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2015-03-02 02:39:17 -0500 commented question catkin make partially not found

This is the problem, there are no message errors. Everything is properly set up, still some ros commands are not found (unless I type again source /opt/ros/indigo/setup.bash)

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2015-02-26 12:18:08 -0500 asked a question catkin make partially not found

Hi folks, I have a pretty new installation of ubuntu 14.04.1 and ros indigo. After a reboot, due to my pc crashing, catkin_make and ros commands were "gone".

My .bashrc contains the string

source /opt/ros/indigo/setup.bash

to avoid typing it in every given shell. If it is executed when a new terminal is opened, several commands are still missing.

Same issue if I reload the bash by

source .bashrc

Instead, if I enter by hand the command

source /opt/ros/indigo/setup.bash

then it works. It seems like .bashrc is "ignoring" the command, which is rather strange.

Do you have any idea about possible solutions?

Thanks,

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2015-02-23 04:56:14 -0500 asked a question Ubuntu 14.04 Ros Indigo unmet dependencies

Hi everyone, I decided to upgrade both OS and Ros distro.

I followed the usual preliminary instructions for the installation, but when I try to install the full version with

sudo apt-get install ros-indigo-desktop-full

I get this error:

Reading package lists... Done
Building dependency tree       
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 ros-indigo-desktop-full : Depends: ros-indigo-perception but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

I have been using Ros since Diamondback and I do not remember having this issue. I browsed the web looking for possible solutions, but I found none.

Does anyone of you have a way to solve it? Thanks in advance,

tambo

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2013-11-12 01:54:24 -0500 asked a question rosbag play & tf extrapolation problems

Hi everyone,

I wrote a program for collecting laser data from a bag (currently I'm using a bag from the gmapping node tutorial).

The bag is executed as usually: rosbag play bag

No problems so far, I can visualize everything in rviz. Problems are on the listener side. The callback, rather basic, is the following:

void callBack(const sensor_msgs::LaserScan::ConstPtr& msg)
{
     tf::TransformListener listener;
     tf::StampedTransform trans;
     try
     {
        ros::Time time=msg->header.stamp;
        listener.waitForTransform("base_laser", "odom", time, ros::Duration(1));
        listener.lookupTransform("base_laser", "odom", time, trans);
            //Do something
      }
      catch(tf::TransformException ex)
      {
             ROS_ERROR("%s",ex.what());
      }
}

In few words, it doesn't work, I always obtain:

Lookup would require extrapolation into the past

or

Lookup would require extrapolation into the future

I modified, by hand, the time variable value as follows:

ros::Time time=ros::Time(msg->header.stamp.sec+1);

Although it worked, to me is not a feasible or general solution.

Changing duration value didn't help either.

Am I doing something wrong? Maybe did I forget some parameter for ROS to set?

Thanks for your help,

Tambo

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2012-11-23 05:38:04 -0500 asked a question cancellAllGoals() to stop a robot?

I'm quite new to ActionLibs and while going trough the several tutorials regarding action servers and clients, I started to think about the client functions

  • cancellAllGoals()
  • cancellGoal()

I'm currently using move_base to send goals to a robot, with action libs. Supposing I gave to a robot a goal position in a map, can I stop it using one of the two aforementioned functions?

Thank you all, T

EDIT after dornhege reply: This is the reply I hoped to receive. Assuming that cancellAllGoals() actually stops the robot's motion, I have the following problem..

typedef actionlib::SimpleActionClient<move_base_msgs::movebaseaction> MoveBaseClient; MoveBaseClient ac("move_base", true); …

ac.cancelAllGoals();

Previous code doesn't stop the robot. Am i doing something wrong? (consider that the way I send goals works fine)

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2012-10-25 11:17:36 -0500 answered a question Need Help with Accessing the kinect Depth Image using OpenCV.

The encoding you are using for the depth stream is wrong, you should use the unsigned 16 bit representation with a single channel, instead of the 3 channels of the RGB representation.

Modify the line -cv_depth = cv_bridge::toCvCopy(depth_image, enc::BGR8);

changing the encoding (check the correct definition for 16 unsigned char) -cv_depth = cv_bridge::toCvCopy(depth_image, enc::16UC1);

In this way, you can access depth data properly. According to the topic you subscribe to, you may obtain either representation in millimeters or in meters (both of them use floats)

Good luck, Tambo

2012-10-25 02:34:52 -0500 asked a question kinect returning wrong depth measurements

Dear folks, I'm working on a node which has to extract and associate information from both the rgb and depth streams of the Kinect sensor. In order to cope with such streams I'm using the cv_bridge, as suggested in the cv bridge tutorials.

Problem is: if the kinect is placed 1 meter far from a robot, several times, I'm not sure if illumination matters, I have completely wrong measurements, sometimes around 40 meters, some others around 5/6 meters.

Did anyone of you have such issue, or a similar one?? And if so, did you solve the problem?

Thank you all, Taigo

2012-10-23 05:35:15 -0500 commented question erratic_player Electric/Fuerte

@joq: yes, from ubuntu 11.10 with electric to 12.04 with fuerte. I'm trying to understand if this issue could be related only to the OS

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2012-09-12 05:57:57 -0500 asked a question erratic_player Electric/Fuerte

Hi everyone, I'm writing to you for some explanation about differences between Electric and Fuerte. I lately moved to the latter and spent some time to update several stuff I coded while on Electric. Today I was testing some package I wrote for the erratic robot (real, not simulated).

On Electric, I mapped the port_name param using a symbolic link in /etc/ folder, without having to change or giving any permission to any user. Needless to say, it always worked.

On Fuerte, I did the same things but as result of executing the erratic_base.launch contained in the erratic_player stack, I had

Erratic::Setup()::Open() permission denied

To solve the problem I changed the owner of the symbolic link mentioned before and everything went fine.

Long story short, is there any relevant between Electric and Fuerte regarding permissions, or something similar, I'm not aware of? Or something I did miss while reading about how to migrate?

Thanks you all, folks