【ros2 control 机器人驱动开发】简单双关节机器人学习-example 1
文章目录 前言一、RR机器人创建description pkg创建demos pkg 二、创建controller相关创建example pkg 三、测试运行总结 前言本系列文件主要有以下目标和内容：
为系统、传感器和执行器创建 HardwareInterface以URDF文件的形式创建机器人描述加载配置并使用启动文件启动机器人控制RRBot的两个关节（两旋转关节机器人）六自由度机器人的控制实现机器人的控制器切换策略使用 ros2_control 中的关节限制和传输概念 一、RR机器人RRBot（ Revolute-Revolute Manipulator Robot）是一个简单的3连杆，2关节的机械臂，我们将使用它来演示各种功能。
它本质上是一个双倒立摆，并在模拟器中演示了一些有趣的控制概念，最初是为Gazebo教程介绍的。
创建description pkg这里主要是完成机器人描述文件的创建，各个轴的物理尺寸、模型信息，各个轴的关节链接方式、链接点。
mkdir ~/ros2_control_demoscd ~/ros2_control_demosros2 pkg create --build-type ament_cmake ros2_control_demo_description# 文件结构$ tree ros2_control_demo_description/ros2_control_demo_description/├── CMakeLists.txt├── package.xml└── rrbot├── rviz│ └── rrbot.rviz└── urdf├── rrbot.materials.xacro└── rrbot_description.urdf.xacro # CMakeLists.txtcmake_minimum_required(VERSION 3.8)project(ros2_control_demo_description)if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")add_compile_options(-Wall -Wextra -Wpedantic)endif()# find dependenciesfind_package(ament_cmake REQUIRED)install(DIRECTORY rrbot/urdf rrbot/rvizDESTINATION share/${PROJECT_NAME}/rrbot)ament_package() # packages.xml<?xml version="1.0"?><?xml-model href="http://download.ros.org/schema/package_format3.xsd" schematypens="http://www.w3.org/2001/XMLSchema"?><package format="3"><name>ros2_control_demo_description</name><version>0.0.0</version><description>TODO: Package description</description><maintainer email="https://blog.csdn.net/Bing_Lee">dev</maintainer><license>TODO: License declaration</license><buildtool_depend>ament_cmake</buildtool_depend><exec_depend>joint_state_publisher_gui</exec_depend><exec_depend>robot_state_publisher</exec_depend><exec_depend>rviz2</exec_depend></package> # rrbot.rvizPanels:- Class: rviz_common/DisplaysHelp Height: 87Name: DisplaysProperty Tree Widget:Expanded: ~Splitter Ratio: 0.5Tree Height: 1096- Class: rviz_common/SelectionName: Selection- Class: rviz_common/Tool PropertiesExpanded:- /2D Goal Pose1- /Publish Point1Name: Tool PropertiesSplitter Ratio: 0.5886790156364441- Class: rviz_common/ViewsExpanded:- /Current View1Name: ViewsSplitter Ratio: 0.5Visualization Manager:Class: ""Displays:- Alpha: 0.5Cell Size: 1Class: rviz_default_plugins/GridColor: 160; 160; 164Enabled: trueLine Style:Line Width: 0.029999999329447746Value: LinesName: GridNormal Cell Count: 0Offset:X: 0Y: 0Z: 0Plane: XYPlane Cell Count: 10Reference Frame: <Fixed Frame>Value: true- Alpha: 1Class: rviz_default_plugins/RobotModelCollision Enabled: falseDescription File: ""Description Source: TopicDescription Topic:Depth: 5Durability Policy: VolatileHistory Policy: Keep LastReliability Policy: ReliableValue: /robot_descriptionEnabled: trueLinks:All Links Enabled: trueExpand Joint Details: falseExpand Link Details: falseExpand Tree: falseLink Tree Style: Links in Alphabetic Orderbase_link:Alpha: 1Show Axes: falseShow Trail: falseValue: truecamera_link:Alpha: 1Show Axes: falseShow Trail: falseValue: truecamera_link_optical:Alpha: 1Show Axes: falseShow Trail: falsehokuyo_link:Alpha: 1Show Axes: falseShow Trail: falseValue: truelink1:Alpha: 1Show Axes: falseShow Trail: falseValue: truelink2:Alpha: 1Show Axes: falseShow Trail: falseValue: truetool_link:Alpha: 1Show Axes: falseShow Trail: falseworld:Alpha: 1Show Axes: falseShow Trail: falseMass Properties:Inertia: falseMass: falseName: RobotModelTF Prefix: ""Update Interval: 0Value: trueVisual Enabled: trueEnabled: trueGlobal Options:Background Color: 48; 48; 48Fixed Frame: base_linkFrame Rate: 30Name: rootTools:- Class: rviz_default_plugins/InteractHide Inactive Objects: true- Class: rviz_default_plugins/MoveCamera- Class: rviz_default_plugins/Select- Class: rviz_default_plugins/FocusCamera- Class: rviz_default_plugins/MeasureLine color: 128; 128; 0- Class: rviz_default_plugins/SetInitialPoseCovariance x: 0.25Covariance y: 0.25Covariance yaw: 0.06853891909122467Topic:Depth: 5Durability Policy: VolatileHistory Policy: Keep LastReliability Policy: ReliableValue: /initialpose- Class: rviz_default_plugins/SetGoalTopic:Depth: 5Durability Policy: VolatileHistory Policy: Keep LastReliability Policy: ReliableValue: /goal_pose- Class: rviz_default_plugins/PublishPointSingle click: trueTopic:Depth: 5Durability Policy: VolatileHistory Policy: Keep LastReliability Policy: ReliableValue: /clicked_pointTransformation:Current:Class: rviz_default_plugins/TFValue: trueViews:Current:Class: rviz_default_plugins/OrbitDistance: 8.443930625915527Enable Stereo Rendering:Stereo Eye Separation: 0.05999999865889549Stereo Focal Distance: 1Swap Stereo Eyes: falseValue: falseFocal Point:X: 0.0044944556429982185Y: 1.0785865783691406Z: 2.4839563369750977Focal Shape Fixed Size: trueFocal Shape Size: 0.05000000074505806Invert Z Axis: falseName: Current ViewNear Clip Distance: 0.009999999776482582Pitch: 0.23039916157722473Target Frame: <Fixed Frame>Value: Orbit (rviz)Yaw: 5.150422096252441Saved: ~Window Geometry:Displays:collapsed: falseHeight: 1379Hide Left Dock: falseHide Right Dock: falseSelection:collapsed: falseTool Properties:collapsed: falseViews:collapsed: falseWidth: 2560X: 0Y: 1470 # rrbot_description.urdf.xacro<?xml version="1.0"?><robot xmlns:xacro="http://www.ros.org/wiki/xacro"><xacro:macro name="rrbot" params="parent prefix *origin"><!-- Constants for robot dimensions --><xacro:property name="mass" value="1" /> <!-- arbitrary value for mass --><xacro:property name="width" value="0.1" /> <!-- Square dimensions (widthxwidth) of beams --><xacro:property name="height1" value="2" /> <!-- Link 1 --><xacro:property name="height2" value="1" /> <!-- Link 2 --><xacro:property name="height3" value="1" /> <!-- Link 3 --><xacro:property name="axel_offset" value="0.05" /> <!-- Space btw top of beam and the each joint --><joint name="${prefix}base_joint" type="fixed"><xacro:insert_block name="origin" /><parent link="${parent}"/><child link="${prefix}base_link" /></joint><!-- Base Link --><link name="${prefix}base_link"><collision><origin xyz="0 0 ${height1/2}" rpy="0 0 0"/><geometry><box size="${width} ${width} ${height1}"/></geometry></collision><visual><origin xyz="0 0 ${height1/2}" rpy="0 0 0"/><geometry><box size="${width} ${width} ${height1}"/></geometry><material name="orange"/></visual></link><joint name="${prefix}joint1" type="continuous"><parent link="${prefix}base_link"/><child link="${prefix}link1"/><origin xyz="0 ${width} ${height1 - axel_offset}" rpy="0 0 0"/><axis xyz="0 1 0"/><dynamics damping="0.7"/></joint><!