ubuntu脚本启动多个launch文件

#!/bin/bash

source /opt/ros/kinetic/setup.sh
source ~/ml_ws/devel/setup.bash

gnome-terminal  "ur5_gazebo" -x bash -c "roslaunch ur_gazebo ur5.launch;exec bash" &&

ti1=`date +%s`  
ti2=`date +%s`
i=$(($ti2 - $ti1 ))

while [[ "$i" -ne "8" ]]
do
    ti2=`date +%s`
    i=$(($ti2 - $ti1 ))
done

gnome-terminal  "ur5_panning" -x bash -c "roslaunch ur5_moveit_config ur5_moveit_planning_execution.launch sim:=true;exec bash" &&

ti1=`date +%s`  
ti2=`date +%s`
i=$(($ti2 - $ti1 ))

while [[ "$i" -ne "5" ]]
do
    ti2=`date +%s`
    i=$(($ti2 - $ti1 ))
done

gnome-terminal  "ur5_rivz" -x bash -c "roslaunch ur5_moveit_config moveit_rviz.launch config:=true;exec bash"