CN107463757B

CN107463757B - Section interpolation method based on section structure and steering angle constraint

Info

Publication number: CN107463757B
Application number: CN201710724765.3A
Authority: CN
Inventors: 谢翔
Original assignee: Chinese Nonferrous Metal Survey And Design Institute Of Changsha Co ltd
Current assignee: Chinese Nonferrous Metal Survey And Design Institute Of Changsha Co ltd
Priority date: 2017-08-22
Filing date: 2017-08-22
Publication date: 2020-07-28
Anticipated expiration: 2037-08-22
Also published as: CN107463757A

Abstract

The invention provides a section interpolation method based on section structure and steering angle constraint, which comprises the following steps: the angular rate of the robot received by the optical fiber gyroscope is suddenly increased, when the rotation angle in unit time exceeds a threshold value, the section is scanned once, and the section is marked as a corner section k; interpolation is used between the corner section k and the corner section m. Because interpolation is carried out between adjacent sections, the section interpolation method based on section structure and steering angle constraint can effectively avoid model errors caused by sharp corners.

Description

Section interpolation method based on section structure and steering angle constraint

Technical Field

The invention relates to the technical field of environment detection and robots, in particular to a section interpolation method based on section structure and steering angle constraint.

Background

At present, common underground spaces refer to underground goafs, mine roadways, civil air defense projects, rail transit tunnels and the like. These structures often need to measure the cross section, obtain the spatial coordinates of the cross section, and if necessary, three-dimensionally model the cross section.

The section scanning of the underground goaf is helpful for knowing the internal situation of the goaf, and the method helps to judge whether a hazard source exists or not and whether personnel are suitable to enter the goaf, and can provide early-stage data for the management of the goaf.

The cross section scanning of the mine tunnel and the civil air defense engineering can help to know the internal conditions, establish three-dimensional models in the tunnel and the civil air defense engineering and provide data support for simulating underground rescue and escape and establishing full-area three-dimensional model simulation.

To the section scanning of track traffic tunnel etc. can confirm the positional information of tunnel inside monitoring point, can detect inner structure and calamity information, avoid personnel to get into the adverse effect that causes the personal safety simultaneously.

Since the profile scans are not performed continuously, the time interval between two profiles may be long, and thus interpolation between profiles is required. Because the cross-section points are space points, the existing space interpolation methods include IDW, kriging interpolation, Natural neighbor interpolation, spline function interpolation and the like, but the interpolation is generally applicable to scattered points with relatively uniform distribution. The section model has the structural characteristics of the section model, and no interpolation method suitable for the section model exists at present.

Disclosure of Invention

The invention aims to provide a section interpolation method based on section structure and steering angle constraint, and aims to solve the technical problem that no suitable section model exists in the conventional interpolation method.

In order to achieve the above object, the present invention provides a section interpolation method based on section structure and steering angle constraint, comprising the steps of:

A. the angular rate of the robot received by the optical fiber gyroscope is suddenly increased, when the rotation angle in unit time exceeds a threshold value, the section is scanned once, and the section is marked as a corner section k;

the spatial rectangular coordinate of the scanning point is (x)_ij,y_ij,z_ij) Wherein i ranges from 1 to 1520, and j ranges from 1 to n;

B. when a corner section m adjacent to the section k is scanned, r +1 sections are included in the range from the corner section k to the corner section m, wherein the r +1 sections are k, k +1, …, k + b, …, m-1, m, 0-b < r, k < m, and m-k ═ r;

C. an interpolation method is adopted between the corner section k and the corner section m:

c1, extracting the first scanning point of all sections, i is 1, j is k, k +1, …, k + b, …, m-1, m, 0< b < r;

obtaining a set of coordinate points P (x)_1j,y_1j,z_1j) Wherein j is k, k +1, …, k + b, …, m-1, m, 0 ≦ b<r；

C2, extracting X, y and z in the coordinate point set P respectively to obtain a set X (X)_1j) Set Y (Y)_1j) Set Z (Z)_1j) Wherein j is k, k +1, …, k + b, …, m-1, m, 0 ≦ b<r；

C3, respectively carrying out interpolation methods such as Lagrange interpolation or Newton interpolation on the coordinate values of the sets X, Y and Z until the coordinate sets X ', Y ' and Z ' after interpolation are achieved;

c4, correspondingly extracting the interpolated coordinate sets X ', Y' and Z 'respectively to form an interpolated coordinate point set P';

and C5, storing the coordinates of the point coordinate set P', repeating the steps, and interpolating the points with the serial numbers of 2-1520.

Preferably, in step a, the threshold value of the angular rate per unit time rotation angle is 10 °/second.

Preferably, the point cloud data of the cross section is obtained by scanning a two-dimensional laser radar.

Preferably, the coordinates of the point cloud data are spatial rectangular coordinates, and are obtained by converting original polar coordinates obtained by a two-dimensional laser radar.

The invention has the following beneficial effects:

because interpolation is carried out between adjacent sections, the section interpolation method based on section structure and steering angle constraint can effectively avoid model errors caused by sharp corners.

Interpolation is the connection of a series of points by smooth curves or surfaces, and the points on the curves or surfaces are the interpolation points. That is, if the sharp corner is not distinguished, the model after interpolation is a smooth model, and the sharp corner, which is an obvious model feature, is lost. The method provided by the invention can store the characteristic points, so that the model is more real.

In addition to the objects, features and advantages described above, other objects, features and advantages of the present invention are also provided. The present invention will be described in further detail below with reference to the drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic diagram of a preferred embodiment of the present invention prior to interpolation;

fig. 2 is a schematic diagram of the preferred embodiment of the present invention after interpolation.

