Self-adaptive spraying device for nondestructive testing robot and control method

Abstract

The invention relates to the technical field of non-destructive testing, in particular to a self-adaptive spraying device for a non-destructive testing robot and a control method.The self-adaptive spraying device comprises an outer rotor motor, a gear pump, a camera and a transmission assembly, the outer rotor motor serves as a power source, and by adjusting the embedding depth between a magnetic coupler and an input shaft of the gear pump, the self-adaptive spraying device of the non-destructive testing robot is driven to rotate; the magnetic coupling strength between the outer rotor motor and the gear pump is changed, so that the torque and the rotating speed transmitted to the gear pump are adjusted in a stepless mode, accurate control over the output flow of the gear pump is achieved, self-adaptive accurate control over the spraying flow can be achieved, in addition, the outer rotor motor can further drive the lens rotating cylinder to rotate, spraying liquid is thrown away from the mirror face through the centrifugal effect, and the spraying effect is improved. And lens water removal is realized. The system has the advantages that lens accumulated liquid is actively removed, clear imaging is guaranteed, the structure is compact, the integration degree is high, cooperative control of spraying and water removal can be achieved, dynamic balance of flow and water removal is achieved, and the adaptability and the intelligent level of the system under complex working conditions are improved.

Description

Technical Field

[0001] This invention relates to the field of nondestructive testing technology, and in particular to an adaptive spraying device and control method for a nondestructive testing robot. Background Technology

[0002] Large pressure equipment (such as reactors, towers, boilers, and pressure pipelines) operates under extreme conditions including high temperature, high pressure, flammable, explosive, and corrosive media. Their surfaces are prone to defects such as cracks, corrosion, and holes, directly affecting the safe and continuous operation of industrial plants. To ensure their safe and reliable operation, non-destructive testing (NDT) technology is crucial. With the development of robotics, using robots to perform NDT on the surfaces of pressure equipment has become an important method. During the testing process, liquid reagents (such as magnetic powder or coupling agents) are typically sprayed onto the workpiece surface to enhance the detectability of defects.

[0003] Currently, traditional spraying methods are mostly manual spraying or automated spraying with fixed parameters, which have the following problems:

[0004] First, when dealing with complex curved surfaces, vertical walls, or surfaces with inconsistent conditions, uneven spraying, liquid accumulation, or reagent buildup can easily occur, resulting in uneven reagent coverage and affecting the detection results.

[0005] Secondly, during the spraying process, the camera lens on the robot is easily covered by liquid, resulting in blurred vision and affecting the accuracy of defect identification and judgment.

[0006] While existing technologies include solutions such as "constant pressure spraying devices," they still have significant shortcomings: on the one hand, constant pressure control lacks adaptive adjustment capabilities and cannot adjust spraying parameters in real time according to the surface condition of the workpiece; on the other hand, such devices mostly rely on ground power sources, have slow response, complex structures, and lack lens anti-liquid accumulation mechanisms, still requiring manual observation and intervention, resulting in low automation and limited detection reliability.

[0007] Therefore, there is an urgent need for a spraying device that can adaptively adjust the spray flow rate according to the surface condition of the workpiece and simultaneously ensure a clear view of the camera, so as to improve the operational reliability and automation level of non-destructive testing robots. Summary of the Invention

[0008] The main objective of this invention is to overcome the shortcomings of the prior art and provide an adaptive spraying device and control method for non-destructive testing robots.

[0009] The technical solution adopted by this invention to achieve its technical objective is: an adaptive spraying device for a non-destructive testing robot, comprising:

[0010] An external rotor motor, a gear pump driven by the external rotor motor via a magnetic coupler, a camera for acquiring spray images, and a transmission assembly for driving the lens barrel of the camera to rotate.

[0011] By adjusting the embedding depth between the magnetic coupler and the input shaft of the gear pump, the magnetic coupling strength between them is changed, thereby steplessly adjusting the torque and speed transmitted to the gear pump and achieving precise control of the output flow of the gear pump.

[0012] The lens barrel is then driven to rotate by the external rotor motor, and the sprayed liquid is thrown away from the lens surface by centrifugal force to remove water from the lens.

[0013] Preferably, it also includes a fixing frame, on one side of which the external rotor motor is fixedly installed, and a magnetic bushing is sleeved on the output shaft of the external rotor motor;

[0014] The gear pump is installed above one side of the fixed frame, and a magnetic bushing is fitted on the input shaft of the gear pump.

