Method and system for constructing multi-floor maps by integrating Z-axis data with QR codes

Abstract

The present invention discloses a multi-floor map construction method and system that integrates Z-axis data through two-dimensional codes, and belongs to the field of map construction technology. It includes: using a visual module to identify a two-dimensional code label, decoding to obtain the two-dimensional code information; using a laser module to obtain the point cloud data of the floor and perform filtering processing, and using the filtered point cloud data to perform two-dimensional mapping; using the identified two-dimensional code information to mark the position of the two-dimensional code label in the corresponding sub-image; performing map fusion, converting the marked two-dimensional grid map into a three-dimensional world coordinate system, and performing position registration of two adjacent sub-images. The present invention uses a visual module to determine the change of the floor where the robot is located, and uses the two-dimensional code label to assist the position registration of two adjacent sub-images. Compared with traditional two-dimensional mapping, the invention is suitable for unmanned mobile platforms to perform mapping and navigation in more complex environments, and has a small amount of calculation and low memory consumption.

Description

Technical Field

[0001] The present invention belongs to the technical field of map construction, and more specifically, relates to a method and system for constructing a multi-floor map by integrating Z-axis data through a two-dimensional code. Background Art

[0002] At present, the main aspects of map fusion technology design are: 1. Research on multi-robot collaborative mapping, and this research mainly focuses on the construction of maps in a single-story building. The purpose is to piece together a complete single-story map. The main difficulty involves the matching of feature points; 2. Multi-building robot navigation and mapping problems. Related research is to build maps for each floor separately, and then store them in the corresponding background server. When the robot needs to use the map of a certain floor, it calls the map of that floor; 3. It is achieved through 3D mapping. Although the mapping effect of this method is better than the above two methods, it has the disadvantage that it needs to process a large amount of point cloud data, which increases the amount of calculation and memory consumption compared to 2D maps.

[0003] Corresponding improvements have also been made to the above problems. For example, Chinese patent application number CN201811110672.2, published on January 15, 2019, discloses a method for real-time positioning and map construction based on the fusion of laser and QR code. The method includes: fusing the travel and speed information of the odometer, the QR code collected by the monocular camera, and the information of the inertial measurement unit into a state vector, constructing the observation equation of the federated Kalman filter according to the observation model of the odometer, the observation model of the inertial measurement unit, and the observation model of the monocular camera, adding the QR code positioning information on the basis of the traditional odometer and inertial measurement unit, so as to obtain the optimal solution of the state vector of the unmanned mobile platform; and then utilizing the characteristics of rapidity and accuracy of QR code information processing to form posture prediction information with higher accuracy, thereby reducing the number of particles in the particle filter real-time positioning and map construction method, thereby improving the positioning accuracy of low-power processors, such as unmanned mobile platforms, ensuring the positioning effect of unmanned mobile platforms in complex environments, completing map construction, and meeting application requirements in complex environments. The shortcoming of this patent is that although it can complete map construction to a certain extent and meet the application requirements of complex environments, the computing workload and memory consumption are high.

[0004] Another example is Chinese patent application number CN201810005934.2, published on June 19, 2018. The patent discloses a two-dimensional code positioning system based on a 3D camera, including: a 3D camera, a computing and processing unit, and a plurality of two-dimensional code label nodes; wherein the 3D camera is loaded with a two-dimensional map generated by map construction, and each two-dimensional code label node is arranged in the application environment of the two-dimensional code positioning system according to the two-dimensional map; and the 3D camera is arranged on the target object; when the two-dimensional code positioning system performs a two-dimensional code positioning operation, the 3D camera takes a picture of the two-dimensional code label node, and obtains a distance value relative to the two-dimensional code label node according to the picture, and the computing and processing unit uses the distance value to calculate the position coordinates of the robot relative to the two-dimensional code label node, and then converts the calculated position coordinates into the map coordinate system. The disadvantage of this patent is that as the number of identified two-dimensional codes increases, the accuracy of matching will continue to decrease when performing coordinate matching conversion. Summary of the invention

