Generic servo tuning advice, yaskawa

Could use some general servo tuning advice. This is my first AC servo experience. Years of DC servo.

We have a 5axis trunnion, on a machining center. I have the 4th axis tuned and running. The 4th drive is a yaskawa SGDC-05AJA. (0.4kw) This series of drives does NOT have autotuning. Old school.

We are having problems tuning the 5th axis motor. The 5th drive is a SGDC-15AJA, (So a bit large at 1.5kw for the small motors) And have to use a 0.9kw motor code.

Could use some tuning advice. Out of the table, the 5th motor jumps wildly and alarms. Or is stable, but jumps when touched by hand, or when jogged 0.01°. Increasing position gain just causes the motor to oscillate and OVERHEAT. It is a brand new motor. When using the same parameters as the 4th, the motor just jumps/alarms consistently when energized.

I have the following tuning parameters:
Position Gain. Kp.
Speed loop gain. Kv.
Speed loop time Ki.
Speed torsion filter.
Load inertia.

The encoder output looks good, and I am getting good encoder position data on the control when spinning the motor by hand.

What gain parameters would you modify in order of priority? Once I get past jumping, and to oscillating, how much incrementally would you decrease position gain? 1, 10, 100, 1000? (Position gain currently set to: 4000. Speed gain: 4500. Time: 550.

What causes the servo energize, and wild jump? Too high speed gain, or too low position gain? Or some other gain parameter?

Does the motor direction correspond to the encoder direction?


Sent from my iPhone using Tapatalk

Strange, according to the manual for that drive on page 308, it should have auto tuning..There is also some formulas to set the gains manually.

Quote:

---

Originally Posted by claya

Could use some general servo tuning advice. This is my first AC servo experience. Years of DC servo.

We have a 5axis trunnion, on a machining center. I have the 4th axis tuned and running. The 4th drive is a yaskawa SGDC-05AJA. (0.4kw) This series of drives does NOT have autotuning. Old school.

We are having problems tuning the 5th axis motor. The 5th drive is a SGDC-15AJA, (So a bit large at 1.5kw for the small motors) And have to use a 0.9kw motor code.

Could use some tuning advice. Out of the table, the 5th motor jumps wildly and alarms. Or is stable, but jumps when touched by hand, or when jogged 0.01°. Increasing position gain just causes the motor to oscillate and OVERHEAT. It is a brand new motor. When using the same parameters as the 4th, the motor just jumps/alarms consistently when energized.

I have the following tuning parameters:
Position Gain. Kp.
Speed loop gain. Kv.
Speed loop time Ki.
Speed torsion filter.
Load inertia.

The encoder output looks good, and I am getting good encoder position data on the control when spinning the motor by hand.

What gain parameters would you modify in order of priority? Once I get past jumping, and to oscillating, how much incrementally would you decrease position gain? 1, 10, 100, 1000? (Position gain currently set to: 4000. Speed gain: 4500. Time: 550.

What causes the servo energize, and wild jump? Too high speed gain, or too low position gain? Or some other gain parameter?

---

The 1500w drive is not suitable for anything lower than 850w motor so if your motor is smaller than this it's not going to work very well

Quote:

---

Originally Posted by claya

Could use some general servo tuning advice. This is my first AC servo experience. Years of DC servo.

We have a 5axis trunnion, on a machining center. I have the 4th axis tuned and running. The 4th drive is a yaskawa SGDC-05AJA. (0.4kw) This series of drives does NOT have autotuning. Old school.

We are having problems tuning the 5th axis motor. The 5th drive is a SGDC-15AJA, (So a bit large at 1.5kw for the small motors) And have to use a 0.9kw motor code.

Could use some tuning advice. Out of the table, the 5th motor jumps wildly and alarms. Or is stable, but jumps when touched by hand, or when jogged 0.01°. Increasing position gain just causes the motor to oscillate and OVERHEAT. It is a brand new motor. When using the same parameters as the 4th, the motor just jumps/alarms consistently when energized.

