Event-driven full-propulsion ship performance tracking control method and system

Abstract

The application discloses a kind of based on event-driven full drive ship predetermined performance tracking control method and system, it is related to predetermined performance tracking control technical field.The steps include: collecting target ship parameter information, establishing ship model based on the closed-loop system of full drive ship;Compensation signal is generated by constructing auxiliary system, and the adverse effects caused by input saturation to ship model are compensated;According to the design of adaptive fixed-time tracking controller of compensation signal;The parameters of adaptive fixed-time tracking controller are set, and the control target in preset time is input to adaptive fixed-time tracking controller, and the control instruction of controller output is executed to the actuator, so that the closed-loop system of ship is completed under the condition of obeying constraint Desired tracking.This application is aimed at a kind of full drive water surface ship, under the condition of full state constraint, lumped disturbance and input saturation, based on event-driven, the control of fixed-time predetermined performance is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of scheduled performance tracking control, and in particular to an event-driven scheduled performance tracking control method and system for a full-drive ship. BACKGROUND

[0002] The statements in this section merely provide background information related to the present application and do not necessarily constitute the prior art.

[0003] Ship control has always played an important role in control theory and control engineering. Marine surface ships can be divided into full-drive and under-drive types. Compared with under-drive ships, full-drive ships have a simple and intuitive form. In 2005, the Ocean Control Laboratory of the Norwegian University of Science and Technology successfully built a full-drive ship named Cybership II. The size of the ship is designed according to a certain supply ship at a scale of 1:70. The experimental results show that the ship has a simple structure and flexible maneuvering. Since then, full-drive marine ships have been attracting attention.

[0004] In order to meet certain performance and safety requirements, the system state of a full-drive ship is often limited to a certain range. For example, a ship working around a sea platform needs to be strictly constrained in terms of speed and position to avoid collision accidents with the platform. In actual ship control, sometimes it is necessary to complete the desired task within a limited time, such as ship docking and interception. Terminal sliding mode control (TSMC) was first used to achieve finite time control of a mechanical arm due to its robustness to disturbances. Subsequently, for various finite time control objectives, TSMC based on disturbance observer, high-order TSMC and TSMC with power integrator were proposed respectively.

[0005] Although time-driven control is easy to implement, it is a conservative approach that may cause overload of the communication channel. Event-driven control does not have the above problems. However, in the existing event-driven control methods, the inventors have found that:

[0006] When a ship sails on the sea, it is inevitably affected by lumped disturbances, and its position and speed are constrained. In addition, in the ship propulsion system, the engine speed can only be changed within a certain range, resulting in limited force supply of the propeller and input saturation. However, the existing event-driven control does not consider the above lumped disturbances and input saturation conditions. Moreover, in the case of state constraints, there is a lack of research on fixed-time control for full-drive ships. SUMMARY

[0007] In view of the deficiencies of the prior art, the purpose of the present application is to provide an event-driven-based full-drive ship predetermined performance tracking control method and system, which is aimed at a type of full-drive water surface ship, and realizes control of fixed time preset performance based on event driving under the conditions of full state constraint, lumped disturbance and input saturation.

[0008] In order to achieve the above-mentioned purpose, the present application is realized by the following technical scheme:

[0009] The first aspect of the present application provides an event-driven-based full-drive ship predetermined performance tracking control method, comprising the following steps:

[0010] Collecting target ship parameter information, and establishing a ship model based on a closed-loop system of the full-drive ship;

[0011] Constructing an auxiliary system to generate a compensation signal to compensate for the adverse effects caused by input saturation of the ship model;

[0012] Designing an adaptive fixed time tracking controller according to the compensation signal;

[0013] Setting parameters of the adaptive fixed time tracking controller, inputting a control target within a preset time to the adaptive fixed time tracking controller, and outputting a control instruction to the actuator by the controller, so that the closed-loop system of the ship completes expected tracking under the condition of obeying constraints.

[0014] The second aspect of the present application provides an event-driven-based full-drive ship predetermined performance tracking control system, comprising:

[0015] A model construction module configured to collect target ship parameter information, and establish a ship model based on a closed-loop system of the full-drive ship;

[0016] A model optimization module configured to construct an auxiliary system to generate a compensation signal to compensate for the adverse effects caused by input saturation of the ship model;

[0017] A controller design module configured to design an adaptive fixed time tracking controller according to the compensation signal;

[0018] A predetermined performance tracking control module configured to set parameters of the adaptive fixed time tracking controller, input a control target within a preset time to the adaptive fixed time tracking controller, and output a control instruction to the actuator by the controller, so that the closed-loop system of the ship completes expected tracking under the condition of obeying constraints.

[0019] The third aspect of the present application provides a medium having a program stored thereon, which realizes the steps in the event-driven-based full-drive ship predetermined performance tracking control method according to the first aspect of the present application when executed by a processor.

[0020] The fourth aspect of the present application provides a device comprising a memory, a processor and a program stored on the memory and executable on the processor, wherein the processor implements the steps in the event-driven full-propulsion ship predetermined performance tracking control method according to the first aspect of the present application when executing the program.

