Advertising on the portal

Functions and varieties of sensors and sensors. Classification of sensors, basic requirements for them Modern sensors purpose device principle of operation

    Modern cars are equipped large quantity sensors, the purpose and principle of operation of which are far from clear to every motorist. Let's try to understand this issue.

    Mass air flow sensor

    The purpose of the mass air flow sensor (DMRV) is to control the operation of the power unit during the generation of electrical voltage by the system through the air entering the motor.

    Based on the data collected by the sensor, the most productive operation of the motor is built, during which the flow of air into the cylinders allows it to be continuously converted into electric current.

    The working part of the sensor - a platinum thread - is a sensitive anemometer. It is heated to a constant temperature, which is maintained by a thermal relay and an electronic control unit.

    The air flow passing through the sensor cools the thread, then the control module of the system increases the current supply to it, as a result of which the heating temperature of the thread continues to increase until it reaches its constant value. From this it follows that the strength of the current required to heat up the thread depends solely on the speed of air flow through the sensor. And already by means of the secondary converter in the sensor system, an electric voltage is generated.

    During operation, various deposits accumulate on the sensor thread, polluting it and degrading the performance of the entire device.

    Efficient cleaning of the thread is possible only by burning it with a pulsed current with a temperature of about 1 thousand degrees.

    However, washing a dirty platinum sensor filament with solutions containing ether or ketone compounds is strictly prohibited, since they:

    They have a detrimental effect on the compound;

    They have the ability to cool the crystal, as a result of which its structure is damaged;

    The so-called mask is washed off the surface of the crystal (a protective polymer layer in its center).

    You should not even try to wash the sensor filament with various solvents and aerosols containing acetone and ethyl, nor should you clean the anemometer filament with cotton wool soaked in gasoline, wound on a match, or a wooden stick. Such manipulations will not bring any effect, but will only worsen the operation of the DMRV.

    You can use VD-40 as a flush, but it is worth considering that it contains diesel fuel and acid compounds. It washes well, however, after itself it leaves a specific film on the surface, which must be removed for normal operation of the sensor. It is better to wash it off with alcohol compounds (distilled water and any alcohol). As practice has shown, it is isopropyl alcohol that is most suitable for this purpose. The most effective will be washing the crystal with an ordinary medical syringe with a small diameter needle. Before flushing, the sensor and the flushing liquid must be warmed up, for example, using a building hair dryer.

    Throttle Position Sensor

    This element is installed on the throttle block next to the drive, and is intended to control the position of the gas pedal. It is worth noting that when washing the power unit, you should be extremely careful so as not to damage this sensor.

    Despite the fact that the throttle sensor is designed for continuous use, it still fails sometimes, failing. Its breakdown is signaled by increased idle speed, the occurrence of jerks and unstable operation of the motor while driving.

    Knock sensor

    It is located on the head of the block between the cylinders (ІІ and ІІІ). Depending on the design features, the following types of these elements are distinguished:

    Broadband (presented as a tablet);

    Resonant (looks like a barrel).

    These sensors are not interchangeable, that is, if one fails, it cannot be replaced with another type.

    The working resource of the element is huge. The only thing that is necessary is to regularly clean the contacts of the connector from oxidation. This sensor works on the principle of a piezo lighter. That is, with an increase in the level of detonation, the electrical voltage begins to increase.

    The sensor measures the level of detonation in the power unit and, depending on this, controls the ignition timing. In case of increased detonation, the ignition will be late. If the sensor stops functioning, the engine will start to work incorrectly, fuel consumption will increase.

    It has a hexagonal design, inside of which there is a special piezoelectric element that generates an electromotive force due to the effect of sound vibrations on its body. It turns out that the knock sensor is a kind of transmitter of sound vibrations, thanks to which the processes occurring inside the motor are available to the EFI unit.

    The voids between the body and the piezoelectric element of the sensor are filled with a compound of a special composition. In addition to the protective purpose, the compound has one more thing: its presence allows you to develop an amplitude-frequency characteristic that is as close as possible to the frequency of detonation processes inside the power unit.

