Ship energy feedback suspension system and cooperative control method thereof

Abstract

The application provides a ship energy feedback suspension system and a cooperative control method thereof, and relates to the technical field of ship energy saving and vibration reduction control. The application realizes efficient conversion of wave energy into electric energy and intelligent suppression of ship body movement by integrating a TPMLG as an energy converter and a variable damper, combining three subsystems of energy feedback execution, energy management and cooperative control; the system can realize cooperative control of three modes of energy recovery priority, stable balance priority and high damping priority according to the sea state, and can utilize wavelet analysis and duty cycle adjustment to optimize power generation and vibration reduction performance, thereby synchronously solving key technical problems such as ship energy saving and carbon reduction, endurance improvement and navigation stability.

Description

Technical Field

[0001] This invention relates to the field of ship energy conservation and vibration reduction control technology, specifically to a ship energy-feeding suspension system and its coordinated control method. Background Technology

[0002] With the International Maritime Organization (IMO) imposing increasingly stringent requirements on the Energy Efficiency Index (EEXI) and Carbon Intensity Index (CII) for ships, energy-saving and carbon-reduction technologies for ships have become a research hotspot. Wave-adaptive vessels (WACs) effectively improve seakeeping by isolating the hull from wave excitation through a levitation system. However, existing technologies have the following significant drawbacks:

[0003] Energy waste problem: Traditional passive or semi-active suspension systems dissipate wave-excited energy through springs and dampers. This energy, lost as heat, is not utilized, resulting in significant energy waste. This contradicts the IMO's carbon reduction requirements.

[0004] Limited functionality: Existing suspension systems are mostly designed with a single vibration reduction function, lacking a mechanism to convert abundant wave energy into electrical energy, and thus cannot provide auxiliary power for ships, thereby limiting the improvement of ship endurance and the reduction of carbon emission intensity.

[0005] Energy efficiency versus stability conflict: A few studies have attempted to integrate energy recovery functions into levitation systems, but there is often an inherent contradiction between "high recovery rate" and "excellent vibration reduction effect". For example, reducing system damping in pursuit of high energy recovery will lead to a deterioration of the ship's motion attitude in bad sea conditions, threatening navigation safety; conversely, increasing damping in pursuit of stability will inhibit relative motion, resulting in low energy recovery efficiency.

[0006] Low recovery efficiency: Ship motion has the characteristics of low frequency and large amplitude, which causes a "dead zone" in the commutation phase of traditional energy recovery devices. The actual energy recovery efficiency is only 20%-35% of the theoretical value, which is not economical and practical.

[0007] Therefore, there is an urgent need for a suspension system and its coordinated control method that aims to simultaneously solve the two major problems of ship motion control and energy recovery. Summary of the Invention

[0008] To address the technical problems of existing suspension systems, such as energy waste, limited functionality, conflict between energy efficiency and stability, and low recovery efficiency, this invention provides a ship-powered suspension system based on a cylindrical permanent magnet linear generator (TPMLG) and a collaborative control method.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] A ship-powered levitation system, the system comprising:

[0011] The energy feeding subsystem includes the main hull, forward arch, aft arch, energy feeding suspension mechanism, propulsion nacelle, rigid skid plate, and pontoons;

[0012] The energy management subsystem includes a three-phase rectifier circuit, a buck-boost converter, a controller, a coordinator, and an energy storage unit;

[0013] The collaborative control subsystem includes a collaborative control module and a sea state identification and target decision module. The collaborative control module includes a first inertial measurement unit mounted on the main hull for measuring the heave, pitch, and roll motions of the main hull; a second inertial measurement unit mounted on the buoys for measuring the heave, pitch, and roll motions of the buoys; linear grating rulers mounted on each TPMLG for measuring relative displacement and velocity; and voltage or current sensors in the circuitry.

[0014] The sea state identification and target decision module: Based on data measured by the first and second inertial measurement units, it uses wavelet analysis mathematical tools to identify the significant wave height and peak period in real time to obtain the sea state level; it dynamically adjusts the system's working objectives according to the sea state level: In calm sea states, the system prioritizes energy recovery efficiency and adopts MPPT control mode; in moderate sea states, the system introduces a ceiling damping control algorithm on the basis of MPPT control mode, and provides damping force by adjusting the equivalent load resistance of the power generation circuit to achieve a balance between energy recovery and motion suppression; in severe sea states, the system prioritizes stability, switches to high damping mode, and increases the equivalent load resistance to provide a large damping force.

[0015] On the other hand, the present invention also provides a cooperative control method based on the above-mentioned ship energy-feeding levitation system, the method comprising the following steps:

[0016] The collaborative control subsystem includes a collaborative control module that collects ship motion signals and electrical signals from the power generation circuit in real time.

[0017] The motion signal is analyzed using wavelet analysis mathematical tools to identify the current sea state level in real time;

[0018] Based on the sea state level and electrical signals, the system operating mode is dynamically adjusted, switching between energy recovery priority mode, energy stability balance mode and high damping priority mode.

[0019] Based on the final duty cycle obtained in the working module, the equivalent load resistance of TPMLG is dynamically adjusted.