[0015] The magnetic bushing one and magnetic bushing two are assembled and connected by a magnetic coupler in a clearance fit manner, so that the magnetic coupler can slide up and down relative to the magnetic bushing one and magnetic bushing two.

[0016] Preferably, a mounting bracket is fixedly provided on one side of the fixed frame, and the gear pump is fixedly mounted on the top of the mounting bracket.

[0017] Preferably, the magnetic coupler is mounted on the lead screw clutch via a bearing and a sliding sleeve. The bearing is fixedly sleeved on the outer wall of the magnetic coupler, and one side of the sliding sleeve is fixedly connected to the bearing, while the other side is threadedly connected to the lead screw of the lead screw clutch.

[0018] The lead screw clutch is fixedly mounted on the top of the mounting bracket and located on one side of the magnetic coupler.

[0019] Preferably, the lead screw clutch, driven by a control signal, drives the magnetic coupler to move axially via a sliding sleeve;

[0020] When the magnetic coupler slides upward to the working position, its upper end is embedded in the second magnetic bushing, while its lower end remains in the first magnetic bushing, thus maintaining magnetic circuit coupling with both simultaneously and transmitting the output torque of the external rotor motor to the gear pump without contact.

[0021] Preferably, the camera is fixedly mounted on the upper side of the other side of the mounting bracket;

[0022] The lens barrel is rotatably mounted inside the other side of the mounting bracket, and the lens barrel is connected to the external rotor motor via a transmission assembly.

[0023] Preferably, the lens barrel is rotatably connected to the camera, and one end of it is fastened to a lens waterproof cover by screws. The lens barrel and the lens waterproof cover form an integral assembly, which can rotate freely around the internal axis of the mounting bracket.

[0024] Preferably, the transmission component is a transmission belt, gear, chain, or steel rope.

[0025] The present invention also provides a control method for an adaptive spraying device, comprising the following steps:

[0026] The camera captures images of the spraying operation, and after image processing, control signals are generated and fed back to control the magnetic coupler and the external rotor motor respectively.

[0027] Image processing includes hardware filtering for noise reduction, two-dimensional wavelet transform for feature enhancement, soft and hard thresholding, and binarization for edge feature extraction;

[0028] The atomization effect is quantified based on edge features, and the coupling degree of the magnetic coupler is adjusted according to the atomization degree.

[0029] The rotational speed of the external rotor motor is adjusted based on the image defocus rate to achieve coordinated control of lens dehydration and spray flow rate.

[0030] Preferably, the formula for calculating the atomization degree D is:

[0031] ;

[0032] Where, in the formula, This indicates the number of pixels in the binarized fogged area. This indicates the number of pixels within the visible area.

[0033] The formula for calculating the defocusing rate p is: ;

[0034] in, The area of ​​the out-of-focus region. The area of ​​the field of view.

[0035] Compared with the prior art, the beneficial effects of the present invention are:

[0036] The adaptive spraying device and control method for non-destructive testing robots can achieve adaptive and precise control of spraying flow: through the cooperation of magnetic coupler and lead screw clutch, the flow of gear pump can be steplessly adjusted. Combined with the atomization feedback of image processing, the system can adjust the spraying volume in real time according to the surface condition of the workpiece, effectively solving the problem of uneven spraying on complex curved surfaces and improving the reliability of inspection.

[0037] The adaptive spraying device and control method for non-destructive testing robots can actively remove liquid accumulated on the lens and ensure clear imaging: the lens barrel is driven to rotate by an external rotor motor, and the liquid on the lens surface is thrown off by centrifugal force to achieve active water removal. Combined with defocusing rate feedback control, the motor speed is adaptively adjusted to ensure clear field of view and improve image quality and detection accuracy.

[0038] The adaptive spraying device and control method for non-destructive testing robots are compact and highly integrated: the device integrates magnetic transmission and lens dehydration system into one compact structure, is suitable for robot mounting, requires no external power source, has a rapid response, and has overload protection capabilities.

[0039] The adaptive spraying device and control method for non-destructive testing robots can achieve coordinated control of spraying and dewatering: through a dual closed-loop control strategy, using atomization degree and defocusing rate as feedback signals, the magnetic coupler and motor speed are coordinated to achieve dynamic balance between flow rate and dewatering, thereby improving the system's adaptability and intelligence under complex working conditions. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the overall structure of an adaptive spraying device used in non-destructive testing robots.

[0041] Figure 2 This is an exploded view of a portion of the structure of an adaptive spraying device used in a non-destructive testing robot.

