1.配置準(zhǔn)備
- 輸入
sudo apt-get install ros-$ROS_DISTRO-turtlesim下載安裝turtlesim測試包，完成后首先運(yùn)行roscore - 再打開一個(gè)終端輸入
rosrun turtlesim turtlesim_node，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上直接按鍵控制樹莓派上的烏龜運(yùn)動(dòng)，要如何操作呢？
主機(jī)與樹莓派信息如下:
| Item | IP | Hostname |
|---|---|---|
| PC | 192.168.31.111 |
robot-dekstop |
| 樹莓派 | 192.168.31.107 |
pi-desktop |
相互ip可以通，因?yàn)槲刺砑觝ostname ip映射，相互無法通過hostname聯(lián)系
- 在樹莓派上運(yùn)行
roscore和啟動(dòng)turtlesim_node
- 在樹莓派上運(yùn)行
- 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，說明PC已經(jīng)可以與ROS_MASTER建立通訊了
- PC上想要與之通訊首先必須設(shè)置
- 這時(shí)PC端啟動(dòng)
rosrun turtlesim turtle_teleop_key無法控制烏龜運(yùn)動(dòng)，為什么呢？這里明明rostopic明明可以看到/turtle/cmd_vel。 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，node地址為http://pi-desktop:46395, PC根本不認(rèn)識(shí)pi-desktop為何物，自然無法發(fā)送數(shù)據(jù)。
- 這時(shí)PC端啟動(dòng)
- 如何修改？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，修改樹莓派端的
ROS_IP環(huán)境變量export ROS_IP=192.168.31.107
再次查看topic信息，
，現(xiàn)在就認(rèn)識(shí)了，啟動(dòng)rosrun turtlesim turtle_teleop_key節(jié)點(diǎn)，發(fā)現(xiàn)仍然無法控制。問題是我認(rèn)識(shí)你，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)，我現(xiàn)在認(rèn)識(shí)下不就行了，PC端修改
/etc/hosts添加一個(gè)192.168.31.107 pi-desktop,同時(shí)樹莓派端一樣修改/etc/hosts添加192.168.31.111 robot-desktop
- 這個(gè)我不認(rèn)識(shí)換個(gè)我認(rèn)識(shí)的來，修改樹莓派端的
- 如何修改？自然有2個(gè)方法：
3.PIBOT配置
PIBOT相關(guān)配置如下
ROS主機(jī)(樹莓派等)
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 $LOCAL_IP`
export PIBOT_MODEL=apollo
export PIBOT_LIDAR=rplidar
export ROS_MASTER_URI=`echo http://xxx.xxx.xx.xx:11311`
source ~/pibot_ros/ros_ws/devel/setup.bash
xxx.xxx.xx.xx為
ROS主機(jī)IP
4. 總結(jié)
多機(jī)通訊只能有一個(gè)master存在，所有都設(shè)置ROS_MASTER_URI為http://MASTER_IP:11311, 各個(gè)終端要能相互通訊就必須設(shè)置自己的ROS_IP。
5. 一鍵配置腳本
PIBOT提供一鍵配置腳本，只需要根據(jù)提示輸入即可配置上面參數(shù)
#!/bin/bash
if [ ! -z "$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
- 樹莓派輸入0，會(huì)自動(dòng)讀取樹莓派ip，寫入變量至~/.piborc文件
- PC端輸入1， 再次輸入樹莓派的ip，寫入變量至~/.piborc文件
source ~/.piborc當(dāng)次生效或使用下面命令寫入到bash的環(huán)境變量中
echo "source ~/.piborc" >> ~/.bashrc
