The Pipe Sorting process.
The purpose of the pipe sorting process is to sort pipes by length.
The sorting of pipes is handled by robots – one per each sorting area.
Once the pipes are sorted they are retrieved by other robots and loaded onto trucks or railcars.
The pipe sorting process consists of eight functions.
Function one: Detect.
A conveyor moves the pipes from the production area to the warehouse.
Ultrasonic sensor A measures when a pipe is ready to be retrieved.
The application transforms the measured distance to the number of degrees
the large motors and thereby the wheels must rotate to move the robot to the pipe.
Function two: Get.
The robot uses Medium motor A to lower and open the gripper.
It then moves forward,
grabs and lifts the pipe.
Function three: Scan.
Color sensor A in 'Color Mode' detects the pipe's color code.
Function four: Move backwards.
The robot moves straight backwards until Color sensor B in 'Color Mode' detects the red line.
To avoid accidents the robot emergency stops if Color sensor B does not detect
the red line before the wheels have rotated a fixed number of degrees.
For pipes without a clearly identifiable color code the robot will place the pipe in the area R for Rejects.
Function eight: Reject.
The robot rotates -90 degrees, places the pipe in the area for rejects and returns to starting position.
Function five: Track.
For pipes with clearly identifiable color codes Control unit A uses Wi-Fi to request the Database for the distance,
and the application transforms the distance to the number of degrees the wheels must rotate,
to bring the robot just short of the red line that corresponds to the color code on the pipe.
8-feet pipes are marked red and moved to area 'A',
10-feet pipes are marked green and moved to area 'B',
and 6-feet pipes are marked yellow and moved to area ‘C’.
The robot starts tracking by using Color sensor B in “Reflected Light Intensity Mode” .
The robot moves straight when the reflected light is 50 %.
The robot turns to the left by increasing power to the Large motor B and decreasing power to the Large motor A
if the reflected light is below 50 %,
and to the right if it is above.
In this way the robot is able to track the left edge of the black line.
Function six: Move forward.
Shortly before the red line, when Large motor B has rotated the number of degrees
that corresponds to the distance received from the Database,
Color sensor B switches from “Reflected Light Intensity Mode” to “Color Mode”,
and the robot moves straight forward until Color sensor B detects the red line.
Function seven: Drop-off.
The robot continues to move a fixed distance straight forward,
places and releases the pipe.
It is important that the pipe is placed entirely within the marked area, because the later process otherwise gets stuck.
Function four: Move backwards.
The robot moves straight backwards until Color sensor B in 'Color Mode' detects the red line.
Function five: Track.
The robot now repeats the tracking step to return to starting position.
Function six: Move forward.
It is now ready to sort the next pipe.