CN-122015768-A - Domain laser elevation measurement method and system combined with GNSS positioning

CN122015768ACN 122015768 ACN122015768 ACN 122015768ACN-122015768-A

Abstract

The invention discloses a domain laser elevation measurement method combining GNSS positioning, which calculates the horizontal distance between a laser emitter and a laser receiver according to the coordinates of the two, and judges the first based on laser pulse data If the characteristic wave peak of the circle is the theoretical beam quantity characteristic value of the laser, the circle data is directly removed, if the characteristic wave peak of the circle is not the theoretical beam quantity characteristic value of the laser, an effective data set is constructed after the instantaneous height difference is calculated based on the horizontal distance and the time stamp according to the space-time geometrical relation of the laser transmitter and/or the laser receiver, a core data set is constructed after the effective data set is arranged according to the ascending order to obtain an ordered sequence, the arithmetic average value of the core data set is used as a final height difference output value in a data updating period, and the elevation of a to-be-measured point is determined based on the final height difference output value. The invention realizes high-precision measurement under the condition of single sensor, eliminates the dependence on a mechanical leveling mechanism and double sensors, greatly reduces the requirement of hardware time sequence precision, and simultaneously realizes accurate elevation measurement under any gesture.

Inventors

CHEN DE
LIU QIUSHI
ZHU JIANXU
JIANG JING

Assignees

西南交通大学

Dates

Publication Date: 20260512
Application Date: 20260302

Claims (10)

1. The domain laser elevation measurement method combined with GNSS positioning is characterized by comprising the following steps of: calculating the horizontal distance between the N-type laser emitter and the N-type laser receiver according to the GNSS coordinates of the N-type laser emitter and the N-type laser receiver, and acquiring the data update period of the N-type laser emitter by the N-type laser receiver Laser pulse data in; Discriminating the first based on laser pulse data If so, according to the space-time geometrical relationship of the 'N' -type laser emitter and/or the 'N' -type laser receiver, calculating the instantaneous height difference based on the horizontal distance and the time stamp, and then constructing an effective data set; the effective data sets are arranged according to ascending order to obtain ordered sequences, then a core data set is constructed, and the arithmetic average value of the core data set is used as the data updating period And determining the elevation of the to-be-measured point based on the final elevation difference output value.
2. The method for measuring the elevation of a domain laser combined with GNSS positioning according to claim 1, wherein the calculation expression of the horizontal distance is: ; In the formula, 、 The abscissa of the arrangement point positions of the N-shaped laser transmitters respectively; 、 respectively the abscissa and the ordinate of the 'N' -type laser receiver; 、 Is the structural installation deviation between the phase center of the GNSS antenna installed on the 'N' -type laser receiver and the photoelectric sensor.
3. The method for measuring domain laser elevation in combination with GNSS positioning of claim 1, wherein said function is determined by a validity discriminant function Judging whether the characteristic wave crest is a theoretical beam quantity characteristic value of laser or not: ; In the formula, The number characteristic value of the theoretical laser beams is; Capture the first image for the photoelectric sensor Actual number of peaks of the circle; Rotate the first for the laser beam A ring; Is the time stamp of the signal received by the 'N' -type laser receiver.
4. The method for measuring the elevation of a domain laser combined with GNSS positioning according to claim 1, wherein the plumb state of the "N" type laser transmitter and/or the "N" type laser receiver comprises: The leading laser and the trailing laser of the N-shaped laser transmitter are both plumbed on the ground, and the N-shaped laser receiver is plumbed on the ground; The leading laser and the trailing laser of the N-shaped laser transmitter are not plumbed to the ground, and the N-shaped laser receiver is plumbed to the ground; the N-shaped laser receiver is not plumbed to the ground, and the leading laser and the trailing laser of the N-shaped laser transmitter are both plumbed to the ground or are both not plumbed to the ground.
5. The method for measuring the elevation of the domain laser combined with the GNSS positioning according to claim 4, wherein the leading laser and the trailing laser of the N-shaped laser transmitter are not plumbed to the ground, and the leading laser and the trailing laser are in a parallel state or a non-parallel state when the N-shaped laser receiver is plumbed to the ground.
6. The method for measuring the elevation of a domain laser combined with GNSS positioning according to claim 5, wherein when the leading laser and the trailing laser are both plumbed to the ground and the "N" laser receiver is plumbed to the ground, the instantaneous elevation difference is: ; when the leading laser and the trailing laser are both non-plumbed to the ground and the N-type laser receiver is plumbed to the ground, when the leading laser and the trailing laser are in a parallel state, the instantaneous height difference is as follows: ; when the leading laser and the trailing laser are both non-plumbed to the ground and the N-type laser receiver is plumbed to the ground, when the leading laser and the trailing laser are in a non-parallel state, the instantaneous height difference is as follows: ; Wherein, the ; When the N-type laser receiver is not plumbed to the ground, the instant height difference is equal to the instant height difference when the leading laser and the trailing laser of the N-type laser transmitter are plumbed to the ground or are not plumbed to the ground; In the formula, The rotation angular velocity of the 'N' -type laser emitter; Is a horizontal distance; A time stamp captured when the leading laser passes through the photoelectric sensor; A time stamp captured when the oblique laser passes through the photoelectric sensor; A time stamp captured when the trailing laser passes through the photoelectric sensor; Is the included angle between the oblique laser and the leading laser; An included angle formed by the inclined laser relative to the vertical direction; Is a sensitivity coefficient; is the angular offset of the trailing laser relative to the leading laser.
7. The method of claim 1, wherein the median is taken as a core dataset in the ordered sequence according to a quartile law, and the arithmetic mean of the core dataset is: ; In the formula, For the number of samples that remain, , For the third quartile, Is the first quartile.
8. The method for measuring the elevation of a domain laser combined with GNSS positioning according to claim 1, wherein the elevation of the point to be measured is: ; In the formula, The elevation of the point location for the "N" laser transmitter; the linear distance between the arrangement points of the laser source and the N-type laser receiver which are the N-type laser transmitters; The final height difference output value is the arithmetic average value of the core data set; Is the length of the mast of the 'N' -type laser receiver.
9. The method for measuring the elevation of a domain laser combined with GNSS positioning according to claim 7, wherein when the "N" type laser receiver is not plumbed to the ground, the elevation of the point to be measured is: ; In the formula, Is the included angle between the laser receiver and the plumb plane.
10. Domain laser elevation measurement system in combination with GNSS positioning, using the method according to any of the claims 1-9, comprising: The RTK base station is used for acquiring plane coordinates of the N-type laser receiver; The N-type laser emitter is used for emitting N-type laser with uniformly distributed energy; the N-type laser receiver is used for capturing a time stamp when the laser signal arrives and determining the inclination angle of the laser receiver relative to the vertical direction; the calculation output module calculates the horizontal distance between the N-type laser emitter and the N-type laser receiver according to the GNSS coordinates of the N-type laser emitter and the N-type laser receiver, and the N-type laser receiver collects the data update period of the N-type laser emitter Laser pulse data in; Discriminating the first based on laser pulse data If the characteristic wave peak of the circle is the theoretical beam quantity characteristic value of the laser, the circle data is directly removed, if the characteristic wave peak of the circle is not the theoretical beam quantity characteristic value of the laser, the circle data is constructed after calculating the instantaneous height difference based on the horizontal distance and the time stamp according to the plumb state of the N-type laser emitter and/or the N-type laser receiver; the effective data sets are arranged according to ascending order to obtain ordered sequences, then a core data set is constructed, and the arithmetic average value of the core data set is used as the data updating period And determining the elevation of the to-be-measured point based on the final elevation difference output value.

