CN107092199B - Ship motion control simulation platform and ship motion control method - Google Patents

Abstract

The invention discloses a ship motion control simulation platform, comprising a control module, a drive module, an attitude measurement module, a position determination module and a power supply module. The drive module is used to control the forward movement and steering of the movement platform; the attitude measurement module and the position determination module are respectively It is used to measure the attitude and position data of the motion platform; the control module is equipped with a track tracking algorithm and a deck motion model. Then, according to the calculation results, the driving module will move according to the desired route, and at the same time, the deck movement of the ship in the waves can be simulated. Further, a ship motion control method is also disclosed. Through the platform or method, the indirect control method which separates the heading control and the track control, the adjustment of the control parameters is simple, and the heading control algorithm and the track control algorithm can be modified separately.

Description

Ship motion control simulation platform and ship motion control method

technical field

The invention belongs to the technical field of ship motion control simulation, in particular to a ship motion control simulation platform and a ship motion control method.

Background technique

The movement of the ship on the sea will affect the landing accuracy of the aircraft, and the attitude of the ship can be judged through pattern recognition, so as to choose the right time to land. In the study of aircraft landing, a ship motion simulation platform is essential. The design and simulation of the prototype system has a very wide range of application value, which can quickly verify the principle scheme of the design system. In order to check whether the control system design is reasonable and the control algorithm is effective, it is necessary to pass several water tests. Each experiment needs to synthesize the motion data of the ship, and then analyze and organize to obtain a comprehensive evaluation of the control performance, so as to compare the advantages and disadvantages of the control methods. Therefore, simulation is a necessary method to study ship motion control algorithm. There are usually the following three simulation methods: computer simulation method, real ship test and semi-physical platform simulation.

The computer simulation method has low cost and simplicity, and is the most commonly used initial simulation method. It has good interactivity and can better simulate the motion of the ship in the waves. The accuracy of the sea state is very important, so it can only be used as a preliminary means to verify various control methods. The real ship test has high reliability, but it is dangerous and costly, so it is generally used after the control method is verified by computer simulation and the feasibility is basically determined. Compared with the first two methods, the semi-physical platform simulation has high reliability, low cost and safety, and is widely used. However, there are few ship motion simulation platforms at present, and the control algorithm is complex, the parameter adjustment is difficult, and the algorithm is portable. Sex is not high.

SUMMARY OF THE INVENTION

In order to solve the problems of the prior art, the present invention proposes a ship motion control simulation platform and a ship motion control method with simple parameter adjustment, strong algorithm portability and low cost.

The ship motion control simulation platform disclosed by the invention includes a control module, a drive module, an attitude measurement module, a position determination module and a power supply module. The drive module is used to control the forward movement and steering of the movement platform; the attitude measurement module and the position determination module are respectively used for Measure the attitude and position data of the motion platform; the control module is equipped with a track tracking algorithm (including heading control and track control) and a deck motion model, and the control module obtains the attitude and position information of the motion platform from the attitude measurement module and the position determination module Then the track tracking calculation is carried out, and then the driving module will move according to the desired route according to the calculation results, and can simulate the deck movement of the ship in the waves at the same time; the power module supplies power to each module of the motion platform; among them, the attitude measurement module and the position The determination modules are connected and communicated with the control module through the asynchronous serial communication interface; the track tracking calculation includes the tracking calculation of the course and the track.

Further, the control module includes a heading control unit and a track control unit, the track control unit receives the real-time position data sent by the position determination module, compares it with the desired track, and then outputs the desired heading; the heading control unit receives the output of the track control unit. The real-time attitude data sent by the desired heading and attitude determination module, calculate and output the control signal of the desired attitude, and then control the drive module to change the attitude of the motion platform. Specifically, the heading control unit receives the real-time attitude data sent by the desired heading and attitude determination module, and outputs the rudder angle control signal of the moving platform after calculation, so as to control the steering gear of the moving platform to drive the rudder blades, so that the attitude of the moving platform changes.

