Towing cable tension observation method based on winch towing model

Abstract

This invention discloses a method for observing traction cable tension based on a winch towing model. The method involves acquiring winch motor parameter sets and cable and environmental parameter sets to construct winch-end tension models and load-end tension models, respectively. These models are then converted into winch-end non-disturbance tension observers and load-end non-disturbance tension observers, respectively. An adaptive robust control algorithm is used to optimize the load-end non-disturbance tension observer. The current winch-end input signal set and load-end input signal set are acquired and input into the winch-end non-disturbance tension observer and the optimized load-end non-disturbance tension observer, respectively, to obtain the current winch-end tension observation value and load-end tension observation value. A sequential Kalman filter algorithm is used to process the current winch-end tension observation value and load-end tension observation value to obtain the current traction cable tension value. This invention reduces reliance on high-cost deep-water sensors, thereby lowering the cost of underwater tension observation.

Description

Technical Field

[0001] This invention relates to the field of tension detection in marine engineering equipment and underwater towing systems, and particularly to a method for observing the tension of traction cables based on a winch towing model. Background Technology

[0002] Underwater winches are critical equipment in marine surveys, resource exploration, equipment deployment and recovery operations, using cables to tow or suspend underwater loads (such as submersibles and sensor arrays). During operations, real-time and accurate sensing of cable tension is essential for ensuring system safety, achieving stable control, and optimizing operational efficiency. For example, tension information is used to prevent cable overload and breakage, avoid collisions between the load and the seabed or ship hull, and is fundamental for achieving constant tension during deployment and retrieval, and precise control of load depth.

[0003] Currently, the main technical approaches to obtaining cable tension fall into two categories: direct measurement and indirect observation.

[0004] Direct measurement typically involves installing a high-precision tension sensor at the end of the winch axle or in the cable path. While intuitive, this method has significant limitations: the sensors themselves are expensive, susceptible to corrosion and damage in the harsh marine environment of high humidity and salinity, leading to decreased reliability; and installation on moving parts complicates signal transmission (e.g., requiring slip rings) and makes maintenance difficult.

[0005] Indirect observation (estimation) methods estimate tension in real time by establishing a dynamic model of the system and utilizing easily measurable state variables (such as winch motor speed, current, and cable length) combined with observer algorithms. This method has potential advantages such as low cost, high reliability, and ease of integration. However, the accuracy of existing indirect observation methods heavily depends on the accuracy of the dynamic model. Underwater winch towing systems are complex, time-varying, and nonlinear systems whose dynamic characteristics are significantly affected by key parameters such as hydrodynamics (water resistance), added mass effects, and marine environmental disturbances (such as ocean currents and waves). These parameters are difficult to measure accurately in actual operations and change drastically with load attitude, speed, and environmental conditions. If a fixed-parameter model is used for observation, parameter mismatch will lead to large deviations or even inaccuracies in the tension estimate, failing to meet the requirements of high-precision control and safety monitoring.

[0006] Therefore, there is a contradiction in the existing technology that urgently needs to be resolved: the reliability and economy of the direct measurement method are insufficient, while the traditional indirect observation method is difficult to cope with the time-varying parameters and unknown disturbances of the system, resulting in the observation accuracy and robustness not meeting the actual needs of complex underwater operations. Summary of the Invention

[0007] To address the shortcomings of the existing technology, this invention provides a method for observing the tension of traction cables based on a winch towing model.

[0008] The technical solution adopted in this invention is:

[0009] This invention includes the following steps:

[0010] S1. Obtain the winch motor parameter set and the cable and environment parameter set, and then construct the winch end tension model and the load end tension model respectively.

[0011] S2. Convert the winch end tension model and the load end tension model into a winch end non-disturbance-resistant tension observer and a load end non-disturbance-resistant tension observer, respectively.

[0012] S3. The load-side non-disturbance tension observer is optimized using an adaptive robust control algorithm to obtain the optimized load-side non-disturbance tension observer.

[0013] S4. Obtain the current input signal set of the winch end and the input signal set of the load end, and then input the input signal set of the winch end and the input signal set of the load end into the winch end non-disturbance tension observer and the optimized load end non-disturbance tension observer, respectively, to obtain the current winch end tension observation value and the load end tension observation value.

