Magnetic crawler and crawling control method thereof

Abstract

The invention relates to a magnetic crawl device and a crawl control method thereof, and the magnetic crawl device comprises a frame and a magnetic component; two moving wheels are mounted at the front end of the frame, a moving wheel is mounted at the rear end of the frame, the moving wheel at the front end is a driving wheel connected with a driving device, and the driving device is mounted in the frame; the magnetic attraction assembly comprises a first magnetic attraction structure and a second magnetic attraction structure. The first magnetic attraction structure comprises three fan-shaped electromagnetic attraction structures in one-to-one correspondence with the three moving wheels, the radius of each fan-shaped electromagnetic attraction structure is smaller than that of each moving wheel, and each fan-shaped electromagnetic attraction structure is coaxial with the corresponding moving wheel and rotatably mounted on the moving wheel; the second magnetic attraction structure comprises a permanent magnet and a lifting mechanism, the permanent magnet is installed in the middle of the frame through the lifting mechanism, and the lifting mechanism is used for adjusting the distance between the permanent magnet and the frame. The crawler solves the problem that an existing crawler is limited in wall scene capable of crawling in single-time crawling motion.

Description

Technical Field

[0001] This application relates to the field of crawlers, and in particular to a magnetic crawler and its crawling control method. Background Technology

[0002] Most existing wall-climbing robots have simple structures and constant adsorption forces, limiting their movement to specific situations. Specifically, due to the constant magnetic force, the crawler is prone to falling when the wall's magnetism is weak, and the crawler experiences excessive resistance when the wall's magnetism is strong, meaning the range of wall magnetic fields the crawler can adapt to is limited. Simultaneously, the crawler is also prone to falling when the wall's angle of inclination is large. To avoid these problems, a stronger magnetic force could be applied to the crawler, but this would result in excessive resistance when moving on horizontal walls. Therefore, current crawlers can only traverse a limited number of wall surfaces in a single crawling motion. Furthermore, due to the fixed shape and magnetic properties of the crawler, it cannot move on walls with significant curvature or corners.

[0003] There is currently no effective solution to the problem that crawlers can only crawl a limited number of wall surfaces in a single crawling motion. Summary of the Invention

[0004] This invention provides a magnetic crawler and its crawling control method to solve the problem that current crawlers can only crawl on a limited number of wall surfaces in a single crawling motion.

[0005] In a first aspect, the present invention provides a magnetic crawler, comprising: a frame and a magnetic assembly; The frame has two casters at the front and one caster at the rear. The front caster is a drive wheel connected to a drive unit, which is installed inside the frame. The magnetic attraction assembly includes a first magnetic attraction structure and a second magnetic attraction structure: the first magnetic attraction structure includes three sector-shaped electromagnetic attraction structures corresponding to the three moving wheels, the radius of the sector-shaped electromagnetic attraction structure is smaller than the radius of the moving wheels, and each sector-shaped electromagnetic attraction structure is coaxially and rotatably mounted on the moving wheels; the second magnetic attraction structure includes a lifting mechanism and a permanent magnet mounted in the middle of the frame through the lifting mechanism, the lifting mechanism being used to adjust the distance between the permanent magnet and the frame.

[0006] Secondly, this invention provides a control method for a magnetic crawler, used to control the adsorption force of the magnetic crawler described in the first aspect when crawling on a magnetic wall surface, comprising: Calculate the first adhesion force limit of the magnetic crawler when it crawls on a magnetic wall. Second Adsorption Force Limit :

[0007]

[0008] in, G and These represent the gravity of the magnetic crawler and the gravity of its load, respectively. and These represent the static friction coefficient and the rolling friction coefficient between the drive wheel and the magnetic wall, respectively. α Indicates the tilt angle of the magnetic wall. η This indicates the transmission efficiency of the reducer in the drive unit. This indicates the maximum driving torque of the motor in the drive unit. R Indicates the radius of the drive wheel; The target attraction force of each sector-shaped electromagnetic adsorption structure and the permanent magnet on the magnetic wall is set at... and between.

[0009] Thirdly, the present invention provides an adaptive crawling system, including the magnetic crawler described in the first aspect and its controller, wherein the controller is used to execute the control method of the magnetic crawler described in the second aspect.

[0010] Compared with related technologies, the magnetic crawler in this invention, by employing an electromagnetic-permanent magnet synergistic adsorption system, can adjust the crawler's adsorption force on the wall surface in real time according to actual conditions. For example, the magnetic force can be increased when crawling a wall with weak magnetism and decreased when crawling a wall with strong magnetism. Or, the magnetic force can be increased when crawling a steep wall and decreased when crawling a horizontal wall. Therefore, the magnetic crawler provided in this embodiment can adjust the adsorption force on the wall surface in real time according to the actual wall surface conditions during a single crawling motion, thereby adapting to more wall surface scenarios and solving the problem that current crawlers can only crawl on a limited number of wall surface scenarios in a single crawling motion.

