High-precision automatic measurement device and method for interaction between laser radar and rangefinder

Abstract

This invention relates to the field of high-precision measurement technology for overhead contact lines, and particularly to a high-precision automatic measurement device and method for interaction between lidar and rangefinder. The system includes a main body and an intelligent control component. The main body is connected to a walking component at both ends. The main body is equipped with a lidar, a laser velocimeter, and a motor that are electrically connected to each other. The intelligent control component includes a remote control module, a positioning module, a tracking module, a triggering module, a fine-tuning module, and a measurement module that are electrically connected to each other. This application solves the problem that existing technologies cannot complete measurements with high precision and high efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of high-precision contact network measurement, and in particular to a high-precision automatic measurement device and method for the interaction of a laser radar and a rangefinder. Background Art

[0002] At present, in the measurement of contact network, single-line or multi-line laser radar can obtain a large number of point clouds at high speed, with coordinate information data of tens of thousands or even millions of points per second, but the coordinates of these points often have large errors in length or angle, and even the use of laser radar with higher accuracy will still have large length and angle errors. On the other hand, even if only laser radar with better error stability is used, it cannot achieve an accuracy of ±2mm or ±1mm. Although it can be achieved with a laser rangefinder, it is limited to manual single-point measurement, resulting in poor efficiency.

[0003] The present invention realizes a set of devices, which interact with the laser rangefinder through the laser radar, identify the target through the laser radar, control the laser ranging angle and target tracking through the motor, trigger high-precision measurement, compare the measurement result with the laser radar result through the algorithm, and improve the accuracy of the laser radar algorithm. Summary of the invention

[0004] The purpose of the present invention is to provide a high-precision automatic measurement device and method for the interaction of a laser radar and a rangefinder, so as to solve the problem that the prior art cannot complete the measurement with high precision and high efficiency.

[0005] The objective of the present invention is achieved by the following technical scheme: a high-precision automatic measuring device for interaction between a laser radar and a rangefinder, comprising a main body and an intelligent control component, wherein walking components are connected to both ends of the main body, and the main body is provided with a laser radar, a laser speed meter, and a motor electrically connected to each other, and the intelligent control component comprises a remote control module, a positioning module, a tracking module, a trigger module, a fine-tuning module, and a measuring module electrically connected to each other.

[0006] It should be noted that the accuracy of the measurement is ensured through the interaction between the laser rangefinder and the laser radar and dual measurement.

[0007] The laser radar and the laser speed meter are arranged at intervals, and the motor is connected to the laser radar.

[0008] It should be noted that the contact line search based on a large number of point clouds obtained by the laser radar can improve the adaptability of track lines in different environments, so that the device can not only adapt to complex sections such as tunnels and stations, but also operate during the day and night.

[0009] The positioning module is arranged in the laser radar and is electrically connected to it. The positioning module can obtain, read and cache the point cloud data detected by the laser radar in real time, and calculate and analyze to obtain the local equation of the contact line.

[0010] It should be noted that the acquisition, reading and caching of points are achieved through the positioning module to ensure the integrity of the data.

[0011] The positioning module performs Gaussian filtering on the cached point cloud data to remove noise points and obtains the straight line equation through RANSAC.

[0012] It should be noted that efficient use and storage of points can be achieved by removing noise points.

[0013] The tracking module is located inside the laser rangefinder and is electrically connected to the laser rangefinder. The positioning module transmits the point cloud data and the equation to the tracking module. The tracking module converts the point cloud coordinates on the contact line from the laser radar coordinate system to the laser rangefinder coordinate system through the equation. The remote control module sends a signal to control the laser rangefinder to measure and obtain the measurement result.

[0014] It should be noted that through the interactive work of the laser radar and laser rangefinder modules, the work of automatically finding the target to be measured and measuring it can be achieved, thereby improving the automation and intelligence of the entire device.

[0015] The remote control module controls the motor to rotate, and the rotation of the motor drives the laser rangefinder to rotate.

