Dex wrist limp after hitting E stop and returning from E stop

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1

Hello,
Sometimes hitting the e stop causes the dex wrist to go limp which causes the wrist to drop into the lidar.
Steps to reproduce are:
stretch_robot_home.py
stretch_robot_stow.py
stretch_robot_keyboard_teleop.py
Press e stop button

The robot wrist will now drop straight down into the lidar sensor and remain limp till homing.

2

Stretch RE2 with dex wrist
dev/noetic

3

Hi @nwright,

When a robot instance runs by default when the Runstop is hit, the wrist_pitch joint of the dex-wrist goes limp, as you mentioned, and would be free to move. You can change this behavior by disabling the runstop for the wrist_pitch joint by modifying the enable_runstop parameter that makes it hold the position. You can do that by copying the below dictionary to your stretch_user_params.yaml file:

wrist_pitch:
  enable_runstop: 0

But note data that this change would now allow the robot instance to move the wrist_pitch joint even on runstop mode.
Let us know if this solves your issue.

4

The wrist pitch parameter disable_torque_on_stop may also work, without overriding the runstop completely