Yaskawa Fully Closed Loop Control Control (Dual Loop, Glass Scale, External Encoder)
Setup Calculator
Use the calculator on the server to get Yaskawa Drive parameters, and steps per settings for Mach
These files are located on the Sharepoint system | Customer Support | Documents/Public Documents/Yaskawa Fully Closed Loop
Yaskawa Fully Closed Loop CalculatorRev13.xlsx
Also see this folder for encoder config files, as well as some info on each encoder in the .txt files
In tuningless mode, you likely will have to adjust the rigidity: Yaskawa Mini Manual.
You will need the Yaskawa SigmaWin software. On this Yaskawa page, search for sigmawin and download version 7 latest revision.
As long as the safety relay is reset and you have drive power, you can test the encoder on large machines by jogging here and making sure feedback pulse counter and Fully closed feedback pulse counter go the same direction. You have to turn off drive enable from the control but leave on hardware enable.
Scale Engineering / Selection
To make sure you engineer a scale with enough resolution, use the Scale Selection tab of the "Yaskawa Fully Closed Loop Calculator" to confirm Pn20A is greater than 100. Otherwise be prepared to have to manually tune the system or that it might not work at all.
Tuning Overview
This is used for boring mill tuning.
Note: Make sure the clamps on boring mills are not clamped when tuning!
Try rigidity and load settings first.
Then try custom tuning.
FF
- Increase model following
- Respond faster
- Watch setting time (Coin)
FB
- Sets Pn100, 101, 102 gains
If that doesn't work, then manually tune.
Test with the most weight and the least weight to make sure it works well.
Manually Tune Servo Gains
If normal tuning doesn't work, you may have to manually tune the servos.
Turn off Tuning-less Function in the drive
Set Pn170.0 to 0 to disable the auto gain adjustment
Calculate the Moment of Inertia Ratio
Run the first step of Auto Tuning with SigmaWin to calculate the Moment of Inertia Ratio and save that to the drive. Also verify that the calculated percent is less than 400, if its greater than 400 then the motor is not sized correctly.
Actual Tuning
To adjust the parameters live, select Edit Online Parameters.
Add the parameters you want to change.
Now adjust your parameters.
PN100 Speed loop Gain. Lower numbers means softer
PN101 Speed Loop Integral Time Constant. Higher number means softer
PN102 Position loop Gain. Lower numbers means softer
Disabling a Scale
Re-enabling a Scale
Replacing a Scale Card
You must re-download the scale file into the drive if switching a card out.
Troubleshooting
Shaking Motion
Scale Resolution
Check your Pn20A ratio to make sure the scale has enough resolution. Open the "Yaskawa Fully Closed Loop Calculator" to run the numbers or for a running system you can just view the parameter in the drive. Our goal is to always be above 100... but we have tuned systems with lower value. If there is backlash on the system, it will be difficult to tune with a lower value.
Jog Testing
Jog from sigmwin and graph encoder feedback. Jogging is in velocity mode.
Tools for Troubleshooting
To track down encoder issues, you can graph the encoder counts and velocity in Mach4.
Here's an example of an encoder overflowing. This should never happen but in this case the encoder wasn't configured correctly.
To see how you are doing while tuning or just overall performance, graph Feedback speed, External encoder speed, and Torque Reference. This allows you to see how much lag there is between the motor and the external encoder... basically shows how backlash is responding.
Here is how to setup a graph inside Sigmawin:
Here is an example of an average move on a sluggish system (lots of backlash):
In this graph, you can see there's almost an 80 ms delay between the motor and the external encoder (80ms of movement with NO movement on the encoder!). This was on a B axis on a boring mill.
This is an example of an unstable tune... the gains are too high.
