Joint limit mismatch in URDF vs Hardware

[leander-dsouza]

Description

• The software shipped with the hardware of the robot has different joint limits set in comparison to the limits set in the URDF.

• These are the limits set in the software shipped with the Gen3 arm hardware: (pg 98)

  

• These are the limits set for actuators in the urdf:

  • Actuator 2 (+-138.08 deg):

  • Actuator 4 (+-152.40 deg):

  • Actuator 6 (+-127.76 deg):

• Due to this mismatch, when MoveIt! plans paths it considers the urdf's limits instead of the hardware. As a result, occasionally, the following error message gets printed onto the console, when actuator 6 exceeds the hardware limits.

  [ERROR] : Joint Trajectory failed validation in the arm. [ERROR] : Error 1 : Invalid Joint Position - Provided joint position for actuator (5) exceeds the joint limits [ERROR] : Error 2 : Invalid Joint Position - Provided joint position for actuator (5) exceeds the joint limits [ERROR] : Error 3 : Invalid Joint Position - Provided joint position for actuator (5) exceeds the joint limits

Version

ROS distribution: noetic

Branch and commit you are using: noetic-devel, adb3315aa90da73875762257a39ec4f60589f634

Steps to reproduce

1. Run the hardware launch file for the Gen3 Kinova arm:

   roslaunch kortex_driver kortex_driver.launch

2. Add the MotionPlanning plugin and select the Joints tab.

   

3. Drag the slider of joint_6 to 128 degrees:

   

4. Finally use the Planning Tab and Plan and Execute.

Expected behavior

The joint limits of the urdf and the software shipped with the robot is supposed to be matched.

Any other information

• A quick fix would be to correct the urdf values as follows:

  • Actuator 2 - (+-128.9 deg):

  • Actuator 4 - (+-147.8 deg):

  • Actuator 6 - (+-120.3 deg):

• This may solve the following issue as well - #245.

[felixmaisonneuve]

Hi @leander-dsouza,

Yes, this is something I am aware of. There is #285 open for exactly this. I will try to update the URDFs this week and close the issue once it is merged if it is good with you.

Thank you, Felix

[leander-dsouza]

I can correct the limits for both arms and create a PR soon to fix this issue.

[felixmaisonneuve]

Sure, it will be greatly appreciated

[leander-dsouza]

I have created the PR to address this issue - #294.

[felixmaisonneuve]

Closing this issue since the pull request has been merged

Thank You again, Felix