A method for accurately measuring the stability of a water robot platform under complex environmental conditions

Abstract

The application discloses a kind of complex environmental conditions under water robot platform stability precision measurement method, belong to water robot operation technical field.The implementation of the method includes: step one, establish water robot multi-body system parameterization model;Step two, consider the complex environmental load quantization modeling of (wind, wave, flow) to water robot effect;Step three, based on the static stability arm GZ curve Static stability restoring moment and static angle of inclination calculation;Step four, dynamic stability evaluation and anti-overturning margin calculation;Step five, establish load configuration optimization model with stability optimal as target, realize the optimization of load configuration based on stability measurement;Step six, realize stability safety monitoring and real-time early warning.The application is coupled modeling by "environmental load-robot platform-task load", accurately calculates the stability index of robot under given load configuration and environmental conditions, and gives optimization direction.

Description

Technical Field

[0001] This invention relates to the field of aquatic robot operation technology, specifically to a method for accurately calculating the stability of an aquatic robot platform under complex environmental conditions. Background Technology

[0002] With the advancement of intelligent and automated technologies, aquatic robots (such as unmanned vessels and intelligent lifebuoys) have been widely applied in various fields, including hydrological environment detection, water quality sampling and monitoring, water emergency rescue, and surface inspection. To adapt to different mission scenarios, aquatic robots typically need to be designed to carry multiple payload modules, such as water quality sensors, robotic arms, and rescue supply delivery devices. Because the installation location, mass, size, and operating status of these payload modules vary on the aquatic robot platform, they significantly affect the platform's overall center of gravity and moment of inertia, thus impacting its stability on the water surface and ultimately operational safety. Therefore, as a multi-purpose platform for carrying these payload modules, the stability calculation of aquatic robots is crucial.

[0003] Furthermore, in complex aquatic environments, the dynamic forces of wind, waves, and currents, as well as the maneuvers required to avoid passing vessels, reefs, and other obstacles, can significantly impact the balance of the aquatic robot. Improper load configuration or environmental conditions exceeding the platform's stability boundaries can easily lead to excessive tilting or even capsizing, resulting in mission failure and equipment damage. Therefore, quickly and accurately calculating the stability of the aquatic robot platform under given load configuration and environmental conditions during the pre-mission planning phase or during mission execution is crucial for ensuring operational safety.

[0004] Existing stability calculation methods are mostly designed for traditional ship designs, typically based on static or quasi-static assumptions, considering fixed loads and standard sea states. They often simplify wind, wave, and current loads independently, failing to effectively characterize the complex disturbances and moments generated on the robot under multi-physics coupling. For small, multi-purpose, and variable-load aquatic robot platforms, loads change frequently, and the local flow fields and wave spectra in operating environments (such as inland rivers, nearshore areas, and reservoirs) are more complex and variable. Traditional methods have limited applicability and accuracy. For rapidly changing modular loads, there is a lack of real-time, accurate stability assessment tools, making it difficult to optimize load distribution before or during missions. Furthermore, existing methods rarely systematically integrate the joint time-domain model of wind, wave, and current disturbances with the platform's multi-degree-of-freedom motion response and variable load distribution for unified analysis, and lack a complete computational process for real-time stability boundary calculations and load configuration optimization.

[0005] Therefore, there is an urgent need to propose a precise stability calculation method for aquatic robot platforms under complex environmental conditions, which can quantify environmental disturbances, take into account load configuration details, and output stability evaluation indicators through an efficient calculation model, so as to provide a basis for load layout optimization and safe operation decisions. Summary of the Invention

[0006] In view of this, the present invention provides a method for accurately calculating the stability of an aquatic robot platform under complex environmental conditions. This method accurately calculates the stability index of the robot under given load configuration and environmental conditions through integrated coupled modeling of "environmental load-robot platform-task load" and provides optimization directions.

