Unmanned ship self-positioning method using radar response object

Abstract

The invention provides an unmanned ship autonomous positioning method using a radar response mark, and the method comprises the steps: inputting the position information of an existing radar navigation mark, and building a radar navigation mark library; identifying a navigation mark in the obtained radar image, and matching the navigation mark with a navigation mark in a navigation mark library; converting radar navigation mark data into a global coordinate system; and estimating the position of the unmanned ship according to the successfully matched navigation mark prior information in the radar navigation mark library and the converted radar real-time data. The device used in the invention is the marine radar, the existing radar navigation mark in the surrounding environment is mainly used as an auxiliary object mark, the position of the unmanned ship is calculated by identifying the radar navigation mark reference on the radar image, and the autonomous positioning capability of the unmanned ship is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of autonomous positioning of unmanned boats, and in particular to an autonomous positioning method of an unmanned boat using a radar transponder beacon. Background Art

[0002] Due to its high intelligence and potential application value, the relevant research on autonomous unmanned boats has received very high attention in the industry. However, autonomous unmanned boats may also face extremely complex external navigation environments, including a variety of obstacles, and moving targets of different types, sizes and speeds, and the surrounding environment changes in real time. Since the sensors used by unmanned boats to perceive the external environment, such as navigation radar and millimeter-wave radar measurement data, are all relative data, the calculation of the actual position of the target needs to rely on the position, attitude and heading of the unmanned boat itself. At present, unmanned boats mainly rely on the global positioning system to obtain their own position and heading. The system may have the following problems in actual operation:

[0003] 1. In an environment with many large-scale buildings and facilities such as ports, the positioning accuracy will be greatly affected due to the influence of multi-path signal propagation;

[0004] 2. When the unmanned boat is sailing at a low speed, the heading estimation error is large;

[0005] 3. Unmanned boats tend to become overly dependent on the global positioning system. In extreme cases, when the global positioning system malfunctions, the autonomous navigation capability deteriorates.

[0006] Therefore, it is necessary to study other means to enable unmanned boats to locate themselves independently in addition to the global positioning system. Summary of the invention

[0007] According to the technical problems raised above, a method for autonomous positioning of an unmanned boat using a radar transponder beacon is provided. The present invention mainly uses a marine radar, and uses the existing radar beacons in the surrounding environment as auxiliary objects to infer the position of the unmanned boat by identifying the radar beacon on the radar image, thereby improving the autonomous positioning capability of the unmanned boat.

[0008] The technical means adopted by the present invention are as follows:

[0009] A method for autonomous positioning of an unmanned boat using a radar transponder beacon, comprising:

[0010] Input the existing radar beacon location information and establish a radar beacon database;

[0011] S2, identifying the navigation mark in the acquired radar image and matching it with the navigation mark in the navigation mark library established in S1;

[0012] S3, transforming the radar navigation data in S2 into the global coordinate system;

[0013] S4, based on the navigation mark prior information in the radar navigation mark library successfully matched in S2 and the radar real-time data converted in S3, the position of the unmanned boat is estimated.

[0014] Furthermore, the step S1 specifically includes:

[0015] Define the state of the unmanned boat at time k:

[0016]

[0017] in, are the positions of the unmanned boat on the x-axis and y-axis in the rectangular coordinate system.

[0018] Furthermore, the step S2 specifically includes:

[0019] Select the beacon that is within the radar range at time k from the radar beacon database, denoted as {Racon k}, identify the radar beacon echo from the radar echo image, and compare it with the selected beacon {Racon k}match;

[0020] Assuming that there are N pairs of successfully matched radar beacons, the radar measurement information corresponding to the beacon echo is extracted from the radar image and recorded as is the distance of the radar echo corresponding to the i-th beacon, is the azimuth of the radar echo corresponding to the i-th beacon, i=1,…N; the actual position of the i-th beacon recorded in the radar beacon database is

[0021] Furthermore, the step S3 specifically includes:

[0022] Based on the measurement information generated by N radar beacons extracted at time k in S2 The radar measurement information defined in polar coordinates is converted through coordinate conversion Converted to the rectangular coordinate system, the converted radar measurement information is expressed as:

[0023]

[0024] in, is the component of the converted radar measurement information in the x-axis direction in the global coordinate system, is the component of the converted radar measurement information in the y-axis direction in the global coordinate system;

[0025] The raw radar data is transformed into the global coordinate system by first rotating and then translating:

[0026]

[0027] Among them, θ k is the heading of the unmanned boat at time k.

