Underwater autonomous collision avoidance method for AUV (Autonomous Underwater Vehicle)

Abstract

The invention provides an underwater autonomous collision avoidance method for an AUV (Autonomous Underwater Vehicle). The requirement of autonomous obstacle avoidance during underwater navigation of the AUV is met. Comprising the following steps: step 1, distance detection: collecting the distance between an obstacle and the AUV through a target detection sensor of the AUV; 2, a speed control loop: adjusting the navigation speed according to the distance, size and characteristic intensity information of the obstacle; step 3, course calculation; calculating a turning route when sailing at the minimum turning radius, judging whether the turning route interferes with an obstacle or not, and selecting the route on one side without interference under the condition that the depth is not changed; if no interference exists on the two sides, the minimum distance between the two air routes and the obstacle is calculated, and the air route with the large minimum distance is selected as the set air route in the horizontal plane; and step 4, course control loop: according to a course calculation result and a speed control loop, selecting an air route to perform obstacle avoidance, and after collision avoidance is completed, enabling the AUV to approach the planned air route.

Description

Technical Field

[0001] The present invention relates to the technical field of AUV (autonomous underwater unmanned vehicle) navigation, and in particular to an AUV underwater autonomous collision avoidance method. Background Art

[0002] When AUVs perform underwater autonomous navigation tasks in special environments such as ports and islands, they will inevitably encounter various obstacles. Having a certain autonomous collision avoidance function is a must for AUVs. Due to the limitations of the environment and detection methods, especially when sailing at high speeds, it is often too late for AUVs to avoid obstacles when they find them, resulting in more serious consequences.

[0003] Therefore, the earlier the AUV detects obstacles, the more beneficial it is to its navigation safety. It is essential for the AUV to have autonomous collision avoidance functions that take into account both high- and low-speed navigation. Summary of the invention

[0004] The present invention provides an autonomous underwater collision avoidance method for an AUV, which realizes the requirement of autonomously avoiding obstacles when the AUV is navigating underwater.

[0005] The present invention is achieved through the following technical solutions.

[0006] An AUV underwater autonomous collision avoidance method comprises the following steps:

[0007] Step 1: Distance detection: The distance between the obstacle and the AUV is collected through the AUV’s built-in target detection sensor;

[0008] Step 2: Speed ​​control loop: adjust the navigation speed according to the distance, size and characteristic strength information of the obstacle;

[0009] Step 3, heading calculation; calculate the turning route when sailing with the minimum turning radius, determine whether the turning route interferes with obstacles, and select the route without interference under the condition of unchanged depth; if there is no interference on both sides, calculate the minimum distance between the two routes and the obstacle, and select the route with the larger minimum distance as the set route in the horizontal plane;

[0010] Step 4: Heading control loop: Based on the heading calculation result and the speed control loop, a route is selected for obstacle avoidance. After completing the collision avoidance, the AUV approaches the planned route.

[0011] Beneficial effects of the present invention:

[0012] 1. The present invention allows the AUV to autonomously select an appropriate range to detect obstacles ahead during high-speed and low-speed navigation;

[0013] 2. When avoiding obstacles, the present invention controls the speed according to the mapping relationship between the obstacle and the AUV heading, and calculates the safe avoidance route of the AUV to avoid horizontal plane collisions;

[0014] 3. When the current navigation depth cannot avoid collision, the present invention performs depth control, floats up a certain distance, and changes to another depth to avoid collision in the horizontal plane, thereby improving the navigation safety of the AUV. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of an AUV underwater autonomous collision avoidance method of the present invention;

[0016] Figure 2 Schematic diagram of AUV collision avoidance in the horizontal plane in a specific embodiment of the present invention;

[0017] Figure 3 It is a schematic diagram of the AUV changing depth to avoid collision in a specific implementation manner of the present invention. DETAILED DESCRIPTION

[0018] The exemplary embodiments of the present invention are described in detail below with reference to the accompanying drawings. It should be understood that the embodiments shown and described in the accompanying drawings are only exemplary and are intended to illustrate the principles and spirit of the present invention, rather than to limit the scope of the present invention.

[0019] like Figure 1 As shown, an AUV underwater autonomous collision avoidance method of the present invention specifically includes the following steps:

[0020] Step 1: Distance detection: The distance between the obstacle and the AUV is collected through the AUV’s built-in target detection sensor;

[0021] In specific implementation, the detection range of the AUV during high-speed and low-speed navigation is automatically switched according to safety requirements. Figure 2 As shown, when the aircraft is navigating along AB, it detects in real time whether there are obstacles ahead.

