Search Results

A frequency domain order tracking method is developed that is able to separate both close and crossing orders. This method is based upon the multiple input H1 FRF estimator. The method can use either the actual tachometer pulse train or a simulated chirp function as an assumed input to formulate the FRFs which are actually order tracks. The advantages and disadvantages of using each type of assumed input are discussed. The performance of this method in both simple and complex order tracking cases is evaluated. Analytical datasets are used to evaluate the performance of these order tracking methods under a variety of operating conditions which include close orders. Finally, this paper will develop the necessary derivation to show the analytical relationship between the Time Variant Discrete Fourier Transform (TVDFT) and the FRF based techniques, one being an order domain method and one being a frequency domain method.

Large channel count data acquisition systems have seen increasing use in the acquisition and analysis of rotating machinery, these systems have the ability to generate very large amounts of data for analysis. The most common operating measurement made on powertrains or automobiles on the road or on dynamometers has become the order track measurement. Order tracking analysis can generate a very large amount of information that must be analyzed, both due to the number of channels and orders tracked. Analysis methods to efficiently analyze large numbers of Frequency Response Function (FRF) measurements have been developed and used over the last 20 years in many troubleshooting applications. This paper develops applications for several FRF based analysis methods as applied for efficient analysis of large amounts of order track data.