An automatic hoist cooperative control system and method for ecological fish reefs

Abstract

The present application relates to the technical field of hoisting control, and discloses an automatic hoist coordination control system and method for ecological fish reefs, comprising a controller, which is internally provided with acquisition, calibration, reconstruction, mapping, admittance and execution modules. The method steps are as follows: firstly, the tension and length data are acquired to calibrate the virtual compliance center of the ecological fish reef, and the basic virtual damping matrix of the admittance model is initialized; then, the tension data are subjected to sequence fitting, the smooth tension value and tension gradient value are extracted, the tension change vector is generated and mapped into the spatial disturbance vector acting on the virtual compliance center; subsequently, the global slack risk factor is generated according to the tension feature evaluation, the damping matrix is dynamically reconstructed, and the spatial disturbance vector is substituted into the admittance model to calculate the pose correction vector. The present application can effectively dynamically offset the external disturbance of the ocean current field, prevent the flexible cable from being slackened and mechanically impacted and damaged, and ensure the stable deployment of the ecological fish reef.

Description

Technical Field

[0001] This invention relates to the field of hoisting control technology, specifically to an automated hoisting control system and method for ecological artificial reefs. Background Technology

[0002] Ecological artificial reefs are important facilities for restoring the marine ecological environment. In the deployment and construction of ecological artificial reefs, it is necessary to use an automated lifting system and multiple flexible cables to work together to smoothly lift the heavy and irregularly shaped artificial reefs to the predetermined position on the seabed.

[0003] Existing hoisting operations rely on the controller to issue action commands to the servo winch mechanism to drive the flexible cable to extend and retract. During operation, the control system reads the data fed back by the tension sensor and absolute encoder, calculates the position compensation amount by combining the admittance control model, and dynamically adjusts the length of each cable according to the changes in external environmental forces to maintain the attitude balance of the hoisting system.

[0004] Current methods do not incorporate the eccentric load distribution characteristics of ecological artificial reefs for mechanical benchmark resetting, leading to torque coupling and error propagation during spatial force calculation. Furthermore, the complex marine construction environment results in high-frequency noise in the data output from tension sensors. Traditional methods using differential calculus to extract tension trends introduce phase delays, causing control signal lag. Additionally, flexible cables are limited to tension only, not compression. Existing admittance control models use fixed damping parameters, making it impossible for the system to dynamically assess and respond to cable slack risks when faced with external flow disturbances such as water flow pulsations. When local tension is lost, the cable is prone to temporary slack followed by instantaneous tightening, causing impact damage to the lifting equipment components and mechanical structure.

[0005] Therefore, the purpose of this invention is to provide an automated lifting device collaborative control system and method for ecological artificial reefs, in order to overcome the shortcomings of the prior art. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides an automated lifting tool collaborative control system and method for ecological artificial reefs, which solves the problems of off-center load torque coupling error, lag in force signal derivative calculation, and flow field disturbance causing slack in flexible cables and mechanical impact damage during the lifting process of ecological artificial reefs.

[0007] To achieve the above objectives, the present invention provides the following technical solution: The first aspect of this invention provides an automated lifting device collaborative control system for ecological artificial reefs, including a controller, wherein the controller internally comprises: The acquisition module is used to acquire the tensile force data output by the tensile sensor and the length data output by the absolute encoder; The calibration module is used to calibrate the virtual compliance center of the ecological reef based on the initial tensile force data and length data, and initialize the basic virtual damping matrix of the admittance model; The reconstruction module is used to perform sequence fitting on the continuous tensile data to extract smooth tensile values ​​and tensile gradient values, and generate a tensile change vector; The mapping module is used to map the tensile force change vector into a spatial perturbation vector acting on the virtual compliance center through the transpose of the spatial Jacobian matrix. The admittance module is used to evaluate and generate a global relaxation risk factor based on the smoothed tension value and the tension gradient value, reconstruct the basic virtual damping matrix using the global relaxation risk factor to generate an actual damping matrix, and substitute the spatial perturbation vector and the actual damping matrix into the admittance model to calculate the pose correction vector. The execution module is used to decouple the pose correction vector inverse kinematics into a comprehensive target angle command to control the coordinated action of the flexible cable.

[0008] This invention's system calibrates a virtual compliance center and maps tension changes as spatial disturbances. It then combines smoothed tension values ​​and tension gradient values ​​to generate a global relaxation risk factor, dynamically reconstructing the fundamental virtual damping matrix of the admittance model. During the hoisting process, the system adaptively adjusts its damping characteristics, enabling the control system to respond in real-time to external disturbances from underwater waves and currents. This counteracts pose shifts caused by transient external forces, prevents slack in the flexible cable, and ensures stable and precise deployment of the ecological artificial reef.

[0009] Preferably, the acquisition module continuously samples the original tensile signal output by the tensile sensor and the length feedback signal output by the absolute encoder within the determination time window, and calculates the tensile variance of the original tensile signal and the displacement change rate of the length feedback signal. The acquisition module compares the tensile variance with a system-preset tensile fluctuation threshold and the displacement change rate with a system-preset displacement fluctuation threshold. When the tensile variance is less than the tensile fluctuation threshold and the displacement change rate is less than the displacement fluctuation threshold, the system is confirmed to have reached a steady-state reference state, and the initial tensile data and length data are extracted based on the original tensile signal and the length feedback signal.

[0010] Preferably, the calibration module calculates the spatial coordinate vector of the connection node corresponding to the flexible cable in the global coordinate system based on the initial length data and the mechanical structural dimensions of the lifting device assembly; the calibration module establishes a static moment balance equation, determines the suspension direction of the flexible cable based on the fixed spatial coordinates of the servo winch mechanism and the spatial coordinate vector of the connection node, generates a three-dimensional spatial tension vector from the initial tension data and the corresponding suspension direction, takes the spatial coordinate vector of the connection node and the three-dimensional spatial tension vector as input, obtains the spatial centroid coordinate vector of the ecological reef by solving the static moment balance equation, and defines the coordinate position of the spatial centroid coordinate vector of the ecological reef as the virtual compliant center.

[0011] Preferably, the reconstruction module establishes a time-series sliding window for the flexible cable containing tensile data of a certain capacity length, performs local polynomial fitting on the tensile data set within the time-series sliding window using a polynomial function, uses the least squares method to solve for the constant term coefficients of the fitting function as the smoothed tensile value, and performs analytical differentiation on the fitting function to obtain the first-order term coefficients as the tensile gradient value; the reconstruction module calculates the difference between the smoothed tensile value and the initial tensile data to generate the tensile change vector.

[0012] Preferably, the mapping module solves the forward kinematic nonlinear equations based on the real-time length data and the mechanical structural dimensions of the lifting device assembly, and updates the spatial centroid coordinate vector of the ecological reef and the spatial coordinate vector of the connecting node in real time; the mapping module calculates the unit direction vector corresponding to the flexible cable and the lever arm vector pointing to the connecting node, and combines the unit direction vector and the lever arm vector to construct a spatial Jacobian matrix; the mapping module uses the transpose of the spatial Jacobian matrix to map the one-dimensional tension change vector into the spatial disturbance vector.

[0013] Preferably, the mapping module uses a nonlinear dead zone mapping function to filter and calculate the components of the spatial disturbance vector in each spatial degree of freedom to generate a six-degree-of-freedom effective disturbance vector; the mapping module extracts the force element and torque element of the six-degree-of-freedom effective disturbance vector according to the translational and rotational physical dimensions, and decouples it into a three-degree-of-freedom translational effective disturbance vector and a three-degree-of-freedom rotational effective disturbance torque vector.

[0014] Preferably, the admittance module extracts the initial tension data and multiplies it by the relaxation safety factor to calculate the relaxation safety threshold, and calculates the difference between the smoothed tension value and the relaxation safety threshold to generate a tension safety margin; when the tension gradient value is less than zero, the admittance module uses an exponential function combined with the margin-sensitive adjustment coefficient, the tension safety margin, and the tension gradient value to calculate a relaxation risk assessment factor, compares the relaxation risk assessment factors corresponding to each flexible cable, extracts the maximum value as the global relaxation risk factor, and triggers damping adaptive adjustment.

