A contactless feedback device and control method for a ship's fin stabilizer system

Abstract

The present application belongs to the technical field of ship navigation control and attitude stabilization, and specifically relates to a contactless feedback device and control method for a ship fin stabilizer system, comprising a base plate mounted on a rotating shaft; an angle sensor magnet and a sensing column fixedly mounted on the base plate, the magnet moving in a circular motion around the axis of rotation with the base plate; a main structure fixedly connected to a fixed seat, a space for accommodating the angle sensor magnet defined between the main structure and the base plate, the main structure being provided with a first arc opening, the sensing column being arranged therein and moving along a trajectory; a proximity switch and an angle sensor body having a sensing gap opposite to the magnet, the signal transmission interface being electrically connected to both. The present application achieves angle sensing and zero-position recognition in a contactless manner, overcoming the problems of mechanical stagnation and signal drift, and resolving the technical problems of existing fin angle feedback devices, such as complex structures, poor reliability of contact elements, and low zero-position recognition accuracy.

Description

Technical Field

[0001] The present invention belongs to the technical field of ship navigation control and attitude stabilization, and in particular relates to a contactless feedback device and control method for a ship fin stabilizer system, which is specifically applied to the fin angle detection and feedback link in a ship fin stabilizer control system. Background Art

[0002] At present, ships often experience rolling motion during navigation due to external disturbances such as waves, which affects the ship's navigation stability and the comfort of the passengers. For this reason, fin stabilizers are widely used in medium and large ships to effectively reduce the roll amplitude. This type of device usually installs fin stabilizers symmetrically on both sides of the hull, collects the motion parameters of the hull (such as angular velocity, angle, angular acceleration, etc.) through sensors, and transmits the signal to the control processor. After calculation, synthesis and amplification, it generates control instructions for the fin angle, drives the electro-hydraulic servo system in the fin stabilizer device to control the movement of the fin mechanism, and then adjusts the fin angle to form a certain angle of attack between the fin and the water flow, generate lift, and thus generate a righting torque to counteract the disturbance torque caused by external waves, thereby achieving the purpose of reducing roll.

[0003] In a fin stabilizer system, the fin angle feedback device is an integral part of the fin stabilizer control system. The actuator's angle signal must be fed back to the control system to form a complete closed-loop control system for the fin stabilizer, ensuring accurate operation and timely response. By controlling the lift forces of the fins on both sides to be equal in magnitude and opposite in direction, and ensuring that the righting torque generated by the lift forces on the ship is of opposite polarity to the wave disturbance torque, the swaying of the ship caused by waves can be actively counteracted, significantly reducing the ship's sway.

[0004] As the instruction manual Figure 1-2 The existing fin angle feedback device includes a connecting shaft A2, a large gear A3, a cam A4, a rotary potentiometer A5, a small gear A6, a micro switch A7, a dial A8, and a pointer A9. The fin angle feedback device is connected to the fin shaft A1 via the connecting shaft A2. The connecting shaft A2 rotates together with the fin shaft A1. The connecting shaft A2 then turns the large gear A3 on the fin angle feedback device to rotate. The large gear A3 drives the small gear A6 to rotate. The rotary potentiometer A5 rotates along with the small gear A6 shaft, converting the linear displacement of the fin cylinder into angular displacement and feeding it back to the control system. When the fin angle exceeds the designed working angle, the cam A4 on the fin angle feedback device triggers the limit micro switch A7. The fin angle over-limit signal is connected and transmitted to the electronic control equipment, causing the system to shut down, reset to zero, and lock. The fin angle is read on the dial A8 through the pointer A9.

[0005] However, this type of fin angle feedback device has many problems. On the one hand, the mechanical connection structure is complex, especially the fit between the connecting shaft and the cam is prone to jamming due to equipment assembly errors, gear clearance and other problems, resulting in interrupted feedback signals, which in turn causes the fin surface movement to be jerked or even out of control; on the other hand, the limit micro switch is prone to loosening or damage during frequent operations, increasing the maintenance cost and failure rate of the system. In addition, the zero position detection of the existing device depends on the resistance value of the rotary potentiometer, and the resistance value of the potentiometer element is prone to drift under long-term use or under the influence of the marine environment, resulting in inaccurate zero position recognition, affecting the reliability of the system's shutdown, reset and locking actions. Therefore, there is an urgent need for an angle feedback device with a simple structure, non-contact, and high-precision zero position recognition capability to improve the reliability and performance of the ship's roll reduction system. Summary of the Invention

[0006] To address these issues, the present invention provides a contactless feedback device and control method for a ship's fin stabilizer system, resolving the issues of lag, signal instability, and wear and tear associated with the mechanical contact structure of conventional fin angle feedback devices. Rather than simply replacing components, this invention reconstructs the feedback path and sensing mechanism. By introducing contactless sensing elements (proximity switches and rotary potentiometers), the system eliminates mechanical gear transmission, operates contactlessly with the proximity switches, and eliminates wear and tear. Zero-position detection is independent of potentiometer resistance changes, improving long-term stability. Multiple limit and observation mechanisms coexist, resulting in high reliability and maintainability.

[0007] In one aspect, the present invention provides a contactless feedback device for a ship fin stabilizer system, the fin stabilizer system comprising a rotating shaft for driving a fin surface in the fin stabilizer device to rotate, and a fixing seat sleeved on the outside of the rotating shaft, the fixing seat being connected to the rotating shaft for relative rotation. The contactless feedback device comprises:

[0008] A base plate mounted on the rotating shaft;

[0009] An angle sensor magnetic block and a sensing column are fixedly mounted on the base plate; the angle sensor magnetic block is a disc structure, the axis of which coincides with the axis of the rotating shaft, and moves in a circular motion around the rotating axis along with the base plate;

[0010] A main structure fixedly connected to the fixing base, wherein a space for accommodating the angle sensor magnetic block is defined between the main structure and the base plate, and a first arc opening is provided on the main structure; the sensing column is arranged in the first arc opening on the main structure and moves along the trajectory of the first arc opening when the base plate rotates;

[0011] an angle sensor body mounted on the main structure, wherein the angle sensor body and the angle sensor magnetic block are arranged opposite to each other with a preset sensing gap between them;

[0012] A proximity switch installed on the main structure, wherein the proximity switch is arranged on one side of the first arc opening of the main structure;

[0013] A signal transmission interface is configured to electrically connect the angle sensor body and the proximity switch; when the sensing column rotates to a position relative to the proximity switch, the proximity switch outputs a signal indicating the extreme position of the rotation axis through the signal transmission interface; and when the angle sensor magnet rotates around the rotation axis, the angle sensor body is configured to identify angular changes of the angle sensor magnet and output the current rotation angle of the rotation axis through the signal transmission interface.

[0014] In a preferred implementation of the present application, further, the angle sensor magnetic block is a radial magnetization structure, whose N pole and S pole are symmetrically distributed along the radial direction, and the angle sensor body is arranged in front of the angle sensor magnetic block, and its sensing area is aligned with the magnetic field distribution area at the outer edge of the angle sensor magnetic block.

[0015] In a preferred implementation of the present application, further, the proximity switch includes a zero position proximity switch, an upper electrical limit proximity switch and a lower electrical end position proximity switch in sequence along the arc path of the first arc opening; the zero position proximity switch is arranged at the central position along the first arc opening; the upper electrical limit proximity switch and the lower electrical end position proximity switch are respectively arranged on both sides of the zero position proximity switch.

