scripts/arm_ros_conn.py

   1 #!/usr/bin/env python
   2 # -*- coding: iso-8859-15 -*-
   3
   4 import rospy
   5 import arm
   6 import actionlib
   7 import numpy as np
   8 from sensor_msgs.msg import JointState
   9 from control_msgs.msg import FollowJointTrajectoryAction, FollowJointTrajectoryActionResult, FollowJointTrajectoryActionFeedback, FollowJointTrajectoryResult
  10 from actionlib_msgs.msg import GoalStatus
  11 from time import sleep
  12 from math import *
  13
  14 lJointNames = ["base_to_link1", "link_1_2_joint", "link_2_3_joint", "link_3_4_joint", "link_4_5_joint", "left_gripper_joint", "right_gripper_joint"]
  15
  16
  17 class ARMRosConn():
  18         _feedback = FollowJointTrajectoryActionFeedback()
  19         _result = FollowJointTrajectoryActionResult()
  20
  21         def __init__(self):
  22                 rospy.init_node('arm')
  23
  24                 self.speed = 220
  25                 self.lAngles = [0] * 6
  26                 arm.switch(0)
  27                 arm.switch(2)
  28                 arm.set_hall_mode(3, 0)
  29                 arm.set_hall_mode(5, 0)
  30                 arm.set_tolerance(3, 0)
  31                 arm.set_tolerance(5, 0)
  32
  33                 self._as = actionlib.SimpleActionServer("arm_controller/follow_joint_trajectory", FollowJointTrajectoryAction, execute_cb=self.execute_joint_trajectory, auto_start = False)
  34                 self._as.start()
  35                 self.pub_joint_states = rospy.Publisher("joint_states", JointState, queue_size=16)
  36                 self.run()
  37
  38         def run(self):
  39                 rate = rospy.Rate(20)
  40                 while not rospy.is_shutdown():
  41                         self.publish_joint_states()
  42                         rate.sleep()
  43
  44         def publish_joint_states(self):
  45                 joint_state = JointState()
  46                 joint_state.header.stamp = rospy.Time.now()
  47                 joint_state.name = lJointNames
  48                 self.lAngles = [-arm.get_angle(0), arm.get_angle(1), -arm.get_angle(2), -arm.get_angle(3), arm.get_angle(4), arm.get_angle(5)]
  49                 joint_state.position = self.lAngles[:-1] + [0.175-self.lAngles[-1]/2, 0.175-self.lAngles[-1]/2]
  50                 self.pub_joint_states.publish(joint_state)
  51
  52         def execute_joint_trajectory(self, goal):
  53                 for point in goal.trajectory.points:
  54                         print goal.trajectory.joint_names
  55                         print point.positions
  56                         lGoalPosOrdered = [
  57                                 point.positions[goal.trajectory.joint_names.index(lJointNames[0])],
  58                                 point.positions[goal.trajectory.joint_names.index(lJointNames[1])],
  59                                 point.positions[goal.trajectory.joint_names.index(lJointNames[2])],
  60                                 point.positions[goal.trajectory.joint_names.index(lJointNames[3])],
  61                                 point.positions[goal.trajectory.joint_names.index(lJointNames[4])],
  62                         ]
  63                         arm.to_angle(0, self.speed, -lGoalPosOrdered[0])
  64                         arm.to_angle(1, self.speed,  lGoalPosOrdered[1])
  65                         arm.to_angle(2, self.speed, -lGoalPosOrdered[2])
  66                         arm.to_angle(3, self.speed, -lGoalPosOrdered[3])
  67                         arm.to_angle(4, self.speed,  lGoalPosOrdered[4])
  68
  69                         error = 0
  70                         while True:
  71                                 error = np.array(lGoalPosOrdered) - np.array(self.lAngles[:-1])
  72                                 if np.linalg.norm(error) < 0.01:
  73                                         break
  74
  75                                 if self._as.is_preempt_requested():
  76                                         self._as.set_preempted()
  77                                         break
  78                                 sleep(0.001)
  79
  80                         self._feedback.status = GoalStatus.SUCCEEDED
  81                         self._feedback.feedback.joint_names = lJointNames[:-1]
  82                         self._feedback.feedback.desired.positions = lGoalPosOrdered
  83                         self._feedback.feedback.actual.positions = self.lAngles[:-1]
  84                         self._feedback.feedback.error.positions = error
  85                         self._as.publish_feedback(self._feedback.feedback)
  86                 self._result.status = FollowJointTrajectoryResult.SUCCESSFUL
  87                 self._as.set_succeeded(self._result.result)
  88
  89
  90 if __name__ == '__main__':
  91         ARMRosConn()