Research On Gravure Printing Press Guiding System Based On Fractional-Order Sliding Mode Control

With the progress of science and technology and the continuous improvement of product quality,people have higher and higher requirements for the stability of gravure printing machine strip transfer and overprint accuracy.Therefore,the web guiding system for unwinding,winding and printing process has become an important part of high precision gravure printing machine.The guiding algorithm is the core of the guiding control system,which directly affects the guiding effect of the material film and thus the printing overprinting accuracy.This topic introduces fractional order calculus theory on the basis of traditional sliding mode variable structure control theory,designs a fractional order sliding mode control algorithm,and develops a gravure printing press deflection correction system based on fractional order sliding mode control algorithm,which improves the transmission stability and overprint accuracy of gravure printing press:(1)Analyzing the causes of transverse deflection of film webs,studying the working principle of the deflection control system,and designing and selecting the deflection control system component modules according to the deflection control system component principle,including: detection module,actuation module,transmission module,controller,etc.(2)Create a film transverse dynamics model,establish a mathematical model of the transfer function of the actuator and transmission process of the guiding system,and establish a mathematical model of the guiding control system by combining the principle of guiding control system composition.By establishing the open-loop transfer function of the deskew system,the stability of the deskew system is verified.(3)By studying the application of fractional order calculus theory and sliding mode control theory,a deflection controller based on fractional order sliding mode theory is designed,and the superiority of the fractional order sliding mode controller compared with the integer order controller is verified through theory,and the stability of the controller is proved.The numerical implementation method and parameter adjustment method of the controller are studied.The Simulink simulation model of the deflection correction system is established,and the deflection correction effect of fractional-order sliding-mode control and traditional PID control is compared and analyzed through simulation by setting different disturbance conditions and different web transfer speeds.(4)Set up the experimental platform of gravure printing machine deflection control system,design the deflection control program and upper computer monitoring interface,and design the communication platform between Matlab and PLC by using OPC technology.By setting different winding line speeds,the actual deflection amount under fractional-order sliding mode control and conventional PID control is obtained,and the control effect of the deflection control system designed in this paper is verified.