CN114595572B

CN114595572B - Underwater robot virtual environment simulation method based on layering ocean data

Info

Publication number: CN114595572B
Application number: CN202210219522.5A
Authority: CN
Inventors: 王景璟; 白琳
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2022-03-08
Filing date: 2022-03-08
Publication date: 2023-05-16
Anticipated expiration: 2042-03-08
Also published as: CN114595572A

Abstract

The invention relates to an underwater robot virtual environment simulation method based on layering ocean data, which belongs to the field of underwater robot simulation and comprises the following steps: performing hierarchical editing treatment on the hierarchical ocean data source; importing the data subjected to layered processing into a virtual environment according to simulation requirements for environmental display, and providing a function of custom creating an environment layer; performing external perception simulation of the underwater robot based on hierarchical marine environment modeling; storing the generated perception analog value sub-modules into different module databases in a plug-in mode, and providing a function of custom creating a perception module; and adding each perception module in the module database into the underwater robot body module according to the requirements. The invention realizes the automation and structuring of environment information processing, display and environment and robot body interaction, designs rich interfaces according to different task scenes, and has convenient self-definition and task-oriented selection function brought by structuring, thereby improving operability and expansibility.

Description

Underwater robot virtual environment simulation method based on layering ocean data

Technical Field

The invention belongs to the field of underwater robot simulation, and relates to an underwater robot virtual environment simulation method based on layered ocean data.

Background

Environmental simulation is a technique of symbolizing and abstracting a real environment in different media such as paper and electronics. Different from the traditional paper representation mode, along with the informatization development of environmental data acquisition, transmission and storage, digitization gradually becomes the main stream environmental simulation direction of the 21 st century. The digital environment simulation obtains environment data in the modes of satellite remote sensing, sonar detection and the like, processes the data by means of tools such as computer software and the like, realizes the visualization of the real environment, and finally presents a virtual real environment in a computer. The modeling method for researching the ocean environment can help sea staff, underwater robot developers and algorithm developers to better grasp the ocean environment, and can also reduce the thresholds for non-professional staff to know the ocean, know the ocean and apply the ocean.

However, the current virtual environment simulation technology mainly focuses on the aspect of topography, and the essence of the technology is to provide a proper environment for a virtual robot placed therein and a perception simulation related to the topography, however, the diversity and complexity of the ocean environment, such as illumination conditions, hydrodynamic conditions, electromagnetic environment conditions, and the like, cause the problems that the current technology is not accurate enough, the ocean environment cannot be switched, the simulation is not good under various sea conditions, and the like. Thus, there is currently a lack of a structural way to describe the different levels of marine environments and provide external perception emulation techniques for interfaces associated therewith.

In addition, the conventional virtual terrain simulation techniques are mainly divided into two types: one is to use three-dimensional drawing software to draw, and the modeling mode can create a marine model with any shape and condition, but has low construction efficiency, high threshold and is difficult to meet the requirement of testing real objects in the field; another method is to use real seabed data obtained by a sonar or other detection device or official published chart data to perform data encoding and decoding and type conversion. However, in the current practice process of the method, the problems of incapability of modifying the simulation interface by combining tasks, incapability of formatting modeling non-topographic information and the like exist. Therefore, when simulating the marine terrain environment, no modeling method which is easy to modify and is close to reality from each dimension exists at present.

Aiming at the problem that the external perception simulation technology is mainly focused on the aspect of topography, the UUV Simulator project in the EU sponsored SWARMS project provides richer but unstructured external perception simulation: hydrodynamic force simulation, visible light domain information obtained by virtual camera data, and the like.

Aiming at the current marine topography environment modeling mode, a three-dimensional topography and radar topography generation method based on S-57 electronic chart data is disclosed in China patent CN103456041A, a route II is adopted for research, partial steps from an S-57 chart to a digital elevation model are involved, wherein the use of the S-57 chart is still concentrated on topography, and other layers of information are drawn and included in a topography layer, so that task-oriented change is difficult and selective display cannot be carried out; the research carried out by the 'UNITY 3D-based underwater vehicle vision simulation system and method' adopts a first route, relates to sea chart construction by taking UNITY3D as a platform, has lower efficiency and does not have layering operation on different resources. External perception simulation aspects relate to external perception information such as elevation information, collision information and the like related to terrain, and also lack structural description of other types of information.

