Driver assistance systems in the car. Driver assistance systems and their meaning. Brake force distribution system

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DRIVING SCHOOL "REAL"

Abstract on the topic:

"Electronic driver assistance systems"

Completed by the student

Cholan Ekaterina

Orekhovo-Zuevo, 2015

1. Systems that improve directional stability and vehicle handling

1.1 System of exchange rate stability and its components

1.1.1 Anti-lock braking system (ABS)

1.1.2 Traction control

1.1.3 Brake force distribution system

1.1.4 Electronic differential lock

2. Additional functions of the system of exchange rate stability

3. Driver assistance systems

3.1 Hill descent assist

3.2 Hill start assist

3.3 Dynamic Start Assist

3.4 Auto parking brake function

3.4.1 Stop-and-Go (traffic jam) assistant

3.4.2 Start assistant

3.4.3 Automatic parking

3.5 Listening brake function

3.6 Assistant steering

3.7 Adaptive cruise control

3.8 Scanning system in front of the vehicle

Conclusion

Literature

1. Systems,improvingcourseworksteadinessandcontrollabilitycar

1. 1 SystemcoursesustainabilityandherComponents

The exchange rate stability system (another name is the dynamic stabilization system) is designed to maintain the stability and controllability of the vehicle by early identification and elimination of a critical situation. Since 2011, the equipping of a system of exchange rate stability of new passenger cars is mandatory in the USA, Canada, and EU countries.

The system allows you to keep the car within the trajectory set by the driver during various driving modes (acceleration, braking, driving in a straight line, cornering and free rolling).

Depending on the manufacturer, the following names for the stability control system are distinguished:

· ESP(Electronic Stability Program) on most cars in Europe and America;

· ESC(Electronic Stability Control) on Honda, Kia, Hyundai cars;

· DSC(Dynamic Stability Control) on BMW, Jaguar, Rover cars;

· DTSC(Dynamic Stability Traction Control) on Volvo cars;

· VSA(Vehicle Stability Assist) on Honda, Acura vehicles;

· VSC(Vehicle Stability Control) on Toyota vehicles;

· VDC(Vehicle Dynamic Control) on Infiniti, Nissan, Subaru cars.

The structure and principle of operation of the stability control system are considered on the example of the most common ESP system, which has been produced since 1995.

The device of the exchange rate stability system

The stability control system is a higher level active safety system and includes anti-lock braking system (ABS), brake force distribution (EBD), electronic differential lock (EDS), traction control (ASR).

The stability control system combines input sensors, a control unit and a hydraulic unit as an actuator.

Inputsensors capture specific vehicle parameters and convert them into electrical signals. With the help of sensors, the dynamic stabilization system evaluates the driver's actions and the vehicle's movement parameters.

The sensors of the steering wheel angle, pressure in the brake system, brake light switch are used in the assessment of the driver's actions. The actual parameters of the movement are estimated by the sensors of wheel rotation speed, longitudinal and lateral acceleration, vehicle angular speed, and pressure in the brake system.

The ESP system control unit receives signals from sensors and generates control actions on the actuators of the monitored active safety systems:

· Inlet and outlet valves of the ABS system;

· Switching and high pressure valves of the ASR system;

· Warning lamps of the ESP system, ABS system, brake system.

In its work, the ESP control unit interacts with the engine management system and the automatic transmission (via the corresponding units). In addition to receiving signals from these systems, the control unit generates control actions on the elements of the engine and automatic transmission control system.

The dynamic stabilization system uses the ABS / ASR hydraulic unit with all components.

The principle of operation of the exchange rate stability system

Determination of the onset of an emergency is carried out by comparing the actions of the driver and the parameters of the vehicle. In the event that the driver's actions (desired driving parameters) differ from the actual driving parameters of the vehicle, the ESP system recognizes the situation as uncontrollable and starts working.

Stabilization of vehicle movement using the stability control system can be achieved in several ways:

· Slowing down of certain wheels;

· Change in engine torque;

· Changing the angle of rotation of the front wheels (in the presence of an active steering system);

· Changing the degree of damping of shock absorbers (in the presence of an adaptive suspension).

In understeer, ESP prevents the vehicle from drifting out of the corner by braking the inner rear wheel and modifying engine torque.

When oversteering, the vehicle will not skid when cornering by braking the front outer wheel and changing the engine torque.

Wheel braking is performed by activating the appropriate active safety systems. The work is cyclical in nature: increasing pressure, holding pressure and releasing pressure in the braking system.

Changing the engine torque in the ESP system can be done in several ways:

· Changing the position of the throttle valve;

· Bypass fuel injection;

· Skipping ignition pulses;

· Changing the ignition timing;

· Cancellation of gear shifting in automatic transmission;

· Redistribution of torque between the axles (in the presence of all-wheel drive).

The system that combines the stability control system, steering and suspension is called the integrated vehicle dynamics control system.

1.1.1 Anti-lock brakingsystem(ABS)

In case of emergency braking of the vehicle, one or more wheels may be blocked. In this case, the entire margin of adhesion of the wheel with the road is used in the longitudinal direction. A locked wheel ceases to perceive lateral forces that keep the car on a given trajectory and slides along the road surface. The car loses control, and the slightest lateral force causes it to skid.

Anti-lock braking system (ABS, ABS, Antilock Brake System) is designed to prevent the wheels from locking during braking and to maintain vehicle controllability. The anti-lock braking system improves braking efficiency, shortens the braking distance on dry and wet surfaces, provides better maneuverability on slippery roads, and emergency braking control. Less and even tire wear can be recorded as an asset of the system.

However, the ABS system is not without its drawbacks. On loose surfaces (sand, gravel, snow), the use of an anti-lock braking system increases the braking distance. On such a surface, the smallest braking distance is ensured just when the wheels are locked. At the same time, a wedge of soil is formed in front of each wheel, which leads to a reduction in the braking distance. In modern ABS designs, this drawback is almost eliminated - the system automatically determines the nature of the surface and implements its own braking algorithm for each.

Anti-lock braking system has been produced since 1978. Over the past period, the system has undergone significant changes. On the basis of the ABS system, a brake force distribution system is built. Since 1985, the system has been integrated with the traction control system. Since 2004, all vehicles manufactured in Europe have been equipped with an anti-lock braking system.

