Berthing control method and control system for underactuated ships considering disturbance compensation

Abstract

The present invention discloses a berthing control method and control system for an underactuated ship considering disturbance compensation, and belongs to the field of automatic berthing of ships. The control method of the present invention comprises constructing a ship responsiveness model, determining the parameters K and T of the ship responsiveness model; obtaining the total internal and external disturbance d of the ship according to the ship responsiveness model, considering the total internal and external disturbance of the ship, designing a controller by combining the sliding mode control algorithm with the self-disturbance rejection control theory, determining the ship rudder angle; and controlling the ship berthing according to the ship rudder angle. The present invention estimates the internal and external disturbances of the system considering factors such as model uncertainty and environmental disturbances, and can realize high-precision berthing track tracking control and berthing under strong environmental disturbances in the port, and has strong robustness to model uncertainty and environmental disturbances.

Description

Technical Field

[0001] The present invention relates to the technical field of automatic ship berthing, and more particularly to a berthing control method and a control system for an under-actuated ship considering disturbance compensation. Background Art

[0002] The current berthing process generally uses tugboat assistance, using a tugboat to pull the ship away from the berth, or using the bow to push the ship's side toward the berth. Since tugboats are not always ready at ports in various places, entering or leaving the port may be restricted.

[0003] In order to safely control the ship when approaching the berth, the ship's position, heading and speed must be controlled. Any hard contact with the dock may cause huge economic losses to the ship or the berth. Therefore, when the captain makes a berthing operation plan, he must anticipate the distance and low-speed maneuvering ability required for the ship to dock and implement the ship's berthing operation.

[0004] In addition, ship berthing operations require a lot of ship operation experience and a full understanding of the ship's maneuverability. Ship operators who lack berthing experience will soon face difficulties in ship berthing operations. During the berthing maneuvering control process, the captain must consider many factors before any maneuvering action, namely ship speed, wind speed, wind direction, water flow direction, available power, heading angle and ship response.

[0005] Therefore, it is characterized by reduced controllability at low speeds, complex nonlinear differential equations of motion, the influence of environmental disturbances and other problems that make the operation very complex and time-consuming. Automatic berthing has always been considered one of the most difficult problems in ship control. Without the use of auxiliary equipment such as tugboats and / or bow thrusters, it is difficult to manually control the ship during the berthing process, which increases the necessity of using a berthing controller. Summary of the invention

[0006] In view of this, the present invention provides a berthing control method and control system for an under-actuated ship considering disturbance compensation. The purpose is to take into account the navigation characteristics of the ship model in the port, such as the lack of dynamics and strong environmental disturbances, and to design a berthing control method for an under-actuated ship considering disturbance compensation for the automatic berthing control problem of an under-actuated double-propeller and double-rudder ship, so as to achieve high-precision track control in low-speed and shallow waters in the port, and have strong robustness against environmental disturbances.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] On the one hand, the present invention discloses a berthing control method for an underactuated ship considering disturbance compensation, comprising:

[0009] Constructing a ship responsiveness model, and determining parameters K and T of the ship responsiveness model;

[0010] In response to the parameters K and T of the ship responsiveness model, the total internal and external disturbances of the ship are obtained;

[0011] Considering the total internal and external disturbances of the ship, the ship rudder angle is determined according to the following formula; and the ship berthing is controlled according to the ship rudder angle;

[0012]

[0013] Where δ represents the ship rudder angle, K represents the ratio of the viscous damping per unit turning moment to the viscous damping per unit turning angular velocity in the ship responsiveness model, T represents the ratio of the inertia to the viscous damping per unit turning angular velocity in the ship responsiveness model, represents the desired heading acceleration, k1, k2, b are controller parameters, s represents the sliding surface, sgn(s) performs symbolic operation on the sliding surface, represents the heading control error, r represents the actual heading rate of the ship, and d represents the total internal and external disturbance.

[0014] As a preferred method, in order to avoid buffeting, the saturation function sat() is used instead of sgn(). At this time, the ship rudder angle is determined according to the following formula:

[0015]

[0016] in,

[0017]

[0018] Where Δ is the thickness of the saturation function boundary layer.