    When knock occurs in the engine compartment, the sensor measures its level and transmits a signal to the EFI unit, which automatically adjusts the ignition timing until the knock level decreases or disappears completely.

    As a result, due to the presence of a knock sensor in the power unit system, the most favorable composition of the fuel mixture is formed. Such a concept, characterized in automotive slang by the phrase "knock of fingers", characterizes the breakdown of the knock sensor. At the same time, the performance of the engine is sharply reduced, and fuel consumption increases.

    Oil pressure sensor

    This control element is located in the main oil pipeline network. The sensor is powered from the car's electrical network and has an indicator on the dashboard. In addition to the indicator, the instrument panel may have an oil pressure controller indicating its value.

    Quite often, this sensor is a controlling part of the engine management system, which, when a critical level of oil pressure is reached, turns off the power unit.

    In addition to the oil pressure sensor, a sensor can be installed that monitors the temperature of the engine oil in the system.

    Antifreeze temperature sensor

    In the design of the power unit, this sensor takes its place between the thermostat and the cylinder head. It has two contacts, and the operation of the device is based on the following principle: the lower the engine temperature, the more enriched the working mixture can be obtained.

    In the cooling system, the sensor is represented by a resistor of a special design (thermistor), which changes its resistance with a change in the temperature of the coolant. The higher the temperature, the lower the resistance, and vice versa - the lower the temperature, the higher the resistance of the thermistor. It is known that a change in coolant temperature affects the operation of the engine in different ways.

    Its design is quite reliable. It can fail only due to the lack of contact on its terminals or inside the device.

    Its malfunction can be judged by the start of the fan while the engine is still cold, the impossibility or problems with starting a warm power unit, and an increase in fuel consumption.

    Lambda probe

    Or in a simple way - an oxygen sensor. Its purpose is to determine the amount of oxygen content in the exhaust gases of a car. This electrochemical element is located in the muffler design.

    The absence of oxygen in the fuel mixture indicates its enrichment, and, conversely, its increased content reduces enrichment. Therefore, the lambda probe is designed to form the correct composition of the working mixture. Learn more about lambda here.

    Leaded gasoline will adversely affect the operation of the oxygen sensor, and in the event of a breakdown, increased fuel consumption and an excess of harmful compounds in the exhaust gases of a car are guaranteed.

    PKV sensor (crankshaft position)

    A fairly durable and reliable element, the design of which is a coil of wire with a magnetic core inside. It is located in the space of the pulley, and according to the risks applied to the pulley, it reads the position of the crankshaft. The element generates a signal as soon as the position of the toothed disk located on the crankshaft changes. Based on this signal, the control unit monitors the working processes occurring inside the cylinder and controls the supply of the fuel mixture and spark.

    In the event of a breakdown, the operating speed of the motor will drop sharply, and in the worst case, the power unit will stop completely.

    Phase sensor or camshaft position sensor (DPRV)

    It is included in the design, as a rule, of eight- and sixteen-valve engines, on which it is located immediately behind the intake camshaft pulley on top of the block head, and is intended to form fuel injection into a single cylinder. Its breakdown disrupts the supply of the fuel mixture, which causes its sharp enrichment, as a result of increased consumption.

    Idle speed controller

    An indispensable element in the engine device, which regulates the idle speed of the engine, ensuring its stable and most productive operation. The design of the device consists of a stepping motor with a cone-type spring needle.

    When the power unit is idling, air circulates past the closed throttle. This is possible thanks to the conical needle of the sensor, which regulates the cross-sectional diameter of the additional air supply line. Thus, the sensor determines the optimal amount of oxygen necessary for the uninterrupted and productive operation of the unit.