[0016] In a preferred implementation of the present application, it further includes a proximity switch adjustment mounting seat; the proximity switch adjustment mounting seat is installed on the main structure, and the zero position proximity switch, the upper electrical limit proximity switch and the lower electrical end position proximity switch are respectively installed on the corresponding proximity switch adjustment mounting seat.

[0017] In a preferred implementation of the present application, further, the end face of the main structure is provided with a second circular arc opening, the central axis of the second circular arc opening is coaxially arranged with the central axis of the rotating shaft, the inner arc surface of the second circular arc opening is arranged opposite to the inner arc surface of the first circular arc opening, and the bisectors of the arc angles of the first circular arc opening and the second circular arc opening coincide with each other.

[0018] In a preferred implementation of the present application, it further includes a dial mounting column and a pointer; one end of the dial mounting column is fixedly connected to the base plate, and the other end passes through the second arc opening and extends to the outside of the main structure to be connected to the pointer.

[0019] In a preferred implementation of the present application, it further includes a dial; the dial is installed on the outside of the second arc opening, and the scale corresponding to the middle vertical axis where the pointer is located on the dial is used as the zero-degree reference point, and angle scales are set on its left and right sides that increase symmetrically from zero outward, and the maximum scale of the angle scale corresponds to the maximum limit position of the rotation axis.

[0020] In a preferred implementation of the present application, further, the zero position proximity switch is correspondingly arranged at the zero degree reference point position on the dial, and the upper electrical limit proximity switch and the lower electrical limit proximity switch are respectively correspondingly arranged at the maximum limit angle positions on both sides of the dial.

[0021] In a preferred implementation of the present application, further comprising an end cover, the end cover being fixedly mounted on the end surface of the main structure and forming a closed space together with the bottom plate;

[0022] It also includes an observation window; the end cover is provided with an arc-shaped opening, and the observation window is installed at the position of the arc-shaped opening.

[0023] In another aspect, the present invention provides a control method for a contactless feedback device for a ship fin stabilizer system using any one of the above-mentioned methods, the control method comprising:

[0024] Step 1: The rotating shaft drives the angle sensor magnet to rotate. During this rotation, the angle sensor magnet generates a magnetic field that changes with the angle. The angle sensor body senses this magnetic field change and outputs a continuous current signal corresponding to the angle change to the fin stabilizer control system.

[0025] Step 2: The sensing column rotates synchronously with the rotation of the rotating shaft. When the sensing column rotates to the proximity switch sensing area corresponding to the preset angle position, the proximity switch senses the proximity of the sensing column and immediately outputs an on-off signal representing the angle state. The electrical signal is transmitted to the fin stabilizer control system through the signal output interface of the feedback device.

[0026] Step 3: After receiving the analog angle signal output by the angle sensor body, the current fin angle is calculated based on the signal and compared with the preset target angle to determine whether the current fin angle reaches the control target value;

[0027] Step 4: When the fin stabilizer control system determines that the current fin angle has reached the preset control target value and receives a limit trigger signal from any limit proximity switch, the fin stabilizer control system executes an action abort instruction, interrupts the continued driving action of the actuator, and triggers the alarm module or starts the system zeroing process; if it receives a trigger signal from the zero position proximity switch, the fin stabilizer control system determines that the current fin angle is at the zero position, enters the reset control state, performs the angle position calibration operation, and outputs a locking control instruction.

[0028] The beneficial effects of the present invention are:

[0029] First, the present invention's contactless feedback device achieves angle sensing in a non-contact manner by installing the angle sensor magnet in the rotating shaft follower structure and placing the angle sensor body in the stationary structure. This effectively avoids mechanical jamming, signal interruption, and resistance drift caused by gear transmission, cam mechanisms, and rotary potentiometer contacts in the prior art. Furthermore, the non-contact coordination between the sensing column and the proximity switch enables highly reliable zero-position detection and limit protection, improving the structural stability and signal output accuracy of the feedback device. By designing the angle sensor magnet as a disc with its axis coaxially aligned with the center of the rotating shaft, the magnetic field distribution is uniform and symmetrical, enhancing the linearity of the signal output and the detectable angle range. By designing the angle sensor magnet as a radial magnet and positioning the sensor body in front of the outer edge of the magnet with the sensing surface aligned with the polarity midline, the accuracy and stability of angle measurement are improved. This structure exhibits excellent assembly tolerance and interference immunity, ensuring stable and accurate angle signal output even in the presence of slight mechanical deviations or external vibration interference. At the same time, the disk magnetic blocks have a compact layout and are easy to integrate, making them convenient for integrated packaging with the rotating structure. This enhances the control response capability and long-term operational reliability of the fin stabilizer system in complex marine environments, reduces maintenance frequency and failure rate, and meets the requirements of marine equipment for high-precision, high-stability, and high-integration angle detection in complex environments.

[0030] Second, in a preferred implementation, the present invention arranges the zero position proximity switch, the upper electrical limit proximity switch and the lower electrical end position proximity switch in sequence along the circular arc path of the first circular arc opening, and sets the zero position proximity switch at the center position of the circular arc path, and the upper limit and lower limit proximity switches are symmetrically distributed on both sides thereof, so that the sensing column can accurately trigger the switch signals corresponding to different angular positions in sequence during the rotation process, thereby realizing accurate zeroing recognition and limit protection of the stabilizer fin angle; in addition, by providing an adjustable proximity switch adjustment mounting seat, each proximity switch can be fine-tuned and positioned in the circular arc direction and the radial direction, thereby improving the matching accuracy and structural adaptability of the limit sensing.

[0031] Third, in a preferred embodiment, the first arc opening and the second arc opening of the present invention are respectively provided on the end surfaces of both sides of the main structure, and the bisectors of the arc angles of the two coincide with each other and are arranged coaxially with the central axis of the rotating shaft, thereby forming a highly symmetrical arc channel structure. This symmetrical arrangement not only ensures the stable rotational motion of the sensing column within the arc path, which is conducive to improving the triggering accuracy between the proximity switch and the sensing column, but also ensures that the indication direction between the pointer and the dial remains consistent.

[0032] Fourth, in a preferred embodiment, the present invention's structural design enables the angle indicator mechanism, formed by the dial mounting post and pointer, to rotate synchronously with the rotation axis. A second arc-shaped opening is provided to extend the pointer outside the device, enabling real-time, intuitive display of the current fin angle in conjunction with the externally mounted dial. By providing a scale layout on the dial with the pointer center as the zero-degree reference point and symmetrically increasing to the rotation axis's extreme angles, operators can visually read the fin stabilizer's angle, calibrate the angle, and determine its limits by observing the pointer's position on the dial, without disassembling the device.

[0033] Fifth, in the preferred implementation, the present invention sets the zero-position proximity switch at the zero-degree reference point position of the dial, and sets the upper electrical limit proximity switch and the lower electrical limit proximity switch at the maximum limit angle positions on both sides of the dial, so that the trigger position of the proximity switch in the feedback device and the manual visual angle reading are one-to-one corresponding. This structure can achieve a coordinated correspondence between the physical position of the fin angle operating state, the sensor signal and the scale reading.

