A compound feedforward cooperative control method and system for a ship controllable pitch propeller

Abstract

The application provides a kind of ship variable pitch propeller propulsion composite feedforward collaborative control method and system, comprising: the establishment of containing ship load inquiry function model and variable pitch propeller propulsion collaborative control model propulsion composite model;Through load inquiry model, the ship resistance characteristics are identified in real time, the main engine power and propeller speed demand under different sailing speed are predicted, and the main engine power margin is calculated;Set the main engine safety threshold based on maximum continuous power margin;Within the allowable range of safety threshold, three kinds of collaborative control modes are adaptively selected and executed according to sailing conditions: pitch-throttle joint control under constant speed of main engine, main engine speed-throttle joint control under constant pitch of variable pitch propeller, variable pitch propeller speed-pitch joint control mode under constant power of main engine.The application realizes closed loop stable control of sailing speed through feedforward prediction and multivariable collaboration, fundamentally avoids the problem of main engine overload, black smoke, high exhaust temperature and large control fluctuation, and improves fuel economy and full working condition sailing safety.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of ship technology, and particularly relates to a compound feedforward cooperative control method and system for ship controllable pitch propeller propulsion. BACKGROUND

[0002] The controllable pitch propeller of the ship is a variable pitch propeller which can meet different navigation conditions by changing the pitch size / direction and rotating speed, and has the characteristics of convenient operation and strong maneuverability. The controllable pitch propeller device has a wide application prospect in military ships, ocean survey ships, roll-on / roll-off passenger ships, research ships, engineering ships and ice region navigation ships.

[0003] In the controllable pitch propeller propulsion system, the power output by the main engine is transmitted to the controllable pitch propeller through the hydraulic coupler and the intermediate shaft, and the thrust generated by the controllable pitch propeller propels the ship to move forward, turn or retreat. During the acceleration process of the ship, if the rotating speed of the controllable pitch propeller and the pitch are not well matched, the thrust of the controllable pitch propeller will change sharply, and the random factors such as sea state disturbance and ship attitude change during navigation will further affect the ship, which can easily cause the main engine to be overloaded, the exhaust temperature to be high, black smoke to be emitted, the speed-throttle-pitch to be fluctuated sharply, affect the stability of the ship during navigation and the performance of the main engine, and the frequent action of the pitch can also cause serious wear and oil leakage.

[0004] On the other hand, the current control mode of the controllable pitch propeller propulsion of the ship includes the main engine constant rotating speed control mode and the controllable pitch propeller constant pitch control mode, which are single target constant value control modes, and lack of feedforward control and compound control strategy based on the load inquiry function of the ship. In particular, the current open loop control of the ship speed has the problems of unstable speed and low efficiency of the main engine.

[0005] Therefore, an intelligent propulsion control method is needed, which can realize closed loop stable control of the speed, smooth load of the main engine, good economy and adapt to all working conditions (especially ice region navigation). SUMMARY

[0006] The purpose of the present application is to provide a ship propulsion compound feedforward cooperative control strategy which can avoid the problems of main engine overload, high exhaust temperature, black smoke emission, large speed-throttle-pitch fluctuation (unstable control), excessive wear of the controllable pitch propeller and ice region navigation, realize optimal control of the controllable pitch propeller propulsion, maintain stable ship speed and optimal main engine performance, and thus improve the safety and maneuverability of the ship during navigation in harsh sea conditions and ice region.

[0007] To achieve the above purpose, the present application provides a compound feedforward cooperative control method for ship controllable pitch propeller propulsion, which comprises the following steps:

[0008] S1: Establish a controllable pitch propeller propulsion composite model to clarify the cooperative relationship between each link of the controllable pitch propeller propulsion system, wherein the propulsion composite model comprises a ship-machine-propeller relationship model, a propulsion main engine characteristic and limitation model, a hydraulic coupler characteristic model, a controllable pitch propeller characteristic model, a controllable pitch propeller propulsion cooperative control model and a ship load inquiry function model;

[0009] The propulsion main engine characteristic and limitation model comprises controllable pitch propeller constant pitch FPP propulsion, variable pitch CPP propulsion, propulsion main engine speed characteristic, propulsion main engine load characteristic, and limitation characteristic of allowable working range of the propulsion main engine;

[0010] The relationship between the controllable pitch propeller speed, pitch and torque is established through the controllable pitch propeller characteristic model to obtain the controllable pitch propeller characteristic curve, and the deviation between the ideal design curve and the actual operation curve of the characteristic shows the performance of the propulsion system and the working condition change thereof;

[0011] The cooperative control among the main engine speed-throttle, the hydraulic coupler output speed and the controllable pitch propeller speed-pitch is established through the controllable pitch propeller propulsion cooperative control model;

[0012] The ship speed, main engine power, main engine speed, controllable pitch propeller speed, pitch and other data are collected in real time through the ship load inquiry function model, the ship resistance characteristic is identified on line based on the data driven extended Kalman filter EKF algorithm, the main engine power-ship speed characteristic relationship (i.e. the first mapping relationship between the ship speed and the main engine power) and the controllable pitch propeller speed-ship speed characteristic relationship (i.e. the second mapping relationship between the ship speed and the propeller speed) are dynamically established based on the identification result; based on the first mapping relationship and the second mapping relationship, the required main engine power and propeller speed under different ship speeds are predicted in advance, and the real-time difference between the current main engine power and the maximum continuous power of the main engine is calculated as the current power margin, a power margin limitation threshold is set, and the maximum continuous power margin Δ P max of the main engine is determined; P max， A main engine safety threshold δ ME is set in the application; in the application, the power margin limitation threshold is set to be not less than 5% of the rated power of the main engine; the main engine safety threshold δ ME is set to be 95% of the maximum continuous power margin Δ P max of the main engine, i.e. δ ME =0.95(Δ P max );

[0013] S2: Calculate the speed deviation between the set speed and the actual speed, input the speed deviation into the ship speed closed loop gradual control link to generate a gradually changing expected speed sequence;

[0014] S3: For each desired speed value in the desired speed sequence, call the ship load query function model to predict the main engine power and controllable pitch propeller speed required to achieve the desired speed; calculate the power demand increment according to the predicted main engine power and the current main engine power; compare the power demand increment with the predetermined main engine safety threshold; if the power demand increment (main engine pre-increment power ΔP ME ) exceeds the main engine safety threshold δ ME , generate a feedforward protection instruction to proactively reduce the controllable pitch propeller pitch, actively reduce the controllable pitch propeller thrust T, and ensure that the pre-increment power is less than δ ME , so as to ensure that the power demand during the actual acceleration process is always lower than the safety threshold, fundamentally prevent the main engine from being overloaded and related failures, avoid the problems of black smoke, high exhaust temperature, overload operation, and large speed-pitch-throttle fluctuations (caused by unstable control), thereby optimizing the ship propulsion performance and preventing frequent reciprocating adjustment;

[0015] The main engine safety threshold δ ME is calculated by the formula: ,

[0016] where ΔP max is the maximum continuous power margin of the main engine (kw), δ ME is the main engine safety threshold, P emax is the maximum continuous power of the main engine (kw), P p is the propeller power (kw), β 1 is the transmission efficiency of the fluid coupling and shafting, β 2 is the influence coefficient after the interaction of the ship and the propeller;

[0017] S4: Within the allowable range of the main engine safety threshold δ ME , use the controllable pitch propeller propulsion cooperative control model to select and execute the following cooperative control modes according to the navigation conditions, so as to realize the stability of the main engine performance and the ship speed; the control modes include:

[0018] Controlling the ship speed in the main engine constant speed mode v s , which is suitable for ocean navigation conditions, and controls the main engine speed as a constant value, cooperates with the main engine throttle L to track the controllable pitch propeller pitch H pAdjustment, i.e. pitch-throttle co-control mode, is suitable for ocean navigation conditions;

[0019] Fixed pitch of controllable pitch propeller H p Controlling the ship speed in the mode v s The main engine speed is fixed in the mode H p The main engine speed is fixed in the mode n e Closed loop control, co-control of main engine throttle L According to the main engine speed n e Follow-up adjustment, i.e. main engine speed-throttle co-control mode, is suitable for regular navigation conditions;

[0020] Controlling the ship speed in the mode of main engine constant power under severe sea conditions v s The main engine throttle is fixed in the mode L The output speed of the fluid coupling n p The pitch of the controllable pitch propeller H p Co-control, i.e. controllable pitch propeller speed-pitch co-control mode, is suitable for navigation under severe sea conditions or in ice areas;

[0021] The three kinds of ship speed v s Control modes are carried out within the allowable range of the main engine safety threshold δ ME And are constrained by the main engine characteristics and limit model.

[0022] The meaning of the composite in the composite feedforward co-control method of the ship controllable pitch propeller propulsion of the application is pitch-throttle co-control, main engine speed-throttle co-control and controllable pitch propeller speed-pitch co-control based on speed closed loop stable control; the meaning of feedforward is ship load inquiry function, ship resistance characteristics are identified based on EKF, and the required power and speed of the ship speed are used for feedforward control to improve rapidity; the meaning of co-control is systematic integrated joint control of ship-main engine-fluid coupling-controllable pitch propeller; the three kinds of ship speed v sThe control mode is selected according to the sea conditions and the sailing working condition, the ship is manually controlled when entering and leaving the port and passing through the special channel, and the three control modes can be automatically / manually selected when the ship sails in the ocean, wherein the main engine constant power mode is automatically selected according to the severe sea conditions, the main engine constant speed control is used in the stable sailing condition, the oil door-pitch linkage control is used for the oil saving mode sailing under the stable ship speed, the other sailing working condition is preferably the constant pitch control, the wear caused by the frequent sliding of the propeller hub is reduced, the main engine speed-oil door linkage control maintains the stable speed and the main engine power, which effectively prevents the main engine overload, high exhaust temperature, black smoke, unstable speed-pitch-oil door (caused by unstable control), improves the main engine thermal efficiency and thermal balance effect, and realizes the automatic control ability of the stable ship speed, safe and reliable ship maneuvering and fast response.

[0023] Further, in step S1, the ship-machine-propeller relationship model includes a machine-propeller characteristic submodel, a ship resistance characteristic submodel and a ship-propeller characteristic submodel.

[0024] The machine-propeller characteristic submodel formula is:

[0025] ;

[0026] In the formula, J is the moment of inertia on the propulsion shaft, n e is the main engine speed, n p is the controllable pitch propeller speed, M e is the main engine output torque, M p is the controllable pitch propeller torque, M m is the shaft friction torque;

[0027] ;

[0028] In the formula, P p is the controllable pitch propeller power, P ME is the main engine output power, η c is the shaft transmission efficiency.

[0029] The ship resistance characteristic submodel formula is:

[0030] ;

[0031] In the formula, R is the ship resistance, and R is the resistance coefficient, v s is the ship speed, mFor the ship index.