-- Middle Link --><link name="${prefix}link1"><collision><origin xyz="0 0 ${height2/2 - axel_offset}" rpy="0 0 0"/><geometry><box size="${width} ${width} ${height2}"/></geometry></collision><visual><origin xyz="0 0 ${height2/2 - axel_offset}" rpy="0 0 0"/><geometry><box size="${width} ${width} ${height2}"/></geometry><material name="yellow"/></visual></link><joint name="${prefix}joint2" type="continuous"><parent link="${prefix}link1"/><child link="${prefix}link2"/><origin xyz="0 ${width} ${height2 - axel_offset*2}" rpy="0 0 0"/><axis xyz="0 1 0"/><dynamics damping="0.7"/></joint><!-- Top Link --><link name="${prefix}link2"><collision><origin xyz="0 0 ${height3/2 - axel_offset}" rpy="0 0 0"/><geometry><box size="${width} ${width} ${height3}"/></geometry></collision><visual><origin xyz="0 0 ${height3/2 - axel_offset}" rpy="0 0 0"/><geometry><box size="${width} ${width} ${height3}"/></geometry><material name="orange"/></visual></link><joint name="${prefix}tool_joint" type="fixed"><origin xyz="0 0 1" rpy="0 0 0" /><parent link="${prefix}link2"/><child link="${prefix}tool_link" /></joint><!-- Tool Link --><link name="${prefix}tool_link"></link></xacro:macro></robot> # rrbot.materials.xacro<?xml version="1.0"?><!--Copied from ROS1 example -https://github.com/ros-simulation/gazebo_ros_demos/blob/kinetic-devel/rrbot_description/urdf/materials.xacro--><robot><material name="black"><color rgba="0.0 0.0 0.0 1.0"/></material><material name="blue"><color rgba="0.0 0.0 0.8 1.0"/></material><material name="green"><color rgba="0.0 0.8 0.0 1.0"/></material><material name="grey"><color rgba="0.2 0.2 0.2 1.0"/></material><material name="orange"><color rgba="${255/255} ${108/255} ${10/255} 1.0"/></material><material name="brown"><color rgba="${222/255} ${207/255} ${195/255} 1.0"/></material><material name="red"><color rgba="0.8 0.0 0.0 1.0"/></material><material name="yellow"><color rgba="1.0 1.0 0.0 1.0"/></material><material name="white"><color rgba="1.0 1.0 1.0 1.0"/></material></robot> 创建demos pkg这个包用于引导编译所有相关依赖包，按照下边格式填好即可。
cd ~/ros2_control_demosros2 pkg create --build-type ament_cmake ros2_control_demos# 文件结构$ tree ros2_control_demos/ros2_control_demos/├── CMakeLists.txt└── package.xml # CMakeLists.txtcmake_minimum_required(VERSION 3.8)project(ros2_control_demos)# find dependenciesfind_package(ament_cmake REQUIRED)ament_package() # package.xml<?xml version="1.0"?><?xml-model href="http://download.ros.org/schema/package_format3.xsd" schematypens="http://www.w3.org/2001/XMLSchema"?><package format="3"><name>ros2_control_demos</name><version>0.0.0</version><description>TODO: Package description</description><maintainer email="https://blog.csdn.net/Bing_Lee">dev</maintainer><license>TODO: License declaration</license><buildtool_depend>ament_cmake</buildtool_depend><exec_depend>ros2_control_demo_example_1</exec_depend><export><build_type>ament_cmake</build_type></export></package> 二、创建controller相关 创建example pkg cd ~/ros2_control_demosros2 pkg create --build-type ament_cmake ros2_control_demo_example_1这里涉及hardware部分的实现，具体如下：
