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2019-05-20 02:31:48 -0600 marked best answer How do I get the displacement vector from one object to another?

I have two objects A and B, each in the form of geometry_msgs/PoseStamped. I would like to calculate the displacement (translation & rotation) vector that I can apply to any (similar) object A' and arrive to a (similar) object B' (respectively).

  1. I guess the vector should also be of the form PoseStamped.

  2. For translation, can I simply take B.PoseStamped.position.x - A.PoseStamped.position.x (similar for y,z)?

  3. For the quaternion, I am not sure if I can simply do division (since adding angles in quaternions is done by multiplication?) i.e. B.PoseStamped.quaternion.x/A.PoseStamped.quaternion.x ?

I would like to avoid having to transform the quaternion to euler and back.

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2018-11-28 13:56:02 -0600 commented answer "rosbag record -a" in C++?

how do you stop the recording in cpp?

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2018-10-17 05:09:13 -0600 asked a question Detect stacked objects with PCL2

Detect stacked objects with PCL2 Hi, I'm using the surface_perception library which segments surface objects using PCL2

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2018-08-27 03:12:40 -0600 marked best answer Invalid argument passed to lookupTransform argument source_frame in tf2 frame_ids cannot be empty

I'm using the surface_perception package to get some table top data but I've been getting this error message

Invalid argument passed to lookupTransform argument source_frame in tf2 frame_ids cannot be empty

after running the surface segmentation for the multiple times and I can't seem to figure out what the problem is.

The error message appears when i launch this file:

<launch>
  <include file="$(find rosbridge_server)/launch/rosbridge_websocket.launch" />
  <node pkg="tf2_web_republisher" type="tf2_web_republisher" name="tf2_web_republisher" launch-prefix="xterm -e gdb --args"/>
</launch>

i tried adding the launch-prefix="xterm -e gdb --args" to the tf2_web_republisher node but it just shows up the same error messages without indicating where its occuring.

An odd thing that happens is that the visualisation shows one of the axes to be enlarged as shown here

I know this is related to some empty frame_ids but i cant seem to figure out where they are. When I run

rostopic echo /tf2_web_republisher/result

then all frame ids are empty even when there's no error message.

any advice would be highly appreciated!

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2018-08-03 08:31:59 -0600 commented answer Invalid argument passed to lookupTransform argument source_frame in tf2 frame_ids cannot be empty

so I included an extra if statement to make sure it doesnt try to lookup the transform if the source or target frames ar

2018-08-03 05:26:58 -0600 commented answer Invalid argument passed to lookupTransform argument source_frame in tf2 frame_ids cannot be empty

i tried doing a grep for empty frame_id for both /tf and /tf_static but didnt get anything. Will try to download the sou

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2018-08-02 09:31:13 -0600 asked a question Invalid argument passed to lookupTransform argument source_frame in tf2 frame_ids cannot be empty

Invalid argument passed to lookupTransform argument source_frame in tf2 frame_ids cannot be empty I'm using the surface_

2018-06-12 08:31:27 -0600 commented question TF error in ar_track_alvar

did you find a solution to this?

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2018-05-18 09:55:10 -0600 asked a question get YAML list of dictionary items with ros::param in C++

get YAML list of dictionary items with ros::param in C++ I would like to define a list of items in a yaml file which I r

2018-05-17 06:33:29 -0600 commented question Unable to run moveit because of assimp packages

I didnt delete the question? it's still there, i marked your answer as correct

2018-05-16 16:59:09 -0600 commented answer Symbol lookup error: libgeometry_shape.so: undefined symbol: _ZN6Assimp8Importer18SetPropertyIntegerEPKciPb

I removed ROS aand reinstalled it but my assimp packages had the wrong version again so I was back at square 1. I ended

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2018-05-16 16:56:00 -0600 marked best answer Unable to run moveit because of assimp packages

When I try to run roslaunch baxter_moveit_config demo_baxter.launch, I get the error

/opt/ros/indigo/lib/rviz/rviz: symbol lookup error: /opt/ros/indigo/lib/libgeometric_shapes.so: undefined symbol: _ZN6Assimp8Importer18SetPropertyIntegerEPKciPb

and it crashes. These are my assimp packages:

$ apt list --installed | grep assimp
assimp-utils/trusty,now 3.0~dfsg-2 amd64 [installed,upgradable to: 3.2~dfsg-3~urp8+1]
libassimp-dev/trusty,now 3.2~dfsg-3~urp8+1 amd64 [installed]
libassimp-doc/trusty,now 3.0~dfsg-2 all [installed,upgradable to: 3.2~dfsg-3~urp8+1]
libassimp3/trusty,now 3.2~dfsg-3~urp8+1 amd64 [installed,automatic]
python-pyassimp/trusty,now 3.2~dfsg-3~urp8+1 all [installed]

I tried to solve it according to a previous thread but the mentioned solution did not work.

