Welding seam tracking system and method for magnetic powder inspection robot

Abstract

The invention discloses a welding seam tracking system and method for a magnetic powder inspection robot, and the system comprises a plurality of pressure sensors which are respectively arranged on suspension devices of moving wheels of the robot and are used for measuring the pressure of the robot at corresponding positions in tracking movement; and the data processing module is used for judging the deviation state of the current robot posture relative to the center of the welding seam according to the pressure measured at different positions, generating a motor driving signal for correcting deviation based on the deviation state, and sending the motor driving signal to the corresponding moving wheel motor. Accurate and continuous path guidance can be provided for the flaw detection robot in the storage tank circumferential weld flaw detection process.

Description

Technical Field

[0001] The present invention relates to the technical field of flaw detection, and in particular to a weld tracking system and method for a magnetic particle flaw detection robot. Background Art

[0002] Currently, most magnetic particle flaw detection robot products still use a manual remote control method to control the flaw detection robot, and weld path recognition is a very important part for the flaw detection robot.

[0003] In the prior art, some magnetic particle flaw detection robots that can operate autonomously mostly use distributed ranging sensors or other optical sensors to identify the weld path. There are many connecting wires, the recognition accuracy is poor, and it is easily affected by environmental light, so it cannot provide accurate path guidance for the movement of the robot. Summary of the Invention

[0004] An object of the present invention is to provide a solution for accurately identifying the autonomous weld path of a magnetic particle flaw detection robot.

[0005] To solve the above technical problems, an embodiment of the present invention provides a weld tracking system for a magnetic particle flaw detection robot, including: a plurality of pressure sensors respectively arranged on the suspension devices of the robot moving wheels, which are used to measure the pressure at corresponding positions during the tracking movement of the robot; a data processing module, which is used to judge the offset state of the current robot posture relative to the weld center according to the pressures measured at different positions, and based on this, generate a motor drive signal for correcting the offset, and then send the motor drive signal to the corresponding moving wheel motor.

[0006] Preferably, the data processing module includes: a main control unit configured to extract the pressure difference of the front moving wheels and the pressure difference of the rear moving wheels according to the pressures at different positions, and determine the offset state according to the pressure difference of the front moving wheels and the pressure difference of the rear moving wheels, and calculate the expected rotational speeds of the respective moving wheel motors when an offset occurs, wherein, based on the moving direction of the robot, the pressure obtained at the left front moving wheel of the robot is marked as the first position pressure, the pressure obtained at the left rear moving wheel is marked as the second position pressure, the pressure obtained at the right front moving wheel is marked as the third position pressure, and the pressure obtained at the right rear moving wheel is marked as the fourth position pressure; a motor drive unit configured to convert the expected rotational speeds of the respective moving wheel motors into motor drive signals for different moving wheel motors, so that each motor outputs the expected rotational speed.

[0007] Preferably, the main control unit is further configured to determine the offset state through the following steps: by judging the numerical signs and magnitudes of the pressure differences of the front-side moving wheels and the pressure differences of the rear-side moving wheels, judge the validity of the collected pressure data, where the pressure difference of the front-side moving wheels is the difference between the pressure at the first position and the pressure at the third position, and the pressure difference of the rear-side moving wheels is the difference between the pressure at the fourth position and the pressure at the second position; when the collected data is valid, then determine the current offset state and the posture to be corrected according to the numerical signs and magnitudes of the pressure differences of the front-side moving wheels and the pressure differences of the rear-side moving wheels.

[0008] Preferably, when the numerical signs of the pressure differences of the front-side moving wheels and the pressure differences of the rear-side moving wheels are both positive, the current robot posture is biased to the left of the weld center position and needs to be corrected to the right; when the numerical signs of the pressure differences of the front-side moving wheels and the pressure differences of the rear-side moving wheels are both negative, the current robot posture is biased to the right of the weld center position and needs to be corrected to the left; when the numerical signs of the pressure differences of the front-side moving wheels and the pressure differences of the rear-side moving wheels are both zero, the current robot posture has no offset.

[0009] Preferably, when the numerical signs of the pressure differences of the front-side moving wheels and the pressure differences of the rear-side moving wheels are the same and the magnitudes are equal, the currently collected voltage data is valid.

