Modeling and Control of Flexible Structures
Abstract
The principal goals of this program were a demonstration of state- space procedure for modeling and control of a flexible structure, and, more generally, increased understanding of control problems for such systems. The state-space approach is based on a model of the distributed system. The model includes the necessary partial differential equations without modal truncation. The basic view is that it is preferable to avoid introducing approximations until they are required (e.g., for numerical calculations). The program (formal modal, state-space model, optimal-control formulation, approximation procedure and numerical calculation) is carried out, in detail, for a simple structural system including a rotating hub, a flexible beam and a tip mass. A final section in this part provides some parallel results for a more complex structure comprised of a hub, two flexible support beams and a tip-body. The second part of the report is concerned with some parasitic effects on the stability of a distributed system with feedback. The approach is based on an input-output description of the system; specifically, a transfer-function approach is used. In order to keep the calculation burden reasonably small the structural model studied is a simple cable which requires only second-order spatial derivatives. The baseline system employs feedback of a force to the 'free-end' of the cable at a magnitude proportional to the velocity at the 'free end'. The gain parameter can be varied to produce a locus of roots; albeit one with a countable infinite number of branches.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1985
- Accession Number
- ADA157959
Entities
People
- E. M. Cliff
- F. H. Lutze
- H. J. Kelley
- John A. Burns
- R. M. Goff