Backup of ROS integration(No. 7)

Tutorial?

The aim of this tutorial is to explain how to integrate SIGVerse with ROS operating system.

First, we will show how to install ROS on your operating system, then we will explain step by step how to run SIGVerse controller in ROS node and how to communicate with another node.

The ROS part tutorial is based on the official ROS wiki, you can check it for more details.

Installing ROS
- Creating ROS workspace
Overview
Creating the package
- Compiling the project
Source Code understanding
world file
Running the server
Download the project

Installing ROS †

= Ubuntu install of ROS Groovy =

We are building Debian packages for several Ubuntu platforms, listed below. These packages are more efficient than source-based builds and are our preferred installation method for Ubuntu.

If you need to install from source (not recommended), please see groovy/Installation/Source|source (download-and-compile) installation instructions?.

=== Installation ===

First, make sure your Debian package index is up-to-date:

 $ sudo apt-get update

There are many different libraries and tools in ROS. We provided four default configurations to get you started. You can also install ROS packages individually.

 
  $ sudo apt-get install ros-groovy-desktop-full

  $ sudo apt-get install ros-groovy-desktop

ROS-Base: (Bare Bones)

ROS package, build, and communication libraries. No GUI tools.

 $ sudo apt-get install ros-groovy-ros-base

Individual Package:

You can also install a specific ROS package (replace underscores with dashes of the package name):

$ sudo apt-get install ros-groovy-PACKAGE

$ sudo apt-get install ros-groovy-slam-gmapping

To find available packages, use:

$ apt-cache search ros-groovy

=== Initialize rosdep ===

Before you can use ROS, you will need to initialize `rosdep`. `rosdep` enables you to easily install system dependencies for source you want to compile and is required to run some core components in ROS.

$ sudo rosdep init
$ rosdep update

=== Getting rosinstall ===

rosinstall? is a frequently used command-line tool in ROS that is distributed separately. It enables you to easily download many source trees for ROS packages with one command.

To install this tool on Ubuntu, run:

$ sudo apt-get install python-rosinstall

↑

Creating ROS workspace †

In our project we are using catkin, here are the steps to follow to create a ROS workspace:

Run the following command:

$ source /opt/ros/groovy/setup.sh

To create a catkin workspace:

$ mkdir -p ~/catkin_ws/src
$ cd ~/catkin_ws/src
$ catkin_init_workspace

You can build even though no project is created yet, you just need MakeLists.txt:

$ cd ~/catkin_ws/
$ catkin_make

Run the setup.bash

$ source devel/setup.bash

↑

Overview †

In order to integrate SIGVerse and ROS, we first need to create ROS package containing two nodes, SIGVerse controller node and ROS command node. The first node, SIGVerse controller node, will receive data from the SIGViewer as messages, then publish them on the message topic, in the other part, ROS command node reads these data and subscribe the corresponding velocity on the velocity topic, the velocity command will be retrieved by the SIGVerse controller node to be used for controlling the robot.

↑

Creating the package †

We need to create a new package in the catkin_ws directory containing two nodes.

To create a new package, go to catkin_ws:

$ cd ~/catkin_ws/src
$ catkin_create_pkg sig_ros

Create two new cpp files named sig_app.cpp and sig_command.cpp

$ cd ~/catkin_ws/sig_ros/src/
$ vim sig_app.cpp
$ vim sig_command.cpp

↑

Compiling the project †

You need to have Cmake installed on your server.

