nodelet的应用

1.创建一个包，如example_pkg

catkin_create_pkg  example_pkg

2.创建MyNodeletClass.h文件

cd ~/catkin_ws/src/example_pkg/
mkdir -p include/example_pkg
touch include/example_pkg/MyNodeletClass.h
vim include/example_pkg/MyNodeletClass.h
其内容为

#include <nodelet/nodelet.h>
namespace example_pkg
{

    class MyNodeletClass : public nodelet::Nodelet
    {
        public:
            virtual void onInit();
    };

}

3.创建MyNodeletClass.cpp文件

cd ~/catkin_ws/src/example_pkg/
mkdir src
touch src/MyNodeletClass.cpp
vim src/MyNodeletClass.cpp
其内容为

// this should really be in the implementation (.cpp file)
#include <ros/ros.h>
#include <pluginlib/class_list_macros.h>
#include <example_pkg/MyNodeletClass.h>


namespace example_pkg
{
    void MyNodeletClass::onInit()
    {
        NODELET_DEBUG("Initializing nodelet...");
        ROS_INFO("Nodelet is Ok for test!!");
    }
}

// watch the capitalization carefully
PLUGINLIB_DECLARE_CLASS(example_pkg, MyNodeletClass, example_pkg::MyNodeletClass, nodelet::Nodelet)
成功则输出"Nodelet is Ok for test!!"

4.创建nodelet_plugins.xml文件

cd ~/catkin_ws/src/example_pkg/
mkdir plugins
touch plugins/nodelet_plugins.xml
vim plugins/nodelet_plugins.xml
其内容为

<library path="lib/libexample_pkg">
  <class name="example_pkg/MyNodeletClass" type="example_pkg::MyNodeletClass" base_class_type="nodelet::Nodelet">
  <description>
  This is my nodelet.
  </description>
  </class>
</library>

5.修改package.xml文件，增加：

cd ~/catkin_ws/src/example_pkg/
vim package.xml
其内容为

 <buildtool_depend>catkin</buildtool_depend>
  <build_depend>nodelet</build_depend>
  <build_depend>roscpp</build_depend>

  <run_depend>nodelet</run_depend>
  <run_depend>roscpp</run_depend>


  <!-- The export tag contains other, unspecified, tags -->
  <export>
    <!-- Other tools can request additional information be placed here -->
    <nodelet plugin="${prefix}/plugins/nodelet_plugins.xml" />
  </export>

6.修改CMakeLists.txt

cd ~/catkin_ws/src/example_pkg
vim  CMakeLists.txt 

其内容为

## Specify additional locations of header files
## Your package locations should be listed before other locations
include_directories(
  include
  ${catkin_INCLUDE_DIRS}
  ${Boost_INCLUDE_DIRS}
)

## Declare a C++ library
add_library(${PROJECT_NAME}  src/MyNodeletClass.cpp)

add_dependencies(${PROJECT_NAME} 
   ${${PROJECT_NAME}_EXPORTED_TARGETS} 
   ${catkin_EXPORTED_TARGETS}
)

target_link_libraries(${PROJECT_NAME}
   ${catkin_LIBRARIES}
)

6.创建mynodelet.launch文件

d ~/catkin_ws/src/example_pkg/
mkdir launch
touch launch/mynodelet.launch
vim  launch/mynodelet.launch
其内容为

<launch>
  <node pkg="nodelet" type="nodelet" name="standalone_nodelet"  args="manager" output="screen"/>

  <node pkg="nodelet" type="nodelet" name="MyNodeletClass" args="load example_pkg/MyNodeletClass standalone_nodelet" output="screen">
  </node>                 
</launch>