[0032] Further, in step S1, the ship-propeller characteristic sub-model formula is:

[0033] ;

[0034] In the formula, M is the ship mass, v s is the ship speed, T is the propeller thrust, ∑ T represents two or more propeller thrusts, R is the ship motion resistance;

[0035] ;

[0036] In the formula, P R is the effective propeller thrust power, η s is the hull efficiency, η p is the propeller wake fraction, η x is the propeller rotation efficiency, P p is the propeller power.

[0037] Further, in step S1, the main engine characteristic and limit model includes a fixed pitch FPP propelling mode, a variable pitch CPP propelling mode, a main engine speed characteristic, a main engine load characteristic, and a limit characteristic of the main engine allowable working range:

[0038] The fixed pitch FPP propelling mode is a constant pitch control at a certain pitch, and enters a main engine speed and throttle coordinated control mode.

[0039] The variable pitch CPP propelling mode is a main engine speed-throttle-pitch compound coordinated control mode.

[0040] The main engine speed characteristic is a full load speed characteristic, an overload speed characteristic, and a partial load speed characteristic obtained by constant throttle control at different throttles, and a main engine torque curve obtained according to the main engine speed characteristic, which is a torque curve with speed change relationship ;

[0041] The main engine load characteristic is a main engine economic load obtained by constant speed control at different speeds, and a power curve , and the main engine power changes linearly with the increase of the load at constant speed.

[0042] The host allows the working range to be the maximum power, the minimum power allowed to be reached by the host at various rotating speeds, and the highest rotating speed and the lowest rotating speed allowed to be reached by the host at various loads.

[0043] The host limiting characteristic curve includes an equal-torque limiting curve and an equal-exhaust temperature limiting line for limiting the over-mechanical load and the over-thermal load of the host, respectively.

[0044] The above characteristic curve realizes characteristic change visualization, and the calibration characteristic curve obtained through the host bench test, the water running test of the pitch propeller, and the sea trial of the new ship reacts the ideal design characteristics of the ship-machine-propeller.

[0045] Further, in step S1, the hydraulic coupler characteristic model converts the rotating speed and the torque of the host into the rotating speed and the torque of the pitch propeller, and visualizes the relationship between the input / output rotating speed, the torque and the variable speed ratio of the hydraulic coupler through the working characteristic curve of the hydraulic coupler. When the hydraulic coupler is in the engagement working condition, the host torque, the hydraulic coupler torque and the pitch propeller torque are balanced, and the host working condition and the pitch propeller are best matched through the characteristic relationship of the hydraulic coupler, so as to prevent the propeller from being heavy or light. The hydraulic coupler adopted in the present application can adjust the rotating speed of the propeller and stabilize the rotating speed of the host, and buffers the direct influence of the propeller on the host.

[0046] Further, in step S1, the pitch propeller propulsion characteristic model includes a pitch propeller torque sub-model, a pitch propeller thrust sub-model, a pitch propeller power sub-model and a pitch propeller water running efficiency sub-model.

[0047] The formula of the pitch propeller torque sub-model is:

[0048] ,

[0049] In the formula, M p is the pitch propeller torque, K M is a pitch propeller torque coefficient, ρ is the mass density of water, D is the diameter of the pitch propeller, n p is the rotating speed of the pitch propeller;

[0050] The formula of the pitch propeller thrust sub-model is:

[0051] ,

[0052] In the formula, T is the pitch propeller thrust, K T is a pitch propeller thrust coefficient,D Dp is the diameter of the controllable pitch propeller, n p Np is the rotation speed of the controllable pitch propeller;

[0053] The formula of the controllable pitch propeller power sub-model is:

[0054] ,

[0055] In the formula, P p Pp is the power of the controllable pitch propeller, K M Cp is the torque coefficient of the controllable pitch propeller, ρ p is the mass density of water, D Dp is the diameter of the controllable pitch propeller, n p Np is the rotation speed of the controllable pitch propeller;

[0056] The formula of the controllable pitch propeller drag coefficient sub-model is:

[0057] ,

[0058] In the formula, η p Cp is the drag coefficient of the controllable pitch propeller, T Tp is the thrust of the controllable pitch propeller, v p Vp is the speed of the controllable pitch propeller, n p Np is the rotation speed of the controllable pitch propeller, D Dp is the diameter of the controllable pitch propeller, M p Cp is the torque coefficient of the controllable pitch propeller.

[0059] Further, in step S1, the controllable pitch propeller propulsion cooperative control realizes the cascade cooperative control of the main engine rotation speed control, the throttle control, the main engine rotation speed and load limit, the hydraulic coupler adjustment of the controllable pitch propeller rotation speed and the controllable pitch propeller pitch adjustment.

[0060] Further, in step S1, the ship load inquiry function model identifies the ship resistance characteristics based on the EKF through the characteristic relationship between the ship speed and the main engine power and the characteristic relationship between the propeller rotation speed and the ship speed, and calculates the difference between the current power of the main engine and the maximum continuous power as the power margin. The power margin limit value cannot be less than 5% of the rated power. The required main engine power and propeller rotation speed at different ship speeds are predicted in advance, the ship speed closed loop control is performed, and the main engine overload and unstable speed are prevented.

[0061] Further, in step S2, when the main engine safety threshold δ ME The process of the composite feedforward cooperative control of the controllable pitch propeller pitch needs to satisfy the following relationship:

[0062] ,

[0063] wherein, P p is the propeller power, P emax is the main engine maximum continuous power, β 1 is the transmission efficiency of the fluid coupling and shafting, β 2 is the influence coefficient after the interaction of the ship and propeller;

[0064] wherein, the main engine output power P ME is less than the main engine maximum continuous power P emax i.e. P ME ≤ P emax , the main engine output power P ME is:

[0065] ,

[0066] wherein, k 1, k 2 and k 3 are the main engine external characteristic curve parameters, n e is the main engine speed;

[0067] the main engine maximum continuous power margin Δ P max is:

[0068] ,

[0069] the main engine safety threshold δ ME is:

[0070] ,

[0071] wherein, δ ME is the main engine safety threshold, Δ P max is the main engine maximum continuous power margin, P emax is the main engine maximum continuous power.

[0072] Further, in step S3, when controlling the ship speed in the main engine constant speed mode, the ocean navigation working condition, the pitch H p position loop servo control, in cooperation with the main engine throttle L tracks the propeller pitch Hp The adjustment, throttle-pitch coordinated control model is as follows:

[0073] ,

[0074] ,

[0075] In the formula, L For the main engine throttle, H p The propeller pitch is... v s For the ship's speed, n p This refers to the propeller speed; D λ is the diameter of the controllable propeller; λ is the pitch. H p With speed v s Rotation speed n p The two-variable function between them, through flexible adjustment of pitch H p and rotational speed n p These two parameters determine the optimal propulsion performance, maneuverability, and main engine protection under different operating conditions; Ψ represents the engine throttle. L With pitch H p The function between these parameters was obtained through sea trials of the ship to determine the different pitches of the controllable propeller at constant main engine speed. H p -Main power P ME The numerical curve of throttle L.

[0076] At host security threshold δ ME Within permissible limits, when the ship accelerates under constant engine speed mode, the composite feedforward collaborative control synchronously increases the pitch-throttle ratio; when the ship decelerates, the composite feedforward collaborative control synchronously decreases the pitch-throttle ratio, thus achieving pitch-throttle linkage control. The lead time of the composite feedforward collaborative control is less than the inertial time of the ship's propulsion system.

[0077] Due to factors such as shipboard fouling, propeller blade deformation, wind, waves, and currents, the throttle-pitch relationship is complex and time-varying. L = Ψ ( H pThe experimental numerical curve can be obtained by new ship launching trial, and continuous values are obtained by polynomial interpolation in actual operation. The main engine constant speed control mode controls the ship speed by adjusting the pitch, which has better performance compared with the conventional ship by adjusting the propeller speed to control the ship speed, and the economic load under the constant speed can be obtained, that is, the SFOC is lowest, the pitch-throttle joint control is controlled as the target of the speed control under the constant speed of the main engine, and the main engine is not overloaded as the limitation, so as to prevent the problems of large fluctuation of speed-pitch-throttle, black smoke of main engine, high exhaust temperature and the like.

[0078] Meanwhile, the ship speed is stable under the stable working condition of ocean navigation, the system automatically selects the lowest SFOC control, determines the lowest SFOC working interval according to the SFOC-main engine power polynomial curve interpolation method, and realizes the energy-saving optimization control of stable ship speed and main engine speed by throttle-pitch collaborative adjustment.

[0079] Further, when the ship speed is controlled in the constant pitch mode of the controllable pitch propeller, the main engine speed closed loop control with constant pitch of the controllable pitch propeller is realized by using the PID controller combined with dynamic compensation epsilon, and the main engine speed is tracked by the main engine throttle follow-up adjustment, and the main engine speed-throttle collaborative control model is

[0080] ,

[0081] In the formula, K p 、 K I and K d are adjustable proportional coefficient, integral coefficient and differential coefficient respectively, and n e is the main engine speed deviation, ε is the dynamic compensation, and the uncertain part of the control, and the deep learning algorithm is used to obtain ε the compensation value.

[0082] In the main engine safety threshold δ ME allowable range, when the ship accelerates in the constant pitch mode, the compound feedforward collaborative control synchronously increases the main engine speed n e and the throttle L, the compound feedforward cooperative control synchronously reduces the main engine throttle and the main engine rotating speed when the ship slows down, realizes the main engine rotating speed-throttle joint control, and the compound feedforward cooperative control leads time is less than the inertia time of the ship propulsion system. The main engine rotating speed-throttle joint control takes the constant pitch under way speed control as the target, synchronously adjusts the main engine rotating speed-throttle at the initial control stage, then takes the throttle adjustment as the inner ring and the main engine rotating speed adjustment as the outer ring of the cascade control, limits the main engine under the non-overload condition, prevents the problems of large way speed-throttle fluctuation, main engine black smoke and high exhaust temperature and the like.

[0083] Further, when the ship way speed is controlled in the main engine constant power (constant throttle) mode, namely the controllable pitch propeller rotating speed (liquid coupling output rotating speed)-pitch joint control mode, the controllable pitch propeller rotating speed-pitch cooperative control is adapted to the ship navigation in the severe sea condition, the control target is to keep the main engine heat balance effect, and the controllable pitch propeller rotating speed-pitch joint control under the main engine constant power is

[0084] ,

[0085] ,

[0086] ,

[0087] In the formula, P ME is the main engine output power, K o is the controllable pitch propeller propulsion coefficient, Γ(H p / D) is the controllable pitch propeller thrust, v s is the ship way speed, L is the main engine throttle (fuel injection amount), n p is the controllable pitch propeller rotating speed, H p is the controllable pitch propeller pitch, η o is the propulsion efficiency, S is the slip rate, K G is the adjustable variable ratio of the variable speed hydraulic coupling; gamma is the function between the main engine power and the throttle, and the relationship between the main engine power and the fuel injection amount is calibrated; Gamma is the thrust related to the controllable pitch propeller pitch, and the meaning is that the pitch is adjusted H p The size and direction of the thrust can be directly and quickly set, and the controllable pitch propeller high maneuverability, high operability and wide working condition adaptability are improved.

