The Tuning Wizard automatically calculates tuning gains for you. The wizard first guides you through the process of obtaining plots, then automatically calculates a range of valid gains, and finally presents you with a simple slider bar to choose conservative or aggressive gains.
The tuning wizard can be used with position, pressure and force axes. The tuning wizard cannot be used for velocity axes.
The Tuning Wizard works as follows:
Using plots of motion, the Tuning Wizard computes a mathematical model of the system. The Tuning Wizard provides two methods of obtaining plots:
Autotuning Wizard - Position Axes Only
The Autotuning Wizard automatically moves the axis as specified by the user. With the plots generated by the motion, the Autotuning Wizard determines the system model.
Using Existing Plots - Position, Pressure, and Force Axes
For position axes, the user chooses existing plots of motion from which the Tuning Wizard determines a system model. The existing plots must be listed in the Plot History pane.
For pressure or force axes, the Tuning Wizard uses the currently displayed plot to determine a system model.
The Gain Calculator uses the system model to determines valid gains. In the Gain Calculator, the user positions a slider bar to pick from a range of appropriate gains for the system. The Gain Calculator stays open, making it easy to move the axis to try out various sets of gains. If a certain set of gains is not acceptable, simply move the slider and click Apply to try out a new set of gains.
Using the Tuning Wizard
Open the Tuning Wizard: In the Axes Parameters Pane, on the Tune tab, in the Tools and Wizards section, on the Position Tuning Wizard row, click Launch. Or, in the Plot Manager, on the Tuning tab, click Tuning Wizard.
Choose Use Autotuning Wizard if you would like RMCTools to move the axis and compute a system model. Choose Use an existing plot if you already have plots of motion of your system that can be used to compute a system model.
If you chose Use Autotuning Wizard, follow the instructions in the wizard. For more detailed information, click the Help button in the wizard.
Use an Existing Plot
If you chose Select an existing plot, you must already have plots of motion of your system in the Plot History pane. Make sure the Output Polarity was correct when the plot was captured, that is, that a positive Control Output results in movement in the direction of increasing position units.
For details on generating plots suitable for the Tuning Wizard, see the Creating Plots for the Tuning Wizard topic.
After the wizard completes, it will open the Gain Calculator. For more details, see the Gain Calculator topic.
Pressure or Force Axes:
First, generate a plot that shows the pressure or force changing. To generate a good plot, do the following:
Set the Pressure/Force Proportional Gain to a small value. For systems scaled in pounds, 0.01 is often a good starting value.
Move the axis to where it encounters pressure or force.
Use the Hold Current Pressure/Force (19) command to enter pressure or force control.
Increase the Pressure/Force Proportional Gain until the Actual Pressure/Force starts moving toward the Target Pressure/Force. It should not get all the way toward to Target Pressure/Force. Give just enough gain to make sure it comes somewhat close.
Use the Ramp Pressure/Force (S-Curve) (41) command to ramp the pressure or force.
Upload the plot. Make sure the Actual Pressure or Force changed significantly in the plot. If it did not, repeat the process. For more details on generating plots suitable for the Tuning Wizard, see the Creating Plots for the Tuning Wizard topic.
In the Plot Manager, on the Tuning tab, choose the Pressure or Force tab and click Tuning Wizard.
Choose your plot from the list and click Next.
A dialog will appear with the calculated model. Click Finish to open the Gain Calculator. For more details, see the Gain Calculator topic.
Copyright (c) 2005-2012 by Delta Computer Systems, Inc.