ROS Robot Operating System. Robotica Prof. Davide Brugali Università degli Studi di Bergamo

Transcription

1 ROS Robot Operating System Robotica Prof. Davide Brugali Università degli Studi di Bergamo

2 Tutorials [online] [2014] Jason M. O Kane A Gentle Introduction to ROS [2013] Aaron Martinez, Enrique Fernández Learning ROS for Robotics Programming NGS/Learning20ROS%20for%20Robotics%20Programming%20% 5BeBook%5D.pdf 2

3 Sviluppo di un sistema composto da tre nodi velocity_keyboard Implementato da noi VelocityCmd velocity_controller Implementato da noi Twist turtlesim Fornito con ROS 3

4 Workspace di sviluppo per ROS mobile_robot / -- WORKSPACE src / -- SOURCE SPACE (contains the packages) CMakeLists.txt -- The 'toplevel' CMake file build / -- BUILD SPACE CATKIN_IGNORE devel / -- DEVELOPMENT SPACE Workspace CMakeList.txt / ROS-Tutorial /mobile_robot/ 4

5 Creazione del Workspace e compilazione $ mkdir ~ / ROS-Tutorial / mobile_robot / src $ cd ~ / ROS-Tutorial / mobile_robot / src $ catkin_init_workspace $ cd ~ / ROS-Tutorial / mobile_robot $ catkin_make $ source devel / setup.bash 5

6 ROS Packages Software in ROS is organized in packages. A package might contain ROS nodes, a ROS-independent library, a dataset, configuration files, a third-party piece of software, or anything else that logically constitutes a useful module. The goal of these packages it to provide this useful functionality in an easy-to-consume manner so that software can be easily reused. This means that a package is the smallest individual thing you can build in ROS and it is the way software is bundled for release (meaning, for example, there is one debian package for each ROS package), respectively. 6

7 Workspace di sviluppo per ROS packages velocity_keyboard velocity_controller Node velocity_keyboard_node.hpp velocity_keyboard_node.cpp velocity_controller_node.hpp velocity_controller_node.cpp Class VelocityKeyboard.hpp VelocityKeyboard.cpp VelocityController.hpp VelocityController.cpp turtlesim Message VelocityCmd.msg CMakeList.txt package.xml CMakeList.txt package.xml Workspace CMakeList.txt / ROS-Tutorial /mobile_robot/ 7

8 Package velocity_keyboard $ cd ~/ROS-Tutorial/mobile_robot/src $ catkin_create_pkg velocity_keyboard std_msgs rospy roscpp $ source ~/ROS-Tutorial/mobile_robot/devel/setup.bash mobile_robot / src / CMakeLists.txt velocity_keyboard/ CMakeLists.txt package.xml -- package 8

9 ROS Nodes A node is a process that performs computation. Nodes are combined together into a graph and communicate with one another using streaming topics, RPC services, and the Parameter Server. These nodes are meant to operate at a fine-grained scale; a robot control system will usually comprise many nodes. For example, one node controls a laser range-finder, one Node controls the robot's wheel motors, one node performs localization, one node performs path planning, one node provide a graphical view of the system, and so on. 9

10 ROS Nodes All running nodes have a graph resource name that uniquely identifies them to the rest of the system. For example, /hokuyo_node could be the name of a Hokuyo driver broadcasting laser scans. Nodes also have a node type, that simplifies the process of referring to a node executable on the fileystem. These node types are package resource name with the name of the node's package and the name of the node executable file. In order to resolve a node type, ROS searches for all executables in the package with the specified name and chooses the first that it finds. As such, you need to be careful and not produce different executables with the same name in the same package. 10

11 Nodo velocity_keyboard velocity_keyboard_node main program N.B. comando per spostarsi direttamente nella cartella base di un package VelocityKeyboard class $ roscd velocity_keyboard/ $ gedit include/velocitykeyboard.hpp $ gedit src/velocitykeyboard.cpp 11

12 VelocityKeyboard.hpp 12

13 13

14 velocity_keyboard_node.hpp 14

15 velocity_keyboard_node.cpp 15

16 Messaggio VelocityCmd 16 velocity_keyboard include VelocityKeyboard.hpp velocity_keyboard_node.hpp msg VelocityCmd.msg src VelocityKeyboard.cpp velocity_keyboard_node.cpp CMakeList.txt package.xml

17 Messaggio VelocityCmd VelocityCmd.msg int8 command 17

18 VelocityController.hpp 18

19 VelocityController.cpp 19 etc.

20 velocity_controller_node.hpp 20

21 velocity_controller_node.cpp 21

22 velocity_controller_node.cpp 22

23 CMakeLists.txt ## Declare a cpp executable add_executable(velocity_keyboard_node src/velocitykeyboard.cpp src/velocity_keyboard_node.cpp) nome del file eseguibile 23

24 Compilare il codice sorgente in ROS Aprire un terminale selezionando l icona Digitare i seguenti comandi: $ cd ~/ROS-Tutorial/mobile_robot/src $ source ~/ROS-Tutorial/mobile_robot/devel/setup.bash $ catkin_make Se serve, modificare il codice sorgente Ricompilare i progetti con il comando catkin_make 24

25 Creare il progetto Eclipse per un package $ catkin_make --force-cmake -G"Eclipse CDT4 Unix Makefiles" $ cd ~/ROS-Tutorial/mobile_robot/build $ cmake../src -DCMAKE_BUILD_TYPE=Debug $ cd ~/ROS-Tutorial/mobile_robot/ $ mkdir eclipse // Eclipse workspace folder $ source ROS-Tutorial/mobile_robot/devel/setup.bash $ eclipse // avvia Eclipse da terminal In Eclipse : File / Import / General /Existing Project Selezionare la cartella ROS-Tutorial/mobile_robot/build Selezionare il progetto elencato 25

26 ROS Messages velocity_controller Twist turtlesim geometry_msgs / Twist.msg nav_msgs / Odometry.msg 26

27 POSE 27

28 TWIST 28

29 Odometry 29

30 Esecuzione di programmi ROS Cambiare workspace di Ubuntu selezionando l icona Selezionare una delle trefinestre libere Aprire quattro terminali cliccando il tasto destro sull icona 30

31 Digitare i seguenti comandi TERMINALE 1 : avviare il core di ROS $ roscore TERMINALE 2 : avviare il simulatore del robot Turtle $ source ~/ROS-Tutorial/mobile_robot/devel/setup.bash $ rosrun turtlesim turtlesim_node 31

32 Digitare i seguenti comandi TERMINALE 3 : avviare l applicazione velocity_controller $ source ~/ROS-Tutorial/mobile_robot/devel/setup.bash $ roscd velocity_controller $ rosrun velocity_controller velocity_controller_node TERMINALE 4 : avviare l applicazione velocity_keyboard $ source ~/ROS-Tutorial/mobile_robot/devel/setup.bash $ roscd velocity_keyboard $ rosrun velocity_keyboard velocity_keyboard_node 32

33 Simulatore TurtleSim 33

34 Sviluppo di un sistema composto da tre nodi Keyboard Target position_controller Twist Odometry turtlesim 34