Electrically driven control method for fin stabilizer

Abstract

An electrically driven control method for a fin stabilizer. The control method comprises the following steps: performing signal isolation processing on a ship attitude signal detected by a sensor, then inputting the ship attitude signal into a PLC, subjecting the ship attitude signal to filtering processing followed by a fractional-order PID operation, then passing the ship attitude signal through a speed adjustment program and a wave-level adjustment program, finally sending a generated anti-rolling fin rotation angle signal to an electric motor drive to control a fin stabilizer to rotate, detecting position information of the rotated fin stabilizer by means of the sensor, generating a mechanical fin rotation angle signal, and feeding the mechanical fin rotation angle signal back to the PLC, so as to further control the fin stabilizer to rotate. The control method further comprises: processing a rolling signal generated inside the PLC, passing the rolling signal through the speed adjustment program, then generating a rolling fin rotation angle signal, and inputting the rolling fin rotation angle signal into the electric motor drive to control the fin stabilizer to rotate.

Description

A control method for electrically driven fin stabilizers

[0001] Related applications

[0002] This application claims priority to Chinese invention patent application No. 202311053650.8, filed on August 21, 2023, entitled “A method for controlling an electric-driven fin stabilizer”. Technical Field

[0003] The present invention relates to the technical field of ship control, and in particular to a method for controlling an electrically driven fin stabilizer. Background Art

[0004] The vast majority of fin stabilizers currently installed on ships in service use hydraulic or pneumatic drive as a power source to control the fins. The disadvantage is that the applicable equipment occupies a large cabin area, is bulky, and has many pipelines. These devices are prone to oil leakage and seepage over time, increasing maintenance costs. Some traditional fin stabilizer control methods have some limitations, such as high energy consumption and slow response speed. To overcome these problems, the current electric drive fin stabilizer control method has emerged. With the development of technology, the accuracy of electric drive control has been continuously improved, and it has been widely used in high-precision machine tools and machining center products. Electric drive control technology has also been widely used in aviation, aerospace, shipbuilding and other fields. The control method of electric drive control of fin stabilizers can also be used in application scenarios with compact structure, small cabin area and light equipment weight.

[0005] For example, the patent with patent number CN.201834187.U transmits the ship's roll motion signal to the motion controller through the roll motion sensor, and then outputs the fin rotation control signal of the anti-roll fin according to the speed and wave level adjustment module, controls the drive controller on each single fin, and drives each single fin to move.

[0006] However, the control method disclosed in this patent is still limited to open-loop control, does not achieve highly automated control, and has limited adjustment accuracy.

[0007] Summary of the Invention

[0008] The purpose of the present invention is to solve the problems of the prior art fin stabilizer control system, such as bulky equipment, large space occupation, and complex piping, and to propose a fin stabilizer control method driven by electricity, which simplifies the equipment structure while improving control accuracy and response speed.

[0009] The technical solution of the present invention provides an electric drive fin stabilizer control method, which is used on a ship. The ship is equipped with a sensor, a PLC controller and a motor driver;

[0010] The electric drive fin stabilizer control method comprises the following steps:

[0011] Step 1: Use sensors to detect ship attitude information and generate ship attitude signals, which are then input into the PLC controller after signal isolation processing.

[0012] Step 2: After receiving the ship attitude signal, the PLC controller first performs filtering processing, then performs fractional-order PID calculation, and then goes through the speed adjustment program and wave level adjustment program to finally generate the fin stabilizer angle signal;

[0013] Step 3: The motor driver receives the stabilizer fin angle signal from the PLC controller and controls the motor to rotate. The motor drives the stabilizer fin to rotate to the specified position.

[0014] Step 4: The sensor detects the position information of the fin stabilizer after rotation and generates a mechanical fin rotation angle signal, and feeds the generated mechanical fin rotation angle signal back to the PLC controller to further control the rotation of the fin stabilizer.

[0015] Furthermore, the electric drive fin stabilizer control method further includes:

[0016] The PLC controller is programmed to generate a swing signal, which is then converted into a fin angle signal after passing through the speed control program. The PLC controller inputs the fin angle signal into the motor driver and controls the motor rotation based on the fin angle signal, thereby driving the fin stabilizer to rotate to the specified position.

