CN103577670A - Rail architectural space 3D point cloud data conversion method - Google Patents

Abstract

The invention relates to a rail architectural space 3D point cloud data conversion method. The method includes figuring out two equivalent bending radiuses corresponding to second starting points of moving trajectory arcs of vehicle wheels on rails in a period and the rotation angle according to moving distance of wheels on two sides of the vehicle in the period that a vehicle-mounted laser scanner lens turns a cycle; projecting scanned points from the last moment to the current moment to the equivalent radius of the current moment approximately, figuring out the relationship among points on the current equivalent bending radius and consistent points on the equivalent bending radius of the last moment, and completing coordinate transformation correspondingly. Compared with the prior art, the method has the advantages of simplicity of algorithms, low hardware requirements and like.

Description

A kind of track space 3D cloud data conversion method

Technical field

The present invention relates to a kind of data processing method, especially relate to a kind of track space 3D cloud data conversion method.

Background technology

The development of urban track traffic operation management, need to carry out record to the track circuit of subterranean tunnel space shape along the line, as the spatial database of digitizing Support management information system.3D laser scanner is arranged to 2D scan pattern and is arranged on small rail car, can complete fast the collection to space shape data along the line.Because can only collecting, 2D scanning independently builds cross-section data, if rebuild tunnel 3D space, the walking path and the attitude that also need to know mobile 2D scanning vehicle, generate after the coordinate information of disappearance, just many 2D cross-section datas in the light of actual conditions can be stitched together.By convention, make the traveling vehicle can the right and wrong degree run trace of track record, need to introduce the space-location method of inertial navigation (IMU) combining global positioning system (GPS).Due to IMU system complex and expensive, at subterranean tunnel, cannot introduce gps system again, this method is also infeasible.Applied for that a patent of invention < < urban track traffic inspection trolley positioning system > > (application number 201110211175.3) has proposed to utilize photoelectric encoder and photoelectric sensor to detect the travel distance of small rail car, but the run trace that the technology that this patent is described can detect is the distance about straight line scalar, the track vector in the time of can't obtaining dolly and walk on warp rail.

Summary of the invention

Object of the present invention is exactly to provide the track space 3D cloud data that a kind of algorithm is simple, hsrdware requirements are low conversion method in order to overcome the defect of above-mentioned prior art existence.

Object of the present invention can be achieved through the following technical solutions:

A space 3D cloud data conversion method, the method realizes by Orbiting work business inspection vehicle, comprises the following steps:

A space 3D cloud data conversion method, the method realizes by Orbiting work business inspection vehicle, it is characterized in that, comprises the following steps:

1) periodically read the wheel of the work business same wheel shaft of inspection vehicle both sides in the positional information of current time n, and compare with the positional information of previous moment n-1, calculate thus the displacement information C of both sides wheel ₁and C ₂;

2) by displacement information C ₁, C ₂with the gauge L of track, calculate respectively the equivalent bending radius of moment n vehicle location point track and the length L of inner track joining ₀with the length L+L with outer side track joining ₀, and the angle theta of this equivalent bending radius of moment and previous moment n-1 equivalence bending radius;

3) previous moment n-1 is projected on n equivalent bending radius line constantly to the spiral analyzing spot of advancing between current time n is approximate;

4) to each the analyzing spot P on current time n equivalent redius line _nmake vertical line, this vertical line ends at previous moment n-1 radius, and this terminal is to put P on corresponding moment n equivalent redius _nmoment n-1 equivalent redius on some P _n-1, and calculate this vertical line distance C _x;

5) according to θ and C _xcalculation level P _ncoordinate system by its place is transformed into a P _n-1the offset value delta u of place coordinate system _xwith Δ v _x, the row-coordinate of going forward side by side conversion;

6) repeating step 3)～step 5), calculate the off-set value in the coordinate system that all points on current time n equivalent redius line are transformed into previous moment n-1, carry out coordinate conversion, obtain track space 3D cloud data output.

Step 1) in, the information cycle constantly of reading synchronizes with the swing circle of the laser scanner camera lens of work business inspection vehicle, makes calculated displacement information C ₁there is enough accuracy with C2.

Compared with prior art, the present invention is based on portable 2D laser scanner technique and tunnel construction space is carried out to the method for data acquisition, utilize simple two-wheel photoelectric encoder to obtain the Vertical Curve information in tunnel, by the spiral analyzing spot of advancing is approximately to cross section formula analyzing spot, solved dexterously the conversion method that portable 2D scan-data is expanded into 3D scan-data, by processing under data line has effectively been completed to the coordinate conversion to motion scan cloud data.Algorithm that this invention relates to is simple, hsrdware requirements are low, and can be widely used in other similar applications.

Accompanying drawing explanation

Fig. 1 is process flow diagram of the present invention;

Fig. 2 is the schematic diagram of coordinate transform of the present invention, and wherein Fig. 2 (a) is actual track while scan, the track while scan that Fig. 2 (b) obtains for laser scanner scans;

Fig. 3 is the schematic diagram of 2D cloud data approximate representation.

Embodiment

Below in conjunction with the drawings and specific embodiments, the present invention is described in detail.