The leading manufacturer of anti-lock braking systems is Bosch. Since 2010, the company has been producing the 9th generation ABS system, which is distinguished by the smallest weight and dimensions. So, the hydraulic block of the system weighs only 1.1 kg. The ABS system is installed in the standard vehicle braking system without changing its design.

The most effective is the anti-lock braking system with individual wheel slip control, the so-called. four-channel system. Individual regulation allows you to obtain the optimal braking torque at each wheel in accordance with road conditions and, as a result, a minimum braking distance.

The anti-lock braking system design includes wheel speed sensors, a brake pressure sensor, a control unit and a hydraulic unit as an actuator. http://systemsauto.ru/active/shema_abs.html

A speed sensor is installed on each wheel. It captures the current value of the wheel speed and converts it into an electrical signal.

Based on the signals from the sensors, the control unit detects a wheel blocking situation. In accordance with the installed software, the unit generates control actions on the actuators - solenoid valves and the electric motor of the return pump of the hydraulic unit of the system.

The hydraulic unit integrates inlet and outlet solenoid valves, pressure accumulators, return pump with electric motor, damping chambers.

In the hydraulic block, each wheel brake cylinder is associated with one inlet and one outlet valve, which control braking within their own circuit.

The pressure accumulator is designed to receive brake fluid when the pressure in the brake circuit is released. The return pump is connected when the capacity of the pressure accumulators is insufficient. It increases the rate of pressure relief. The damping chambers receive the brake fluid from the return pump and dampen its vibrations.

The hydraulic block contains two pressure accumulators and two damping chambers according to the number of hydraulic brake circuits.

A warning lamp on the instrument panel signals a system malfunction.

How anti-lock braking system works

Anti-lock braking system operation is cyclical. The cycle of the system includes three phases:

1. holding pressure;

2. pressure relief;

3. increase in pressure.

Based on the electrical signals from the yaw rate sensors, the ABS control unit compares the yaw rate of the wheels. If there is a danger of blocking one of the wheels, the control unit closes the corresponding inlet valve. The outlet valve is also closed in this case. There is a retention of pressure in the wheel brake cylinder circuit. Pressing the brake pedal further does not increase the pressure in the wheel brake cylinder.

If the wheel is still blocked, the control unit opens the corresponding outlet valve. The inlet valve remains closed. The brake fluid is bypassed into the pressure accumulator. There is a release of pressure in the circuit, while the speed of rotation of the wheel increases. If the capacity of the pressure accumulator is insufficient, the ABS control unit connects the return pump to work. The return pump pumps the brake fluid into the damping chamber, reducing the pressure in the circuit. The driver senses the pulsation of the brake pedal.

As soon as the angular speed of the wheel exceeds a certain value, the control unit closes the exhaust valve and opens the intake valve. There is an increase in pressure in the wheel brake cylinder circuit.

The cycle of work of the anti-lock braking system is repeated until the end of braking or the end of blocking. ABS is not deactivated.

1.1.2 Anti-slipsystem

Traction control system (also known as traction control system) is designed to prevent the drive wheels from slipping.

Depending on the manufacturer, the traction control system has the following trade names:

· ASR(Automatic Slip Regulation, Acceleration Slip Regulation) for Mercedes, Volkswagen, Audi, etc .;

· ASC(Anti-Slip Control) on BMW vehicles;

· A-TRAC(Active Traction Control) on Toyota vehicles;

· DSA(Dynamic Safety) on Opel vehicles;

· DTC(Dynamic Traction Control) on BMW vehicles;

· ETC(Electronic Traction Control) on Range Rover vehicles;

· ETS( Electronic Traction System) on Mercedes vehicles;

· STC(System Traction Control) on Volv vehicles o;

· TCS(Traction Control System) on Honda vehicles;

· TRC(Traking Control) on Toyota vehicles.

Despite the variety of names, the design and principle of operation of these traction control systems are in many ways similar, therefore, they are considered on the example of one of the most common systems - the ASR system.

The traction control system is based on the anti-lock braking system. ASR system implements two functions: electronic differential lock and engine torque control. http://systemsauto.ru/active/shema_asr.html

To implement anti-slip functions, the system uses a return pump and additional solenoid valves (changeover and high pressure valve) for each of the drive wheels in the ABS hydraulic unit.

The ASR system is controlled by the corresponding software included in the ABS control unit. In its work, the ABS / ASR control unit interacts with the control unit of the engine management system.

The principle of operation of the traction control system

ASR prevents wheel spin across the entire vehicle speed range:

1. at low speeds (from 0 to 80 km / h), the system provides torque transmission by braking the driving wheels;

2. At speeds above 80 km / h, the forces are regulated by reducing the torque transmitted from the engine.

Based on the signals from the wheel speed sensors, the ABS / ASR control unit determines the following characteristics:

· Angular acceleration of driving wheels;

· Vehicle speed (based on the angular speed of non-driving wheels);

· The nature of the vehicle's movement - straight or curved (based on a comparison of the angular velocities of non-driving wheels);

· The amount of slippage of the driving wheels (based on the difference in the angular velocities of the driving and non-driving wheels).

Depending on the current performance value, brake pressure control or engine torque control is performed.

Controlinhibitorypressure carried out cyclically. The working cycle has three phases - pressure build-up, pressure hold and pressure release. The increase in the brake fluid pressure in the circuit ensures the braking of the drive wheel. It is done by turning on the return pump, closing the changeover valve and opening the high pressure valve. Pressure hold is achieved by shutting off the return pump. The pressure is released at the end of the slip with the inlet and changeover valves open. The cycle of work is repeated if necessary.

Controltwistingmomentengine carried out in conjunction with the engine management system. Based on the wheel slip information from the wheel speed sensors and the actual torque from the engine control unit, the traction control control unit calculates the required torque. This information is transmitted to the control unit of the engine management system and is implemented using various actions:

· Changes in the position of the throttle valve;

· Skipping fuel injections in the injection system;

· Skipping ignition pulses or changing the ignition timing in the ignition system;

· Cancellation of gear shifting in cars with automatic transmission.

When the traction control system is triggered, a warning lamp on the instrument panel lights up. The system has the ability to turn off.

