Nodo de ejemplo para la clase de Robótica del año 2020 (Introducción a ROS)

ejecutable.launch

<launch>
  <node name="mi_nodo_utn" pkg="mi_nuevo_paquete" type="mi_nodo.py" />

  <include file="$(find ca_gazebo)/launch/create_empty_world.launch"/>
</launch>

mi_nodo.py

#! /usr/bin/env python

import rospy
from nav_msgs.msg import Odometry
from geometry_msgs.msg import Twist, Vector3

class MiNodo():

  def __init__(self):
      self.x = 0.0
      rospy.init_node('mi_nodo')
      rospy.Subscriber("/create1/odom", Odometry, self.callback)
      self.pub = rospy.Publisher('/create1/cmd_vel', Twist, queue_size=10)

      r = rospy.Rate(10) # 10hz

      while not rospy.is_shutdown():
          vel = Twist()

          if(self.x < 0):
              vel.linear.x = 0.1 # m/s
              vel.angular = Vector3(0, 0, 0)
          else:
              vel.linear.x = 0
              vel.angular.z = 0.5 # rad/s

          self.pub.publish(vel)
          r.sleep()

  def callback(self, data):
      self.x = data.pose.pose.position.x


if __name__ == "__main__":
    mi_nodo = MiNodo()