[0021] The above one or more technical solutions have the following beneficial effects:

[0022] The present application is directed to a class of full-drive water surface ships, and under the conditions of full state constraints, lumped disturbances and input saturation, the control of fixed time preset performance is realized based on event driving. In the control design, an auxiliary signal is introduced to compensate for the influence of input saturation on the system, and a barrier Lyapunov function (BLF) is used to ensure state constraints. In order to achieve the given tracking performance, an error transformation based on the velocity function is introduced, so that the proposed algorithm can ensure the expected transient and steady-state tracking performance without violating the full state constraints. The remarkable features of the proposed method are that the convergence speed, tracking accuracy and stable time can be preset in advance, and the communication cost of the controller is low.

[0023] The advantages of the additional aspects of the present application will be partially given in the following description, partially will become apparent from the following description, or will be understood by the practice of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0024] The drawings accompanying the specification of the present application form a part thereof and serve to provide further understanding of the present application, the illustrative embodiments of the present application and its description serve to explain the present application, and do not constitute improper limitations on the present application.

[0025] Figure 1 It is a schematic diagram of the full-drive ship in the earth coordinate system and the ship body coordinate system in the embodiment one of the present application;

[0026] Figure 2 It is a schematic diagram of the closed-loop system state satisfying the constraints in the simulation verification experiment of the embodiment one of the present application;

[0027] Figure 3 It is a schematic diagram of the tracking error reaching the predetermined accuracy in the simulation verification experiment of the embodiment one of the present application;

[0028] Figure 4 It is a schematic diagram of the adaptive parameter boundedness in the simulation verification experiment of the embodiment one of the present application;

[0029] Figure 5 It is a schematic diagram of the forward force actuator output and signal transmission time in the simulation verification experiment of the embodiment one of the present application;

[0030] Figure 6Fig. 1 is a schematic diagram of the output of the lateral drift force actuator and the signal transmission time in the simulation verification experiment of the first embodiment of the present application;

[0031] Figure 7 Fig. 2 is a schematic diagram of the output of the rudder yawing force actuator and the signal transmission time in the simulation verification experiment of the first embodiment of the present application. DETAILED DESCRIPTION

[0032] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0033] The following assumptions, definitions and lemmas are used in the event-driven predetermined performance tracking control method for fully-driven ships:

[0034] Assumption 1: For the vector d(x1, x2, t), there exists an unknown normal number θ and a known positive smooth function ψ(x1, x2, t) such that ||d(x1, x2, t) || 2 ≤ θψ(x1, x2, t).

[0035] Assumption 2: x d (t) and its derivative with respect to time are continuous, and there exist positive continuous functions and positive constants satisfying

[0036] Assumption 3: There exist constants K a , K b such that k a (t) < K a and k b (t) < K b . In addition, there exist normal numbers and such that the derivatives of k a (t) and k b (t) satisfy and

[0037] Definition 1: The equilibrium point η = 0 of a nonlinear system is called the constrained fixed-time practical stability (CPFTS) if for all η(t0) = η0 ∈ Ω, there exists a scalar ε > 0 such that when t ≥ t0 + t1, there is ||η(t)|| < ε, and η(t) ∈ Ω is always satisfied throughout the control process. Ω is a given constraint set, and t1 is an upper limit of the rest time T(η(0)) independent of the initial value of the system.

[0038] Note 1: In control problems with state constraints, the constraint function k a (t) and k b x1(t) is given in advance. One of the design goals of the controller is to ensure that all states of the system do not violate the given constraints throughout the control process, i.e., the inequality ||x1(t)|| < k. a (t), ||x2(t)||<k b (t) holds true for any time. Therefore, Definition 1 has a stable property, rather than an attractive property.

[0039] Lemma 1: If there exists a positive definite function Satisfy: 1) 2) Where α1 > 0, α2 > 0, 0 < p1 < 1, p2 > 1. All are constants. Therefore, the system is CPFTS, meaning that when t ≥ t1, it has... Established, among which And 0 < c < 1 is a constant. When hour, when hour,

[0040] Lemma 2: Define an open set and Where k ci is a positive constant, and l is a positive integer. Consider the system. Define function Where f is The function is locally Lipschitz with respect to η. Assume there exists a positive definite and continuously differentiable function. as well as And satisfy the following on each custom domain:

[0041] W i (w i →∞,|w i |→k ci ,

[0042] α1(||ξ||)≤W(t,ξ)≤α2(||ξ||), (1)

[0043] Where α1 and α2 are Function. Based on this, further define V(η) = W(t,ξ) + W i (w i ), while limiting w i (0)∈Π i Furthermore, if V is in the set... satisfy

[0044]

[0045] where 0 < pi < 1, p2 > 1. Then: 1) the system is CPFTS, 2) w i ∈Π i ,

[0046] Lemma 3: Assume d and e are positive constants, then for any real numbers x, y and a function γ(x, y) > 0, the following inequality holds: d |y| e ≤ (dγ |x| d+e + eγ -d / e |y| d+e ) / (d + e).

