Added script to follow tf uwb beacon
[ros_wild_thumper.git] / scripts / follow_uwb.py
1 #!/usr/bin/env python
2 # -*- coding: iso-8859-15 -*-
3
4 import rospy
5 import tf
6 import actionlib
7 import tf2_ros
8 import dynamic_reconfigure.client
9 import numpy as np
10 import thread
11 from move_base_msgs.msg import MoveBaseAction, MoveBaseGoal
12 from actionlib_msgs.msg import GoalStatus
13 from math import *
14
15 class FollowUWB:
16         def __init__(self):
17                 rospy.init_node('follow_uwb')
18                 rospy.on_shutdown(self.on_shutdown)
19
20                 self.move_base = actionlib.SimpleActionClient("move_base", MoveBaseAction)
21                 self.tfBuffer = tf2_ros.Buffer()
22                 self.listener = tf2_ros.TransformListener(self.tfBuffer)
23
24                 rospy.loginfo("Setting paramters")
25                 self.dynreconf = dynamic_reconfigure.client.Client("/move_base/TrajectoryPlannerROS")
26                 #self.dynreconf.update_configuration({'max_vel_x': 1.0, 'max_vel_theta': 1.2, 'min_in_place_vel_theta': 1.0})
27
28                 rospy.loginfo("Waiting for the move_base action server to come up")
29                 self.move_base.wait_for_server()
30                 rospy.loginfo("Got move_base action server")
31
32         def next_pos(self, x, y):
33                 rospy.loginfo("Moving to (%f, %f)" % (x, y))
34
35                 # calculate angle between current position and goal
36                 angle_to_goal = atan2(y, x)
37                 odom_quat = tf.transformations.quaternion_from_euler(0, 0, angle_to_goal)
38
39                 goal = MoveBaseGoal()
40                 goal.target_pose.header.frame_id = "base_link"
41                 goal.target_pose.header.stamp = rospy.Time.now()
42                 goal.target_pose.pose.position.x = x
43                 goal.target_pose.pose.position.y = y
44                 goal.target_pose.pose.orientation.x = odom_quat[0]
45                 goal.target_pose.pose.orientation.y = odom_quat[1]
46                 goal.target_pose.pose.orientation.z = odom_quat[2]
47                 goal.target_pose.pose.orientation.w = odom_quat[3]
48                 self.move_base.send_goal(goal)
49
50                 while not self.move_base.wait_for_result(rospy.Duration(1.0)) and not rospy.is_shutdown():
51                         # Get the current position
52                         pos = self.tfBuffer.lookup_transform("uwb_beacon", 'base_link', rospy.Time(0), rospy.Duration(2.0))
53                         # Cancel if we are close enough to goal
54                         if np.linalg.norm([pos.transform.translation.y, pos.transform.translation.x]) < 1:
55                                 rospy.loginfo("Goal within 1m, canceling")
56                                 self.move_base.cancel_goal()
57                                 return
58
59                 if self.move_base.get_state() == GoalStatus.SUCCEEDED:
60                         rospy.loginfo("The base moved to (%f, %f)" % (x, y))
61                 else:
62                         rospy.logerr("The base failed to (%f, %f). Error: %d" % (x, y, self.move_base.get_state()))
63                         exit(1)
64
65         def on_shutdown(self):
66                 rospy.loginfo("Canceling all goals")
67                 self.move_base.cancel_all_goals()
68
69         def run(self):
70                 rate = rospy.Rate(2.0)
71                 while not rospy.is_shutdown():
72                         # Get the current position
73                         beacon_pos = self.tfBuffer.lookup_transform('base_link', "uwb_beacon", rospy.Time(0), rospy.Duration(2.0))
74                         # Create a position 1m away by creating an inverse vector
75                         coords_cur = (beacon_pos.transform.translation.x, beacon_pos.transform.translation.y)
76
77                         # Check difference to last goal
78                         if np.linalg.norm(np.array(coords_cur)) > 0.5:
79                                 print "Setting new goal"
80                                 # Set a new goal
81                                 thread.start_new_thread(self.next_pos, (coords_cur[0], coords_cur[1]))
82                         rate.sleep()
83
84
85 if __name__ == "__main__":
86         p = FollowUWB()
87         p.run()