#!/usr/bin/env python
import sys
import rospy
import threading
from px4.msg import vehicle_local_position
from gazebo_msgs.srv import SpawnModel
from gazebo_msgs.srv import SetModelState
from geometry_msgs.msg import Pose
from geometry_msgs.msg import Twist
from numpy import linalg
import numpy as np
import math
#
# Helper to test if vehicle stays in expected flight path.
#
class FlightPathAssertion(threading.Thread):
def __init__(self, positions, tunnelRadius = 1, yawOffset = 0.2):
threading.Thread.__init__(self)
rospy.Subscriber("px4_multicopter/vehicle_local_position", vehicle_local_position, self.position_callback)
self.spawn = rospy.ServiceProxy('gazebo/spawn_sdf_model', SpawnModel)
self.setModelState = rospy.ServiceProxy('gazebo/set_model_state', SetModelState)
self.positions = positions
self.tunnelRadius = tunnelRadius
self.yawOffset = yawOffset
self.hasPos = False
self.shouldStop = False
self.center = positions[0]
self.endOfSegment = False
def position_callback(self, data):
self.hasPos = True
self.localPosition = data
def spawn_indicator(self):
xml = "<?xml version='1.0'?><sdf version='1.4'><model name='indicator'><static>true</static><link name='link'><visual name='visual'><transparency>0.7</transparency><geometry><sphere><radius>%f</radius></sphere></geometry><material><ambient>1 0 0 0.5</ambient><diffuse>1 0 0 0.5</diffuse></material></visual></link></model></sdf>" % self.tunnelRadius
self.spawn("indicator", xml, "", Pose(), "")
def position_indicator(self):
state = SetModelState()
state.model_name = "indicator"
pose = Pose()
pose.position.x = self.center[0]
pose.position.y = (-1) * self.center[1]
pose.position.z = (-1) * self.center[2]
state.pose = pose
state.twist = Twist()
state.reference_frame = ""
self.setModelState(state)
def distance_to_line(self, a, b, pos):
v = b - a
w = pos - a
c1 = np.dot(w, v)
if c1 <= 0: # before a
self.center = a
return linalg.norm(pos - a)
c2 = np.dot(v, v)
if c2 <= c1: # after b
self.center = b
self.endOfSegment = True
return linalg.norm(pos - b)
x = c1 / c2
l = a + x * v
self.center = l
return linalg.norm(pos - l)
def stop(self):
self.shouldStop = True
def run(self):
rate = rospy.Rate(10) # 10hz
self.spawn_indicator()
current = 0
while not self.shouldStop:
if (self.hasPos):
# calculate distance to line segment between first two points
# if distances > tunnelRadius
# exit with error
# advance current pos if not on the line anymore or distance to next point < tunnelRadius
# exit if current pos is now the last position
self.position_indicator()
pos = np.array((self.localPosition.x,
self.localPosition.y,
self.localPosition.z))
aPos = np.array((self.positions[current][0],
self.positions[current][1],
self.positions[current][2]))
bPos = np.array((self.positions[current + 1][0],
self.positions[current + 1][1],
self.positions[current + 1][2]))
dist = self.distance_to_line(aPos, bPos, pos)
bDist = linalg.norm(pos - bPos)
rospy.loginfo("distance to line: %f, distance to end: %f" % (dist, bDist))
if (dist > self.tunnelRadius):
rospy.logerr("left tunnel at position (%f, %f, %f)" % (self.localPosition.x, self.localPosition.y, self.localPosition.z))
# FIXME: assertion
break
if (self.endOfSegment or bDist < self.tunnelRadius):
rospy.loginfo("next segment")
self.endOfSegment = False
current = current + 1
if (current == len(self.positions) - 1):
rospy.loginfo("no more positions")
break
rate.sleep()