Description
The cantilever displacement device is made of elastic sensitive elements, and the energy storage spring made of elastic sensitive elements is used to drive the electrical contacts to complete the conversion from gravity changes to electrical signals. It is widely used in mid-to-high-end smart phones, tablets and computers. .
Introduction
It is a new type of sensor technology. It uses elastic sensitive elements to make cantilever displacement devices, and uses elastic sensitive elements to make energy storage springs to drive electrical contacts to complete the conversion from gravity changes to electrical signals. At present, most mid-to-high-end smartphones, tablets and computers have built-in gravity sensors, such as Apple's series of products iPhone and iPad, and Android series of mobile phones. The gravity sensor will automatically turn the screen when the phone is horizontal and vertical, which can be used instead of up, down, left and right when playing games, such as the Xiaomi Mi Band.
Working principle
Gravity sensors work on the principle of piezoelectric effect.
The so-called piezoelectric effect is "for a heteropolar crystal without a center of symmetry, the external force applied to the crystal will not only deform the crystal, but also change the polarization state of the crystal and establish an electric field inside the crystal. The phenomenon of polarizing a medium is called the positive piezoelectric effect".
Gravity sensors take advantage of the internal crystal deformation caused by acceleration. Since this deformation generates a voltage, the acceleration can be converted into a voltage output by simply calculating the relationship between the generated voltage and the applied acceleration. Of course, there are many other methods to make acceleration sensors, such as capacitive effect, thermal bubble effect, light effect, but the most basic principle is that a certain medium is deformed due to acceleration. voltage output.
Application
1. By measuring the acceleration caused by gravity through the gravity sensor, the tilt angle of the device relative to the horizontal plane can be calculated. By analyzing dynamic acceleration, you can analyze how the device moves. But at first, you'll find that measuring inclination and acceleration with light doesn't seem very useful. But now engineers have come up with a lot of ways to get more useful information.
2. The accelerometer can help the bionic robot understand its current environment. Whether you are climbing a mountain, or going downhill, whether you fall down. Or for flying robots, it is also crucial to control the attitude. A good programmer can answer all of the above questions using an accelerometer.
3. The gravity sensor can be used to analyze the vibration of the engine.
4. Before entering the consumer electronics market, gravity sensors have actually been widely used in the field of automotive electronics, mainly focusing on body control, safety systems and navigation. Typical applications such as airbags (Airbags), ABS anti-lock braking systems , Electronic Stability Program (ESP), electronically controlled suspension system, etc.
Mobile application
The gravity sensor is a device first developed by Apple, and it is now used in mobile phones. To put it simply, the mobile phone is held vertically in your hand. You turn it 90 degrees and turn it horizontally, and its page will automatically respond to your center of gravity. That is to say, the page is also turned 90 degrees, which is extremely Humanize.