What is the principle of accelerometer, and who knows better?

I have learned about accelerometers before, so here is a brief introduction.

An accelerometer is an electronic device that measures the force of acceleration. The acceleration force is the force that acts on the object during the acceleration process, just like the gravitational pull of the earth, that is, the gravitational force. The acceleration force can be a constant, such as g, or a variable.

There are two types of accelerometers: one is the angular accelerometer, which is an improvement from the gyroscope (angular velocity sensor). The other is a line accelerometer.

The working principle of the accelerometer is: the sensitive element converts the acceleration signal of the measurement point into the corresponding electrical signal, enters the pre-amplification circuit, improves the signal-to-noise ratio of the signal through the signal conditioning circuit, and then converts the analog-to-digital signal to obtain the digital signal, and finally sends it to the computer, and the computer then stores and displays the data.

When the sensing element moves with acceleration a, the mass is subjected to an inertial force opposite to the direction of acceleration, and a deformation proportional to the acceleration a occurs, so that the cantilever beam also generates stress and strain. This deformation is felt by the diffusion resistance affixed to the cantilever beam. According to the piezoresistive effect of silicon, the resistance of the diffusion resistance changes proportionally to the strain, and the resistance is used as an arm of the bridge, and the acceleration can be measured by measuring the change of the output voltage of the bridge.

The principle of the linear accelerometer is the principle of inertia, that is, the balance of force, a (acceleration) = f (inertial force) m (mass) we only need to measure f. How do you measure f? It is enough to balance this force with an electromagnetic force.

You can get the relation that f corresponds to the current. It is only necessary to use experiments to calibrate this scale factor. Of course, the signal transmission, amplification, and filtering in the middle are the business of the circuit.

Most accelerometers work according to the principle of the piezoelectric effect.

The so-called piezoelectric effect is.

In addition to deforming the crystal, the external force applied to the heteropolar crystal without a symmetry center will also change the polarization state of the crystal and establish an electric field inside the crystal, which is called the positive piezoelectric effect due to the polarization of the medium due to the action of mechanical force.

In general, accelerometers take advantage of the deformation of crystals due to acceleration within them. Since this deformation generates a voltage, the relationship between the generated voltage and the applied acceleration can be calculated to convert the acceleration into a voltage output. Of course, there are many other ways to make accelerometers, such as piezoresistive technology, capacitive effect, hot bubble effect, light effect, but the most basic principle is that a certain medium is deformed due to acceleration, and the deformation is measured and converted into a voltage output by the relevant circuit.

Each technology has its own opportunities and problems.

Hope, thank you.

The working principle of the automotive sensor is to convert the information of various working conditions in the operation of the car, such as vehicle speed, temperature of various media, engine operating conditions, etc., into electrical signals and transmit them to the computer, so that the engine is in the best working condition. Automotive sensors, which used to be used solely for engines, have expanded to chassis, body, and lighting electrical systems. These systems use more than 100 sensors.

You said that the role and working principle of the accelerometer sensor, I think that if this should be a sensor, it should be able to add this speed better, so this should work a little better, you can understand it better.

1. What is an accelerometer?

An accelerometer is an electronic device that measures the force of acceleration. The acceleration force is the force that acts on the object during its acceleration, just like the gravitational pull of the earth.

That is, gravity. The acceleration force can be a constant.

For example, g can also be a variable.

Accelerometer. There are two kinds: one is an angular accelerometer, which is made by a gyroscope.

angular rate sensor). The other is a line accelerometer.

2. Accelerometers are generally used in **.

By measuring the acceleration due to gravity, you can calculate the angle of inclination of the device relative to the horizontal plane. By analyzing dynamic acceleration, you can analyze how the device is moving. But in the beginning, you will find that light measurement of inclination and acceleration does not seem to be very useful.

Or for flying robots, it is also crucial to control attitudes. Make sure that your robot doesn't go to a crowded area on its own with a bomb. A good programmer is able to use an accelerometer to solve all of the above problems.

Accelerometers can even be used to analyze engine vibrations.

The working principle of the automotive sensor is to convert the information of various working conditions in the operation of the car, such as vehicle speed, temperature of various media, engine operating conditions, etc., into electrical signals and transmit them to the computer, so that the engine is in the best working condition. The detection method of the camshaft position sensor is as follows:

1. Pull out the plug, open the key and use the voltmeter to measure and determine that the power line has voltage output;

2. Use the meter to determine the iron wire, use the voltage block to connect a meter rod with the determined power line, and connect the other meter rod with the other two wires to measure the voltage is the iron wire, and the rest is the signal line;

3. At this time, turn off the key to draw out the signal line, plug back into the plug to start the engine, measure the signal line and the tie wire to see if there is a signal voltage, the output voltage should be less than the power supply voltage, if not, the sensor is basically broken;

4. At the same time of the above operation steps, check whether the signal teeth on the camshaft are good, whether there are debris between the camshaft sensor and the signal teeth, and whether the gap is normal.

The working principle of the body accelerometer: the acceleration sensor uses the principle of the inertia coefficient of the object to generate different pressures under different accelerations, and uses different resistances to distinguish different accelerations.

Body accelerometer application: mainly used in ABS system and airbags.

