[ROS] 小乌龟案例（topic通信）publisher+GUI实现

---

---

[ROS] [笔记] 20201119 小乌龟案例

[ROS] [笔记] 20201119 了解小乌龟控制需求+任务package创建

1. 了解需求

2. 创建新的工作单元（package）（在工作空间、src下）

3. 在工作空间（workspace）下编译，完成，source setup.bash

4. 使用 clion 打开项目

5. 干掉 cmake-build-debug（略）

---

---

[ROS] [笔记] 小乌龟控制需求 cpp+qt 代码框架搭建

1. 在 turtle_demo 工作单元（package）创建新节点（node）

一个节点就是一个进程（process）

2. 配置 cmake （包含qt环境配置）

 add_executable(turtle_control src/turtle_control.cpp)target_link_libraries(turtle_control${catkin_LIBRARIES}Qt5::CoreQt5::GuiQt5::WidgetsQt5::PrintSupport)##############################################################################
# Qt Environment
##############################################################################set(CMAKE_INCLUDE_CURRENT_DIR ON)
set(CMAKE_AUTOMOC ON)find_package(Qt5 COMPONENTS Core Gui Widgets PrintSupport)
##############################################################################

3. 在工作空间（WS）下编译工作单元（package），catkin_make（略）

...\*_ws\src\catkin_make

4. rosrun 验证输出

如果编译成功，但是 rosrun 新编译单元 无法使用 tab 补齐，那么直接手动输入新编译单元名称后（如：turtle_demo）tab一下会补齐单元下的节点名（node）

---

---

[ROS] [笔记] 简易，cpp+qt 实现 Gui

1. cpp+qt 简单节点的实现

实现步骤：

1. 代码
2. 编译+source（略）
3. 实现（略）

1. 代码

//
// Created by jacob on 11/19/20.
// cpp+qt simple gui pop
//#include <iostream>
#include <ros/ros.h>
#include <QApplication>
#include <QtWidgets>using namespace std;/***-------------------- btnclicked event callback --------------------***/
void btnClicked(){cout << "clicked" << endl;
}int main(int argc, char **argv) {/***-------------------- for node --------------------***/string nodeName = "turtle_ctrl_node";ros::init(argc, argv, nodeName);ros::NodeHandle node;/***-------------------- for qt --------------------***/QApplication app(argc, argv);    // create qt appQWidget window;                     // create qt windowQApplication::setActiveWindow(&window);       // set window as activate window// layout and widgetsauto layout = new QFormLayout();window.setLayout(layout);auto editLinear = new QLineEdit();editLinear->setText("0.0");layout->addRow("L-speed", editLinear);auto editAngular = new QLineEdit();editAngular->setText("0.0");layout->addRow("A-speed", editAngular);auto *btnSend = new QPushButton("send");layout->addRow(btnSend);// eventsbtnSend->connect(btnSend, &QPushButton::clicked, &window, btnClicked);window.show();QApplication::exec();return 0;}

---

2. cpp+qt publisher 节点的实现

实现步骤：

1. 代码
2. 编译+source（略）
3. 实现

角度弧度转换公式
// radian = angle * PI / 180
// angle = radian * 180 / PI

1. 代码

//
// Created by jacob on 11/19/20.
// cpp+qt simple gui pop
//#include <iostream>
#include <ros/ros.h>
#include <geometry_msgs/Twist.h>
#include <QApplication>
#include <QtWidgets>using namespace std;/***-------------------- global variable --------------------***/
const ros::Publisher *publisher_ptr;
QLineEdit *editLinear;
QLineEdit *editAngular;
QPushButton *btnSend;/***-------------------- btnclicked event callback --------------------***/
void btnClicked(){cout << "clicked" << endl;// get data from line editordouble linearX = editLinear->text().toDouble();double angularZ = editAngular->text().toDouble();// create msggeometry_msgs::Twist twist;twist.linear.x = linearX;// radian = angle * PI / 180// angle  = radian * 180 / PItwist.angular.z = angularZ * M_PI / 180;// send msgpublisher_ptr->publish(twist);
}int main(int argc, char **argv) {/***-------------------- for node ops --------------------***/// 1. create a noderos::init(argc, argv, "turtle_ctrl_node");              // alt+ctrl+n: inlineros::NodeHandle node;// 2. create publisher through nodestring topicName = "/turtle1/cmd_vel";                           // frequency bandconst ros::Publisher &publisher = node.advertise<geometry_msgs::Twist>(topicName, 1000);publisher_ptr = &publisher;/***-------------------- for qt ops --------------------***/QApplication app(argc, argv);                                // create qt appQWidget window;                                                 // create qt windowQApplication::setActiveWindow(&window);                         // set window as activate window// layout and widgetsauto layout = new QFormLayout();window.setLayout(layout);editLinear = new QLineEdit();editLinear->setText("0.0");layout->addRow("L-speed", editLinear);editAngular = new QLineEdit();editAngular->setText("0.0");layout->addRow("A-speed", editAngular);btnSend = new QPushButton("send");layout->addRow(btnSend);// eventsQPushButton::connect(btnSend, &QPushButton::clicked, &window, btnClicked);window.show();QApplication::exec();return 0;}