Disclosure of Invention

In view of the above, the invention aims to provide a method for simulating the virtual environment of an underwater robot by using structured and layered ocean data.

In order to achieve the above purpose, the present invention provides the following technical solutions:

an underwater robot virtual environment simulation method based on layering ocean data comprises the following steps:

s1: performing hierarchical editing treatment on the hierarchical ocean data source;

s2: importing the data subjected to layered processing into a virtual environment according to simulation requirements for environmental display, and providing a function of creating an environment layer by user definition;

s3: performing external perception simulation of the underwater robot based on hierarchical marine environment modeling;

s4: storing the generated perception analog value sub-modules into different module databases in a plug-in mode, and providing a function of custom creating perception modules;

s5: and adding each perception module in the module database into the underwater robot body module according to the requirements.

Furthermore, the hierarchical ocean data source has the hierarchical characteristic, the data of the hierarchical ocean data source comprises various information layers, the information layers have different types and characteristics according to the areas of the chart file, and the structured processing is convenient after the preprocessing.

Further, in the step S1, the specific steps of layering the layered marine data source are as follows:

s11: firstly, judging a task, if the task can utilize the existing function to perform layer processing, executing a step S12, otherwise, defining a new object type, writing a custom layer processing function according to the new object type, and storing the custom layer processing function into a function library;

s12: reading the object type and layer data;

s13: reading and splitting tasks according to object types, indexing the existing layer processing functions, and adopting corresponding layer processing functions for each layer;

s14: executing a corresponding layer processing function;

s15: and outputting the display information in the corresponding format.

Further, in the step S1, for the processing of the topographic layer, the layer processing function includes:

filtering and smoothing the region to reduce data errors;

cutting and editing the region to select the region in which the simulation is performed;

and performing region interpolation and fitting processing to fit coarse discrete values to continuous values to improve accuracy, and finally generating a digital elevation model format which can be imported into the virtual environment.

In step S2, the generated digital elevation model file and other preprocessed object type layers are simulated in layers, and the topographic information display layer is used as a base layer of other layers; the environment simulation part provides a new custom information display layer function, can custom add an information display layer for a user by taking a task as a guide, can also facilitate further processing of unusual or non-unified information layers, and provides the capability of integrating data from different sources; for each layer except the terrain layer, respectively executing corresponding processing operation according to the corresponding object type of each layer, and simulating and superposing the real object represented by each layer into the terrain layer; the hierarchy to be simulated is manually selected according to the requirements of different tasks; the mode of simulating and superposing the real objects is to introduce an external object library as a default example, so that discrete point information representing the positions of the real objects is added into the environment simulation; when other layers conflict with the content and range of the terrain layer, the method is to delete or ask the user how to deal with the conflict part of the other layers.

Further, in step S2, the environmental entity is divided into information display layers, each layer has different effects on the underwater robot, and in step S3, the different information display layers are subjected to perception simulation, which specifically includes the following steps:

s31: firstly, judging a task, if the task can perform perception simulation by using the existing function, executing a step S32, otherwise, defining an output perception module, defining input environment information, writing a custom perception simulation function, and storing the custom perception simulation function into a function library;

s32: reading environment information;

s33: indexing the existing perception simulation functions according to the environmental information, and adopting corresponding perception simulation functions for each layer;

s34: executing a corresponding perception simulation function;

s35: outputting to a corresponding sensing module;

s36: and performing sensing synthesis with other sensing values in the sensing module.

In step S3, the information display layers are respectively classified, the mapping relationship between the information display layers and the sensing module is not necessarily a single shot, each mapping relationship generates an influence vector, and finally, all influence vectors are calculated according to the output sensing module type to generate all final sensing module values.

Further, in the module database described in step S4, corresponding to the terrain layer being an environmental foundation layer, the collision detection module is a foundation module for simulating each module by external perception; the impact of other information display layers on the underwater robot is processed by a force sensing module, a vision/light sensing module, a sonar sensing module, an electromagnetic communication sensing module and a geomagnetic sensing module according to the categories of the impact; each module allows selective use of task guidance, has preset calculation parameters and supports modification, prioritizes base layer processing, and allows a user-defined module to guide tasks.