[0014] S5. The sequential Kalman filter algorithm is used to process the current winch end tension observation value and the load end tension observation value to obtain the current traction cable tension value.

[0015] The winch motor parameter set includes the drum's moment of inertia, the drum's radius, the motor's moment of inertia, electromagnetic parameters, cable laying torque, and friction torque.

[0016] The cable and environmental parameter set includes the hydrodynamic resistance of the cable and load, the added mass resistance, the net buoyancy, the internal forces of the cable, and the mass.

[0017] The winch end non-disturbance tension observer is specifically set according to the following formula:

[0018]

[0019]

[0020]

[0021]

[0022] in, This represents the observed tension value at the winch end. This represents the current in the quadrature-axis stator coil. Indicates the current component coefficient. Indicates the acceleration component coefficient, Indicates the winch acceleration. This represents the upper bound of the prior-obtained lumped disturbance at the winch end. This represents the motor torque constant. Indicates permanent magnet flux linkage. Indicates the drum radius, This represents the moment of inertia of the motor rotor. This represents the moment of inertia of the winch. Indicates the gear reduction ratio. This represents the screw force component coefficient, and d represents the screw pitch diameter. Indicates the helix angle of the thread. This represents the equivalent friction angle.

[0023] The load-side non-disturbance-resistant tension observer is specifically set according to the following formula:

[0024]

[0025]

[0026] in, This represents the observed tension value at the load end. This indicates the total mass of the unmanned remote-controlled vehicle. Indicates the total mass of the cable. Indicates the winch acceleration. Indicates cable displacement. This represents the velocity vector of the cable relative to the fluid. Indicates fluid acceleration. Indicates the load power output. Indicates fluid density, Indicates the diameter of the cable. Indicates the total length of the cable. These represent the coefficients for cable hydrodynamic resistance, vehicle hydrodynamic resistance, cable added mass resistance, and vehicle added mass resistance, respectively.

[0027] Step S3 specifically involves:

[0028] S3.1. Based on the simultaneous processing of the winch end tension model and the load end tension model, the cable length control equation of the winch system is obtained.

[0029] S3.2. Based on the cable length control equation of the winch system, construct an adaptive robust control input and parameter update function. Then, based on the cable length control error, optimize the parameters in the load-end non-disturbance tension observer to obtain the optimized parameters.

[0030] S3.3 Substitute the optimized parameters into the load-side non-disturbance tension observer to obtain the optimized load-side non-disturbance tension observer.

[0031] The adaptive robust control input is set according to the following formula:

[0032]

[0033]

[0034]

[0035] The parameter update function is set according to the following formula:

[0036]

[0037] in, This represents the current in the quadrature-axis stator coil. For robust feedback coefficients, For systematic error, This is a low-frequency estimate of the system's lumped disturbance. It is the minimum value. Indicates the current component coefficient. Indicates the helix angle of the thread. This indicates the load power output, and T represents the transpose of the matrix. Represents model parameters The estimated value, =[ ], Let h denote the saturation function, and h denote the upper bound approaching function. This represents the rate of change of the low-frequency estimate of the system's lumped disturbance. This represents the upper bound of the total system disturbance estimate. Let | be the upper bound of the total system disturbance, and | denote the absolute value. , The norm of a vector For bias functions, The proximity coefficient, These represent the coefficients for cable hydrodynamic drag, vehicle hydrodynamic drag, cable-added mass drag, and vehicle-added mass drag, respectively. and They are respectively The maximum and minimum values ​​in the range. This indicates the total mass of the unmanned remote-controlled vehicle. Indicates the total mass of the cable. Indicates the winch acceleration. Indicates cable displacement. This represents the velocity vector of the cable relative to the fluid. It represents fluid acceleration.

[0038] The winch end input signal set includes the winch motor quadrature-axis current and cable acceleration;

[0039] The load-side input signal set includes cable length, cable acceleration, relative velocity of ambient flow, and relative acceleration.

[0040] A computer-readable storage medium storing program data thereon, which, when executed by a processor, implements a method for observing the tension of a traction cable based on a winch towing model.

[0041] A computer device includes a processor and a memory, the memory storing a computer program that, when executed by the processor, implements any step of the traction cable tension observation method based on a winch towing model.

[0042] The beneficial effects of this invention are:

[0043] This invention provides a method for observing the tension of traction cables based on a winch towing model, transforming the tension detection method for underwater winch towing systems from the traditional high-cost, low-reliability direct measurement method to an indirect observation method based on model and parameter adaptation. By establishing tension models at the winch end and the load end, and combining them with the adaptive robust control model parameters of the underwater winch cable deployment and recovery system, two sets of tension observers are constructed. A more accurate tension estimate is obtained through a sequential Kalman filter method. This invention reduces reliance on high-cost deep-water sensors, thereby lowering the cost of underwater tension observation. Attached Figure Description

[0044] Figure 1 This is a flowchart illustrating the indirect tension detection method and method verification for an underwater winch towing system according to an embodiment of the present invention.

[0045] Figure 2 This is a schematic diagram of the underwater winch towing system according to an embodiment of the present invention;

[0046] Figure 3 This is a schematic diagram of the structure of the indirect tension observer of the underwater winch towing system according to an embodiment of the present invention;

[0047] Figure 4 This is a schematic diagram illustrating the use of an electronic device in an embodiment of the present invention;

[0048] Figure 5 This is a MATLAB / Simulink simulation experiment design diagram of the tension observer according to an embodiment of the present invention;

[0049] Figure 6 This is a result diagram of the uniform motion simulation experiment 1 according to an embodiment of the present invention;

[0050] Figure 7 The figure shows the results of the acceleration and deceleration simulation experiment 2 in this embodiment of the invention. Detailed Implementation

[0051] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0052] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of protection of this invention.

[0053] like Figure 1 As shown, this embodiment includes the following steps:

[0054] S1. Obtain the winch motor parameter set and cable and environment parameter set, perform dynamic analysis on the underwater winch towing system, and then construct the winch end tension model and load end tension model respectively.

[0055] Specifically, such as Figure 2 As shown, this example takes a classic underwater winch towing system as the research object. The underwater winch is driven by a permanent magnet synchronous motor. The motor output torque drives the drum to rotate and the cable layup device to translate. The cable is wound up and unwound through the drum rotation. The cable is delivered out of the winch platform through a pulley system, and its end is connected to the load to transmit tension, thus achieving the towing of the load. The winch motor adopts zero direct-axis current control, and its torque drive equation is:

[0056]

[0057] in The moment of inertia of the motor rotor; Output angular velocity; This refers to the frictional torque of the motor. This is the motor torque constant, which is related to the number of pole pairs; This refers to the current in the quadrature-axis stator coil; It is a permanent magnet flux linkage. The torque required for the cable laying mechanism is:

[0058]

[0059] in, The pressure of the cable puller on the thread; This is the screw force component coefficient; For cable tension; The screw's mean diameter; For thread helix angle; Let be the equivalent friction angle. Then the cable tension balance equation is:

[0060]

[0061] in, The total mass of the cable. The total mass of the ROV. For cable displacement, Where is the radius of the drum. The resistance of the water body to the ROV, For load power (if any).

[0062] The expression for the winch end tension is:

[0063]

[0064]

[0065] in, This refers to the gear reduction ratio; This refers to the lumped disturbance at the winch end.

[0066] The system cable is modeled as a taut, rigid, zero-buoyancy cable. The external forces acting on the cable and load include hydrodynamic resistance and additional mass forces.

[0067] The expression for hydrodynamic resistance can be given as:

[0068]

[0069] in, The density of the water body; This is the normal drag coefficient; The diameter of the cable; The load-facing area; , and It is the drag loading coefficient, which is the angle between the cable and the fluid vector direction. The function; Let be the velocity vector of the cable relative to the fluid. This force is essentially the resistance created by the cable obstructing the water flow.

[0070] The additional mass force can be expressed as:

[0071]

[0072] in, For additional quality coefficients; For load volume; This refers to fluid acceleration.

[0073] Considering the potential power source carried by the load, the expression for the load-end tension is:

[0074]

[0075] in, This refers to the total length of the cable. For load power output (if applicable); This is a lumped disturbance at the load end.

[0076] S2. Convert the winch end tension model and the load end tension model into a winch end non-disturbance-resistant tension observer and a load end non-disturbance-resistant tension observer, respectively.

[0077] Step S2: Convert the two sets of tension models into non-disturbance-resistant tension observers respectively.

[0078] Define the winch end tension observer as follows:

[0079]

[0080] in, ; ; Perturbation obtained a priori The upper boundary.

[0081] Define the load-end tension observer as follows:

[0082]

[0083] in, ; These are the coefficients of each term in the expression for the load-end tension.

[0084] During this process, none of the tension observers can estimate the system disturbance, so further optimization is required.

[0085] S3. The load-side non-disturbance tension observer is optimized using an adaptive robust control algorithm to obtain the optimized load-side non-disturbance tension observer.

[0086] Step S3: Obtain adaptive values ​​of model parameters by using the cable length control error achieved through the adaptive robust control of the underwater winch, and optimize the load-end tension observer.

[0087] like Figure 3 As shown, this embodiment of the invention uses adaptive robust control for the winch's cable winding and unwinding control. The cable length control equation for the winch system is:

[0088]

[0089] in = ;

[0090] The adaptive robust control input of the system is:

[0091]

[0092] in, The robust feedback coefficient; This is a systematic error; This is a low-frequency estimate of the system's lumped disturbance; ; This is the upper bound of the total system disturbance; and They are respectively The upper and lower bounds; It is the bias function; This is a minimum value used to drive nonlinear robust feedback.

[0093] Error-driven, the update function is:

[0094]

[0095] in, The proximity coefficient, This is the upper bound of the total system disturbance. Through this update rate, It gradually approaches a system disturbance.

[0096] System model coefficients The update rate is implemented by the standard adaptive robust control parameter adaptive module, and its update rate is:

[0097]

[0098] Based on this update rate, the system model coefficients It gradually approaches the true value.

[0099] The system model coefficients and disturbance estimates obtained above are then used to optimize the performance of the load-side tension observer.

[0100] S4. Obtain the current input signal set of the winch end and the input signal set of the load end, and then input the input signal set of the winch end and the input signal set of the load end into the winch end non-disturbance tension observer and the optimized load end non-disturbance tension observer, respectively, to obtain the current winch end tension observation value and the load end tension observation value.

[0101] Step S4: Obtain the winch motor quadrature-axis current, cable release length, cable acceleration, relative velocity and relative acceleration of the ambient flow, and input them into the tension observer to obtain two sets of tension observation values.

[0102] Specifically, the quadrature-axis current of the motor during winch operation... Cable acceleration during operation Substituting the tension observation device at the winch end, we get:

[0103]

[0104] Length of cable release during operation Cable acceleration relative velocity of ambient flow and relative acceleration Substituting the load-end tension observer, we get:

[0105]

[0106] As shown above, two sets of tension observation values ​​were obtained.

[0107] S5. The sequential Kalman filter algorithm is used to process the current winch end tension observation value and the load end tension observation value to obtain the current traction cable tension value.

[0108] Step S5: Based on two sets of tension observations, estimate the actual tension of the system using a sequential Kalman filter algorithm. Define the system state recursive equation as follows:

[0109]

[0110] Wherein, the system state transition matrix and observation matrix are And omitted; To control the input matrix; The input vector; Let its process noise covariance matrix be ; For system observations; For system observation noise; Its observation noise covariance matrix, the observation values ​​are obtained through Distinguish between observations from different tension observers, i.e.:

[0111]

[0112] The system forecasts have been updated as follows:

[0113]

[0114] The system observations have been updated as follows:

[0115]

[0116] in, and The Kalman gains for the different observers proposed in this paper are shown below. The tension observation is updated sequentially to achieve Kalman filtering compatible with multiple observers. The sequential Kalman filtering algorithm flow is shown below.

[0117] Sequential Kalman Filter Algorithm Flow:

[0118] Step 1: Parameter Initialization

[0119] Initialize state variables, error covariance matrix, process noise covariance matrix, and measurement noise covariance matrix:

[0120]

[0121] Step 2: State Variable Update

[0122] Calculate the state variables and the error covariance matrix:

[0123]

[0124] Step 3: System Coefficient Update

[0125] a) Update the Kalman coefficients:

[0126] b) State estimation update:

[0127] Step 4: Observation Cycle

[0128] a) Check the next observer:

[0129] b) Determine if all observers have been checked. If not, proceed to step 3.

[0130] Step 5: System Status Update

[0131] a) Update the state variables and error covariance matrix:

[0132]

[0133] b) Proceed to the next observation: Proceed to step 2.

[0134] Based on the above steps, the embodiments of the present invention provide an electronic device architecture for a traction cable tension observation method based on a winch towing model, as follows: Figure 4 As shown.

[0135] This involves performing dynamic analysis on the underwater winch towing system and constructing a winch end tension model and a load end tension model.

[0136] The two sets of tension models were converted into non-disturbance-resistant tension observers respectively;

[0137] The adaptive values ​​of model parameters are obtained through cable length control achieved by the adaptive robust control of the underwater winch, and the load-end tension observer is optimized.

[0138] The winch motor quadrature-axis current, cable release length, cable acceleration, ambient flow relative velocity and relative acceleration are obtained and input into the tension observer to obtain two sets of tension observation values.

[0139] Based on two sets of tension observations, the actual tension of the system is estimated using a sequential Kalman filter algorithm.

[0140] Subsequently, a Lyapunov function was designed to determine the accuracy of the tension estimate, and a simulation experiment was designed to determine the performance of the tension observer.

[0141] The winch motor parameter set includes the drum's moment of inertia, the drum's radius, the motor's moment of inertia, electromagnetic parameters, cable laying torque, and friction torque.

[0142] The cable and environmental parameter set includes the hydrodynamic resistance of the cable and load, the added mass resistance, the net buoyancy, the internal forces of the cable, and the mass.

[0143] The process of performing dynamic analysis on an underwater winch towing system and constructing the winch end tension model and load end tension model includes:

[0144] Dynamic analysis of the underwater winch was conducted, and a winch end tension model was constructed by combining parameters such as the rotational inertia and radius of the drum, the rotational inertia and electromagnetic parameters of the motor, the torque of the cable laying device, and the frictional torque.

[0145] The winch end tension model includes: the winch end tension equals the product of the winch motor cross-axis current and the motor current coefficient, plus the sum of the winch lumped disturbances minus the product of the cable acceleration and the inertia coefficient.

[0146] A dynamic analysis of the cable and load is performed, and parameters such as the hydrodynamic resistance, additional mass resistance, net buoyancy, internal force and mass of the cable and load are combined to construct a load-end tension model.

[0147] The load-end tension model includes: load-end tension equals the product of the sum of the cable and load mass and the cable acceleration, the product of the square of the load-end ambient flow velocity and the hydrodynamic coefficient, the product of the load-end ambient flow acceleration and the added mass coefficient, the load-end power output (if any), and the sum of the load-end lumped disturbances.

[0148] The process of converting the two sets of tension models into non-disturbance-resistant tension observers includes:

[0149] The observed non-disturbance tension at the winch end is equal to the product of the motor's quadrature-axis current and the motor's current coefficient, minus the product of the cable acceleration and the inertia coefficient, plus the upper limit of the winch's lumped disturbance. The inertia coefficient is the sum of the winch drum's rotational inertia plus the product of the motor rotor's rotational inertia and the reduction ratio, divided by the square of the drum radius plus the sum of the product of the drum radius and the cable tension coefficient.

[0150] The observed non-protest tension at the load end is equal to the product of the sum of the cable and load mass and the cable acceleration, plus the product of the square of the load end ambient flow velocity and the hydrodynamic coefficient, plus the product of the load end ambient flow acceleration and the added mass coefficient, plus the load end power output (if any), and then minus the estimated low-frequency disturbance of the system.

[0151] The winch end non-disturbance tension observer is specifically set according to the following formula:

[0152]

[0153]

[0154]

[0155]

[0156] in, This represents the observed tension value at the winch end. This represents the current in the quadrature-axis stator coil. Indicates the current component coefficient. Indicates the acceleration component coefficient, Indicates the winch acceleration. This represents the upper bound of the prior-obtained lumped disturbance at the winch end. This represents the motor torque constant. Indicates permanent magnet flux linkage. Indicates the drum radius, This represents the moment of inertia of the motor rotor. This represents the moment of inertia of the winch. Indicates the gear reduction ratio. This represents the screw force component coefficient, and d represents the screw pitch diameter. Indicates the helix angle of the thread. Indicates the equivalent friction angle;

[0157] The load-side non-disturbance-resistant tension observer is specifically set according to the following formula:

[0158]

[0159]

[0160] in, This represents the observed tension value at the load end. This indicates the total mass of the unmanned remote-controlled vehicle. Indicates the total mass of the cable. Indicates cable displacement. This represents the velocity vector of the cable relative to the fluid. Indicates fluid acceleration. Indicates the load power output. Indicates fluid density, Indicates the diameter of the cable. Indicates the total length of the cable. These represent the coefficients for cable hydrodynamic resistance, vehicle hydrodynamic resistance, cable added mass resistance, and vehicle added mass resistance, respectively.

[0161] Step S3 specifically involves:

[0162] S3.1. Based on the simultaneous processing of the winch end tension model and the load end tension model, the cable length control equation of the winch system is obtained.

[0163] S3.2. Based on the cable length control equation of the winch system, construct an adaptive robust control input and parameter update function. Then, based on the cable length control error, optimize the parameters in the load-end non-disturbance tension observer to obtain the optimized parameters. Specifically, the adaptive robust control algorithm optimizes the cable hydrodynamic drag coefficient, the vehicle hydrodynamic drag coefficient, the cable added mass drag coefficient, the vehicle added mass drag coefficient, and the low-frequency disturbance parameters in the load-end non-disturbance tension observer.

[0164] S3.3 Substitute the optimized parameters into the load-side non-disturbance tension observer to obtain the optimized load-side non-disturbance tension observer.

[0165] The adaptive robust control input is set according to the following formula:

[0166]

[0167]

[0168] Parameter update function Set it according to the following formula:

[0169]

[0170] in, This represents the current in the quadrature-axis stator coil. For robust feedback coefficients, For systematic error, This is a low-frequency estimate of the system's lumped disturbance. It is the minimum value. Indicates the current component coefficient. Indicates the helix angle of the thread. This indicates the load power output, and T represents the transpose of the matrix. Represents model parameters The estimated value, =[ ], Let h denote the saturation function, and h denote the upper bound approaching function. This represents the rate of change of the low-frequency estimate of the system's lumped disturbance. This represents the upper bound of the total system disturbance estimate. Let | be the upper bound of the total system disturbance, and | denote the absolute value. , The norm of a vector For bias functions, The proximity coefficient, These represent the coefficients for cable hydrodynamic drag, vehicle hydrodynamic drag, cable-added mass drag, and vehicle-added mass drag, respectively. and They are respectively The maximum and minimum values ​​in the range. This indicates the total mass of the unmanned remote-controlled vehicle. Indicates the total mass of the cable. Indicates the winch acceleration. Indicates cable displacement. This represents the velocity vector of the cable relative to the fluid. It represents fluid acceleration.

[0171] The process of obtaining adaptive values ​​for model parameters by controlling cable length error through adaptive robust control of an underwater winch, and optimizing the load-end tension observer, includes:

[0172] Through adaptive robust control of the underwater winch's cable deployment and retrieval, its parameter adaptive module can gradually converge the estimated values ​​of key parameters such as hydrodynamic coefficients, added mass coefficients, and low-frequency disturbances of the system to the true values ​​based on control errors. Subsequently, these high-precision adaptive parameter values ​​are imported into the load-side tension observer to achieve continuous optimization.

[0173] The winch end input signal set includes the winch motor quadrature-axis current and cable acceleration;

[0174] The load-side input signal set includes cable length, cable acceleration, relative velocity of ambient flow, and relative acceleration.

[0175] The process of acquiring the winch motor quadrature-axis current, cable release length, cable acceleration, ambient flow relative velocity, and ambient flow relative acceleration, and inputting these into the tension observer to obtain two sets of tension observation values ​​includes:

[0176] Input the winch motor quadrature axis current and cable acceleration into the winch end tension observer to obtain the winch end tension observation value;

[0177] The cable length, cable acceleration, relative velocity of the ambient flow, and relative acceleration of the ambient flow are input into the load-end tension observer to obtain the load-end tension observation value.

[0178] The process of estimating the actual tension of the system using a sequential Kalman filter algorithm based on two sets of tension observations includes:

[0179] 1) Construct the state recursion function;

[0180] 2) Construct the system update function;

[0181] 3) Construct a sequential Kalman filter;

[0182] 4) Estimate the cable tension based on the aforementioned two sets of tension observations;

[0183] 5) Perform low-frequency filtering on the tension estimate to obtain the final tension estimate.

[0184] The process of designing a Lyapunov function to determine the accuracy of the tension estimate includes:

[0185] 1) Design the Lyapunov function;

[0186] 2) Determine system stability based on the derivative of Lyapunov function.

[0187] 3) The process of designing simulation experiments to determine the performance of the tension observer includes:

[0188] 4) Establish a MATLAB / Simulink simulation model;

[0189] 5) Determine the performance of the tension observer based on the simulation model.

[0190] Then, a Lyapunov function was designed to determine whether the tension estimate was accurate.

[0191] Design a Lyapunov function:

[0192]

[0193] in, The system tension error is the difference between the expected tension and the observed tension. This is the system lumped error estimation error. Additionally, ,but:

[0194]

[0195] According to Lassalle's invariant set principle, the maximal invariant set contains only equilibrium points. According to Barbalat's lemma, when hour, If the system is asymptotically stable, then the system is asymptotically stable.

[0196] Design a simulation experiment to determine the performance of the tension observer.

[0197] Design a MATLAB / Simulink simulation experiment for a traction cable tension observer based on a winch towing model. The observer simulation model design is as follows: Figure 5 As shown, the upper Fc_obs1 module is the winch end tension observer, the lower Fc_obs2 module is the aircraft end tension observer, the seq_kelman module is the sequential Kalman filter, and the output Fc_obs is the final tension observation value.

[0198] In the experiment, adaptive robust winch cable release and take-up control was used to realize winch cable release and take-up control. During the control process, the system model parameters and low-frequency disturbances were adapted. The adapted parameters were then input into an indirect tension observer to observe the cable tension.

[0199] This invention designs two sets of simulation experiments: one for uniform motion and one for acceleration / deceleration motion. The experimental results are as follows: Figure 6 and Figure 7 As shown, the tension observed by the observer has a certain oscillation error compared to the actual tension of the system, but the error is small and can achieve the observation of the system tension. In the initial stage of observation, the disturbance of the observation error mainly comes from the warm-up process of the adaptive parameter module. When the system parameters tend to stabilize, the tension observation also tends to stabilize. In addition, the mean absolute errors of the curves are 2.57N and 1.98N, and the mean square errors are 5.16N and 3.93N, respectively, all of which are at an advanced level.

[0200] In summary, this invention provides a method for observing the tension of a traction cable based on a winch towing model. It transforms the tension detection method for underwater winch towing systems from the traditional high-cost, low-reliability direct measurement method to an indirect observation method based on model and parameter adaptation. By establishing tension models at the winch end and the load end, two sets of tension observers are constructed. The tension observers are optimized using a model parameter adaptation module for the underwater winch cable deployment and recovery adaptive robust control, causing the measured values ​​from the load end observers to gradually approach the true values. Then, a more accurate tension estimate is obtained by combining the data from the two sets of tension observers using a sequential Kalman filter method. This invention reduces reliance on high-cost underwater equipment and lowers the cost of underwater tension observation.

[0201] The above detailed embodiments illustrate the technical solution and beneficial effects of the present invention. It should be understood that the above description is only the most preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, additions, and equivalent substitutions made within the scope of the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for observing the tension of a traction cable based on a winch towing model, characterized in that, The method includes the following steps: S1. Obtain the winch motor parameter set and the cable and environment parameter set, and then construct the winch end tension model and the load end tension model respectively. S2. Convert the winch end tension model and the load end tension model into a winch end non-disturbance-resistant tension observer and a load end non-disturbance-resistant tension observer, respectively. S3. The load-side non-disturbance tension observer is optimized using an adaptive robust control algorithm to obtain the optimized load-side non-disturbance tension observer. S4. Obtain the current input signal set of the winch end and the input signal set of the load end, and then input the input signal set of the winch end and the input signal set of the load end into the winch end non-disturbance tension observer and the optimized load end non-disturbance tension observer, respectively, to obtain the current winch end tension observation value and the load end tension observation value. S5. The sequential Kalman filter algorithm is used to process the current winch end tension observation value and the load end tension observation value to obtain the current traction cable tension value. Step S3 specifically involves: S3.

1. Based on the simultaneous processing of the winch end tension model and the load end tension model, the cable length control equation of the winch system is obtained. S3.

