• 1.配置準(zhǔn)備
• 2.多機(jī)通訊
• 3.PIBOT配置
• 4. 總結(jié)
• 5. 一鍵配置腳本

1.配置準(zhǔn)備

• 輸入sudo apt-get install ros-$ROS_DISTRO-turtlesim下載安裝turtlesim測(cè)試包狡逢，完成后首先運(yùn)行roscore
• 再打開(kāi)一個(gè)終端輸入rosrun turtlesim turtlesim_node奢浑，不出意外的話會(huì)出現(xiàn)一只烏龜
  
• 再另外一個(gè)終端輸入rosrun turtlesim turtle_teleop_key
  可以通過(guò)上下左右鍵控制烏龜運(yùn)動(dòng)了

2.多機(jī)通訊

想在PC上直接按鍵控制樹(shù)莓派上的烏龜運(yùn)動(dòng)印荔，要如何操作呢详羡？
主機(jī)與樹(shù)莓派信息如下:

相互ip可以通实柠，因?yàn)槲刺砑觝ostname ip映射窒盐，相互無(wú)法通過(guò)hostname聯(lián)系

• 1. 在樹(shù)莓派上運(yùn)行roscore和啟動(dòng)turtlesim_node
• 2. PC上想要與之通訊首先必須設(shè)置ROS_MASTER_URI,export ROS_MASTER_URI='http:192.168.31.107:11311'即可，在PC中斷輸入rostopic
     list即可看到當(dāng)前的所有topic列表炕横，說(shuō)明PC已經(jīng)可以與ROS_MASTER建立通訊了
     
• 3. 這時(shí)PC端啟動(dòng)rosrun turtlesim turtle_teleop_key無(wú)法控制烏龜運(yùn)動(dòng)份殿，為什么呢卿嘲？這里明明rostopic明明可以看到/turtle/cmd_vel拾枣。 鍵入rostopic info /turtle/cmd_vel 顯示如下
     
     
     這就明顯了,主機(jī)從master里面取到的node發(fā)送/訂閱的topic信息梅肤，node地址為http://pi-desktop:46395, PC根本不認(rèn)識(shí)pi-desktop為何物凭语，自然無(wú)法發(fā)送數(shù)據(jù)撩扒。
• 4. 如何修改搓谆？自然有2個(gè)方法：
     • 這個(gè)我不認(rèn)識(shí)換個(gè)我認(rèn)識(shí)的來(lái)泉手，修改樹(shù)莓派端的ROS_IP環(huán)境變量 export ROS_IP=192.168.31.107
       再次查看topic信息，
       
       缝裤，現(xiàn)在就認(rèn)識(shí)了憋飞，啟動(dòng)rosrun turtlesim turtle_teleop_key節(jié)點(diǎn)榛做，發(fā)現(xiàn)仍然無(wú)法控制检眯。問(wèn)題是我認(rèn)識(shí)你昆淡，可是你不認(rèn)我啊，所有本地PC也需要export ROS_IP=192.168.31.111,現(xiàn)在就正常了
     • 這個(gè)我不認(rèn)識(shí)避凝，我現(xiàn)在認(rèn)識(shí)下不就行了恕曲，PC端修改/etc/hosts 添加一個(gè)192.168.31.107 pi-desktop,同時(shí)樹(shù)莓派端一樣修改/etc/hosts 添加 192.168.31.111 robot-desktop

3.PIBOT配置

PIBOT相關(guān)配置如下

ROS主機(jī)(樹(shù)莓派等)

source /opt/ros/indigo/setup.bash
LOCAL_IP=`hostname -I`
export ROS_IP=`echo $LOCAL_IP`
export ROS_HOSTNAME=`echo $LOCAL_IP`
export PIBOT_MODEL=apollo
export PIBOT_LIDAR=rplidar
export ROS_MASTER_URI=`echo http://$ROS_IP:11311`
source ~/pibot_ros/ros_ws/devel/setup.bash

PC

source /opt/ros/indigo/setup.bash
LOCAL_IP=`hostname -I`
export ROS_IP=`echo $LOCAL_IP`
export ROS_HOSTNAME=`echo $LOCAL_IP`
export PIBOT_MODEL=apollo
export PIBOT_LIDAR=rplidar
export ROS_MASTER_URI=`echo http://xxx.xxx.xx.xx:11311`
source ~/pibot_ros/ros_ws/devel/setup.bash

xxx.xxx.xx.xx為ROS主機(jī)IP

4. 總結(jié)

