Basic electronic systems modern car mobile
It is already difficult to imagine a modern car without various electronic systems that control and monitor the work. various nodes and aggregates. At present, widespread onboard systems control based on electronic control units (ECU).
All electronic units according to their functional purpose can be classified into three main control systems: engine; transmission and undercarriage; interior equipment and vehicle safety.
A wide variety of engine control systems have been developed and mass-produced in the world. These systems, according to the principle of operation, have much in common, but also differ significantly.
Control system gasoline engine ensures optimal performance by controlling the injection. fuel, ignition timing, speed crankshaft engine on Idling and performing diagnostics. Electronic control system diesel engine controls the amount of injected fuel, the moment of injection start, the current of the torch plug, etc.
In the electronic transmission control system, the object of regulation is mainly automatic transmission. Based on the signals from the throttle angle sensors and vehicle speed, the ECU selects the optimal transmission ratio and clutch engagement time. The electronic control system of the transmission increases the accuracy of regulation compared to the previously used hydromechanical system gear ratio, simplifies the control mechanism, increases efficiency and controllability. Chassis control includes control of the processes of movement, changes in the trajectory and braking of the car. They affect the suspension steering and brake system, ensure the maintenance of the set speed.
Interior equipment management is designed to increase the comfort and consumer value of the car. For this purpose, an air conditioner, an electronic instrument panel, a multifunctional Information system, compass, headlights, wiper with intermittent mode operation, lamp burnt out indicator, obstacle detection device when driving in reverse power windows, reclining seats. Electronic systems security include: anti-theft devices, communication equipment, central locking of door locks, security modes, etc.
Every electronic system in a modern car is controlled by electronic unit computer control unit (ECU). They relate to brakes, transmission, suspension, security system, air conditioner, navigation and more. In terms of functionality, ECUs are as similar to each other as the corresponding control systems are. Actual differences can be large, but the power supply, interaction with relays and other solenoid loads are identical for most different ECUs. One of the most important is the engine control unit. The list of electronic control units (ECU) shown defines the variety of installed electronic systems, in this case the example of the Audi A6
Variety of ECUs in modern car on the example of the Audi A6
1. Control box auxiliary heater
2. Control box ABS brakes with EDS
3. Control unit for maintaining a safe distance
4. Tire pressure monitoring transmitter, front left
5. Control box onboard network
6. Control unit in the driver's door
7. Block access control and start
8. Control unit in the instrument cluster
9. Control box electronic devices on the steering column
10. Control unit for telephone, telematics system
11. Engine control unit
12. Climatronic control unit
13. Seat adjustment control unit with memory and steering column adjustment;;
14. Adjustment control unit ground clearance; headlight range control unit
15. CD changer; CD-ROM drive
16. Control unit in the rear left door
17. Air-Bag system control unit
18. Vehicle rotation speed sensor around the vertical axis
19. Door control unit front passenger
20. Front passenger seat adjustment control unit with memory
21. Control unit in the rear right door
22. Tire pressure monitoring transmitter, rear left
23. Parking heater radio
24. Navigation system control unit with CD drive; voice input control unit;;
25. Tire pressure monitoring transmitter, rear right
26. Parking aid control unit
27. Central control unit for the comfort system
28. Electric parking "manual" brake control unit
29. Power supply control unit (battery manager)
Currently, the most important and economically justified is the widespread introduction of electronic systems to improve the performance and reduce the cost of operating the engine and transmission, as well as systems to improve safety.
Today you will not surprise anyone with an abundance of electronics in a car, especially high class. The number of electronic systems and components in a car is so large and varied that sometimes you can get confused in all its abundance.
E automotive electronics and troubleshooting of cars of Russian and foreign production. Here you will find a description, device and principles of operation of the whole variety of electronic systems of a modern car.
All materials and software posted on the site and available for download are non-commercial and distributed free of charge. and do not imply liability for possible damage caused to you or your car as a result of inept or incorrect use of materials and programs.
Amendments, additions, on the subject of the site are welcome. If you have programs, articles or interesting links, please send it.
Electronic systems of a modern car on the example of the Audi A6
http://awtoel.narod.ru
There are a huge number of engine control systems and their modifications. For this, consider various options ECM that has ever been installed on mass-produced vehicles.
ECM is an electronic engine management system or, in a simple way, an engine computer. It reads data from engine sensors and sends instructions to executive systems. This is done so that the engine operates in the optimal mode for it and maintains the norms of toxicity and fuel consumption.
Let's review with an example injection cars VAZ. Let's break the ESUD into some groups according to the criteria.