[0020] The system provides feedback based on continuously monitored changes in sea state.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1. Efficient Energy Recovery and Utilization to Solve the Problem of Energy Waste: Existing technologies use traditional passive / semi-active levitation systems that dissipate wave energy as heat through springs and dampers, resulting in significant waste and failing to provide auxiliary power for ships, thus contradicting IMO's carbon reduction requirements. This invention employs a cylindrical permanent magnet linear generator (TPMLG) to directly convert wave vibration energy into electrical energy, achieving high energy conversion efficiency. Combined with maximum power point tracking (MPPT) control technology, it effectively overcomes the commutation "dead zone" problem of traditional devices, increasing the energy recovery rate to over 30% (theoretical value 20%-35%), significantly improving ship endurance. The recovered electrical energy is used to power shipboard equipment or assist propulsion through energy storage units (supercapacitors / lithium batteries), directly reducing carbon emission intensity and meeting IMO's EEXI and CII requirements.

[0023] 2. Multimodal Cooperative Control to Resolve the Conflict Between Energy Efficiency and Stability: Existing technologies for levitation systems with integrated energy recovery suffer from an inherent conflict between "high recovery rate" and "excellent vibration reduction effect." In severe sea conditions, increasing damping to pursue stability leads to low energy recovery efficiency, while conversely, it threatens navigation safety. This invention proposes a sea state adaptive cooperative control strategy, which dynamically switches between three operating modes by identifying sea state levels (calm, moderate, and severe) in real time. By adjusting the equivalent load resistance of the TPMLG power generation circuit, the electromagnetic damping force is controlled in real time, fundamentally resolving the conflict between the goals of "energy recovery" and "motion suppression," achieving optimal performance under all sea states.

[0024] 3. Significantly improved energy recovery efficiency, overcoming the limitations of low-frequency, large-amplitude vibrations: The low-frequency, large-amplitude characteristics of ship motion in existing technologies result in a "dead zone" in the commutation phase of traditional energy recovery devices, with actual efficiency only reaching 20%-35% of the theoretical value, leading to insufficient economic efficiency and practicality. This invention uses a TPMLG as the transducer element, whose structural characteristics (the relative motion between the permanent magnet and the primary coil cutting magnetic field lines) naturally adapt to low-frequency, large-amplitude excitation. Combined with MPPT control technology to dynamically adjust the operating point, it effectively reduces commutation "dead zone" losses, increasing the system's energy recovery rate to over 30%, nearly double that of traditional devices, significantly enhancing economic efficiency and practicality.

[0025] 4. Enhanced Ship Stability and Comfort, Ensuring Safety in Harsh Sea Conditions: Traditional suspension systems suffer from insufficient damping in harsh sea conditions, leading to violent hull movements that threaten navigational safety and passenger comfort. This invention switches to a high-damping mode in harsh sea conditions, increasing the equivalent load resistance of the TPMLG power generation circuit to provide variable damping force far exceeding that of passive dampers. This significantly suppresses hull heave, pitch, and roll movements, greatly improving operational safety and passenger comfort while also meeting energy recovery requirements.

[0026] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the installation structure of the energy-feeding levitation system according to the present invention on a catamaran.

[0028] Figure 2 This is a diagram illustrating the energy-feeding suspension mechanism according to the present invention;

[0029] Figure 3 This is a structural diagram of a cylindrical permanent magnet linear generator (TPMLG) according to the present invention;

[0030] Figure 4 This is a circuit block diagram of the energy management subsystem according to the present invention;

[0031] Figure 5 This is a flowchart of the collaborative control method for a ship energy-feeding levitation system according to the present invention.

[0032] Figure label:

[0033] 1-1. Main hull; 1-2. Forward arch; 1-3. Aft arch; 1-4. Energy feeding suspension mechanism; 1-5. Propulsion nacelle; 1-6. Rigid sliding plate; 1-7. Float; 2-1. Rocker arm; 2-2. Leaf spring; 2-3. Cylindrical permanent magnet linear generator; 3-1. Primary sleeve; 3-2. Primary coil; 3-3. Vibration damper shaft; 3-4. Secondary shaft; 3-5. Permanent magnet; 4-1. First inertial measurement unit; 4-2. Second inertial measurement unit; 4-3. Linear grating ruler; 4-4. Energy management subsystem. Detailed Implementation

[0034] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings, so as to more clearly understand the purpose, features and advantages of this invention. It should be understood that the embodiments shown in the drawings are not intended to limit the scope of this invention, but are only for illustrating the essential spirit of the technical solutions of this invention. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0035] Unless the context requires otherwise, throughout the specification and claims, the word “comprising” and its variations, such as “including” and “having”, shall be understood to have an open, inclusive meaning, that is, to be interpreted as “including, but not limited to”.

[0036] Throughout this specification, references to "an embodiment" or "an embodiment" indicate that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Therefore, the appearance of "in an embodiment" or "an embodiment" in various places throughout the specification does not necessarily refer to the same embodiment. Furthermore, a particular feature, structure, or characteristic may be combined in any manner in one or more embodiments.

[0037] The singular forms “a” and “the” used in this specification and the appended claims include plural references unless otherwise expressly stated herein. It should be noted that the term “or” is generally used to mean “and / or” unless otherwise expressly stated herein.

[0038] In the following description, in order to clearly demonstrate the structure and working method of the present invention, a number of directional terms will be used. However, terms such as "front", "back", "left", "right", "outside", "inside", "outward", "inward", "up", and "down" should be understood as convenient terms and not as limiting terms.

[0039] The implementation details of the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following content is only for the convenience of understanding the implementation details and is not necessary for implementing this solution.

