OPTIMUM STABILIZATION OF A NEAR-SURFACE SUBMARINE IN A RANDOM OCEAN.
Abstract
The vehicle-environment interactions are modelled using strip theory and a spectral seaway representation. Expressions are derived for the generalized forces in Lebesque and Rieman integrals as functions of the vehicle motion and the stochastic time variation due to waves. A careful linearization and Taylor expansion yield linear equations of motion with two new features: suction and parametric excitation. The former makes the vehicle motion inherently unstable without controller. The latter has been traditionally overlooked. Our derivations specialized to the beam sea case coincide with a previously obtained result provided that a new transcendental identity holds. The control problem of maintaining a horizontal straight path ought ideally be solved in an input adaptive fashion. A Wiener-optimal controller is derived but implies a difficult a priori input global identification as well as only an approximate synthesis. An all-out digital simulation of a submarine in a seaway at various speeds and headings shows that neglecting parametric excitation can cause large errors in predicting motion amplitudes and that the proposed full thrust controller compares quite successfully with a conventionally designed controller. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1967
- Accession Number
- AD0651821
Entities
People
- Pierre P. Dogan
Organizations
- Massachusetts Institute of Technology