[0022] Step 2: Speed ​​control loop: adjust the navigation speed according to the distance, size and characteristic strength information of the obstacle;

[0023] In specific implementation, when the AUV detects an obstacle, it slows down while continuing to detect, obtains obstacle distance, size, direction, and target feature intensity information, and performs speed control.

[0024] Step 3, heading calculation; calculate the turning route (left turn or right turn) when sailing with the minimum turning radius, determine whether the turning route interferes with obstacles, and select the route on the side without interference (left or right) under the condition of unchanged depth; if there is no interference on both sides, calculate the minimum distance between the two routes and the obstacle, and select the route with the larger minimum distance as the set route in the horizontal plane (the depth remains unchanged);

[0025] like Figure 2 As shown, the AUV calculates the obstacle ahead and its own minimum turning radius, autonomously plans the route, and selects the right side as the safe collision avoidance route.

[0026] Step 4, heading control loop: According to the heading calculation result combined with the speed control loop, a route is selected for obstacle avoidance. After completing the collision avoidance, the AUV approaches the planned route;

[0027] like Figure 2 As shown in FIG. 1 , when the AUV selects route BC for avoidance, it checks the distance between the route and the obstacle and adjusts the heading according to the calculation result. After completing the collision avoidance, the AUV approaches the planned route.

[0028] In this embodiment, step 4 is followed by step 5, a depth control loop: when the collision avoidance in the horizontal plane cannot be completed at the current depth, the collision avoidance is performed at a deeper depth, specifically: comparing the current navigation depth of the AUV with the minimum safe navigation depth, choosing to float up to a certain depth in sequence, performing heading calculation and heading control, performing collision avoidance in the horizontal plane at the new navigation depth, and finally performing surface collision avoidance.

[0029] like Figure 3 As shown, when the AUV cannot avoid collisions in the horizontal plane at the current navigation depth H1, it rises to H2 to avoid collisions in the horizontal plane until it rises to the water surface to avoid collisions on the water surface.

[0030] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0031] It is obvious to those skilled in the art that the embodiments of the present invention are not limited to the details of the exemplary embodiments described above, and that the embodiments of the present invention can be implemented in other specific forms without departing from the spirit or basic features of the embodiments of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the embodiments of the present invention is limited by the attached claims rather than the above description, so it is intended to include all changes that fall within the meaning and scope of the equivalent elements of the claims in the embodiments of the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved. In addition, it is obvious that the word "comprising" does not exclude other units or steps, and the singular does not exclude the plural. Multiple units, modules or devices stated in the system, device or terminal claims can also be implemented by the same unit, module or device through software or hardware. The words first, second, etc. are used to indicate names, and do not indicate any particular order.

[0032] Finally, it should be noted that the above implementation modes are only used to illustrate the technical solutions of the embodiments of the present invention and are not intended to limit them. Although the embodiments of the present invention have been described in detail with reference to the above preferred implementation modes, those skilled in the art should understand that the technical solutions of the embodiments of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An AUV underwater autonomous collision avoidance method, characterized in that: The following steps are involved: Step 1: Distance detection: The distance between the obstacle and the AUV is collected through the AUV’s built-in target detection sensor; Step 2: Speed ​​control loop: adjust the navigation speed according to the distance, size and characteristic strength information of the obstacle; Step 3, heading calculation; calculate the turning route when sailing with the minimum turning radius, determine whether the turning route interferes with obstacles, and select the route without interference under the condition of unchanged depth; if there is no interference on both sides, calculate the minimum distance between the two routes and the obstacle, and select the route with the larger minimum distance as the set route in the horizontal plane; Step 4: Heading control loop: Based on the heading calculation result and the speed control loop, a route is selected for obstacle avoidance. After completing the collision avoidance, the AUV approaches the planned route.

2. The AUV underwater autonomous collision avoidance method according to claim 1, characterized in that: During distance detection, the detection range is automatically switched between high-speed and low-speed navigation of the AUV according to safety requirements.

3. An AUV underwater autonomous collision avoidance method as claimed in claim 1 or 2, characterized in that: When the AUV detects an obstacle, it slows down.

4. An AUV underwater autonomous collision avoidance method as claimed in claim 1 or 2, characterized in that: The turning route is a left turn or a right turn.

5. The AUV underwater autonomous collision avoidance method according to claim 1 or 2, characterized in that: Step 4 is followed by step 5, depth control loop: when the current depth cannot avoid collision in the horizontal plane, the depth is increased to avoid collision, specifically, the current navigation depth of the AUV is compared with the minimum safe navigation depth, and a certain depth is selected to float up in sequence, and the heading is calculated and controlled, and the horizontal plane is avoided at the new navigation depth, and finally the surface collision is avoided.

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