What is cruise control and how to use?

Cruise control is an indispensable assistant on a long journey. Thanks to him, many truckers overcome thousands of kilometers a day without much fatigue. Now, in many modern, even budget cars, a “cruise” system is provided. So, how useful, how it works, why cruise control is needed at all - read on!

What is cruise control?

Cruise control is a system that allows you to keep a constant speed of the car, regardless of the type of road surface, while driver control is not required. The system is extremely in demand for long-distance country trips, where the car moves at a constant speed. The first "cruises" were equipped with American cars, because it is there that the vast majority of country roads. 

Cruise control began its existence with a passive system, which consists of:

• control lever;
• automatic controller;
• servo;
• system control solenoid valve;
• additional throttle actuator.

Principle of operation: the collector controls the servo valves, which respond to the difference between the real and the set speed. Using the vacuum in the intake manifold, the servo diaphragm feeds a signal to the throttle, adjusting the fuel supply. 

For safety, the system does not work at speeds below 40 km / h.

The device and the principle of operation

Cruise control is a servo device that connects to the vehicle's on-board computer. It regulates the opening of the throttle valve. The connection is carried out using a cable (sometimes traction), and in the latest generation cars - to an electronic transport system.

The kit (it depends on the system model and its manufacturer) may include:

• Control block;
• Throttle position regulator;
• Speed ​​sensor (or connects to an existing one);
• Throttle position sensor (or connected to the standard one);
• Fuse;
• Control panel (carried out on the steering wheel or on the console).

The principle of operation of the cruise control is as follows. When the driver of the motor vehicle presses the switch, the control unit memorizes the position of the accelerator pedal and records the speed of the vehicle. When the device is turned on, the corresponding icon lights up (either on the dashboard, if the system is standard, or on the activation button).

When the vehicle speed changes, a signal is sent from the sensors to the control unit, and it sends a command to the servo to open or close the throttle. Such an assistant will come in handy when driving for a long time on the motorway or highway. It will also be indispensable when driving on long slopes (both uphill and downhill).

Depending on the model of the system, it can be deactivated by pressing the OFF button, by pressing the clutch or brake pedal.

Cruise control operation on a manual transmission

Contrary to popular belief, the cruise control system can even work with a manual transmission. Of course, cars with manual transmission are not equipped with such a system from the factory. Most cars with a manual cruise are the result of self-modernization of the vehicle.

Regardless of the type of system, its principle remains the same: an additional cable for the accelerator pedal and an additional bracket are installed in the car. Otherwise, the principle of operation of the system is similar to cruise control, paired with an automatic transmission.

The only difference is the lack of independent speed switching. In a car with automatic transmission, the system changes gear to maintain speed, for example, when driving uphill. Mechanically, this cannot be done. The system will maintain the speed of the car only on a flat road. In advance, the transport will not accelerate, since in this case the car will move faster than the set limit.

On the mechanics, the electronics will only adjust the throttle position. If the car is moving on a level road, the cruise control will maintain a constant speed. When the driver needs to perform a maneuver, he can independently press the accelerator pedal, add speed and shift to a higher gear. The system will then continue to maintain cruising speed on its own by opening/closing the throttle.

But before installing such a system on your car, the motorist must determine whether he needs it or not. From the economic side, trying how it works is not profitable.

What is an adaptive cruise

Adaptive cruise control (ACC) is an advanced “cruise” system that allows you to independently change the speed of movement, depending on the traffic situation. For example, a car can brake on its own if a potential danger of a collision is noticed ahead.

AAS consists of three main components:

• touch sensors that determine the distance and interval between your car and other road users. The range is from 30 to 200 meters. The emitter may be infrared, electromagnetic or ultrasonic;
• the control unit that collects information from sensors takes into account the distance to the previous transport, the speed of your car, then adjusts the process of speeding up or braking;
• a set of equipment connecting the transmission, safety sensors (ABS + EBD), and brake mechanisms.