[0017] Furthermore, the signal isolation processing module is used to isolate and protect the ship attitude signal from interference from various factors inside or outside the ship, and uses differential signal isolation to offset common mode interference to ensure that the PLC controller receives complete and accurate ship attitude signals.

[0018] Furthermore, the filtering process is in the form of arithmetic mean filtering. After the arithmetic mean filtering of the ship attitude signal, the signal extracted is smoother. The formula is as follows:

[0019] Among them, U0 is the filtered ship attitude signal, U I is a series of continuous sampling values ​​of the original ship attitude signal, n is the number of sampling values, and the filtered signal is the sum of the multiple sampling values ​​of the original signal divided by the number of sampling values. The filtered ship attitude signal includes the angular velocity signal and the signal containing the angle information.

[0020] Furthermore, the method of performing fractional-order PID operation on the ship attitude signal includes:

[0021] First, determine the desired target attitude of the ship. Then use the transfer function of fractional-order PID control to calculate the ship attitude signal. According to the ship attitude signal and the target attitude, calculate the proportional term, integral term, and differential term respectively, and add them to obtain the final fin stabilizer angle signal. The fractional-order PID control transfer function is:

[0022] Where C(s) represents the transfer function of the fractional-order PID, s is a complex frequency domain variable, and K P is the proportional gain, K i is the integral gain, K d is the differential gain, γ is the integration order, and μ is the differential order;

[0023] The time domain analysis of fractional-order PID is as follows: u(t)=K P e(t)+K i I γ e(t)+K i D μ e(t)

[0024] Among them, u(t) represents the fin angle signal output after the fractional-order PID operation, e(t) is the angular velocity signal, and the fractional-order PID includes the proportional K in the time domain. P , integral K i I γ and differential K i D μ Three links.

[0025] Furthermore, speed regulation is an adjustment of the fin stabilizer angle signal generated after fractional-order PID calculation, which can increase the stability of the ship while ensuring the speed and efficiency of the ship.

[0026] The PLC controller receives the speed signal detected by the external device and adjusts the fin angle signal obtained by the fractional-order PID operation in inverse square proportion based on the speed signal. When the speed is lower than 4kn, the fin angle needs to be reset to zero and the controller shuts down. The speed adjustment rules are as follows:

[0027] Among them, V is the current speed, V0 is the target speed, F is the lift generated by the fin, U Fmax is the fin stabilizer angle signal after inverse square adjustment.

[0028] Furthermore, the wave level adjustment is performed after the speed adjustment. The wave level adjustment is to adjust the fin stabilizer angle signal after the speed adjustment according to the sea conditions.

[0029] The required attitude and heading control is achieved by setting and adjusting the trinity value of the fin angle. The difference between the probability of the maximum fin angle exceeding the set maximum fin angle and the designed expected probability, as well as the ship's residual roll angle, are used as inputs to the fuzzy control. The wave level adjustment coefficient is used as output. The ship's residual roll angle is obtained from the filtered ship attitude signal collected by the sensor.

[0030] When the residual roll angle of the ship is greater than the design value and the fin angle has not reached the maximum fin rotation angle, the wave level adjustment coefficient is increased, and the fin stabilization angle signal increases. When the residual roll angle of the ship is greater than the design value, the fin angle has reached the maximum fin rotation angle and the fin angle saturation rate is greater than the set value, the wave level adjustment coefficient is reduced, and the fin stabilization angle signal decreases. When the residual roll angle of the ship is less than the design value, the fin angle saturation rate is less than or equal to the design value, and the wave level adjustment coefficient remains unchanged, the fin stabilization angle signal remains unchanged.

[0031] Furthermore, the PLC controller is connected to the motor driver via a network cable, and the stabilizer fin angle signal is transmitted to the motor driver via the Profinet network in the form of a control word.