多機(jī)通訊只能有一個(gè)master存在佩谣，所有都設(shè)置ROS_MASTER_URI為http://MASTER_IP:11311, 各個(gè)終端要能相互通訊就必須設(shè)置自己的ROS_IP茸俭。

5. 一鍵配置腳本

PIBOT提供一鍵配置腳本安皱，只需要根據(jù)提示輸入即可配置上面參數(shù)

#!/bin/bash
if [ ! -z "$PIBOT_HOME" ]; then
    PIBOT_HOME_DIR=$PIBOT_HOME
else
    PIBOT_HOME_DIR=~/pibot_ros
fi


code_name=$(lsb_release -sc)

if [ "$code_name" = "trusty" ]; then
    ros_version="indigo"
elif [ "$code_name" = "xenial" ]; then
    ros_version="kinetic"
elif [ "$code_name" = "bionic" ] || [ "$code_name" = "stretch" ]; then
    ros_version="melodic"
else
    echo -e "\033[1;31m PIBOT not support "$code_name"\033[0m"
    exit
fi 


content="#!/bin/bash
#source ros
if [ ! -f /opt/ros/${ros_version}/setup.bash ]; then 
    echo \"please run cd $PIBOT_HOME_DIR && ./pibot_install_ros.sh to install ros sdk\"
else
    source /opt/ros/${ros_version}/setup.bash
fi
"
echo "${content}" > ~/.pibotrc

#LOCAL_IP=`ifconfig eth0|grep "inet addr:"|awk -F":" '{print $2}'|awk '{print $1}'`
#LOCAL_IP=`ip addr | grep 'state UP' -A2 | tail -n1 | awk '{print $2}' | awk -F"/" '{print $1}'`

#if [ ! ${LOCAL_IP} ]; then
#    echo "please check network"
#    exit
#fi

LOCAL_IP=`ip addr | grep 'state UP' -A2 | tail -n1 | awk '{print $2}' | awk -F"/" '{print $1}'`
echo "LOCAL_IP=\`ip addr | grep 'state UP' -A2 | tail -n1 | awk '{print \$2}' | awk -F"/" '{print \$1}'\`" >> ~/.pibotrc

if [ ! ${LOCAL_IP} ]; then
    echo -e "\033[1;31muse 127.0.0.1 as local ip\033[0m"
    LOCAL_IP=127.0.0.1
fi


echo "export ROS_IP=\`echo \$LOCAL_IP\`" >> ~/.pibotrc
echo "export ROS_HOSTNAME=\`echo \$LOCAL_IP\`" >> ~/.pibotrc

echo -e "\033[1;34mplease specify the current machine(ip:$LOCAL_IP) type:\033[1;32m
                        (0: pibot board,
                        \033[31m1: control PC or Virtual PC\033[1;34m)\033[1;33m" 
read PIBOT_INPUT
if [ "$PIBOT_INPUT" = "0" ]; then
    ROS_MASTER_IP_STR="\`echo \$LOCAL_IP\`"
    ROS_MASTER_IP=`echo $LOCAL_IP`
else
    echo -e "\033[1;34mplase specify the pibot board ip for commnication(e.g. 192.168.12.1):" 
    read -p "" PIBOT_INPUT
    ROS_MASTER_IP_STR=`echo $PIBOT_INPUT`
    ROS_MASTER_IP=`echo $PIBOT_INPUT`
fi

echo "export ROS_MASTER_URI=`echo http://${ROS_MASTER_IP_STR}:11311`" >> ~/.pibotrc

echo -e "\033[1;35m*****************************************************************"
echo "local_ip:     " ${LOCAL_IP} 
echo "onboard_ip:   " ${ROS_MASTER_IP}
echo ""
echo -e "please execute \033[1;36;4msource ~/.bashrc\033[1;35m to make the configure effective\033[0m"
echo -e "\033[1;35m*****************************************************************\033[0m"

復(fù)制上面腳本保存至文件init_env.sh,執(zhí)行bash init_env.sh, 按照提示輸入

init_env.gif

• 樹(shù)莓派輸入0缀踪，會(huì)自動(dòng)讀取樹(shù)莓派ip驴娃，寫(xiě)入變量至~/.piborc文件
• PC端輸入1循集， 再次輸入樹(shù)莓派的ip咒彤，寫(xiě)入變量至~/.piborc文件

source ~/.piborc當(dāng)次生效或使用下面命令寫(xiě)入到bash的環(huán)境變量中

echo "source ~/.piborc" >> ~/.bashrc