[0019] As a preference, the total internal and external disturbance d is obtained by the following formula:

[0020]

[0021] in, Represents the derivative of the actual heading.

[0022] Preferably, the total internal and external disturbances are estimated according to the following formula, and the ship rudder angle is determined according to the estimated value of the total internal and external disturbances;

[0023]

[0024] In the formula, in the formula, is the estimated value of the total disturbance inside and outside the system, and z3 is the output of the extended state observer.

[0025] Preferably, a ship maneuvering model is constructed, and the propeller thrust and parameter K in the model are identified based on the least square method with a forgetting factor through a Z-type maneuverability test.

[0026] Preferably, the ship maneuvering model includes the Inoue model and the Yoshimura model;

[0027] When the ship moves in the normal speed range, the forward speed is large, and the drift angle |β|≤20°, the Inoue model is used:

[0028] When the ship moves in the low-speed range and the drift angle |β|≥30°, the Fangcun model is used;

[0029] When the drift angle is 20°<|β|<30°, the interpolation is performed by using the cubic spline interpolation method for the above two models.

[0030] Preferably, the propeller thrust is obtained according to the following relationship:

[0031]

[0032] In the formula, C T is the thrust coefficient of the propeller when it is in reverse, P is the propeller thrust, ρ is the density of water, V is the incoming flow velocity; n is the propeller speed; D is the propeller diameter.

[0033] On the other hand, the present invention discloses a berthing control system for an under-actuated ship considering disturbance compensation, comprising:

[0034] A parameter identification module, used to construct a ship responsiveness model and identify and obtain the KT parameters of the ship;

[0035] A disturbance observer, used for obtaining the total internal and external disturbances of the ship;

[0036] The ship controller determines the ship rudder angle according to the following formula based on the responsiveness model parameters K and T and taking into account the total internal and external disturbances of the ship; and controls the berthing of the ship according to the ship rudder angle;

[0037]

[0038] Where δ represents the ship's rudder angle, represents the desired heading acceleration, k1, k2, b are controller parameters, s represents the sliding surface, sgn(s) performs symbolic operation on the sliding surface, represents the heading control error, r represents the actual heading rate of the ship, and d represents the total internal and external disturbance.

[0039] Preferably, the ship controller determines the ship rudder angle according to the following formula:

[0040]

[0041] in,

[0042]

[0043] Where Δ is the thickness of the saturation function boundary layer.

[0044] Preferably, a heading feedback module is also included, which is used to monitor the heading of the ship in real time and feed it back to the ship controller together with the expected track.

[0045] It can be seen from the above technical solution that, compared with the prior art, the present invention discloses a practical and feasible under-actuated ship berthing control method and control system considering disturbance compensation, which estimates the internal and external disturbances of the system by considering factors such as model uncertainty and environmental disturbances, and designs the berthing controller by using a strong robust control algorithm sliding mode control.

[0046] The control algorithm adopted by the present invention can realize high-precision berthing track tracking control and berthing track tracking under strong environmental disturbances in the port, and has strong robustness to model uncertainty and environmental disturbances.

[0047] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings.

[0048] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0050] Figure 1 This is a flow chart of the berthing control method of an under-actuated ship considering disturbance compensation according to the present invention;

[0051] Figure 2 This is a schematic diagram of the berthing control steps of an under-actuated ship considering disturbance compensation in the present invention;

[0052] Figure 3 The structural block diagram of the under-actuated ship berthing control system considering disturbance compensation of the present invention;

[0053] Figure 4 is a graph of parameters T and K of the present invention;

[0054] Figure 5 It is the track control response curve during the berthing process of the present invention;

[0055] Figure 6 is a heading control error curve during the berthing process of the present invention;

[0056] Figure 7 is a track control error curve during the berthing process of the present invention;

[0057] Figure 8 This is the ship rudder angle error curve during the berthing process of the present invention. DETAILED DESCRIPTION

[0058] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0059] The embodiment of the present invention takes into account the navigation characteristics of the ship model in the port, such as the lack of dynamics and strong environmental disturbance, and discloses a berthing control method and control system for an under-actuated ship considering disturbance compensation, so as to solve the problem of difficulty in manual control during the berthing process.

