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The stability test of multi-station precision machining fixtures can improve the safety of multi-station precision machining fixture. This paper puts forward a stability test method of multi-station precision machining fixtures based on the pressure pulsation amplitude test. The fundamental frequency characteristic detection of airflow pulsation is adopted to collect the stability characteristic parameters of multi-station precision machining machine clamps, and the wave number analysis model of airflow pulsation in the stable state of multi-station precision machining machine clamps is constructed. The time domain characteristic parameter analysis and spectrum gain control are adopted to realize the stability condition parameter analysis and spectrum characteristic decomposition of multi-station precision machining machine clamps. The end-face pulsation attenuation characteristic method of detection is followed to realize noise reduction of the stable air pulsation attenuation signal of multi-station precision machining fixture, and the rotor meshing frequency component of the stable air pulsation attenuation signal of multi-station precision machining fixture is extracted. The multi-scale wavelet air pulsation attenuation signal decomposition is adopted to realize the correlation spectrum characteristic detection of the signal, and the multi-dimensional space fusion is employed to realize signal characteristic clustering, thus realizing the stability detection of multi-station precision machining fixture. The test output shows that the proposed method has better convergence and strong feature clustering in the stability detection of multi-station precision machining machine fixtures, which improves the confidence level of multi-station precision machining machine fixture failure instability detection.

In this paper, three dual-mode (mixed-mode) analog filters using only grounded capacitors and two to three second-generation current conveyors (CCIIs) are presented. The first proposed filter can provide a transimpedance-mode (TIM) second-order filter transfer function (TF), and is free from passive component matching constraints, which is advantageous in integrated circuit (IC) design. Other two mixed-mode filters having the property of tunability are derived from the first proposed filter. However, the developed filters in this work, like other active filters, suffer from nonidealities such as nonideal gain and parasitic impedance effects which increase the order of the filter TFs; accordingly, stability problem may arise. In this study, stability analysis using gain and phase margins is accomplished. To explain the claimed ideas, several computer simulations and an experimental test are performed.