publish array velocities in a topic?

asked 2015-04-29 05:35:15 -0600

Alvaro Salcedo
149 ●38 ●44 ●49

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!

edit retag flag offensive close merge delete

add a comment

2

answered 2015-04-29 09:05:05 -0600

marguedas

3621 ●17 ●109 ●57

Hi, You can create your own message Velocity array. Then you fill your array with twist messages. Finally you publish it.
You have an example in python in this answer.

edit flag offensive delete link

add a comment

1

answered 2015-04-30 23:00:53 -0600

130s

10937 ●203 ●339 ●330 http://www.linkedin.co...

Although I haven't done it personally, I would try using TwistStamped, put its instances into an array (as @marguedas does in the link provided), particularly when you want to specify the timing where the Twist gets executed. You can specify it in its header.stamp.

edit flag offensive delete link

add a comment

0

answered 2015-07-13 06:27:01 -0600

Alvaro Salcedo
149 ●38 ●44 ●49

Hi. First of all thanks for your responses Did you do this @130s ?

I am trying it. I have done this:

  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!

edit flag offensive delete link

add a comment

publish array velocities in a topic?

3 Answers

Question Tools

Stats

Related questions

publish array velocities in a topic? edit

3 Answers

Question Tools

Stats

Related questions

publish array velocities in a topic?