1.1.3 Systemdistributionbrakeefforts

The brake force distribution system is designed to prevent locking of the rear wheels by controlling the braking force of the rear axle.

A modern car is designed so that the rear axle has less load than the front. Therefore, to maintain the vehicle's directional stability, the front wheels must be locked before the rear wheels.

When the vehicle is braked sharply, there is an additional reduction in the load on the rear axle, since the center of gravity is shifted forward. And the rear wheels, in this case, may be blocked.

The brake force distribution system is a software extension of the anti-lock braking system. In other words, the system uses the structural elements of the ABS system in a new way.

Common trade names for the system are:

· EBD, Electronic Brake Force Distribution;

· EBV, Elektronishe Bremskraftverteilung.

The principle of operation of the brake force distribution system

The EBD system, like the ABS system, is cyclical. The cycle of work includes three phases:

1. holding pressure;

2. pressure relief;

3. increase in pressure.

The ABS control unit compares the braking forces of the front and rear wheels using the wheel speed sensors. When the difference between them exceeds a predetermined value, the brake force distribution system is activated.

Based on the difference in the sensor signals, the control unit determines when the rear wheels are locked. It closes the intake valves in the rear brake cylinder circuits. The pressure in the rear wheel circuit is kept at the current level. The front wheel inlet valves remain open. The pressure in the circuits of the brake cylinders of the front wheels continues to increase until the front wheels begin to block.

If the wheels of the rear axle continue to block, the corresponding exhaust valves open and the pressure in the circuits of the brake cylinders of the rear wheels decreases.

When the angular speed of the rear wheels exceeds the set value, the pressure in the circuits increases. The rear wheels are braked.

The work of the brake force distribution system ends when the front (driving) wheels begin to block. In this case, the ABS system is activated.

1.1.4 Systemeblockingdifferential

The electronic differential lock (EDS, Elektronische Differenzialsperre) is designed to prevent the drive wheels from slipping when starting off, accelerating on slippery roads, driving in a straight line and when cornering by braking the driving wheels. The system gets its name by analogy with the corresponding differential function.

EDS is triggered when one of the drive wheels slips. It slows down the sliding wheel, thereby increasing the torque on it. Since the drive wheels are connected by a symmetrical differential, the torque on the other wheel (with better grip) also increases.

The system operates in a speed range from 0 to 80 km / h.

The EDS system is based on the anti-lock braking system. In contrast to the ABS system, the electronic differential lock is designed to self-generate pressure in the brake system. To implement this function, a return pump and two solenoid valves (for each of the driving wheels) are used, included in the ABS hydraulic unit. It is a changeover valve and a high pressure valve.

The system is controlled by the corresponding software in the ABS control unit. The electronic differential lock is usually part of the traction control system.

How the electronic differential lock works

The electronic differential lock is cyclical. The cycle of the system includes three phases:

1. increase in pressure;

2. retention of pressure;

3. pressure relief.

The drive wheel slip is determined by comparing the signals from the wheel speed sensors. The control unit then closes the changeover valve and opens the high pressure valve. To create pressure in the brake cylinder circuit of the drive wheel, the return pump is switched on. There is an increase in the pressure of the brake fluid in the circuit and the braking of the drive wheel.

When the braking force required to prevent slipping is reached, the pressure is maintained. This is achieved by turning off the return pump.

At the end of the slip, the pressure is released. In this case, the intake and changeover valves in the brake cylinder circuit of the drive wheel are open.

If necessary, the EDS cycle is repeated. The ETS (Electronic Traction System) from Mercedes has a similar principle of operation.

2. Additionalfunctionsystemscoursesustainability

In the design of the exchange rate stability system, the following additional functions (subsystems) can be implemented: hydraulic brake booster, rollover prevention, collision avoidance, road train stabilization, increasing the effectiveness of brakes when heated, removing moisture from brake discs, etc.

All of these systems, in general, do not have their own structural elements, but are a software extension of the ESP system.

SystempreventingrolloverROP(Roll Over Prevention) stabilizes vehicle movement in the event of a rollover threat. Roll-over prevention is achieved by reducing lateral acceleration by braking the front wheels and reducing engine torque. Additional pressure in the braking system is generated by the active brake booster.

Systempreventingcollisions(Braking Guard) can be implemented in a vehicle equipped with adaptive cruise control. The system prevents the risk of collision by visual and audible signals and, in an emergency, by pressurizing the braking system (automatic activation of the return pump).

Systemstabilizationroad trains can be implemented in a vehicle equipped with a towing hitch. The system prevents the yaw of the trailer when the vehicle is moving, which is achieved by braking the wheels or reducing the torque.

SystemenhancementsefficiencybrakesatheatingFBS(Fading Brake Support, also known as Over Boost) prevents insufficient adhesion of the brake pads to the brake discs, which occurs during heating, by further increasing the pressure in the brake actuator.

Systemdeletingmoisturewithbrakedisks activated at speeds over 50 km / h and included wipers. The principle of operation of the system consists in a short-term increase in pressure in the circuit of the front wheels, due to which the brake pads are pressed against the discs and moisture evaporates.

3. Assistant systemsdriver

Driver support functions, or systems, are designed to assist the driver in performing certain maneuvers or in certain situations. Thus, they increase the driving comfort and safety. Such systems, as a rule, do not interfere with control in critical situations, but are always on and can be disabled if desired.

3.1 Assistantmovementon thedownhill

Hill Descent Control, also called HDC, assists the driver on mountain roads. When the car is on an inclined plane, the force of gravity acting on it is decomposed, according to the parallelogram rule, into normal and parallel components.

The latter is the rolling force acting on the vehicle. If the car has its own traction force, then it is added to the rolling force. The rolling force acts on the vehicle at all times, regardless of the vehicle speed. As a result, a car rolling down an inclined plane will accelerate all the time, that is, the faster it moves, the longer it rolls.

Principle of operation:

The hill descent assist is activated when the following conditions are met:

Vehicle speed is less than 20 km / h,

The slope exceeds 20-,

The engine is running

Neither the gas pedal nor the brake pedal is depressed.

If these conditions are met and the data on the accelerator pedal position, engine speed and wheel speed received by the downhill assistant indicate an increase in vehicle speed, the assistant assumes that the vehicle is rolling downhill and the brakes must be applied. The system starts operating at a speed slightly faster than the speed of a pedestrian.

