Questions tagged [rospy]
The rospy tag has no usage guidance.
478 questions
1
vote
1
answer
29
views
Accessing rviz view (Camera + Marker) in rospy
I want to get the rviz view, which is showing me visualization marker on the top of camera view in a single image. Please see below the rviz view:
I tried to view the image topic but it doesn't ...
- 1,421
0
votes
1
answer
67
views
How to plot the path and the movement of a robot?
I am using turtlebot in gazebo and rviz. The robot moves from A to B, and I am wondering if there is an easy way (without the need to use matlab) to plot
the path that robot finds (e.g. based on the ...
Turtle
0
votes
1
answer
13
views
Can I use the Python Ros bag API without making a workspace?
I'm using roscpp, but I'd like to make a transferrable python script for working with bag files. However, the docs only tell me how to do it through a catkin workspace. Is there a way to import the ...
cpagravel
0
votes
1
answer
10
views
How can I dynamically get the coordinate of a model from gazebo?
I'm using Gazebo/ROS with TurtleBot. My robot needs to find the distance from itself to all the obstacles that exist in the environment. I believe Laserscan has this information, but I am not sure how ...
Turtle
0
votes
1
answer
1
view
ros python creating strange side effects
Ubuntu 16.04
ROS Kinetic
I have been working on a program in python. Created my package just like I always do. This time I thought I would give dynamic reconfigure a try. I did the tutorial and ran ...
sonyccd
0
votes
1
answer
132
views
Python OpenCV namedWindow and imshow freeze
Hi there,
I try to view a subscribed image via cv2.imshow() like the following:
...
UllusParvus
1
vote
1
answer
43
views
is rospy.Publisher.publish() thread safe?
Want to publish() in main and also in child thread on one rospy.Publisher(),is this safe?
Originally posted by dyan on ROS Answers with karma: 7 on 2017-03-17
Post score: 0
dyan
0
votes
1
answer
19
views
how to close subscriber
After rospy.Subscriber(),after a period of time or after an event this may no longer need,how to close this subscriber
Originally posted by dyan on ROS Answers with karma: 7 on 2017-03-16
Post score: ...
dyan
0
votes
1
answer
7
views
catkin rospy package structure
Hi have been writing a ros python package with the following structure (I checked my structure against moveit_commander).
...
gpldecha
0
votes
3
answers
86
views
How to obtain list of all available topics [python]
In my gazebo model I have 9 differential drive vehicles.
When I execute rostopic list i get
...
vvyogi
0
votes
1
answer
7
views
Controlling each UAV separately in a UCTF project
I have a multiple UAV launched in Gazebo world using the UCTF project which launch two groups of gold and blue colors which compete against each other in a game cube and grass pitch in the Gazebo ...
DinoM
0
votes
1
answer
11
views
How to process PointCloud2 message data in python?
I am trying to save a pointcloud data using python. Bu I haven't been able to import pcl.
I am no sure if my installation in correct as I keep getting this error : ...
Joy16
0
votes
1
answer
9
views
subscriber cannot receive topic on rospy
I made a node which has 1 action client, 5 subscribers and 1 publisher. I wrote its pseudo code is following.
When I tried a certain sequence, one of the subscribers sub1 did not call its callback cb1 ...
graziegrazie
0
votes
1
answer
41
views
Interrupting rospy.spin() or writing a custom loop that does the equivalent
Hi,
Is there a way to exit the rospy.spin() loop without completely shutting down the node?
Or possibly is there a way to write my own equivalent rospy.spin() loop which answers service calls ...
lwoiceshyn
0
votes
2
answers
3
views
import tf2/StaticTransformPublisher in Python
I'm following this tutorial[1] and having trouble with importing.
[1] http://wiki.ros.org/tf2/Tutorials/Writing%20a%20tf2%20static%20broadcaster%20(Python)
...
- 4,294
0
votes
1
answer
29
views
How does rospy.Timer behave if it triggers while the previous callback is still busy?
I'm using a rospy.Timer (periodic, not one-shot) to handle a long-running process in a non-blocking way. I only want one instance of the process to be running at ...
spmaniato
0
votes
1
answer
44
views
speed up RViz/MoveIt
I am working with a KaWaDa nextage robot using rtmros_nextage and Moveit via the moveit_commander python interface like this:
...
robotfan
0
votes
1
answer
14
views
Best way to get FK for many different joint-states
Hello!
