#! /usr/bin/env python

import rospy 
from geometry_msgs.msg import Twist

rospy.init_node('vel_pub')
pub = rospy.Publisher('/cmd_vel', Twist, queue_size=1)
rate = rospy.Rate(2)
move = Twist()
move.linear.x=0.5
move.angular.z=0.5

while not rospy.is_shutdown():
  pub.publish(move)
  rate.sleep()