[0007] A method for accurately calculating the stability of an aquatic robot platform under complex environmental conditions, the implementation of which includes:

[0008] Step 1: Establish a parameterized model of the multibody system of the aquatic robot based on the platform's body parameters and considering the multibody system synthesis scenario;

[0009] Step 2: Quantitative modeling of complex environmental loads (wind, waves, currents) affecting the water robot;

[0010] Step 3: Calculation of static stability restoring moment and static tilt angle based on the modified static stability arm GZ curve;

[0011] Step 4: Through dynamic stability assessment and overturning margin calculation, support the transmission from dynamic response analysis to safety decision-making;

[0012] Step 5: Establish a load configuration optimization model with stability optimization as the goal, and realize the optimization of load configuration based on stability calculation;

[0013] Step 6: Implement stability and security monitoring and real-time early warning.

[0014] Furthermore, the process of establishing the parameterized model of the multibody system of the aquatic robot in step one is as follows:

[0015] The multibody system of the aquatic robot includes an aquatic robot platform and multiple operational payload modules. The geometric and mass properties of the aquatic robot platform and each optional operational payload module are parameterized. The platform's body coordinate system is defined. With global coordinate system ;

[0016] The platform's main parameters include drainage volume. Waterline surface area Center of gravity position , position of buoyancy Platform inertia tensor ;

[0017] Let the first The mass of each load module parameter is Installation position in the body coordinate system Inertial tensor ;

[0018] In this context, the superscript 'b' indicates the body coordinate system. All vectors or coordinates with this superscript are described in a coordinate system fixed to the robot platform and do not change with the overall movement of the robot. The subscript 'g' represents the center of gravity; the subscript 'c' represents the center of buoyancy; and the subscript 'i' represents the i-th load module.

[0019] (1)

[0020] Meaning: The center of gravity position vector of an unloaded platform (without any load).

[0021] Component explanation:

[0022] The center of gravity is in the body coordinate system Coordinates on the axis (usually along the ship's length, with the bow being positive).

[0023] The focus is on Coordinates on the axis (usually in the direction of the ship's width, with starboard being positive).

[0024] The focus is on Coordinates on the axis (usually vertical, with upward being positive).

[0025] (2)

[0026] Meaning: The buoyancy center position vector of the unloaded platform (centroid of the displacement volume).

[0027] Component explanation:

[0028] : Floating Heart Coordinates on the axis.

[0029] : Floating Heart Coordinates on the axis.

[0030] : Floating Heart Coordinates on the axis.

[0031] (3)

[0032] Meaning: The The installation position vector of each load module (i.e., the coordinates of the center of gravity of the module in the platform coordinate system).

[0033] Component explanation:

[0034] The load is in Mounting position on the shaft.

[0035] The load is in Mounting position on the shaft.

[0036] The load is in Mounting height on the shaft.

[0037] Considering multi-body system synthesis scenarios, when equipped with When there are one load module, the total mass of the system is Overall center of gravity (the combined center of gravity of the platform body and all payload modules) and total inertia tensor The calculation is as follows:

[0038]

[0039]

[0040]

[0041] in, and For the mass and center of gravity of the unloaded platform, It is an identity matrix. The centroid is... The superscript 'b' represents the body frame, indicating that the vector was measured in a coordinate system fixed to the robot, and the subscript 'G' represents the combined center of gravity. (Uppercase letters are used here.) This indicates that this is the center of gravity of the entire multibody system (platform + all loads), distinct from the center of gravity of the unloaded platform (in lowercase). express).

[0042] Furthermore, the process of quantitatively modeling the complex environmental loads (wind, waves, currents) affecting the water robot in step two is as follows:

[0043] Based on the parameterized model of the multibody system of the aquatic robot established above, the following is carried out: Figure 3 The analysis of the effects of complex environmental loads (wind, waves, and currents) on the aquatic robot is presented. This analysis involves physically modeling the wind, wave, and current loads and uniformly expressing them as the resultant force acting on the aquatic robot. With resultant torque ;

[0044] The wind load is related to the robot's wind-receiving area, wind speed, and wind direction, and is calculated using the coefficient method as follows:

[0045]

[0046] in, air density, This is the drag coefficient. The windward projected area, Relative wind speed, This is a unit vector representing wind direction. The location of the wind pressure center;

[0047] The factors to consider for flow loads include viscous drag and added mass effect, and the calculation is as follows:

[0048]

[0049] in, For the density of water, The drag coefficient is... The underwater wetted surface area, For flow rate, The flow direction is a unit vector. To add a mass matrix, This is the flow acceleration (usually small);

[0050] For aquatic robots, wave loads are expressed by estimating the first-order wave force and the second-order drift force using regular wave or spectral methods, as detailed below:

[0051]

[0052] in, For amplitude, For the frequency of encounters, This is the wave force coefficient.

