Crawler-type ship inspection robot

Abstract

The invention relates to the technical field of robots, in particular to a crawler-type ship inspection robot which comprises a crawler supporting plate and a robot body arranged on the crawler supporting plate, and the robot further comprises a data acquisition mechanism used for conducting three-dimensional environment data acquisition on an inspection area and sending the acquired data to a control unit; the magnetic adsorption adjusting mechanism comprises a permanent magnet arranged below the crawler belt supporting plate; the control unit generates a gap adjusting instruction based on the wall surface information provided by the data acquisition mechanism; and the magnetic adsorption adjusting mechanism responds to the gap adjusting instruction to change the air gap between the permanent magnet and the ferromagnetic wall surface, so that the motion resistance is reduced while the adsorption safety is ensured. According to the invention, the air gap between the permanent magnet and the ferromagnetic wall surface is dynamically adjusted through the magnetic adsorption adjusting mechanism based on environmental risk assessment, the motion resistance can be reduced while the adsorption safety is ensured, and the self-adaptive mode under various special working conditions is provided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of robots, in particular to a tracked ship inspection robot. BACKGROUND

[0002] During the operation of a ship, various complex and dangerous situations are faced. When the ship collides or is attacked, a breach often appears below the ship side. Due to the fact that the structure of the ship body is mostly designed to be inclined, this special structure makes it difficult for the crew to directly observe the damage situation, and it is impossible to timely and accurately grasp the degree of damage to the ship body, thereby affecting the subsequent maintenance and rescue work arrangement. Moreover, in the daily operation of the ship, the inspection work of fire hazards and narrow spaces such as oil tanks is also very important. However, these areas usually have harsh environments such as high temperature and toxic gas, which seriously threaten the life safety of personnel entering for inspection operations.

[0003] At present, although inspection robots have been applied to related scenes, the existing inspection robots have obvious deficiencies in the technical aspect. Among them, the problem of unadjustable adsorption force is prominent, which makes the robot unable to flexibly adjust the adsorption force according to the actual situation when facing ferromagnetic walls with different inclination angles or surface conditions, and it is difficult to ensure stable adsorption under various working conditions. At the same time, poor adaptability to complex environments is also a major shortcoming of existing inspection robots. In complex environments such as inclined or vertical ferromagnetic walls, the robot often cannot work stably and cannot effectively meet the actual needs of ship inspection. Therefore, it is of great practical significance to develop an inspection robot that can adapt to complex ship environments and work stably. SUMMARY

[0004] The purpose of the present application is to provide a tracked ship inspection robot to solve at least one of the above technical problems.

[0005] The present application achieves the above-mentioned purpose through the following technical solutions: A tracked ship inspection robot, comprising a tracked support plate and a robot main body arranged on the tracked support plate, the robot further comprising: a data acquisition mechanism for acquiring three-dimensional environmental data of the inspection area and sending the acquired data to a control unit; a magnetic adsorption adjusting mechanism comprising a permanent magnet arranged below the tracked support plate; The control unit generates a gap adjusting instruction based on the wall surface information provided by the data acquisition mechanism; and the magnetic adsorption adjusting mechanism changes the air gap between the permanent magnet and the ferromagnetic wall surface in response to the gap adjusting instruction, so as to reduce the movement resistance while ensuring adsorption safety.

[0006] Further, the magnetic adsorption adjusting mechanism further comprises: a gap control module, which is arranged above the permanent magnet; a lifting rod, the upper end of which is connected with the output end of the gap control module, and the lower end of which is connected with the permanent magnet; the lifting rod is driven by the gap control module to stretch and retract along a direction perpendicular to the wall surface, thereby continuously adjusting the air gap.

[0007] Further, the gap control module is a servo electric push rod or a ball screw sliding table with a built-in displacement sensor; the axis of the lifting rod coincides with the center line of the magnetic field of the permanent magnet; the displacement sensor detects the extension amount of the lifting rod and feeds back the extension amount to the control unit.

[0008] Further, the data acquisition mechanism comprises a depth camera; the depth camera is mounted on the top of a gimbal, and the gimbal is fixed to the front section of the robot; the gimbal is used to drive the depth camera to rotate in the horizontal and pitch directions, so as to realize omnidirectional acquisition of three-dimensional environmental data around the robot.

[0009] Further, the gimbal comprises: left and right rotating servos for adjusting the horizontal viewing angle of the depth camera; forward and backward rotating servos for adjusting the pitch viewing angle of the depth camera.

[0010] Further, the adjustment range of the air gap is 2mm-15mm; the control unit constructs a three-dimensional terrain based on the data collected by the data acquisition mechanism, extracts the wall roughness and obstacle height of the intended direction of travel, calculates the optimal air gap value according to the built-in magnetic force-resistance balance model, and generates corresponding gap adjustment instructions.

[0011] Further, the robot further comprises: a transmission mechanism arranged on the left and right sides of the track support plate; the transmission mechanism is used to drive the track to realize forward movement, backward movement, and differential steering in place; a shock absorption mechanism arranged between the transmission mechanism and the main body of the robot, which is used to absorb impact and keep the track adhering to the wall when overcoming obstacles; an anti-overturning wheel arranged at the front end of the bottom of the robot, which is hinged to the track support plate through a torsional spring support; the anti-overturning wheel is used to support the wall when the angle of the robot exceeds a preset threshold.

[0012] Further, the transmission mechanism comprises: The track covers the driving wheel, the driven wheel, the upper support wheel and the tensioning wheel; The step motor with a speed reducer is fixed to the track support plate through a motor support link plate, and the output shaft of the step motor is connected with the driving wheel. The left and right step motors are independently controlled, and the robot realizes in-situ steering through the speed difference of the left and right step motors.

