Study On Morphological Control Method And Experimental Research Of Adaptive Cable-strut Structure

With the development of technology and society,the service environment of radar is becoming more and more complicate,which put forward higher requirements for the high precision,light weight,and controllability of phased array radar.The tension structure composed of cable and rod units makes full use of the compressive strength of rigid rods and the tensile strength of flexible cables,and has the characteristics of light weight and high efficiency,which coincides with the requirements of radar.A new type of cable-strut antenna array structure with the design idea of the tensegrity is proposed in this paper.And the research is divided into three aspects: design of structure,adaptive control and experimental research.The main contents are as follows:(1)An antenna array structure composed of two-way cross of planar fish-belly cable and rod elements is proposed,which is analyzed the control parameters of the structure(configuration parameters and cross-sectional parameters).The MATLAB-Python-ABAQUS which is used to calculate data is established.Based on this framework,a parametric design method is proposed,which aims at the best profile accuracy and the smallest structure quality,and uses the NSGA-? algorithm to optimize.The analysis shows that while meeting the design index requirements,the optimization method greatly reduces the structural quality and meets the lightweight requirements.Based on the optimized parameters,this paper conducts finite element analysis on the force performance and profile accuracy of the front under different pitch,azimuth and load conditions,which is proved that the structure can meet the accuracy requirements under normal service conditions,and can meet the strength index under extreme conditions.(2)A method for reconstruction of deformation field based on stress information is proposed.This method calculates the coordinates of the cable and rod node by monitoring the stress change of the cable and rod back frame.From this,the coordinates of the front nodes are derived.Therefore,the corresponding relationship between the cable rod stress and the front deformation field is established,and a variety of calculation examples are performed using this method to verify the effectiveness of the method.(3)Through the introduction of actuators in the struts,the active control design is carried out.A hierarchical profile control optimization algorithm considering the optimal arrangement of actuators and the calculation of optimal control variables is proposed.And we can use genetic algorithm to solve this.According to the configuration proposed in this paper,the control effect under different number and arrangement of actuators is compared.The results show that the number of actuators is better in the range of 10-25.(4)Using the machine learning method,a two-stage adaptive control framework is designed by directly learning the corresponding relationship between the cable force and the control signal.The first stage is response system,which distinguishes by identifying the cable force information and provides the actuator start command(0 or 1);the second stage is control system,which calculates the control quantity of each actuator according to the start command of the response system.The result shows that the framework can more accurately and quickly monitor cable force information to give control instructions,and the profile accuracy after adjustment meets the requirements of use.(5)A cable-strut antenna array structure with an array size of 1.5m×1.5m is designed.The overall content of the test includes static load test and adaptive control test.The test result proves the effectiveness and feasibility of the adaptive control system for surface accuracy control.