Pipe hole inner surface detection control method based on automatic positioning of crawling robot

Abstract

The invention discloses a pipe hole inner surface detection control method based on automatic positioning of a crawling robot, and belongs to the technical field of condenser heat exchange pipe detection. The invention aims to solve the problems of large positioning deviation and low detection efficiency in the existing condenser heat exchange tube detection. Comprising the steps that a crawling robot is adopted to bear an endoscope, the path of the crawling robot is planned, and the crawling robot is controlled to be positioned to a starting end pipe opening of a target heat exchange pipe; setting the wire outlet speed and the wire take-up speed of the push-pull device according to requirements, controlling the endoscope to move to the tail end pipe opening of the target heat exchange pipe through the push-pull device under the control of the wire outlet speed, and starting the endoscope to carry out image acquisition on the inner surface of the pipe hole of the heat exchange pipe; in the image collection process of the endoscope, the endoscope is controlled to move from the tail end pipe opening to the starting end pipe opening through the push-pull device based on the take-up speed until the inner surface image collection of the pipe hole of the target heat exchange pipe is completed; and carrying out defect identification to obtain a detection result. According to the invention, automatic detection of pipe hole inner surface defects is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to a pipe hole inner surface detection control method based on automatic positioning of a crawling robot, and belongs to the technical field of condenser heat exchange pipe detection. BACKGROUND

[0002] The traditional manual detection method of condenser heat exchange pipes requires hole-by-hole operation, and its detection efficiency is low. The detection of a single tube plate (containing 3000+ pipe holes) takes more than 72 hours, which cannot meet the requirements of the overhaul cycle.

[0003] In the existing detection, firstly, the positioning accuracy of the pipe hole is insufficient, and the positioning error is greater than ±2mm, which easily leads to collision of the probe with the edge of the pipe hole; secondly, the image acquisition device relies on manual wire feeding, and the positioning error of the defect position is large, which can reach ±2mm; then, for the acquired images, manual interpretation is required, and the defect quantification is difficult due to the subjectivity of the human, resulting in a large defect recognition error.

[0004] At present, wheeled robots have been applied to heat exchange pipe detection. Due to the complex arrangement and layout of heat exchange pipes, the wheeled robot is prone to positioning deviation, and the error is greater than or equal to 1.5mm; at the same time, the wheeled robot cannot realize continuous 360° circumferential detection. Each hole is detected only once, and the detection efficiency is low. The mechanical limiting turntable needs to be adjusted multiple times, and the cumulative error is significant. The missed detection rate is greater than 15%. Not only is the interactive operation process tedious, but also the function is incomplete and the operation is too complex, and it does not have path planning capability. SUMMARY

[0005] In view of the large positioning deviation and low detection efficiency in the existing condenser heat exchange pipe detection, the present application provides a pipe hole inner surface detection control method based on automatic positioning of a crawling robot.

[0006] The pipe hole inner surface detection control method based on automatic positioning of a crawling robot of the present application comprises:

[0007] The crawling robot carries an endoscope, the path of the crawling robot is planned according to the arrangement and layout of the heat exchange pipe, and the crawling robot is positioned to the starting end of the target heat exchange pipe.

[0008] The push-pull device is set to the wire feeding speed and the wire collecting speed according to the requirements. Under the control of the wire feeding speed, the endoscope is moved to the end of the target heat exchange pipe by the push-pull device, and the endoscope starts to collect images of the inner surface of the pipe hole of the heat exchange pipe. During the image collection of the endoscope, the endoscope is moved from the end to the starting end of the pipe hole by the push-pull device based on the wire collecting speed, until the image collection of the inner surface of the pipe hole of the target heat exchange pipe is completed.

[0009] The collected pipe hole inner surface images are processed and defects are identified to obtain the detection results.

[0010] According to the pipe hole inner surface detection control method based on the automatic positioning of the crawling robot of the application, the defect recognition is realized through an AI algorithm.

[0011] According to the pipe hole inner surface detection control method based on the automatic positioning of the crawling robot of the application, the crawling robot is sequentially transformed to the current target heat exchange pipe according to the planned crawling robot path.

[0012] According to the pipe hole inner surface detection control method based on the automatic positioning of the crawling robot of the application, the determination method of the endoscope moving to the end opening of the target heat exchange pipe is:

[0013] The length of the push-pull device is acquired in real time, and the time when the endoscope moves to the end opening of the target heat exchange pipe is determined in combination with the length of the heat exchange pipe.