[0005] 1. Problems to be solved

[0006] In view of the problems existing in the prior art, the present invention provides a multi-floor map construction method and system by integrating Z-axis data through QR codes, which can be used in multi-floor robot operations. Point cloud data is obtained through a laser module, and after filtering, it is transmitted to a mapping module for mapping; then the specific QR code label attached to the floor is identified through a visual module, and then the QR code information is processed to obtain the current floor number, and then the floor height value is added to the z-axis of the origin coordinate of each sub-image to reduce the amount of calculation and memory consumption; finally, the constructed 2D map is converted into a three-dimensional world coordinate system through coordinate conversion, and after the conversion, the positions of two adjacent sub-images are aligned to facilitate the correct orientation of the map.

[0007] 2. Technical solution

[0008] To solve the above problems, the present invention adopts the following technical solutions.

[0009] As one aspect of the present application, a method for constructing a multi-floor map by integrating Z-axis data with a QR code is provided, which is applied to an unmanned mobile platform, wherein the unmanned mobile platform includes a visual module, a laser module, and a mapping module respectively connected to the visual module and the laser module, and the method includes the following steps:

[0010] Step S100, using a visual module to identify a QR code label and decode it to obtain QR code information; wherein the QR code label is arranged on each floor, the visual module is arranged at a position corresponding to the QR code label, and the QR code information at least includes the floor number and sequence number of the current floor, and coordinate information representing the location of the current QR code label on the current floor;

[0011] Step S200, obtaining point cloud data of the floor through a laser module and performing filtering processing, and using the filtered point cloud data to perform two-dimensional mapping to obtain multiple sub-images, each sub-image corresponding to a floor;

[0012] Step S300: using the identified QR code information, mark the position of the QR code label in the corresponding sub-image;

[0013] Step S400: perform map fusion, convert the marked two-dimensional grid map into a three-dimensional world coordinate system, and perform position registration of two adjacent sub-images.

[0014] Furthermore, before executing step S200, the method further includes: determining whether the current unmanned mobile platform is located between elevators or stairs between adjacent floors; which specifically includes:

[0015] Decode the QR code label to obtain the location information of the current QR code label;

[0016] Control the unmanned mobile platform to move to the location of the QR code label, and determine whether the current unmanned mobile platform is located between the elevators or stairs between adjacent floors based on the distance between the two;

[0017] If it is located, the unmanned mobile platform is controlled to continue moving to the location of the QR code label; if it is not located, the QR code label is decoded to obtain the floor number of the current QR code label.

[0018] Furthermore, in step S400, converting the marked two-dimensional grid map into a three-dimensional world coordinate system specifically includes:

[0019] Step S410, establishing a two-dimensional coordinate system xoy on the marked two-dimensional grid map, wherein two axes of the two-dimensional coordinate system xoy are respectively an x-axis and a y-axis, and the origin is o;

[0020] Step S420, create a new three-dimensional coordinate system, and assume that the plane mapped by the two-dimensional coordinate system xoy in the three-dimensional coordinate system is the plane x′o′y′, wherein the two axes of the plane x′o′y′ are the x′ axis and the y′ axis, the origin is o′, and the x′ axis, the o′ origin, and the y′ axis are the mappings of the x axis, the origin o, and the y axis in the three-dimensional coordinate system respectively;

[0021] Step S430, using translation transformation, rotate the plane x′o′y′ mapped by the two-dimensional coordinate system xoy in the three-dimensional coordinate system to coincide with the origin of the two-dimensional coordinate system xoy;

[0022] Step S440, using rotation change to make the x' axis and y' axis in the plane x'o'y' coincide with the x axis and y axis in the two-dimensional coordinate system xoy respectively;

[0023] Step S450: convert the sub-map of each layer into a three-dimensional coordinate system through coordinate conversion, and assign corresponding data to the z-axis of each layer of the map using the identified two-dimensional code information.