[0011] Details of one or more embodiments of this application are set forth in the following drawings and description to make other features, objects and advantages of this application more readily apparent. Attached Figure Description

[0012] Figure 1 This is a structural diagram of the magnetic crawler provided in this embodiment; Figure 2 This is a perspective view of the fan-shaped electromagnetic adsorption structure provided in this embodiment; Figure 3 This is a planar structural diagram of the fan-shaped electromagnetic adsorption structure provided in this embodiment; Figure 4 This is a structural diagram of the second magnetic attraction structure provided in this embodiment; Figure 5 This is a structural diagram of the rotating mechanism provided in this embodiment; Figure 6 This is a force analysis diagram of the magnetic crawler provided in this embodiment; Figure 7 This is a diagram showing the crawling posture of the magnetic crawler provided in this embodiment on a flat wall surface; Figure 8 This is a flowchart illustrating the crawling process of the magnetic crawler on a flat wall surface provided in this embodiment. Figure 9 This is a diagram showing the crawling posture of the magnetic crawler on the curved wall surface provided in this embodiment; Figure 10 This is a flowchart illustrating the crawling process of the magnetic crawler on the curved wall surface provided in this embodiment. Figure 11 This is a diagram showing the change in the crawling posture of the magnetic crawler provided in this embodiment when passing through a right-angled wall; Figure 12 This is a flowchart illustrating the crawling process of the magnetic crawler provided in this embodiment when passing through a right-angled wall. Figure 13 This is a flowchart illustrating the crawling process of the magnetic crawler provided in this embodiment when passing over uneven walls. Detailed Implementation

[0013] To better understand the purpose, technical solution, and advantages of this application, the application is described and illustrated below in conjunction with the accompanying drawings and embodiments.

[0014] Unless otherwise defined, the technical or scientific terms used in this application shall have the general meaning understood by one of ordinary skill in the art to which this application pertains. Words such as “a,” “an,” “an,” “the,” “the,” and “these” used in this application do not indicate quantitative limitation and may be singular or plural. The terms “comprising,” “including,” “having,” and any variations thereof used in this application are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or device that comprises a series of steps or modules (units) is not limited to the listed steps or modules (units) but may include steps or modules (units) not listed, or may include other steps or modules (units) inherent to these processes, methods, products, or devices. Words such as “connected,” “linked,” and “coupled” used in this application are not limited to physical or mechanical connections but may include electrical connections, whether direct or indirect. “Multiple” used in this application refers to two or more. “And / or” describes the relationship between related objects, indicating that three relationships may exist; for example, “A and / or B” can represent: A alone, A and B simultaneously, and B alone. Normally, the character " / " indicates that the objects before and after it are in an "or" relationship. The terms "first," "second," "third," etc., used in this application are merely to distinguish similar objects and do not represent a specific order of objects.

[0015] This embodiment provides a magnetic crawler. Figure 1 This is a structural diagram of the magnetic crawler provided in this embodiment, as shown below. Figure 1 As shown, the magnetic crawler includes a frame and a magnetic assembly.

[0016] The frame has two movable wheels at the front end and one movable wheel at the rear end. The movable wheel at the front end is a drive wheel 13 connected to a drive unit 14, which is installed inside the frame.

[0017] In this embodiment, the crawler adopts a three-wheel structure. The front two wheels are drive wheels 13, which provide support and drive force for the crawler. The rear wheel is a swivel wheel, which does not provide drive force and is only used for support and adsorption. Combined with the symmetrical mechanical layout design, the crawler has omnidirectional movement capability while maintaining structural balance.

[0018] The drive unit 14 is equipped with a dual-drive differential steering system. Its power core is driven by an integrated geared motor, which synchronously drives the two drive wheels 13 at the front end. Flexible steering is achieved by adjusting the speed difference between the two drive wheels 13 in real time.