[0013] Further, the shock-absorbing mechanism comprises: A suspension fork is hinged at the front end to the track support plate and hinged at the rear end to the robot main body. A spring is sleeved outside the guide rod of the suspension fork, and the spring is used to provide nonlinear stiffness. A suspension telescopic cylinder is used to actively adjust the suspension height of the robot main body and compensate for the deformation amount of the track when the track overcomes obstacles.

[0014] Further, the permanent magnet is a Halbach array permanent magnet which is composed of a plurality of rare earth permanent magnet blocks with different magnetization directions arranged in a ring shape with a phase difference of 90 degrees.

[0015] The track-type ship inspection robot has the following advantages: The track-type ship inspection robot has a magnetic gap adjustment function, and integrates a transmission mechanism, a shock-absorbing mechanism, a magnetic adsorption adjustment mechanism and a data acquisition mechanism. The transmission mechanism is driven by a step motor with a speed reducer, and the in-situ steering can be easily realized by differential control of the left and right motors, which greatly improves the flexibility and maneuverability of the robot in a complex cabin environment. The shock-absorbing mechanism adopts a combination design of a suspension telescopic cylinder and a spring with nonlinear stiffness. When facing the complex terrain of the inclined ship side, the undulating uneven surface and the narrow space in the ship, the shock-absorbing mechanism can effectively absorb the impact and ensure the smooth driving of the robot, providing stable support for accurate inspection. The magnetic adsorption adjustment mechanism selects a Halbach array permanent magnet, and the unique ring arrangement structure of the Halbach array permanent magnet gives strong magnetic adsorption capacity. At the same time, the magnetic adsorption adjustment mechanism precisely controls the lifting rod, which can adjust the air gap between the permanent magnet and the ferromagnetic wall surface in real time according to different wall surface conditions, realize the dynamic balance of the adsorption force and the motion resistance, ensure the reliable adsorption of the robot in various working conditions, and significantly reduce the resistance in the motion process, improve the energy utilization efficiency. The data acquisition mechanism is equipped with a depth camera and a two-axis steering engine, which can drive the depth camera to rotate flexibly in the horizontal and pitch directions, realize omnidirectional observation without dead angle, and provide comprehensive and clear environmental information for the inspection personnel.

[0016] The application successfully solves the technical problems of ship inspection, such as damage observation of a tilted ship side, fire detection in a dangerous place, and inspection in a narrow space, and has the advantages of reliable adsorption, excellent obstacle crossing performance, high intelligent degree, and the like, thereby providing an efficient, safe and intelligent solution for ship inspection. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 Figure 1 is a schematic diagram of the overall structure of a ship inspection robot according to an embodiment of the application. Figure 2 Figure 2 is a sectional view of a tracked ship inspection robot according to an embodiment of the application. Figure 3 Figure 3 is a front view of a tracked ship inspection robot according to an embodiment of the application. Figure 4 Figure 4 is a left view of a tracked ship inspection robot according to an embodiment of the application. Figure 5 Figure 5 is a top view of a tracked ship inspection robot according to an embodiment of the application.

[0018] In the figure, 1 is a driving wheel, 2 is a driven wheel, 3 is a stepping motor, 4 is a suspension fork, 5 is a spring, 6 is a tensioning wheel, 7 is a screw, 8 is a suspension telescopic cylinder, 9 is an upper support wheel, 10 is a track, 11 is a left-right rotation rudder, 12 is a depth camera, 13 is a motor support link plate, 14 is a track support plate, 15 is a gap control module, 16 is a holder, 17 is a permanent magnet, 18 is a front-rear rotation rudder, 19 is a battery, 20 is a lifting rod, and 21 is an anti-overturning wheel. DETAILED DESCRIPTION

[0019] The present application will now be discussed with reference to example embodiments. It should be appreciated that the discussed embodiments are merely for the purpose of enabling those of ordinary skill in the art to better understand and thus implement the present application, and are not intended to imply any limitation of the scope of the present application.

[0020] As used herein, the term “includes” and its variants are to be read as open-ended terms that mean “includes, but is not limited to.” The term “based on” is to be construed as “based at least in part on.” The terms “one embodiment” and “an embodiment” are to be construed as “at least one embodiment.”

[0021] Embodiment One Figure 1 Figure 1 is a schematic diagram of the overall structure of a ship inspection robot according to an embodiment of the application. As shown in the figure, according to an embodiment of the application, a tracked ship inspection robot comprises a track support plate 14, a robot main body arranged on the track support plate 14, a data acquisition mechanism, a magnetic adsorption adjusting mechanism, and a control unit. Figure 1 The robot main body comprises a robot body 1, a driving wheel 2, a driven wheel 3, a stepping motor 4, a suspension fork 5, a spring 6, a tensioning wheel 7, a screw 8, a suspension telescopic cylinder 9, an upper support wheel 10, a track 11, a left-right rotation rudder 12, a depth camera 13, a motor support link plate 14, a track support plate 15, a gap control module 16, a holder 17, a permanent magnet 18, a front-rear rotation rudder 19, a battery 20, a lifting rod 21, and an anti-overturning wheel 22. a data acquisition mechanism for acquiring three-dimensional environmental data of the inspection area and sending the acquired data to the control unit; a magnetic attraction adjustment mechanism including a permanent magnet 17 arranged below the track support plate 14; The control unit generates a gap adjustment instruction based on the wall information provided by the data acquisition mechanism, and the magnetic attraction adjustment mechanism changes the air gap between the permanent magnet 17 and the ferromagnetic wall in response to the gap adjustment instruction to reduce the motion resistance while ensuring the safety of the adsorption.