[0060] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention are further described in detail below.

[0061] Embodiment 1

[0062] This embodiment discloses a method for controlling berthing of an underactuated ship considering disturbance compensation. Figure 1 As shown, the following steps are included:

[0063] Constructing a ship responsiveness model, and obtaining the total internal and external disturbances of the ship according to the ship responsiveness model;

[0064] Considering the total internal and external disturbances of the ship, the ship rudder angle is determined according to the following formula; and the ship berthing is controlled according to the ship rudder angle;

[0065]

[0066] Where, δ represents the ship rudder angle, K represents the ratio of the viscous damping per unit turning moment to the viscous damping per unit turning angular velocity in the ship responsiveness model, and T represents the ratio of the viscous damping per unit turning angular velocity to the inertia in the ship responsiveness model. represents the desired heading acceleration, k1, k2, b are controller parameters, s represents the sliding surface, sgn(s) performs symbolic operation on the sliding surface, represents the heading control error, r represents the actual heading rate of the ship, and d represents the total internal and external disturbance.

[0067] The first step is to construct a ship responsiveness model and determine the parameters K and T of the ship responsiveness model;

[0068] like Figure 2 As shown, in the present invention, a low-speed motion MMG model in a port, namely a ship maneuvering model, is constructed, and the KT parameter in the model is identified based on the least square method with a forgetting factor through a Z-type maneuverability test.

[0069] In the present invention, the ship maneuvering model is a low-speed motion control model in the port. Since ship maneuvering in the port is different from ship maneuvering in wide waters, it is necessary to comprehensively consider the influence of factors such as shallow water, low speed and propeller staggered, thereby providing a technical basis for berthing control parameter setting and path planning.

[0070] The water depth of the test berthing area applied by the present invention is in the range of 4.3 to 9.2 m, corresponding to a water depth-draft ratio of 1.75 to 3.74. Therefore, when modeling the maneuvering motion thereof, the influence of water depth change on maneuverability is not considered. On the basis of the traditional wide water maneuvering modeling, the ship maneuvering model in the low-speed domain is corrected, and the hydrodynamic characteristics of the propeller in the four-quadrant navigation condition are considered.

[0071] First, the ship maneuvering models include the Inoue model and the Yoshimura model;

[0072] During the low-speed domain correction, when the ship moves in the normal speed domain, the forward speed is large, and the drift angle |β|≤20°, the well model is used. In the present invention, the well model is:

[0073] X H =X(u)+X vv v 2 +X vr vr+X rr r 2

[0074] Y H =Y v v+Y r r+Y |v|v |v|v+Y |r|r |r|r+Y vvr v 2 r+Y vrr vr 2

[0075] N H =N v v+N r r+N |v|v |v|v+N |r|r |r|r+N vvr v 2 r+N vrrvr 2

[0076] Wherein, XH, YH, NH are the inertial hydrodynamic forces in the X, Y, and N directions respectively, v and r are the ship speed and the angular velocity of the bow respectively, and X(u) is the straight-line resistance; Xvv is the longitudinal drag coefficient, Xvr is the longitudinal force caused by the coupling of speed and angular velocity of the bow, and Xrr is the longitudinal force coefficient caused by the square of the angular velocity of the bow; Yv, Yr, Y|v|v, Y|r|r, Yvvr, and Yvrr are the lateral force coefficients caused by speed, angular velocity of the bow, speed square, angular velocity square, speed square and angular velocity, and speed and angular velocity square respectively; Nv, Nr, N|r|r, and N|v|v are the heading moment coefficients caused by speed, angular velocity of the bow, angular velocity square, and speed square respectively;

[0077] When the ship moves in the low-speed range and the drift angle |β|≥30°, the Fangcun model is used; the Fangcun model is:

[0078] X H =X H (r0)+X vr vr+X rr r 2

[0079]

[0080]

[0081] Where r0=0,X H (r0) indicates X when r is 0 H ; C ry and C rn are the model correction coefficients in the Y and N directions, L is the ship length, d is the draft; C d is the cross-flow resistance coefficient of the hull, ρ is the density of water;

[0082] When the drift angle is 20°<|β|<30°, the interpolation is performed by using the cubic spline interpolation method for the above two models.