Manufacturer of electronic control system
For VAZ vehicles, Bosch engine management systems were used, General Motors And domestic production. If you want to replace any part of the injection system, for example manufactured by Bosch, then this will be impossible, because parts are not interchangeable. But domestic fuel injection parts sometimes turn out to be similar to foreign-made parts.Varieties of controllers
On VAZ cars You can find the following types of controllers:- January 5 - production Russia;
- M1.5.4 - manufactured by Bosch;
- MP7.0 - manufactured by Bosch;
Injection types
According to this parameter, it can be divided into a system of central (single-point) and distributed (multi-point) fuel injection. In a central injection system, the injector delivers fuel to the intake manifold before the throttle valve. In multiport injection systems, each cylinder has its own injector, which delivers fuel directly in front of the intake valve.Distributed injection systems are divided into phased and non-phased. In non-phased systems, fuel injection can be carried out either by all injectors at the same time or by pairs of injectors. In phased systems, fuel injection is carried out sequentially by each nozzle.
Toxicity standards
IN different times cars were assembled that met the requirements of exhaust gas toxicity standards from Euro-0 to Euro-4. Cars that comply with Euro-0 standards are produced without converters, gasoline vapor recovery systems, oxygen sensors.You can distinguish a car in the Euro-3 configuration from a car with the Euro-2 configuration by the presence of a rough road sensor, appearance adsorber, as well as the number of oxygen sensors in exhaust system engine (in the configuration "Euro-2" it is one, and in the configuration "Euro-3" there are two of them).
Definitions and concepts
Controller- the main component of the electronic COURT. Evaluates information from sensors about the current mode of operation of the engine, performs rather complex calculations and controls actuators.Sensor mass flow air (DMRV)- converts the value of the mass of air entering the cylinders into an electrical signal.
Speed sensor- converts the value of the vehicle speed into an electrical signal.
oxygen sensor- converts the value of the oxygen concentration in the exhaust gases after the converter into an electrical signal.
Control oxygen sensor- converts the value of the oxygen concentration in the exhaust gases up to the converter into an electrical signal.
Rough road sensor- converts the amount of body vibration into an electrical signal.
Phase sensor- its signal informs the controller that the piston of the first cylinder is at TDC (top dead center) on the compression stroke of the air-fuel mixture.
coolant temperature sensor- converts the temperature of the coolant into an electrical signal.
crankshaft position sensor- converts the angular position of the crankshaft into an electrical signal.
Throttle position sensor- converts the value of the throttle opening angle into an electrical signal.
Knock sensor- converts the amount of mechanical noise of the engine into an electrical signal.
ignition module- an element of the ignition system that accumulates energy to ignite the mixture in the engine and provides high voltage on the spark plug electrodes.
Nozzle- an element of the fuel supply system that provides fuel dosing.
Fuel pressure control- an element of the fuel supply system that ensures the constancy of fuel pressure in the supply line.
Adsorber - main element gasoline vapor recovery systems.
fuel pump module- an element of the fuel supply system that provides excess pressure in the fuel line.
Canister purge valve- an element of the gasoline vapor recovery system that controls the adsorber purge process.
Fuel filter- an element of the fuel supply system, a fine filter.
Converter- an element of the engine injection system to reduce toxicity exhaust gases. As a result of a chemical reaction with oxygen in the presence of a catalyst, carbon monoxide, CH hydrocarbons and nitrogen oxides are converted into nitrogen, water, and also into carbon dioxide.
diagnostic lamp- system element on-board diagnostics, which informs the driver about the presence of a malfunction in the SUD.
Diagnostic connector- an element of the on-board diagnostics system, for connecting diagnostic equipment.
idle speed controller- an element of the idle speed control system that regulates the air supply to the engine at idle.
There are more and more cars on the roads, drive them in dense stream becomes more and more difficult. In addition, the movement takes part a large number of young drivers who do not have sufficient driving experience.
For driver assistance and safety traffic A large number of electronic car safety systems are being developed.
Automotive security systems
All security systems are divided into active and passive:
- appointment active systems– prevent car collisions;
- passive safety systems reduce the severity of the consequences of an accident.
Overview of active safety systems
This review is an attempt to list and characterize modern systems active safety.
1. (ABS, ABS). Prevents wheel slippage during vehicle braking. Often (but not always) ABS work reduces braking distances vehicle, especially on slippery roads.
3. System emergency braking(EBA, BAS). In the event quickly raises the pressure in the brake system. used vacuum way management.
4. Dynamic braking control system (DBS, HBB). It quickly raises pressure during emergency braking, but the implementation method is different, hydraulic.