[0088] When the main engine throttle controller keeps the throttle constant, the main engine rotating speed cannot keep constant, and the rotating speed of the propeller required by the pitch controller is controlled by the hydraulic coupling output n p , and the pitch of the propeller is adjusted by the pitch controller H p , and the rotating speed of the propeller and the pitch are cooperatively controlled P ME , the throttle scale is constant, and the main engine thermal balance effect is obtained L When the ship speed control is performed under the constant power of the main engine, the sea state disturbance will make the ship speed deviate from the set speed of the driver, for example, when the ship speed is slow in the head wind and head current, the compound feedforward cooperative control reduces the pitch and adjusts the hydraulic coupling output rotating speed; when the ship speed is fast in the tail wind and tail current, the compound feedforward cooperative control increases the hydraulic coupling output rotating speed and adjusts the pitch, so that the power of the main engine is kept constant, but the ship speed is fast, or the compound feedforward cooperative control reduces the hydraulic coupling output rotating speed and the pitch of the controllable pitch propeller, so that the power of the main engine is reduced, and the ship speed is kept constant; the compound feedforward cooperative control synchronously adjusts the rotating speed and the pitch of the controllable pitch propeller, so that the main engine performance is stable under the severe sea state, the main engine thermal balance effect is kept, and the problems of black smoke and high exhaust temperature of the main engine are prevented. The main engine constant throttle control of the present application is innovative in that the rotating speed of the propeller is adjusted by the hydraulic coupling, so that the rotating speed of the main engine is kept stable under the constant throttle.

[0089] Two mass flow meters are used on the ship to detect the oil inlet amount G 1 and the oil return amount G 2 of the main engine, and the fuel consumption amount of the main engine is obtained as G = G 1- G 2, and the SFOC expression of the main engine is:

[0090] ,

[0091] In the formula, P ME is the output power of the main engine, T ME is the running time of the main engine.

[0092] The output power of the main engine P ME is in a complex relationship with the fuel amount G ∆G, and under the condition of good combustion, the fuel consumption amount P ME increases with the increase of P MEBoth have minimum-maximum limit, there is a minimum ratio SFOC between them, which is the goal of the propulsion main machine field has been pursuing. SFOC reflects the fuel quality, working condition and main machine performance, the present application realizes the SFOC minimization trend through the composite feedforward cooperative control.

[0093] The above three kinds of joint control mode are all in the safe threshold of main engine δ ME The allowable range is automatically carried out, the selection of manual control is free mode, the artificial habit changes one or two quantities of ship speed, main engine speed or pitch, and the composite feedforward cooperative control system still works, ensuring that the propulsion system operates in the allowable working range, therefore, the goal of the composite feedforward cooperative control of the present application is to pursue the stable main engine performance and heat balance effect, the stable ship speed and the safety and reliability of ship maneuvering, the automatic control of rapid response, the prevention of main engine overload, high exhaust gas temperature, black smoke, large speed-pitch-throttle fluctuation (unstable control) problem. Meet the main engine stable control of ship navigation in bad sea conditions, the control of adding and subtracting speed given value, the time-varying disturbance, the minimum trend control of main engine SFOC in ocean navigation working condition.

[0094] When the ship is designed, the maximum power of the main engine under the full load state and at the rated speed is determined as the rated power, and the main engine fuel consumption SFOC is optimal in the range of (75-80)% rated power. The output power of the main engine in actual operation should not exceed 95% of the maximum continuous power margin, and the main engine power margin limit is at least 5% of the rated power. On the other hand, the overload of the main engine is generally 105% of the rated power, and the main engine is not allowed to run continuously under overload. The main engine is the source power of the ship navigation, and ensuring the safety of the main engine operation is one of the most important control targets.

[0095] The present application meets the requirements of ship speed optimal control in all working conditions based on the composite feedforward cooperative control strategy of ship load inquiry function and variable pitch propeller propulsion cooperative control, cooperatively controls the main engine speed and throttle, the hydraulic coupler output speed, the variable pitch propeller speed and pitch in the allowable range of the safety threshold of main engine power margin, considers the inertia of the ship navigation and the acceleration and deceleration process of the main engine, obtains the best ship speed control performance and the stable heat balance effect of the main engine, realizes the automatic control of safety and reliability of ship maneuvering, prevents the problems of main engine overload, high exhaust gas temperature, black smoke, large speed-pitch-throttle fluctuation (unstable control), variable pitch propeller oil leakage and the like.

[0096] Further, the present application uses a hydraulic coupler to replace a reduction gear box to buffer the impact of the propeller on the main engine, and is suitable for ship navigation in ice area working condition.

[0097] Further, the application also proposes a compound feedforward cooperative control system of a ship's controllable pitch propeller propulsion, which is used to realize the compound feedforward cooperative control method.

[0098] A data processing and modeling unit is used to store and run the controllable pitch propeller propulsion compound model, and specifically to perform the ship load inquiry function, the ship speed closed loop gradual control calculation, and the main engine safety threshold calculation.

[0099] A data acquisition unit is used to acquire signals such as ship speed, main engine rotating speed, main engine power, controllable pitch propeller pitch, throttle position, and hydraulic coupler output rotating speed in real time.

[0100] A cooperative control decision unit is used to calculate power margin, judge main engine safety threshold, and select a cooperative control mode.

[0101] An execution unit includes a main engine speed regulation and throttle execution mechanism, a hydraulic coupler speed ratio control mechanism, and a controllable pitch propeller pitch hydraulic regulation mechanism, which are in communication connection with the cooperative control decision unit, and are used to execute the cooperative control instruction.

[0102] The application also proposes a ship equipped with the compound feedforward cooperative control system of the ship's controllable pitch propeller propulsion.

[0103] The ship speed closed loop regulation, controllable pitch propeller pitch-main engine throttle joint control, main engine rotating speed-throttle joint control, and controllable pitch propeller rotating speed (hydraulic coupler output rotating speed)-pitch joint control of the application fill the gap in the optimal control field of the controllable pitch propeller propulsion ship.

[0104] Compared with the prior art, the application has the following advantages:

[0105] The compound feedforward cooperative control method of the ship's controllable pitch propeller propulsion proposed by the application realizes automatic switching of three cooperative control modes according to the navigation working condition within the allowable range of the main engine safety threshold, realizes cooperative control of the controllable pitch propeller pitch-main engine throttle joint control, main engine rotating speed-throttle joint control, and controllable pitch propeller rotating speed-pitch joint control under the ship speed closed loop stable control, automatically pursues the lowest fuel consumption under the ocean navigation working condition, maintains the main engine power stable under the severe sea condition, and guarantees safety. The application of the hydraulic coupler is particularly suitable for ice area navigation, buffers impact, and solves the problems of main engine overload, high exhaust temperature, black smoke, large speed-pitch-throttle fluctuation (unstable control), frequent reciprocating regulation, controllable pitch propeller oil leakage, and the like.

[0106] The application learns the main engine power-ship speed characteristic relation and the controllable pitch propeller speed-ship speed characteristic relation through a ship load inquiry function model, identifies the ship resistance characteristic in real time based on an EKF, predicts the required main engine power and propeller speed in advance under different ship speeds, calculates the difference between the current main engine power and the maximum continuous power as a power margin, the power margin limit value cannot be less than 5% of the rated power, triggers the feedforward regulation (adjusts the pitch in advance) by using a safety threshold, realizes the compound feedforward control, prevents the main engine overload and unstable speed, eliminates the main engine overload risk in advance, and completely solves the problems of accelerating black smoke, high exhaust temperature and the like.

[0107] The application adopts a hydraulic coupler to replace a reduction gear box, adapts to the complex working conditions of ship ice area navigation, eliminates the direct influence of the propeller on the propulsion main engine, adjusts the controllable pitch propeller speed through the hydraulic coupler, makes the speed-pitch-throttle coordinated control more flexible, and can maintain the main engine thermal balance effect; the ship main engine of the application is suitable for marine medium-speed engine, low-speed engine, and a series of ship diesel engine that can burn methanol, ammonia or fuel oil.

[0108] The systematized main engine, hydraulic coupler and controllable pitch propeller are controlled in a multivariable coordinated manner as a whole, the feedforward and feedback are combined, the fluctuations of the speed, pitch and throttle are significantly reduced, the smooth and accurate control of the speed is realized, and the speed control quality and system stability are improved.

[0109] The controllable pitch propeller propulsion compound model established in the method of the application is not only the core of the control algorithm, but also can be used for system state monitoring, performance evaluation and fault diagnosis, and provides a platform for the intelligent management of the ship propulsion system. BRIEF DESCRIPTION OF DRAWINGS

[0110] Figure 1 It is a principle framework schematic diagram of the controllable pitch propeller propulsion compound model in the system of the embodiment of the application;

[0111] Figure 2 It is a function flowchart of the compound feedforward coordinated control system of the embodiment of the application;

[0112] Figure 3 It is a principle block diagram of the compound feedforward coordinated control system of the embodiment of the application;

[0113] Figure 4 It is a schematic diagram of the propulsion main engine characteristic and limit curve in the embodiment of the application;

[0114] Figure 5 It is a schematic diagram of the hydraulic coupler working characteristic curve in the embodiment of the application;

[0115] Figure 6 It is a schematic diagram of the controllable pitch propeller propulsion characteristic curve in the embodiment of the application. DETAILED DESCRIPTION

[0116] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be further described below.

[0117] Referring to Figures 1-3 , the embodiment proposes a compound feedforward cooperative control system for a ship's controllable pitch propeller propulsion, which comprises the following core functional units connected with each other in communication:

[0118] A data processing and modeling unit is used to run a controllable pitch propeller propulsion compound model, which specifically performs: 1) stores and calls the characteristic curves and limit data of six sub-models in the controllable pitch propeller propulsion compound model; 2) runs a basic control algorithm based on the controllable pitch propeller propulsion compound model, which includes a speed control module that receives target and feedback speeds, performs speed closed-loop gradual PID control, and generates a preliminary main engine speed setting value.

[0119] A data acquisition unit is used to acquire signals such as ship speed, main engine speed, main engine power, controllable pitch propeller pitch, throttle position and hydraulic coupler output speed in real time, which includes a distance recorder (acquiring ship speed), a main shaft speed sensor (acquiring main engine speed and controllable pitch propeller shaft speed), a power meter (directly acquiring main engine power), a pitch feedback sensor (acquiring pitch), a throttle opening degree sensor (acquiring throttle scale / fuel injection amount), an axle power instrument and a torque instrument (acquiring axle power and axle torque output by the hydraulic coupler); the unit is responsible for converting real-time physical signals into digital signals.