[0010] Preferably, the main control unit is further configured to calculate the desired speeds of the respective moving wheel motors using the following expressions:

[0011] V d = K × D1

[0012] V L = V + V d

[0013] V R = V - V d

[0014] where V represents the desired rotational speed of the moving wheels of the robot as a whole, K represents the proportionality coefficient corresponding to the relationship between the offset and the rotational speed difference, D1 represents the pressure difference of the front-side moving wheels, V L represents the desired rotational speed provided to the left moving wheel motor, V R represents the desired rotational speed provided to the right moving wheel motor.

[0015] Preferably, the data processing module further includes: a data acquisition unit, which is configured to receive the pressure data of each pressure sensor, convert the pressure data into a voltage signal that meets the voltage processing conditions of the main control unit, and then perform analog-to-digital conversion and noise reduction and filtering processing on the voltage signal to obtain the pressure data to be transmitted to the main control unit.

[0016] Preferably, the data acquisition unit is further configured to perform noise reduction filtering processing by using a moving average filtering algorithm.

[0017] Preferably, the data processing module further includes: an interface unit, which is configured to receive pressure data from multiple pressure sensors and send the motor drive signal to each mobile wheel motor.

[0018] On the other hand, an embodiment of the present invention further provides a weld seam tracking method for a magnetic particle flaw detection robot. The weld seam tracking method is implemented by using the weld seam tracking system as described above. Wherein, the weld seam tracking method includes: Step 1, measuring the pressure at corresponding positions of the robot during tracking movement through multiple pressure sensors respectively arranged on the suspension devices of the robot's mobile wheels; Step 2, the data processing module determines the offset state of the current robot posture relative to the weld seam center according to the pressures measured at different positions, and based on this, generates a motor drive signal for correcting the offset, and then sends the motor drive signal to the corresponding mobile wheel motor.

[0019] Compared with the prior art, one or more of the above embodiments may have the following advantages or beneficial effects:

[0020] The present invention proposes a weld seam tracking system and method for a magnetic particle flaw detection robot. The system and method include a pressure sensor and a data processing module. Mainly, the data acquisition unit in the data processing module real-time obtains the pressure values of the pressure sensors distributed at 4 positions, and transmits these values to the data main control unit in the main control circuit board. The main control unit analyzes and gives the offset amount of the current robot posture relative to the weld seam center position, and gives the difference in rotational speeds of the two motors required for correcting this offset amount through closed-loop operation, thereby achieving the purpose of the robot's weld seam tracking. The present invention can provide accurate and continuous path guidance for the flaw detection robot during the inspection of the circumferential weld of the storage tank, and the overall structure is simple and the volume is small, which is convenient for integration with the flaw detection robot.

[0021] Other features and advantages of the present invention will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present invention. The objectives and other advantages of the present invention can be realized and obtained by the structures specifically pointed out in the specification, claims, and drawings. Description of the Drawings

[0022] The drawings are used to provide a further understanding of the present invention, and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the present invention, and do not constitute a limitation to the present invention. In the drawings:

[0023] Figure 1It is a schematic diagram of the overall structure of the weld tracking system for the magnetic particle flaw detection robot according to the embodiment of the present application.

[0024] Figure 2 It is a schematic diagram of the specific structure of the weld tracking system for the magnetic particle flaw detection robot according to the embodiment of the present application.

[0025] Figure 3 It is a schematic diagram of the installation of the pressure sensor at the moving wheel in the weld tracking system for the magnetic particle flaw detection robot according to the embodiment of the present application.

[0026] Figure 4 It is a cross-sectional schematic diagram of the installation of the pressure sensor on the robot in the weld tracking system for the magnetic particle flaw detection robot according to the embodiment of the present application.

[0027] Figure 5 It is a schematic diagram of the step flow of the weld tracking method for the magnetic particle flaw detection robot according to the embodiment of the present application. Detailed implementation manners

[0028] The following will combine the drawings and embodiments to detail the implementation manners of the present invention, so as to fully understand how the present invention uses technical means to solve technical problems and achieve the implementation process of technical effects and implement accordingly. It should be noted that as long as there is no conflict, the various embodiments in the present invention and the various features in each embodiment can be combined with each other, and the formed technical solutions are all within the protection scope of the present invention.

