【RK3399Pro学习笔记】十二、ROS参数的使用与编程方法

创建功能包

cd ~/catkin_workspace/src
catkin_create_pkg learning_parameter roscpp rospy std_srvs

参数命令行使用

YAML参数文件

background_b: 255
background_g: 86
background_r: 69
rosdistro: 'lunar' 
roslaunch: 
uris: {host_hcx_vpc__43763: 'http://hcx-vpc:43763/'}
rosversion: '1.14.31'
run_id: 077058de-a38b-11e9-818b-000c29d22e4d

rosparam

# 新建一个终端
roscore# 新建一个终端
rosrun turtlesim turtlesim_node

# 新建一个终端
rosparam

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列出当前参数

rosparam list

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显示某个参数值

rosparam get param_key

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设置某个参数值

rosparam set param_key param_value

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保存参数到文件

rosparam dump file_name

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从文件读取参数

rosparam load file_name

删除参数

rosparam delete param_key

C++

编写程序

nano ~/catkin_workspace/src/learning_parameter/src/parameter_config.cpp

/***********************************************************************
Copyright 2020 GuYueHome (www.guyuehome.com).
***********************************************************************//*** 该例程设置/读取海龟例程中的参数*/
#include <string>
#include <ros/ros.h>
#include <std_srvs/Empty.h>int main(int argc, char **argv)
{int red, green, blue;// ROS节点初始化ros::init(argc, argv, "parameter_config");// 创建节点句柄ros::NodeHandle node;// 读取背景颜色参数ros::param::get("/background_r", red);ros::param::get("/background_g", green);ros::param::get("/background_b", blue);ROS_INFO("Get Backgroud Color[%d, %d, %d]", red, green, blue);// 设置背景颜色参数ros::param::set("/background_r", 255);ros::param::set("/background_g", 255);ros::param::set("/background_b", 255);ROS_INFO("Set Backgroud Color[255, 255, 255]");// 读取背景颜色参数ros::param::get("/background_r", red);ros::param::get("/background_g", green);ros::param::get("/background_b", blue);ROS_INFO("Re-get Backgroud Color[%d, %d, %d]", red, green, blue);// 调用服务，刷新背景颜色ros::service::waitForService("/clear");ros::ServiceClient clear_background = node.serviceClient<std_srvs::Empty>("/clear");std_srvs::Empty srv;clear_background.call(srv);sleep(1);return 0;
}

配置CMakeLists.txt

nano ~/catkin_workspace/src/learning_parameter/CMakeLists.txt

添加

add_executable(parameter_config src/parameter_config.cpp)
target_link_libraries(parameter_config ${catkin_LIBRARIES})

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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 turtlesim turtlesim_node
# 新建一个终端
source ~/catkin_workspace/devel/setup.bash
rosrun learning_parameter parameter_config

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python

编写程序

cd ~/catkin_workspace/src/learning_parameter
mkdir scripts
nano ~/catkin_workspace/src/learning_parameter/scripts/parameter_config.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-########################################################################
####          Copyright 2020 GuYueHome (www.guyuehome.com).          ###
######################################################################### 该例程设置/读取海龟例程中的参数import sys
import rospy
from std_srvs.srv import Emptydef parameter_config():# ROS节点初始化rospy.init_node('parameter_config', anonymous=True)# 读取背景颜色参数red   = rospy.get_param('/background_r')green = rospy.get_param('/background_g')blue  = rospy.get_param('/background_b')rospy.loginfo("Get Backgroud Color[%d, %d, %d]", red, green, blue)# 设置背景颜色参数rospy.set_param("/background_r", 255);rospy.set_param("/background_g", 255);rospy.set_param("/background_b", 255);rospy.loginfo("Set Backgroud Color[255, 255, 255]");# 读取背景颜色参数red   = rospy.get_param('/background_r')green = rospy.get_param('/background_g')blue  = rospy.get_param('/background_b')rospy.loginfo("Get Backgroud Color[%d, %d, %d]", red, green, blue)# 发现/spawn服务后，创建一个服务客户端，连接名为/spawn的servicerospy.wait_for_service('/clear')try:clear_background = rospy.ServiceProxy('/clear', Empty)# 请求服务调用，输入请求数据response = clear_background()return responseexcept rospy.ServiceException, e:print "Service call failed: %s"%eif __name__ == "__main__":parameter_config()

运行

sudo chmod +x ~/catkin_workspace/src/learning_parameter/scripts/parameter_config.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 turtlesim turtlesim_node
# 新建一个终端
source ~/catkin_workspace/devel/setup.bash
rosrun learning_parameter parameter_config.py

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