Let's edit the CMakeLists.txt file to compile the project:

Cmake parameters:

cmake_minimum_required(VERSION 2.8.3)
project(Sigvers_Ros)
 find_package(catkin REQUIRED COMPONENTS roscpp rospy std_msgs message_generation )
## Generate messages in the 'msg' folder
    add_message_files(
    FILES
    Velocity.msg
    )
 ## Generate added messages and services with any dependencies listed here
    generate_messages(
    DEPENDENCIES
    std_msgs
    )
 ## include libraries
 include_directories(include ${catkin_INCLUDE_DIRS})
 include_directories(/home/ericgt/sigverse-2.2.0/include/sigverse/home/ericgt/sigverse-2.2.0/include/sigverse/comm/controller)

These lines allow to generate the sig_command node:

add_executable(sig_command src/sig_command.cpp)
target_link_libraries(sig_command ${catkin_LIBRARIES})
add_dependencies(sig_command sig_ros_gencpp)

These lines allow to generate the sig_app library:

ADD_LIBRARY(sig_ros/sig_app src/sig_app.cpp)
target_link_libraries(sig_ros/sig_app ${catkin_LIBRARIES})
add_dependencies(sig_ros/sig_app sig_ros_gencpp)

To compile the package, run the following commands:
```
$ cd ~/catkin_ws
$ catkin_make
```

A new library will be generated in ~/catkin_ws/devel/libsig_ros.

Run the following command to add this package to ROS packages:

  $source ~/catkin_ws2/devel/setup.sh

Now let's check if our package is recognized by ROS:
```
& Roscd sig_ros
```

We must have the following output:

$ CMakeLists.txt include msg package.xml src

This shows that the sig_ros package exists.

↑

Source Code understanding †

↑

SIGVerse controller node †

sig_app.cpp

Let’s study this example step by step The following is the callback function which preforms the command on the velocity of the robot’s wheels:

↑

Message Sender †

  void SendController::poseCallback(const Sigvers_Ros::VelocityConstPtr& vel)
  {     Wheel_one =  vel->linear;
        Wheel_two =  vel->angular;
     
        printf("Velocity 1!!!  %f\n", Wheel_one);
        printf("Velocity 2!!!  %f\n", Wheel_two);
     
  }

Read from the Velocity Topic.
Print the Velocity value applied on the robot.

↑

Node Initialization †

 void SendController::onInit(InitEvent &evt)
  { Wheel_one = 0.0;
   Wheel_two = 0.0;
   int argc =0;
   char** argv = NULL;
   my = this->getRobotObj(this->myname());
   my->setWheel(10.0, 10.0);
   ros::init(argc, argv, "Sigvers_controller_node");
   ros::NodeHandle n;
   velocity = 1;
   chatter_pub = n.advertise<std_msgs::String>("CommandMess", 1);
   pose_sub = n.subscribe<Sigvers_Ros::Velocity>("mycommand_velocity",    1,&SendController::poseCallback,this);
   ros::Rate loop_rate(10);
  }

↑

Robot Controller †

double SendController::onAction(ActionEvent &evt)
{
 my->setWheelVelocity(Weel_one,Weel_two);
 ros::spinOnce();
 return 1.0;
}

↑

ROS command node †

sig_command.cpp:

This is the node that controls the robot’s velocity:

↑

Command Node initialization ROS Side †

 CommandSig::CommandSig():
  linear_(0),
  angular_(0),
  l_scale_(2.0),
  a_scale_(2.0)
  {
   nh_.param("scale_angular", a_scale_, a_scale_);
   nh_.param("scale_linear", l_scale_, l_scale_);
   vel_pub_ = nh_.advertise<Sigvers_Ros::Velocity>("mycommand_velocity", 1);
   mess_sub =    nh_.subscribe("CommandMess",100,&CommandSig::chatterCallback,this);
   
   }

Initialization of the command Node's Parameters

The Node will send velocity information using mycommand_velocity Topic

The Node will receive information using CommandMess Topic

And finally let’s write the main function which launches the command node

↑

Main to execute the Node †

int main(int argc, char** argv)
 {
  ros::init(argc, argv, "Sigvers_Command_node");
  CommandSig Command_sig;
  ros::Rate loop_rate(10);
  ros::spin();
  return(0);
 }

this command creates and does initialization on the Sigvers_Command_node Node

↑

Message Sender †

Now let’s create the callback function which receveces message from Sigverse - Node and sends the right command to the robot:

↑

Robot Motion Command ROS Side †

  void CommandSig::chatterCallback (const std_msgs::String::ConstPtr& msg)
  {
   Sigvers_Ros::Velocity vel;
   if(strcmp("go",msg->data.c_str())==0)
   {
   vel.angular = 3.0;
   vel.linear = 3.0;
   vel_pub_.publish(vel);
   }
   else if(strcmp("back",msg->data.c_str())==0)
  {
   vel.angular = -3.0;
   vel.linear = -3.0;
   vel_pub_.publish(vel);
   }
   else if(strcmp("left" ,msg->data.c_str())==0)
  {
  vel.angular = 0.78;
  vel.linear = -0.78;
  vel_pub_.publish(vel);
  sleep(1.8);
  vel.angular = 0.0;
  vel.linear = 0.0;
  vel_pub_.publish(vel);
  }
  else if(strcmp("right" ,msg->data.c_str())==0)
  {
  vel.angular = -0.78;
  vel.linear = 0.78;
  vel_pub_.publish(vel);
  sleep(1.8);
  vel.angular = 0.0;
  vel.linear =  0.0;
  vel_pub_.publish(vel);
  }
  else if(strcmp("stop",msg->data.c_str())==0)
 {
  vel.angular = 0.0;
  vel.linear = 0.0;
  vel_pub_.publish(vel);
 }
………
}

↑

world file †

RobotInMove.xml:

<?xml version="1.0" encoding="utf-8"?>
<world name="myworld1">
 <gravity x="0.0" y="-980.7" z="0.0"/>
<instanciate class="WheelRobot-nii-v1.xml" type="Robot">
   <set-attr-value name="name" value="robot_000"/>
   <set-attr-value name="language" value="c++"/>
   <set-attr-value name="implementation"
                   value="./libSig_app.so"/>
   <set-attr-value name="dynamics" value="false"/>
   <set-attr-value name="x" value="-100.0"/>
   <set-attr-value name="y" value="30.0"/>
   <set-attr-value name="z" value="-130.0"/>
   <set-attr-value name="collision" value="true"/>
   <!--stereo camera right-->
   <camera id="1"
           link="REYE_LINK"
           direction="0.0 -1.0 1.0"
           position="0.0 0.0 3.0"/>
   <!--stereo camera left-->
   <camera id="2"
           link="LEYE_LINK"
           direction="0.0 -1.0 1.0"
           position="0.0 0.0 3.0"/>
   <!--distance sensor-->
   <camera id="3"
           link="WAIST_LINK0"
           direction="0.0 1.0 0.0"
           position="0.0 -5.0 20.0"/>
   <!--monitoring camera-->
   <camera id="4"
           link="WAIST_LINK2"
           direction="0 0 1"
           quaternion="0.0 0.0 -0.966 0.259"
           position="0.0 40.0 120.0"/>
 </instanciate>
</world>

↑

Running the server †

To run the server you have to follow the following steps:

Go to catkin_ws and execute the follwing command :

Run the ROS system:

$ roscore

run the ros ROS node :

$ rosrun key_sig sig_app

Go to ~/catkin_ws/devel/lib/libsig_app and run the sigverse controller:

$ cd ~/catkin_ws/devel/lib/libsig_app
$ sigserver.sh -w ./move_robot.xml

↑

Download the project †

To download the project from GIT repository, use the following link:

git@socio4.iir.nii.ac.jp:~/SigverseGitServer/unstable/usersContribution/tafifet/ROS_SIG_Integration.git

Backup of ROS integration (No. 7)

Installing ROS †

Creating ROS workspace †

Overview †

Creating the package †

Compiling the project †

Source Code understanding †

SIGVerse controller node †

Message Sender †

Node Initialization †

Robot Controller †

ROS command node †

Command Node initialization ROS Side †

Main to execute the Node †

Message Sender †

Robot Motion Command ROS Side †

world file †

Running the server †

Download the project †