A Pulsed Laser Proximity Dynamic Gain Control Circuit

Abstract

The invention provides a pulse laser short-range dynamic gain control circuit for a pulse laser ranging receiver, the receiver includes a voltage-controlled amplifier, the circuit includes an FPGA chip and a D / A converter, and the FPGA chip is provided with a There is a ROM module and an STC control machine module, the ROM module is interactively connected with the STC control machine module, and the output end of the STC control machine module is connected with the input end of the voltage-controlled amplifier through a D / A converter. The invention expands the dynamic range of the pulse laser distance measurement, improves the distance measurement precision, and the circuit structure is very simple.

Description

technical field [0001] The invention relates to the technical field of pulse laser measurement, in particular to a pulse laser short-range dynamic gain control circuit. Background technique [0002] Pulse laser radar detects the relative distance of the target by measuring the time-of-flight of the laser pulse. In the short-range (tens of meters) measurement, its single measurement accuracy reaches the meter level. However, as an effective Means, this accuracy is still not enough, the main reason for the poor accuracy is due to the limitation of the dynamic range of the receiver electronic system. Most pulse laser radars measure non-cooperative targets ahead. In the case of short-range ranging, the echo power of laser pulses changes drastically because the distance and emission characteristics of the targets change within a large dynamic range. In order to ensure high-precision distance measurement, the echo receiving circuit must work strictly in the linear region to avoid...

AI Technical Summary

Problems solved by technology

[0003] In the application of pulsed laser ranging, when the laser pulse echo power changes greatly, the realization of high-precision ranging of laser radar requires the introduction of AGC (automatic gain control) circuit or STC (sensitivity time control) circuit in the echo receiving circuit. However, the research on the application of AGC or STC in lidar is not very mature at present or the circuit is more complicated to realize, and the development is difficult. For example, the AGC circuit, the typical method is to use a logarithmic amplifier, and at the same time cooperate with addition and multiplication operations circuit

Zhou Qiang and others proposed a short-range gain control method using CPLD in the paper "Short-range Pulse Laser Detection Reception and Processing". The measurement range is 50-500 meters, but the accuracy is poor, and the method does not give 50 The short-range implementation method within meters; Hu Chunsheng proposed a method of using RC network charging and discharging to realize the control curve in his doctoral thesis "Research on Pulsed Semiconductor Laser High-speed 3D Imaging Lidar", and achieved gain control within 30 meters. The charging and discharging characteristics of the RC network, the flexibility of the gain curve is poor

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