    The location of the regulator is the throttle body. Here it is necessary to pay attention to the fact that it is fastened with two screws, the heads of which in most cars are covered with a layer of varnish or simply drilled, which presents some hindrance when removing the idle speed controller. Therefore, it is often necessary to resort to removing the damper housing in order to replace the regulator or clean the contaminated air line.

    Since the regulator belongs to the executive type of devices, its system diagnostics is not provided. Therefore, in the event of a breakdown, the “Check Engine” error on the instrument panel may not light up.

    The following factors indicate its malfunction:

    - “floating” idle engine speed;

    Often the power unit stalls after the gear is turned off;

    Cold start of the engine is not accompanied by an increase in speed idle move how it should be;

    Instability of idling during load switching.

    Remove the idle speed control only when the battery is disconnected. To do this, the connector is removed from it and the screws securing the sensor are unscrewed. The regulator is installed in the reverse order. The only thing that needs to be done at the time of its installation is to lubricate the seal on the flange. Motor oil is ideal for this.

    Relationship different types sensors in the engine idle control system

    The amount of air in the engine is controlled by the DMRV sensor described above, and depending on its volume, the ECU calculates the supply of an enriched working mixture to the engine.

    Using the crankshaft position sensor, the control unit determines the speed of the engine unit, and based on this, the idle control system controls the air supply, bypassing the closed throttle valve.

    During parking, the control unit maintains a constant idle speed on a warm engine. If the power unit is cold, the system, by adjusting the idle speed, increases them, providing the engine with warm-up at high speeds. This allows movement without warming up the power unit.

    All of these sensors are found on most modern cars, and now it will be much easier for you to navigate the results of diagnostics and purchase the necessary spare parts in a car shop.

Often in electronics, such a radio element as a reed switch finds its application. Its feature is the ability to close contacts when irradiated with a magnetic field. What does this mean? Taking a simple magnet or placing an electromagnet near the reed switch, you can easily close and open the contacts of this radio element. At its core, it is a kind of non-contact sensor.

Concept definition

What is a proximity sensor? It is understood as such an electronic device that registers the presence of a certain object in the zone of its action and works without any mechanical or any other influences.

Non-contact sensors are used in a wide variety of applications. This creation household appliances and systems of protection of objects, industrial technologies and automotive industry. By the way, in the people this element is called a "proximity switch".

Advantages

Among the main advantages of non-contact sensors, they are distinguished:

Compact dimensions;

High degree of tightness;

Durability and reliability;

Light weight;

Variety of installation options;

No contact with the object and no feedback.

Classification

There are various types of proximity sensors. They are classified according to the principle of action and are:

capacitive;

optical;

inductive;

ultrasonic;

Magnetically sensitive;

pyrometric.

Let's consider each of these types of devices separately.

Capacitive sensors

These devices are based on the measurement of electric capacitors. In their dielectric is the object that is subject to registration. The purpose of this type of proximity sensor is to work with a variety of applications. This is, for example, gesture recognition. Capacitive produce automotive rain sensors. Such devices remotely measure the liquid level during processing. various materials etc.

The capacitive proximity sensor is analog system operating at a distance of up to seventy centimeters. Unlike other types of similar devices, it has greater accuracy and sensitivity. After all, the change in capacitance in it occurs only in a few picofarads.

The circuit of a proximity sensor of this type includes plates consisting of a conductive printed circuit board, as well as charging. In this case, a capacitor is formed. Moreover, this will happen at any time either in a conductive grounded element, or in some object, the dielectric constant of which is different from air. Such a device will also work if a person or a part of his body appears in the coverage area of ​​​​the device, which will be similar to the ground potential. As you approach, for example, a finger, the capacitance of the capacitor will change. And even taking into account that the system is non-linear, it will not be difficult for it to detect a foreign object that has arisen within the viewed boundaries.

The wiring diagram for such a proximity sensor can be complicated. Several elements independent of each other can be used in the device at once in the left / right, as well as down / up directions. This will expand the capabilities of the device.

