Wide-range high-speed high-precision laser range finding system

Abstract

A wide-range high-speed high-precision laser range finding system comprises a main control module, a display circuit module, a keyboard circuit module, a laser diode high-voltage driving circuit module, a pulse laser emission circuit module, an avalanche photodiode photoelectric switching circuit module, a pre-stage trans-impedance circuit module, an automatic gain control amplification circuit and a time discriminating circuit module, wherein the laser diode high-voltage driving circuit module is in electric control connection with the pulse laser emission circuit module and the main control module; the avalanche photodiode photoelectric switching circuit module, the pre-stage trans-impedance circuit module, the automatic gain control amplification circuit and the time discriminating circuit module are in electrical control connection successively and then in electrical connection with the main control module; the avalanche photodiode photoelectric switching circuit is also connected with an avalanche photodiode high voltage bias circuit module; and the avalanche photodiode high voltage bias circuit module is in electrical connection with the main control module.

Description

technical field [0001] The invention relates to the field of laser ranging equipment manufacturing, in particular to a large-range, high-speed and high-precision laser ranging system. Background technique [0002] With the continuous development and popularization of contemporary electronic technology, ranging products are widely used in daily life and industrial control fields. As important performance indicators of rangefinders, accuracy and range are increasingly valued by the market. The methods used to achieve these two indicators are endless and varied. [0003] The traditional ranging methods include the distance measurement calibration method, the dual optical path error cancellation method, and the amplifier circuit AGC method. AGC is Automatic Gain Control (Automatic Gain Control). The distance measurement calibration method takes increasing the range as the circuit goal on the hardware circuit, mainly to increase the transmission power, and adopts a large and fix...

AI Technical Summary

Problems solved by technology

But often in practical applications, it is far from enough to only adjust the APD gain. The difference of the signal is still too large under extreme conditions, which cannot meet the requirements of ultra-large range and high precision.

Amplifying circuit AGC method, this method is based on the dual optical path method, and a first-level AGC circuit is built on the receiving amplifier circuit to realize the expansion of gain adjustment. Similarly, due to short distance or high reflection, the signal of the transimpedance part of the previous stage has already Saturation and broadening appear, the post-stage AGC has lost its function, and the performance shown still cannot meet the requirements

[0004] Since the measurement accuracy and range are basically contradictory in terms of the performance of the rangefinder, the first reason is that the signal-to-noise ratio is high and the accuracy is high when the measurement distance is short, and the signal-to-noise ratio and accuracy are poor when the measurement distance is long.

The second reason is that in order to increase the measurement range, the transmission power is increased while the gain of the receiving circuit is increased. When this method is used, another problem will be introduced, that is, the received signal is distorted due to the strong optical signal when the distance is short. The problem causes the dead zone of the rangefinder to become larger

[0005] In traditional ranging, the signal processing method is too conservative, and the adjustment degree of the received signal is small, resulting in a small range or poor ranging accuracy. How to make the adjustment degree of the received signal large, maximize the system range, and minimize nonlinear distortion to make Technical problems to be solved urgently at present in laser ranging

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