June 6, 2022
Control scheme of blow molding machine
The automatic air ring is an online real-time control system. The controlled objects of the system are several motors distributed on the air ring. The cooling airflow sent by the fan is distributed to each air duct after constant pressure in the air ring air chamber. The motor drives the valve to open and close to adjust the size of the air outlet and air volume, and to change the cooling effect of the film blank at the outlet of the die head. Therefore, the film thickness is controlled. From the control process, there is no clear relationship between the film thickness change and the motor control amount. The distance between the thickness change of different thickness films and different valve positions and the control amount changes non-linearly and irregularly. Each time a valve is adjusted The time has a great influence on adjacent points, and the adjustment has hysteresis, so that different times are related to each other. For such a highly nonlinear, strongly coupled, time-varying and control uncertainty system, its accurate mathematical model is almost impossible. Establishment, even if a mathematical model can be established, it is very complicated and difficult to solve, so it has no practical value, and the traditional control has better control effect than deterministic control model, but the control effect of highly nonlinear, uncertain and complex feedback information is very poor. even powerless. In view of this, we choose the fuzzy control algorithm. At the same time, the method of changing the fuzzy quantization factor is used to better adapt to the change of system parameters.