[0024] As another aspect of the present application, the present application also provides a multi-floor map construction system integrating Z-axis data through a QR code, including an unmanned mobile platform, wherein the unmanned mobile platform specifically includes:

[0025] A visual module is used to identify a QR code label and decode it to obtain QR code information; wherein the QR code label is arranged on each floor, the visual module is arranged at a position corresponding to the QR code label, and the QR code information at least includes the floor number and sequence number of the current floor, and coordinate information representing the location of the current QR code label on the current floor;

[0026] Laser module, used to obtain point cloud data of the floor and perform filtering;

[0027] The mapping module uses the filtered point cloud data to perform two-dimensional mapping and obtain multiple sub-images, each of which corresponds to a floor.

[0028] A marking module is used to mark the position of the QR code label in the sub-map obtained by the mapping module according to the QR code information recognized by the visual module;

[0029] The fusion module is used to perform map fusion and convert the two-dimensional grid map marked by the marking module into a three-dimensional world coordinate system;

[0030] And the registration module is used to register the positions of two adjacent sub-images after the base map is fused.

[0031] Furthermore, a processing module is included, and the processing module is used to determine whether the current unmanned mobile platform is located between elevators or stairs between adjacent floors; which specifically includes:

[0032] Decode the QR code label to obtain the location information of the current QR code label;

[0033] Control the unmanned mobile platform to move to the location of the QR code label, and determine whether the current unmanned mobile platform is located between the elevators or stairs between adjacent floors based on the distance between the two;

[0034] If it is located, the unmanned mobile platform is controlled to continue moving to the location of the QR code label; if it is not located, the QR code label is decoded to obtain the floor number of the current QR code label.

[0035] Furthermore, the fusion module converts the two-dimensional grid map marked by the marking module into a three-dimensional world coordinate system, specifically including:

[0036] Step S410, establishing a two-dimensional coordinate system xoy on the marked two-dimensional grid map, wherein two axes of the two-dimensional coordinate system xoy are respectively an x-axis and a y-axis, and the origin is o;

[0037] Step S420, create a new three-dimensional coordinate system, and assume that the plane mapped by the two-dimensional coordinate system xoy in the three-dimensional coordinate system is the plane x′o′y′, wherein the two axes of the plane x′o′y′ are the x′ axis and the y′ axis, the origin is o′, and the x′ axis, the o′ origin, and the y′ axis are the mappings of the x axis, the origin o, and the y axis in the three-dimensional coordinate system respectively;

[0038] Step S430, using translation transformation, rotate the plane x′o′y′ mapped by the two-dimensional coordinate system xoy in the three-dimensional coordinate system to coincide with the origin of the two-dimensional coordinate system xoy;

[0039] Step S440, using rotation change to make the x' axis and y' axis in the plane x'o'y' coincide with the x axis and y axis in the two-dimensional coordinate system xoy respectively;

[0040] Step S450: convert the sub-map of each layer into a three-dimensional coordinate system through coordinate conversion, and assign corresponding data to the z-axis of each layer of the map using the identified two-dimensional code information.

[0041] 3. Beneficial effects

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] (1) The present invention obtains point cloud data through a laser module, filters it, and then transmits it to a mapping module for mapping; then the visual module identifies the specific QR code label attached to the floor, processes the QR code information, obtains the current floor number, and then adds the floor height value to the z-axis of the origin coordinate of each sub-image to reduce the amount of calculation and memory consumption; finally, the constructed 2D map is converted into a three-dimensional world coordinate system through coordinate conversion, and after the conversion, the positions of two adjacent sub-images are aligned to facilitate the correct orientation of the map;

[0044] (2) The present invention converts the two-dimensional map of each floor into the world coordinate system by means of coordinate transformation and integration of floor values, and then uses the information in the two-dimensional code to obtain the relative position of the two-dimensional code of each sub-image, and then aligns the coordinates with the two-dimensional code in another sub-image to ensure that the two sub-images are in a vertical up-and-down relationship in the world coordinate system, thereby solving the problem of high difficulty in aligning two adjacent sub-images;

[0045] (3) When calculating the distance and angle between the unmanned mobile platform and the QR code tag, the present invention uses the estimated distance value between the QR code tag and the unmanned mobile platform, and determines whether the unmanned mobile platform is in the stairs or elevator through the distance |d| between the unmanned mobile platform and the QR code tag, which can reduce the positioning error and mapping error caused by the failure of laser radar matching. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A schematic flow chart of a method for constructing a multi-floor map by integrating Z-axis data with a QR code in one aspect of the present application;

