TI F28069M Launchpad with BOOSTXL-DRV8305 inverter: closed-loop speed control via host model not working properly.

I'm "getting started" with MATLAB Motor Control Blockset and I have the F28069M LaunchpadXL with a BOOSTXL-DRV8305 inverter and a Teknic 2301 BLDC motor.

I'm able to run the "mcb_pmsm_qep_offset_f28068mLaunchPad" example for estimating encoder position. I'm also able to run the "mcb_pmsm_foc_qep_f28069Lauchpad" example for FOC and speed control. After building and deploying the FOC-example on the Lauchpad, I can communicate with the board using the "mcb_host_model_f28069m" host model, but the motor is running at a constant speed of either 4000 RPM or -5000 RPM. The "start/stop" motor switch works fine and the amp- and speed-scopes works fine, so I know that the communication is up and running.

BTW, the motor is running with speed +5000 RPM when the speed reference is between -6000 up to the point of +6000, where the the motor suddenly changes direction and runs at -4000 RPM. Similarly, the motor runs with speed -4000 RPM at reference +6000 down to the point of -6000, where again the motor changes direction and runs at +5000 RPM. Anyone knows what the problem is ?

Answer 1

[Ronny Landsverk]

The reason for the ill behaviour was due to rotor alignment.

Even though I ran the encoder position offset estimation program, I somehow did not get the updated parameter as part of the main build. Once the steps were carried out with more awareness the motor runs fine and follows the speed reference.