[0034] Sixth, in a preferred implementation, the present invention provides an end cover on the end face of the main structure, and together with the bottom plate, it forms a closed space, which can effectively protect the angle sensor, sensing column, proximity switch and other key components inside the device from erosion by the external environment (such as salt spray, moisture, dust), thereby improving the protection level and service life of the entire feedback device; further, by providing an arc-shaped opening on the end cover that matches the angle display structure and providing a transparent observation window at the opening, on-site monitoring, manual calibration and confirmation of the operating status are facilitated.

[0035] Seventh, the control method provided by this invention achieves continuous and accurate angle signal feedback through contactless sensing between the angle sensor magnet and the angle sensor body. Combined with the contactless limit and zero-position detection mechanism of the sensing column and proximity switch, this method improves the reliability and response speed of the feedback signal. This method avoids the signal errors and failure risks associated with gear backlash and contact wear in traditional mechanical structures, ensuring that the system can promptly identify and trigger limit or reset control commands at critical angles. This improves the control accuracy, stability, and safety of the entire fin stabilizer system, making it particularly suitable for demanding dynamic ship attitude control applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a cross-sectional side view of a fin angle feedback device in the prior art;

[0037] Figure 2 It is a front view of a fin angle feedback device in the prior art;

[0038] Figure 3 is a cross-sectional side view of a contactless feedback device for a ship fin stabilizer system provided by an embodiment of the present invention;

[0039] Figure 4 2. This is a front view of a contactless feedback device for a ship fin stabilizer system provided by an embodiment of the present invention;

[0040] Figure 5 Schematic diagram of the magnetization direction and sensor layout of the angle sensor magnetic block of the contactless feedback device for a ship fin stabilizer system provided by an embodiment of the present invention;

[0041] Figure 6 A schematic diagram of the layout of a contactless feedback device for a ship fin stabilizer system using dual sensors provided by an embodiment of the present invention;

[0042] Figure 7 It is a structural schematic diagram of a contactless feedback device for a ship fin stabilizer system provided by an embodiment of the present invention in an electrical limit angle state.

[0043] Among them, 1-base plate; 2-main structure; 3-sensing column; 4-end cover; 5-proximity switch adjustment mounting base; 6-angle sensor body; 7-angle sensor magnet; 8-dial mounting column; 9-pointer; 10-observation window; 11-dial; 12-magnet adjustment mounting base; 13-rotating axis; 14-fixed base; 15-aviation socket; 16-zero position proximity switch; 17-upper electrical limit proximity switch; 18-lower electrical end position proximity switch. DETAILED DESCRIPTION

[0044] 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.

[0045] The terms "up", "down", "left", "right", "front", and "back" in this application are based on the positional relationships shown in the accompanying drawings. The corresponding positional relationships may vary depending on the drawings, and should not be construed as limiting the scope of protection.

[0046] In this application, the terms "installed," "connected," "connected," "connected," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, integral connection, mechanical connection, electrical connection, or mutual communication. They can also be directly connected or indirectly connected through an intermediate medium. They can also refer to internal communication between two components or interaction between two components. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0047] Example

[0048] Refer to the instruction manual Figure 3-4 A contactless feedback device for a ship's fin stabilizer system is mounted on the fin stabilizer's rotating shaft 13. This device senses changes in the fin angle in real time and outputs feedback signals to the control system, forming part of a closed-loop control system. The rotating shaft 13 is the drive shaft that drives the fin stabilizer's rotational motion. A stationary mounting base 14 is mounted on the shaft. A rotary connection is used between the rotating shaft 13 and the mounting base 14, allowing the shaft to rotate freely within the mounting base with low friction.

[0049] It should be noted that the rotating shaft 13 is a rotatably mounted rotating shaft, one end of which is connected to the component to be detected (such as a fin stabilizer or a servo mechanism), and the other end passes through the fixed seat 14. The fixed seat 14 is provided with a bearing hole or a rotating support structure for the rotating shaft 13 to pass through and support. Specifically, the rotating shaft 13 is supported and guided by a rolling bearing or a sliding sleeve structure provided in the fixed seat 14, so that it can perform low-friction rotational motion in the axial direction in the fixed seat 14. This rotational relationship ensures that the rotating shaft 13 can rotate smoothly relative to the fixed seat 14 when it is driven or loaded externally, thereby driving the base plate 1, the sensing column 3 and the angle sensor magnet 7 connected thereto to rotate synchronously with the shaft, thereby realizing the detection and feedback of angle changes.

[0050] This contactless feedback device comprises a base plate 1, a main structure 2, a sensing column 3, an angle sensor body 6, an angle sensor magnet 7, a proximity switch, and a signal transmission interface. One end surface of the base plate 1 is fixedly connected to a rotating shaft 13, rotating synchronously with the shaft. The angle sensor magnet 7 and the sensing column 3 are both mounted on the other end surface of the base plate 1 and rotate with the base plate. The main structure 2 is fixedly mounted on a mounting base 14, with a space between it and the base plate 1 for accommodating the angle sensor magnet 7. The angle sensor body 6 is mounted on the main structure 2 and positioned opposite the angle sensor magnet 7, maintaining a preset sensing gap between them. The angle sensor body 6 is connected to the signal transmission interface via a signal line, sensing the rotation angle of the angle sensor magnet 7 and outputting a corresponding electrical signal representing the current angle of the fin surface. A first arc-shaped opening is defined on the end surface of the main structure 2. The sensing column 3 is mounted perpendicular to the base plate 1 and rotates synchronously with the base plate 1 within the first arc-shaped opening of the main structure 2. The proximity switch is arranged on the side of the first arc opening area of ​​the main structure 2 and is connected to the signal transmission interface through a wire. It is used to be turned on when the sensing column 3 rotates to a preset position and output a limit or zeroing signal to the control system.

[0051] It should be noted that a proximity switch is a non-contact detection device used to detect whether an object is approaching or reaching a specific position without the need for direct contact with the target object. Types of proximity switches include inductive proximity switches, capacitive proximity switches, photoelectric proximity switches, and magnetic proximity switches. In the preferred implementation of the present application, a magnetic proximity switch is used. Through magnetic field induction, no contact with the target is required. It is suitable for long-term operation in humid or underwater environments, has no friction parts, a long life, and is insensitive to interference such as temperature and electromagnetic waves. It can be flexibly adapted to different working conditions by adjusting the magnet strength and installation distance. The induction column 3 is made of corrosion-resistant metal material, such as stainless steel 316L.

