USV-ROV umbilical cable cooperative winding and unwinding control method

Abstract

The application discloses a USV-ROV umbilical cable cooperative winding and unwinding control method, which comprises the following steps: collecting the umbilical cable tension, the unwinding cable length, the ROV depth, the relative horizontal distance between the USV and the ROV, calculating the remaining cable index, and constructing the anti-loose cable risk criterion according to the remaining cable index and the umbilical cable tension; switching the task mode based on the task stage and the anti-loose cable risk criterion; generating the target tension and the tension window constraint in the task mode, and calculating the tension deviation; generating the speed instruction of the winch winding and unwinding cable mechanism according to the tension deviation, and setting the speed limit and the acceleration limit for the speed instruction; sending the speed instruction to the driver of the winch winding and unwinding cable mechanism, and synchronously and jointly adjusting the fixed-point keeping target or the following target of the USV, so that the umbilical cable is prevented from being loose and compressed and the tension is prevented from being overlimited. The application can realize the cooperation between the winch winding and unwinding cable and the USV fixed-point / following, thereby reducing the tension peak value, avoiding the loose cable compression, and improving the safety of the near-structure operation and the fault recovery.

Description

Technical Field

[0001] This invention belongs to the field of underwater detection and unmanned system collaborative control technology in marine engineering, and in particular relates to a collaborative deployment and retrieval control method for USV-ROV umbilical cables. Background Technology

[0002] When unmanned surface vessels (USVs) carrying underwater robots (ROVs) inspect underwater structures such as wind turbine piles, bridge piers, and docks, the ROVs typically rely on umbilical cables for power supply and data communication. However, sea disturbances and the movement of the USV itself can cause severe fluctuations in the tension of the umbilical cable, easily leading to tension exceeding limits and cable breakage or cable fatigue damage. Furthermore, when the USV approaches or follows the ROV, if the winch's cable deployment and retrieval are not synchronized with the USV's movement, the umbilical cable may experience slack, compression, knotting, or collisions with the inspected structure.

[0003] For example, Chinese patent document CN116880516A discloses an underwater environment monitoring method and system that combines multiple underwater robots. It connects USV and ROV with cables and simultaneously debugs an underwater AUV cluster. The ROV adjusts its coordination with the USV on the water surface through the cable angle relationship, so that the ROV and USV move in coordination.

[0004] Chinese patent document CN120364100A discloses an intelligent monitoring underwater robot combination system for deep-water cable laying, which consists of USV, ROV and ARV. It adopts a hierarchical relay communication method. The operation support mother ship realizes real-time communication with USV through radio station, and ROV establishes real-time communication link with USV through umbilical cable.

[0005] However, existing technologies mostly employ constant speed cable deployment or a single constant tension control strategy, which makes it difficult to simultaneously address the following constraints: (1) tension upper limit constraint to avoid cable breakage or damage; (2) anti-loosening cable constraint to avoid slack compression and knotting; (3) safety constraints for near-structure operations to avoid umbilical cable scraping or entanglement with the inspected structure; and (4) safe retrieval requirements in case of failure. Especially when working near structures, umbilical cables are prone to entanglement due to slack winding, relative orientation changes caused by USV following, and snagging caused by protrusions on the structure surface. Existing constant speed / constant tension control lacks constraints on the "relative orientation of the structure" and "safety sector," making it difficult to effectively ensure the safety of near-structure operations.

[0006] Therefore, there is an urgent need for a method for umbilical cable take-up and release control that can integrate multi-source sensor information, adaptively switch control modes according to the task stage, and achieve coordination between the winch and the USV. Summary of the Invention

[0007] This invention provides a USV-ROV umbilical cable coordinated take-up and release control method. Through sensor information fusion, task mode switching and tension window constraint control, the method realizes the coordination of winch take-up and release and USV fixed point / follow-up, thereby reducing tension peak, avoiding cable compression, and improving the safety of near-structure operations and fault recovery.