Optical sensors

Such proximity switches today find their wide application in many branches of human activity where the equipment necessary for detecting objects operates. When connecting a proximity sensor, coding is used. This prevents false operation of the device when outside influence light sources. These sensors also work at low temperatures. Under these conditions, thermal jackets are put on them.

What are optical non-monitoring sensors? it electronic circuit, which reacts to a change in the light flux that falls on the receiver. This principle of operation allows you to fix the presence or absence of an object in a particular spatial area.

There are two main blocks in the design of optical proximity sensors. One of them is a source of radiation, and the second is a receiver. They can be in the same building or in different buildings.

When considering the principle of operation of a non-contact sensor, three types of optical devices can be distinguished:

  1. Barrier. The operation of optical switches of this type (T) is carried out on a direct beam. In this case, the devices consist of two separate parts - a transmitter and a receiver, located coaxially with respect to each other. The radiation flux that is emitted by the emitter must be directed exactly to the receiver. When the beam is interrupted by an object, the switch is activated. Such sensors have good noise immunity. In addition, they are not afraid of raindrops, dust, etc.
  2. diffuse. The operation of type D optical switches is based on the use of a beam reflected from an object. The receiver and transmitter of such a device are located in the same housing. The emitter directs the flow to the object. The beam, reflected from its surface, is distributed in different directions. In this case, part of the flow returns back, where it is captured by the receiver. As a result, the switch is activated.
  3. Reflex. These optical proximity sensors are type R. They use a beam reflected from a reflector. The receiver and emitter of such a device are also located in the same housing. When it hits the reflector, the beam is reflected, it turns out to be in the receiver zone, as a result of which the device is triggered. Such devices operate at a distance to the object of no more than 10 meters. Perhaps their use for fixing translucent objects.

Inductive sensors

The operation of this device is based on the principle of taking into account changes in the inductance of its main components - the coil and the core. Hence the very name of such a sensor.

Changes in induction indicate that a metal object appeared in the magnetic field of the coil, which changed it and, accordingly, the entire connection scheme, the main function of which is assigned to the comparator. In this case, a signal is sent to the relay and the electric current is turned off.

Based on this, we can talk about the main purpose of such a device. It is used to measure the movements of a piece of equipment that must be turned off if the limits of traffic are exceeded. The sensors themselves have limits of movement ranging from one micron to twenty millimeters. In this regard, such a device is also called an inductive position switch.

An overview of contactless sensors of this type allows us to distinguish several varieties of them. This classification is based on a different number of connection wires:

  1. Two-wire. Such inductive sensors are connected directly to the circuit. This is the simplest, but at the same time rather capricious option. It requires a nominal load resistance. With a decrease or increase in this indicator, the operation of the device becomes incorrect.
  2. Three-wire. This type of induction sensor is the most common. In such circuits, two wires should be connected to the voltage, and one - directly to the load.
  3. Four and five wire. In these sensors, two wires are connected to the load, and the fifth is used to select the desired operating mode.

Ultrasonic sensors

These devices find their wide application in various fields of production, solving many tasks of automating technological cycles. Ultrasonic proximity sensors are used to determine the location and distance of various objects.

For example, they serve to detect labels, even transparent ones, to measure distance and control the movement of an object. They are used to determine the liquid level. The need for this arises, for example, to account for fuel consumption during transport operations. And these are just some of the many uses for ultrasonic switches.

Such sensors are quite compact. They are distinguished by high-quality construction and the absence of various moving parts. This equipment is not afraid of pollution, which is quite important in production conditions, and also requires almost no maintenance.

The ultrasonic sensor contains a piezoelectric heater, which is both an emitter and a receiver. This structural detail reproduces the flow of sound impulses, accepting it and converting the received signal into voltage. Then it is fed to the controller, which processes the data and calculates the distance at which the object is located. This technology is called echolocation.

The active range of the ultrasonic sensor is the operating range of the detection. This is the distance within which an ultrasonic instrument can "see" an object, whether it approaches the sensing element in the axial direction or moves across the sound cone.