Further, heading control uses anti-windup PID control.

Further, the track control uses the line-of-sight navigation method.

Further, the control module has built-in attitude data interrupt program and attitude data receiving program. When there is attitude data sent to the control module, an interrupt will be generated. After the attitude data interrupt program recognizes the frame header of the attitude data frame, it will send a complete frame The data is saved to the buffer. When a frame of data is received, the receiving flag will be set and the receiving program will wait for the data to be read; the attitude data receiving program will first read the value of the receiving flag to determine that a frame of data has been completely stored in the buffer. If you want to update the attitude data, you can call the attitude data receiving program.

Further, the control module has built-in position data interrupt program and position data receiving program. When there is position data sent to the control module, an interrupt will be generated, and the position data interrupt program will save the data to the buffer. The receiving program in the module will fetch the data into the corresponding variable; the position data receiving program first reads the value of the received flag bit, confirms that a frame of data has been completely stored in the buffer, and then reads the data after verification ; If you want to update the location data, just call the location data receiving program.

Further, the control module adopts the minimum system of MC9S12XS128MAA single-chip microcomputer.

Further, the attitude measurement module outputs the pitch angle, yaw angle, roll angle and height of the motion platform.

Further, the attitude measurement module can use the miniAHRS attitude module.

Further, the position determination module adopts WF-NEO-6M positioning chip.

Further, the drive module adopts a single propeller and double rudder structure.

Further, the drive module includes a motor, a transmission shaft, a propeller, a remote control, a steering gear, a lever and a rudder blade, wherein the remote control is used to control the motor to move forward, backward, and stop; the motor rotates to drive the propeller through the transmission shaft; the steering gear rocker arm rotates The rudder blade is driven by the pull rod.

Further, the software part in the control module adopts a modular design, and each module has a separate bottom-level program to ensure that the module function can be realized only by calling the subroutine of the module separately in the control process.

Further, the control module also has a built-in deck motion model. The control module conducts ocean wave modeling and obtains various effective wave inclination angles. The obtained effective wave inclination angles are respectively input into the corresponding motion transfer function, and the deck attitude motion function is calculated. The attitude data fed back by the measurement module is calculated in combination with the deck attitude motion function, and the control signal is output to the drive module to control the attitude of the moving platform; among them, the deck motion includes roll motion, pitch motion, and heave motion, and the effective wave inclination includes roll. Effective wave inclination angle, pitch effective wave inclination angle, hesitation effective wave inclination angle, transfer functions include roll motion transfer function, pitch motion transfer function, and heave motion transfer function.

The invention also discloses a ship motion control method, which separates the heading control and the track control, firstly receives the real-time position data of the ship and compares it with the desired track, and then outputs the desired heading; and then receives the outputted desired heading and the ship The real-time attitude data of the ship is calculated and output the control signal of the desired attitude; then the motion attitude of the ship is changed according to the control signal.

Further, the heading control uses the anti-windup PID control method.

Further, the track control uses the line-of-sight navigation method.

Further, the ship includes a control module, a drive module, an attitude measurement module, and a position determination module. The drive module is used to control the forward movement and steering of the motion platform; the attitude measurement module and the position determination module are respectively used to measure the attitude and position of the motion platform. Data; the control module includes a heading control unit and a track control unit, which separate and indirectly control the heading control and the track control. The track control unit receives the real-time position data sent by the position determination module, compares it with the desired track, and then outputs the desired heading The course control unit receives the desired course output from the track control unit and the real-time attitude data sent by the attitude determination module, calculates and outputs the control signal of the desired attitude, and then controls the drive module to change the motion attitude of the ship.

Beneficial effects:

(1) The indirect control method that separates the heading control and the track control, the adjustment of the control parameters is simple, and the heading control algorithm and the track control algorithm can be modified separately. Among them, the heading control adopts anti-saturation PID control, which is convenient for debugging and avoids the system out of control due to the saturation of the integrator; the track control adopts the line-of-sight navigation method, which does not depend on the kinematic model, and requires less design parameters and is easy to set parameters. , Good convergence.

