d2c

Converts a discrete model to continuous time model.

Syntax

SYSC = d2c(SYSD)

SYSC = d2c(SYSD, METHOD)

SYSC = d2c(SYSD, METHOD, W0)

Inputs

SYSD
Specifies a discrete model in a transfer function, or state-space form.
METHOD
A string to specify the method used to convert the SYSD model to the SYSC model.
zoh
Zero-Order-Hold method (default method).
prewarp
Pre-warp method. This method requires W0, the pre-warp frequency.
tustin
Tustin approximation method.
bilin
Bilinear transformation.
W0
The pre-warp frequency.

Outputs

SYSD
A continuous model as a transfer function, or state-space form.

Examples

Default Method (Zero-order-hold): 
Ts = 0.01;
g = tf(0.1, [2 2 4], Ts);
sc = d2c(g)
Transfer function for input 1, output 1
 
              -3.172 s + 481.7
          -------------------------
          s^2 - 69.31 s + 3.853e+04
Using the tustin method: 
Hnum = [1 -2];
Hden = [1 2 3];
H = tf(Hnum, Hden, 0.01);
Hc2 = d2c(H,'tustin')
Transfer function for input 1, output 1
 
          -1.5 s^2 + 400 s - 2e+04
          ------------------------
           s^2 - 400 s + 1.2e+05

Comments

Converts a discrete system model to a continuous model using the specified method.

Based on the SLICOT library function ab04md and logm.