临海城市建设网站,网站建设有那些内容,有没有做推文的网站,嘚嘚笔记 wordpress主推1 action介绍
ROS通信机制也会被常常用到——那就是动作。从这个名字上就可以很好理解这个概念的含义#xff0c;这种通信机制的目的就是便于对机器人某一完整行为的流程进行管理。
1.1 客户端/服务器模型
动作和服务类似#xff0c;使用的也是客户端和服务器模型#xf…1 action介绍
ROS通信机制也会被常常用到——那就是动作。从这个名字上就可以很好理解这个概念的含义这种通信机制的目的就是便于对机器人某一完整行为的流程进行管理。
1.1 客户端/服务器模型
动作和服务类似使用的也是客户端和服务器模型客户端发送动作的目标想让机器人干什么服务器端执行动作过程 控制机器人达到运动的目标同时周期反馈动作执行过程中的状态。 客户端发送一个运动的目标想让机器人动起来服务器端收到之后就开始控制机器人运动一边运动一边反馈当前的状态如果是一个导航动作这个反馈可能是当前所处的坐标如果是机械臂抓取这个反馈可能又是机械臂的实时姿态。当运动执行结束后服务器再反馈一个动作结束的信息。整个通信过程就此结束。
1.2 action通信特点 一对多通信 和服务一样动作通信中的客户端可以有多个大家都可以发送运动命令但是服务器端只能有一个毕竟只有一个机器人先执行完成一个动作才能执行下一个动作。 同步通信 既然有反馈那动作也是一种同步通信机制之前我们也介绍过动作过程中的数据通信接口使用.action文件进行定义。 由服务和话题合成 大家再仔细看下上边的动图是不是还会发现一个隐藏的秘密。 动作的三个通信模块竟然有两个是服务一个是话题当客户端发送运动目标时使用的是服务的请求调用服务器端也会反馈一个应带表示收到命令。动作的反馈过程其实就是一个话题的周期发布服务器端是发布者客户端是订阅者。 没错动作是一种应用层的通信机制其底层就是基于话题和服务来实现的。
2 action自定义通信接口
延续上一讲[ROS2] — action中创建的自定义接口功能包在src目录下创建action/Concatenate.action文件 Concatenate.action
int16 num_concatenations
---
string final_concatenation
---
string partial_concatenation3 action编码示例
这里创建功能包名为learning04_action
3.1 class_action_client.cpp
/*** file class_action_client.cpp** brief A class defined ROS2 action client node that sends as goal the number of string* concatenation the action server should perform. * The server will send back feedbacks and the final result** author Antonio Mauro Galiano* Contact: https://www.linkedin.com/in/antoniomaurogaliano/**/#include custom_interface/action/concatenate.hpp
#include rclcpp/rclcpp.hpp
#include rclcpp_action/rclcpp_action.hppclass ConcatenateActionClient : public rclcpp::Node
{
public:using Concatenate custom_interface::action::Concatenate;using GoalHandleConcatenate rclcpp_action::ClientGoalHandleConcatenate;explicit ConcatenateActionClient(const rclcpp::NodeOptions node_options rclcpp::NodeOptions()): Node(class_action_client, node_options), goalDone_(false){this-clientPtr_ rclcpp_action::create_clientConcatenate(this-get_node_base_interface(),this-get_node_graph_interface(),this-get_node_logging_interface(),this-get_node_waitables_interface(),concatenation);this-timer_ this-create_wall_timer(std::chrono::milliseconds(500),std::bind(ConcatenateActionClient::SendGoal, this));}bool GoalDone() const;void SendGoal();private:rclcpp_action::ClientConcatenate::SharedPtr clientPtr_;rclcpp::TimerBase::SharedPtr timer_;bool goalDone_;void FeedbackCallback(GoalHandleConcatenate::SharedPtr,const std::shared_ptrconst Concatenate::Feedback feedback);void ResultCallback(const GoalHandleConcatenate::WrappedResult result);// be sure to define the parameter as its here// more info at the declarationvoid GoalResponseCallback(const GoalHandleConcatenate::SharedPtr goalHandle);
};bool ConcatenateActionClient::GoalDone() const
{return this-goalDone_;
}void ConcatenateActionClient::SendGoal()
{using namespace std::placeholders;this-timer_-cancel();this-goalDone_ false;if (!this-clientPtr_){RCLCPP_ERROR(this-get_logger(), Action client not initialized);}if (!this-clientPtr_-wait_for_action_server(std::chrono::seconds(10))){RCLCPP_ERROR(this-get_logger(), !!ATTENTION!! Action server not available);this-goalDone_ true;return;}auto goalMsg Concatenate::Goal();goalMsg.num_concatenations 9;RCLCPP_INFO(this-get_logger(), Sending goal);auto send_goal_options rclcpp_action::ClientConcatenate::SendGoalOptions();send_goal_options.feedback_callback std::bind(ConcatenateActionClient::FeedbackCallback, this, _1, _2);send_goal_options.result_callback std::bind(ConcatenateActionClient::ResultCallback, this, _1);// send_goal_options.goal_response_callback // std::bind(ConcatenateActionClient::GoalResponseCallback, this, _1);auto goal_handle_future this-clientPtr_-async_send_goal(goalMsg, send_goal_options);
}void ConcatenateActionClient::FeedbackCallback(rclcpp_action::ClientGoalHandleConcatenate::SharedPtr,const std::shared_ptrconst Concatenate::Feedback feedback)
{RCLCPP_INFO(this-get_logger(),Feedback received: %s,feedback-partial_concatenation.c_str());
