Cruise Control Sytem in Cars and How Cruise Control Sytem works ?

What is cruise control?

The purpose of a cruise control system is to accurately maintain a speed set by the driver without any outside intervention by  controlling the throttle-accelerator pedal linkage.

The earliest variants of cruise control were actually in use even before the creation of automobiles. The inventor and mechanical engineer James Watt developed a version as early as the 17th century, which allowed steam engines to maintain a constant speed up and down inclines. Cruise control as we know it today was invented in the late 1940s, when the idea of using an electrically-controlled device that could manipulate road speeds and adjust the throttle accordingly was conceived.

Working

The cruise control system controls the speed of your car the same way you do – by adjusting the throttle (accelerator) position. However, cruise control  engages the throttle valve by a cable connected to an actuator, rather than by pressing a pedal. The throttle valve controls the power and speed of the engine by limiting how much air it takes in (since it’s an internal combustion engine).

The driver can set the cruise control with the cruise switches, which usually consist of ON, OFF, RESUME, SET/ACCEL and COAST. These are commonly located on the steering wheel or on the windshield wiper or turn signal stalk. The SET/ACCEL knob sets the speed of the car. One tap will accelerate it by 1 mph, two by 2 mph and so on. Tapping the knob in the opposite direction will decelerate the vehicle. As a safety feature, the cruise control system will disengage as soon as you hit the brake pedal.

However, with the number of cars on roads increasing more than ever, the functionality of normal cruise control is becoming obsolete. Adaptive cruise control is quickly gaining popularity, and with good reason!

Adaptive Cruise Control is the next big thing in terms of automated speed management in new cars. It is an intelligent form of cruise control that slows down and speeds up automatically to keep pace with the car in front of you.

How Does Adaptive Cruise Control Work?

The driver sets a maximum speed similar to what one would do with normal cruise control. A radar sensor located in the front end of the car locates traffic ahead of it and locks on to the car ahead. This sensor then controls the speed of your car so that it always stays 2-3 seconds behind the car in front.  

Using the input from the radar sensors, the computer unit measures the distance of the car ahead and calculates the speed relative to it. If there are multiple vehicles in the sensor’s field of coverage at the same time, it automatically selects which of the vehicles the system should track.

For instance, if you’re approaching a slower vehicle ahead or if another vehicle cuts in front of you, the adaptive cruise control slows down the car by initiating corrective controls in the engine management and, if necessary, in the braking system as well.