[0032] Furthermore, in step 4, new position information is generated after the fin stabilizer rotates. The sensor detects the new position information and generates a mechanical fin angle signal. The mechanical fin angle signal is fed back to the PLC controller after signal isolation processing. After receiving the mechanical fin angle signal, the PLC controller first performs filtering processing, then performs fractional-order PID operation, and then goes through the speed control program and the wave level control program to finally generate the fin angle signal and perform closed-loop control of the fin stabilizer.

[0033] The beneficial effects of the present invention are:

[0034] First, the electric-driven fin stabilizer control method of the present invention utilizes a fractional-order PID algorithm, which solves the problems of differential noise and integral saturation compared to traditional PID algorithms, providing more stable and reliable ship roll control. Compared to traditional hydraulically driven fin stabilizers, the electric-driven fin stabilizer control method of the present invention shortens the entire process from ship attitude input to control solution and command output, and then to fin rotation, thereby increasing the speed of fin stabilizer control and thus improving the roll reduction effect of the stabilization device.

[0035] Second, the electric-driven fin stabilizer control method of the present invention adds a speed adjustment program and a wave level adjustment program after the fractional-order PID calculation. Under different sea conditions, the ship's speed is kept constant and the stability of the ship is increased by controlling the fin stabilizers.

[0036] Third, the electrically driven fin stabilizer control method of the present invention feeds back the state of the fin stabilizer after rotation to the controller in the form of a mechanical fin angle signal, which participates in the adjustment of the control signal and forms a position feedback loop for the fin stabilizer. This eliminates the angular deviation of the fin angle caused by operating time and ensures the accuracy of the fin angle. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] FIG1 is a schematic diagram of a closed-loop feedback control operation of an electric drive fin stabilizer control method according to an embodiment of the present invention;

[0038] FIG2 is a schematic diagram of internal communication of a method for controlling an electric-driven fin stabilizer according to an embodiment of the present invention. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the technical solution of the present application, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0040] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present invention and the features therein can be combined with each other without conflict.

[0041] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0042] Example 1:

[0043] As shown in FIG1 and FIG2 , this embodiment controls the ship's fin stabilizers based on the stabilization mode in the electric drive fin stabilizer control method. The method includes the following steps:

[0044] Step 1: Use a gyroscope to detect the ship's attitude information and generate a ship attitude signal. The ship attitude signal is input into the PLC controller after signal isolation processing.

[0045] The ship is equipped with a gyroscope for detecting the required input signal, and the gyroscope has a sensor for measuring the ship's attitude data.

[0046] The ship's control module uses a PLC controller, which is connected to the gyroscope and receives the analog ship attitude signal from the gyroscope. Because the ship's control cabin is an environment with severe signal interference, the ship's electronic and communication equipment generate electromagnetic radiation, which interferes with nearby electronic equipment. The power system also experiences electrical interference, and electromagnetic radiation or induction from cables and transmission lines can also interfere with surrounding equipment. Therefore, a signal isolation module is introduced during the process of sending the gyroscope's input signal to the PLC controller. This module isolates and protects the ship's attitude signal from interference, preventing interference signals from entering the PLC controller and ensuring that the PLC receives complete, accurate, and realistic ship attitude signals.

[0047] Step 2: After receiving the ship attitude signal, the PLC controller first filters the signal, then performs fractional-order PID calculation, and then goes through the speed adjustment program and the wave level adjustment program to finally generate the fin stabilizer angle signal;

[0048] PLC controllers support fractional-order PID control, a control algorithm based on fractional-order calculus that achieves precise system control. Compared to traditional integer-order PID controllers, fractional-order PID controllers incorporate the concept of fractional-order calculus, making them more adaptable to nonlinear and time-varying systems.

[0049] In step 2.1, the PLC controller receives the isolated ship attitude signal, filters the ship attitude signal and performs fractional-order PID operation.

[0050] The filtering method uses arithmetic mean filtering to reduce noise and fluctuations in the signal. After filtering, the ship attitude signal produces a relatively smooth ship body angular velocity signal and a signal containing angle information. These signals serve as input signals for ship roll reduction control. A fractional-order PID operation is performed on the filtered angular velocity signal to produce a fin angle signal. The angle information signal is used in subsequent wave level adjustment.