[0047] Lemma 4: For a vector If ||x|| < ||b|| is satisfied, then the following inequality holds: 0 < ln(b T b / (b T b - x T x)) ≤ x T x / (b T b - x T x), where l > 0.

[0048] Lemma 5: For positive real numbers k = 1,..., n, and any constant l, if l > 1, then If 0 < l < 1, then

[0049] Lemma 6: For any 0 ≤ |U| - Utanh(U * ) ≤ k ** where k * = 0.2785 and ∈ * > 0 is a real number.

[0050] Lemma 7: Define a function Y(x) = sign(x) |x| 2k-1 tanh(|x| 2k / ∈ * ), where ∈ * > 0, 3 / 4 < k < 1. Let its first derivative be Ψ(x) and its second derivative be G(x). Then Y(x), Ψ(x), and G(x) are all continuous on

[0051] Lemma 8: Define a vector: Then the following inequality holds: -χ T Ξ ≤ - (χ T χ) k + n ∈ * k​* where

[0052] Proof: Directly from Lemma 5 and Lemma 6

[0053]

[0054] The proof of Lemma 8 is complete.

[0055] Embodiment one:

[0056] The embodiment one of the present application provides a kind of event-driven full drive ship predetermined performance tracking control method, comprising the following steps:

[0057] Step 1: collect target ship parameter information, and establish ship model based on the closed loop system of full drive ship.

[0058] Step 2: construct auxiliary system to generate compensation signal, and compensate the adverse effects caused by input saturation to ship model;

[0059] Step 3: design adaptive fixed time tracking controller according to compensation signal;

[0060] Step 4: set adaptive fixed time tracking controller parameter, input preset time control target to adaptive fixed time tracking controller, and the control instruction of controller output is executed to the actuator, so that the closed loop system of ship is completed under the condition of obeying constraint desired tracking.

[0061] In step 1, the closed loop system of full drive ship is established based on the ship model of earth coordinate system, and the relationship between earth coordinate system and ship coordinate system is as shown in Figure 1 Specific steps are as follows:

[0062] Full drive water surface ship is modeled according to the following formula to closed loop system:

[0063]

[0064]

[0065] Where the configuration vector , (x, y) represents the position of ship in earth coordinate system, indicates the heading angle. Velocity vector Each element in it respectively indicates forward speed, lateral speed and yaw speed. Vector is used to represent lumped disturbance, possible modeling deviation and neglected dynamics. f (τ) = [f1 (τ1), f2 (τ2), f3 (τ3)] T Is the output of actuator with saturation characteristics, τ = [τ1, τ2, τ3] Tis the original control signal to be designed. J(η) is the rotation matrix, D(v) is the damping matrix, is the symmetric and positive definite inertia matrix, is the centripetal force and Coriolis force matrix, is the restoring force due to gravity, ocean current, and buoyancy. The detailed expressions of J(η), M, C(v), D(v) are:

[0066]

[0067] The elements of M are: The elements of C(v) are: The elements of D(v) are: 11 (v) = -X u -X |u|u |u|-X uuu u 2 , d 22 (v) = -Y ν -Y |ν|ν |v|-Y |r|ν |r|, d 23 (v) = -Y r -Y |ν|r |v|-Y |r|r |r|, d 32 (v) = -N ν -N |ν|ν |v|-N r|ν |r|, d 33 = -N r -N |ν|r |v|-N |r|r |r|. The coefficients X (·) , Y (·) , N (·) are hydrodynamic coefficients. m is the mass of the ship, I z is the moment of inertia about the yawing rotation, x g denotes the distance from O b to the center of mass of the ship. f i (τ i ) can be described as:

[0068]

[0069] where f imax > 0 and f imin < 0 are known saturation parameters. It is easy to know that J(η) has the following properties: J T = J -1 and ||J(η)|| = 1.

[0070] By choosing x1= η and x2= v, we can obtain an equivalent form of (3), i.e., the ship model of the closed-loop system:

[0071]

[0072]

[0073] where H(x1, x2) = M -1 (-C(x2)x2- D(x2)x2- g(x1)).

[0074] The purpose of this embodiment is to achieve the following based on the event-driven adaptive control strategy: 1) all signals of the closed-loop system (4) are bounded. 2) the desired trajectory x d = [x d1 , x d2 , x d3 ] T can be tracked by the system configuration trajectory x1= [x 11 , x 12 , x 13 ] T before a pre-specified time T, while the tracking error satisfies: lim t→T |x 1i - x di | < ε and |x 1i - x di | t≥T < ε (i = 1, 2, 3), where ε is a pre-set arbitrarily small constant. 3) the system state does not violate the desired constraint: ||x1(t)|| < k a (t), ||x2(t)|| < k b (t), where k a (t) and k b (t) are strictly positive continuous functions.

[0075] In Step 2, in order to compensate for the adverse effects of input saturation on the closed-loop system, this embodiment constructs the following auxiliary system to generate compensation signals and

[0076]

[0077]

[0078] where

[0079]

[0080]

[0081] where Δτ = M -1 f(τ) - M -1 τ, λ1 = βξ1, λ2 = βξ2, Ξ1 = [Y 11 ,Y 12 ,Y 13 ] T , 3 / 4 < r1 < 1, r2 > 2, Ξ2 = [Y 21 ,Y 22 ,Y 23 ] T , ω1 > 0.

[0082] In the auxiliary system (5), Δτ is the input, and ξ1 and ξ2 are the outputs. Before the control design, it is necessary to prove the boundedness of the compensation signals ξ1 and ξ2.

[0083] The Lyapunov function is selected as:

[0084]

[0085] The derivative of which is calculated as:

[0086]

[0087] By combining Lemma 4 and applying Young's inequality, we get

[0088]

[0089]

[0090]

[0091]

[0092] Thus, we have

[0093]

[0094]

[0095] Therefore, it can be obtained that, under the premise that Δτ is bounded, the auxiliary system (5) is fixed-time practically stable, and ξ1 and ξ2 can enter an arbitrarily small bounded set within a fixed time t 1* .

[0096] The principle is that, by using Lemma 5, (6) can be written as where q2 = min{2q 21 , 2q 22}, and 1 = ω1maxt≥0 {‖Δτ(t)‖ 2}+3k * (q 11*1 +q 12*2 )。

[0097] Set T≥t 1* , we have This means

[0098]

[0099]

[0100] By Lemma 2, the closed-loop system (4) is fixed-time practically stable, and the upper bound of settling time t 1* can be expressed as or where and 0 < c < 1.

[0101] Based on the above analysis, for any small constant ε > 0, by setting we have ||ξ i ||≤ε / 2 for t≥T.

[0102] In Step 3, the specific design process of the adaptive fixed-time tracking controller is as follows:

[0103] Based on the tracking control performance, velocity function and rate function are introduced;

[0104] Combined with the compensation signal, the error transformation based on the velocity function is obtained;

[0105] BLF is constructed according to the constraint state;

[0106] An event-triggered fixed-time adaptive tracking control algorithm is designed;

[0107] According to the analysis of the tracking control algorithm, the tracking controller is designed.

[0108] More specifically, the velocity function β(t) is introduced to ensure the tracking performance of the system, and the tracking performance is designed according to the actual demand, and the specific formula is:

[0109]

[0110] where ρ(t) is the rate function, 0 < b f < 1 is a design parameter, and 0 < T < ∞ is the pre-allocated time.

[0111] Combined with the compensation signal, the error transformation based on the velocity function is obtained:

[0112] z1= x1- x d -ξ1, z2= x2- α1- ξ2,

[0113] e1= βz1, e2= βz2, (9)

[0114] where α1is a virtual control signal.

[0115] The construction of BLF based on the constraint state is divided into two steps as follows:

[0116] Step 1: To guarantee the constraint state by constructing BLF. The BLF V1is constructed as follows:

[0117]

[0118] where For simplicity, define The derivative of BLF V1is calculated as follows:

[0119]

[0120] Using Young's inequality, we have:

[0121]

[0122]

[0123] where l1> 0 is a design parameter.

[0124] Let and construct Ξ3= [Y 31 ,Y 32 ,Y 33 ] T where and 3 / 4 < k < 1.

[0125] The virtual controller is designed as:

[0126]

[0127] where

[0128]

[0129]

[0130] Meanwhile, 3 / 4 < k < 1, μ 11 > 0, and μ 12 > 0.

[0131] Based on β ≥ 1, combined with equations (11), (12), and (13), we have:

[0132]

[0133] Note 2 According to Lemma 8, Ξ1, Ξ2 and Ξ3 introduced in the virtual controller are well defined, and Y 1i , Y 2i and Y 3i (i = 1, 2, 3) are also continuously differentiable, and thus α1 is continuously differentiable.

[0134] Step 2: Consider the second candidate BLF:

[0135]

[0136] where k2(t) > 0, and Meanwhile denotes the estimate of θ.

[0137] Define and take the derivative of V2, we have

[0138]

[0139] Let L1 = (σ - K2(t))e2, (15) can be rewritten as

[0140]

[0141] Note that β 2 ≥ 1, and thus we can use Young's inequality to obtain the following result:

[0142]

[0143]

[0144] where l2 is a positive design parameter.

[0145] By Lemma 6, we have

[0146]

[0147] where

[0148] Substitute (17) and (18) into (16), we have

[0149]

[0150] Next, construct the virtual control signal α2 as follows:

[0151]

[0152] where Ξ4 = [Y41 ,Y 42 ,Y 43 ] T , It is a vector The i-th element, and ∈ *5 >0, i = 1, 2, 3.

[0153] By using Lemma 8, (19) can be rewritten as:

[0154]

[0155] Therefore, the adaptive fixed-time tracking controller can be designed as follows:

[0156]

[0157] Where τ i (t) is the i-th component of the control signal τ, α 2i It is the i-th element of α2. Represents the control signal τ i The update time of (t).

[0158] The event-driven strategy is set as follows:

[0159]

[0160]

[0161]

[0162] in, Represents the control signal τ i The update time of (t), This represents the sampling error of the i-th actuator. M is the corresponding signal transmission time. i Let m1 represent the i-th row of matrix M, where m1 > 0 is a design parameter, and i = 1, 2, 3.