[0019] Reference Figures 1 to 5The vehicle frame includes a first frame 11 (front body, front vehicle body) and a second frame 12 (rear body, rear vehicle body). The first frame 11 is rotatably connected to the second frame 12 via a rotating mechanism. The rotating mechanism is used to adjust the angle between the first frame 11 and the second frame 12 in the direction of travel. Two drive wheels 13 and a drive unit 14 are both mounted on the first frame 11, and casters are mounted on the second frame 12. In this embodiment, the rotating mechanism includes an angle motor 33 and a connecting shaft. The first frame 11 and the second frame 12 are rotatably connected via the connecting shaft. The angle motor 33 can be mounted on either the first frame 11 or the second frame 12 and is used to control the rotation of the connecting shaft, thereby controlling the angle between the first frame 11 and the second frame 12. For example, the first frame 11 and the second frame 12 are rotatably connected by a connecting shaft. One end of the connecting shaft is rotatably mounted on the first frame 11, and the other end is fixedly connected to the second frame 12. When the connecting shaft rotates on the first frame 11, it drives the second frame 12 to rotate relative to the first frame 11, thereby adjusting the angle between the first frame 11 and the second frame 12. Essentially, the connecting shaft constitutes a hinge mechanism. The connecting shaft is coaxially fixed with the first gear 31, and the angle motor 33 is fixedly mounted on the first frame 11. The output shaft of the angle motor 33 is coaxially fixed with the second gear 32, and the first gear 31 and the second gear 32 mesh. When the angle motor 33 mounted on the first frame 11 drives the first gear 31 to rotate through the second gear 32, and thus drives the connecting shaft to rotate on the first frame 11, the connecting shaft can drive the second frame 12 to rotate relative to the first frame 11.

[0020] The magnetic attraction assembly includes a first magnetic attraction structure and a second magnetic attraction structure. The first magnetic attraction structure includes three sector-shaped electromagnetic attraction structures corresponding to the three moving wheels. The radius of the sector-shaped electromagnetic attraction structure is smaller than the radius of the moving wheel. Each sector-shaped electromagnetic attraction structure is coaxial with the moving wheel and rotatably mounted on the moving wheel. The second magnetic attraction structure includes a permanent magnet 24 and a lifting mechanism. The permanent magnet 24 is mounted in the middle of the frame through the lifting mechanism, which is used to adjust the distance between the permanent magnet and the frame.

[0021] In this embodiment, the magnetic crawler adopts an electromagnetic-permanent magnet synergistic adsorption system. The crawler relies on magnetic adsorption force to adhere to the wall surface. The drive wheel and universal wheel are designed with a fan-shaped electromagnetic adsorption mechanism, which can rotate actively. A permanent magnet is installed at the bottom of the crawler, and the permanent magnet block can also be raised and lowered.

[0022] Please refer to this again. Figure 2 and Figure 3The fan-shaped electromagnetic adsorption structure includes a fan-shaped mounting shell 211 and multiple columnar electromagnetic actuation units 212. The multiple columnar electromagnetic actuation units 212 are uniformly installed within the fan-shaped mounting shell 211 along its arc direction. The axes of the columnar electromagnetic actuation units 212 are orthogonal to the radial lines of the fan-shaped mounting shell 211. (Refer to...) Figure 1 The first magnetic attraction structure also includes a micro motor 22 and a drive shaft. The drive shaft is coaxial with and rotatably mounted on the movable wheel. The micro motor 22 is fixed to one side of the movable wheel via a connecting rod 23 and provides rotational driving force to the drive shaft. The fan-shaped electromagnetic adsorption mechanism is mounted on the drive shaft. When the micro motor 22 is working, the drive shaft can drive the fan-shaped electromagnetic adsorption mechanism to rotate relative to the movable wheel, thereby adjusting the direction of the adsorption force. Exemplarily, the movable wheel may have an inner cavity in which the fan-shaped electromagnetic adsorption structure is disposed. Additionally, the movable wheel may have an installation area on one side in which the fan-shaped electromagnetic adsorption structure is disposed.

[0023] and reference Figure 4 The lifting mechanism includes a lifting motor 252, a ball screw 251, and a limiting rod 253. The lifting motor 252 is used to drive the ball screw 251 to rotate. The permanent magnet 24 is mounted on the ball screw 251. The limiting rod 253 is parallel to the ball screw 251 and slides through the permanent magnet 24 to limit the rotation of the permanent magnet 24, so that the permanent magnet 24 can be driven to move up and down when the ball screw 251 rotates.

[0024] In summary, the electromagnetic-permanent magnet synergistic adsorption system used in this embodiment of the magnetic crawler has the following characteristics: 1. Adopting a dual-mode design of active electromagnetic drive and passive magnetic oscillation, the innovative sector-based magnetic pole array design achieves matching between the magnetic pole structure and the sector geometry through three sets of columnar electromagnetic actuation units conformally arranged along the sector contour. The central axis of the magnetic poles is orthogonal to the radial baseline of the sector. This spatial arrangement can generate a composite magnetic field distribution with gradient characteristics through the phase superposition of magnetic pole vectors. The sector-shaped electromagnetic adsorption structure can actively adjust the direction and magnitude of the magnetic field through motor control. If the motor does not work, the sector-shaped electromagnetic adsorption structure can also achieve passive oscillation through the magnetism of the wall.

