High-speed laser ranging method and high-speed laser ranging system

Abstract

The invention provides a high-speed laser ranging system which comprises a transmitting module, a receiving module, a mixer circuit and the like. Single measuring frequency is adopted, phase measurement is converted into time measurement within a single cycle, and a simple and universal time measurement integrated circuit (such as a CPLD (complex programmable logic device)) is used for measuring time difference within a cycle of moderate-frequency (such as dozens of Khz) down-converted signals, so that linear distance can be measured. Single measuring frequency signals are used, the frequency of the down-converted signals is moderate, and only the time difference needs to be measured, so that compromise can be made in terms of measuring speed and measuring resolution ratio, and an application example meeting both the measuring speed and the measuring resolution ratio is designed, the high-speed laser ranging method is low in cost, can be widely used for the scheme of ranging modules on various robots, and can also be widely used for the field of industrial automation, an automotive anti-collision system and the like.

Description

technical field [0001] The invention relates to the technical field of laser ranging, in particular to a method capable of realizing high-speed, high-precision and short-distance laser ranging and a laser ranging system for realizing the ranging method. Background technique [0002] The laser phase ranging method is a method to accurately measure the target distance by using laser as a light source. At present, laser ranging is mainly realized by three methods: interference method, phase method and pulse method. Among them, the interferometric laser distance measurement is very sensitive to vibration and is only suitable for measuring relative displacement. It can be applied in precision measurement without vibration and short measurement range. Therefore, this laser distance measurement method has a narrow application range and cannot be widely used. Applications. The pulse method laser ranging is to measure the distance by converting the flight time of the laser pulse int...

AI Technical Summary

Problems solved by technology

Among them, the interferometric laser distance measurement is very sensitive to vibration and is only suitable for measuring relative displacement. It can be applied in precision measurement without vibration and short measurement range. Therefore, this laser distance measurement method has a narrow application range and cannot be widely used. Applications

The pulse method laser ranging is to measure the distance by converting the flight time of the laser pulse into the distance measurement. Since the laser transmitter can output the laser pulse of the infrared band with super power in an instant, and the duration of a single pulse is very short, Therefore, the advantages of this ranging method are: ultra-long distance, no harm to the human body, strong anti-interference ability, etc.; the disadvantage is that the measurement resolution is low

The phase laser ranging method calculates the range by calculating the phase difference of two high-frequency measurement signals. The laser transmitter emits modulated visible light, so the advantages of this ranging method are: high measurement resolution, The application is flexible; the disadvantages are: short measurement range, slow single measurement speed, and poor ability to resist visible light interference due to the use of visible light

It is not difficult to see from the above method that to measure the distance once, it is necessary to use two measuring ruler frequencies F1 and F2 for secondary measurement, processing and calculation, and the calculation of the phase in each measurement is more complicated, because the frequencies of F1 and F2 Higher, so this method is time-consuming and cannot be used as a high-speed measurement

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