机器人编程趣味实践14-机器人三维仿真（Gazebo+TurtleBot3）-php黑洞网

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2023-06(4)

机器人编程趣味实践14-机器人三维仿真（Gazebo+TurtleBot3）

发布于2021-06-07 21:12 阅读(781) 评论(0) 点赞(5) 收藏(1)

之前，介绍了节点、主题、服务和行动等基本概念，以及rqt和rosbag2等工具。

采用了官方改版的二维环境，那么现在玩耍一下更为逼真的三维仿真环境吧。

仿真软件Gazebo
机器人TurtleBot3

TurtleBot3支持仿真开发环境，可以在仿真中用虚拟机器人编程开发。有两种开发环境可以做到这一点，一种是使用带有 3D 可视化工具 RViz 的假节点，另一种是使用 3D 机器人模拟器 Gazebo。

假节点适合用机器人模型和运动进行测试，但不支持传感器。
如果需要执行 SLAM 或导航，Gazebo 将是一个可行的解决方案，因为它支持 IMU、LDS 和摄像头等传感器。

环境配置


# TURTLEBOT3_MODEL
export GAZEBO_MODEL_PATH=$GAZEBO_MODEL_PATH:/home/zhangrelay/RobSoft/turtlebot3/src/simulations/turtlebot3_gazebo/models
export TURTLEBOT3_MODEL=burger
 
# ROS2
source /opt/ros/foxy/setup.bash
 
#colcon
source /usr/share/colcon_cd/function/colcon_cd.sh

源码编译

可以使用deb直接安装：

sudo apt install ros-foxy-turtlebot3-gazebo

注意包要装全。

这里，采用源码编译如下：

colcon build

功能包列表如上所示。

仿真实践

1 启动环境

ros2 launch turtlebot3_gazebo empty_world.launch.py

蓝色射线为激光的可视化效果。

empty_world.launch代码如下：


import os
 
from ament_index_python.packages import get_package_share_directory
from launch import LaunchDescription
from launch.actions import ExecuteProcess
from launch.actions import IncludeLaunchDescription
from launch.launch_description_sources import PythonLaunchDescriptionSource
from launch.substitutions import LaunchConfiguration
 
TURTLEBOT3_MODEL = os.environ['TURTLEBOT3_MODEL']
 
 
def generate_launch_description():
    use_sim_time = LaunchConfiguration('use_sim_time', default='True')
    world_file_name = 'empty_worlds/' + TURTLEBOT3_MODEL + '.model'
    world = os.path.join(get_package_share_directory('turtlebot3_gazebo'),
                         'worlds', world_file_name)
    launch_file_dir = os.path.join(get_package_share_directory('turtlebot3_gazebo'), 'launch')
    pkg_gazebo_ros = get_package_share_directory('gazebo_ros')
 
    return LaunchDescription([
        IncludeLaunchDescription(
            PythonLaunchDescriptionSource(
                os.path.join(pkg_gazebo_ros, 'launch', 'gzserver.launch.py')
            ),
            launch_arguments={'world': world}.items(),
        ),
 
        IncludeLaunchDescription(
            PythonLaunchDescriptionSource(
                os.path.join(pkg_gazebo_ros, 'launch', 'gzclient.launch.py')
            ),
        ),
 
        ExecuteProcess(
            cmd=['ros2', 'param', 'set', '/gazebo', 'use_sim_time', use_sim_time],
            output='screen'),
 
        IncludeLaunchDescription(
            PythonLaunchDescriptionSource([launch_file_dir, '/robot_state_publisher.launch.py']),
            launch_arguments={'use_sim_time': use_sim_time}.items(),
        ),
    ])

2 圆周运动

之前和之前二维环境圆周运动的指令非常类似哦。

ros2 topic pub --rate 2 /cmd_vel geometry_msgs/msg/Twist "{linear: {x: 1.0, y: 0.0, z: 0.0}, angular: {x: 0.0, y: 0.0, z: 0.8}}"

