ravenII's profile - activity

Is there a way to adjust the duration the link trail is displayed in robot_model in rviz? Currently it only captures a few seconds.

I am using ar_kinect and I'm getting some noise in the orientation. Since my camera motion is relatively slow I wanted to filter the transforms over time. I have designed an FIR filter. I was wondering what is the best way of filtering the transformations.

I was not sure if filtering quaternions would make any sense. Should I convert to RPY and apply the filter?

I have been wondering about the same. It would be helpful to know the answers for ar_kinect as well.

I got to fix this by including "ros/ros.h" before including "tf/transform_datatypes.h" Not quite sure what change in tf from diamondback to electric caused this.

I think this page explains the procedure. http://www.ros.org/wiki/rosbuild/CMakeLists/Examples#Linking_against_an_external_library

Not sure if it is the best way I did this with the following in CMakeLists.txt

set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -I/usr/include/festival -I/usr/lib/speech_tools/include")

For linking target libraries

target_link_libraries(example rt
python2.6
other_libraries)

Thanks for the answer. I forgot to mention. I had done make clean . rosmake --pre-clean did not fix it either.

This was not a standard ros package. It was a package someone wrote which worked under diamondback (still does if I switch back). So I could not just get a fresh copy. In order to start fresh I created a ros package with the dependencies, edited the CMakelist.txt and Manifest files, and copied the msg, src and include folders to make sure an incompatibility between the msg headers is not causing the problem. I still get the same error.

That made me think it can be a problem with ros electric and boost library. (rebuilding libboost1.40-dev - as suggested in another thread- did not fix the problem either). Does this have to do anything with rosdep.yaml file?

I have provided a traceback of the error here. My apologies for the detailed post. I appreciate any help.

/usr/include/boost/math/special_functions/math_fwd.hpp:615: error: invalid type in declaration before ‘;’ token 

In file included from 
/opt/ros/electric/stacks/ros_comm/utilities/rostime/include/ros/time.h:58,

from /opt/ros/electric/stacks/ros_comm/clients/cpp/roscpp_serialization/include/ros/serialization.h:34,

from /opt/ros/electric/stacks/common_msgs/geometry_msgs/msg_gen/cpp/include/geometry_msgs/PointStamped.h:8,

from /opt/ros/electric/stacks/geometry/tf/include/tf/transform_datatypes.h:36,

I am trying to migrate a package working under diamondback to electric. When I switch to electric I get errors with boost header files. It appears that the implementation of ros/time.h in electric is not compatible with the current boost version installed.

No errors when compiling with diamondback on the same machine.

ubuntu 10.04 libboost1.40-dev

1 kHz freq used in many robotics applications is due to errors caused by sampling for example quantization (not sure about this paper but it is generally the case)

Deterministic sampling rate is of great importance. for instance if you want to calculate velocity from sampled position data using the first difference: v = delta(x)/delta(t) where delta(t) is the sampling rate. You will then need your position samples to be taken exactly every ms.

I set up ar_kinect and printed the 4x4 pattern on a piece of paper (letter size). Everything seems to be working except that the recognition of pattern is on and off. In particular it only recognizes a transform when the paper is tilted (not perpendicular to the camera) and even then the update rate is slow (compared to what I see on the videos posted). I get the following message whenever a pose is not published

TF_NAN_INPUT: Ignoring transform for child_frame_id "/TEST_PATTERN" from authority "/ar_kinect" because of a nan value in the transform (nan nan nan) (nan nan nan nan)--

here is the roslaunch file for ar_kinect

<launch>
<node name="ar_kinect" pkg="ar_kinect" type="ar_kinect" respawn="false" output="screen">
    <param name="marker_pattern_list" type="string" value="$(find ar_kinect)/data/objects_kinect"/>
    <param name="marker_data_directory" type="string" value="$(find ar_pose)"/>
    <param name="threshold" type="int" value="100"/>
    <remap from="/camera/rgb/points" to="/camera/depth_registered/points"/>
</node>

</launch>

Is this because ar_kinect uses the depth information and there is very little depth info on a piece of paper? If so what is the proper setup?

I will appreciate it if anyone can help with this.