機(jī)器人操作系統(tǒng)（ROS2）入門與實(shí)踐 課件 第6章 IMU在ROS2中的使用

機(jī)器人操作系統(tǒng)（ROS2）入門與實(shí)踐機(jī)器人操作系統(tǒng)（ROS2）入門與實(shí)踐第1章LinuxUbuntu入門基礎(chǔ)第2章ROS2安裝與系統(tǒng)架構(gòu)第3章ROS2編程基礎(chǔ)第4章ROS2機(jī)器人運(yùn)動(dòng)控制第5章激光雷達(dá)在ROS2中的使用第6章IMU在ROS2中的使用第7章ROS2中的SLAM環(huán)境建圖第8章ROS2中的NAV2自主導(dǎo)航第9章ROS2中的圖像視覺應(yīng)用第10章ROS2的三維視覺應(yīng)用第11章ROS2的機(jī)械臂應(yīng)用第12章基于ROS2的綜合應(yīng)用第6章6.3基于IMU的航向鎖定實(shí)現(xiàn)

第6章IMU在ROS2中的使用6.2IMU數(shù)據(jù)獲取6.1IMU的話題名稱6.4本章小結(jié)

與激光雷達(dá)一樣，ROS2中的IMU節(jié)點(diǎn)會(huì)在特定的話題里發(fā)布數(shù)據(jù)消息。話題名稱在REP-145中建議為“/imu/data_raw”、“/imu/data”和“/imu/mag”三個(gè)。6.1ROS2里的IMU數(shù)據(jù)話題內(nèi)容/imu/data_raw加速度計(jì)輸出的矢量加速度和陀螺儀輸出的旋轉(zhuǎn)加速度。/imu/data/imu/data_raw的數(shù)據(jù)再加上融合后的四元數(shù)姿態(tài)描述/imu/mag磁強(qiáng)計(jì)輸出的磁強(qiáng)數(shù)據(jù)IMU數(shù)據(jù)的獲取是通過訂閱IMU節(jié)點(diǎn)發(fā)布的話題，從話題中獲取IMU節(jié)點(diǎn)發(fā)出的消息包來實(shí)現(xiàn)的。如圖所示：6.2IMU數(shù)據(jù)獲取詳細(xì)操作步驟見教材P155-P166頁(yè)cd~/ros2_ws/srcros2pkgcreateimu_pkg1、編寫節(jié)點(diǎn)代碼新建文件，命名為“imu_data.cpp”。6.2IMU數(shù)據(jù)獲取6.2.1編寫IMU數(shù)據(jù)獲取程序#include<rclcpp/rclcpp.hpp>#include<sensor_msgs/msg/imu.hpp>#include<tf2/LinearMath/Quaternion.h>#include<tf2/LinearMath/Matrix3x3.h>

std::shared_ptr<rclcpp::Node>node;

voidIMUCallback(constsensor_msgs::msg::Imu::SharedPtrmsg){tf2::Quaterniontf2_quaternion;tf2_quaternion.setX(msg->orientation.x);tf2_quaternion.setY(msg->orientation.y);tf2_quaternion.setZ(msg->orientation.z);tf2_quaternion.setW(msg->orientation.w);

tf2::Matrix3x3matrix(tf2_quaternion);

doubleroll,pitch,yaw;matrix.getRPY(roll,pitch,yaw);roll=roll*180/M_PI;pitch=pitch*180/M_PI;yaw=yaw*180/M_PI;RCLCPP_INFO(node->get_logger(),"roll=%.0fpitch=%.0fyaw=%.0f",roll,pitch,yaw);}6.2IMU數(shù)據(jù)獲取intmain(intargc,char**argv){rclcpp::init(argc,argv);

node=std::make_shared<rclcpp::Node>("imu_data_node");

autosub=node->create_subscription<sensor_msgs::msg::Imu>("/imu",10,IMUCallback);

rclcpp::spin(node);

rclcpp::shutdown();

return0;}6.2IMU數(shù)據(jù)獲取2、設(shè)置編譯規(guī)則3、修改軟件包信息4、編譯軟件包find_package(rclcppREQUIRED)find_package(sensor_msgsREQUIRED)find_package(tf2REQUIRED)add_executable(imu_datasrc/imu_data.cpp)ament_target_dependencies(imu_data"rclcpp""sensor_msgs""tf2")install(TARGETSimu_dataDESTINATIONlib/${PROJECT_NAME})<depend>rclcpp</depend><depend>sensor_msgs</depend><depend>tf2</depend>cd~/ros2_wscolconbuild6.2IMU數(shù)據(jù)獲取6.2.2仿真運(yùn)行雷達(dá)數(shù)據(jù)獲取程序sourceinstall/setup.bashros2launchwpr_simulation2wpb_simple.launch.pysourceinstall/setup.bashros2runimu_pkgimu_data6.2IMU數(shù)據(jù)獲取打開第2個(gè)子窗口。6.2IMU數(shù)據(jù)獲取

