ros第二天

3.6.6自定义话题消息

1.自定义的话题消息放在功能包文件下~/.catkin_ws/src/my_package/msg 创建Person.msg文件内容如下

string name

uint8  sex

uint8  age

uint8 unknown = 0

uint8 male    = 1

uint8 female  = 2

1. 在package.xm添加功能包依赖

<build_depend>message_generation</build_depend>

<exec_depend>message_runtime</exec_depend>

在CMakeLists.txt中添加编译选项

find_package(catkin REQUIRED COMPONENTS

geometry_msgs

roscpp

rospy

std_msgs  

message_generation)

catkin_package(CATKIN_DEPENDS roscpp rospy std_msgs roscpp rospy std_msgs message_runtime )

add_message_files(

 FILES

 person.msg )

generate_messages( DEPENDENCIES    std_msgs  )

在功能包目录下编译：~/catkin_ws$  catkin_make

出错：

Assertion failed: file '/home/zzy/catkin_ws/src/my_package/msg/person.msg' does not exist.  Message: message file not found

原因是文件名person.msg的大小写不一致

查看自定义person.msg消息类型： rosmsg show person

3.7服务器中的Sever应答和Client请求

创建服务器、创建客户机、添加编译、运行可执行文件

1.自定义的服务放在功能包文件下~/.catkin_ws/src/my_package/srv 创建AddTwoInts.srv文件内容如下

int64 a

int64 b

---

int64 sum

##---的上面是请求数据，下面服务应答数据

在package.xml添加功能包依赖

<build_depend>message_generation</build_depend>

<exec_depend>message_runtime</exec_depend>

在CMakeLists.txt中添加编译选项

find_package(catkin REQUIRED COMPONENTS roscpp  rospy  std_msgs  message_generation)

add_service_files(FILES AddTwoInts.srv)

catkin_package(CATKIN_DEPENDS roscpp rospy std_msgs roscpp rospy std_msgs message_runtime )

generate_messages( DEPENDENCIES    std_msgs  )

在功能包目录下编译：~/catkin_ws$  catkin_make//一定要先运行这个

1. 在~/.catkin_ws/src/my_package/src 创建client.cpp 和 server.cpp

/*AddTwoInts Server */

#include "ros/ros.h"

#include "my_package/AddTwoInts.h"

// service回调函数，输入参数req，输出参数res,回调函数是真正实现服务功能的部分

bool add(my_package::AddTwoInts::Request  &req,

         my_package::AddTwoInts::Response &res)

{

    // 将输入参数中的请求数据相加，结果放到应答变量中

    res.sum = req.a + req.b;

    ROS_INFO("request: x=%ld, y=%ld", (long int)req.a, (long int)req.b);

    ROS_INFO("sending back response: [%ld]", (long int)res.sum);

    return true;

}

int main(int argc, char **argv)

{

    // ROS节点初始化

    ros::init(argc, argv, "add_two_ints_server");

    // 创建节点句柄

    ros::NodeHandle n;

    // 创建一个名为add_two_ints的server，注册回调函数add()

    ros::ServiceServer service = n.advertiseService("add_two_ints", add);

    // 循环等待回调函数

    ROS_INFO("Ready to add two ints.");

    ros::spin();

    return 0;

}

 

/* AddTwoInts Client */

#include <cstdlib>

#include "ros/ros.h"

#include "my_package/AddTwoInts.h"

int main(int argc, char **argv)

{

    // ROS节点初始化

    ros::init(argc, argv, "add_two_ints_client");

    // 从终端命令行获取两个加数

    if (argc != 3)

    {

        ROS_INFO("usage: add_two_ints_client X Y");

        return 1;

    }

    // 创建节点句柄

    ros::NodeHandle n;

    // 创建一个client，请求add_two_int service

    // service消息类型是my_package::AddTwoInts

    ros::ServiceClient client = n.serviceClient<my_package::AddTwoInts>("add_two_ints");

    // 创建my_package::AddTwoInts类型的service消息

    my_package::AddTwoInts srv;

    srv.request.a = atoll(argv[1]);

    srv.request.b = atoll(argv[2]);

    // 发布service请求，等待加法运算的应答结果

    if (client.call(srv))

    {

        ROS_INFO("Sum: %ld", (long int)srv.response.sum);

    }

    else

    {

        ROS_ERROR("Failed to call service add_two_ints");

        return 1;

    }

    return 0;

}

编辑CMakeList.txt文件，本文中为：~/catkin_ws/src/my_package/目录中，配置如下

add_executable(server src/server.cpp)

target_link_libraries(server ${catkin_LIBRARIES})

add_dependencies(server ${PROJECT_NAME}_gen_cpp)

add_executable(client src/listener.cpp)

target_link_libraries(client ${catkin_LIBRARIES})

add_dependencies(client ${PROJECT_NAME}_gen_cpp)

catkin_make出错fatal error: my_package/AddTwoInts.h: 没有那个文件或目录待解决

修改如下：编辑CMakeList.txt文件

cmake_minimum_required(VERSION 2.8.3)

project(my_package)

find_package(catkin REQUIRED COMPONENTS

  roscpp

  rospy

  std_msgs

  message_generation

)

add_message_files(

    FILES

    Person.msg

)

add_service_files(

   FILES

   AddTwoInts.srv

 )

generate_messages(

    DEPENDENCIES

    std_msgs

    #message_generation

 )

catkin_package(

  INCLUDE_DIRS include

  LIBRARIES my_package

  CATKIN_DEPENDS roscpp rospy std_msgs message_runtime

  DEPENDS system_lib

)

include_directories(

  include

  ${catkin_INCLUDE_DIRS}

)

add_executable(talker src/talker.cpp)

target_link_libraries(talker ${catkin_LIBRARIES})

add_executable(listener src/listener.cpp)

target_link_libraries(listener ${catkin_LIBRARIES})

 

add_executable(server src/server.cpp)

target_link_libraries(server ${catkin_LIBRARIES})

add_dependencies(server ${PROJECT_NAME}_gencpp)

add_executable(client src/client.cpp)

target_link_libraries(client ${catkin_LIBRARIES})

add_dependencies(client ${PROJECT_NAME}_gencpp)

 

编译成功  打开新的中断输入roscore 保证ROS Master已经启动

打开新的终端输入rosrun my_package server//运行server

打开新的终端输入rosrun my_package client 3 5 //运行server