[0015] Preferably, the admittance module uses the damping gain amplification factor and the global relaxation risk factor to perform nonlinear amplification calculation on the basic virtual damping matrix to generate the actual damping matrix; the admittance module substitutes the actual damping matrix and the six-degree-of-freedom effective disturbance vector composed of the combination of the three-degree-of-freedom translational effective disturbance moment vector and the three-degree-of-freedom rotational effective disturbance moment vector into the six-degree-of-freedom virtual admittance control differential equation established in the task space coordinate system, and solves it using a discretization numerical method to obtain the pose correction vector of the current discrete control cycle.

[0016] Preferably, the execution module extracts the inverse of the spatial Jacobian matrix, decouples the pose correction vector mapping into length compensation commands assigned to each of the flexible cables, and converts the length compensation commands into compensation angle commands for the servo winch mechanism by combining the actual drum working radius and the reducer transmission ratio. The execution module algebraically adds the compensation angle commands to the system's preset basic deployment position commands to generate the comprehensive target angle command, which is then sent to the servo driver to control the flexible cables to perform coordinated tightening or unwinding actions.

[0017] The second aspect of this invention provides an automated lifting device collaborative control method for an ecological artificial reef, applied to the automated lifting device collaborative control system for an ecological artificial reef described in the first aspect, comprising the following steps: Acquire the tension data output by the tension sensor and the length data output by the absolute encoder; The virtual compliance center of the ecological reef is calibrated based on the initial tensile and length data, and the basic virtual damping matrix of the admittance model is initialized. Perform sequence fitting on the continuous tensile data to extract smoothed tensile values ​​and tensile gradient values, and generate a tensile change vector; The tensile force change vector is mapped to a spatial perturbation vector acting on the virtual compliance center through the transpose of the spatial Jacobian matrix. A global relaxation risk factor is generated based on the smoothed tension value and the tension gradient value. The basic virtual damping matrix is ​​reconstructed using the global relaxation risk factor to generate the actual damping matrix. The spatial perturbation vector and the actual damping matrix are substituted into the admittance model to calculate the pose correction vector. The pose correction vector is decoupled from the inverse kinematics into a comprehensive target angle command to drive the servo winch mechanism, thereby controlling the coordinated action of the flexible cable to counteract disturbances and prevent the flexible cable from slack.

[0018] This invention acquires and processes length and tension data, and establishes a complete closed-loop mapping from disturbance to compensation command using a spatial Jacobian matrix and admittance control logic. The method introduces the concept of a global relaxation risk factor, predicts the cable tension attenuation trend through sequence fitting and gradient calculation of continuous data, and implements nonlinear damping compensation calculations to solve the problems of uneven cable stress and slack unhooking caused by changes in marine hydrodynamics during flexible hoisting operations, thereby improving the consistency of multi-winch mechanism collaborative operations.

[0019] This invention provides an automated lifting device collaborative control system and method for ecological artificial reefs. It has the following beneficial effects: 1. This invention establishes a static moment balance equation by setting up a calibration module based on the initial tension and length data, calculates the coordinate vector of the spatial center of gravity of the ecological reef, and extracts the coordinate position as the virtual compliance center. This eliminates the spatial moment coupling effect caused by the offset size of the lifting equipment and the off-center load distribution of the ecological reef, maps the physical center of gravity to the spatial mechanical reference required by the control system, and avoids error transmission in the force calculation process.

[0020] 2. This invention establishes a time-series sliding window containing continuous tension data for flexible cables by setting up a reconstruction module. It uses local polynomial fitting to solve the constant term coefficients as smooth tension values ​​and performs analytical differentiation on the fitting function to obtain the first term coefficients as tension gradient values. This solves the problem that tension sensors at marine operation sites are easily affected by high-frequency noise interference and eliminates the phase delay associated with conventional differential differentiation. It improves the real-time observation of tension change trends while ensuring the smoothness of the underlying control signal.

[0021] 3. This invention sets up an admittance module and uses an exponential function that includes the tension safety margin and the tension gradient value to calculate the relaxation risk assessment factor. The maximum value is extracted to generate a global relaxation risk factor, and based on this, the basic virtual damping matrix is ​​nonlinearly amplified to generate an actual damping matrix. In view of the limitation that flexible cables can only be subjected to tension and not compression, the damping parameters are dynamically adjusted when the system faces the threat of relaxation, so as to cause the system to generate an appropriate target position yield. While offsetting the external disturbance of the flow field, the tension stability of multiple cables is maintained, and mechanical impact damage is prevented. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a system architecture diagram of the present invention; Figure 3 This is a flowchart of the method of the present invention; Figure 4 This is a line graph illustrating the micro-relaxation risk approximation response process of the present invention. Figure 5 This is a bar chart comparing the engineering application effects of the control method of the present invention.

[0023] Among them, 10 is a servo hoisting mechanism; 20 is a flexible cable; 30 is a tension sensor; 40 is a lifting device assembly; 50 is an absolute encoder; and 60 is a controller. Detailed Implementation

[0024] The technical solutions in 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.

[0025] See attached document Figure 1 With appendix Figure 2 The present invention provides an automated lifting device collaborative control system for an ecological artificial reef, including a controller 60, a servo winch mechanism 10, a flexible cable 20, a lifting device assembly 40, a tension sensor 30, and an absolute encoder 50.

[0026] The controller 60 is communicatively connected to the servo winch mechanism 10, the tension sensor 30, and the absolute encoder 50. The controller 60 is used to perform low-level data calculations and equipment scheduling. There are at least three servo winches 10. Each servo winch mechanism 10 is connected to a corresponding flexible cable 20. The servo winch mechanism 10 performs a winding or releasing action to change the actual suspension length of the flexible cable 20.

[0027] The end of the flexible cable 20 is connected to the lifting assembly 40. The lifting assembly 40 has multiple connection nodes and is used to fix the ecological reef to be deployed. The tension sensor 30 is connected in series at the connection between the flexible cable 20 and the lifting assembly 40. The tension sensor 30 is used to acquire the one-dimensional axial tension signal borne by each flexible cable 20 in real time. The absolute encoder 50 is set at the rotating shaft end of the servo winch mechanism 10. The absolute encoder 50 is used to measure the rotation angle data and convert it into the corresponding length feedback signal of the flexible cable 20.

[0028] The controller 60 is internally equipped with an acquisition module, a calibration module, a reconstruction module, a mapping module, an admittance module, and an execution module.

[0029] See attached document Figure 3 This invention provides an automated lifting device collaborative control method for ecological artificial reefs, comprising the following steps: During the initial hovering phase after the ecological reef is lifted and completely detached from the support surface, the acquisition module synchronously reads the initial tension data output by all tension sensors 30 and the initial length data output by all absolute encoders 50. The calibration module receives the initial tension data and initial length data, and calculates the spatial center of gravity coordinates of the current ecological reef by combining the mechanical structure dimensions and the static equilibrium equation. The calibration module defines the origin of the spatial center of gravity coordinates as the virtual compliance center. At the same time, the calibration module establishes the admittance model and initializes the basic virtual mass matrix, the basic virtual damping matrix, and the basic virtual stiffness matrix.

[0030] During the dynamic deployment of the ecological artificial reef, the acquisition module continuously acquires the raw tension data sequence fed back by each tension sensor 30 according to the set discrete control cycle. The reconstruction module receives the raw tension data sequence, establishes a time series sliding window, performs local polynomial fitting within the time series sliding window, and uses the analytical features of the polynomial to extract the smoothed tension value and tension gradient value of the current control cycle. The reconstruction module calculates the difference between the smoothed tension value and the corresponding initial tension data to generate a tension change vector.

[0031] The mapping module calculates the spatial Jacobian matrix of the current system based on the real-time acquired length feedback signal. The mapping module maps the one-dimensional tension change vector into a spatial disturbance vector acting on the virtual compliance center through the transpose operation of the spatial Jacobian matrix. The admittance module evaluates the risk state of each flexible cable approaching the relaxation threshold based on the tension gradient value and the smoothed tension value. Based on the risk state, the diagonal elements of the basic virtual damping matrix are nonlinearly reconstructed to generate a dynamic actual damping matrix.

[0032] The admittance module substitutes the spatial disturbance vector and the actual damping matrix into the admittance model and solves it using a numerical integration algorithm to calculate the pose correction vector of the virtual compliant center in the current control cycle. The execution module receives the pose correction vector and decouples it into target length compensation amounts allocated to each flexible cable 20 through parallel inverse kinematic equations. The execution module converts the target length compensation amounts into motor rotation commands and sends them to each servo winch mechanism 10, which drives the motors to move. The controller 60 repeatedly executes the data acquisition and command issuance process during dynamic deployment until the ecological reef is stably positioned.

