Sawyer Simulation Vibrating

I am currently running ubuntu 16.04, gazebo 7 and ros kinetic.

I'm trying to run the new sawyer simulation on gazebo that was recently released. Has anyone noticed small vibrations in the model? I am running a force/torque sensor on the end effector but the output has a weird amount of noise. the noise isn't being caused by the model of the sensor. I know this because i've also tested the force/torque sensor on a baxter simulation and it works fine.

If anyone has experienced this and has been able to resolve it, please let me know.

Asked by lr101095 on 2018-03-28 00:07:58 UTC

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Answers

vibrations are possibly due to an error in the calculations of gravity compensation within gazebo.

Courtesy of Ian McMahon from RethinkRobotics:

*The caveat when working with the simulator is that it will never perform exactly the same as the real robot. That said, you have indeed encountered a bug with how gravity_compensation_torques are being calculated: one of the KDL::JntArray vectors being used to calculate the gravity torques is being used uninitialized. The uninitialized values cause the calculated simulated gravity torque to vary a fair amount, which causes jitter. I have a fix for this that has not been yet merged into master, but I will hotfix the simulator shortly:

https://github.com/RethinkRobotics/sa...

I will update this topic with details once merged into master. In the mean time, if you like living life on the bleeding edge, free to checkout the kinematics_gravity_torques branch on github:

$ roscd sawyer_gazebo && git fetch origin && git checkout kinematics_gravity_torques $ roscd sawyer_robot && git fetch origin && git checkout gravity_inertia $ catkin build*

Asked by lr101095 on 2018-04-23 01:27:54 UTC