[0008] A USV-ROV umbilical cable collaborative deployment and retrieval control method is applied to a system consisting of an unmanned surface vessel (USV), an underwater robot (ROV), an umbilical cable, a winch deployment and retrieval mechanism, and a central control unit. The central control unit executes the following steps: S1, Real-time acquisition of umbilical cord tension Cable length The pose and velocity information of unmanned surface vessels (USVs) and the depth information of underwater robots (ROVs). The relative horizontal distance between the USV and ROV is calculated based on the USV pose and ROV position. ; S2, based on cable length L and relative horizontal distance and ROV depth Calculate the remaining cable index And according to the remaining cable index With umbilical cable tension Construct risk criteria for anti-loosening cables; S3, based on the task stage and the anti-loosening cable risk criterion, the task mode is switched, and the task mode includes at least the deployment mode, the scanning mode, the near-structure mode, the retrieval mode and the fault-safe retrieval mode. S4, Generate target tension in task mode With tension window constraints, and calculate tension deviation. ; S5, based on tension deviation Generate speed command for winch cable winding and unwinding mechanism and speed command Set speed limit and rate of change limit; S6, under the conditions of satisfying the tension window constraint and the remaining cable index constraint, will send the speed command. The drive is sent to the winch cable winding mechanism and the USV’s stationary or following target is adjusted synchronously to prevent the umbilical cable from becoming slack, compressed, or over-tensioned.

[0009] Further, in step S2, the remaining cable index is calculated. The formula is: .

[0010] Furthermore, in step S2, based on the remaining cable index... With umbilical cable tension The risk criteria for preventing cable loosening are as follows: when , or when And the relative horizontal distance between USV and ROV Less than the preset threshold At that time, it was determined to be a risk of slack cable; when At that time, it was determined to be a risk of tension exceeding the limit; among which , , These are the preset minimum excess cable threshold, minimum tension threshold, and maximum tension threshold, respectively.

[0011] Furthermore, in step S3, the task mode is switched based on the task stage and the anti-loosening cable risk criterion, specifically as follows: In the delivery mode, based on the target remaining cable or target tension Gradually lower the umbilical cable and constrain its tension. ; Maintain umbilical cable tension in scan mode. Within the tension window constraint and while maintaining the slack cable index ; In near-structure mode, when the relative distance between the ROV and the inspected structure... Less than the near-structure threshold Time-triggered, the minimum tension threshold is changed from Adjusted to minimum tension threshold in near-structural mode and limit speed command The rate of change; In recovery mode, under umbilical cable tension Under these conditions, increase the cable retrieval speed of the winch cable retrieval mechanism to enable the ROV to return along the predetermined path and increase the recovery speed; In fail-safe recovery mode, the system is triggered when ROV thrust loss, communication interruption, low battery, or abnormal attitude is detected, and a phased recovery strategy is adopted: in the long-distance phase, the cable retrieval speed of the winch cable retrieval mechanism is increased to improve the ROV recovery speed and meet the umbilical cable tension requirements. During the close-range phase, reduce the cable winding speed of the winch's cable winding mechanism and limit the speed command. The rate of change.

[0012] Furthermore, in near-structure mode, it also includes safety sector constraints, specifically: The safe operating sector and the restricted sector are defined by the azimuth angle of the ROV relative to the structure being inspected; when the outgoing cable direction falls into the restricted sector or the relative distance between the ROV and the structure being inspected... Less than the forbidden threshold At that time, the winch cable winding mechanism slows down and, in conjunction with the USV, adjusts the desired relative horizontal distance. This ensures that the cable direction avoids the structure being inspected.

[0013] Furthermore, in step S4, the tension window constraint is... Tension deviation ;in, and These are the preset minimum tension threshold and maximum tension threshold, respectively.

