MaxError =PeakErrors+ωcDCError
s+ωc.
When you select this option, enter the following parameters in the text boxes:
- Response Time — Enter the target response time. The tracking bandwidth is given
by ωc = 2/Response Time. Express the target response time in the time units of your
model. - Steady-state error (%) — Enter the maximum steady-state fractional tracking error,
expressed in percent. For MIMO tracking goals, this steady-state error applies to all
I/O pairs. The steady-state error is the DC error expressed as a percentage, DCError/
100. - Peak error across frequency (%) — Enter the maximum fractional tracking error
across all frequencies, expressed in percent.
Maximum error as a function of frequency
Select this option to specify the maximum tracking error profile as a function of
frequency.
Enter a SISO numeric LTI model in the text box. For example, you can specify a smooth
transfer function (tf, zpk, or ss model). Alternatively, you can sketch a piecewise error
profile using an frd model. When you do so, the software automatically maps the error
profile to a smooth transfer function that approximates the desired error profile. For
example, to specify a maximum error of 0.01 below about 1 rad/s, gradually rising to a
peak error of 1 at 100 rad/s, enter frd([0.01 0.01 1],[0 1 100]).
For MIMO tracking goals, this error profile applies to all I/O pairs.
If you are tuning in discrete time, you can specify the maximum error profile as a
discrete-time model with the same sampling time as you use for tuning. If you specify the
attenuation profile in continuous time, the tuning software discretizes it. Specifying the
error profile in discrete time gives you more control over the profile near the Nyquist
frequency.
Options
Use this section of the dialog box to specify additional characteristics of the tracking goal.
- Enforce goal in frequency range
Reference Tracking Goal