CN112698273B - A collaborative operation method for multi-AUV single-marker ranging - Google Patents

Abstract

The invention discloses a collaborative operation method for multi-AUV single-marker ranging. and initialize its own position; confirm the working area of each AUV, and complete the scanning task of the target area in a circular maneuver; each AUV completes the operation and returns, extracts the data in each AUV and splices it to generate the final complete result . The present invention uses distance information as the benchmark for collaborative operation, the AUV carries few sensors, and does not need to measure the speed information of the operating AUV, and can be applied to AUV scenarios without speed measuring sensors such as large water depths.

Description

A collaborative operation method for multi-AUV single-marker ranging

technical field

The invention relates to a collaborative operation method for multi-AUV single-marker ranging, in particular to a multi-AUV collaborative operation method based on ranging information between AUVs and a single acoustic beacon, belonging to a multi-intelligent underwater vehicle (Autonomous Underwater Vehicle, AUV) underwater collaboration field.

Background technique

The refined detection and scanning of the sea area is a necessary step for the development of marine resources. Compared with surface ships, AUVs have the advantages of being closer to the detected area and having higher accuracy when performing deep-water detection tasks, and at the same time, they do not require personnel to be on duty to save labor costs. Due to the serious attenuation of electromagnetic waves underwater, the mature electromagnetic wave-based positioning and communication systems cannot work effectively underwater. The inherent high latency and low bandwidth limitations of underwater acoustic technology make it impossible for AUVs to directly utilize the mature technology of drones and unmanned vehicles.

Compared with the traditional long baseline, the single beacon positioning technology has a shorter time in the beacon preparation stage, and has higher positioning accuracy than the ship-borne ultra-short baseline system in deep sea operations. The multi-AUV cooperative operation method based on single beacon ranging uses the distance information between the beacon and the AUV to complete the position initialization and delineate the operation area and operation path of each AUV. The single beacon positioning technology can be used to obtain speed in the situation where the DVL cannot be used. The water area completes the scanning task of the operation area. Compared with the existing AUV collaborative methods such as patent number CN111535348A, the name is a master-slave collaborative positioning method of an autonomous underwater vehicle integrated navigation system, but this method requires the use of AUV speed information, patent number CN109596128A, named as a A method based on multiple hydrophones to improve the performance of multi-AUV co-location, but this method needs to use multiple hydrophones.

SUMMARY OF THE INVENTION

Aiming at the above-mentioned prior art, the technical problem to be solved by the present invention is to provide a collaborative operation method for multi-AUV single-marker ranging that does not require speed assistance and that AUVs only need to be equipped with a single hydrophone.

In order to solve the above-mentioned technical problem, a kind of cooperative operation method of multi-AUV single-marker ranging of the present invention is characterized in that, comprises the following steps:

Step 1: Determine the operation area to be scanned, place the beacon at the center of the area, calibrate the beacon, determine the position (x _b , y _b , z _b ) and the depth information d _b of the beacon in the geodetic coordinate system, At the same time, establish the navigation coordinate system with the beacon as the origin O and determine the conversion relationship between the navigation coordinate system and the geodetic coordinate system;

Step 2: The m operating AUVs are respectively numbered as AUV1, AUV2...AUVn...AUVm, n∈[1,m], and the AUV clusters approach the operation area in a fixed-depth navigation manner, while keeping each AUV at different depths In order to prevent collisions between AUVs, the AUV communicates with the beacon and measures the distance L between itself and the beacon. The AUV searches for the direction in which the distance L decreases the fastest through maneuvering, and travels in this direction to the location of the beacon. The projection position of the plane where it is located. At this time, the position of the initialized AUV is (0, 0);

Step 3: After completing the position initialization, the AUV divides the operation area according to the operation requirements, uses the single beacon positioning and navigation technology to provide positioning and navigation for itself in the navigation coordinate system, and drives to the operation area in a fixed-depth straight line navigation;

Step 4: After the AUV arrives at the operation area, record the coordinates of the starting point of the operation, use the circular motion with the beacon projection point as the origin to scan the area and record the data in the memory, and use the single beacon positioning technology to record each AUV. The position information in the navigation coordinate system at the moment;

Step 5: Extract the recorded scan data, splicing the scan data based on the positioning information to obtain the scan result of the positive film area, and convert the data as a whole to the geodetic coordinate system to obtain the scan data corresponding to the geodetic coordinate.