The vehicle speed that the brake assistant must maintain (by braking all wheels) depends on the speed at which the downhill movement was started and the gear engaged. In this case, the hill descent assist activates the return pump. The high pressure valves and ABS inlet valves open, and the ABS outlet valves and changeover valves close. Brake pressure builds up in the wheel brake cylinders and the vehicle decelerates. When the vehicle's speed has dropped to the value that must be maintained, the hill descent assist stops braking the wheels and again reduces the pressure in the braking system. If the speed then starts to increase (with the accelerator pedal not depressed), the assistant assumes that the car is still going downhill. In this way, the vehicle's speed is constantly kept within a safe range that can be easily driven and monitored by the driver.

3.2 Assistantmoving awayon therise

When the car stops on a rise, i.e. on an inclined plane, the force of gravity acting on it is decomposed (in accordance with the parallelogram rule) into normal and parallel components. The latter is the rolling force, that is, the force under the influence of which the car will begin to roll back if the brake is released. When the vehicle starts off after stopping on a hill, its tractive effort must first balance the rolling force. If the driver presses the accelerator pedal too lightly or releases the brake (or parking brake) pedal too early, the traction force will be less than the rolling force and the car will begin to roll back before moving off. Hill Hold Control (also HHC) is designed to help the driver cope with this situation. The hill start assist is based on the ESP system. The ESP sensor unit G419 is supplemented by a longitudinal acceleration sensor that detects the vehicle's position.

The hill start assist is activated under the following conditions:

The vehicle is stationary (wheel speed sensor data).

The lift is greater than approx. 5- (data of the sensor unit for ESP G419).

The driver's door is closed (data from the control unit for the comfort system, depending on the model).

The engine is running (engine control unit data).

Foot brake applied (Touareg).

In this case, the hill start assist always works in the upward travel direction (upward). Including the HCC function - and starting off when driving in reverse, the starting direction is recognized by engaging reverse gear. How it works The Hill Start Assistant makes it easier to start on an uphill, allowing you to do it without using the parking brake. To this end, the start assist slows down the brake pressure reduction with hydr. system. This prevents the vehicle from rolling backwards while the traction force is still insufficient to compensate for the rolling force. The hill start assist can be divided into 4 phases.

PhaseI- creationbrakingpressure

The driver stops or holds the vehicle by pressing the brake pedal.

The brake pedal is depressed. The changeover valve is open, the high pressure valve is closed. The inlet valve is open, the required pressure is created in the brake cylinder. The outlet valve is closed.

Phase2 --retentionbrakingpressure

The car is stationary. The driver takes his foot off the brake pedal to place it on the accelerator pedal.

The hill start assist maintains the same brake pressure for 2 seconds to prevent the vehicle from rolling backwards.

The brake pedal is no longer depressed. The changeover valve closes. The brake pressure is maintained in the wheel contours. This prevents premature pressure drop.

Phase3 --doseddecreasebrakingpressure

The car is still stationary. The driver presses the accelerator pedal.

As the driver increases the torque transmitted to the wheels (tractive torque), the Start Assistant reduces the braking torque so that the vehicle does not roll backwards, but also does not become braked upon subsequent start-off.

The inlet valve is open, the changeover valve is metered open and the brake pressure is gradually reduced.

Phase4 --dischargebrakingpressure

The traction torque is sufficient for starting and subsequent acceleration of the vehicle. The hill start assist reduces the brake pressure to zero. The car starts to move.

The changeover valve is fully open. There is no pressure in the brake circuits.

3.3 Dynamicassistantmoving away

The dynamic starting assistant DAA (Dynamischer AnfahrAssistent) is also suitable for vehicles with an electromechanical parking brake. The DAA Dynamic Assistant makes it easier to start when the electric parking brake is on and when starting up on a hill.

The prerequisites for the implementation of this assistant are the presence of an ESP system and an electromechanical parking brake. The function of this assistant itself is a software extension for the electromechanical brake control unit. When the driver wants to set in motion a car that is standing on an electric / fur. parking brake, it does not have to turn off the electric / fur. parking brake with a key for switching off the el / mech. parking brake.

The dynamic starting assistant will automatically switch off the electric / mech. parking brake if the following conditions are met:

The intention of the driver to start driving off must be expressed.

When the vehicle is stopped, for example at a traffic light, activating the parking brake removes the need to keep the brake pedal depressed. After depressing the accelerator pedal, the parking brake is automatically released and the vehicle can start moving. Starting off with the parking brake on.

Touchingon therise

The driver does not need to release the parking brake when starting off, which he has to do in precise coordination with the operation of the clutch and accelerator pedals, while observing the traffic situation. Undesirable rolling backwards is reliably prevented, since the parking brake is only released automatically when the vehicle's tractive torque exceeds the rolling force calculated by the control unit.

Principlework

The car is stationary. The electromechanical parking brake is applied. The driver decides to get under way, engages 1st gear and presses the accelerator pedal. The Dynamic Start Assist checks all data relevant to determining when the parking brake is released:

Tilt angle (Detected by the longitudinal acceleration sensor.),

Engine torque

Accelerator pedal position,

Clutch pedal position (On cars with manual gearbox, the signal from the clutch pedal position sensor is used. On cars with automatic gearbox, the current value of the engaged gear is requested instead of the clutch pedal position.),

Desired direction of travel (On vehicles with automatic gearbox, set in the selected direction of travel, on vehicles with manual gearboxes - by signal from the switch of reversing lights.)

Based on these data, the control unit el / mech. parking brake calculates the rolling force acting on the vehicle and the optimum moment to release the electric parking brake, so that the vehicle can start without rolling back. When the vehicle's traction moment becomes greater than the rolling force calculated by the control unit, the control unit sends a control signal to both actuator motors for the rear wheel brakes. The parking brake applied to the rear wheels is released electromechanically. The vehicle starts without rolling backwards. Dynamic Start Assist performs its function without using the hydraulic brakes, it just uses the information provided by the ESP sensors.