[0047] Figure 2 A schematic diagram of a system for constructing a multi-floor map by integrating Z-axis data with a QR code in one aspect of the present application;

[0048] Figure 3 This is a schematic diagram of the steps of converting a marked two-dimensional raster map into a three-dimensional world coordinate system;

[0049] Figure 4 The second schematic diagram of the steps of converting the marked two-dimensional raster map into a three-dimensional world coordinate system;

[0050] Figure 5 The third step of converting the marked two-dimensional raster map into a three-dimensional world coordinate system;

[0051] In the figure: 100, visual module; 200, laser module; 300, marking module; 400, mapping module; 500, fusion module; 600, registration module. DETAILED DESCRIPTION

[0052] The present invention is further described below in conjunction with specific embodiments and drawings.

[0053] Figure 1A schematic flow chart of a method for constructing a multi-floor map by integrating Z-axis data through a QR code according to one aspect of the present application is shown, wherein the method is applied to an unmanned mobile platform, wherein the unmanned mobile platform includes a visual module, a laser module, and a mapping module connected to the visual module and the laser module respectively. Optionally, the visual module is arranged at each floor position of each building to be constructed, and the visual module may be an image acquisition device such as a camera, and the laser module may be installed on the front of the unmanned mobile platform, and the laser module may specifically be a laser radar, etc.

[0054] The method comprises steps S100 to S400. In step S100, a visual module is used to identify a two-dimensional code tag and decode it to obtain two-dimensional code information. The two-dimensional code tag is arranged on each floor, and the visual module is arranged at a position corresponding to the two-dimensional code tag. The two-dimensional code information at least includes the floor number and serial number of the current floor, and coordinate information representing the position of the current two-dimensional code tag on the current floor. In step S200, point cloud data of the floor is obtained by a laser module and filtered, and two-dimensional mapping is performed using the filtered point cloud data to obtain multiple sub-maps, each of which corresponds to one floor. In step S300, the position of the two-dimensional code tag is marked in the corresponding sub-map using the identified two-dimensional code information. In step S400, map fusion is performed to convert the marked two-dimensional grid map into a three-dimensional world coordinate system, and position registration of two adjacent sub-maps is performed. The two-dimensional maps of each floor are converted into the world coordinate system through coordinate transformation and integration of floor values. The information in the QR code is then used to obtain the relative position of the QR code of each sub-image. The coordinates are then aligned with the QR code in another sub-image to ensure that the two sub-images are in a vertical relationship in the world coordinate system, thus solving the problem of difficulty in aligning two adjacent sub-images.

[0055] Specifically, in step S100, the visual module is used to identify the two-dimensional code tag, and the two-dimensional code information is decoded; wherein, the two-dimensional code tag is arranged on each floor, the visual module is arranged at a position corresponding to the two-dimensional code tag, and the two-dimensional code information at least includes the floor number and serial number of the current floor, and the coordinate information representing the location of the current two-dimensional code tag on the current floor. In one embodiment of the present application, the visual module can be an image acquisition device such as a camera or a video camera, and the two-dimensional code tag needs to be arranged on each floor. Preferably, the two-dimensional code tag needs to be arranged at the elevator entrance or staircase entrance of each floor. In the present application, the setting of the two-dimensional code tag can use the two-dimensional code tag to assist the unmanned mobile platform in positioning and navigation, and each two-dimensional code tag becomes a positioning node. The two-dimensional code information, including the floor number and serial number of the current floor, and the coordinate information representing the location of the current two-dimensional code tag on the current floor, is pre-stored in each two-dimensional code tag, so as to be recognized by the visual module.

