ROS服务数据该怎样去使用呢

自定义服务数据
定义srv文件
cd ~/catkin_workspace/src/learning_service
mkdir srv
nano ~/catkin_workspace/src/learning_service/srv/Person.srv
string name
uint8  age
uint8  sex
uint8 unknown = 0
uint8 male    = 1
uint8 female  = 2
---
string result
在package.xml中添加功能包依赖
nano ~/catkin_workspace/src/learning_service/package.xml
message_generation
message_runtime


在CMakeLists.txt添加编译选项
...
find_package(... message_generation)
...
add_service_files(FILES Person.srv)
generate_messages(DEPENDENCIES std_msgs)
...
catkin_package(... message_runtime)
...
nano ~/catkin_workspace/src/learning_service/CMakeLists.txt





编译生成语言相关文件

cd ~/catkin_workspacecatkin_make

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• 2
  

结果
cd ~/catkin_workspace/devel/include/learning_servicels

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可见已生成如下文件：


使用
C++
编写程序
person_server.cpp
nano ~/catkin_workspace/src/learning_service/src/person_server.cpp
/***********************************************************************
Copyright 2020 GuYueHome (www.guyuehome.com).
***********************************************************************/
/**
* 该例程将执行/show_person服务，服务数据类型learning_service::Person
*/
#include
#include "learning_service/Person.h"
// service回调函数，输入参数req，输出参数res
bool personCallback(learning_service::Person::Request  &req,
          learning_service::Person::Response &res)
{
    // 显示请求数据
    ROS_INFO("Person: name:%s  age:%d  sex:%d", req.name.c_str(), req.age, req.sex);
// 设置反馈数据
res.result = "OK";
    return true;
}
int main(int argc, char **argv)
{
    // ROS节点初始化
    ros::init(argc, argv, "person_server");
    // 创建节点句柄
    ros::NodeHandle n;
    // 创建一个名为/show_person的server，注册回调函数personCallback
    ros::ServiceServer person_service = n.advertiseService("/show_person", personCallback);
    // 循环等待回调函数
    ROS_INFO("Ready to show person informtion.");
    ros::spin();
    return 0;
}
person_client.cpp
nano ~/catkin_workspace/src/learning_service/src/person_client.cpp
/***********************************************************************
Copyright 2020 GuYueHome (www.guyuehome.com).
***********************************************************************/
/**
* 该例程将请求/show_person服务，服务数据类型learning_service::Person
*/
#include
#include "learning_service/Person.h"
int main(int argc, char** argv)
{
    // 初始化ROS节点
ros::init(argc, argv, "person_client");
    // 创建节点句柄
ros::NodeHandle node;
    // 发现/show_person服务后，创建一个服务客户端，连接名为/show_person的service
ros::service::waitForService("/show_person");
ros::ServiceClient person_client = node.serviceClient("/show_person");
    // 初始化learning_service::Person的请求数据
learning_service::Person srv;
srv.request.name = "Tom";
srv.request.age  = 20;
srv.request.sex  = learning_service::Person::Request::male;
    // 请求服务调用
ROS_INFO("Call service to show person[name:%s, age:%d, sex:%d]",
srv.request.name.c_str(), srv.request.age, srv.request.sex);
person_client.call(srv);
// 显示服务调用结果
ROS_INFO("Show person result : %s", srv.response.result.c_str());
return 0;
}
配置CMakeLists.txt
nano ~/catkin_workspace/src/learning_service/CMakeLists.txt
添加
add_executable(person_server src/person_server.cpp)
target_link_libraries(person_server ${catkin_LIBRARIES})
add_dependencies(person_server ${PROJECT_NAME}_gencpp)
add_executable(person_client src/person_client.cpp)
target_link_libraries(person_client ${catkin_LIBRARIES})
add_dependencies(person_client ${PROJECT_NAME}_gencpp)
设置需要编译的代码和生成的可执行文件；
设置链接库；
添加依赖项。



编译并运行
cd ~/catkin_workspace
catkin_make
# 新建一个终端
source ~/catkin_workspace/devel/setup.bash
roscore
# 新建一个终端
source ~/catkin_workspace/devel/setup.bash
rosrun learning_service person_server
# 新建一个终端
source ~/catkin_workspace/devel/setup.bash
rosrun learning_service person_client


python
编写程序
person_server.py
nano ~/catkin_workspace/src/learning_service/scripts/person_server.py
person_client.py
nano ~/catkin_workspace/src/learning_service/scripts/person_client.py
#!/usr/bin/env python
# -*- coding: utf-8 -*-
########################################################################
####          Copyright 2020 GuYueHome (www.guyuehome.com).          ###
########################################################################
# 该例程将请求/show_person服务，服务数据类型learning_service::Person
import sys
import rospy
from learning_service.srv import Person, PersonRequest
def person_client():
# ROS节点初始化
    rospy.init_node('person_client')
# 发现/spawn服务后，创建一个服务客户端，连接名为/spawn的service
    rospy.wait_for_service('/show_person')
    try:
        person_client = rospy.ServiceProxy('/show_person', Person)
# 请求服务调用，输入请求数据
        response = person_client("Tom", 20, PersonRequest.male)
        return response.result
    except rospy.ServiceException, e:
        print "Service call failed: %s"%e
if __name__ == "__main__":
#服务调用并显示调用结果
    print "Show person result : %s" %(person_client())
运行
sudo chmod +x ~/catkin_workspace/src/learning_service/scripts/person_server.py
sudo chmod +x ~/catkin_workspace/src/learning_service/scripts/person_client.py
# 新建一个终端
source ~/catkin_workspace/devel/setup.bash
roscore
# 新建一个终端
source ~/catkin_workspace/devel/setup.bash
rosrun learning_service person_server.py
# 新建一个终端
source ~/catkin_workspace/devel/setup.bash
rosrun learning_service person_client.py