Types of cruise control

There are two types of cruise control:

• Active (or adaptive cruise control) - not only fixes the speed of a given car, but also monitors the position of the leading car (you first need to install it on a specific car, along which the radar and video camera will be guided). This system allows you to control the speed on the track depending on the traffic.
• Passive cruise control only maintains a preset speed. The control is carried out based on the preset of the accelerator pedal. The driver must follow the vehicles ahead and change the lane or brake accordingly.

The system can be installed both in a car with a manual gearbox and in a car with an automatic gearbox. In the case of an automatic machine, intelligent cruise control automatically adjusts the throttle. Together with this, the car can change gear. This will come in handy when traveling on a road with small passes.

On mechanics, the system works a little differently. The principle of operation remains the same, only the universal cruise control with a mechanical gas pedal needs some driver input. For example, when the car starts to climb a hill, the system does not detect the load coming from the wheels, so the throttle may not open enough for the car to accelerate well.

The included mechanical cruise control does not make it possible to switch to a lower gear, therefore, on the rise, you need to either add gas or turn off the system and turn on a low one.

How to use cruise control

Cruise control operates between 40 and 200 km/h. At the minimum speed, the system will not turn on, and when the maximum threshold is reached, it will turn off. Otherwise, the control of the car passes into the hands of the driver.

How to turn on and how to turn off cruise control?

Regardless of whether cruise control is a factory system or optional equipment, cruise control is activated by pressing the appropriate button on the center console (but more often it is located on the steering wheel or in the steering column switch block). Depending on the car model, this may be a button with a speedometer, with the words Cruise On / Off, and so on.

In the case of a regular cruise, the system does not turn on from the moment the car is started. It must be activated from a speed of 40 km/h. and more. Further on the cruise enable module, using the Set button, the maximum speed at which the car should move is set.

The system can turn itself off. For example, it goes into standby mode when you press the brake pedal or when the car is moving at a speed below 40 kilometers per hour. In some modern car models, adaptive cruise control can also be installed, which is equipped with its own sensors that determine the distance to the car in front.

In general, in order to appreciate the presence of cruise control as an additional comfort option, it must be standard, and not installed independently. Only in this case the car will really maintain speed without the active participation of the driver.

Safety measures

Any additional device that facilitates the process of driving has a significant drawback. It can lull the driver's vigilance. It is strictly forbidden to use the device in such conditions:

• Ice on the road;
• Wet road;
• Fog, rain, snow or night.

Even if your vehicle is fitted with the latest smart cruise control, it will not replace driver response and alertness. Also, you should always make allowances for the possibility of an error in the electronic system of the car, which can lead to a device failure.

Advantages and disadvantages of cruise control

The indisputable advantages of this driver assistance system include:

• Opportunity for the driver to rest during a tiring ride on a straight road;
• If the driver is distracted from driving a little, then the adaptive cruise control will hedge by tracking the approach of the car in front;
• The system is connected to both the mechanics and the machine;
• During long journeys, the system saves fuel by approximately 7 percent.
• It turns off quickly - just press the brake or throttle all the way;
• Increased level of frontal security;
• If the driver takes his hands off the steering wheel, the system is also deactivated.

Like any additional system, cruise control has its drawbacks:

• The system is only effective over long distances;
• The driver is tempted to distract himself from driving (if the latest generation smart model is installed);
• Costly repair of individual components
• The more electronic devices there are, the higher the probability of an error;
• Cannot be used in difficult weather conditions.

Video review 

In this video you will learn more about the work of cruise control, as well as their modifications.

What is cruise control? Concept and principle of work

Questions and answers:

What is cruise control for? It is an electronic assistant for the driver. The purpose of the system is to ensure the movement of vehicles at a given speed. When the car / motorcycle slows down, the system increases the speed to the limit.

How does manual transmission cruise control work? In this case, an additional gas pedal cable and bracket are installed. These elements allow the system to automatically adjust the speed of the vehicle.