(2) The ship motion control simulation platform can be equipped with track tracking algorithm (including heading and track tracking calculation) and deck motion model. Simulate the deck movement of the ship in the waves.

(3) The drive module includes a remote controller, which can manually control the forward, backward and pause of its motion platform to avoid hardware damage caused by the loss of control of the motion platform during the algorithm debugging process.

(4) The software part of the present invention adopts a modular design, and each hardware module has a separate bottom-level program. In the control process, as long as the subroutine of the module is called, the module function can be realized, the program structure is clear, and the portability is strong; It is also possible to debug each module separately, which is convenient for troubleshooting and chip replacement, thereby reducing the cost of the simulation platform; designers can also replace the algorithm of heading control and the algorithm of track control according to their needs, and carry out secondary development to further expand the simulation platform. Function.

Description of drawings

Fig. 1 is the hardware structure diagram of the simulation platform in the embodiment

Fig. 2 is the main program flow chart in the embodiment

Fig. 3 is the flow chart of the attitude data interruption procedure in the embodiment

Fig. 4 is the flow chart of the attitude data receiving procedure in the embodiment

FIG. 5 is a flow chart of the position data interruption program in the embodiment

FIG. 6 is a flow chart of the position data receiving procedure in the embodiment

FIG. 7 is a block diagram of the track tracking control algorithm in the embodiment

Fig. 8 is the control block diagram of the anti-saturation PID algorithm in the heading control module in the embodiment

FIG. 9 is the geometric model when the desired track is from west to east in the track tracking algorithm in the embodiment

FIG. 10 is the geometric model when the desired track is from east to west in the track tracking algorithm in the embodiment

Detailed ways

As shown in Figure 1, an embodiment of a ship motion control simulation platform is disclosed. The ship motion control simulation platform is a "motion platform", "platform" or "hull", and the platform includes a power module, a drive module, and an attitude measurement module. , position determination module and control module, the power supply module provides power supply for each chip and drive module of the motion platform; the drive module controls the forward movement and steering of the motion platform; the attitude measurement module and the position determination module measure the attitude and position data of the motion platform; the control module As the core of the simulation platform, the attitude and position information of the motion platform are obtained, and then the track tracking calculation is performed to control the steering of the rudder blade to achieve the effect of motion control.

The design scheme is described below in conjunction with specific embodiments and accompanying drawings:

The control module described in the embodiment adopts the MC9S12XS128MAA single-chip minimum system, and the main program flow chart is shown in Figure 2: every 0.5 seconds, the data sent by the attitude measurement module and the position determination module are received, and the rudder angle control signal is calculated according to the track tracking algorithm, The PWM wave is output to the steering gear to drive the rudder blade to deflect, thereby controlling the motion trajectory of the motion platform.

The attitude measurement module can use the miniAHRS attitude module, which is composed of STM32F103T8 (main control chip), MPU6050 (acceleration sensor), HMC5883L (three-axis geomagnetic sensor) and BMP180 (barometric height sensor), which can directly output the original measurement value of the sensor. Calculate the measured values of each sensor, and output the pitch angle, yaw angle, roll angle and height of the motion platform. The attitude measurement module communicates with the control module through an asynchronous serial communication interface.

An interrupt is generated when there is attitude data sent to the control module. The flowchart of the attitude data interrupt function is shown in Figure 3: after the program recognizes the frame header of the attitude data frame, it saves a complete frame of data to the buffer. Set the value of the flag bit to 1) and wait for the receiving program to read the data. In Figure 3, oxa5 and ox5a represent the frame header of the data frame.

