ROS 接口调参加载参数动态参数从NodeHandle中加载参数

参数类型

 ROS 参数服务器本质上是可以网络访问的参数词典， ROS 参数服务器能保存的数据类型包括字符串、整型、浮点型、布尔型、列表、词典等；

 参数根据类型不同可以分为全局参数、相对参数、私有参数等；

 其中以 “/” 开头的参数为全局参数，以 “ ～ ” 开头的参数为私有参数，其他参数为相对参数；

参数接口

操作参数的四种方法：

 ROS 提供了两种管理参数的 API 实时的存储、获取参数：

一个是通过 ros::param 命令空间一个是通过 ros::NodeHandle 接口

 从 Launch 文件中加载参数

 从参数文件中加载参数

 通过动态参数 dynamic_reconfigure 接口调整参数

获取的两种方式：

通过NodeHandle操作参数

参数的设置、删除、获取、查询等操作方式。

 void NodeHandle::setParam(const std::string& key, double d) 设置

 bool NodeHandle::deleteParam(const std::string& key) 删除

 bool NodeHandle::getParam(const std::string& key, double& d) 获取

 bool NodeHandle::searchParam(const std::string& key, std::string& result_out) 查询

查看参数

在 ROS 中，

rosparam 命令可以用来查看参数。需注意，利用 rosparam 操作参数必须在 roscore 启动后才能

进行，主要方法有：

 # 设置参数 $rosparam set [参数名 ]

 # 删除参数 $rosparam delete

 # 获取参数 $rosparam get [参数名 ]

 # 查看参数列表 $rosparam list

从NodeHandle中加载参数---实例查看参数：


#include 
 
int main(int argc, char **argv){
    ros::init(argc,argv,"hello");        // 初始化节点
    ros::NodeHandle nh("~");             // 初始化句柄
    bool isRun = false;
    nh.setParam("is_run",true);          // 注入全局参数
    nh.setParam("/is_test",true);      
    if(nh.hasParam("is_run") == true){   // 判断是否有该节点
         nh.getParam("is_run",isRun);
         ROS_INFO("the status is %d",isRun);
    }else{
         ROS_INFO("the is_run status is not defined");
    }
    return 0;
}

从launch文件中加载参数

参数通过 param 标签实现。

 参数为全局参数， param 标签作为 launch 标签的子标签

 参数为相对参数， param 标签作为 node 标签的子标签


 
"serial" value="5"/>
 
"client" pkg="example_3" type="client" output="screen">
 
"client_x" type="int" value="1" />

从配置文件中加载参数

YAML 是一种可读性高、轻量级的标记语言，

广泛用于 ROS 、 Spring 等框架的配置，它对大小写敏感，

使用缩进表示层级关系，但缩进使用空格（２个或者４个）而非Tab 键表示。

YAML 支持对象、数组、常量三种数据类型。

 参数配置在 YAML 文件中，注意冒号后面有空格

 YAML 文件通常放置于程序包的 config 目录下

 通过 launch 文件的 rosparam 标签加载配置文件来完成参数配置，添加路径


 "yaml" pkg="example_2" type="yaml" clear_params="true" output="screen"> 
     
    "$(find example_2)/config/test.yaml"/>

加载参数示例

 步骤1：创建 load.launch （从 Launch 中加载参数）

 步骤2：创建配置文件 config/test.yaml

 步骤3：创建 yaml.launch （从配置文件中加载参数）

 步骤4：读取参数，创建 yaml.cpp

 步骤5：修改 CMakeLists.txt

 步骤1：创建load.launch


   "isLoad" type="bool" value="true"/>       #定义全局标签 bool 
   "yaml" pkg="example_2" type="yaml" clear_params="true" output="screen">
   #四个相对应的参数
       "first_name" type="string" value="fabio" />
       "last_name" type="string" value="miao" />
       "age" type="int" value="39" />
       "score" type="int" value="150" />

 步骤2：创建配置文件config/test.yaml


first_name: fabio
last_name: miaozl
age: 37
score: 100
 
 
#注意中间一定需要空格

 步骤4：读取参数，创建yaml.cpp


#include 
 
int main(int argc, char **argv)
{
  ros::init(argc, argv, "yaml");           // 生成yaml的节点
  ros::NodeHandle nh;                      // 
  std::string first,last;
  int age = 0 , score = 100;
  bool isLoad = false;
  nh.getParam("/yaml/first_name",first);  // 读出节点中的值加入读出
  nh.getParam("/yaml/last_name",last);
  ROS_INFO("his first name is %s,his last name is %s",first.c_str(),last.c_str());  
  nh.getParam("/yaml/age",age);            // 读年龄 读分数
  ROS_INFO("first name is %d",age);
  nh.getParam("/yaml/score",score);
  ROS_INFO("first name is %d",score);
  nh.getParam("/isLoad",isLoad);
  if(isLoad){
    ROS_INFO("the param is load");
  }else{
    ROS_INFO("the param isn't load");
  }
}