Embodiment

Principle of the present invention is that the 2D cloud data of laser scanner output is converted to 3D cloud data, 2D motion scan is the space tracking of spirality walking in fact in the Y direction, but in the time of only exporting synchronizing signal in each scanning lens cycle due to system, read 2D scan-data, these data can be approximately separate building shaped cross { X, the data of Z}.Such these cross sections will being stitched together, { Z} space, also needs to supplement the Y-axis information lacking for X, Y in formation.Owing to representing that the Y-axis of working direction can be crooked, by each cross section { X, the projection line of the scan-data of Z} on surface level regarded the X-axis line in a specific X-Y coordinate system as, so the foundation of 3D digital space be exactly by these in different X-Y coordinate systems X, and Z} data be transformed into a unification X-Y coordinate system in.Because different cross section is consistent at the height of Z direction, therefore do not need to adjust.The method realizes by Orbiting work business inspection vehicle, specifically comprises several steps as shown in Figure 1:

1) first system is carried out to initialization, and the signal of laser scanner is carried out synchronously, periodically read the wheel of the work business same wheel shaft of inspection vehicle both sides in the positional information of current time n, by comparing with the positional information of previous moment n-1, calculate the displacement information C of both sides wheel ₁and C ₂.Wherein the information cycle constantly of reading synchronizes with the swing circle of the laser scanner camera lens of work business inspection vehicle, makes calculated displacement information C ₁and C ₂there is enough accuracy.

2) by displacement information C ₁, C ₂with the gauge L of track, calculate respectively the equivalent bending radius of moment n vehicle location point track and the length L of inner track joining ₀with the length L+L with outer side track joining ₀, and the angle theta of this equivalent bending radius of moment and previous moment n-1 equivalence bending radius;

3) previous moment n-1 is projected on n equivalent bending radius line constantly to the spiral analyzing spot of advancing between current time n is approximate;

4) to each the analyzing spot P on current time n equivalent redius line _nmake vertical line, this vertical line ends at previous moment n-1 radius, and this terminal is to put P on corresponding moment n equivalent redius _nmoment n-1 equivalent redius on some P _n-1, and calculate this vertical line distance C _x;

5) according to θ and C _xcalculation level P _ncoordinate system by its place is transformed into a P _n-1the offset value delta u of place coordinate system _xwith Δ v _x, the row-coordinate of going forward side by side conversion;

6) repeating step 3)～step 5), calculate the off-set value in the coordinate system that all points on current time n equivalent redius line are transformed into previous moment n-1, carry out coordinate conversion, obtain track space 3D cloud data output.

As shown in Figures 2 and 3, wherein Fig. 2 is approximately spirality spacescan point in fact the principle of multi-section blended space point, { X in Fig. 3 to concrete principle _n-1, Y _n-1n-1 coordinate system constantly, X ' _n, Y ' _nbe n constantly if coordinate system during straight ahead, { X _n, Y _nbe n constantly if coordinate system during crooked advancing, P _n(x _n, y _n) be the arbitrfary point of current time n on equivalent redius line, P _n-1(x _n-1, y _n-1) be previous moment n-1 radius and some P _n(x _n, y _n) corresponding point, vertical line C _xarise from P _n(x _n, y _n) intersection point is P _n-1(x _n-1, y _n-1).θ is flexibility, and L is gauge, L ₀for the distance of gauge inner side apart from the center of circle, C ₁, C ₂, C ₀displacement for inner side, outside and track mid point.During calculating, L is known, C ₁, C ₂can survey, can obtain:

C ₂＝(L+L ₀)×θ，C ₁＝L ₀×θ

L ₀＝(C ₁×L)/(C ₂-C ₁)，θ＝(C ₂-C ₁)/L

C ₀＝(C ₂+C ₁)/2

For arbitrfary point x on equivalent redius line:

C _x＝C ₀×(L/2+L ₀+x)/(L ₀+L/2)

Side-play amount for previous moment coordinate system corresponding point:

Δu _x＝C _x×sinθ，Δv _x＝C _x×cosθ

Its coordinate transform is closed:

x _n＝x _n-1-Δu _x(n)

y _n＝y _n-1+Δv _x(n)

z _n＝z _n。

Claims (2)

1. a track space 3D cloud data conversion method, the method realizes by Orbiting work business inspection vehicle, it is characterized in that, comprises the following steps:

1) periodically read the wheel of the work business same wheel shaft of inspection vehicle both sides in the positional information of current time n, and compare with the positional information of previous moment n-1, calculate thus the displacement information C of both sides wheel ₁and C ₂;

2) by displacement information C ₁, C ₂with the gauge L of track, calculate respectively the equivalent bending radius of moment n vehicle location point track and the length L of inner track joining ₀with the length L+L with outer side track joining ₀, and the angle theta of this equivalent bending radius of moment and previous moment n-1 equivalence bending radius;

3) previous moment n-1 is projected on n equivalent bending radius line constantly to the spiral analyzing spot of advancing between current time n is approximate;

4) to each the analyzing spot P on current time n equivalent redius line _nmake vertical line, this vertical line ends at previous moment n-1 radius, and this terminal is to put P on corresponding moment n equivalent redius _nmoment n-1 equivalent redius on some P _n-1, and calculate this vertical line distance C _x;

5) according to θ and C _xcalculation level P _ncoordinate system by its place is transformed into a P _n-1the offset value delta u of place coordinate system _xwith Δ v _x, the row-coordinate of going forward side by side conversion;

6) repeating step 3)～step 5), calculate the off-set value in the coordinate system that all points on current time n equivalent redius line are transformed into previous moment n-1, carry out coordinate conversion, obtain track space 3D cloud data output.

2. a kind of track space 3D cloud data conversion method according to claim 1, is characterized in that step 1) in information read the be engaged in swing circle of laser scanner camera lens of inspection vehicle of cycle constantly and work and synchronize.

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