Lesson 10:
Object Detection II

1. Use inequalities to determine whether a condition has been met

2. Use the ultrasonic sensor to detect objects at a distance

3. Combine various sensors to make more complex programs

1. Use inequalities to determine whether a condition has been met

Check for mission success in ‘Diagonal Dilemma Dos’ and ‘Ultraside’. If neither of those missions are completed, ‘Red is the New Green’ may be used as an alternate assessment activity.

2. Use the ultrasonic sensor to detect objects at a distance

Check for mission success in ‘Diagonal Dilemma Dos’ and ‘Ultraside’. If neither of those missions are completed, ‘Red is the New Green’ may be used as an alternate assessment activity.

3. Combine various sensors to make more complex programs

Check for mission success in ‘Diagonal Dilemma Dos’ and ‘Ultraside’

1. What’s one way the ultrasonic sensor is more like the touch sensor, and one way it is more like the gyroscope?

Student answers may vary, but should reflect the way that the three sensors work. Students may notice that the touch sensor and ultrasonic sensor are both used to detect objects in the environment (while the gyroscope detects rotational displacement), and that the ultrasonic sensor and the gyroscope both provide numbers as data (while the touch sensor provides True/False which is Boolean data).

2. Why is it important that the robot have different ways to detect objects in its environment?

Students should describe an advantage of multiple detection systems, rather than just one. For example, students may refer to the multiple ultrasonic sensors on the robot, which are important for the robot to detect objects both in front and to the side of it. They also may refer to different types of detection system, noting that the limitations of one (such as the distance sensor only detecting objects closer than 2.5 meters, or a camera only operating when there is sufficient light) can be compensated for by another.

3. The ultrasonic sensor bounces sound waves off objects to detect them. What’s another way a sensor could detect objects from a distance?

Student answers will vary, but may include examples such as cameras, radar, or lidar. Ensure that all examples are of sensors that can be used at a distance.

• Familiarize yourself with the above resources.

• Allow students to complete the missions on their own time.

• Use the ‘U’ key to show the Ultrasonic beam in the simulation.

Q1. What does the ultrasonic sensor detect?

A1. Distance.

Q2. What is the maximum distance the ultrasonic sensor can detect?

A2. 250cm.

Q3. Which direction does the ultrasonic sensor face?

A3. Forward.