[0014] Furthermore, in step S5, the speed command is... The speed limit is set based on the current task mode, specifically: In both the delivery mode and the scanning mode, the first speed limit is used. In near-structure mode, a second velocity limit is used. ,in Furthermore, in step S6, the USV's following target is adjusted, specifically as follows: Maintain the desired relative horizontal distance from the ROV. When the risk of slack cable is triggered, the central control unit increases... Alternatively, reduce the USV's speed to near its maximum limit and simultaneously increase the recovery speed of the winch's cable take-up and release mechanism; When the risk of tension exceeding the limit is triggered, the central control unit reduces the USV away from the speed limit and simultaneously increases the cable release speed, thereby achieving coordinated prevention of cable loosening and tension exceeding the limit by USV movement and winch cable release and take-up.

[0015] A USV-ROV umbilical cable coordinated deployment and retrieval control system includes an unmanned surface vessel (USV), an underwater robot (ROV), an umbilical cable connecting the USV and the ROV, a winch deployment and retrieval mechanism mounted on the USV, and a central control unit; the central control unit is used to execute the aforementioned USV-ROV umbilical cable coordinated deployment and retrieval control method.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. By using tension window constraints and velocity / acceleration limiting strategies, wave-induced tension peaks are effectively suppressed, reducing the risk of cable breakage due to excessive tension.

[0017] 2. By using the excess cable index S and the anti-loosening cable risk criterion, proactively identify and suppress the risks of loose cable compression, knotting, and entanglement / collision between the cable and structures.

[0018] 3. By linking and coordinating the movement of the USV with the cable winding and unwinding of the winch, the trajectory stability and operational continuity of the ROV scanning phase are improved.

[0019] 4. By employing a phased recovery strategy in a fail-safe recovery mode, the system achieves both long-distance rapid recovery and short-distance low-impact recovery under constrained tension, thereby improving system reliability and safety.

[0020] 5. By introducing near-structure mode and safety sector constraints, the safety margin of the umbilical cable is significantly improved when the ROV is operating near a structure. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the overall structure of a USV-ROV umbilical cable collaborative deployment and retrieval control system according to the present invention.

[0023] Figure 2 This is a block diagram of the internal structure of the central control unit of the present invention.

[0024] Figure 3 This is a flowchart illustrating the overall process of a USV-ROV umbilical cable coordinated deployment and take-up control method according to the present invention.

[0025] Figure 4 This is a schematic diagram illustrating the task mode switching of the present invention.

[0026] Figure 5 This is a schematic diagram of the tension window constraint and the residual cable index constraint of the present invention.

[0027] Figure 6 This is a schematic diagram of the near-structure operation safety sector and cooperative collision avoidance of the present invention.

[0028] Figure 7 This is a schematic diagram of the internal structure and winch installation of the unmanned surface vessel of the present invention.

[0029] Figure 8 This is a schematic diagram of the winch cable winding and unwinding mechanism of the present invention.

[0030] In the diagram: 1-Underwater robot; 2-Unmanned surface vessel; 3-Wind reeling / deploying mechanism; 4-Umbilical cable; 5-Tension sensor; 6-Length measuring device; 7-USV navigation sensor; 8-Depth sensor; 9-Central control unit; 10-Structure under inspection; 21-Hull; 22-Thruster; 23-Battery compartment; 24-Communication antenna; 25-USV navigation sensor; 26-Central control compartment; 27-Dynamic positioning controller; 28-Wind mounting platform; 31-Drum; 32-Drive motor; 33-Brake; 34-Cable guide; 35-Tension sensor; 36-Length measuring device; 37-Reducer; 38-Frame. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] It should be noted that, unless otherwise specified, the features in the following embodiments and implementation methods can be combined with each other.

[0033] like Figure 1 As shown, a USV-ROV umbilical cable coordinated deployment and retrieval control system includes an unmanned surface vessel 2 (USV), an underwater robot 1 (ROV), an umbilical cable 4 connecting the USV and ROV, a winch deployment and retrieval mechanism 3 mounted on the USV, and a central control unit 9. The winch deployment and retrieval mechanism 3 includes a drum 31, a drive motor 32, a brake 33, and a cable guide 34. A tension sensor 5 is located at the cable guide 34 or on the cable exit path of the umbilical cable 4 to measure real-time tension. The length measuring device 6, employing a rotary encoder or meter wheel, is installed on the drum 31 or cable guide 34 to obtain the cable length. The USV navigation sensor 7 is used to obtain the USV's position, heading, and speed; the depth sensor 8 is installed on the ROV to obtain the ROV's depth. The central control unit 9 is electrically or communicatively connected to the drive of the winch cable-laying mechanism 3 and the navigation / dynamic positioning controller of the USV.