[0120] A cooperative control decision unit corresponds to the compound feedforward cooperative control module and related logic selectors in Figure 3 . The unit receives all information from the data processing and modeling unit, and performs: power margin and safety threshold calculation; control mode selection: one of the three cooperative modes is selected automatically or under manual confirmation according to sea conditions, driver instructions and power margin. Generate cooperative instructions: according to the selected mode, operate the "speed selection" and "throttle selection" switches in Figure 3 , fuse the output of the speed control module, the feedforward prediction of the load inquiry model, and the safety protection logic to generate the final, cooperative throttle instruction, pitch instruction and hydraulic coupler speed ratio instruction;

[0121] An execution unit includes a main engine speed regulation and throttle execution mechanism, a hydraulic coupler speed ratio control mechanism, and a controllable pitch propeller pitch hydraulic adjustment mechanism in communication with the above-mentioned cooperative control decision unit; wherein the main engine speed regulation and throttle execution mechanism is used to receive the throttle instruction issued by the cooperative control decision unit to drive the fuel rack or electronic fuel injection system; the hydraulic coupler speed ratio control mechanism receives the speed ratio instruction to adjust the working oil amount of the hydraulic coupler to change the output speed; the controllable pitch propeller pitch hydraulic adjustment mechanism receives the pitch instruction to drive the oil distributor and the hydraulic piston in the hub to change the pitch.

[0122] The working process of the composite feedforward cooperative control system is as follows:

[0123] First, a variable pitch propeller propulsion composite model as shown in Figure 1 is established, which is a digital simulation system running in a control computer, integrating the following six sub-models:

[0124] 1) Ship-machine-propeller relationship model: as shown in Figure 1 , which includes machine-propeller characteristic sub-model, ship resistance characteristic sub-model and ship-propeller characteristic sub-model obtained through new ship launching experiment, and the equations are as follows, which provide physical constraints for system dynamics.

[0125] The machine-propeller characteristic sub-model formula is:

[0126] ;

[0127] In the formula, J is the rotational inertia on the propeller shaft, n e is the main engine speed, n p is the variable pitch propeller speed, M e is the main engine output torque, M p is the torque of the variable pitch propeller, M m is the shaft friction torque;

[0128] ;

[0129] In the formula, P p is the variable pitch propeller power, P ME is the main engine output power, η c is the shaft transmission efficiency.

[0130] The ship resistance characteristic sub-model formula is:

[0131] ;

[0132] In the formula, R is the ship resistance, α R is the resistance coefficient, v s is the ship speed, m is the ship index.

[0133] The ship-propeller characteristic sub-model formula is:

[0134] ;

[0135] wherein, M is the ship mass, v s is the ship speed, T is the propeller thrust, T represents two or more propeller thrusts, R is the ship motion resistance;

[0136] ;

[0137] wherein, P R is the propeller effective thrust, η s is the hull efficiency, η p is the propeller open water efficiency, η x is the propeller rotation efficiency, P p is the propeller power.

[0138] 2) Propulsion main engine characteristics and limitation model: the model stores the fixed pitch FPP propulsion mode (constant pitch control), the controllable pitch CPP propulsion mode (variable pitch control), the propulsion main engine speed characteristics, the propulsion main engine load characteristics curve, the propulsion main engine limitation characteristics (including the mechanical load and thermal load limitation, the equal torque limitation curve, and the equal exhaust temperature limitation curve) and the boundary curve of the allowable working range (as shown in FIG. 1) of the propulsion main engine, and defines the boundary of the safe working of the main engine. Figure 4

[0139] wherein, the fixed pitch FPP propulsion mode is the constant pitch control at a certain pitch, and the entering main engine rotating speed and the throttle are cooperatively controlled; the controllable pitch CPP propulsion mode is the compound cooperative control mode of the main engine rotating speed-throttle-pitch; the main engine speed characteristics are the full load speed characteristics, the overload speed characteristics and the partial load speed characteristics obtained by the constant throttle control at different throttles, and the torque curve of the main engine torque changing with the speed is obtained according to the main engine speed characteristics ; the main engine load characteristics are the main engine economic load obtained by the constant rotating speed control at different rotating speeds, and the power curve , the main engine power changes linearly with the increase of the load at the constant rotating speed; the allowable working range of the main engine is the maximum power and the minimum power allowed to be reached by the main engine at various rotating speeds, and the highest rotating speed and the lowest rotating speed allowed to be reached by the main engine at various loads; the main engine limitation characteristics curve includes the equal torque limitation curve and the equal exhaust temperature limitation curve, which are respectively used for limiting the over-mechanical load and the over-thermal load of the main engine;

[0140] ​3) Fluid coupling characteristic model: the speed and torque of the main engine are converted into the speed and torque of the controllable pitch propeller, and the relationship between the input / output speed and torque of the fluid coupling and the variable speed ratio of the fluid coupling is input / output through the working characteristic curve of the fluid coupling. When the fluid coupling is engaged, the main engine torque, the fluid coupling torque and the controllable pitch propeller torque are balanced, and the main engine working condition and the controllable pitch propeller are optimally matched through the characteristic relationship of the fluid coupling to prevent the propeller from being heavy or light. The fluid coupling characteristic curve as shown in FIG. 3 stores the relationship curve of input / output torque, speed and transmission efficiency obtained through the bench test of the fluid coupling, and is used for accurately controlling the variable speed ratio of the fluid coupling. Figure 5

[0141] 4) Controllable pitch propeller characteristic model: including controllable pitch propeller torque sub-model, controllable pitch propeller thrust sub-model, controllable pitch propeller power sub-model and controllable pitch propeller drag efficiency sub-model; as shown in FIG. 4, it stores the propeller characteristic curve obtained through the controllable pitch propeller drag experiment. Figure 6

[0142] The formula of the controllable pitch propeller torque sub-model is as follows:

[0143] ,

[0144] In the formula, M p is the controllable pitch propeller torque, K M is the controllable pitch propeller torque coefficient, ρ is the mass density of water, D is the diameter of the controllable pitch propeller, n p is the speed of the controllable pitch propeller;

[0145] The formula of the controllable pitch propeller thrust sub-model is as follows:

[0146] ,

[0147] In the formula, T is the controllable pitch propeller thrust, K T is the controllable pitch propeller thrust coefficient, D is the diameter of the controllable pitch propeller, n p is the speed of the controllable pitch propeller;

[0148] The formula of the controllable pitch propeller power sub-model is as follows:

[0149] ,

[0150] In the formula, P p is the controllable pitch propeller power, K M is the controllable pitch propeller torque coefficient, ρ ​​mass density of water, D propeller diameter, n p propeller speed,

[0151] propeller efficiency sub-model formula is:

[0152] ,

[0153] wherein, η p propeller efficiency, T propeller thrust, v p propeller advance speed, n p propeller speed, D propeller diameter, M p propeller torque.

[0154] 5) Ship load inquiry function model: It is the core model, which is used to collect sensor data in real time, to identify the ship resistance coefficient online through the characteristic relationship between the ship speed and the main engine power, and the characteristic relationship between the ship speed and the propeller speed. Using the identification results and the above physical model, two mapping relationships are dynamically constructed through the ship design and trial correction: the main engine power-ship speed characteristic relationship (i.e. the first mapping relationship between ship speed and main engine power) and the propeller speed-ship speed characteristic relationship (i.e. the second mapping relationship between ship speed and propeller speed), as well as the allowed continuous working range boundary.

[0155] 6) Propeller propulsion collaborative control model: It is used to receive the prediction results of the load inquiry model, the driver instructions and the system feedback, to establish the collaborative control between the main engine speed-throttle, the hydraulic coupler output speed, and the propeller speed-pitch, to calculate and output the collaborative control instructions.

[0156] In this embodiment: The machine-propeller characteristics, resistance characteristics, ship-propeller characteristic relationship curves and numerical models, propeller characteristic curves and numerical models, ship-machine propulsion characteristic curves and numerical models obtained through the new ship launching experiment, the main engine speed characteristics, load characteristics, limitation characteristics and the boundary curve of the allowed working range obtained through the main engine bench experiment, the hydraulic coupler characteristic curve obtained through the hydraulic coupler bench experiment, the propeller characteristic curve obtained through the propeller towing experiment, and the corresponding relationship curve between the ship speed and the main engine power and the allowed continuous working range boundary obtained through the ship design and trial correction; The above characteristic curves reflect the ideal design characteristics of the ship-machine-propeller propulsion system, and the above characteristic curves are not a few lines shown in the figure, but a large number of continuous curve clusters.

[0157] The automatic data collection in the ship operation identifies the predicted values and curves of the above characteristics through the extended Kalman filter (EKF) online adaptive prediction algorithm under data driving, and the deviation of the predicted curves from the design characteristic curves indicates the ship propulsion performance and working condition change, which is fed back to the propeller pitch control model.

[0158] When the driver pushes the ship steering handle to change the ship speed setting value, the navigation data recorder feeds back the actual speed to obtain the speed deviation; the speed deviation is input into the ship load inquiry function model after being processed by the ship speed closed-loop gradual PID control link; the ship load inquiry function model automatically identifies the ship resistance characteristics based on the numerical model of the main engine power-ship speed characteristic relationship and the propeller speed-ship speed characteristic relationship, predicts the required main engine power and propeller speed at different ship speeds, and calculates the difference between the current power and the maximum continuous power as the current power margin, determines the main engine maximum continuous power margin Δ P max ; the set power margin limit value cannot be less than 5% of the rated power, the main engine safety threshold is determined as 95% of the maximum continuous power margin value, and the main engine characteristic and limit model is fed back in advance to prevent the main engine from overloading during acceleration and the main engine speed from rising too fast during deceleration. In this process, if the ship load inquiry function model predicts that the main engine pre-increase power ΔP ME required to reach the target speed is greater than the main engine safety threshold δ ME , the front feed protection is triggered immediately: while increasing the throttle command, the combined front feed cooperative control model module commands to reduce the pitch in advance, sacrificing part of the instantaneous acceleration to ensure the absolute safety of the main engine, and then continuing to accelerate normally after the power margin is restored.

[0159] In this embodiment, the controllable pitch propeller propulsion cooperative control model includes the pitch-throttle joint control mode of the main engine constant speed under the ship speed closed-loop stable control, the speed-throttle joint control mode of the constant pitch of the controllable pitch propeller, and the controllable pitch propeller speed-pitch joint control mode of the main engine constant power (constant throttle), and the manual control mode is selected as the free combination mode of the main engine speed-throttle + propeller speed-pitch, all of which can realize the automatic control of the ship speed closed loop. The specific function implementation process is shown in Figure 2 .