[0083] It should be noted that the traditional propeller modeling only considers the thrust coefficient and torque coefficient when sailing forward. The thrust coefficient is represented as a function of the advance coefficient. However, when the propeller speed is 0, the infinite advance coefficient will cause overflow and crash. In addition, when berthing in the port, reverse operation is often used, so it is necessary to establish a unified hydrodynamic expression model covering the propeller forward and reverse conditions.

[0084] Under normal berthing conditions, the propeller operates in the forward forward driving state (quadrant I) and the forward reverse driving state (quadrant II), so the present invention does not consider the propeller in the reverse driving state (quadrant III and quadrant IV).

[0085] When calculating the propeller thrust coefficient when in reverse, define the propeller dimensionless thrust coefficient as follows:

[0086]

[0087] where the coefficient is a function of the hydrodynamic pitch angle β, which is defined as follows:

[0088]

[0089] Where P is propeller thrust; V is incoming flow velocity; n is propeller speed; D is propeller diameter, and ρ is water density.

[0090] Step 2: In response to the parameters K and T in the ship responsiveness model, the total internal and external disturbances of the ship are obtained based on the expansion state;

[0091] As the core part of the active disturbance rejection control, ESO (Extended State Observer) can transform the system into an integral series type and treat the disturbance as a new state.

[0092] If the internal and external disturbances d(t) of the ship are designed as an expansion state, the first-order Nomoto model of the ship can be expressed as:

[0093]

[0094] Where: d is the total disturbance inside and outside the system. The derivative representing the actual heading, since the total disturbance cannot be obtained directly, it is estimated according to the following process;

[0095] First, define the state variables For the design space state equation, the state equation can be obtained as:

[0096]

[0097] Define the ship state variable x i The estimated value of (i=1,2,3) is z i , e i =x i -z i represents the error between the true value and the estimated value of the system state variable. According to formula (2), the improved ESO (Improved Extended State Observer, IESO) can be obtained as follows:

[0098]

[0099] To facilitate IESO tuning, β1, β2, and β3 represent observer gains. To facilitate pole parameter configuration, this paper configures the observer poles at -ω0, and ω0>0 is the observer bandwidth. α1>0, α2>0 are constant coefficients, and the disturbance estimate of IESO is finally obtained as:

[0100] Step 3: Considering the total internal and external disturbances of the ship, the ship rudder angle is determined according to the following formula; and the ship berthing is controlled according to the ship rudder angle;

[0101]

[0102] In the formula, in the formula, in the formula, δ represents the ship's rudder angle, represents the desired heading acceleration, k1, k2, b are controller parameters, s represents the sliding surface, sgn(s) represents the symbolic operation of the sliding surface, represents the heading control error, r represents the actual heading rate of the ship, and d represents the total internal and external disturbance.

[0103] The derivation process is:

[0104] In the present invention, the controller output is the ship rudder angle δ, and the input is the ship heading. The sliding surface is selected as:

[0105]

[0106] Where b>0. S represents the sliding surface

[0107] Choose the exponential reaching law as:

[0108]

[0109] By taking the derivative of formula (3), we can get:

[0110]

[0111] By making equation (4) equal to equation (5), we can obtain:

[0112]

[0113] From the ship KT equation (1), we can get:

[0114]

[0115] Substituting formula (7) into formula (6) yields:

[0116]

[0117] Since the switching characteristics of the sign function can cause chattering in the controller, the saturation function sat() is used instead:

[0118]

[0119] Where Δ is the thickness of the saturated function boundary layer, and the controller form after disturbance compensation is finally obtained:

[0120]

[0121] The underactuated ship berthing control considering disturbance compensation designed in this embodiment is generally divided into three parts, namely:

[0122] Firstly, the present invention discretizes the first-order response model of the ship and identifies the KT index of the ship based on the least square method with a forgetting factor;

[0123] Secondly, considering the uncertainty of model parameters and strong wind disturbance at low speed in the port, an improved extended state observer is designed to estimate the internal and external disturbances of the system;

[0124] Finally, a first-order linear sliding surface is designed, and the exponential reaching law is adopted to design the berthing heading controller based on the sliding mode control theory. Disturbance compensation is added to achieve high-precision berthing control under environmental disturbances.