Depending on the principle of operation, ultrasonic sensors are distinguished:

  1. Provisions. Such devices are used to calculate the time interval required for the passage of sound from the device to a particular object and back. Non-contact ultrasonic position sensors are used to control the location and presence of various mechanisms, as well as to count them. Such devices are also used as a level indicator for various liquids or bulk materials.
  2. Distances and movements. The principle of operation of such devices is similar to that used in the device described above. The difference is only in the type of the signal that is present at the output. It's analog, not discrete. Sensors of this type are used to convert the available indicators of the distance to the object into certain electrical signals.

Magnetically sensitive sensors

These switches are used for position monitoring. The sensors are triggered by the approach of a magnet, which is located on the moving part of the mechanism. Such devices have an extended temperature range (from -60 to +125 degrees Celsius). This functionality allows you to automate a large number of complex production processes.

A non-contact temperature sensor of a magnetically sensitive type is used:

In chemical and metallurgical industries;

In the regions of the Far North;

On rolling stock;

in refrigeration units;

On truck cranes;

They find their application in security systems buildings, as well as for automatic opening of windows and entrance doors.

The most modern and fastest are magnetically sensitive sensors operating on the Hall effect. They are not subject to mechanical wear, as they have an electronic output key. The resource of such sensors is practically unlimited. In this regard, their use is a profitable and practical solution to the problems of measuring the number of shaft revolutions, fixing the location of fast moving objects, etc.

When measuring the level of liquids, float magnetically sensitive sensors are widely used. They are the best option to determine the required indicators due to the inexpensive price and simplicity of design.

Microwave sensors

This kind of proximity switches is the most universal option construction, which allows you to achieve continuous scanning of the serviced area. At the same time, it should be borne in mind that they are in a higher price category than, for example, ultrasonic counterparts.

The operation of such a device is due to the radiation of electromagnetic waves having a high frequency, the value of which is somewhat different in devices from different manufacturers. Microwave sensors are tuned to scan and receive reflected waves. This allows the device to record even the slightest changes in the electromagnetic background. If this happens, then the warning system connected to the sensor is immediately triggered in the form of an alarm, lighting, etc.

Microwave devices have increased accuracy and sensitivity. They are not barriers brick walls, doors and pieces of furniture. This fact should be taken into account when installing the system. The sensitivity level of the device can be changed by adjusting the motion sensor.

Microwave switches are used to control indoor and outdoor lighting, alarm devices, electrical appliances, etc.

Pyrometric sensors

The body of any living being is characterized by the presence of thermal radiation, which is a beam of electromagnetic waves of different lengths. As the body temperature rises, the amount of energy it radiates also increases.

Based on the fixation of thermal radiation, sensors work, which are called pyrometric sensors. They are:

total radiation, measuring the total thermal energy body;

Partial radiation, measuring the energy of the area limited by the receiver;

Spectral ratio, which gives an indicator of the ratio of the energy of certain parts of the spectrum.

Non-contact sensors-sensors are most often used in devices that record the movement of objects.

Touch switches

Developing technologies have affected almost all spheres of human life. They did not bypass the issues of home improvement. One striking example of this is the touch switch. This device allows you to control the lighting of the room with a light touch.

The touch switch immediately works even with the slightest touch on the button. Its design includes three main elements. Among them:

  1. A control unit that processes the incoming signal and transmits it to the necessary elements.
  2. Switching device. This part closes and opens the circuit, and also changes the amount of current consumed by the lamp.
  3. Control (touch) panel. With this part, the switch receives signals from the remote control or from touch. The most modern devices are triggered by passing a hand next to them.

Standard models can:

Turn on and off the light;

Adjust brightness;

Monitor the operation of heating devices, reporting temperature changes;

Open and close blinds;

Turn on and off household devices.