[0056] Specifically, in step S200, the laser module is a laser radar, and the point cloud data of the current floor can be obtained by continuously scanning the current floor with the laser radar. Since the original point cloud data obtained contains a lot of noise, there is a large error between the three-dimensional reconstruction model and the actual geometric shape of the measured object. In order to obtain a more accurate three-dimensional reconstruction model, it is necessary to effectively denoise the acquired point cloud data based on the analysis of the original point cloud data and the source of noise. Therefore, in this application, it is also necessary to obtain the point cloud data of the floor and perform filtering processing, and use the filtered point cloud data to perform two-dimensional mapping to obtain multiple sub-images, each of which corresponds to a floor. Among them, the following two methods can be used for filtering processing methods: one is a smoothing denoising method, such as point cloud filtering based on the Laplacian operator, bilateral filtering, iterative method of surface energy minimization, etc.; the other is a method for removing bad points, such as curve inspection method, angle judgment method, chord height difference method, etc. The point cloud filtering method is used in this application. It should be noted that the point cloud filtering method is only a method for obtaining point cloud data of floors and performing filtering processing in one embodiment of the present application. Other existing or future methods for obtaining point cloud data of floors and performing filtering processing, if applicable to the present application, should also be included in the scope of protection of the present application and are included here by reference.

[0057] It is worth noting that the setting of the QR code label in the above steps mainly utilizes the method of vision + QR code label, which can import the number of floors of the corresponding floors when building the map, and then calculate the height of the map, thereby providing a basis for the subsequent conversion of the two-dimensional grid map into a three-dimensional world coordinate system. Therefore, in a preferred embodiment, before step S200, the method further includes: determining whether the current unmanned mobile platform is located between elevators or stairs between adjacent floors; which specifically includes:

[0058] Decode the QR code label to obtain the location information of the current QR code label;

[0059] Control the unmanned mobile platform to move to the location of the QR code label, and determine whether the current unmanned mobile platform is located between the elevators or stairs between adjacent floors based on the distance between the two;

[0060] If it is located, the unmanned mobile platform is controlled to continue moving to the location of the QR code label; if it is not located, the QR code label is decoded to obtain the floor number of the current QR code label.

[0061] The above method of calculating whether the current unmanned mobile platform is located between the elevator or stairs between adjacent floors based on the distance between the current unmanned mobile platform and the QR code tag provides a basis for real-time control of the timing of turning on the laser radar of the unmanned mobile platform in step S200. In a preferred embodiment, when calculating the distance between the unmanned mobile platform and the QR code tag, it can be assumed that the position coordinates of the robot are (x1, y1) and the position coordinates of the QR code are (x2, y2). The distance |d| between the unmanned mobile platform and the QR code tag can be obtained by the following formula:

[0062] |d|=√[(x2-x1)^2+(y2-y1)^2+(z2-z1)^2]).

[0063] This embodiment uses the estimated distance value between the QR code tag and the unmanned mobile platform when calculating the distance and angle between the unmanned mobile platform and the QR code tag. The distance |d| between the unmanned mobile platform and the QR code tag is used to determine whether the unmanned mobile platform is in the stairs or elevator. This can reduce the positioning error and mapping error caused by the failure of laser radar matching.

[0064] In step S300, as mentioned above, the QR code information pre-stored in the QR code tag at least includes the floor number and serial number of the current floor, and the coordinate information representing the location of the current QR code tag on the current floor. By identifying the QR code information, for example, by capturing the QR code information through a camera, and then decoding the captured QR code information through some decoding units, the coordinate information of the location of the current QR code tag on the current floor can be extracted. The coordinate information of the location of the current QR code tag on the current floor is marked in the corresponding sub-graph.

[0065] In step S400, map fusion is performed to convert the marked two-dimensional grid map into a three-dimensional world coordinate system, and position registration of two adjacent sub-images is performed.