[0125] Embodiment 2

[0126] This embodiment discloses a berthing control system for an under-actuated ship considering disturbance compensation, comprising:

[0127] A parameter identification module, used to construct a ship responsiveness model and identify and obtain the parameters T and K of the ship;

[0128] A disturbance observer, for obtaining total internal and external disturbances of the vessel; and

[0129] A ship controller is used for responsive model parameters K and T, taking into account the total internal and external disturbances of the ship, and determining the ship rudder angle according to the following formula; and controlling the ship berthing according to the ship rudder angle;

[0130]

[0131] In the formula, δ represents the ship's rudder angle, represents the desired heading acceleration, k1, k2, b are controller parameters, s represents the sliding surface, sgn(s) is the symbolic operation of the sliding surface, represents the heading control error, r represents the actual heading rate of the ship, and d represents the total internal and external disturbance.

[0132] In one embodiment, the ship rudder angle is determined according to the following formula:

[0133]

[0134] in,

[0135]

[0136] Where Δ is the thickness of the saturation function boundary layer.

[0137] To further optimize the above technical solution, the present invention considers that the disturbance compensation under-actuated ship berthing control system also includes: Figure 3 As shown,

[0138] The heading feedback module is used to monitor the ship's heading in real time and feed it back to the ship controller together with the expected track to control the ship's berthing;

[0139] The speed feedback module is used to monitor the speed of the ship in real time and feed it back to the expert system together with the expected speed. The expert system is used to act on the actuator of the controlled ship to control its speed and make it converge.

[0140] Position feedback module,Since an underactuated ship cannot provide lateral driving force, a position feedback module is used to monitor the position of the ship in real time and feed it back to the LOS, so that the ship controller can consider the real-time position of the ship and perform ship berthing control.

[0141] In order to verify the implementation effect of the present invention, the following simulation experiment was carried out.

[0142] In the simulation test, a patrol ship was used as the research object. The ship is 47 meters long, 8 meters wide, and has a draft of 2.4 meters. It is a typical underdriven twin-propeller and twin-rudder ship with good maneuverability and maneuverability. The simulation is set to the initial position of the ship as the coordinate origin. The ship berths at an angle of 30°. The entire berthing process is a low-speed sailing process, and the berthing speed does not exceed 6kn. The berthing control process is that the ship first undergoes a linear acceleration process, then enters an arc course adjustment and decelerates to arrive at the berth. Figure 4 As shown, it is a curve diagram of the obtained parameters T and K.

[0143] Figure 5 The simulation results are shown in Figure 2, where the red curve is the sliding mode active disturbance rejection control method (SMC-ESO) and the blue curve is the sliding mode control method (SMC). Figure 5 It can be seen from the track control response curve that both control methods can control the ship to reach the berth;

[0144] To further analyze the control effect, the heading control error and track control error are plotted. Figure 6 and Figure 7 .from Figure 6It can be seen that during the entire control process, the heading control error of the sliding mode anti-disturbance control method is smaller than that of the sliding mode control method, and the heading control error when arriving at the berth is 0.014°, which meets the berthing control requirements. Figure 7 It can be seen that the track control error of the sliding mode anti-disturbance control method in the straight line segment continues to converge and is smaller than the sliding mode control method, while the sliding mode control has a track control static error. When it finally arrives at the berth, the track control error is 1.976 meters, which meets the berthing control requirements. Figure 8 is the ship rudder angle error curve during the berthing process of the present invention; Figure 8 It can be seen that the SMC-ESO method proposed in the present invention has a smaller track error in the berthing process than the traditional SMC method. The simulation results show that the sliding mode anti-disturbance control method for automatic berthing of underactuated ships proposed in the present invention can achieve high-precision berthing control, and the steering is smooth and in line with the captain's experience.

