In a terminal (Source the files)
$ roslaunch husky_gazebo mowito_world.launch
gazebo_world/src/gazebo/worlds/wall.world
To edit the trajectory, change the POSE values which are x,y coordinates in Lines (2493,2497,2501,2505,2509).
To change the velocity of the moving obstacle change the TIME value in each waypoint in Lines (2492,2496,2500.2504,2508) .The time is in seconds, counted from the beginning of the script, when the pose should be reached.Higher the time the obstacles moves slowly.
gazebo_world/src/gazebo/worlds/wall.world