[0163] It is important to note that in the event-driven strategy described above, the updating and transmission of control signals are separated. Because control signals are subject to saturation, when both the control signals before and after the update are in a saturated state, the actuator's output f... i (τ i The signal τ remains unchanged, and there is no need for signal transmission at this time. In short, in the event triggering mechanism (22)-(24), if the triggering condition (23) is activated, the control signal τ will be transmitted. i (t) is updated to On this basis, if further then the control signal τ i is sent to the i-th actuator. Thus, the signal transmission time is a sub-sequence of the trigger time , which also makes the proposed event-driven strategy further reduce the communication burden. On the other hand, the update of the control signal τ i (t) at the trigger time guarantees for all t.

[0164] If assumptions 1-3 hold, and the initial value of the closed-loop system (4) satisfies ||x1(0)||<k a (0), ||x2(0)||<k b (0), then applying the event-based control strategy (21)-(24) can achieve the control objectives: 1) all signals of the closed-loop system (4) are bounded. 2) the desired trajectory x d =[x d1 ,x d2 ,x d3 ] T can be tracked by x1=[x 11 ,x 12 ,x 13 ] T before the pre-specified time T, while the tracking error satisfies: lim t→T |x 1i -x di |<ε and |x 1i -x di | t≥T <ε (i=1,2,3), where ε is a pre-set arbitrarily small constant. 3) the system state does not violate the desired constraint: ||x1(t)||<k a (t), ||x2(t)||<k b (t), where k a (t) and k b (t) are strictly positive continuous functions.

[0165] The derivation process is as follows: from equations (22) and (24), we can derive:

[0166]

[0167] where |θ1(t)|≤1, |θ2(t)|≤1 are two time-varying parameters. Therefore, τ(t)=τ s (t) / (1+θ1δ1)+N holds, where N=[(-m1θ2(t)) / (1+θ1(t)δ1),(-m1θ2(t)) / (1+θ1(t)δ1),(-m1θ2(t)) / (1+θ1(t)δ1),...].* (t)δ1)] T .

[0168] Since it is guaranteed that Thus, there are Further, it is known that:

[0169]

[0170] On the basis of (25), it can be derived that

[0171]

[0172] Bringing (26) into (20) gives

[0173]

[0174] For the coupling term in (27), the present embodiment has

[0175] Let x = 1, d = 1 - k, e = k, γ = k k / (1-k) Then, based on Lemma 3, it can be obtained that

[0176]

[0177] That is,

[0178]

[0179] Similarly, there are

[0180]

[0181] By combining inequalities (27)-(29), it can be obtained that:

[0182]

[0183] By Lemma 4 and Lemma 5, formula (30) can be further written as:

[0184]

[0185] Where σ1 = min{2 k μ 11 ,2 k μ 21 ,μ 31}, σ2 = min{(4 / 3)μ 12 ,(4 / 3)μ 22 ,(1 / 3)μ 32}, Since V2 ≥ 0, it has

[0186]

[0187] Definition Then for any t≥0, we have Thus and

[0188] Further, if the initial errors satisfy ||e1(0)||<k1(0), ||e2(0)||<k2(0), then we have Since β(t) is bounded, we have and Recall (9), we have and Further, we have and According to and the above analysis, we have and Thus, we have and Further, we can conclude that all the signals of the closed-loop system (4) are bounded. The proof of the control objective 1) is completed.

[0189] By Lemma 1 and Lemma 2, we can analyze (31) and know that the closed-loop system (4) is CPFTS. Definition After some simple calculations, we can easily obtain that when t≥t 2* , we have

[0190]

[0191] where and K * = max t≥0 {k1(t), k2(t)}. When , we have When , we have j = 1, 2.

[0192] The parameters of the velocity function are set as follows:

[0193] T≥max{t 1* , t 2*},

[0194]

[0195] Then (32) can be rewritten as:

[0196]

[0197]

[0198] This means that the generalized error z j (t) is able to decay to arbitrarily small before a preset time T and does not escape after T.

[0199] For the tracking error z 1i* = x 1i - x di , based on the above analysis, we have |z 1i* |≤ |x1- x d | + |ξ1|. In conjunction with (9) and (34), we have

[0200] |z 1i* |≤ (1- b f ) p -1 (t) Θ1+ ε, max{t 1* , t 2*}≤ t < T,

[0201] |z 1i* |≤ ε, t≥ T,

[0202] where Thus, we have

[0203]

[0204] The above results show that the tracking error can decay to arbitrarily small within T, thus completing the desired tracking, and its decay rate is not slower than ((T-t) / T) 4 e -t . The proof for control objective 2) is completed.

[0205] From the above analysis, for any t≥ 0, as long as the initial conditions of the system satisfy the constraint, i.e., there exists a constant , in conjunction with the structure of V2, we can further know and Since all signals of the system are bounded, there must exist a positive constant such that Therefore, as long as we choose we will have Similarly, by choosing we will have This means that all states are subject to the constraint throughout the control process, thus achieving control objective 3).

