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2019-05-20 02:10:38 -0500 marked best answer How to create point cloud data using webcam

Hi all, I am using ros indigo. Is it possible to create point cloud data using webcam in ros? Is there any packages available for the conversion?

2019-05-20 02:05:16 -0500 marked best answer error while launching robot model

Hi all, I am trying to launch a robot model in gazebo(using ros indigo and ubuntu 14.04). But a node 'spawn_model' which is specified in launch file is automatically killed while running roslaunch and robot model is not yet launched in gazebo . My urdf file is fine and I checked it using gzsdf tool and by launching the model in Rviz. So I edited the launch file by adding respawn="true". So I am getting error "[ERROR] [1506783269.127628154, 11.257000000]: SpawnModel: Failure - model name hobo already exist.". What does this error mean? please help

C:\fakepath\Screenshot from 2017-09-30 20:28:28.png

launch file is :

<launch>
<param name="robot_description" textfile="$(find hobo_description)/urdf/hobo_description.urdf" />
<include file="$(find gazebo_ros)/launch/empty_world.launch">
</include>
<node name="spawn_urdf" pkg="gazebo_ros" type="spawn_model" respawn="true" args="-param robot_description -urdf -model hobo" />

</launch>

urdf file is :

<?xml version="1.0"?>
<robot name="hobo">
<link name="base_link">
<visual>
    <geometry>
        <cylinder length="0.01" radius="0.25"/>
    </geometry>
    <material name="silver">
        <color rgba="0.75 0.75 0.75 1"/>
    </material>
</visual>
<collision>
    <geometry>
        <cylinder length="0.01" radius="0.25"/>
    </geometry>
</collision>
</link>

<link name="left_wheel">
<visual>
    <geometry>
        <cylinder length="0.05" radius="0.05"/>
    </geometry>
    <material name="black"/>            
</visual>
<collision>
    <geometry>
        <cylinder length="0.05" radius="0.05"/>
    </geometry>
</collision>
</link>

<joint name="left_wheel_to_base" type="continuous">
<axis xyz="0 0 1"/>
<parent link="base_link"/>
<child link="left_wheel"/>
<origin rpy="0 -1.5708 0" xyz="-0.275 0 0"/>
<inertial>
<mass value="1.0"/>
<inertia ixx="5.1458e-5" iyy="5.1458e-5" izz="5.1458e-5" ixy="0" ixz="0" iyz="0"/>
</inertial>
</joint>

<link name="right_wheel">
<visual>
    <geometry>
        <cylinder length="0.05" radius="0.05"/>
    </geometry>
    <material name="black"/>            
</visual>
<collision>
    <geometry>
        <cylinder length="0.05" radius="0.05"/>
    </geometry>
</collision>
</link>

<joint name="right_wheel_to_base" type="continuous">
<axis xyz="0 0 1"/>
<parent link="base_link"/>
<child link="right_wheel"/>
<origin rpy="0 -1.5708 0" xyz="0.275 0 0"/>
<inertial>
<mass value="0.1"/>
<inertia ixx="5.1458e-5" iyy="5.1458e-5" izz="5.1458e-5" ixy="0" ixz="0" iyz="0"/>
</inertial>
</joint>


<link name="box">
<visual>
    <geometry>
        <box size="0.2 0.2 0.2"/>
    </geometry>
    <material name="orange"/>           
</visual>
<collision>
    <geometry>
        <box size="0.2 0.2 0.2"/>
    </geometry>
</collision>
</link>

<joint name="box_to_base" type="fixed">
<parent link="base_link"/>
<child link="box"/>
<origin xyz="0 0 0.1"/>
<inertial>
<mass value="1.0"/>
<inertia ixx="0.015" iyy="0.0375" izz="0.0375" ixy="0" ixz="0" iyz="0"/>
</inertial>
</joint>
</robot>
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2017-09-30 10:24:14 -0500 edited question error while launching robot model

error in launch file Hi all, I am trying to launch a robot model in gazebo(using ros indigo and ubuntu 14.04).