Further, a sonar sensing module, a geomagnetic sensing module, a visual sensing module and a light sensing module are provided for simulating the submarine topography matching navigation in the module database; providing an electromagnetic communication sensing module for simulating the underwater communication networking; and a hydrodynamic sensing module is provided for simulating and controlling the motion of the underwater robot.

The invention has the beneficial effects that: the method basically realizes the automation and structuring of environment information processing, display and environment and robot body interaction, designs rich interfaces according to different task scenes, has convenient self-definition and task-oriented selection functions by structuring, and has good operability and expandability.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and other advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the specification.

Drawings

For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in the following preferred detail with reference to the accompanying drawings, in which:

FIG. 1 is a diagram of the overall architecture of a simulation method of an underwater robot virtual environment based on layered ocean data according to the invention;

FIG. 2 is a flow chart of a layer processing method;

FIG. 3 is a flow chart of a perception modeling method.

Detailed Description

Other advantages and effects of the present invention will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present invention with reference to specific examples. The invention may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present invention. It should be noted that the illustrations provided in the following embodiments merely illustrate the basic idea of the present invention by way of illustration, and the following embodiments and features in the embodiments may be combined with each other without conflict.

Wherein the drawings are for illustrative purposes only and are shown in schematic, non-physical, and not intended to limit the invention; for the purpose of better illustrating embodiments of the invention, certain elements of the drawings may be omitted, enlarged or reduced and do not represent the size of the actual product; it will be appreciated by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.

The same or similar reference numbers in the drawings of embodiments of the invention correspond to the same or similar components; in the description of the present invention, it should be understood that, if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc., that indicate an azimuth or a positional relationship based on the azimuth or the positional relationship shown in the drawings, it is only for convenience of describing the present invention and simplifying the description, but not for indicating or suggesting that the referred device or element must have a specific azimuth, be constructed and operated in a specific azimuth, so that the terms describing the positional relationship in the drawings are merely for exemplary illustration and should not be construed as limiting the present invention, and that the specific meaning of the above terms may be understood by those of ordinary skill in the art according to the specific circumstances.

The invention aims to design a structured and layered underwater robot virtual environment simulation method.

The specific composition is shown in figure 1 and is divided into four major parts: hierarchical data sources-standardized chart, environment display module, perception module and data processing program. The data processing program comprises a layer processing program and a perception simulation program, and the internal structures of the data processing program are shown in fig. 2 and fig. 3 respectively.

On the marine environment data source, the definition of the standardized chart such as S-57 chart and the like of the layering data source has layering characteristics. As shown in the left box of fig. 1, it generally includes a depth information layer, a hydrologic information layer, and various information layers, and the layers included in the chart files of different areas often differ to some extent.

By utilizing the characteristics, layering processing is carried out on the layering data source by utilizing GIS software such as QGIS and the like, namely, a layering processing program is entered. As shown in fig. 2, task judgment is first performed, for performing layer processing tasks by using existing functions, the program reads and splits the tasks according to object types, and a corresponding layer processing function is adopted for each layer. For this sub-flow, it is particularly important that the basic functions provided for the processing of the topographic layer therein should be such that filtering and smoothing of the areas can be performed to prevent excessive errors in the topography from the poor quality chart; the cutting and editing of the region can be performed to improve the operation and the reading and writing speed; the region interpolation and fitting process is performed to fit the coarse discrete values to a better-resolved continuous value, ultimately producing a digital elevation model format that can be imported into the virtual environment. If more elaborate processing is required, more specialized three-dimensional modeling software may be resorted to.

And carrying out layer processing tasks on the custom new function, wherein a user can define a new object type, write the custom function according to the identification and store the custom function into a database.

