CN-121994152-A - Laser disturbance real-time correction method and system

CN121994152ACN 121994152 ACN121994152 ACN 121994152ACN-121994152-A

Abstract

The invention relates to the technical field of large-scale shaft centering measurement and discloses a laser disturbance real-time correction method and system. The method comprises the steps of establishing a laser datum line, extracting a dynamic drift vector of a tail light spot through a CMOS (complementary metal oxide semiconductor), obtaining real-time axial positions of all measuring points through femtosecond ranging, calculating a scale factor based on the datum distance, linearly mapping out local two-dimensional drift quantity of the measuring points, projecting the drift vector to a diameter measuring direction to obtain a precise compensation quantity, and rectifying the deviation of an original diameter measuring value. The invention breaks through the limitation of absolute stability of measurement dependence reference lines, thoroughly eliminates the system error caused by environmental disturbance by using a dynamic detection and closed-loop compensation mechanism, and greatly improves the centering measurement precision of the multi-axis tile section equipment.

Inventors

Jia Dongyou
XU DONG
QI XINJIAN
XU SHANGNIAN
REN YONGJIE
CHEN XINYU

Assignees

中国能源建设集团天津电力建设有限公司

Dates

Publication Date: 20260508
Application Date: 20260410

Claims (10)

1. The laser disturbance real-time correction method is applied to a system comprising a laser emission unit, a tail end CMOS receiving unit, a diameter measuring unit, a femtosecond ranging unit and an upper computer processing unit, and is characterized by comprising the following steps of: Step A, a laser datum line is established between a shafting transmitting end and a tail end, and any time is acquired through the tail end CMOS receiving unit Is the end spot position of (2) Initial reference position Calculating to obtain the end drift vector ; Step B, the diameter measuring device is moved to the first position When measuring points, the original diameter measuring value measured by the diameter measuring unit And the first measured by the femtosecond ranging unit Real-time axial distance from measuring point to transmitting end ; Step C, pairing the end drift vectors based on the same timestamp Distance from real-time axis Calculating a scaling factor Wherein For the calibration reference distance between the transmitting end and the terminal receiving end, calculating the first according to the proportionality coefficient Laser drift estimation vector at measurement point Step D, obtaining the first Unit vector of measuring point in diameter measuring direction Estimating the laser drift vector Projecting to the diameter measuring direction to obtain the compensation amount along the diameter measuring direction ; Step E, the original diameter measurement value is obtained Subtracting the compensation amount Obtaining a deviation correcting and diameter measuring value after drift compensation 。
2. The method of claim 1, wherein the step C of matching based on the same time stamp comprises searching for two frames of data closest to the moment in the spot data stream output by the terminal CMOS receiving unit by taking the diameter measurement trigger moment as a reference time stamp, and performing linear interpolation on the central coordinates of the spots to obtain the terminal drift vector accurately aligned with the diameter measurement moment 。
3. The method according to claim 1, wherein the calibration method of the reference distance comprises setting an end calibration target surface coaxial with the light sensitive surface of the end CMOS receiving unit in front of the end CMOS receiving unit, moving the diameter measuring device to the end calibration target surface to keep static, continuously sampling by a femtosecond ranging unit to obtain a distance sequence, eliminating abnormal values of the distance sequence by adopting a median absolute deviation criterion, calculating an arithmetic mean value of the residual effective samples after eliminating the abnormal values, and taking the obtained result as the reference distance in the configuration parameters 。
4. The method according to claim 1, wherein the radial unit vector in step D The expression of (2) is Wherein The calculation formula of the compensation quantity is developed into the following formula: Wherein And (3) with Respectively, end drift vectors Components in the transverse and longitudinal directions.
5. The method according to claim 1, wherein after the data are acquired in the step A and the step B, the terminal drift vector sequence and the original diameter measurement value sequence required for calculation are subjected to double preprocessing, and the preprocessing process comprises the steps of firstly applying sliding median filtering to the data sequence, then introducing Hampel criteria to the filtered sequence for residual outlier detection, and replacing samples determined as outliers with the median of a window in which the samples are located.
6. A laser disturbance real-time correction system for implementing the method of any one of claims 1 to 5, comprising: the laser emission unit is arranged at one end of the shaft system and is used for emitting a reference laser line which propagates along the axis; The terminal CMOS receiving unit is arranged at the other end of the shafting and is used for receiving a reference light spot formed by a reference laser line, continuously collecting light spot images at a set frame rate, extracting a center coordinate and outputting a terminal drift vector; The diameter measuring unit is used for obtaining an original diameter measuring value from the inner side surface of the bearing bush at the measuring point to the laser datum line; the femtosecond ranging unit adopts an independent femtosecond laser light path and is used for measuring the real-time axial distance from a measuring point where the measuring unit is positioned to a transmitting end; The synchronous control and communication unit maintains a global unified clock and is used for respectively stamping time stamps on data of the tail end CMOS receiving unit, the diameter measuring unit and the femtosecond ranging unit and packaging unified time stamp data frames; the upper computer processing unit is in communication connection with the synchronous control and communication unit, receives the data frame, calculates a laser drift estimation vector at the measuring point based on the proportional mapping relation between the real-time axial distance and the calibration reference distance, projects the laser drift estimation vector to the diameter measuring direction to obtain compensation quantity, and outputs the diameter measuring value subjected to compensation and rectification.
7. The system of claim 6, wherein the femtosecond ranging unit and the caliper unit are integrated on the same portable caliper device, at least three femtosecond reflection targets are arranged at non-collinear positions of the caliper device body, and the femtosecond ranging unit synchronously outputs position information of the caliper device along the axial direction and tilt and rotation gesture information by performing multi-objective calculation on flight time or phase difference of each target.
8. The system of claim 6, wherein the laser emitting unit employs a laser in an invisible light band, an output beam of the laser is split by a half mirror arranged at a center position of the device, and then transmitted or reflected along an axis to the terminal CMOS receiving unit, and an operating wavelength of the laser is matched with an imaging chip peak response band of the terminal CMOS receiving unit.
9. The system of claim 6, wherein when the measured shaft system comprises a plurality of intermediate bearing bush segments, one or more intermediate CMOS light spot detection nodes are added at the intermediate position of the shaft system, the reference distances are calibrated in the segments respectively, and the proportional mapping and the error compensation calculation are performed in the segments independently.
10. The system of claim 6, further comprising a power supply unit, wherein the power supply unit is an industrial-level regulated power supply module matched with the uninterruptible power supply device, and the output end of the power supply unit is provided with a multi-level filtering and isolating circuit for providing regulated power supply for the laser emission unit, the tail end CMOS receiving unit, the diameter measuring unit, the femtosecond ranging unit, the synchronous control and communication unit and the upper computer interface circuit.

