Function Reference

obsv

Form the observability matrix

Syntax

• Ob = obsv(A,B)
  Ob = obsv(sys)
  

Description

obsv computes the observability matrix for state-space systems. For an n-by-n matrix A and a p-by-n matrix C, obsv(A,C) returns the observability matrix

with n columns and np rows.

Ob = obsv(sys) calculates the observability matrix of the state-space model sys. This syntax is equivalent to executing

• Ob = obsv(sys.A,sys.C)
  

The model is observable if Ob has full rank n.

Example

Determine if the pair

• A =
       1     1
       4    -2
  
  C =
       1     0
       0     1
  

is observable. Type

• Ob = obsv(A,C);
  
  % Number of unobservable states
  unob = length(A)-rank(Ob)
  

MATLAB responds with

• unob =
       0
  

See Also
obsvf       Compute the observability staircase form

nyquist

obsvf