[0040] As ship technology continues to pursue high efficiency, energy conservation, safety, and stability, existing ship suspension systems have revealed numerous pressing problems in meeting the increasingly stringent energy efficiency and carbon intensity requirements of the International Maritime Organization. The unnecessary dissipation of wave-excited energy by traditional passive or semi-active suspension systems not only results in enormous energy waste but also contradicts carbon reduction goals. The limitations of single vibration damping functions make it difficult to convert abundant wave energy into auxiliary ship power, restricting the potential for increased range and reduced carbon emissions. Furthermore, research integrating energy recovery functions is mired in the dilemma of achieving both high recovery rates and excellent vibration damping effects, making it difficult to balance navigation safety and energy recovery efficiency in harsh sea conditions. In addition, the low-frequency, high-amplitude characteristics of ship motion lead to a "dead zone" problem in the reversing of traditional energy recovery devices, resulting in actual recovery efficiency far below theoretical values, significantly reducing economic viability and practicality. Against this backdrop, this invention innovatively proposes a ship energy feeding suspension system and a collaborative control method based on a cylindrical permanent magnet linear generator (TPMLG), aiming to simultaneously overcome the two key technical bottlenecks of ship motion control and energy recovery.

[0041] Example 1

[0042] This invention provides a ship-powered levitation system, the core of which lies in integrating a TPMLG (Transient Power Medium Gauge) as an energy converter and variable damper into the ship's levitation system. Through ingenious mechanical structure and control strategies, it achieves the conversion of mechanical energy into electrical energy, while simultaneously generating adjustable damping force to suppress hull motion. The ship-powered levitation system includes a power-feeding execution subsystem, an energy management subsystem, and a cooperative control subsystem.

[0043] Specifically, in conjunction with the appendix Figure 1 and 2 The energy feeding subsystem includes: a main hull 1-1, lower left and right hulls, and a front arch 1-2 and a rear arch 1-3 connecting the main hull 1-1 and the lower left and right hulls. Two sets of energy feeding suspension mechanisms 1-4 connect the front arch 1-2 to the left and right hulls. Each energy feeding suspension mechanism 1-4 includes a cylindrical permanent magnet linear generator (TPMLG) 2-3 and a leaf spring 2-2 installed in parallel with it. Wave excitation causes relative motion between the hulls and the main hull, driving the rocker arm to rotate along the pin between itself and the rigid sliding plate, compressing or stretching the damper shaft, and driving the TPMLG to generate electricity.

[0044] In some embodiments, the energy feeding execution subsystem of the ship's energy feeding suspension system can be applied to a catamaran, which includes a main hull 1-1, a forward arch 1-2, a rear arch 1-3, an energy feeding suspension mechanism 1-4, a propulsion nacelle 1-5, a rigid sliding plate 1-6, and a float 1-7. The main hull 1-1 is fixedly connected to the rear arch 1-3, and the main hull 1-1 and the forward arch 1-2 are connected in the longitudinal direction by a ball joint mechanism. In one case, the ball joint mechanism includes a ball head rod installed on the main hull 1-1 and a ball socket installed on the forward arch 1-2. The ball head rod and the ball socket are connected as one unit in the longitudinal direction of the hull, thereby allowing a certain angle of rotational movement between the main hull 1-1 and the forward arch 1-2. In this way, the main hull 1-1 and the forward arch 1-2 can absorb and buffer at least some wind and wave loads and / or external stresses through the movement of the connection point, avoiding the generation of excessive structural internal forces. The pontoon 1-7 extends along the longitudinal axis of the ship. The rigid sliding plate 1-6 is fixed to the pontoon 1-7, and the propulsion nacelle 1-5 is installed at the stern of the rigid sliding plate 1-6. The aft arch 1-3 and the rigid sliding plate 1-6 are connected by two mutually perpendicular bearings. One bearing allows the aft arch 1-3 to rotate at a certain angle relative to the pontoon 1-7 in the horizontal plane, and the other bearing allows the aft arch 1-3 to rotate at a certain angle relative to the pontoon 1-7 in the longitudinal plane. The specific connection structure between the aft arch 1-3 and the rigid sliding plate can be found in the prior application CN108116635A, and will not be elaborated here. This allows for two degrees of freedom between the aft arch 1-3 and the rigid sliding plate 1-6: rotation in the longitudinal plane along the ship's length and rotation in the horizontal plane. Preferably, the pontoon 1-7 is a flexible inflatable pontoon.

[0045] Please refer to the attached image. Figure 2 The energy-feeding suspension mechanism 1-4 is an active suspension mechanism, specifically including a rocker arm 2-1, a leaf spring 2-2, and a cylindrical permanent magnet linear generator TPMLG 2-3. The rocker arm 2-1 is connected to the rigid slide plate 1-6 by a transverse pin and can rotate around a horizontal direction perpendicular to the ship's length. The leaf spring 2-2 and TPMLG 2-3 are respectively connected between the rocker arm 2-1 and the rigid slide plate 1-6 by transverse pins and support the rocker arm 2-1 in an upward tilting posture. The front arch 1-2 is connected to the rocker arm 2-1 by a ball joint mechanism in the vertical direction. The leaf spring 2-2 and TPMLG 2-3 are installed in parallel. Their main function is to bear the static load of the hull and provide basic positioning stiffness for the system. On the other hand, when the waves excite the float 1-7, the leaf spring 2-2 buffers the wave impact and stores some of the wave's kinetic energy. On the other hand, when the buoy 1-7 is excited by waves, the front arch 1-2 and the rigid slide plate 1-6 compress or stretch the rocker arm 2-1, the rocker arm 2-1 rotates around the pin shaft, and compresses or stretches the leaf spring 2-2 and TPMLG 2-3 to generate electricity.

[0046] In some embodiments, the cylindrical permanent magnet linear generator TPMLG 2-3 serves as a damper for the active suspension mechanism, and its specific structure is shown in the attached figure. Figure 3 As shown, it mainly consists of a primary sleeve 3-1, a primary coil 3-2, a damper shaft 3-3, a secondary shaft 3-4, and permanent magnets 3-5. The primary sleeve 3-1 is connected to a rigid sliding plate 1-6 via a pin; the primary coil 3-2 is fixedly installed in the groove of the primary sleeve 3-1; the permanent magnets 3-5 are evenly distributed and fixed on the secondary shaft 3-4, which is fixed to the damper shaft 3-3. The secondary shaft 3-4 and permanent magnets 3-5 are fitted inside the primary coil 3-2 and are fixedly connected. The damper shaft 3-3 is connected to a rocker arm 2-1 via a pin; the damper shaft 3-3 is connected to the front arch 1-2 via the rocker arm 2-1 and a ball joint mechanism. When waves cause relative motion between the main hull and the plate, the permanent magnets 3-5 of the TPMLG 2-3 and the primary coil 3-2 generate relative motion that cuts magnetic field lines, thereby generating electricity. On the other hand, changing the equivalent load resistance of the circuit can also change the damping force of the TPMLG 2-3, thereby achieving motion suppression and improving the ride comfort of the main hull.

[0047] In some embodiments, the ship-powered levitation system includes an energy management subsystem for efficiently recovering energy generated by wave excitation during navigation and for performing refined power management, such as... Figure 4As shown, the energy management subsystem 4-4 includes a three-phase rectifier circuit, a buck-boost converter, a controller (including a maximum power point tracking (MPPT) controller and a damping controller), a coordinator, and an energy storage unit (such as a supercapacitor or a lithium battery).

[0048] Specifically, the three-phase rectifier circuit is responsible for converting the alternating current (AC) generated by the cylindrical permanent magnet linear generator (TPMLG) into direct current (DC). Since the TMLG continuously generates AC under wave excitation, while the subsequent energy storage and management system requires a stable DC input, the three-phase rectifier circuit is the primary step in the energy conversion process.

[0049] Buck-Boost Converter: Rectified DC power may be unstable and cannot be directly used for energy storage or power supply. A buck-boost converter, by adjusting its duty cycle, can flexibly adjust the output voltage, ensuring a stable DC voltage suitable for subsequent circuits regardless of changes in the TPMLG's power generation status.

[0050] Controller: This section includes the maximum power point tracking (MPPT) controller and the damping controller.

[0051] MPPT Controller: The MPPT controller monitors the output power of the TPMLG in real time and dynamically adjusts the parameters of the buck-boost converter to ensure that the TPMLG always operates near its maximum power point, thereby maximizing energy capture efficiency. This is crucial for maintaining efficient energy recovery under different sea states and wave conditions.

[0052] Damping Controller: The damping controller, based on the ship's motion state and needs, adjusts the damping force generated by the TPMLG to suppress excessive hull movement, thereby improving navigation stability and comfort. Simultaneously, the adjustment of the damping force indirectly affects the efficiency of energy recovery, requiring the finding of an optimal balance between the two.

[0053] Coordinator: This module is responsible for resolving potential command conflicts between the MPPT controller and the damping controller. Based on the instructions from the sea state identification and target decision module, it outputs a unified duty cycle signal to the buck-boost converter, which simultaneously accommodates maximum power point tracking and the generation of the desired damping force.

[0054] Energy storage unit: The energy storage unit uses high-performance supercapacitors or lithium batteries to store recovered electrical energy. These energy storage components have high energy density, long lifespan, and fast charge / discharge capabilities, which can meet the continuous power supply needs of shipboard equipment (such as navigation and communication equipment), or provide additional power support for auxiliary propulsion systems when needed, directly improving the ship's range and operational efficiency.

[0055] In summary, the AC power generated by the TPMLG is converted into DC power by a three-phase rectifier circuit. The DC power is then processed by a buck-boost converter to charge the energy storage unit. Subsequently, the output signals from the MPPT controller and the damping controller are sent to the coordinator, which generates the final control commands to drive the switching transistors of the buck-boost converter and adjust the duty cycle of the buck-boost converter, ensuring that the TPMLG always operates at its optimal output power. This achieves coordinated control of power generation and vibration reduction, maximizing energy capture efficiency.

[0056] In some embodiments, the ship-powered levitation system includes a cooperative control subsystem, combined with Figure 4 and Figure 5 As shown, the collaborative control subsystem includes a collaborative control module and a sea state identification and target decision module.

[0057] Specifically, the collaborative control module includes a first inertial measurement unit (IMU4-1) installed on the main hull for measuring the heave, pitch, and roll motions of the main hull; a second inertial measurement unit (IMU4-2) installed on the pontoons for measuring the heave, pitch, and roll motions of the pontoons; a linear grating ruler (4-3) installed on each TPMLG for measuring relative displacement and velocity; and voltage / current sensors in the circuit.

[0058] Sea state identification and target decision-making module: such as Figure 5 As shown, based on IMU data, the significant wave height (Hs) and peak period (Tp) are identified in real time using wavelet analysis and other methods. The system's operating objectives are dynamically adjusted according to sea state: In calm sea states (Hs < 1.5m), the system prioritizes energy recovery efficiency, employing the MPPT control mode; in moderate sea states (1.5m ≤ Hs ≤ 4m), the system, based on the MPPT control mode, introduces a skyhook damping control algorithm to provide appropriate damping force by adjusting the equivalent load resistance of the power generation circuit, achieving a balance between energy recovery and motion suppression; in severe sea states (Hs > 4m), the system prioritizes stability, switching to a high-damping mode, increasing the equivalent load to provide strong damping force, significantly suppressing violent hull motion, where energy recovery becomes a secondary objective.