I am trying to calculate the end-effector pose for a huge amount of different JointStates.
The two ingredients to do that are my URDF and the numpy array that contains the joint angles.
I am ...
Alex_Nitsch
0
votes
1
answer
14
views
rostest fails when run using "catkin_make run_tests"
Hi all,
I have a node and some_test.test file like this:
...
ZdenekM
0
votes
1
answer
24
views
image_transport republish One Time Use
Folks,
I have several rosbags, 8 seconds long each, which only contain compressed depth images. Since rospy does not support compressedDepth (as far as I know) I am using
...
Pototo
0
votes
1
answer
1
view
how to open/close nextage grippers in simulation
I am using rtmros_nextage in simulation and would like the robot to pick up objects. So far I cannot even open or close the grippers. Minimal example that does not do anything:
rtmlaunch ...
robotfan
0
votes
1
answer
2
views
running rosmsg show from code
Hi,
is there a way (possibly in Python) to call the command line command rosmsg show from code, passing as an argument the name of the message/service and getting ...
McKracken82
0
votes
1
answer
62
views
What should be the messageType for a custom message?
HI,
I created a custom ROS message:
string message
int32 a
int32 b
I will need to publish the messages from the web browser (roslibjs) and show it on the terminal, ...
nerdyTurtle
0
votes
1
answer
27
views
Delay incoming messages
Is there a way in Rospy to delay incoming messages? Specifically, I wish to delay incoming velocity commands for teleop.
I can't use a sleep because I still need my program/node to run other processes....
piraka9011
0
votes
1
answer
13
views
Pass parameters to a service handler in rospy
In rospy, message callbacks can have additional parameters, which allows me to write only one callback for different subscribers. For example:
...
antonio
0
votes
1
answer
7
views
delete TransformListener object in python to release computational resource
Hello! Recently I notice that, after I create a TransformListener object in a class in python, e.g.:
self.tf = TransformListener(),
the created tf object gets stuck in the memory, even I try deleting ...
Mike Gao
0
votes
1
answer
69
views
Calculating Mass Inertia Matrix in Joint Space
Hi,
I am doing simulation of Baxter Robot. Hence I need to calculate Mass Inertia Matrix in Joint Space. I have Baxter URDF files. I see here that Mass Inertia Matrix in Joint Space is defined in ...
- 1,421
0
votes
2
answers
23
views
Using MoveIt programmatically and integrating with ros_control
I have a question about using moveit for my custom 6 dof manipulator robot. I am pretty new to ROS, and I really hope to learn from the community.
Basically I want to go from a URDF file to actually ...
t27
0
votes
1
answer
11
views
Issues with header seq value (first value in rospy is 1, first value in roscpp is 0, access from roscpp)
I was planning to use Header seq value to verify that communication in my system of ROS-nodes (using ROS Indigo) is synchronized, however, I discovered a couple issues with that value. If that's a bug,...
sd1074
0
votes
1
answer
61
views
How to call a rosservice within a python code?
I am trying to write a code in python where I want to be able to run a node or a launch file, and do a rosservice call with an argument.
I am trying to find some examples , please kindly guide me if ...
Abdullah
0
votes
1
answer
7
views
Access AR.Drone camera with OpenCV while connected to ROS
Hi,
I am having an issue where by I am unable to connect to the AR Drone camera when the drone is connected through ROS using the ardrone_autonomy ardrone.launch.
I think the issue is due to the fact ...
pyro229
0
votes
1
answer
56
views
DC MOTOR + ENCODER + PYTHON
Hello, everyone.
I have the next equipment:
https://www.pololu.com/product/2598 ,
https://www.pololu.com/product/2208
and raspberry pi.
I want to control the dc motors via ROS and Python. Is it ...
Tvlad
0
votes
1
answer
4
views
Transform geometry_msgs/TransformedStamped() to sensor_msgs/PointCloud2 on rospy
Hi people,
I have a geometry_msgs/TransformedStamped() vector which I am trying to translate to sensor_msgs/PointCloud2.
I have looked aroun in the rospy api docs but nothing clear comes out strking.