[0042] Figure 3 This is a flowchart illustrating the steps of an adaptive sprinkler control method.

[0043] Figure 4 This is a control strategy diagram for an adaptive sprinkler system control method.

[0044] The components include: 1. Gear pump; 2. Screw clutch; 3. Magnetic coupler; 4. External rotor motor; 5. Fixing frame; 6. Transmission assembly; 7. Camera; 8. Lens waterproof cover; 9. Lens rotating cylinder; 10. Magnetic bushing two; 11. Bearing; 12. Sliding sleeve; 13. Magnetic bushing one; 14. Mounting bracket. Detailed Implementation

[0045] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0046] In the description of this invention, it should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to or indirectly connected to the other element.

[0047] In the description of this invention, it should be noted that the terms "center," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. "Several" means one or more, unless otherwise explicitly specified.

[0048] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0049] Example 1:

[0050] Please see Figures 1-2 An adaptive spraying device for a non-destructive testing robot includes an external rotor motor 4, a gear pump 1 driven by the external rotor motor 4 via a magnetic coupler 3, a camera 7 for acquiring spray images, and a transmission assembly for driving the lens cylinder 9 of the camera 7 to rotate. By adjusting the embedding depth between the magnetic coupler 3 and the input shaft of the gear pump 1, the magnetic coupling strength between them is changed, thereby steplessly adjusting the torque and speed transmitted to the gear pump 1 and precisely controlling the output flow of the gear pump 1. Then, the external rotor motor 4 drives the lens cylinder 9 to rotate, using centrifugal force to throw the sprayed liquid away from the lens surface, thereby achieving lens dehydration.

[0051] Furthermore, in this embodiment, the adaptive spraying device also includes a fixing frame 5, on one side of which an external rotor motor 4 is fixedly installed. A magnetic bushing 13 is fitted on the output shaft of the external rotor motor 4. At the same time, a gear pump 1 is installed above one side of the fixing frame 5, and a magnetic bushing 10 is fitted on the input shaft of the gear pump 1. A mounting frame 14 is fixedly installed above one side of the fixing frame 5, and the gear pump 1 is fixedly installed on the top of the mounting frame 14.

[0052] The magnetic bushing 13 and the magnetic bushing 2 10 are assembled and connected by a magnetic coupler 3 in a clearance fit manner, so that the magnetic coupler 3 can slide up and down relative to the magnetic bushing 13 and the magnetic bushing 2 10.

[0053] Furthermore, in this embodiment, the magnetic coupler 3 is mounted on the screw clutch 2 via a bearing 11 and a sliding sleeve 12. The bearing 11 is fixedly sleeved on the outer wall of the magnetic coupler 3. One side of the sliding sleeve 12 is fixedly connected to the bearing 11, and the other side of the screw clutch 2 is threadedly connected to the screw. The screw clutch 2 is located on one side of the magnetic coupler 3 and is fixedly mounted on the top of the fixing frame 5.

[0054] Driven by a control signal, the lead screw clutch 2 drives the magnetic coupler 3 to move axially through the sliding sleeve 12. When the lead screw clutch 2 drives the magnetic coupler 3 to slide upward to the working position, the upper part of the magnetic coupler 3 is embedded in the magnetic bushing 10, while the lower part remains in the magnetic bushing 13. At this time, the magnetic coupler 3 maintains magnetic circuit coupling with both the magnetic bushing 13 and the magnetic bushing 10, thereby transmitting the output torque of the external rotor motor 4 to the gear pump 1 through magnetic non-contact transmission, driving it to start working.

[0055] The insertion depth of the magnetic coupling 3 and the magnetic bushing 10 on the input shaft of the gear pump 1 can be adjusted by the lead screw clutch 2, thereby changing the magnetic coupling strength between the two, thus steplessly adjusting the torque and speed transmitted to the gear pump 1, and finally achieving precise control of the output flow of the gear pump.

[0056] Furthermore, in this embodiment, a camera 7 is fixedly installed on the upper side of the other side of the fixing frame 5; simultaneously, a lens cylinder 9 is rotatably installed inside the other side of the fixing frame 5, and the lens cylinder 9 is connected to the external rotor motor 4 through a transmission assembly 6. The transmission assembly 6 includes a transmission belt, gears, chains, and steel ropes.