[0028] Furthermore, the step S4 specifically includes:

[0029] Using each group of successfully matched radar beacons A i And the corresponding converted radar measurement information The position of the unmanned boat is deduced;

[0030] The converted radar data and the radar beacon position data in the beacon library are defined in the same coordinate system, and the following is obtained:

[0031]

[0032] The calculation formula of the unmanned boat position is:

[0033]

[0034] in, Represents the estimated value of the unmanned boat based on the i-th group of matched radar beacons and radar data; since there are N groups of successfully matched data at time k, the final estimated value of the unmanned boat position is the weighted average of the estimated values ​​calculated based on each beacon

[0035]

[0036] Among them, the weight w i Depends on the distance between the i-th beacon and the unmanned boat;

[0037]

[0038] Among them, d i Represents the distance between the i-th beacon and the unmanned boat.

[0039] Compared with the prior art, the present invention has the following advantages:

[0040] The present invention provides an autonomous positioning method for unmanned boats using radar transponder beacons, which solves the problem of autonomous positioning of unmanned boats. The present invention uses a marine radar, which mainly uses existing radar beacons in the surrounding environment as auxiliary objects, and calculates the position of the unmanned boat by identifying the radar beacons on the radar image, thereby improving the autonomous positioning capability of the unmanned boat.

[0041] The present invention provides an autonomous positioning method for an unmanned boat using a radar transponder beacon. A radar beacon is also called a radar transponder beacon or a radar beacon. It is a radio navigation device used in conjunction with a marine radar and is generally installed on islands, reefs, underwater buildings, lightships and other objects. The advantage of the present invention is that it makes full use of the identifiable and easy-to-identify characteristics of the radar beacon on the marine radar image, studies an additional autonomous positioning method for unmanned boats in addition to the global positioning system, and improves the autonomy and navigation safety of the unmanned boat.

[0042] Based on the above reasons, the present invention can be widely promoted in the fields of autonomous positioning of unmanned boats and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0044] Figure 1 This is a schematic diagram of the principle of the autonomous positioning method for an unmanned boat using a radar transponder beacon according to the present invention.

[0045] Figure 2 It is a schematic diagram of positioning an unmanned boat using a radar beacon in an embodiment of the present invention.

[0046] Figure 3 This is a diagram showing the positioning error of an unmanned boat using a radar beacon in an embodiment of the present invention. DETAILED DESCRIPTION

[0047] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0048] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0049] like Figure 1 As shown, the present invention provides an autonomous positioning method for an unmanned boat using a radar transponder beacon, comprising:

[0050] S1. Input the existing radar beacon location information and establish a radar beacon database;

[0051] In specific implementation, as a preferred embodiment of the present invention, the step S1 specifically includes:

[0052] Define the state of the unmanned boat at time k:

[0053]

[0054] in, are the positions of the unmanned boat on the x-axis and y-axis in the rectangular coordinate system.

[0055] S2, identifying the navigation mark in the acquired radar image and matching it with the navigation mark in the navigation mark library established in S1;

[0056] In specific implementation, as a preferred embodiment of the present invention, step S2 specifically includes:

[0057] Select the beacon that is within the radar range at time k from the radar beacon database, denoted as {Racon k}, identify the radar beacon echo from the radar echo image, and compare it with the selected beacon {Racon k}match;

[0058] Assuming that there are N pairs of successfully matched radar beacons, the radar measurement information corresponding to the beacon echo is extracted from the radar image and recorded as is the distance of the radar echo corresponding to the i-th beacon, is the azimuth of the radar echo corresponding to the i-th beacon, i=1,…N; the actual position of the i-th beacon recorded in the radar beacon database is

[0059] S3, transforming the radar navigation data in S2 into the global coordinate system;

[0060] In specific implementation, as a preferred embodiment of the present invention, step S3 specifically includes:

[0061] Based on the measurement information generated by N radar beacons extracted at time k in S2 The radar measurement information defined in polar coordinates is converted through coordinate conversion Converted to the rectangular coordinate system, the converted radar measurement information is expressed as:

[0062]

[0063] in, is the component of the converted radar measurement information in the x-axis direction in the global coordinate system, is the component of the converted radar measurement information in the y-axis direction in the global coordinate system;

[0064] The raw radar data is transformed into the global coordinate system by first rotating and then translating:

[0065]

[0066] Among them, θ k is the heading of the unmanned boat at time k. It can be obtained through the compass.

[0067] S4, based on the navigation mark prior information in the radar navigation mark library successfully matched in S2 and the radar real-time data converted in S3, the position of the unmanned boat is estimated.

