Update name of scan_filter.py node.

src/scan_filter.py

@@ -0,0 +1,55 @@
+#!/usr/bin/env python
+
+# Every python controller needs these lines
+import rospy
+from numpy import linspace, inf
+from math import sin
+# We're going to subscribe to a LaserScan message.
+from sensor_msgs.msg import LaserScan
+
+class Scanfilter:
+	def __init__(self):
+
+		# We're going to assume that the robot is pointing up the x-axis, so that any points with y coordinates further
+		# than half a robot width from the axis are not in front of the robot.
+		self.extent = .5 / 2.0
+
+		# Set up a subscriber.  We're going to subscribe to the topic "counter",
+		# looking for Int64 messages.  When a message comes in, ROS is going to pass
+		# it to the function "callback" automatically.
+		self.sub = rospy.Subscriber('/scan', LaserScan, self.callback)
+		self.pub = rospy.Publisher('filtered_scan', LaserScan, queue_size=10)
+
+
+	def callback(self,msg):
+		# print('Minimum scan value = ' + str(len(msg.ranges)))
+		#
+		# center_index = len(msg.ranges)/3
+		# rospy.sleep(1)
+		"""
+		:param self: Self reference.
+		:param msg: LaserScan message.
+		"""
+
+		# Figure out the angles of the scan.  We're going to do this each time, in case we're subscribing to more than one
+		# laser, with different numbers of beams.
+		angles = linspace(msg.angle_min, msg.angle_max, len(msg.ranges))
+
+		# # Work out the y coordinates of the ranges.
+		points = [r * sin(theta) if (theta < -2.5 or theta > 2.5) else inf for r,theta in zip(msg.ranges, angles)]
+		#
+		# If we're close to the x axis, keep the range, otherwise use inf, which means "no return".
+		new_ranges = [r if abs(y) < self.extent else inf for r,y in zip(msg.ranges, points)]
+
+		# Substitute in the new ranges in the original message, and republish it.
+		msg.ranges = new_ranges
+		self.pub.publish(msg)
+
+if __name__ == '__main__':
+	# Initialize the node, and call it "move".
+	rospy.init_node('scan_filter')
+
+	# Setup Move class to base_motion
+	Scan()
+
+	rospy.spin()