AliAs's profile - activity

I tried to detect a marker using aruco_ros using two following launch files and faced the same problem. roslaunch usb_ca

I have slam_gmapping package that contains these folders:

    slam_gmapping-hydro-devel

       gmapping

           launch

           src

           test

       slam_gmapping

I want to launch it with launch file with my own parameters.

the steps I have done are as follow:

• download the package

• copy the package to the catkin_ws --> src

• make a build folder in gmapping folder, so it is now look like this:

  slam_gmapping-hydro-devel
  
     gmapping
  
         launch
  
         src
  
         test
  
         build
  
     slam_gmapping
  

• build the package using make, cmake .., catkin_make (don't know exactly what they do!)

The question is after those steps, "roslaunch gmapping [Tab]" does not find any launch file But there is a launch file "slam_gmapping_pr2.launch" in launch folder I also tried to use launch file provided here . But the same problem exist. The problem is that ROS does not detect any launch file in the gmapping package! how can I solve the problem?

Thanks

Could you please give me information about structure of reflectance value? how can I use reflectance values? It is of crouse related to the object substance. Is it proportional to distance? is it also related to the difference between ray's angle and normal of surfaces it is reflected from?

Thank you. I saw the first paper and it seems they did every thing (e.g. extracting visual features, ...) using point clouds and next used Octomap to just reduce the map size. I added this, just to clarify the subject for future readers.

I know what I am saying here is not precise.I know Octomap is a 3D occupancy grid mapping approach based on an octree and there are some SLAM methods that works based on 2D occupancy grids. E.g. Gmapping: a 2D grid-based SLAM algorithm that provides a 2-D occupancy grid map from laser and pose data collected by a mobile robot and Hector SLAM: a 2D grid-based SLAM algorithm that provides a 2-D occupancy grid map using combination of high update 2D mapping and 6DOF pose estimation.

I wanted to know is there any available package (or publication) that tries to use octomap representation to tackle SLAM problem?

I want to have access to hitting points, colors and pose coordinate values in the octomap datasets (e.g. to use octomap datasets in MATLAB). The datasets I am talking about are available in this link . The dataset are in the form of .ot, .bt and .graph files. It says that .graph files contain raw sensor readings at registered poses in a binary format. You can convert them to .bt and .ot (the final occupancy map format).

How can I have access to the point and color information? I mean to have them (hitting points, colors and pose coordinate) in the from of a text file or something like that.

Yes. I want to use ROS. Thank you for you useful information. I will have more questions to ask, ...

Background + Objective!: I am a MATLAB/Computer Vision guy and I want to start to write a some piece of useful code in ROS. I have a basic understanding of ROS (topic, node, message ...). What I want to do is to write a 3D version of local occupancy grid map in 5-6 months (It will be as a part of my PhD thesis). Result of 2d version of local occupancy grid map that I have done in MATLAB is available in here: Link

Problems!: The problem is ROS is a bit confusing for me. Maybe because of the lack of my skills in ROS and CPP. In my view MATLAB is a small body with huge amount of muscles (lots of codes, toolboxes and a great source of helps for writing small project) and ROS has a just big skeleton (very good structured for making big/real projects) and building every chunk of muscle for filling this skeleton will needs a lots of time and efforts... . Most of my questions are regarding programming skills in CPP and ROS. Some one please give me a big picture of what should I do:

• Is it possible to directly write/implement a medium size cpp project in ROS or should I use an ide? e.g. Qt creator, Eclipse ...
• how can I debug my codes in ROS?
• how can I visualize 3D grids in ROS/CPP?

P.S. I will add more questions later.

Thank you SaiHV. Should I write your piece of code in a launch file? I tried to launch the following launch file but it fail.

faketf.launch:

<launch>

<node pkg="tf" type="static_transform_publisher" name="base_to_laser_tf" args="0 0 0 0 0 0 base_link laser 100"/>

</launch>

and this is the error:

Usage: rosrun PACKAGE EXECUTABLE [ARGS]

rosrun will locate PACKAGE and try to find

an executable named EXECUTABLE in the PACKAGE tree.

If it finds it, it will run it with ARGS.