[0059] This embodiment proposes a ship energy feeding and suspension system based on a cylindrical permanent magnet linear generator (TPMLG). This system integrates the TPMLG as an energy converter and variable damper, combined with an energy feeding execution subsystem (containing two energy feeding and suspension mechanisms, each consisting of a TPMLG and a leaf spring in parallel), an energy management subsystem (containing a three-phase rectifier, a step-up / step-down converter, an MPPT / damping controller, and an energy storage unit), and a collaborative control subsystem (containing a sea state recognition and multi-modal control module). This achieves efficient conversion of wave energy to electrical energy and intelligent suppression of ship motion. The system can dynamically switch operating modes according to sea state: prioritizing energy recovery in calm sea states (MPPT control), balancing power generation and vibration reduction in moderate sea states (MPPT + Skyhook damping control), and prioritizing stability in severe sea states (high damping control), thereby simultaneously solving key technical challenges in improving ship energy efficiency and motion control.

[0060] Example 2

[0061] Based on the above embodiment one, this embodiment also proposes a cooperative control method based on the aforementioned ship energy-feeding levitation system, such as... Figure 5 As shown, the specific steps include the following:

[0062] S1. The collaborative control module collects ship motion signals and electrical signals from the power generation circuit in real time.

[0063] Motion signal acquisition: The first inertial measurement unit (IMU4-1) measures the heave, pitch, and roll motion of the main hull; the second inertial measurement unit (IMU4-2) measures the heave, pitch, and roll motion of the pontoons; and the linear grating ruler (4-3) measures the relative displacement and velocity of the cylindrical permanent magnet linear generator (TPMLG).

[0064] Electrical signal acquisition: The output voltage, current and power of the power generation circuit are monitored through voltage / current sensors.

[0065] S2. Analyze the motion signal using wavelet analysis mathematical tools to identify the current sea state level in real time.

[0066] The acquired raw motion signal is subjected to wavelet threshold denoising to eliminate high-frequency noise interference. The time spectrum is generated by continuous wavelet transform (CWT) to identify the dominant frequency component of the signal, the corresponding peak period Tp, and the energy distribution, corresponding to the effective wave height Hs.

[0067] Sea state is classified according to peak period Tp and significant wave height Hs as follows:

[0068] Calm sea state: significant wave height Hs < 1.5m, peak period Tp < 6s;

[0069] Moderate sea state: 1.5m≤Hs≤4m, 6s≤Tp≤8s;

[0070] Severe sea conditions: Hs>4m or Tp>8s.

[0071] S3. Based on the sea state level and electrical signal, dynamically adjust the system's operating mode, switching between energy recovery priority mode, energy stability balance mode, and high damping priority mode.

[0072] Specifically, the core idea of ​​this dynamic adjustment system is to adjust the magnitude of the electromagnetic damping force generated by the TPMLG power generation circuit in real time by controlling the equivalent load resistance of the TPMLG power generation circuit, thereby dynamically adjusting the system's focus between the two objectives of "energy recovery" and "motion suppression" when the sea state changes.

[0073] The basic principle of the dynamic adjustment system's operating mode is based on damping force control, as detailed below:

[0074] When the permanent magnet on the secondary shaft of the TPMLG moves relative to the primary coil, an induced electromotive force is generated in the armature. E :

[0075] E = K e × v

[0076] in, v It is the relative velocity; K e The back electromotive force coefficient, K e It is strongly correlated with design parameters such as permanent magnet magnetization, air gap flux density, and number of turns. It can be obtained through preliminary theoretical estimation or precise finite element simulation, and finally calibrated through bench tests.

[0077] When the generator circuit is closed, the current... I According to Ohm's law, when current flows through the coil, we can obtain:

[0078] I = E / R eq

[0079] in, R eq The equivalent load resistance of the power generation circuit, and the current. I This will generate an electromagnetic damping force that hinders motion. F em :

[0080] F em = K f × I

[0081] in, K f Let be the thrust constant. K f It is strongly correlated with the air gap flux density and the total effective conductor length of the armature winding. It can be obtained through preliminary theoretical estimation or precise finite element simulation, and finally calibrated through bench tests. Ideally, K e ≈ K f .

[0082] By controlling the duty cycle of the subsequent power converter (Buck-Boost circuit) D This can effectively change the equivalent load resistance of the power generation circuit. R eq This changes the power generation current. I To achieve the change of electromagnetic damping force F em .

[0083] Therefore, duty cycle D It becomes a unified control command that simultaneously determines the system's energy recovery power and motion damping characteristics.

[0084] Based on the above fundamental principles, this invention proposes a three-mode switching strategy for dynamically adjusting the system's operating mode: the system identifies sea conditions in real time; if the sea conditions are calm, the MPPT priority mode is activated; if the sea conditions are moderate, the MPPT+Skyhook energy-stability balance mode is activated, with the coordinator integrating the needs of the two controllers; if the sea conditions are severe, the high-damping priority mode is activated, in which the command weight of the damping controller is highest to quickly suppress motion. The derivation process and specific control method are as follows:

[0085] a. Calm sea conditions H s<1.5m, T (p<6s) — MPPT priority mode, where the control objective is to maximize energy recovery efficiency. The control method is as follows:

[0086] 1) MPPT Algorithm: Employs either the "Perturbation and Observation (P&O)" method or the "Incremental Conductivity (InC)" method. The MPPT controller continuously fine-tunes the duty cycle. D and monitor output power P out = V × I The changes.

