Establishment And Experiment Of Static Active Control Closed-loop System For Beam String Structure

An important problem in spatial structure study is to broaden the application of the structure,pursuit of more efficient and lighter structure,the concept of active control of the structure provides a new field for the research.This paper,takes the beam-string structure as the research object,and aims to achieve the whole process of structural closed-loop active control.The research is carried out at the aspects of control algorithm theory,model design and production,control system integration,sample verification test and closed-loop control testFirstly,the structural control problem is transformed into an optimization problem,and the optimization model of structural active control is established with the minimum structural displacement and the minimum stress of the main beam as the optimization target.The genetic gradient algorithm is introduced to solve control problem based on load information.Then the structural response information and the control strategy are set as the input value and the output value in the training sample library to develop the structure control method based on BP neural networkThen the design and production of the test model and the closed-loop control system are completed.The structural parameters of the model are determined,and the design of beams,cables,rods,supports and nodes is completed.A sensing system for measuring beam stress and displacement are established,and an actuation system consisting of a stepping motor and an electric linear actuator are established to realize accurate quantitative output of the actuating Finally,a closed-loop control system based on serial communication is developed,and the control method is integrated with the sensing and actuation system to realize the whole process of closed-loop active control,to achieve automatic measurement,calculation and actuationThen select the structural parameters that have big influence on the test model to make the measured calibration,so that the theoretical model is more consistent with the actual model.The stress and displacement are taken as the control targets.The control sample tests including full-span load,half-span load,random load.It's shown that the measured results are in good agreement with the theoretical analysis.It's proved that the control model based on the genetic gradient algorithm can effectively optimize the structural response to improve the stress stateFinally,experiments are done to verify the validity and accuracy of the closed-loop active control,the stress and displacement are taken as the control targets and the control sample tests including full-span load,half-span load,random load.The results show that the control method based on this paper has strong response recognition and structure control ability,can effectively generate control strategy based on actual structural response,realize closed-loop control process based on measured data,and optimize structural state.The control system trained by sample library including the unloading phase can effectively control the structure after the structural response change on account of unloading,and lead the structure to the initial state.The research in this paper provides a reference for the theoretical research and practical application of static active control of beam-string structure.