When I am launching my model I am getting the following error:

glv@VaraPrasad:~/catkin_ws$ roslaunch my_mobilebot my_mobilebot.launch
... logging to /home/glv/.ros/log/d607c60a-e3f6-11e8-ae2d-9829a64aa0d2/roslaunch-VaraPrasad-1347.log
Checking log directory for disk usage. This may take awhile.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.

started roslaunch server http://VaraPrasad:34401/

SUMMARY
========

PARAMETERS
 * /rosdistro: kinetic
 * /rosversion: 1.12.14
 * /use_sim_time: True

NODES
  /
    gazebo (gazebo_ros/debug)
    gazebo_gui (gazebo_ros/gzclient)

auto-starting new master
process[master]: started with pid [1357]
ROS_MASTER_URI=http://localhost:11311

setting /run_id to d607c60a-e3f6-11e8-ae2d-9829a64aa0d2
process[rosout-1]: started with pid [1374]
started core service [/rosout]
process[gazebo-2]: started with pid [1382]
/opt/ros/kinetic/lib/gazebo_ros/debug: 5: [: Linux: unexpected operator
process[gazebo_gui-3]: started with pid [1399]
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Reading symbols from gzserver...(no debugging symbols found)...done.
[tcsetpgrp failed in terminal_inferior: Inappropriate ioctl for device]
[tcsetpgrp failed in terminal_inferior: Inappropriate ioctl for device]
[ INFO] [1541750994.532718810]: Finished loading Gazebo ROS API Plugin.
[ INFO] [1541750994.534274778]: waitForService: Service [/gazebo/set_physics_properties] has not been advertised, waiting...
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
[tcsetpgrp failed in terminal_inferior: Inappropriate ioctl for device]
[New Thread 0x7fffceb98700 (LWP 1493)]
[tcsetpgrp failed in terminal_inferior: Inappropriate ioctl for device]

[tcsetpgrp failed in terminal_inferior: Inappropriate ioctl for device]
[tcsetpgrp failed in terminal_inferior: Inappropriate ioctl for device]
[tcsetpgrp failed in terminal_inferior: Inappropriate ioctl for device]
[New Thread 0x7fffca683700 (LWP 1494)]
[New Thread 0x7fffc9e82700 (LWP 1495)]
[New Thread 0x7fffc9681700 (LWP 1498)]
[New Thread 0x7fffc8e80700 (LWP 1499)]
[New Thread 0x7fffc3fff700 (LWP 1501)]
[New Thread 0x7fffc37fe700 (LWP 1513)]
[New Thread 0x7fffc2ffd700 (LWP 1514)]
[New Thread 0x7fffc27fc700 (LWP 1515)]
[New Thread 0x7fffc1ffb700 (LWP 1516)]

[New Thread 0x7fffc17fa700 (LWP 1519)]
[New Thread 0x7fffc0ff9700 (LWP 1520)]
[New Thread 0x7fffabfff700 (LWP 1521)]
[New Thread 0x7fffab7fe700 (LWP 1522)]
[New Thread 0x7fffaaffd700 (LWP 1523)]
[New Thread 0x7fffaa7fc700 (LWP 1524)]
[New Thread 0x7fffa9ffb700 (LWP 1525)]
[ INFO] [1541750996.963564299]: Finished loading Gazebo ROS API Plugin.
[ INFO] [1541750996.965872363]: waitForService: Service [/gazebo/set_physics_properties] has not been advertised, waiting...
[New Thread 0x7fffa97fa700 (LWP 1527)]
[tcsetpgrp failed in terminal_inferior: Inappropriate ioctl for device]


  [tcsetpgrp failed in terminal_inferior: Inappropriate ioctl for device]
    [

tcsetpgrp failed in terminal_inferior: Inappropriate ioctl for device]
[tcsetpgrp failed in terminal_inferior: Inappropriate ioctl for device]
[tcsetpgrp failed in terminal_inferior: Inappropriate ioctl for device]
[New Thread 0x7fff7ffff700 (LWP 1528)]
[New Thread 0x7fff7f7fe700 (LWP 1529)]
[New Thread 0x7fff7effd700 (LWP 1530)]
[New Thread 0x7fff7e7fc700 (LWP 1531)]
[New Thread 0x7fff7dffb700 (LWP 1536)]

[New Thread 0x7fff7d7fa700 (LWP 1537)]
[New Thread 0x7fff7cff9700 (LWP 1540)]
[New Thread 0x7fff63fff700 (LWP 1541)]
[tcsetpgrp failed in terminal_inferior: Inappropriate ioctl for device]
[New Thread 0x7fff637fe700 (LWP 1553)]
[New Thread 0x7fff62ffc700 (LWP 1554)]
[New Thread 0x7fff633fd700 (LWP 1555)]
[New Thread 0x7fff62bfb700 (LWP 1556)]
[New Thread 0x7fff623f9700 (LWP 1558)]
[New Thread 0x7fff627fa700 (LWP 1557)]
[New Thread 0x7fff61ff8700 (LWP 1559)]

[New Thread 0x7fff61bf7700 (LWP 1652)]
[New Thread 0x7fff613f6700 (LWP 1656)]
[New Thread 0x7fff60bf5700 (LWP 1657)]
[New Thread 0x7fff27fff700 (LWP 1658)]
[tcsetpgrp failed in terminal_inferior: Inappropriate ioctl for device]
[ INFO] [1541750997.801048423]: DiffDrive missing <robotNamespace>, defaults is my_mobilebot
[ INFO] [1541750997.801215769]: Starting plugin DiffDrive(ns = my_mobilebot/)
[ WARN] [1541750997.801294600]: DiffDrive(ns = my_mobilebot/): missing <rosDebugLevel> default is na
[ INFO] [1541750997.802481643]: DiffDrive(ns = my_mobilebot/): <tf_prefix> = my_mobilebot
[ WARN] [1541750997.802639269]: DiffDrive(ns = my_mobilebot/): missing <publishWheelTF> default is false
[ WARN] [1541750997.802678246]: DiffDrive(ns = my_mobilebot/): missing <publishOdomTF> default is ture
[ WARN] [1541750997.802708892]: DiffDrive(ns = my_mobilebot/): missing <publishWheelJointState> default is false


  [ WARN] [1541750997.802845253]: DiffDrive(ns = my_mobilebot/): missing <wheelAcceleration> default 

is 0
[ WARN] [1541750997.802883375]: DiffDrive(ns = my_mobilebot/): missing <wheelTorque> default is 5
[ WARN] [1541750997.802997898]: DiffDrive(ns = my_mobilebot/): missing <odometrySource> default is 1
[ WARN] [1541750997.803092272]: GazeboRosDiffDrive Plugin (ns = ) missing <publishTf>, defaults to 1
[ INFO] [1541750997.804349553]: DiffDrive(ns = my_mobilebot/): Try to subscribe to cmd_vel
[ INFO] [1541750997.809908502]: DiffDrive(ns = my_mobilebot/): Subscribe to cmd_vel
[ INFO] [1541750997.811088877]: DiffDrive(ns = my_mobilebot/): Advertise odom on odom 
[New Thread 0x7fff26c9b700 (LWP 1676)]
    [ INFO] [1541750997.835758765, 0.022000000]: waitForService: Service [/gazebo/set_physics_properties] is now available.
    [ INFO] [1541750997.895648491, 0.076000000]: waitForService: Service [/gazebo/set_physics_properties] is now available.
    [ INFO] [1541750997.926633418, 0.107000000]: Physics dynamic reconfigure ready.

[Thread 0x7fffa9ffb700 (LWP 1525) exited]
[ INFO] [1541750997.990394536, 0.170000000]: Physics dynamic reconfigure ready.
[New Thread 0x7fff2649a700 (LWP 2484)]

Thanks In Advance!!!