摘要
利用主振动模态对Galfenol智能悬臂梁进行数学建模,通过对不同频率的悬臂梁位移数据进行研究发现,悬臂梁的模型参数具有频率相关性,频率大于220 Hz时参数的变化较明显。为了克服模型参数的频率相关性,提出一种基于状态观测器的鲁棒性自适应控制算法,通过对模型参数进行自适应识别的方法来改善悬臂梁的控制效果。将该算法与Luenberger观测器进行对比,分别进行数值仿真和试验研究。研究结果表明,自适应观测器可以有效预测悬臂梁的状态变量,所提出的基于死区的参数识别算法,可以抑制悬臂梁高阶模态带来的信号畸变,使模型参数仍收敛于有效值。动态跟踪控制试验表明,驱动频率为100 Hz和500 Hz时,采用相同的初始模型参数仍然可以达到较好的控制效果。
The first order vibration mode is used in the mathematic modeling of the Galfenol cantilever beam. The frequency dependences of the model parameters are found by analyzing the experimental displacement data. It is found that when the excitation frequency is higher than 220 Hz, the divergences of the model parameters are obvious. In order to solve the frequency dependence problem, a robust adaptive control strategy is proposed based on state observer. The performance of the control can be improved by estimating the model parameters adaptively. Numerical simulation and experimental researches are conducted by comparing the proposed method with the Luenberger observer. It is found that the adaptive observer can predict the state variable of the beam effectively. The aberrant disturbance resulted from the high order vibration modes of the beam can be suppressed by using the proposed dead zone adaptive law. The model parameters also can be estimated to effective values. It is found from the tracking experiments that effective control performance can be obtained by using the same initial model parameters, even when the cantilever beam is excited at 100 Hz and 500 Hz, respectively.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2012年第13期80-88,共9页
Journal of Mechanical Engineering
基金
国家自然科学基金(51175395)
教育部博士点专项基金(20090143110005)
浙江省重大科技专项计划(2011C11086)资助项目
