Development And Application Of Laser Ranging Sensor

Development and application of laser ranging sensor

In 1960 a magical light was born, it is the laser. The English name of the laser is Laser, an abbreviation consisting of the first letter of each word in English LightAmplificationbyStimulatedEmissionofradiation. It means "light amplification of stimulated radiation". Because the laser has good characteristics in terms of brightness, directionality, monochromaticity and coherence, it has attracted the attention of many scientists and has been rapidly applied in industrial production and defense industry. Real estate industry, scientific research institutions at all levels, engineering, anti-theft security and other industries. Laser ranging is one of the applications of lasers.

Working principle: When the laser sensor is working, the laser diode is first directed to the target to emit laser pulses. The laser scatters in all directions after being reflected by the target. Part of the scattered light is returned to the sensor receiver, which is received by the optical system and imaged onto the avalanche photodiode. An avalanche photodiode is an optical sensor with an internal amplification function, so it can detect very weak optical signals. The target distance can be determined by recording and processing the time elapsed from the time the light pulse is emitted until the return is received.

Laser sensors need to accurately measure the transmission time because the speed of light is too fast.

For example, if the speed of light is about 3×10^8m/s, to achieve a resolution of 1mm, the electronic circuit of the distance measuring sensor needs to be able to distinguish the following extremely short time:

0.001m (3X10^8m/s) = 3ps

To distinguish the time of 3ps, this is an excessive demand for electronic technology, and the cost is too high.

But today's laser sensors cleverly avoid this obstacle, using a simple statistical principle, that is, the average law achieves a resolution of 1mm, and can guarantee the response speed.