6.编译

cd ~/catkin_ws/
catkin_make
rospack profile

7.运行

新终端，运行roscore

$ roscore

新终端，运行launch

$ rosluanch examples_pkg mynodelet.launch


参考：
http://www.ncnynl.com/archives/201702/1326.html
http://blog.csdn.net/zhangrelay/article/details/62048915
http://rosclub.cn/post-164.html
http://blog.csdn.net/yiranhaiziqi/article/details/53308657
http://www.lai18.com/content/2386868.html


例子

http://blog.csdn.net/zyh821351004/article/details/52143309
创建包nodelet_test,依赖项nodelet roscpp std_msgs

CMakeLists.txt

cmake_minimum_required(VERSION 2.8.3)
project(nodelet_test_pkg)
find_package(catkin REQUIRED COMPONENTS nodelet roscpp std_msgs)#
## Setup include directories
include_directories(${catkin_INCLUDE_DIRS})
catkin_package(
)
add_library(nodelet_test plus.cpp)
target_link_libraries(nodelet_test ${catkin_LIBRARIES})

package.xml

<package>
<name>nodelet_test_pkg</name>
<version>0.0.0</version>
<description>Nodelet test.</description>
<maintainer email="huasheng_zyh@163.com">kint zhao</maintainer>
<license>BSD</license>
<buildtool_depend>catkin</buildtool_depend>
<build_depend>nodelet</build_depend>
<build_depend>roscpp</build_depend>
<build_depend>std_msgs</build_depend>
<run_depend>nodelet</run_depend>
<run_depend>roscpp</run_depend>
<run_depend>std_msgs</run_depend>
<export>
<nodelet plugin="${prefix}/nodelet_test_plugin.xml"/>
</export>
</package>

plugin

<library path="lib/libnodelet_test_lib">
<class name="nodelet_ns/Plus" type="nodelet_ns::Plus" base_class_type="nodelet::Nodelet">
<description>
A node to add a value and republish.
</description>
</class>
</library>

launch

<launch>
<node pkg="nodelet" type="nodelet" name="manager_1" args="manager" output="screen"/>
<node pkg="nodelet" type="nodelet" name="test1" args="load nodelet_ns/Plus manager_1" output="screen"/>
<node pkg="nodelet" type="nodelet" name="test2" args="load nodelet_ns/Plus manager_1" output="screen"/>
<node pkg="nodelet" type="nodelet" name="test3" args="load nodelet_ns/Plus manager_1" output="screen"/>
<node pkg="nodelet" type="nodelet" name="manager_2" args="manager" output="screen"/>
<node pkg="nodelet" type="nodelet" name="test4" args="load nodelet_ns/Plus manager_2" output="screen"/>
<node pkg="nodelet" type="nodelet" name="test5" args="load nodelet_ns/Plus manager_2" output="screen"/>
<node pkg="nodelet" type="nodelet" name="test6" args="standalone nodelet_ns/Plus " output="screen"/>
</launch>

.cpp文件

#include <pluginlib/class_list_macros.h>
#include <nodelet/nodelet.h>
#include <ros/ros.h>
#include <std_msgs/Float64.h>
#include <stdio.h>
#include <math.h> //fabs
namespace nodelet_ns
{
class Plus : public nodelet::Nodelet
{
public:
Plus()
: value_(0)
{}
private:
virtual void onInit()
{
ros::NodeHandle& private_nh = getPrivateNodeHandle();
private_nh.getParam("value", value_);
pub = private_nh.advertise<std_msgs::Float64>("out", 10);
sub = private_nh.subscribe("in", 10, &Plus::callback, this);
}
void callback(const std_msgs::Float64::ConstPtr& input)
{
std_msgs::Float64Ptr output(new std_msgs::Float64());
output->data = input->data + value_;
NODELET_DEBUG("Adding %f to get %f", value_, output->data);
pub.publish(output);
}
ros::Publisher pub;
ros::Subscriber sub;
double value_;
};
PLUGINLIB_DECLARE_CLASS(nodelet_ns, Plus, nodelet_ns::Plus, nodelet::Nodelet);//*******
}