找到 advertise 模板类型 M 的方法

jacob@ubuntu:~/ROSWS/first_ws$ rosnode info /turtlesim
--------------------------------------------------------------------------------
Node [/turtlesim]
Publications:* /rosout [rosgraph_msgs/Log]* /turtle1/color_sensor [turtlesim/Color]* /turtle1/pose [turtlesim/Pose]Subscriptions:* /turtle1/cmd_vel [unknown type]                      // here to find subscription frequency bandServices:* /clear* /kill* /reset* /spawn* /turtle1/set_pen* /turtle1/teleport_absolute* /turtle1/teleport_relative* /turtlesim/get_loggers* /turtlesim/set_logger_levelcontacting node http://ubuntu:35049/ ...
Pid: 3578
Connections:* topic: /rosout* to: /rosout* direction: outbound (53525 - 127.0.0.1:51236) [24]* transport: TCPROSjacob@ubuntu:~/ROSWS/first_ws$ rostopic
rostopic is a command-line tool for printing information about ROS Topics.Commands:rostopic bw	display bandwidth used by topicrostopic delay	display delay of topic from timestamp in headerrostopic echo	print messages to screenrostopic find	find topics by typerostopic hz	display publishing rate of topicrostopic info	print information about active topic                    // here to get topic-inforostopic list	list active topicsrostopic pub	publish data to topicrostopic type	print topic or field typeType rostopic <command> -h for more detailed usage, e.g. 'rostopic echo -h'jacob@ubuntu:~/ROSWS/first_ws$ rostopic info /turtle1/cmd_vel               // here to get topic-info of subs.
Type: geometry_msgs/TwistPublishers: NoneSubscribers:* /turtlesim (http://ubuntu:35049/)

2. 编译+source（略）

3. 实现

L-speed: linear speed，直线速度
A-speed: angular speed，角速度（使用的是角度）
点击send，龟娃儿会转圈圈

启动龟龟模拟器

---

---

[ROS] [笔记] 面向对象，cpp+qt 实现 Gui

面向对象窗口框架搭建

1. 创建窗口类：VelCtrlWindow.h, VelCtrlWindow.cpp (velocity control window)
2. 将 VelCtrlWindow.h 头文件移动到 ..\turtle_demo\include\turtle_demo 中
3. 编写 CmakeLists

1. 创建窗口类
2. 移动头文件

将 VelCtrlWindow.cpp 中 画圈部分去掉也可以

3. 编写 CmakeLists(只显示对窗口类的配置)

修改 include_directories()，加载窗口类的头文件

修改 add_executable()，添加窗口类的源文件

思考：如何使用 aux_source_directory()

面向对象代码实现

能照抄，绝不敲键盘，高效代码产出金玉良言 — 某知名码农

VelCtrlWindow.h

//
// Created by jacob on 11/19/20.
//#ifndef TURTLE_DEMO_VELCTRLWINDOW_H
#define TURTLE_DEMO_VELCTRLWINDOW_H#include <QtWidgets/QWidget>
#include <QtWidgets/QFormLayout>
#include <QtWidgets/QLineEdit>
#include <QtWidgets/QPushButton>
#include <ros/ros.h>class VelCtrlWindow : public QWidget {
public:explicit VelCtrlWindow(ros::NodeHandle node, QWidget *parent = nullptr);~VelCtrlWindow() override;public:void btnClicked();private:QFormLayout *layout;QLineEdit *editLinear;QLineEdit *editAngular;QPushButton *btnSend;private:ros::NodeHandle node;ros::Publisher publisher;};#endif //TURTLE_DEMO_VELCTRLWINDOW_H