[0052] As the instruction manual Figure 5 As shown, in the preferred implementation of the present application, in order to overcome the technical bottlenecks of the existing angle sensors, such as the limited detectable rotation angle range, high sensitivity to mechanical assembly errors, nonlinear output signals, insufficient anti-interference capabilities, and limited structural layout, the present application systematically optimizes the shape and installation method of the angle sensor magnetic block 7 through structural innovation. Specifically, the present application designs the angle sensor magnetic block 7 used in the angle sensor as a disc structure, and precisely arranges its axis coaxially on the central axis of the rotating shaft 13. The angle sensor magnetic block 7 adopts radial magnetization and is a bipolar magnetic block structure, with the N / S poles distributed radially (for example, Figure 5The left half is the S pole and the right half is the N pole). The angle sensor body 6 is arranged at the front end of the angle sensor magnet 7, and the sensing area of ​​the angle sensor body 6 is aligned with the magnetic field distribution area at the outer edge of the angle sensor magnet 7. The sensing area at the edge of the magnet is directly opposite the position where its magnetic field changes most dramatically. This radial magnetization method will produce periodic changes in the direction of the magnetic field at its edge when the magnet rotates. The magnetic induction lines are radially emitted from one half and converge radially at the other, showing obvious directionality and angular dependence at the outer edge. The magnetic field direction in this area includes a radial component (along the radius of the magnet, that is, the X-axis direction - the direction from the center of the circle to the edge of the disk), an axial component (along the rotation axis direction, that is, the Z-axis direction - the axis of the magnet's rotation) and a tangential component (which changes with the rotation of the magnet, that is, the Y-axis direction - perpendicular to the X-axis and along the tangent direction of the magnet's edge, clockwise or counterclockwise around the center). In the implementation of the present application, the angle sensor body 6 adopts a three-axis magnetic field sensing device, including but not limited to a magnetoresistive angle sensor, a Hall effect angle sensor, and an inductive non-contact sensor, which can simultaneously sense the magnetic field components in the X, Y, and Z directions.

[0053] Furthermore, the sensing area of ​​the angle sensor body 6 is facing the polarity center line of the magnetic block, that is, the N / S pole junction, which is defined as the zero position of the rotating shaft 13. This is because the N / S pole junction is the place where the magnetic field direction suddenly changes, and its magnetic induction vector has a clear and steep change trend here, which can obtain the highest sensitivity and is suitable as a physical "reference line" for angle measurement. Setting a sensor at this point can clearly sense the change in this magnetic field characteristic, making the "zero position" definition repeatable and stable.

[0054] Because angle sensor magnet 7 is a circular disk, the direction of the magnetic field generated by its periphery continuously changes as it rotates around axis 13. The three-axis magnetic sensor acquires the three-dimensional magnetic field vector, allowing real-time observation of the current magnetic field direction and vector analysis to calculate the current rotation angle. This output is a continuous analog or digital signal for angle feedback to external control systems (such as the main controller of the fin stabilizer control system).

[0055] In order to achieve accurate solution, a certain initial angle θ = 0 can be selected as a reference, and the magnetic field component in the rotating plane at that moment is recorded as At any subsequent time, the current magnetic field vector is obtained in real time During system initialization, the rotating axis 13 is positioned sequentially at several known angles (covering the full cycle from 0° to 360°, with an accuracy of ≤1°). The magnetic field components corresponding to each angle are recorded, and a database of correspondences between magnetic field vectors and angles is constructed. During operation, the current rotation angle is obtained by finding the closest item in the database for the current magnetic field vector and performing interpolation or fitting calculations, thereby achieving stable and unambiguous continuous angle calculation.

[0056] As the instruction manual Figure 6 The angle sensor body 6 of the present application is provided with two sensors, wherein the first sensor is arranged in front of the outer edge of the angle sensor magnet block 7, and the sensing area is directly opposite the polarity centerline of the magnet block. The second sensor is also arranged in front of the outer edge of the angle sensor magnet block 7 and is arranged 90° away from the second sensor around the center of the magnet block. The two sensors are arranged equidistant from the magnet block, respectively sensing radial magnetic field components in different directions. The two sensors respectively detect magnetic field components with a 90° phase difference, and the precise angle can be calculated through vector synthesis / inverse tangent function. This method can continuously decode the angle without dead zones within the full 360° range, with extremely high accuracy. In addition, if there is a slight eccentricity when the magnet block rotates, the output signal of a single sensor will be distorted; however, since the two sensors differ in angle by 90°, they are subject to interference in different directions. After joint algorithm processing (such as filtering, fitting, and error correction), the eccentricity error can be effectively offset. Under vibration conditions, the magnetic field perception in a certain direction may be greatly disturbed; in this case, the second sensor can provide a stable compensation signal to maintain reliable operation of the system. The redundant design supports fault-tolerant detection. Even if one sensor is damaged, the other can still provide angle trend signals, achieving degraded operation and improving system reliability.

[0057] Specifically, each set of sensors is independently calibrated during the system initialization phase: by rotating the rotating shaft 13 to multiple known angle points in sequence (covering the full cycle of 0°-360°, with an accuracy of ≤1°), recording the magnetic field vector data corresponding to each angle, and establishing a mapping database between each magnetic field direction and angle. Since there is a 90° physical offset in the installation direction of the two sets of sensors, when the mapping model they establish outputs the angle, the angle value measured by the second sensor itself is equivalent to the angle value of the first sensor plus 90°. During system operation, the current magnetic field vector is obtained from the two sets of sensors respectively, and the current angle is calculated by table lookup or interpolation. In order to eliminate the influence of the installation offset between the two sets of sensors, the system will deduct 90° from the calculated angle value of the second set of sensors to convert it into an equivalent angle value based on the coordinate system of the first set of sensors. Subsequently, the converted angle value is averaged with the angle value calculated by the first set of sensors through its own database, and the final angle output is used as the current angle of the rotating shaft. This processing method effectively eliminates the systematic deviation caused by the sensor installation direction, improves the solution accuracy and stability, and enhances the robustness and reliability of the system in the event of single sensor anomalies.

[0058] Through comparison, the present application found that compared with the use of rectangular magnets, especially the design in which the rotation axis of the magnet is eccentric to the rotation axis, the structure proposed in the present application in which the disk magnet, the rotation center of the magnet and the rotation axis coincide, the sensor is arranged in front of the outer edge of the magnet, and the sensing area is directly opposite the polarity center line of the magnet, has the following advantages:

[0059] 1. The angle sensor magnet block 7 of this application is a circular disc structure with natural 360° rotational symmetry. Its radial magnetization ensures uniform magnetic field distribution and component variation at every rotation angle. The polarity centerline is stably defined in the radial direction, allowing for precise sensor alignment and facilitating the construction of a high-precision, low-distortion angle measurement model. While eccentrically designed elongated magnet blocks are also radially magnetized, their elongated structure results in poor symmetry, with the magnetic field primarily concentrated at the ends of their short sides. This results in uneven spatial distribution and inconsistent magnetic field density, making it susceptible to magnetic field intensity fluctuations and nonlinear changes at the ends of the strip during rotation.

[0060] 2. The magnetic block of the present application is coaxially arranged with the axis of rotation, and the center of rotation is the center of the magnetic block. During rotation, the sensor is always aligned with the outer edge of a fixed radius, and the measured angle corresponds to a unique magnetic field state. The strong geometric symmetry facilitates assembly, eliminates the adverse effects of mechanical errors on angle decoding, and ensures that the magnetic field response is stable, uniform, and corresponds one-to-one with the angle, making it suitable for high-precision control systems. Although the eccentrically designed long strip magnetic blocks have the same magnetization method, the long strip structure is usually installed eccentrically. During rotation, the center of the magnetic block does not coincide with the axis of rotation, which will cause the magnetic field direction to change nonlinearly, the magnetic field amplitude to change periodically with rotation, and introduce eccentricity errors and amplitude modulation noise.

