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Sebastian Rockel's profile - activity

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2016-07-28 12:41:33 -0500 asked a question rosbag 'UnicodeDecodeError'

I have some rosbags. Most of them seem to be okay according to 'rosbag check <file>'. But a few of them cause the check to be aborted in the middle of the bag with the error below.

What is the best way to avoid this decoding error?

Traceback (most recent call last):
  File "/opt/ros/indigo/bin/rosbag", line 35, in <module>
    rosbag.rosbagmain()
  File "/opt/ros/indigo/lib/python2.7/dist-packages/rosbag/rosbag_main.py", line 863, in rosbagmain
    cmds[cmd](argv[2:])
  File "/opt/ros/indigo/lib/python2.7/dist-packages/rosbag/rosbag_main.py", line 452, in check_cmd
    migrations = checkbag(mm, args[0])
  File "/opt/ros/indigo/lib/python2.7/dist-packages/rosbag/migration.py", line 76, in checkbag
    for topic, msg, t in bag.read_messages(raw=True):
  File "/opt/ros/indigo/lib/python2.7/dist-packages/rosbag/bag.py", line 2331, in read_messages
    yield self.seek_and_read_message_data_record((entry.chunk_pos, entry.offset), raw)
  File "/opt/ros/indigo/lib/python2.7/dist-packages/rosbag/bag.py", line 2469, in seek_and_read_message_data_record
    msg_type = _get_message_type(connection_info)
  File "/opt/ros/indigo/lib/python2.7/dist-packages/rosbag/bag.py", line 1565, in _get_message_type
    message_type = genpy.dynamic.generate_dynamic(info.datatype, info.msg_def)[info.datatype]
  File "/opt/ros/indigo/lib/python2.7/dist-packages/genpy/dynamic.py", line 168, in generate_dynamic
    tmp_file.file.write(full_text.encode())
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 2788: ordinal not in range(128)
2016-06-18 05:02:18 -0500 commented answer Automated rosbag on start up

Thanks for the pointer. I eventually got it working with Upstart instead of Systemd since it was used on my system.

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2016-06-16 10:20:30 -0500 asked a question Automated rosbag on start up

My plan is to use a remote computer to create a rosbag. I was wondering what is the best practice to automatically start a rosbag record instance after boot on an Ubuntu 14.04 Odroid system. Any experiences ?

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2015-06-26 09:22:07 -0500 asked a question Cannot launch PR2 navigation under Hydro-simulation

Hi,

when trying to run the PR2 navigation under Hydro the laser_filters die always. It's namely the scan_to_cloud_filter_chain node form the laser_filters package. To reproduce, do the following under Hydro:

roslaunch pr2_gazebo pr2_empty_world.launch
rosrun map_server map_server <a map>
roslaunch pr2_2dnav pr2_2dnav.launch

The latter leads to the following error:

[base_shadow_filter-8] restarting process
process[base_shadow_filter-8]: started with pid [11826]
[tilt_shadow_filter-5] process has died [pid 11736, exit code -11, cmd /opt/ros/hydro/lib/laser_filters/scan_to_cloud_filter_chain scan:=tilt_scan cloud_filtered:=tilt_scan_shadow_filtered __name:=tilt_shadow_filter __log:=/homeL/rockell/.ros/log/b25ec3a4-1c06-11e5-8a27-5cf9dd7459f2/tilt_shadow_filter-5.log].
log file: /homeL/rockell/.ros/log/b25ec3a4-1c06-11e5-8a27-5cf9dd7459f2/tilt_shadow_filter-5*.log
respawning...
[tilt_shadow_filter-5] restarting process
process[tilt_shadow_filter-5]: started with pid [11870]
[base_shadow_filter-8] process has died [pid 11826, exit code -11, cmd /opt/ros/hydro/lib/laser_filters/scan_to_cloud_filter_chain scan:=base_scan cloud_filtered:=base_scan_shadow_filtered __name:=base_shadow_filter __log:=/homeL/rockell/.ros/log/b25ec3a4-1c06-11e5-8a27-5cf9dd7459f2/base_shadow_filter-8.log].
log file: /homeL/rockell/.ros/log/b25ec3a4-1c06-11e5-8a27-5cf9dd7459f2/base_shadow_filter-8*.log
respawning...
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2015-01-09 09:31:58 -0500 commented answer How to run a ROS service call in another thread with boost

Hi Martin, Thanks!