[0051] The filtering form is arithmetic mean filtering, and the output signal after filtering is:

[0052] Among them, U0 is the filtered ship attitude signal, U I is a series of consecutive sampling values ​​of the original ship attitude signal, and n is the number of sampling values. The filtered signal is the sum of the multiple sampling values ​​of the original signal divided by the number of sampling values. In other words, the arithmetic mean of the sampling values ​​is taken as the filtered signal value. By taking the average value, random noise in the original signal can be offset, resulting in a smoother signal.

[0053] To perform a fractional-order PID operation, the first step is to determine the desired target attitude of the ship and set the target attitude. For example, if the ship needs to maintain a level attitude, the target attitude is a roll angle and a pitch angle of zero. Then, the fractional-order PID operation is performed. Based on the angular velocity signal and the target attitude, the proportional term, the integral term, and the differential term are calculated respectively, and they are added together to obtain the final fin stabilizer angle signal. The transfer function of the fractional-order PID controller is:

[0054] Where C(s) represents the transfer function of the fractional-order PID, s is a complex frequency domain variable, and K P is the proportional gain, K i is the integral gain, K d is the differential gain, γ is the integration order, and μ is the differentiation order.

[0055] The time domain analysis of fractional-order PID is as follows: u(t)=K P e(t)+K i I γ e(t)+K i D μ e(t)

[0056] Among them, u(t) represents the fin angle signal output after the fractional-order PID operation, e(t) is the angular velocity signal, and the fractional-order PID includes the proportional K in the time domain. P , integral K i I γ and differential K i D μ Three links.

[0057] The above formula is used to perform calculations to solve the problems of differential noise and integral saturation in traditional PID control, making the anti-roll control more stable and reliable.

[0058] Step 2.2: After the fractional-order PID operation, a speed adjustment program and a wave level adjustment program are added to adjust the output signal after the fractional-order PID operation according to the current ship speed and sea conditions;

[0059] The speed is adjusted first and then the wave level is adjusted. According to the current speed and movement state of the ship, the rotation angle of the anti-roll fin is adjusted to increase the stability of the ship while ensuring the speed and efficiency of the ship. It is suitable for navigation tasks that require speed and fuel saving.

[0060] The main goal of speed regulation is to adjust the fin angle while maintaining the ship's speed to ensure smooth operation. To achieve this goal, a speed regulation program is introduced to monitor the current speed of the ship and adjust the anti-roll fin angle signal obtained by PID calculation to make the fin rotation angle adapt to the speed.

[0061] The vessel is equipped with a speed log. The serial data interface of the PLC controller's communication module uses RS485 as the standard, communicating with the speed log. The PLC controller receives the speed signal detected by the speed log. The signal generated by the fractional-order PID calculation is then inversely squared to control the lift applied to the vessel. During navigation, the lift generated by the fins is proportional to the square of the vessel's speed. When the fin stabilizers are operating, the lift generated by the fins increases with increasing speed. When the electric-driven fin stabilizers utilize closed-loop fin angle control, the system ultimately converts the fin angle to an angle opposite to the wave inclination, thereby achieving the desired roll reduction. If the fin angle remains unchanged when the speed exceeds the design speed, the lift generated will be higher than required in the current sea conditions, making the vessel unstable. Therefore, speed control is required after the PID calculation, so that the fin angle varies inversely with the square of the speed to ensure consistent lift at different speeds. When the speed drops below 4 kn, the fin angle is reset to zero and the system shuts down. The speed control rules are as follows:

[0062] Among them, V is the current speed, V0 is the target speed, F is the lift generated by the fin, U Fmax is the fin stabilizer angle signal after inverse square adjustment.

[0063] The signal output after the fractional-order PID operation is subjected to inverse square adjustment and then subjected to the wave level adjustment program. The ultimate goal of the wave level adjustment is to control the fin angle so that the probability of exceeding the trinity value of the fin angle is no more than 13.5%.

