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Issue in encoder mode

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limeng06217
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Last seen: 4 years 6 days ago
Joined: 2019-07-04 10:01
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Issue in encoder mode

Hello!

New VESC user here. I have worked with VESC for a couple of months so far.

The current setup is that we use two VESC and motors on the same shaft in a steering actuator for a prototype vehicle. 

  • The power supply is 12V.
  • The maximum input current to the motor has been limited to 85A.
  • There is one ECU sending motor current request through ADC port to VESC.
  • Before we haven't implemented encoder, so it only worked under sensor-less mode without any issues. 
  • A solver was implemented recently and connected to both VESCs through SENSE port as ABI encoder configuration.
  • Encoder detection did not give constant offset and ration, so we tried different values manually. Ratios were set as 4 since we use 8 poles E-motor. Offset is different for both motors.
  • Over ABS current faults happened a lot and has been solved by changing Current Kp in the encoder tab.
  • Right now only one issue left is that when we use joystick to conduct steering in the torque control mode.  it worked fine if we do normal speed steering. But if we manipulate the joystick very very slowly and it did not start steering at all, even the motor current has reached the maximum value. From the real-time data in VESC tool in the current tab, the 'current motor' (red line) has gradually ramped up from 0 to ~80A, but the 'current in' (blue line) ramped up from 0 to ~10A and did not go up anymore. This current-in is probably too low since normally when the motor current is 85, the input current to VESC is 45A. One thing that I don't understand is why the 'current-in' stopped increasing and the steering system is just stuck here to generate some high pitch sound.

Sorry English is not my native language, I will upload figures later on.

Ths steering system works fine in sensorless mode, we only have the issue in encoder mode.

 

 

limeng06217
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Last seen: 4 years 6 days ago
Joined: 2019-07-04 10:01
Posts: 3

This is the figure when the issue happens.

 

log data

limeng06217
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Last seen: 4 years 6 days ago
Joined: 2019-07-04 10:01
Posts: 3

This is the figure when we steer with normal speed steering.