The present invention also includes:

1. Step 2 specifically includes the following steps:

Step 2.1: The depth difference between the depth d _n where the nth AUVn is located and the beacon Δd _n =d _b -d _n , the distance L _n1 between the AUVn and the beacon at time t ₀ calculates its horizontal distance

Step 2.2: AUVn maintains a fixed-depth straight line navigation, the distance between the AUV and the beacon at time _t1 is L _n1 , and the horizontal distance is

Step 2.3: After the AUVn turns to the bow angle θ, it maintains a fixed depth and straight line navigation. The distance between the AUV and the beacon at time _t2 is L _n2 , and its horizontal distance is

Step 2.4: Determine the position of the AUVn according to L _n0s , L _n1s , and L _n2s to initialize the maneuvering mode, so that it sails in the direction close to the beacon until it reaches the projection position of the beacon on the plane where the AUV is located;

Step 2.5: After the AUV arrives at the position of the beacon projection point, initialize its own position to (0, 0).

2. In step 2.4, according to L _n0s , L _n1s , and L _{n2s to} determine the position of the AUVn, the initial maneuvering method is as follows:

(1) Adjust the heading direction of the AUV so that the AUV sails in the direction close to the beacon, specifically:

If L _n1s >L _n1s >L _n2s , it means that the AUV is getting closer and closer to the position of the beacon, and the bow continues to turn at this time;

If L _n1s >L _n1s , L _n1s <L _n2s , it means that the AUV first approaches the beacon and then moves away from the beacon, and then turns in the opposite direction until the distance from the beacon becomes smaller again;

If L _n1s <L _n1s <L _n2s , it indicates that the AUV is getting farther and farther away from the position of the beacon, and at this time, the bow continues to turn until the distance between the AUV and the beacon decreases;

If L _n1s <L _n1s , L _n1s >L _n2s , it means that the AUV first moved away from the beacon and then approached the beacon. At this time, continue to turn the bow to observe whether the AUV continues to approach the beacon.

(2) After adjusting the AUV heading, adjust the AUV maneuvering method according to the ranging information to keep it close to the beacon, specifically:

When the AUV determines that the AUV itself is sailing towards the beacon position, it determines whether the AUV is oversteering by determining the speed at which the distance between the AUV and the beacon decreases in the adjacent Δt time period, specifically: assuming that the adjacent time periods Δt ₁ and Δt ₁ The distance between the AUV and the beacon decreases by Δl ₀ and Δl ₁ , respectively:

If Δl ₀ >Δl ₁ , it means that the speed of decreasing the distance between the AUV and the beacon becomes slower, that is, oversteering, and turning in the opposite direction;

If Δl ₀ <Δl ₁ , it indicates that the distance between the AUV and the beacon decreases faster, and at this time, the AUV can continue to turn in order to get closer to the beacon to complete the initialization process.

Beneficial effects of the present invention: The present invention uses distance information as a benchmark for collaborative operation, and the AUV carries few sensors, so there is no need to measure the speed information of the operating AUV, and it can be applied to AUV scenarios without speed measuring sensors such as large water depths. The method includes: deploying and calibrating beacons, and establishing a navigation coordinate system with the beacon as a far point; the AUV uses the ranging information to navigate to the projected position of the beacon at the current depth, and initializes its own position; confirming the working area of each AUV , complete the scanning task of the target area in a circular maneuver; each AUV completes the operation and returns, extracts the data in each AUV and splices it to generate the final complete result. The invention provides a multi-AUV cooperative operation method based on a single acoustic beacon. The method uses a single beacon positioning technology to realize positioning and navigation for AUVs, and adopts a concentric ring operation method with a beacon as the origin to realize the target area. collaborative scanning. This system can be based on underwater fixed beacons, or can use AUVs with self-positioning capabilities as beacons to provide operational benchmarks for AUV clusters. In this method, the operation AUV does not need to carry complex underwater equipment such as DVL, USBL, etc., and the entire scanning task can be completed by using the distance information between the beacon and the beacon combined with its own heading, which can greatly save the layout cost of the entire operation AUV system. At the same time, this method can also use Kalman filter, particle filter and other data fusion algorithms to achieve data fusion of other systems such as inertial navigation systems to improve its own positioning and operation accuracy, and has good expansion compatibility with other positioning and navigation systems. .

Description of drawings

Fig. 1 is the flow chart of the present invention;

Figure 2 is a schematic diagram of beacon calibration;

3 is a schematic diagram of a navigation coordinate system;

Fig. 4 is the horizontal plane schematic diagram of position initialization;

Fig. 5 is the vertical plane schematic diagram of position initialization;

Figure 6 is a schematic diagram of initial maneuvering direction determination;

FIG. 7 is a schematic diagram of the maneuvering mode of position initialization;

FIG. 8 is a schematic diagram of an AUV scanning operation mode.

