小波包变换自适应振动控制方法

针对主动隔振中输入信号频率成分复杂导致收敛慢、控制失效的问题,提出一种变步长的小波包自适应算法(WPx-LMS).通过小波包变换将输入信号分解到若干互不重叠的带频上,并为每个分解信号设计独立的控制滤波器和迭代步长.对比分析不同小波基对信号的分解结果,基于误差信号设计变步长算法,搭建双层隔振控制实验台架.仿真实验表明,与传统LMS算法相比,所提出的WPx-LMS算法可在输入信号频率成分复杂的双层隔振平台中取得良好的控制效果.

Adaptive vibration control method based on wavelet packet transform

Aiming at the problem of slow convergence and control failure due to complex frequency components of input signals in the an active vibration isolation system, a variable-step wavelet packet least mean square algorithm (WPx-LMS) is proposed. At first, the input signal is decomposed into a series of non-overlapping band frequency through wavelet packet transform. And then, an independent control filter and iterative variable-step are designed for each of the decomposition signals. The decomposition results of different wavelet basis are compared to determine the optimal wavelet basis in control system. By using error signals and decomposition signals to design the variable step strategy, the sensors and the controller are used to build the two-layer vibration isolation control test bench. The simulations experiments are carried out to verifily that the WPx-LMS algorithm, for the two-layer vibration isolation platform with complex input signals, can achieve better robustness and control effect than the conventional LMS algorithm.