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Reverse rotation command during forward rotation

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nisigundam
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Reverse rotation command during forward rotation

If a reverse duty command is sent to the VESC(BLDC  hybrid mode) during forward rotation, will it actually be excited in the opposite direction?
When actually giving a command, it seems to rotate in the reverse direction after stopping with applying the brake.

I am trying to stop the load rapidly.

A feedback system is configured through an external MCU and a rotary encoder
However, the desired stopping performance can not be obtained with the brake command.

I am aware that there is a risk of failure when excited in the reverse direction during forward rotation.

benjamin
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The BLDC implementation is only able to excite the motor in the direction it is turning, because the sensorless tracking would not work otherwise. FOC on the other hand can apply voltage in the opposite direction if reverse is requested, as the observer tracks seamlessly through zero. You can give FOC a try. Also, the hall sensor implementation in FOC is far better than the BLDC implementation.

nisigundam
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Thank you very much for quick reply.

If BLDC sensored is used, can it be excited in the opposite direction?

Also, I tried setting of FOC in the past, but when I performed Hall sensor detection and detect and calculate palameter, overcurrent occurred and the detection did not go well.
Overcurrent protection(30A) occurred when CV / CC power supply was used, and when operated with Lipo, the FET burned.
The same was true when Encoder offset detection was performed using AMT102.

Is there anything you can do in this case?

Current configuration
VESC HW 4.12 FW 3.35
motor NTM 50-50 580 KV
Lipo 6S 65C 3.0 Ah
Use VESC tool 0.87

yosoufe
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30 amps? for Hall sensor detection?? isn't it too much?? I would say decrease it to 12 or 10 amps.

nisigundam
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Thank you for your reply.

30 A means the set value of the CV / CC power supply.
The current setting of VESC tool when performing detection was performed at 10 A.

Also, I have additional questions.
I logged the motion of the motor with MCU and rotary encoder.
When the motor sent the duty command from the stopped state to the VESC step by step, it took about 20 ms until the motor started to turn.

Even if we sent other commands, we observed a response time of about 20 ms.
I think that this time is slower than the responsiveness of a general DC motor driver.

Is there a way to shorten this time?
I am also considering changing the firmware source code.

JesseMadsen
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Vesc project has general discussion forums on which you can easily post your comments via login your account etc. Also, you can

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