修改nav2导航速度发布名称

目录

• [tf graph](#tf graph)
• 当前速度发布架构
• • [1. 节点关系与数据流](#1. 节点关系与数据流)
  • [2. 速度话题映射](#2. 速度话题映射)
  • [3. 关键配置修改](#3. 关键配置修改)
• 速度处理流程详解
• • 阶段1：速度生成
  • 阶段2：速度平滑
  • 阶段3：最终输出
• 并发速度处理机制
• • [1. 话题竞争机制](#1. 话题竞争机制)
  • [2. 行为状态切换](#2. 行为状态切换)
• 关键代码（navigation_launch.py）
• 直接编译调用示例

tf graph

当前速度发布架构

1. 节点关系与数据流

controller_server  →  velocity_smoother  →  机器人底盘
behavior_server    ↗

2. 速度话题映射

节点	输入话题	输出话题	说明
controller_server​	-	cmd_vel_nav	路径跟踪控制，发布导航速度
behavior_server​	-	cmd_vel_nav	行为动作（旋转、后退等），发布行为速度
velocity_smoother​​	cmd_vel_nav	/remote_cmd_vel	速度平滑处理，输出最终速度

3. 关键配置修改

在启动文件中的修改：

• behavior_server 节点添加了重映射：[('cmd_vel', 'cmd_vel_nav')]
• controller_server 节点已有重映射：[('cmd_vel', 'cmd_vel_nav')]

velocity_smoother​ 节点配置：

• 输入：cmd_vel_nav（来自controller和behavior）
• 输出：/remote_cmd_vel（平滑后速度）

速度处理流程详解

阶段1：速度生成

• controller_server：根据全局路径和局部代价地图，计算路径跟踪速度
• behavior_server：执行特定行为（如旋转、后退、等待等）生成行为速度

两者都发布到同一话题：cmd_vel_nav

阶段2：速度平滑

velocity_smoother​ 订阅 cmd_vel_nav话题

对接收到的速度命令进行平滑滤波：

• 加速度限制
• 减速度限制
• 急停处理
• 速度曲线平滑

阶段3：最终输出

平滑后的速度发布到 /remote_cmd_vel

机器人底盘驱动订阅此话题执行运动

并发速度处理机制

1. 话题竞争机制

controller_server和 behavior_server都向 cmd_vel_nav发布速度

最后一个发布的消息会覆盖之前的消息，这是ROS2话题的标准行为

2. 行为状态切换

正常导航：controller_server持续发布速度

行为执行：behavior_server临时接管速度发布

平滑过渡：velocity_smoother确保切换时的速度连续性

关键代码（navigation_launch.py）

位于Navigation2官方源码 nav2_bringup 文件夹下的launch文件夹

# Copyright (c) 2018 Intel Corporation
#
# 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.

import os

from ament_index_python.packages import get_package_share_directory

from launch import LaunchDescription
from launch.actions import DeclareLaunchArgument, GroupAction, SetEnvironmentVariable
from launch.conditions import IfCondition
from launch.substitutions import LaunchConfiguration, PythonExpression
from launch_ros.actions import LoadComposableNodes
from launch_ros.actions import Node
from launch_ros.descriptions import ComposableNode, ParameterFile
from nav2_common.launch import RewrittenYaml


def generate_launch_description():
    # Get the launch directory
    bringup_dir = get_package_share_directory('nav2_bringup_xu')

    namespace = LaunchConfiguration('namespace')
    use_sim_time = LaunchConfiguration('use_sim_time')
    autostart = LaunchConfiguration('autostart')
    params_file = LaunchConfiguration('params_file')
    use_composition = LaunchConfiguration('use_composition')
    container_name = LaunchConfiguration('container_name')
    container_name_full = (namespace, '/', container_name)
    use_respawn = LaunchConfiguration('use_respawn')
    log_level = LaunchConfiguration('log_level')

    lifecycle_nodes = ['controller_server',
                       'smoother_server',
                       'planner_server',
                       'behavior_server',
                       'bt_navigator',
                       'waypoint_follower',
                       'velocity_smoother']

