Ranging device based on laser phase method

Abstract

The invention discloses a ranging device based on a laser phase method, and the ranging device provided by the invention comprises a laser emitting and electro-optical modulating module, an internal-external optical path module, and a photoelectric detecting and data processing module, wherein the laser emitting and electro-optical modulating module is used for emitting an infrared laser subjected to high frequency modulation, the internal-external optical path module comprises an internal optical path and an external optical path; the infrared laser is transmitted to the photoelectric detecting and signal processing module respectively through the internal optical path and the external optical path; the photoelectric detecting and signal processing module is used for respectively performing the conversion and frequency-conversion process on the two transmitted optical signals to obtain a phase difference between two optical signals so as to obtain a to-be-measured distance value. Thedevice directly transmits the light emitted by the laser to an integrated electro-optical modulator through an optical fiber; an exit beam is transmitted to the focus point of a range finder emittinglens through the optical fiber so as to greatly simplify the optical path structure; and meanwhile, the modulation frequency of the integrated electro-optical modulator is much higher than the directmodulation frequency of the laser, thereby achieving higher measurement precision.

Description

technical field [0001] The invention belongs to the technical field of linear dimension measurement, and in particular relates to a laser distance measuring device, which is used for measuring the absolute distance between a target object and the measuring device. Background technique [0002] Laser phase ranging technology measures the distance by measuring the phase change caused by the modulated laser flying between the distances to be measured. In short-to-medium range ranging, the factors that affect the measurement accuracy mainly include the relative error change of the modulation frequency and the phase difference measurement error. Under the same phase difference measurement accuracy, increasing the frequency of the laser modulation signal can improve the measurement accuracy. The laser modulation frequency of the current laser phase rangefinder is generally in the tens of megahertz to hundreds of megahertz, and the distance measurement error of the medium and shor...

AI Technical Summary

Problems solved by technology

The limitation of the first method is that the modulation frequency is low, and the defect of the second method is that the optical path is more complicated, the volume is larger, it is difficult to adjust, and it is not conducive to practical application

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