[Unitree A1] Diagnosis of robot that keeps failing


We are from the institute for Intelligent-Machine-Brain-Interfacing-Technology (IMBIT) at the University of Freiburg. Our group is using a Unitree A1 robot and have had great support from you. Unfortunately, we have another problem.

When we carried out the control command on A1 robot with the official Unitree SDK on our laptop, the power distribution board and the motor of the rear right elbow seem to have broken. The robot couldn’t be started with the battery anymore (video). We utilized an external power supply to start the robot, but the motor mentioned still couldn’t move at all (tried with both SDK and built-in controller) (video).

This is the second time we’ve had a problem with the power distribution board, and the third time with a motor. Both times a power distribution board failed a motor failed at the same time. And our first issue with the A1, was that a single motor that failed. Here is the topic we created after we replaced the previous distribution board and noticed that a motor failed as well. Previously, we replaced the broken parts with new motors and a new power distribution board, and the robots could start and walk again. However, since we have so many problems, we now believe that it might be caused by some internal defects of this robot.

To avoid similar problems happening again in the future, we wonder whether we could have you do a thorough diagnosis of the A1 and the broken parts to fix this problem. We would be glad to hear your ideas and solutions on this and are looking forward to hearing from you.

Dear Felix,

We have forwarded your problem to the manufacturers to get feedback and hopefully a solution to this issue! As soon as we have a response, we will get back to you!

S. O. Sohail

Dear @felix,

may you could tell us a bit more what you have already tested and in which condition the delivered A1 spare leg & Spare motor is? Both of them were already mounted and exchanged?
After the posted video do you have changed any cabeling, hardware etc? I’m asking because at us, the issue has been shifted to the left rear leg.


Dear @MYBOTSHOP_Support,

thanks for having a look at our A1!

The spare leg and motor that we added to the shipment are the old/broken parts, that we replaced with new replacement parts. Oh and yeah the broken leg was switched with the left rear one by my colleagues. I’m sorry that I forgot to mention that.

Some additional info: The PD values we used, were 40 and 0.6. This is the SDK we used.
I’ve also noticed in your video, that it can start with the internal battery. Did you already fix that issue, or did it just work for you?

I think it might be helpful to talk on the phone for a proper diagnosis, what do you think? I could call you at a specified time or email my number to you directly.