Touch switches produce various types. A specific model is selected depending on the needs of an office or residential building. For example, the desire to purchase and install a sensor device may arise due to the location of a fixed switch in an inconvenient place with the impossibility of transferring it. Or maybe a person lives in a house or apartment, whose mobility is limited. Sometimes stationary switches are at such a height that they are inaccessible to children. Solving the problem will require the selection of a specific model. Some owners prefer to install touch switches to change the brightness of the light without getting out of bed, etc.

What is a sensor?



Surely you have heard the word “sensor” more than once. It is obvious that this word means some technical device. What is a sensor and how does it work? What types of sensors are there? Let's consider all these questions in more detail.

The concept of a sensor

Currently, it is customary to call a sensor an element that converts information received from the environment into an electrical signal in order to further transfer information to some other device. Typically, the sensor is a structurally separate part of the measuring system.

Sensors are used everywhere: in cars, heating systems, water supply, in production, in medicine, even in catering establishments to measure temperature in order to determine the degree of readiness of a dish.

Sensor classification

There are several types of sensor classification. We present the most basic ones.

By type of measurement:

  • Pressure Sensors;
  • Flow sensors;
  • Level measurement sensors;
  • Temperature measurement sensors;
  • Concentration sensors;
  • Radioactivity sensors;
  • Movement sensors;
  • Angular position sensors;
  • Sensors for measuring mechanical quantities;
  • Vibration sensors.

Classification by manufacturing technology:

  • Elemental sensors;
  • The sensors are integral.

Classification according to the principle of action:

This includes:

  • Optical sensors that use electromagnetic radiation and react to water vapour, smoke and different kinds aerosols. Refer to proximity sensors. The principle of their work is based on capturing by a sensitive sensor the impact of any irritant, for example, water vapor. These sensors are widely used in automated control systems.
  • inductive sensors. They belong to non-contact sensors, designed to calculate the position of an object. Inductive sensors perfectly capture the fluctuations of the electromagnetic field. Their design is based on a generator, which creates an electromagnetic field, the impact of which on a metal object generates oscillation amplitudes, to which the sensor reacts. Such sensors are widely used in metal detectors, as well as in various kinds of electronic locks.
  • capacitive sensors. It is these sensors that are used in cars as rain sensors, touch buttons household appliances, fluid measurement sensors. The principle of their action is to respond to the action of the liquid. The insulator of such sensors has a dielectric constant. The liquid, acting on the insulator, causes the appearance of an electrical signal, which is converted into information. Such sensors are widely used in household appliances.
  • Load cells. Load cells are a device for measuring force, pressure, torque, acceleration or displacement. The mechanism of their action is based on the principle of elastic force. These sensors are widely used in various types scales. They convert the amount of deformation into an electrical signal, in other words, the sensor detects the impact of some force on it, after which the elastic element is deformed and the resistance of the strain gauge, which is built into such a sensor, changes. Next, the information is converted into an electrical signal and transferred to another device, such as a display.
  • Piezoelectric sensors. Such sensors are widely used in microphones and sonars. Their principle of operation is based on the polarization of the dielectric under the influence of mechanical stresses. In other words, piezoelectric sensors pick up a change in the electric field that has been mechanically affected. For example, in a microphone, this is the effect of voice. The result of the deformation will be the conversion of the received signal into an electrical one and its transmission to another device. These sensors were born thanks to Jacques and Pierre Curie in 1880.
  • Magnetic-electric sensors. These are sensors whose operating principle is based on the so-called Hall effect. These sensors are used in smartphones as the basis for the operation of an electronic compass, in electric motors, and in current meters.
  • Nano sensors. Are under development. The most demanded sphere for them should be medicine and robotics. It is assumed that these sensors will become a new class and will find widespread use in the future. Their principle of operation will be similar to many other sensors (hence the names nano-piezo sensors, nano-strain sensors, etc.), but their dimensions will be many times smaller

To learn more about sensors, read these articles.

