TYPES OF SENSES IN AUTOMOBILES TODAY - DOUBLE briefly
(Video Subtitles on various types of sensors on cars for unknown listeners)
Hello everyone, I wish you all the best of luck. Today, I would like to present the types of sensors that are usually in cars, this is the video that I follow the idea of a contributor, please follow along.
So today, many of the activities of automotive CAs are through sensors and ECUs that are likened to the senses on the human body, and ECUs are like the brain that receives words. The senses give the body the right instructions, so what kind of sensors will there be in the car? And what are their roles? Then we will go to learn something about some of the sensors as follows:
- The first is the crankshaft position sensor: Camshaft positions and speed sensors, I combine these three as one, because the general rule of the three is that it will have a small coil attached to an iron plate with serrated edges. , this iron disc is attached to a back wheel either to the camshaft or to the wheel. When this iron plate rotates, the cog will move through the head of the coil, causing the magnetic field in the coil to change so that the inductive current appears in the coil, The result is a series of electrical impulses. So this principle of operation is based on the effect of kissing in physics, when the ECU it receives these electrical impulses it will count this number of pulses and from there it will calculate the position. position of crankshaft, or position of camshaft as well as speed of CA. The effect of the crank position sensor and the camshaft position sensor is to help the ECU to determine the optimum fuel injection and ignition timing, and the speed sensor on the wheel. makes the ABS anti-roll brake system work and on some CAs the speed it is displayed in digital form, the display unit also takes the signal from this sensor, when the shaft sensor If the elbow is broken, the engine will be able to stop running. If the camshaft sensor is damaged, it may be difficult for the vehicle to start or stall, or fail to meet the capacity and then the engine fault indicator lights will light up.
- The second is throttle position sensor (abbreviated as TPS): This sensor is responsible for measuring the throttle opening, helping ECU to adjust the optimal fuel injection according to the throttle opening. On automatic cars, the throttle position sensor helps to operate the gear shift control system, the throttle position sensor is available in many types, but the simplest and cheapest is just a variable. The resistance is attached to the throttle shaft, so when the throttle is turned, the rheostat rotates along that axis, and the ECU will measure the throttle opening through a change in voltage applied to the throttle. rheumatism. When this sensor is damaged, the engine error light will light and when accelerating, the car will not respond promptly and the automatic transmission will shift when it changes normally, and it may be good. Encountered condition is often dead.
- The third is the flow meter of the intake air (abbreviated as AFM): The role of this type of sensor is to measure the amount of air charged into the engine, helping the ECU to adjust the amount of fuel injected, so that it is in proportion to the ratio. The intake air flow sensor is mounted on the suction neck and is usually constructed of a heated mesh and when the air is blown through, it will make the mesh depending on the strength of the flow. the gas that this net will reduce or decrease its temperature. Thereby, the resistance of this grid will be reduced by a lot or at least correspondingly, based on this thermistor effect, ECU will determine the flow of air into the engine. When this sensor fails, the engine error light will light up or blink, the engine will run more noise and reduce power, fuel consumption.
- The fourth is a knock sensor called knock sensor: The detonator is made of quartz crystal, when there is pressure on it, it will generate voltage, the detonator is attached to the cylinder wall or is on the lid, it has a picture It looks like a normal snail, its task is to detect the early detonation of the fuel, especially when we use a gas that has a lower snail index than the one. at the rate that the car manufacturer set, that is, it can help prevent the self-ignition of gasoline before the buri ignites, when it detonates early, it will vibrate more than usual and usually emits loud knock. That's why some places also call this sensor a knock sensor, the sensor is designed to have the operating frequency coincides with the vibration of the engine when detonation occurs. If there is a detonation, it will have the effect of the gate effect and now the pressure on the quartz crystal is greatest and generates a voltage, so that ECU it identify the phenomenon of detonation occurring, and make appropriate adjustments such as reducing the ignition origin of the buri and on some vehicles it may give an indication to limit the speed. of the engine, when this sensor is broken, the car often emits a knock when accelerating, and lights engine error.