3 键盘遥控

使用如下命令启动键盘遥控：

ros2 run turtlebot3_teleop teleop_keyboard

键盘遥控代码如下：


import os
import select
import sys
import rclpy
 
from geometry_msgs.msg import Twist
from rclpy.qos import QoSProfile
 
if os.name == 'nt':
    import msvcrt
else:
    import termios
    import tty
 
BURGER_MAX_LIN_VEL = 0.22
BURGER_MAX_ANG_VEL = 2.84
 
WAFFLE_MAX_LIN_VEL = 0.26
WAFFLE_MAX_ANG_VEL = 1.82
 
LIN_VEL_STEP_SIZE = 0.01
ANG_VEL_STEP_SIZE = 0.1
 
TURTLEBOT3_MODEL = os.environ['TURTLEBOT3_MODEL']
 
msg = """
Control Your TurtleBot3!
---------------------------
Moving around:
        w
   a    s    d
        x
w/x : increase/decrease linear velocity (Burger : ~ 0.22, Waffle and Waffle Pi : ~ 0.26)
a/d : increase/decrease angular velocity (Burger : ~ 2.84, Waffle and Waffle Pi : ~ 1.82)
space key, s : force stop
CTRL-C to quit
"""
 
e = """
Communications Failed
"""
 
 
def get_key(settings):
    if os.name == 'nt':
        return msvcrt.getch().decode('utf-8')
    tty.setraw(sys.stdin.fileno())
    rlist, _, _ = select.select([sys.stdin], [], [], 0.1)
    if rlist:
        key = sys.stdin.read(1)
    else:
        key = ''
 
    termios.tcsetattr(sys.stdin, termios.TCSADRAIN, settings)
    return key
 
 
def print_vels(target_linear_velocity, target_angular_velocity):
    print('currently:\tlinear velocity {0}\t angular velocity {1} '.format(
        target_linear_velocity,
        target_angular_velocity))
 
 
def make_simple_profile(output, input, slop):
    if input > output:
        output = min(input, output + slop)
    elif input < output:
        output = max(input, output - slop)
    else:
        output = input
 
    return output
 
 
def constrain(input_vel, low_bound, high_bound):
    if input_vel < low_bound:
        input_vel = low_bound
    elif input_vel > high_bound:
        input_vel = high_bound
    else:
        input_vel = input_vel
 
    return input_vel
 
 
def check_linear_limit_velocity(velocity):
    if TURTLEBOT3_MODEL == 'burger':
        return constrain(velocity, -BURGER_MAX_LIN_VEL, BURGER_MAX_LIN_VEL)
    else:
        return constrain(velocity, -WAFFLE_MAX_LIN_VEL, WAFFLE_MAX_LIN_VEL)
 
 
def check_angular_limit_velocity(velocity):
    if TURTLEBOT3_MODEL == 'burger':
        return constrain(velocity, -BURGER_MAX_ANG_VEL, BURGER_MAX_ANG_VEL)
    else:
        return constrain(velocity, -WAFFLE_MAX_ANG_VEL, WAFFLE_MAX_ANG_VEL)
 
 
def main():
    settings = None
    if os.name != 'nt':
        settings = termios.tcgetattr(sys.stdin)
 
    rclpy.init()
 
    qos = QoSProfile(depth=10)
    node = rclpy.create_node('teleop_keyboard')
    pub = node.create_publisher(Twist, 'cmd_vel', qos)
 
    status = 0
    target_linear_velocity = 0.0
    target_angular_velocity = 0.0
    control_linear_velocity = 0.0
    control_angular_velocity = 0.0
 