[0087] 2) Decision logic: If the power increases, continue to perturb in the same direction. DIf the power decreases, a reverse perturbation occurs. Through iteration, the system is brought to operate near its optimum. Specifically, when the MPPT controller adjusts the duty cycle... D After making a small adjustment (i.e., a disturbance), the output power was monitored. P out This indicates the current direction of the disturbance (increasing or decreasing the duty cycle). D The direction (of the rotation) is beneficial for improving energy recovery power. Therefore, we will continue to follow this direction (which is the previous adjustment of the duty cycle). D Further fine-tune the duty cycle (in the same direction). D In order to find the duty cycle that maximizes the output power. D Value. For example, if the first time is to set the duty cycle. D The power increased after the duty cycle was increased from 0.3 to 0.31, so the duty cycle will be increased again next time. D For example, increasing it to 0.32, etc.

[0088] When the MPPT controller adjusts the duty cycle D After making a minor adjustment, the output power was monitored. P out The decrease indicates that the current perturbation direction is unfavorable for improving energy recovery power. Therefore, it is necessary to change the duty cycle. D The direction of adjustment is to perform a reverse disturbance. For example, if the first time is to adjust the duty cycle... D The power decreased after increasing from 0.3 to 0.31, so the duty cycle will be adjusted next time. D By decreasing the value from 0.31, for example, to 0.305, the duty cycle that maximizes output power is found through such reverse adjustments. D value.

[0089] 3) In this mode, the system is equivalent to a variable resistor pursuing maximum power. The damping force generated at this time is a "side effect" of the process of pursuing maximum power and is not actively constrained.

[0090] b. Moderate sea state (1.5m≤ H s≤4m, 6s≤ T (p≤8s) — MPPT+Skyhook energy stability balance mode. The control objective of this mode is to improve comfort by introducing active damping control while ensuring good energy recovery. The control method (hybrid control) is as follows:

[0091] 1) Skyhook damping force calculation:

[0092] Ideal Skyhook damping force F sky : F sky =-C sky × v cabin

[0093] in, C sky This is the ceiling damping coefficient. v cabin This is the absolute velocity of the main hull (sprung mass) (obtained by IMU integration or state observer). This damping force... F sky The physical meaning is that there is a damper connected between the main hull and the stationary "sky" (the "sky" does not refer to the actual atmosphere or outer space, but a virtual, hypothetical fixed reference point) to directly dissipate the kinetic energy of the main hull, thereby effectively suppressing its vibration.

[0094] 2) Target damping force setting:

[0095] Under moderate sea states, we set a target damping force. F desired It can be F sky Or F sky Combined with a fixed damping force.

[0096] 3) Coordinator Algorithm:

[0097] MPPT command: D mppt (From MPPT controller)

[0098] Damping command: D damp ,Depend on F desired This is derived by reverse deduction. Based on... F em = K f ×( K e × v / R eq It can be deduced that... R eq =( K e × K f × v ) / F desired And then according to R eq and D Relationship calculation D damp.

[0099] Coordination Logic: Coordinator Receives D mppt and D damp And output the final duty cycle. D final The coordination strategy adopted is:

[0100] when D mppt and D damp When the differences are small, take the average or prioritize the average value. D damp .

[0101] When the two conflict significantly (e.g., MPPT requires small damping to generate more power, but Skyhook requires large damping to reduce vibration), a weighting factor positively correlated with the severity of sea conditions is introduced. α Perform a weighted average: D final =(1- α )× D mppt + α × D damp The worse the sea conditions, α The larger the value, the more it leans towards damping control.

[0102] c. Severe sea conditions H s>4m or T (p>8s) – High-damping priority mode. The control objective of this mode is to prioritize ship stability, with energy recovery as a secondary objective. The control method is as follows:

[0103] 1) Set the maximum damping coefficient: Directly set a very large target damping coefficient. C max Calculate the target damping force F desired =- C max × v relative ( v relative (Relative speed between the main hull and the hull).

[0104] 2) Calculate the duty cycle: based on F desired Calculate the corresponding D damp The result calculated at this time R eq Typically very small, meaning close to short-circuit power generation, which generates a huge damping force to "lock" the suspension and suppress movement to the maximum extent.

[0105] 3) In this mode, the MPPT controller is completely disabled, and the coordinator outputs directly. D final = D damp .

[0106] S4. Perform dynamic adjustment of the equivalent load resistance of TPMLG.

[0107] The coordinator will D final Send to the buck-boost converter to adjust the equivalent load resistance of the TPMLG generator circuit. R eq Thus controlling the electromagnetic damping force of TPMLG F em In addition, the energy management subsystem optimizes the charging and discharging strategies of the energy storage units (supercapacitors / lithium batteries) according to the current mode to ensure energy recovery and power supply stability.

[0108] S5. Provide system feedback based on monitored sea state changes.

[0109] During this process, the data from the IMU, grating ruler, and circuit sensors are continuously monitored in real time. If a change in sea state is detected, the process returns to step S2 above; otherwise, the process ends.

