Laser phase ranging module

Abstract

The present invention relates to a laser ranging technology and provides a laser phase ranging module. The laser phase ranging module includes a laser emitting assembly, an echo receiving and pre-processing assembly, a local receiving and pre-processing assembly and an FPGA processor; the FPGA processor generates two clock frequencies f1 and f2 by using a phase-locked loop, and a square wave signal with a measurement ruler frequency fs is generated through frequency division based on the clock frequency f1, and the square wave signal is transmitted to the laser emitting assembly; the laser emitting assembly emits laser to a target; echoes reflected by the target are processed by the echo receiving and pre-processing assembly, and then, square waves A of which the frequency is fs can be outputted; the local receiving and pre-processing assembly partially leads in the emitted laser and performs the same pre-processing as the echo receiving and pre-processing assembly on the led-in laser, and then outputs square waves B; and the FPGA processor synchronously reads the square waves A and the square waves B through using the clock frequency f2 and calculates out the distance of the target through data processing. According to the laser phase ranging module, frequency mixing processing is not required, and one measurement ruler can be adopted to realize remote precise ranging. The laser phase ranging module is suitable for single-point ranging and multi-path simultaneous ranging equipment.

Description

technical field [0001] The present invention relates to laser distance measurement technology, mainly relates to the laser distance measurement technology using phase detection, specifically a laser phase distance measurement module. Background technique [0002] Laser phase ranging technology measures distance by detecting the phase delay produced by the target echo. Laser phase ranging often uses two optical paths, one is the target measurement optical path, and the other is the reference zero calibration optical path in the machine. The phase difference generated by the two output waveforms corresponds to the distance value of the target. There are many schemes for phase ranging, the main difference is reflected in the way of processing the photoelectric signal. In the traditional laser phase ranging technology, a laser modulated by a sine wave is emitted, and the received echo is converted into an electrical signal through photoelectric conversion, and then mixed with a...

AI Technical Summary

Problems solved by technology

In order to increase the measurement range without increasing the complexity of the circuit as much as possible, the indirect measuring ruler method is generally used, that is, two or more short measuring rulers are used to equivalent long measuring rulers, so measuring a target point requires Perform frequency switching several times. During the switching process, it is necessary to wait for enough time to ensure the stability of the signal, so it is not good for fast measurement, especially for the situation where multiple simultaneous fast ranging is required.

In addition, the laser phase range finder uses semiconductor lasers as the emission light source. Semiconductor lasers that can achieve high-power and high-speed modulation are relatively expensive and difficult to obtain, while low-power semiconductor lasers cause the measurement distance to be limited. To increase the measurement distance, it is often necessary to equip prisms or reflectors to enhance the echo, so it needs to pay a higher cost to achieve the distance measurement of distant uncooperative targets

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