Study On Hydraulic Roll-bending Flatness Control Based On Cloud Model

The country cannot develop without a strong steel industry, the users put forwardhigher level of requirements to plate strip quality with the development of society.Because it is difficult to establish accurate online flatness control system in the rollingprocess, the flatness as a measure of plate strip quality indicators has not beensatisfactory control effect. It is great significance to study of new the flatness controltheory and establish accurate online flatness control system for improving the accuracy offlatness.The hydraulic roll bending system is the primary means to control the quadraticshape defects in the flatness control system. The hydraulic bending roll control systemhas the characteristics of nonlinearity, slow time-variance and strong outside interferenceand flatness control also has the characteristics of multivariate, nonlinearity and strongcoupling, so they have a lot of uncertainty which leads to the involved control processand objects are often difficult to establish a precise mathematical model. This paper forthe first time applied cloud model which combines the randomness and fuzziness to thehydraulic bending roll control system, it achieves uncertainty transformation betweenqualitative and quantitative, so that non-linear and uncertain problems can be disposedof.The fuzzy control theory has its fuzzy lack of thoroughness because of its precisemembership function. In order to further improve the flatness control precision, Thispaper establishes the cloud model simulation device of secondary flatness and the forceof bending roll based on Matlab software programming simulation. Because the cloudmodel has certain subjectivity, then we used the scene rolling data to establish hydraulicbending roll flatness control system based on cloud fuzzy neural on this basis. Thesimulation results indicate that all aspects of control performance of the hydraulicbending roll flatness control system based on cloud fuzzy neural is superior to the singlecontrol of the cloud model and fuzzy control. The system can respond quickly to thesecondary flatness deviation and rapidly restore target flatness when it encounters interference and be more better to meet online secondary flatness control, all of this fullyembodies the feasibility of the cloud model in the flatness control and the superiority ofdealing with uncertainty problem compared with the traditional fuzzy control.It is difficult to meet the high precision hydraulic bending roll control requirementsbecause the traditional PID control parameters tuning is a tedious process. This paperputs forward the cloud model PID control algorithm, and introduce genetic algorithm tooptimize PID membership cloud model on the basis, in order to get the best PIDparameters in different time. The simulation results indicate that the proposed method ofthe cloud model PID control algorithm based on genetic algorithm in this paper is veryeffective for improving dynamic response speed and steady tracking precision of oilpressure of the hydraulic roll bending circuit, and simultaneously realize hydraulic gooddynamic and static control performance, which has universal significance for flatnessadjustment.