下面實(shí)現(xiàn)一個(gè)航向鎖定的功能。編寫一個(gè)節(jié)點(diǎn)，先訂閱“/imu/data”話題。從此話題中接收IMU節(jié)點(diǎn)發(fā)來的sensor_msgs::Imu類型消息包，解析出機(jī)器人的姿態(tài)角度。設(shè)置一個(gè)目標(biāo)航向角度，讓機(jī)器人朝著這個(gè)航向運(yùn)動(dòng)。若運(yùn)行過程中機(jī)器人的姿態(tài)被改變了，導(dǎo)致航向角與目標(biāo)角度不一致。則根據(jù)航向角偏差值，計(jì)算出糾偏速度值，打包成geometry_msgs::Twist類型的消息包，發(fā)布到“/cmd_vel”話題中。機(jī)器人底盤節(jié)點(diǎn)會(huì)從“/cmd_vel”話題獲取速度值并執(zhí)行，以此來實(shí)現(xiàn)航向鎖定的行為。如圖所示：6.3基于IMU的航向鎖定實(shí)現(xiàn)詳細(xì)操作步驟見教材P167-P179頁(yè)1、編寫節(jié)點(diǎn)代碼新建文件，命名為“imu_behavior.cpp”。6.3基于IMU的航向鎖定實(shí)現(xiàn)6.3.1編寫航向鎖定程序按照上一個(gè)實(shí)驗(yàn)，在工作空間中創(chuàng)建一個(gè)imu_pkg軟件包。如果已經(jīng)創(chuàng)建好了，可以直接使用，不用再重復(fù)創(chuàng)建。具體操作步驟如下：#include<rclcpp/rclcpp.hpp>#include<sensor_msgs/msg/imu.hpp>#include<geometry_msgs/msg/twist.hpp>#include<tf2/LinearMath/Quaternion.h>#include<tf2/LinearMath/Matrix3x3.h>

std::shared_ptr<rclcpp::Node>node;rclcpp::Publisher<geometry_msgs::msg::Twist>::SharedPtrvel_pub;

voidIMUCallback(constsensor_msgs::msg::Imu::SharedPtrmsg){tf2::Quaterniontf2_quaternion;tf2_quaternion.setX(msg->orientation.x);tf2_quaternion.setY(msg->orientation.y);tf2_quaternion.setZ(msg->orientation.z);tf2_quaternion.setW(msg->orientation.w);

tf2::Matrix3x3matrix(tf2_quaternion);

doubleroll,pitch,yaw;matrix.getRPY(roll,pitch,yaw);roll=roll*180/M_PI;pitch=pitch*180/M_PI;yaw=yaw*180/M_PI;RCLCPP_INFO(node->get_logger(),"roll=%.0fpitch=%.0fyaw=%.0f",roll,pitch,yaw);6.3基于IMU的航向鎖定實(shí)現(xiàn)doubletarget_yaw=90;

geometry_msgs::msg::Twistvel_msg;doublediff_angle=target_yaw-yaw;vel_msg.angular.z=diff_angle*0.01;vel_msg.linear.x=0.1;vel_pub->publish(vel_msg);}

intmain(intargc,char**argv){rclcpp::init(argc,argv);

node=rclcpp::Node::make_shared("imu_behavior_node");

autosub=node->create_subscription<sensor_msgs::msg::Imu>("imu",10,IMUCallback);

vel_pub=node->create_publisher<geometry_msgs::msg::Twist>("/cmd_vel",10);

rclcpp::spin(node);

rclcpp::shutdown();

return0;}6.3基于IMU的航向鎖定實(shí)現(xiàn)2、設(shè)置編譯規(guī)則3、修改軟件包信息4、編譯軟件包find_package(rclcppREQUIRED)find_package(sensor_msgsREQUIRED)find_package(tf2REQUIRED)find_package(geometry_msgsREQUIRED)add_executable(imu_behaviorsrc/imu_behavior.cpp)ament_target_dependencies(imu_behavior"rclcpp""sensor_msgs""tf2""geometry_msgs")install(TARGETSimu_dataimu_behaviorDESTINATIONlib/${PROJECT_NAME})<depend>rclcpp</depend><depend>sensor_msgs</depend><depend>tf2</depend><depend>geometry_msgs</depend>cd~/ros2_wscolconbuild6.3基于IMU的航向鎖定實(shí)現(xiàn)sourceinstall/setup.bashros2launchwpr_simulation2wpb_simple.launch.pysourceinstall/setup.bashros2runimu_pkgimu_behavior6.3基于IMU的航向鎖定實(shí)現(xiàn)6.3.2仿真運(yùn)行航向鎖定程序打開第2個(gè)子窗口。6