    # Map fully qualified names to relative ones so the node's namespace can be prepended.
    # In case of the transforms (tf), currently, there doesn't seem to be a better alternative
    # https://github.com/ros/geometry2/issues/32
    # https://github.com/ros/robot_state_publisher/pull/30
    # TODO(orduno) Substitute with `PushNodeRemapping`
    #              https://github.com/ros2/launch_ros/issues/56
    remappings = [('/tf', 'tf'),
                  ('/tf_static', 'tf_static')]

    # Create our own temporary YAML files that include substitutions
    param_substitutions = {
        'use_sim_time': use_sim_time,
        'autostart': autostart}

    configured_params = ParameterFile(
        RewrittenYaml(
            source_file=params_file,
            root_key=namespace,
            param_rewrites=param_substitutions,
            convert_types=True),
        allow_substs=True)

    stdout_linebuf_envvar = SetEnvironmentVariable(
        'RCUTILS_LOGGING_BUFFERED_STREAM', '1')

    declare_namespace_cmd = DeclareLaunchArgument(
        'namespace',
        default_value='',
        description='Top-level namespace')

    declare_use_sim_time_cmd = DeclareLaunchArgument(
        'use_sim_time',
        default_value='false',
        description='Use simulation (Gazebo) clock if true')

    declare_params_file_cmd = DeclareLaunchArgument(
        'params_file',
        default_value=os.path.join(bringup_dir, 'params', 'nav2_params.yaml'),
        description='Full path to the ROS2 parameters file to use for all launched nodes')

    declare_autostart_cmd = DeclareLaunchArgument(
        'autostart', default_value='true',
        description='Automatically startup the nav2 stack')

    declare_use_composition_cmd = DeclareLaunchArgument(
        'use_composition', default_value='False',
        description='Use composed bringup if True')

    declare_container_name_cmd = DeclareLaunchArgument(
        'container_name', default_value='nav2_container',
        description='the name of conatiner that nodes will load in if use composition')

    declare_use_respawn_cmd = DeclareLaunchArgument(
        'use_respawn', default_value='False',
        description='Whether to respawn if a node crashes. Applied when composition is disabled.')

    declare_log_level_cmd = DeclareLaunchArgument(
        'log_level', default_value='info',
        description='log level')

    load_nodes = GroupAction(
        condition=IfCondition(PythonExpression(['not ', use_composition])),
        actions=[
            Node(
                package='nav2_controller',
                executable='controller_server',
                output='screen',
                respawn=use_respawn,
                respawn_delay=2.0,
                parameters=[configured_params],
                arguments=['--ros-args', '--log-level', log_level],
                remappings=remappings + [('cmd_vel', 'cmd_vel_nav')]),
            Node(
                package='nav2_smoother',
                executable='smoother_server',
                name='smoother_server',
                output='screen',
                respawn=use_respawn,
                respawn_delay=2.0,
                parameters=[configured_params],
                arguments=['--ros-args', '--log-level', log_level],
                remappings=remappings),
            Node(
                package='nav2_planner',
                executable='planner_server',
                name='planner_server',
                output='screen',
                respawn=use_respawn,
                respawn_delay=2.0,
                parameters=[configured_params],
                arguments=['--ros-args', '--log-level', log_level],
                remappings=remappings),
            Node(
                package='nav2_behaviors',
                executable='behavior_server',
                name='behavior_server',
                output='screen',
                respawn=use_respawn,
                respawn_delay=2.0,
                parameters=[configured_params],
                arguments=['--ros-args', '--log-level', log_level],
                remappings=remappings + [('cmd_vel', 'cmd_vel_nav')]),  # 添加这行
            Node(
                package='nav2_bt_navigator',
                executable='bt_navigator',
                name='bt_navigator',
                output='screen',
                respawn=use_respawn,
                respawn_delay=2.0,
                parameters=[configured_params],
                arguments=['--ros-args', '--log-level', log_level],
                remappings=remappings),
            Node(
                package='nav2_waypoint_follower',
                executable='waypoint_follower',
                name='waypoint_follower',
                output='screen',
                respawn=use_respawn,
                respawn_delay=2.0,
                parameters=[configured_params],
                arguments=['--ros-args', '--log-level', log_level],
                remappings=remappings),
            Node(
                package='nav2_velocity_smoother',
                executable='velocity_smoother',
                name='velocity_smoother',
                output='screen',
                respawn=use_respawn,
                respawn_delay=2.0,
                parameters=[configured_params],
                arguments=['--ros-args', '--log-level', log_level],
                remappings=remappings +
                        [('cmd_vel', 'cmd_vel_nav'), ('cmd_vel_smoothed', '/remote_cmd_vel')]),
            Node(
                package='nav2_lifecycle_manager',
                executable='lifecycle_manager',
                name='lifecycle_manager_navigation',
                output='screen',
                arguments=['--ros-args', '--log-level', log_level],
                parameters=[{'use_sim_time': use_sim_time},
                            {'autostart': autostart},
                            {'node_names': lifecycle_nodes}]),
        ]
    )