Detailed ways

The specific embodiments of the present invention will be further described below with reference to the accompanying drawings.

The invention uses the deployed and calibrated beacon as the origin to establish the navigation coordinate system, establishes communication between the AUV and the beacon and measures the relative distance, and the AUV uses the distance information to complete the position initialization. AUV uses the single beacon positioning technology to provide positioning for itself, and makes circular motions with the beacon as the origin in the working area to scan the respective target areas and record them in the local memory. After each AUV operation is completed, it returns to the ship, and extracts the data and splices it into a complete scanning result, so as to realize the scanning operation of the entire target area.

Based on the distance information between the AUV and a single acoustic beacon, the present invention provides a set of multi-AUV cooperative area scanning methods, and the implementation is as follows:

1. Deploy acoustic beacons and perform location calibration, including the beacon's latitude, longitude and depth information. The navigation coordinate system is established with the acoustic beacon as the origin.

2. The AUV cluster obtains communication with the beacon and moves to the location of the beacon. When the AUV arrives directly above the beacon, the position of the AUV is initialized to (0, 0), that is, at the origin of the navigation coordinate system.

3. Each AUV drives to the operation area according to the operation requirements, and uses the distance and heading information to calculate its own position information during the travel process, and records its own position when the AUV arrives at the starting point of the operation area.

4. The AUV maneuvers around the beacon circular path, scans the seabed and records the information locally. When the scanning of the entire operation area is completed, the AUV returns to the predetermined recovery point for recovery. The entire seabed can be obtained by summarizing the scanning results of each AUV. scan results.

Detailed steps include:

Step 1: Determine the operation area to be scanned, place the beacon at the center of the area, use the shipborne equipment such as the ultra-short baseline system to calibrate the beacon, and determine the position of the beacon in the geodetic coordinate system (x _b , y _b , z _b ) and depth information d _b , establish a navigation coordinate system with the beacon as the origin O at the same time, and determine the conversion relationship between the navigation coordinate system and the geodetic coordinate system.

Step 2, the m operating AUVs are respectively numbered as AUV1, AUV2...AUVn...AUVm. The AUV cluster approaches the operation area by means of fixed-depth navigation, while keeping each AUV at different depths to prevent collisions between AUVs. , the AUV communicates with the beacon and measures the distance L between itself and the beacon. The AUV searches for the direction in which the distance L decreases the fastest by maneuvering, and travels in this direction to reach the projected position of the beacon position on the plane where the AUV is located. At this time, the position of the initial AUV is (0, 0). Specifically include:

(1) The depth difference between the depth dn where the nth AUVn is located and the beacon Δd _n =d _b -d _n , the distance L _n1 between the AUVn and the beacon at time t ₀ calculates its horizontal distance

(2) The AUVn maintains a fixed-depth straight line navigation, the distance between the AUV and the beacon at time _t1 is L _n1 , and the horizontal distance is

(3) After the AUVn turns to the bow angle θ, it maintains a fixed-depth straight line navigation, the distance between the AUV and the beacon at time _t2 is L _n2 , and the horizontal distance is

(4) Determine the initial maneuvering mode of the AUVn according to L _n1s , L _n1s , and L _n2s , so that it sails in the direction close to the beacon until it reaches the projection position of the beacon on the plane where the AUV is located.

(5) After the AUV arrives at the position of the beacon projection point, initialize its own position to (0, 0).

Step 3: After completing the position initialization, the AUV divides the operation area according to the operation requirements, uses the single beacon positioning and navigation technology to provide positioning and navigation for itself in the navigation coordinate system, and drives to the operation area in a fixed-depth straight line navigation.

Step 4: After the AUV arrives at the operation area, record the coordinates of the starting point of the operation, use the circular motion with the beacon projection point as the origin to scan the area and record the data in the AUV's own memory, and use the single beacon positioning technology to record The position information of the AUV in the navigation coordinate system at each moment, when the operation is completed, it will go up and return by itself.

Step 5: After the AUV returns home, extract all the scanned data recorded by the AUV, splicing the scanned data based on the positioning information, and finally obtain the scanning result of the positive area, and convert the data as a whole to the geodetic coordinate system, which finally corresponds to the geodetic coordinate scan data.

In conjunction with Fig. 1, the specific embodiment of the present invention is as follows:

Step 1: Determine the operation area to be scanned, place the beacon at the center of the area, and use the shipborne equipment such as the ultra-short baseline system to calibrate the beacon. As shown in Figure 2, determine the position of the beacon in the geodetic coordinate system (x _b , y _b , z _b ) and depth information _db , the calibration process can use multiple multi-point measurements to improve the calibration accuracy, and at the same time establish a navigation coordinate system with the beacon as the origin O as shown in Figure 3 and determine the navigation coordinate system The transformation relationship with the geodetic coordinate system.