The flow chart of the attitude data receiving program is shown in Figure 4: the program first reads the value of the receiving flag bit, confirms that a frame of data has been completely stored in the buffer, and then reads the data after verification. In Figure 4, the A1 type data is the calculated attitude data, and the A2 type is the original measurement data of the sensor. They are sent in two frames, so they need to be analyzed separately. If you want to update the attitude data, you can call the attitude data receiving program (because the attitude receiving function directly assigns the data of the buffer to the corresponding variable, and calling it can update the value of the variable).

The position determination module adopts WF-NEO-6M positioning chip, and communicates with the control module through the asynchronous serial communication interface.

An interrupt is generated when position data (ie, position data representing latitude and longitude) is sent to the control module. The flow chart of the position data interrupt function is shown in Figure 5: the program saves the data to the buffer, and when a frame of program is received, the receiving program in the control module will fetch the data into the corresponding variable.

The flow chart of the position data receiving program is shown in Figure 6: the program first reads the value of the received flag bit, confirms that a frame of data has been completely stored in the buffer, and then reads the data after verification. If you want to update the location data, just call the location data receiving program.

The power module includes two sets of 12V lithium batteries, all of which are made up of three 18650 lithium batteries in series. One set of protection boards has a current limit of 10A to supply power to the drive module alone; the other set of protection boards has a current limit of 5A, which supplies all chips. and servo power supply.

The drive module adopts a single propeller and double rudder structure, including RS-550 high-speed motor, transmission shaft, propeller, remote control, steering gear, pull rod and rudder blade; the motor rotates to drive the propeller through the transmission shaft; the remote control is connected between the motor and the power supply. During the time, the motor can be controlled by the remote control to move forward, backward and stop; the rotation of the steering gear rocker arm drives the rudder blade through the pull rod.

In the embodiment, the control module includes a track control unit and a heading control unit, and adopts an indirect control method that separates the heading control and the track control. The block diagram of the control algorithm is shown in Figure 7: the track control unit receives the real-time position data sent by the position determination module, compares it with the desired track, and then outputs the desired heading; the heading control unit receives the desired heading and the real-time attitude data sent by the attitude determination module, calculates Then output the rudder angle control signal, so as to control the steering gear to drive the rudder blade and change the attitude of the moving platform.

It is worth noting that in the prior art, direct control is mostly used. The control module receives attitude and position data at the same time, and outputs the rudder angle control signal after calculation. Although it can be controlled more accurately, it is difficult to adjust parameters. In this method, the indirect control is the relative separation of the heading control and the track control, the control accuracy is basically not affected, but the parameter debugging is simpler.

In the embodiment, the anti-windup PID control is used for the heading control, which avoids the oversaturation phenomenon of the integrator caused by the limitation of the mechanical structure.

The control block diagram of the anti-saturation PID algorithm in the heading control module is shown in Figure 8, where,

是实际航向，ν是不经限幅的舵角控制信号，u表示限幅后的舵角控制信号；此外，图8中，t表示时间，K_p表示比例系数，K_i表示积分系数，K_d表示微分系数，K_f表示抗饱和反馈增益。where _θd is the desired heading,

is the actual heading, ν is the rudder angle control signal without limitation, u is the rudder angle control signal after limitation; in addition, in Fig. 8, t is the time, K _p is the proportional coefficient, K _i is the integral coefficient, K _d is the differential coefficient, and K _f is the anti-windup feedback gain.

When the output ν is too small, the difference between u and ν (positive) can be added to the integral control process to increase ν; when the output ν is too large, the difference between u and ν (negative ) is added to the integral control process, at this time, the integral control is weakened, so that the output ν becomes smaller; when the output ν is within a reasonable range, then u and ν are equal, which is equivalent to ordinary PID control.

