TMS320F28069M: About delay until the motor turns

Hello,

I work with stepper motors myself and there such delays are mostly due to the engine breakaway torque. What is connected behind the motor? can you reduce the torque?

Otherwise, a speed control is always an option to optimize a motor control.

Best regards

Leon

Sh.Sasaki said:

This system may have a delay between the current being applied to the motor and th

Notice 2nd vertical white makers also indicate a single encoder pulse resulted in single large current spike. The 1st marker (current) also has encoder low transition long delay as if the sensor wheel is slipping on rotor shaft during sudden torque changes. Yet the speed ramp being late too may be interrupt condition to adjust trajectory lags behind encoder changes. Perhaps the sensor set screw is easiest first checking. 

Hi Leon-san,

Thank you for your reply.

Leon Linder said:

What is connected behind the motor? can you reduce the torque?

I check with our customers about these.

Best regards,
Sasaki

Hi GI-san,

Thank you for your reply.

Genatco said:

Perhaps the sensor set screw is easiest first checking. 

Does the customer check the set screw of the sensor to make sure it is not loose?

Best regards,
Sasaki

The lab10b is sensorless-foc based instaspin-motion, you might enable the force angle and tune the related parameters below to improve the startup performance.

1. In spintac_velocity.h, #define ST_MIN_ID_SPEED_RPM (5) 

2. The acceleration, gMotorVars.MaxAccel_krpmps

3. USER_SYSTEM_BANDWIDTH and USER_ZEROSPEEDLIMIT in user.h

Leon-san,

Thank you for your information.

I will contact the customer with this information.

Best regards,
Sasaki

Sh.Sasaki said:

Does the customer check the set screw of the sensor to make sure it is not loose?

That would be a good thing to check too. Yanming suggest Lab10b is not encoder FOC. Seems customer is using encoder sensor to detect the rotor speed angle keeps with inductor current.

Sasaki,

Any feedback? Is the customer developing their project based on instaspin-foc or instaspin-motion? They should change the startup process without using a force angle function if they are using an encoder.

Hi Luo-san,GI-san,

I asked the customer about the encoder.

The encoder in the waveform is an external evaluation encoder to check the rotation.
The encoder input is not used to control the motor.

The customer is using lab10b as it is and wants to improve the problem that the motor accelerates suddenly when the start of the motor is delayed.

Yanming Luo said:

1. In spintac_velocity.h, #define ST_MIN_ID_SPEED_RPM (5) 

2. The acceleration, gMotorVars.MaxAccel_krpmps

3. USER_SYSTEM_BANDWIDTH and USER_ZEROSPEEDLIMIT in user.h

The customer adjusted the above parameters but the problem did not improve.

I would like to know if there are other ideas for improvement.

Best regards,
Sasaki

Hi Luo-san,

Thank you for the useful information.
I ask the customer to confirm this.

Best regards,
Sasaki