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#!/usr/bin/env python3
import argparse
import copy
import importlib
import time
import numpy as np
import rospy
from geometry_msgs.msg import Twist
from numpy.random import default_rng
from std_msgs.msg import Header
import murl.sensors as sensors
from murl.world.simple import SimpleWorld
RNG = default_rng()
class Robot:
SENSORS_TO_WHEELS = np.array([[0.2, 0.2, -0.2, 0.1, -0.1],
[0.2, -0.2, 0.2, -0.1, 0.1]])
WHEELS_TO_UW = np.array([[.5, .5], [.5, -.5]])
SENSORS_TO_UW = np.matmul(WHEELS_TO_UW, SENSORS_TO_WHEELS)
def __init__(self, world, robot, cloud_module):
self._robot = robot
self._publisher = rospy.Publisher('/robot{}/cmd_vel'.format(robot), Twist, queue_size=5)
self._laser = sensors.SimpleLaser(robot)
self._motion = sensors.Motion(robot)
self._groundtruth = sensors.GroundtruthPose(robot)
self._particles = cloud_module.Cloud(world, robot, RNG)
self._particles.resample_all()
def move(self):
f, fl, fr, l, r = self._laser.measurements
inputs = np.clip(np.array([f, fl, fr, l, r]), 0, 3.0)
uw = np.matmul(self.SENSORS_TO_UW, inputs)
u = uw[0]
w = uw[1]
if f < 0.3:
u = -0.01
w = 0.5
elif fl < 0.5:
u = -0.01
w = -0.5
elif fr < 0.5:
u = -0.01
w = 0.5
elif l < 0.5:
w = -0.5
elif r < 0.5:
w = 0.5
msg = Twist()
msg.linear.x = u
msg.angular.z = w
self._publisher.publish(msg)
@property
def ready(self):
return self._laser.ready and self._motion.ready and self._groundtruth.ready
@property
def delta_pose(self):
return self._motion.delta_pose
@property
def pose(self):
return self._groundtruth.pose
@property
def scan(self):
return self._laser._measurements
@property
def particles(self):
return self._particles
def run(args):
rospy.init_node('localisation')
# Update control every 100 ms.
rate_limiter = rospy.Rate(100)
world = SimpleWorld(RNG)
cloud_module = importlib.import_module(args.cloud)
robots = [Robot(world, i, cloud_module) for i in range(args.robots)]
robot_guesses = [None for i in range(args.robots)]
robot_scans = [[None for i in range(args.robots)] for i in range(args.robots)]
for i, robot in enumerate(robots):
robot_guesses[i] = robot.particles.guess_position()
print('Ready!')
pose_history = []
with open('/tmp/gazebo_exercise.txt', 'w'):
pass
frame_id = 0
while not rospy.is_shutdown():
# Make sure all measurements are ready.
if not all(map(lambda robot: robot.ready, robots)):
rate_limiter.sleep()
continue
# Update robot positions
for robot in robots:
robot.move()
# Recalculate relative robot positions
for i in range(args.robots):
for j in range(args.robots):
if i == j:
continue
dist = robots[j].pose[:2] - robots[i].pose[:2]
angle = np.arctan2(dist[1], dist[0]) - robots[i].pose[2]
robot_scans[i][j] = np.sqrt(dist[0]**2 + dist[1]**2), angle
for i, robot in enumerate(robots):
delta = robot.delta_pose
angle_dists = zip(sensors.SCAN_ANGLES, robot.scan)
robot.particles.move(delta)
guesses = robot_guesses[:i] + robot_guesses[i+1:]
scans = robot_scans[i][:i] + robot_scans[i][i+1:]
robot.particles.calculate_weight(angle_dists, guesses, scans)
# Resample particles and update guesses
for i, robot in enumerate(robots):
if frame_id % 10:
robot.particles.publish(frame_id)
robot.particles.average()
robot_guesses[i] = robot.particles.guess_position()
# Log positions
pose_history.append([(robot.pose[:2], guess[0]) for robot, guess in zip(robots, robot_guesses)])
if len(pose_history) % 10:
def entry_to_string(per_robot):
return ','.join(','.join(str(v) for v in robot) + ',' + ','.join(str(v) for v in guess) for robot, guess in per_robot)
with open('/tmp/data.csv', 'a') as fp:
fp.write('\n'.join(entry_to_string(entry) for entry in pose_history) + '\n')
pose_history = []
# Loop again
rate_limiter.sleep()
frame_id += 1
if __name__ == '__main__':
parser = argparse.ArgumentParser(description='Runs a particle filter')
parser.add_argument('--robots', action='store', type=int, help='Number of robots.')
parser.add_argument('--cloud', action='store', type=str, help='Particle cloud module.')
args, unknown = parser.parse_known_args()
try:
# cProfile.run('run(args)', '/tmp/profile-stats')
run(args)
except rospy.ROSInterruptException:
pass
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