[0025] Specifically, this structure integrates multiple cylindrical electromagnets within a single fan-shaped area of ​​the wheel, achieving concentrated magnetic force output and localized enhancement, thus improving adhesion stability and adsorption efficiency. It boasts advantages such as compact structure, flexible control, and strong adaptability. Three cylindrical electromagnet units are arranged side-by-side within the fan-shaped installation area; each electromagnet unit includes a cylindrical iron core and a surrounding coil structure; each cylindrical electromagnet can be electrically connected to an electromagnetic control system, enabling independent adjustment of the adsorption force; the fan-shaped area faces the external wall. The three cylindrical electromagnets are symmetrically arranged along the arc of the fan-shaped area, close to the inner wall of the wheel rim; magnetic isolation structures or non-magnetic materials are used between the electromagnets to reduce magnetic flux interference; the wheel rim body is made of non-magnetic high-strength material to ensure concentrated magnetic flux output to the wall; the electromagnetic control system can independently control the on / off state, current magnitude, and operating sequence of each electromagnet. A comparison of this fan-shaped electromagnetic adsorption mechanism with common rectangular electromagnet blocks is shown in the table below: Table 1. Comparison of Fan-Shaped Electromagnetic Adsorption Mechanism and Rectangular Electromagnetic Block

[0026] As shown in Table 1, the advantages of the sector-shaped electromagnetic adsorption mechanism are as follows: Greater control flexibility: Multiple cylindrical electromagnets can be controlled by independent circuits to achieve multi-level magnetization, adsorption logic optimization, dynamic switching, and other functions, adapting to different climbing postures and complex wall surfaces. Rectangular electromagnet structures provide overall excitation and cannot achieve local control or intelligent management of adsorption rhythm.

[0027] Superior thermal management performance: This invention employs a distributed low-power electromagnet combination, resulting in a shorter heat dissipation path, more uniform heat source distribution, and easier overall heat generation control, which is beneficial for long-term stable system operation. In contrast, heat is concentrated in a single rectangular electromagnet structure, and prolonged energization may lead to localized overheating of the magnetic core, affecting adsorption performance.

[0028] Higher space utilization efficiency: Cylindrical electromagnets are arranged in an arc and embedded in a fan-shaped area. The geometry fits the edge of the wheel better, maximizing the use of limited space. Rectangular block electromagnets often create dead angles when placed in circular edge areas, resulting in wasted space or structural interference.

[0029] It has a stronger ability to adapt to complex wall surfaces: When encountering uneven walls, local obstacles or holes, some of the multiple cylindrical electromagnets can still be independently attracted to maintain the crawler's adhesion; while rectangular electromagnets have an integral attraction structure, and once some areas cannot be attached tightly, the overall attraction will be significantly reduced.

[0030] 2. The bottom of the equipment is equipped with a modular permanent magnet adsorption body, which adopts a combination of precision ball screw and motor. The vertical lifting and lowering of the permanent magnet block is achieved through the screw and nut pair, thereby adjusting the adsorption force.

[0031] 3. The casters do not provide driving force here, but serve a supporting and adsorption function. Their structural design eliminates power transmission, enabling 360° free steering. A single motor controls the fan-shaped electromagnetic adsorption structure, allowing it to actively adjust the direction and magnitude of the magnetic field, providing a more stable adsorption and support force.

[0032] Therefore, the core of this electromagnetic-permanent magnet synergistic adsorption system lies in combining the high transmission efficiency (low friction loss, high positioning accuracy) of the ball screw with the precise pulse control capability of the motor, enabling real-time adjustment of the magnetic adsorption force and its range of action according to requirements. For example, in a magnetic adsorption wall-climbing robot, by adjusting the distance between the permanent magnet and the wall surface, both strong magnetic adsorption force and adaptive adsorption and stable operation on complex curved surfaces (such as weld seams and rivet surfaces) can be ensured.

[0033] In summary, the magnetic crawler in this embodiment, by employing an electromagnetic-permanent magnet synergistic adsorption system, can adjust the crawler's adsorption force on the wall surface in real time according to actual conditions. For example, the magnetic force can be increased when crawling a wall with weak magnetism and decreased when crawling a wall with strong magnetism. Or, the magnetic force can be increased when crawling a steep wall and decreased when crawling a horizontal wall. Therefore, the magnetic crawler provided in this embodiment can adjust its adsorption force on the wall surface in real time according to the actual wall conditions during a single crawling motion, thereby adapting to more wall surface scenarios and solving the problem that current crawlers can only crawl on a limited number of wall surface scenarios in a single crawling motion.