3.4 Functionautomaticinclusionsparkingbrakes

The AUTO HOLD function is designed to work in vehicles in which an electromechanical parking brake is installed instead of a mechanical one. AUTO HOLD provides automatic holding in place of a stopped car, regardless of how it stopped moving, and helps the driver to perform the subsequent start-off (forward or backward). AUTO HOLD combines the following driver support functions:

3.4.1 AssistantmovementStop-and-Go(movementintraffic jam)

When the car comes to a standstill after a slow roll-out, the Stop-and-Go assistant automatically applies the brakes to keep it in this position. This makes it especially easy for the driver to control when driving in a traffic jam, since he no longer has to press the brake pedal just to keep the vehicle at a standstill.

3.4.2 Assistantmoving away

Automation of the stopping and starting process makes it easier for the driver to control when starting off on a hill. When starting off, the assistant releases the brakes at the right time. No unwanted rolling back occurs.

3.4.3 Automaticparking lot

When the vehicle has stopped with the AUTO HOLD function turned on, the driver's door opens or the driver's seat belt buckle is unbuckled or the ignition is turned off, the AUTO HOLD function automatically turns on the parking brake.

The AUTO HOLD function is also a software extension of the ESP system and requires an ESP system and an electromechanical parking brake for its implementation.

To enable the AUTO HOLD function, the following conditions must be met:

The driver's door must be closed.

The driver's seat belt must be fastened.

The engine must be on.

To enable the AUTO HOLD function, press the AUTO HOLD key.

Activation of the AUTO HOLD function is indicated by the indicator lamp lighting up in the key.

If one of the conditions is no longer met, the AUTO HOLD function is disabled. After each new ignition on, the AUTO HOLD function must be switched on again by pressing the button.

Principlework

The AUTO HOLD function is on. Based on the wheel speed signals and the brake light switch, AUTO HOLD recognizes that the vehicle is stationary and that the brake pedal is depressed. The braking pressure generated by it is "frozen" by closing the valves of the hydraulic unit, the driver must no longer hold down the pedal. That is, when the AUTO HOLD function is activated, the car is first held at a standstill by the hydraulic brakes of the four wheels. If the driver does not press the brake pedal and the car, after having already recognized its stationary state, will start moving again, the ESP system is activated. It independently (actively) creates brake pressure in the wheel contours so that the car stops moving. The pressure value required for this is calculated and set, depending on the angle of the road, by the ABS / ESP control unit. To build up pressure, the function turns on the return pump and opens the high-pressure valves and the ABS inlet valves, the outlet and changeover valves are closed or respectively. remain closed.

When the driver presses the accelerator pedal to drive away, the ABS exhaust valves open and the return pump pumps the brake fluid through the open changeover valves towards the expansion reservoir. This takes into account the tilt of the vehicle and the road to one side or the other to prevent the vehicle from rolling.

After 3 minutes the vehicle is stationary, the braking function is transferred from the ESP hydraulic system to the electromechanical brake.

In this case, the ABS control unit informs the electric / mech control unit. the required braking torque calculated by the brake. Both electric parking brake motors (rear wheels) are controlled by the electro-mechanical brake control unit. The vehicle is braked by hydraulic ESP mechanisms

The vehicle is braked with an electromechanical parking brake. The braking function is transferred to the electromechanical brake. The hydraulic brake pressure is automatically reduced. To do this, the ABS exhaust valves are reopened and the return pump pumps the brake fluid towards the expansion tank via the open changeover valves. This prevents overheating of the valves in the hydraulic unit.

3.5 SystemdryingbrakesBSW

The BSW brake drying system (short for the former German name Bremsscheibenwischer) was also sometimes called Rain Brake Support (RBS).

In rainy weather, a thin film of water can form on the brake discs. This leads to a certain slowdown in the occurrence of the braking torque, since the brake linings first slide on this film until the water evaporates as a result of heating the brake parts or is "erased" by the linings from the surface of the disc. Only then does the braking mechanism develop its full braking torque. When braking in a critical situation, every fraction of a second of delay is of the utmost importance. Therefore, a brake drying system has been developed to prevent this delay in brake application in wet weather. The BSW brake drying system ensures that the front brake discs are always dry and clean. This is achieved by lightly and briefly pressing the brake pads against the discs. In this way, the full braking torque is achieved without delay if required and the braking distance is shortened. A prerequisite for the implementation of the BSW brake drying system on the car is the presence of the ESP system on it.

Conditions for switching on the BSW brake drying system:

the car is moving at a speed of at least 70 km / h

The wiper is on.

If these conditions are met, then during the operation of the wiper in continuous or intermittent mode, the front brake pads are applied to the brake discs at regular intervals. The brake pressure does not exceed 2 bar. When the wiper is turned on once, the pads are brought to the discs also once. Such light pressings of the lining, as they are carried out by the BSW system, are invisible to the driver.

Principlework

The ABS / ESP control unit receives a message via the CAN data bus that the speed signal corresponds to> 70 km / h. Further, the system requires a signal for the operation of the wiper motor. Based on this, the BSW system concludes that it is raining and a water film may form on the brake discs, leading to slower brake response. The BSW then engages the braking cycle. A control signal is sent to the front brake cylinder filling valves. The return pump starts up and builds up a pressure of approx. 2 bar and holds it for approx. x wheel revolutions. During this entire cycle, the system constantly monitors the brake pressure. If the braking pressure exceeds a certain value stored in the system's memory, the system immediately reduces the pressure in order to avoid any noticeable braking effect. When the driver presses the brake pedal, the cycle is interrupted and, when the pressure is completed, starts over.

3.6 Assistantsteeringcorrections

The Steering Assistant, also called DSR (Driver-Steering Recommandation), is an optional ESP feature that ensures safe driving. This function makes it easier for the driver to stabilize the vehicle in critical situations (for example, when braking on a road surface with uneven grip or during sudden lateral maneuvers).

Let's consider the work of the steering correction assistant on the example of a specific road situation: the car brakes on the road, the right edge of which is potholes repaired by filling them with rubble. Due to the different grip on the right and left sides, a cornering moment will arise during braking, which should be compensated for by turning the steering wheel in the opposite direction in order to stabilize the vehicle on the course.

On a car without steering assist, the moment, character and amount of steering wheel rotation is determined only by the driver. It is easy for an inexperienced driver to make a mistake, for example. adjust the steering wheel too much each time, which can lead to dangerous rocking of the vehicle and loss of stability.

