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2014-11-24 20:54:40 -0500 asked a question Accesing RosAria Point cloud sensor data

HI and thank you in advance for your help,

I have recently installed RosAria on my computer to communicate to a pioneer robot over usb to serial. I have tested RosAria using rostopic echo RosAria/sonar to ensure connection and check the sonar data which is returned in a pointcloud. I have been trying to subscribe to RosAria/sonar from a c file I have created. I believe that I have succeeded in connecting because the sonars are clicking but I do not get any viable data into my program observed by ROS_INFO_STREAM. I believe that this is because I have not been able to gain access to the specific array holding the distance readings. I was not able to use PointCoud_To_LaseScan because of errors which I believe are due to it requiring pointcloud2 along with camera data which I do not have because I am simply trying to subscribe to the sonar data. I believe the error in my code is caused by the subscription to the data

Sonar_msg.points=msg->points;

because pointcloud has a header file shown below it would seem the above line should be

Sonar_msg.points.x=msg->points.x; or Sonar_msg.points.x=msg->points;

but these cause an error shown below, so what are the members of PointCloud, and how do you access them?

: error: ‘sensor_msgs::PointCloud_<std::allocator<void> >::_points_type’ has no member named ‘x’

rosmsg show sensor_msgs/PointCloud std_msgs/Header header uint32 seq time stamp string frame_id geometry_msgs/Point32[] points float32 x float32 y float32 z sensor_msgs/ChannelFloat32[] channels string name float32[] values, pointclouds

some of the data I have received which I believe should be of type double with no special characters in them.

Please help me find where I'am going wrong subscribing

Thanks

2014-10-27 20:20:20 -0500 commented answer How to convert a Hydro launch file to an indigo launch file

Thanks, I had the Stageroscam files in the wrong folder.

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2014-10-25 17:00:26 -0500 asked a question How to convert a Hydro launch file to an indigo launch file

Thank you in advance for your help, I have the following launch file which runs well on other ubuntu 12.04 systems with ros hydro. My system is ubuntu 14.04 with ros indigo, and the files do not work. I believe the problem is within the launch file shown below, along with the error I receive.

<launch>
  <param name="/use_sim_time" value="true"/>
  <node pkg="stage_ros" type="stageros" name="IGVC_stage" args="$(find stageroscam)/world/20Mx20M.world" output="screen">
  </node>
 <!--include file="$(find stageroscam)/rviz.launch"/-->
 </launch>

Error:

raise ResourceNotFound(name, ros_paths=self._ros_paths)
ResourceNotFound: stageroscam
ROS path [0]=/opt/ros/indigo/share/ros
ROS path [1]=/home/martin/catkin_ws/src
ROS path [2]=/opt/ros/indigo/share
ROS path [3]=/opt/ros/indigo/stacks
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2014-03-24 04:43:43 -0500 answered a question stageroscam, using stage, and rviz

It works, thanks!

2014-03-23 13:48:14 -0500 commented question stageroscam, using stage, and rviz

I changed my file, it ran and shut down [Loading __name:=IGVC2013_Auto-Nav_Basic]err: unable to open world file __name:=IGVC2013_Auto-Nav_Basic : No such file or directory (/tmp/buildd/ros-fuerte-stage-1.6.6/debian/ros-fuerte-stage/opt/ros/fuerte/stacks/stage/build/stage/libstage/worldfile.cc Load)

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2014-03-22 06:33:23 -0500 asked a question stageroscam, using stage, and rviz

received the folowing error using command roslaunch IGVC2013_AutoNavBasic.launch which is supposed to launch roscore, stage environment and rviz. instead only rviz opens and the following error is displayed.

ERROR: cannot launch node of type [stage_ros/stageros]: stage_ros ROS path [0]=/opt/ros/fuerte/share/ros ROS path [1]=/home/amrl/ros/stageroscam ROS path [2]=/opt/ros/fuerte/stacks ROS path [3]=/opt/ros/fuerte/share ROS path [4]=/opt/ros/fuerte/share/ros e I am new at using ros, and need to know what files might not be included in the installation, and how to add them or edit them to clear up this error.

Thanks

2014-03-16 12:17:41 -0500 asked a question Error with jmb_init_node Matlab ros

I get this error when I try to run my Image Processing matlab code using hydro ros. It was working successfully when I was using fuerte ros, I tried to find the DefaultNodeFactory in my files but I was unsuccessful. The MASTER_URI is just my localhost.

Do you guys have any idea how to fix it? It'll be really appreciated.

This is the error that I get in matlab when I try to run it:

No constructor 'org.ros.node.DefaultNodeFactory' with matching signature found.

Error in jmb_init_node (line 92) nf=DefaultNodeFactory();

Error in IGVCIPmainQuick (line 132) node=jmb_init_node(NODE_NAME, MASTER_URI);

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