Research On Active Control Of Stiffened Plate Vibration Based On Improved Sliding Mode Variable Structure

The stiffened plate structure has excellent mechanical properties and physical properties,as well as good economics,and is widely used in many industrial manufacturing and processing fields such as aviation,mechanical processing and shipping.However,when the stiffened plate structure is disturbed or stimulated by the outside,it will generate forced vibration,which will affect the normal operation of the stiffened plate and the overall structure.When the forced vibration is small,the service life of the structure will be affected;When forced vibration is violent,it may even cause safety problems.Therefore,it is very important to study the vibration condition of the stiffened plate related mechanism and vibration control analysis.For the vibration analysis of stiffened plates,great achievements have been obtained.However,the"flicker" and vibration decay time in the sliding mode variable structure control are too long,and the local strain effect of the piezoelectric plate in the same position leads to poor vibration control.The problem needs to be solved.In this paper,the stiffened plate in the aircraft wall plate is used as the object of research and analysis.The piezoelectric effect of the piezoelectric ceramic plate is used as the sensor and the actuator,and the vibration of the stiffened plate with the piezoelectric ceramic plate is further controlled.The system performs dynamic modeling,identification of relevant vibration modal parameters,analysis based on power law of reaching laws,sliding mode variable structure control algorithm,improved power reaching law,sliding mode variable structure control algorithm,and proposes an improved power based on local strain compensation scheme.Sliding Mode Variable Structure Algorithm for Sub-Law Law,Study on the Theory and Experiment of Active bration Control of Stiffened Plate Vibration Control System.The main papers are as follows:The second chapter describes and analyzes the positive and negative piezoelectric effect and working principle of piezoelectric element.Finally,according to the basic theory of mechanical vibration,the electromechanical coupled vibration model of the stiffened plate vibration control system and its state space equation are established so that the following is based on the power Sliding Mode Variable Structure Vibration Active Control Simulation and Experiment Preparation.In the third chapter,the basic principle of sliding mode variable structure control algorithm based on power reaching law is analyzed and deduced.Combining the state space equation of stiffened plate vibration control system,the control law expression of control algorithm and the calculation formula of related parameters are further deduced..Then,the modal analysis function of the ANSYS-Workbench module is used to determine the relevant modal parameters of the stiffened plate vibration control system;the sinusoidal frequency sweep test method is used to determine the actual modal parameters of the stiffened plate vibration control system;finally,MATLAB-is used.The Simulink simulation system simulates and analyzes the vibration active control of the stiffened plate vibration control system based on the power-sliding sliding mode variable structure control algorithm to determine the optimal control parameters.Based on the relevant data of the simulation,based on NI's CompactRIO real-time controller,an experimenta]platform for vibration active control of the stiffened plate vibration control system was set up;and the CompactRIO real-time controller was programmed with the Lab VIEW virtual instrument to realize the sliding based on the power law.The variable structure control algorithm is used to actively control the vibration of the stiffened plate vibration control system.Finally,the experimental results are used to verify the feasibility of the control algorithm,and the related problems in the active vibration control experiment process are analyzed.In the fourth chapter,based on the experimental analysis of the vibration control of stiffened plates based on sliding law variable structure control algorithm based on the power law of reaching law,there are problems such as "flicker" and excessively long vibration attenuation time.The insufficiency of the analysis algorithm is finally based on the above.The problem was raised to improve the power law of reaching the sliding mode variable structure control algorithm,mainly to construct an adaptive power coefficient a;then use MATLAB-Simulink control and simulation system to write a sliding mode variable structure algorithm based on improved power reaching law The simulation program of the active control of the stiffened plate vibration was performed,and the simulation analysis of the active vibration control was performed.Finally,with reference to the relevant parameters of the simulation,combined with the CompacrRIO real-time controller,a sliding mode variable structure control algorithm based on the improved power reaching law is implemented to perform an active vibration control experiment on the stiffened plates,and the experimental results are analyzed to verify the feasibility of the algorithm.In the fifth chapter,through actual experimental analysis,we know that due to the existence of local effects,the vibration signal in the control experiment process is not a simple bending strain,which is different from the strain in the thickness direction of the stiffened plate electromechanical coupling vibration system model;this problem is proposed.Based on the local strain compensation scheme,an active vibration control experiment of the stiffened plate was performed based on the improved local-sliding mode variable-structure sliding mode variable structure control algorithm to verify the feasibility of this scheme.