[0110] This embodiment proposes a collaborative control method based on the aforementioned ship-powered levitation system. This method uses a collaborative control module to collect ship motion signals (IMU data of the main hull / float and relative displacement of the TPMLG) and electrical signals (voltage / current) from the power generation circuit in real time. After identifying the sea state level by combining wavelet analysis, it dynamically switches between three control strategies: in calm sea states, the MPPT priority mode is used to maximize energy recovery; in moderate sea states, the MPPT+Skyhook energy stability balance mode is activated to coordinate power generation and vibration reduction; and in severe sea states, it switches to the high damping priority mode to ensure navigation stability. At the same time, by adjusting the duty cycle of the step-up / step-down converter, the equivalent load resistance of the TPMLG is dynamically controlled to achieve real-time optimization of electromagnetic damping force and power generation efficiency, ultimately achieving a synergistic improvement in ship energy efficiency and motion stability under all sea states.

[0111] This invention provides a ship energy-feeding suspension system and its collaborative control method. By integrating a TPMLG as an energy converter and a variable damper, and combining three subsystems—energy feeding execution, energy management, and collaborative control—it achieves efficient conversion of wave energy to electrical energy and intelligent suppression of ship motion. The system can dynamically switch between three modes according to sea conditions: MPPT priority, energy stability balance, and high damping priority. It also utilizes wavelet analysis and duty cycle adjustment to optimize power generation and vibration reduction performance, simultaneously solving key technical challenges such as ship energy conservation and carbon reduction, improved endurance, and navigation stability.

[0112] Although the present invention has been described in detail with reference to the accompanying drawings and preferred embodiments, the invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the invention by those skilled in the art without departing from the spirit and essence of the invention. Such modifications or substitutions should all fall within the scope of the invention, or any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the invention should be covered within the protection scope of the invention. Therefore, the protection scope of the invention should be determined by the scope of the claims.

Claims

1. A ship feed-energy suspension system, characterized by, The system comprises: The energy feedback execution subsystem comprises a main hull, a front arch, a rear arch, an energy feedback suspension mechanism, a propulsion nacelle, a rigid skateboard and a float; the energy management subsystem comprises a three-phase rectifier circuit, a boost-buck converter, a controller, a coordinator and an energy storage unit; the cooperative control subsystem comprises a cooperative control module and a sea state identification and target decision module; the cooperative control module comprises a first inertial measurement unit installed on the main hull, used to measure the heave, pitch and roll movements of the main hull; a second inertial measurement unit installed on the float, used to measure the heave, pitch and roll movements of the float; a linear grating ruler installed on each cylindrical permanent magnet linear generator, used to measure the relative displacement and speed; and a voltage or current sensor in the circuit; the sea state identification and target decision module, based on the data measured by the first and second inertial measurement units, identifies the significant wave height and peak period in real time through wavelet analysis mathematical tools to obtain the sea state grade; and dynamically adjusts the working target of the system according to the sea state grade: in calm sea conditions, the system prioritizes energy recovery efficiency and adopts the maximum power point tracking control mode; in moderate sea conditions, the system introduces a sky damping control algorithm on the basis of the maximum power point tracking control mode, adjusts the equivalent load resistance of the power generation circuit to provide damping force, and realizes the balance between energy recovery and movement suppression; in severe sea conditions, the system prioritizes stability and switches to a high-damping mode to increase the equivalent load resistance to provide large damping force. The cooperative control method of the ship energy feedback suspension system comprises the following steps: The cooperative control module collects ship movement signals and power generation circuit electrical signals in real time; the movement signals are analyzed based on wavelet analysis mathematical tools to identify the current sea state grade in real time; the system working mode is dynamically adjusted according to the sea state grade and electrical signals, and switched between the energy recovery priority mode, the energy stability balance mode and the high-damping priority mode; the equivalent load resistance of the cylindrical permanent magnet linear generator is dynamically adjusted based on the final duty cycle obtained in the working module; the system is fed back based on the continuously monitored sea state changes; Wherein, the stable equilibrium mode includes: when 1.5m≤ H s≤4m,6s≤ T p≤8s, the sea state level is medium sea state, and the maximum power point tracking + ceiling stable equilibrium mode is adopted, the control target of the mode is to introduce active damping control to improve comfort while ensuring good energy recovery, H s and T p are respectively the effective wave height and peak period obtained by analyzing the motion signal based on wavelet analysis mathematical tools; the control method is as follows: 1) Calculation of the ceiling damping force: ideal ceiling damping force F sky : F sky - C sky x v cabin ; wherein, C sky is the ceiling damping coefficient, v cabin is the absolute velocity of the main hull; the damping force F sky The physical meaning of the damping force is that a damper is assumed to be connected between the main hull and the fixed reference point, which directly dissipates the kinetic energy of the main hull, thereby effectively suppressing its vibration. 2) Target damping force setting: Set a target damping force in medium sea conditions F desired , the F desired is F sky , or F sky in combination with a fixed damping force; 3) Coordinator algorithm: Maximum power point tracking instruction: duty cycle from maximum power point tracking controller D mppt ; Damping command: D damp ; according to F em = K f ×( K e × v / R eq ), derive R eq =( K e × K f × v ) / F desired , and according to the relationship between the equivalent load resistance of the power generation circuit R eq and the duty cycle of the boost-buck converter D , the damping control duty cycle D damp ; wherein, F em is the electromagnetic damping force, K f is the thrust constant, K e is the back electromotive force coefficient, v is the relative speed; Coordination logic: Coordinator receives D mppt and outputs final duty cycle D damp D final The coordination strategy adopted is: when D mppt the difference is not large, take the average or give priority D damp to one of them D damp When the conflict is serious, introduce a weight factor positively related to the severity of sea conditions α , weighted average: D final = (1- α ) × D mppt + α × D damp , the worse the sea conditions, α the larger, the more biased damping control.​ 2. The system of claim 1, wherein, The main hull of the energy feedback execution subsystem is fixedly connected with the rear arch, the main hull and the front arch are connected in the longitudinal direction by a spherical hinge mechanism, the float extends along the longitudinal direction of the ship, the rigid skateboard is fixed to the float, the propulsion nacelle is installed at the tail of the rigid skateboard, and the rear arch and the rigid skateboard are installed by two mutually perpendicular bearings; the energy feedback suspension mechanism is connected between the front arch and the rigid skateboard.