[0014] According to the pipe hole inner surface detection control method based on the automatic positioning of the crawling robot of the application, the time when the endoscope moves from the end opening to the start opening is determined according to the length of the push-pull device.

[0015] According to the pipe hole inner surface detection control method based on the automatic positioning of the crawling robot of the application, the crawling robot is a crawling robot in a series RPR joint configuration.

[0016] According to the pipe hole inner surface detection control method based on the automatic positioning of the crawling robot of the application, the crawling robot is controlled through a robot control box; and the robot control box is connected with the crawling robot through a CAN bus.

[0017] According to the pipe hole inner surface detection control method based on the automatic positioning of the crawling robot of the application, the crawling robot comprises toes, feet, a base, a linear driver, a lifting driver and a rotating driver,

[0018] A pair of feet are symmetrically arranged on the two sides of the base, the feet and the bottom end of the base are provided with toes, and the toes are positioned by being inserted into the pipe hole of the heat exchange pipe.

[0019] The base is in a cylindrical shape, the rotating driver and the lifting driver are arranged, the rotating driver drives the rotation of the crawling robot, the lifting driver drives the lifting movement of the crawling robot, the linear driver is arranged between the base and the pair of feet, and the linear driver drives the horizontal movement of the crawling robot.

[0020] According to the pipe hole inner surface detection control method based on the automatic positioning of the crawling robot of the application, the toes are in a six-claw expansion structure and are driven by air.

[0021] According to the pipe hole inner surface detection control method based on the automatic positioning of the crawling robot of the present application, the linear driver is connected with a tool clamp, and the tool clamp is used to fix the endoscope during the movement of the crawling robot.

[0022] The present application has the advantages that the method of the present application combines industrial nondestructive testing with artificial intelligence cross technology, is realized based on a modularized crawling robot platform, has the ability of full domain continuous positioning and intelligent path planning of heat exchange pipes, and can realize efficient quality detection of heat exchanger pipe holes.

[0023] The method of the present application can realize full coverage detection of multiple pipe holes on the condenser, improve the detection positioning precision and detection efficiency, reduce the artificial detection error, and greatly avoid missed detection.

[0024] The method of the present application realizes automatic positioning, detection and result saving of multiple pipe holes of a tube sheet, and has less time cost and higher efficiency than artificial detection and other existing detection schemes. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a flow chart of the pipe hole inner surface detection control method based on the automatic positioning of the crawling robot of the present application;

[0026] Figure 2 is a control block diagram of the pipe hole inner surface detection control method based on the automatic positioning of the crawling robot of the present application;

[0027] Figure 3 is a structural schematic diagram of the crawling robot. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0029] Specific implementation one, combined Figure 1 and Figure 2 As shown in the drawings, the present application provides a pipe hole inner surface detection control method based on the automatic positioning of a crawling robot, which comprises the following steps.

[0030] The crawling robot carries the endoscope, the crawling robot path is planned according to the arrangement and layout of the heat exchange pipe, the crawling robot is positioned at the initial end of the target heat exchange pipe, and the endoscope is aligned with the initial end of the heat exchange pipe;

[0031] The push-pull device is used to set the outgoing speed and the winding speed of the endoscope according to the requirements. Under the control of the outgoing speed, the endoscope is moved to the terminal end of the target heat exchange pipe by the push-pull device, and the endoscope starts to collect images of the inner surface of the pipe hole of the heat exchange pipe. During the image collection of the endoscope, the endoscope is moved from the terminal end to the initial end by the push-pull device based on the winding speed until the image collection of the inner surface of the pipe hole of the target heat exchange pipe is completed.

[0032] The collected images of the inner surface of the pipe hole are processed and defects are identified to obtain the detection results.

[0033] In the embodiment, the defect identification is realized by an AI algorithm.

[0034] The crawling robot sequentially changes positions to the current target heat exchange pipe according to the planned crawling robot path.

[0035] The push-pull device is used to send and receive the endoscope, so that the endoscope can move in the heat exchange pipe at different speeds. The image data collected by the endoscope can be transmitted to the operation computer for defect identification of the inner surface of the pipe hole.

[0036] Further, the determination method that the endoscope moves to the terminal end of the target heat exchange pipe is as follows:

[0037] The outgoing length of the push-pull device is acquired in real time, and the time when the endoscope moves to the terminal end of the target heat exchange pipe is determined in combination with the length of the heat exchange pipe.

[0038] According to the outgoing length of the push-pull device, the time when the endoscope moves from the terminal end to the initial end is determined.