[0206] Finally, it needs to be noted that the entire control process will not occur Zeno phenomenon. The derivatives of τ si (i = 1, 2, 3) can be expressed as

[0207]

[0208] where

[0209]

[0210] From Lemma 7, it can be known that 1i , and are continuous functions. Based on this, the continuity of 2i , and can be directly derived, and it can be further known that is also continuous. For the sampling error the following inequality holds:

[0211]

[0212] Since is continuous on the interval and all signals are bounded, it is not difficult to deduce the boundedness of . Therefore, there exists a positive constant i such that holds for any . Taking the integral of to for (36) can obtain

[0213]

[0214] Since and , it always holds that . Thus, it has that is, the Zeno phenomenon is avoided in the control process.

[0215] Note 4: Equation (33) gives the selection principle of T and b f in the conservative case. In fact, due to the fixed-time stability property of the closed-loop system, the system can achieve tracking with a given precision before the pre-allocated time T, which reflects the fixed-time regulation property of the control algorithm in this embodiment.

[0216] Note 5: Although Lemma 2 is applied in the form of p2=2 in this embodiment, in fact, p2 can take any integer greater than 1. This can be achieved through a similar control design as this embodiment. For example, replace in A2 with and replace in the adaptive law with Then (31) will be rewritten as that is, p2=3 is achieved.

[0217] The simulation verification is performed according to step 4. The specific verification process is as follows:

[0218] The effectiveness of the algorithm was verified using the existing fully-driven vessel CyberShip II. The main physical parameters of CyberShip II are shown in Table 1; other parameters are Y... |r|ν =-0.805, Y |ν|r = -0.845, Y |r|r =3.45, N |r|ν =-0.13, N r =1.9, N |ν|r =0.08, N |r|r = -0.75. Set the restoring force vector to: g(x1) = [0.36sin(x1)] 13 )+0.2cos(x 13 ),0.36cos(x 13 )+0.2sin(x 13 [0.18]. The control objective is: reference trajectory x d =[0.5sin(t),0.5cos(t),0.5sin(t)] T In the perturbation x d =[0.5sin(t),0.5cos(t),0.5sin(t)] T The position output x1 of the ship's system is to be tracked within a pre-specified time T = 4 seconds, with a tracking accuracy set to ε = 0.001. System states x1 and x2 are required to satisfy constraint k respectively. a (t) = 0.15sin(t) + 0.9 and k b (t) = 0.15sin(t) + 1.

[0219] Table 1. Key physical parameters of CyberShip II

[0220]

[0221] The corresponding control parameters are set as follows: l1 = l2 = 0.002, q 11 =q 12 =q 21 =q 22 =10000, r1=k=0.8, r2=3, ω1=0.001, μ 11 =μ 12 =2, μ 21 =μ 22 =μ 31 =μ 32 =15, δ=0.5, m1=0.3, *1 = *2= *3 = 0.0001, *4 = *5 = *6 = 0.01. The parameters of the saturation function f i are set to f max = [50, 17, 4] T N, f min = [-13, -50, -0.5] T N. The system initial values are set to x1(0) = [0.08, 0.45, 0.1] T m, x2(0) = [0, 0, 0] T m / s, ξ1(0) = ξ2(0) = [0, 0, 0] T , In addition, take k1(t) = 0.15sin(t) + 0.3, k2(t) = 0.15sin(t) + 0.4. The simulation results are shown in Figures 2-7 .

[0222] From Figure 2 and Figure 3 , it can be seen that the closed-loop system not only completes the desired tracking, but also the state always obeys the constraint. Figure 4 The boundedness of the adaptive parameters is shown. The output signals of the advance force actuator, the cross drift force actuator, and the bow yaw force actuator under the influence of saturation and their corresponding update times are shown in Figures 5-7 . Specifically, the number of times that the three actuators deliver signals within 20s is 588, 669, and 707, respectively. Obviously, the simulation results prove that the technical solution in the embodiment can ensure the expected transient and steady-state tracking performance without violating the full-state constraint, the method proposed in the application has the characteristics that the convergence speed, tracking accuracy, and stabilization time can be preset in advance, and the communication cost of the controller is low.

[0223] Embodiment two:

[0224] The embodiment two of the application provides an event-driven full-drive ship predetermined performance tracking control system, which comprises:

[0225] A model construction module is configured to collect target ship parameter information, and establish a ship model based on a closed-loop system of a full-drive ship;

[0226] A model optimization module is configured to construct an auxiliary system to generate a compensation signal, and compensate for adverse effects caused by input saturation of the ship model;

[0227] A controller design module is configured to design an adaptive fixed-time tracking controller according to the compensation signal;

[0228] A predetermined performance tracking control module is configured to set adaptive fixed-time tracking controller parameters, input control targets of the adaptive fixed-time tracking controller within a preset time, and output control instructions of the controller to actuators, so that a closed-loop system of the ship completes expected tracking under the condition of obeying constraints.

