在 ROS 中，节点的启动通常有两种方式：

1. 直接通过 rosrun 启动单个节点
2. 通过 roslaunch 启动多个节点及其参数

下面以一个完整的示例，展示如何在 ROS 包内启动节点，包括 rosrun 和 roslaunch 的使用方法。

---

示例背景

假设我们有一个工作包名为 my_cpp_package，其中包含两个节点：

• talker.cpp（发布者）
• listener.cpp（订阅者）

参考前面创建的 ROS 包模板,ROS1/ROS2中工作空间和工作包创建详解

---

方法 1：使用 rosrun 启动单个节点

# 启动 roscore（必须的）
roscore

新终端：启动 talker

rosrun my_cpp_package talker

再开一个终端：启动 listener

rosrun my_cpp_package listener

---

方法 2：使用 roslaunch 启动节点（推荐方式）

创建 launch 目录并添加启动文件

cd ~/catkin_ws/src/my_cpp_package
mkdir launch
touch launch/start_nodes.launch

start_nodes.launch 内容如下：

<launch>
  <!-- 启动发布者 -->
  <node pkg="my_cpp_package" type="talker" name="talker_node" output="screen" />

  <!-- 启动订阅者 -->
  <node pkg="my_cpp_package" type="listener" name="listener_node" output="screen" />
</launch>

启动方法

cd ~/catkin_ws
catkin_make
source devel/setup.bash

roslaunch my_cpp_package start_nodes.launch

你会看到两个节点都启动了，输出类似：

[INFO] [talker_node]: hello world 1
[INFO] [listener_node]: I heard: [hello world 1]

---

注意事项

项目	说明
<node pkg=...>	指定节点所在的包名
type="xxx"	可执行文件名称，位于 devel/lib/your_package/xxx
name="xxx"	ROS 中节点的名称，可用于参数命名空间等
output="screen"	输出日志到终端，便于调试

---

完整示例

下面是一个完整的 C++ ROS 工作包模板，包含以下内容：

---

功能概览

• 包名：my_cpp_package

• 节点：

  • talker: 发布字符串消息并读取参数
  • listener: 订阅字符串消息

• 启动文件：

  • start_nodes.launch：同时启动两个节点并传参

---

项目结构

my_cpp_package/
├── CMakeLists.txt
├── package.xml
├── launch/
│   └── start_nodes.launch
├── src/
│   ├── talker.cpp
│   └── listener.cpp

---

CMakeLists.txt

cmake_minimum_required(VERSION 3.0.2)
project(my_cpp_package)

find_package(catkin REQUIRED COMPONENTS
  roscpp
  std_msgs
)

catkin_package()

include_directories(
  ${catkin_INCLUDE_DIRS}
)

add_executable(talker src/talker.cpp)
add_executable(listener src/listener.cpp)

target_link_libraries(talker ${catkin_LIBRARIES})
target_link_libraries(listener ${catkin_LIBRARIES})

---

package.xml

<?xml version="1.0"?>
<package format="2">
  <name>my_cpp_package</name>
  <version>0.0.1</version>
  <description>A simple ROS C++ demo package</description>
  <maintainer email="your_email@example.com">Your Name</maintainer>
  <license>MIT</license>

  <buildtool_depend>catkin</buildtool_depend>
  <depend>roscpp</depend>
  <depend>std_msgs</depend>

</package>

---

src/talker.cpp

#include "ros/ros.h"
#include "std_msgs/String.h"

int main(int argc, char **argv)
{
  ros::init(argc, argv, "talker_node");
  ros::NodeHandle nh("~");  // 私有命名空间

  ros::Publisher pub = nh.advertise<std_msgs::String>("/chatter", 10);
  ros::Rate rate(1);

  std::string base_msg;
  nh.param<std::string>("message", base_msg, "Hello from talker!");

  int count = 0;
  while (ros::ok())
  {
    std_msgs::String msg;
    msg.data = base_msg + " [" + std::to_string(count++) + "]";
    ROS_INFO_STREAM("[talker] Publishing: " << msg.data);
    pub.publish(msg);
    rate.sleep();
  }

  return 0;
}

---

src/listener.cpp

#include "ros/ros.h"
#include "std_msgs/String.h"

void callback(const std_msgs::String::ConstPtr& msg)
{
  ROS_INFO_STREAM("[listener] Heard: " << msg->data);
}

int main(int argc, char **argv)
{
  ros::init(argc, argv, "listener_node");
  ros::NodeHandle nh;

  ros::Subscriber sub = nh.subscribe("/chatter", 10, callback);
  ros::spin();

  return 0;
}

---

launch/start_nodes.launch

<launch>
  <!-- 启动 talker -->
  <node pkg="my_cpp_package" type="talker" name="talker_node" output="screen">
    <param name="message" value="Custom Hello ROS!" />
  </node>

  <!-- 启动 listener -->
  <node pkg="my_cpp_package" type="listener" name="listener_node" output="screen" />
</launch>

---

构建与运行步骤

cd ~/catkin_ws/src
git clone <your_repo> my_cpp_package
cd ~/catkin_ws
catkin_make
source devel/setup.bash

roslaunch my_cpp_package start_nodes.launch

---

输出示例

[talker] Publishing: Custom Hello ROS! [0]
[listener] Heard: Custom Hello ROS! [0]
...