[0033] During the initial hovering phase after the ecological artificial reef is lifted and completely detached from the support surface, the system acquires the basic zero-point parameters, and the acquisition module performs steady-state reference data acquisition operations.

[0034] When the lifting assembly 40 lifts the ecological reef and completely detaches from the support surface to enter the hovering stage, the acquisition module synchronously acquires the length feedback signals output by each absolute encoder 50 and the original tension signals output by each tension sensor 30 through the industrial communication bus. For the specific numerical conversion process of the absolute encoder 50 converting the motor rotation angle signal into the straight suspension length signal of the flexible cable 20, those skilled in the art can perform conventional kinematic conversion based on the drum pitch diameter of the servo winch mechanism 10, the reduction ratio of the reducer, and the number of winding layers of the wire rope. Mechanical transmission conversion is a well-known technology in this field.

[0035] The acquisition module establishes a decision time window in its internal memory. The decision time window is implemented using a fixed-length first-in-first-out (FIFO) data queue. Within the decision time window, the acquisition module continuously samples the original tension signal and the length feedback signal, and calculates the tension variance of the original tension signal and the displacement change rate of the length feedback signal contained in the FIFO data queue.

[0036] To avoid transient impacts caused by mechanical transmission gaps during lifting that could interfere with data accuracy, the acquisition module confirms that the entire hoisting structure is in a state of static equilibrium. This static equilibrium state corresponds to the initial hovering stage mentioned above. The static equilibrium state means that the ecological reef does not exhibit spatial sway displacement or axial elastic oscillation of the flexible cable 20 when suspended in the air.

[0037] The acquisition module compares the tension variance with the system's preset tension fluctuation threshold and the displacement change rate with the system's preset displacement fluctuation threshold. To ensure the accuracy of the control system's initialization, the specific value of the tension fluctuation threshold is determined by the system configuration personnel based on the static noise floor variance of the tension sensor 30 under no-load conditions multiplied by a calibration coefficient; the specific value of the displacement fluctuation threshold is determined by the system configuration personnel based on the mechanical brake creep limit rate of the servo hoist mechanism 10. When the tension variance corresponding to all tension sensors 30 is less than the tension fluctuation threshold, and the displacement change rate corresponding to all absolute encoders 50 is less than the displacement fluctuation threshold, the acquisition module determines that the ecological reef has reached a steady-state baseline state.

[0038] If the tensile variance corresponding to any tensile sensor 30 is greater than or equal to the tensile fluctuation threshold, or the displacement change rate corresponding to any absolute encoder 50 is greater than or equal to the displacement fluctuation threshold, the acquisition module determines that the ecological reef has not reached the steady-state baseline state. The acquisition module controls the judgment time window to slide backward along the time axis for updating.

[0039] The specific sliding update method is as follows: each time the first-in-first-out data queue receives a new sampled data, the oldest sampled data is removed, and the acquisition module re-samples, calculates, and compares the data with the threshold until the ecological reef reaches a steady-state baseline state.

[0040] When the ecological reef is confirmed to have reached a steady-state baseline, the acquisition module extracts the arithmetic mean of the original tension signals within the judgment time window, and records the arithmetic mean as the initial tension data of the corresponding flexible cable 20. ; Among them, symbols This represents the physical number of the flexible cable 20 within the system. ;symbol This represents the total number of flexible cables 20 and corresponding servo winch mechanisms 10 configured in the system. The acquisition module synchronously extracts the length feedback signals output by each absolute encoder 50 at the end of the judgment time window and records the length feedback signals as the initial length data of the corresponding flexible cable 20. .

[0041] The initial tension data includes information on the uneven distribution of static load tension at each lifting point caused by the physical center of gravity offset due to the asymmetric porous structure of the ecological reef. The initial length data includes the initial spatial geometric attitude information of each connection node of the current lifting assembly 40. The initial tension data and initial length data are sent synchronously to the calibration module and the reconstruction module to jointly form the benchmark reference data for subsequent spatial center of gravity calculation and extraction of dynamic tension changes.

[0042] After acquiring the initial tensile force and initial length data, the calibration module performs the calibration and mapping operation of the virtual compliance center.

[0043] The calibration module receives initial tension and initial length data. The ecological reef has an asymmetric porous structure, causing its physical center of gravity to deviate from its geometric center. Based on the initial length data and the mechanical structural dimensions of the spreader assembly 40, the calibration module calculates the spatial coordinate vectors of the connection nodes corresponding to each flexible cable 20 in the global coordinate system. The calibration module then establishes the static moment balance equations. ; Among them, symbols This represents the physical number of the flexible cable 20 in the system; Representative and the The spatial coordinate vector of the connection node corresponding to the flexible cable 20; Represents the spatial centroid coordinate vector of the ecological artificial reef; Representing the Initial tension data of flexible cable 20 The corresponding three-dimensional tension vector is derived from the initial tension data. It is generated by combining the suspension direction vector of the corresponding flexible cable 20; This represents the total number of flexible cables 20 and corresponding servo winch mechanisms 10 configured in the system; This represents the cross product symbol for vectors.

[0044] Since the ecological artificial reef is in its initial hovering stage, the direction of the three-dimensional spatial tension vector is along the suspension direction of the corresponding flexible cable 20. The calibration module determines the suspension direction of the flexible cable 20 based on the fixed spatial coordinates of the servo winch mechanism 10 and the spatial coordinate vectors of the connecting nodes. The calibration module obtains the specific value of the spatial centroid coordinate vector of the ecological artificial reef by solving the static moment balance equation. For the algebraic operation process of solving the static moment balance equation to obtain the spatial centroid coordinate vector of the ecological artificial reef, those skilled in the art can use the conventional linear algebra matrix inversion method, and matrix operations are well-known techniques in this field.

[0045] The calibration module extracts the coordinate position of the spatial center of gravity vector of the ecological reef, defines the coordinate position as the virtual compliant center, and maps the spatial center of gravity to the virtual compliant center. This can eliminate the spatial torque coupling effect caused by the offset size and off-center load distribution of the spreader assembly 40, so that the subsequent input control commands can directly act on the real mass center of the ecological reef, avoiding spatial attitude instability of the ecological reef caused by eccentric disturbance.

[0046] The calibration module establishes an admittance model in the internal memory of the controller 60. The admittance model is used to establish the dynamic mapping relationship between the external equivalent disturbance force and the virtual compliance center reference correction displacement. The calibration module initializes the basic virtual mass matrix, basic virtual damping matrix, and basic virtual stiffness matrix for the admittance model.

[0047] The basic virtual mass matrix is ​​a positive definite diagonal matrix. The diagonal elements of the basic virtual mass matrix correspond to the equivalent inertial parameters of the ecological reef in six spatial degrees of freedom. The calibration module sets the translational dimension diagonal elements of the basic virtual mass matrix based on the arithmetic sum of all initial tension data.

[0048] The basic virtual damping matrix is ​​used to set the basic energy dissipation rate of the system when there is no risk of cable slack. The calibration module configures the basic virtual damping matrix as a constant diagonal matrix pre-stored inside the system.

[0049] The basic virtual stiffness matrix is ​​used to define the restoring force characteristics of the system when it deviates from the equilibrium position. Under the working condition of free suspension into the water, since it is not necessary to maintain a fixed absolute position in space, the calibration module configures each diagonal element of the basic virtual stiffness matrix to zero, so that the admittance model exhibits pure damping following characteristics. Pure damping following characteristics allow the ecological reef to adapt to the impact of water flow and generate compliant displacement, avoiding the tensile sudden change caused by rigid resistance.

[0050] After completing the virtual compliant center calibration and initialization of the ecological reef, the system enters the dynamic deployment process. During the dynamic deployment process, the reconstruction module performs time series sliding window construction and data update operations.

[0051] During the dynamic deployment of the ecological artificial reef, the controller 60 operates according to a set discrete control cycle. The acquisition module continuously reads the raw tension data sequence fed back by the tension sensor 30 and sends the raw tension data sequence to the reconstruction module. The reconstruction module establishes an independent time series sliding window for each flexible cable 20. The time series sliding window is implemented using a first-in-first-out (FIFO) data queue built from the internal memory of the controller 60. The reconstruction module sets the capacity length of the FIFO data queue, which represents the total number of consecutive discrete data points simultaneously cached within the time series sliding window.