[0034] To better enable the crawler to move, the crawler also integrates the following sensors: The ultrasonic thickness gauge is installed at the front end of the chassis (on the first frame) and collects the wall thickness in real time by contacting the surface being measured.

[0035] An ultrasonic rangefinder is installed at the rear of the chassis (on the second frame) to measure the distance between the bottom surface of the permanent magnet and the wall surface.

[0036] Inductive sensors are installed at the front end of the crawler (on the first frame) to detect the magnetic properties of the wall surface and help determine the magnetic permeability of the material.

[0037] Laser contour sensors are installed at the front, middle and rear of the chassis (on both the first and second frames) to measure the curvature of the wall and generate the three-dimensional contour of the object (height, width, curvature, etc.) in real time.

[0038] The data obtained from the aforementioned sensors can be used for the movement control of the crawler. For example, when the thickness and magnetic properties of the wall surface and the distance between the permanent magnet and the wall surface are measured, the attraction force of the permanent magnet on the wall surface and the attraction force of the fan-shaped electromagnetic adsorption structure on the wall surface (the distance between the fan-shaped electromagnetic adsorption structure and the wall surface is known) can be calculated.

[0039] Based on the aforementioned magnetic crawler, this embodiment also provides a control method for the magnetic crawler. This control method mainly consists of two parts: first, controlling the adsorption force of the magnetic crawler when crawling on a magnetic wall surface; and second, controlling the angle between the first and second frames of the magnetic crawler through a rotating mechanism.

[0040] The first part includes steps S110 to S150.

[0041] Step S110: Calculate the first adsorption force limit when the magnetic crawler crawls on the magnetic wall surface. :

[0042] in, G This indicates the gravity of the magnetic crawler. This indicates the gravity of the load on the magnetic crawler. This represents the coefficient of static friction between the drive wheel and the magnetic wall. α This indicates the tilt angle of the magnetic wall.

[0043] Please combine Figure 6 The first adsorption force limit is the minimum adsorption force exerted by each magnetic adsorption unit (fan-shaped electromagnetic adsorption structure or permanent magnet) on the wall surface. To maintain the crawler's stability on the wall surface and prevent slippage, the following conditions must be met:

[0044] Combining the above equations, we get:

[0045] The adsorption force provided by each magnetic adsorption unit must meet the following conditions:

[0046] Step S120: Calculate the second adsorption force limit when the magnetic crawler crawls on the magnetic wall surface. :

[0047] in, η This indicates the transmission efficiency of the reducer in the drive unit. This indicates the maximum driving torque of the motor in the drive unit. G This indicates the gravity of the magnetic crawler. This indicates the gravity of the load on the magnetic crawler. R Indicates the radius of the drive wheel. This represents the coefficient of rolling friction between the drive wheel and the magnetic wall. α This indicates the tilt angle of the magnetic wall.

[0048] Meanwhile, considering that the greater the adsorption force, the greater the friction between the crawler and the wall, the greater the driving force required by the drive device. However, the driving force of the drive device has an upper limit, so it is necessary to limit the upper limit of the adsorption force. The second adsorption force limit is the maximum adsorption force of each magnetic adsorption unit (fan-shaped electromagnetic adsorption structure or permanent magnet) on the wall.

[0049] Specifically, the adsorption force of each magnetic adsorption unit is introduced into the motor torque expression. Then, the driving torque required by each motor is:

[0050] The calculation yields:

[0051] Therefore, the second adsorption force limit is:

[0052] Step S130: Set the target adsorption force of each sector-shaped electromagnetic adsorption structure and the permanent magnet on the magnetic wall between the first adsorption force limit and the second adsorption force limit.

[0053] By controlling the adsorption force of each magnetic adsorption unit on the wall surface between a first adsorption force limit and a second adsorption force limit, it can be ensured that the crawler will not fall off, but at the same time, it will not hinder the crawler's progress. Therefore, the target adsorption force of each sector-shaped electromagnetic adsorption structure on the magnetic wall surface is set between the first adsorption force limit and the second adsorption force limit.

[0054] Step S140: Control the power of the fan-shaped electromagnetic adsorption structure according to the target adsorption force of the fan-shaped electromagnetic adsorption structure on the magnetic wall.

[0055] For a sector-shaped electromagnetic adsorption structure, its power can be controlled to adjust the adsorption force on the wall. Specifically, for the electromagnet in the sector-shaped electromagnetic adsorption structure, there are four main factors affecting the magnitude of the electromagnet's magnetic force: the number of turns of the coil wound around the iron core, the intensity of the current in the coil, the distance between the coil and the iron core, and the size and shape of the iron core. The direction of the magnetic field is determined by the direction of the current and the winding direction of the coil, following the right-hand screw rule: If the magnetic induction intensity B is uniformly distributed along the surface of the magnetic poles, then the basic formula for calculating the electromagnetic attraction force is:

[0056] in, F Indicates adsorption force (unit: Newton, N); B The magnetic flux density in the air gap is expressed in Tesla (T). A Indicates the effective area of ​​the magnetic poles (unit: square meters, m²). Represents the vacuum permeability (4π×10⁻⁶) -7 H / m).