On a vehicle with steering assist, the power steering generates forces on the steering wheel that “prompt” the driver when, where and how much to turn it. As a result, the braking distance is shortened, the deviation from the trajectory is reduced and the directional stability of the vehicle is increased.

The condition for the implementation of the function is:

ESP system availability

Electric power steering.

Principlework

On the example of the road situation discussed above, the difference in braking pressures of the front right and left wheels in the ABS operation mode will be recorded. Further, further data will be collected using the traction control systems. The assistant calculates from this data how much torque needs to be applied to the steering wheel to help the driver make the necessary adjustments. In this way, interference with the ESP control system is reduced or completely prevented.

According to this data, the ABS / ESP control unit indicates to the power steering control unit which control signal to send to the electromechanical power steering electromechanical motor. The requested supporting torque of the electromechanical amplifier makes it easier for the driver to turn the steering wheel in the direction required to stabilize the vehicle. Rotation in the wrong direction is not facilitated and therefore requires more effort from the driver. The supporting torque is generated for as long as required by the ABS / ESP control unit to stabilize the vehicle and shorten the braking distance. The ESP warning lamp does not light up at the same time, this only happens when the ESP system intervenes in driving. The steering assist assist is activated prior to ESP intervention. The steering assist assist does not actively engage the hydraulic braking system, but only uses the ESP sensors to obtain the necessary data. Actually, the work of the steering correction assistant is carried out through communication with the electromechanical power steering.

3.7 AdaptiveCruise control

Research shows that maintaining the correct distance on long journeys requires a lot of effort on the part of the driver and leads to driver fatigue. Adaptive Cruise Control ACC (Adaptive Cruise Control) is a driver assistance system that improves driving comfort. It relieves the burden on the driver and thus improves driving safety. Adaptive cruise control is a further development of the conventional cruise control system (GRA, for Geschwindigkeitsregelanlage).

As with conventional GRA cruise control, adaptive cruise control maintains the vehicle speed at the driver's pre-set speed. But adaptive cruise control can also ensure that the minimum distance set by the driver to the next vehicle in front is maintained. To do this, adaptive cruise control reduces the speed to the speed of the vehicle ahead. The control unit for adaptive cruise control determines the speed and distance of the vehicle ahead of the vehicle. In this case, the system considers only objects (cars) moving in the same direction.

If the distance becomes less than the driver's preset value because the vehicle in front is slowing down or a vehicle moving slowly from an adjacent lane, the vehicle decelerates to maintain the preset distance. This deceleration can be achieved by recoil acc. commands to the engine control system. If deceleration by reducing engine power is not sufficient, the braking system is activated. Deceleration Acceleration The Touareg's Adaptive Cruise% Control can brake the vehicle to a standstill if traffic conditions require it. The required braking action is achieved by a hydraulic unit with a return pump. The changeover valve in the hydraulic block closes and the high pressure valve opens. A control signal is applied to the return pump and the pump starts to run. This creates brake pressure in the wheel contours.

3.8 Systemscanspacefrontby carFrontAssist

Front Assist is a driver assistance system with a warning function that prevents collisions with the vehicle in front. Stopping distance shortening systems AWV1 and AWV2 (from German Anhaltewegverkürzung, literally - stopping distance shortening) are part of the Front Assist system. If the distance to the next vehicle in front is dangerously close, Front Assist reacts in two stages - the so-called pre-warning and main warning.

Preliminarya warning. In the event of a preliminary warning, a warning symbol is first displayed in the instrument cluster (in addition, an acoustic signal can be heard). At the same time, the brake system is pre-pressurized (Prefill) and the hydraulic brake assist (HBA) switches to "increased sensitivity".

The main thinga warning. If the driver does not react, the system warns him with a short push. At the same time, the brake assistant switches to "maximum sensitivity".

Stopping distance reduction is not activated at speeds below 30 km / h.

brake directional stability parking

Conclusion

All traction control systems evolved from the anti-lock braking system ABS, which is a braking system that controls only the brakes. EBV, EDS, CBC, ABSplus and GMB are extensions of the ABS system, either at the software level or with the addition of additional components.

The ASR system is a further development of the ABS system, in addition to actively controlling the brakes, it also allows you to control the operation of the engine. Braking systems that only work with engine management include M-ABS and MSR. If ESP is installed in the vehicle, then the operation of all traction control systems is subject to it.

When the ESP function is deactivated, the traction control systems continue to operate independently. The ESP stability control system independently makes adjustments to the dynamics of the car when the electronics detects the deviation of the actual movement of the car from the desired by the driver. In other words, the electronic ESP system decides when, depending on the specific driving conditions, it is necessary to activate or deactivate one or another traction control system. ESP thus fulfills the function of a coordinating and controlling center in relation to other systems.

And in conclusion, I would like to note that electronic security systems are most likely to save lives and avoid a traffic accident. Thanks to the autonomous control of the car from the driver, the risk is minimal.

Literature

1.http: //vwts.ru/electro/syst_control_dvizh_rus.pdf

Posted on Allbest.ru

Are your nerves overwhelmed during rush hour when you are driving? Take advantage of the ADAS N2 driver assistance system, which will avoid accidents on the road!

The number of cars on the roads is increasing and the traffic density is increasing day by day. This is especially noticeable on the streets of large cities with multi-lane traffic, where cars are almost close to each other, and numerous violations by drivers and pedestrians cause accidents. In this situation, when a person is trying to control the situation on the road at the limit of his capabilities, the electronic assistance system "ADAS N2" will greatly facilitate driving.

This innovative device with the help of modern technologies is able to track the position of the car relative to the road marking lines, identify suddenly appeared pedestrians, determine the distance to the vehicles in front and signal if they are in dangerously close proximity. Thanks to the help of this smart gadget, you will always be warned of abnormal dangerous situations created by other road users, and you will feel more confident on the road even at rush hour in heavy traffic.

Advantages

Early Frontal Collision Warning (FCW). The device recognizes vehicles in front and calculates the time to approach, taking into account the distance and speed of both vehicles. When dangerous parameters are reached, a warning signal sounds and a light alarm is turned on.

Lane Departure Warning (LDW)... The gadget is able to determine your lane on a multi-lane road. When the car leaves the lane, a warning signal sounds, which is especially useful when it is necessary to strictly adhere to the lane of movement.