# robot.hpp// Copyright 2020 ros2_control Development Team//// Licensed under the Apache License, Version 2.0 (the "License");// you may not use this file except in compliance with the License.// You may obtain a copy of the License at//// http://www.apache.org/licenses/LICENSE-2.0//// Unless required by applicable law or agreed to in writing, software// distributed under the License is distributed on an "AS IS" BASIS,// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.// See the License for the specific language governing permissions and// limitations under the License.#ifndef ROS2_CONTROL_DEMO_EXAMPLE_1__RRBOT_HPP_#define ROS2_CONTROL_DEMO_EXAMPLE_1__RRBOT_HPP_#include <memory>#include <string>#include <vector>#include "hardware_interface/handle.hpp"#include "hardware_interface/hardware_info.hpp"#include "hardware_interface/system_interface.hpp"#include "hardware_interface/types/hardware_interface_return_values.hpp"#include "rclcpp/macros.hpp"#include "rclcpp_lifecycle/node_interfaces/lifecycle_node_interface.hpp"#include "rclcpp_lifecycle/state.hpp"#include "ros2_control_demo_example_1/visibility_control.h"namespace ros2_control_demo_example_1{class RRBotSystemPositionOnlyHardware : public hardware_interface::SystemInterface{public:RCLCPP_SHARED_PTR_DEFINITIONS(RRBotSystemPositionOnlyHardware);ROS2_CONTROL_DEMO_EXAMPLE_1_PUBLIChardware_interface::CallbackReturn on_init(const hardware_interface::HardwareInfo & info) override;ROS2_CONTROL_DEMO_EXAMPLE_1_PUBLIChardware_interface::CallbackReturn on_configure(const rclcpp_lifecycle::State & previous_state) override;ROS2_CONTROL_DEMO_EXAMPLE_1_PUBLICstd::vector<hardware_interface::StateInterface> export_state_interfaces() override;ROS2_CONTROL_DEMO_EXAMPLE_1_PUBLICstd::vector<hardware_interface::CommandInterface> export_command_interfaces() override;ROS2_CONTROL_DEMO_EXAMPLE_1_PUBLIChardware_interface::CallbackReturn on_activate(const rclcpp_lifecycle::State & previous_state) override;ROS2_CONTROL_DEMO_EXAMPLE_1_PUBLIChardware_interface::CallbackReturn on_deactivate(const rclcpp_lifecycle::State & previous_state) override;ROS2_CONTROL_DEMO_EXAMPLE_1_PUBLIChardware_interface::return_type read(const rclcpp::Time & time, const rclcpp::Duration & period) override;ROS2_CONTROL_DEMO_EXAMPLE_1_PUBLIChardware_interface::return_type write(const rclcpp::Time & time, const rclcpp::Duration & period) override;private:// Parameters for the RRBot simulationdouble hw_start_sec_;double hw_stop_sec_;double hw_slowdown_;// Store the command for the simulated robotstd::vector<double> hw_commands_;std::vector<double> hw_states_;};} // namespace ros2_control_demo_example_1#endif // ROS2_CONTROL_DEMO_EXAMPLE_1__RRBOT_HPP_ // Copyright 2021 ros2_control Development Team//// Licensed under the Apache License, Version 2.0 (the "License");// you may not use this file except in compliance with the License.// You may obtain a copy of the License at//// http://www.apache.org/licenses/LICENSE-2.0//// Unless required by applicable law or agreed to in writing, software// distributed under the License is distributed on an "AS IS" BASIS,// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.// See the License for the specific language governing permissions and// limitations under the License./* This header must be included by all rclcpp headers which declare symbols* which are defined in the rclcpp library. When not building the rclcpp* library, i.e. when using the headers in other package's code, the contents* of this header change the visibility of certain symbols which the rclcpp* library cannot have, but the consuming code must have inorder to link.