Laser ranging method

Abstract

The invention discloses a laser ranging method. The laser ranging method includes that an initial threshold value is set by an MCU (microprogrammed control unit), and a first pulse is emitted to trigger a time-to-digital converter to start timing; a second pulse is emitted after a certain time delay to trigger an emitting module to emit laser, and simultaneously, a receiving module is opened to receive an echo signal of the laser; when the echo signal received by the receiving module is larger than the initial threshold value, a high-speed comparator outputs a measurement timing stop pulse to the time-to-digital converter, the MCU reads time difference of the measured earlier pulse and the measured later pulse of the time-to-digital converter so as to compute the measurement distance and drive an LCD (liquid crystal display) to display a measurement result in real time, if the echo signal received by the receiving module is not larger than the initial threshold value, the MCU sets the threshold value to a lower threshold value, the time-to-digital converter and the receiving module are initiated to enter a ranging procedure with the low threshold, when an echo signal is larger than the low threshold value, the high-speed comparator outputs a measurement timing stop pulse to the time-to-digital converter, and if the echo signal is not larger than the low threshold value, the ranging procedure is terminated.

Description

technical field [0001] The invention relates to a photoelectric combination method for measuring the distance to a measured object, in particular to a laser distance measuring method for short-distance ranging without blind spots. Background technique [0002] At present, the ranging capability and the ranging blind area are a pair of contradictions to be solved by the pulse laser range finder. For the pulse laser range finder, the ranging blind zone is a key parameter, which refers to the shortest measurable distance of the pulse laser range finder. Existing pulsed laser range finders with a range of 1Km all have a ranging blind zone (generally 5m to 15m). There are three main reasons for the ranging blind area: first, the blind area of ​​the pulse laser time-of-flight measurement method itself; second, the blind area caused by the saturation or even damage of the photoelectric receiving diode due to the excessive peak power of the target echo; third, It is the parasitic ...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a method of laser ranging, which solves the problem of the echo peak and the blind area where the echo pulse and the parasitic pulse overlap

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