 步骤5：修改CMakeLists.txt

主要添加修改文件 --- 编译link Libraries 库文件


cmake_minimum_required(VERSION 3.0.2)
project(example_2)
 
## Compile as C++11, supported in ROS Kinetic and newer
# add_compile_options(-std=c++11)
 
## Find catkin macros and libraries
## if COMPONENTS list like find_package(catkin REQUIRED COMPONENTS xyz)
## is used, also find other catkin packages
find_package(catkin REQUIRED COMPONENTS
  roscpp
  rospy
  std_msgs
  message_generation
  dynamic_reconfigure
)
 
## System dependencies are found with CMake's conventions
# find_package(Boost REQUIRED COMPONENTS system)
 
 
## Uncomment this if the package has a setup.py. This macro ensures
## modules and global scripts declared therein get installed
## See http://ros.org/doc/api/catkin/html/user_guide/setup_dot_py.html
# catkin_python_setup()
 
################################################
## Declare ROS messages, services and actions ##
################################################
 
## To declare and build messages, services or actions from within this
## package, follow these steps:
## * Let MSG_DEP_SET be the set of packages whose message types you use in
##   your messages/services/actions (e.g. std_msgs, actionlib_msgs, ...).
## * In the file package.xml:
##   * add a build_depend tag for "message_generation"
##   * add a build_depend and a exec_depend tag for each package in MSG_DEP_SET
##   * If MSG_DEP_SET isn't empty the following dependency has been pulled in
##     but can be declared for certainty nonetheless:
##     * add a exec_depend tag for "message_runtime"
## * In this file (CMakeLists.txt):
##   * add "message_generation" and every package in MSG_DEP_SET to
##     find_package(catkin REQUIRED COMPONENTS ...)
##   * add "message_runtime" and every package in MSG_DEP_SET to
##     catkin_package(CATKIN_DEPENDS ...)
##   * uncomment the add_*_files sections below as needed
##     and list every .msg/.srv/.action file to be processed
##   * uncomment the generate_messages entry below
##   * add every package in MSG_DEP_SET to generate_messages(DEPENDENCIES ...)
 
## Generate messages in the 'msg' folder
# add_message_files(
#   FILES
#   Message1.msg
#   Message2.msg
# )
 
## Generate services in the 'srv' folder
# add_service_files(
#   FILES
#   Service1.srv
#   Service2.srv
# )
 
## Generate actions in the 'action' folder
# add_action_files(
#   FILES
#   Action1.action
#   Action2.action
# )
 
## Generate added messages and services with any dependencies listed here
# generate_messages(
#   DEPENDENCIES
#   std_msgs
# )
 
################################################
## Declare ROS dynamic reconfigure parameters ##
################################################
 
## To declare and build dynamic reconfigure parameters within this
## package, follow these steps:
## * In the file package.xml:
##   * add a build_depend and a exec_depend tag for "dynamic_reconfigure"
## * In this file (CMakeLists.txt):
##   * add "dynamic_reconfigure" to
##     find_package(catkin REQUIRED COMPONENTS ...)
##   * uncomment the "generate_dynamic_reconfigure_options" section below
##     and list every .cfg file to be processed
 
## Generate dynamic reconfigure parameters in the 'cfg' folder
 generate_dynamic_reconfigure_options(
   cfg/Test.cfg
 )
 
###################################
## catkin specific configuration ##
###################################
## The catkin_package macro generates cmake config files for your package
## Declare things to be passed to dependent projects
## INCLUDE_DIRS: uncomment this if your package contains header files
## LIBRARIES: libraries you create in this project that dependent projects also need
## CATKIN_DEPENDS: catkin_packages dependent projects also need
## DEPENDS: system dependencies of this project that dependent projects also need
catkin_package(
#  INCLUDE_DIRS include
#  LIBRARIES example_2
#  CATKIN_DEPENDS roscpp rospy std_msgs
#  DEPENDS system_lib
)
 
###########
## Build ##
###########
 
## Specify additional locations of header files
## Your package locations should be listed before other locations
include_directories(
# include
  ${catkin_INCLUDE_DIRS}
)
 
## Declare a C++ library
# add_library(${PROJECT_NAME}
#   src/${PROJECT_NAME}/example_2.cpp
# )
 
## Add cmake target dependencies of the library
## as an example, code may need to be generated before libraries
## either from message generation or dynamic reconfigure
# add_dependencies(${PROJECT_NAME} ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})
 
## Declare a C++ executable
## With catkin_make all packages are built within a single CMake context
## The recommended prefix ensures that target names across packages don't collide
# add_executable(${PROJECT_NAME}_node src/example_2_node.cpp)
add_executable(yaml src/yaml.cpp)
add_executable(param src/param.cpp)
## Rename C++ executable without prefix
## The above recommended prefix causes long target names, the following renames the
## target back to the shorter version for ease of user use
## e.g. "rosrun someones_pkg node" instead of "rosrun someones_pkg someones_pkg_node"
# set_target_properties(${PROJECT_NAME}_node PROPERTIES OUTPUT_NAME node PREFIX "")
 
