The Velocity of Vehicles
Teacher Toolbox
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The Purpose of this Section
This Apply section will help students understand how setting a robot’s velocity connects to daily experiences such as self-driving cars, adaptive cruise control, and elevators. Begin the section by asking students to identify some situations where changing the velocity would be beneficial. Students may have some misconceptions about what it means for an object to change its velocity. List the students’ answers in the classroom so they can be referenced after the reading. The Apply section also discusses in what ways setting a robot’s velocity can be used in a VEX Robotics competition.
These Apply pages can be worked through as a class.
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Together, read the Apply page “The Velocity of Vehicles”.
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Facilitate a class discussion on the topic.
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Together, read the page “Changing the Velocity of Competition Robots”.
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Facilitate a class discussion on the topic.
If you have time available in class or as homework, Extend Your Learning sections provide other options to get students thinking about how robotics is used throughout their lives.
Adaptive Cruise Control
Today’s robots and cars in particular have the ability to perform many automated movements. Some cars can park and even drive themselves. Many new vehicles and self-driving cars have Adaptive Cruise Control (ACC). This feature sets the vehicle at a certain velocity and uses sensors to determine if it should slow down or speed up depending on the objects in front of it. How is this helpful? The faster an object is moving, the more momentum or energy it has. So, colliding with objects like other cars is dangerous. Let’s say you are driving on the highway and you set your ACC to 65 mph. Your car will drive at 65 mph until it needs to change its velocity. If a car in front of you suddenly uses their brakes, your car will be able to sense the car slowing down in front of you and also slow down so that you do not crash into them. When the car in front speeds up, your car will speed up. When the road starts up a hill, the car will speed up in order to maintain the 65 mph that you set.
Elevators are another example of robots that need to change velocities in order to function properly. Can you imagine stepping into an elevator and it immediately started going up or down at its max velocity? You would probably fall over! Elevators must start and end at a lower velocity to ensure the safety of its passengers.
Extend Your Learning
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Everyday Velocity Changes
There are many robots and everyday objects that change velocities on their own or have the ability to change velocities to ensure safety or to maximize performance. To get students thinking about different robots that change velocity, ask them to brainstorm five robots or objects that they believe change velocity. After they have decided on five, ask the students to research their five choices in order for them to be able to confirm if they change velocity or not. Some examples include, but are not limited to: a hairdryer, cooking mixer, bicycles, automatic vacuums or doors that automatically open. Students should be prepared to share their findings with the class and can write their findings in their engineering notebook.