[0053] Therefore, the total environmental load is: The same applies to the resultant torque.

[0054] Furthermore, the calculation process for the static stability restoring torque and static tilt angle based on the modified static stability arm GZ curve in step three is as follows:

[0055] First, calculate the static restoring moment of the robot in still water, for the tilt angle. and pitch angle Static restoring torque This is caused by the torque difference between gravity and buoyancy, and therefore a modified static stability arm (GZ) formula is used as follows:

[0056]

[0057]

[0058] in, For drainage volume, It is the acceleration due to gravity. To ensure high initial stability (eliminating the adverse effects of the height increase caused by the internal fluid flow leading to an equivalent increase in the center of gravity). The coefficients for fitting the platform-shaped line are... This is the pitch-roll coupling function;

[0059] Environmental static moment (Under the action of constant wind tilt moment) static equilibrium tilt angle The following equilibrium equations are obtained by solving:

[0060] .

[0061] Furthermore, in step four, the process of transferring information from dynamic response analysis to safety decision-making is supported by dynamic stability assessment and overturning margin calculation as follows:

[0062] Considering dynamic environmental torque The robot's motion response under conditions such as wave periodic torque is established, and the equation of motion for a single-degree-of-freedom roll is established:

[0063]

[0064] in, For the system's roll moment of inertia, Add an additional moment of inertia to the roll. This is the roll damping coefficient. The static recovery coefficient;

[0065] The maximum roll angle can be obtained through time-domain simulation or frequency-domain response analysis. Therefore, the overturning margin can be defined. :

[0066]

[0067] in, This is the critical overturning angle (usually taken as the ingress angle or the angle corresponding to the peak value of the GZ curve). Requirements: (Safety threshold, such as 0.3).

[0068] Furthermore, in step five, a load configuration optimization model with stability optimization as the objective is established. The process of optimizing load configuration based on stability calculation is as follows:

[0069] Considering both overturning margin and center of gravity height, a load configuration optimization model is established with stability as the objective, defining the decision variable as the installation position of each load module. (Discrete or continuous), the objective function is to maximize the overturning margin and minimize the center of gravity height:

[0070]

[0071] in, and These are the weighting coefficients assigned to the overturning margin and the weighting coefficients assigned to the reduction in center of gravity height, respectively. Here, This refers to the overall vertical coordinate of the system's center of gravity after carrying all loads, which differs from the vertical coordinate of the platform's own center of gravity mentioned in the previous steps. The concept and constraints mainly consider: geometric installation space limitations, task accessibility requirements, no overlap between modules, and system tilt angle less than the permissible value. This optimization problem is solved using heuristic algorithms (such as genetic algorithms and simulated annealing) to output the optimal load layout scheme.

[0072] Furthermore, the process of achieving stability and security monitoring and real-time early warning in step six is ​​as follows:

[0073] To achieve stability and safety monitoring, the current stability indicators of the water robot are calculated and updated in real time based on the measured or estimated water environment data (wind speed, wave height) and its own attitude information. The current stability index is obtained based on calculations. The numerical value is used to determine whether an alert is triggered and the alert level through a multi-level early warning mechanism established as follows;

[0074] 1) If If the condition is stable, no warning will be triggered. At this time, the stability state is normal, and continuous monitoring is sufficient.

[0075] 2) If If so, it is judged as a Level 1 warning: at this time, attention should be paid to the decline in stability;

[0076] 3) If If the warning level is 2, it is recommended to adjust the course or speed to reduce the environmental load.

[0077] 4) If If the condition is met, it is determined to be a Level 3 warning: at this time, a safety strategy is forcibly triggered, such as automatic return to base or release of ballast.

[0078] After assessing the warning situation according to the aforementioned multi-level early warning mechanism, take corresponding measures and intervene when necessary.