[0057] magnetic induction intensity B It can be derived from Ohm's law for magnetic circuits:

[0058] in, μ The magnetic permeability of the magnetic circuit material (unit: H / m, core). N Indicates the number of coil turns. I This indicates the coil current (unit: ampere, A). l This indicates the total length of the magnetic circuit (including the core and air gap, unit: meter, m).

[0059] Substituting into the adsorption force formula, we get:

[0060] Step S150: Based on the target attraction force of the permanent magnet on the magnetic wall, the distance between the permanent magnet and the magnetic wall is controlled by the lifting mechanism.

[0061] For permanent magnets, the distance between them and the ground can be controlled to adjust the magnet's attraction force on the wall.

[0062] The second part includes: based on the target angle, using a PID closed-loop control strategy to control the angle between the first frame and the second frame to tend towards the target angle.

[0063] The PID closed-loop control strategy is as follows:

[0064] in, , and These are all PID control parameters. Indicates the included angle of the target. This represents the angle between the first and second frames at time t. This represents the difference in angles at time t. This indicates the control signal for the motor.

[0065] The controller acquires encoder angle feedback in real time. Dynamically update the error and control it until... .

[0066] When the magnetic crawler passes through the bend in the magnetic wall, the formula for calculating the target angle is:

[0067] in, Indicates the included angle of the target. n1 and n 2 are the unit normal vectors of the magnetic walls on both sides of the bend.

[0068] When the magnetic crawler passes through the bend in the magnetic wall, the formula for calculating the target angle is:

[0069] in, Indicates the target angle (target angle). ds This indicates the distance the first structure travels per unit of time. R This represents the radius of curvature at the bend in the magnetic wall.

[0070] Specifically, the angle control of the crawler in some common scenarios is as follows: 1. Vertical connection: Wall to ceiling, the connecting shaft rotates clockwise by +90°; Wall to floor, the connecting shaft rotates counterclockwise by -90°.

[0071] The angle between the two walls is 90°, and the connecting shaft should be rotated about 90° to make the rear vehicle body parallel to the new wall.

[0072] 2. Angled connection: The included angle with the wall is α. If 0° < α < 180°, the connecting shaft should be rotated 180° - α to compensate for the angle and maintain the overall attachment of the crawler.

[0073] If the included angle between the walls is 120° (obtuse angle), the connecting shaft needs to be rotated 60°; If the included angle is 60° (acute angle), it needs to be rotated 120°.

[0074] 3. Plane-Curved Surface: The wall curvature is continuous and the transition is smooth; the central angle changes gradually, requiring dynamic and continuous small-angle adjustment; the angle increment is synchronized with the change of the wall tangent direction; the adjustment range of the connecting shaft angle is usually fine-tuned within ±15°~±45°.

[0075] 4. Plane-Curved Surface: The angle between the tangent angle of the curved surface and the plane needs to be calculated dynamically. The final rotation angle is equal to the angle between the tangent direction at the end of the curved surface and the plane, which is generally 45°~90°.

[0076] In summary, this embodiment provides a magnetic crawler and its control method. Based on the above magnetic crawler and its control method, some examples of the crawling process of the magnetic crawler are provided below.

[0077] Reference Figure 7 This describes the crawling posture of the crawler on a flat wall surface. (Refer to...) Figure 8The process of the crawler crawling on a flat wall surface is as follows: The crawler is placed on the wall; an inductive sensor detects the magnetic permeability of the wall and transmits the information to the control system. The system processes the data and controls the sector-shaped electromagnet block, adjusting the attraction force of the sector-shaped electromagnet block in conjunction with the material database; an ultrasonic thickness gauge measures the wall thickness and transmits the data to the roller screw, which raises and lowers to find the appropriate attraction force of the permanent magnet block; it is determined whether the crawler can be attracted. If it can, the crawler crawls normally on the plane; otherwise, it returns to the step of adjusting the attraction force of the sector-shaped electromagnet block.

[0078] Reference Figure 9 This describes the crawling posture of the crawler on a curved wall. (Refer to...) Figure 10 The crawling process of the crawler on the curved wall is as follows: The crawler device crawls on the plane; the laser contour sensor measures the curvature of the wall; it determines whether the wall has curvature. If so, the laser contour sensor transmits the wall curvature information to the control system. The system processes the data and controls the sector-shaped electromagnet block to adjust the magnitude and angle of the electromagnetic attraction force according to data such as the radius of curvature. Otherwise, it returns to the previous step; the ultrasonic rangefinder on the chassis measures the gap distance between the wall and the permanent magnet block, and the ball screw rises and falls to adjust the appropriate attraction force of the permanent magnet block; the hinge mechanism actively adjusts the angle of the rotating shaft to prevent interference between the vehicle body and the wall, so that the device is in a stable state.

[0079] Reference Figure 11 This refers to the change in the crawling posture of a crawler when passing through a right-angled wall. Figure 11 The image shows four postures of the crawler, in the following order: upper left, upper right, lower left, and lower right. Specifically, when the crawler's front end contacts a right-angled wall, its onboard magnetic permeability sensor initiates a real-time detection program, acquiring the magnetic permeability parameters of the wall material through electromagnetic induction. Based on the detection data, the fan-shaped electromagnet block (fan-shaped electromagnetic adsorption structure) built into the drive wheel performs dynamic vector control, adjusting the direction of the fan-shaped magnetic poles to align the main direction of the magnetic field strength perpendicular to the wall. It also adjusts the magnetic field strength according to the wall's magnetic permeability to generate sufficient wall adsorption force. This, through the driving force generated by friction, enables the robot to crawl along the wall. When transitioning between surfaces (where there is an angle between the two surfaces), while still on the previous surface, the axis of the fan-shaped electromagnet block remains perpendicular to the horizontal plane, as shown below. Figure 11 As shown in the upper left posture; when the front moving wheel (drive wheel) encounters the rear surface, its sector-shaped electromagnet block senses the presence of magnetism and immediately changes direction. Under the control of the motor, at this time, the axis of the sector-shaped electromagnet block on the front moving wheel is perpendicular to the vertical plane, as shown in the upper left posture. Figure 11As shown in the upper right posture; at this time, the drive wheel moves forward along the vertical direction under the action of the motor and the sector-shaped electromagnet block, while the omnidirectional wheel remains on the horizontal plane. Meanwhile, the hinge mechanism (connecting shaft), under the control of the motor, adjusts the body angle to bring the crawler to a stable state. Under the control of the motor, the axis of the sector-shaped electromagnet block on the rear moving wheel (omnidirectional wheel) is perpendicular to the horizontal plane, as shown in the upper right posture. Figure 11 As shown in the lower left posture; when the omnidirectional wheel encounters the next surface, its sector-shaped electromagnet block senses the magnetism and immediately changes direction. Under the control of the motor, the axis of the sector-shaped electromagnet block on the omnidirectional wheel is now perpendicular to the vertical plane. Finally, the omnidirectional wheel successfully transitions, and the entire crawler transitions, as shown... Figure 11 As shown in the lower right of the image. During the transition, the permanent magnet blocks of the chassis also rise and fall under the action of the ball screw, and the attraction force is in dynamic equilibrium.

[0080] Reference Figure 12 and Figure 13 , Figure 12 This describes the crawling process of the crawler when it passes through a right-angled wall. Figure 13 The flowchart illustrates the crawling process of a magnetic crawler over uneven walls: The crawler moves along a flat surface; whether the drive wheel contacts a right-angled wall is determined by a magnetic permeability sensor. The drive wheel's built-in sector-shaped electromagnetic array performs dynamic vector control, adjusting the magnetic field strength primarily to be perpendicular to the wall. The magnetic field strength is adjusted based on the wall's permeability to generate sufficient adhesion; otherwise, the process returns to the previous step. The drive wheel rolls along the wall, lifting the front of the vehicle and propelling it upwards. The articulation mechanism actively adjusts the rotation axis angle to prevent interference between the vehicle and the wall, ensuring stability. The ultrasonic rangefinder on the chassis measures the gap between the wall and the permanent magnet block, and the ball screw adjusts the adhesion force of the permanent magnet block accordingly. The crawler achieves a smooth transition between surfaces.

[0081] In summary, the control method for the magnetic crawler provided in this embodiment further includes: when the magnetic crawler passes through the first wall and the second wall with an angle in sequence, and any moving wheel simultaneously contacts the first wall and the second wall, the direction of the magnetic field strength of the fan-shaped electromagnetic adsorption structure is adjusted from perpendicular to the first wall to perpendicular to the second wall.

[0082] It should be understood that the specific embodiments described herein are merely illustrative of the application and not intended to limit it. All other embodiments derived by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application.

[0083] Obviously, the accompanying drawings are merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar situations based on these drawings without any creative effort. Furthermore, it is understood that although the work done in this development process may be complex and lengthy, for those skilled in the art, certain design, manufacturing, or production modifications made based on the technical content disclosed in this application are merely conventional technical means and should not be considered as insufficient disclosure of this application.

Claims

1. A control method for a magnetic crawler, characterized in that, The magnetic crawler includes a frame and a magnetic assembly. The frame has two movable wheels at the front and one at the rear. The front wheels are drive wheels connected to a drive unit, which is installed inside the frame. The magnetic assembly includes a first magnetic structure and a second magnetic structure. The first magnetic structure includes three fan-shaped electromagnetic adsorption structures corresponding to the three movable wheels. The radius of each fan-shaped electromagnetic adsorption structure is smaller than the radius of the movable wheel, and each fan-shaped electromagnetic adsorption structure is coaxially and rotatably mounted on the movable wheel. The second magnetic structure includes a lifting mechanism and a permanent magnet mounted in the middle of the frame via the lifting mechanism. The control method includes: Calculate the first adhesion force limit of the magnetic crawler when it crawls on a magnetic wall. Second Adsorption Force Limit : ； ； in, G and These represent the gravity of the magnetic crawler and the gravity of its load, respectively. and These represent the static friction coefficient and the rolling friction coefficient between the drive wheel and the magnetic wall, respectively. α Indicates the tilt angle of the magnetic wall. η This indicates the transmission efficiency of the reducer in the drive unit. This indicates the maximum driving torque of the motor in the drive unit. R Indicates the radius of the drive wheel; The target attraction force of each sector-shaped electromagnetic adsorption structure and the permanent magnet on the magnetic wall is set at... and between.

2. The control method for the magnetic crawler according to claim 1, characterized in that, Also includes: The power of the sector-shaped electromagnetic adsorption structure is controlled based on the target adsorption force of the sector-shaped electromagnetic adsorption structure on the magnetic wall surface. The distance between the permanent magnet and the magnetic wall is controlled by a lifting mechanism based on the target attraction force of the permanent magnet on the magnetic wall.

3. The control method for the magnetic crawler according to claim 1, characterized in that, In the magnetic crawler, the rear movable wheel is a universal wheel, and the frame includes a first frame and a second frame. The first frame is rotatably connected to the second frame through a rotating mechanism. The rotating mechanism is used to adjust the angle between the first frame and the second frame in the direction of travel. Two drive wheels are installed on the first frame, and the universal wheel is installed on the second frame. The control method further includes: The angle between the first frame and the second frame is controlled by a rotating mechanism.

4. The control method for the magnetic crawler according to claim 3, characterized in that, The control of the angle between the first frame and the second frame via the rotating mechanism includes: Based on the target angle, a PID closed-loop control strategy is used to control the angle between the first frame and the second frame to tend towards the target angle.

5. The control method for the magnetic crawler according to claim 4, characterized in that, When the magnetic crawler passes through the bend in the magnetic wall, the formula for calculating the target angle is: ； in, Indicates the included angle of the target. n 1 and n 2 are the unit normal vectors of the magnetic walls on both sides of the bend.

6. The control method for the magnetic crawler according to claim 4, characterized in that, When the magnetic crawler passes through the bend in the magnetic wall, the formula for calculating the target angle is: ； in, Indicates the included angle of the target. ds This indicates the distance the first structure travels per unit of time. R This represents the radius of curvature at the bend in the magnetic wall.

7. The control method for the magnetic crawler according to claim 1, characterized in that, In the magnetic crawler, the fan-shaped electromagnetic adsorption structure includes a fan-shaped mounting shell and multiple columnar electromagnetic actuation units. The multiple columnar electromagnetic actuation units are uniformly installed inside the fan-shaped mounting shell along the arc direction of the fan-shaped mounting shell, and the axis of the columnar electromagnetic actuation unit is orthogonal to the radial line of the fan-shaped mounting shell.

8. The control method for the magnetic crawler according to claim 1, characterized in that, In the magnetic crawler, the first magnetic structure also includes a micro motor and a drive shaft. The drive shaft is coaxial with the moving wheel and rotatably mounted on the moving wheel. The micro motor is fixedly mounted on one side of the moving wheel and is used to provide rotational driving force to the drive shaft. The fan-shaped electromagnetic adsorption mechanism is mounted on the drive shaft.

9. The control method for the magnetic crawler according to any one of claims 1-8, characterized in that, The control method further includes: As the magnetic crawler passes sequentially over the first and second walls with an angle, when any of the moving wheels simultaneously contacts the first and second walls, the direction of the magnetic field strength of the control sector electromagnetic adsorption structure is adjusted from being perpendicular to the first wall to being perpendicular to the second wall.

10. An adaptive crawling system, characterized in that, Includes the magnetic crawler and its controller as described in claim 1; The controller is used to execute the control method of the magnetic crawler as described in claim 1.

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