*/#ifndef ROS2_CONTROL_DEMO_EXAMPLE_1__VISIBILITY_CONTROL_H_#define ROS2_CONTROL_DEMO_EXAMPLE_1__VISIBILITY_CONTROL_H_// This logic was borrowed (then namespaced) from the examples on the gcc wiki:// https://gcc.gnu.org/wiki/Visibility#if defined _WIN32 || defined __CYGWIN__#ifdef __GNUC__#define ROS2_CONTROL_DEMO_EXAMPLE_1_EXPORT __attribute__((dllexport))#define ROS2_CONTROL_DEMO_EXAMPLE_1_IMPORT __attribute__((dllimport))#else#define ROS2_CONTROL_DEMO_EXAMPLE_1_EXPORT __declspec(dllexport)#define ROS2_CONTROL_DEMO_EXAMPLE_1_IMPORT __declspec(dllimport)#endif#ifdef ROS2_CONTROL_DEMO_EXAMPLE_1_BUILDING_DLL#define ROS2_CONTROL_DEMO_EXAMPLE_1_PUBLIC ROS2_CONTROL_DEMO_EXAMPLE_1_EXPORT#else#define ROS2_CONTROL_DEMO_EXAMPLE_1_PUBLIC ROS2_CONTROL_DEMO_EXAMPLE_1_IMPORT#endif#define ROS2_CONTROL_DEMO_EXAMPLE_1_PUBLIC_TYPE ROS2_CONTROL_DEMO_EXAMPLE_1_PUBLIC#define ROS2_CONTROL_DEMO_EXAMPLE_1_LOCAL#else#define ROS2_CONTROL_DEMO_EXAMPLE_1_EXPORT __attribute__((visibility("default")))#define ROS2_CONTROL_DEMO_EXAMPLE_1_IMPORT#if __GNUC__ >= 4#define ROS2_CONTROL_DEMO_EXAMPLE_1_PUBLIC __attribute__((visibility("default")))#define ROS2_CONTROL_DEMO_EXAMPLE_1_LOCAL __attribute__((visibility("hidden")))#else#define ROS2_CONTROL_DEMO_EXAMPLE_1_PUBLIC#define ROS2_CONTROL_DEMO_EXAMPLE_1_LOCAL#endif#define ROS2_CONTROL_DEMO_EXAMPLE_1_PUBLIC_TYPE#endif#endif // ROS2_CONTROL_DEMO_EXAMPLE_1__VISIBILITY_CONTROL_H_attribute((visibility(“default”))) 是 GCC（GNU 编译器集合）中的一个特性，它允许程序员控制特定部分的代码的可见性。在 C 和 C++ 中，代码的可见性是指其他源文件能否访问特定的函数或变量。
当你在一个函数或变量声明中使用 attribute((visibility(“default”)))，表示这个函数或变量默认对所有其他源文件可见。也就是说，这个函数或变量可以在其他源文件中被调用，或者被其他源文件中的变量间接引用。
这种特性在编写库和模块时非常有用，因为它允许程序员更灵活地组织和隐藏代码。例如，你可以创建一个库，其中包含一些默认可见的函数和变量，这些函数和变量可以被其他源文件调用，但不被直接暴露给用户。这种方式可以隐藏库的内部实现细节，同时仍然允许用户使用库的功能。
需要注意的是，attribute((visibility(“default”))) 并不是 C 或 C++ 标准的一部分，而是 GCC 编译器的一个特性。这意味着不是所有的编译器都会支持这个特性，特别是那些不支持 GCC 的编译器。此外，不同的编译器可能对 attribute((visibility)) 的行为有微小的差异，所以在使用这个特性时需要特别小心。
# robot.cpp// Copyright 2020 ros2_control Development Team//// Licensed under the Apache License, Version 2.0 (the "License");// you may not use this file except in compliance with the License.// You may obtain a copy of the License at//// http://www.apache.org/licenses/LICENSE-2.0//// Unless required by applicable law or agreed to in writing, software// distributed under the License is distributed on an "AS IS" BASIS,// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.// See the License for the specific language governing permissions and// limitations under the License.#include "ros2_control_demo_example_1/rrbot.hpp"#include <chrono>#include <cmath>#include <limits>#include <memory>#include <vector>#include "hardware_interface/types/hardware_interface_type_values.hpp"#include "rclcpp/rclcpp.hpp"namespace ros2_control_demo_example_1{hardware_interface::CallbackReturn RRBotSystemPositionOnlyHardware::on_init(const hardware_interface::HardwareInfo & info){if (hardware_interface::SystemInterface::on_init(info) !