How cruise control in cars work?

Answer 1

You get up to the speed that you want to go, press the Cruise Control button. You can then take your foot off the accelerator and the car will maintain that speed.

Answer 2

I don't know all the ins and out of it but I can give you a general idea.

Cruise control works on a feedback system. What you do is you set the desire speed. This differes for every car but it usually requires the puch of a button. The spped is then send to the computer. The computer then sets the appropiate fuel to air mixture to keep that speed. The computer can also control the throttle body of the car. Ofcourse this is also part of the air fuel mixing process. The computer keeps pilling the speed of the car. It checks if the speed had satyed the same, increased or decreased. If the speed is the same then great, bussiness as usual. If the speed is less then the computer makes the nesseary adjustments by moving the trhottle and adding more fule and air to the mix. It keeps polling untill it reaches the desire speed. If it still hasn't reached the desire speed then it increments the fuel air mixture. If if close to the speed then it decrease the fuel air mixture to maintain a certain speed. The oposite also happenes. If the car speeds up, the comouter in your car cuts fuel and air to your engine to slow it down.

This process happens amny times but you don't notice it because the computer works really fast. It could be that the comuter ask about the current speed of the car over 1,000 times. Maybe more maybe less. It is always adjusting itself ever so slightly.

Answer 3

Here is all I know mate... And trust me its very comphrehensive....

Cruise control is an invaluable feature on American cars. Without cruise control, long road trips would be more tiring, for the driver at least, and those of us suffering from lead-foot syndrome would probably get a lot more speeding tickets.

Cruise control is far more common on American cars than European cars, because the roads in America are generally bigger and straighter, and destinations are farther apart. With traffic continually increasing, basic cruise control is becoming less useful, but instead of becoming obsolete, cruise control systems are adapting to this new reality -- soon, cars will be equipped with adaptive cruise control, which will allow your car to follow the car in front of it while continually adjusting speed to maintain a safe distance.

In this article, we'll learn how a conventional cruise control system works, and then we'll take a look at adaptive cruise control systems that are under development.

What It Does
The cruise control system actually has a lot of functions other than controlling the speed of your car. For instance, the cruise control pictured below can accelerate or decelerate the car by 1 mph with the tap of a button. Hit the button five times to go 5 mph faster. There are also several important safety features -- the cruise control will disengage as soon as you hit the brake pedal, and it won't engage at speeds less than 25 mph (40 kph).

The system pictured below has five buttons: On, Off, Set/Accel, Resume and Coast. It also has a sixth control -- the brake pedal, and if your car has a manual transmission the clutch pedal is also hooked up to the cruise control.


* The on and off buttons don't actually do much. Hitting the on button does not do anything except tell the car that you might be hitting another button soon. The off button turns the cruise control off even if it is engaged. Some cruise controls don't have these buttons; instead, they turn off when the driver hits the brakes, and turn on when the driver hits the set button.

* The set/accel button tells the car to maintain the speed you are currently driving. If you hit the set button at 45 mph, the car will maintain your speed at 45 mph. Holding down the set/accel button will make the car accelerate; and on this car, tapping it once will make the car go 1 mph faster.

* If you recently disengaged the cruise control by hitting the brake pedal, hitting the resume button will command the car to accelerate back to the most recent speed setting.

* Holding down the coast button will cause the car to decelerate, just as if you took your foot completely off the gas. On this car, tapping the coast button once will cause the car to slow down by 1 mph.

* The brake pedal and clutch pedal each have a switch that disengages the cruise control as soon as the pedal is pressed, so you can shut off the cruise control with a light tap on the brake or clutch.

How It's Hooked Up
The cruise control system controls the speed of your car the same way you do -- by adjusting the throttle position. But cruise control actuates the throttle valve by a cable connected to an actuator, instead of by pressing a pedal. The throttle valve controls the power and speed of the engine by limiting how much air the engine takes in (see How Fuel Injection Systems Work for more details).


One of the cables is connected to the gas pedal, the other
to the vacuum actuator.

In the picture above, you can see two cables connected to a pivot that moves the throttle valve. One cable comes from the accelerator pedal, and one from the actuator. When the cruise control is engaged, the actuator moves the cable connected to the pivot, which adjusts the throttle; but it also pulls on the cable that is connected to the gas pedal -- this is why your pedal moves up and down when the cruise control is engaged.


The electronically-controlled vacuum actuator
that controls the throttle

Many cars use actuators powered by engine vacuum to open and close the throttle. These systems use a small, electronically-controlled valve to regulate the vacuum in a diaphragm. This works in a similar way to the brake booster, which provides power to your brake system.

Answer 4

The cruise control is a very interesting device. There are just 3 easy steps to use it.

1. You gotta go in a constant speed more then 30kmp.
2. Press the crise control button.
3. Lift your leg off the accelerator.
The car goes in the same speed till you press stop.

Answer 5

Cruise control is a very simple devise. It makes the accelerator of the car inoperative and fixes the cars speed at a particular pre decided rate. Takes the strain from the leg during long cross country drives. not advisable for city driving.

Answer 6

it may if not used properly. in case you're usually on the line this is flat then no it won't harm the automobile. once you're a mountain motive force then that isn't continuously actual. some human beings don't understand that the cruise administration is to maintain a persevering with velocity, yet maximum vehicles won't be able to verify quickly sufficient to atone for the variation in terrain. the automobile then boggs down and reason severe torque on the force practice to atone for that. vehicles with overdrive and cruise are the worst for this.

Answer 7

you go at more than 30mph, hit the cruise button, let go of acceleration and your car will go by itself at that constant speed, but it's not auto pilot, so you have to pay attention to the road and resume control of your car when necessary!

Answer 8

once you are driving the desire speed you turn it on and "set" let go of the gas pedal and it will stay at that speed.

if you're question is in the "mechanical" part of it here it goes.
when you turn it on it send a signal to a module with uses a valve with a diaphragm to pull a cable that is in the same place of the accelerator cable and uses a vacuum system to stay put.

Answer 9

it just puts your current speed into the computer (when you set it), and then adjusts the throttle to keep that value constant.