How does Adaptive Cruise Control work in a Car?
Hey friends, Happy Wednesday!
This is my 25th Newsletter issue! Thank you for following my work.
I’m including an extended summary of how a gadget works in my newsletter, from which you can understand the essence in less than 3 minutes. But you can choose to read the blog posts for a more detailed version involving the nuances, from the links I attach.
Let’s look at how Adaptive Cruise control works this week, as we went over Cruise Control last week. I aim to write my newsletter issues in a way one can follow them while traveling on a bus, having a coffee, waiting for food, etc. Let's jump in!
Tweet of the week
I’m sharing a cool fact about gadgets every day on Twitter. And here is one of them for you.
How does Adaptive Cruise Control work?
I am referring to cars that run on gasoline as I can explain the entire sequence using a particular type as an example. Though the essence is not different in an electric one.
Why do we need Adaptive Cruise Control?
Let’s say we’re driving at a constant speed of 60mph with the Cruise Control activated. What would happen if a car appeared in front of us and then traveled at 40mph? Intervening and applying brakes becomes necessary to slow the car down, as maintaining a speed of 60mph will lead to a collision.
This problem is solved by Adaptive Cruise Control (ACC) - It constantly measures the distance between your car and the one in front of you using Radar. Once the other car gets closer to yours beyond a safe distance, the speed of your car is reduced automatically to follow the one in front of you at a constant distance until it’s safe to cruise again at 60mph. Leaving a constant distance between your car and the one in the front makes sure that the ACC can safely apply brakes when needed, and avoid a collision.
What is a Radar?
RADAR (RAdio Detecting And Ranging) is a radiolocation system used to determine other objects’ distance, angle, and velocity relative to the source. A radar system in an automobile produces electromagnetic waves with frequencies that have wavelengths between 1mm and 10mm (AKA Millimeter Wave Band).
Figure: Adaptive Cruise Control in Action
How is Radar used to achieve Adaptive Cruise Control?
The radar is typically placed in front of your car behind the grill. Short pulses are sent out as waves and are reflected back to the radar when they encounter a car in front of them. This concept is similar to hearing an echo.
The faster the pulses return to your car and the radar detects it, the closer the distance between the two cars. So once it receives the pulses back in a short time, it sends a signal to the ECU which then commands the throttle valve to close further and this restricts the air intake to the engines, thereby reducing the speed of your car.
Once the car in front of you moves away beyond a safe distance or to the adjacent lanes, your car speeds up again to travel at a constant speed in regular Cruise control mode. This is how Adaptive Cruise Control works!
Question of the week
What methods, besides radar, can be used to detect the distance of the car in front of us? Reply to this email with your thoughts, and we’ll have a discussion.
Blog posts
My blog post S2E3 on Cruise Control and S2E4 on Adaptive Cruise Control is out now! Read it here, happy learning!
Read How Adaptive Cruise Control works
I’m thinking of writing about Radars & their applications for the next episode S2E5 as they’re super fascinating and are used by ships, airplanes, the Navy, and whatnot! Also, by replying to this email, let me know if you’d like to read about a specific gadget/device. And I can write about it.
Gadget of the week
Codable Dog: Pyxel is a programmable robot dog designed for kids to learn how to code, which was featured at CES 2023. Children can use the kid-friendly Blockly language or programming languages like Python to program the robot dog. And it can perform various actions such as sitting, speaking, shaking, and running around.
Thank you for reading!
Have a nice rest of the week, and take care!
Until next Wednesday,
Chendur
