Multi-wheel drive intelligent welding seam detecting and spraying integrated device in pipeline and control method

Abstract

The invention discloses a multi-wheel drive intelligent welding seam detecting and spraying integrated device in a pipeline and a control method. The device comprises a cab arranged in a hexagonal truss, and a plurality of driving wheels are connected with the hexagonal truss and the lower side of the cab; the storage chamber is located at one end of the hexagonal truss, and multiple clamping mechanisms are arranged at the other end of the hexagonal truss. A mechanical arm is arranged on one side of the storage chamber, and the spraying equipment and the welding seam detection equipment are connected with the mechanical arm; the mechanical arm drives the spraying equipment and the welding seam detection equipment to rotate by 360 degrees so as to detect and spray a circular welding seam in the pipeline; the detection mechanism and the spraying mechanism are integrated, welding seam detection and spraying are completed in a semi-automatic mode through robot execution and detection personnel monitoring, and on the premise that quality is guaranteed, efficiency is improved, and personnel safety is guaranteed.

Description

Technical Field

[0001] The invention belongs to the field of mechanical devices and control technologies, and relates to a multi-wheel driven intelligent weld detection and spraying integrated device in a pipeline. Background Art

[0002] At present, in order to pursue water head, pumped storage power station construction mostly adopts water diversion power station, which generally has a long water diversion tunnel, inclined shaft or vertical shaft. Compared with conventional hydropower stations, pumped storage power stations have smaller reservoir capacity but higher operating head and larger head fluctuation. The pipes used in water conservancy projects are large-diameter and heavy-weight pressure steel pipes. When welding, multiple sections of pipes need to be aligned and welded with the same coaxiality, and anti-rust paint is sprayed after the weld quality is tested. Traditional welding methods often use manual welding, which is time-consuming, inefficient and cannot guarantee quality. At the same time, because the construction site is hundreds of meters underground and the construction environment is harsh, working in the environment for a long time will cause damage to human physiological and mental health.

[0003] The main pipeline weld inspection technologies include penetration testing, magnetic particle testing, X-ray photography, ultrasonic testing, etc. Especially with the development of new ultrasonic sensor technology, automatic control technology, chip technology and image processing technology, ultrasonic inspection technology has become more automated.

[0004] Currently, two-section welded pipelines are used, and the welded sections at both ends overlap, which may cause missed detection during detection. In addition, the dust generated during welding in the pipeline will hinder the accuracy of ultrasonic detection, resulting in false detection and missed detection.

[0005] At the same time, anti-rust treatment is an important step in post-welding treatment. Long-term use of steel pipes will cause rust on their surface. In order to extend the service life of steel pipes, the surface of steel pipes needs to be sprayed. The coating will prevent the surface of steel pipes from rusting and thus extend the service life of steel pipes. The traditional anti-rust spraying method for pipelines is manual spraying, and the thickness of the spraying layer cannot be guaranteed; in addition, there is no fixed spraying order for workers to spray, which poses a safety problem. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a multi-wheel drive intelligent weld detection and spraying integrated device and control method in a pipeline, which integrates the detection mechanism and the spraying mechanism into one, and semi-automatically completes the weld detection and spraying by means of robot execution and detection personnel monitoring, thereby improving efficiency and ensuring personnel safety while ensuring quality.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is: a multi-wheel drive intelligent weld detection and spraying integrated device in a pipeline, which includes a cab arranged in a hexagonal truss, and multiple driving wheels are connected to the hexagonal truss and the lower side of the cab; a storage room is located at one end of the hexagonal truss, and multiple clamping mechanisms are arranged at the other end of the hexagonal truss; a mechanical arm is arranged on one side of the storage room, and the spraying equipment and the weld detection equipment are connected to the mechanical arm; the mechanical arm drives the spraying equipment and the weld detection equipment to rotate 360° to detect and spray the circular welds in the pipeline.

[0008] The hexagonal truss is a hollow frame structure; the driving wheel is an electric wheel; the clamping mechanism is an electric push rod, and an arc plate is arranged at the telescopic end of the electric push rod.

[0009] The robotic arm includes an end effector, which is sequentially connected to a wrist rotation joint, a wrist pitch joint, a wrist, an elbow joint, a forearm, a shoulder joint, an upper arm, a waist rotation joint and a base; the base is connected to an output end of a rotating motor, and the rotating motor is fixed to a storage chamber.

[0010] The wrist and the outer side of the upper arm are both provided with attitude sensors; the wrist pitch joint is fixed to the wrist rotation joint through a ball-type universal joint; the end effector is connected to a monitoring camera, a spraying device and a weld detection device.

[0011] The waist rotation joint controls the horizontal rotation movement of the robotic arm, and the upper arm controls the forearm to move up and down and forward and backward; the forearm performs telescopic movement, and the forearm and upper arm drive the wrist movement; the wrist controls the movement of the wrist rotation joint and the wrist pitch joint; the wrist rotation joint controls the circular rotation movement of the end effector, and the wrist pitch joint controls the pitch movement of the end effector.

[0012] The storage room is provided with a controller, a power distribution cabinet and a paint storage bottle; the controller is electrically connected to the power distribution cabinet, and the paint storage bottle is connected to the spraying equipment through a pipeline; the controller is also electrically connected to the driving wheel, the clamping mechanism, the robotic arm, the spraying equipment and the weld detection equipment.

[0013] The weld detection equipment adopts ultrasonic phased array detection, which electronically controls the focusing and scanning of ultrasonic waves and is used for the detection of thick-walled pipes. The phased array accurately controls the time when each array element of the probe transmits a signal according to the focusing law. The existence of the time difference enables the ultrasonic waves excited by each array element to propagate to a certain position at the same time, thereby realizing the adjustment of the ultrasonic focusing direction and focusing depth. The detection includes three parts: focusing law, sensitivity setting and scanning method.

[0014] The method for using and controlling the above-mentioned multi-wheel drive intelligent weld detection and spraying integrated device in a pipeline comprises the following steps: SA1, use a trolley to deliver the integrated device to the entrance of the pressure steel pipe; at this time, the clamping mechanism is in a retracted state; SA2, the operator in the cab starts the overall power-on, and the integrated device enters the standby state; SA3, after issuing the start command, the driving wheel drives the integrated device to move slowly into the pipeline; SA4, when the integrated device moves into the working range of the spraying equipment and the weld inspection equipment, the integrated device stops; at the same time, the clamping mechanism stretches and contacts the inner wall of the pipeline, limiting the movement of the integrated device in the pipeline; SA5: The robot arm drives the weld inspection device to rotate along the weld for one circle. During this period, the weld inspection device emits ultrasonic waves to check the internal structure of the weld. If the weld is qualified, it enters the spraying mode. SA6, the robotic arm rotates and switches to spraying mode, driving the spraying equipment to complete the anti-rust spraying work on the weld.

[0015] The weld detection control method of the multi-wheel drive intelligent weld detection and spraying integrated device in the pipeline as described above comprises the following steps: SB1, assuming the speed of sound is c According to the Pythagorean theorem and the time-distance relationship of sound waves, The delay value of each array element relative to the central array element is ; (1) in From center point to focal point The distance between is the distance between adjacent array elements; the running track of the weld detection device is an arc shape, and the radius is 0.1m less than the radius of the pipeline to ensure that the center point to the focal point The distance between them remains unchanged; SB2, for beam deflection and focusing, the array element farthest from the focal point is excited first, and the array element closest to the focal point is excited last. The excitation delay of other array elements is controlled accordingly according to the sound path propagation time. Assuming that the incident angle of the sound wave from the center point to the focal point is , the above formula can be changed into: ; (2) For by The array probe consists of array elements. Each array element is excited in turn, and all array elements receive signals at the same time. In one acquisition cycle, each array element of the array emits a sound wave, that is, there are a total of array elements are fired successively; for each firing, Each of the array elements receives a one-dimensional signal; thus, there are The signals are combined in a matrix, the rows of the matrix represent the transmitting array elements, and the columns represent the receiving array elements; SB3, due to the different spatial positions of the probe array elements, the time for the reflected echo of the defect to reach each array element will also be different; synthetic aperture focusing imaging is based on the spatial position of the imaging point, and the delay device calculates the receiving delay of each array element according to the receiving focusing law, and appropriately delays the received signal. After A / D conversion, phase shift and superposition processing, the point-by-point focused sound image of the defect target is obtained. The defect in the focusing area will form a reflection wavefront with a large amplitude, which greatly improves the detection resolution and signal-to-noise ratio; assuming In the Cartesian coordinate system Ultrasonic function of the point, the combination of transmitting and receiving sources In delay time The measured signal e is expressed as the spatial integral of the wave function: ; (3) in is the Dirac function, the delay time It is expressed as: ; (4) Further superimpose all one-dimensional time signals corresponding to the delay time to synthesize the focused sound field for: ; (5) When setting the fan scanning angle, in order to avoid the primary reflection wave entering the wedge or causing too many bottom deformation signals, and to avoid the effective identification of the defect signal by the deformation signal, the starting angle should not be less than 35°; in order to increase the coverage of the sound beam and avoid surface deformation wave signals or other interference signals, the fan scanning end angle generally does not exceed 80°; when setting the angle resolution, the angle resolution is set to 1° taking into account the amount of detection data and defect resolution; when setting the focus depth, the focus depth is set to 1 times the wall thickness; SB4, for sensitivity setting, select DAC mode to set the sensitivity; DAC is an electronic device that converts digital signals into analog signals; in sensitivity setting, DAC is used to generate accurate analog voltage or current in response to changes in digital input; for scanning mode, scan both sides of the outer wall of the weld during detection, and set the primary wave and the primary reflected wave to complete the coverage of the detection area; SB5, during detection, the weld is divided into multiple areas according to the actual situation, and the height of each area is controlled at 2-3 mm. Ultrasonic beams are used for detailed detection to avoid missed detection and false detection of weld overlaps. Since the pipeline working environment is a semi-closed environment, and welding will bring a lot of dust, which will affect the detection results; during detection, a disposable protective cover is installed on the ultrasonic probe to prevent dust from directly contacting the probe. In addition, the signal spectrum is analyzed using fast Fourier transform to identify and filter out the noise part that does not belong to the target signal frequency band; SB6, the ultrasonic signal obtained by scanning is displayed to the inspectors in the device through the central control system. When a defect is detected, the inspectors mark the weld and perform another welding. If there is no defect in the welding, the robot arm rotates and switches to the spraying mechanism to execute the anti-rust paint spraying.

[0016] The spraying control method of the above-mentioned multi-wheel drive intelligent weld detection and spraying integrated device in the pipeline includes the following steps: SC1, in order to speed up the fluidity of anti-rust paint, rheology modifier is added to the paint bucket; rheology modifier controls the fluidity of paint, reduces dripping, enhances hiding power and prolongs the shelf life; the control process of executing spraying is an automated process, with PLC as the core control unit; the monitoring personnel issue spraying instructions on the central control system screen, and the signal is sent to PLC; SC2, the paint in the paint bucket is introduced into the system through the paint injection solenoid valve; then, the paint meter measures the paint flow and feeds the data back to the PLC through the paint quantity sensor. When the paint inventory is low, the PLC alarms the central control system and stops the spraying operation; the PLC controls the air inlet solenoid valve and the air outlet solenoid valve according to the preset program and sensor feedback to adjust the supply of compressed air to achieve paint atomization; then, the paint spraying solenoid valve controls the paint to flow from the paint meter to the spray gun according to the instructions of the PLC, and the spray gun sprays along the weld; SC3, the spray gun trajectory adopts a z-shaped trajectory, and the coating thickness is calculated using Gaussian distribution; it assumes that the coating deposition rate during the spraying process is related to the distance from the spray gun to the surface of the coated object, and this relationship is described by Gaussian distribution; a laser sensor is installed on the nozzle to calculate the distance from the nozzle to the surface of the coated object; ; (6) in, Is the spray point at a distance from the spray gun The coating deposition rate at is the standard deviation of the Gaussian distribution, which affects the width of the spraying area; SC4, control function to determine the accumulation of spray points ,Since the device works in a pipeline, the spraying surface is designed to be a curved surface; ; (7) in Is the spray gun in time Spraying point To the destination The unit direction vector of is the distance between the spray gun and the target point; i, j, k are three mutually perpendicular unit vectors, whose directions coincide with the positive directions of the coordinate axes of the three-dimensional space coordinate system; p x (t), py (t), p z (t) is the three-dimensional spatial coordinate of the spray gun at time t; ; (8) in It is the control function related to the spraying angle; ; (9) in It is the target point Normal vector to the center axis of the spray gun The angle between ; (10) in is the maximum effective spraying angle of the spray gun. is the proportionality factor related to the spraying process and is set to 0.5; SC5, in robot spraying, the spray beam is spread in space in a cone shape. In order to obtain a uniform spray thickness on the surface, the spray beam must be superimposed on the surface of the workpiece to achieve the purpose of compensating the edge thickness and achieving uniform spray thickness; the thickness distribution of the two spray points is superimposed, ; (11) in is the interval between two spray points; SC6, to find the spray point interval , let the second-order derivative of thickness be at the midpoint between the two spray points , and the solution is and ; It indicates the spacing of the spraying track of the spray gun during the spraying process or the distance between two adjacent points on the spraying path. represents the initial coating thickness; According to the spray speed , spray gun speed , distance between spray gun and working surface , determine the maximum thickness of the paint layer for a single track as : ; (12) Differentiate the spraying process on the curved pipe to form a plane with a certain slope; the spray gun sprays on the plane in an elliptical shape; during spraying, the spray gun is assumed to move at a uniform speed; the center of the coating is set to point, the major and minor semi-axes are Indicates that the height of the spray gun from the spraying plane is , the angle between the spraying plane and the ground is ;in: ; (13) in , is the spray point in the coordinate system with the center of the pipe circle as the origin Axis coordinates; SC7, volume of paint sprayed per unit time by spray gun It can be obtained by the following formula: ; (14) Single track spray gun spraying time It can be obtained by the following formula: ; (15) Spray gun spraying time according to a single track To control the moving speed of the robot arm; because two sections of welding are used for welding, the welding sections at both ends overlap, and it moves 1 / 5 more semicircle during spraying; assuming that the robot arm moves at a constant speed, the moving speed of a single section is ; (16) in is the pipe radius; SC8, a single track is not enough to achieve the maximum spray thickness , analyze the superposition of multiple trajectories. Considering continuous spraying, the coating thickness is expressed by integration: ; (17) When two spraying trajectories overlap, the thickness distribution is the superposition of the two trajectories: ; (18) Similarly, by analyzing the second derivative of the thickness distribution , find the offset distance and maximum thickness ; If you need to achieve a target coating thickness , by adjusting the number of spray layers To achieve this, that is, the number of times the spraying robot arm moves, when If it is a decimal, it will be rounded to the integer value; ; (19) When completed When spraying is completed for the first time, the PLC sends a stop signal to the paint solenoid valve. During the spraying process, the PLC continuously monitors the status of each link to ensure the quality of spraying. If a link fails, the work will be stopped immediately. The central control system display provides an interface for the operator to monitor the progress and quality of spraying in real time.

[0017] The main beneficial effects of the present invention are: The fully automated control method can automatically complete weld positioning, detection and spraying, without the need for operators to perform complex technical operations, thus reducing the operator's work pressure.

[0018] The cab of the integrated device isolates the operator from the harsh environment in the pipeline, greatly reducing the damage to human health caused by the harsh environment. Compared with the traditional manual weld inspection and spraying methods, the mobile device is not only highly efficient, but also saves the subsequent labor costs.

[0019] The mobile device adopts an integrated design of weld inspection and spraying equipment, and only uses one robotic arm to control the work of both. This design greatly reduces the weight of the mobile device and reduces the damage of the mobile device to the pressure steel pipe.

[0020] The integrated design is simpler in control method than separate control, which can reduce the risk of failure of weld inspection and spraying equipment during operation.

[0021] In addition, an ultrasonic phased array detection method is used to effectively detect weld defects; a mathematical model is constructed to calculate the single-track coating thickness, thereby controlling the robot arm trajectory speed; and the target coating thickness is achieved by superimposing multiple tracks.

[0022] The driving method of the multi-wheel driven weld inspection and spraying integrated device in the pipeline adopts a servo motor to control multiple driving wheels to move inside the pipe wall. The servo motor used has high control accuracy, which can reduce the radial displacement of the mobile device during the movement, ensuring that there is no large deviation between the center position of the device and the central axis of the pipeline, which is conducive to the device to perform weld positioning. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0024] Figure 1 It is a flow chart of the present invention.

[0025] Figure 2 It is a schematic diagram of the structure of the present invention.

[0026] Figure 3 It is a schematic structural diagram of the mechanical arm of the present invention.

[0027] Figure 4 It is a schematic diagram of the structure inside the storage room of the present invention.

[0028] Figure 5 It is a schematic diagram of the weld structure in the pipeline of the present invention.

[0029] Figure 6 This is a spray gun spraying model diagram of the present invention.

[0030] Figure 7This is the spray control structure diagram of the present invention.

[0031] Markings in the figure: hexagonal truss 1; cab 2; driving wheel 3; storage room 4; clamping mechanism 5; robotic arm 6; spraying equipment 7; weld detection equipment 8; end effector 601; wrist rotation joint 602; wrist pitch joint 603; wrist 604; elbow joint 605; forearm 606; shoulder joint 607; upper arm 608; waist rotation joint 609; base 610; rotating motor 611; monitoring camera 612; posture sensor 613; controller 410; distribution cabinet 412; paint storage bottle 413; weld 10; spray gun 01, spraying plane 02. DETAILED DESCRIPTION

[0032] like Figure 1 to Figure 7 In the invention, a multi-wheel driven intelligent weld detection and spraying integrated device in a pipeline is provided, which includes a cab 2 arranged in a hexagonal truss 1, and multiple driving wheels 3 are connected to the hexagonal truss 1 and the lower side of the cab 2; a storage room 4 is located at one end of the hexagonal truss 1, and multiple clamping mechanisms 5 are arranged at the other end of the hexagonal truss 1; a mechanical arm 6 is arranged on one side of the storage room 4, and a spraying device 7 and a weld detection device 8 are connected to the mechanical arm 6; the mechanical arm 6 drives the spraying device 7 and the weld detection device 8 to rotate 360° to detect and spray the circular weld in the pipeline.

[0033] Embodiment 1, The hexagonal truss 1 is a hollow frame structure; the driving wheel 3 is an electric wheel; the clamping mechanism 5 is an electric push rod, and an arc plate is arranged at its telescopic end.

[0034] The robotic arm 6 includes an end effector 601, which is sequentially connected to a wrist rotation joint 602, a wrist pitch joint 603, a wrist 604, an elbow joint 605, a forearm 606, a shoulder joint 607, an upper arm 608, a waist rotation joint 609 and a base 610; the base 610 is connected to the output end of a rotating motor 611, and the rotating motor 611 is fixed to the storage chamber 4.

[0035] Attitude sensors 613 are provided on the outside of the wrist 604 and the upper arm 608; the wrist pitch joint 603 is fixed to the wrist rotation joint 602 through a ball-type universal joint; the end effector 601 is connected to the monitoring camera 612, the spraying equipment 7 and the weld detection equipment 8.

[0036] The waist rotation joint 609 controls the horizontal rotation movement of the robot arm 6, and the upper arm 608 controls the forearm 606 to move up and down and forward and backward; the forearm 606 performs telescopic movement, and the forearm 606 and the upper arm 608 drive the wrist 604 to move; the wrist 604 controls the movement of the wrist rotation joint 602 and the wrist pitch joint 603; the wrist rotation joint 602 controls the circular rotation movement of the end effector 601, and the wrist pitch joint 603 controls the pitch movement of the end effector 601.

[0037] A controller 410, a power distribution cabinet 412 and a paint storage bottle 413 are provided in the storage room 4; the controller 410 is electrically connected to the power distribution cabinet 412, and the paint storage bottle 413 is connected to the spraying equipment 7 through a pipeline; the controller 410 is also electrically connected to the driving wheel 3, the clamping mechanism 5, the robotic arm 6, the spraying equipment 7 and the weld detection equipment 8.

[0038] Preferably, the six driving wheels 3 of the integrated device are fixed to the two sides of the bottom of the mobile device by bolts, and the four clamping mechanisms 5 of the device are fixed to the hexagonal trusses 1 by bolts. Two sets of hexagonal trusses 1 are welded to the two ends of the cab 2, and a storage room 4 is welded to one set of hexagonal trusses 1. The base of the monitoring camera 612 is fixed to the mechanical arm with screws, and the spraying equipment 7 and the weld detection equipment 8 are also fixed to the mechanical arm by bolts for easy disassembly.

[0039] Preferably, the device drives six driving wheels 3 to move in the pipeline through a servo motor, accurately controls the movement of the device, and ensures that the center line of the device is aligned with the center axis of the pipeline, so that the detection and spraying equipment can be accurately positioned at the weld of the steel pipe. When the device reaches the specified position, the sensing module identifies and activates the clamping mechanism fixture, and the robotic arm extends to send the detection and spraying equipment to a distance of 4-5 cm from the weld. The detection equipment checks the quality of the weld by emitting ultrasonic waves, and completes 360-degree weld detection driven by the robotic arm. If the weld quality is qualified, the spraying equipment will spray the weld with anti-rust paint; if it is unqualified, the operator will mark and re-weld.

[0040] Embodiment 2, When the multi-wheel driven weld inspection and spraying integrated device in the pipeline is delivered to the entrance of the pressure steel pipe by the rail trolley, the device enters the working state. First, the four sets of clamping mechanisms 5 of the device are in a tightened state to avoid hindering the normal movement of the device in the pressure steel pipe. When the operator in the cab 2 starts the overall power supply system, the electrical equipment on the device enters the standby state. Then, after the driver issues a start command, the six driving wheels 3 of the mobile device will slowly move axially.

[0041] When the device moves into the working range of the weld inspection and spraying equipment, the device will stop moving. At the same time, the clamping mechanism 5 on the device will stretch out and support on the inner wall of the pipeline to lock the moving state of the device. First, the quality of the pipeline weld 10 is inspected, and the mechanical arm 6 drives the weld inspection device 8 to rotate along the weld 10 for one circle. During this period, the weld inspection device 8 emits an ultrasonic wave to check the internal structure of the weld. If the quality of the weld 10 is qualified, the weld inspection device 8 stops working, and the mechanical arm 6 rotates and switches to the spraying mode, driving the spraying device 7 to complete the anti-rust spraying work on the weld 10; if the quality of the weld 10 is unqualified, the weld inspection device 8 will issue a warning to the operator of the cab 2, and the operator will mark the pipeline weld 10 and re-weld it. During the operation of the inspection and spraying equipment, the operator also observes the working condition of the equipment through the monitoring camera 612 on the mechanical arm 6, manually checks the progress of the inspection and spraying work, and prevents the working equipment from being in a dangerous situation. When the weld inspection and spraying process is completed, the clamping mechanism 5 on the device will be tightened, and the drive wheel 3 will continue to move forward.

[0042] Embodiment 3, The positive power supply harness and the negative power supply harness of the power distribution cabinet 412 are respectively connected to the positive power supply interface and the negative power supply interface of the integrated device, and the communication bus is connected to the communication interface of the integrated device. When the integrated device starts working, the output shaft of the rotating motor 611 provides power to drive the base 610 to complete a 360° rotation movement.

[0043] The waist rotation joint 609 controls the horizontal rotation movement of the robot arm 6, and the upper arm 608 controls the upper and lower and front and back movements of the forearm 606. The forearm 606 performs telescopic movement, and the forearm 606 and the upper arm 608 are responsible for sending the wrist 604 to a distance of 4-5 cm from the weld.

[0044] The wrist 604 is used for more delicate operations and is responsible for controlling the movement of the wrist rotation joint 602 and the wrist pitch joint 603 .

[0045] When the wrist 604 moves to the designated working area, the wrist rotation joint 602 controls the circular rotation movement of the end effector 601, and the wrist pitch joint 603 controls the pitch movement of the end effector 601, and the maximum allowed pitch angle is 180°.

[0046] The spraying device 7 and the weld inspection device 8 are respectively fixed on both sides of the end effector 601 , and the working sequence of the two is controlled by the end effector 601 .

[0047] The two groups of posture sensors 613 are used to detect the overall motion posture of the robot arm 6 and transmit the detection results to the controller 410 to adjust the overall motion posture of the robot arm 6.

[0048] Embodiment 4, The power distribution cabinet 412 is welded on the inner wall of the storage room 4, and the paint storage bottle 413 is fixed on the inner wall of the storage room 4 through two sets of fixing frames. The positive power supply harness and the negative power supply harness constitute the power supply circuit between the controller 410 and the power distribution cabinet 412, and the communication bus is responsible for the communication between the controller 410 and the cab 2.

[0049] The power distribution cabinet 412 supplies power to the robot arm 6 and the weld inspection spraying equipment through the positive power supply harness and the negative power supply harness. The controller 410 is responsible for controlling the extension and rotation movement of the robot arm 6, the working state of the weld inspection equipment 8 and the spraying equipment 7.

[0050] The communication between the controller 410 and the cab 2 is completed based on the communication bus. The controller 410 uses the communication bus to send relevant data of the equipment to the cab 2 in real time, and the cab 2 sends control instructions to the controller 410 through the communication bus.

[0051] The paint storage bottle 413 is used to store anti-rust spray paint, and the bottle body is fixed on the inner wall of the storage room to prevent the paint storage bottle from falling during the operation of the mobile device. The controller 410 extracts the spray paint from the paint storage bottle 413 through the paint delivery pipe and supplies it to the spraying device 7, which is evenly sprayed on the weld.

[0052] Embodiment 5, The pipeline welding involved in the present invention is achieved by butt-jointing two sections of pipeline grooves. The present invention is based on an ultrasonic phased array detection method, which can electronically control the focusing and scanning of ultrasonic waves and is suitable for the detection of thick-walled pipes. The phased array accurately controls the time for each array element of the probe to transmit a signal according to the focusing law. The existence of the time difference enables the ultrasonic waves excited by each array element to propagate to a certain position at the same time, thereby achieving the adjustment of the ultrasonic focusing direction and focusing depth. The detection process mainly includes three parts: focusing law, sensitivity setting and scanning method. The specific weld detection control method is as follows: Assume that the speed of sound is c According to the Pythagorean theorem and the time-distance relationship of sound waves, The delay value of each array element relative to the central array element is ; (1) in From center point to focal point The distance between The running track of the weld detection device is an arc shape, and the radius is 0.1m less than the radius of the pipe to ensure that the center point to the focal point The distance between them remains unchanged.

[0053] For beam deflection and focusing, the array element farthest from the focal point is excited first, and the array element closest to the focal point is excited last. The excitation delay of other array elements is controlled accordingly according to the sound path propagation time. Assume that the incident angle of the sound wave from the center point to the focal point is , the above formula can be changed into: ; (2) For by The array probe consists of array elements. Each array element is excited in turn, and all array elements receive signals at the same time. In one acquisition cycle, each array element of the array emits a sound wave, that is, there are a total of The array elements are transmitted successively. For each transmission, Each of the array elements receives a one-dimensional signal. The signals are combined in a matrix, where the rows of the matrix represent the transmitting array elements and the columns represent the receiving array elements. Due to the different spatial positions of the probe array elements, the time it takes for the reflected echo of the defect to reach each array element will also be different. Synthetic aperture focusing imaging calculates the receiving delay of each array element according to the receiving focusing law based on the spatial position of the imaging point. The received signal is appropriately delayed. After A / D conversion, phase shift and superposition processing, a point-by-point focused image of the defect target is obtained. The defects in the focusing area will form a reflection wavefront with a large amplitude, which greatly improves the detection resolution and signal-to-noise ratio. Assume In the Cartesian coordinate system Ultrasonic function of the point, the combination of transmitting and receiving sources In delay time The measured signal e is expressed as the spatial integral of the wave function: ; (3) in is the Dirac function, the delay time It is expressed as: ; (4) Further superimpose all one-dimensional time signals corresponding to the delay time to synthesize the focused sound field for: ; (5) When setting the fan scanning angle, in order to avoid the primary reflection wave entering the wedge or causing too many bottom deformation signals, and to avoid the effective identification of the defect signal by the deformation signal, the starting angle should not be less than 35°; in order to increase the coverage of the sound beam and avoid surface deformation wave signals or other interference signals, the fan scanning end angle generally does not exceed 80°. When setting the angle resolution, it is necessary to comprehensively consider the amount of detection data and defect resolution. If the angle resolution is set to 0.5°, the amount of data doubles compared to 1°, and the signal response speed is slow. If the angle is set to 2°, it is impossible to distinguish the upper and lower endpoint signals of smaller planar defects, so the angle resolution is optimized at 1°. When setting the focus depth, the focus depth is generally set to 1 times the wall thickness.

[0054] For sensitivity setting, the DAC method is used to set the sensitivity. DAC is an electronic device that converts digital signals into analog signals. In sensitivity setting, DAC is used to generate accurate analog voltage or current in response to changes in digital input. For scanning mode, scanning is performed on both sides of the outer wall of the weld during detection, and the primary wave and the primary reflected wave are set to complete the coverage of the detection area.

[0055] During the inspection, the weld is divided into multiple areas according to the actual situation. The height of each area is controlled at 2-3 mm. Ultrasonic beams are used for detailed inspection to avoid missed inspections and false inspections at the overlapped welds. Since the pipeline working environment is a semi-closed environment and welding will bring a lot of dust, it will affect the detection results. During the detection, a disposable protective cover is installed on the ultrasonic probe to prevent dust from directly contacting the probe. In addition, the fast Fourier transform is used to analyze the signal spectrum to identify and filter out the noise part that does not belong to the target signal frequency band.

[0056] The ultrasonic signal obtained by scanning is displayed to the inspectors in the device through the central control system. When a defect is detected, the inspectors mark the weld and perform another welding. If there is no defect in the welding, the robot arm rotates and switches to the spraying mechanism to perform anti-rust paint spraying.

[0057] Embodiment 6, In order to speed up the fluidity of anti-rust paint, rheology modifier is added to the paint bucket. Rheology modifier controls the fluidity of paint, reduces dripping, enhances hiding power and prolongs shelf life. The control process for executing spraying is an automated process, with the PLC programmable logic controller as the core control unit. The monitoring personnel issue spraying instructions on the central control system screen, and the signal is sent to the PLC programmable logic controller. First, the paint in the paint bucket is introduced into the system through the paint injection solenoid valve. Then, the paint meter measures the paint flow and feeds the data back to the PLC programmable logic controller through the paint quantity sensor. When the paint inventory is low, the PLC programmable logic controller alarms the central control system and stops the spraying operation. The PLC programmable logic controller controls the air inlet solenoid valve and the air outlet solenoid valve according to the preset program and sensor feedback to adjust the supply of compressed air to achieve paint atomization. Subsequently, the paint spraying solenoid valve controls the paint to flow from the paint meter to the spray gun according to the instructions of the PLC programmable logic controller, and the spray gun sprays along the weld.

[0058] The spray gun trajectory adopts a z-shaped trajectory. The present invention adopts Gaussian distribution to calculate the coating thickness. It assumes that the coating deposition rate during the spraying process is related to the distance from the spray gun to the surface of the coated object, and this relationship is described by Gaussian distribution. A laser sensor is installed on the nozzle to calculate the distance from the nozzle to the surface of the coated object.

[0059] (6) in, Is the spray point at a distance from the spray gun The coating deposition rate at is the standard deviation of the Gaussian distribution, which affects the width of the spray area.

[0060] First determine the control function of the spray point accumulation ,Since the device works in a pipeline, the spraying surface is designed to be a curved surface.

[0061] (7) in Is the spray gun in time Spraying point To the destination The unit direction vector of is the distance between the spray gun and the target point; i, j, k are three mutually perpendicular unit vectors, whose directions coincide with the positive directions of the coordinate axes of the three-dimensional space coordinate system; p x (t), p y (t), p z (t) is the three-dimensional spatial coordinate of the spray gun at time t; (8) in It is a control function related to the spraying angle.

[0062] (9) in It is the target point Normal vector to the center axis of the spray gun The angle between.

[0063] (10) in is the maximum effective spraying angle of the spray gun. It is a proportional coefficient related to the spraying process and is generally 0.5.

[0064] In robot spraying, the spray beam is spread in space in a cone shape. In order to obtain a uniform spray thickness on the surface, the spray beam must be superimposed on the surface of the workpiece to compensate for the edge thickness and achieve uniform spray thickness. The thickness distribution of the two spray points is superimposed. (11) in is the interval between two spray points.

[0065] To find the spray interval , let the second-order derivative of thickness be at the midpoint between the two spray points , and the solution is and . It indicates the spacing of the spraying track of the spray gun during the spraying process or the distance between two adjacent points on the spraying path. Indicates the initial coating thickness.

[0066] According to the spray speed , spray gun speed , distance between spray gun and working surface , determine the maximum thickness of the paint layer for a single track as : (12) Differentiate the spraying process on the curved pipe to form a plane with a certain slope, such as Figure 6 The shape of the spray gun spraying on the plane is an ellipse. During the spraying period, it is assumed that the spray gun moves at a constant speed. 01 is the spray gun, 02 is the spraying plane; the coating center is set to point, the major and minor semi-axes are Indicates that the height of the spray gun from the spraying plane is , the angle between the spraying plane and the ground is .in: (13) in , is the spray point in the coordinate system with the center of the pipe circle as the origin Axis coordinates.

[0067] Volume of paint sprayed per unit time by spray gun It can be obtained by the following formula: (14) Single track spray gun spraying time It can be obtained by the following formula: (15) Spray gun spraying time according to a single track To control the moving speed of the robot arm. Since the welding platform involved in the present invention uses two-section welding trolleys for two-section welding, where the welding sections at both ends overlap, it moves an extra 1 / 5 semicircle during spraying. Assuming that the robot arm moves at a constant speed, the moving speed of a single section is (16) in is the pipe radius.

[0068] A single track is not enough to achieve the maximum spray thickness , analyze the superposition of multiple trajectories. Considering continuous spraying, the coating thickness is expressed by integration: (17) When two spraying trajectories overlap, the thickness distribution is the superposition of the two trajectories: (18) Similarly, by analyzing the second derivative of the thickness distribution , find the offset distance and maximum thickness .

[0069] If you need to achieve a target coating thickness , by adjusting the number of spray layers To achieve this, that is, the number of times the spraying robot arm moves, when If the number is a decimal, it will be rounded to the integer value.

[0070] (19) When completed When the spraying is completed, the PLC sends a stop signal to the paint solenoid valve. During the spraying process, the PLC continuously monitors the status of each link to ensure the spraying quality. If a link fails, it stops working immediately. The central control system display provides an interface for operators to monitor the progress and quality of spraying in real time. The entire spraying process control structure is as follows Figure 7 .

[0071] The above-mentioned embodiments are only preferred technical solutions of the present invention and should not be regarded as limitations of the present invention. The embodiments and features in the embodiments of the present application can be arbitrarily combined with each other without conflict. The protection scope of the present invention shall be the technical solutions recorded in the claims, including the equivalent replacement solutions of the technical features in the technical solutions recorded in the claims. That is, equivalent replacement improvements within this scope are also within the protection scope of the present invention.

Claims

1. A multi-wheel drive intelligent weld detection and spraying integrated device in a pipeline, characterized by: The invention comprises a cab (2) arranged in a hexagonal truss (1), a plurality of driving wheels (3) connected to the hexagonal truss (1) and the lower side of the cab (2); a storage room (4) is located at one end of the hexagonal truss (1), and a plurality of clamping mechanisms (5) are arranged at the other end of the hexagonal truss (1); a mechanical arm (6) is arranged on one side of the storage room (4), and a spraying device (7) and a weld detection device (8) are connected to the mechanical arm (6); the mechanical arm (6) drives the spraying device (7) and the weld detection device (8) to rotate 360 ​​degrees to detect and spray the circular weld in the pipeline.

2. The multi-wheel drive intelligent weld detection and spraying integrated device in a pipeline according to claim 1 is characterized by: The hexagonal truss (1) is a hollow frame structure; the driving wheel (3) is an electric wheel; and the clamping mechanism (5) is an electric push rod, a curved plate being arranged at the telescopic end thereof.

3. The multi-wheel drive intelligent weld detection and spraying integrated device in a pipeline according to claim 1 is characterized in that: The mechanical arm (6) comprises an end effector (601), wherein the end effector (601) is sequentially connected to a wrist rotation joint (602), a wrist pitch joint (603), a wrist (604), an elbow joint (605), a forearm (606), a shoulder joint (607), an upper arm (608), a waist rotation joint (609) and a base (610); the base (610) is connected to an output end of a rotation motor (611), and the rotation motor (611) is fixed to the storage chamber (4).

4. The multi-wheel drive intelligent weld detection and spraying integrated device in a pipeline according to claim 3 is characterized by: The wrist (604) and the outer side of the upper arm (608) are both provided with a posture sensor (613); the wrist pitch joint (603) is fixed to the wrist rotation joint (602) via a ball-type universal joint; and the end effector (601) is connected to a monitoring camera (612), a spraying device (7) and a weld detection device (8).

5. The multi-wheel drive intelligent weld detection and spraying integrated device in a pipeline according to claim 3 is characterized by: The waist rotation joint (609) controls the horizontal rotation movement of the mechanical arm (6), and the upper arm (608) controls the forearm (606) to move up and down and forward and backward; the forearm (606) performs telescopic movement, and the forearm (606) and the upper arm (608) drive the wrist (604) to move; the wrist (604) controls the movement of the wrist rotation joint (602) and the wrist pitch joint (603); the wrist rotation joint (602) controls the circular rotation movement of the end effector (601), and the wrist pitch joint (603) controls the pitch movement of the end effector (601).

6. The multi-wheel drive intelligent weld detection and spraying integrated device in a pipeline according to claim 1 is characterized by: The storage room (4) is provided with a controller (410), a power distribution cabinet (412) and a paint storage bottle (413); the controller (410) is electrically connected to the power distribution cabinet (412), and the paint storage bottle (413) is connected to the spraying equipment (7) through a pipeline; the controller (410) is also electrically connected to the driving wheel (3), the clamping mechanism (5), the mechanical arm (6), the spraying equipment (7) and the weld detection equipment (8).

7. The multi-wheel drive intelligent weld detection and spraying integrated device in a pipeline according to claim 1 is characterized by: The weld inspection device (8) adopts ultrasonic phased array inspection, and controls the focusing and scanning of ultrasonic waves by electronic means, and is used for the inspection of thick-walled pipes; the phased array accurately controls the time when each array element of the probe transmits a signal according to the focusing law, and the existence of the time difference causes the ultrasonic waves excited by each array element to propagate to a certain position at the same time, thereby realizing the adjustment of the ultrasonic focusing direction and focusing depth; the inspection includes three parts: focusing law, sensitivity setting and scanning method.

8. The method for controlling the use of the multi-wheel drive intelligent weld detection and spraying integrated device in a pipeline according to any one of claims 1 to 7, characterized in that: The steps include: SA1, using a trolley to deliver the integrated device to the entrance of the pressure steel pipe; at this time, the clamping mechanism (5) is in a retracted state; SA2, the operator in the cab (2) starts the overall power-on, and the integrated device enters the standby state; SA3, after issuing a start command, the driving wheel (3) drives the integrated device to move slowly into the pipeline; SA4, when the integrated device moves into the working range of the spraying equipment (7) and the weld inspection equipment (8), the integrated device stops; at the same time, the clamping mechanism (5) stretches to contact the inner wall of the pipeline, limiting the movement of the integrated device in the pipeline; SA5, the robot arm (6) drives the weld inspection device (8) to rotate along the weld (10) for one revolution, during which the weld inspection device (8) emits ultrasonic waves to inspect the internal structure of the weld; if the weld (10) is qualified, the spraying mode is entered; SA6, the robot arm (6) rotates and switches to the spraying mode, driving the spraying equipment (7) to complete the anti-rust spraying work on the weld (10).

9. The weld detection control method of the multi-wheel drive intelligent weld detection and spraying integrated device in a pipeline according to any one of claims 1 to 7, characterized in that: The steps include: SB1, assuming the speed of sound is According to the Pythagorean theorem and the time-distance relationship of sound waves, The delay value of each array element relative to the central array element is ；(1) in From center point to focal point The distance between is the distance between adjacent array elements; the running track of the weld detection device is an arc shape, and the radius is 0.1m less than the radius of the pipeline to ensure that the center point to the focal point The distance between them remains unchanged; SB2, for beam deflection and focusing, the array element farthest from the focal point is excited first, and the array element closest to the focal point is excited last. The excitation delay of other array elements is controlled accordingly according to the sound path propagation time. Assuming that the incident angle of the sound wave from the center point to the focal point is , the above formula can be changed into: ； (2) For by The array probe consists of array elements. Each array element is excited in turn, and all array elements receive signals at the same time. In one acquisition cycle, each array element of the array emits a sound wave, that is, there are a total of array elements are fired successively; for each firing, Each of the array elements receives a one-dimensional signal; thus, there are The signals are combined in a matrix, the rows of the matrix represent the transmitting array elements, and the columns represent the receiving array elements; SB3, due to the different spatial positions of the probe array elements, the time for the reflected echo of the defect to reach each array element will also be different; synthetic aperture focusing imaging is based on the spatial position of the imaging point, and the delay device calculates the receiving delay of each array element according to the receiving focusing law, and appropriately delays the received signal. After A / D conversion, phase shift and superposition processing, the point-by-point focused sound image of the defect target is obtained. The defect in the focusing area will form a reflection wavefront with a large amplitude, which greatly improves the detection resolution and signal-to-noise ratio; assuming In the Cartesian coordinate system Ultrasonic function of the point, the combination of transmitting and receiving sources In delay time The measured signal e is expressed as the spatial integral of the wave function: ；(3) in is the Dirac function, the delay time It is expressed as: ；(4) Further superimpose all one-dimensional time signals corresponding to the delay time to synthesize the focused sound field for: ；(5) When setting the fan scanning angle, in order to avoid the primary reflection wave entering the wedge or causing too many bottom deformation signals, and to avoid the effective identification of the defect signal by the deformation signal, the starting angle should not be less than 35°; in order to increase the coverage of the sound beam and avoid surface deformation wave signals or other interference signals, the fan scanning end angle generally does not exceed 80°; when setting the angle resolution, the angle resolution is set to 1° taking into account the amount of detection data and defect resolution; when setting the focus depth, the focus depth is set to 1 times the wall thickness; SB4, for sensitivity setting, select DAC mode to set the sensitivity; DAC is an electronic device that converts digital signals into analog signals; in sensitivity setting, DAC is used to generate accurate analog voltage or current in response to changes in digital input; for scanning mode, scan both sides of the outer wall of the weld during detection, and set the primary wave and the primary reflected wave to complete the coverage of the detection area; SB5, during detection, the weld is divided into multiple areas according to the actual situation, and the height of each area is controlled at 2-3 mm. Ultrasonic beams are used for detailed detection to avoid missed detection and false detection of weld overlaps. Since the pipeline working environment is a semi-closed environment, and welding will bring a lot of dust, which will affect the detection results; during detection, a disposable protective cover is installed on the ultrasonic probe to prevent dust from directly contacting the probe. In addition, the signal spectrum is analyzed using fast Fourier transform to identify and filter out the noise part that does not belong to the target signal frequency band; SB6, the ultrasonic signal obtained by scanning is displayed to the inspectors in the device through the central control system. When a defect is detected, the inspectors mark the weld and perform another welding. If there is no defect in the welding, the robot arm rotates and switches to the spraying mechanism to execute the anti-rust paint spraying.

10. The spraying control method of the multi-wheel drive intelligent weld detection and spraying integrated device in a pipeline according to any one of claims 1 to 7, characterized in that: The steps include: SC1, in order to speed up the fluidity of anti-rust paint, rheology modifier is added to the paint bucket; rheology modifier controls the fluidity of paint, reduces dripping, enhances hiding power and prolongs the shelf life; the control process of executing spraying is an automated process, with PLC as the core control unit; the monitoring personnel issue spraying instructions on the central control system screen, and the signal is sent to PLC; SC2, the paint in the paint bucket is introduced into the system through the paint injection solenoid valve; then, the paint meter measures the paint flow and feeds the data back to the PLC through the paint quantity sensor. When the paint inventory is low, the PLC alarms the central control system and stops the spraying operation; the PLC controls the air inlet solenoid valve and the air outlet solenoid valve according to the preset program and sensor feedback to adjust the supply of compressed air to achieve paint atomization; then, the paint spraying solenoid valve controls the paint to flow from the paint meter to the spray gun according to the instructions of the PLC, and the spray gun sprays along the weld; SC3, the spray gun trajectory adopts a z-shaped trajectory, and the coating thickness is calculated using Gaussian distribution; it assumes that the coating deposition rate during the spraying process is related to the distance from the spray gun to the surface of the coated object, and this relationship is described by Gaussian distribution; a laser sensor is installed on the nozzle to calculate the distance from the nozzle to the surface of the coated object; ；(6) in, Is the spray point at a distance from the spray gun The coating deposition rate at is the standard deviation of the Gaussian distribution, which affects the width of the spraying area; SC4, control function to determine the accumulation of spray points ,Since the device works in a pipeline, the spraying surface is designed to be a curved surface; ；(7) in Is the spray gun in time Spraying point To the destination The unit direction vector of is the distance between the spray gun and the target point; x, y, z are the three-dimensional spatial coordinates of the target point s; i, j, k are three mutually perpendicular unit vectors, whose directions coincide with the positive directions of the coordinate axes of the three-dimensional spatial coordinate system; p x (t), p y (t), p z (t) is the three-dimensional spatial coordinate of the spray gun at time t; ；(8) in It is the control function related to the spraying angle; ；(9) in It is the target point Normal vector to the center axis of the spray gun The angle between ；(10) in is the maximum effective spraying angle of the spray gun. is the proportionality factor related to the spraying process and is set to 0.5; SC5, in robot spraying, the spray beam is spread in space in a cone shape. In order to obtain a uniform spray thickness on the surface, the spray beam must be superimposed on the surface of the workpiece to achieve the purpose of compensating the edge thickness and achieving uniform spray thickness; the thickness distribution of the two spray points is superimposed, ；(11) in is the interval between two spray points; SC6, to find the spray point interval , let the second-order derivative of thickness be at the midpoint between the two spray points , and the solution is and ; It indicates the spacing of the spraying track of the spray gun during the spraying process or the distance between two adjacent points on the spraying path. represents the initial coating thickness; According to the spray speed , spray gun speed , distance between spray gun and working surface , determine the maximum thickness of the paint layer for a single track as : ；(12) Differentiate the spraying process on the curved pipe to form a plane with a certain slope; the spray gun sprays on the plane in an elliptical shape; during spraying, the spray gun is assumed to move at a uniform speed; the center of the coating is set to point, the major and minor semi-axes are Indicates that the height of the spray gun from the spraying plane is , the angle between the spraying plane and the ground is ;in: ；(13) in , is the spray point in the coordinate system with the center of the pipe circle as the origin Axis coordinates; SC7, volume of paint sprayed per unit time by spray gun It can be obtained by the following formula: ；(14) Single track spray gun spraying time It can be obtained by the following formula: ；(15) Spray gun spraying time according to a single track To control the moving speed of the robot arm; because two sections of welding are used for two-section welding, the welding sections at both ends overlap, and it moves 1 / 5 more semicircle during spraying; assuming that the robot arm moves at a constant speed, the moving speed of a single section is ；(16) in is the pipe radius; SC8, a single track is not enough to achieve the maximum spray thickness , analyze the superposition of multiple trajectories. Considering continuous spraying, the coating thickness is expressed by integration: ；(17) When two spraying trajectories overlap, the thickness distribution is the superposition of the two trajectories: ；(18) Similarly, by analyzing the second-order derivative of the thickness distribution , find the offset distance and maximum thickness ; If you need to achieve a target coating thickness , by adjusting the number of spray layers To achieve this, that is, the number of times the spraying robot arm moves, when If it is a decimal, it will be rounded to the integer value; ；(19) When completed When spraying is completed for the first time, the PLC sends a stop signal to the paint solenoid valve. During the spraying process, the PLC continuously monitors the status of each link to ensure the quality of spraying. If a link fails, the work will be stopped immediately. The central control system display provides an interface for the operator to monitor the progress and quality of spraying in real time.

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