| 摘要 |
A drive system for a vibrating tube-based measurement instrument employing a spatial filter to produce a drive signal having modal content only at a desired vibration mode. Multiple feedback sensors located at different locations along a vibrating tube produce multiple feedback sensors. Each feedback signal has applied to it a weighting or gain factor. All of the weighted feedback signals are then summed to produce a drive signal, or a signal proportional to a drive signal, having improved modal content as compared to any of the feedback signals by themselves. The weighting factors are selected by any of several means. One method is to build the eigenvector matrix for the vibrating flow tube by extracting the eigenvectors from a finite element model of the vibrating structure. The inverse or psuedo-inverse of the eigenvector matrix is calculated to obtain the modal filter vector. The appropriate set of weighting coefficients are selected from the modal filter vector.
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