The track control uses the line-of-sight navigation method, does not depend on the kinematic model, and the parameter debugging is simple, among which:

When the desired route is from west to east (as shown in Figure 9), the heading angle calculation formula is as follows:

θ(t)=α _k +arctan(e(t)/Δ)

When the desired route is from east to west (as shown in Figure 10), the heading angle calculation formula is as follows:

θ(t)=α _k -arctan(e(t)/Δ)+π

In Fig. 9 and Fig. 10: P _k to P _k+1 are desired routes. P(t) is the position of the hull, P _m (t) is the projection point of the hull position to the desired route, P _d (t) is the virtual tracking point, α _k is the angle between the desired route and the north, θ(t) is Desired heading, e(t) is the distance between P(t) and P _m (t) (i.e. the distance between where the moving platform is located and its projected point on the desired course), Δ is P _m ( The distance between t) and P _d (t) (that is, the distance between the projected point representing the position of the motion platform on the desired route and the virtual tracking point, is an adjustable parameter).

Among them, the calculation formula of α _k is as follows:

α _k =π/2-arctan(y _k+1 -y _k ,x _k+1 -x _k )

In the formula: x _k represents the longitude of the starting point of the desired trajectory, y _k represents the latitude of the starting point of the desired trajectory; x _k+1 represents the longitude of the target point of the desired trajectory; y _k+1 represents the latitude of the target point of the desired trajectory.

When the desired route is from west to east (as shown in Figure 9), the calculation formula of e(t) is as follows:

e(t)=(x(t)-x _k )cosα _k -(y(t)-y _k )sinα _k

When the desired route is from east to west (as shown in Figure 10), the calculation formula of e(t) is as follows:

e(t)=(x(t)-x _k+1 )cosα _k -(y(t)-y _k+1 )sinα _k

In the formula: x(t) represents the longitude of the location of the motion platform; y(t) represents the latitude of the location of the motion platform.

When setting the desired path, you need to input the desired path points, and the motion platform will move along the polyline formed by the sequence of the points. When the motion platform sails through a polyline P _k P _k+1 , the control program will automatically switch the desired path to the next polyline P _{k+ 1} P _k+2 , and the path update principle is as follows:

[x(t)-x _k ] ² +[y(t)-y _k ] ² ≤R ²

In the formula: R represents the distance between the position of the hull and the target track point, which is an adjustable parameter.

When the desired path is updated, the desired heading changes greatly and a step response occurs, so a first-order inertial filter is added to smooth the desired heading obtained by the guidance algorithm. The smoothed heading is:

θ _d (t)=αθ(t)+(1-α)θ _d (t-1)

In the formula: θ _d (t) represents the smoothed desired heading; α represents the filter coefficient; θ (t) represents the desired heading calculated in the above line-of-sight navigation method; θ _d (t-1) represents the Smooth desired heading.

All the operation programs in the control module described in the embodiments can be written in C language, and of course can also be written in other languages.

The software part of the present invention adopts a modular design, and each hardware module has a separate bottom-level program. In the control process, the module function can be realized as long as the subroutine of the module is called, and the program structure is clear and the algorithm is convenient to modify. If you want to simulate other track tracking algorithms, you only need to modify the track tracking function (the indirect control method in the control module that separates the heading control and the track control is used in the embodiment, and the direct control method in the prior art can also be used. At the same time, each module can be debugged separately, which is convenient for troubleshooting, chip replacement and cost saving.

The main program structure diagram is shown in Figure 2. The position data and attitude data are read every 0.5 seconds, and then through the calculation of the control algorithm, the steering gear control signal is output to control the rudder blade.

The subroutines of each module are described as follows:

①Clock part:

void INIT_PLL(void): The crystal frequency is 16MHz. The function of this function is to overclock the bus frequency to 32MHz.

②GPS part:

void INIT_SCI1(void): Initialize the serial port;

unsigned char change(unsigned char*a): The data type of the GPS chip is the symbol type, this function changes the symbol type into the corresponding number;

void Get_GPS(void): Get GPS data from the buffer;

interrupt 21 void USART2_IRQHandler_GPS(void): GPS data reception interrupt function;

unsigned char Sum_check_GPS(void): data check;

void UART2_CommandRoute_GPS(void): The main function of GPS data reception, call this function to update GPS data.