[0061] 3. The sensor of this application is arranged at the outer edge of the magnetic block, sensing orthogonally to the radial distribution direction of the magnetic field. In addition, if two sensors are arranged 90° apart, the orthogonal magnetic field component (sinθ / cosθ) can also be obtained. The continuous angle can be directly calculated using the atan2 function, effectively utilizing the 360° outer edge magnetic field changes without blind spots. However, during the rotation of the eccentrically designed long strip magnetic block, due to the discontinuous edge of the long strip, the actual sensing point may fall on the area where the magnetic field changes unevenly. If the sensor is only placed in front of the two ends of the short side, it can only receive local magnetic flux changes, resulting in low signal amplitude, easy distortion of the curve, lack of circular continuity, and irregular magnetic field change trajectory throughout the angle.

[0062] 4. This application utilizes dual sensors to achieve complementary fault tolerance and redundancy. The magnetic field applied to the sensors is always in a region of equal amplitude, equal diameter, and concentricity, minimizing interference. However, the eccentric, long magnetic strip design introduces fluctuating signals, and extreme angles can lead to magnetic field dead zones or asymmetric regions, making signal distortion difficult to eliminate through filtering.

[0063] To ensure stable and reliable non-contact sensing between the angle sensor magnet 7 and the angle sensor body 6, the contactless feedback device also includes a magnetic adjustment mount 12. This mount is positioned between the base plate 1 and the angle sensor magnet 7 and secured to the base plate 1 along with the angle sensor magnet 7 via a locking screw. By configuring the magnetic adjustment mount 12 with a suitable thickness, the sensing gap between the angle sensor magnet 7 and the angle sensor body 6 can be fine-tuned.

[0064] In the present application, the rotating shaft 13 refers to the main shaft or transmission shaft in the anti-roll fin device that can change its angle as it rotates. This shaft directly drives the rotation of the fin and is the original motion source of the angle feedback. The fixed seat 14 refers to a fixed support structure for mounting the body of the angle feedback device. The fixed seat 14 is specifically a static support structure outside the actuator or drive housing, which is used to ensure that the device remains stable and unchanged in position during operation, so as to accurately sense the angle change of the rotating shaft. The mounting seat 3 is the mounting part of the device body, which is firmly connected to the fixed seat 14 by bolts or other structural means. The mounting seat 3 does not participate in the movement, but only provides a stable platform to support the sensing, signal output and other functions of the feedback device.

[0065] During the operation of the fin stabilizer system, the rotating shaft 13 receives instructions from the electronic control device and rotates, thereby driving the fin surface to rotate. The rotating shaft 13 also drives the base plate 1 fixed to it to rotate synchronously. The angle sensor magnet 7 on the base plate 1 makes a circular motion around its own axis during the rotation process, and its angular displacement is sensed in real time by the angle sensor body 6 fixed on the main structure 2, and outputs a corresponding electrical signal to feedback the current fin surface angle. At the same time, the sensing column 3 on the base plate 1 rotates in the first arc opening of the main structure 2. When the sensing column 3 rotates to the extreme position relative to the proximity switch, the proximity switch senses the proximity signal of the sensing column 3, generates a limit or zeroing signal, and transmits it to the system electronic control device through the signal line to trigger the shutdown, reset or angle locking function to ensure the safety and accuracy of the system operation.

[0066] In the implementation of the present application, the proximity switches include a zero position proximity switch 16, an upper electrical limit proximity switch 17, and a lower electrical end position proximity switch 18. These three proximity switches are arranged in sequence along the arc path of the first arc opening of the main structure 2. The zero position proximity switch 16 is set at the center position of the first arc opening. The zero position proximity switch 16 serves as an angle reference point for detecting the zero position of the rotating shaft 13 and triggering the system reset, ensuring that the sensor starts reading from a consistent zero point during each detection and ensuring that the system reset function is accurate. The upper electrical limit proximity switch 17 and the lower electrical end position proximity switch 18 are symmetrically arranged on the left and right sides of the zero position proximity switch 16. When the sensing column 3 rotates to the position of the upper electrical limit proximity switch 17, the upper electrical limit proximity switch 17 is triggered and outputs the upper limit angle reached by the rotating shaft 13, triggering the shutdown protection; similarly, the lower electrical end position proximity switch 18 is used to detect when the rotating shaft 13 reaches the lower limit angle, triggering the shutdown protection. The three proximity switches are distributed at angles within the arc channel, corresponding to the rotation path of the sensing column 3. When the sensing column 3 rotates to the corresponding position, the sensing is triggered, thereby outputting the corresponding switch signal, realizing the zero return, limit protection and safety control functions of the device.

[0067] This application utilizes a disc-shaped, bipolar, radially magnetized angle sensor magnet with radially distributed N / S poles. The magnetic field exhibits dramatic changes at the polarity junction. Therefore, the polarity midline (i.e., the N / S pole junction) becomes the magnetic induction zero position. The sensor, placed at this junction, senses the steepest magnetic field changes. Using a three-axis magnetic sensor, this characteristic point can be captured with high precision. The control system defines the magnetic field state sensed at this point as "logical 0 degrees." Starting from this zero-position magnetic vector, the system combines the magnetic field vector at any subsequent moment to calculate the angle change using vector dot and cross products. The atan2 function is used for 360-degree continuous decoding. The magnetic field at the edge of the magnet is linear and uniform, facilitating high-precision angle tracking. A zero-position proximity switch is installed at a specific arc angle position on the main structure 2. The sensing column 3, which rotates with the base plate 1, triggers the switch when it reaches this position. This signal is used by the control system to identify the current zero position of the rotating shaft 13, trigger the system reset logic, and reset the position after power-up or error accumulation. Although the magnet and sensor can continuously output angle values, the system may encounter the following situations: the angle of rotating shaft 13 is unknown during power-up initialization; after long-term operation, the magnetic sensor may experience zero drift or nonlinear accumulation errors; and there may be slight mechanical deviations during initial installation. In these cases, the zero-position proximity switch can serve as a redundant reference signal, jointly confirming the true zero point with the magnetic induction zero position, aligning rotating shaft 13 with the logical angle of 0°. This ensures that the magnetic induction zero position detected by the sensor coincides with the actual zero-angle mechanical position of rotating shaft 13. This consistency reconstruction essentially aligns the magnetic induction angle space (magnetic field coordinate system) with the rotating shaft angle space (mechanical coordinate system) through the proximity switch trigger point, ensuring the absolute zero position accuracy of the system during power-up, operation, and after fault recovery.

[0068] Specifically, when the system is initialized or the zero-point calibration process is executed, the control system first drives the rotating shaft 13 to rotate at a low speed, driving the base plate 1 and the angle sensor magnet 7 coaxially mounted therewith to rotate synchronously. When the follower sensing column 3 rotates to align with the zero-position proximity switch 16 at the set position, the zero-position proximity switch is triggered and outputs a zero-position signal. At this time, the control system calibrates the current mechanical position of the rotating shaft 13 as "physical zero position". Synchronously, the angle sensor body 6 collects the three-axis magnetic field vector data in this instantaneous state in real time and enters the "zero-point calibration" mode. The control system sets the angle value calculated by the magnetic field vector output by the angle sensor at this time to 0°, and updates the initial reference vector of the angle solution algorithm accordingly, completing the zero-point alignment of the magnetic field coordinate system and the mechanical angle coordinate system.

