scripts/umbmark.py

   1 #!/usr/bin/env python
   2 # -*- coding: iso-8859-15 -*-
   3 #
   4 # Gazebo Position: rostopic echo -n 1 /gazebo/model_states
   5 #
   6 # x_err = x_real - x_odom
   7 # y_err = y_real - y_odom
   8 # phi_err = phi_real - phi_odom
   9 #
  10 # x_cg_cw/ccw: avg x_err
  11 # y_cg_cw/ccw: avg y_err
  12 #
  13 # r_cg_cw = sqrt(x_cg_cw**2 + y_cg_cw**2)
  14 # r_cg_ccw = sqrt(x_cg_ccw**2 + y_cg_ccw**2)
  15 #
  16 # L: length (2)
  17 # D(l/r): Wheel diameter left/right
  18 # b: wheelbase
  19 #
  20 # Wheel diameter correction:
  21 # beta = (y_cg_cw + y_cg_ccw)/(-4*L)
  22 # R = (L/2)/sin(beta/2)
  23 # Ed = Dr/Dl*(R+b/2)/(R-b/2)
  24 #
  25 # Wheelbase correction:
  26 # alpha = (y_cg_cw - y_cg_ccw)/(-4*L) * 180/pi
  27 # Eb = (90)/(90-alpha)
  28
  29 import sys
  30 import rospy
  31 import tf
  32 import actionlib
  33 import operator
  34 from time import sleep
  35 from math import *
  36 from nav_msgs.msg import Odometry
  37 from move_base_msgs.msg import MoveBaseAction, MoveBaseGoal
  38 from actionlib_msgs.msg import GoalStatus
  39
  40 class UMBMark:
  41         def __init__(self):
  42                 rospy.init_node('umbmark')
  43                 self.move_base = actionlib.SimpleActionClient("move_base", MoveBaseAction)
  44                 rospy.Subscriber("odom", Odometry, self.odom_received)
  45                 self.odom_pose = None
  46                 while not self.move_base.wait_for_server(rospy.Duration(5)):
  47                         rospy.loginfo("Waiting for the move_base action server to come up")
  48
  49         def odom_received(self, msg):
  50                 orientation = tf.transformations.euler_from_quaternion(msg.pose.pose.orientation.__getstate__())
  51                 self.odom_pose = (msg.pose.pose.position.x, msg.pose.pose.position.y, orientation[2])
  52
  53         def next_pos(self, x, y, angle):
  54                 odom_quat = tf.transformations.quaternion_from_euler(0, 0, angle)
  55
  56                 rospy.loginfo("Moving to (%.2f, %2f), %d°.." % (x, y, angle*180/pi))
  57
  58                 goal = MoveBaseGoal()
  59                 goal.target_pose.header.frame_id = "base_footprint"
  60                 goal.target_pose.header.stamp = rospy.Time.now()
  61                 goal.target_pose.pose.position.x = x
  62                 goal.target_pose.pose.position.y = y
  63                 goal.target_pose.pose.orientation.x = odom_quat[0]
  64                 goal.target_pose.pose.orientation.y = odom_quat[1]
  65                 goal.target_pose.pose.orientation.z = odom_quat[2]
  66                 goal.target_pose.pose.orientation.w = odom_quat[3]
  67                 self.move_base.send_goal(goal)
  68
  69                 self.move_base.wait_for_result()
  70
  71                 if self.move_base.get_state() == GoalStatus.SUCCEEDED:
  72                         rospy.loginfo("The base moved to (%.2f, %2f), %d°" % (x, y, angle*180/pi))
  73                 else:
  74                         rospy.logerr("The base failed to (%.2f, %2f), %d°" % (x, y, angle*180/pi))
  75                         raise
  76
  77         def run(self, direction=-1):
  78                 while self.odom_pose is None:
  79                         sleep(0.1)
  80                 init_pose = self.odom_pose
  81                 for i in range(4):
  82                         self.next_pos(2, 0, 0)
  83                         self.next_pos(0, 0, direction*90*pi/180)
  84                 final_pose = map(operator.sub, self.odom_pose, init_pose)
  85                 print "Odom Pose: x=%.2f, y=%.2f, angle=%.2f°" % (final_pose[0], final_pose[1], final_pose[2]*180/pi)
  86
  87         def run_cw(self):
  88                 self.run(-1)
  89
  90         def run_ccw(self):
  91                 self.run(1)
  92
  93 if __name__ == "__main__":
  94         p = UMBMark()
  95         if len(sys.argv) > 1 and sys.argv[1] == "ccw":
  96                 p.run_ccw()
  97         else:
  98                 p.run_cw()