- The fifth is the Oxygen sensor: Oxygen sensors are supposed to control the flow of emissions and thus help regulate the ratio of air and fuel, so that the combustion of fuel is the best, the one that has a lot of oxygen in the exhaust gas will contribute to increasing the content of NOX very toxic to the environment, feeling oxygen is often placed in the exhaust pipe, usually in the position before and after the catalytic converter, when flow The exhaust gas passes through the sensor with high oxygen content, the voltage on the sensor will be low, whereas if the oxygen content is low, the output voltage will be high, based on the voltage levels. This ECU will adjust the injector opening and closing time, so that the mixing ratio between air and fuel is suitable.
- Sixth is a parking sensor or a collision sensor: These sensors are often mounted around cars, to detect and alert the potential collisions to cars. The way it works is that it will measure the distance from the vehicle to the surrounding obstacles, it is similar to the principle of a military radar, that is, the way these sensors will transmit to release the discharges and it will pick up the bounce back signals, so that it can calculate the distance to the obstacles, these sensors are usually the kind used ultrasound or electromagnetic waves, as you can see in a new generation of cars, some of the cars are equipped with a radar scanner on the back of the windshield, it is possible to detect obstacles that support the driver's driving or as some of the new technologies available today, such as image recognition technology, but This technology has some limitations, so it has not been widely applied on commercial vehicles.
- Seventh is the tire pressure sensor: In addition to measuring the tire pressure, the tire pressure sensors also tell us the temperature of each tire, which can help the driver to know the conditions early. could lead to danger. Especially tire pressure is very important for the operation and fuel economy of the vehicle, current tire pressure sensors are usually resistive or capacitive sensors, i.e. when the pressure impacts on a membrane, it will cause that membrane to be deformed and bent, since it will change the resistance or capacitance of that membrane, the signal processing circuit will receive. these changes and propagate to the vehicle via a radio transmitter that falls within a 40-hectare circuit, the circuits usually have a small battery, if the tire pressure sensor system is found. If not working, it is most likely that the battery will run out of power and need to be replaced with a new battery, not sure that it has broken the sensor system. On cars that do not have a tire pressure sensor system, we can now install more, the price somewhere is about 2-3 million a set. The signal will then be sent directly to our smartphone via an accompanying app.
- Eighth is the cooling water temperature sensor: The purpose of this sensor is to monitor and adjust the temperature of the cooling water to help the engine run stably, the main structure of this sensor is actually an electrical thermometer. resistance, then when the temperature changes, it will cause the resistance of the measuring head it will change. The temperature sensor signals sent back to the ECU can help the ECU make a decision affecting whether the fuel injection can be changed or the ignition timing is changed, or it may be on. Some vehicles can turn off or turn on the electric cooling fan system.
- Ninth is the rotation angle sensor and steering speed: Regarding the structure of this sensor on modern vehicles is like a speed sensor, and the crank position that I have just mentioned above, the thing that determines the steering angle as well as the steering speed will cater to the power steering system and the electric balance system itself operates.
- Finally, there is an airbag detonator sensor: This is a problem that many people have been very interested in recently, when Toyota's cars when the collision occurred, the airbag did not inflate, many people posed the problem. This airbag's sensor will not work properly, this airbag's sensor is located at the position of the car's frame. It's essentially like an electrical switch that only closes when a strong impact occurs, the structure of the airbag detonation sensor is quite simple so you can observe it. it may consist of a rolled steel plate, and in the event of an inertia the coil will expand and roll towards pin B from which it will close the circuit, or Some types are made up of a marble that is placed in a cylindrical tube, and when touched hard, it will send the marble to the right hand side of the drawing. At that time, it would overwrite the two yellow electrodes and close the circuit, the thing that when a car collides without opening the airbag, it may be because the detonating sensor has not closed the circuit or told even it has closed circuit to other parameters that it is not satisfied, such as the deceleration, for example, ECU it has not detonated the airbag.
So I have briefly presented some of the sensors in the car, because the time is quite tight so my presentation is very sketchy looking forward to your suggestions. Hello and see you again in your next videos!