[0079] Beneficial effects:

[0080] 1. This invention establishes a parameterized model of a multibody system suitable for water robots. By using parameterized representation, it overcomes the errors caused by traditional empirical methods, significantly improves the accuracy of stability calculation, and realizes precise calculation of the stability of water robots.

[0081] 2. This invention fully considers the environmental impact factors under actual complex water conditions. By establishing the yaw motion equation of the water robot, it evaluates the robot's motion response mechanism and anti-tipping margin under dynamic environmental excitation, and has good dynamic response analysis capabilities, which meet the needs of actual applications.

[0082] 3. This invention integrates stability calculation into the load configuration optimization process, which can provide the optimal load module layout scheme for different water operation scenarios.

[0083] 4. This invention establishes a graded early warning and active safety control mechanism by calculating the stability margin of the water robot online, thereby improving the autonomous safety level of the water robot and realizing real-time safety monitoring and early warning.

[0084] 5. The stability mathematical model and calculation method of the aquatic robot established in this invention are applicable to aquatic robots of different configurations and various payload modules, and have good universality and scalability. Attached Figure Description

[0085] Figure 1 A flowchart illustrating the steps involved in accurately calculating the stability of an aquatic robot platform.

[0086] Figure 2 A schematic diagram of the parametric model of a multibody system for an aquatic robot;

[0087] Figure 3 A flowchart for analyzing the effects of complex environmental loads (wind, waves, currents) on aquatic robots;

[0088] Figure 4 This is a schematic diagram illustrating the principle of solving the static equilibrium tilt angle based on the modified static stability arm GZ curve;

[0089] Figure 5 Flowchart for calculating the roll motion response time history curve and overturning margin;

[0090] Figure 6 Example of optimized payload configuration for an aquatic robot. Detailed Implementation

[0091] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0092] This embodiment takes a catamaran-type aquatic robot as an example, whose unloaded parameters are as follows: displacement ,captain , boat width Unloaded center of gravity position Unloaded buoyancy center position Rolling moment of inertia .

[0093] The task scenario and payload configuration are as follows: This embodiment involves multi-point water quality sampling, requiring three modules. One of these is a multi-parameter water quality sensor (mass sensor). Small size, default installation location The first is Module A; the second is the robotic arm (mass). Medium size, default installation location ), denoted as module B; the third is the sampling box and pump set (mass). Large size, default installation location ), denoted as module C.

[0094] The aquatic environmental conditions are as follows: wind speed The wind direction is perpendicular to the robot's longitudinal axis (crosswind); the flow rate... The direction forms a 30° angle with the vertical axis; the wave: a small, regular wave with a wave height of... ,wavelength The encounter angle is 90°.

[0095] As attached Figure 1 As shown, the method for accurate stability calculation of the aquatic robot platform of the present invention includes the following steps:

[0096] Step 1: Establish a parameterized model of the multibody system of the aquatic robot; as shown in the attached figure. Figure 2 As shown, the multibody system of the aquatic robot includes an aquatic robot platform and multiple operational payload modules. The geometric and mass attributes of the aquatic robot platform and each optional operational payload module are parameterized. The platform's body coordinate system is defined. With global coordinate system The platform's main parameters include drainage volume. Waterline surface area Center of gravity position , position of buoyancy Platform inertia tensor .

[0097] Based on the foregoing, the total mass of the aquatic robot system is calculated as follows:

[0098]

[0099] The total center of gravity is calculated as follows:

[0100]

[0101] This shows that although the longitudinal position of the center of gravity of the water robot is close to the center line, its height is relatively low. It is still slightly higher than when there is no load.

[0102] Step 2: Quantitative modeling of complex environmental loads;

[0103] Based on the parameterized model of the multibody system of the aquatic robot established in step one, the following steps are performed: Figure 3 The analysis of the effects of complex environmental loads (wind, waves, and currents) on the aquatic robot is presented. This analysis involves physically modeling the wind, wave, and current loads and uniformly expressing them as the resultant force acting on the aquatic robot. With resultant torque .

[0104] For wind load estimation, the wind-receiving area is estimated. ,Pick , .