3. The system of claim 2, wherein, The energy feedback suspension mechanism is an active suspension system, comprising a rocker arm, a leaf spring and a cylindrical permanent magnet linear generator, and the leaf spring and the cylindrical permanent magnet linear generator are installed in parallel, characterized in that: the cylindrical permanent magnet linear generator is composed of a primary sleeve, a primary coil, a damper shaft, a secondary shaft and permanent magnets; the primary coil is fixedly installed in the primary sleeve slot, the permanent magnets are uniformly distributed and fixed on the secondary shaft, the secondary shaft is fixed on the damper shaft, and the secondary shaft and the permanent magnets are sleeved in the primary coil and are fixedly connected.

4. The system of claim 3, wherein, The rocker arm is connected to the rigid slide plate by a transverse pin shaft and rotates around a horizontal direction perpendicular to the length of the ship; the plate spring and the cylindrical permanent magnet linear generator are connected to the rocker arm and the rigid slide plate by transverse pin shafts and support the rocker arm in an upwardly inclined posture; the front arch and the rocker arm are connected by a spherical hinge mechanism in the vertical direction; the primary sleeve is connected to the rigid slide plate of the lower piece by a pin shaft; the shock absorber shaft is connected to the front arch through the rocker arm and the spherical hinge mechanism; the shock absorber shaft and the rocker arm are connected by a pin shaft.

5. The system of claim 4, wherein, The energy management subsystem specifically includes: The three-phase rectifier circuit is responsible for converting the alternating current generated by the cylindrical permanent magnet linear generator into direct current; the buck-boost converter outputs stable direct current voltage by adjusting the duty cycle; the controller includes a maximum power point tracking controller and a damping controller: the maximum power point tracking controller dynamically adjusts the parameters of the buck-boost converter by real-time monitoring of the output power of the cylindrical permanent magnet linear generator, so that the cylindrical permanent magnet linear generator operates near the maximum power point; the damping controller adjusts the power generation damping force of the cylindrical permanent magnet linear generator to suppress excessive motion of the main hull according to the motion state and demand of the ship; the coordinator is used to solve the instruction conflict between the maximum power point tracking controller and the damping controller, and outputs a duty cycle signal to the buck-boost converter according to the instructions of the sea state identification and target decision module; the energy storage unit uses supercapacitors or lithium battery energy storage elements to store recovered electrical energy.

6. The system of claim 5, wherein, The basic principle of the dynamic adjustment system working mode is power generation damping force control, which is specifically as follows: When the relative motion between the permanent magnet on the secondary shaft of the cylindrical permanent magnet linear generator and the primary coil occurs, the induced electromotive force is generated in the armature E : E = K e × v When the power generation circuit is closed, current I flows through the coil, according to Ohm's law: I = E / R eq Current I Electromagnetic damping forces that impede movement F em : F em = K f × I By controlling the duty cycle of a boost-buck converter D , equivalently changing the equivalent load resistance of the power generation circuit R eq , thereby changing the power generation current I , achieving changing the electromagnetic damping force F em .

7. The system of claim 6, wherein, The energy recovery priority mode includes: when H s < 1.5m, T p < 6s, the sea state level is calm sea state, a maximum power point tracking control priority mode is adopted, the control target under the mode is to maximize the energy recovery efficiency, and the control method is as follows: 1) Using the maximum power point tracking algorithm, the maximum power point tracking controller continuously fine-tunes the duty cycle D , and monitors the output power P out = V × I of the change; 2) Decision logic: When the maximum power point tracking controller adjusts the duty cycle... D After making a minor adjustment, the output power was monitored. P out The increase indicates that the current perturbation direction is beneficial to improving energy recovery power; the duty cycle should be further fine-tuned according to the perturbation direction. D In order to find the duty cycle that maximizes the output power. D value; When the maximum power point tracking controller makes a slight adjustment to the duty cycle D , the output power is monitored P out If the output power is reduced, it indicates that the current perturbation direction is not conducive to improving the energy recovery power, so the adjustment direction of the duty cycle is changed D , and a reverse perturbation is made to find the duty cycle value that maximizes the output power D ; Through iteration, the system works near the optimal point. Through iteration, the system works near the optimal point.

8. The system of claim 7, wherein, The high-damping priority mode includes: when H s>4m or T p>8s, the sea state level is rough sea state, the high-damping priority mode is adopted, the control target of the mode is to preferentially guarantee the stability of the ship, and energy recovery is a secondary target, and the control method is as follows: 1) Set maximum damping coefficient: directly set a large target damping coefficient C max , calculate target damping force F desired C max v relative wherein, v relative is the relative velocity of the main hull and the plate​​ 2) Calculate duty cycle: according to F desired The corresponding D damp ; the calculated R eq Usually very small, meaning close to short-circuit power generation, thereby generating a large damping force to maximize the suppression of movement; 3) In this mode, the maximum power point tracking controller is completely disabled and the coordinator directly outputs D final = D damp .

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