[0069] The contactless feedback device also includes a proximity switch adjustment mount 5, which is mounted on the main structure 2. Each proximity switch is mounted on each proximity switch adjustment mount 5 with a set screw to ensure stability and stability in vibration environments. The sensing area of ​​each proximity switch faces the rotational path of the sensing column 3, maintaining a preset sensing distance.

[0070] The proximity switch adjustment mount 5 can be fine-tuned in radial or arc directions to adapt to the working angles of different models of rotating shafts. In a preferred embodiment of the present application, the proximity switch adjustment mount 5 includes an adjustment base structure with an array of guide grooves or guide holes, which can be fine-tuned in the radial direction (i.e., the direction pointing to the center of the rotating shaft) and the arc direction (i.e., the tangential direction along the rotation path of the sensing column) on the main structure 2. In the radial direction, by moving the mount farther or closer, the sensing distance between the proximity switch and the sensing column can be adjusted to ensure that it remains within a reasonable sensing distance range; in the arc direction, by fine-tuning the angular position of the mount along the rotation path, the sensing position of each proximity switch accurately corresponds to the predetermined zero position or limit angle. The proximity switch adjustment mount 5 is preferably provided with an oblong groove or multiple positioning holes. The proximity switch is connected to the mount by screws and can slide or switch the mounting hole position on the mount to achieve fine-tuning. After adjustment, it can be locked with bolts to ensure installation stability.

[0071] In an implementation of the present application, the contactless feedback device further includes a scale display structure for manually reading the rotation angle, specifically including a scale mounting column 8, a pointer 9, and a scale 11. A second arc opening is provided on the end face of the main structure 2, and the central axis of the second arc opening is coaxially arranged with the central axis of the rotating shaft 13 to maintain structural symmetry and sensing accuracy. The inner arc surface of the second arc opening is arranged opposite to the inner arc surface of the first arc opening provided in another part of the main structure, and the bisectors of the arc angles of the first and second arc openings coincide with each other, thereby achieving highly reliable position detection.

[0072] Specifically, one end of the dial mounting post 8 is fixedly connected to the base plate 1, while the other end passes through a second arc-shaped opening provided on the end surface of the main structure 2 and extends to the outside of the main structure 2, connecting to the pointer 9, allowing the pointer to rotate synchronously with the base plate and the rotating shaft. A dial 11 is fixedly mounted outside the second arc-shaped opening. The dial has an arc-shaped structure, and its curved display surface is arranged in an arc manner concentric with the rotating shaft 13, expanding from the inside out to form a clearly visible scale area. The position and shape of the dial 11 precisely correspond to the rotation trajectory of the pointer 9, allowing the pointer to slide on it to indicate angle changes. The dial 11 uses the scale corresponding to the central vertical axis where the pointer 9 is located as the zero-degree reference point. The left and right sides of the dial 11 are respectively provided with angle scales that increase symmetrically from zero outward. In this embodiment, the scale is marked from the center to both sides to a maximum of ±70°, covering a total angle of 140°. The scales are evenly spaced at regular intervals and feature subdivisions, allowing users to read the scales with high accuracy through the observation window. The symmetrical layout of the scale structure, combined with the real-time position of the rotating pointer, enables two-way dynamic visualization of the fin stabilizer angle and assists in positioning, facilitating system installation, commissioning, and manual verification.

[0073] As the instruction manual Figure 7 As shown, the zero position proximity switch 16 is located in the middle of the circular opening of the main structure 2, corresponding to the zero reference point on the scale plate 11. When the sensing column 3 rotates to this position, the zero position proximity switch 16 is triggered and outputs a zero position signal. The electronic control system uses this signal to identify that the fin surface has returned to zero and can perform reset, lock, and other operations. The upper electrical limit proximity switch 17 is located at the forward maximum limit of the sensing column's rotation path, corresponding to the +α (i.e., +70°) scale position on the scale plate. When the sensing column 3 rotates to this position, the upper electrical limit proximity switch 17 is triggered and outputs an upper limit signal. The electronic control device then determines that the current angle has reached the upper limit and enters limit protection. The lower electrical limit proximity switch 18 is located at the reverse maximum limit of the sensing column's rotation path, corresponding to the -α (i.e., -70°) scale position on the scale plate. When the sensing column 3 rotates to this position, the lower electrical limit proximity switch 18 is triggered and outputs a lower limit signal, causing the system to enter lower limit protection control. The three sets of proximity switches are strategically arranged along a circular arc, with their trigger points corresponding to the three points –α, 0, and +α on the dial 11. This structure allows the position of the sensing column 3 to be electronically limited through proximity switch feedback while also enabling visual comparison of readings on the dial, improving the safety, reliability, and debuggability of the system.

[0074] In the implementation of the present application, the contactless feedback device also includes an end cap 4 and an observation window 10, which are used to achieve sealed protection of the device structure and manual reading function. The end cap 4 is an integrally formed "J"-shaped structure with a closed annular curved surface profile. It is fixedly connected to the end face of the main structure 2 by fasteners such as bolts, forming a front protective cover of the outer shell of the angle feedback device. The end cap 4 and the base plate 1 together form an enclosed space for enclosing and protecting multiple key functional components within the device, including the sensing column 3, the proximity switch adjustment mounting base 5, the angle sensor body 6, the angle sensor magnet 7, the dial mounting column 8, the pointer 9, the dial 11, the magnet adjustment mounting base 12, the zero position proximity switch 16, the upper electrical limit proximity switch 17, and the lower electrical end position proximity switch 18. This structure not only prevents the external environment (such as salt spray, moisture, and impact) from affecting the internal sensitive components, but also improves the system's operational reliability and protection level in complex marine environments.

[0075] To enable manual reading of the fin angle, a circular, transparent window opening is provided on the end cap 4. Its shape and size match the scale plate 11 located behind it. An observation window 10 is fixedly mounted in this opening, preferably made of a transparent, weather-resistant material (such as plexiglass or tempered glass). It visually displays the angle indicated by the pointer 9. The observation window allows the user to clearly read the current fin stabilizer angle without disassembling the device, facilitating operational monitoring, manual calibration, and maintenance inspections.

[0076] In a preferred embodiment of the present application, the signal transmission interface is selected as an aviation socket 15. This aviation socket 15 serves as the electrical signal output connection component between the contactless feedback device and the electronic control system, and is used to stably and reliably transmit the electrical signals output by the angle sensor body and the proximity switch. The aviation socket 15 is fixedly mounted on the outer shell wall of the main structure 2 and is positioned by a threaded mounting seat or panel flange. The socket terminal is internally connected to the signal wires leading from the angle sensor body 6, the zero position proximity switch 16, the upper electrical limit proximity switch 17, and the lower electrical end position proximity switch 18. The socket terminal is externally connected to the control system of the fin stabilizer system via an aviation plug to form an integrated signal path. This structural design is dustproof, waterproof, and corrosion-resistant, and is suitable for long-term use under complex ship working conditions.