The resulting digital elevation model file and other preprocessed object type layers are then imported hierarchically into simulation software such as Gazebo. Thereafter, the topographic information display layer will become the base layer for the other layers. As shown in the middle box of fig. 2, after simulation software such as Gazebo is introduced, corresponding processing operations are respectively executed according to the corresponding object type of each layer, and the real object represented by each layer is simulated and superimposed into the terrain layer. It should be noted that, the first hierarchy to be simulated may be manually selected according to the requirements of different tasks. For example, when only a water environment is involved, the land-based layers such as RAILWY (railway) need not be selected, but the layers such as LAKARE (Lake) need to be focused on. 2. The way to simulate and superimpose real objects is to introduce an external Gazebo object library as a default example, for example, the BRIDGE (bridge) layer can simulate by using a common standard bridge style, and align the data structure, the coordinate format and the content information with the coordinates in the terrain layer, so as to automatically and structurally simulate all the needed real terrain contents. Of course, if more realistically and personalizedly, the user may also import custom object files. 3. When other layers conflict with the content and range of the terrain layer, the method is to delete or ask the user how to deal with the conflict part of the other layers. 4. The environment simulation part provides a new custom information display layer function, can custom add an information display layer for a user by taking a task as a guide, can also facilitate further processing of unusual or non-unified information layers, and provides the capability of integrating data from different sources, and the requirement of timely and conveniently replacing the task guide simulation environment. For example, a preset barrier or a communication forbidden zone can be added on a newly built layer, and the entity can be added into the whole environment by opening the layer, so that the switching under different task scenes is facilitated.

The next step is the external perception simulation of the underwater robot based on the hierarchical marine environment modeling. As mentioned above, the environmental entity is partitioned into different levels, each level will have a different impact on the underwater robot. Thus, as shown in fig. 1, different information display layers are input to the perception simulator, the details of which are shown in fig. 3. Firstly, task judgment is carried out, for the task of perception simulation by using the existing function, the program reads and splits the task according to the environment information, and a corresponding perception simulation function is adopted for each layer.

For this sub-flow, it is particularly important that the mapping relationship between the information display layers and the sensing modules is not necessarily a single shot for the respective classification processing of the different information display layers, that is, one information display layer may affect different sensing modules, or a plurality of information display layers may affect the same sensing module, so each mapping relationship may generate an impact vector, and finally, all the impact vectors are calculated by corresponding calculation according to the output sensing module types, to generate all final sensing module values. And carrying out layer processing tasks on the custom new function, wherein a user can define the output perception module and the input environment information type, write the custom function according to the output perception module and the input environment information type, and store the custom function into a database.

The resulting perception module values are then stored in a plug-in form into different module databases. For a module database shown in the right frame of fig. 1, corresponding to the terrain layer being the foundation layer of each environment layer, the collision detection module is the foundation module of each module of the external perception simulation, which determines whether the simulation can be continued or not, and the basic implementation is to use a bounding box method to determine whether the terrain, the object and other robots are in the bounding box of the robot in the space. In addition to the collision detection module, the influence exerted by other information display layers on the underwater robot is processed by a force sensing module, a vision/light sensing module, a sonar sensing module, an electromagnetic communication sensing module, a geomagnetic sensing module and the like according to the categories of the influence. Notably, these modules employ design considerations and features similar to hierarchical modeling—allowing for selective use, preset computing parameters (water transparency, density, etc.), base layer, i.e. collision layer, preferential treatment, and task oriented customization of the modules. The above flow provides needed interfaces for different tasks, for example, a sonar sensing module, a geomagnetic sensing module and a vision/light sensing module are provided for simulating submarine topography matching navigation, and the method is mainly applied to a single robot and is used for providing the existence and corresponding simulation information of submarine topography detection and geomagnetic information of corresponding positions, and the method mainly depends on the relative positions and angles of a robot body and topography, illumination, depth and other factors; the electromagnetic communication sensing module is mainly applied to underwater robot clusters or underwater robot-satellite communication and is used for testing the communication state between the marked entities, and the communication state depends on the distance between the marked entities, the topography between the marked entities and the like; the hydrodynamic force sensing module is mainly applied to motion control projects and is used for providing mechanical effects such as heavy buoyancy and hydrodynamic correlation of water environment on the robot, and the hydrodynamic force sensing module is used for simulating and controlling the motion of the underwater robot and depends on factors such as the motion state of the robot body relative to water, the water density and ocean current conditions.

And finally, outputting each sensing module to the underwater robot body module according to the requirements. In summary, the method of the invention basically realizes the automation and structuring of environment information processing, displaying and environment and robot body interaction, designs rich interfaces according to different task scenes, and has convenient self-definition and task-oriented selection function brought by structuring, thus having good operability and expandability.