[0057] The lens barrel 9 is rotatably connected to the camera 7. At the same time, one end of the lens barrel 9 is fastened to the lens waterproof cover 8 by screws. The lens barrel 9 and the lens waterproof cover 8 form an integral component. The integral component rotates freely around the internal axis of the fixing frame 5, and then drives the lens barrel 9 to rotate through the external rotor motor 4. The centrifugal force is used to throw the sprayed liquid away from the lens surface, thereby realizing the removal of water from the lens.

[0058] The working principle and specific usage procedure of this adaptive sprinkler system are as follows:

[0059] The external rotor motor 4 drives the magnetic coupler 3, which in turn drives the gear pump 1 in a non-contact manner. In conjunction with the lead screw clutch 2, stepless and precise control of the spray flow rate is achieved. At the same time, the external rotor motor 4 also drives the lens drum 9 to rotate at high speed through the transmission component 6, using centrifugal force to throw off the liquid adhering to the lens surface of the camera 7, keeping the lens clean.

[0060] Its specific workflow is as follows: the camera 7 collects images of the spray area in real time, and after analysis by the image processing module, it generates control signals for adjusting the embedding depth of the magnetic coupler 3 and control signals for adjusting the speed of the external rotor motor 4, thereby achieving adaptive adjustment of the spray flow rate and synchronous optimization of the lens dewatering function.

[0061] Example 2:

[0062] Please see Figures 1-4 Based on the above embodiments, this invention also provides a control method for an adaptive spraying device, comprising the following steps:

[0063] The camera 7 collects image signals during the spraying operation. These image signals are then processed and used as feedback control signals for the magnetic coupler 3 and the external rotor motor 4, respectively.

[0064] In the image processing workflow, hardware filtering is first used to reduce noise in the image to suppress interference from bright areas. Then, two-dimensional wavelet transform is used for software filtering to further enhance the features of the sprayed image. The two-dimensional wavelet transform of the image can be expressed as:

[0065] ;

[0066] In the formula, Indicates image noise. Represents the two-dimensional wavelet fundamental function. represents the scale and translation parameters of the wavelet function sliding window.

[0067] Based on two-dimensional wavelet transform, soft and hard thresholding methods are used to filter high-frequency components in the image data. Then, binarization is performed on the denoised image to extract edge features of the atomized area on the workpiece surface. Based on this edge information, the atomization effect of the spray can be quantitatively evaluated. The specific quantification method is as follows:

[0068]

[0069] In the formula, This indicates the number of pixels in the binarized fogged area. Indicates the number of pixels within the visible area. The calculation method is as follows:

[0070] ;

[0071] In the formula, Indicates the visible range One pixel within, This indicates the location of a pixel.

[0072] Therefore, based on the above method, the liquid atomization on the workpiece surface can be quantitatively evaluated. atomization The transfer function between the coupling degree of the magnetic coupler and the workpiece surface can be used to control the movement of the lead screw clutch 2, thereby adjusting the output torque of the magnetic coupler 3.

[0073] Furthermore, the dewatering effect of the camera lens is closely related to the rotational speed of the external rotor motor 4. Since the output torque of the external rotor motor 4 decreases during the driving of the gear pump 1, the reduced motor speed can easily lead to insufficient centrifugal force on the lens surface, causing liquid residue and affecting the clarity of the image. To solve this problem, the lens defocus rate can be determined by analyzing the images captured by the camera, and the relationship between the motor speed and output torque can be adaptively adjusted to achieve coordinated control of lens dewatering and spray flow rate. The specific method is as follows:

[0074] The defocused area of ​​the lens is calculated using a defocus detection algorithm, and the image defocus rate is defined as: ;

[0075] in, The area of ​​the out-of-focus region. The area of ​​the field of view;

[0076] Defocus rate Transfer function of motor speed control, defocusing rate It serves as a feedback signal to adjust the motor speed.

[0077] Among them, the transfer functions G1(1-α) and G2(α) respectively establish the control models of "coupling degree-flow rate" and "speed-flow rate". The adaptive weight α is used to adjust the weight distribution of the magnetic coupler and speed in the coordinated control, so as to realize the adaptive spraying of the output flow rate.

[0078] The solution in this embodiment can be selectively combined with solutions in other embodiments.

[0079] It should be noted that although the above embodiments have been described herein, this does not limit the scope of patent protection of this invention. Therefore, any changes and modifications made to the embodiments described herein based on the innovative concept of this invention, or equivalent structural, procedural, or functional transformations made using the description and drawings of this invention, directly or indirectly applying the above technical solutions to other related technical fields, are all included within the scope of protection of this invention.

