gerhenz's profile - activity

Hello,

I'm completely new to ROS (and Ubuntu) and I'm having some trouble when trying to use the command catkin_make (I'm following the tutorial to configure ROS environment).

The error message is the following:

-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-- ~~  traversing 1 packages in topological order:
-- ~~  - beginner_tutorials
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-- +++ processing catkin package: 'beginner_tutorials'
-- ==> add_subdirectory(beginner_tutorials)
CMake Error at /opt/ros/hydro/share/catkin/cmake/catkinConfig.cmake:75 (find_package):
  Could not find a package configuration file provided by "std/-msgs" with
  any of the following names:

    std/-msgsConfig.cmake
    std/-msgs-config.cmake

  Add the installation prefix of "std/-msgs" to CMAKE_PREFIX_PATH or set
  "std/-msgs_DIR" to a directory containing one of the above files.  If
  "std/-msgs" provides a separate development package or SDK, be sure it has
  been installed.
Call Stack (most recent call first):
  beginner_tutorials/CMakeLists.txt:7 (find_package)


-- Configuring incomplete, errors occurred!
make: *** [cmake_check_build_system] Error 1
Invoking "make cmake_check_build_system" failed

I'm not sure, but I think I did something wrong when I created the beginner_tutorials package in another tutorial. Maybe I mistyped the name of the package std_msgs in the dependencies field? Anyway, even if this is the case, I don't know how to proceed to fix it.

How should I proceed to fix this error?

Yes. Just remove the .cpp from the type argument as stated in ahendrix's answer below.

Therefore, I assume the best approach (at least for now) is to use the data from the inclinometer sensor since it provides the orientation angles of the robot. Thanks Tom!

Everything is clearer now. Thanks Murilo!

Hi, I'm trying to use the robot_localization package in my project to improve my turtlebot pose estimate.

I've read the package page and the tutorials but I'm still confused in some parts:

1. In the package page it states that the ekf_localization is the only node in the package. However, in the GPS integration tutorial it is used utm_transform_node. Do I need to use both of them? Is utm_transform_node output one of the inputs for ekf_localization? If yes, should I use the same IMU data for both nodes?

2. I've attached a cellphone to the robot and I'm retrieving the data from its internal sensors. Since my GPS data is already in latitude/longitude format, may I just publish this data in the fix topic in the utm_odometry_node from the gps_common package? This way I wouldn't need to use the nmea_navsat_driver package.

3. I know I'm supposed to use the data from the cellphone accelerometer as my IMU data. But I'm also receiving the data from the inclinometer sensor which provides me roll/pitch/yaw angle values. Wouldn't this data be more useful than the one from the accelerometer? Could it be easily implemented in the position estimate?

I'm sorry for the several questions, but I'm quite new to ROS and some things are still not very clear to me.

Thanks!

My intention was to use a Windows phone, but in case I don't manage to do it I will end up using an Android device. This package you mentioned seems really good, I will take a look. Thanks!

Hello,

I want to add GPS data to my project in order to improve robot localization estimate. I've read that some people did this successfully using an external GPS device. However, I would like to do this by pulling the GPS data from a smartphone.

A few questions:

1. Does someone have already done this? I did some research but I couldn't find it.

2. How could I pull the GPS data from the smartphone?

3. Does the smartphone output the GPS data in the same format as a regular GPS device?

Thanks!

which YAML file are you referring to?

Hi,

I'm using a turtlebot 2 to build the map of a room and a corridor. I was having some problems because there's a glass wall between them and the kinect doesn't detect it very well. To solve this problem I manually edited the map file by drawing black lines. You can check the map here.

However, when the robot is in the room and I set a goal in the corridor the robot fails to get there. I think the problem is that the local planner tries to make the robot go through the wall (since the kinect doesn't detect it completely), even though the global planner works fine and it establishes a correct path. You can take a look at this image to help you visualize what I'm saying. The robot keeps rotating and moving to other directions and it doesn't follow the red line.

Doing a little research I found that I can change the values of a few parameters in the dwa_local_planner to solve this issue. For this reason, I changed the parameters path_distance_bias (increasing it) and goal_distance_bias (decreasing it) in the DWAPlannerConfig.h file.

Changing these parameters solved my problem, but I've got some questions about it:

1. Is this the best approach to solve my problem?

2. How these changes will affect the robot navigation in other situations? In order to solve my problem I had to set extremely high (path_distance_bias) and low (goal_distance_bias) values. I've done a few tests and the robot moves fine, but I'm afraid that there are a few situations where these parameter changes will make the robot behave incorrectly.

Thanks!

I'll take a look in the link. Thanks!

Hi,

I'm using pocketsphinx on ROS Hydro to implement speech recognition in my project. Unfortunately, its accuracy is not so good for a few specific words, and this affects system reliability.

Therefore, in order to find a way to improve its efficiency, I've got a few questions:

1. Is it possible to "train" it? (e.g. I keep saying the words and stating if pocketpshinx understood them right or not, so it gets better with time).

2. No matter what I say, it always finds the most similar word defined in the .dic file. Is it possible to define a threshold so it'll only output a word if the similarity between the spoken word and the one defined in the file is above this threshold?

3. Is it ok to manually edit the .dic file in order to include different ways a word can be spoken? Do I need to change anything in the .lm file?

P.S: The speech recognition works really well for almost all the word I defined, but it's really unstable to some specifc ones. For example, the words toilet and lift are usually recognised as the words to the or go to, even though they're very different.

Does anyone have any recommendation of how to improve the accuracy?

Thanks!

Hi,

I'm trying to create a node using this code in order to obtain the turtlebot coordinates in the map reference frame.

I've tried adding the node in an existing package, but I wasn't successful.

Therefore, I've created a new package (following this, this and this tutorials). In the last tutorial, instead of using the publisher and subscriber codes, I used the one I mentioned above.

I've used xy_pos as the package name and turtlebot_coordinates as the node name.

I'm able to use rosrun xy_pos turtlebot_coordinates, it works fine.

However, when I try to use the node via a launch file, I've got the following error:

ERROR: cannot launch node of type [xy_pos/turtlebot_coordinates.cpp]: can't locate node [turtlebot_coordinates.cpp] in package [xy_pos].

The part of the launch file related to this node is:

<node name="turtlebot_coordinates" pkg="xy_pos" type="turtlebot_coordinates.cpp" output="screen"> </node>

It's not a problem with ROS_PACKAGE_PATH ( roscd xy_pos works fine)

I've tried the solution for this question but it didn't work.

Does someone have any suggestion?

P.S: I don't know if this influences in something, but my launch file is inside an existing package. So while the new package is inside catkin/src/, the launch file is in a package inside opt/ros/hydro/share/. Is it a problem?

Thanks!

I was getting confused because for nodes written in python you need to include the source file name in the launch file. I didn't know it was different for nodes written in C++. Thanks ahendrix!