DQN代码-ROS-turtlebot3_ros系统用dqn进行路径规划源代码

DQN代码解析

代码来自turtlebot3_qdn/environment_stage_4.py
发布话题：cmd_vel
订阅话题：odom
服务话题:
gazebo/reset_simulation,gazebo/unpause_physics
gazebo/pause_physics\

def:
getGoalDistace（计算获得目标距离）:
return goal_distance

getOdometry（读取里程信息计算航向角）:
self.position=odom.pose.pose.position
goal_angle=math.atan2(self.goal_y - self.position.y, self.goal_x - self.position.x)
#欧拉变换
heading = goal_angle - yaw
if heading > pi:
heading -= 2 * pi
elif heading < -pi:
heading += 2 * pi
self.heading=round(heading, 2)

getState(判断是否到达目标的，返回get_goalbox，碰到障碍物返回done)：
return
scan_range+[heading,current_distance,obstacle_min_range,obstacle_angle],done

setReward(奖励设置：碰撞-500，到达目标1000)：
return reward

step（）：
发布一个线速度和角速度
等待激光雷达信息
state, done = self.getState(data)
reward = self.setReward(state, done, action)
return np.asarray(state), reward, done
reset(重新开始):
等待尕gazebo重置返回gazebo/reset_simulation
接受激光雷达信息
如果到达目标点就不重置小车位置
return np.asarray(state)

#!/usr/bin/env python
#################################################################################
# Copyright 2018 ROBOTIS CO., LTD.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#################################################################################

# Authors: Gilbert #

import rospy
import numpy as np
import math
from math import pi
from geometry_msgs.msg import Twist, Point, Pose
from sensor_msgs.msg import LaserScan
from nav_msgs.msg import Odometry
from std_srvs.srv import Empty
from tf.transformations import euler_from_quaternion, quaternion_from_euler
from respawnGoal import Respawn

class Env():
    def __init__(self, action_size):
        self.goal_x = 0
        self.goal_y = 0
        self.heading = 0
        self.action_size = action_size
        self.initGoal = True
        self.get_goalbox = False
        self.position = Pose()
        self.pub_cmd_vel = rospy.Publisher('cmd_vel', Twist, queue_size=5)
        self.sub_odom = rospy.Subscriber('odom', Odometry, self.getOdometry)
        self.reset_proxy = rospy.ServiceProxy('gazebo/reset_simulation', Empty)
        self.unpause_proxy = rospy.ServiceProxy('gazebo/unpause_physics', Empty)
        self.pause_proxy = rospy.ServiceProxy('gazebo/pause_physics', Empty)
        self.respawn_goal = Respawn()

    def getGoalDistace(self):
        goal_distance = round(math.hypot(self.goal_x - self.position.x, self.goal_y - self.position.y), 2)

        return goal_distance

    def getOdometry(self, odom):
        self.position = odom.pose.pose.position
        orientation = odom.pose.pose.orientation
        orientation_list = [orientation.x, orientation.y, orientation.z, orientation.w]
        _, _, yaw = euler_from_quaternion(orientation_list)

        goal_angle = math.atan2(self.goal_y - self.position.y, self.goal_x - self.position.x)

        heading = goal_angle - yaw
        if heading > pi:
            heading -= 2 * pi

        elif heading < -pi:
            heading += 2 * pi

        self.heading = round(heading, 2)

    def getState(self, scan):
        scan_range = []
        heading = self.heading
        min_range = 0.13
        done = False

        for i in range(len(scan.ranges)):
            if scan.ranges[i] == float('Inf'):
                scan_range.append(3.5)
            elif np.isnan(scan.ranges[i]):
                scan_range.append(0)
            else:
                scan_range.append(scan.ranges[i])

        obstacle_min_range = round(min(scan_range), 2)
        obstacle_angle = np.argmin(scan_range)
        if min_range > min(scan_range) > 0:
            done = True

        current_distance = round(math.hypot(self.goal_x - self.position.x, self.goal_y - self.position.y),2)
        if current_distance < 0.2:
            self.get_goalbox = True

        return scan_range + [heading, current_distance, obstacle_min_range, obstacle_angle], done

    def setReward(self, state, done, action):
        yaw_reward = []
        obstacle_min_range = state[-2]
        current_distance = state[-3]
        heading = state[-4]

        for i in range(5):
            angle = -pi / 4 + heading + (pi / 8 * i) + pi / 2
            tr = 1 - 4 * math.fabs(0.5 - math.modf(0.25 + 0.5 * angle % (2 * math.pi) / math.pi)[0])
            yaw_reward.append(tr)

        distance_rate = 2 ** (current_distance / self.goal_distance)

        if obstacle_min_range < 0.5:
            ob_reward = -5
        else:
            ob_reward = 0

        reward = ((round(yaw_reward[action] * 5, 2)) * distance_rate) + ob_reward

        if done:
            rospy.loginfo("Collision!!")
            reward = -500
            self.pub_cmd_vel.publish(Twist())

        if self.get_goalbox:
            rospy.loginfo("Goal!!")
            reward = 1000
            self.pub_cmd_vel.publish(Twist())
            self.goal_x, self.goal_y = self.respawn_goal.getPosition(True, delete=True)
            self.goal_distance = self.getGoalDistace()
            self.get_goalbox = False

        return reward


    def step(self, action):
        max_angular_vel = 1.5
        ang_vel = ((self.action_size - 1)/2 - action) * max_angular_vel * 0.5

        vel_cmd = Twist()
        vel_cmd.linear.x = 0.15
        vel_cmd.angular.z = ang_vel
        self.pub_cmd_vel.publish(vel_cmd)

        data = None
        while data is None:
            try:
                data = rospy.wait_for_message('scan', LaserScan, timeout=5)
            except:
                pass

        state, done = self.getState(data)
        reward = self.setReward(state, done, action)

        return np.asarray(state), reward, done

    def reset(self):
        rospy.wait_for_service('gazebo/reset_simulation')
        try:
            self.reset_proxy()
        except (rospy.ServiceException) as e:
            print("gazebo/reset_simulation service call failed")

        data = None
        while data is None:
            try:
                data = rospy.wait_for_message('scan', LaserScan, timeout=5)
            except:
                pass

        if self.initGoal:
            self.goal_x, self.goal_y = self.respawn_goal.getPosition()
            self.initGoal = False

        self.goal_distance = self.getGoalDistace()
        state, done = self.getState(data)

        return np.asarray(state)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172