[0022] In this embodiment, a tracked ship inspection robot is proposed, which takes the track support plate 14 as the framework, and the robot body is fixed above the track support plate 14 through a damping connecting piece; a magnetic adsorption adjusting mechanism is arranged below the track support plate 14, which is composed of a permanent magnet 17, a lifting rod 20 and a gap control module 15, wherein the permanent magnet 17 can generate a single-sided magnetic field on the wall surface side, and the back side magnetic field is almost zero, which not only improves the adsorption efficiency but also avoids the magnetic leakage interference to the instruments in the cabin; the upper end of the lifting rod 20 is coaxially fixed with the output end of the gap control module 15, and the lower end is connected with the permanent magnet 17, the axis is coincident with the magnetic field center line of the permanent magnet 17, which ensures that the magnetic force direction is always perpendicular to the wall surface during lifting; the gap control module 15 selects a servo electric push rod with a built-in rotary encoder, which converts the motor rotation into linear motion through the screw-nut pair, and has a holding brake, which is self-locked when power off to prevent the permanent magnet 17 from sliding down due to gravity; the control unit is an embedded controller, which internally stores a “magnetic force-resistance balance” mathematical mapping model, the input of the model is the wall surface roughness and the obstacle height, and the output is the optimal gap, which adopts a quadratic polynomial, and the coefficients of each term of the quadratic polynomial are obtained through the early calibration experiment; the data acquisition mechanism collects the three-dimensional environmental data of the inspection area, and sends the point cloud data to the control unit, which can be realized by using a camera, a sensor and the like; after receiving the three-dimensional environmental data of the inspection area, the control unit first fits the local wall surface normal vector through the RANSAC algorithm, calculates the wall surface roughness, detects and extracts the obstacle height, and based on the wall surface roughness and the obstacle situation, calculates the best air gap by using the “magnetic force-resistance balance” mathematical mapping model, and generates a gap adjusting instruction; the gap adjustment adopts a “feedforward + feedback” double-loop control: the feedforward value is directly given by the mapping table, and the feedback loop is a PID closed loop with the actual position of the encoder, which can reduce the control error; when it is detected that the wall surface inclination angle increases (such as the wall surface inclination angle > 60°) or the surface friction coefficient decreases (such as judging the friction coefficient μ < 0.2 according to the surface oil state), the control unit automatically enters the safety priority mode, and forcibly shrinks the air gap to the minimum gap (such as 2 mm) and limits the speed to 0.1 m / s; when a weld (height > 5 mm) or a surface is extremely rough is detected, the robot switches to the obstacle avoidance mode according to the “magnetic force-resistance balance” mathematical mapping model, and the logic automatically controls the air gap to approach the maximum gap (such as 15 mm), which maximizes the reduction of the magnetic hysteresis resistance under the premise of maintaining the safety adsorption threshold, preventing the motor from being overloaded. The gap adjustment is no longer a simple “high-low switching”, but a continuous dynamic optimization based on environmental risk assessment.

[0023] The tracked ship inspection robot of the present application realizes continuous dynamic gap adjustment based on environmental risk assessment through the magnetic adsorption adjusting mechanism and the “magnetic force-resistance balance” mathematical mapping model, which can reduce the movement resistance while ensuring adsorption safety, and also has self-adaptive mode in various special working conditions.

[0024] Figure 2A cross-sectional view of a tracked ship inspection robot according to an embodiment of the present application. As shown in Figure 2 The magnetic adsorption adjusting mechanism according to an embodiment of the present application further comprises: A gap control module 15 arranged above the permanent magnet 17; A lifting rod 20, the upper end of which is connected to the output end of the gap control module 15, and the lower end of which is connected to the permanent magnet 17; The lifting rod 20 is driven by the gap control module 15 to extend and retract in a direction perpendicular to the wall surface, thereby continuously adjusting the air gap. Preferably, the gap control module 15 is a servo electric push rod or a ball screw sliding table with a built-in displacement sensor; The axis of the lifting rod 20 coincides with the center line of the magnetic field of the permanent magnet 17; The displacement sensor detects the extension amount of the lifting rod 20 and feeds back the extension amount to the control unit.

[0025] In this embodiment, the magnetic adsorption adjusting mechanism takes the gap control module 15 as the control core and is arranged above the permanent magnet 17. The gap control module 15 selects a servo electric push rod with a built-in 0.1 mm precision rotary encoder. The motor drives the screw nut pair after planetary reduction, converts the rotary motion into linear motion of the lifting rod 20, and integrates the power-off brake in the push rod to generate a static braking torque at the moment of power failure. The lifting rod 20 is coaxially fixed to the output end of the gap control module 15 at the upper end through a flange, and is rigidly connected to the back iron of the permanent magnet 17 at the lower end. The axis of the lifting rod 20 coincides with the center line of the magnetic field of the permanent magnet 17, ensuring that the magnetic field direction is always perpendicular to the wall surface within the full stroke range of 2-15 mm, avoiding lateral component force causing the track 10 to slip. The displacement sensor reads the number of screw rotations and converts it into an absolute position through the controller to feed back the extension amount to the control unit in real time, forming a position closed loop. When the control unit receives the "obstacle avoidance" or "safety first" signal, it can quickly complete the switching of the air gap, so that the robot can continuously and reliably adjust the air gap on the ship side weld, rust depression or oil surface, taking into account the maximum adsorption force and the minimum motion resistance.