[0064] In order to realize the statistics of the probability of the fin angle exceeding the threshold, the difference between the probability of the maximum fin angle exceeding the set maximum fin angle and the design expected probability and the residual roll angle of the ship are used as the input of the fuzzy control, and the output is the wave level adjustment coefficient. The membership function of the fuzzy controller is a trigonometric function, the output is the center of gravity method, and the setting rules and thresholds are:

[0065] Input 1: The ship's roll angle value is divided into 7 fuzzy subsets, with the domain being [-3, 3];

[0066] Input 2: The fin rotation angle percentage is divided into 7 fuzzy subsets with a domain of [0, 1];

[0067] Output wave level adjustment coefficient: The wave level adjustment coefficient is divided into 7 fuzzy subsets, and the domain is [0, 2].

[0068] The residual roll angle of a ship refers to the difference between the actual roll angle of the ship and the set value after a given roll angle setting value is given. In other words, it refers to the roll angle of the ship after the fin stabilizers are working, relative to the roll angle of the ship before roll reduction. The ship roll angle is obtained from the filtered ship attitude signal collected by the gyroscope.

[0069] When the ship's residual roll angle is greater than the design value and the fin angle has not reached the maximum fin rotation angle, the wave level adjustment coefficient can be increased, the fin rotation angle value can be increased, and the fin angle saturation rate can be adjusted to improve the roll reduction effect. When the ship's residual roll angle is greater than the design value, the fin angle has reached the maximum fin rotation angle, and the fin angle saturation rate is greater than the set value, the wave level adjustment coefficient can be reduced to reduce the fin angle saturation rate to the set value to reduce equipment wear. When the ship's residual roll angle is less than the design value and the fin angle saturation rate is less than or equal to the design value, the wave level adjustment coefficient remains unchanged. When adjusting the fin angle saturation rate, it is necessary to comprehensively consider the characteristics of the ship, sea conditions, and the capabilities of the control system. If the fin angle saturation rate is set too low, the wave level adjustment coefficient's ability to adjust may be limited, resulting in ineffective control of the ship's attitude. Conversely, if the fin angle saturation rate is set too high, it may cause control system instability or over-regulation. Therefore, actual testing and verification are necessary to find the fin angle saturation rate that is suitable for the ship to achieve good wave level adjustment. For this embodiment, the simulation test results are as follows. Tables 1 and 2 show the statistical data of the ship's irregular wave level adjustment under different sea conditions.

[0070] Table 1

[0071] Table 2

[0072] When the wave level adjustment coefficient increases, the fin stabilizer angle signal will increase. In this case, the fin stabilizer angle signal is multiplied by a coefficient greater than 1 during calculation. When the wave level adjustment coefficient decreases, the fin stabilizer angle signal will decrease. In this case, the fin stabilizer angle signal is multiplied by a coefficient less than 1 and greater than 0 during calculation. If the wave level adjustment coefficient remains unchanged, the fin stabilizer angle signal remains unchanged.

[0073] From the data in Table 1 and Table 2, it can be seen that in the design sea condition H 1 / 3 =3.0m, β=90° and H 1 / 3 =3.0m, β=76.7° resonant heading angle, with or without wave level adjustment, the fin angle saturation rate and anti-rolling effect are similar; when the input sea state is lower than the design sea state, both the fin angle saturation rate and anti-rolling effect are significantly improved; when the sea state is greater than the design sea state H 1 / 3 =3.0m, β=90° and H 1 / 3=3.0m, β=76.7° resonant heading angle navigation, without starting the wave grade regulator fin angle saturation rate is greater than 46.5% and reaches more than 49.0%. After starting the wave grade regulator, the average fin angle saturation rate can be reduced to below 46.5%, indicating that the wave grade regulator design plays a good regulatory role.

[0074] The PLC controller outputs the fin-stabilizing angle signal after speed adjustment and wave level adjustment.

[0075] Step 3: The servo driver receives the fin stabilizer angle signal output by the PLC controller, controls the servo motor to rotate according to the fin stabilizer angle signal, and the servo motor drives the fin stabilizer to work.

