Hypomania's profile - activity

Hello,

PLEASE NOTE THIS IS NOT MY HOMEWORK, I AM JUST ASKING FOR DIRECTIONS

I am quite new to ROS. I'm working on a research project where we have to move a mid-sized vehicle (1m^2) from point A to point B, along a curved track (outdoors), ROS Kinetic, Ubuntu 16.04 LTS.

I considered using OpenCV for edge detection/line detection, but the track is very wide so there aren't many reference points, and no lanes either.

I have looked recently looking into ROS navigation stack as well as SLAM. It looked very promising until I realized it's probably suited better for indoor use (correct me if I am wrong)?

My sensor payload is this:

1. Doppler sensor (50m range, noise resistant)
2. GPS INS (up to 2cm position accuracy)
3. LEDDAR VU8 unit (20 degrees beam, up to 185m range, not a 360 LIDAR)
4. Many ultrasonic proximity detectors (~50 degrees beam, 7m range)
5. Stereoscopic cameras

So that's my sensor payload, I have them all integrated into ROS. I am, however, slightly confused where to go from here. I understand how SLAM and then navigation stack do it, but they use a 360 degree LSD for mapping/localisation, plus, all the examples I have seen are done indoors.

The only current idea I've is to use GPS INS sensor to follow pre-recorded set of waypoints, however that wouldn't account for any changes on the map (like obstacle avoidance in SLAM/navigation stack).

I am not exactly sure where to start looking. Can it be done with the ROS navigation stack? Are there any other navigation packages that I can research?

Again, I am not asking for a solution, I would extremely be grateful if any of you could provide any links, sources, books, suggestions or directions.

Thanks!

Hi,

I have been reading on how to install packages INTO ROS that aren't included in the ROS installation for a while now and I still don't get it. I am trying to modify source before installing, hence I would like to build it myself.

I am using Kinetic (Ubuntu 16.04 LTS) distro using catkin filesystem. The package I am trying to install is this: serial

It is available as a .deb package so initially I installed it using sudo apt-get install ros-kinematic-serial and that installed fine.

1. First of all, I don't quite get how a package like this one works when installed (or any ROS package). I checked its CMakeLists.txt file, it only installs headers and an example binary file. Going into cd /opt/ros/kinetic/share/serial there is only package.xml file and a cmake folder with serialConfig.cmake and serialConfig-version.cmake files. I compiled a basic ROS node using this library and it works fine, so how does ROS know where to find the src files if it only has headers and cmake configs installed?

2. Secondly, if I try to install package from source into ROS, what's the proper way of doing it? I have tried:

   cd ~/catkin_ws/src

   git clone https://github.com/wjwwood/serial.git

   cd ~/catkin_ws/ && catkin_make

   source ~/catkin_ws/devel/setup.bash

   That works fine, my example node works and I can adjust the source to my liking, but the package is installed to my catkin workspace and not the global ROS path. How do I add the package into the ROS environment so that something like rospack listcan identify it?

3. Lastly, how come after catkin_make I can't find my package using rosrun my_package serial_example_node?

Any help is really appreciated!

Hi,

I know this have been asked a few times but I have wasted 2 days trying to make this work and still no resolution. I think it's something to do with URDF which I am not very familiar with so any suggestions or help are greatly appreciated!

I am trying to install this package here: waypoint_nav, whilst following the tutorials here: tutorial

Whenever I launch roslaunch outdoor_waypoint_nav outdoor_waypoint_nav_sim.launchI get this:

roslaunch outdoor_waypoint_nav outdoor_waypoint_nav_sim.launch
... logging to /home/arthur/.ros/log/e5783a58-881f-11e8-ace3-08002758e07b/roslaunch-Doge-17757.log
Checking log directory for disk usage. This may take awhile.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.

xacro: Traditional processing is deprecated. Switch to --inorder processing!
To check for compatibility of your document, use option --check-order.
For more infos, see http://wiki.ros.org/xacro#Processing_Order
Undefined substitution argument urdf_extras None
when processing file: /opt/ros/kinetic/share/husky_description/urdf/husky.urdf.xacro
included from: /home/arthur/catkin_ws/src/waypoint_nav/husky_customization/husky_custom_description/urdf/custom_description.urdf.xacro
included from: /home/arthur/catkin_ws/src/waypoint_nav/husky_customization/husky_custom_gazebo/urdf/custom_description.gazebo.xacro
while processing /home/arthur/catkin_ws/src/waypoint_nav/outdoor_waypoint_nav/launch/include/gazebo.launch:
while processing /home/arthur/catkin_ws/src/waypoint_nav/husky_simulator/husky_gazebo/launch/husky_empty_world.launch:
while processing /home/arthur/catkin_ws/src/waypoint_nav/husky_simulator/husky_gazebo/launch/spawn_husky.launch:
Invalid <param> tag: Cannot load command parameter [robot_description]: command [/opt/ros/kinetic/share/xacro/xacro.py '/home/arthur/catkin_ws/src/waypoint_nav/husky_customization/husky_custom_gazebo/urdf/custom_description.gazebo.xacro'     laser_enabled:=true     ur5_enabled:=false     kinect_enabled:=false     ] returned with code [2]. 

Param xml is <param command="$(find xacro)/xacro.py '$(arg husky_gazebo_description)'     laser_enabled:=$(arg laser_enabled)     ur5_enabled:=$(arg ur5_enabled)     kinect_enabled:=$(arg kinect_enabled)     " name="robot_description"/>The traceback for the exception was written to the log file

I have looked into the launch and URDF files, I still can't find out what the problem is. Could anyone with more experience please try compiling this package and see how to launch it?

Any input is greatly appreciated!

I solved it, my TF was incorrect!

Awesome, thank you!

Hi,

I was wondering what coordinate space RViz markers work in (Pose or Points parameters).

I have an object with Pose of 5000, 5000, 0, however when I open RViz and draw a Marker with 0, 0, 0 coordinate, it draws it directly over the object.

What's wrong?

RViz marker coordinate space Hi, I was wondering what coordinate space RViz markers work in (Pose or Points parameters)

Solved by adding rospy in package.xml and CMakeLists.txt.

ImportError: No module named msg - standard ROS message Hi, I am trying to use geodesy package https://github.com/ros-g

Hi,

I keep stumbling upon these two equations in odom calculations as they are used quite frequently in literature, however I can't seem to find any explanation on to how they are derived (an full example here: https://answers.ros.org/question/9494... ):

double delta_x = (vx * cos(th) - vy * sin(th)) * dt;
double delta_y = (vx * sin(th) + vy * cos(th)) * dt;

Could anyone please help me understand what's happening here? Perhaps if you have a reference that would be really helpful!