Step 2: After the beacon calibration is completed, the AUV is deployed into the operation area. After the AUV and the beacon obtain communication, the distance measurement is performed, and the position initialization process of the AUV as shown in Figure 4 and Figure 5 is started. Each AUV is at different depths and maneuvers in the direction of the beacon according to the ranging results.

The specific process is shown in Figure 6 and Figure 7:

(1) Calculate the horizontal distance L _n0s between the AUVn and the beacon at time t ₀ .

(2) Time Δt of AUV straight-line fixed-depth navigation, and calculate the distance L _n1s between AUVn and the beacon at time t ₁ .

(3) After the AUV turns the bow at a certain angle θ, it maintains a fixed-depth straight line navigation for Δt time, and calculates the distance L _n2s between the AUVn and the beacon at time t ₂ .

(4) According to L _n1s , L _n1s , and L _n2s , determine whether the initial turning direction of the AUVn is the direction close to the beacon, and formulate the initial maneuvering method of the AUV:

If L _n1s >L _n1s >L _n2s , it indicates that the AUV is getting closer and closer to the position of the beacon, and at this time, the bow continues to turn.

If L _n1s >L _n1s , L _n1s <L _n2s , it means that the AUV first approaches the beacon and then moves away from the beacon, and then turns in the opposite direction until the distance from the beacon becomes smaller again.

If L _n1s <L _n1s <L _n2s , it indicates that the AUV is getting farther and farther away from the position of the beacon, and at this time, the bow continues to turn until the distance between the AUV and the beacon decreases.

If L _n1s <L _n1s , L _n1s >L _n2s , it means that the AUV first moved away from the beacon and then approached the beacon. At this time, continue to turn the bow to observe whether the AUV continues to approach the beacon.

(5) After the AUV determines that the AUV is sailing towards the beacon position through the process (4), the maneuvering method as shown in FIG. 6 is adopted. By determining the speed at which the distance between the AUV and the beacon decreases within the adjacent Δt time, it is determined whether the AUV is oversteering. Assuming that the distance between the AUV and the beacon decreases by Δl ₀ and Δl ₁ in the adjacent time periods Δt ₁ and Δt ₁ , respectively:

If Δl ₀ >Δl ₁ , it indicates that the speed of decreasing the distance between the AUV and the beacon has slowed down, that is, the steering is over-steered and needs to be turned in the opposite direction.

If Δl ₀ <Δl ₁ , it indicates that the distance between the AUV and the beacon decreases faster, and at this time, the AUV can continue to turn in order to get closer to the beacon to complete the initialization process.

In the process of the AUV approaching the beacon, the speed of the AUV is gradually reduced according to the decrease of the absolute distance between the AUV and the beacon to prevent the AUV from navigating near the beacon and unable to approach the beacon accurately due to the fast speed of the AUV.

(6) After the AUV arrives at the position of the beacon projection point, it initializes its own position to (0, 0), and completes the entire initialization process.

Step 3: Allocate the operation area of each AUV, based on the sailing distance of each AUV when the scanning is completed, and strive to ensure that the operation range of each AUV is consistent under the premise of ensuring that the operation area is completely covered, so as to be recycled in batches after the operation is completed, and at the same time avoid individual AUVs. Excessive AUV operation travel leads to problems such as insufficient energy.

Step 4, after the AUV arrives at the operation area, record the coordinate position of its operation starting point in the navigation coordinate system and start the scanning operation. The operation mode of AUV is shown in Figure 8. It scans the operation area by means of fixed-depth circular motion. During the operation, the distance-based single beacon positioning method is used to determine its own position and correct its own motion trajectory. The AUV records the scan data and the corresponding position information in its own memory. After the AUV completes the task of scanning the area, it can go to the target point of the next task or directly return to the home for recovery as required.

Step 5: After the AUV returns home, extract the scan data stored in the AUV, stitch the scan data into a complete area scan result according to the positional relationship in the navigation coordinate system, and convert the result to the earth according to the conversion relationship between the navigation coordinate system and the geodetic coordinate system. In the coordinate system, the construction of the entire scan result map is completed.