The most important and most widely used technical means of automation are sensors.

sensor is called the primary converter of a controlled or regulated value into an output signal, convenient for remote transmission and further use. The sensor consists of a perceiving (sensitive) organ and one or more intermediate transducers. Quite often, the sensor consists of only one receiving element (for example: thermocouple, resistance thermometer, etc.). The sensor is characterized by input and output values.

Change in the output value depending on the change in the input value

called sensor sensitivity;

A change in the output signal resulting from a change in the internal

properties of the sensor or changes in the external conditions of its operation - changes

ambient temperature, voltage fluctuations, etc. called sensor error;

The lag of changes in the output value from changes in the input value

called sensor inertia.

All these indicators of sensors must be taken into account when choosing sensors for automating a particular machine or process.

Sensors designed to measure physical (non-electrical input values ​​of humidity level, density, temperature, etc.) convert them into electrical output values ​​transmitted at a distance to act on the actuator.

Sensors are divided into:

- by appointment- measurement of movement of forces, temperature, humidity, speed

- according to the principle of action- electrical, mechanical, thermal, optical, and

- according to the method of transformation- non-electric quantity into electrical -

inductive, thermoelectric, photovoltaic, radioactive, active

resistances (potentiometric, tensometric, etc.).

Sensors are:

- contact(directly in contact);

- contactless(do not touch: photoelectric, ultrasonic,

radioactive, optical, etc.).

SCROLL

used in the construction industry for automation construction machines and technological processes, technical means of automation and automated control systems.

1. For control and information:

1.1 quality of compacted soil (density);

1.2 calculation of the amount of work performed (km traveled, water supplied, etc.);

1.3 the speed of the machine;

1.4 the presence of liquid in the container and its quantity;

1.5 the amount of bulk materials in the tank (cement, sand, crushed stone

2. For regulation:

2.1 maintaining the set temperature during concrete heating;

2.2 coolant thermostat of the internal combustion engine;

2.3 liquid pressure in the container (system);

2.4 pressure of gases (air) in the system (tank);

2.5 carrying capacity of lifting and other machines;

2.6 lifting height of the working body of the machine (crane boom, working platform,

hoists and elevators, loading skip, bucket, etc.);

2.7 lifting height of the load of the lifting machine;

2.8 rotation of the crane boom;

2.9 restriction of the movement of the machine along the tracks (tower or overhead crane, trolleys

2.10 limiting the approach to live wires (boom and

crane cable);

2.11 maintaining the specified level and slope of the bottom of the pit and trench during operation

excavator;

2.12 short circuit protection;

2.13 protection against overvoltage (undervoltage);

2.14 shutdown of all engines and fixing with grabs for the rails of the tower crane, depending on the wind speed.

3. For local automation of the control system:

3.1 engine operation mode depending on the load on the working body (bulldozer - dump deepening, scraper and grader - knife deepening, excavator - bucket deepening);

3.2 setting the doses of the components of the concrete mixture in accordance with the recipe;

3.3 dosing of constituent materials for the preparation of concrete mix;

3.4 determination of the duration and maintenance of this duration during the preparation of the concrete mix.

4. To automate the control system:

4.1 automated control system for the operation of a concrete mixing plant;

4.2 automated control system for a bulldozer - a set of "AKA-Dormash", "Combiplan-10 LP", when performing work at specified elevations, slope and direction;

4.3 automated motor grader control system - “Profile-20”,

”Profile-30” for road grading and territory planning;

4.4 automated scraper control system - “Kopir-Stabiplan-10” when excavating or leveling to a given level (altitude position of the bucket, moving the rear wall of the bucket, deepening (raising) the bucket knife and adjusting the tractor engine and its direction;

4.5 automated control system for a bucket-wheel excavator when developing trenches in a given direction, digging depth, a given slope of the trench bottom and regulating engine operation.

For visual image automated (automatic) system uses graphic images:

Structural diagram, which reflects the improved structure of the system and the relationship between the points of control and management of objects;

Functional diagram, the drawing on which is schematically symbols technological equipment, communications, controls and automation tools (instruments, regulators, sensors) are shown, indicating the links between

technological equipment and automation elements. The diagram shows the parameters that are subject to control and regulation;

As well as principal, assembly and other schemes.