Zebra Pedestrian Identification (ZCPD). The device reminds the driver that there are people at the crosswalk who have the upper hand on the road, so there is a potential risk of collision if the speed is not reduced.

Driver Attention Monitoring (AAS)... The system assesses the driver's behavior and detects when the driver is prone to falling asleep. An alarm sounds to prevent the driver from falling asleep.

The principle of operation of the assistance system "ADAS N2"

The device is equipped with a high-speed 8-core Cortex A53 processor with 2 GB of RAM and 16 GB of flash memory, the operating system Android 6.0 is installed. There are also all the necessary sensors that determine the position of the car and its dynamics in motion: GPS, 6-axis gyroscope and 3-axis geomagnetic sensor. High-quality video is provided by a dual-lens camera. The system processes data from sensors and a video camera using special algorithms and issues warning signals to the driver in case of potential danger.

Statistical studies of the ADAS N2 assistance system showed that, on average, warning signals about danger arrive 2.7 seconds earlier than the driver notices them, which reduces the risk of getting into an accident by 79%!

An example of the "ADAS N2" system
Download this video [.mp4, 16 Mb]

Duplicates traffic signals

The device can read traffic signals and, by color, determines whether traffic is allowed or not. The driver receives the corresponding voice prompts, so he does not need to follow the green light at the intersection all the time - the system will prompt in time to start driving.

Records high quality video

The system is equipped with a video camera that works in the mode of a video recorder - it records videos in HD quality on a removable memory card with a capacity of up to 32 GB.

You can find out the exact location of the car at any time

The system constantly records the location of the vehicle using GPS signals. You can get the exact coordinates of your car at any time, wherever it is.

Automatic alarm in case of emergency

In the event of an accident, when the gyroscope sensors are triggered, the system is able to detect a dangerous situation and send an alarm signal automatically. These can be specialized services (police, ambulance) and pre-assigned phone numbers of people close to you.

Left lane departure detection function

The system constantly monitors vehicle retention in its lane. In the case of leaving the left lane, which happens if the driver falls asleep, an alarm sounds with a request to return to the right lane.

Can work as a Wi-Fi router

The device works in GSM, WCDMA, CDMA, FDD-LTE and TSCDMA networks, in addition, it is equipped with a Wi-Fi module with a router function and is able to distribute the Internet from mobile networks in the car for a smartphone, tablet and other devices.

Specifications:

System "ADAS N2" - side view

Contents of delivery:

electronic driver assistance system "ADAS N2";
user manual;
warranty card;
package.

Warranty: 12 months

Not so long ago, the main, and often the only electronic system on board a car was the electronic ignition system. But times are changing, and the automotive industry, with leaps and bounds moving into the future, with enviable zeal is stuffing "iron horses" with more and more electronic assistants. ABS, ASR, CDC, EBC, HBA ... from one variety of English-language abbreviations it becomes scary (besides, different manufacturers call the same systems differently). Apparently, the time is approaching when the car, as if descended from the screen of the movie "The Fifth Element", will not only fly over the roadway and give the driver advice in a pleasant female voice, but will generally take over the control process. If you, dear readers of the portal, do not want a bright automated future to meet you with frightening abbreviations, then read the article below.

Control comfort

Recently, all leading car manufacturers have been paying close attention to comfort and safety in driving, and more and more electronic systems are being created precisely in order to make the process of driving a real rest and pleasure.

The most famous and widespread electronic system that helps car enthusiasts is, of course, ABS. ABS is an anti-lock braking system that prevents the wheels from locking and prevents skidding when braking. If there is a threat of blocking, ABS reduces the pressure in the working cylinders of the brakes of the corresponding wheels until they begin to rotate, providing the most effective deceleration. ABS comes in handy for the driver in order to maintain the vehicle's controllability in critical situations. (used in cars such as: Citroen C4, Land Rover New Range Rover). The next most popular system is EBD- electronic distribution of braking forces. It takes into account the distribution of the dynamic load between the wheels during braking and redistributes the braking forces accordingly between the corresponding wheels. Recently, these two systems have been combined into one. (For example used on: Citroen C4, Hyundai Grandeur).

Also a very common system is parktronic(in our time it can be found even on the Oka). Many people have problems with parking their car, and this wonderful system, as you probably already guessed, helps the driver to park the car in the most “painless” way. There are two types of parking sensors: passive (when the car approaches an obstacle from behind or in front, an audible or visual signal is activated to warn the driver) and active (when approaching an obstacle, the car will automatically stop) (for example, used on: Land Rover Range Rover).

The day of the invention of this system, many traffic police officers declared their professional day of mourning. Guess what I'm talking about? O cruise control. Cruise control or GRA, maintains a constant set speed of the car, preventing the driver from accidentally reaching a higher speed than necessary (and getting a well-deserved penalty in this case). In addition, there is also adaptive cruise control or ACC... It differs from conventional cruise control in that ACC includes an automatic distance control system, which maintains a constant set time distance to the vehicle in front. (For example used on: Jaguar X-Type, Hyundai Grandeur).

Another electronic assistant is the system ASR... It is a traction control system that prevents wheel spin by reducing engine torque during a sharp start or when hitting a slippery or loose road section, ensuring efficient acceleration.

Also frequently used EDS- electronic differential lock. Provides a braking effect on the respective drive wheel, preventing it from slipping on slippery road surfaces to increase traction.

It has been noticed that some drivers, in a situation where emergency braking is necessary, get lost and do not “press” the brake pedal enough. It is for such motorists that ingenious manufacturers have come up with - HBA- hydraulic "assistant" braking. The HBA recognizes this braking attempt and independently provides effective braking. (For example used on: Jaguar X-Type).

Quite often, in the conditions of Russian roads, we have to brake with the engine, but this is not so easy and not everyone succeeds in doing it correctly. To make it easier for car drivers, manufacturers have come up with a system MSR. MSR is a Controlled Engine Braking System. Prevents the drive wheels from blocking during engine braking, for example, when the accelerator pedal is suddenly released (or in the case of braking downshifting) or when the engine is braking in difficult road conditions.