Description

Laser disturbance real-time correction method and system Technical Field The invention relates to the technical field of large-scale shaft centering measurement, in particular to a laser disturbance real-time correction method and system. Background In the industries of electric power, energy, ships, metallurgy and the like, the alignment (centering) of the central lines of a plurality of bearing bush sections of a large-scale shaft system is a key link for ensuring long-term stable operation of equipment. At present, the shaft system centering measurement is usually carried out in an engineering site by establishing a laser datum line matched with a diameter measuring device. In such a measurement process, the laser reference line in an ideal state should always maintain the absolute stability of the spatial position, so as to provide a uniform absolute reference coordinate for each measuring point. However, in an actual engineering field environment, the laser datum line is inevitably subject to dynamic drift due to the influence of objective environmental factors such as continuous interference of a thermal current gradient, micro vibration of mechanical equipment or micro displacement of a support bracket, and the disturbance deviation is gradually amplified with the increase of a measurement distance. The traditional measuring method usually ignores the dynamic drift of the laser datum line in the whole measuring period, so that unknown datum line deviation is mixed in the original diameter measuring data of each measuring point, the unknown datum line deviation cannot be identified and removed, and finally the centering measuring precision and engineering quality of a large-scale shafting are seriously affected. Disclosure of Invention The invention provides a laser disturbance real-time correction method and system for solving the problem that the dynamic drift of a laser datum line is caused by environmental factors in the prior art so as to seriously influence the measurement accuracy of a large-scale axis system. The invention firstly provides a laser disturbance real-time correction method which is applied to a system comprising a laser emission unit, a tail end CMOS receiving unit, a diameter measuring unit, a femtosecond ranging unit and an upper computer processing unit and comprises the following steps: Step A, a laser datum line is established between a shafting transmitting end and a tail end, and any time is acquired through the tail end CMOS receiving unit Is the end spot position of (2)Initial reference positionCalculating to obtain the end drift vector; Step B, the diameter measuring device is moved to the first positionWhen measuring points, the original diameter measuring value measured by the diameter measuring unitAnd the first measured by the femtosecond ranging unitReal-time axial distance from measuring point to transmitting end; Step C, pairing the end drift vectors based on the same timestampDistance from real-time axisCalculating a scaling factorWhereinFor the calibration reference distance between the transmitting end and the terminal receiving end, calculating the first according to the proportionality coefficientLaser drift estimation vector at measurement pointStep D, obtaining the firstUnit vector of measuring point in diameter measuring directionEstimating the laser drift vectorProjecting to the diameter measuring direction to obtain the compensation amount along the diameter measuring direction; Step E, the original diameter measurement value is obtainedSubtracting the compensation amountObtaining a deviation correcting and diameter measuring value after drift compensation。 The process based on the same time stamp pairing in the step C specifically comprises the steps of taking the diameter measurement trigger time as a reference time stamp, searching the front and rear frame data closest to the time in the spot data stream output by the tail end CMOS receiving unit, and carrying out linear interpolation on the central coordinates of the spots to obtain the tail end drift vector accurately aligned with the diameter measurement time。 As a preferable embodiment of the present invention, the reference distanceThe calibration method comprises the steps of arranging a tail end calibration target surface coaxial with a light sensitive surface of a tail end CMOS receiving unit in front of the tail end CMOS receiving unit, moving a diameter measuring device to the tail end calibration target surface to keep static, continuously sampling by a femtosecond ranging unit to obtain a distance sequence, adopting a median absolute deviation criterion to reject abnormal values of the distance sequence, calculating an arithmetic mean value of residual effective samples after the abnormal values are removed, and taking the obtained result as a reference distance in configuration parameters。 As a preferable technical scheme of the invention, the unit vector in the radial direction in the s