Control Theory And Design Method Research Of Adaptive Beam String Structure

Based on the progress and applications of smart tensile structure and beam string structure (BBS), the adaptive BSS (ABBS) is put forward as a type of widely used smart tensile structure. Based on BBS, ABBS is a smart structure which replaces the vertical poles or cables of the original structure with adjustable bars used as actuators, and adding additional sensors testing the status of the structure and controllers processing test information. In order to guarantee the normal working condition of the structure, the thesis has carried an intensive research and investigation towards the common scientific problems and key technical challenges of control theory, static performance, optimization design and optimal arrangement of sensors with theory and numerical methods such as stochastic search algorithm, linear force method, nonlinear finite element method and fuzzy decision.With the force method, the theory control model of ABSS, the geometric configuration equations under dead loads and the working-status control equations under uniform live load and wind load have been put forward. With the finite element method, finite element equation of the structure with consideration of actuator coupling effect is deduced. An optimized model of geometry configuration and working-status linear control is established with the analysis of sensitivity and achieve the optimal solution of the linear control using simulated annealing algorithms. The nonlinear finite element method is introduced to reevaluate the control effect and modify the iterative process in order to achieve the single-objective nonlinear optimization control of ABSS.A multi-objective control model of ABSS considering the priority of the objectives s is developed. The objectives include internal force, displacement and energy consumption. Using fuzzy decision theory, the satisfaction degree and the order of satisfaction degree are introduced to describe the priority of the objectives. The two parameters can help to evaluate the control objectives of the structure in the same dimension. According to hierarchical interactive optimization, the interactive fuzzy optimization algorithm based on the satisfaction degree order and the additive model of the objectives is proposed to aid the decision-maker to decide and introduce the priori and local preference information and finally achieve the multi-objective control of ABBS.According to the arrangement of actuators, ABSS be divided into bar type and cable type and the bar type can be continuous and discontinuous. The control effect and control efficiency of the bar type is found to be best with the study of the static performance of the two types of structures under uniform load non-uniform load. The changing law of the static performance with parameters such as geometric configuration parameters, section characteristic parameters and actuator parameters is analyzed. The optimization design method based on the structure performance is put forward with the above work.To optimize objective as the best controllability performance, an optimal arrangement model of actuators is set up in consideration of the controllability of the structure. The model is solved with the sequence method and random search algorithm. The appropriate initial solution is chosen with the learning strategy and the analysis of the computational complexity of the optimal arrangement model. The initial solution can reduce the number of iterations and improve the efficiency of algorithm. Some improvements to accelerate the speed of search algorithm are proposed according to the idea of multi-core computer operation for improving the parallel operating of simulated annealing algorithm and test paralleling strategy.The study has advanced the development of the control theory of ABSS and the theory of optimization design, and has provided theoretical basis and technical support for the engineering application of this kind of structure. Meanwhile, the study can also be applied to other types of smart tensile structures though it is based on ABBS.