I have the following tuning parameters:
Position Gain. Kp.
Speed loop gain. Kv.
Speed loop time Ki.
Speed torsion filter.
Load inertia.

The encoder output looks good, and I am getting good encoder position data on the control when spinning the motor by hand.

What gain parameters would you modify in order of priority? Once I get past jumping, and to oscillating, how much incrementally would you decrease position gain? 1, 10, 100, 1000? (Position gain currently set to: 4000. Speed gain: 4500. Time: 550.

What causes the servo energize, and wild jump? Too high speed gain, or too low position gain? Or some other gain parameter?

---

You will need to do a few things; Each drive will need to have its internal parameters set to the correct motor. If you do not do this, any tuning external to the drive will be very difficult, a waste of time.
In addition you will be able to set some of the tuning parameters.

1. Download Sigma Win software or purchase the Digital Operator.
2. Each servo drive's parameters must be configure to its attached motor.
3. Are these step-dir or +- 10V.
4. What software / hardware is connected to the drives? The loop in this software will also have to be set / tuned.

In summary, the software loop and the {drive loop and proper motor configuration} will need to be set.

Bottom Line, you MUST configure each drive to the attached motor first!!!
Second Tune: the PID loop.

Hope this helps,

Iron-Man

Iron-Man,

So far, you know more about these drives than anyone we have talked to. So that helps a lot.

The SGDC-15AJA drive does NOT have the PCB & connector for the Digital operator. The AJA drives are just simple amps. All the parameters come from the Machine control.
We do have an SGDC-05AJA that works like it should. The problem we are having is with the higher wattage -15AJA drive. The control uses motor codes to configure the drive/motor. And an Encoder code to configure the encoder. The drive (or control) does not recognize the correct motor code as valid for the -15 drive. So we have a work-around that according to one Yaskawa expert should be working.

So some VERY basic servo questions:

We are getting motor jumps, or oscillation at drive energize. Changing parameters one at a time on the control does NOT converge the symptoms, at least that we can tell.
What causes the Jumps? Gain Parameters, or servo configuration? The error is 3045, Encoder pulse following error.
What causes the oscillations? Gain parameters, encoder errors, or servo configuration. We get no error with the oscillations, but the motor heats up FAST, and is at 200% max current load.
On this era drive do we have to adjust the Kp/Kv/Ti gains together to get the rough motor tune? Or just the fine tuning? In other words, change two or all three parameters to stabilize the motor.

A Fanuc expert suggests it might be a commutation error. These motor/drive use the C-channel, but I don't really understand how. We have seen a commutation error on a different motor/encoder, but that was from taking the Encoder off the motor, and not getting it timed correctly. How do the Yaskawa AC motors manage commutation? Could the jumps/oscillation instability be a commutation error?

Quote:

---

Originally Posted by Iron-Man

You will need to do a few things; Each drive will need to have its internal parameters set to the correct motor. If you do not do this, any tuning external to the drive will be very difficult, a waste of time.
In addition you will be able to set some of the tuning parameters.

1. Download Sigma Win software or purchase the Digital Operator.
2. Each servo drive's parameters must be configure to its attached motor.
3. Are these step-dir or +- 10V.
4. What software / hardware is connected to the drives? The loop in this software will also have to be set / tuned.

In summary, the software loop and the {drive loop and proper motor configuration} will need to be set.

Bottom Line, you MUST configure each drive to the attached motor first!!!
Second Tune: the PID loop.

Hope this helps,

Iron-Man

---

What manual are you looking at? You have a link? The AJA version of the Drive has no capability of connecting an operator. So not sure how auto-tuning gets initiated. I would LOVE to auto-tune, if its possible. We can do the "tuning" manually by formula via control parameter. But I am not sure we are even in the ballpark for that yet. See my response to Iron-Man for the details/basic questions.

Quote:

---

Originally Posted by underthetire

Strange, according to the manual for that drive on page 308, it should have auto tuning..There is also some formulas to set the gains manually.

