Specifications Page (Interactive Control Design Dialog Box)

Requires: Control Design and Simulation Module

Guide to interactive control design process

This topic describes the Specifications page of the Interactive Control Design dialog box you access through the SISO Controller function or the CD Interactive Control Design VI. Use this page in conjunction with the following pages in the same interface to design and analyze a controller:

• Configuration
• Synthesis
• Analysis

Tip  Use features that allow you to analyze the system and controller more effectively.

Dialog Box Options

Dialog Box Options

Parameter	Description
Interactive Root Locus	Plots the root locus controller. Closed-loop poles appear red. You can move the closed-loop poles to change the closed-loop gain by clicking and dragging the poles on the graph. You can tune the gain by changing position of the closed-loop poles. Controller poles and zeros appear blue. Open-loop poles or zeros appear gray. You cannot move open-loop poles or zeros.
Step Response	Displays the output of the system when it is excited by a step input.
Interactive Open-Loop Bode Magnitude	Displays the Bode magnitude of an open-loop transfer function defined by the loop transfer function, which calculates the controller in series with the plant, sensor (if any), and actuator (if any) (CAPH). Closed-loop poles appear red. You can move the closed-loop poles to change the closed-loop gain by clicking and dragging the poles on the graph. Controller poles and zeros appear blue. You cannot move open-loop poles or zeros.
Interactive Bode Phase	Displays the phase (in degrees) of the model plotted against a set of frequencies.
Step Response	Contains the following options you can choose to include in the list of constraints to monitor: Maximum Settling Time (s)—Specifies the greatest amount of time to allow the step response to reach the 2% envelope of its final value. Maximum Overshoot (%)—Specifies the greatest amount by which LabVIEW allows the response value to exceed unity, expressed as a percent. Maximum Rise Time (s)—Specifies the greatest time to allow the system response to rise from 10% of its final value to 90% of its final value. Maximum Steady State Error—Specifies the greatest steady state error to allow the system. The difference between the mean square error of the error signal and zero is known as the steady state error.
Root Locus	Contains the following options you can choose to include in the list of constraints to monitor: Maximum Damping Ratio—Specifies the maximum damping ratio to allow poles in the system. Maximum Natural Frequency (rad/s)—Specifies the maximum natural frequency, in radians per second, to allow poles in the system. Maximum Time Constant (s)—Specifies the maximum, or slowest, time constant to allow an equivalent first-order system. Maximum Undamped Frequency (rad/s)—Specifies the maximum undamped frequency, in radians per second, to allow poles in the system.
Frequency Response	Contains the following options you can choose to include in the list of constraints to monitor: Minimum Gain Margin Frequency (rad/s)—Specifies the smallest –180 degrees crossover frequency to allow the system gain margin. Minimum Phase Margin Frequency (rad/s)—Specifies the smallest 0 decibels crossover frequency to allow the system phase margin. Minimum Gain Margin (dB)—Specifies the smallest gain margin to allow the system. Minimum Phase Margin (deg)—Specifies the smallest phase margin to allow the system.