[0160] Figure 2 The specific running function flowchart of the combined front feed cooperative control system of the ship controllable pitch propeller propulsion is shown in the figure: the driver operates the ship speed control handle to obtain the ship speed setting value V s * , the actual ship speed measured by the navigation recorder is V s , the speed deviation Δ V s= V s * - V s ; the deviation Δ V s The ship speed closed-loop gradual PID control link processing method is: according to a certain adjustment interval time Δ t And amplitude δ (Δ t ) output speed control command, that is , instead of stepwise one-time increase or decrease, to prevent impact on the main engine, fluid coupling and controllable pitch propeller, V s → V s * The process needs to consider the ship acceleration and deceleration inertia, and the ship speed inertia difference under the conditions of ship heavy load / empty load, head wind / following wind, etc. Through the adjustment of Δ t And δ (Δ t ) to ensure that the acceleration and deceleration process is adapted to the ship inertia; the advantage of gradual PID control is that it does not directly respond to the step change of the speed set value, but makes the input given speed command signal step by step to approach the required set speed step signal, so that the ship runs smoothly. The obtained speed control command is input to the ship load inquiry function model. In the prior art, the "speed control command" is generally directly applied to the main engine, and the innovation of the present application is that the speed control command obtained after the ship speed closed-loop gradual PID control link processing is first passed through the ship load inquiry function model, and Δ V s The required main engine power ΔP ME And power margin limit value, output the gradual value δ (Δ t ) corresponding to the main engine power and does not exceed the allowed power margin range of the main engine.

[0161] Ship resistance includes friction resistance, wave resistance, viscous pressure resistance, appendage resistance and resistance generated by wind and current, which cannot be directly measured and need to be identified and predicted by EKF algorithm driven by data of real ship sailing. Traditional ship resistance prediction methods mostly rely on trial data or offline fitting model, which is difficult to adapt to complex and variable sailing conditions. The present application realizes sailing resistance identification by using measurable signals of the ship (such as sailing speed, propeller speed, shaft power, etc.). The ship resistance characteristic identification process is as follows: 1) the running data of ship sailing related parameters are collected by the communication mode of the existing monitoring and alarm system of the ship, which includes main engine fuel consumption, main engine speed, main engine power, ship speed, propeller shaft torque, propeller speed pitch, slip ratio, etc. which can be directly obtained; 2) the data preprocessing is carried out, the data is reconstructed synchronously to solve the problems of different data frequencies, abnormal or missing values, and non-uniform time, and the abnormal data caused by sensor abnormalities and propulsion system failures are cleaned; at the same time, considering that weather conditions, sea conditions, loading conditions, ship body and propeller cleanliness all affect ship speed, main engine load, etc., and it is difficult to accurately evaluate the influence of weather conditions, sea conditions and ship body fouling conditions, the ship resistance characteristic change needs to be identified and applied to the composite feedforward control of the present application; 3) the present application establishes a relationship model of the ship-propeller characteristic sub-model , propeller thrust T p and speed n p , wherein, ζ T is a comprehensive coefficient to be identified thrust, ζ T which integrates wake coefficient, water density ρ, propeller diameter D, propeller efficiency, etc., and can be used as an identified state of EKF to avoid dependence on K T , K Q map. , a 1, a 2, a 3 are identified coefficients; and v s , a 1, a 2, a 3 and ζ T are defined as state vector , the discretized coefficient state transition equation, speed model and resistance observation model are established, and the measurable propeller speed n p (k) and speed v s ​(k) to the resistance observation model, the resistance coefficient estimate value can be obtained 、 、 and the estimated sailing speed , the thrust coefficient and the resistance estimate value . The current sailing speed is obtained by identifying the resistance v s The effective power estimate under the stable v s sailing thrust , the sailing speed v s is further identified, and the total propulsion efficiency ( P p is the measured shaft power), and the total propulsion efficiency η D is generally in the range of 0.55-0.75, and the identified value is larger than the original value η D , indicating that the sailing is downwind and downstream, and if it is small, it indicates that it is upwind and upstream or the ship body is dirty; the difference between and η D is used to quantify the change of the ship sailing resistance characteristic curve, to obtain the evaluation result of the ship condition and sailing working condition change, and send it to the cooperative control decision unit.

[0162] The ship trial meets the following conditions: the ship body and propeller are clean, the deep water open sea area (water depth > 100 meters), no wind, no wave, no current, and the main engine power (P ME ) ~ ship speed (v s ) curve, propeller speed (n p ) ~ main engine power (P ME ) curve, propeller speed (n p ) ~ ship sailing speed (v s ) curve, and main engine-hydraulic coupling-contrapropeller propulsion system characteristic curves, especially propeller torque (M p ) ~ speed (n p ) curve, etc. These curves are stored in the computer to establish a numerical model as a reference for ship operation characteristics. By comparing the measured main engine power ~ ship speed curve with the trial curve, the main engine power difference at the same speed can be obtained. If the measured power corresponding to the same speed value is greater than the power during the trial, it indicates that it is upwind and upstream or the ship body is dirty; if it is small, it indicates that it is downwind and downstream, which is consistent with the resistance identification result, and is also sent to the cooperative control decision unit.

[0163] The data packet output by the load query model (predicting the required host power and the more efficient propeller speed, the current power margin ΔP P * , δ ME ) is sent to the cooperative control decision unit together with the progressive speed control instruction, i.e. Figure 3 The decision layer shown in the figure, which comprises a "load feedforward cooperative control module", a "selector" and a "host set speed limit link", performs the following links:

[0164] Link 1: safety threshold judgment - the decision unit calculates the host power demand increment and judges whether the power demand increment ΔP ME is greater than the host safety threshold δ ME If not, the check is passed; if yes, the feedforward protection mechanism is triggered.

[0165] Link 2: control mode selection - according to the current sea conditions, the system automatically selects the control mode; in this embodiment, the relationship between the ship resistance characteristics, the ship speed and the host power, the propeller speed is obtained by the data-driven EKF online adaptive prediction algorithm, and the relationship is effective when the correlation is 0.95 or more. The following control modes are selected by the controllable pitch propeller propulsion cooperative control model:

[0166] Mode 1: when the ship speed is controlled in the host constant speed mode, the ocean navigation working condition, the pitch position of the host speed is a constant value H p Position ring servo control, cooperates with the host throttle L to track the controllable pitch propeller pitch H p Adjustment, throttle-pitch cooperative control model is

[0167] ,

[0168] ,

[0169] In the formula, L is the host throttle, H p is the controllable pitch propeller pitch, v s is the ship speed, n p is the controllable pitch propeller speed.

[0170] When the host safety threshold δ MEWithin the allowable range, the compound feedforward cooperative control synchronously increases the pitch-throttle when the ship accelerates in the host constant speed mode; the compound feedforward cooperative control synchronously reduces the pitch-throttle when the ship decelerates, realizing the pitch-throttle joint control, and the lead time of the compound feedforward cooperative control is less than the inertia time of the ship propulsion system.

[0171] The pitch-throttle relationship is relatively complex and time-varying due to the influence of the dirty bottom of the ship, deformation of the blade, wind and waves, etc. L = Ψ ( H p The experimental numerical curve can be obtained from the trial sailing of a new ship, and the continuous value is obtained through polynomial interpolation in actual operation. In the host constant speed control mode, the ship speed is controlled by adjusting the pitch, which has better performance compared with the conventional ship speed control by adjusting the propeller speed, and the economic load under the constant speed, i.e., the lowest SFOC, can be obtained. The pitch-throttle joint control takes the speed control under the constant speed of the host as the target and limits the overload of the host, preventing the problems of large fluctuation of the speed-pitch-throttle, black smoke of the host, high exhaust temperature and the like.

[0172] Meanwhile, the ship speed is stable in the stable working condition of the ocean voyage, the system automatically selects the lowest SFOC control, determines the lowest SFOC working interval according to the SFOC-host power polynomial curve interpolation method, and realizes the energy-saving optimization control of the stable ship speed and host speed through the throttle-pitch cooperative adjustment.

[0173] Mode two: when the ship speed is controlled in the constant pitch mode of the adjustable pitch propeller, the host speed closed loop control with the constant pitch of the adjustable pitch propeller is adopted, and the host throttle follows the host speed tracking adjustment cooperatively. The host speed-throttle cooperative control model is:

[0174] ,

[0175] In the formula, K p , K I and K d are respectively adjustable proportional coefficient, integral coefficient and differential coefficient, and n e is the host speed deviation, ε is the dynamic compensation, and the uncertain part of the control, the deep learning algorithm is adopted to obtain the compensation value. ε

[0176] Within the allowable range of the host safety threshold δ ME When the ship accelerates in the constant pitch mode, the compound feedforward cooperative control synchronously increases the host speed n e and the throttle​L When the ship is decelerating, the compound feedforward cooperative control synchronously reduces the main engine throttle and the main engine speed, realizes the main engine speed-throttle joint control, and the compound feedforward cooperative control has a lead time less than the inertia time of the ship propulsion system. The throttle L change affects the main engine speed and power, and the throttle adjustment is the actuator of the governor, that is, the main engine speed control is realized through the throttle control, therefore, the given throttle output by the governor and the feedforward action throttle jointly work at the initial stage of the main engine speed-throttle joint control, and the joint control is effective only after being limited by the main engine load. The present application is different from the conventional main engine speed-throttle adjustment system in which the throttle is passively followed for adjustment by the governor output, the main engine speed-throttle joint control takes the constant pitch underway speed control as the target, the main engine speed-throttle is synchronously adjusted at the initial stage, then the throttle adjustment is taken as the inner ring and the main engine speed adjustment is taken as the outer ring of the cascade control, the feedforward throttle is attenuated to the basic governor throttle, the main engine is limited not to be overloaded, and the problems of large fluctuation of the speed-throttle, black smoke of the main engine and high exhaust temperature are prevented.

[0177] Mode three: when the ship speed is controlled in the main engine constant power (constant throttle) mode, that is, the controllable pitch propeller speed (liquid coupling output speed)-pitch joint control mode, the mode is suitable for ship navigation in severe sea conditions, the controllable pitch propeller speed-pitch cooperative control is taken with the main engine throttle scale (fuel injection amount) as a constant value, the control target is to maintain the main engine thermal balance effect, and the controllable pitch propeller speed-pitch joint control under the main engine constant power is:

[0178] ,

[0179] ,

[0180] ,

[0181] In the formula, P ME is the main engine output power, K o is the controllable pitch propeller propulsion coefficient, Γ(H p / D) is the controllable pitch propeller thrust, v s is the ship speed, L is the main engine throttle (fuel injection amount), n p is the controllable pitch propeller speed, H p is the controllable pitch propeller pitch, η o is the propulsion efficiency, S is the slip rate, K G is the adjustable variable ratio of the variable speed hydraulic coupling.

