【作者】 何丽丽；

【导师】 张京军；

【作者基本信息】 河北工程大学 ， 结构工程， 2009， 硕士

【摘要】 压电材料作为一种新型的智能材料,以其良好的机电耦合特性,在结构振动主动控制领域得到了广泛应用。本文以压电悬臂梁振动系统为研究对象,利用压电材料的正、逆压电效应,分析压电元件和悬臂梁之间的相互耦合关系,建立压电悬臂梁的机电耦合动力学模型和基于闭环控制系统的状态方程,并应用ANSYS软件对系统进行静力学和动力学分析,为压电智能悬臂梁振动控制系统的设计提供依据。确立压电传感器/驱动器的优化布置准则,即D优化设计准则,通过对结构振动特性的研究,将该优化准则简化到只需利用结构模态信息就能确定压电元件的最优位置。针对压电智能结构的振动主动控制问题,考虑到布置压电元件对主体结构动力学特性的影响,采用线性二次型高斯(Linear Quadratic Gauss)最优控制方法,设计Kalman滤波器对结构模型噪声和量测噪声进行过滤,对系统的状态及输出做出比较精确的估计,从而达到最优的控制效果。针对系统在不确定性因素作用下的控制问题,设计基于H_∞的鲁棒控制器,能够保证系统在模态参数摄动情况下,具有较强的鲁棒性以及较好的闭环动态性能,同样具有良好的振动抑制效果。提出模态空间范数的概念和计算方法,建立控制系统模态空间的传递函数与状态方程,并利用模态空间范数作为各个模态对结构动力响应贡献大小的度量,给出一种基于所配置的驱动器对各个模态的控制能力大小,对压电柔性结构进行模态挑选而获得降阶模型的方法,并与常规方法进行比较研究。以上方法均在MATLAB环境中进行了仿真研究,验证了其有效性。更多还原

【Abstract】 The piezoelectric materials have been widely used in the field of structural active vibration control as a new type of smart materials because of their excellent mechanical-electrical coupling characteristics. With the positive and negative piezoelectric effect of the piezoelectric materials, a vibration system of piezoelectric cantilever beam is taken as the study object in the paper, the interaction coupling relations are analyzed between the piezoelectric elements and cantilever beam, the dynamical model of mechanical-electrical coupling and the state equation which based on the closed-loop control system are established, the static and dynamic analysis by the application of ANSYS software provides theoretical basis to the design of the vibration control system for piezoelectric cantilever beam.The optimal collocation principle of piezoelectric sensor/actuator is established, namely the D optimum design principle. The principle is simplified by the study of the vibration characteristics of the system, and the optimal location of piezoelectric elements could be determined only by the modal information of the structure.For the active vibration control of the piezoelectric flexible structures, the optimal control method of Linear Quadratic Gauss (LQG) is applied with the dynamical influence of piezoelectric elements to the main structure. A Kalman filter is designed to filtrate the model noise and measurement noise of the structure, therefore, the status and output of the system could be estimated more precisely, so as to achieve optimal control effect.A robust controller is designed based on H_∞method in response to the control problem of the vibration system with uncertainty factors acted, the method could be able to guarantee the system has good robustness and better closed-loop dynamic performance when the modal parameters has some perturbation, also, it has a good effect of vibration suppression.The concept and calculation method of modal space norm is put forward in this paper, the modal space transfer function and state equation of the control system is set up, and the modal space norm is used as the measurement of each modes contribute to the dynamical response of the structure, a model reduction method which based on the control ability of collocated actuators contributed to each modes is introduced in this paper, and it is compared with the conventional methods.The simulation study of the above methods has been done in MATLAB, and improve the effectively of them.更多还原