[0077] Furthermore, by comparing the structures of the existing fin angle feedback device with the contactless feedback device of the present application, and systematically analyzing the structural innovations and advantages of the present application, the following are obtained:

[0078]

[0079]

[0080] The present invention also provides a control method for a contactless feedback device for a ship's fin stabilizer system. This control method is applicable to ship fin stabilizer systems equipped with a contactless feedback device and is primarily used to obtain fin angles in real time, determine the current angle state, and perform position limit protection control and system linkage command responses. Specifically, it includes:

[0081] Step 1: The rotating shaft drives the angle sensor magnet to rotate. During the rotation process, the angle sensor magnet generates a magnetic field that changes with the angle. The angle sensor body senses the magnetic field change and outputs a continuous current signal corresponding to the angle change to the fin stabilizer control system.

[0082] The magnitude of the current signal is proportional to the current fin angle offset, which is used to indicate the current fin angle position. The analog electrical signal corresponding to the fin angle is generated in real time. The relationship between the magnitude of the current signal and the fin angle offset is determined by the following formula:

[0083] I=k·θ (1)

[0084] Where: I is the current signal output by the angle sensor body, in mA or V; θ is the angular offset of the current fin surface relative to the zero position, in degrees (angle) or rad; k is the proportional coefficient (i.e., the sensor sensitivity coefficient), in mA / ° or V / °.

[0085] In the implementation of the present application, since a zero position is introduced, a zero position offset term needs to be added. At this time, the relationship between the magnitude of the current signal and the fin surface angle offset is determined by the following formula:

[0086] I=I0+k·θ (2)

[0087] Where: I0 represents the bias current at zero angle (θ=0).

[0088] For example, if the system is designed for a current signal range of 4–20mA, the zero point is 12mA, indicating a ±70° symmetrical distribution. The 4–20mA current signal range covers a total of 140°, and the current signal range corresponds to an angle of ±70°, covering a total of 16mA. The proportionality factor k represents the current change corresponding to a unit angle change, that is:

[0089]

[0090] Substituting the k value into the linear formula (2), I = 12 + 0.114·θ.

[0091] When θ=0°, I=12; when θ=+70°, I=12+0.114×70=20mA; when θ=-70°, I=12-0.114×70=4mA.

[0092] It should be noted that after receiving the continuous current signal output by the angle sensor, the fin stabilizer control system can establish a control curve for the fin angle change based on this signal and perform dynamic response adjustment operations through control strategies. The control strategy includes control curve calculation, PID regulation control (proportional-integral-derivative control), and predictive scheduling control (feedforward regulation).

[0093] Control curve calculation involves periodically sampling the current signal output by the angle sensor, constructing a time series of angle changes, and using this series to generate a real-time angle change curve. This control curve calculation can be used to monitor derivative information such as fin velocity and acceleration, providing input for subsequent control strategies.

[0094] PID control compares the target angle with the actual angle, calculates the deviation, and uses the proportional (P), integral (I), and differential (D) terms in the PID algorithm to dynamically adjust the actuator, achieving fast, stable, and overshoot-free fin response. PID parameters can be adjusted online based on navigation conditions (such as speed and wave height) to enhance system robustness.

[0095] Predictive dispatch control is a control system that models and predicts real-time angle trends. If an accelerating angle trend or impending disturbance is detected, the target angle or output control variable is adjusted in advance, forming a feedforward control path, reducing hysteresis and improving response to wave disturbances. Predictive models can be implemented by integrating historical data, wave spectrum characteristics, or data sources such as motion sensors.

[0096] In summary, the fin stabilizer control system uses a current signal sequence as input to perform curve calculations, achieving real-time modeling of angle states; it uses the current angle error as input to perform PID regulation to achieve closed-loop control and stable output; and it uses predictive scheduling to predict angle trends and disturbances, achieving early compensation response. However, the contactless feedback device of this application only provides an "angle current signal" output; its essential function is to provide electrical signal feedback of the current fin angle.

[0097] Step 2: The sensing column rotates synchronously with the rotation of the rotating shaft. When the sensing column rotates to the proximity switch sensing area corresponding to the preset angle position, the proximity switch senses the proximity of the sensing column and immediately outputs an on-off signal representing the angle state. The electrical signal is transmitted to the fin stabilizer control system through the signal output interface of the feedback device.

[0098] In this control method, a sensing column is positioned along the feedback device's rotational path, producing a circular arc-shaped rotational motion in sync with the angle of the rotating shaft. The main structure of the contactless feedback device is pre-installed with multiple proximity switches along the sensing column's rotational path, corresponding to the key angular positions the system monitors, including zero, upper, and lower limits. The on / off signals generated by the proximity switches are digitally generated to determine three positions (zero, upper, and lower limits), triggering a safety control response or automatic reset, and determining whether to trigger zero return, limit protection, or alarm logic.

[0099] Step 3: After receiving the analog angle signal output by the angle sensor body, the current fin angle is calculated based on the signal and compared with the preset target angle to determine whether the current fin angle reaches the control target value.

[0100] Specifically, the electrical signal is transmitted to the fin stabilizer control system via a unified electrical interface (such as an aviation socket), ensuring signal stability and reliability in complex environments. The fin stabilizer control system converts the analog signal into the current fin angle using a preset conversion formula. This is then compared with the preset target angle to determine control deviations and trigger subsequent response actions.

[0101] The input electrical signal of the fin stabilizer control system is the current signal output by the angle sensor body, that is, I in =Sensor output current signal (mA).

[0102] The current fin angle is determined by the following formula:

[0103]

[0104] Where: θ current Indicates the current fin angle; I in Indicates the current input current (mA), such as 4-20mA; I0 indicates the zero current value, such as 12mA, indicating 0°; k indicates the proportional coefficient, such as the typical value 0.114mA / °.

[0105] For example: front input current I in is 16mA, then

[0106] The fin stabilizer control system has a preset target angle value θ stored in it. target , which is given by the main control module or the adjustment algorithm. Therefore, the current fin angle error is determined by the following formula:

[0107] Δθ=θ target -θ current (4)

[0108] Based on the fin stabilizer control system's judgment logic, if |Δθ| ≤ ε, the control target value is considered to have been achieved. ε is the permissible error tolerance, typically set between 0.5° and 1°. If the ε range is exceeded, the fin stabilizer control system enters the next round of regulation or protection logic.

[0109] Step 4: When the fin stabilizer control system determines that the current fin angle has reached the preset control target value and receives a limit trigger signal from any limit proximity switch, the fin stabilizer control system executes an action abort instruction, interrupts the continued driving action of the actuator, and triggers the alarm module or starts the system zeroing process; if it receives a trigger signal from the zero position proximity switch, the fin stabilizer control system determines that the current fin angle is at the zero position, enters the reset control state, performs the angle position calibration operation, and outputs a locking control instruction.

[0110] It should be noted that the locking control instruction is used to drive the locking mechanism to lock the execution unit, thereby completing the resetting and steady-state maintenance of the fin stabilizer device.