}void ConcatenateActionClient::ResultCallback(const GoalHandleConcatenate::WrappedResult result)
{this-goalDone_ true;switch (result.code) {case rclcpp_action::ResultCode::SUCCEEDED:break;case rclcpp_action::ResultCode::ABORTED:RCLCPP_ERROR(this-get_logger(), Goal was aborted);return;case rclcpp_action::ResultCode::CANCELED:RCLCPP_ERROR(this-get_logger(), Goal was canceled);return;default:RCLCPP_ERROR(this-get_logger(), Unknown result code);return;}RCLCPP_INFO(this-get_logger(), Result received);for (auto number : result.result-final_concatenation){RCLCPP_INFO(this-get_logger(), %d, number);}
}// defining the parameter directly as a GoalHandleConcatenate::SharedPtr goalHandle
// its wrong for the send_goal_options.goal_response_callback
// so it doesnt compile
void ConcatenateActionClient::GoalResponseCallback(const GoalHandleConcatenate::SharedPtr goalHandle){if (!goalHandle){RCLCPP_ERROR(this-get_logger(), Goal was rejected by server);} else{RCLCPP_INFO(this-get_logger(), Goal accepted by server, waiting for result);}}int main(int argc, char ** argv)
{rclcpp::init(argc, argv);auto action_client std::make_sharedConcatenateActionClient();while (!action_client-GoalDone()){rclcpp::spin_some(action_client);}rclcpp::shutdown();return 0;
}3.2 class_action_server.cpp
/*** file class_action_server.cpp** brief A class defined ROS2 action server node that concatenates a string * based on the number of string concatenation sent by a client within a goal request** author Antonio Mauro Galiano* Contact: https://www.linkedin.com/in/antoniomaurogaliano/**/#include custom_interface/action/concatenate.hpp
#include rclcpp/rclcpp.hpp
#include rclcpp_action/rclcpp_action.hppclass ConcatenateActionServer : public rclcpp::Node
{
public:using Concatenate custom_interface::action::Concatenate;using GoalHandleConcatenate rclcpp_action::ServerGoalHandleConcatenate;explicit ConcatenateActionServer(const rclcpp::NodeOptions options rclcpp::NodeOptions()): Node(class_action_server, options){using namespace std::placeholders;this-actionServer_ rclcpp_action::create_serverConcatenate(this-get_node_base_interface(),this-get_node_clock_interface(),this-get_node_logging_interface(),this-get_node_waitables_interface(),concatenation,std::bind(ConcatenateActionServer::HandleGoal, this, _1, _2),std::bind(ConcatenateActionServer::HandleCancel, this, _1),std::bind(ConcatenateActionServer::HandleAccepted, this, _1));}private:rclcpp_action::ServerConcatenate::SharedPtr actionServer_;rclcpp_action::GoalResponse HandleGoal(const rclcpp_action::GoalUUID uuid,std::shared_ptrconst Concatenate::Goal goal);rclcpp_action::CancelResponse HandleCancel(const std::shared_ptrGoalHandleConcatenate goalHandle);void execute(const std::shared_ptrGoalHandleConcatenate goalHandle);void HandleAccepted(const std::shared_ptrConcatenateActionServer::GoalHandleConcatenate goalHandle);
};rclcpp_action::GoalResponse ConcatenateActionServer::HandleGoal(const rclcpp_action::GoalUUID uuid,std::shared_ptrconst Concatenate::Goal goal)
{RCLCPP_INFO(rclcpp::get_logger(server),Got goal request with %d string concatenations,goal-num_concatenations);(void)uuid;// conditional to reject numbers of concatenationsif ((goal-num_concatenations 10) (goal-num_concatenations 2)) {return rclcpp_action::GoalResponse::REJECT;}return rclcpp_action::GoalResponse::ACCEPT_AND_EXECUTE;
}rclcpp_action::CancelResponse ConcatenateActionServer::HandleCancel(const std::shared_ptrGoalHandleConcatenate goalHandle)
{RCLCPP_INFO(rclcpp::get_logger(server), Got request to cancel goal);(void)goalHandle;return rclcpp_action::CancelResponse::ACCEPT;
}void ConcatenateActionServer::execute(const std::shared_ptrGoalHandleConcatenate goalHandle)
