Robot in RViz doesn't move

[Lukas]

Hi,
I m trying to implement MoveIt with my code but I run into a problem which cannot solve.

In my code the odometry is going to be published as explained in this tutorial.
So the3 odometry information is calculated and published as tf transform on the topic /odom.

Questions:

1) Will Moveit only sensor_msgs/JointState information and not tf transformation? Or I can use the published odometry to feed directly into the move_group of Moveit?

2) If I must changed the published information from tf into  sensor_msgs/JointState messages, how can it be done? I defined a virtual floating point between /odom and /base_link, that means that the "joint" could move on 3 different axes and rotate on 3 different angles. But the messae  sensor_msgs/JointState allows only to publish one value for rotation or translation;

Regards

[Lukas]

I forgot to add...hat the displayed robot in RViz is not moving at all.
Running RViz AND my code works perfectly. But launching demo.launch created by moveit_it doesn't move my robot.
From the rqt_graph could I see that the the tf is going to be send to /move_group and /joint_states also. For this reason I suspect that /move_group doesn't read any /tf informations.

Am I right?

[Rabe]

Hey,

I'm only working with robot arms, so I have no direct experience with your problems, but here are some thoughts:

- Just to be safe: The fixed frame in Rviz is not set to the base of your robot, but something else?
- If my understanding is correct, the joint-states get fed into the robotStatePublisher, which then publishes transforms for each part of the robot, which then are read by moveit. So moveit should be listening to transofrms, at least in general.
- About the JointStats: I don't have a definitive answer, but I guess your keyword to look for might be "multiDOFJoints". Maybe you can find out how they are implemented with other robots.

As I said, I don't have any personal experience with those aspects of moveit, but maybe it'll help you.

Cheers,
Rabe

Am Sonntag, 16. November 2014 22:05:28 UTC+1 schrieb Lukas:

[Davide Picchi]

Hello everybody, hello Fabian,

I tried the solution with the MultiDOFJointState but the problem persists.

I' ve a virtual joint between /odom and /base_link (as example you can see the file developed for MoveIt, between /odom_combined and /base_footprint).

The virtual joint has 6 DOF, is also a virtual floating joint.

Later on I pass to the MultiDOFJointState the following informations:

joint_state.header.frame_id = "odom";
joint_state.joint_names[0] = "world";
joint_state.transforms[0].translation ...
joint_state.transforms[0].rotation ...

where translation and rotation are taken from the calculated odometry by my robot's drivers.

The joint_state is then published over ROS through the following publisher:

joint_pub_ = nh_.advertise<sensor_msgs::MultiDOFJointState>( "joint_states", 1 );

Problem: The program crashes after few seconds with the following error:

[ERROR] [1416345970.180590249]: Client [/robot_state_publisher] wants topic /joint_states to have datatype/md5sum [sensor_msgs/JointState/3066dcd76a6cfaef579bd0f34173e9fd], but our version has [sensor_msgs/MultiDOFJointState/690f272f0640d2631c305eeb8301e59d]. Dropping connection.
[ERROR] [1416345970.181654144]: Client [/move_group] wants topic /joint_states to have datatype/md5sum [sensor_msgs/JointState/3066dcd76a6cfaef579bd0f34173e9fd], but our version has [sensor_msgs/MultiDOFJointState/690f272f0640d2631c305eeb8301e59d]. Dropping connection.

It seems also that the robot_state_publisher, which listens to the topic /joint_states, doesn't accept the MultiDOFJointState

How can I get a solution for this problem? Is something "wrong" in the way I feed the move_group?

I' m really willing to understand how MoveIt works. The lack of documentation and examples is overwhelming me!!!

Regards

Again here a screenshot of rqt_graph.

--

Davide Picchi

Mobil: +49 176 86308958

pav...@gmail.com