Why does AKD fail to drive a 3-phase brushless motor?

[yuefeiw]

Now I am working for a project on 2-axis machine control.Our Hardware lists as follow:

1 CRIO-9O74 . 2 NI9514 . 3 AKD driver. 4.Linar stage with 24V Brusless motor of  3A Continuous Current

The software is Labview2010Sp1   Softmotion module...

When I use the Interactive Test Panel to test our system, there is the buzzing soud from Motor and the software displays that  motor  rotates a small angular and then oscillates in new position?

I have check the voltage input of the motor and it is about 24 v.

I don't know how to fix the problem. It has taken me a week .Could somebody help me?

[Matt_McLaughlin]

Hi yuefeiw,

I have a few questions for you to help narrow down what the problem might be.

Just to confirm, the motor makes a buzzing noise, but does not actually move, correct? What do you mean when you say the software displays the motor oscillating in the new position? Is 24 V the input required by the motor or is this the value you measured when monitoring the input to the motor? Is the AKD drive the Analog AKD Drive or the EtherCAT AKD Drive?

Sorry to send so many questions at once, but I just want to get a better idea of your setup and the problems you are seeing. As far as I can see, the hardware should all be compatible. Please fill me in on that info.

Thanks!

[yuefeiw]

Thanks for your kind reply.I answer your question as follow:

1 the motor makes a buzzing noise, but does not actually move, correct?

   Yes,

2  What do you mean when you say the software displays the motor oscillating in the new position?

 We use the Interacitve Test Panel or Gain Tune Panel to test our motor. When click 'Enables the axis and the drive' and 'Start ..'buttons, we can see the 'current positon' is oscillating near a value on the panel. The value is very very small. And The noise is making.

3 Is 24 V the input required by the motor or is this the value you measured when monitoring the input to the motor?

The maximum voltage of motor is 40v. 24 is the value  we measured.

4 the AKD drive the Analog AKD Drive or the EtherCAT AKD Drive?

The  Analog AKD Drive. Part No.is 781522-01.

Furthermore, the input wire of our brushless motor is denoted as A,B,C and I  conenect them to the U,V and W of AKD ,respectively.The hall wire A,B,C is also connected to the hall A ,hall B and hall C of AKD. Is the order ok?Can

it have effect on the commutation of Brushless motor.

Thanks a lot .I hope you can help me fix the boring problem which so much time is spent on.

Yuefei

[Matt_McLaughlin]

Hi Yuefei,

I think the problem may be due to how the drive is connected to the motor. The drive is capable of outputting the required 3 A and you monitor voltage of 24 V, which indicates that what is actually being sent on the lines is appropriate.

What is the manufacturer and part number of your motor? Do you have a datasheet or manual on the motor that you can link me to?

Thanks!

[Nate.H]

Hi Yuefei,

Control of a brushless servo motor with the AKD requires the connection of a feedback device from your motor to the AKD drive. The drive uses the encoder input to close the torque control loop locally on the drive. The drive also creates an emulated encoder input, which is sent back to the 9514 drive interface module to close the position and velocity loops (drive is in torque mode). This emulated encoder feedback is sent from the X9 drive connector to the MVR 9514 connector over the AKD to 9514 cable. See the getting started guide for more details.

So:

1. Make sure the motor feedback device is connected to the drive appropriately as per the AKD drive manual. 

2. Make sure the encoder feedback settings on your axis in the LabVIEW project match the specs for the emulated encoder feedback signal from the AKD by following the steps on p.17 of the getting started manual linked above. 

3. Use the interactive test panel to see if this solves the problem.

Best Regards,

Nate