    load_composable_nodes = LoadComposableNodes(
        condition=IfCondition(use_composition),
        target_container=container_name_full,
        composable_node_descriptions=[
            ComposableNode(
                package='nav2_controller',
                plugin='nav2_controller::ControllerServer',
                name='controller_server',
                parameters=[configured_params],
                remappings=remappings + [('cmd_vel', 'cmd_vel_nav')]),
            ComposableNode(
                package='nav2_smoother',
                plugin='nav2_smoother::SmootherServer',
                name='smoother_server',
                parameters=[configured_params],
                remappings=remappings),
            ComposableNode(
                package='nav2_planner',
                plugin='nav2_planner::PlannerServer',
                name='planner_server',
                parameters=[configured_params],
                remappings=remappings),
            ComposableNode(
                package='nav2_behaviors',
                plugin='behavior_server::BehaviorServer',
                name='behavior_server',
                parameters=[configured_params],
                remappings=remappings + [('cmd_vel', 'cmd_vel_nav')]),  # 添加这行
            ComposableNode(
                package='nav2_bt_navigator',
                plugin='nav2_bt_navigator::BtNavigator',
                name='bt_navigator',
                parameters=[configured_params],
                remappings=remappings),
            ComposableNode(
                package='nav2_waypoint_follower',
                plugin='nav2_waypoint_follower::WaypointFollower',
                name='waypoint_follower',
                parameters=[configured_params],
                remappings=remappings),
            ComposableNode(
                package='nav2_velocity_smoother',
                plugin='nav2_velocity_smoother::VelocitySmoother',
                name='velocity_smoother',
                parameters=[configured_params],
                remappings=remappings +
                           [('cmd_vel', 'cmd_vel_nav'), ('cmd_vel_smoothed', '/remote_cmd_vel')]),
            ComposableNode(
                package='nav2_lifecycle_manager',
                plugin='nav2_lifecycle_manager::LifecycleManager',
                name='lifecycle_manager_navigation',
                parameters=[{'use_sim_time': use_sim_time,
                             'autostart': autostart,
                             'node_names': lifecycle_nodes}]),
        ],
    )

    # Create the launch description and populate
    ld = LaunchDescription()

    # Set environment variables
    ld.add_action(stdout_linebuf_envvar)

    # Declare the launch options
    ld.add_action(declare_namespace_cmd)
    ld.add_action(declare_use_sim_time_cmd)
    ld.add_action(declare_params_file_cmd)
    ld.add_action(declare_autostart_cmd)
    ld.add_action(declare_use_composition_cmd)
    ld.add_action(declare_container_name_cmd)
    ld.add_action(declare_use_respawn_cmd)
    ld.add_action(declare_log_level_cmd)
    # Add the actions to launch all of the navigation nodes
    ld.add_action(load_nodes)
    ld.add_action(load_composable_nodes)

    return ld

直接编译调用示例

可以下载文件直接编译 nav2_bringup_xu

nav2_bringup_dir = get_package_share_directory('nav2_bringup_xu')
rviz_config_dir = os.path.join( nav2_bringup_dir, 'rviz', 'nav2_default_view.rviz')
patrol_config_path = os.path.join( autopatrol_robot_dir, 'config', 'patrol_config.yaml')
# 创建 Launch 配置
use_sim_time = launch.substitutions.LaunchConfiguration('use_sim_time', default='false')

nav2_bringup_node = IncludeLaunchDescription(
        PythonLaunchDescriptionSource(
            [nav2_bringup_dir, '/launch', '/bringup_launch.py']),
        # 使用 Launch 参数替换原有参数
        launch_arguments={
            'map': '',
            'use_sim_time': use_sim_time,
            'params_file': nav2_param_path}.items(),
    )