[0016] It should be noted that the laser rangefinder is driven to rotate by a motor to minimize the angle error during the measurement process, and the angle of the motor is adjusted in real time by the tracking module, so that the laser rangefinder can quickly aim at the contact line to be measured and perform measurements, which is efficient and real-time.

[0017] The laser rangefinder is also provided with a trigger module, which can be started by controlling a first trigger signal or a second trigger signal. The first trigger signal is issued after detecting and identifying a designated point on the contact line, and the second trigger signal is issued after the subject walks a designated distance.

[0018] It should be noted that a variety of selection methods are used to start the measurement work, thereby improving the applicability of the laser rangefinder.

[0019] The laser rangefinder is also provided with a measuring module, and the measuring module is configured to measure the mileage information of the main body during movement and store the information.

[0020] It should be noted that the measurement module is used to achieve accurate measurement of points and storage of data.

[0021] The walking assembly is provided with the fine adjustment module and the automatic walking component. After the automatic walking component moves a specified distance, it triggers the laser rangefinder to measure and store the measurement data.

[0022] It should be noted that the automatic walking component enables the entire device to move automatically, realizing unmanned operation and saving labor.

[0023] The present application also provides a high-precision automatic measurement method for interaction between a laser radar and a range finder, which comprises the following steps:

[0024] S1, the positioning module for each frame of point cloud data f, the x coordinate of the point corresponds to the pull-out value, which is the left and right position of the deviation from the track; the y coordinate corresponds to the guide height, which is the height position from the train track surface; z is the odometer data, indicating the travel distance along the track;

[0025] S2, obtain all points that meet the contact line range through filtering, and select the point with the lowest y coordinate as the contact line candidate point;

[0026] S3, the candidate points of consecutive frames are combined into a point cloud cache queue, denoted as f k ,f k+1 ,...f n , each frame has one or more points, and the mileage, i.e., the z coordinate, of each point in each frame is the same. The basis for caching the frame sequence is z(f n )-z(f k ) is greater than or equal to a certain threshold L;

[0027] S4, for the points in the sliding window, calculate the variance δ and mean of x and y. Points whose x or y value is more than max(2.5*δ,off) away from the mean need to be filtered out.

[0028] S5, randomly select two frames with a specific interval, take the lowest point in the two frames, and make a straight line equation; judge the distance between all points in the sliding window and the straight line equation, and the points with a distance less than the threshold D are the inner points of the straight line. The calculation stops when the ratio of the inner points to all points meets a certain threshold. Otherwise, continue to randomly select points for several times, and take the straight line equation with the largest number of inner points. The least squares method is used for all inner points to fine-tune the straight line equation. The calculated straight line equation is recorded as LE (line equal);

[0029] S6, after the new radar frame data is processed by S2, the distance from the point to the LE line is directly determined. If it meets the threshold, it is an inner point and is added to the cache queue. When the accumulated mileage of the newly added frame exceeds a certain threshold S, S4 and S5 are repeated to update LE. LE is required by the positioning module to guide the tracking module and the aiming angle of the laser rangefinder;

[0030] S7, the tracking module calculates the position of the laser rangefinder. The installation positions of the laser radar and the laser rangefinder are fixed to form the internal parameters of the equipment. In the laser radar coordinate system, the equation of the plane (Laser Panel) where the laser rangefinder and the rotation axis are located is known according to the internal parameter position. The intersection point is obtained according to the straight line equation and the plane equation;

[0031] S8, converting the intersection point into the laser rangefinder coordinate system, converting it into polar coordinates, and obtaining the rotation angle for controlling the laser rangefinder, thereby achieving tracking and aiming of the contact line;

[0032] S9, the trigger module uses a recognition algorithm to identify the hanging string and the positioning point, or when the distance from the last distance measurement exceeds Dmm, issues a command for the laser rangefinder to measure, obtains high-precision measurement data, reversely converts it to the laser radar coordinate system, and records the measured data;

[0033] S10, for the main body of the automatic walking component, when the laser radar measures the key point in real time, the Laser Panel is translated to the key point, the translation distance of the laser rangefinder along the track is calculated, the motor is controlled to move the main body to the specified position, and the laser rangefinder is triggered to measure.

