基于子空间辨识算法的压电悬臂梁振动主动控制研究

发布时间：2018-12-31 12:22

【摘要】：柔性材料的机械结构往往易于产生不必要的振动,其可导致干扰辐射,影响结构的性能。抑制振动的方法可分为被动和主动两类,传统的振动被动控制无法取得理想的控制效果,而振动主动控制具有响应速度快、自适应能力强、控制精度高等诸多优点,成为目前振动控制领域的研究热点。将压电智能材料与振动主动控制结合起来,能够使结构的振动主动控制更具优越性。本文针对压电悬臂梁的振动控制问题,以一表面粘贴有压电材料的悬臂梁作为实验研究对象,设计了基于LABVIEW的振动信号实时采集系统,并进行了振动控制实验。在建模方法上,针对柔性结构的振动普遍存在复杂性、非线性和建模难的特点,本文跳过了复杂的机械-电压建模,采用子空间辨识算法,从输入输出数据辨识出系统的参数,并进行了详细的理论推导。在控制器设计方面,鉴于子空间辨识方法无需得到系统模型的详细参数就可以得到LQG控制器的最优解,所以将子空间辨识和LQG最优控制结合考虑,进行了LQG最优控制器的设计,并给出了程序框图和算法主要步骤。为了验证算法的有效性,本文采用Matlab设计了子空间辨识仿真测试,并利用LABVIEW开发环境结合NI USB-6221数据采集卡、电荷放大器、PC机等硬件搭建了振动控制实物实验平台,进行了振动信号采集、分析、显示和控制实验。实验结果表明,该系统能够实时、有效地对悬臂梁进行振动控制,自适应能力强、控制精度高、控制效果理想。相比较于其他传统方法,本文设计的控制方法可以在保证模型精确度的基础上大大降低计算量,加快了系统的响应速度。
[Abstract]:Mechanical structures of flexible materials are often prone to produce unnecessary vibration, which can lead to interference radiation and affect the performance of structures. Vibration suppression methods can be divided into passive and active methods. Traditional passive vibration control can not achieve ideal control effect. Active vibration control has many advantages, such as fast response speed, strong adaptive ability, high control precision and so on. It has become a research hotspot in the field of vibration control. The combination of piezoelectric intelligent material and active vibration control can make the vibration active control of the structure more advantageous. Aiming at the vibration control of piezoelectric cantilever beam, a real-time vibration signal acquisition system based on LABVIEW is designed, and the vibration control experiment is carried out with a cantilever beam with piezoelectric material on the surface as the experimental research object. In view of the complexity, nonlinearity and difficulty in modeling the vibration of flexible structures, this paper skips the complex mechanical-voltage modeling and uses subspace identification algorithm to identify the parameters of the system from the input and output data. And the detailed theoretical derivation is carried out. In the aspect of controller design, since the subspace identification method can get the optimal solution of LQG controller without getting the detailed parameters of the system model, this paper combines subspace identification with LQG optimal control to design the LQG optimal controller. The program block diagram and the main steps of the algorithm are also given. In order to verify the validity of the algorithm, this paper designs a subspace identification simulation test using Matlab, and uses the LABVIEW development environment combined with NI USB-6221 data acquisition card, charge amplifier, PC computer and other hardware to build a physical vibration control experimental platform. Vibration signal acquisition, analysis, display and control experiments are carried out. The experimental results show that the system can control the vibration of cantilever beam in real time and effectively, has strong adaptive ability, high control precision and ideal control effect. Compared with other traditional methods, the control method designed in this paper can greatly reduce the computational complexity and accelerate the response speed of the system on the basis of ensuring the accuracy of the model.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB535

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