[0039] In combination with Figure 1 As shown in the figure, the detection process is as follows:

[0040] S110: Place the crawling robot at any hole position of the tube plate, set this hole position as the initial hole position of the robot in the system, select the pipe hole area to be detected in the system, and start the detection.

[0041] S120: The crawling robot automatically moves to the next pipe hole position to be detected by the algorithm, and the endoscope is aligned with the pipe hole.

[0042] S130: The system automatically sets the outgoing speed of the push-pull device, controls the push-pull device to start to send out the endoscope, and moves the endoscope along the pipe hole;

[0043] S140: The system acquires the pusher wire length in real time, judges whether the endoscope reaches the end of the pipe hole, if not, continue to pay out the wire, if it reaches the end, start the endoscope to shoot the video in the pipe, the system AI algorithm module starts to identify the defects in the pipe;

[0044] S150: The system automatically sets the pusher wire speed, controls the pusher to start winding, and the AI algorithm module identifies the defects in the pipe in real time;

[0045] S160: The system judges whether the endoscope has retreated to the pipe opening position, if not, controls the pusher to continue winding, if it has reached the pipe opening, stops defect identification, closes the camera, and stops the pusher winding, the system saves the video in the pipe and the defect picture, and completes the current pipe hole detection;

[0046] S170: The system judges whether all pipe hole detection is completed, if not, continue S120~S160 steps, and detect the remaining undetected pipe holes; if all are completed, complete the current detection task.

[0047] As an example, in combination with Figure 3 The crawling robot is a series RPR (rotation-translation-rotation) joint configuration crawling robot. The series RPR joint configuration crawling robot has the ability of continuous and accurate positioning, and the pipe hole positioning accuracy is less than 1mm, which is higher than other detection positioning methods.

[0048] The crawling robot is controlled by a robot control box; the robot control box is connected with the crawling robot through CAN bus.

[0049] The crawling robot comprises toes, feet, a base, a linear driver, a lifting driver and a rotating driver,

[0050] A pair of feet are symmetrically arranged on both sides of the base, the toes are installed at the bottom end of the feet and the base, and the toes are positioned by being inserted into the pipe hole of the heat exchange pipe;

[0051] The base is a cylindrical shape, and the rotating driver and the lifting driver are arranged on the base, the rotating driver drives the rotation of the crawling robot, the lifting driver drives the lifting movement of the crawling robot, and the linear driver is arranged between the base and the pair of feet, and the linear driver drives the horizontal movement of the crawling robot.

[0052] In this embodiment, the toes are six-claw expansion structures driven by pneumatic.

[0053] The linear driver is connected with a tool clamp, and the tool clamp is used to fix the endoscope during the movement of the crawling robot.

[0054] In combination withFigure 2 and Figure 3 As shown in FIG. 1, the system for implementing the method of the present application comprises five modules: an operation computer, an endoscope, a cable puller, a robot control box and a crawling robot, which are described as follows:

[0055] S210: Operation computer. Responsible for controlling the detection process, controlling the automatic positioning of the robot, processing the collected images, displaying the detection results and setting the equipment index parameters, etc. The operation computer is connected with the cable puller and the robot control box through a network cable, and can sequentially position and detect the inner surface quality of multiple pipe holes.

[0056] S220: Endoscope. Responsible for collecting images of the inner surface of the pipe hole, mainly including a lens, an LED and a centralizer. The endoscope is connected with the operation computer through a USB, and communicates through a UVC protocol.

[0057] S230: Cable puller. Precisely controls the entry and exit of the camera into the pipe hole through the control of the wire feeding and winding operation. The puller is connected with the operation computer through a network cable.

[0058] S240: Robot control box. Responsible for controlling the basic actions of the crawling robot, including the insertion, lifting, holding, releasing, translation and rotation of the foot and base, and can complete the crawling of the robot in different directions on the pipe plate. The operation computer sends instructions to the robot control box according to the business logic, and the control box controls the corresponding operation of the crawling robot through a CAN bus.

[0059] S250: Crawling robot. Responsible for automatically positioning the pipe hole, mainly including toes, feet, bases, linear drives, lifting drives and rotary drives. The toes are installed at the bottom of the feet and the base, and are used to insert the pipe hole to support and fix the robot body. The feet and the base, which are equivalent to the legs of the robot, complete the crawling of the robot through the lifting and lowering actions. The linear drive and the rotary drive are mainly used to control the linear movement and direction adjustment of the robot. The basic actions of the robot are controlled by the control box, and the crawling robot is as shown in FIG. 2: Figure 3

[0060] Toes, six-claw expansion structure, driven by pneumatic. Work flow: extend the toes → insert into the pipe hole → expand and fix → release and retract.