Description

Domain laser elevation measurement method and system combined with GNSS positioning Technical Field The invention relates to the technical field of engineering surveying and mapping, in particular to a domain laser elevation measurement method and system combined with GNSS positioning. Background In road paving, flatness detection and digital construction, elevation measurement technology based on a rotary scanning laser (commonly referred to as "N-Beam" or "domain laser") is widely used, and the principle is that a fan-shaped laser Beam arranged in an "N" shape is emitted by a rotary laser emitter, and the receiving end uses the detected light pulse time difference ratio to calculate the elevation. In order to solve the problem that the measurement range is limited due to uneven energy distribution of the traditional Gaussian beam, in the prior art, a scheme for shaping the beam by adopting a hawk prism is proposed in the published Chinese patent application (publication number is CN 119126084A), and the signal-to-noise ratio and edge triggering stability of a signal are remarkably improved by converting the Gaussian beam into a flat-top beam. Although the introduction of the powell lens optimizes the signal quality at the optical level, the existing domain laser measurement system still has the following technical bottlenecks in terms of system architecture and resolution: First, hardware redundancy is high and mechanical errors are easily introduced. In order to eliminate the influence of inclination of the transmitter or fluctuation of the rotation speed, the prior art is generally forced to adopt a dual sensor or sensor array structure at the receiving end, namely, vertically install two sensors with fixed spacing. The algorithm must rely on the physical spacing between the two sensors as a baseline reference. This design not only increases the weight, bulk and manufacturing costs of the receiving device, but, more seriously, severe vibration and temperature changes in the construction site easily cause small deformations of the receiving rod, so that the physical spacing shifts, thereby introducing imperceptible systematic errors. Second, the true "level-free" anti-tilt solver capability is lacking. In the prior art, although some statistical filtering or a dual-sensor differential method is adopted to relieve the influence caused by the inclination of the transmitter, a core mathematical model is still established on the assumption that the transmitter and the receiving end are approximately plumb. When the construction site fluctuates greatly, so that the receiver is inclined significantly, the projection of the N-shaped light beam in the space is geometrically distorted. The lack of an accurate geometric compensation model combined with a spatial three-dimensional position in the prior art leads to measurement failure or sharp reduction of accuracy under such working conditions, and forces a constructor to frequently stop calibration or be equipped with an expensive automatic platform. Thirdly, relying solely on optical measurements results in extremely high requirements on time measurement accuracy. The existing solution is essentially a purely optical "goniometric intersection system", and the Gao Chengjie calculation is completely dependent on small variations in pulse time differences in the case of unknown horizontal distances. According to the error propagation law, extremely high requirements are put forward on the time resolution of the signal acquisition circuit during long-distance operation, so that the hardware cost of equipment is greatly increased, and the low-cost popularization and application of the technology are limited. Fourth, existing data processing algorithms lack versatility and are weak against interference. The existing domain laser elevation measurement system is developed for the single N-shaped (generally, three beams of lasers (two beams are parallel and one beam is inclined) laser characteristics, and the N-shaped laser characteristics are formed during space scanning, so that logic solidification is judged to be effective (only 3 pulses are identified). The design is difficult to be compatible with novel scanning modes such as M type (four light beams) with higher redundancy or simplified V type (double light beams) and the like, hardware upgrading and expansion are limited, and when the design faces complex environment interference of a construction site, a dynamic filtering mechanism based on statistics is lacking, so that elevation misjudgment is easily generated due to accidental matching of pulse number, and the safety of automatic construction is seriously influenced. Disclosure of Invention The invention aims to provide a domain laser elevation measurement method and system combined with GNSS positioning, which solve the technical problems that in the existing domain laser elevation measurement technology, the hardware structure of a receiving end is complex