Claims

1. An adaptive spraying device for a non-destructive testing robot, characterized in that, include: An external rotor motor (4), a gear pump (1) driven by the external rotor motor (4) via a magnetic coupler (3), a camera (7) for acquiring spray images, and a transmission assembly for driving the lens barrel (9) of the camera (7) to rotate; By adjusting the embedding depth between the magnetic coupler (3) and the input shaft of the gear pump (1), the magnetic coupling strength between them is changed, thereby steplessly adjusting the torque and speed transmitted to the gear pump (1) and achieving precise control of the output flow of the gear pump (1). Then, the lens cylinder (9) is driven to rotate by the external rotor motor (4), and the sprayed liquid is thrown away from the lens surface by centrifugal force to achieve lens dehydration.

2. The adaptive spraying device for a non-destructive testing robot according to claim 1, characterized in that: It also includes a fixing frame (5), on one side of which the external rotor motor (4) is fixedly installed, and a magnetic bushing (13) is sleeved on the output shaft of the external rotor motor (4). The gear pump (1) is installed above one side of the fixed frame (5), and a magnetic bushing (10) is sleeved on the input shaft of the gear pump (1). The magnetic bushing one (13) and the magnetic bushing two (10) are assembled and connected by a magnetic coupler (3) in a clearance fit manner, so that the magnetic coupler (3) can slide up and down relative to the magnetic bushing one (13) and the magnetic bushing two (10).

3. The adaptive spraying device for a non-destructive testing robot according to claim 2, characterized in that: A mounting bracket (14) is fixedly installed on one side of the fixed bracket (5), and the gear pump (1) is fixedly installed on the top of the mounting bracket (14).

4. The adaptive spraying device for a non-destructive testing robot according to claim 2, characterized in that: The magnetic coupler (3) is mounted on the screw clutch (2) via a bearing (11) and a sliding sleeve (12). The bearing (11) is fixedly sleeved on the outer wall of the magnetic coupler (3). One side of the sliding sleeve (12) is fixedly connected to the bearing (11), and the other side is threadedly connected to the screw of the screw clutch (2). The lead screw clutch (2) is fixedly installed on the top of the fixed frame (5) and located on one side of the magnetic coupler (3).

5. The adaptive spraying device for a non-destructive testing robot according to claim 4, characterized in that: The lead screw clutch (2) drives the magnetic coupler (3) to move axially through the sliding sleeve (12) under the control signal. When the magnetic coupler (3) slides upward to the working position, its upper end is embedded in the magnetic bushing two (10), and its lower end remains in the magnetic bushing one (13), thereby maintaining magnetic circuit coupling with both at the same time, and transmitting the output torque of the outer rotor motor (4) to the gear pump (1) in a non-contact manner.

6. The adaptive spraying device for a non-destructive testing robot according to claim 2, characterized in that: The camera (7) is fixedly installed on the upper side of the other side of the mounting bracket (5); The lens barrel (9) is rotatably mounted inside the other side of the fixing frame (5), and the lens barrel (9) is connected to the external rotor motor (4) through the transmission assembly (6).

7. The adaptive spraying device for a non-destructive testing robot according to claim 6, characterized in that: The lens barrel (9) is rotatably connected to the camera (7), and one end of it is fastened to the lens waterproof cover (8) by screws. The lens barrel (9) and the lens waterproof cover (8) form an integral assembly, which can rotate freely around the internal axis of the fixing frame (5).

8. The adaptive spraying device for a non-destructive testing robot according to claim 6, characterized in that: The transmission component (6) is a transmission belt, gear, chain, or steel rope.

9. A control method for the adaptive spraying device according to any one of claims 1-8, characterized in that, Includes the following steps: The camera (7) collects images of the spraying operation, and after image processing, generates control signals, which are fed back to control the magnetic coupler (3) and the external rotor motor (4). Image processing includes hardware filtering for noise reduction, two-dimensional wavelet transform for feature enhancement, soft and hard thresholding, and binarization for edge feature extraction; The atomization effect is quantified based on edge features, and the coupling degree of the magnetic coupler (3) is adjusted according to the atomization degree. The rotational speed of the external rotor motor (4) is adjusted based on the image defocus rate to achieve coordinated control of lens dewatering and spray flow rate.

10. The control method for the adaptive spraying device according to claim 9, characterized in that: The formula for calculating the atomization degree D is: ； Where, in the formula, This indicates the number of pixels in the binarized fogged area. Indicates the number of pixels within the visible area; The formula for calculating the defocusing rate p is: ; in, The area of ​​the out-of-focus region. The area of ​​the field of view.

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