[0061] Base, mainly used for fixing the robot body. The base has multiple toes, rotary drives and lifting drives on the top.

[0062] Linear drive, controls the linear motion of the feet and the tool clamp, and is used for the positioning of the toes of the feet and the positioning of the detection tool.

[0063] Lifting drive, controls the lifting and lowering of the base through the lifting and lowering of the base, and the lifting and lowering of the feet.​

[0064] The foot is provided with toes, and the toes on both sides can be used to fix the robot body.

[0065] The rotating driver controls the continuous rotation of the base, and completes the action of robot turning.

[0066] The tool clamp is mainly used for fixing the endoscope, and the endoscope is positioned at the pipe opening position through system planning.

[0067] The crawling robot adopts a modular design, and can complete the quick replacement of the endoscope probe / toes / driving module within 5 minutes at most.

[0068] The method can automatically plan a detection path according to different tube plate models, and achieves full coverage and no missed detection.

[0069] Through experimental verification, for a heat exchanger with a tube plate diameter of Φ2000mm, 3100 tube holes and a material of Ti, comprehensive detection can be completed within 30 hours.

[0070] Although the present application is described herein with reference to particular embodiments, it should be understood that these examples are merely set forth in order to explain the principles and applications of the present application. Thus, it should be understood that numerous modifications can be made to the exemplary embodiments, and that other arrangements can be devised without departing from the spirit and scope of the present application as defined by the appended claims. It should be understood that the different dependent claims and features described herein can be combined with different embodiments of the original claims. It should also be understood that features described in relation to one embodiment can be used in other embodiments.

Claims

1. A method for controlling the detection of the inner surface of a pipe hole based on the automatic positioning of a crawling robot, characterized by, The method comprises the following steps: A crawling robot carries an endoscope, and a crawling robot path is planned according to the arrangement of heat exchange pipes, and the crawling robot is positioned at the starting end of the target heat exchange pipe; The push-pull device is set to have an outgoing speed and a reeling speed, and under the control of the outgoing speed, the endoscope is moved to the end of the target heat exchange pipe by the push-pull device, and the endoscope starts to collect images of the inner surface of the pipe hole of the heat exchange pipe; during the image collection of the endoscope, the endoscope is moved from the end to the start of the pipe hole by the push-pull device based on the reeling speed, until the image collection of the inner surface of the pipe hole of the target heat exchange pipe is completed. The collected images of the inner surface of the pipe hole are processed and defects are identified to obtain detection results.

2. The method of claim 1, wherein, The defect identification is realized by an AI algorithm.

3. The method of claim 1, wherein, The crawling robot changes positions to the current target heat exchange pipe according to the planned crawling robot path.

4. The method of claim 1, wherein, The determination method of the endoscope moving to the end of the target heat exchange pipe is: The outgoing length of the push-pull device is obtained in real time, and the time when the endoscope moves to the end of the target heat exchange pipe is determined based on the length of the heat exchange pipe.

5. The method of claim 1, wherein, The time when the endoscope moves from the end to the start of the pipe hole is determined based on the outgoing length of the push-pull device.

6. The method of claim 1, wherein, The crawling robot is a crawling robot with a series RPR joint configuration.

7. The method of claim 6, wherein the method further comprises: The crawling robot is controlled by a robot control box, and the robot control box is connected with the crawling robot through a CAN bus.

8. The method of claim 7, wherein, The crawling robot comprises toes, feet, a base, a linear driver, a lifting driver and a rotating driver, A pair of feet is symmetrically arranged on both sides of the base, the feet and the bottom end of the base are provided with toes, and the toes are positioned by being inserted into the pipe hole of the heat exchange pipe; The base is a cylinder, and the rotating driver and the lifting driver are arranged on the base, the rotating driver drives the rotation of the crawling robot, the lifting driver drives the lifting movement of the crawling robot, and the linear driver is arranged between the base and the pair of feet, and the linear driver drives the horizontal movement of the crawling robot.

9. The method of claim 8, wherein the method further comprises: The toes are six-claw expansion structures driven by air.

10. The method of claim 9, wherein, The linear driver is connected with a tool clamp, and the tool clamp is used to fix the endoscope during the movement of the crawling robot.

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