Wheel accelerometers work on the principle that Hall circuits produce magnetic offsets, resulting in different magnitudes of current.

Wheel accelerometer application: the vehicle speed is mostly used in the speed display on the instrument panel, and sometimes in the auxiliary fuel injection signal of the EFI engine.

How car acceleration works.

The accelerator pedal of the car, we are used to calling it the accelerator pedal. In the carburetor era, it was indeed the throttle of control. But in the era of electronic injection, the accelerator pedal is actually the throttle opening that is controlled.

The intake air flow is controlled. The central control computer calculates the intake volume according to the throttle opening, and then accurately injects a certain amount of fuel according to the intake volume. Achieve the best oil-gas mixing ratio.

After the engine burns, the exhaust gases go into the exhaust pipe. The front and rear oxygen sensors will send back the exhaust emission signal to the central control computer. Then the central control computer makes appropriate optimization and correction according to the exhaust emissions of the previous working stroke.

This process is called closed-loop control.

The working principle of the car speed sensor is to detect the speed of the electronically controlled car, and the control computer uses this input signal to control the engine idling, the torque lock of the automatic transmission, the automatic transmission shift, the opening and closing of the engine cooling fan and cruise control and other functions. The output signal of the vehicle speed sensor can be a magnetoelectric AC signal, and the vehicle speed sensor is usually installed in the drive axle housing or transmission housing, and displays the speed of the car by swinging the pointer, or generates an alternating current signal, usually consisting of a magnetic core and coil with two binding posts. These two coil binding posts are the terminals of the sensor output, which translates into current amplitude to indicate the vehicle speed.

Accelerometers typically measure collisions and provide signals to airbags.

Accelerometer is a sensor that can feel acceleration and convert it into a usable output signal, which has the advantages of accurate measurement, stable performance, high reliability, flexible use, etc., and is widely used in many fields.

Most sensors basically have one principle in common, and that is the piezoelectric effect. The piezoelectric effect refers to the phenomenon that when some dielectrics are deformed by external influences, polarization occurs inside the crystal, and at the same time, the positive and negative electrode charges are generated on the surface of the crystal. When the external influence disappears, it will return to the initial state of uncharged, which is the piezoelectric effect.

Most accelerometers commonly used in daily life work by taking advantage of the fact that acceleration deforms the crystal. Normally, deformation is a property that generates voltage, and as long as we understand the relationship between voltage and acceleration, we can make acceleration become voltage, and thus generate power. There are other ways to do accelerometers, such as piezoresistive technology and light effects.

Piezoresistive accelerometers are most commonly found in the automotive industry. There are more and more safety accidents in cars, so safety has become the primary factor for everyone to buy a car, and the corresponding additional system has also emerged. In industrial production, piezoelectric technology is the most common, and its main purpose is to prevent machine failures.

The accelerometer consists of a silicon diaphragm, an upper cover, and a lower cover, and the diaphragm is between the upper cover and the lower cover, bonded together; One- or two-dimensional nanomaterials, gold electrodes and leads are distributed on the diaphragm, and the wires are drawn out by a pressure welding process; Industrial field vibration sensors, mainly piezoelectric accelerometers. Its working principle is mainly conducive to the piezoelectric effect of piezoelectric sensitive components, and the amount of charge or voltage proportional to vibration or pressure is obtained. IEPE accelerometers and piezoelectric accelerometers with built-in IC circuits are typically used in industrial sites, and the output of the sensors is proportional to the vibration amount.

Accelerometers are test instruments used to convert the physical signal of acceleration into an electrical signal that is easy to measure. A capacitive force-balanced accelerometer converts the measured acceleration into a capacitance change in a capacitor.

The method of realizing this function has variable clearance, variable area, variable dielectric constant, differential capacitance force balance accelerometer uses variable gap, and uses differential structure, its advantage is that the structure is simple, the dynamic response is good, can achieve non-contact measurement, good sensitivity, strong resolution, can measure even smaller displacement, but because its own capacitance is generally very small, only a few pf to several hundred pf, its capacitive reactance can be as high as a few m to hundreds of m, so the requirements for insulation resistance are higher, and the parasitic capacitance ( Lead capacitors and capacitors between components and plates in the instrument) should not be ignored. In recent years, due to the wide application of integrated circuits, the electronic circuit is close to the plate of the sensor, so that the shortcomings such as parasitic capacitance and nonlinearity have been continuously overcome.

The mechanical part of the differential force balance accelerometer is close to the circuit board, and the change in acceleration is converted into the displacement change of the middle pole of the capacitor, and the subsequent circuit outputs a corresponding voltage value through the detection of the displacement, so that the acceleration value can be obtained. In order to ensure the normal operation of the sensor. The bias voltage applied to both plates of the capacitor must be provided by the output square wave voltage of the zero-crossing comparator.

Hello, detect the longitudinal acceleration of the car body. Because the longitudinal acceleration of the car exceeds a certain amount. Reducing its longitudinal acceleration, the stabilization system controls the car according to its signals.

It should be a longitudinal acceleration sensor, which detects the longitudinal acceleration of the body, and the stabilization system controls the car according to its signal to reduce its longitudinal acceleration. Because the longitudinal acceleration of the car exceeds a certain amount, the car will roll over. [If you have a problem with the car, ask the car master.]

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