Extraction of Stability Derivative Values from Test Data Taken on Undersea Vehicles - A Computerized Method.
Abstract
The modified Newton-Rhapson technique is capable of identifying the stability derivatives (hydrodynamic coefficients) of a vehicle from dynamic flight test data. The technique computes a maximum likelihood estimate of the stability derivatives. This report documents an application of the modified Newton-Rhapson technique to undersea vehicles. To ensure convergence in a small number of iterations, a specialized starting technique is used to develop the initial value estimates of the stability derivatives. For a typical undersea vehicle, examples are provided which illustrate the results of varying the initial starting value and the effects of iteration number on the fit error. A user's guide for the FORTRAN computer program and background information for applying the technique to undersea vehicles are included, together with a general discussion of instrumentation considerations, test and measurement techniques, and piloting techniques for manned vehicles. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1975
- Accession Number
- ADA016813
Entities
People
- Frederick O. Smetana
- W. Donald Johnson
Organizations
- North Carolina State University