[0052] Within the current discrete control cycle, the acquisition module obtains the original tension value of the corresponding flexible cable 20. The reconstruction module receives the original tension value sent by the acquisition module and pushes it to the tail of the time series sliding window. Simultaneously, it removes the oldest historical original tension value that has existed at the head of the time series sliding window. This sliding update operation ensures that the time series sliding window always maintains the latest original tension value within the specified capacity length. The data set extracted by the reconstruction module within the current discrete control cycle is represented as follows: ; in, This represents the set of raw tension data contained within the time-series sliding window corresponding to the flexible cable 20 in the current discrete control cycle; This represents the physical number of the flexible cable 20 in the system; Represents the current discrete control cycle; Represents capacity length; This represents the initial tension value obtained within the current discrete control cycle; This represents the historical raw tension value acquired in the previous discrete control cycle; The time series sliding window represents the oldest historical original tension value retained within the time series sliding window. The time series sliding window ensures that the reconstruction module has a continuous and fixed number of tension history segments within any discrete control period. The continuous and fixed number of tension history segments constitute the data basis for subsequent local polynomial fitting.

[0053] The setting conditions for capacity length must satisfy the following relationship: ; in, This represents the polynomial order and capacity length used in subsequent local polynomial fitting. The specific value is determined by the system's expected noise reduction frequency band and discrete control period. According to the principle of digital filtering, the product of the capacity length and the discrete control period is greater than the lowest fluctuation period of the high-frequency mechanical noise in the system.

[0054] If the capacity length is too small, the time series sliding window cannot cover the fluctuation period of high-frequency noise, causing the subsequently extracted gradient data to oscillate. If the capacity length is too large, the local polynomial fitting spans too long a time, causing the tension reconstruction result to not truly reflect the transient force change within the current discrete control cycle. The system configuration personnel write the determined capacity length into the controller 60 based on the noise spectrum characteristics collected by the field tension sensor 30.

[0055] After acquiring the set of raw tensile data contained within the time series sliding window, the reconstruction module performs the analytical tensile gradient extraction operation.

[0056] Traditional control systems use a first-order difference algorithm to calculate the tension gradient. The first-order difference algorithm amplifies high-frequency mechanical noise. If a low-pass filter is introduced into the control system to process the high-frequency mechanical noise, the low-pass filter will produce a physical phase delay, causing oscillations in the closed-loop control system. The reconstruction module performs local polynomial fitting within the time series sliding window to extract smooth tension values ​​and tension gradient values.

[0057] The reconstruction module establishes a local relative time coordinate system for the corresponding flexible cable 20. In this system, the module sets the current discrete control cycle as the origin. It then discretizes the time corresponding to each historical sampling point within the time series sliding window according to the discrete control cycle, obtaining the corresponding local relative time variables. Finally, the module uses a polynomial function to fit the original tension data set within the time series sliding window. The fitting function is expressed as: ; in, This represents the fitted continuous function of the tensile force; Represents a local relative time variable; Represents the coefficient of the constant term; Represents the coefficient of the linear term; Represents the coefficient of the quadratic term; Represents the coefficient of the highest-order term; This indicates the order of the polynomial used for subsequent local polynomial fitting. The polynomial order used for subsequent local polynomial fitting is configured as either second or third order, balancing real-time computation with nonlinearity tracking capability.

[0058] The reconstruction module constructs a target cost function, which measures the overall deviation between the fitted continuous tensile force function and the original tensile force data set. The target cost function is expressed as: ; in, The sum of squared residuals obtained from the calculation of the objective cost function; Represents capacity length; Represents the data point number within the time series sliding window; The specific value of the local relative time variable corresponding to the data point number; This represents the actual original tensile force value contained within the time series sliding window. The reconstruction module uses the least squares method to solve the target cost function, seeking a set of polynomial coefficients that minimizes the sum of squared residuals. For the matrix differentiation and algebraic operations involved in solving the polynomial coefficients using the least squares method, those skilled in the art can employ conventional numerical analysis algorithms, and matrix parameter fitting is a well-known technique in this field.

[0059] After obtaining the polynomial coefficients, the reconstruction module uses the analytical characteristics of the fitted continuous force function to extract the smoothed force value and force gradient value of the current discrete control cycle. Because the current discrete control cycle is located at the origin in the local relative time coordinate system, the reconstruction module substitutes the local relative time variable value of zero into the fitted function to obtain the smoothed force value. The smoothed force value is numerically directly equal to the constant term coefficient. The reconstruction module performs analytical differentiation on the fitted function to obtain the analytical derivative equation of the force: ; in, The tensile analytical derivative function is represented by the reconstructing module. The local relative time variable is set to zero and substituted into the tensile analytical derivative equation to obtain the tensile gradient value. The tensile gradient value is directly equal to the coefficient of the first term. The smooth tensile value and tensile gradient value are obtained directly using the analytical state, avoiding the delay in differential calculation caused by the time span.

[0060] After obtaining the smoothed tension value, the reconstruction module calls the initial tension data of the corresponding flexible cable 20 stored in the calibration module. The reconstruction module calculates the difference between the smoothed tension value and the initial tension data to generate the tension change. The formula for calculating the tension change is as follows: ; in, This represents the change in tension of the corresponding flexible cable 20 within the current discrete control cycle; This represents the physical number of the flexible cable 20 in the system; Represents the smoothing tensile force value; This represents the initial tension data. The reconstruction module combines the tension changes of multiple flexible cables 20 into a one-dimensional tension change vector. The reconstruction module sends the tension change vector to the mapping module. Simultaneously, the reconstruction module sends the tension gradient value and the smoothed tension value to the admittance module. The tension gradient value and the smoothed tension value constitute the state evaluation data for the admittance module to perform asymmetric variable damping control.

[0061] After obtaining the one-dimensional vector of tensile force change, the mapping module performs the construction of the spatial Jacobian matrix and the mapping operation of the disturbance force.

[0062] The mapping module obtains the fixed spatial coordinate vectors of the servo winch mechanism 10 corresponding to each flexible cable 20, which are pre-stored within the system. The mapping module receives the length feedback signal of the current discrete control cycle sent by the absolute encoder 50. Based on the length feedback signal and the mechanical structure dimensions of the lifting assembly 40, the mapping module establishes a set of forward kinematic nonlinear equations. For the numerical iterative process of solving the set of forward kinematic nonlinear equations using the length feedback signal to obtain the spatial attitude, those skilled in the art can use the conventional Newton-Raphson iterative algorithm. The forward kinematic solution is a well-known technology in this field.

[0063] The mapping module updates the spatial centroid coordinate vector of the ecological artificial reef and the spatial coordinate vectors of the connection nodes corresponding to each flexible cable 20 in real time by solving the nonlinear equations of forward kinematics. The mapping module calculates the unit direction vector corresponding to each flexible cable 20. The formula for calculating the unit direction vector is as follows: ; in, Representative and the The unit direction vector corresponding to the 20 flexible cables; This represents the physical number of the flexible cable 20 in the system; Representative and the The fixed spatial coordinate vector of the servo winch mechanism 10 corresponding to the flexible cable 20; Representative and the The spatial coordinate vector of the connection node corresponding to the flexible cable 20; Representative and the The length feedback signal value of the current discrete control cycle corresponding to the flexible cable 20.

[0064] The mapping module calculates the lever arm vector from the spatial centroid coordinate vector of the ecological reef to the connection node corresponding to each flexible cable 20. The mapping module combines the unit direction vector and lever arm vector corresponding to each flexible cable 20 to construct a spatial Jacobian matrix. The specific expression of the spatial Jacobian matrix is ​​as follows: ; in, Represents the Jacobian matrix of the space; Represents the unit direction vector corresponding to the first flexible cable 20; This represents the unit direction vector corresponding to the last flexible cable 20; The spatial coordinate vector representing the connection node corresponding to the first flexible cable 20; This represents the spatial coordinate vector of the connection node corresponding to the last flexible cable 20; Represents the spatial centroid coordinate vector of the ecological artificial reef; This represents the total number of flexible cables 20 and corresponding servo winch mechanisms 10 configured in the system; Represents the cross product symbol for vectors; The transpose operator represents a matrix or vector.