[0066] Furthermore, in step S400, converting the marked two-dimensional grid map into a three-dimensional world coordinate system specifically includes:

[0067] Step S410, establishing a two-dimensional coordinate system xoy on the marked two-dimensional grid map, wherein two axes of the two-dimensional coordinate system xoy are respectively an x-axis and a y-axis, and the origin is o;

[0068] Step S420, create a new three-dimensional coordinate system, and assume that the plane mapped by the two-dimensional coordinate system xoy in the three-dimensional coordinate system is the plane x′o′y′, wherein the two axes of the plane x′o′y′ are the x′ axis and the y′ axis, the origin is o′, and the x′ axis, the o′ origin, and the y′ axis are the mappings of the x axis, the origin o, and the y axis in the three-dimensional coordinate system respectively;

[0069] Step S430, using translation transformation, rotate the plane x′o′y′ mapped by the two-dimensional coordinate system xoy in the three-dimensional coordinate system to coincide with the origin of the two-dimensional coordinate system xoy;

[0070] Step S440, using rotation change to make the x' axis and y' axis in the plane x'o'y' coincide with the x axis and y axis in the two-dimensional coordinate system xoy respectively;

[0071] Step S450: convert the sub-map of each layer into a three-dimensional coordinate system through coordinate conversion, and assign corresponding data to the z-axis of each layer of the map using the identified two-dimensional code information.

[0072] For a specific example, please refer to Figure 3 , for each layer of the two-dimensional map, it is composed of many coordinate points, which can be regarded as point P. The coordinates of o′ in the xoy coordinate system are (x0, y0), and the coordinates of P in the xoy coordinate system are (x, y). Converting point P from the xoy coordinate system to x′o′y′ is equivalent to converting each layer of the two-dimensional map to the xoy plane of the three-dimensional coordinate system. For the data of the z-axis, the robot can scan the QR code to obtain information, determine the current position, obtain the z-axis data through calculation, and then directly add it to the converted sub-map. In this way, each sub-map of each floor can belong to a different height in the three-dimensional coordinate system.

[0073] The specific method of converting point P from the xoy coordinate system to x′oy′ is as follows:

[0074] Translation Transformation

[0075] The translation transformation is to transform the x′oy′ coordinate system to coincide with the xoy coordinate origin. Figure 4 ;

[0076] Rotation Change

[0077] The rotation change is to coincide the x′ axis with the x axis and the y′ axis with the y axis, so that the coordinates of P in the x′oy′ (and the three-dimensional coordinate system) can be obtained. The above steps can be expressed by the transformation matrix:

[0078]

[0079] Please refer to the effect of the transformation Figure 5 .

[0080] Figure 2 A schematic diagram of a multi-floor map construction system integrating Z-axis data by QR codes according to another aspect of the present application is shown, wherein the system includes an unmanned mobile platform, and the unmanned mobile platform specifically includes:

[0081] The visual module 100 is used to identify the QR code label and decode it to obtain the QR code information; wherein the QR code label is arranged on each floor, the visual module is arranged at a position corresponding to the QR code label, and the QR code information at least includes the floor number and sequence number of the current floor, and the coordinate information representing the location of the current QR code label on the current floor;

[0082] Laser module 200, used to obtain point cloud data of the floor and perform filtering processing;

[0083] A mapping module 400 performs two-dimensional mapping using the filtered point cloud data to obtain multiple sub-images, each of which corresponds to a floor.

[0084] A marking module 300 is used to mark the position of the QR code label in the sub-map obtained by the mapping module according to the QR code information recognized by the visual module;

[0085] A fusion module 500 is used to perform map fusion and convert the two-dimensional grid map marked by the marking module into a three-dimensional world coordinate system;

[0086] And a registration module 600 is used to register the positions of two adjacent sub-images after the base image is fused.

[0087] Specifically, it also includes a processing module, which is used to determine whether the current unmanned mobile platform is located between elevators or stairs between adjacent floors; it specifically includes:

[0088] Decode the QR code label to obtain the location information of the current QR code label;

[0089] Control the unmanned mobile platform to move to the location of the QR code label, and determine whether the current unmanned mobile platform is located between the elevators or stairs between adjacent floors based on the distance between the two;

[0090] If it is located, the unmanned mobile platform is controlled to continue moving to the location of the QR code label; if it is not located, the QR code label is decoded to obtain the floor number of the current QR code label.

[0091] Specifically, the fusion module converts the two-dimensional grid map marked by the marking module into a three-dimensional world coordinate system, which specifically includes:

[0092] Step S410, establishing a two-dimensional coordinate system xoy on the marked two-dimensional grid map, wherein two axes of the two-dimensional coordinate system xoy are respectively an x-axis and a y-axis, and the origin is o;

[0093] Step S420, create a new three-dimensional coordinate system, and assume that the plane mapped by the two-dimensional coordinate system xoy in the three-dimensional coordinate system is the plane x′o′y′, wherein the two axes of the plane x′o′y′ are the x′ axis and the y′ axis, the origin is o′, and the x′ axis, the o′ origin, and the y′ axis are the mappings of the x axis, the origin o, and the y axis in the three-dimensional coordinate system respectively;

[0094] Step S430, using translation transformation, rotate the plane x′o′y′ mapped by the two-dimensional coordinate system xoy in the three-dimensional coordinate system to coincide with the origin of the two-dimensional coordinate system xoy;

[0095] Step S440, using rotation change to make the x' axis and y' axis in the plane x'o'y' coincide with the x axis and y axis in the two-dimensional coordinate system xoy respectively;

[0096] Step S450: convert the sub-map of each layer into a three-dimensional coordinate system through coordinate conversion, and assign corresponding data to the z-axis of each layer of the map using the identified two-dimensional code information.

[0097] Step S460, compare the QR code information of the corresponding sub-images of the upper and lower adjacent layers in turn, convert the two-dimensional maps of each floor into the world coordinate system through coordinate transformation and integration of floor values, and then use the information in the QR code to obtain the relative position of the QR code of each sub-image, and then align the coordinates with the QR code in another sub-image to ensure that the two sub-images are in a vertical relationship in the world coordinate system, thereby solving the problem of high difficulty in aligning two adjacent sub-images.

[0098] This embodiment obtains point cloud data through a laser module, filters it and then transmits it to a mapping module for mapping; then the visual module identifies the specific QR code label attached to the floor, processes the QR code information, obtains the current floor number, and then adds the floor height value to the z-axis of the origin coordinate of each sub-image to reduce the amount of calculation and memory consumption; finally, the constructed 2D map is converted into a three-dimensional world coordinate system through coordinate conversion, and after the conversion, the positions of two adjacent sub-images are aligned to facilitate the correct orientation of the map.

[0099] The examples described in the present invention are merely descriptions of the preferred implementation modes of the present invention, and are not intended to limit the concept and scope of the present invention. Without departing from the design concept of the present invention, various modifications and improvements made to the technical solutions of the present invention by engineers and technicians in this field should all fall within the protection scope of the present invention.

Claims

1. A multi-floor map construction method integrating Z-axis data with QR codes is applied to an unmanned mobile platform, and is characterized by: The unmanned mobile platform includes a visual module, a laser module, and a mapping module connected to the visual module and the laser module respectively, and the method includes the following steps: Step S100, using a visual module to identify a QR code label and decode it to obtain QR code information; wherein the QR code label is arranged on each floor, the visual module is arranged at a position corresponding to the QR code label, and the QR code information at least includes the floor number and sequence number of the current floor, and coordinate information representing the location of the current QR code label on the current floor; Step S200, obtaining point cloud data of the floor through a laser module and performing filtering processing, and using the filtered point cloud data to perform two-dimensional mapping to obtain multiple sub-images, each sub-image corresponding to a floor; Step S300: using the identified QR code information, mark the position of the QR code label in the corresponding sub-image; Step S400: perform map fusion, convert the marked two-dimensional grid map into a three-dimensional world coordinate system, and perform position registration of two adjacent sub-images.

2. The method for constructing a multi-floor map by integrating Z-axis data with a QR code according to claim 1, characterized in that: Before executing step S200, the method further includes: determining whether the current unmanned mobile platform is located between elevators or stairs between adjacent floors; which specifically includes: Decode the QR code label to obtain the location information of the current QR code label; Control the unmanned mobile platform to move to the location of the QR code label, and determine whether the current unmanned mobile platform is located between the elevators or stairs between adjacent floors based on the distance between the two; If it is located, the unmanned mobile platform is controlled to continue moving to the location of the QR code label; if it is not located, the QR code label is decoded to obtain the floor number of the current QR code label.