[0076] The PLC controller's built-in network port is connected to the switch via a network cable. The Ethernet card port installed in the servo drive is also connected to the switch via a network cable. The servo drive receives the stabilizer fin angle signal from the PLC controller via the Ethernet card. This stabilizer fin angle signal is then transmitted to the servo drive via the PROFINET network in the form of a control word, which controls the servo motor. PROFINET is an Ethernet-based industrial communication protocol used for real-time data communication, equipment control, and monitoring in industrial automation and control systems. Switches provide faster data transmission and improved network security. Using a switch increases the transmission speed and security of the stabilizer fin angle signal, improving control speed and accuracy. The output stabilizer fin angle signal is limited and converted into a control word for Ethernet communication with the servo drive.

[0077] Step 4: The high-precision rotary potentiometer detects the position information of the fin stabilizer after rotation and generates a mechanical fin angle signal. The mechanical fin angle signal is fed back to the PLC controller to further control the rotation of the fin stabilizer.

[0078] The high-precision rotary potentiometer installed at the end of the actuator detects the position information after the fin stabilizer changes, converts it into a mechanical fin angle signal, and then feeds it back to the PLC controller through the signal isolation module. The mechanical fin angle signal is an analog signal.

[0079] The mechanical fin angle signal is first filtered in the PLC controller, then subjected to fractional-order PID calculation, and finally the speed adjustment program and wave level adjustment program are carried out to finally output the fin angle signal, which is used to perform closed-loop adjustment on the fin stabilizer.

[0080] In this embodiment, the PLC controller processes the ship attitude signal and the mechanical fin angle signal using cascaded PID control, where the output of one PID controller serves as the input of the other. The control process for the attitude signal and the mechanical fin angle signal in this embodiment is broken down into two levels: first, a fractional-order PID operation is performed on the ship attitude signal, and then a fractional-order PID operation is performed on the mechanical fin angle signal, with each level performing control and adjustment.

[0081] The PLC controller outputs the fin stabilizer angle signal to control the operation of the ship's fin stabilizer, and the mechanical fin angle signal after the ship's fin stabilizer is isolated is fed back to the PLC controller. This forms a position closed-loop feedback control, which prevents the fin angle from shifting over time during operation, and achieves the target fin angle more accurately, as shown in Figure 1. This ensures that the fin speed and position accuracy of the electric fin stabilizer are within the required range.

[0082] Example 2:

[0083] This embodiment controls the ship's fin stabilizers based on the oscillation mode in the electric drive fin stabilizer control method, that is, controls the fin stabilizers using oscillation signals. The method includes the following steps:

[0084] Step A: Use a PLC controller to generate a vibration signal.

[0085] A sine wave signal is a sinusoidal signal generated by programming within a PLC controller, with adjustable amplitude and period. A sine wave signal is a periodic, continuous signal with a smooth waveform, requiring no filtering. The sine wave signal can be generated within the PLC by programming commands and parameters. The amplitude can be adjusted by adjusting the output voltage of the PLC's output module, and the signal period can be adjusted by setting parameters in a timer or counter.

[0086] Step B: The PLC controller performs a speed adjustment process on the fin swing signal, and after adjustment, generates a fin swing angle signal which is input into the motor driver;

[0087] According to the requirements of the ship and the specific application, a suitable target speed is set, the current speed is compared with the target speed, and then the swing signal is adjusted. After adjustment, the swing fin angle signal is generated and input into the servo drive through the Profinet network.

[0088] The oscillation signal is adjusted according to the current speed of the ship and the target speed. The fin angle is adjusted while maintaining the ship's speed to make the ship run smoothly and the fin rotation angle adapt to the speed.

[0089] The PLC controller communication module receives the detected speed signal from the odometer installed on the ship. Combined with the speed signal, it adjusts the vibration signal in inverse proportion to the square, controlling the lift force on the ship so that the fin angle changes in inverse proportion to the square of the speed, ensuring the same lift at different speeds. Similarly, when the speed drops below 4kn, the fin angle must be reset to zero and the controller shuts down. The speed adjustment formula is as follows:

[0090] Among them, V is the current speed, V0 is the target speed, F is the lift generated by the fin, U F U′ is the live signal. Fmax The fin angle signal is generated by performing inverse square adjustment on the shaking signal.