5. (EBD, EBV). In fact, this software extension latest generations ABS. The braking force is correctly distributed between the axles of the car, preventing blocking, in the first place, of the rear axle.
6. Electromechanical braking system (EMB). Brake mechanisms on wheels are activated by electric motors. On production cars not yet applied.
7. (ACC). Maintains the vehicle speed selected by the driver while maintaining safe distance to the vehicle in front. To maintain distance, the system can change the speed of the vehicle by acting on the brakes or the engine throttle.
8. (Hill Holder, HAS). When starting off on a hill, the system prevents the vehicle from rolling back. Even with the brake pedal released, the pressure in the brake system is maintained and begins to decrease when you press the "gas" pedal.
9. (HDS, DAC). Saves safe speed vehicle when driving downhill. Turned on by the driver, but activated at a certain steepness of the descent and enough low speed car.
10. (ASR, TRC, ASC, ETC,TCS). Prevents car wheels from slipping when accelerating.
11. (APD, PDS). Allows you to detect a pedestrian whose behavior may lead to a collision. In case of danger, it alerts the driver and activates the brake system.
12. (PTS, Park Assistant, OPS). Helps the driver to park the car in cramped conditions. Some types of systems perform this work in automatic or automated mode.
13. (Area View, AVM). With the help of a system of video cameras, or rather, an image synthesized from them on a monitor, it helps to drive a car in cramped conditions.
14. . Takes control of the car dangerous situation to get the car out of the way.
15. . Effectively keeps the vehicle in the lane marked by lane markings.
16. . Controlling the presence of interference in " dead zones» rear-view mirrors help you safely perform a lane change maneuver.
17. . With the help of video cameras that react to the thermal radiation of objects, an image is created on the monitor that helps to drive a car in low visibility.
18. . Reacts to speed limit signs, brings this information to the driver.
19. . Monitors the driver's condition. If, in the opinion of the system, the driver is tired, it requires a stop and rest.
20. . In the event of an accident, after the first collision, it activates the vehicle's braking system to avoid subsequent collisions.
21. . Observes the situation around the vehicle and, if necessary, takes measures to prevent an accident.
The use of electronic automatic control systems (ESAU for the engine, transmission, running gear and additional equipment) allows:
reduce fuel consumption;
exhaust toxicity,
increase engine power
active vehicle safety,
improve the working conditions of the driver.
Compliance with the requirements limiting the toxicity of exhaust gases and fuel consumption requires maintaining the stoichiometric composition combustible mixture, turning off the fuel supply in the forced XX mode, precise and optimal control of the ignition timing or fuel injection.
These requirements cannot be met without the use of ESAU.
Applied ESAU by the engine include control systems:
fuel supply,
ignition (in gasoline engines),
cylinder valves,
exhaust gas recirculation.
The first two systems are the most widely used.
Valve control systems are used to shut off a group of cylinders to save fuel and to control valve timing. Exhaust gas recirculation control systems ensure that the required amount of exhaust gases is returned to the intake manifold for mixing with fresh combustible mixture.
ESAU facilitates starting a cold engine, reduces the warm-up time before driving.
Anti-lock braking systems allow you to reduce the braking distance on a slippery road by 2 times, eliminating the occurrence of skidding.
6.2. Electronic engine management
Electronic fuel management systems for gasoline engines
The use of electronic automatic control systems (ESAU) for the fuel supply of gasoline engines is due to the need to reduce the toxicity of exhaust gases and improve the fuel efficiency of internal combustion engines. ESAUs make it possible to optimize the mixture formation process to a greater extent and make it possible to use three-way neutralizers that work effectively at a constant excess air coefficient a close to 1.
In addition, the ESAU engine allows you to increase the acceleration of the car, the reliability of cold start, accelerate warm-up and increase engine power.
ESAU for fuel supply of gasoline engines is divided into injection systems (into the intake manifold or directly into the combustion chamber) and electronically controlled carburetor systems.
The principle of operation of the electronic control system of the carburetor is the coordinated control of the air and throttle valves.
So the Ecotronic system from Bosch maintains the stoichiometric composition of the working mixture in most modes, provides the necessary enrichment of the mixture in the modes of starting and warming up the engine. The system provides the functions of shutting off the fuel supply at forced idle and maintaining the crankshaft speed at idle at a given level.
The most widely used injection systems in the intake manifold. They are divided into systems with injection into the zone intake valves and with central injection (Fig. 6.1, where: A - central injection; b - distributed injection into the intake valve area; c - direct injection into the engine cylinders; 1 - fuel supply; 2 - air supply; 3 - throttle valve; 4 - inlet pipeline; 5 - nozzles; 6 - engine).