  • I understand the second point and regarding the first point I completely agree. Unfortunately it's not my package and it was designed by uos like this on purpose;-)

    • ros::AsyncSpinner looks interesting. I'll have a look if I can solve the problem pragmatically with it.
2015-01-09 03:36:02 -0500 asked a question How to run a ROS service call in another thread with boost

Hi, my node as a class which calls a service. During that service call it needs to get notified by a topic. The callback is set up respectively. The problem is that during the service call no messages are received. I suspect that the node is blocked by the service call and cannot handle any callback calls. They just pop up after the service call has terminated.

Below is a similar example of that node.

class MyClass {
    callService(){
       my_srv.call(request);  // blocking here!
    }
    callback(){
       // do something <-- is never called during service request
    }
}
int main.. {
  ros::ServiceClient my_srv = n.serviceClient<..>("..");
  MyClass my_class(my_srv);
  n.subscribe(my_topic, 100, &MyClass::callback, &my_class);
  my_class.callService();
}

When trying to put the service call in another boost thread compilation leads to the error (see below)

 my_srv.call(request);  // blocking here!

Changed to:

 boost::thread myThread = boost::thread(boost::bind(&ros::ServiceClient::call, &my_srv, request));

Error:

 »bind(<unresolved overloaded function type>, ros::ServiceClient*, request&)«

Any hints? Thanks

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2014-04-01 02:01:32 -0500 commented answer Cannot rosmake teleop_base, getting fatal error in Fuerte

This should be then: sensor_msgs::Joy::ConstPtr& joy_msg

2014-01-28 17:24:56 -0500 marked best answer RViz Camera View is up-side down

Hi all,

We have mounted an Kinect (to be precise an Asus Xtion Live Pro) sensor up-side down onto our PR2. We added the appropriate config (camera frames) into the robot.xml (via the python script provided at the ROS wiki). Furthermore the TF (rpy angles) were modified and it was verified that the point cloud was indeed at the right orientation (regarding the robot) with RViz.

Nevertheless the camera view (2D) in RViz is still up-side down. Does anyone have a clue why?

Cheers, Sebastian

2013-10-22 06:48:58 -0500 asked a question How can I run Gazebo and the real PR2 simultaneously?

Hello,

I try to run a Gazebo simulation of a physical environment and the (real) PR2 at the same time. Running the PR2 first and launching Gazebo then leads to a broken PR2 connection (Dashboard disconnects..).

I suppose this is mainly because of Gazebo sets 'use_sim_time' to true on the param server and publishes on the /clock topic.

My question is then actually if someone tried something similar already or has any ideas or hints to bring me on the right track.

BTW I want to validate robot actions in simulation before executing them.

Thanks a lot.

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2013-08-01 04:46:45 -0500 commented answer service exception using tf listener in rospy

As this seems to be not fixed on Fuerte as of today I created a patch and want to share it. Therefore the following pull request has been created: https://github.com/ros/geometry/pull/26

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2012-07-25 06:05:27 -0500 answered a question PR2 Calibration Graphs and Improvement

We just upgraded to Fuerte and did a full system calibration on the PR2. The results are notably bad (see plot image [0]), especially the sensor to arm calibration errors. We did it twice with almost the same result.

Does anyone have the same issue after upgrading to Fuerte? Any suggestions on what might be the reason or what can improve the result?

P.S. I wanted to post this as a comment to your answer, but there was no comment field.

[0] http://tams.informatik.uni-hamburg.de/people/rockel/img/calibration_plots_120725_b.png

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