National Instruments 370753C-01 Manual De Usuario

© National Instruments Corporation

From Figure 4-6 you see that the delay time (t

) is about 0.5 seconds, 

the rise time (t

) is 0.8 seconds, the peak time (t

) is 1.6 seconds, the 

settling time (t

) is about 5.5 seconds, and the maximum overshoot (M

) 

is about 24%.

Figure 4-6.  15-Second Step Response, Showing Performance Measures

You can compute these values from the 151-point step response data vector 

Y

 and substantiate your estimates.

First, you find the final value of the response:

Yf = makematrix(Y(151));

Get indices of all values 

>

 half the final value:

gt_half = find(Y > 0.5*Yf);

Time corresponding to first index in 

gt_half

:

td = domain(Y(gt_half(1,1)))

td (a scalar) = 0.5

Get indices of all values > 0.1 * final value:

gt_1_10 = find(Y > 0.1*Yf);