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unitreerobotics / unitree_legged_sdk

SDK tools for control robots.
BSD 3-Clause "New" or "Revised" License
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Rear left calf motor does not receive command #54

Open anahrendra opened 1 year ago

anahrendra commented 1 year ago

Hi!

We are doing a research with the Unitree A1 robot. So we made our own locomotion controller and run it on an Intel NUC placed on top of the robot. We connect the NUC via LAN cable to the LAN port on the Jetson NX of the robot.

Everything works fine for most conditions, including stairs and rough terrain. However, we have a strange issue. Everytime the robot climbs a relatively steep slope (maybe around 18 degree), the rear left calf suddenly crippled.

When we log the data of the motor, we noticed that for that leg only, the control mode became 0x00 (or 8), which according to the A1 Dev. guide indicates 'electronic braking mode' due to disconnection protection. However, I couldn't find further details about it.

We checked the LowState and got this data at the time the leg crippled

Temperature, mode, reserve, torque, position, velocity 48.000000 10.000000 0.000000 24.382812 -1.543421 0.541724 48.000000 10.000000 0.000000 24.347656 -1.542578 0.028331 49.000000 10.000000 0.000000 24.347656 -1.540724 0.637019 48.000000 10.000000 0.000000 24.562500 -1.537394 1.049966 48.000000 10.000000 0.000000 17.593750 -1.530820 0.804430 48.000000 10.000000 0.000000 16.777344 -1.530778 -0.183723 48.000000 10.000000 0.000000 16.847656 -1.530736 0.254121 48.000000 10.000000 0.000000 17.308594 -1.528418 0.723729 48.000000 8.000000 4.000000 3.234375 -1.523024 1.309238 49.000000 8.000000 4.000000 5.367188 -1.531073 -2.379808 48.000000 8.000000 4.000000 3.339844 -1.539923 -1.243990 49.000000 8.000000 4.000000 1.847656 -1.544179 -0.746909 48.000000 8.000000 4.000000 1.101562 -1.547508 -0.522837 49.000000 8.000000 4.000000 0.531250 -1.549616 -0.291896 49.000000 8.000000 4.000000 -0.035156 -1.550248 0.097012 48.000000 8.000000 4.000000 0.000000 -1.549953 -0.117617 48.000000 8.000000 4.000000 -0.035156 -1.549742 0.084135

It looks like everything did not surpass the motor limits. So I have no idea why this problem happens. And what does reserve=4 mean?

Notes:

  1. The NUC is powered using an external battery and regulator
  2. Realsense camera is connected directly to the NUC

Thanks in advance for your help!

TrivasZhang commented 1 year ago

As shown in mode and reserve, this motor is under temperature protection, and turn off it's own power. Did this motor temperature high?

anahrendra commented 1 year ago

Hi! Thanks for your quick reply.

As the log that I attached above, the temperature of the motor is 48. And when i touched the motor, i can feel that the other motor (front legs) feel even warmer compared to this motor.

So that means, it is certainly not about the disconnection problem?

TrivasZhang commented 1 year ago

Maybe the temperature sensor fails. Please contact our sales for more help.