Synergetic Control For Slab Thickness Deviation Rectification Of MDF Continuous Press

In process control of medium density fiberboard(MDF) continuous press, slab thickness control is an important part which has a critical effect on final quality of the product. The thickness deviation rectification control to slab is a key point of slab thickness control. In the production line, press plate outputs displacement or pressure. It is driven by hydraulic cylinder-array and executes hot-pressing and thickness setting. The cylinder-array is an individual autonomy system which contains local information exchanging and output consistently overall. From the point of flocking control, behavior-based synergetic control for multi actuators is researched in this dissertation, which concludes thickness deviation rectification synergetic control mechanism for MDF continuous press, and is funded by the Specialized Research Fund for the Doctoral Program of Higher Education of China-Key Techniques of Synergetic Control for Flatness Deviation Auto-Rectification of MDF Continuous Press-(20120062110012). The main contents of this dissertation are as follows:Firstly, a hierarchical synergetic control structure is proposed for cylinder-array. It is Synergy Nuclear-Control Agent-Motion Terminal structure. Synergetic control method for cylinder-array is researched and thickness deviation rectification synergetic control mechanism for MDF continuous press is concluded based on the structure.Secondly, hydraulic displacement control system and static pressure load control system with single terminal are modeled, and the synergetic controllers are designed. The established Langevin’s equations have taken the viscoelastie of the slab. The order-parameter equations of the two kinds of system are derived. And synergetic control rule, which is also called fluctuating force of system, is formulated. To simulate the two kinds of system, the results demonstrate that synergetic control method enables the motion terminal to output without overshoot. It is suitable for application of continuous press which should avoid overshoot strictly.Thirdly, hot pressing process modes are defined. And hierarchical synergetic correction solution for multi terminals is proposed. For multi terminals synchronized output, study on the correction method of control agent and form the hierarchical synergy correction solution. Synergetic correction controller based on equal statue structure is employed to eliminate synchronized error for self-synergy terminals. Disturbance compensator is introduced into the system to enhance stability. And tracking controller is improved based on fuzzy theory so as to overcome dependence of synergetic controller on system’s precise mathematical model. Synergetic correction controller based on primary-minor structure is employed to eliminate synchronized error for inter-synergy terminals. To simulate self-synergy and inter-synergy terminals, the results demonstrate that synergetic synchronized correction method is effective to eliminate errors in self-synergy and inter-synergy synchronized system.Fourthly, slab thickness deviation thresholds are defined so as to make a distinction among thickness deviation levels. And thickness deviation rectification decision rules of synergy nuclear are formulated. Slab thickness deviation rectification system of MDF continuous press is developed. To test the established thickness deviation rectification synergetic control mechanism by the system, let the simulated data and slab for experiment be detected. The dynamic surfaces of displacement output and pressure output of slab thickness deviation rectification system demonstrate that the hydraulic cylinder-array’s outputs are consistent with slab deviation rectification decision. Synergy nuclear could shift decision rules according to slab features under each hydraulic cylinder.In summary, this dissertation mainly researches on behavior-based synergetic control method for cylinder-array, and finally formulates thickness deviation rectification synergetic control mechanism for MDF continuous press. It achieves slab thickness deviation dynamic rectifying for MDF continuous press without overshoot. The outputs of cylinder-array are consistent overall. The conclusions are meaningful for MDF continuous slab thickness control research.