=hardware_interface::CallbackReturn::SUCCESS){return hardware_interface::CallbackReturn::ERROR;}// BEGIN: 这一段是出测试使用考虑，请勿拷贝至实际生产环境hw_start_sec_ = stod(info_.hardware_parameters["example_param_hw_start_duration_sec"]);hw_stop_sec_ = stod(info_.hardware_parameters["example_param_hw_stop_duration_sec"]);hw_slowdown_ = stod(info_.hardware_parameters["example_param_hw_slowdown"]);// END: 这一段是出测试使用考虑，请勿拷贝至实际生产环境hw_states_.resize(info_.joints.size(), std::numeric_limits<double>::quiet_NaN());hw_commands_.resize(info_.joints.size(), std::numeric_limits<double>::quiet_NaN());for (const hardware_interface::ComponentInfo & joint : info_.joints){// RRBotSystemPositionOnly 只有一种状态和命令(state,command)if (joint.command_interfaces.size() != 1){RCLCPP_FATAL(rclcpp::get_logger("RRBotSystemPositionOnlyHardware"),"Joint '%s' has %zu command interfaces found. 1 expected.", joint.name.c_str(),joint.command_interfaces.size());return hardware_interface::CallbackReturn::ERROR;}if (joint.command_interfaces[0].name != hardware_interface::HW_IF_POSITION){RCLCPP_FATAL(rclcpp::get_logger("RRBotSystemPositionOnlyHardware"),"Joint '%s' have %s command interfaces found. '%s' expected.", joint.name.c_str(),joint.command_interfaces[0].name.c_str(), hardware_interface::HW_IF_POSITION);return hardware_interface::CallbackReturn::ERROR;}if (joint.state_interfaces.size() != 1){RCLCPP_FATAL(rclcpp::get_logger("RRBotSystemPositionOnlyHardware"),"Joint '%s' has %zu state interface. 1 expected.", joint.name.c_str(),joint.state_interfaces.size());return hardware_interface::CallbackReturn::ERROR;}if (joint.state_interfaces[0].name != hardware_interface::HW_IF_POSITION){RCLCPP_FATAL(rclcpp::get_logger("RRBotSystemPositionOnlyHardware"),"Joint '%s' have %s state interface. '%s' expected.", joint.name.c_str(),joint.state_interfaces[0].name.c_str(), hardware_interface::HW_IF_POSITION);return hardware_interface::CallbackReturn::ERROR;}}return hardware_interface::CallbackReturn::SUCCESS;}hardware_interface::CallbackReturn RRBotSystemPositionOnlyHardware::on_configure(const rclcpp_lifecycle::State & /*previous_state*/){// BEGIN: 这一段是出测试使用考虑，请勿拷贝至实际生产环境RCLCPP_INFO(rclcpp::get_logger("RRBotSystemPositionOnlyHardware"), "Configuring ...please wait...");for (int i = 0; i < hw_start_sec_; i++){rclcpp::sleep_for(std::chrono::seconds(1));RCLCPP_INFO(rclcpp::get_logger("RRBotSystemPositionOnlyHardware"), "%.1f seconds left...",hw_start_sec_ - i);}// END: 这一段是出测试使用考虑，请勿拷贝至实际生产环境// 在切换状态到configure时总是初始化所有值for (uint i = 0; i < hw_states_.size(); i++){hw_states_[i] = 0;hw_commands_[i] = 0;}RCLCPP_INFO(rclcpp::get_logger("RRBotSystemPositionOnlyHardware"), "Successfully configured!");return hardware_interface::CallbackReturn::SUCCESS;}std::vector<hardware_interface::StateInterface>RRBotSystemPositionOnlyHardware::export_state_interfaces(){std::vector<hardware_interface::StateInterface> state_interfaces;for (uint i = 0; i < info_.joints.size(); i++){state_interfaces.emplace_back(hardware_interface::StateInterface(info_.joints[i].name, hardware_interface::HW_IF_POSITION, &hw_states_[i]));}return state_interfaces;}std::vector<hardware_interface::CommandInterface>RRBotSystemPositionOnlyHardware::export_command_interfaces(){std::vector<hardware_interface::CommandInterface> command_interfaces;for (uint i = 0; i < info_.joints.size(); i++){command_interfaces.emplace_back(hardware_interface::CommandInterface(info_.joints[i].name, hardware_interface::HW_IF_POSITION, &hw_commands_[i]));}return