Fuzzy control-based special PID (Proportion Integration Differentiation) method for controlling temperature of plastic extrusion device

Abstract

The invention provides a fuzzy control-based special PID (Proportion Integration Differentiation) method for controlling temperature of a plastic extrusion device. By taking the traditional PID control for reference and introducing an algorithm and an implementation mode of fuzzy rules, the method comprises a few important parts such as parameter fuzzification, fuzzy rule reasoning, parameter defuzzification, PID controller and the like. The method comprises the following steps of: calculating the deviation between an actual temperature and a theoretical temperature and current deviation variation speed according to reference input and feedback signals, performing fuzzy reasoning in a fuzzy reasoning device by means of fuzzy experience, performing fuzzification to convert an input value into a membership degree by means of a membership function of an input fuzzy set, outputting a proportion coefficient, an integration coefficient and a differentiation coefficient of a PID controller by the fuzzy reasoning device, and performing PID control by using the coefficients as references of the current controller. By calling the fuzzy rules of the heating and water cooling processes of a plastic extruder, nonlinear effect produced by water vaporizing and cooling in the cooling process can be effectively controlled, the temperature control of the whole main machine meets the requirement of the extrusion temperature, the extrusion quantity of the plastics is stabilized, and the product quality is improved.

Description

technical field [0001] The present invention relates to the application function research in the temperature control process in the field of industrial control. By referring to the traditional PID control, introducing fuzzy rule algorithms and implementation methods, the cooling process can be effectively controlled by calling the fuzzy rules in the heating and water cooling process of plastic extruders. The non-linear effect produced by the water vaporization and cooling in the machine makes the temperature control of the whole main machine meet the requirements of extrusion temperature, stabilizes the plastic extrusion volume and improves product quality. Background technique [0002] There are many occasions for temperature control applications in the field of industrial control. Generally speaking, the temperature control in the process mainly includes heating devices, cooling devices, detection devices, control units and control objects, etc., such as figure 1 The schem...

AI Technical Summary

Problems solved by technology

Therefore, it is difficult to ensure that the fluctuation stability of the entire host temperature control system meets the extrusion temperature requirements of various plastics by using the traditional PID temperature controller, such as Figure 5 The traditional PID temperature control curve of the plastic extruder heating and water cooling process shown

Images