A modern car is made up of many mechanical, electromechanical and electronic components. Optimal operation of the engine must be ensured regardless of external conditions. When external factors change, the operation of nodes and components must adapt to them. Vehicle sensors serve as a kind of tracking device for the operation of the car. Consider the main sensors:

3. Air flow sensor in a car - what does it affect?

The principle of operation of the air flow sensor is based on measuring the amount of heat given off to the air flow in the engine intake manifold. Heating
the sensor element is installed in front of the vehicle's air filter. Change
air flow rate and, accordingly, its mass fraction, is reflected in the degree
changes in the temperature of the heating coil of the MAF sensor.

"Tripling" of the engine during operation and loss of power indicates a possible failure of the air flow sensor.

4. Oxygen sensor, lambda probe - sensor malfunction

An oxygen sensor or lambda probe detects the amount of oxygen left in the exhaust manifold after fuel combustion. The lambda probe is part of the electronic engine management system, which regulates the amount of fuel, ensuring its complete combustion. Increased fuel consumption characterizes possible malfunction sensor.

5. Throttle sensor - symptoms of malfunction

This sensor is an electromechanical device consisting of a sensing element and a stepper motor.

The sensitive element is
temperature sensor, and the stepper motor is the actuator.
This electromechanical device changes the position of the throttle valve
relative to the coolant temperature. Thus, the rotation frequency
crankshaft of the engine depends on the degree of heating of the coolant.

A characteristic symptom of a malfunction of this sensor is the lack of warm-up speed and increased fuel consumption.

6. Oil pressure sensor - functions, failure

On cars of the Japanese brand, a diaphragm oil pressure sensor is installed
type. The sensor consists of two cavities separated by a flexible membrane. Oil
acts on the membrane on one side, bending from pressure. In the measuring
The membrane of the sensor cavity is connected to the rheostat rod.

Depending on the engine oil pressure, the diaphragm flexes more or less, changing the overall resistance of the sensor. The oil pressure sensor is located on the engine block.

A burning oil pressure light on the car panel may indicate a sensor failure.

7. Is the knock sensor in the engine not working?

The engine knock sensor measures the ignition timing. During normal engine operation, the sensor is in "idle" mode. When the process changes
combustion in the direction of the explosive nature of the combustion of fuel-detonation, the sensor sends a signal electronic system engine control to change the advance angle
ignition in the direction of decreasing.

It is located in the air filter area on the cylinder block. To check the performance of the knock sensor, you must run.

8. Camshaft angle sensor - troit engine

This sensor is located on the cylinder head and measures the engine speed.
camshaft of the engine, and based on the signals from the sensor, the control unit determines the current position of the pistons in the cylinders.

Uneven engine operation and tripling indicate incorrect operation of the sensor. The check is carried out using an ohmmeter, measuring the resistance between the sensor terminals.

9. ABS / ABS sensor in the car - check the performance

Electromagnetic type ABS sensors are installed on the wheels of the car and are part of the car's anti-lock braking system.

Sensor function is the measurement of wheel speed. The object of measurement of the sensor is the signal gear disk, which is mounted on the wheel hub. If the ABS sensor is faulty, the control light on the control panel does not go out after starting the engine.

The technology for determining the operability of the sensor is to measure the resistance between the contacts of the sensor, in case of a malfunction, the resistance is zero.

10. Fuel level sensor in a car - how to check if it works?

The fuel level sensor is installed in the fuel pump housing and consists of several components. The float, through a long rod, acts on a sector rheostat, which changes the resistance of the sensor depending on the fuel level in the car's tank. The sensor signals are sent to a pointer or electronic pointer on the vehicle control panel. Checking the performance of the fuel level sensor is carried out with an ohmmeter, which measures the resistance between the sensor contacts.