turtle_tf_listener.py
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00001 #!/usr/bin/env python
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00033 
00034 import roslib
00035 roslib.load_manifest('turtle_tf')
00036 import rospy
00037 
00038 import math
00039 import tf
00040 import geometry_msgs.msg
00041 import turtlesim.srv
00042 
00043 if __name__ == '__main__':
00044     rospy.init_node('tf_turtle')
00045 
00046     listener = tf.TransformListener()
00047 
00048     rospy.wait_for_service('spawn')
00049     spawner = rospy.ServiceProxy('spawn', turtlesim.srv.Spawn)
00050     spawner(4, 2, 0, 'turtle2')
00051 
00052     turtle_vel = rospy.Publisher('turtle2/cmd_vel', geometry_msgs.msg.Twist, queue_size=1)
00053 
00054     rate = rospy.Rate(10.0)
00055     while not rospy.is_shutdown():
00056         try:
00057             (trans, rot) = listener.lookupTransform('/turtle2', '/turtle1', rospy.Time())
00058         except (tf.LookupException, tf.ConnectivityException, tf.ExtrapolationException):
00059             continue
00060 
00061         angular = 4 * math.atan2(trans[1], trans[0])
00062         linear = 0.5 * math.sqrt(trans[0] ** 2 + trans[1] ** 2)
00063         msg = geometry_msgs.msg.Twist()
00064         msg.linear.x = linear
00065         msg.angular.z = angular
00066         turtle_vel.publish(msg)
00067 
00068         rate.sleep()


turtle_tf
Author(s): James Bowman, Isaac Saito
autogenerated on Thu Jun 6 2019 17:37:21