run sensorless control and read encoder angle

Dezhi Li71

Other Parts Discussed in Thread: TMS320F28069, CONTROLSUITE

Hi,

I got some problem with encoder reading while running sensorless control of the motor. If I disconnected the encoder from the TI chip TMS320F28069, the motor spins in sensorless mode. Once I connected the encoder to the TI chip, the motor stop spinning, and I can read encoder angle and speed. Then I disconnected the encoder, and the motor starts spinning again. I would like to run motor in sensorless mode and read encoder angle and speed, so I can compare the angle and speed from both encoder and sensorless. Could anyone help me on that?

Someone mentioned that I should connect EQEP1ERR TO TZ4, and EQEP1ERR comes from QFLG[PHE]. But I don't see TZ4 on TMS320F28069 chip. Is there another way to do it? Would I reach my goal with this method?

Thank you.

over 9 years ago

0 Ramesh Ramamoorthy over 9 years ago

TI__Mastermind 27240 points

Well, in sensorless mode, the encoder is not part of the loop and I cant understand this behavior. Look at your QEP initialization code and verify its configuration. The default code from controlsuite would not exhibit this way.

0 Dezhi Li71 over 9 years ago in reply to Ramesh Ramamoorthy

Prodigy 50 points

Thank you for your answer. I also tried the sensorless control code without any encoder related code. It gives the same behavior. Once I connected the encoder, the motor stops running in sensorless control. I disconnected the encoder, the motor runs. I measured the encoder channels A, B and index signals input to the TI chip. The high level voltage is 2.5V and low level voltage is 0V. They are in the reasonable range of the TI chip I/O.

0 Ramesh Ramamoorthy over 9 years ago in reply to Dezhi Li71

TI__Mastermind 27240 points

If it happens without any encoder related code, I have to suspect the voltage level of QEP signals. Is the F28069 operating at 3.3V and QEP at 2.5V? Can you convert the QEP signals to 3.3V and verify?

0 Dezhi Li71 over 9 years ago in reply to Ramesh Ramamoorthy

Prodigy 50 points

Thank you. Problem solved. The encoder draws too much current, so the inverter does not work well.

C2000™︎ microcontrollers

C2000 microcontrollers forum

run sensorless control and read encoder angle