[0029] In addition, the steps shown in the flowchart of the drawings can be executed in a computer system such as a set of computer executable instructions. And although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0030] The terms used here are only for describing specific embodiments and do not intend to limit the exemplary embodiments. Unless the context clearly indicates otherwise, the singular forms "a" and "an" used here also intend to include the plural. It should also be understood that the terms "including" and / or "comprising" used here specify the presence of the stated features, integers, steps, operations, units, and / or components, and do not exclude the presence or addition of one or more other features, integers, steps, operations, units, components, and / or their combinations.

[0031] To solve the problems in the above-mentioned background technology, the embodiments of the present application propose a weld tracking system and method for a magnetic particle flaw detection robot. The system and method determine the offset of the robot's posture relative to the center position of the weld by real-time monitoring the change trend and change amount of the pressure sensor values at the suspension devices of the moving wheels at different positions, thereby calculating the desired rotational speed values of each moving wheel motor, so that each moving wheel motor completes the accurate tracking of the robot according to the corresponding desired rotational speed.

[0032] Figure 1 It is a schematic diagram of the overall structure of the weld tracking system for the magnetic particle flaw detection robot according to the embodiments of the present application. As Figure 1 shown, the weld tracking system described in the embodiments of the present invention includes: a plurality of pressure sensors A and a data processing module B. Each pressure sensor A is respectively connected to the data processing module B. The data processing module B is arranged on the circuit board to form a main control circuit board.

[0033] In the embodiments of the present invention, a plurality of pressure sensors A are respectively arranged on the suspension devices of each moving wheel in the magnetic particle flaw detection robot. In the actual application process, the magnetic particle flaw detection robot has a plurality of moving wheels for controlling movement (direction and movement amount), and each moving wheel is controlled by a moving wheel motor (for example: a DC motor). Moreover, in order to reduce the vibration of each moving wheel, the magnetic particle flaw detection robot also installs a suspension device with a shock absorption function above each moving wheel. The pressure sensor A is installed between the elastic rod in the suspension device and the robot platform to sense the offset state of the corresponding moving wheel during movement, as Figure 3 shown. By arranging the pressure sensor A on the robot suspension device, the adsorption state of the corresponding side moving wheel motor is inferred based on the pressure value at this position.

[0034] In one embodiment, a plurality of pressure sensors A are connected to the module B through the interface unit in the data processing module B. In addition, the data processing module B is also connected to each moving wheel motor through the internal interface unit.

[0035] In one embodiment, the type of weld tracked by the magnetic particle flaw detection robot described in the embodiments of the present invention is a circumferential weld.

[0036] Specifically, a plurality of pressure sensors A are used to measure the pressure at the corresponding positions during the tracking movement of the robot. The data processing module B is used to judge the offset state of the current robot posture relative to the center of the weld according to the pressures measured at different positions, and generate a motor drive signal for correcting the offset according to the current offset state, so as to send the motor drive signal to the corresponding moving wheel motor, so that each moving wheel motor adjusts to the desired rotational speed according to the corresponding motor drive signal to correct the offset of the current tracking movement.

[0037] Figure 2 FIG. 1 is a schematic diagram of the specific structure of the weld tracing system for the magnetic particle flaw detection robot according to an embodiment of the present application. Figure 2 As shown, the data processing module B described in the embodiment of the present invention includes: a data acquisition unit, a main control unit, a motor drive unit and an interface unit. In one embodiment, the main control unit is implemented by a single chip microcomputer.

[0038] In one embodiment, the interface unit is used to receive pressure data from a plurality of pressure sensors A. In addition, the interface unit is also used to send a motor driving signal corresponding to a desired rotation speed to each moving wheel motor.

[0039] The data acquisition unit is used to receive the pressure data of each pressure sensor A, convert the original pressure data into a voltage signal that meets the voltage processing conditions of the main control unit, and then perform analog-to-digital conversion and noise reduction filtering on the voltage signal to obtain the pressure data to be transmitted to the main control unit.

