【作者】 龙连春；

【导师】 隋允康； L.H.Yam；

【作者基本信息】 北京工业大学 ， 机械设计及理论， 2003， 博士

【摘要】 以具有广泛应用前景的智能结构为背景，集力学、电磁学、材料科学、最优控制和数学规划为一体，从事压电智能结构这个崭新且具有挑战性的多学科研究，在智能结构最优控制的理论分析和数值建模方面，做了如下贡献：1 提出了加强静不定智能桁架结构承载能力的方法利用静不定结构的内力耦合特性，建立的以结构强度为控制目标，考虑位移约束的规划法控制模型，可以使结构工作实时处于最佳状态；编制了程序，数值模拟结果表明：在满足位移要求的同时使静不定桁架的最大应力有明显下降。2 提出了使精密结构刚度最大的最小化节点位移的控制方法针对嵌入了任意类型作动器的智能桁架，以待控制节点的最大位移达到最小为目标，实现了静不定桁架和静定桁架在任意载荷作用下的最优控制，进行了程序实现，大量算例表明了该方法的适应范围和控制能力。3 构造了考虑强度、精度和控制能耗的多目标控制模型，使智能结构的可靠性、精确性和经济性得到统一克服单目标控制的局限性，控制模型分别被转化为简单有效的极小化极大问题和线性加权和二次规划问题；编制了程序并对两种控制方法的结果进行了数值对比。4 以智能抛物面天线精度和控制能耗作为综合控制目标，创建了考虑强度和作动器性能等的天线最优控制模型研究了大型天线结构的精度控制问题，用矩阵方法推导了智能抛物面天线反射面精度误差与作动器伸长的关系；采用线性加权和法与分层序列法对控制模型进行处理，完成了相关程序并对简化的平面天线和复杂的三维天线结构进行了控制模拟；数值结果表明用较小的控制成本可实现大型天线的零误差。5 对压电智能桁架结构的综合性能进行了控制推导了含有压电作动器智能桁架结构的机电耦合有限元方程，建立了压电智能桁架两种控制模型；模型以电压作为控制变量，分别以位移及位移、应力、控制能耗为目标，实现了机电耦合智能桁架结构的最优控制，数值结果支持了理论。<WP=5>6 解决了采用压电作动器时智能天线结构的综合最优控制问题以电压为控制变量建立了多项约束的天线综合控制模型，用加权和法予以处理；对机电耦合天线的几种作动器配置进行了方案对比，分析了在自重载荷作用下天线从仰天位置到指平位置的整个控制过程，研究了主要参数的影响；编制了相应计算程序，数值模拟实例进行了验证；有望成为具体应用的有效方法。更多还原

【Abstract】 The background is the broad prospect intelligent structures. Research is on the new and challenging multidisciplinary subject, piezoelectric intelligent structures. Mechanics, electromagnetics, material science, optimal control and mathematical programming are integrated in this dissertation. Contribution is about theoretical analysis and numerical modeling of optimal control for intelligent structures. Details as following:1 Presented a method to increase load capacity of static indeterminate intelligent trusses. By using the coupling property of indeterminate structures, a programming method control model established here, which takes strength of the structure as objective, subjects to constraint of nodal displacement, can make structures work at optimal status. Program has been finished. Numerical simulation results show that the maximum stress in static indeterminate trusses decreased obviously by using this method.2 Control method to make the maximum nodal displacement to be minimized was brought out in order to solve the stiffness problem of precision structures. For intelligent trusses with any kind of actuators, optimal control taking the controlled nodal displacements to be minimized as objective was realized for static determinate trusses and static indeterminate trusses under every kind of loading cases. Computing program simulated it. The control capacity and adaptability of this method were demonstrated by large numbers of numerical examples.3 A multi-objective optimal control model was set up, which takes the maximum stress, the maximum controlled nodal displacement and the energy consumption of the controlled structure as objectives. The reliability, precision and economization are all assured in the control model of intelligent structures. The localization of single objective control model of intelligent structures were<WP=7>overcome. The model was transformed to a simple and efficient minimize maximum problem and a weighting factors method quadratic programming, respectively. Program corresponding were finished and numerical results of the two methods were compared.4 Taking the precision and control energy consumption as synthesis objective, subjecting to constraints of structural strength and characteristic of actuators, an optimal control model was set up. Research work on precision control of large antenna structures has been finished. For parabolic antenna adopting intelligent structure, the relation between precision of the antenna reflector and the active elongation of actuators was derived by matrix operation method. The control model was dealt with weighting factor method and sequence layer method. Control simulation of simplified planar and complicated spatial antennas were carried out. Numerical results show that the no error large intelligent antenna is realizable even under not much control cost.5 Synthesis properties control of piezoelectric intelligent trusses was realized.　 Mech-electric coupling FEM equations of intelligent structures with piezoelectric actuators were deduced. Two control models were set up for two cases. The models take voltages as control variables; take displacements and displacements, stress, control energy consumption as objectives, respectively. Optimal control of mech-electric coupling intelligent structures was realized. Numerical examples support the theory.6 Synthesis optimal control of intelligent antenna structures embedded piezoelectric actuators was finished. Taking voltages of control as variables, subjecting to constraints of structural strength and limited voltages of actuators, synthesis control model of antenna was established. It was dealt with weighting factors method. Results of several actuator placement cases of a mech-electric coupling antenna were compared. Control simulation was carried out for the elevation from 0( to 90( under load of gravitation. Effecting of some main<WP=8>parameters has been analyzed. Corresponding computing program was finished and a numerical example verified更多还原