hi:
I have one DRV10983 EVM board . my motor is 14 poles /2800rmp max ,24VDC. there are some question to ask :
1) : motor can not run at low speed . I want 15_30rmp;
2): when I jump up J1 (cw/ccw) , there are very shark attack when it is runing ,can not stop first then convert diraction ;
3): there is vibrate at first order accelerate to second order acceleration when motor start run.
best regard
hunk
Hello Hunk,
1). motor can not run at low speed . I want 15_30rmp;
Looking at 15RPM this equates to approximately 2Hz of electrical frequency:
RPM = 120*(f_electrical)/(n_#poles)
f_electrical = RPM*(n_#poles)/120
1.75 Hz = (15)*(14)/120
Our minimum electrical frequency is 1Hz according to our recommend application range in the datasheet and motors with lower Kt values struggle to generate a large enough BEMF for our device to correctly drive the motor. This is a know limitation of the device.
2). when I jump up J1 (cw/ccw) , there are very shark attack when it is runing ,can not stop first then convert direction ;
Please review the settings on the DRV10983. Sometimes, abnormal behavior occurs when the brake done threshold (BrkDoneThr) is disabled because the device tries to align the motor before the motor has finished spinning (this is the yellow highlight below). I encourage you to increase the brake done threshold and repeat the experiment.
In addition, enabling inital speed detect (ISD) and reverse drive (RvsDr) should improve the reverse drive behavior. Consult the motor sequence flow chart below and in the datasheet for more information.
3). there is vibrate at first order accelerate to second order acceleration when motor start run.
When you say "vibrate", I'm going to assume that the motor tried to start up but the motor ended vibrating by switching back and forth in place and then stopping. This sometimes happens when the open to closed loop threshold is too low, I recommend starting at 25.6Hz and increasing if it the motor does not start up successfully.
In addition, monitoring the locks will help diagnose the issue. Please go onto the display tab of the GUI, do a manual refresh, and read which lock/fault code is occuring when the motor does not successfully start up.
If the motor is vibrating and start up is successful, I'd recommend double checking the motor parameters (phase to center tap resistance and Kt) and increasing the accleration coefficients to make start up more smooth.
Best,
-Cole