[0105] Therefore, the wind load is calculated as follows:

[0106] Take the height of the wind pressure center The lateral tilting moment generated by the crosswind is calculated as follows:

[0107]

[0108] For flow loads, due to the wetted surface area ,Pick , Flow loads primarily affect drag and contribute little to the tilting moment; therefore, their moment effect is temporarily ignored here.

[0109] For wave loads, wave amplitude ,Pick , Therefore, the amplitude of the maximum first-order wave heel moment was estimated to be:

[0110]

[0111] The wave's tilt moment is a periodic moment, and it has the following characteristics: .

[0112] Step 3: Calculation of static stability restoring moment and static tilt angle based on the modified static stability arm GZ curve;

[0113] Based on the physical modeling of wind, wave, and current environmental loads, a principle for solving the static equilibrium tilt angle based on the modified static stability arm GZ curve is designed, as detailed in the appendix. Figure 4As shown, the GZ curve (left side) contains three key features: initial stability slope, maximum restoring force, and critical overturning angle; the environmental load (middle left) represents the input wind tilting moment as an external disturbance. The equilibrium solution (middle part) mainly establishes the solution conditions through the moment balance equation and uses the graphical intersection method to solve on the GZ curve to obtain the static equilibrium tilt angle.

[0114] To calculate the effective initial stability First, calculate the no-load stability height as follows: ,in , Let be the transverse moment of inertia at the waterline. For catamarans, the following approximation can be made:

[0115]

[0116] in, For draft. Considering the load, its center of buoyancy changes little, and its center of gravity rises. Therefore, the statically restoring torque is obtained as: .

[0117] To calculate the static tilt angle, due to the static tilt moment... Here, the linear recovery coefficient is used. The static equilibrium tilt angle is calculated as follows:

[0118]

[0119] It can be seen that this static tilt angle is very small.

[0120] Step 4: Through dynamic stability assessment and overturning margin calculation, support the transmission from dynamic response analysis to safety decision-making;

[0121] Based on the calculation results of the static stability restoring moment and static tilt angle in step three, the dynamic stability assessment and overturning margin are calculated. (Appendix) Figure 5 The diagram shows the time history curve of the roll motion response and the calculation flowchart of the overturning margin, illustrating the complete process from dynamic response analysis to safety decision-making. Input and Equations (left): Using wave disturbance torque as input, dynamic analysis is performed using the roll motion equation, which includes moment of inertia, damping coefficient, and restoring moment. Response and Calculation (middle): The roll angle time history curve is obtained by solving for it, and the maximum roll angle and critical overturning angle are extracted to calculate the overturning margin. Safety Decision-Making (right): A three-level assessment mechanism is initiated based on the margin value.

[0122] Total roll moment of inertia The estimate is obtained Furthermore, the additional moment of inertia is: Damping coefficient .

[0123] Therefore, the following equation for the roll motion is established:

[0124]

[0125] Based on this, frequency domain response analysis is performed. Assume the water robot experiences a rolling frequency of... The frequency response characteristics are calculated as follows:

[0126] amplification factor in steady state , where the natural frequency Damping ratio . because The response is close to static. Therefore, the dynamic roll angle amplitude .

[0127] The maximum roll angle was calculated as follows: .

[0128] Take the critical overturning angle (Based on the profile estimation). The overturning margin is then calculated as follows:

[0129]

[0130] It can be seen that this value is greater than the safety threshold. However, the margin is not large.

[0131] Step 5: Establish a load configuration optimization model with stability optimization as the objective, and realize load configuration optimization based on stability calculation;

[0132] To optimize the vertical () of modules A, B, and C ) and vertical ( The target is the installation location, which needs to be maximized. At the same time, it restricts each module from exceeding the installation area, and , .

[0133] By using simple enumeration, it was found that the heavier module C ( Lowering and positioning the installation location as close as possible to the longitudinal centerline of the underwater robot is most beneficial for stability. For example, the adjusted installation position would be: The positions of modules A and B remain unchanged.