{RCLCPP_INFO(rclcpp::get_logger(server), Executing the concatenation);rclcpp::Rate loop_rate(1);const auto goal goalHandle-get_goal();auto feedback std::make_sharedConcatenate::Feedback();std::string myString HELLOWORLD;auto concatenation feedback-partial_concatenation;concatenation myString;concatenation concatenation myString;auto result std::make_sharedConcatenate::Result();for (int i 1; (i goal-num_concatenations) rclcpp::ok(); i){// check if there is a cancel requestif (goalHandle-is_canceling()){result-final_concatenation concatenation;goalHandle-canceled(result);RCLCPP_INFO(rclcpp::get_logger(server), Goal Canceled);return;}// update the final concatenationconcatenation concatenation myString;// update and publish feedback of the partial concatenationgoalHandle-publish_feedback(feedback);RCLCPP_INFO(rclcpp::get_logger(server), Publish Feedback);loop_rate.sleep();}// check if goal is doneif (rclcpp::ok()){result-final_concatenation concatenation;goalHandle-succeed(result);RCLCPP_INFO(rclcpp::get_logger(server), Goal Succeeded);}
}void ConcatenateActionServer::HandleAccepted(const std::shared_ptrGoalHandleConcatenate goal_handle)
{using namespace std::placeholders;// this needs to return quickly to avoid blocking the executor, so spin up a new threadstd::thread{std::bind(ConcatenateActionServer::execute, this, _1), goal_handle}.detach();
}int main(int argc, char ** argv)
{rclcpp::init(argc, argv);auto action_server std::make_sharedConcatenateActionServer();rclcpp::spin(action_server);rclcpp::shutdown();return 0;
}3.3 CMakeLists.txt
cmake_minimum_required(VERSION 3.5)
project(learning04_action)# Default to C99
if(NOT CMAKE_C_STANDARD)set(CMAKE_C_STANDARD 99)
endif()# Default to C14
if(NOT CMAKE_CXX_STANDARD)set(CMAKE_CXX_STANDARD 14)
endif()if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES Clang)add_compile_options(-Wall -Wextra -Wpedantic)
endif()# find dependencies
find_package(ament_cmake REQUIRED)
find_package(custom_interface REQUIRED)
find_package(rclcpp REQUIRED)
find_package(rclcpp_action REQUIRED)
find_package(rclcpp_components REQUIRED)# add_executable(simple_action_server src/simple_action_server.cpp)
# ament_target_dependencies(simple_action_server
# rclcpp
# rclcpp_action
# custom_interface)add_executable(class_action_server src/class_action_server.cpp)
ament_target_dependencies(class_action_serverrclcpprclcpp_actioncustom_interface)# add_executable(simple_action_client src/simple_action_client.cpp)
# ament_target_dependencies(simple_action_client
# rclcpp
# rclcpp_action
# custom_interface)add_executable(class_action_client src/class_action_client.cpp)
ament_target_dependencies(class_action_clientrclcpprclcpp_actioncustom_interface)if(BUILD_TESTING)find_package(ament_lint_auto REQUIRED)ament_lint_auto_find_test_dependencies()
endif()install(TARGETS# simple_action_serverclass_action_server# simple_action_clientclass_action_clientDESTINATION lib/${PROJECT_NAME})ament_package()3.4 package.xml
?xml version1.0?
?xml-model hrefhttp://download.ros.org/schema/package_format3.xsd schematypenshttp://www.w3.org/2001/XMLSchema?
package format3namelearning04_action/nameversion0.0.0/versiondescriptionAction based tutorial/descriptionmaintainer emailusertodo.todoAntonio Mauro Galiano/maintainerlicenseTODO: License declaration/licensebuildtool_dependament_cmake/buildtool_dependdependcustom_interface/dependdependrclcpp/dependdependrclcpp_action/dependdependrclcpp_components/dependtest_dependament_lint_auto/test_dependtest_dependament_lint_common/test_dependexportbuild_typeament_cmake/build_type/export
/package
4 编译运行
# 编译
colcon build# source环境变量
source install/setup.sh# 运行publisher
ros2 run learning04_action class_action_client# 运行subsriber
ros2 run learning04_action class_action_server5 action常用指令
# 查看action信息
ros2 action info /turtle/roate_absolute# 设置action通信结构
ros2 interface show /turtle/roate_absolute# 发送action请求
ros2 action send_goal action_name action_type values
ros2 action send_goal /turtle/roate_absolute turtlesim/action/RotateAbsolute {theta: 1.57}
ros2 action send_goal /turtle/roate_absolute turtlesim/action/RotateAbsolute {theta: 1.57} --feedback