[0091] Step C: The servo driver controls the servo motor to rotate according to the received fin stabilizer angle signal, thereby driving the fin stabilizer to rotate.

[0092] A closed-loop position feedback loop is established between the servo drive and the servo motor. The servo motor is equipped with a multi-turn absolute encoder, which connects to the encoder card installed on the servo drive, forming a closed-loop position feedback control loop. The fin stabilizer rotates, generating new position information. This new position information is detected by the absolute encoder and fed back to the servo drive. This closed-loop position control improves fin angle accuracy.

[0093] The life signal and the ship attitude signal are mutually exclusive. The PLC controller can only choose one of the two to process when processing the signal. In practice, it is necessary to set up an internal program according to the ship's own conditions and working conditions to determine the type of signal to be processed.

[0094] In summary, the electric-driven fin stabilizer control method of the present invention is used on a ship. The PLC controller receives the ship attitude signal from the sensor after signal isolation, performs fractional-order PID calculation after filtering, and then passes the signal through the speed control program and the wave level control program to finally generate a fin stabilizer angle signal. The motor driver controls the motor to drive the fin stabilizer to rotate to a specified position based on the received fin stabilizer angle signal. The PLC controller also receives the current mechanical fin angle signal detected by the sensor to perform closed-loop control of the fin stabilizer. The PLC controller can also generate a swing signal inside the PLC controller. The swing signal generates a swing fin angle signal after passing through the speed control program. The swing fin angle signal also controls the motor to rotate the fin stabilizer to a specified position.

[0095] Compared with the traditional hydraulically driven fin stabilizer method, the electrically driven fin stabilizer control method of the present invention no longer uses a hydraulic oil circuit to control the fin stabilizers, can eliminate oil contamination, and improve the degree of automation of fin stabilizer control. It also has a simple structure, high reliability, and is easy to install and debug. It is particularly suitable for small ships with short rolling periods.

[0096] In the present invention, terms such as "installed," "connected," "connected," and "fixed" should be understood broadly. For example, "connected" may refer to a fixed connection, a detachable connection, or an integral connection; and "connected" may refer to a direct connection or an indirect connection via an intermediary. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0097] The shapes of the various components in the drawings are schematic, and certain differences from their actual shapes are not excluded. The drawings are only used to illustrate the principles of the present invention and are not intended to limit the present invention.

[0098] Although the present invention has been disclosed in detail with reference to the accompanying drawings, it should be understood that these descriptions are merely illustrative and are not intended to limit the application of the present invention. The scope of the present invention is defined by the appended claims and includes various modifications, variations, and equivalents made to the invention without departing from the scope and spirit of the present invention.

Claims

1. An electric drive fin stabilizer control method, the method is used on a ship, the ship is equipped with a sensor, a PLC controller, and a motor driver; It is characterized in that The electric drive fin stabilizer control method comprises the following steps: Step 1, the sensor detects the ship attitude information and generates a ship attitude signal, and the ship attitude signal is input into the PLC controller after signal isolation processing; Step 2: After receiving the ship attitude signal, the PLC controller first performs filtering, then performs fractional-order PID calculation, and then goes through the speed adjustment program and the wave level adjustment program to finally generate the fin angle signal; Step 3: The motor driver receives the fin stabilizer angle signal sent by the PLC controller, controls the motor to rotate, and the motor drives the fin stabilizer to rotate to a specified position; Step 4: The sensor detects the position information of the fin stabilizer after rotation and generates a mechanical fin rotation angle signal, and the generated mechanical fin rotation angle signal is fed back to the PLC controller to further control the rotation of the fin stabilizer.

2. The electric drive fin stabilizer control method according to claim 1, characterized in that: The electric drive fin stabilizer control method further comprises: The PLC controller is programmed to generate a swing signal, which is then converted into a fin angle signal after passing through a speed control program. The PLC controller inputs the fin angle signal into a motor driver to control the motor to rotate, thereby driving the fin stabilizer to rotate to a specified position.