[0034] Compared with the prior art, the present invention has the following advantages and beneficial effects: high-precision measurement is achieved through the interactive working mode between the laser radar and the laser rangefinder, and the measurement results of the laser velocimeter are compared with the results of the laser radar, finally achieving effective improvement in the accuracy of the laser radar algorithm. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is one of the structural schematic diagrams of the present invention;

[0036] Figure 2 This is the second structural schematic diagram of the present invention.

[0037] Legend: 1-main body; 2-laser radar; 3-laser rangefinder; 4-motor. DETAILED DESCRIPTION

[0038] Please refer to the attached instructions Figure 1-2 This embodiment provides a high-precision automatic measuring device for the interaction of a laser radar and a rangefinder. The high-precision automatic measuring device for the interaction of a laser radar and a rangefinder is mainly used to solve the problem that the prior art cannot complete measurement with high precision and efficiency. The high-precision automatic measuring device for the interaction of a laser radar and a rangefinder is already in the actual use stage.

[0039] The present application is carried out through the following embodiments. A high-precision automatic measuring device in which a laser radar 2 interacts with a rangefinder includes a main body 1 and an intelligent control component. Walking components are connected to both ends of the main body 1. The main body 1 is provided with a laser radar 2, a laser speed meter, and a motor 4 electrically connected to each other. The intelligent control component includes a remote control module, a positioning module, a tracking module, a trigger module, a fine-tuning module, and a measuring module electrically connected to each other.

[0040] It should be noted that the present application realizes target recognition through the interactive working mode between the laser radar 2 and the laser rangefinder 3 by means of the set laser mine, and then realizes target tracking by controlling the angle of the laser rangefinder 3 through the motor 4, thereby realizing high-precision measurement, and performing an algorithm comparison between the measurement result and the laser radar 2 result, and finally realizing effective improvement of the accuracy of the laser radar 2 algorithm, thereby solving the problem that the prior art cannot complete measurement with high precision and efficiency.

[0041] The laser radar 2 is spaced apart from the laser speed meter, and the motor 4 is connected to the laser radar 2 .

[0042] It should be noted that the angle of the laser radar 2 is controlled by the motor 4 to ensure the accuracy of the angle of the measurement data.

[0043] The positioning module is arranged in the laser radar 2 and is electrically connected thereto. The positioning module can obtain, read and cache the point cloud data detected by the laser radar 2 in real time, and calculate and analyze to obtain the local equation of the contact line.

[0044] It should be noted that the present application obtains each frame of point cloud data of the contact line in real time through the laser radar 2, and searches for one or more continuous point cloud data within the pull-out value ±400 that meets the height range, and caches these data in a cache queue of a specific size, and then analyzes and calculates these data to finally obtain the local equation of the contact line.

[0045] The positioning module performs Gaussian filtering on the cached point cloud data to remove noise points and obtains the straight line equation through RANSAC.

[0046] It should be noted that before analyzing the equation through the collected point cloud data, the cached data must be Gaussian filtered to remove noise, and the straight line equation must be obtained by RANSAC to ensure the accuracy of the obtained equation. In detail, the above analysis and equation process is continued, but based on the local equation, new points can be judged faster to determine whether the new points belong to the contact line points, and then the cache queue is updated in real time. When the new points collected by the detection reach the specified amount, the straight line equation is updated, which is equivalent to a sliding window with a certain step length, and the straight line equation is solved for the point cloud in the window; at the same time, the contact line trend can be predicted.