[0182] When the main engine throttle controller keeps the throttle constant, the main engine speed cannot remain constant. The required speed for the controllable pitch propeller is then output through the hydraulic coupling. n p Simultaneously adjusted via pitch controller H p The prerequisite for coordinated control of controllable propeller speed and pitch is the main engine power. P ME Constant throttle position L To achieve a constant throttle value and maintain the thermal balance of the main engine, the ship's speed is controlled under constant main engine power. During ship speed control, sea state disturbances can cause the ship's speed to deviate from the pilot's set speed. For example, when facing headwinds or currents, the ship's speed decreases. The composite feedforward control reduces the propeller pitch while adjusting the output speed of the hydraulic coupler. When sailing with the wind or current, the ship's speed increases. The composite feedforward control increases the output speed of the hydraulic coupler while adjusting the propeller pitch to maintain a constant main engine power, but the speed increases. Alternatively, the composite feedforward control reduces the output speed of the hydraulic coupler and the pitch of the controllable pitch propeller to reduce the main engine power and maintain a constant speed. The composite feedforward control synchronously adjusts the controllable pitch propeller speed-pitch, stabilizing the ship's main engine performance under adverse sea conditions, maintaining the thermal balance of the main engine, and preventing problems such as black smoke and high exhaust temperatures. The innovation of this invention's constant throttle control lies in adjusting the propeller speed through the hydraulic coupler to maintain a stable main engine speed under this constant throttle.

[0183] All three of the above-mentioned joint control modes are within the host security threshold. δ ME Within permissible limits, the goal of composite feedforward collaborative control is to achieve automatic control that ensures stable main engine performance and thermal balance, stable ship speed, and rapid response in ship maneuvering safety and reliability. It aims to prevent problems such as main engine overload, high exhaust temperature, black smoke, and large fluctuations in speed-pitch-throttle (unstable control). It satisfies the requirements of main engine stability control during ship navigation in adverse sea conditions, control of acceleration and deceleration setpoints, and time-varying disturbance conditions, as well as the trend of minimizing main engine SFOC under stable ocean navigation conditions.

[0184] Step 3: Multi-signal collaborative synthesis, such as Figure 3 As shown, this is the control principle of the controllable pitch propeller propulsion composite feedforward cooperative control system: First, the ship's speed is detected by the voyage recorder. V s Two sets of non-contact magnetic pulse sensors detect the main engine output speed and the controllable propeller shaft speed (hydraulic coupler output speed) respectively; the pitch Hp / propeller angle θ is detected by the displacement of the dual oil pipes inside the distribution shaft, and the position sensor (pitch feedback sensor) detects the displacement ζ of the dual oil pipes and converts it into pitch. H p(zeta) / pitch angle theta(zeta), zeta and pitch Hp / pitch angle theta exist strict geometric relationship; throttle displacement (opening) sensor detects throttle position L, each throttle position L corresponds to different fuel injection amount; shaft power instrument detects the shaft power output by the hydraulic coupling; these key signals are fed back to the speed control module and the composite feedforward collaborative control module respectively.

[0185] Path A (speed main ring): the speed control module will give the given speed (ship speed set value) V s * and feedback speed (actual speed of the ship) V s The speed deviation Δ V s of the ship is converted into the main engine power demand and the main engine power set value through the relationship between the speed of the ship v S and the main engine power P ME P ME * , P ME * The main engine speed set value is converted into the main engine speed set value through the main engine speed generator n * ME , and the main engine speed set value is generated through the main engine speed set value Figure 4 limiting link (such as the main engine minimum / maximum speed limit, critical speed limit, acceleration rate limit and program load limit) n * e , n * e The speed deviation Δ n e is obtained by comparing the main engine speed feedback value n e , n e The main engine throttle control set value is output after the PID+ intelligent algorithm operation of the governor L 1 * .

[0186] Path B (throttle feedforward): at the same time, the feedforward throttle instruction is generated according to the selection control module collaborative logic L 2 * (for example: pitch-throttle joint control, the system depends on the current pitch H p (or target pitch) and the calibration function L = Ψ (​H p A feedforward throttle command is directly generated. L 2 * ).

[0187] Path C (Speed ​​Feedforward): The ship's speed is queried from the model based on the ship's load. v S - Propeller speed ( n p The relationship is converted into a controllable pitch propeller speed demand command, which is then applied to the hydraulic coupler via the speed ratio controller to adjust the propeller shaft speed output by the hydraulic coupler, thereby meeting the ship's speed requirements and achieving optimal ship-propeller matching.

[0188] Generate final throttle command L * , L * Throttle feedback L Compared to obtain the throttle deviation ∆ L , ∆ L The throttle controller obtains the throttle opening value (fuel injection quantity) and sends this final throttle opening value to the "main engine load limiting module" to limit the fuel injection quantity and prevent excessive mechanical and thermal loads. The limited final fuel injection quantity command is then sent to the throttle actuator (servo follower mechanism).

[0189] The implementing agency will take the following actions:

[0190] The main engine throttle actuator performs the final command after being restricted.

[0191] The pitch control hydraulic unit operates according to the calculated target pitch (from Hp=λ(v)). s / n p D) Determine the action.

[0192] The hydraulic coupling adjusts the speed ratio according to the command, so that the output shaft speed approaches the target speed of the controllable pitch propeller.

[0193] When the ship begins to accelerate, the data acquisition unit ( Figure 3 Sensors throughout the ship collect real-time data on ship speed, main engine parameters, etc., and feed this data back to the system input, forming a closed loop. The load query model continuously identifies and updates predictions online. Throughout the process, the ship speed increases smoothly, and the main engine load remains constant. Figure 4 Within the indicated safe area, there is no overshoot or black smoke.

[0194] In this embodiment, the three control modes are realized by the host speed and throttle, adjusting the output speed of the hydraulic coupling, and the pitch adjustment of the propeller, and are processed through the host control and limiting module, the hydraulic coupling control module, and the pitch adjustment propeller control module, and are simultaneously applied to the host governor and throttle controller, the hydraulic coupling variable speed ratio control, and the pitch adjustment propeller pitch adjustment hydraulic system. According to the required law of the control mode, the pitch adjustment propeller acts on the ship to change the ship speed, identifies the ship resistance characteristic, and feeds back the required propulsion power and speed of the ship to the ship load inquiry function module, and timely calculates the required host power, propeller speed, and host power margin limit (not less than 5% rated power) for maintaining the ship speed. The ship closed-loop gradual control module slightly changes the speed control instruction to ensure that the ship speed control process is soft and the propulsion system is not impacted.

[0195] In this embodiment, the load feedforward cooperative control module controls the "speed selection" and "throttle selection" through the throttle "selector". L 1 * is effective, and is "0" when L 1 * is not effective. L 2 * is effective, and is "0" when L 2 * is not effective.

[0196] If the load feedforward cooperative control module selects the constant power mode of the propeller speed-pitch joint control, "speed selection" is "0", the control instruction of the governor output is given throttle L 1 * is not effective; "throttle selection" is "1", L 2 * is effective, then L = L 2 * - L , the throttle controller makes L =0, L 2 * = L , L is a constant value, unless the given value L 2 *The host constant power mode is changed. The host rotating speed is no longer a constant value but varies with the load, but the host rotating speed limit still works. The propeller shaft rotating speed is adjusted by changing the variable speed ratio of the fluid coupling to adapt to the propeller rotating speed under different pitches, that is, the product of the propeller rotating speed and the torque change caused by the pitch adjustment is a constant value, which is suitable for the ship speed control under severe sea conditions, and the stable thermal balance effect of the host is obtained to prevent the problems of host overload, unstable combustion, frequent throttle changes and large rotating speed changes. The innovation of the application is that the propeller rotating speed and the propeller pitch (there is a corresponding relationship between the thrust and the pitch) are cooperatively controlled to stabilize the ship speed and the host load, and the safety and reliability of the ship navigation under severe sea conditions are improved. When the propeller is out of water under severe sea conditions, the fluid coupling can quickly reduce the output rotating speed to prevent the host from flying.

[0197] If the load feedforward cooperative control module selects the constant pitch control mode of the host rotating speed-throttle joint control, the "rotating speed selection" and "throttle selection" are both "1", at this time L 2 * and L 1 * both work, and L ( L 1 * + L 2 * )- L the host rotating speed-throttle joint control is carried out; the ship speed control under constant pitch is realized by host rotating speed control, when the ship accelerates or decelerates, the L 2 * throttle instruction is generated according to the required ship propulsion power, L 1 * the L 1 * throttle given value is generated according to the required host rotating speed through the speed regulator, L 1 * + L 2 * act on the throttle and are limited by the host load, but the throttle feedforward L 2 * finally disappears on the basis of L 1 * , the process of this L 2 * → L 1 * is the process that the actual ship speed quickly approaches the given ship speed, at this time L 2 * is only related to the change speed of the ship speed given value, L 2 *The feedforward function accelerates the speed regulation; during the speed setting process, the throttle control is the inner loop and the main engine speed control is the outer loop. When the operator increases the ship speed, the load inquiry module generates the required power of the main engine, which is outputted by the load feedforward collaborative control module L 2 * The increase is applied to the throttle controller to increase the throttle; at the same time, the required speed of the main engine is increased to generate the throttle command through the governor L 1 * The increase is also applied to the throttle controller to increase the throttle, L 1 * + L 2 * The throttle feedforward is applied to the throttle actuator after the load limitation, and the throttle feedforward L 2 * is finally eliminated on L 1 * the basis of the load limitation, which includes the maximum fuel injection (throttle) limitation, the minimum fuel injection (throttle) limitation, the supercharged air pressure limitation, the maximum torque limitation, the high exhaust temperature limitation, and the effective throttle command of the throttle actuator after the load limitation, so that L 1 * + L 2 * the throttle controller will not cause the main engine to be overloaded. When the ship is against the wind and current, the L 1 * is increased, and if only the main engine governor is used, the main engine will be overloaded. At this time, the ship load inquiry function module will identify that the corresponding power at a certain speed suddenly increases, and the L 2 * is outputted as a negative value to inhibit L 1 * from being too large to cause the main engine to be overloaded; when the ship is with the wind and current, L 1 * will be reduced, at which time the ship load inquiry function module will identify that the corresponding power at a certain speed suddenly decreases, and the L 2 * is outputted as 0, the actual ship speed is greater than the set speed, achieving the effect of accelerating the ship speed with less fuel consumption, or the L 2 * is outputted as a negative value to further reduce the throttle to maintain the given ship speed.

[0198] If the load feedforward collaborative control module selects the pitch-throttle joint control of the main engine constant speed mode, the "speed selection" and "throttle selection" are both "1", the L 2 * and L 1 * both work, andL ( L 1 * + L 2 * )- L . When the ship accelerates, the propeller pitch increases, and the load feedforward cooperative control module outputs a positive throttle feedforward instruction L = Ψ ( H p ))according to the increase of the pitch L 2 * , preventing the main engine speed from falling too much. At this time, L 2 * is related to the change speed of the given value of the pitch of the controllable pitch propeller; when the ship speed deviation approaches 0, ( L 1 * + L 2 * )→ the governor outputs an increased L 1 * , and the main engine speed remains unchanged in the process of increasing ship speed and thrust. Similarly, when the ship decelerates, the propeller pitch decreases, and the load feedforward cooperative control module outputs a negative throttle feedforward instruction L 2 * according to the decrease of the pitch Ψ = H ( L p ))to prevent the main engine from over-speeding; when the ship speed deviation approaches 0, ( L 1 * + L 2 * )→ the governor outputs a decreased L 1 * , and the main engine speed remains unchanged in the process of decreasing ship speed and thrust.

