Init commit of the tf2 broadcaster node.

src/tf2_broadcaster.py

@@ -0,0 +1,93 @@
+#!/usr/bin/env python
+
+# Import modules
+import rospy
+
+# Because of transformations
+import tf.transformations
+
+# The TransformStamped message is imported to create a child frame
+from geometry_msgs.msg import TransformStamped
+
+# Import StaticTransformBroadcaster to publish static transforms
+from tf2_ros import StaticTransformBroadcaster
+
+class FixedFrameBroadcaster():
+    """
+    This node publishes three child static frames in reference to their parent frames as below:
+    parent -> link_mast            child -> fk_link_mast
+    parent -> link_lift            child -> fk_link_lift
+    parent -> link_wrist_yaw       child -> fk_link_wrist_yaw
+    """
+    def __init__(self):
+        """
+        A function that creates a broadcast node and publishes three new transform
+        frames.
+        :param self: The self reference.
+        """
+        # Create a broadcast node
+        self.br = StaticTransformBroadcaster()
+
+        # Create a stamped transform to broadcast
+        self.mast = TransformStamped()
+
+        # Define parent and child frames
+        self.mast.header.stamp = rospy.Time.now()
+        self.mast.header.frame_id = 'link_mast'
+        self.mast.child_frame_id = 'fk_link_mast'
+
+        # Set pose values to transform
+        self.mast.transform.translation.x = 0.0
+        self.mast.transform.translation.y = 2.0
+        self.mast.transform.translation.z = 0.0
+        q = tf.transformations.quaternion_from_euler(1.5707, 0, -1.5707)
+        self.mast.transform.rotation.x = q[0]
+        self.mast.transform.rotation.y = q[1]
+        self.mast.transform.rotation.z = q[2]
+        self.mast.transform.rotation.w = q[3]
+
+        # Repeat broadcast transform for fk_link_lift
+        self.lift = TransformStamped()
+        self.lift.header.stamp = rospy.Time.now()
+        self.lift.header.frame_id = 'link_lift'
+        self.lift.child_frame_id = 'fk_link_lift'
+        self.lift.transform.translation.x = 0.0
+        self.lift.transform.translation.y = 1.0
+        self.lift.transform.translation.z = 0.0
+        q = tf.transformations.quaternion_from_euler(1.5707, 0, -1.5707)
+        self.lift.transform.rotation.x = q[0]
+        self.lift.transform.rotation.y = q[1]
+        self.lift.transform.rotation.z = q[2]
+        self.lift.transform.rotation.w = q[3]
+
+        # Repeat broadcast transform for fk_link_wrist_yaw
+        self.wrist = TransformStamped()
+        self.wrist.header.stamp = rospy.Time.now()
+        self.wrist.header.frame_id = 'link_wrist_yaw'
+        self.wrist.child_frame_id = 'fk_link_wrist_yaw'
+        self.wrist.transform.translation.x = 0.0
+        self.wrist.transform.translation.y = 1.0
+        self.wrist.transform.translation.z = 0.0
+        q = tf.transformations.quaternion_from_euler(1.5707, 0, -1.5707)
+        self.wrist.transform.rotation.x = q[0]
+        self.wrist.transform.rotation.y = q[1]
+        self.wrist.transform.rotation.z = q[2]
+        self.wrist.transform.rotation.w = q[3]
+
+        # Publish transforms in a list
+        self.br.sendTransform([self.mast, self.lift, self.wrist])
+
+        # Create rospy log message
+        rospy.loginfo('Publishing TF frames. Use RViz to visualize')
+
+if __name__ == '__main__':
+    # Initialize the node, and call it "tf2_broadcaster"
+    rospy.init_node('tf2_broadcaster')
+
+    # Instantiate the FixedFrameBroadcaster class
+    FixedFrameBroadcaster()
+
+    # Give control to ROS.  This will allow the callback to be called whenever new
+	# messages come in.  If we don't put this line in, then the node will not work,
+	# and ROS will not process any messages
+    rospy.spin()