[0068] In specific implementation, as a preferred embodiment of the present invention, step S4 specifically includes:

[0069] Using each group of successfully matched radar beacons A i And the corresponding converted radar measurement information The position of the unmanned boat is deduced;

[0070] The converted radar data and the radar beacon position data in the beacon library are defined in the same coordinate system, and the following is obtained:

[0071]

[0072] The calculation formula of the unmanned boat position is:

[0073]

[0074] in, Represents the estimated value of the unmanned boat based on the i-th group of matched radar beacons and radar data; since there are N groups of successfully matched data at time k, the final estimated value of the unmanned boat position is the weighted average of the estimated values ​​calculated based on each beacon

[0075]

[0076] Among them, the weight w i It depends on the distance between the i-th beacon and the unmanned boat. The closer the distance, the higher the weight.

[0077]

[0078] Among them, d i Represents the distance between the i-th beacon and the unmanned boat.

[0079] During implementation, since the radar data of close-range targets has higher accuracy, the closer the distance between the beacon and the unmanned boat, the higher the weight.

[0080] Example

[0081] like Figure 1 As shown, the present invention provides an autonomous positioning method for an unmanned boat using a radar transponder beacon, referring to the attached Figure 2 In this embodiment, the speed of the unmanned boat is set to 10 knots, the heading is 45 degrees, and the radar beacon is located at (1000, 1000). The rotation speed of the marine radar antenna is 24 revolutions per minute (the corresponding scanning period is 2.5 seconds). The measurement errors of the distance and azimuth are assumed to obey Gaussian distribution, and their standard deviations are 20 meters and 0.5 degrees respectively. In each scanning period, the positioning of the unmanned boat is carried out according to the following three steps.

[0082] First, radar beacon identification, matching and location information extraction are performed. All radar beacons are identified from the acquired radar image, and the distance and azimuth corresponding to the beacon are extracted, which are recorded as

[0083] Then the radar data coordinate conversion is realized. Referring to formula (1), the original radar data is converted to the global coordinate system by first rotating and then translating, and the converted radar measurement is obtained as

[0084] Finally, the position of the unmanned boat is estimated. i And its corresponding converted radar data The position of the unmanned boat can be estimated.

[0085] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0086] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0087] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0088] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0089] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0090] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk and other media that can store program codes.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for autonomous positioning of an unmanned boat using a radar transponder beacon, characterized in that: include: S1. Input the existing radar beacon location information and establish a radar beacon database; S2, identifying the navigation mark in the acquired radar image and matching it with the navigation mark in the navigation mark library established in S1; S3, transforming the radar navigation data in S2 into the global coordinate system; S4, based on the navigation mark prior information in the radar navigation mark library successfully matched in S2 and the radar real-time data converted in S3, the position of the unmanned boat is estimated.

2. The autonomous positioning method for an unmanned boat using a radar transponder according to claim 1, characterized in that: The step S1 specifically includes: Define the state of the unmanned boat at time k: in, are the positions of the unmanned boat on the x-axis and y-axis in the rectangular coordinate system.

3. The autonomous positioning method for an unmanned boat using a radar transponder according to claim 1, characterized in that: The step S2 specifically includes: Select the beacon that is within the radar range at time k from the radar beacon database, denoted as {Racon k }, identify the radar beacon echo from the radar echo image, and compare it with the selected beacon {Racon k }match; Assuming that there are N pairs of successfully matched radar beacons, the radar measurement information corresponding to the beacon echo is extracted from the radar image and recorded as is the distance of the radar echo corresponding to the i-th beacon, is the azimuth of the radar echo corresponding to the i-th beacon, i=1,…N; the actual position of the i-th beacon recorded in the radar beacon database is 4. The autonomous positioning method for an unmanned boat using a radar transponder according to claim 1, characterized in that: The step S3 specifically includes: Based on the measurement information generated by N radar beacons extracted at time k in S2 The radar measurement information defined in polar coordinates is converted through coordinate conversion Converted to the rectangular coordinate system, the converted radar measurement information is expressed as: in, is the component of the converted radar measurement information in the x-axis direction in the global coordinate system, is the component of the converted radar measurement information in the y-axis direction in the global coordinate system; The raw radar data is transformed into the global coordinate system by first rotating and then translating: Among them, θ k is the heading of the unmanned boat at time k.

5. The autonomous positioning method for an unmanned boat using a radar transponder according to claim 1, characterized in that: The step S4 specifically includes: Using each group of successfully matched radar beacons A i And the corresponding converted radar measurement information The position of the unmanned boat is deduced; The converted radar data and the radar beacon position data in the beacon library are defined in the same coordinate system, and the following is obtained: The calculation formula of the unmanned boat position is: in, Represents the estimated value of the unmanned boat based on the i-th group of matched radar beacons and radar data; since there are N groups of successfully matched data at time k, the final estimated value of the unmanned boat position is the weighted average of the estimated values ​​calculated based on each beacon Among them, the weight w i Depends on the distance between the i-th beacon and the unmanned boat; Among them, d i Represents the distance between the i-th beacon and the unmanned boat.

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