Problem with low-speed control of the motor.

[Danu_Park]

Hello,

I am experiencing an issue with low-speed RPM control in a project created using MC Workbench. After setting a specific RPM in ST Motor Pilot and pressing Start, the motor does not initially rotate. When I set the RPM to -2000 and then suddenly change it to around 3000~4000, the motor starts rotating. Once the motor is running, it can be controlled properly in the 3000~5000 RPM range, but it cannot be controlled in the 0~3000 RPM range.

I have attached the specifications for the motor I am using. It is the 024 model, and I am using a 1024-pulse encoder. The board I am using is the EVLSPIN32G4-ACT board.

Changing the PI coefficients does not improve the issue.

I have also attached the STWB6 file.

Thank you.

 

[GMA]

Hello @Danu_Park,

Could you verify motor connect connection: U, V and W phases and Encoder signal?
Did you try using Sensor Less as Main speed sensing and Encoder as Auxiliary to check that both reported electrical angles are aligned?

[Danu_Park]

Hello,

Currently, when the motor is driven using the Hall sensor installed on it as the main sensor, the motor operates correctly. However, when the encoder is connected as the main sensor, the issue I previously explained continues to occur.

I have verified that the encoder signals are functioning without issues, and I confirmed that the values in the timer CNT register increment and decrement as expected. However, I am unable to measure the UVW signals at this time.

My ultimate goal is position control using the encoder. Specifically, I aim to fix the motor at a certain position and maintain it in place even when an external load is applied.

Could you please explain how I can check if the two electrical angles you mentioned are aligned?

Thank you.

[Danu_Park]

This is the U-phase waveform when the motor start button is pressed in encoder mode.

 

[GMA · Accepted solution]

Hello @Danu_Park,

Using Motor Control Pilot tool, "Graph & Record" left button, and select ELectrical ANGLEs to display:

[Danu_Park]

Hello,

Using the mentioned method, I discovered that the encoder channel was incorrectly connected and corrected it. As a result, Speed Control is now working well. Thank you.

Ultimately, what I want to achieve is to fix the motor position at a desired location using Position Control and then set the RPM to 0, maintaining torque only, so that the motor does not rotate even under external load.

After selecting Position Control through the Drive Setting, I set the Target Position using the PositionControlApp and clicked Start. However, the motor makes a "beep" sound and fails to stabilize at the correct position. In such cases, which parameters should I check?

Thank you.

[GMA]

Hello @Danu_Park,

Using Motor Control Pilot "Advanced Configuration", you can tune the position control PID regulator: