setup ros indigo with tutlesim

• Ubuntu에 ROS Indigo 설치
• ROS2 Rox Fitzroy
• ros on companion computer
  • Introduction
  • Results
  • Hardware Setup
  • Companion Computer
  • Software configuration
  • MAVROS configuration
  • Operatimg the quadrotor

Ubuntu에 ROS Indigo 설치

1. ROS Indigo란? http://www.slideshare.net/yoonseokpyo/20160406-ros-1-for ROS는 특이하게 버전이 알파벳 형식을 따라가면서 이름이 붙습니다. 현재 가장 최신 버전은 Kinetic이지만 저희는 두 번째 전의 버전인 Indigo를 사용하기로 하였습니다.

ros-kinetc_install

1. ROS Indigo설치 http://wiki.ros.org/indigo/Installation/Ubuntu 위 사이트는 ros wiki페이지로 ros 설치부터 시작해서 여러가지 튜토리얼도 올라와 있습니다. 또한 어떤 문제들이 있으면 바로 업데이트가 된다는 장점이 있습니다. 아래는 오로카 사이트에서 이 ros wiki page를 참고해서 올린 ros indigo 설치 페이지입니다. 저는 ros wiki 글대로 설치하겠습니다. 아래 명령어들을 따라서 설치하시면 되고 각 step에 대한 설명은 생략하도록 하겠습니다. 자세한 내용은 ros wiki 홈페이지를 참고해주시면 되겠습니다. http://cafe.naver.com/openrt/5413

(1) Setup your sources.list

sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'

(2) Setup your key

curl -s https://raw.githubusercontent.com/ros/rosdistro/master/ros.asc | sudo apt-key add -

(3) Installation https://youtu.be/9pOydoNeV_U

sudo apt-get update

sudo apt-get upgrade

or

sudo apt-get update && sudo apt-get install dpkg

sudo apt-get install ros-indigo-desktop-full

위 명령어로만 설치가 안 될 경우에 다음을 실행해보세요

sudo apt-get install libsdformat1

(4) Initialize rosdep

sudo rosdep init
rosdep update

(5) environment setup

echo "source /opt/ros/indigo/setup.bash" >> ~/.bashrc
source ~/.bashrc

(5) getting rosinstall

sudo apt-get install python-rosinstall

(6) make workspace for ros (오로카)

mkdir -p ~/catkin_ws/src

cd ~/catkin_ws/src

catkin_init_workspace

(7) catkin make test

cd ~/catkin_ws/

catkin_make

[출처] 로봇 운영체제 강좌 : ROS Indigo 설치 (오픈소스 소프트웨어 & 하드웨어: 로봇 기술 공유 카페 (오로카)) |작성자 표윤석

https://hiro-group.ronc.one/ros_kinetic_installation.html 여기서 말하는 것과 같이 터미널 창에서

vim ~/.bashrc 을 실행시켜주시면 어떤 문서파일이 뜰 겁니다. 그 끝에 자신의 IP 등등 필요한 정보들을 입력해줍니다 오로카 홈페이지에서 말하는 것처럼 세가지를 설정해줍니다.

set ROS Indigohttps://hiro-group.ronc.one/ros_kinetic_installation.html

IP는 터미널 창에서 ifconfig를 입력해주면 확인할 수 있습니다.

부분을 첨가해주고 저장해주고 종료해 줍니다.

1. ROS 개발환경구축 http://cafe.naver.com/openrt/7242 오로카에 나와있는 내용입니다. ros node파일 등등을 edit하고 생성할 때 사용할 수 있는 QtCreator를 설치합니다.

(1) 설치

sudo apt-get install qtcreator

(2) 실행

qtcreator

1. ROS Indigo 동작테스트 http://cafe.naver.com/openrt/2382 터미널 창을 키고 roscore 실행을 시켜주시기 바랍니다.

roscore

(1) turtlesim 예제 실행 가장 간단한 예제인 turtlesim예제를 실행해보겠습니다. roscore가 돌아가는 터미널 창은 놔두고 새로운 터미널 창을 열어주고 밑의 코드를 입력하시면 됩니다.

rosrun turtlesim turtlesim_node

(2) turtle_teleop_key 실행 또 새로운 터미널 창을 열어줘서 밑의 코드를 실행시키면 위의 turtle을 키보드로 조종할 수 있습니다.

rosrun turtlesim turtle_teleop_key

ROS2 Rox Fitzroy

official

turtle예제가 성공적으로 실행이 된다면 ROS설치가 완료되었습니다.

ros on companion computer

link

Introduction

Implementing a onboard computer on a small UAS can have many benefits such as being able to use ROS onboard the system. This can speed up the development process and enable to use various sensors and actuators that are supported by the ROS community. I have recently written articles on how to use MAVROS to fly a PX4 based quadrotor. However the articles do not cover operating such a system outdoors. Operating outdoors can have many issues as configuring a network or the change of localization performances and the presence of the environment. This article describes my experience on the implementation and operation of a ROS controlled MAV outdoors so that the reader can avoid the mistakes that I have made. Raspberry Pi 2 B+ was used for the onboard computer running ROS.

Results

A simple trajectory generation node was implemented to generate a circular trajectory for the quadrotor to follow. The radius was 6 m at a 15m altitude with the angular rate of 0.4 rad/s.

The video shows the comparison of the real flight with the gazebo SITL simulation. The video shows that the SITL is pretty accurate with the real flight.

Hardware Setup

• Quadrotor Hardware

IMG_1039 The quadrotor is a custom built quadrotor based on the PX4 flight stack. The quadrotor has a 8X4.5 inch props with a 1200kv motor running on a 3S Lipo. Pixhawk was used for the flight controller and the quadrotor is capable of flying and basic waypoint based autonomous missions without the existence of the companion computer.

Companion Computer

Raspberry Pi 2 B+ was used for the companion computer with the pixhawk flight controller. It is not specificly a good choice to use the Raspberry Pi as a companion computer. Raspberry Pis are cheap and fun to use but using raspbian may cause build problems in some packages in ROS.

pixhawk_raspberryPi

The companion computer is stacked on top of the flight controller. The TX/RX pins are connected to the TELEM2 port on Pixhawk. From the guide Raspberry Pi is getting power from the TELEM2 port but the Raspberry Pi was keep turning off as the 5V bus on the TELEM2 port was not providing enough current. Thus, the power is provided from the 5V bus on the servo rail which is powered by a UBEC from the ESC. Powering Raspberry Pi through GPIO is not recommended as there are no regulator or backward protection. However, As I am powering the Raspberry Pi through a UBEC, it is safer.

A 5.4 wifi dongle was used for network connections.

Software configuration

• softwareOverview

PX4 configuration As the Raspberry Pi UART port only supports upto 57600 bps, the baudrate of the SYS_COMPANION parameter should be set accordingly. This is different with using the FTDI. This degrades the performance of the OFFBOARD control capabilities, but as the example on this article covers only setpoint position messages, 57600bps is enough to do the job.

SYS_COMPANION 57600 ROS configuration Ubuntu 14.04 was used for the OS as there were some build issues using Raspbian Jessie. Ubuntu officially supports raspberry Pi, so the image was used on the raspberry Pi. ROS indigo was used in this project. This was a decision made from the fact that ubuntu 14.04 and ROS indigo on raspberry pi was tested in a previous example.

MAVROS configuration

The name of the UART port on Raspberry Pi 2 is ttyAMA0. This should be configured in the launch file.

fcu_ur:=/dev/ttyAMA0:57600

To test run a mavros node without making a launch file you can use:

ronrun mavros mavros_node _fcu_url:="/dev/ttyAMA0:57600"

You can check if the connection with the flight controller is properly done using rostopic tools such as:

rostopic echo /mavros/imu/data

This command echos the imu data from the flight controller and prints it on the screen.

Trajectory Publisher node rqtgraph

The node is a simple publisher publishing position setpoints to the quadrotor. https://youtu.be/9pOydoNeV_U

#include 
#include 
#include 
#include 
#include 
#include "math.h"

double r;
double theta;
double count=0.0;https://youtu.be/9pOydoNeV_U
mavros_msgs::State current_state;
void state_cb(const mavros_msgs::State::ConstPtr& msg){
    current_state = *msg;
}

int main(int argc, char **argv)
{
    ros::init(argc, argv, "offb_node");
    ros::NodeHandle nh;

    ros::Subscriber state_sub = nh.subscribe
            ("mavros/state", 10, state_cb);
    ros::Publisher https://youtu.be/9pOydoNeV_Ulocal_pos_pub = nh.advertise
            ("mavros/setpoint_position/local", 10);

    //the setpoint publishing rate MUST be faster than 2Hz
    ros::Rate rate(20.0);
    

    nh.param("pub_setpoints_traj/wn, 1.0);
    nh.param("pub_setpoints_traj/r 1.0);
    // wait for FCU connection
    while(ros::ok() && current_state.connected){
        ros::spinOnce();
        rate.sleep();
    }

    geometry_msgs::PoseStamped pose;
    pose.pose.position.x = 0;
    pose.pose.position.y = 0;
    pose.pose.position.z = 2;

    //send a few setpoints before starting
    for(int i = 100; ros::ok() && i > 0; --i){
        local_pos_pub.publish(pose);
        ros::spinOnce();
        rate.sleep();
    }

    ros::Time last_request = ros::Time::now();

    while(ros::ok()){
       

    theta = wn*count*0.05;

        pose.pose.position.x = r*sin(theta);
        pose.pose.position.y = r*cos(theta);
        pose.pose.position.z = 15;

    count++;

        local_pos_pub.publish(pose);
        ros::spinOnce();
        rate.sleep();
    }

    return 0;
}

https://youtu.be/9pOydoNeV_U There are two parameters in the launch file which are the radius and the angular rate of the quadrotor. This can be configured from the launch file.

Operatimg the quadrotor

A field box is essential to take all the necessary equipment without forgetting something. The photo below is my go-to toolbox for field tests. IMG_20160804_131026

For operating a flight controller and a companion computer outdoors, it is convinient to configure a wifi network on the field. A wifi router is used to build a wifi network around a field which is powered by a 3S battery. A connector was built to connect the battery to the DCIn port to power a Wifi router.

IMG_1034

I used putty for the ssh client for the Raspberry Pi. The basic operation procedures in running ROS is as follows.

IMG_20160810_153257

First, the laptop should be connected to the same network as the raspberry pi is connected. Then, open a ssh session and run roscore:

roscore

Start a new session and run the launch file that has been configured. In this case:

rosrun modudculab_ros ctrl_traj_test.launch

For longer range applications, a more powerful router or antenna should be used. Using an ordinary wifi router outdoors seems to work well and simplify the operation process to make the system work.

The following wiki, pages and posts are tagged with jdlab