...
lakehanne
0
votes
1
answer
6
views
Callback function not updating values (Rospy)
I have a program used to read in command velocities from two sources (teleop/navigation), blend them, and then publish the blended velocity to the Turtlebot. While debugging, I noticed that the code ...
piraka9011
0
votes
1
answer
1
view
How do you modify the velocity multiplexer for turtlebot?
I have a Kobuki Turtlebot and would like to publish to the multiplexer on my own topic. The official documentation hasn't done me well explaining how to modify the parameters.
Where can I find the ...
piraka9011
0
votes
2
answers
8
views
tf::TransformListener gets wrong tf
Hello,
TL;DR tf::TransformListener gets a different transform than shown in RVIZ
I am having quite a strange problem. I am using a rosbag file to playback recorded data and I am adding new transforms ...
Tobias Neumann
0
votes
1
answer
33
views
Getting 'rosgraph resource not found' when trying to get turtlebot local_plan?
Hi,
I'm trying to get the 'geometry_msgs/Poses' message from the '/move_base/DWAPlannerROS/local_plan' topic for the Kobuki ...
piraka9011
0
votes
1
answer
4
views
Can't import rospy
Hello,
I have a ROS aplication in Python and Qt, and when I run it from the terminal all is ok, but I try to run with double click (the script with the permissions and Nautilus configuration ...
akb
0
votes
1
answer
5
views
How to programmatically attach link to a model during simulation?
Indigo on Ubuntu 14.04 with Gazebo 7.3 and Python 2.7
I have non-colliding URDF models to be used as markers in Gazebo. The markers will be attached to objects to be grasped, and their positions ...
jwatson_utah_edu
0
votes
1
answer
5
views
Deleting Gazebo model causes Python to freeze
Indigo on Ubuntu 14.04 with Gazebo 7.3 and Python 2.7
Whenever I call the Gazebo model deletion service, Python freezes. No errors or special messages appear when the deletion code runs. This ...
jwatson_utah_edu
0
votes
3
answers
277
views
point_cloud2.read_points and then?
I have a topic publishing a point cloud of type sensors_msgs.PointCloud2. I can subscribe to it and read it using ...
Mehdi.
0
votes
3
answers
288
views
tf.LookupException: "base_link" passed to lookupTransform argument target_frame does not exist
Hello together,
I am new with ros tf's and already worked myself threw the tf tutorials. (I am using ros indigo)
As my first test with tf's after the tutorial I wrote 2 small nodes.
The first one is ...
Bant
0
votes
1
answer
6
views
Waiting for "gazebo_msgs/GetLinkState" causes Python to freeze
ROS Indigo on Ubuntu 14.04 with Gazebo 7.3.0 and Python 2.7:
I have an issue withs starting a Gazebo service proxy for getting link states programmatically from a Python file I run after running the ...
jwatson_utah_edu
0
votes
1
answer
33
views
Python Import not being recognized
Hi guys,
I'm currently working through a textbook call Programming Robots with ROS. There is a chapter that goes over a simple movement code for a turtlebot simulator. The code is pasted below.
...
Starmit
0
votes
1
answer
9
views
How to convert slot_types of messages to actual data types
Hi All,
I am currently implementing a little python script that takes parameters for actions from a string and automatically populates an action goal to send it to the action server. The goal ...
Chrissi
1
vote
2
answers
275
views
How do you implement a rospy KeyboardInterrupt without killing the node?
I want to run a process in a while loop that prints to screen, and exit the while loop by pressing a key or 'Ctrl+C'. But I don't want the same key press to also kill the ros node - I just want to ...
M@t
0
votes
1
answer
11
views
How do you change a rosservice parameter in python?
I'm using the robot_localization package, specifically the ekf_localization and ...
M@t
0
votes
1
answer
165
views
How to exit a ROS node on keyboard interrupt?
How do you write a Python ROS node so that it exits in response to a KeyboardInterrupt exception?
I have a trivial node like:
...
Cerin
0
votes
1
answer
54
views
How to write to a text file in python in a ROS node?
I need to record a topic message called "message" only when a "message sent" button is pressed. I have made a separate node for GUI that has "message sent" button. I ...
Ros User
0
votes
2
answers
18
views
Unable to read a file while using relative path
Hi,
I want to read a file inside python script in ros indigo in the following way -
file_name = rospy.get_param("~file", None)
Below is the snippet of ...
- 1,421