Line Following Vocabulary

Word Bank

Fill In the Blanks

1. The reads how much light bounces back off the floor.
2. is that amount of light, as a number from 0 to 100.
3. Black tape reflects a number; white floor reflects a high number.
4. The is the midpoint between the BLACK and WHITE readings.
5. How far the reading is from the threshold is called the .
6. Steering in proportion to how far off you are is called .
7. The decides how hard the robot steers — too low is sloppy, too high is wobbly.
8. The robot follows the of the line, not the center, so a small wobble is normal.

Quick Checks

• Circle what line_sensor.reflection() returns:
  a color / a number 0-100 / a distance in mm

• Over black tape, is the reflection reading high or low?
  Circle one: high / low

• Your robot wobbles back and forth along the line. Should you make GAIN bigger or smaller?
  Circle one: bigger / smaller

• Put these calibration steps in order (number them 1-3):
  Compute the threshold (midpoint)
  Read reflection on the black tape
  Read reflection on the white floor

Stretch: Read the Code

What does this loop make the robot do? Write it in plain words.

while True:
    deviation = line_sensor.reflection() - threshold
    robot.drive(DRIVE_SPEED, GAIN * deviation)
    wait(10)

It will: