Use all the line sensor to steer the robot and follow the line.
Sensor #1 - Robot Rotate Left
Sensor #2 - Robot Sharp Left
Sensor #3 - Robot Turn slightly Left
Sensor #4 - Robot go Forward
Sensor #5 - Robot Turn slightly Right
Sensor #6 - Robot Sharp Right
Sensor #7 - Robot Rotate Right
SENSOR# -------- Motor Speed
#2 -------- ML: 0 ; MR: 50
#3 -------- ML: 25 ; MR: 50
#4 -------- ML: 50 ; MR: 50
#5 -------- ML: 50 ; MR: 25
#6 -------- ML: 50 ; MR: 0
** ML = Motor Left
** MR = Motor Right
90° Junction (Left) :
Once Line sensor 1 (Junction) is detected,
Move the robot forward for (0.3s ~ 1s).
Robot rotate left until Line Sensor 4 detected.
90° Junction (Right) :
Once Line sensor 7 (Junction) is detected,
Move the robot forward for (0.3s ~ 1s).
Robot rotate right until Line Sensor 4 detected.