3. The method for constructing a multi-floor map by integrating Z-axis data with a QR code according to claim 1, characterized in that: In step S400, converting the marked two-dimensional grid map into a three-dimensional world coordinate system specifically includes: Step S410, establishing a two-dimensional coordinate system xoy on the marked two-dimensional grid map, wherein two axes of the two-dimensional coordinate system xoy are respectively an x-axis and a y-axis, and the origin is o; Step S420, create a new three-dimensional coordinate system, and assume that the plane mapped by the two-dimensional coordinate system xoy in the three-dimensional coordinate system is the plane x′o′y′, wherein the two axes of the plane x′o′y′ are the x′ axis and the y′ axis, the origin is o′, and the x′ axis, the o′ origin, and the y′ axis are the mappings of the x axis, the origin o, and the y axis in the three-dimensional coordinate system respectively; Step S430, using translation transformation, rotate the plane x′o′y′ mapped by the two-dimensional coordinate system xoy in the three-dimensional coordinate system to coincide with the origin of the two-dimensional coordinate system xoy; Step S440, using rotation change to make the x' axis and y' axis in the plane x'o'y' coincide with the x axis and y axis in the two-dimensional coordinate system xoy respectively; Step S450: convert the sub-map of each layer into a three-dimensional coordinate system through coordinate conversion, and assign corresponding data to the z-axis of each layer of the map using the identified two-dimensional code information.

4. A multi-floor map construction system integrating Z-axis data through QR codes, including an unmanned mobile platform, characterized in that: The unmanned mobile platform specifically includes: A visual module is used to identify a QR code label and decode it to obtain QR code information; wherein the QR code label is arranged on each floor, the visual module is arranged at a position corresponding to the QR code label, and the QR code information at least includes the floor number and sequence number of the current floor, and coordinate information representing the location of the current QR code label on the current floor; Laser module, used to obtain point cloud data of the floor and perform filtering; The mapping module uses the filtered point cloud data to perform two-dimensional mapping and obtain multiple sub-images, each of which corresponds to a floor. A marking module is used to mark the position of the QR code label in the sub-map obtained by the mapping module according to the QR code information recognized by the visual module; The fusion module is used to perform map fusion and convert the two-dimensional grid map marked by the marking module into a three-dimensional world coordinate system; And the registration module is used to register the positions of two adjacent sub-images after the base map is fused.

5. The multi-floor map construction system according to claim 4, characterized in that: It also includes a processing module, which is used to determine whether the current unmanned mobile platform is located between elevators or stairs between adjacent floors; it specifically includes: Decode the QR code label to obtain the location information of the current QR code label; Control the unmanned mobile platform to move to the location of the QR code label, and determine whether the current unmanned mobile platform is located between the elevators or stairs between adjacent floors based on the distance between the two; If it is located, the unmanned mobile platform is controlled to continue moving to the location of the QR code label; if it is not located, the QR code label is decoded to obtain the floor number of the current QR code label.

6. The multi-floor map construction system according to claim 4, characterized in that: The fusion module converts the two-dimensional grid map marked by the marking module into a three-dimensional world coordinate system, specifically comprising: Step S420, create a new three-dimensional coordinate system, and assume that the plane mapped by the two-dimensional coordinate system xoy in the three-dimensional coordinate system is the plane x′o′y′, wherein the two axes of the plane x′o′y′ are the x′ axis and the y′ axis, the origin is o′, and the x′ axis, the o′ origin, and the y′ axis are the mappings of the x axis, the origin o, and the y axis in the three-dimensional coordinate system respectively; Step S430, using translation transformation, rotate the plane x′o′y′ mapped by the two-dimensional coordinate system xoy in the three-dimensional coordinate system to coincide with the origin of the two-dimensional coordinate system xoy; Step S440, using rotation change to make the x' axis and y' axis in the plane x'o'y' coincide with the x axis and y axis in the two-dimensional coordinate system xoy respectively; Step S450: convert the sub-map of each layer into a three-dimensional coordinate system through coordinate conversion, and assign corresponding data to the z-axis of each layer of the map using the identified two-dimensional code information.

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