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2018-06-07 07:27:50 -0500 marked best answer Stage vs Gazebo

Hi Users:

I would like to know the pros and cons between Stage and Gazebo. Is there any document where I can find out?

Thanks!!!

2018-03-17 18:18:13 -0500 marked best answer Calibration pattern chessboard

Hi Ros users:

I am doing a calibration camera and I have to have a calibration pattern in Gazebo. I like to know if there is a .stl calibration pattern chessboard file on the internet to do that. And if there is not, how can I do it?

Thanks a lot.

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2018-01-11 20:35:51 -0500 marked best answer publish array velocities in a topic?

Hi Ros users! I have just done a .cpp wich publish velocities in a opic (p3dx/cmd_vel) Here it is:

int main(int argc, char **argv)
{
  ros::init(argc, argv, "lanzando_vel");
  ros::NodeHandle n;
  ros::Publisher vel_pub_ = n.advertise<geometry_msgs::Twist>("p3dx/cmd_vel", 1);

  while (ros::ok())
  {
  geometry_msgs::Twist cmd;
  cmd.linear.x = 0;
  cmd.linear.y = 0;
  cmd.linear.z = 0;

  cmd.angular.x = 0;
  cmd.angular.y = 0;
  cmd.angular.z = 0;
    vel_pub_.publish(cmd);
  }
    return 0;
}

I would like to publish an array velocities, for example:

at 1seg ==> cmd.linear.x=1 at 3 seg==> cmd.linear.x=4 . . .

how can I do that?

Thank you so much!

2018-01-11 20:23:28 -0500 marked best answer How can I put noise to my P3DX model?

Hi Ros Users :

I am trying to put noise to my P3DX model wich is https://github.com/RafBerkvens/ua_ros... Because the model behaviour is unrealistic.

Does Anybody know what I must modify in the code to do that?

Thanks!!!!

In respose to your comment @Javi V.

I modify this part of the code:

 <!-- ground truth -->
<gazebo>
<plugin name="p3d_base_controller" filename="libgazebo_ros_p3d.so">
<alwaysOn>true</alwaysOn>
<updateRate>100.0</updateRate>
<bodyName>base_link</bodyName>
<topicName>${ns}/base_pose_ground_truth</topicName>
<gaussianNoise>0.01</gaussianNoise>
<frameName>map</frameName>
<!-- initialize odometry for fake localization -->
<xyzOffsets>0 0 0</xyzOffsets>
<rpyOffsets>0 0 0</rpyOffsets>
</plugin>
</gazebo>

in Gaussian noise but it does the same... any ideas? Do I have to change something else to make this work ?

2017-04-30 03:11:23 -0500 marked best answer Simple problem with TwistStamped msg

hi Ros users:

I am trying to do an array of velocities. This is my code:

  geometry_msgs::Twist cmd;
  geometry_msgs::TwistStamped tiempo;
  cmd.linear.x = 1; 
  cmd.linear.y = 0;
  cmd.linear.z = 0;

  tiempo.header.stamp=5;
  cmd.angular.x = 0;
  cmd.angular.y = 0;
  cmd.angular.z = 4;
  vel_pub_.publish(cmd);

But when it is compiled i can see these errors on terminal

/home/alcor/catkin_ws/src/lanzar_velocidades/src/arrayvel.cpp:52:3: error: ‘geometry’ has not been declared geometry::TwistStamped tiempo; ^ /home/alcor/catkin_ws/src/lanzar_velocidades/src/arrayvel.cpp:52:26: error: expected ‘;’ before ‘tiempo’
geometry::TwistStamped tiempo; ^ /home/alcor/catkin_ws/src/lanzar_velocidades/src/arrayvel.cpp:57:3: error: ‘tiempo’ was not declared in this scope tiempo.header.stamp=5;
^ make[2]: * [lanzar_velocidades/CMakeFiles/arrayvel_node.dir/src/arrayvel.cpp.o] Error 1 make[1]: * [lanzar_velocidades/CMakeFiles/arrayvel_node.dir/all] Error 2

Any ideas?

Thanks!

2017-03-29 16:43:53 -0500 marked best answer OpenCV in ROS indigo

Hi Ros users:

I have a script where I use OpenCV functions and ROS functions. But I have a problem when I run this script. Mi question is: What version of OpenCV have I to install to work with Ros Indigo?