The system with injection into the intake valve area (another name is distributed or multi-point injection) includes a number of nozzles equal to the number of cylinders, a system with central injection - one or two nozzles for the entire engine. Injectors in systems with central injection are installed in a special mixing chamber, from where the resulting mixture is distributed over the cylinders. The fuel supply by injectors in the distributed injection system can be coordinated with the intake process into each cylinder (phased injection) and inconsistent - the injectors work simultaneously or in a group (unphased injection).
Systems with direct injection due to the complexity of the design, they were not used on gasoline engines for a long time. However, the tightening of environmental requirements for engines makes it necessary to develop these systems.
Modern engine ESAUs combine the functions of fuel injection and ignition system operation, since the control principle and input signals (speed, load, engine temperature) for these systems are common.
In ESAU, the engine uses software-adaptive control. For implementation program control in the ROM of the control unit (CU), the dependence of the injection duration (the amount of fuel supplied) on the load and engine speed is recorded. On fig. 6.2 shows a generalized adjustment characteristic of a gasoline engine in terms of mixture composition.
The dependence is set in the form of a table (characteristic map) developed on the basis of comprehensive engine tests. The data in the table are presented with a certain step, for example 5 min -1 , the intermediate values are obtained by the BU by interpolation. Similar tables are used to determine the ignition timing. Selecting data from predefined tables is a faster process than performing calculations.
Direct measurement of the engine torque on a car is associated with great technical difficulties, so the main load sensor is the air flow sensors and (or) the pressure sensor in the intake manifold. To determine the engine speed, a pulse counter from an induction-type crankshaft position sensor or from an ignition distribution sensor is usually used.
The values obtained from the tables are corrected depending on the signals from the coolant temperature sensors, throttle position, air temperature, as well as the voltage of the on-board network and other parameters.
Adaptive control (feedback control) is used in systems with an oxygen sensor (λ-probe). The presence of information on the oxygen content in the exhaust gases allows you to maintain the excess air coefficient a (λ) close to 1. When controlling the fuel supply according to the OS, the control unit initially determines the duration of the pulses according to the data of the load sensors and the speed of the engine HF, and the signal from the oxygen sensor is used to fine-tune . Feedback fuel injection control is carried out only on a warm engine and in a certain load range.
The adaptive control principle is also used to stabilize the idle speed of the crankshaft and to control the ignition timing according to the knock limit.
Modern ESAU fuel supply of gasoline engines have a self-diagnosis function. The control unit checks the operation of sensors and actuators and identifies faults. When a malfunction is detected, the control unit memorizes the corresponding code and turns on the CHECK ENGINE emergency lamp on the instrument panel.
The diagnostic tool allows you to receive information from the control unit:
read fault codes;
determine the current values of the engine parameters,
activate the actuators.
the functions of the diagnostic tool are limited by the capabilities of the control unit.
The use of ESAU increases the reliability of the engine by providing the possibility of its operation in a "truncated" mode. In the event of a malfunction in one or more sensors, the control unit determines that their readings are not true and disables these sensors. In the "truncated" mode of operation, information from faulty sensors is replaced by a reference value or indirectly calculated from data from other sensors. For example, if the throttle position sensor malfunctions, its readings can be simulated by calculating the crankshaft speed and air flow. When one of the actuators fails, an individual fault bypass algorithm is used. If there is a defect in the ignition circuit, for example, the injection to the corresponding cylinder is turned off in order to prevent damage to the catalytic converter.
When the engine is running in a "truncated" mode, a decrease in power, a deterioration in throttle response, difficult starting of a cold engine, an increase in fuel consumption, etc.
To compensate for the technological spread in the characteristics of the ESAU elements and the engine, taking into account their changes during operation, the CU program provides a self-learning algorithm. As mentioned above, the signal from the oxygen sensor is used to correct the value of the injection duration obtained from the table from the ROM of the ECU. However, with significant discrepancies, such a process takes a long time.
Self-learning consists in saving the values of the correction factor in the memory of the control unit. The entire range of engine operation is divided, as a rule, into four characteristic learning zones:
idling, high frequency rotation at light load, partial load, high load.
