Digital Filtering of Helicopter Flight Data.
Abstract
Data obtained during flight trials on a Sea King Mk. 50 helicopter contain significant noise, especially in measurements of components of linear acceleration and angular velocity. Spectral analysis of representative flight data show significant unwanted signal components to be mostly at the rotor frequency and higher harmonics, especially the fifth, which is the blade passing frequency. For channels requiring filtering, two suitable digital Butterworth lowpass filters are designed and their effect demonstrated. Direct representation of the transfer function as a high-order filter is used, in preference to representation as a number of second-order and first-order sub-filters. By using double precision to overcome the usual problems of numerical accuracy with the direct form, the advantages of simplicity and economy of programming effort are realized. For a general-order filter, the mathematical derivation of the filter coefficients in direct form is given. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1982
- Accession Number
- ADA122221
Entities
People
- J. A. Fleming
- N. E. Gilbert