[0034] like Figure 2As shown, the central control unit 9 includes a state perception and data fusion module, a cable slack index and criterion module, a task mode switching module, a target tension and tension window constraint generation module, and a collaborative control module in its internal structure. It receives real-time data from the tension sensor 5, the length measuring device 6, the USV navigation sensor 7, and the depth sensor 8, and outputs control commands to the winch drive motor 32 / brake 33 and the USV navigation / dynamic positioning controller.

[0035] like Figure 3 As shown, a USV-ROV umbilical cable coordinated deployment and retrieval control method is executed cyclically at a fixed period, including the following steps: In step S1, the central control unit 9 acquires tension at a fixed period (e.g., 10 Hz to 100 Hz). Cable length L, USV pose and velocity information, and ROV depth The relative horizontal distance between the USV and ROV is calculated based on the USV pose and ROV position (obtained through underwater acoustic positioning, ultra-short baseline USBL, or umbilical cable geometric inversion). .

[0036] Step S2, calculate the remaining cable index according to the following formula. : ; Remaining cable index Physically, it represents the difference between the cable length and the geometrically shortest straight-line distance between the USV and ROV, indicating the current umbilical cable margin. According to... and Constructing risk criteria for anti-loosening cables: When or Furthermore, when the USV and ROV are relatively close, it is considered a risk of slack cable; when At that time, it was determined to be a risk of tension exceeding the limit. , , The minimum excess cable threshold, minimum tension threshold, and maximum tension threshold are preset by the working conditions.

[0037] S3 switches between task modes based on task phase and anti-loosening cable risk criteria. For example... Figure 4 As shown, it includes the following modes: (a) Deployment mode: During the ROV's diving and relocation phases, the central control unit 9 operates according to the target cable. or target tension Gradually release the cable to ensure umbilical cable tension. No more than ; (b) Scanning mode: The ROV scans along the planned trajectory, and the central control unit 9 maintains the umbilical cable tension. At tension window Maintain cable margin within. ; (c) Near-structure mode: when the relative distance between the ROV and the inspected structure 10 Less than the threshold Time-triggered, increases minimum tension threshold And speed limit command The rate of change, to reduce the risk of slack, entanglement and collision; (d) Recovery Mode: After the task is completed, the ROV is recovered, provided that the umbilical cable tension is met. Under these conditions, increase the winch cable retrieval speed to allow the ROV to return along the predetermined path and increase the recovery speed; (e) Fail-safe recovery mode: Triggered when ROV thrust loss, communication interruption, low battery, or abnormal attitude is detected, a phased recovery strategy is adopted: In the long-distance phase, the winch cable retrieval speed is increased to improve the ROV recovery speed and meet the umbilical cable tension. During the close-range phase, reduce the winch cable winding speed and limit the speed command. The rate of change (i.e., acceleration) is used to suppress tension peaks and avoid collisions between the ROV and USV.

[0038] Step S4, as follows Figure 5 As shown, target tension is generated in each task mode. With tension window constraint The upper and lower boundaries of the tension window are dynamically adjusted according to the current mode: for example, in near-structure mode, Set to a higher value To improve the tension of the excess cable; in fail-safe recovery mode, It is tightened to avoid tension spikes. Meanwhile, according to the remaining cable specifications... Real-time monitoring of cable slack risk.

[0039] Step S5: A tension outer loop – speed inner loop control structure is adopted in the winch control loop. The tension outer loop controls the speed according to the tension deviation. Generate speed command : in, , This is the proportional-integral coefficient. For Apply speed limit To suppress wave-induced tension peaks. When a risk of cable slack is triggered, prioritize increasing the recovery speed or limiting the approach speed of the USV; when a risk of tension exceeding limits is triggered, prioritize releasing the cable or limiting the departure speed of the USV.

