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Module 2 · Line Tracking

Lesson 6 · Two-Sensor Line Following — Knowledge Checks

Name Date

  1. The left sensor reads 0.8 and the right reads 0.2. What is the error, and which way has the robot drifted?

    1. A.error +0.6, drifted left
    2. B.error −0.6, drifted right
    3. C.error 0.0, centered
    4. D.error 1.0, at an intersection

    Answer Why?

  2. Why is the correction negated in arcade(base_effort, -correction) here, when Lesson 5 didn't negate it?

    1. A.The meaning of a positive error flipped, so the steer direction has to flip too
    2. B.Two sensors always need a negative sign no matter what
    3. C.It makes the robot go faster
    4. D.It fixes a bug in arcade()

    Answer Why?

  3. Both sensors suddenly read high (0.9 and 0.9), so error ≈ 0 and the robot drives straight. What has it most likely reached?

    1. A.The edge of the table
    2. B.An intersection — a second line crossing the first
    3. C.A dead battery
    4. D.The end of the program

    Answer Why?