[0026] The magnetic adsorption adjusting mechanism of the present application takes the gap control module as the core, and realizes continuous and reliable adjustment of the air gap through high-precision servo electric push rod, coaxial lifting rod and displacement sensor, so that the robot can take into account the maximum adsorption force and the minimum motion resistance on the complex ship surface.

[0027] Figure 3 A front view of a tracked ship inspection robot according to an embodiment of the present application. As shown in Figures 2-3 The data acquisition mechanism according to an embodiment of the present application comprises: a depth camera 12; The depth camera 12 is installed on the top of the gimbal 16; the gimbal 16 is fixed to the front section of the robot; The gimbal 16 is used to drive the depth camera 12 to rotate in the horizontal and pitch directions to realize omnidirectional collection of three-dimensional environment data around the robot. Preferably, the gimbal 16 comprises: A left-right rotation rudder 11 for adjusting the horizontal viewing angle of the depth camera 12; A front-rear rotation rudder 18 for adjusting the pitch viewing angle of the depth camera 12.

[0028] In the embodiment, the data collection mechanism takes the depth camera 12 as the sensing core, the depth camera 12 is arranged at the top of the gimbal 16, the gimbal 16 is mounted on the front beam of the robot through a damping washer, the gimbal 16 adopts an orthogonal double-rudder structure, the left-right rotation rudder 11 provides a horizontal scanning of ±180°, and the front-rear rotation rudder 18 provides a pitch of ±90°; the depth camera 12 sends the point cloud to the control unit, the control unit firstly uses the RANSAC to fit the local wall surface normal vector, then calculates the roughness with a 50mm*50mm grid, extracts the obstacle profile with a height >3mm, and generates a feedforward gap; after the feedforward value is subtracted from the real-time position of the built-in displacement sensor in the gap control module 15, a PWM drive servo electric push rod is output through a PID position loop, so that the lifting rod 20 completes the air gap adjustment; when the wall surface roughness is less than the minimum roughness threshold and there is no obstacle, the air gap is set to the minimum gap threshold to provide the maximum adsorption force, when the wall surface roughness is greater than the maximum roughness threshold or the obstacle height is greater than the obstacle height threshold, the air gap is set to the maximum gap threshold, the hysteresis loss is reduced, and the motor current is reduced.

[0029] The data collection mechanism of the application takes the depth camera as the core, realizes omnidirectional three-dimensional environment data collection through the orthogonal double-rudder gimbal, helps the control unit to accurately calculate and dynamically adjust the air gap, and makes the robot consider the maximum adsorption force and low motion resistance under different wall surface conditions.

[0030] According to an embodiment of the application, the adjustment range of the air gap is 2mm-15mm; The control unit constructs a three-dimensional terrain based on the data collected by the data collection mechanism, extracts the wall surface roughness and obstacle height in the intended direction of travel, calculates the optimal air gap value according to the built-in magnetic force-resistance balance model, and generates the corresponding gap adjustment instruction.

[0031] In this embodiment, the air gap is strictly constrained in the continuous interval of 2mm-15mm to balance the maximum adsorption force and the minimum motion resistance; the control unit firstly uses the disparity point cloud of the front 50mm*50mm collected by the depth camera 12, constructs the local three-dimensional terrain after filtering and sliding window smoothing, obtains the normal vector by plane fitting of RANSAC, calculates the arithmetic average roughness with a grid step of 0.5mm, and extracts the obstacle profile with a height difference of >3mm to obtain the obstacle height; the built-in magnetic force-resistance balance model takes the roughness and the obstacle height as input and outputs the optimal air gap, and the model coefficients are stored in the control unit Flash and can be updated on site through CAN; when the wall inclination is >60° or the image glossiness determines that the friction coefficient is <0.2, the model output is forcibly covered by the safety monitoring layer to 2mm, and the speed is limited to 0.1m / s, otherwise, the "feedforward pulse" is executed in the welding seam area-the air gap is lifted to 15mm in advance, and immediately returns to the model calculation value after passing the obstacle, so that the robot can realize reliable adsorption and the lowest energy consumption for continuous inspection on complex ferromagnetic surfaces such as ship sides and oil tanks.

[0032] The application realizes reliable adsorption and the lowest energy consumption for continuous inspection of the robot on complex ferromagnetic surfaces by constraining the air gap in the interval of 2mm-15mm, and the control unit constructs a three-dimensional terrain based on collected data and calculates an optimal value based on a magnetic force-resistance balance model.

[0033] Figure 4 A left view of the track-type ship inspection robot according to an embodiment of the application is shown in FIG. 1. Figure 5 A top view of the track-type ship inspection robot according to an embodiment of the application is shown in FIG. 2. Figures 1-5 As shown in FIG. 2, according to an embodiment of the application, the robot further comprises: A transmission mechanism is arranged on the left and right sides of the track support plate 14; the transmission mechanism is used to drive the track 10 to move forward, backward and turn in place at different speeds; A shock-absorbing mechanism is arranged between the transmission mechanism and the robot main body, and is used to absorb impact and keep the track 10 adhering to the wall when the robot is climbing over obstacles; An anti-overturning wheel 21 is arranged at the front end of the robot bottom; the anti-overturning wheel 21 is hinged to the track support plate 14 through a torsion spring support; the anti-overturning wheel 21 is used to support the wall when the robot inclination exceeds a preset threshold.

[0034] Preferably, the transmission mechanism comprises: The drive wheel 1, the driven wheel 2, the upper support wheel 9 and the tensioning wheel 6 covered by the track 10; A stepper motor 3 with a reducer, which is fixed to the track support plate 14 through a motor support link plate 13, and the output shaft of the stepper motor 3 is connected with the drive wheel 1; The left and right side stepping motors 3 are independently controlled, and the robot realizes in-place steering through the speed difference of the two side stepping motors 3. Preferably, the shock-absorbing mechanism comprises: A suspension fork 4 is hinged at the front end to the track support plate 14 and at the rear end to the robot body. A spring 5 is sleeved on the guide rod of the suspension fork 4, and the spring 5 is used to provide nonlinear stiffness. A suspension telescopic cylinder 8 is used to actively adjust the suspension height of the robot body and compensate for the deformation of the track 10 when the track 10 overcomes obstacles.

[0035] In the embodiment, the robot takes the left and right symmetrical track support plates 14 as the skeleton, and the transmission mechanism is arranged outside the track support plates 14: the driving wheel 1, the driven wheel 2, the upper support wheel 9, and the tensioning wheel 6 are collectively arranged around the track 10, the tensioning wheel 6 is hinged to the track support plate 14 through an eccentric shaft, and the tensioning force can be manually adjusted to adjust the sag of the track 10; the stepping motor 3 with a speed reducer is fixed to the track support plate 14 through the flange of the motor support connecting plate 13, and the output shaft is directly connected to the driving wheel 1 through a flat key; the left and right stepping motors 3 generate 16 kHz PWM through independent 32-bit MCUs, the stepping drive chip realizes stepless speed regulation in the preset speed range, and in-place steering is realized by controlling the speed difference of the left and right motors 3; the shock-absorbing mechanism is clamped between the transmission mechanism and the robot body: the suspension fork 4 is hinged at the front end to the track support plate 14 through a screw 7 and at the rear end to the robot body, forming a four-bar linkage floating structure, the spring 5 with an outer diameter of the guide rod provides nonlinear stiffness, and the suspension telescopic cylinder 8 selects a micro electric push rod, which is used to adjust the suspension height to absorb the impact of the ground; the control unit samples the voltage of the potentiometer at 200 Hz, outputs the push rod motor PWM after PID closed loop, compensates for the deformation of the track 10 caused by overcoming obstacles, and keeps the gap between the permanent magnet 17 and the wall surface constant; the anti-overturning wheel 21 is arranged at the front end of the bottom of the robot and is hinged to the track support plate 14 through a torsional spring support; when the body elevation angle exceeds a preset threshold (such as 15°), the anti-overturning wheel 21 touches the wall before the track 10, triggers the limit switch, and the control unit immediately switches the left and right stepping motors 3 to a high-torque mode, and limits the speed at the same time, thereby providing a reverse supporting torque for the body to prevent the body from falling backward when vertically climbing a wall or crossing a raised weld.

[0036] The track-type inspection robot can stably travel on a ship steel plate, cross high welds, and keep the track in contact with the wall throughout the process, thereby ensuring that the inspection robot safely and efficiently performs forward, backward, and in-place differential steering motion on complex ferromagnetic surfaces such as ship sides and oil tanks.

[0037] According to an embodiment of the present application, the permanent magnet 17 is a Halbach array permanent magnet, which is formed by annularly arranging a plurality of rare earth permanent magnet blocks with different magnetization directions at a phase difference of 90°.

[0038] In this embodiment, the permanent magnet 17 adopts a Halbach array structure, which is composed of a plurality of rare earth magnetic blocks with different magnetization directions arranged in a "closed magnetic circuit" unit with a 90° phase difference. The magnetization direction rotates continuously on the circumference, so that the magnetic field is superimposed and enhanced on the side facing the hull wall, while it is weakened and offset on the side away from the wall. The magnetic flux density on the side facing the hull wall is increased by 30-50% compared with the conventional bipolar arrangement, and the surface field strength is high, while the field strength on the back side is almost zero, thereby significantly reducing the magnetic interference on the cabin compass, sensors and electronic equipment while ensuring strong adsorption force. When the gap control module 15 drives the lifting rod 20 to adjust within the range of 2-15 mm, the magnetic field gradient characteristics of the Halbach array make the adsorption force decrease exponentially, which can not only provide rated adsorption force at a 2 mm gap, but also reduce hysteresis loss at a 15 mm gap, reduce the load and heating of the stepping motor 3, and realize efficient and low-energy consumption reliable wall climbing of ferromagnetic surfaces such as ship plates, oil tank walls and the like.

[0039] The application adopts a Halbach array permanent magnet, which not only enhances the adsorption force on the hull wall and reduces the back side magnetic interference, but also cooperates with the gap adjustment by the magnetic field gradient characteristics to achieve efficient and low-energy consumption reliable wall climbing of ferromagnetic surfaces of the ship.

[0040] Example two According to an embodiment of the application, a tracked ship inspection robot comprises a transmission mechanism, a shock absorption mechanism, a magnetic adsorption adjustment mechanism, a data acquisition mechanism, an anti-overturning mechanism and a control unit. Transmission mechanism: adopts a double-sided independent driving structure, and is powered by a battery 19. A stepping motor 3 is integrated with a reducer to provide large torque, and a driving wheel 1 drives a driven wheel 2 through a track 10. The track tension is adjusted by an upper support wheel 9 and a tensioning wheel 6 to ensure that the track does not derail during vertical climbing.

[0041] Shock absorption mechanism: for the uneven structure of the ship deck or bulkhead, a shock absorption mechanism composed of a suspension telescopic cylinder 8, a suspension fork 4 and a spring 5 is designed. The shock absorption mechanism not only has physical shock absorption, but also has a "posture maintaining" function. When encountering obstacles, the suspension telescopic cylinder 8 actively intervenes or the spring 5 passively compresses to compensate for the deformation of the track caused by the change of the magnetic adsorption force, so as to ensure that the effective contact area of the track 10 with the ferromagnetic wall surface is constant, prevent local slipping during vertical climbing, and make the track always adhere to the wall surface and keep the body stable.

[0042] Magnetic adsorption adjustment mechanism: A Helbeck array permanent magnet 17 is installed at the bottom, utilizing the unilateral enhancement characteristic of the magnetic field to improve adsorption efficiency. The lifting rod 20 is driven by the gap control module 15, which can precisely control the distance (i.e., air gap) between the permanent magnet 17 and the wall surface. On a flat wall surface, the gap is reduced to enhance the adsorption force. On a rough wall surface or a wall surface with welds, the magnetic field gradient characteristic of the Helbeck array is used to increase the gap, minimizing hysteresis loss and frictional resistance while ensuring a safe adsorption coefficient.

[0043] Data acquisition mechanism: The gimbal 16 integrates dual-axis servos (left-right rotation servo 11 and front-back rotation servo 18), driving the depth camera 12 to achieve omnidirectional searching. The depth camera 12 is not only used to observe damage, but also to scan the "magnetic quality" of the path ahead. When rust (decreased magnetic permeability) or thickening of non-magnetic coating is detected, the robot will automatically retract the lifting rod 20 in advance to compensate for magnetic loss.

[0044] Anti-tipping mechanism: The anti-tipping wheel 21 at the front provides auxiliary support when the center of gravity shifts, preventing the robot from tipping over when working on an inclined wall.

[0045] This invention employs a composite control logic of "feedforward + feedback" (to improve response speed). The depth camera 12 not only identifies the current position but also performs a "terrain pre-scan" of the path 5-10cm ahead of the robot. The control unit extracts the three-dimensional features of the wall surface (such as weld height, rust pit depth, and obstacle slope) through algorithms, calculates the expected gap adjustment amount, and sends it to the gap control module 15 as a feedforward signal in advance. The built-in displacement sensor monitors the actual physical position of the lifting rod 20 in real time. When the actuator fails to reach the predetermined height due to load or vibration, the displacement sensor feeds back the deviation value, which is then corrected in real time through a PID algorithm. This combination of "looking far ahead (feedforward) + moving in the present (feedback)" effectively solves the problem of adjustment lag caused by visual processing delay during the movement of the track 10.

[0046] A pre-built mathematical mapping model for "magnetic force-resistance balance" is used, and the control unit incorporates a dynamic database to perform weighted calculations based on the "wall roughness" and "magnetic quality (permeability)" fed back by the depth camera 12. When an increased wall inclination angle or oil contamination (reduced friction coefficient) is detected, the robot switches to a safety-priority mode, and the logic-automated control gap control module 15 moves towards a 2mm (minimum air gap), sacrificing movement speed for maximum adsorption force. When a weld (height > 5mm) or extremely rough surface is detected, the robot switches to obstacle avoidance mode, and the logic-automated control gap control module 15 moves towards a 15mm (maximum air gap). Utilizing the magnetic field gradient characteristics of the Helbeck array, the robot maximizes the reduction of hysteresis resistance while maintaining a safe adsorption threshold, preventing motor overload. This makes gap adjustment no longer a simple "high-low switching" but a continuous dynamic optimization based on environmental risk assessment.

[0047] An "environmental noise filtering and adaptive calibration" logic is employed to overcome the complexities of the ship's environment, where visual data may be affected by smoke and reflections. This logic incorporates a Kalman filter algorithm to fuse the roughness data fed back by the depth camera 12 with the position data from the displacement sensor, eliminating noise caused by robot vibration or changes in lighting. When the robot starts in a flat area, the system automatically performs a "zero-point calibration," where the lifting rod 20 drives the permanent magnet 17 to touch the wall and retract, using the displacement sensor to record the absolute zero point, ensuring absolute accuracy within the 2mm-15mm adjustment range.

[0048] A "safety protection under abnormal operating conditions" logic is adopted to overcome the danger of robot falling due to sensor failure. The control unit monitors the communication status between the depth camera 12 and the displacement sensor in real time. Once an abnormal sensor data is detected (such as visual occlusion or sensor disconnection), the gap control module 15 immediately triggers the "physical safety protection logic": automatically retracting the lifting rod to the minimum air gap (2mm) to ensure that the robot is locked to the wall with maximum suction force, and sending an alarm to the backend.

[0049] Example 3 According to one embodiment of the present invention, a control method for a tracked ship inspection robot, employing any tracked ship inspection robot of the present invention, includes the following steps: Step S102: Perform "zero-position calibration"; The robot is placed on a flat area. The lifting rod 20 drives the permanent magnet 17 to touch the wall and retract to the minimum air gap (2mm). The absolute zero point is recorded by the displacement sensor to ensure the absolute accuracy of the air gap adjustment range (2mm-15mm).

[0050] Step S104: The control unit switches modes based on the data collected by the data acquisition mechanism; The data acquisition mechanism collects three-dimensional environmental data of the inspection area and sends the collected data to the control unit. The control unit fuses the roughness data fed back by the depth camera 12 with the position data of the displacement sensor, removes noise caused by the robot's own vibration or changes in light and shadow, constructs three-dimensional terrain, and extracts the wall inclination angle, wall roughness and obstacle height in the pre-travel direction. Step 1: Determine if the wall tilt angle is greater than the tilt angle threshold (e.g., 60°); if so, switch the target mode to safety priority mode; otherwise, proceed to step 2. Step 2: Determine if the wall roughness is less than the minimum roughness threshold. If so, switch the target mode to safety priority mode; otherwise, proceed to step 3. Step 3: Determine if the obstacle height is greater than the obstacle height threshold (e.g., 5mm); if so, switch the target mode to obstacle avoidance mode; otherwise, proceed to step 4. Step 4: The "magnetic force-resistance balance" mathematical mapping model obtains the optimal air gap based on wall roughness and obstacle height; The control unit sends the target mode or optimal air gap as a gap adjustment command to the magnetic adsorption adjustment mechanism; In step S106, the magnetic adsorption adjustment mechanism changes the air gap between the permanent magnet 17 and the ferromagnetic wall surface in response to the gap adjustment command. When the gap adjustment command is in safety priority mode, the air gap will be reduced to the minimum air gap (2mm). When the gap adjustment command is in obstacle avoidance mode, the air gap is set to the maximum air gap (15mm). When the gap adjustment command is set to the optimal air gap, the air gap is set to the optimal air gap.

[0051] The thresholds in this embodiment can be set specifically based on the specific conditions of the ship and the state of the robot, and are not limited to the specific values ​​used in this embodiment.

[0052] The control method for a tracked ship inspection robot provided by this invention ensures absolute accuracy in air gap adjustment through "zero-point calibration," laying the foundation for subsequent precise control. The control unit intelligently switches modes based on data feedback from the data acquisition mechanism, integrates data from depth cameras and displacement sensors to construct a 3D terrain, accurately extracts key information such as wall inclination angle, roughness, and obstacle height, and flexibly switches between safety-priority and obstacle avoidance modes based on set thresholds, or obtains the optimal air gap through a "magnetic-resistance balance" model. The magnetic adsorption adjustment mechanism responds to gap adjustment commands, quickly and accurately adjusting the air gap between the permanent magnet and the ferromagnetic wall, effectively balancing adsorption force and motion resistance. This method can adapt to the complex and ever-changing inspection environment of ships, significantly improving the robot's stability, safety, and inspection efficiency under different working conditions. Furthermore, various thresholds can be flexibly set according to actual conditions, enhancing the flexibility and applicability of control.

[0053] Example 4 The tracked ship inspection robot of this invention is applied to ship inspection work, including performing ship hull damage investigation and damage assessment, fire detection and life search and rescue at fire scene, and inspection of oil tanks and confined spaces with double bottoms.

[0054] After a ship is damaged, personnel cannot directly observe the tilted outer side of the hull. The tracked ship inspection robot of this invention is deployed to perform hull damage inspection and assessment. The permanent magnet 17 is adjusted to a smaller gap (e.g., 2-5mm) via the gap control module 15. The robot system has a built-in dynamic database that weights the "wall roughness" and "magnetic quality (permeability)" fed back by the depth camera 12, making gap adjustment no longer a simple "high-low switching" but a continuous dynamic optimization based on environmental risk assessment. When an increased wall tilt angle or oil contamination (reduced friction coefficient) is detected, a safety-priority mode is switched, and the logic automatically moves towards 2mm, sacrificing movement speed for maximum adsorption force. When a weld (height > 5mm) or extremely rough surface is detected, an obstacle avoidance mode is switched, and the logic automatically moves towards 15mm. Utilizing the magnetic field gradient characteristics of the Helbeck array, the robot maximizes the reduction of magnetic hysteresis resistance while maintaining a safe adsorption threshold, preventing motor overload. The robot crawls along the outer side of the ship, and the depth camera 12 adjusts its viewing angle via the left and right rotation servo motor 11 and the forward and backward rotation servo motor 18 to perform 3D modeling and scanning of the breach edge. The system transmits the breach location, size, and structural tearing status back to the deck personnel in real time, providing accurate data support for damage control decisions.

[0055] When a fire breaks out in a cabin, with thick smoke and high temperatures, the tracked ship inspection robot of this invention is deployed to replace personnel to perform fire detection and life search and rescue operations. Utilizing the high mobility of the tracks 10, it traverses scattered firefighting equipment or debris. When crossing obstacles, the shock absorption mechanism (including the suspension fork 4, spring 5, and suspension telescopic bar 8) actively intervenes. The suspension telescopic bar 8 adjusts the angle of the suspension fork 4 in real time according to the obstacle height, ensuring that the image from the depth camera 12 does not shake violently. The depth camera 12, combined with infrared thermal imaging (optional), assists in identifying the core location of the fire source and searching for trapped personnel, and can quickly turn around in narrow corridors using its on-the-spot turning function.

[0056] In confined spaces such as oil tanks where toxic or harmful gases are present, the tracked ship inspection robot of this invention can be deployed to enter and perform inspections of oil tanks and double-bottomed confined spaces using its compact structure. For potential reinforcing ribs or weld protrusions at the bottom of the oil tank, the clearance control module 15 appropriately raises the height of the permanent magnet to prevent physical collisions and sparks between the magnet and obstacles. Simultaneously, the anti-tipping wheels 21 at the bow provide auxiliary support when the robot climbs over vertical reinforcing ribs, preventing a shift in the center of gravity that could cause the robot to tip over, ensuring absolute safety during the inspection process.