③miniAHRS part:

void INIT_SCI0(void): Initialize the serial port;

void UART2_Get_IMU(void): Get attitude data;

void UART2_Get_Motion(void): Get ADC data (ie, undecoded data);

void interrupt 20USART2_IRQHandler(void): data reception interrupt;

unsigned char Sum_check(void): data check;

void UART2_CommandRoute(void): The main function for receiving attitude data, which can be called to update attitude data.

④Steering gear part:

void init_pwm(void): PWM signal initialization;

void rudder(void): According to the rudder angle signal of the control module, the steering gear is deflected by a certain angle.

⑤ Control module part:

float atand(float x): redefine trigonometric functions to operate in units of angles;

void control(void): heading and track control functions.

⑥PIT timing module:

void init_PIT(): PIT module initialization;

interrupt 66void PIT_INTER(void): Interrupt function called after every timer.

For example, when you need to update the attitude data of the motion platform, you don't need to call all the functions of the miniAHRS module, you only need to call the function UART2_CommandRoute() to complete the update of the attitude data; similarly, when you need to update the position data, you only need to Call UART2_CommandRoute_GPS().

The present invention can also simulate the ship deck motion, including roll motion, pitch motion, and heave motion, according to the sea state specified by the user. The deck motion is modeled as follows:

The motion of the waves leads to the motion of the ship's deck, so to simulate the motion of the deck, wave modeling must be done first.

(1) Wave modeling

Using the long-peaked wave model, the random long-peaked wave can be regarded as the superposition of countless cosine waves with different frequencies, different amplitudes and different initial phases, without considering higher harmonics, and study a fixed point wave model When , the harmonic amplitude ξ can be expressed by the following formula:

In the formula: t represents time, ξ _i represents the amplitude of the ith harmonic; ω _i represents the angular frequency of the ith harmonic; ε _i represents the initial phase angle of the ith harmonic (randomly uniform between 0 and π). distributed).

The energy value of the corresponding frequency harmonic can be obtained by discretizing the wave spectrum. The wave spectrum uses the ITTC single-parameter spectrum. The empirical expression of the harmonic energy value S _ξ is as follows:

Where: ω is the wave frequency; g is the acceleration of gravity; h _1/3 is the significant wave height.

The relationship between the harmonic energy value and the harmonic amplitude is as follows:

Where: ω _i represents the harmonic frequency; S _ξ (ω _i ) represents the harmonic energy value; ξ _i represents the harmonic amplitude.

From this, the magnitude of the corresponding harmonic can be calculated.

The calculation of the effective wave inclination angle includes the roll effective wave inclination angle α _φe , the pitch effective wave inclination angle α _θe , and the heave effective wave inclination angle ξ _ze . The calculation formula is as follows:

V是航速；X_φ表示横滚有效波倾角修正系数；X_θ表示俯仰有效波倾角修正系数；X_z表示沉浮有效波倾角修正系数。In the formula: β represents the encounter angle; ω _ei represents the ship encounter frequency,

V is the speed; X _φ represents the correction coefficient of the inclination angle of the roll effective wave; X _θ represents the correction coefficient of the inclination angle of the pitch effective wave; X _z represents the correction coefficient of the inclination angle of the up and down effective wave.

(2) Deck motion modeling

Including roll motion transfer function, pitch motion transfer function, and heave motion transfer function, the above effective wave inclination angle is used as the system input, after the calculation of the transfer function, the obtained output is the deck attitude motion function.