2. Based on the cable length control equation of the winch system, construct an adaptive robust control input and parameter update function. Then, based on the cable length control error, optimize the parameters in the load-end non-disturbance tension observer to obtain the optimized parameters. S3.3 Substitute the optimized parameters into the load-side non-disturbance tension observer to obtain the optimized load-side non-disturbance tension observer.

2. The method for observing traction cable tension based on a winch towing model according to claim 1, characterized in that: The winch motor parameter set includes the drum's moment of inertia, the drum's radius, the motor's moment of inertia, electromagnetic parameters, cable laying torque, and friction torque. The cable and environmental parameter set includes the hydrodynamic resistance of the cable, the hydrodynamic resistance of the load, the additional mass resistance of the cable, the additional mass resistance of the load, the net buoyancy of the cable, the net buoyancy of the load, the internal forces of the cable, the mass of the cable, and the mass of the load.

3. The method for observing traction cable tension based on a winch towing model according to claim 1, characterized in that: The winch end non-disturbance tension observer is specifically set according to the following formula: in, This represents the observed tension value at the winch end. This represents the current in the quadrature-axis stator coil. Indicates the current component coefficient. Indicates the acceleration component coefficient. Indicates the winch acceleration. This represents the upper bound of the prior-obtained lumped disturbance at the winch end. This represents the motor torque constant. Indicates permanent magnet flux linkage. Indicates the drum radius, This represents the moment of inertia of the motor rotor. This represents the moment of inertia of the winch. Indicates the gear reduction ratio. This represents the screw force component coefficient, and d represents the screw pitch diameter. Indicates the helix angle of the thread. This represents the equivalent friction angle.

4. The method for observing traction cable tension based on a winch towing model according to claim 1, characterized in that: The load-side non-disturbance-resistant tension observer is specifically set according to the following formula: in, This represents the observed tension value at the load end. This indicates the total mass of the unmanned remote-controlled vehicle. Indicates the total mass of the cable. Indicates the winch acceleration. Indicates cable displacement. This represents the velocity vector of the cable relative to the fluid. Indicates fluid acceleration. Indicates the load power output. Indicates fluid density, Indicates the diameter of the cable. Indicates the total length of the cable. These represent the coefficients for cable hydrodynamic resistance, vehicle hydrodynamic resistance, cable added mass resistance, and vehicle added mass resistance, respectively.

5. The method for observing traction cable tension based on a winch towing model according to claim 1, characterized in that: The adaptive robust control input is set according to the following formula: The parameter update function is set according to the following formula: in, This represents the current in the quadrature-axis stator coil. For robust feedback coefficients, For systematic error, This is a low-frequency estimate of the system's lumped disturbance. It is the minimum value. Indicates the current component coefficient. Indicates the helix angle of the thread. This indicates the load power output, and T represents the transpose of the matrix. Represents model parameters The estimated value, =[ ], Let h denote the saturation function, and h denote the upper bound approaching function. This represents the rate of change of the low-frequency estimate of the system's lumped disturbance. This represents the upper bound of the total system disturbance estimate. This is the upper bound of the total system disturbance. The norm of a vector For bias functions, The proximity coefficient These represent the coefficients for cable hydrodynamic drag, vehicle hydrodynamic drag, cable-added mass drag, and vehicle-added mass drag, respectively. and They are respectively The maximum and minimum values ​​in the range. This indicates the total mass of the unmanned remote-controlled vehicle. Indicates the total mass of the cable. Indicates the winch acceleration. Indicates cable displacement. This represents the velocity vector of the cable relative to the fluid. It represents fluid acceleration.

6. The method for observing traction cable tension based on a winch towing model according to claim 1, characterized in that: The winch end input signal set includes the winch motor quadrature-axis current and cable acceleration; The load-side input signal set includes cable length, cable acceleration, relative velocity of ambient flow, and relative acceleration.

7. A computer-readable storage medium storing program data thereon, characterized in that, When the program data is executed by the processor, it implements the method as described in any one of claims 1-6.

8. A computer device, characterized in that, It includes a processor and a memory, the memory storing a computer program that, when executed by the processor, implements the various steps of the traction cable tension observation method based on the winch towing model as described in any one of claims 1 to 6.

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