2017-09-30 10:19:08 -0500 edited question error while launching robot model

error in launch file Hi all, I am trying to launch a robot model in gazebo(using ros indigo and ubuntu 14.04).

2017-09-30 10:15:30 -0500 asked a question error while launching robot model

error in launch file Hi all, I am trying to launch a robot model in gazebo(using ros indigo and ubuntu 14.04).

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2017-09-23 05:46:38 -0500 asked a question How to create point cloud data using webcam

How to create point cloud data using webcam Hi all, I am using ros indigo. Is it possible to create point cloud dat

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2017-04-20 14:41:38 -0500 marked best answer how to localize my robot

Hi all, I used gmapping to obtain the map.Now i want to localize my robot in this map,so that i can apply my path planning algorithm(A*).someone please help me to do this.

2017-04-20 14:14:27 -0500 marked best answer problem with hector_slam

Hi all,I am using ROS INDIGO.I used hector_slam to build a 2D map from kinect data.Laser scan data is published on the topic /scan.I used the command roslaunch hector_slam_launch tutorial.launch and getting "[ WARN] [1453709644.419967908]: No transform between frames /map and scanmatcher_frame available after 20.001889 seconds of waiting. This warning only". Please help me for solving this problem.

This is my launch file hector.launch


<launch>

<arg name="geotiff_map_file_path" default="$(find hector_geotiff)/maps"/>

<arg name="base_frame" default="base_link"/> <arg name="odom_frame" default="nav"/>

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

<node pkg="rviz" type="rviz" name="rviz" args="-d $(find hector_slam_launch)/rviz_cfg/mapping_demo.rviz"/>

<include file="$(find hector_mapping)/launch/mapping_default.launch"/>

<include file="$(find hector_geotiff)/launch/geotiff_mapper.launch"> <arg name="trajectory_source_frame_name" value="scanmatcher_frame"/> <arg name="map_file_path" value="$(arg geotiff_map_file_path)"/> </include>

</launch>

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2017-02-15 20:44:44 -0500 marked best answer how to convert pointcloud to laser scan in ros indigo

Hi all, I am using ros indigo.I want to convert point cloud to laser scan data.I used freenect to collect kinect data( using kinect Xbox 360).Now I want to convert this data to lasercan data to construct 2D map.I read that we can use depthimage_to_laserscan package.I used the command rosrun depthimage_to_laserscan depthimage_to_laserscan image:=/camera/depth/image_raw,but it is not showing anything.I am new to ROS and someone please help.

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2016-04-27 09:42:34 -0500 marked best answer How to install laser_scan_matcher in ros indigo

Hi all, I want to install 'laser_scan_matcher' to generate a 2D map from laser scan using gmapping in ros. someone please help me install this.

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2016-03-01 04:25:35 -0500 marked best answer data format of /scan

Hi all, I'm using ROS INDIGO. I used depthimage_to_laserscan to obtain scan data. what does the values under /scan represent? is it the range from the obstacles(metres or centimetres).?

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2016-03-01 04:21:22 -0500 commented answer algorithm used in depthimage_to_laserscan

thank you...

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2016-02-26 04:23:00 -0500 asked a question algorithm used in depthimage_to_laserscan

hi all, i would like to know the algorithm used in 'depthimage_to_laserscan ' to convert 3D data to 2D data.is it RANSAC algorithm.someone please help.

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2016-02-25 22:32:12 -0500 asked a question adding A* path planning algorithm as plugin

Hi all, I am using ROS indigo.i am using gmapping to obtain the map.i wrote my A* path planning algorithm in python.someone please help me to integrate this.when i searched link text.But it is written in c++.someone please help..

2016-02-25 06:44:17 -0500 commented answer how to localize my robot

thank you sir..But when i do the same i'm getting the x,y coordinates of the robot in its current position. I want to know the index of the grid in which the robot is situated in the map so that I can apply my A* algorithm. Could you please help me to solve this problem.?

2016-02-25 04:23:07 -0500 commented answer how to localize my robot

I did rosrun amcl amcl _use_map_topic:=true. I got map also but how can i find the grid in which the robot resides so that i can apply my A* algorithm.