add joint_state_publisher plugin

dynamixel_controllers/src/dynamixel_controllers/joint_state_publisher.py

@@ -0,0 +1,116 @@
+# -*- coding: utf-8 -*-
+#
+# Software License Agreement (BSD License)
+#
+# Copyright (c) 2015, Kei Okada.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+#  * Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+#  * Redistributions in binary form must reproduce the above
+#    copyright notice, this list of conditions and the following
+#    disclaimer in the documentation and/or other materials provided
+#    with the distribution.
+#  * Neither the name of Kei Okada nor the names of its
+#    contributors may be used to endorse or promote products derived
+#    from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+
+from threading import Thread
+
+import rospy
+
+from sensor_msgs.msg import JointState
+
+class JointStatePublisher():
+    def __init__(self, controller_namespace, controllers):
+        self.update_rate = 1000
+        self.state_update_rate = 50
+        self.trajectory = []
+
+        self.controller_namespace = controller_namespace
+        self.joint_names = [c.joint_name for c in controllers]
+
+        self.joint_to_controller = {}
+        for c in controllers:
+             self.joint_to_controller[c.joint_name] = c
+
+        self.port_to_joints = {}
+        for c in controllers:
+            if c.port_namespace not in self.port_to_joints: self.port_to_joints[c.port_namespace] = []
+            self.port_to_joints[c.port_namespace].append(c.joint_name)
+
+        self.port_to_io = {}
+        for c in controllers:
+            if c.port_namespace in self.port_to_io: continue
+            self.port_to_io[c.port_namespace] = c.dxl_io
+
+    def initialize(self):
+        self.msg = JointState()
+        return True
+
+
+    def start(self):
+        self.running = True
+        self.state_pub = rospy.Publisher('joint_states', JointState , queue_size=100)
+
+        Thread(target=self.update_state).start()
+
+
+    def stop(self):
+        self.running = False
+
+    def update_state(self):
+        rate = rospy.Rate(self.state_update_rate)
+        while self.running and not rospy.is_shutdown():
+            self.msg.header.stamp = rospy.Time.now()
+            self.msg.name = []
+            self.msg.position = []
+            self.msg.velocity = []
+            self.msg.effort = []
+
+            for port, joints in self.port_to_joints.items():
+                vals = []
+                for joint in joints:
+                    j = self.joint_names.index(joint)
+
+                    motor_id = self.joint_to_controller[joint].motor_id
+                    co = self.joint_to_controller[joint]
+                    io = self.port_to_io[port]
+
+                    self.msg.name.append(joint)
+                    po = ve = ef = 0
+                    try:
+                        ret = io.get_feedback(motor_id)
+                        po = self.raw_to_rad_pos(ret['position'],co)
+                        ve = self.raw_to_rad_spd(ret['speed'],co)
+                        ef = self.raw_to_rad_spd(ret['load'],co)
+                    except Exception as e:
+                        rospy.logerr(e)
+                    self.msg.position.append(po)
+                    self.msg.velocity.append(ve)
+                    self.msg.effort.append(ef)
+
+            self.state_pub.publish(self.msg)
+            rate.sleep()
+
+    def raw_to_rad_pos(self, raw, c):
+        return (c.initial_position_raw - raw if c.flipped else raw - c.initial_position_raw) * c.RADIANS_PER_ENCODER_TICK
+    def raw_to_rad_spd(self, raw, c):
+        return (- raw if c.flipped else raw ) * c.RADIANS_PER_ENCODER_TICK