[0199] The above three control modes must work within the allowable working range of the main engine, Figure 4 as shown in the main engine characteristics and limit curve, to ensure stable, reliable and economical operation of the propulsion main engine. The horizontal coordinate is the propulsion main engine speed percentage ( n e / n eN )% ， , and the vertical coordinates are the propulsion power percentages ( P e / P eN )%, wherein curve 1 is the constant temperature limit characteristic line, curve 2 is the full load speed characteristic line, curve 3 is the full load constant torque limit line, curve 4 is the overload speed limit characteristic line, curve 5 is the rated throttle opening (rated fuel injection amount) governing characteristic line, and curve 6 is the overload (110% PeN ) speed limit characteristic line, curve 7 is the main engine rated speed n eN characteristic line, curve 8 is the minimum load speed limit characteristic line, curve 9 is the minimum steady speed limit characteristic line, curve 10 is the minimum speed characteristic line of the main engine that can be continuously operated for a long time, and curve 11 is the propeller propulsion characteristic line; by Figure 4 It can be seen that the main engine can be safely and continuously operated in the range of the boundary line area surrounded by 3-1-10-8-5-3, wherein the MCR is the maximum continuous power operation of the main engine, and the ship is rarely operated at 100% MCR, and is mostly operated at about 80% MCR. The present application adjusts the pitch-speed-oil throttle through load feedforward control, so that the main engine is suitable for different sea conditions and working conditions of the ship, and the main engine works in a low fuel consumption working area.

[0200] The propeller shaft speed of the conventional ship is realized by adjusting the speed of the main engine, which limits the performance optimization of the main engine. The present application adjusts the shaft speed by using a fluid coupling to improve the ship-machine-propeller matching characteristics, as shown in Figure 5 The two outer characteristic curves of the fluid coupling are shown in the figure, the abscissa is the speed n e , and the ordinate is the torque M e , the speed ratio i = b 1, b 2, b 3 …, that is, the input and output speed ratio, also known as the transmission efficiency; the transmission torque M of the fluid coupling changes in a quadratic law with the speed n , that is M = f ( n 2 ) function, the transmission efficiency of the fluid coupling is a certain constant i . When the input speed n of the fluid coupling is a certain constant a , that is n 1, n 2, n 3 …= a 1, a 2, a 3…, the M-( n 输出 / n 输入 ) is an elliptical curve, and the intersection points of the elliptical curve and the equivalent efficiency curve P 1, P 2, P 3 … indicate that the fluid coupling uses the input main engine speed variation to adapt to the output end speed variation, and the transmission efficiency iFor a certain constant b. The purpose of the hydraulic coupling selected by the application is to meet the ice area navigation of the ship, have flexible transmission, no torque conversion capability (main and driven shaft torque is equal), realize the role of buffering and vibration reduction.

[0201] Figure 6 For the propeller characteristic curve, the propeller main geometric parameters propeller diameter D, pitch ratio H / D and disc ratio have great influence on its propelling performance, and the propeller diameter D has the greatest influence. For a propeller with a certain propeller diameter D, the greater the pitch H and the propeller blade expansion area, the greater the generated thrust, and the greater the absorbed torque and power; the thrust and efficiency of the adjustable pitch propeller not only depend on the advance coefficient, but also change with the pitch ratio H / D. When the ship resistance condition is unchanged, the characteristic curve changes once for each adjustment of the pitch, and the greater the H / D, the steeper the characteristic curve, and the greater the propeller thrust and efficiency. Figure 6 As can be seen, the influence of H / D on the adjustable pitch propeller characteristic form is similar to the influence of ship resistance on the fixed pitch propeller characteristic form. When the pitch is unchanged, the characteristic under a certain ship resistance is reflected, and when the ship resistance condition is unchanged and the pitch is changed, the same characteristic can be obtained, therefore, when the ship resistance condition changes, the characteristic can be maintained unchanged by changing the pitch, and the propelling system is stabilized.

[0202] Therefore, through the composite feedforward cooperative control system of the ship adjustable pitch propeller propulsion of the embodiment, the host engine power margin can be predicted in real time, and the ship-machine-propeller matching control characteristic can be changed in advance, so that the system overshoot is effectively reduced, and the host engine is stably operated under the premise of being less than the speed-load limit line.

[0203] Embodiment 2: Resistance identification method in load query model

[0204] Embodiment 2 supplements the specific algorithm level of the "resistance characteristic identification" in embodiment 1. The following specific method can be used to identify the resistance in the load query model:

[0205] An online data-driven EKF adaptive prediction algorithm for ship navigation resistance is used to learn the ship navigation data online, and the application proposes an online identification method of K T , K Q map, which realizes real-time estimation of resistance and its parameters by only using the speed and propeller speed, and the steps are as follows:

[0206] According to the ship-propeller characteristic sub-model , the propeller thrust T p and the speed n p relationship model , the ship navigation resistance empirical model , the EKF state vector is defined , then the five states are x 1= vs 、 x 2= a 1、 x 3= a 2、 x 4= a 3、 x 5= ξ T , the discretized state equation is established as

[0207] wherein T s is the sampling period;

[0208] the sampling T s the coefficient changes slowly in a short time, the discretized coefficient state equation is: a 1( k +1)= a 1( k ), a 2( k +1)= a 2( k ), a 3( k +1)= a 3( k ), ξ T ( k +1)= ξ T ( k );

[0209] the nonlinear state transition function is wherein w ( k ) is the process noise, f (·) is the state transition function from k time to k+1 time, namely:

[0210] ,

[0211] ,

[0212] ,

[0213] ,

[0214] ,

[0215] then, the state transition function is ,

[0216] the observation model is established as whereiny k is the measured value of the ship's speed at time k, v k is the measurement noise, a nonlinear observation function mapping the state to the speed , v s k is the estimated speed at time k;

[0217] f and h are locally linearized by first order Taylor expansion around x, obtaining f is the linear approximation of the state transition Jacobian matrix around the current estimate point x, h is the linear approximation of the observation Jacobian matrix around the current prediction point x, are the partial derivative matrices with respect to the state x.

[0218] The input of the EKF identification of the ship's resistance is the measured propeller speed n p k and the speed y k , and the output is the estimated value , , , , and ; therefore, the steps of the EKF-based identification of the ship's resistance characteristics are:

[0219] Step 1: initialization (k = 0), set the initial state estimate and the observation covariance matrix P(0);

[0220] Step 2: prediction iteration, where is the prior state prediction at time k, is the posterior state estimate at time k-1;

[0221] the prediction covariance, where is the prior error covariance matrix, P k -1) is the updated error covariance in the last step, Ω( k -1) is the state Jacobian matrix, Q is the process noise covariance matrix;

[0222] Step 3: calculate the Kalman gain , where H is the observation Jacobian matrix, and Γ is the observation noise covariance matrix;

[0223] ​​​​​​Status Update: , where y(k) is the measured speed at time k. To predict speed;

[0224] Covariance update: Where I is the identity matrix, P ( k Let be the posterior error covariance matrix at time k;

[0225] Step 4: Estimate the resistance as ,

[0226] Based on the current estimated drag coefficient , , Current speed can be estimated v s resistance below Thus, the drag characteristics are obtained;

[0227] The coefficient remains approximately constant within a short time window, allowing for prediction of drag at future speeds. When the pilot changes the speed setpoint... v s * At that time, v s * The predicted resistance is Using predictive resistance Achieve the final target speed v s * Required effective power ,maintain v s * Thrust required for stability ,but v s * The required propeller speed is This allows for the prediction of future speeds. v s * Required propulsion power (Overall progress efficiency) From the current speed v s (estimated) and propeller speed n p * Simultaneously calculate the predicted host power and maximum continuous power. P emax The difference is used to obtain the predicted power margin Δ. P * And according to the formula Calculate the host security thresholdδ * ME Predicted value.

[0228] Example 3: Detailed logic of safety threshold triggering and "advance pitch reduction" protection mechanism

[0229] Trigger condition: When the cooperative control decision unit judges that the pre-increase power ΔP ME > host safety threshold δ ME , immediately trigger.

[0230] Protection action: The compound feedforward cooperative control module immediately outputs a negative "pitch emergency correction amount" . This correction amount is directly superimposed on the normal pitch , so that the actual executed pitch instruction becomes .

[0231] Action effect: According to the variable pitch propeller thrust sub-model, the reduction of pitch will directly lead to the decrease of thrust coefficient K T , thereby instantaneously reducing the thrust T and the variable pitch propeller torque n p under the condition that the variable pitch propeller speed M p is unchanged. This makes the host load demand curve be actively "flattened", ensuring that even if there is acceleration inertia, the actual power peak will not exceed δ ME , thereby eliminating overload.

[0232] Restoration logic: The system continuously monitors the power margin. When the current power margin rises to the safety level, the emergency correction amount is gradually returned to zero, and the system returns to the normal cooperative control process.

[0233] The above is only the preferred embodiment of the present application, and does not limit the present application in any way. Any person skilled in the art can make any form of equivalent replacement, modification or change to the technical solutions and technical contents disclosed by the present application without departing from the scope of the technical solutions of the present application, which still belongs to the protection scope of the present application.

Claims

1. A composite feedforward cooperative control method for ship controllable pitch propeller propulsion, characterized in that, Includes the following steps: S1: Establish a composite propulsion model for controllable pitch propellers, which includes a ship-engine-propeller relationship model, a propulsion main engine characteristics and limitation model, a hydraulic coupler characteristics model, a controllable pitch propeller characteristics model, a controllable pitch propeller collaborative control model, and a ship load inquiry function model. The coordinated control model for controllable pitch propeller propulsion establishes coordinated control between main engine speed and throttle, hydraulic coupler output speed, and controllable pitch propeller speed and pitch. The ship load interrogation function model identifies the ship's resistance characteristics, establishes the characteristic relationships between ship speed and main engine power and between ship speed and controllable pitch propeller speed, predicts the required main engine power and propeller speed at different ship speeds in advance, and calculates the real-time difference between the current main engine power and the maximum continuous main engine power as the current power margin. A power margin limit threshold is set to determine the maximum continuous main engine power margin Δ. P max and host security threshold; S2: Calculate the speed deviation between the set speed and the actual speed, and input the speed deviation into the ship speed closed-loop progressive PID control loop to generate a progressively changing desired speed sequence. S3: For each desired speed value in the desired speed sequence, call the ship load query function model to predict the main engine power and controllable pitch propeller speed required to achieve the desired speed; calculate the power demand increment based on the predicted main engine power and the current main engine power; compare the power demand increment with a predetermined main engine safety threshold; if the power demand increment exceeds the main engine safety threshold, generate a feedforward protection command to reduce the controllable pitch propeller pitch in advance. S4: At the host security threshold δ ME Within the permissible range, using the aforementioned controllable pitch propeller propulsion cooperative control model, one of the following three cooperative control modes is selected and executed according to the navigation conditions: Main engine constant speed mode: The main engine speed is controlled as a constant value, in conjunction with the main engine throttle. L Tracking pitch propeller H p Adjustment, i.e., pitch-throttle linkage control mode; Controlled pitch propeller fixed pitch mode: based on the pitch of the controlled pitch propeller H p The main engine speed is a constant value. n e Closed-loop control, coordinated with main engine throttle L According to the main unit speed n e Follow-up adjustment, i.e., the main engine speed-throttle linkage control mode; Main unit constant power mode: based on the main unit throttle L The output speed of the hydraulic coupling is a constant value. n p - Pitch H p Cooperative control, namely the controllable pitch propeller speed-pitch joint control mode.

