Feasibility Research On Extension Intelligent Synchronous Control Strategy In Rotary Screen Printing Machine

Since the printing precision and the printing quality of rotary screen printingmachine depend on the synchronicity among DC-motors applied in fabric-entry,printing unit, drying, and fabric-exit unit respectively, the dynamic behaviors of theseDC-motors must be controlled on-line to realize the synchronous speed. The traditionalspeed-current double closed loop control strategy with PI controller is classic andcommon, but it has a few limitations when it is applied to the rotary screen printingprocess which is strong nonlinear and time-varying.. These limitations could includeparameter tuning, the ability of self-adaptive control online and handling thecontradictions among some performance criteria, e.g. stability, swiftness, accuracy andso on.While the traditional PI double closed-loop control approach is not adequate tosolve the problem of synchronous control, an extension intelligent controller is designedhere. The main research involves following aspects:⑴Several control algorithms including traditional PID algorithm, fuzzy theory,and extension control algorithm are combined into a multi-mode intelligent controlstrategy, which can meet the requirements of some performance criteria at the same timeby expanding the control domain so as to. A multi-mode switch is established in termsof the correlation function of the characteristic state whose characteristic values areextracted from controlled system. The simulation experiments demonstrate that the newintelligent control strategy applied in the linear system, nonlinear system or large timedelay system can facilitate to achieve the ideal control behavior. In order to display thecontrol results and the specific structure of the controller clearly, a GUI demo interfacewas designed in the paper.⑵Take Netherland Stoke rotary screen printing machine for an example, theDC-motor speed control model was established in the MATLAB/SIMULINKsimulation environment. The core algorithm was compiled in S-function. And the three control strategy, i.e. traditional double-closed-loop PI control strategy, fuzzy PIDcontrol strategy and extension intelligent control strategy were compared in thesimulation. The result verifies the effectiveness and advantage of the extensionintelligent control strategy.⑶Goodness evaluation method was introduced into optimizing the extensionintelligent synchronous control strategy. The goodness evaluation method is a basicmethod to evaluate a plant, including object, strategy or method in extenics. Bycalculate the goodness, and compared with the other two control strategies, their controleffect differences can be displayed quantitatively. It also provides a new idea to improvea control strategy.In addition, during this investigating, some literatures describing the updateachievements on extenics theory and extension control theory are referenced to build upand improve the extension intelligent control strategy. Through lots of simulationexperiments, determine the best control model which ingrates extension set theory,traditional control algorithm, fuzzy theory, and self-adaptive theory. The simulationresults prove the new control strategy have great advantages. It can effectively handlethe contradictions among various performance indexes including stability, swiftness andaccuracy in a controlled system.