---

Quote:

---

Originally Posted by mactec54

The 1500w drive is not suitable for anything lower than 850w motor so if your motor is smaller than this it's not going to work very well

---

Not work very well, meaning what? Can't get it to work at all, or we can't set the gain values low enough to work well? Is the higher wattage drive not able to fine adjust the current to match the smaller motor? One of the techs we talked to said this is doable, as these AJA drives are just simple amps. They do whatever the machine control/feedback tells them to do, so long as the drive wattage is high enough to match the motor.

Is motor direction correspond to encoder direction?

Quote:

---

Originally Posted by claya

Not work very well, meaning what? Can't get it to work at all, or we can't set the gain values low enough to work well? Is the higher wattage drive not able to fine adjust the current to match the smaller motor? One of the techs we talked to said this is doable, as these AJA drives are just simple amps. They do whatever the machine control/feedback tells them to do, so long as the drive wattage is high enough to match the motor.

---

"You answered part of the question yourself " ( so long as the drive wattage is high enough to match the motor )

No you most likely won't get it to work correctly as that drive will not support the encoder motor codes the drive is to large for the motor you are driving all Yaskawa Drives only support a small range of motors with in the wattage range of the drive you are using

As I said Yaskawa does not recommend any smaller motor than 850w on a 1500watt drive

Yes they have Auto tuning and can connect with a remote operator with 7CN port

Do you have absolute or incremental encoder ??

What size motor are you trying to run ??

There are only 2 motor sizes that will run on that drive 13A=183 code and 15A=202 code

Quote:

---

Originally Posted by Autophanous

Is motor direction correspond to encoder direction?

---

Same thing I asked. No response. It’s the first that should be checked.


Sent from my iPhone using Tapatalk

According to an experienced yasnac tech, we can run the lower wattage motor on this drive. However he did not know what gain values to use. The encoder codes 'seem" to be working, using encoder code 22. 14 also works. We are getting the correct position readout, and direction.

2048 incremental.
Motor:SGMP-04A314M

The AJA drives do not have autotuning. There is no 7CN connector to use a digital operator.

Quote:

---

Originally Posted by mactec54

"You answered part of the question yourself " ( so long as the drive wattage is high enough to match the motor )

No you most likely won't get it to work correctly as that drive will not support the encoder motor codes the drive is to large for the motor you are driving all Yaskawa Drives only support a small range of motors with in the wattage range of the drive you are using

As I said Yaskawa does not recommend any smaller motor than 850w on a 1500watt drive

Yes they have Auto tuning and can connect with a remote operator with 7CN port

Do you have absolute or incremental encoder ??

What size motor are you trying to run ??

There are only 2 motor sizes that will run on that drive 13A=183 code and 15A=202 code

---

Yes. Responded to another thread. I don't know how to respond to multiple threads with one reply.

I believe Motor direction corresponds to encoder direction. We have two drives. Both motors turning the same direction. The jump/oscillation does not vary by changing motor direction on the drive we are having trouble with.

Quote:

---

Originally Posted by chemphd

Same thing I asked. No response. It’s the first that should be checked.


Sent from my iPhone using Tapatalk

---

Quote:

---

Originally Posted by claya

According to an experienced yasnac tech, we can run the lower wattage motor on this drive. However he did not know what gain values to use. The encoder codes 'seem" to be working, using encoder code 22. 14 also works. We are getting the correct position readout, and direction.

2048 incremental.
Motor:SGMP-04A314M

The AJA drives do not have autotuning. There is no 7CN connector to use a digital operator.