[0145] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0146] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for controlling berthing of an underactuated ship considering disturbance compensation, characterized in that: include, Construct a ship responsiveness model, construct an MMG model for low-speed motion in the port, and identify the KT parameters in the responsiveness model, including correcting the ship maneuvering model in the low-speed domain based on the traditional wide-water maneuvering modeling; When the ship moves in the normal speed range, the forward speed is large, and the drift angle |β|≤20°, the Inoue model is used: When the ship moves in the low-speed range and the drift angle |β|≥30°, the Fangcun model is used; When the drift angle is 20°<|β|<30°, the interpolation is performed by using the cubic spline interpolation method for the Inoue model and the Fangcun model; And establish a unified hydrodynamic expression model covering both forward and reverse propeller conditions; According to the ship responsiveness model, the improved ESO is used to obtain the total internal and external disturbances of the ship; β1, β2, β3 represent the observer gain, z i is the ship state variable x i The estimated value of (i=1,2,3), e i =x i -z i Represents the error between the true value and the estimated value of the system state variable, α1>0, α2>0 are constant coefficients; Considering the total internal and external disturbances of the ship, the ship rudder angle is determined according to the following formula; and the ship berthing is controlled according to the ship rudder angle; Where δ represents the ship rudder angle, K represents the ratio of the viscous damping per unit turning moment to the viscous damping per unit turning angular velocity in the ship responsiveness model, T represents the ratio of the inertia to the viscous damping per unit turning angular velocity in the ship responsiveness model, represents the desired heading acceleration, k1, k2, b are control parameters, s represents the sliding surface, sgn(s) represents the symbolic operation of the sliding surface, represents the heading control error, r represents the actual heading rate of the ship, and d represents the total internal and external disturbance.

2. The method for controlling berthing of an underactuated ship considering disturbance compensation according to claim 1, characterized in that: In order to avoid the buffeting phenomenon, the saturation function sat() is used instead of sgn(). At this time, the ship rudder angle is determined according to the following formula: in, Where Δ is the thickness of the saturation function boundary layer.

3. The method for controlling berthing of an underactuated ship considering disturbance compensation according to claim 2, characterized in that: The total internal and external disturbance d is obtained by the following formula: in, Represents the derivative of the actual heading.

4. The method for controlling berthing of an underactuated ship considering disturbance compensation according to claim 3, characterized in that: The total internal and external disturbances are estimated according to the following formula, and the ship rudder angle is determined according to the estimated value of the total internal and external disturbances; In the formula, is the estimated value of the total disturbance inside and outside the system, and z3 is the output of the extended state observer.

5. The method for controlling berthing of an underactuated ship considering disturbance compensation according to claim 1, characterized in that: A ship maneuvering model is constructed, and the KT parameters in the responsiveness model are identified based on the least squares method with forgetting factor through Z-type maneuverability test.

6. The method for controlling berthing of an underactuated ship considering disturbance compensation according to claim 1, characterized in that: The propeller thrust is obtained according to the following relationship: In the formula, C T is the thrust coefficient of the propeller when it is in reverse, P is the propeller thrust, ρ is the density of water, V is the incoming flow velocity; n is the propeller speed; D is the propeller diameter.

7. A berthing control system for an underactuated ship considering disturbance compensation, characterized in that: A method for controlling berthing of an underactuated ship considering disturbance compensation as described in any one of claims 1 to 6 is applied, comprising: Parameter identification module, used to build a ship responsiveness model and identify and obtain the ship's parameters T and K; A disturbance observer to obtain the total internal and external disturbances of the ship; and A ship controller is used for responsive model parameters K and T, taking into account the total internal and external disturbances of the ship, and determining the ship rudder angle according to the following formula; and controlling the ship berthing according to the ship rudder angle; Where δ represents the ship's rudder angle, represents the desired heading acceleration, k1, k2, b are the control parameters of the controller, s represents the sliding surface, sgn(s) represents the symbolic operation of the sliding surface, represents the heading control error, r represents the actual heading rate of the ship, and d represents the total internal and external disturbance.

8. The underactuated ship berthing control system considering disturbance compensation according to claim 7, characterized in that: The ship controller determines the ship rudder angle according to the following formula: in, Where Δ is the thickness of the saturation function boundary layer.

9. The underactuated ship berthing control system considering disturbance compensation according to claim 7, characterized in that: It also includes a heading feedback module for monitoring the ship's heading in real time and feeding it back to the ship controller together with the expected track.

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