[0065] The mapping module performs a transpose operation on the spatial Jacobian matrix to obtain its transpose. The mapping module then uses this transpose to map the one-dimensional vector of tensile force change into a spatial disturbance vector. The mapping calculation formula is as follows: ; in, Represents the spatial perturbation vector; The transpose of the spatial Jacobian matrix; This represents a one-dimensional vector of the change in tensile force.

[0066] The spatial disturbance vector contains translational disturbance forces along the three spatial rectangular coordinate axes and rotational disturbance torques about the three spatial rectangular coordinate axes. The mapping module sends the spatial disturbance vector to the admittance module, and the spatial disturbance vector serves as the input condition for driving the admittance model to generate the reference correction displacement.

[0067] After obtaining the spatial perturbation vector, the mapping module performs dead zone filtering and effective component calculation operations for the external equivalent perturbation force.

[0068] In the system's operating environment, there is water flow pulsation noise. The mechanical vibration of multiple flexible cables 20 will cause small force changes in the system. If the mapping module directly inputs the small force changes into the admittance model, it will cause high-frequency small jumps in the subsequently calculated displacement commands. These high-frequency small jumps will cause the servo hoist mechanism 10 to reciprocate frequently, increasing the mechanical wear of the system and reducing the service life of the equipment. The mapping module performs nonlinear dead zone mapping calculation on the spatial disturbance vector.

[0069] The mapping module retrieves pre-configured dead-zone thresholds corresponding to each spatial degree of freedom from the internal memory of the controller 60. To ensure sufficient disclosure and engineering feasibility, the specific values ​​of the dead-zone thresholds are determined by the system configuration personnel based on the mechanical residual variances of each spatial degree of freedom collected under still water hovering conditions, multiplied by a safety confidence coefficient. This ensures that the dead-zone thresholds accurately cover the system's background mechanical noise amplitude. The mapping module uses a nonlinear dead-zone mapping function to filter and calculate the external equivalent disturbance force components of the spatial disturbance vector. The nonlinear dead-zone mapping function is expressed as follows: ; in, The effective perturbation vector representing the six degrees of freedom is in the th... Effective disturbance force components in each spatial degree of freedom; Physical designations representing degrees of freedom in space. ; The spatial perturbation vector is represented in the th... External equivalent disturbance force components in each spatial degree of freedom; Representing the The set dead zone threshold corresponding to each spatial degree of freedom; Represents mathematical symbolic functions; The symbol represents the absolute value operator; the above six-degree-of-freedom effective perturbation vector is generated by filtering the spatial perturbation vector through nonlinear dead zone mapping.

[0070] The mapping module recombines the effective disturbance force components calculated on each spatial degree of freedom according to the spatial coordinate axis order to generate a complete six-degree-of-freedom effective disturbance force vector. The six-degree-of-freedom effective disturbance force vector eliminates mechanical jitter interference near the zero point.

[0071] The mapping module decomposes and decouples the six-degree-of-freedom effective perturbation force vector according to the translational and rotational physical dimensions. The mapping module extracts the force elements along the three spatial rectangular coordinate axes from the six-degree-of-freedom effective perturbation force vector and combines them to generate a three-degree-of-freedom translational effective perturbation force vector. The mapping module also extracts the torque elements about the three spatial rectangular coordinate axes from the six-degree-of-freedom effective perturbation force vector and combines them to generate a three-degree-of-freedom rotational effective perturbation force torque vector. The three-degree-of-freedom translational effective perturbation force vector and the three-degree-of-freedom rotational effective perturbation force torque vector are sent to the admittance module simultaneously. The three-degree-of-freedom translational effective perturbation force vector and the three-degree-of-freedom rotational effective perturbation force torque vector together serve as the real mechanical input source for driving the admittance model to generate the target following trajectory.

[0072] After obtaining the tension gradient value and the smoothed tension value, the admittance module performs the operation of setting the physical boundary of the unilateral constraint of the flexible cable 20 and the relaxation safety threshold.

[0073] The flexible cable 20 exhibits purely flexible mechanical properties, capable only of withstanding axial tensile force but not axial compressive force. It constitutes a unilateral constraint physical boundary for the control system. If, during dynamic deployment, the tensile force on the flexible cable 20 drops to zero, it will slack off. This slack will cause the control system to lose its ability to constrain the position and orientation of the corresponding suspension points on the ecological reef. When the ecological reef is subjected to renewed force, causing the flexible cable 20 to momentarily tighten, an impact load will be generated, leading to mechanical structural damage. The admittance module needs to perform real-time quantitative assessment of the slack risk of the flexible cable 20.

[0074] The admittance module retrieves a pre-written relaxation safety factor from the internal memory of the controller 60. This relaxation safety factor is used to reserve physical response time for the control system to perform damping adjustments. System configuration personnel calculate and determine the relaxation safety factor based on the maximum braking acceleration of the servo hoist mechanism 10 and the communication bus delay period of the controller 60. The admittance module extracts the initial tension data stored internally in the calibration module. The admittance module multiplies the initial tension data by the relaxation safety factor to calculate the corresponding relaxation safety threshold for the flexible cable 20. The formula for calculating the relaxation safety threshold is: ; in, This represents the relaxation safety threshold corresponding to the flexible cable 20; Represents the relaxation safety factor; This represents the initial tensile force data.

[0075] The admittance module obtains the smoothed tension value sent by the reconstruction module. The admittance module calculates the difference between the smoothed tension value and the relaxation safety threshold of the corresponding flexible cable 20, generating a tension safety margin for the corresponding flexible cable 20. This tension safety margin characterizes the degree of danger of the current stress state of the corresponding flexible cable 20 approaching the physical boundary of a single-sided constraint. The formula for calculating the tension safety margin is as follows: ; in, This represents the safety margin of tensile force for the corresponding flexible cable 20; This represents the smoothed tension value. The process by which the controller 60 calls data from its internal memory and performs basic algebraic multiplication and subtraction operations can be implemented using conventional microprocessor instruction logic by those skilled in the art; data retrieval and algebraic operations are well-known techniques in this field.

[0076] The admittance module determines the positive or negative attribute of the tension safety margin of the corresponding flexible cable 20. When the tension safety margin of the corresponding flexible cable 20 is greater than zero, it indicates that the current tension state of the corresponding flexible cable 20 is within the safe range. When the tension safety margin of the corresponding flexible cable 20 is less than or equal to zero, it indicates that the corresponding flexible cable 20 is about to or has already become slack. The admittance module uses the tension safety margin of the corresponding flexible cable 20 as the trigger condition and adjustment scale input for the subsequent asymmetric variable damping control strategy.

[0077] After obtaining the tension safety margin and tension gradient value of the corresponding flexible cable 20, the admittance module performs the operation of establishing relaxation risk assessment factors.

[0078] The ecological artificial reef is subjected to complex flow field impacts underwater, and the stress state of the flexible cable 20 is in a dynamic state. The tension safety margin of the corresponding flexible cable 20 can only reflect the current static stress state and cannot predict the stress evolution trend. When the tension of the flexible cable 20 decreases rapidly, even if the tension safety margin of the corresponding flexible cable 20 is large, the control system may cross the unilateral constraint physical boundary in the next discrete control cycle. The admittance module needs to integrate the smoothed tension value and the tension gradient value of the corresponding flexible cable 20 to construct a dynamic evaluation model.

[0079] The admittance module extracts the tension gradient value of the corresponding flexible cable 20 calculated by the reconstruction module. The admittance module determines the sign of the tension gradient value of the corresponding flexible cable 20. When the tension gradient value of the corresponding flexible cable 20 is greater than or equal to zero, it indicates that the tension borne by the flexible cable 20 is increasing or remaining stable. The flexible cable 20 does not have a physical movement trend toward the slack boundary. The admittance module directly sets the slack risk assessment factor of the corresponding flexible cable 20 to zero.

[0080] When the tension gradient value of the corresponding flexible cable 20 is less than zero, it indicates that the tension borne by the flexible cable 20 is continuously decreasing. The admittance module calculates the slack risk assessment factor of the corresponding flexible cable 20 based on the tension safety margin and the tension gradient value of the corresponding flexible cable 20. The calculation formula for the slack risk assessment factor is as follows: ; in, This represents the slack risk assessment factor corresponding to flexible cable 20; Represents the natural constant; Represents the margin-sensitive adjustment coefficient; This represents the safety margin of tensile force for the corresponding flexible cable 20; This represents the tension gradient value corresponding to the flexible cable 20; This represents the absolute value operator.

