation of introducing its technical process briefly and resting on its performance index, this thesis put forward the overall system design proposal.In this thesis author's prime task was as follows:Firstly, after having confirmed the hardware architecture of computer control system, author carried on the initialization establishment of each pcl board, and then compiled corresponding program module.Secondly, according to the communication request between the position and lower machine of system, in the data link regulations as well as the mistake control technology foundation, this thesis designed the frame, the fundamental unit of data communication in this system. According to the frame, author compiled the data receive and transmission program module as well as write the system communication order collection. In addition, according the characteristic of communication between the position and lower machine as well as the RS-232 communication standard, the system determined the connection way of asynchronous serial communication.Thirdly, this thesis used the mechanism analytic method to determinate the mathematical model of system. Considering the system every kind of possibly complex factor create the parameter inaccurate as well as the pure time delay link influence, the paper also simply discussed in the project the PID parameter installation method as well as the processing pure time delay link Smith estimate algorithm.Fourthly, because the system model input was the pitch signal, different from step signal of general control system, according to the system performance index, the author used the traditional PID control algorithm, but also has used the smallest racket non-ripple design method. Considering the control action of smallest racket non-ripple design easy to surpass the scope, the paper also discussed the integral saturation characteristic influence in the actual system.Fifthly, considering the existence of every kind of high frequency noise jamming as well as the industry unique 50Hz noise jamming in the actual production environment, this thesis discussed digital filter and software anti-jamming technology, then, determined the useful signal the frequency range and designed the effective low pass filter.Finally, passing through the Matlab simulation computation as well as the scene debugging confirmation, it was displayed that the overall system work satisfied the design request.