[0047] The tracking module is located inside the laser rangefinder 3 and is electrically connected thereto. The positioning module transmits the point cloud data and the equation to the tracking module. The tracking module converts the point cloud coordinates on the contact line from the laser radar 2 coordinate system into the laser rangefinder 3 coordinate system through the equation. The remote control module sends a signal to control the laser rangefinder 3 to measure and obtain the measurement result.

[0048] It should be noted that, based on the equations obtained in the above prediction, the point cloud coordinates on the contact line are converted from the laser radar 2 coordinate system into the laser rangefinder 3 coordinate system, and then the laser rangefinder 3 is controlled to perform a secondary measurement of the points on the contact network to obtain another set of data. By comparing and analyzing multiple sets of data, the measurement accuracy is checked, determined and improved.

[0049] The remote control module controls the motor 4 to rotate, and the rotation of the motor 4 drives the laser rangefinder 3 to rotate.

[0050] It should be noted that, in order to ensure the accuracy of the angle during the measurement of the laser rangefinder 3, the motor 4 is controlled by the remote control module to drive the laser rangefinder 3 to rotate to a specified position, and a command is issued to trigger the laser rangefinder 3 to measure the contact network.

[0051] The laser rangefinder 3 is also provided with a trigger module, which can be started by controlling a first trigger signal or a second trigger signal. The first trigger signal is issued after detecting and identifying a designated point on the contact line, and the second trigger signal is issued after the main body 1 travels a designated distance.

[0052] It should be noted that the measurement operation of the laser rangefinder 3 can be started in two different ways. The first trigger signal belongs to a feature point or a target point, which is based on the judgment of the key points on the contact line of the entire device. Specifically, the laser rangefinder 3 is immediately triggered to start distance measurement after the key position information is obtained by the suspension string and positioning point recognition algorithm; the second trigger signal belongs to a distance signal, which triggers the laser rangefinder 3 to start distance measurement when the entire device travels a set interval distance.

[0053] The laser rangefinder 3 is also provided with a measuring module, and the measuring module is configured to measure the mileage information of the main body 1 during the movement and store the information.

[0054] It should be noted that the measurement module is mainly used for measurement and analysis and storage of all data during the measurement process.

[0055] The walking assembly is provided with the fine adjustment module and the automatic walking component. After the automatic walking component moves a specified distance, it triggers the laser rangefinder 3 to measure and store the measurement data.

[0056] It should be noted that, by setting up the automatic walking component, the entire device can move forward automatically, reducing the input of human resources, and realizing intelligent, automated and efficient operation that saves manpower, material and financial resources.

[0057] Please refer to Figure 2 The present application also provides a high-precision automatic measurement method for the interaction between a laser radar 2 and a range finder, comprising the following steps:

[0058] S1, the positioning module, for each frame of point cloud data f, the x-coordinate of the point corresponds to the pull-out value, that is, the left and right position of the deviation from the track; the y-coordinate corresponds to the guide height, which is the height position from the train track surface; z is the odometer data, indicating the distance traveled along the track.

[0059] S2, all points that meet the contact line range are obtained through filtering. Since there may be multiple groups, the point with the lowest y coordinate is selected as the candidate point of the contact line.

[0060] S3, organizes the candidate points of multiple consecutive frames into a point cloud cache queue, recorded as fk, fk+1,...fn, and each frame has one or more points. The mileage, i.e., the z coordinate, of each point in each frame is the same. The basis for caching the frame sequence is that z(fn)-z(fk) is greater than or equal to a certain threshold L, where L is approximately the length of the local straight line of the contact line, and L also determines the size of the sliding window.

[0061] S4, for the points in the sliding window, the variance δ and mean of x and y are counted. The points whose x or y value exceeds the mean and the max(2.5*δ,off) value is taken need to be filtered out. The off parameter here is to prevent the point cloud from being over-filtered when the variance is too small when x and y are well unified.