[0081] The margin-sensitive adjustment coefficient is used to control the nonlinear decay rate of the exponential function. System configuration personnel determine the specific value of the margin-sensitive adjustment coefficient based on the elastic modulus of the flexible cable 20 and the operating bandwidth of the control system. An evaluation model is constructed using an exponential function, which generates nonlinear response characteristics as the tensile safety margin of the flexible cable 20 gradually decreases. This nonlinear response characteristic allows the control system to instantaneously increase system damping at the relaxation critical state. For the process of the microprocessor executing the exponential function and absolute value calculation, those skilled in the art can implement it using standard mathematical library function calls; basic mathematical function calls are well-known techniques in this field.

[0082] The admittance module calculates the relaxation risk assessment factor for all flexible cables 20 in the system. The admittance module compares the relaxation risk assessment factors for all flexible cables 20 and extracts the relaxation risk assessment factor with the largest value as the global relaxation risk factor. The formula for calculating the global relaxation risk factor is as follows: ; in, Represents the global relaxation risk factor; This represents the function for selecting the maximum value. These represent the slack risk assessment factors corresponding to the first to the last flexible cable 20 in the system, respectively. This represents the total number of flexible cables 20 and corresponding servo winch mechanisms 10 configured in the system.

[0083] The global relaxation risk factor represents the maximum relaxation threat faced by the current ecological artificial reef hoisting system. The admittance module uses the global relaxation risk factor to drive the asymmetric evolution of the basic virtual damping matrix, thereby achieving adaptive adjustment of the damping parameters.

[0084] After obtaining the global relaxation risk factor, the effective perturbation force vector of three degrees of freedom translation, and the effective perturbation moment vector of three degrees of freedom rotation, the admittance module performs asymmetric reconstruction and discretization of the damping matrix.

[0085] The admittance module retrieves the basic virtual damping matrix from the internal memory of controller 60. System configuration personnel pre-configure the basic virtual damping matrix based on the mass distribution parameters of the ecological reef and the desired critical damping ratio. To prevent unnecessary motion hysteresis in the control system when far from the relaxation hazard boundary, the admittance module introduces an asymmetric reconfiguration mechanism. This mechanism controls the control system to dynamically increase virtual damping only when facing relaxation hazard. The admittance module uses a global relaxation risk factor to perform nonlinear amplification calculations on the basic virtual damping matrix. The damping reconfiguration calculation formula is: ; in, Represents the asymmetric reconstruction damping matrix; Represents the basic virtual damping matrix; This represents the damping gain amplification factor; This represents the global relaxation risk factor.

[0086] The system configuration personnel determine the specific value of the damping gain amplification factor based on the maximum allowable output torque of the servo hoisting mechanism 10, so as to avoid the increased virtual damping exceeding the physical limits of the hardware. The basic virtual damping matrix is ​​dynamically adjusted using the global relaxation risk factor, and the motion viscous resistance of the control system is increased instantaneously when the flexible cable 20 tends to relax, so as to consume the external disturbance energy.

[0087] The admittance module substitutes the asymmetric reconstruction damping matrix into the six-degree-of-freedom virtual admittance control differential equation established in the mission space coordinate system. The six-degree-of-freedom virtual admittance control differential equation is expressed as: ; in, Represents the virtual quality matrix; Represents the reference correction acceleration vector; Represents the reference correction velocity vector; Represents the virtual stiffness matrix; Represents the pose correction vector; This represents the effective perturbation vector for six degrees of freedom.

[0088] The six-degree-of-freedom effective disturbance force vector is composed of a three-degree-of-freedom translational effective disturbance force vector and a three-degree-of-freedom rotational effective disturbance moment vector. The virtual mass matrix is ​​used to simulate the inertial characteristics of the ecological reef, and the virtual stiffness matrix is ​​used to provide the elastic restoring force that drives the ecological reef back to the desired position. The system configuration personnel write the virtual mass matrix and virtual stiffness matrix into the internal memory of the controller 60 in advance, in conjunction with the stability margin of the control system.

[0089] The admittance module performs discretized numerical solutions to the six-degree-of-freedom virtual admittance control differential equations. For the calculation process of obtaining displacement and velocity states by solving second-order ordinary differential equations using discretized numerical methods, those skilled in the art can employ the conventional fourth-order Runge-Kutta algorithm. Discretization of ordinary differential equations is a well-known technique in this field and will not be elaborated upon here.

[0090] Through discretized numerical solution, the admittance module obtains the pose correction vector of the current discrete control cycle. The pose correction vector contains three linear displacement components and three rotational angular displacement components. The admittance module outputs the pose correction vector to the subsequent inverse kinematics control node. The inverse kinematics control node uses the inverse matrix of the spatial Jacobian matrix to map the pose correction vector into the length compensation command of each flexible cable 20. Combined with the drum radius parameter, the compensation angle command of each servo winch mechanism 10 is calculated, driving the servo winch mechanism 10 to generate adaptive motion compensation action.

[0091] After obtaining the pose correction vector, the inverse kinematics control node performs the inverse kinematics assignment operation for the small correction displacement.

[0092] The inverse kinematics control node's mapping extraction module calculates the updated spatial Jacobian matrix. For a system driven by multiple flexible cables 20 in parallel, within a small motion range, there is an approximately linear mapping relationship between the pose change in the task space and the cable length change in the joint space. The inverse kinematics control node uses the spatial Jacobian matrix to convert the pose correction vector into a length compensation vector for the multiple flexible cables 20. Using linear matrix mapping instead of solving nonlinear inverse kinematic equations reduces the computation time of the microprocessor performing discrete calculations. The mapping calculation formula for the length compensation vector is: ; in, This represents the length compensation vector for multiple flexible cables 20; Represents the Jacobian matrix of the space; Representing the pose correction vector, the length compensation vector of the multiple flexible cables 20 is a one-dimensional column vector containing the scalar length compensation value corresponding to each flexible cable 20 in the system.

[0093] The inverse kinematics control node decomposes the length compensation vectors of multiple flexible cables 20 into corresponding length compensation instructions for the flexible cables 20 according to their physical numbers. The inverse kinematics control node calls the mechanical configuration parameters of the servo winch mechanism 10. The mechanical configuration parameters include the initial drum physical radius and the reducer transmission ratio. The system configuration personnel pre-write the initial drum physical radius and the reducer transmission ratio to the controller 60 according to the actual mechanical structure dimensions of the servo winch mechanism 10 and the gearbox specifications.

[0094] The multi-layer winding of the flexible cable 20 on the drum of the servo winch mechanism 10 causes a change in the actual working radius. The inverse kinematics control node dynamically calculates the actual drum working radius under the current working state using the length feedback signal of the corresponding flexible cable 20, the physical diameter of the flexible cable 20, and the width of the rope arrangement on the drum of the servo winch mechanism 10. Based on the actual drum working radius and the gearbox transmission ratio, the inverse kinematics control node converts the length compensation command of the corresponding flexible cable 20 into a compensation angle command for the corresponding servo winch mechanism 10. The calculation formula for the compensation angle command is: ; in, This represents the compensation angle command corresponding to the servo hoist mechanism 10; This represents the length compensation instruction for the corresponding flexible cable 20; Represents the gear ratio of the reducer; Represents the actual working radius of the drum; This represents the physical number of the flexible cable 20 in the system.

[0095] Through the inverse kinematics calculation process, the inverse kinematics control node distributes the pose correction vector established in the ecological reef task space to the motor rotation shaft of each servo winch mechanism 10. The compensation angle command of each servo winch mechanism 10 and the basic deployment position command sent by the main trajectory planner are fed forward and superimposed to form the reference input benchmark for the servo driver to perform position closed-loop following control. The servo driver drives the corresponding servo motor to produce position retreat or tightening action, dynamically eliminating the external disturbance force of the ocean current field applied to the ecological reef.

[0096] After obtaining the compensation angle command of each servo hoist mechanism 10, the control system executes servo low-level control and global iterative closed-loop operation.