## Add cmake target dependencies of the executable
## same as for the library above
# add_dependencies(${PROJECT_NAME}_node ${${PROJECT_NAME}_EXPORTED_TARGETS} ${catkin_EXPORTED_TARGETS})
 
## Specify libraries to link a library or executable target against
# target_link_libraries(${PROJECT_NAME}_node
#   ${catkin_LIBRARIES}
# )
target_link_libraries(yaml
   ${catkin_LIBRARIES}
)
target_link_libraries(param
   ${catkin_LIBRARIES}
)
#############
## Install ##
#############
 
# all install targets should use catkin DESTINATION variables
# See http://ros.org/doc/api/catkin/html/adv_user_guide/variables.html
 
## Mark executable scripts (Python etc.) for installation
## in contrast to setup.py, you can choose the destination
# catkin_install_python(PROGRAMS
#   scripts/my_python_script
#   DESTINATION ${CATKIN_PACKAGE_BIN_DESTINATION}
# )
 
## Mark executables for installation
## See http://docs.ros.org/melodic/api/catkin/html/howto/format1/building_executables.html
# install(TARGETS ${PROJECT_NAME}_node
#   RUNTIME DESTINATION ${CATKIN_PACKAGE_BIN_DESTINATION}
# )
 
## Mark libraries for installation
## See http://docs.ros.org/melodic/api/catkin/html/howto/format1/building_libraries.html
# install(TARGETS ${PROJECT_NAME}
#   ARCHIVE DESTINATION ${CATKIN_PACKAGE_LIB_DESTINATION}
#   LIBRARY DESTINATION ${CATKIN_PACKAGE_LIB_DESTINATION}
#   RUNTIME DESTINATION ${CATKIN_GLOBAL_BIN_DESTINATION}
# )
 
## Mark cpp header files for installation
# install(DIRECTORY include/${PROJECT_NAME}/
#   DESTINATION ${CATKIN_PACKAGE_INCLUDE_DESTINATION}
#   FILES_MATCHING PATTERN "*.h"
#   PATTERN ".svn" EXCLUDE
# )
 
## Mark other files for installation (e.g. launch and bag files, etc.)
# install(FILES
#   # myfile1
#   # myfile2
#   DESTINATION ${CATKIN_PACKAGE_SHARE_DESTINATION}
# )
 
#############
## Testing ##
#############
 
## Add gtest based cpp test target and link libraries
# catkin_add_gtest(${PROJECT_NAME}-test test/test_example_2.cpp)
# if(TARGET ${PROJECT_NAME}-test)
#   target_link_libraries(${PROJECT_NAME}-test ${PROJECT_NAME})
# endif()
 
## Add folders to be run by python nosetests
# catkin_add_nosetests(test)

执行launch后得到


... logging to /home/xtark/.ros/log/deb4219e-2151-11ed-a25f-874955d4690a/roslaunch-xtark-vmpc-6737.log
Checking log directory for disk usage. This may take a while.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.
 
started roslaunch server http://xtark-vmpc:33649/
 
SUMMARY
========
 
CLEAR PARAMETERS
 * /yaml/
 
PARAMETERS
 * /isLoad: True
 * /rosdistro: noetic
 * /rosversion: 1.15.13
 * /yaml/age: 39
 * /yaml/first_name: fabio
 * /yaml/last_name: miao
 * /yaml/score: 150
 
NODES
  /
    yaml (example_2/yaml)
 
ROS_MASTER_URI=http://localhost:11311
 
process[yaml-1]: started with pid [6755]
[ INFO] [1661087150.225233609]: his first name is fabio,his last name is miao
[ INFO] [1661087150.226000645]: first name is 39
[ INFO] [1661087150.226231003]: first name is 150
[ INFO] [1661087150.226447102]: the param is load
[yaml-1] process has finished cleanly
log file: /home/xtark/.ros/log/deb4219e-2151-11ed-a25f-874955d4690a/yaml-1*.log
all processes on machine have died, roslaunch will exit
shutting down processing monitor...
... shutting down processing monitor complete
done

相关阅读:
uni-app+vue3会遇到哪些问题
 软考备考-程序员-备考笔记
 Unity工具 - 工具聚合页（UEWindow）
docker 构建并运行 python项目
 docker使用bind9实现域名解析
 MySQL(十一) 用户管理
 原生Js Canvas去除视频绿幕背景
 基于低能耗自适应聚类层次结构(LEACH)（Matlab代码实现）
设计模式3、工厂方法模式 Factory Method
六、数组及其操作《2022 solidity8.+ 版本教程到实战》
原文地址：https://blog.csdn.net/weixin_44025389/article/details/126455136

ROS 接口调参 加载参数 动态参数 从NodeHandle中加载参数