command_interfaces;}hardware_interface::CallbackReturn RRBotSystemPositionOnlyHardware::on_activate(const rclcpp_lifecycle::State & /*previous_state*/){// BEGIN: 这一段是出测试使用考虑，请勿拷贝至实际生产环境RCLCPP_INFO(rclcpp::get_logger("RRBotSystemPositionOnlyHardware"), "Activating ...please wait...");for (int i = 0; i < hw_start_sec_; i++){rclcpp::sleep_for(std::chrono::seconds(1));RCLCPP_INFO(rclcpp::get_logger("RRBotSystemPositionOnlyHardware"), "%.1f seconds left...",hw_start_sec_ - i);}// END: 这一段是出测试使用考虑，请勿拷贝至实际生产环境// command和state开始时应该是相同的for (uint i = 0; i < hw_states_.size(); i++){hw_commands_[i] = hw_states_[i];}RCLCPP_INFO(rclcpp::get_logger("RRBotSystemPositionOnlyHardware"), "Successfully activated!");return hardware_interface::CallbackReturn::SUCCESS;}hardware_interface::CallbackReturn RRBotSystemPositionOnlyHardware::on_deactivate(const rclcpp_lifecycle::State & /*previous_state*/){// BEGIN: 这一段是出测试使用考虑，请勿拷贝至实际生产环境RCLCPP_INFO(rclcpp::get_logger("RRBotSystemPositionOnlyHardware"), "Deactivating ...please wait...");for (int i = 0; i < hw_stop_sec_; i++){rclcpp::sleep_for(std::chrono::seconds(1));RCLCPP_INFO(rclcpp::get_logger("RRBotSystemPositionOnlyHardware"), "%.1f seconds left...",hw_stop_sec_ - i);}RCLCPP_INFO(rclcpp::get_logger("RRBotSystemPositionOnlyHardware"), "Successfully deactivated!");// END: 这一段是出测试使用考虑，请勿拷贝至实际生产环境return hardware_interface::CallbackReturn::SUCCESS;}hardware_interface::return_type RRBotSystemPositionOnlyHardware::read(const rclcpp::Time & /*time*/, const rclcpp::Duration & /*period*/){// BEGIN: 这一段是出测试使用考虑，请勿拷贝至实际生产环境RCLCPP_INFO(rclcpp::get_logger("RRBotSystemPositionOnlyHardware"), "Reading...");for (uint i = 0; i < hw_states_.size(); i++){// 模拟RRBot的运动hw_states_[i] = hw_states_[i] + (hw_commands_[i] - hw_states_[i]) / hw_slowdown_;RCLCPP_INFO(rclcpp::get_logger("RRBotSystemPositionOnlyHardware"), "Got state %.5f for joint %d!",hw_states_[i], i);}RCLCPP_INFO(rclcpp::get_logger("RRBotSystemPositionOnlyHardware"), "Joints successfully read!");// END: 这一段是出测试使用考虑，请勿拷贝至实际生产环境return hardware_interface::return_type::OK;}hardware_interface::return_type RRBotSystemPositionOnlyHardware::write(const rclcpp::Time & /*time*/, const rclcpp::Duration & /*period*/){// BEGIN: 这一段是出测试使用考虑，请勿拷贝至实际生产环境RCLCPP_INFO(rclcpp::get_logger("RRBotSystemPositionOnlyHardware"), "Writing...");for (uint i = 0; i < hw_commands_.size(); i++){// 仿真发送命令到hardwareRCLCPP_INFO(rclcpp::get_logger("RRBotSystemPositionOnlyHardware"), "Got command %.5f for joint %d!",hw_commands_[i], i);}RCLCPP_INFO(rclcpp::get_logger("RRBotSystemPositionOnlyHardware"), "Joints successfully written!");// END: 这一段是出测试使用考虑，请勿拷贝至实际生产环境return hardware_interface::return_type::OK;}} // namespace ros2_control_demo_example_1#include "pluginlib/class_list_macros.hpp"PLUGINLIB_EXPORT_CLASS(ros2_control_demo_example_1::RRBotSystemPositionOnlyHardware, hardware_interface::SystemInterface)hardware_interface::SystemInterface类的说明：1
rclcpp_lifecycle::node_interfaces::LifecycleNodeInterface类的说明：2
也可通过上一篇博客《 ROS2 LifecycleNode讲解及实例》中的介绍学习。
三、测试运行 总结先把当前完成部分更新到博客，运行结果截图如上所示，这两天继续完善。
ROS2 Control: hardware_interface::SystemInterface Class Reference ↩︎
Class LifecycleNodeInterface ↩︎