Among them, the effective wave inclination is the above time-related formula. After the pull-type transformation, it becomes a formula with s, and s is used to represent the transfer function in the automation. After the pull-type inverse transformation, it will become a time-related function. . Taking the effective wave inclination angle as the input of the transfer function, the deck attitude motion function with s can be obtained by multiplying the two formulas. The deck motion attitude function is the function of the deck attitude angle changing with time. The transfer function is as follows:

①Rolling motion transfer function:

J_φ表示横滚转动惯量；ΔJ_φ表示横滚附加转动惯量；D表示舰船排水质量；h表示横稳定中心高；ζ_φ表示横滚阻尼因子，与船的自身特性有关。where: ω _φ represents the roll natural angular frequency of the ship,

J _φ represents the rolling moment of inertia; ΔJ _φ represents the rolling additional moment of inertia; D represents the displacement mass of the ship; h represents the height of the lateral stability center; ζ _φ represents the rolling damping factor, which is related to the ship's own characteristics.

②Pitch motion transfer function

J_θ表示俯仰转动惯量；ΔJ_θ表示俯仰附加转动惯量；ζ_θ表示俯仰阻尼因子，与船的自身特性有关。where: ω _θ represents the natural pitch frequency of the ship;

J _θ represents the pitch moment of inertia; ΔJ _θ represents the pitch additional moment of inertia; ζ _θ represents the pitch damping factor, which is related to the ship's own characteristics.

③The transfer function of ups and downs

In the formula: ω _z represents the natural frequency of the ship's ups and downs, λ _z represents the additional mass of ups and downs; ρ represents the density of seawater; _Sw represents the waterplane area of the ship; ζ _z represents the ups and downs damping factor.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments and application fields, and the above-mentioned specific embodiments are only illustrative and instructive, rather than restrictive . Under the enlightenment of this specification, those skilled in the art can also make many forms without departing from the scope of protection of the claims of the present invention, which all belong to the protection of the present invention.

Claims (8)

1. A ship motion control simulation platform is characterized by comprising a control module, a driving module, an attitude measurement module, a position determination module and a power supply module,

the driving module is used for controlling the forward movement and the steering of the motion control simulation platform;

the attitude measurement module and the position determination module are respectively used for measuring attitude and position data of the motion control simulation platform;

the control module acquires the attitude and position information of the motion control simulation platform from the attitude measurement module and the position determination module, then carries out track tracking calculation, and then realizes motion control through the driving module according to the calculation result;

the power supply module supplies power to each module of the motion control simulation platform;

the attitude measurement module and the position determination module are connected and communicated with the control module through asynchronous serial communication interfaces;

the control module comprises a course control unit and a track control unit, wherein the track control unit receives the real-time position data sent by the position determination module, compares the real-time position data with an expected track and then outputs an expected course; the course control unit receives the expected course output by the track control unit and the real-time attitude data sent by the attitude measurement module, calculates and outputs a control signal of the expected attitude, and then controls the driving module to change the attitude of the motion control simulation platform; the track tracking calculation comprises the tracking calculation of the course and the track; the track control adopts a line-of-sight navigation method;

the control module is also internally provided with a deck motion model for simulating the movement of the deck of the ship according to a specified sea condition, wherein the sea condition is the wave motion causing the movement of the deck of the ship; the method specifically comprises the following steps: firstly, sea wave modeling is carried out to obtain various effective wave dip angles, then a deck motion model is constructed, the obtained effective wave dip angles are respectively input into corresponding motion transfer functions, a deck attitude motion function is obtained through calculation, finally, calculation is carried out according to attitude data fed back by an attitude measurement module and in combination with the deck attitude motion function, and a control signal is output to a driving module to control the attitude of a motion control simulation platform;

the deck movement of the ship comprises rolling movement, pitching movement and sinking and floating movement; the effective wave inclination angle comprises a rolling effective wave inclination angle, a pitching effective wave inclination angle and a sinking and floating effective wave inclination angle;

the motion transfer function comprises a roll motion transfer function, a pitch motion transfer function and a sinking and floating motion transfer function;

wherein the roll effective wave inclination angle alpha_φeEffective pitch wave inclination angle alpha_θeEffective wave dip angle xi_zeThe calculation formula of (a) is as follows:

in the formula: β represents the encounter angle; omega_eiThe frequency of encounter of the ship is represented,

v is the speed of the ship; x_φRepresenting a roll effective wave inclination angle correction coefficient; x_θRepresenting a pitch effective wave inclination angle correction coefficient; x_zRepresenting the dip angle correction coefficient of the sinking and floating effective wave; g represents the gravitational acceleration; omega_iRepresents the angular frequency of the ith harmonic; s_ξ(ω_i) Representing the harmonic energy value; epsilon_iRepresenting the initial phase angle of the ith harmonic;

the roll motion transfer function is calculated as follows:

in the formula: omega_φRepresenting the roll natural angular frequency of the ship,