[0229] Embodiment three

[0230] Embodiment three of the present application provides a medium having a program stored thereon, which, when executed by a processor, implements the steps in the event-driven full-drive ship predetermined performance tracking control method according to embodiment one of the present application, and the steps are as follows:

[0231] Step 1: Collect target ship parameter information, and establish a ship model based on a closed-loop system of a full-drive ship.

[0232] Step 2: Construct an auxiliary system to generate a compensation signal to compensate for adverse effects caused by input saturation of the ship model;

[0233] Step 3: Design an adaptive fixed-time tracking controller according to the compensation signal;

[0234] Step 4: Set adaptive fixed-time tracking controller parameters, input control targets of the adaptive fixed-time tracking controller within a preset time, and output control instructions of the controller to actuators, so that a closed-loop system of the ship completes expected tracking under the condition of obeying constraints.

[0235] The detailed steps are the same as those in the event-driven full-drive ship predetermined performance tracking control method provided in embodiment one, and will not be repeated here.

[0236] Embodiment four

[0237] Embodiment four of the present application provides a device including a memory, a processor, and a program stored on the memory and executable on the processor, and the processor implements the steps in the event-driven full-drive ship predetermined performance tracking control method according to embodiment one of the present application when executing the program, and the steps are as follows:

[0238] Step 1: Collect target ship parameter information, and establish a ship model based on a closed-loop system of a full-drive ship.

[0239] Step 2: Construct an auxiliary system to generate a compensation signal to compensate for adverse effects caused by input saturation of the ship model;

[0240] Step 3: Design an adaptive fixed-time tracking controller according to the compensation signal;

[0241] Step 4: setting adaptive fixed time tracking controller parameters, inputting control targets in preset time to adaptive fixed time tracking controller, and outputting control instructions to actuators to make the closed loop system of the ship complete desired tracking under the condition of obeying constraints.

[0242] The detailed steps are the same as the event-driven full-propulsion ship predetermined performance tracking control method provided in Embodiment 1, and thus will not be described herein.

[0243] The steps and methods involved in Embodiments 2, 3 and 4 correspond to Embodiment 1, and the specific implementation can be referred to the relevant description part of Embodiment 1. The term "computer readable storage medium" should be understood as including a single medium or multiple media of one or more instruction sets; and should also be understood as including any medium capable of storing, encoding or carrying instruction sets for execution by a processor and making the processor execute any method in the present application.

[0244] Those skilled in the art should understand that each module or step of the present application described above can be realized by a general computer device, and alternatively, they can be realized by program codes executable by a computing device, so that they can be stored in a storage device for execution by a computing device, or they can be respectively made into individual integrated circuit modules, or a plurality of modules or steps among them can be made into a single integrated circuit module. The present application is not limited to any specific combination of hardware and software.

[0245] The specific embodiments of the present application are described above in combination with the accompanying drawings, but are not a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications or variations made by those skilled in the art on the basis of the technical solutions of the present application without creative labor are still within the protection scope of the present application.

Claims

1. A method for tracking control of a full-propulsion vessel based on event-driven performance reservation, characterized by, The method comprises the following steps: Collecting target ship parameter information, establishing a ship model based on a closed-loop system of the full-drive ship, and modeling the full-drive water surface ship according to the following formula: where the shape vector In this paper, denotes the position of the ship in the earth coordinate system, denotes the heading angle, the velocity vector The elements of the vector are used to represent lumped disturbances, possible modeling errors, and neglected dynamics, is the actuator output with saturation characteristics, is the original control signal to be designed, is the rotation matrix, is the damping matrix, is the symmetric and positive definite inertia matrix, is the centripetal and Coriolis force matrix, is the restoring force due to gravity, ocean current, and buoyancy; , , , The detailed expression of is ， ， ， where each element is respectively: , , , ; where each element is respectively: , ; where each element is respectively: , , , , ; the coefficient , , is the hydrodynamic coefficient; is the mass of the ship, is the moment of inertia about the yaw rotation, denotes the distance to the center of gravity of the ship; is described as: ， ， where and are known saturation parameters; has the following properties: and By choosing x1= η and x2= v, the ship model of the system is obtained as: wherein ; The goals achieved by the adaptive control strategy include: All signals in the ship model of the closed-loop system are bounded; Desired trajectory System configuration trajectory At a pre-specified time The tracking is completed before, while the tracking error satisfies: And Where Is a pre-set arbitrary small constant; The system state does not violate the expected constraints: , , where and are strictly positive continuous functions; The construction assistance system generates a compensation signal to compensate for the adverse effects on the ship model due to input saturation, and the following assistance system is constructed to generate the compensation signal and : Wherein, ， ， , , , , , , , , , , , , , are inputs, and are outputs; An adaptive fixed-time tracking controller is designed according to the compensation signal; the specific design process of the adaptive fixed-time tracking controller is as follows: A velocity function and a rate function are introduced based on tracking control performance; Based on the compensation signal, an error transformation based on the velocity function is obtained; BLF is constructed according to the constraint state; A fixed-time adaptive tracking control algorithm based on event triggering is designed; The tracking controller is designed according to the analysis of the tracking control algorithm; The adaptive fixed-time tracking controller parameters are set, the control target in the preset time is input to the adaptive fixed-time tracking controller, the controller outputs the control instruction to the actuator, and the closed-loop system of the ship completes the expected tracking under the condition of obeying the constraint.