    try:
        print(msg)
        while(1):
            key = get_key(settings)
            if key == 'w':
                target_linear_velocity =\
                    check_linear_limit_velocity(target_linear_velocity + LIN_VEL_STEP_SIZE)
                status = status + 1
                print_vels(target_linear_velocity, target_angular_velocity)
            elif key == 'x':
                target_linear_velocity =\
                    check_linear_limit_velocity(target_linear_velocity - LIN_VEL_STEP_SIZE)
                status = status + 1
                print_vels(target_linear_velocity, target_angular_velocity)
            elif key == 'a':
                target_angular_velocity =\
                    check_angular_limit_velocity(target_angular_velocity + ANG_VEL_STEP_SIZE)
                status = status + 1
                print_vels(target_linear_velocity, target_angular_velocity)
            elif key == 'd':
                target_angular_velocity =\
                    check_angular_limit_velocity(target_angular_velocity - ANG_VEL_STEP_SIZE)
                status = status + 1
                print_vels(target_linear_velocity, target_angular_velocity)
            elif key == ' ' or key == 's':
                target_linear_velocity = 0.0
                control_linear_velocity = 0.0
                target_angular_velocity = 0.0
                control_angular_velocity = 0.0
                print_vels(target_linear_velocity, target_angular_velocity)
            else:
                if (key == '\x03'):
                    break
 
            if status == 20:
                print(msg)
                status = 0
 
            twist = Twist()
 
            control_linear_velocity = make_simple_profile(
                control_linear_velocity,
                target_linear_velocity,
                (LIN_VEL_STEP_SIZE / 2.0))
 
            twist.linear.x = control_linear_velocity
            twist.linear.y = 0.0
            twist.linear.z = 0.0
 
            control_angular_velocity = make_simple_profile(
                control_angular_velocity,
                target_angular_velocity,
                (ANG_VEL_STEP_SIZE / 2.0))
 
            twist.angular.x = 0.0
            twist.angular.y = 0.0
            twist.angular.z = control_angular_velocity
 
            pub.publish(twist)
 
    except Exception as e:
        print(e)
 
    finally:
        twist = Twist()
        twist.linear.x = 0.0
        twist.linear.y = 0.0
        twist.linear.z = 0.0
 
        twist.angular.x = 0.0
        twist.angular.y = 0.0
        twist.angular.z = 0.0
 
        pub.publish(twist)
 
        if os.name != 'nt':
            termios.tcsetattr(sys.stdin, termios.TCSADRAIN, settings)
 
 
if __name__ == '__main__':
    main()