[0057] When a tracked ship inspection robot encounters extreme terrain (welds and rusted surfaces), it executes the following procedure: Step 1: Conduct terrain prediction; When the robot detects a hull weld or a severely corroded area ahead, it uses depth camera 12 to identify the height of the weld or the depth of the rust pits. Step 2: Based on the terrain prediction results, perform gap pre-adjustment and suspension compensation; The gap control module 15 drives the lifting rod 20 to lift slightly, increasing the air gap between the permanent magnet 17 and the wall, preventing hard friction between the bottom surface of the magnet and the weld. This prevents the permanent magnet base from directly impacting the weld and generating sparks, which is crucial in the inspection of oil and gas tanks. The suspension telescopic cylinder 8 works in coordination to ensure that the track 10 maintains a sufficient envelope area when crossing the weld seam, ensuring that the magnetic attraction force, although weakened, is still within the safe threshold. Step 3: Pass through extreme terrain at low speed; Stepper motor 3 switches to high torque low speed mode and smoothly crosses extreme terrain. After that, gap control module 15 automatically returns to the initial set height.

[0058] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

[0059] It should be understood that the sequence number of each step in the invention and embodiments of the present invention does not absolutely imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

Claims

1. A tracked ship inspection robot, comprising a track support plate (14) and a robot body disposed on the track support plate (14), characterized in that, The robot also includes: The data acquisition mechanism is used to collect three-dimensional environmental data of the inspection area and send the collected data to the control unit. The magnetic adsorption adjustment mechanism includes a permanent magnet (17) disposed below the track support plate (14). The control unit generates a gap adjustment command based on the wall information provided by the data acquisition mechanism; the magnetic adsorption adjustment mechanism responds to the gap adjustment command to change the air gap between the permanent magnet (17) and the ferromagnetic wall to reduce motion resistance while ensuring adsorption safety.

2. The tracked ship inspection robot according to claim 1, characterized in that, The magnetic adsorption adjustment mechanism further includes: A gap control module (15) is disposed above the permanent magnet (17); The lifting rod (20) has its upper end connected to the output end of the gap control module (15) and its lower end connected to the permanent magnet (17). The lifting rod (20) extends and retracts in a direction perpendicular to the wall under the drive of the gap control module (15), thereby continuously adjusting the air gap.

3. The tracked ship inspection robot according to claim 2, characterized in that: The gap control module (15) is a servo electric push rod or ball screw slide with a built-in displacement sensor. The axis of the lifting rod (20) coincides with the center line of the magnetic field of the permanent magnet (17); The displacement sensor detects the extension amount of the lifting rod (20) and feeds back the extension amount to the control unit.

4. The tracked ship inspection robot according to claim 1, characterized in that, The data acquisition mechanism includes: a depth camera (12); The depth camera (12) is mounted on the top of the gimbal (16); the gimbal (16) is fixed to the front of the robot; The gimbal (16) is used to drive the depth camera (12) to rotate in the horizontal and pitch directions, so as to collect three-dimensional environmental data around the robot from all directions.

5. The tracked ship inspection robot according to claim 4, characterized in that, The gimbal (16) includes: A left-right rotation servo (11) is used to adjust the horizontal viewing angle of the depth camera (12); A forward and backward rotating servo (18) is used to adjust the pitch angle of the depth camera (12).

6. The tracked ship inspection robot according to claim 1, characterized in that: The air gap can be adjusted from 2mm to 15mm. The control unit constructs a three-dimensional terrain based on the data collected by the data acquisition mechanism, extracts the wall roughness and obstacle height in the pre-travel direction, calculates the optimal air gap value according to the built-in magnetic-resistance balance model, and generates the corresponding gap adjustment command.

7. The tracked ship inspection robot according to claim 1, characterized in that, The robot also includes: The transmission mechanism is located on the left and right sides of the track support plate (14); the transmission mechanism is used to drive the track (10) to achieve forward, backward and differential steering in place; A shock-absorbing mechanism is provided between the transmission mechanism and the robot body to absorb impact and keep the track (10) close to the wall when crossing obstacles; An anti-tipping wheel (21) is located at the front end of the bottom of the robot. The anti-tipping wheel (21) is hinged to the track support plate (14) through a torsion spring bracket. The anti-tipping wheel (21) is used to support the robot when the robot's pitch angle exceeds a preset threshold.

8. The tracked ship inspection robot according to claim 7, characterized in that, The transmission mechanism includes: The track (10) covers the drive wheel (1), driven wheel (2), upper support wheel (9), and tension wheel (6). A stepper motor (3) with a speed reducer is fixed to the track support plate (14) via a motor support connecting plate (13), and the output shaft of the stepper motor (3) is connected to the drive wheel (1). The stepper motors (3) on the left and right sides are independently controlled, and the robot can turn in place by the speed difference of the stepper motors (3) on both sides.

9. The tracked ship inspection robot according to claim 7, characterized in that, The shock absorption mechanism includes: The suspension fork (4) is hinged at the front end to the track support plate (14) and at the rear end to the robot body; A spring (5) is sleeved on the outside of the guide rod of the suspension fork (4), and the spring (5) is used to provide nonlinear stiffness; The suspension telescopic cylinder (8) is used to actively adjust the suspension height of the robot body and compensate for the deformation of the track (10) when crossing obstacles.

10. The tracked ship inspection robot according to any one of claims 1-9, characterized in that: The permanent magnet (17) is a Heilbeck array permanent magnet, which is composed of multiple rare earth permanent magnet blocks with different magnetization directions arranged in a ring with a 90° phase difference.

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