2. The composite feedforward cooperative control method for ship controllable pitch propeller propulsion according to claim 1, characterized in that, In step S1, the power margin limit threshold is set to be no less than 5% of the host's rated power; The ship-engine-propeller relationship model includes an engine-propeller characteristic sub-model, a ship resistance characteristic sub-model, and a ship-propeller characteristic sub-model. The formula for the engine-propeller characteristic sub-model is: ； In the formula, J To increase the rotational inertia of the shaft system, n e For the main unit's rotation speed, n p For the controllable pitch propeller speed, M e For the main unit to output torque, M p For the torque of the controllable pitch propeller, M m This refers to the frictional torque of the shaft system. ； In the formula, P p For controllable pitch propeller power, P ME This refers to the output power of the main unit. η c For shaft transmission efficiency; The formula for the ship resistance characteristic sub-model is as follows: ； In the formula, R For ship resistance, α R The drag coefficient, v s For ship speed, m For ship index; The formula for the ship-propeller characteristic sub-model is: ； In the formula, M For ship quality, v s For ship speed, T For the thrust of the controllable pitch propeller, ∑ T This indicates propulsion by two or more controllable pitch propellers. R For the resistance of the ship's motion; ； In the formula, P R To maximize the propulsion power of the controllable pitch propeller, η s For hull efficiency, η p To improve the efficiency of the controllable pitch propeller in flowing water, η x To improve the rotational efficiency of the controllable pitch propeller P p This refers to the power of the controllable pitch propeller.

3. The composite feedforward cooperative control method for ship controllable pitch propeller propulsion according to claim 1, characterized in that, In step S1, the main engine characteristics and limiting models include the controllable pitch propeller fixed pitch FPP propulsion mode, variable pitch CPP propulsion mode, main engine speed characteristics, main engine load characteristics, and limiting characteristics of the main engine's allowable operating range: When the constant pitch FPP propulsion mode is a constant pitch control at a certain pitch, it enters the main engine speed and throttle coordinated control mode. The variable pitch CPP propulsion mode is a composite coordinated control mode of main engine speed-throttle-pitch; The main engine speed characteristics are obtained by constant throttle control at different throttle levels, resulting in full-load speed characteristics, overload speed characteristics, and partial-load speed characteristics. Based on these main engine speed characteristics, the torque curve representing the relationship between the main engine torque and speed is obtained. M e = f ( n e ); The host load characteristic is obtained by constant speed control at different speeds to achieve the host's economic load, power curve. P e = f ( n e Under constant speed, the main engine power changes linearly with increasing load; The operating range of the host is the maximum and minimum power that the host can reach at various speeds, as well as the maximum and minimum speeds that the host can reach under various loads. The main engine limiting characteristic curves include the constant torque limiting curve and the constant exhaust temperature limiting line, which are used to limit the main engine's excessive mechanical load and excessive thermal load, respectively.

4. The composite feedforward cooperative control method for ship controllable pitch propeller propulsion according to claim 1, characterized in that, In step S1, the hydraulic coupler characteristic model converts the main engine's speed and torque into the controllable pitch propeller's speed and torque. The relationship between the input / output speed and torque and the hydraulic coupler's gear ratio is visualized through the hydraulic coupler's operating characteristic curve. When the hydraulic coupler is engaged, the main engine torque, hydraulic coupler torque, and controllable pitch propeller torque are balanced. The main engine's operating conditions and the controllable pitch propeller are optimally matched through the hydraulic coupler's characteristic relationship to prevent the propeller from being too heavy or too light.

5. The composite feedforward cooperative control method for ship controllable pitch propeller propulsion according to claim 1, characterized in that, In step S1, the controllable pitch propeller propulsion characteristic model includes a controllable pitch propeller torque sub-model, a controllable pitch propeller thrust sub-model, a controllable pitch propeller power sub-model, and a controllable pitch propeller flow efficiency sub-model: The formula for the controllable pitch propeller torque sub-model is: ； In the formula, M p For controllable pitch propeller torque, K M This is the torque coefficient of the controllable pitch propeller. ρ The mass density of water, D The diameter of the controllable pitch propeller. n p This refers to the controllable pitch propeller speed; The formula for the controllable pitch propeller thrust sub-model is: ； In the formula, T For controllable pitch propeller thrust, K T This is the thrust coefficient of the controllable pitch propeller. D The diameter of the controllable pitch propeller. n p This refers to the controllable pitch propeller speed; The formula for the controllable pitch propeller power sub-model is: ； In the formula, P p For controllable pitch propeller power, K M This is the torque coefficient of the controllable pitch propeller. ρ The mass density of water, D The diameter of the controllable pitch propeller. n p This refers to the controllable pitch propeller speed; The formula for the flow efficiency sub-model of the controllable pitch propeller is: ； In the formula, η p To improve the efficiency of the controllable pitch propeller in flowing water; T For controllable pitch propeller thrust; v p The advance speed of the controllable pitch propeller is equal to the speed of the ship. v s ; n p For the controllable pitch propeller speed, D The diameter of the controllable pitch propeller. M p This refers to the torque of the controllable pitch propeller.

6. The composite feedforward cooperative control method for ship controllable pitch propeller propulsion according to claim 1, characterized in that, In step S3, the host security threshold is set. δ ME Δ is 95% of the host's maximum continuous power margin. P max At the host security threshold δ ME Within permissible limits, the composite feedforward cooperative control pitch control process for pitch-controlled propellers must satisfy the following relationship: ； In the formula, P p For controllable pitch propeller power, P emax This is the maximum continuous power of the host. β 1 represents the transmission efficiency of the hydraulic coupling and shaft system. β 2 represents the influence coefficient after the interaction between the ship and the paddle; Among them, the main unit output power P ME Less than the host's maximum continuous power P emax ,Right now P ME ≤ P emax Main unit output power P ME for: ； In the formula, k 1. k 2 and k 3 represents the external characteristic curve parameters of the host computer. n e This refers to the main unit's rotational speed; The host's maximum continuous power margin Δ P max The calculation formula is: ； The host security threshold δ ME The calculation formula is: ； In the formula, δ ME Δ is the host security threshold. P max This is the maximum continuous power margin of the host. P emax This represents the maximum continuous power of the host unit.

7. The composite feedforward cooperative control method for ship controllable pitch propeller propulsion according to claim 1, characterized in that, In step S4, when controlling the ship's speed in the main engine constant speed mode, the throttle-pitch cooperative control model is as follows: ； ； In the formula, L For the main engine throttle, H p For the pitch of the controllable propeller, v s For the ship's speed, n p This refers to the controllable pitch propeller speed; D λ is the diameter of the controllable propeller; λ is the pitch. H p With speed v s Rotation speed n p The two-variable function between them, through flexible adjustment of pitch H p and rotational speed n p These two parameters determine the optimal propulsion performance, maneuverability, and main engine protection under different operating conditions; Ψ represents the engine throttle. L With pitch H p The function between these parameters was obtained through sea trials of the ship to determine the different pitches of the controllable propeller at constant main engine speed. H p -Main power P ME The numerical curve of throttle L; When controlling the ship's speed in the fixed-pitch controllable propeller mode, the main engine speed closed-loop control, with the controllable propeller pitch as a constant, is achieved using a PID controller combined with dynamic compensation ε; the main engine speed-throttle coordinated control model is as follows: ； In the formula, K p , K I and K d These are the adjustable proportional coefficient, integral coefficient, and differential coefficient, respectively. n e For the main engine speed deviation, ε For dynamic compensation, the data is trained using a deep learning algorithm. The main engine constant power mode is suitable for ship navigation in adverse sea conditions. When the ship speed decreases due to disturbances, the pitch is increased and the hydraulic coupling is adjusted to reduce the speed of the controllable pitch propeller. n p This achieves low-speed, high-thrust control; when the ship speed increases due to disturbances, the control only reduces the pitch to achieve high-speed, light-load control, all to maintain ship speed and main engine power. P ME The goal is to maintain a constant speed; the controllable propeller speed-pitch linkage under constant main engine power is as follows: ； ； ； In the formula, P ME This refers to the output power of the main unit. K o For the controllable pitch propeller propulsion coefficient, Γ(H p / D) For controllable pitch propeller thrust, v s For ship speed, L For the main engine throttle, n p For the controllable pitch propeller speed, H p For the pitch of the controllable propeller, η o To improve efficiency, S For slippage rate, K G γ is the adjustable gear ratio of the variable speed hydraulic coupling; γ is a function of main engine power and throttle, used to calibrate the relationship between main engine power and throttle; Γ is the thrust related to the pitch of the controllable propeller, meaning the thrust is adjusted by the pitch. H p The thrust magnitude and direction can be set quickly and directly, improving the high maneuverability, high controllability and wide operating condition adaptability of the controllable propeller; The hydraulic coupling is used to replace the reduction gearbox to buffer the impact of the propeller on the main engine and is suitable for ship navigation in ice-covered areas.

8. A composite feedforward cooperative control system for ship controllable pitch propeller propulsion, characterized in that, The system for implementing the method according to any one of claims 1-7 comprises: Data processing and modeling unit: used to store and run the controllable pitch propeller propulsion composite model, specifically performing the ship load query function, the ship speed closed-loop progressive control calculation, and the main engine safety threshold calculation; Data acquisition unit: used to acquire ship speed, main engine speed, main engine power, controllable pitch propeller pitch, throttle position and hydraulic coupler output speed signals in real time; Cooperative control decision unit: used to calculate power margin, determine host safety threshold and select cooperative control mode; The execution unit includes a main engine speed regulation and throttle actuator, a hydraulic coupler gear ratio control mechanism, and a pitch control propeller pitch hydraulic adjustment mechanism, which are communicatively connected to the collaborative control decision unit, and is used to execute the collaborative control commands.

9. A ship, characterized in that, It is equipped with a composite feedforward cooperative control system for ship controllable pitch propeller propulsion as described in claim 8.

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