FEM simulation-determined band pass filter method with continuously changed bandwidth for fault detection in axial piston pumps

Abstract

The development of bearing fault detection methods is of great significance for the performance maintenance of axial piston pumps. However, the reciprocating movement induced strong natural periodic impulses that completely submerged the fault characteristic frequencies of the axial piston pump. To solve this problem, a finite element method (FEM)-based band-pass filter method was proposed, combined with minimum entropy deconvolution. However, the performance is determined by the selected band-pass filter bandwidth and the pre-treated denoise techniques. In the present study, an improved version of the FEM-based band-pass filter method was developed by continuously changing the bandwidth of the filter. First, the central frequency was determined using the FEM-based band-pass filter method. Second, the bandwidths of the constructed band-pass filters were continuously changed with a certain incremental step to obtain multiple filtered signals from the raw signals. Third, the normalized Hilbert envelope spectra were collected from the filtered signals. Finally, the projection figure is obtained by automatically taking the spectrum lines with maximum amplitudes in the normalized Hilbert envelope spectra, and the fault features are further determined. The experimental results show that the bearing faults in the axial piston pump can be successfully detected using the proposed method. Compared to the original FEM-based band-pass filter method, the improved version does not require bandwidth selection of the band-pass filter and pre-treated denoising method.

Simulation-driven bandpass filter in association with an optimal bandwidth to detect faults in axial piston pumps

“…The Similarly, the present BPF method is compared with the fault detection results of the two previously developed methods using the BPF with a fixed bandwidth Hz) and the BPF developed with multiple-bandwidth projection, respectively, and the results are shown in figures 17 and 18. From figures 16(b), 17(b) and 18(b), and the same conclusion are obtained: the fault detection performance of proposed method is superior to that of the BPF with a fixed bandwidth (2000 Hz) [37] and the BPF developed with the multiplebandwidth projection methods [38]. It is worth noting here that the artificial intelligence models [39][40][41][42] might also be Fault detection result of the inner race with a fault using the BPF developed with the multiple-bandwidth projection [38].…”

“…From figures 16(b), 17(b) and 18(b), and the same conclusion are obtained: the fault detection performance of proposed method is superior to that of the BPF with a fixed bandwidth (2000 Hz) [37] and the BPF developed with the multiplebandwidth projection methods [38]. It is worth noting here that the artificial intelligence models [39][40][41][42] might also be Fault detection result of the inner race with a fault using the BPF developed with the multiple-bandwidth projection [38].…”

“…Figure 9(a) shows the determined bandwidth process: the optimal bandwidth of the designed BPF is 880 Hz. To show the performance of the present BPF method, the fault detection results of the two previously methods are given in figures 11 and 12 using the BPF with a fixed bandwidth (2000 Hz) [37] and the BPF with the multiplebandwidth projection [38], respectively. In figure 11 Fault detection result of the outer race with a fault using the BPF with the multiple-bandwidth projection [38].…”

“…However, bandwidth prediction of the FEM-simulation-driven BPF method has not been solved and still depends on trial and error. Recently, Guo et al implemented a continuously changing bandwidth method by combining all envelop spectra into one projection figure and enhancing the fault detection results [38]. However, the optimal bandwidth has not been uniquely determined.…”

“…Figure18. Fault detection result of the inner race with a fault using the BPF developed with the multiple-bandwidth projection[38].…”