ROS节点与OROCOS组件通信--构建组件

完成ROS、orocos_toolchain、rtt_ros_integration三个部分的安装后，开始构建orocos组件。

一、构建catkin编译包

使用ocl脚本构建orocos的catkin编译包：

cd ~/ws/underlay/srcrosrun ocl orocreate-catkin-pkg hello_world

orocos的catkin编译包结构如下：

my_orocos_pkg├── CMakeLists.txt├── package.xml├── include│   └── my_orocos_pkg└── src

此时直接编译不能通过，因为无法通过orocos_typegen_hearders()生成.so文件，因此需要修改CMakelist.txt文件如下：

...

#orocos_typegen_headers(include/hello_world/hello_world-types.hpp) # ...you may add multiple header files

...

完成这个操作后，可以再~/ws/underlay/目录下执行catkin_make编译通过。

二、添加依赖项

1、修改CMakelist.txt文件如下：

...

find_package(OROCOS-RTT QUIET)if (NOT OROCOS-RTT_FOUND)  message (FATAL_ERROR "\nCould not find Orocos. Please use the shell command\n 'source orocos_toolchain/env.sh' and then run cmake again.")endif()<span style="color:#ff6666;">find_package(catkin REQUIRED COMPONENTS  rtt_ros  )</span>

...

orocos_generate_pkg(

<span style="color:#ff6666;">  INCLUDE_DIRS include  DEPENDS rtt_ros  DEPENDS rtt_std_msgs</span>

)

第一步是为catkin编译过程添加依赖组件rtt_ros，以便后续代码中顺利实现桥接功能。

第二步是在生成编译结果时添加依赖项。

2、修改package.xml文件如下：

...

  <build_depend>rtt</build_depend>  <build_depend>orogen</build_depend><span style="color:#ff6666;">  <build_depend>ocl</build_depend>  <build_depend>rtt_ros</build_depend>  <build_depend>rtt_roscomm</build_depend>  <build_depend>rtt_std_msgs</build_depend></span><pre name="code" class="html">...

  <run_depend>rtt</run_depend>
  <run_depend>ocl</run_depend>
  <run_depend>rtt_ros</run_depend>
  <run_depend>rtt_roscomm</run_depend>
  <run_depend>rtt_std_msgs</run_depend>...

三、建立组件

修改hello_world-component.hpp文件如下：

#ifndef OROCOS_HELLO_WORLD_COMPONENT_HPP#define OROCOS_HELLO_WORLD_COMPONENT_HPP

#include <rtt/RTT.hpp>#include <rtt/os/main.h>#include <rtt_roscomm/rtt_rostopic.h>#include <std_msgs/String.h>#include <ros/ros.h>class hello_world : public RTT::TaskContext{  public:    hello_world(std::string const& name);    bool configureHook();    bool startHook();    void updateHook();    void stopHook();    void cleanupHook();  private:    RTT::OutputPort<std_msgs::String> outPort;};#endif

修改hello_world-component.cpp文件如下：

#include "hello_world-component.hpp"#include <rtt/Component.hpp>#include <iostream>hello_world::hello_world(std::string const& name) : TaskContext(name){  //initialize ros before create output stream  if(!ros::isInitialized()){    int argc = __os_main_argc();    char ** argv = __os_main_argv();    ros::init(argc,argv,"rtt",ros::init_options::AnonymousName);    if(ros::master::check())      ros::start();  }  //set the priority and period  this->setActivity( new RTT::Activity(0, 0.001));  //add output port to hello_world component  this->ports()->addPort("out_port", outPort);  outPort.createStream(rtt_roscomm::topic("/chatter"));  std::cout << "hello_world constructed !" <<std::endl;}bool hello_world::configureHook(){  std::cout << "hello_world configured !" <<std::endl;  return true;}bool hello_world::startHook(){  std::cout << "Hello_world started !" <<std::endl;  return true;}void hello_world::updateHook(){  //say hello world to ros node every period.  std_msgs::String val;  val.data = "hello World, orocos.";  outPort.write( val );  std::cout << "hello_world executes updateHook !" <<std::endl;}void hello_world::stopHook() {  std::cout << "hello_world executes stopping !" <<std::endl;}void hello_world::cleanupHook() {  std::cout << "hello_world cleaning up !" <<std::endl;}/* * Using this macro, only one component may live * in one library *and* you may *not* link this library * with another component library. Use * ORO_CREATE_COMPONENT_TYPE() * ORO_LIST_COMPONENT_TYPE(Hello_world) * In case you want to link with another library that * already contains components. * * If you have put your component class * in a namespace, don't forget to add it here too: */ORO_CREATE_COMPONENT(hello_world)

在hello_world/src/文件夹下添加orocos组件加载脚本文件hello_world.ops，内容如下：

require("print")import("rtt_std_msgs")import("hello_world")print.ln("Script imported hello_world package:")displayComponentTypes()loadComponent("hello_world_task", "hello_world")print.ln("Script created Hello Component with period: " + hello_world_task.getPeriod() )

至此组件构建完毕。