VelCtrlWindow.cpp

//
// Created by jacob on 11/19/20.
//#include "VelCtrlWindow.h"#include <iostream>
#include <QtWidgets>
#include <geometry_msgs/Twist.h>VelCtrlWindow::VelCtrlWindow(ros::NodeHandle node, QWidget *parent): node(node), QWidget(parent) {// layout and widgetslayout = new QFormLayout();this->setLayout(layout);editLinear = new QLineEdit();editLinear->setText("0.0");layout->addRow("L-speed", editLinear);editAngular = new QLineEdit();editAngular->setText("0.0");layout->addRow("A-speed", editAngular);btnSend = new QPushButton("send");layout->addRow(btnSend);// eventQPushButton::connect(btnSend, &QPushButton::clicked, this, &VelCtrlWindow::btnClicked);// 2. create publisher through nodestd::string topicName = "/turtle1/cmd_vel";publisher = node.advertise<geometry_msgs::Twist>(topicName, 1000);
}VelCtrlWindow::~VelCtrlWindow() {std::cout << "deconstructed..." << std::endl;
}void VelCtrlWindow::btnClicked() {std::cout << "clicked..." << std::endl;// get data from line editordouble linearX = editLinear->text().toDouble();double angularZ = editAngular->text().toDouble();// create msggeometry_msgs::Twist twist;twist.linear.x = linearX;twist.angular.z = angularZ * M_PI / 180;// send msgpublisher.publish(twist);
}

turtle_control_publisher_OOP 启动项

#include <ros/ros.h>
#include <QtWidgets/QApplication>#include "VelCtrlWindow.h"int main(int argc, char **argv) {/***-------------------- for node ops --------------------***/// 1. create a noderos::init(argc, argv, "turtle_ctrl_node");              // alt+ctrl+n: inlineros::NodeHandle node;// 2. create windowQApplication app(argc, argv);VelCtrlWindow window(node);window.show();return QApplication::exec();}

---

---

[ROS] [笔记] 简易，pyqt 实现 Gui

1. 配置 python 环境

#!/usr/bin/env python
# coding: utf-8

注意：
写python脚本时要加环境头
ros melodic集成了pyqt开发环境，可以直接调用pyqt包
ros 的python代码在执行之前需要修改权限 chomd u+x …py，获取执行权限

2. 代码实现（见面向对象gui实现）

3. 验证结果（见面向对象gui实现）

---

---

[ROS] [笔记] 面向对象，pyqt 实现 Gui

1. 代码实现

**turtle_ctrl.py启动程序 **

#! /usr/bin/env python
# coding-utf-8import sys
import rospyfrom PyQt5.QtWidgets import *
from VelCtrlWindow import MainWindow"""------------------------- testing block -------------------------"""
if __name__ == '__main__':# 1. create noderospy.init_node("turtle_ctrl_node")  # py code will add .py for node# 2. create windowapp = QApplication(sys.argv)window = MainWindow()  # change here for OOD window classwindow.show()app.exec_()

VelctrlWindow.py窗口程序

#! /usr/bin/env python
# coding = utf-8
import rospy
from PyQt5.QtWidgets import QWidget, QFormLayout, QLineEdit, QPushButton
from geometry_msgs.msg import Twist
from math import radiansclass MainWindow(QWidget):def __init__(self):super(MainWindow, self).__init__()# set windowself.setWindowTitle("turtle-sim-py")layout = QFormLayout()self.setLayout(layout)self.editLinear = QLineEdit("0.0")layout.addRow("v_linear", self.editLinear)self.editAngular = QLineEdit("0.0")layout.addRow("a_linear", self.editAngular)self.btn = QPushButton("send")layout.addRow(self.btn)# set button eventself.btn.clicked.connect(self.btn_clicked)# create publisher c+a+n--inlineself.publisher = rospy.Publisher("/turtle1/cmd_vel", Twist, queue_size=1000)def btn_clicked(self):print "clicked..."# get data from widgetlinearX = float(self.editLinear.text())angularY = radians(float(self.editAngular.text()))  # angle --> radianprint "linearX:{0}, angularY:{1}".format(linearX, angularY)# create msgtwist = Twist()twist.linear.x = linearXtwist.angular.z = angularY# publishself.publisher.publish(twist)

2. 验证结果