Claims (2)

1. A multi-AUV single-standard distance measurement cooperative operation method is characterized by comprising the following steps:

step 1: determining the operation area to be scanned, putting a beacon at the central position of the area, calibrating the beacon, and determining the position (x) of the beacon in a geodetic coordinate system _b ,y _b ,z _b ) And depth information d _b Meanwhile, establishing a navigation coordinate system with the beacon as an origin O and determining a conversion relation between the navigation coordinate system and a geodetic coordinate system;

step 2: the m operation AUVs are numbered AUV1, AUV2 … AUVn … AUVm, n belongs to [1, m ], an AUV cluster approaches to an operation area in a depth-fixed navigation mode, and simultaneously keeps the AUVs at different depths to prevent collision accidents among the AUVs, the AUVs are communicated with beacons and measure the distance L between the AUVs and the beacons, the AUVs search the direction in which the distance L is reduced most quickly through maneuvering navigation, and the AUV drives to the direction to reach the projection position of the beacon on the plane of the AUV, wherein the position of the initialized AUV is (0,0), and the method specifically comprises the following steps:

step 2.1: depth d of No. n AUVn _n Depth difference Δ d from the beacon _n ＝d _b -d _n 、t ₀ Distance between time AUVn and beaconIs far from L _n0 Calculating its horizontal distance

Step 2.2: AUVn keeping straight line navigation at fixed depth, t ₁ Distance between time AUV and beacon is L _n1 At a horizontal distance of

Step 2.3: keeping straight line navigation at constant depth after AUVn changes bow angle theta, t ₂ Distance between time AUV and beacon is L _n2 At a horizontal distance of

Step 2.4: according to L _n0s 、L _n1s 、L _n2s Judging the position of AUVn to initialize maneuvering mode, making it sail to the direction close to beacon until reaching the projection position of beacon on the plane where AUV is located;

step 2.5: initializing the position of the AUV to be (0,0) after the AUV reaches the position of the beacon projection point;

and step 3: after the AUV completes position initialization, dividing an operation area according to operation requirements, providing positioning navigation for the AUV by using a single beacon positioning navigation technology in a navigation coordinate system, and driving to the operation area in a depth-fixed straight line navigation mode;

and 4, step 4: recording the coordinates of an operation starting point after the AUV arrives at an operation area, scanning the area in a circular motion mode with a beacon projection point as an origin, recording data in a memory, and recording the position information of the AUV under a navigation coordinate system at each moment by using a single beacon positioning technology;

and 5: and extracting the recorded scanning data, splicing the scanning data by taking the positioning information as a reference to obtain a scanning result of the positive film area, and converting the data into a geodetic coordinate system integrally to obtain scanning data corresponding to the geodetic coordinate.

2. Root of herbaceous plantThe cooperative operation method of multi-AUV single-standard ranging according to claim 1, characterized in that: step 2.4 according to L _n0s 、L _n1s 、L _n2s The method for judging the position initialization maneuvering mode of the AUVn specifically comprises the following steps:

(1) adjusting the heading direction of the AUV to enable the AUV to navigate towards the direction close to the beacon, and specifically:

if L is _n0s ＞L _n1s ＞L _n2s If so, indicating that the AUV is closer to the position of the beacon, and continuing to turn the bow;

if L is _n0s ＞L _n1s ，L _n1s ＜L _n2s If the AUV is close to the beacon and is far away from the beacon, the AUV turns to the reverse direction until the distance between the AUV and the beacon is reduced again;

if L is _n0s ＜L _n1s ＜L _n2s If the distance between the AUV and the beacon is smaller, the AUV is far away from the position of the beacon, and the bow continues to turn until the distance between the AUV and the beacon is reduced;

if L is _n0s ＜L _n1s ，L _n1s ＞L _n2s If so, indicating that the AUV is far away from the beacon and is close to the beacon, and continuing to turn the bow to observe whether the AUV is continuously close to the beacon;

(2) after AUV heading is adjusted, adjusting an AUV maneuvering mode according to the ranging information to enable the AUV maneuvering mode to continuously approach the beacon, specifically:

after the AUV determines that the AUV sails towards the beacon position, judging whether the AUV oversteers or not by judging the speed of the distance between the AUV and the beacon within adjacent delta t time, specifically: suppose that adjacent time segments at ₀ And Δ t ₁ In each case, the distance between AUV and beacon is reduced by Δ l ₀ And Δ l ₁ ：

If Δ l ₀ ＞Δl ₁ If the distance between the AUV and the beacon is reduced, the speed is reduced, namely the distance between the AUV and the beacon is over-steered, and the AUV and the beacon are steered in the opposite direction;

if Δ l ₀ ＜Δl ₁ This indicates that the speed of the decrease in the distance between the AUV and the beacon is fast, and the AUV can continue to turn to approach the beacon more quickly to complete the initialization process.

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