Thanks a lot!!!!!

2017-03-20 00:45:22 -0500 marked best answer base_pose_ground_truth type?

Hello ros users. I am trying to subscribe to base_pose_ground_truth topic but I can't. My code is this:

nav_msgs::base_pose_ground_truth subs;
 double variable1;
 double variable2;
 void velsubcallback(const nav_msgs::base_pose_ground_truth& msg)
   {

  variable1=msg.twist.twist.linear.x;
    variable2=msg.twist.twist.angular.z;
     lectura_ros.linear=variable1;
     lectura_ros.angular=variable2;
     ROS_INFO("variable %f",lectura_ros.linear);

How can i subscribe on that topic?

Thanks!

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2017-02-17 15:25:32 -0500 marked best answer How can I download camera Gazebo

Hi Ros users:

I would like to download the pkg of this camera which Gazebo provides us:

image description

So I would like that when I launch a .launch the camera is in the same place and I would like to be able to access topics (for example "camera/link/camera/image" as you can see below on the pic) in the terminal or in RVIZ. So it is possible to download this camera as pkg? Or to do that in any way?

Thanks!!!

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2016-08-08 02:02:12 -0500 marked best answer Adding noise to P3DX model

Hi Ros users:

I am trying to add gaussian noise to velocities of P3DX. The model that I am using is from this source https://github.com/RafBerkvens/ua_ros... I have modified this part of code:

  <!-- ground truth -->
    <gazebo>
        <plugin name="p3d_base_controller" filename="libgazebo_ros_p3d.so">
            <alwaysOn>true</alwaysOn>
            <updateRate>100.0</updateRate>
            <bodyName>base_link</bodyName>
            <topicName>${ns}/base_pose_ground_truth</topicName>
             <gaussianNoise>0.01</gaussianNoise>
            <frameName>map</frameName>
            <!-- initialize odometry for fake localization -->
            <xyzOffsets>0 0 0</xyzOffsets>
            <rpyOffsets>0 0 0</rpyOffsets>
    <velocityGaussianNoise>10 10 10</velocityGaussianNoise>
        </plugin>
    </gazebo>

I change the part where it says "gaussiannoise nad velocityGaussianNoise" but it works in the same way.

Does anybody know how i can add gaussian noise to P3DX model??

Thank you so much.

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2016-06-03 02:40:11 -0500 commented answer nav2d autonomous exploration

@Sebastian Kasperski @Icehawk101 Hello my friends. I have just edited the post!!! Thanks again,

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2016-06-02 05:25:40 -0500 commented answer nav2d autonomous exploration

@Sebastian Kasperski It gives me this error as well: LaserRangeFinder::Validate() - LocalizedRangeScan contains 672 range readings, expected 673

2016-06-02 05:04:54 -0500 commented answer nav2d autonomous exploration

@Sebastian Kasperski I have just eddited with more information!! thanks!!

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2016-06-02 04:31:46 -0500 commented answer nav2d autonomous exploration

I have just editted post! @Sebastian Kasperski

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2016-06-01 12:52:59 -0500 commented answer nav2d autonomous exploration

@Icehawk101 Done!!

2016-06-01 12:14:31 -0500 commented answer nav2d autonomous exploration

@Icehawk101 I have just fixed that error. Now the error is the next when I call rosservice StartExploration:

[ERROR] Exploration failed, could not get current position.

2016-06-01 10:06:51 -0500 commented answer nav2d autonomous exploration

@Sebastian Kasperski thanks a lot for answering. I have just edited first post with the current error.!

2016-06-01 03:05:36 -0500 asked a question nav2d autonomous exploration

Every problems before fixed:

EDIT 6: Hi friends!! I have just fixed every problems with your help. So now my robot moves with StartMapping and with StartExplorer, but not really well...

I think that it do good StartMapping but when I do StartExplorer, my robot explores just a few second and it gets stuck in a wall. I think that this problem is for some .yaml parameters.

But I modify a lot of parameters to check if it does a good navigatiion and alwais it gets stuck. Which parameters have I to modify or what I can do???

Thanka lot!

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