[0062] S5, randomly select two frames with a certain interval, take the lowest point in the two frames, and make a straight line equation; judge the distance between all points in the sliding window and the straight line equation, and the points with a distance less than the threshold D are the inliers of the line. If the ratio of inliers to all points meets a certain threshold, stop. Otherwise, continue to randomly select points for several times, and take the straight line equation with the largest number of inliers. For all inliers, use the least squares method to fine-tune the straight line equation, and record the calculated straight line equation as LE (line equal).

[0063] S6, the new radar frame data, after being processed by S2 above, directly determines the distance from the point to the LE line. If it meets the threshold, it is an inner point and is added to the cache queue. When the accumulated mileage of the newly added frame exceeds a certain threshold S, repeat S4 and S5 to update LE. LE is required by the positioning module and guides the aiming angle of the laser rangefinder 3 in the tracking module.

[0064] S7, the tracking module calculates the position of the laser rangefinder 3. The installation positions of the laser radar 2 and the laser rangefinder 3 are fixed to form the internal parameters of the equipment. In the laser radar 2 coordinate system, the equation of the plane (Laser Panel) where the laser rangefinder 3 and the rotation axis are located is known based on the internal parameter position. According to the equation of the line and the plane, the intersection point is obtained, such as Figure 2 As shown in the figure, it is point B. This plane is referred to as Laser Panel in the following text.

[0065] S8, convert the intersection point to the laser rangefinder 3 coordinate system and convert it into polar coordinates, such as Figure 2 As shown, the polar coordinates of point B in the ECG plane are obtained to control the rotation angle of the laser rangefinder 3, thereby achieving tracking and aiming of the contact line.

[0066] S9, the trigger module uses the recognition algorithm to identify the suspension string and the positioning point, or when the distance from the last distance measurement exceeds Dmm, it issues a laser ranging measurement command to obtain high-precision measurement data, reversely converts it to the laser radar 2 coordinate system, and records the measured data.

[0067] S10, for the main body 1 with an automatic walking component added, the laser radar 2 measures the key points such as the suspension string or the positioning point in real time, translates the Laser Panel to the key point, calculates the translation distance of the laser rangefinder 3 along the track, and controls the measuring device motor 4 according to the odometer to move to the corresponding position, triggering the rangefinder measurement.

[0068] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for a high-precision automatic measurement device based on the interaction between a laser radar and a rangefinder, characterized in that: A high-precision automatic measurement device for interaction between a laser radar and a rangefinder, comprising: a main body (1) and an intelligent control component, wherein both ends of the main body (1) are connected to walking components, the main body (1) is provided with a laser radar (2), a laser rangefinder (3), and a motor (4) which are electrically connected to each other, and the intelligent control component comprises a remote control module, a positioning module, a tracking module, a trigger module, a fine adjustment module, and a measurement module which are electrically connected to each other; the laser radar (2) and the laser rangefinder (3) are arranged at intervals, and the motor (4) is connected to the laser radar (2); The method comprises the following steps: S1, the positioning module for each frame of point cloud data f, the x coordinate of the point corresponds to the pull-out value, which is the left and right position of the deviation from the track; the y coordinate corresponds to the guide height, which is the height position from the train track surface; z is the odometer data, indicating the travel distance along the track; S2, obtain all points that meet the contact line range through filtering, and select the point with the lowest y coordinate as the contact line candidate point; S3, the candidate points of multiple consecutive frames are organized into a point cloud cache queue, recorded as fk, fk+1, ... fn, each frame has one or more points, and the mileage, i.e., the z coordinate, of each frame point is the same. The basis for caching the frame sequence is that z(fn)-z(fk) is greater than or equal to a certain threshold L; S4, for the points in the sliding window, calculate the variance δ and mean of x and y. Points whose x or y value is more than max(2.5*δ,off) away from the mean need to be filtered out. S5, randomly select two frames with a specific interval, take the lowest point in the two frames, and make a straight line equation; judge the distance between all points in the sliding window and the straight line equation, and the points with a distance less than the threshold D are the inner points of the straight line. The calculation stops when the ratio of the inner points to all points meets a certain threshold. Otherwise, continue to randomly select points for several times, and take the straight line equation with the largest number of inner points. Use the least squares method for all inner points to fine-tune the straight line equation, and record the calculated straight line equation as LE; S6, the new radar frame data, after being processed by S2, directly determines the distance from the point to the LE line. If it meets the threshold, it is an inner point and is added to the cache queue. When the accumulated mileage of the newly added frame exceeds a certain threshold S, S4 and S5 are repeated to update LE; LE is required by the positioning module, guiding the tracking module and the laser rangefinder (3) to aim at an angle; S7, the tracking module calculates the position of the laser rangefinder (3), the laser radar (2) and the laser rangefinder (3) are installed at fixed positions to form an internal parameter of the device, and in the coordinate system of the laser radar (2), the plane equation where the laser rangefinder (3) and the rotation axis are located is known according to the internal parameter position, and the intersection point is calculated according to the straight line equation and the plane equation; S8, converting the intersection point into the coordinate system of the laser rangefinder (3), converting it into polar coordinates, and obtaining the rotation angle of the laser rangefinder (3) to achieve tracking and aiming of the contact line; S9, the trigger module uses a recognition algorithm to identify the suspension string and the positioning point, or when the distance from the last distance measurement exceeds D mm, issues a command for the laser rangefinder (3) to measure, obtains high-precision measurement data, reversely converts it to the laser radar (2) coordinate system, and records the measured data; S10, for the main body (1) with the automatic walking component added, when the laser radar (2) measures the key point in real time, the plane is translated to the key point, the translation distance of the laser rangefinder (3) along the track is calculated, the motor (4) is controlled to move the main body (1) to the specified position, and the laser rangefinder (3) is triggered to measure.