When the engine is running in any of the zones, the duration of the injection pulses is adjusted until the actual composition of the mixture reaches the optimal value. The correction coefficients obtained in this way characterize a specific engine and are involved in the formation of the injection pulse duration in all modes of its operation. The self-learning process is also used to control the ignition timing in the presence of knock feedback. The main problem of the functioning of the self-learning algorithm is that sometimes an incorrect sensor signal can be perceived by the system as a change in the engine parameter. If the sensor signal error is not large enough for a DTC to be set, the damage may go undetected. In most systems, correction factors are not retained when the VU is powered down.
» Car electronic systems - to help the driver
Auxiliary electronic systems are designed to create conditions conducive to improved driving. Many different electronic systems have been developed that operate in conjunction with vehicle components, which can be classified:
- Auxiliary systems working in conjunction with the mechanisms of the brake circuit:
- auto blocking
- extreme braking. - Compliance exchange rate stability.
- Maintain distance between vehicles.
- Support for rebuilding cars when driving with a change of lanes of the highway.
- Parking using ultrasonic signals.
- Using the rear view camera.
- bluetooth.
- Cruise control
Anti-lock braking system
ABS () - specifically to improve the efficiency of the brakes under various road weather conditions.
It reads the speed of rotation of each wheel and, under heavy braking, prevents blocking and slipping, thereby leaving the ability to steer and maneuver the vehicle to a complete stop.
It includes:
- electronic control unit;
- mechanism - modulator for adjusting the pressure of the working (brake) fluid, (ABS block);
- showing angular velocity wheel rotation.
Extreme braking system
Intended for emergency braking in conditions requiring an immediate stop of the car. And it helps the driver to press the brake pedal, when calculating the inefficiency of braking.
Consists of blocks:
- hydraulic module assembled with ABS unit and return pump brake fluid;
- a sensor showing the pressure in the hydraulic circuit;
- a sensor that records the speed of rotation of the wheels;
- devices for switching off the signal transmitted to the extreme braking amplifier.
vehicle stability control
Allows you to stabilize the transverse dynamics of the car, prevents the vehicle from skidding. Works in conjunction with ABS and engine management system.
It includes:
- electronic block controller;
- a sensor showing the position of the steering wheel;
- pressure sensor in the brake system.
Exchange rate stability proved to be high efficiency on icy roads, helping the driver in difficult situations
Distance control system between moving vehicles
SARD is an electronic system for maintaining the required, predetermined distance between vehicles, operating in automatic mode. The effectiveness of the SARD is possible at speeds up to 180 km / h and works in conjunction with the speed control system, allowing the driver to drive the car in more comfortable conditions.
Lane change assist system
Designed to control the environment when maneuvering on the track. It allows using radar to control the dead zone around the car and warns the driver about the occurrence of obstacles while driving, prevents traffic accidents.
Electronic car parking system
Designed to ensure the safety of maneuvers when parking a car. The electronic system consists of several ultrasonic sensors that transmit information to the driver about possible obstacles using special sound and visual signals. Signal sensors operate in the mode of receiving and transmitting a signal and allow you to use them with the greatest efficiency.
Rear View Camera
Designed to transmit visual images behind the car. The combined use of sound sensors and a rear view camera prevents collision situations with obstacles behind the vehicle during maneuvers.
Auxiliary Bluetooth system
Bluetooth - provides mobile communications For various devices installed on the vehicle:
- telephone;
- laptop.
Helps the driver to be less distracted from the road. Ensuring safety and comfort when driving a car.
Consists of blocks:
- electronic transceiver unit;
- antennas.
Cruise control
Helps the driver by increasing driving comfort.
Supports set speed vehicle, regardless of the terrain, on the descents and ascents of the road. It has control with the addition of speed and speed limit, there is also a memorization of the set limit. It turns off when you press the brake or clutch pedal, it also has its own switch. When you press the gas pedal vehicle accelerates, after releasing, returns to its speed limit.
The user has the opportunity to significantly simplify and automate the use of vehicle systems, taking into account autonomous control.
Electronic diagnostics of vehicle systems is carried out at the passage of each Maintenance official dealer. A paper is issued on the presence of malfunctions with a printout of error codes. However, there is a slight difference between installed equipment and regular. For standard equipment, the dealer is obliged to provide repairs and its diagnostics, but for installed equipment, it may refuse you, especially if the equipment was installed in garage conditions with the introduction into the wiring and changing the algorithms of work. In such situations, if the car is under warranty, then you can lose warranty service. Be careful when installing additional equipment!
Vehicle door control unit - CAN network functions Peugeot 308 - disadvantages and reviews of the owners of the new model 
What is ABS (ABS) - anti-lock system brakes 
Brake system car repair or replacement What is a start-stop system? 
Car engine cooling system, principle of operation, malfunctions
