针对空间微振动环境模拟的需求,以Hexapod平台为对象,进行正弦振动激励控制的研究.当Hexapod平台工作在共振频段时,其输出的振动信号中因含有谐波成分而产生了显著的控制误差.为此,提出了一种自适应谐波消除算法.该算法以LMS滤波器为基础,将与谐波同频率的正弦信号和余弦信号作为滤波器的基底信号,将平台实际的输出响应作为滤波器的误差信号,以此实现谐波分量的自适应消除.将基于该算法的控制回路引入传统的控制器,进行了共振频段的单输入单输出和多输入多输出的微振动激励试验,结果表明,该算法可有效地消除谐波失真,大幅提高了Hexapod平台在共振频段的控制精度.%A Hexapod platform driven by voice coil motors is used to simulate the micro-vibration environment in space. The response signal of the Hexapod platform contains harmonics when it works at resonance frequencies, resulting in a significant error between the actual output and the desired output. To reduce the harmonic distortion and improve the control performance of the Hexapod platform, an adaptive harmonic cancellation (AHC) algorithm based on the LMS filter is developed. The reference signals of the LMS filter are a sine signal and a cosine signal with the same frequency of the harmonics. Meanwhile, the output signal is directly used as the error signal of the LMS filter. Experimental results show that the proposed approach can efficiently eliminate the harmonic distortion and greatly enhance the control accuracy in both SISO and MIMO cases.
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