[0097] The main trajectory planner uses the discrete control cycle to perform time-valued integration on the preset lowering speed. Combined with the preset lowering depth of the ecological reef and the actual drum working radius of the servo winch mechanism 10, it generates the basic deployment position command for the corresponding servo winch mechanism 10. The inverse kinematics control node algebraically adds the compensation angle command and the basic deployment position command of the corresponding servo winch mechanism 10 to calculate the comprehensive target angle command. This comprehensive target angle command serves as the control reference for the underlying drive components. The formula for calculating the comprehensive target angle command is: ; in, This represents the comprehensive target rotation angle command corresponding to the servo hoisting mechanism 10; This represents the basic deployment position command for the corresponding servo hoisting mechanism 10; This represents the compensation angle command for the corresponding servo hoisting mechanism 10.

[0098] The servo driver receives the comprehensive target rotation angle command from the corresponding servo hoisting mechanism 10. The servo driver is internally configured with a position regulator, a speed regulator, and a current regulator, forming a three-stage closed-loop control loop. The servo driver reads the actual rotor position signal fed back by the encoder at the tail of the servo motor and calculates the position deviation between the actual rotor position signal and the comprehensive target rotation angle command from the corresponding servo hoisting mechanism 10. For the underlying control logic of the servo driver to drive the servo motor by performing position loop proportional regulation, speed loop proportional-integral regulation, and current loop space vector pulse width modulation using the position deviation, those skilled in the art can use conventional AC servo motor drive algorithms. The three-stage closed-loop control of AC servo motors is a well-known technology in this field and will not be described in detail here.

[0099] The servo motor outputs electromagnetic torque to drive the drum of the corresponding servo winch mechanism 10 to rotate, performing tightening or unwinding actions on multiple flexible cables 20. The multiple flexible cables 20 work together to change their physical length, forcing the ecological reef to undergo attitude deflection and position translation underwater. The attitude deflection and position translation generated by the ecological reef can counteract the external disturbance force exerted on the ecological reef by the ocean current field. Combined with the aforementioned asymmetric variable damping control strategy, when the flexible cable 20 approaches the physical boundary of the unilateral constraint, the control system increases the kinematic viscous resistance, limits the release speed of the servo motor, and prevents the flexible cable 20 from slackening and causing mechanical impact damage.

[0100] After the servo action of the current discrete control cycle is completed, the system time steps to the next discrete control cycle. The displacement compensation generated by the servo winch mechanism 10 and the external disturbance force applied by the ocean current field jointly change the force state of the multiple flexible cables 20. The change in the physical tension of the multiple flexible cables 20 is transmitted to the multi-dimensional force sensor set on the water surface support platform. The underlying data acquisition hardware rereads the analog voltage signal output by the multi-dimensional force sensor and converts it into digital tensile data.

[0101] The reconstruction module receives the digital tension data of the next discrete control cycle, restarts the signal smoothing filtering and tension gradient calculation process, and the mapping module and admittance module re-evaluate the global relaxation risk factor based on the updated mechanical state and update the pose correction vector. The continuous iterative calculation of multiple cycles enables the control system to form a closed-loop data flow. The closed-loop data flow continuously offsets external hydrodynamic interference and avoids the risk of unilateral constraint failure, maintaining the stability of the ecological reef in the underwater environment.

[0102] Specific application examples: To verify the effectiveness of the automated lifting device collaborative control system and method for ecological artificial reefs proposed in this invention in solving the problems of attitude instability and mechanical impact damage caused by the offset of the center of gravity and the slack of the flexible cable 20 in asymmetric porous ecological artificial reefs under ocean current pulsation interference, this embodiment is based on the deployment application scenario of a large concrete ecological artificial reef in a nearshore area with a water depth of 20 meters, and combined with the attached... Figure 4 and attached Figure 5 The data shown will be explained in detail.

[0103] Appendix Figure 4 and attached Figure 5 The data in this document are all control logic operation data captured in real time in the background of this control system, as well as engineering comparison data with traditional rigid position closed-loop control methods.

[0104] In the application scenario of this embodiment, the system is configured with four sets of servo hoisting mechanisms 10 and flexible cables 20 (i.e., The ecological reef is designed with an asymmetric porous structure. The lifting assembly 40 adopts a four-point array connection. The dynamic deployment control strategy is executed through this control system to prevent cross-current impact and the risk of unilateral constraint failure during the water entry process.

[0105] Implementation of spatial parameter calibration and dynamic disturbance extraction: During the initial hovering phase after the ecological artificial reef is lifted and completely detached from the deck support surface, the system determines that the structure is in a state of static equilibrium. The initial tensile force data extracted by the acquisition module are as follows: , , , Due to uneven initial tension distribution, it was proven that there was a physical center of gravity offset. The calibration module was based on the static torque balance equation. Mapping the spatial center of gravity to a virtual compliant center And initialize the basic virtual mass matrix and the basic virtual damping matrix. .

[0106] During the dynamic deployment process, when the reef was lowered to a water depth of 10 meters, it encountered a sudden bottom-level pulsating crosscurrent, causing a sharp decrease in tension in the third flexible cable (20). The reconstruction module performed local polynomial fitting within a time-series sliding window to extract the smoothed tension value for the current discrete control cycle. Tension gradient value The reconstruction module calculates the change in tensile force. The one-dimensional tensile force change is transformed into an external equivalent disturbance force by the mapping module through the Jacobian matrix transpose operation, and low-frequency mechanical noise is filtered out by nonlinear dead zone mapping.

[0107] Minor relaxation risk assessment and shock damping reconfiguration implementation: To verify the system's anti-relaxation and compliance control capabilities, the admittance module performed a real-time quantitative evaluation. This was based on the system's set relaxation safety factor. The relaxation safety threshold corresponding to the third flexible cable 20 is calculated. The system further calculates the safety margin of the tensile force of the third flexible cable 20: .

[0108] From the appendix Figure 4 It can be seen that the appendix Figure 4 The horizontal axis represents the descent time (s), and the vertical axis represents the tension value (N). During the stable descent interval from 20s to 23s, the smooth tension value of the third flexible cable 20 is maintained at a high initial tension level of nearly 16000N, and the system is in a safe mechanical constraint state. As time progresses to 23s, a sudden underwater crossflow causes the stress state to deteriorate, and the smooth tension solid line shows a nonlinear and sharp decline, rapidly dropping to the relaxation safety threshold dashed line of 4800N. The control system continuously solves this sudden drop process through the reconstruction module. At the high-risk characteristic moment of 25s, it not only extracts the current tension value of 5600N, but also calculates in advance that the system has a downward movement trend that breaks through the physical safety boundary based on the derivative model. At this time, the tension safety margin drops rapidly to only 5600N-4800N=800N.

[0109] Admittance module determines tensile gradient Adjust the system based on the system's configured margin sensitivity coefficient. Calculate the slack risk assessment factor for the three flexible cables (20). .

[0110] This value has been determined to be the global maximum value; therefore, the global relaxation risk factor is... Set the damping gain amplification factor The admittance module reconstructs the basic virtual damping matrix: Through asymmetric reconstruction, when the control system approaches the unilateral constraint physical boundary (i.e., the relaxed safety threshold), the virtual damping is instantaneously amplified to 4.6 times the base value. This surge in damping forces the reference correction displacement to decay, and the inverse kinematics control node is based on the actual drum working radius ( ) and the gear ratio of the reducer ( ), calculate compensation angle command This limits the rope release speed of the servo drive and forcibly increases viscous resistance before the flexible cable 20 approaches slack, maintaining the tension of the system.

[0111] Experimental Verification and Effect Comparison: To compare the control effect of this invention, multiple artificial reef hoisting operations were performed under the same sea conditions, using both traditional rigid constant-speed lowering control and the automated collaborative control of this system. (See attached...) Figure 5The detailed data in the bar chart is visible in the appendix. Figure 5 The system features a dual Y-axis structure, where the left longitudinal axis represents the maximum peak impact tensile force (kN), and the right longitudinal axis represents the number of physical relaxations (times). Traditional methods, in cross-current waves, result in up to six relaxation events due to repeated relaxation and sudden tightening of the cable. The maximum peak impact tensile force instantaneously generated by traditional methods reaches 38.5kN, easily leading to cable breakage and reef overturning due to eccentric loading. However, this system, by incorporating an asymmetric variable damping control strategy based on a relaxation risk assessment factor, reduces the number of relaxation events to zero. Through adaptive position retraction of the servo motor, the maximum peak impact tensile force is constrained within a safe range of 18.2kN, eliminating the risk of mechanical impact damage.