J_φrepresenting rolling moment of inertia △ J_φRepresenting roll additional moment of inertia; d represents the ship drainage quality; h represents the transverse center of stability height; zeta_φRepresents a roll damping factor;

the pitch motion transfer function is calculated as follows:

in the formula: omega_θRepresenting the natural angular frequency of pitching of the ship;

J_θrepresenting pitch moment of inertia △ J_θRepresenting a pitch additional moment of inertia; zeta_θRepresents a pitch damping factor;

the sinking-floating motion transfer function is calculated as follows:

in the formula: omega_zThe natural frequency of the ship in the ups and downs is shown,λ_zrepresenting the sinking and floating additional mass; ρ represents the seawater density; s_wShowing the area of the waterline surface of the ship; zeta_zRepresenting the heave damping factor.

2. The vessel motion control simulation platform of claim 1, wherein: the course control uses an anti-saturation PID control method.

3. The vessel motion control simulation platform of claim 1, wherein: the control module is internally provided with a posture data interrupt program and a posture data receiving program, when posture data are sent to the control module, an interrupt is generated, after the posture data interrupt program identifies a frame header of a posture data frame, a complete frame of data is stored in a buffer area, and when the frame of data is completely received, a receiving flag bit is set to wait for the posture data receiving program to read the data; firstly, the attitude data receiving program reads the value of a receiving zone bit, determines that a frame of data is completely stored in a buffer area, and then reads the data after checking without errors; if the attitude data is required to be updated, calling an attitude data receiving program; the control module is internally provided with a position data interrupt program and a position data receiving program, when position data are sent to the control module, an interrupt is generated, the position data interrupt program stores the data into a buffer area, and when one frame of program is received, the position data receiving program in the control module can take the data into a corresponding variable; the position data receiving program firstly reads the value of the receiving zone bit, determines that a frame of data is completely stored in a buffer area, and then reads the data after checking without errors; if the position data is required to be updated, the position data receiving program is called to realize the updating.

4. The vessel motion control simulation platform of claim 1, wherein: the attitude measurement module adopts a miniAHRS attitude module, and outputs a pitch angle, a yaw angle, a roll angle and a height of the motion control simulation platform; the position determination module adopts WF-NEO-6M to position the chip.

5. The vessel motion control simulation platform of claim 1, wherein: the driving module adopts a single-paddle double-rudder structure.

6. The vessel motion control simulation platform of claim 5, wherein: the driving module comprises a motor, a transmission shaft, a propeller, a remote controller, a steering engine, a pull rod and a rudder blade, wherein the remote controller is used for controlling the motor to advance, retreat and stop; the motor rotates to drive the propeller through the transmission shaft; the steering engine rocker arm rotates to drive the rudder blade through the pull rod.

7. The vessel motion control simulation platform of claim 1, wherein: the software part in the control module adopts a modular design, and each module has an independent bottom layer program so as to ensure that the function of the module can be realized by only calling the bottom layer program of the module in the control process.

8. A ship motion control method is characterized in that based on the ship motion control simulation platform of any one of claims 1 to 7, course control and track control are separately controlled, real-time position data of a ship are received and compared with an expected track, and then an expected course is output; then receiving the output expected course and the real-time attitude data of the ship, and calculating and outputting a control signal of the expected attitude; and then the motion attitude of the ship is changed according to the control signal.

Images