Any help? I feel like I have tried everything that I could but keep going in circles...

EDIT: This is what I did previously:

My assimp libraries were too high, so i reverted them to 3.0 manually (I downloaded the .deb file from launchpad and installed them using dbpk)

$ apt list --installed | grep assimp
assimp-utils/trusty,now 3.0~dfsg-2 amd64 [installed,upgradable to: 3.2~dfsg-3~urp8+1]
libassimp-dev/trusty,now 3.0~dfsg-2 amd64 [installed,upgradable to: 3.2~dfsg-3~urp8+1]
libassimp-doc/trusty,now 3.0~dfsg-2 all [installed,upgradable to: 3.2~dfsg-3~urp8+1]
libassimp3/trusty,now 3.0~dfsg-2 i386 [installed,upgradable to: 3.2~dfsg-3~urp8+1]
python-pyassimp/trusty,now 3.0~dfsg-2 all [installed,upgradable to: 3.2~dfsg-3~urp8+1]

However, once that was done, I would get this error message when starting rviz:

/opt/ros/indigo/lib/rviz/rviz: error while loading shared libraries: libassimp.so.3: wrong ELF class: ELFCLASS32

since this didnt work, I did a sudo apt-get -f install again and ended up with the 3.2 assimp versions as mentioned above.

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2018-05-16 11:56:44 -0600 commented question Unable to run moveit because of assimp packages

it worked! thanks!

2018-05-16 09:29:23 -0600 commented answer Unable to run moveit because of assimp packages

I edited my post so that it is a bit more clear. Sorry for the confusion

2018-05-16 09:28:56 -0600 edited question Unable to run moveit because of assimp packages

Unable to run moveit because of assimp packages When I try to run roslaunch baxter_moveit_config demo_baxter.launch, I g

2018-05-16 09:26:58 -0600 commented answer Unable to run moveit because of assimp packages

my current version is libassimp3/trusty,now 3.2~dfsg-3~urp8+1 amd64 [installed,automatic], what should i do?

2018-05-16 09:23:13 -0600 commented answer Unable to run moveit because of assimp packages

this was my previous error message. so should i manually revert the packages again to version 3.0?

2018-05-16 09:07:39 -0600 asked a question Unable to run moveit because of assimp packages

Unable to run moveit because of assimp packages When I try to run roslaunch baxter_moveit_config demo_baxter.launch, I g

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2018-05-16 05:42:25 -0600 commented answer My workspace cannot build because assimp library update

Hi, I'm facing the same issue but all of my assimp packages (assimp-utils, libassimp-dev/-doc/3, python-pyassimp) were a

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2017-10-04 19:18:39 -0600 commented question Moveit Tutorials pick place tutorial on Baxter

I would like to know this too!

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2017-08-01 12:23:40 -0600 asked a question How do I get the displacement vector from one object to another?

How do I get the displacement vector from one object to another? I have two objects A and B, each in the form of geometr

2016-05-03 11:50:15 -0600 asked a question Unable to register with master node but roscore works

Hi,

I have recently moved and now i cannot connect to baxter anymore. it works fine if i run roscore, but if i try to enable it with baxter_tools enable_robot.py i get the error message

Unable to register with master node [ http://baxter_hostname:11311 ]: master may not be running yet. Will keep trying.

Any idea? it worked fine before the move.

2016-05-03 11:50:14 -0600 asked a question Unable to enable baxter while roscore service works

Hi,

I have recently moved and now i cannot connect to baxter anymore. it works fine if i run roscore, but if i try to enable it with baxter_tools enable_robot.py i get the error message

Unable to register with master node [http://<baxter_hostname>:11311]: master may not be running yet. Will keep trying.

Any idea? it worked fine before the move.