简单加入中文方便使用：

阅读源码非常重要。

4 节点

5 主题

6 服务

ros2 service list -t

/apply_joint_effort [gazebo_msgs/srv/ApplyJointEffort]
/apply_link_wrench [gazebo_msgs/srv/ApplyLinkWrench]
/clear_joint_efforts [gazebo_msgs/srv/JointRequest]
/clear_link_wrenches [gazebo_msgs/srv/LinkRequest]
/delete_entity [gazebo_msgs/srv/DeleteEntity]
/gazebo/describe_parameters [rcl_interfaces/srv/DescribeParameters]
/gazebo/get_parameter_types [rcl_interfaces/srv/GetParameterTypes]
/gazebo/get_parameters [rcl_interfaces/srv/GetParameters]
/gazebo/list_parameters [rcl_interfaces/srv/ListParameters]
/gazebo/set_parameters [rcl_interfaces/srv/SetParameters]
/gazebo/set_parameters_atomically [rcl_interfaces/srv/SetParametersAtomically]
/get_model_list [gazebo_msgs/srv/GetModelList]
/pause_physics [std_srvs/srv/Empty]
/reset_simulation [std_srvs/srv/Empty]
/reset_world [std_srvs/srv/Empty]
/robot_state_publisher/describe_parameters [rcl_interfaces/srv/DescribeParameters]
/robot_state_publisher/get_parameter_types [rcl_interfaces/srv/GetParameterTypes]
/robot_state_publisher/get_parameters [rcl_interfaces/srv/GetParameters]
/robot_state_publisher/list_parameters [rcl_interfaces/srv/ListParameters]
/robot_state_publisher/set_parameters [rcl_interfaces/srv/SetParameters]
/robot_state_publisher/set_parameters_atomically [rcl_interfaces/srv/SetParametersAtomically]
/rqt_gui_py_node_4338/describe_parameters [rcl_interfaces/srv/DescribeParameters]
/rqt_gui_py_node_4338/get_parameter_types [rcl_interfaces/srv/GetParameterTypes]
/rqt_gui_py_node_4338/get_parameters [rcl_interfaces/srv/GetParameters]
/rqt_gui_py_node_4338/list_parameters [rcl_interfaces/srv/ListParameters]
/rqt_gui_py_node_4338/set_parameters [rcl_interfaces/srv/SetParameters]
/rqt_gui_py_node_4338/set_parameters_atomically [rcl_interfaces/srv/SetParametersAtomically]
/spawn_entity [gazebo_msgs/srv/SpawnEntity]
/teleop_keyboard/describe_parameters [rcl_interfaces/srv/DescribeParameters]
/teleop_keyboard/get_parameter_types [rcl_interfaces/srv/GetParameterTypes]
/teleop_keyboard/get_parameters [rcl_interfaces/srv/GetParameters]
/teleop_keyboard/list_parameters [rcl_interfaces/srv/ListParameters]
/teleop_keyboard/set_parameters [rcl_interfaces/srv/SetParameters]
/teleop_keyboard/set_parameters_atomically [rcl_interfaces/srv/SetParametersAtomically]
/turtlebot3_diff_drive/describe_parameters [rcl_interfaces/srv/DescribeParameters]
/turtlebot3_diff_drive/get_parameter_types [rcl_interfaces/srv/GetParameterTypes]
/turtlebot3_diff_drive/get_parameters [rcl_interfaces/srv/GetParameters]
/turtlebot3_diff_drive/list_parameters [rcl_interfaces/srv/ListParameters]
/turtlebot3_diff_drive/set_parameters [rcl_interfaces/srv/SetParameters]
/turtlebot3_diff_drive/set_parameters_atomically [rcl_interfaces/srv/SetParametersAtomically]
/turtlebot3_imu/describe_parameters [rcl_interfaces/srv/DescribeParameters]
/turtlebot3_imu/get_parameter_types [rcl_interfaces/srv/GetParameterTypes]
/turtlebot3_imu/get_parameters [rcl_interfaces/srv/GetParameters]
/turtlebot3_imu/list_parameters [rcl_interfaces/srv/ListParameters]
/turtlebot3_imu/set_parameters [rcl_interfaces/srv/SetParameters]
/turtlebot3_imu/set_parameters_atomically [rcl_interfaces/srv/SetParametersAtomically]
/turtlebot3_joint_state/describe_parameters [rcl_interfaces/srv/DescribeParameters]
/turtlebot3_joint_state/get_parameter_types [rcl_interfaces/srv/GetParameterTypes]
/turtlebot3_joint_state/get_parameters [rcl_interfaces/srv/GetParameters]
/turtlebot3_joint_state/list_parameters [rcl_interfaces/srv/ListParameters]
/turtlebot3_joint_state/set_parameters [rcl_interfaces/srv/SetParameters]
/turtlebot3_joint_state/set_parameters_atomically [rcl_interfaces/srv/SetParametersAtomically]
/turtlebot3_laserscan/describe_parameters [rcl_interfaces/srv/DescribeParameters]
/turtlebot3_laserscan/get_parameter_types [rcl_interfaces/srv/GetParameterTypes]
/turtlebot3_laserscan/get_parameters [rcl_interfaces/srv/GetParameters]
/turtlebot3_laserscan/list_parameters [rcl_interfaces/srv/ListParameters]
/turtlebot3_laserscan/set_parameters [rcl_interfaces/srv/SetParameters]
/turtlebot3_laserscan/set_parameters_atomically [rcl_interfaces/srv/SetParametersAtomically]
/unpause_physics [std_srvs/srv/Empty]