2. The event-driven based full-propulsion vessel pre-performance tracking control method according to claim 1, wherein, The compensation signal generated by the auxiliary system has boundedness.

3. The event-driven based full-propulsion vessel pre-performance tracking control method according to claim 1, wherein, When designing the adaptive fixed-time tracking controller, the velocity function is introduced to ensure the tracking performance of the system.

4. The event-driven based full-propulsion vessel pre-performance tracking control method of claim 1, wherein: The specific design process of the adaptive fixed-time tracking controller is as follows: Introducing the velocity function to ensure the system tracking performance, which is designed according to the actual demand, the specific formula is: ， ， wherein is a rate function, is a design parameter, is a preallocation time; Based on the compensation signal, an error transformation based on the velocity function is obtained: wherein is a virtual control signal; BLF is constructed according to the constraint state, which is divided into the following two steps: The constraint state is guaranteed by constructing a BLF; the BLF is constructed as follows : wherein ; The second candidate BLF: ， wherein , and while denotes an estimate of ; Definitions , where is the derivative of , is the derivative of The following results are obtained by using Young's inequality: where is a positive design parameter, by virtue of the fact that , holds where and is a real number, we obtain: wherein ; Next, the virtual control signal is constructed as follows: wherein , , is the th element of the vector and , , ; The adaptive fixed-time tracking controller is designed as follows: wherein: is a control signal of the th component, is the th element of denotes an update time of the control signal . The event-driven strategy of the adaptive fixed-time tracking controller is taken as follows: ， in, Indicates control signal Update time, Indicates the first Sampling error of each actuator This is the corresponding signal transmission time. Right now The Okay, at the same time For design parameters, and .

5. An event-driven full-propulsion vessel scheduled performance tracking control system characterized by, It includes: The model construction module is configured to collect target ship parameter information, establish a ship model based on a closed-loop system of the full-drive ship, and model the full-drive water surface ship according to the following formula: where the configuration vector in which, denotes the position of the ship in the earth coordinate system, denotes the heading angle, the velocity vector in which the elements represent the forward speed, lateral speed, and yaw speed, respectively; the vector is used to represent the lumped disturbances, possible modeling errors, and neglected dynamics; is the actuator output with saturation characteristics, is the original control signal to be designed, is the rotation matrix, is the damping matrix, is the symmetric and positive definite inertia matrix, is the centripetal and Coriolis force matrix, is the restoring force caused by gravity, ocean current, and buoyancy; , , , The detailed expression of is as follows: ， ， ， ； where each element is respectively: , , , ; where each element is respectively: , ; where each element is respectively: , , , , ; the coefficient , , is a hydrodynamic coefficient; is the mass of the ship, is the moment of inertia about the yaw rotation, denotes the distance to the center of gravity of the ship; is described as: ， ， where and are known saturation parameters; has the following properties: and By choosing x1= η and x2= v, the ship model of the closed loop system is obtained as wherein ; The goals achieved by the adaptive control strategy include: All signals in the ship model of the closed-loop system are bounded; Desired trajectory System configuration trajectory At a pre-specified time The tracking is completed before, while the tracking error satisfies: And Where Is a pre-set arbitrary small constant; The system state does not violate the expected constraints: , , where and are strictly positive continuous functions; The model optimization module is configured to construct an auxiliary system to generate a compensation signal to compensate for the adverse effects of input saturation on the ship model, and the following auxiliary system is constructed to generate the compensation signal and : Wherein, ， , , , , , , , , , , , , , , are inputs, and are outputs; The controller design module is configured to design an adaptive fixed-time tracking controller according to the compensation signal; the specific design process of the adaptive fixed-time tracking controller is as follows: A velocity function and a rate function are introduced based on tracking control performance; Based on the compensation signal, an error transformation based on the velocity function is obtained; BLF is constructed according to the constraint state; A fixed-time adaptive tracking control algorithm based on event triggering is designed; The tracking controller is designed according to the analysis of the tracking control algorithm; The predetermined performance tracking control module is configured to set the adaptive fixed-time tracking controller parameters, input the control target in the preset time to the adaptive fixed-time tracking controller, and output the control instruction to the actuator, so that the closed-loop system of the ship completes the expected tracking under the condition of obeying the constraint.

6. A computer-readable storage medium, characterized in that, A plurality of instructions are stored in the memory, and the instructions are adapted to be loaded and executed by the processor of the terminal device to implement the event-driven full-drive ship predetermined performance tracking control method in any one of claims 1-4.

7. A terminal device, characterized by comprising: The application comprises a processor and a computer readable storage medium, the processor is used to realize instructions; the computer readable storage medium is used to store a plurality of instructions, the instructions are suitable for being loaded and executed by the processor and the event-driven full-propulsion ship predetermined performance tracking control method in any one of claims 1-4.

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