---

You should of said you where using Yasnac

The SGDC drives do have Auto tuning but with your Yasnac configuration that would most likely not be possible, there is a port for remote control also on the AJA drives

Your SGMP-04A314M ( 400w motor ) is to small to be controlled with the 1500w drive, unless you can change the drive software, ( which is not likely ) if you do get it running, in the end you will have a fried motor

Check all your Ground wire connection are correct

Buy another drive suitable for the motor

Quote:

---

Originally Posted by mactec54

You should of said you where using Yasnac

The SGDC drives do have Auto tuning but with your Yasnac configuration that would most likely not be possible, there is a port for remote control also on the AJA drives

Your SGMP-04A314M ( 400w motor ) is to small to be controlled with the 1500w drive, unless you can change the drive software, ( which is not likely ) if you do get it running, in the end you will have a fried motor

Check all your Ground wire connection are correct

Buy another drive suitable for the motor

---

Did not think to add the Yasnac detail, since this was a Yaskawa servo forum. All my AJA drives don't have the 7CN connector, so what is the remote port? I think it was a Tech at Precision zone that said that the AJA is a simple amp, and has no real intelligence.

I did not really expect auto-tuning with the Yasnac anyway.
Drive wise, is what you are saying is the Yaskawa drives operate in a narrow 1.5Kw-0.850Kw current range that is way above what the small 400W motor can handle? So I we were to set the gains to 1, it still is too much current?

Another experienced tech said it was possible to run the small motor on the larger drive, but at this point I am not so sure anymore. Curiously we can get it "almost" working, by using really low gains (Kp=100 range) but I don't have enough experience with AC gain parameters to "rough tune" the drive. Hence the original generic query. I don't know how the AC gains interact with each other by any hands on experience. I have the formulas, but need some mentoring on how to apply the theory. And what values to even use in the equations. Basically some "feedback" from all you old school PID experts on what gains effect the Oscillation we are getting at stationary, and what gain/parameters does nothing. I understand PID theory at the most basic level from some college courses, and study. But my only practical experience is on DC servo... Much simpler..

You have some advice on what J300/I-80 parameters we can adjust to reduce the oscillation, and how they interact with each other. I could really use the education.

I just ordered a smaller SGDC-05AJA drive. But if we can get the -15 drive working, that has some usefulness for the future. Really like to understand tuning better if you can point in the right direction.

Grounds: Besides the motor and drive grounds, are you talking about shielding? This is a 4th/5th axis trunnion, so all the cabling is bundled. And I can swap everything without issues. The oscillation/jump problem moves with the drive.

This is the most activity I have ever gotten on a post, so don't know how to respond to everyone in one reply, or if that is even possible.

Have you looked at this document SIE-S800-22.pdf on the Yaskawa site?
It appears to show the digital operator connected to CN7.

Are your drives running in speed or torque mode, there is a difference?
Can you post pictures.

Iron-Man

Quote:

---

Originally Posted by Iron-Man

Have you looked at this document SIE-S800-22.pdf on the Yaskawa site?
It appears to show the digital operator connected to CN7.

Are your drives running in speed or torque mode, there is a difference?
Can you post pictures.

Iron-Man

---

Wrong PDF information, this is not for his AJA drives which are quite different

Quote:

---

Originally Posted by mactec54

Wrong PDF information, this is not for his AJA drives which are quite different

---

OK, can someone post the manual. I will take a look.

Thanks,

Iron-Man

Quote:

---

Originally Posted by Iron-Man

OK, can someone post the manual. I will take a look.

Thanks,

Iron-Man

---

You have to look at Yasnac it is a whole different system than regular Yaskawa system here is a diagram of some of there how there control is configured I have some Yasnac manuals but they are to big to load on here you may find a PDF at the Yaskawa web site

He has done the right thing by getting a smaller rated drive 05 which will be fine for his 400w motor, just hope his motor has not been damaged by someone's bad information

Quote:

---

Originally Posted by mactec54

You have to look at Yasnac it is a whole different system than regular Yaskawa system here is a diagram of some of there how there control is configured I have some Yasnac manuals but they are to big to load on here you may find a PDF at the Yaskawa web site

He has done the right thing by getting a smaller rated drive 05 which will be fine for his 400w motor, just hope his motor has not been damaged by someone's bad information

---

Mactec54 thanks.

Can you provide a higher resolution image of the first schematic. From what I can tell, the 2nd image shows CN14 which has a rs232 input. It may be possible to access the drive's parameters and settings from this port.
He will need a generic terminal program.


Iron-Man