Backup of SIGVerse ROS Integration(No. 2)

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SIGVerse Ros tutorial on SIGverse

How to Use ROS with SIGverse
User has to create A SIGverse node using the following code:
- In this tutorial two topics are used
- Message Topic to send messages from SIGverse Node to Command Node and Velocity --format Topic to send the value of velocity to the SIGverse node.

Overview
The Topic

Overview †

↑

The Topic †

Let’s study this example step by step Now let’s create 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
Printing 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;
}

Now let’s create a Node to control 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);
 }
………
}

Create a new ROS Package :
We need to create a new Ros Package to perform the ROS SIGverse integration

Let’s create a new directory named catkin_ws and let’s perform those few tasks

Create a new folder named src.

Now let’s initialize our workspace by using the following command:

↑

Catkin command †

 $catkin_init_workspace in the ~/catkin_ws folder

Now we have our workspace let’s create our SIGverse ROS Package

Firstable we need to make a new folder named SIGverse then edit the Cmake file and Sig_app.cpp in a new src folder which PATH is:

 $~/catkin_ws/src/Sigvers_Ros/src.

Now make Cmake file in order to create the wanted package. Catkin_make will generate a /devel folder with contains /devel/lib folder and in there the Cmake file generated a libSig_app.so file which will be used by the xml world file to control the robot simulation. Now let’s souce our package by using the following command:

  $source ~/catkin_ws2/devel/setup.sh

Now we can check our package by executing this command
- Roscd Sigvers_Ros so we get the following result:

CMakeLists.txt include msg package.xml src

This shows that the Sigvers_Ros packages exists

Cmake parameters: For Sig.cpp:

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
    )

 ADD_LIBRARY(Sig_app src/Sig_app.cpp)
 target_link_libraries(Sig_app ${catkin_LIBRARIES})
 add_dependencies(Sig_app Sigvers_Ros_gencpp)

We use the target_link_libraries which generates the .so file

 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)

We include SiGverse .h files to compile our controller’s source code Catkin Command:
- catkin_make we compile our code using Cmake parameters so we generate .so file used by the xml world file to control the robot simulation.

Backup of SIGVerse ROS Integration (No. 2)

Overview †

The Topic †

Message Sender †

Node Initialization †

Robot Controller †

Command Node initialization ROS Side †

Main to execute the Node †

Message Sender †

Robot Motion Command ROS Side †

Catkin command †