[0040] Step S6: Send winch speed command The drive is sent to the winch cable-laying mechanism 3; simultaneously, a USV coordination command is sent to the USV navigation / dynamic positioning controller, the USV coordination command including the desired offset distance for the USV to maintain a fixed target or follow a target. When the risk of slack cable is triggered, the central control unit 9 increases... Alternatively, the approach speed limit of the USV can be reduced, and the winch recovery speed can be adjusted simultaneously to achieve coordinated anti-loosening of the cable by the movement of the USV and the cable release and take-up of the winch.

[0041] like Figure 6 As shown, the near-structure mode of this invention also incorporates safety sector constraints. Using the geometric center of the inspected structure 10 as the origin, a safe operating sector and a restricted sector are divided on the horizontal plane where the ROV is located. When the outgoing cable direction falls into the restricted sector, or the relative distance between the ROV and the inspected structure 10... Less than the forbidden threshold At that time, the central control unit 9 triggers an emergency unwinding sequence: (i) the winch slows down and increases speed. (ii) Tighten the umbilical cable 4; (ii) Adjust the following bias of the linked USV. (iii) Rotate the cable outgoing direction to a safe operating sector; and restore normal operating mode after confirming that the relative orientation is safe.

[0042] In one specific embodiment, such as Figure 7 As shown, the unmanned surface vessel 2 includes a hull 21, a propulsion unit 22, a battery compartment 23, a communication antenna 24, a USV navigation sensor 25, a central control compartment 26, a dynamic positioning controller 27, and a winch mounting platform 28. The winch cable winding and unwinding mechanism 3 is installed on the winch mounting platform 28. The central control compartment 26 is equipped with a central control unit 9 and related control equipment.

[0043] like Figure 8 As shown, the winch cable winding and unwinding mechanism 3 includes a drum 31, a drive motor 32, a brake 33, a cable guide 34, a tension sensor 35, a length measuring device 36, a reducer 37, and a frame 38. The drive motor 32 drives the drum 31 to rotate via the reducer 37. The brake 33 is used to brake and stop the cable. The cable guide 34 is used to guide the umbilical cable 4 to smoothly exit or retract. The tension sensor 35 and the length measuring device 36 are used to obtain the real-time tension and winding / unwinding length parameters of the umbilical cable 4, respectively.

[0044] In one specific embodiment, the control period is 50 Hz, and the tension window is set to... = 50 N, =800 N, = 200 N; Near-structure threshold = 5 m, forbidden threshold = 1 m; Minimum slack cable margin =0.5 m, target slack cable margin = 1.5 m; speed limit = 0.5 m / s², acceleration limit = 0.3 m / s 2 ; near-structural mode The torque is increased to 150 N, and the velocity limit is reduced to 0.2 m / s. Under these parameters, the system of the present invention can significantly reduce the peak tension amplitude and avoid umbilical cable slack compression under typical sea conditions.

[0045] The embodiments described above provide a detailed explanation of the technical solutions and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, additions, and equivalent substitutions made within the scope of the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for coordinated deployment and retrieval control of USV-ROV umbilical cables, characterized in that, Includes the following steps: S1, Real-time acquisition of umbilical cord tension Cable length The pose and velocity information of unmanned surface vessels (USVs) and the depth information of underwater robots (ROVs). The relative horizontal distance between the USV and ROV is calculated based on the USV pose and ROV position. ; S2, based on cable length Relative horizontal distance and ROV depth Calculate the remaining cable index And according to the remaining cable index With umbilical cable tension Construct risk criteria for anti-loosening cables; S3, based on the task stage and the anti-loosening cable risk criterion, the task mode is switched, and the task mode includes at least the deployment mode, the scanning mode, the near-structure mode, the retrieval mode and the fault-safe retrieval mode. S4, Generate target tension in task mode With tension window constraints, and calculate tension deviation. ; S5, based on tension deviation Generate speed command for winch cable winding and unwinding mechanism and speed command Set speed limit and rate of change limit; S6, under the conditions of satisfying the tension window constraint and the remaining cable index constraint, will send the speed command. The drive is sent to the winch cable winding mechanism and the USV’s stationary or following target is adjusted synchronously to prevent the umbilical cable from becoming slack, compressed, or over-tensioned.