Finally, it is noted that the above embodiments are only for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications and equivalents may be made thereto without departing from the spirit and scope of the present invention, which is intended to be covered by the claims of the present invention.

Claims

1. An underwater robot virtual environment simulation method based on layering ocean data is characterized by comprising the following steps of: the method comprises the following steps:

s1: performing hierarchical editing treatment on the hierarchical ocean data source; in the step S1, the specific steps of performing hierarchical editing processing on the hierarchical ocean data source are as follows:

s12: reading the object type and layer data;

s14: executing a corresponding layer processing function;

s15: outputting display information in a corresponding format;

2. The method for simulating the virtual environment of the underwater robot based on the hierarchical ocean data according to claim 1, wherein the method comprises the following steps: the hierarchical ocean data source has the hierarchical characteristic, the data of the hierarchical ocean data source comprises various information layers, the information layers have different types and characteristics according to the areas of the chart file, and the structured processing is convenient after the preprocessing.

3. The method for simulating the virtual environment of the underwater robot based on the hierarchical ocean data according to claim 1, wherein the method comprises the following steps: in the step S1, for the processing of the topographic layer, the layer processing functions include:

filtering and smoothing the region to reduce data errors;

the region interpolation and fitting process is performed to fit coarse discrete values to continuous values to improve accuracy, ultimately producing a digital elevation model format that can be imported into the virtual environment.

4. The method for simulating the virtual environment of the underwater robot based on the hierarchical ocean data according to claim 1, wherein the method comprises the following steps: in the step S2, the generated digital elevation model file and other preprocessed object type layers are simulated in layers, and the topographic information display layer is used as a base layer of other layers; the environment simulation part provides a new custom information display layer function, allows a user to custom add an information display layer by taking a task as a guide, further processes unusual or non-uniformly processed information layers, and provides the capability of integrating data from different sources; for each layer except the terrain layer, respectively executing corresponding processing operation according to the corresponding object type of each layer, and simulating and superposing the real object represented by each layer into the terrain layer; the hierarchy to be simulated is manually selected according to the requirements of different tasks; the mode of simulating and superposing the real objects is to introduce an external object library as a default example, so that discrete point information representing the positions of the real objects is added into the environment simulation; when other layers conflict with the content and range of the terrain layer, the method is to delete or ask the user how to deal with the conflict part of the other layers.

5. The method for simulating the virtual environment of the underwater robot based on the hierarchical ocean data according to claim 1, wherein the method comprises the following steps: in the step S2, the environmental entity is divided into information display layers, each layer has different effects on the underwater robot, and in the step S3, the different information display layers are subjected to perception simulation, which specifically comprises the following steps:

s32: reading environment information;

s34: executing a corresponding perception simulation function;

s35: outputting to a corresponding sensing module;

6. The method for simulating the virtual environment of the underwater robot based on the hierarchical ocean data according to claim 1, wherein the method comprises the following steps: in step S3, the information display layers are respectively classified, the mapping relationship between the information display layers and the sensing module is not necessarily a single shot, each mapping relationship generates an influence vector, and finally, all influence vectors are calculated according to the output sensing module type to generate final all sensing module values.

7. The method for simulating the virtual environment of the underwater robot based on the hierarchical ocean data according to claim 1, wherein the method comprises the following steps: in the module database in step S4, the collision detection module is a basic module of each module for external perception simulation; the impact of other information display layers on the underwater robot is processed by a force sensing module, a vision/light sensing module, a sonar sensing module, an electromagnetic communication sensing module and a geomagnetic sensing module according to the categories of the impact; each module allows selective use of task guidance, has preset calculation parameters and supports modification, prioritizes base layer processing, and allows a user-defined module to guide tasks.

8. The method for simulating the virtual environment of an underwater robot based on hierarchical ocean data according to claim 7, wherein: the module database provides a sonar sensing module, a geomagnetic sensing module, a visual sensing module and a light sensing module for simulating the matching navigation of the submarine topography; providing an electromagnetic communication sensing module for simulating the underwater communication networking; and a hydrodynamic sensing module is provided for simulating and controlling the motion of the underwater robot.