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The center of mass especially for some links of the arm is not correct. And also for the base the center of mass seems to be a little bit too high.

Any word on if Groovy has been looked at with the youBot or if consideration has been made to look into migrating to catkin?

Also, might it be better to break up all of the various stacks (metapackages) into separate repositories and adhere closer to the branching strategies in ROS (e.g., groovy-devel, hydro-devel...). This would also make it a lot easier to eventually add support to integrate into the ROS build system to create debian packages for the youBot.

Thoughts? 🐹

For some applications we need to have the arm joint limits available. Therefore it would be nice to have them on the parameter server. Maybe adding the limits to the "arm_joint_universal_control.yaml":

arm_controller:
type: youbot_description/YouBotUniversalController
joints:
- arm_joint_1
- arm_joint_2
- arm_joint_3
- arm_joint_4
- arm_joint_5

limits:
arm_joint_1:
min: 0.0100692
max: 5.84014
arm_joint_2:
min: 0.0100692
max: 2.61799
arm_joint_3:
min: -5.02655
max: -0.015708
arm_joint_4:
min: 0.0221239
max: 3.4292
arm_joint_5:
min: 0.110619
max: 5.64159

gains:
arm_joint_1:
p: 1000
d: 1
arm_joint_2:
p: 1000
d: 1
arm_joint_3:
p: 1000
d: 1
arm_joint_4:
p: 1000
d: 1
arm_joint_5:
p: 1000
d: 1

And to the "gripper_joint_position_control.yaml":

gripper_controller:
type: youbot_description/JointPositionController
joints:
- gripper_finger_joint_l
- gripper_finger_joint_r

limits:
gripper_finger_joint_l:
min: 0.0
max: 0.0115
gripper_finger_joint_r:
min: 0
max: 0.0115

gains:
gripper_finger_joint_l:
p: 10
d: 2.0
gripper_finger_joint_r:
p: 10
d: 2.0

I am trying to update the youbot-ros-pkg files on my custom rolled kuka youbot system. Following the instructions in the readme I am able to proceed until the following step:

youbot@kukaros1:~/ros_stacks/youbot-ros-pkg$ ./repository.debs
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package libopencv2.3-dev
E: Couldn't find any package by regex 'libopencv2.3-dev'

There do not seem to be packages for libopencv2.3-dev available on 12.04. We are using ROS fuerte.

There is a minor bug in the youbot_oodl which I came across recently.

In the file "youbot_oodl / src / YouBotOODLWrapper.cpp" lines 797 - 803 currently are:

/*
Yet another hack to make the published values compatible with the URDF description.
We actually flipp the directions of the wheel on the right side such that the standard ROS controllers
(e.g. for PR2) can be used for the youBot
*/
baseJointStateMessage.position[2] = -baseJointStateMessage.position[2];
baseJointStateMessage.position[4] = -baseJointStateMessage.position[4];

These indexes are wrong, they should be 0 and 2 instead of 2 and 4 so then the wheel turn correctly in rviz.

We recorded the ROS topic "joint_states" and find that no message arrives during regular time intervals. We could isolate the issue to be the gripper sensor readings:
https://github.com/youbot/youbot-ros-pkg/blob/master/youbot_drivers/youbot_oodl/src/YouBotOODLWrapper.cpp#L868

You can reproduce the error by simply looking at the frequency of the youbot_oodl:
$ rostopic hz /joint_states
You will see that the frequency is not at 50Hz (the default value for the youbot_oodl), but around 40Hz. If you look at the data, you will see something like in this plot:

As a workaround we just commented out these lines. A possible fix to this issue would be to put the sensor readings of the gripper to a separate thread that does not block the main thread.