2. The USV-ROV umbilical cable coordinated deployment and retrieval control method according to claim 1, characterized in that, In step S2, the remaining cable index is calculated. The formula is: .

3. The USV-ROV umbilical cable coordinated deployment and retrieval control method according to claim 1, characterized in that, In step S2, based on the remaining cable index With umbilical cable tension The risk criteria for preventing cable loosening are as follows: when , or when And the relative horizontal distance between USV and ROV Less than the preset threshold At that time, it was determined to be a risk of slack cable; when At that time, it was determined to be a risk of tension exceeding the limit; among which , , These are the preset minimum excess cable threshold, minimum tension threshold, and maximum tension threshold, respectively.

4. The USV-ROV umbilical cable coordinated deployment and retrieval control method according to claim 1, characterized in that, In step S3, the task mode is switched based on the task stage and the anti-loosening cable risk criterion, specifically as follows: In the delivery mode, based on the target remaining cable or target tension Gradually lower the umbilical cable and constrain its tension. ; Maintain umbilical cable tension in scan mode. Within the tension window constraint and while maintaining the slack cable index ; In near-structure mode, when the relative distance between the ROV and the inspected structure... Less than the near-structure threshold Time-triggered, the minimum tension threshold is changed from Adjusted to minimum tension threshold in near-structural mode and limit speed command The rate of change; In recovery mode, while meeting the umbilical cable tension... Under these conditions, increase the cable retrieval speed of the winch cable retrieval mechanism to enable the ROV to return along the predetermined path and increase the recovery speed. In fail-safe recovery mode, the system is triggered when ROV thrust loss, communication interruption, low battery, or abnormal attitude is detected, and a phased recovery strategy is adopted: in the long-distance phase, the cable retrieval speed of the winch cable retrieval mechanism is increased to improve the ROV recovery speed and meet the umbilical cable tension requirements. During the close-range phase, reduce the cable winding speed of the winch's cable winding mechanism and limit the speed command. The rate of change.

5. The USV-ROV umbilical cable coordinated deployment and retrieval control method according to claim 4, characterized in that, In near-structure mode, it also includes safe sector constraints, specifically: The safe operating sector and the restricted sector are defined by the azimuth angle of the ROV relative to the structure being inspected; when the outgoing cable direction falls into the restricted sector or the relative distance between the ROV and the structure being inspected... Less than the forbidden threshold At that time, the winch cable winding mechanism slows down and, in conjunction with the USV, adjusts the desired relative horizontal distance. This ensures that the cable direction avoids the structure being inspected.

6. The USV-ROV umbilical cable coordinated deployment and retrieval control method according to claim 1, characterized in that, In step S4, the tension window constraint is... Tension deviation ;in, and These are the preset minimum tension threshold and maximum tension threshold, respectively.

7. The USV-ROV umbilical cable coordinated deployment and retrieval control method according to claim 1, characterized in that, In step S5, the speed command is given. The speed limit is set based on the current task mode, specifically: In both the delivery mode and the scanning mode, the first speed limit is used. In near-structure mode, a second velocity limit is used. ,in .

8. The USV-ROV umbilical cable coordinated deployment and retrieval control method according to claim 1, characterized in that, In step S6, the USV's following target is adjusted, specifically as follows: Maintain the desired relative horizontal distance from the ROV. ; When the risk of slack cable is triggered, the central control unit increases... Alternatively, reduce the USV's speed to near its maximum limit and simultaneously increase the recovery speed of the winch's cable take-up and release mechanism; When the risk of tension exceeding the limit is triggered, the central control unit reduces the USV away from the speed limit and simultaneously increases the cable release speed, thereby achieving coordinated prevention of cable loosening and tension exceeding the limit by USV movement and winch cable release and take-up.

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