[0134] Therefore, the calculation is as follows:

[0135] Total center of gravity height , reduce by approximately Thus, we obtain The static stability restoring torque is improved. Therefore, The dynamic roll angle amplitude is determined through time-domain simulation or frequency-domain response analysis. . The new overturning margin is calculated as follows:

[0136]

[0137] It can be seen that the new anti-overturning margin is improved by approximately [percentage missing] compared to the previous one. Objective function The values ​​also increased accordingly, as shown in the attached figure. Figure 6 The results of the optimized payload configuration for the water robot are shown.

[0138] Step Six: Stability and Safety Monitoring and Real-time Early Warning.

[0139] Monitor the roll angle in real time during the mission; if measured... Then in real time At this time, it is still in the first-level warning zone ( The system prompts, "Stability margin is moderate; pay attention to changes in wind and waves." If gusts occur, causing estimation errors... Descending to If this occurs, a Level 2 warning will be triggered. It is recommended to automatically adjust the course to the direction with the waves to reduce the possibility of encountering rolling frequency and wave moment, or to move the movable module A to the windward side to generate a trim moment.

[0140] The calculations in this embodiment show that, under a given aquatic environment and default load configuration, the capsizing margin of the aquatic robot is [value missing]. After simple optimization of the vertical load position, the margin was increased to [percentage missing]. This verifies the effectiveness of the method of the present invention in optimizing configuration and improving stability. It also shows that the established real-time margin calculation and early warning mechanism can provide dynamic protection for the safe operation of the water robot.

[0141] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for accurately calculating the stability of an underwater robot platform under complex environmental conditions, characterized in that, The implementation of this method includes: Step 1: Establish a parameterized model of the multibody system of the aquatic robot based on the platform's body parameters and considering the multibody system synthesis scenario; Step 2: Quantitative modeling of complex environmental loads considering the effects of wind, waves, and currents on the water robot; Step 3: Calculation of static stability restoring moment and static tilt angle based on the modified static stability arm GZ curve; Step 4: Through dynamic stability assessment and overturning margin calculation, support the transmission from dynamic response analysis to safety decision-making; Step 5: Establish a load configuration optimization model with stability optimization as the goal, and realize the optimization of load configuration based on stability calculation; Step 6: Implement stability and security monitoring and real-time early warning.

2. The method for accurately calculating the stability of an aquatic robot platform under complex environmental conditions as described in claim 1, characterized in that, The process of establishing the parameterized model of the multibody system of the aquatic robot in step one is as follows: The multibody system of the aquatic robot includes an aquatic robot platform and multiple operational payload modules. The geometric and mass attributes of the aquatic robot platform and each optional operational payload module are parameterized, and the platform's body coordinate system is defined. With global coordinate system ; The platform's main parameters include drainage volume. Waterline surface area Center of gravity position , position of buoyancy Platform inertia tensor ; Let the first The mass of each load module parameter is Installation position in the body coordinate system Inertial tensor ; In this context, the superscript b represents the body coordinate system. All vectors or coordinates with this superscript indicate that the point or vector is described in a coordinate system fixed to the robot platform and does not change with the movement of the robot as a whole. The subscript g represents the center of gravity; the subscript c represents the center of buoyancy; and the subscript i represents the i-th load module. Considering multi-body system synthesis scenarios, when equipped with When there are one load module, the total mass of the system is Overall center of gravity position and total inertia tensor The calculation is as follows: ； ； ； in, and For the mass and center of gravity of the unloaded platform, It is an identity matrix. The centroid is... The superscript 'b' represents the body coordinate system, indicating that the vector is measured in a coordinate system fixed to the robot, and the subscript 'G' represents the composite center of gravity.