2. The method of the high-precision automatic measurement device based on the interaction between laser radar and rangefinder according to claim 1 is characterized in that: The positioning module is arranged in the laser radar (2) and is electrically connected thereto. The positioning module is capable of acquiring, reading and caching point cloud data detected by the laser radar (2) in real time, and calculating and analyzing to obtain a local equation of the contact line.

3. The method of the high-precision automatic measurement device based on the interaction between laser radar and rangefinder according to claim 2 is characterized in that: The positioning module performs Gaussian filtering on the cached point cloud data to remove noise points and obtains the straight line equation through RANSAC.

4. The method of the high-precision automatic measurement device based on the interaction between laser radar and rangefinder according to claim 3 is characterized in that: The tracking module is located in the laser rangefinder (3) and is electrically connected thereto; the positioning module transmits the point cloud data and the equation to the tracking module; the tracking module converts the point cloud coordinates on the contact line from the laser radar (2) coordinate system to the laser rangefinder (3) coordinate system through the equation; and the remote control module sends a signal to control the laser rangefinder (3) to measure and obtain a measurement result.

5. The method of the high-precision automatic measurement device based on the interaction between laser radar and rangefinder according to claim 4 is characterized in that: The remote control module controls the motor (4) to rotate, and the rotation of the motor (4) drives the laser rangefinder (3) to rotate.

6. The method of the high-precision automatic measurement device based on the interaction between laser radar and rangefinder according to claim 4 is characterized in that: The laser rangefinder (3) is also provided with a trigger module, which can be activated by controlling a first trigger signal or a second trigger signal. The first trigger signal is issued after a specified point on the contact line is detected and identified, and the second trigger signal is issued after the main body (1) travels a specified distance.

7. The method of the high-precision automatic measurement device based on the interaction between laser radar and rangefinder according to claim 4 is characterized in that: The laser rangefinder (3) is also provided with a measuring module, and the measuring module is configured to measure the mileage information of the main body (1) during the movement and store the information.

8. The method of the high-precision automatic measurement device based on the interaction between laser radar and rangefinder according to claim 4 is characterized in that: The fine adjustment module and the automatic walking component are arranged in the walking assembly. After the automatic walking component moves a specified distance, it triggers the laser rangefinder (3) to measure and store the measurement data.

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