基于过采样ADC的振动信号分析仪滤波算法

摘要

针对振动信号分析仪采用模拟滤波器进行抗混叠干扰和噪声去除存在非线性相位，降噪效果差，硬件成本高等缺点，提出了振动信号的过采样ADC滤波算法。算法通过采样频率倍增降低了对抗混叠滤波的要求，同时噪声的滤除采用FIR数字滤波器对振动信号的相位有很好的保证。对算法的原理进行了详细分析，并对算法的实现进行了说明，在此基础上通过仿真分析对算法性能进行了讨论，并验证了算法对振动信号滤波的有效性。仿真分析表明，算法能够在噪声去除的同时保证线性相位，而加宽数字滤波器过渡带、增大阻带衰减能够保证算法的滤波效果和实现效率。研究确定的滤波算法在汽轮机振动信号分析仪中得到了实际应用，取得了较好的振动信号滤波效果。%For the problems of nonlinear phase ,bad noise reduction effect and high cost of hardware w hen vibration signal analyzer uses analog filter for anti-aliasing and noise reduction ,the over-sampling ADC technology to vibration signal is proposed .The Algorithm can reduce the demands to anti-aliasing by doubling sampling frequence .At the same time ,FIR digital filter is used to reduce noise which provides good linear phase of vibration signal .T he theory of algorithm is analyzed in detail ,the algorithm is implemented ,the property of algorithm is simulated and discussed ,and the effectiveness of vibration signal filtering is proved .Simulation analysis shows :Algorithm removes the noise ,at the same time , ensures linear phase ,widens digital filter transition zone and enlarges the stopband attenuation .The filtering algorithm has been used in turbine ’ s vibration signal analyzing and achieved better filtering effect .