Fast Intelligent Research And Application Of The Extruder Barrel Temperature Control Algorithm

Temperature is one of the main objects of industry control. In industry process ,we often need to control the temperature. Excellent control over temperature can not only enhance the quality of products ,but also reduce energy consume and enhance efficiency. Plastic extruder is the pivotal equipment on plastic tube materials product line . The temperature control effect of extruder's stuff container influences the capability and quality of extrusion products directly.Thus,the dependability of temperature control over stuff container has become a key point of product molding,and at the same time,temperature control has become an important part of extruder product manufacture.PID control method is used in temperature control the most comprehensively.It is very simple and has good stability as well as dependability,so it is often used in those linear constant system.But it cann't bring us perfect control effect when it is used in nonlinear systems, one of which is hysteresis system, such as temperature control system.On the other hand,because the parameters of PID must be adjusted accordingly when the plant changes,that is, adjustor's parameters are related with the steady condition of the system,it is very inconvenient to adjust parameters over again offline in a project.In this paper, we analyse temperature control problem deeply.On base of the analyse about the principles and characteristics of traditional linear PID controller,we analyse and study Active-Disturbance-Rejection-Controller(ADRC) and Nonlinear PID(NLPID),and put them into temperature control experiment by B&R PCC controUer.The experiment results indicate that more excellent control effects for large lag objects are obtained with these methods than with traditional linear PID controller.and these controllers have excellent robust and self-adaptation performance.The main works in this paper are as following:(l)analysing the research status of temperature control problem,then putting forward the difficulty,emphases and the route of solution;(2)analysing the characteristics and insufficiencies of traditional linear PID controller,and looking for proper nonlinear functions to construct nonlinear PID controller in a proper way;(3)introducing and analysing ADRC theory,and using it to solve temperature control problem;(4)having simulation tests and experiments, verifying the feasibility and advantages of nonlinear PID adjustment method in temperature control problem,and acquired perfect control performance.