Detailed Description

Embodiments of the invention will be described in detail below with reference to the drawings, but the invention can be implemented in many different ways, which are defined and covered by the claims.

Due to the characteristics of the two-dimensional laser radar, when each section is scanned, the scanning range is 190 degrees, the angular resolution is 0.125 degrees, and therefore each section has 1520 points. Numbered 1,2,3 …,1520 from left to right in a clockwise direction. The robot performs n section scans in the process, and the section numbers are 1,2,3 …, n-1, n.

And the robot is provided with an optical fiber gyroscope for recording the angular rate of horizontal rotation of the robot. When the angular velocity of the robot suddenly increases over a threshold value theta, one scan of the cross section is automatically performed. If the azimuth angle difference value exceeds the threshold phi before and after the robot normally travels at the moment and the robot is being operated and controlled to steer, the tunnel, the roadway and the like are considered to have larger horizontal bending, and the section is marked as a corner section.

The angular rate is increased by a threshold of 10 deg./sec, taking into account the precision of the gyroscope itself and the mechanical properties of the rotation of the robot itself. Since the robot travels in a straight track while traveling, it is necessary to control the robot to turn in place after stopping the robot when turning is required, and the robot may have a slight turn due to a bump while traveling on a rough road. Therefore, according to the actual situation and the data of the actual test, the azimuth difference value threshold value needs to exceed 30 degrees when the robot normally travels, and the robot is performing pivot steering operation and is the corner section.

When scanning the corner section, the spatial rectangular coordinates of the scanning points are shown in the specification, wherein i ranges from 1 to 1520, and j ranges from 1 to n.

Since the section scanning is not continuously performed and may be at long intervals, when scanning adjacent sections, if a plurality of corner sections with large corners exist between two sections, a large error is caused to an interpolation result, so that the section interpolation method based on the section structure and steering angle constraint firstly cuts the whole tunnel or roadway into a plurality of parts according to the corner sections, and interpolates the parts respectively. Interpolation is carried out between the sections, so that the whole section model is more real; if the original spaced sections are directly connected to form a roadway model, the model is hard and unreal.

Assuming a section k, section m is two adjacent corner sections, where k < m, m-k ═ r, r > 0. Then the section range includes r +1 sections, which are k, k +1, …, k + b, …, m-1, m, 0 ≤ b < r.

The following interpolation method is adopted between the section k and the section m:

in a first step, the first scanning point of all the slices, i.e., i is 1, j is k, k +1, …, k + b, …, m-1, m, 0< b < r, is extracted. A set of coordinate points P is obtained, where j ═ k, k +1, …, k + b, …, m-1, m, 0 ≦ b < r.

Secondly, extracting X, y and z in the coordinate point set P respectively to obtain a set X (X)_1j) Set Y (Y)_1j) Set Z (Z)_1j) Wherein j is k, k +1, …, k + b, …, m-1, m, 0 ≦ b<r。

And thirdly, respectively carrying out interpolation methods such as Lagrange interpolation or Newton interpolation on the coordinate values of the sets X, Y and Z until the interpolated coordinate sets X ', Y ' and Z ' are obtained.

And fourthly, correspondingly extracting the interpolated coordinate sets X ', Y' and Z 'respectively to form an interpolated coordinate point set P'.

And fifthly, storing the coordinates of the point coordinate set P', repeating the steps, and interpolating the points with the serial numbers of 2-1520.

Example (c): the scanning model diagrams of 7 sections are shown in figure 1, the method of the application is adopted, cubic spline interpolation is adopted in the set, the point cloud model shown in figure 2 is obtained, and the whole section model is more real, smoother and stronger in practicability.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A section interpolation method based on section structure and steering angle constraint is characterized by comprising the following steps:

the spatial rectangular coordinates of the scanning points are

Wherein i ranges from 1 to 1520, j ranges from 1 to n, and n is the number of sections;

B. when a corner section m adjacent to the section k is scanned, r +1 sections are included in the range from the corner section k to the corner section m, wherein the sections are k, k +1, …, k + b, …, m-1, m, 0 is more than or equal to b and is less than r, k is less than m, and m-k = r;

C. and (3) adopting an interpolation method between the corner section k and the corner section m, and sequentially repeating the following steps of C1-C5 when i is 1,2,3, …, 1519 and 1520:

c1, extracting ith scanning points of all sections, wherein j = k, k +1, …, k + b, …, m-1, m, 0 is more than or equal to b and is less than r;

obtaining a set of coordinate points P, wherein j = k, k +1, …, k + b, …, m-1, m, 0 ≦ b < r;

c2, extracting X, y and z in the coordinate point set P respectively to obtain a set X (X)_ij) Set Y (Y)_ij) Set Z (Z)_ij) Wherein j = k, k +1, …, k + b, …, m-1, m, 0 ≦ b<r；

C3, respectively carrying out Lagrange interpolation or Newton interpolation on the coordinate values of the sets X, Y and Z to obtain interpolated coordinate sets X ', Y ' and Z ';

and C5, storing the point coordinate set P' coordinates.

2. The cross section interpolation method according to claim 1, wherein in the step a, the threshold value of the angular velocity in the unit time rotation angle is 10 °/second.

3. The section interpolation method according to claim 1, wherein the point cloud data of the section is obtained by two-dimensional laser radar scanning.

4. The cross section interpolation method according to claim 3, wherein the coordinates of the point cloud data are spatial rectangular coordinates obtained by converting original polar coordinates obtained by a two-dimensional laser radar.