[0112] Application Implementation Summary: This implementation demonstrates the engineering practicality of the ecological artificial reef automated lifting device collaborative control system. On the one hand, it reconstructs and smooths the tension and tension gradient based on the original tension data sequence, dynamically deduces the tension safety margin, and overcomes the interference of high-frequency noise from underwater sensors. On the other hand, when it is determined that the flexible cable 20 is under stress approaching the physical boundary of the unilateral constraint, it amplifies the virtual damping based on the exponential nonlinear model, consumes the energy of external water flow disturbance, and distributes the small correction displacement of the motor through inverse kinematic mapping, which not only ensures the trajectory tracking during the lowering process, but also avoids attitude instability and mechanical damage caused by rigid following.

Claims

1. An automated lifting device collaborative control system for an ecological artificial reef, comprising a controller (60), characterized in that, The controller (60) is internally equipped with: The acquisition module is used to acquire the tension data output by the tension sensor (30) and the length data output by the absolute encoder (50); The calibration module is used to calibrate the virtual compliance center of the ecological reef based on the initial tensile force data and length data, and initialize the basic virtual damping matrix of the admittance model; The reconstruction module is used to perform sequence fitting on the continuous tensile data to extract smooth tensile values ​​and tensile gradient values, and generate a tensile change vector; The mapping module is used to map the tensile force change vector into a spatial perturbation vector acting on the virtual compliance center through the transpose of the spatial Jacobian matrix. The admittance module is used to evaluate and generate a global relaxation risk factor based on the smoothed tension value and the tension gradient value, reconstruct the basic virtual damping matrix using the global relaxation risk factor to generate an actual damping matrix, and substitute the spatial perturbation vector and the actual damping matrix into the admittance model to calculate the pose correction vector. The execution module is used to decouple the pose correction vector inverse kinematics into a comprehensive target angle command to control the coordinated action of the flexible cable (20).

2. The automated lifting device collaborative control system for an ecological artificial reef according to claim 1, characterized in that, The acquisition module continuously samples the original tensile signal output by the tensile sensor (30) and the length feedback signal output by the absolute encoder (50) within the judgment time window, and calculates the tensile variance of the original tensile signal and the displacement change rate of the length feedback signal. The acquisition module compares the tensile variance with the system's preset tensile fluctuation threshold and the displacement change rate with the system's preset displacement fluctuation threshold. When the tensile variance is less than the tensile fluctuation threshold and the displacement change rate is less than the displacement fluctuation threshold, the system is confirmed to have reached a steady-state reference state. The module then extracts the initial tensile data and length data based on the original tensile signal and the length feedback signal.

3. The automated lifting device collaborative control system for an ecological artificial reef according to claim 2, characterized in that, The calibration module calculates the spatial coordinate vector of the connection node corresponding to the flexible cable (20) in the global coordinate system based on the initial length data and the mechanical structure dimensions of the lifting assembly (40); The calibration module establishes a static torque balance equation, determines the suspension direction of the flexible cable (20) based on the fixed spatial coordinates of the servo winch mechanism (10) and the spatial coordinate vector of the connecting node, generates a three-dimensional spatial tension vector by combining the initial tension data with the corresponding suspension direction, takes the spatial coordinate vector of the connecting node and the three-dimensional spatial tension vector as input, obtains the spatial centroid coordinate vector of the ecological reef by solving the static torque balance equation, and defines the coordinate position of the spatial centroid coordinate vector of the ecological reef as the virtual compliant center.

4. The automated lifting device collaborative control system for an ecological artificial reef according to claim 1, characterized in that, The reconstruction module establishes a time series sliding window for the flexible cable (20) containing the tensile data of the capacity length, performs local polynomial fitting on the tensile data set in the time series sliding window using a polynomial function, uses the least squares method to solve the constant term coefficient of the fitting function as the smoothed tensile value, and performs analytical differentiation on the fitting function to obtain the first term coefficient as the tensile gradient value. The reconstruction module calculates the difference between the smoothed tension value and the initial tension data, and generates the tension change vector.

5. The automated lifting device collaborative control system for an ecological artificial reef according to claim 3, characterized in that, The mapping module solves the forward kinematic nonlinear equations based on the real-time length data and the mechanical structure dimensions of the lifting assembly (40), and updates the spatial centroid coordinate vector of the ecological reef and the spatial coordinate vector of the connecting node in real time. The mapping module calculates the unit direction vector corresponding to the flexible cable (20) and the lever arm vector pointing to the connection node, and combines the unit direction vector and the lever arm vector to construct a spatial Jacobian matrix. The mapping module uses the transpose of the spatial Jacobian matrix to map the one-dimensional tension change vector into the spatial disturbance vector.

6. The automated lifting device collaborative control system for an ecological artificial reef according to claim 1, characterized in that, The mapping module uses a nonlinear dead zone mapping function to filter and calculate the components of the spatial disturbance vector in each spatial degree of freedom, generating a six-degree-of-freedom effective disturbance vector. The mapping module extracts the force and torque elements from the six-degree-of-freedom effective disturbance vector according to the translational and rotational physical dimensions, and decouples it into a three-degree-of-freedom translational effective disturbance vector and a three-degree-of-freedom rotational effective disturbance torque vector.

7. The automated lifting device collaborative control system for an ecological artificial reef according to claim 2, characterized in that, The admittance module extracts the initial tensile force data and multiplies it by the relaxation safety factor to calculate the relaxation safety threshold. The difference between the smoothed tensile force value and the relaxation safety threshold is then calculated to generate a tensile force safety margin. When the tension gradient value is less than zero, the admittance module uses an exponential function combined with the margin-sensitive adjustment coefficient, the tension safety margin and the tension gradient value to calculate the slack risk assessment factor, compares the slack risk assessment factors corresponding to each of the flexible cables (20) and extracts the maximum value as the global slack risk factor to trigger damping adaptive adjustment.

8. The automated lifting device collaborative control system for an ecological artificial reef according to claim 6, characterized in that, The admittance module uses the damping gain amplification factor and the global relaxation risk factor to perform nonlinear amplification calculation on the basic virtual damping matrix to generate the actual damping matrix; The admittance module substitutes the actual damping matrix and the six-degree-of-freedom effective disturbance vector, which is composed of the three-degree-of-freedom translational effective disturbance vector and the three-degree-of-freedom rotational effective disturbance torque vector, into the six-degree-of-freedom virtual admittance control differential equation established in the mission space coordinate system, and solves it using a discretized numerical method to obtain the pose correction vector for the current discrete control cycle.

9. The automated lifting device collaborative control system for an ecological artificial reef according to claim 5, characterized in that, The execution module extracts the inverse of the spatial Jacobian matrix, decouples the pose correction vector mapping into length compensation commands assigned to each of the flexible cables (20), and converts the length compensation commands into compensation angle commands for the servo winch mechanism (10) by combining the actual drum working radius and the gearbox transmission ratio. The execution module algebraically adds the compensation angle commands to the system preset basic placement position commands to generate the comprehensive target angle commands and sends them to the servo driver to control the flexible cables (20) to perform coordinated tightening or unwinding actions.

10. A method for coordinated control of automated lifting equipment for ecological artificial reefs, characterized in that, An automated lifting device collaborative control system for an ecological artificial reef as described in any one of claims 1-9 includes the following steps: Acquire the tension data output by the tension sensor (30) and the length data output by the absolute encoder (50); The virtual compliance center of the ecological reef is calibrated based on the initial tensile and length data, and the basic virtual damping matrix of the admittance model is initialized. Perform sequence fitting on the continuous tensile data to extract smoothed tensile values ​​and tensile gradient values, and generate a tensile change vector; The tensile force change vector is mapped to a spatial perturbation vector acting on the virtual compliance center through the transpose of the spatial Jacobian matrix. A global relaxation risk factor is generated based on the smoothed tension value and the tension gradient value. The basic virtual damping matrix is ​​reconstructed using the global relaxation risk factor to generate the actual damping matrix. The spatial perturbation vector and the actual damping matrix are substituted into the admittance model to calculate the pose correction vector. The pose correction vector inverse kinematics is decoupled into a comprehensive target rotation command to drive the servo winch mechanism (10), and the flexible cable (20) is controlled to cooperate in the action to counteract disturbances and prevent the flexible cable (20) from slackening.

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