[0111] The present invention presents a contactless feedback device and control method for ship fin stabilizer systems, specifically designed for these systems. This device achieves contactless angle detection by installing the angle sensor magnet in the rotating shaft's follower structure and the sensor body in the stationary structure. This effectively avoids the problems of sticking, signal interruption, and resistance drift associated with traditional mechanical structures such as gears, cams, and potentiometers. It employs a sensing column in conjunction with a proximity switch for zero position detection and limit protection. Symmetrical, optimized layout and fine-tuning of the proximity switch positions ensure the accuracy and stability of the feedback signal. Symmetrical arc openings and a dial indicator mechanism are located at each end of the device. The pointer rotates synchronously with the shaft and indicates the current fin angle, enabling visual angle reading and calibration. The limit switch trigger position in the feedback system corresponds one-to-one with the dial reading, enhancing intuitive operation and consistent control. Furthermore, the device utilizes a sealed structure to protect key components from environmental corrosion, and a transparent observation window facilitates monitoring and calibration. Through non-contact sensing and intelligent limit control, the overall solution improves control accuracy, response speed, and operational reliability in complex marine environments, making it particularly suitable for high-precision dynamic ship attitude control applications.

[0112] The above is only an embodiment of the present invention, and common sense such as the specific structure and characteristics of the scheme are not described in detail here. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes that fall within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claim involved.

Claims

1. A contactless feedback device for a ship fin stabilizer system, the fin stabilizer system comprising a rotating shaft (13) for driving a fin surface in the fin stabilizer device to rotate, and a fixing seat (14) sleeved on the outside of the rotating shaft (13), the fixing seat (14) being connected to the rotating shaft (13) for relative rotation, characterized in that: The contactless feedback device comprises: A base plate (1) mounted on a rotating shaft (13); An angle sensor magnetic block (7) and a sensing column (3) are fixedly mounted on the base plate (1); the angle sensor magnetic block (7) is a disk structure, the axis of which coincides with the axis of the rotating shaft (13), and moves in a circular motion around the rotating axis along with the base plate (1); A main structure (2) fixedly connected to a fixing seat (14), a space for accommodating an angle sensor magnetic block (7) is defined between the main structure (2) and the base plate (1), and a first arc opening is provided on the main structure (2); the sensing column (3) is arranged in the first arc opening on the main structure (2), and moves along the trajectory of the first arc opening when the base plate (1) rotates; an angle sensor body (6) mounted on the main structure (2), the angle sensor body (6) and the angle sensor magnetic block (7) being arranged opposite to each other, with a preset sensing gap between them; A proximity switch installed on the main structure (2), the proximity switch being arranged on one side of the first arc opening of the main structure (2); A signal transmission interface is used to electrically connect the angle sensor body (6) and the proximity switch; wherein, when the sensing column (3) rotates to a position relative to the proximity switch, the proximity switch outputs a signal indicating the extreme position of the rotation axis (13) through the signal transmission interface; and when the angle sensor magnet (7) rotates around the rotation axis (13), the angle sensor body (6) is used to identify the angle change of the angle sensor magnet (7) and output the current rotation angle of the rotation axis through the signal transmission interface.

2. The contactless feedback device for a ship fin stabilizer system according to claim 1, characterized in that: The angle sensor magnetic block (7) is a radial magnetization structure, with its N pole and S pole symmetrically distributed along the radial direction. The angle sensor body (6) is arranged in front of the angle sensor magnetic block (7), and its sensing area is aligned with the magnetic field distribution area at the outer edge of the angle sensor magnetic block (7).

3. The contactless feedback device for a ship fin stabilizer system according to claim 1, characterized in that: The proximity switch includes a zero position proximity switch (16), an upper electrical limit proximity switch (17) and a lower electrical end position proximity switch (18) in sequence along the circular arc path of the first circular arc opening; the zero position proximity switch (16) is arranged at a central position along the first circular arc opening; the upper electrical limit proximity switch (17) and the lower electrical end position proximity switch (18) are respectively arranged on both sides of the zero position proximity switch (16).

4. The contactless feedback device for a ship fin stabilizer system according to claim 3, characterized in that: It also includes a proximity switch adjustment mounting seat (5); the proximity switch adjustment mounting seat (5) is installed on the main structure (2), and the zero position proximity switch (16), the upper electrical limit proximity switch (17) and the lower electrical end position proximity switch (18) are respectively installed on the corresponding proximity switch adjustment mounting seat (5).

5. The contactless feedback device for a ship fin stabilizer system according to claim 4, characterized in that: The end surface of the main structure (2) is provided with a second circular arc opening, the central axis of the second circular arc opening is coaxially arranged with the central axis of the rotating shaft (13), the inner arc surface of the second circular arc opening is arranged opposite to the inner arc surface of the first circular arc opening, and the bisectors of the arc angles of the first circular arc opening and the second circular arc opening coincide with each other.

6. The contactless feedback device for a ship fin stabilizer system according to claim 5, characterized in that: It also includes a dial mounting column (8) and a pointer (9); one end of the dial mounting column (8) is fixedly connected to the base plate (1), and the other end passes through the second arc opening and extends to the outside of the main structure (2) to be connected to the pointer (9).

7. The contactless feedback device for a ship fin stabilizer system according to claim 6, characterized in that: The invention also includes a scale plate (11); the scale plate (11) is installed outside the second arc opening, and the scale corresponding to the middle vertical axis where the pointer (9) is located on the scale plate (11) is used as a zero-degree reference point, and angle scales are respectively provided on the left and right sides thereof, increasing symmetrically from zero outwards, and the maximum scale of the angle scale corresponds to the maximum limit position of the rotation axis (13).

8. The contactless feedback device for a ship fin stabilizer system according to claim 7, characterized in that: The zero position proximity switch (16) is correspondingly arranged at the zero reference point position on the scale plate (11), and the upper electrical limit proximity switch (17) and the lower electrical limit proximity switch (18) are respectively correspondingly arranged at the maximum limit angle positions on both sides of the scale plate (11).

9. The contactless feedback device for a ship fin stabilizer system according to claim 1, characterized in that: It also includes an end cover (4), which is fixedly mounted on the end surface of the main structure (2) and together with the bottom plate (1) forms a closed space; It also includes an observation window (10); the end cover (4) is provided with an arc-shaped opening, and the observation window (10) is installed at the position of the arc-shaped opening.

10. A control method using the contactless feedback device for a ship fin stabilizer system according to claim 8, characterized in that: The control method includes: Step 1: The rotating shaft drives the angle sensor magnet to rotate. During this rotation, the angle sensor magnet generates a magnetic field that changes with the angle. The angle sensor body senses this magnetic field change and outputs a continuous current signal corresponding to the angle change to the fin stabilizer control system. Step 2: The sensing column rotates synchronously with the rotation of the rotating shaft. When the sensing column rotates to the proximity switch sensing area corresponding to the preset angle position, the proximity switch senses the proximity of the sensing column and immediately outputs an on-off signal representing the angle state. The electrical signal is transmitted to the fin stabilizer control system through the signal output interface of the feedback device. Step 3: After receiving the analog angle signal output by the angle sensor body, the current fin angle is calculated based on the signal and compared with the preset target angle to determine whether the current fin angle reaches the control target value; Step 4: When the fin stabilizer control system determines that the current fin angle has reached the preset control target value and receives a limit trigger signal from any limit proximity switch, the fin stabilizer control system executes an action abort instruction, interrupts the continued driving action of the actuator, and triggers the alarm module or starts the system zeroing process; if it receives a trigger signal from the zero position proximity switch, the fin stabilizer control system determines that the current fin angle is at the zero position, enters the reset control state, performs the angle position calibration operation, and outputs a locking control instruction.

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