ROS service 프로그래밍

아래의 블로그를 보고 ROS를 복기하고 있다.

 

catkin_create_pkg ros_tutorials_service roscpp std_msgs message_generation

 

package.xml파일 수정

<?xml version="1.0"?>
<package format="2">
  <name>ros_tutorials_service</name>
  <version>0.0.1</version>
  <description>request/response service</description>
  <license>Apache License 2.0</license>
  <maintainer email="root@to.do">someone</maintainer>

  <buildtool_depend>catkin</buildtool_depend>
  <build_depend>message_generation</build_depend>
  <build_depend>roscpp</build_depend>
  <build_depend>std_msgs</build_depend>

  <build_export_depend>roscpp</build_export_depend>
  <build_export_depend>std_msgs</build_export_depend>

  <exec_depend>roscpp</exec_depend>
  <exec_depend>std_msgs</exec_depend>
  <exec_depend>message_runtime</exec_depend>

  <export></export>
</package>

CMakeLists.txt 수정

cmake_minimum_required(VERSION 3.0.2)
project(ros_tutorials_service)

find_package(catkin REQUIRED COMPONENTS
  message_generation
  std_msgs
  roscpp
)

add_service_files(FILES SrvTutorial.srv)
generate_messages(DEPENDENCIES std_msgs)
catkin_package(
  LIBRARIES ros_tutorials_service
  CATKIN_DEPENDS std_msgs roscpp
)

include_directories(${catkin_INCLUDE_DIRS})

add_executable(srv_server src/server.cpp)
add_dependencies(srv_server ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})
target_link_libraries(srv_server ${catkin_LIBRARIES})

add_executable(srv_client src/client.cpp)
add_dependencies(srv_client ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})
target_link_libraries(srv_client ${catkin_LIBRARIES})

서비스 파일 작성

roscd ros_tutorials_service
mkdir srv
gedit srv/SrvTutorial.srv

int64 a
int64 b
---
int64 result

src/server.cpp 작성

#include "ros/ros.h"
#include "ros_tutorials_service/SrvTutorial.h"

// 서비스 요청이 있을 경우, 아래의 처리를 수행
// 요청 = req / 응답 = res
bool add(ros_tutorials_service::SrvTutorial::Request &req, ros_tutorials_service::SrvTutorial::Response &res) {
  // add and save result
  res.result = req.a + req.b;
  // print info
  ROS_INFO("request: %ld + %ld", (long int)req.a, (long int)req.b);
  ROS_INFO("response: %ld", (long int)res.result);
  return true;
}

int main(int argc, char** argv) {
  ros::init(argc, argv, "service_server");
  ros::NodeHandle nh;
  // service name = ros_tutorial_srv
  // callback = add
  ros::ServiceServer ros_tutorials_service_server = nh.advertiseService("ros_tutorial_srv", add);
  ROS_INFO("ready srv server");
  // 요청이 들어오면 add 호출
  // 아니면 대기합니다.
  ros::spin();
  return 0;
}

src/client.cpp 코드 작성

#include <cstdlib>
#include "ros/ros.h"
#include "ros_tutorials_service/SrvTutorial.h"

int main(int argc, char** argv) {
  ros::init(argc, argv, "service_client");
  if (argc != 3) {
    ROS_INFO("cmd: rosrun ros_tutorials_service service_client arg0 arg1");
    ROS_INFO("arg0: double number, arg1: double number");
    return 1;
  }

  ros::NodeHandle nh;
  ros::ServiceClient client = nh.serviceClient<ros_tutorials_service::SrvTutorial>("ros_tutorial_srv");

  ros_tutorials_service::SrvTutorial srv;
  srv.request.a = atoll(argv[1]);
  srv.request.b = atoll(argv[2]);

  if (client.call(srv)) {
    ROS_INFO("send srv: %d + %d", (long int)srv.request.a, (long int)srv.request.b);
    ROS_INFO("receive srv: %d", (long int)srv.response.result);
  } else {
    ROS_ERROR("Failed to call service ros_tutorial_srv");
    return 1;
  }
  return 0;
}

빌드 및 실행

roscore
rosrun ros_tutorials_service srv_server
rosrun ros_tutorials_service srv_client 1 2

 

작동 이상무.

 

빌드가 안 되는 상황이 발생했었는데 build와 devel파일을 삭제하고 다시 빌드하니 문제가 해결되었다.

 

 

 

https://roomedia.tistory.com/entry/8%EC%9D%BC%EC%B0%A8-ROS-Service-%ED%94%84%EB%A1%9C%EA%B7%B8%EB%9E%98%EB%B0%8D?category=877499

8일차 - ROS Service 프로그래밍