3. The electric drive fin stabilizer control method according to claim 1, characterized in that: The signal isolation processing is used to isolate and protect the ship attitude signal from interference from various factors inside or outside the ship, and differential signal isolation is used to offset common mode interference to ensure that the PLC controller receives a complete and accurate ship attitude signal.

4. The electric drive fin stabilizer control method according to claim 1, characterized in that: The filtering process is in the form of arithmetic mean filtering. After the arithmetic mean filtering of the ship attitude signal, the signal extracted is smoother. The formula is as follows: Among them, U0 is the filtered ship attitude signal, U1 is the continuous multiple sampling values ​​of the original ship attitude signal, n is the number of sampling values, and the filtered signal is the sum of multiple sampling values ​​of the original signal divided by the number of sampling values. The filtered ship attitude signal includes an angular velocity signal and a signal containing angle information.

5. The electric drive fin stabilizer control method according to claim 4, characterized in that: The fractional-order PID calculation method for the ship attitude signal comprises: First, determine the desired target attitude of the ship, and then use the transfer function of fractional-order PID control to calculate the ship attitude signal. According to the ship attitude signal and the target attitude, calculate the proportional term, integral term and differential term respectively, and add them to get the final fin angle signal. The fractional-order PID control transfer function is: Where C(s) represents the transfer function of the fractional-order PID, s is a complex frequency domain variable, and K P is the proportional gain, K i is the integral gain, K d is the differential gain, γ is the integration order, and μ is the differential order; The time domain analysis of fractional-order PID is expressed as follows: u(t)=K P e(t)+K i I γ e(t)+K i D μ e(t) Among them, u(t) represents the fin angle signal output after fractional-order PID operation, e(t) is the angular velocity signal, and the fractional-order PID includes the proportional K in the time domain. P , integral K i I γ and differential k i D μ Three links.

6. The electric drive fin stabilizer control method according to claim 5, characterized in that: The speed regulation is to adjust the fin angle signal generated after the fractional-order PID operation, which can increase the stability of the ship while ensuring the speed and efficiency of the ship; The PLC controller receives the speed signal detected by the external device, and adjusts the anti-roll fin angle signal obtained by the fractional-order PID operation in inverse square proportion based on the speed signal. When the speed is lower than 4kn, the fin angle needs to be reset to zero and shut down. The speed adjustment rules are as follows: Among them, V is the current speed, V0 is the target speed, F is the lift generated by the fin, U Fmax It is the fin angle signal after inverse square adjustment.

7. The electric drive fin stabilizer control method according to claim 1, characterized in that: The wave level adjustment is performed after the speed adjustment, and the wave level adjustment is to adjust the angle signal of the fin stabilizer after the speed adjustment according to the sea conditions; When the residual roll angle of the ship is greater than the design value, the fin angle has not reached the maximum fin turning angle, the wave grade adjustment coefficient is increased, and the roll reduction fin turning angle signal increases; when the residual roll angle of the ship is greater than the design value, the fin angle has reached the maximum fin turning angle and the fin angle saturation rate is greater than the set value, the wave grade adjustment coefficient is reduced, and the roll reduction fin turning angle signal decreases; when the residual roll angle of the ship is less than the design value, the fin angle saturation rate is less than or equal to the design value, and the wave grade adjustment coefficient remains unchanged, the roll reduction fin turning angle signal remains unchanged.

8. The electric drive fin stabilizer control method according to claim 1, characterized in that: The PLC controller is connected to the motor driver via a network cable, and the anti-roll fin angle signal is transmitted to the motor driver via a PROFINET network in the form of a control word.

9. The electric drive fin stabilizer control method according to claim 1, characterized in that: In step 4, new position information is generated after the fin stabilizer rotates, and the sensor detects the new position information and generates a mechanical fin angle signal. The mechanical fin angle signal is fed back to the PLC controller after signal isolation processing. After receiving the mechanical fin angle signal, the PLC controller first performs filtering processing, then performs fractional-order PID operation, and then passes through the speed adjustment program and the wave level adjustment program, and finally generates a fin angle signal to perform closed-loop control on the fin stabilizer.

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