I think everyone somehow got into a situation when, when the front wheels are demolished on a bend, the front of the car slides to the edge of the road (or the rear wheels slip with a U-turn during a skid). ESP- a system for maintaining exchange rate stability. The system's sensors read information about the drift or drift of the vehicle and activate the corresponding left or right system of the front (when drifting) or rear (when drifting) brakes. At the same time, I still strongly recommend not to forget about the laws of physics. (For example used on: Citroen C4).

The next electronic system required for comfortable and safe driving is automatic drying of brakes. As you probably already guessed, it is effective in the rain. Special sensors give a signal that the car is in wet conditions and the brake pads are periodically pressed against the brake discs for a short period of time, drying the brakes with little effort. This ensures that the brakes are always ready for efficient operation when the need arises to brake.

Less frequently used system CDC- is an independent air suspension of all wheels with an automatically variable ground clearance depending on the speed of movement and road conditions. Provides high smoothness under any road conditions.

There is an opinion that due to the spread of all these technological amenities, the driver's skill in getting out of difficult situations on the road decreases, but as a blonde it seems to me that driving comfort is an important factor when choosing an iron companion on the road.

Interior comfort

Personally, as a woman, what interests me most about cars is their level of comfort in the cabin. Like any owner of long legs, I appreciate the amount of usable space inside the car, and like any owner of complex hair styling, I respect the presence of climate control in the car (and not an open window as an alternative to it). So, dear men, if the comfort of your second half is not of the last importance for you, then pay attention to the systems described below, and for you, I think their presence will be no less pleasant.

The first and, in my opinion, the most important system is Climate control - programmable automatic system for maintaining the set climate parameters in the cabin. Do not say so, but with our changeable climate, such a system will never be superfluous. There are even more advanced climate control systems - air conditioners, with the ability to maintain an individual temperature in 2-4 zones of the passenger compartment, respectively. The special construction of the system ensures complete absence of drafts. (For example used on: Toyota RAV4, Citroen C4, KIA Cerato).

Very convenient, in the conditions of the Russian winter, the system is heater... This is a heater that works regardless of the ventilation or heating system of the car, and can be used both when the car is moving and when it is parked.

The next system is Easy-Entry greatly facilitates the process of boarding and disembarking passengers. This system automatically moves the chair back when the door is opened. And in the two-door car, the forward-sliding seats make it easier for rear passengers to board. There is also its analogue, which ensures the comfort of the driver's landing. A special system automatically remembers the position of the steering wheel that is convenient for you and the seat moves them back if you leave the passenger compartment and returns to the previous position when you return (For example, used on: Toyota RAV4, Volvo XC90). There is also an option thanks to which the head restraint in the event of an accident keeps the driver's or passenger's head tilted, thereby protecting the neck from fractures.

If the ability to always stay connected is a prerequisite for your life, then especially for you, the developers of internal auto-tuning have invented a unique option - Bluetooth speakerphone constantly in full working readiness. Simple and ingenious: the driver's mobile phone is wirelessly connected to the onboard electronics and can be left in the pocket. The functions of a mobile phone are taken over by a stationary car phone using the data of the mobile SIM card. For this, the mobile phone must be able to access the SIM card via the Bluetooth interface. (For example used on: Land Rover Range Rover).

The next system is Gps- global positioning system. Once a military development, which has found application for peaceful purposes. A satellite system that allows you to determine the position of an object on the ground with an accuracy of 5-10 meters. That will not allow you to get lost either in the city or outside of it.

Also a successful development of automakers are rain sensors- a special device that controls the weather outside the car and in case of rain (windscreen pollution) automatically activates the wipers. (For example used on: Hyundai Grandeur, Renault Megane). The same principle works light sensors- automatically turning on the headlights at dusk (entering the tunnel). (For example, used on: Hyundai Grandeur, Land Rover Range Rover).

An advantageous advantage when shopping or traveling is provided by the luggage compartment lid that can be opened radio key, saving you the hassle of freeing your hands from bags and luggage. (Land Rover New Range Rover). Also thanks to the appearance of such a device as Electroluk, the driver no longer has to manually open the sunroof of the vehicle. The opening and closing of the sunroof is carried out by means of a rotary switch. (For example used on: Hyundai Grandeur). And for those who do not like to use the ignition key, there is an option: Keyless access... The starter button, located in a convenient place, starts and stops the engine at the touch of a button.

In order to facilitate the process of managing all these technical amenities, ingenious car builders came up with a place on Multifunctional steeringwheel keys designed to control various devices and systems of the car. (For example, used on: Toyota RAV4).

All of these systems are designed to make it easier for you to control the car and increase its comfort and safety. However, these are far from all existing electronic systems. In only one single limousine, the number of electronic and electrical devices has long exceeded a hundred, and apparently this is not the limit. And what may not please all these ingenious options that make life easier for a motorist can now be found not only in a limousine worth fabulous money, but also in VAZ cars sold for reasonable money. Not so long ago, AvtoVAZ pleased the fans of its cars by installing an electric power steering, ABS and other joys on the Kalina.

used in the operation of the fuel system	fuel pressure sensor;
used in the operation of the injection system	fuel high pressure sensor;
used in the operation of the intake system	air flow meter; intake air temperature sensor; throttle position sensor; intake manifold pressure sensor
used in the operation of the ignition system	gas pedal position sensor; crankshaft speed sensor; knock sensor; air flow meter; intake air temperature sensor; coolant temperature sensor; oxygen sensors;
used in the operation of the exhaust system	exhaust gas temperature sensor; oxygen sensor in front of the neutralizer; oxygen sensor after the neutralizer; nitrogen oxide sensor;
used in the operation of the cooling system	coolant temperature sensor; oil temperature sensor;
used in the work of the vacuum brake booster	pressure sensor in the line of the vacuum brake booster

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The device of the exchange rate stability system

The principle of operation of the exchange rate stability system

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The principle of operation of the traction control system

The principle of operation of the brake force distribution system

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Similar documents

Are your nerves overwhelmed during rush hour when you are driving? Take advantage of the ADAS N2 driver assistance system, which will avoid accidents on the road!

Advantages

The principle of operation of the assistance system "ADAS N2"

Duplicates traffic signals

Records high quality video

You can find out the exact location of the car at any time

Automatic alarm in case of emergency

Left lane departure detection function

Can work as a Wi-Fi router

Specifications:

Contents of delivery:

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