A New Adaptive Observer.
Abstract
An adaptive observer is defined as one which estimates the state variables and parameters of an unknown stable linear time-invarient plant from its input-output data. At the present time, there are two distinct approaches to the design of adaptive observers for a plant whose input output behavior can be represented by an n-th order differential equation. In the first approach, the observer is of the same order as the plant and is referred to as a minimal (order) observer. Using the second approach, a non-minimal observer of order (2n-1) is obtained. Minimal observers are considerably more difficult to synthesize than non-minimal observers and require the generation of additional signals for the stabilization of the adaptive loop. However, they have the advantage of yielding simultaneously both parameter and state estimates of the plant. Non-minimal observers are considerably simpler in structure both the n state variables of the plant have to be estimated from the available (2n-1) state variables of the observer. In this brief paper, a new observer is proposed which appears to combine the advantages of the two types of observers described above, With this observer, the parameter estimates of the plant are directly obtained with a structure which is no more complex than that of a non-minimal observer which is widely used at the present time. The parameter estimates are simultaneously used to determine directly the state estimates of the plant. Under certain conditions, the new observer has a faster rate of convergence than the observers known at present, which makes it particularly attractive for use in the control problem.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1976
- Accession Number
- ADA033122
Entities
People
- Kumpati S. Narendra
- Lena S. Valavani
Organizations
- Yale University