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Function Reference: lqi

Function File: [g, x, l] = lqi (sys, q, r)
Function File: [g, x, l] = lqr (sys, q, r, s)

Linear-quadratic integral control.

Inputs

sys
Continuous or discrete-time LTI model (m inputs, n states, p outputs).
q
State weighting matrix (n+p-by-n+p).
r
Input weighting matrix (m-by-m).
s
Optional cross term matrix (n+p-by-m). If s is not specified, a zero matrix is assumed.

Outputs

g
State feedback matrix (m-by-n).
x
Unique stabilizing solution of the continuous-time Riccati equation (n+p-by-n+p).
l
Closed-loop poles (n-by-1).

Equations $$ \dot{x} = A\,x + B\,u,\quad x(0) = x_0 $$$$ J(x_0) = \int_0^\infty z^T Q\, z + u^T R\, u + 2\, z^T S\, u \,\, dt $$$$ z = \left[\matrix{ x \cr x_i }\right],\qquad x_i = \int_0^t r - y \,\, dt $$$$ L = \sigma (A - B\, G) $$

See also: care, dare, dlqr

Source Code: lqi