3. The method for accurately calculating the stability of an aquatic robot platform under complex environmental conditions as described in claim 2, characterized in that, The process of quantitative modeling of complex environmental loads considering the effects of wind, waves, and currents on the water robot in step two is as follows: Based on the parameterized model of the multibody system of the aquatic robot established above, the effects of complex environmental loads on the aquatic robot are analyzed. By physically modeling the environmental loads of wind, waves, and currents, they are uniformly expressed as the resultant force acting on the aquatic robot. With resultant torque ; The wind load is related to the robot's wind-receiving area, wind speed, and wind direction, and is calculated using the coefficient method as follows: ； in, air density, This is the drag coefficient. The windward projected area, Relative wind speed, This is a unit vector representing wind direction. The location of the wind pressure center; The factors to consider for flow loads include viscous drag and added mass effect, and the calculation is as follows: ； in, For the density of water, The drag coefficient is... The underwater wetted surface area, For flow rate, The flow direction is a unit vector. To add a mass matrix, For flow acceleration; For aquatic robots, wave loads are expressed by estimating the first-order wave force and the second-order drift force using regular wave or spectral methods, as detailed below: ； in, For amplitude, For the frequency of encounters, Wave force coefficient; Therefore, the total environmental load is: The same applies to the resultant torque.

4. The method for accurately calculating the stability of an aquatic robot platform under complex environmental conditions as described in claim 3, characterized in that, The calculation process for the static stability restoring moment and static tilt angle based on the modified static stability arm GZ curve in step three is as follows: First, calculate the static restoring moment of the robot in still water, for the tilt angle. and pitch angle Static restoring torque This is caused by the torque difference between gravity and buoyancy, and therefore a modified static stability arm (GZ) formula is used as follows: ； ； in, For drainage volume, It is the acceleration due to gravity. To ensure high initial stability, The coefficients for fitting the platform-shaped line are... This is the pitch-roll coupling function; Environmental static moment Under the action, static equilibrium tilt angle The following equilibrium equations are obtained by solving: 。 5. The method for accurately calculating the stability of an underwater robot platform under complex environmental conditions as described in claim 4, characterized in that, In step four, the process of transferring information from dynamic response analysis to safety decisions is supported by dynamic stability assessment and overturning margin calculation as follows: Considering dynamic environmental torque The robot's motion response under the following conditions is used to establish the equation of motion for a single-degree-of-freedom roll: ； in, For the system's roll moment of inertia, Add an additional moment of inertia to the roll. This is the roll damping coefficient. The static recovery coefficient; The maximum roll angle can be obtained through time-domain simulation or frequency-domain response analysis. Therefore, the overturning margin can be defined. : ； in, For the critical overturning angle, it is required that .

6. The method for accurately calculating the stability of an underwater robot platform under complex environmental conditions as described in claim 5, characterized in that, In step five, a load configuration optimization model with stability optimization as the objective is established. The process of optimizing load configuration based on stability calculation is as follows: Considering both overturning margin and center of gravity height, a load configuration optimization model is established with stability as the objective, defining the decision variable as the installation position of each load module. The objective function is to maximize the overturning resistance margin and minimize the center of gravity height: ； in, and These are the weighting coefficients assigned to the overturning margin and the weighting coefficients assigned to the reduction in center of gravity height, respectively. Here, This refers to the overall vertical coordinate of the system's center of gravity after carrying all loads, which differs from the vertical coordinate of the platform's own center of gravity mentioned in the previous steps. The concept and constraints mainly consider: geometric installation space limitations, task accessibility requirements, no overlap between modules, and system tilt angle less than the permissible value. A heuristic algorithm is used to solve this optimization problem and output the optimal load layout scheme.

7. The method for accurately calculating the stability of an aquatic robot platform under complex environmental conditions as described in claim 6, characterized in that, The process of achieving stability and security monitoring and real-time early warning in step six is ​​as follows: To achieve stability and safety monitoring, the current stability indicators of the water robot are calculated and updated in real time based on the measured or estimated water environment data (wind speed, wave height) and its own attitude information. The current stability index is obtained based on calculations. The numerical value is used to determine whether an alert is triggered and the alert level through a multi-level early warning mechanism established as follows; 1) If If the condition is stable, no warning will be triggered. At this time, the stability state is normal, and continuous monitoring is sufficient. 2) If If so, it is judged as a Level 1 warning: at this time, attention should be paid to the decline in stability; 3) If If the warning level is 2, it is recommended to adjust the course or speed to reduce the environmental load. 4) If If the condition is met, it is determined to be a Level 3 warning: at this time, a safety strategy is forcibly triggered, such as automatic return to base or release of ballast. After assessing the warning situation according to the aforementioned multi-level early warning mechanism, take corresponding measures and intervene when necessary.

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