[0040] In one embodiment, the data acquisition unit is also used to implement noise reduction processing by using a sliding average filtering algorithm. In the digital filtering process, the possible fluctuation interference signal is mainly filtered out, and the sliding average filtering algorithm is used to implement real-time data processing, wherein the input and output relationship of this part of the filtering function is:

[0041]

[0042] Among them, y(k) represents the pressure data after filtering output at the current kth moment, y(k-1) represents the pressure data after filtering output at the k-1th moment, N represents the length of the filter, and x(k), x(k-1),..., x(kN) represent the pressure data before filtering at the kth, k-1,...kNth moments respectively.

[0043] The raw pressure data collected by pressure sensor A is transmitted to the data acquisition unit for conversion. The raw pressure data is first converted into a voltage signal that can be processed by the back-end main control unit, and then these voltage signals are converted from analog to digital to obtain digital signals corresponding to the pressure values. Since these digital signals may contain more interference components, they are finally processed by filtering algorithm for noise reduction to obtain multi-channel pressure data (i.e. pressure at different positions) to be transmitted to the main control unit.

[0044] In one embodiment, the magnetic particle inspection robot has four moving wheels, such as Figure 4As shown in the figure. In an embodiment of the present invention, with the moving direction of the robot as a reference, a first pressure sensor is provided at the left front moving wheel of the robot, and the pressure obtained from the first pressure sensor is marked as the first position pressure; a second pressure sensor is provided at the left rear moving wheel of the robot, and the pressure obtained from the second pressure sensor is marked as the second position pressure; a third pressure sensor is provided at the right front moving wheel of the robot, and the pressure obtained from the third pressure sensor is marked as the third position pressure; a fourth pressure sensor is provided at the right rear moving wheel of the robot, and the pressure obtained from the fourth pressure sensor is marked as the fourth position pressure.

[0045] In the present invention, the pressure values collected by the four pressure sensors are respectively denoted as PressureL1, PressureL2, PressureR1, and PressureR2, which respectively represent the original pressure values collected by the corresponding sensors of the front left suspension device, the original pressure values collected by the corresponding sensors of the rear left suspension device, the original pressure values collected by the corresponding sensors of the front right suspension device, and the original pressure values collected by the corresponding sensors of the rear right suspension device. After the voltage conversion, analog-to-digital conversion, and noise reduction filtering of these pressure data at different positions from the sensors through the interface unit and the data acquisition unit, the values of each pressure sensor are recorded as the first position pressure Pressure L1OUT , the second position pressure Pressure L2OUT , the third position pressure Pressure R1OUT , and the fourth position pressure Pressure R2OUT .

[0046] Furthermore, the main control unit is mainly configured to extract the pressure difference of the front moving wheels and the pressure difference of the rear moving wheels according to the pressures at different positions, and determine the offset state of the current robot relative to the weld center according to the current pressure difference of the front moving wheels and the current pressure difference of the rear moving wheels. Then, when an offset occurs currently, the desired rotational speeds of each moving wheel motor are calculated.

[0047] After that, the motor drive unit is configured to receive the desired rotational speeds of each moving wheel motor sent by the main control unit, and convert the desired rotational speeds of each moving wheel motor into motor drive signals for different moving wheel motors, so that each moving wheel motor operates according to the output desired rotational speed.

[0048] In this way, the interface unit part transmits the pressure sensor data to the data acquisition unit. The data acquisition unit performs data voltage processing, analog-to-digital conversion, and noise reduction processing, and then transmits the data to the main control unit for corresponding algorithm processing. The expected rotational speeds of the respective drive motors obtained after processing, after the motor drive unit converts the expected rotational speeds into corresponding motor drive signals, are transmitted via the interface unit to the respective mobile wheel motors connected to the interface unit, so that each motor reaches the corresponding rotational speed, thereby realizing robot attitude control and enabling the robot to continue moving along the weld path.

[0049] In the embodiment of the present invention, the pressure sensor A is connected to the interface unit in the main control circuit board (i.e., the data processing module B) through a wire. In the main control circuit board, each unit circuit part is connected through PCB traces. Among them, the input of the data acquisition unit is connected to the interface unit, the output of the data acquisition unit is connected to the main control unit, the output of the main control unit is connected to the input of the motor drive circuit, and the output of the motor drive unit is connected to the interface unit.

[0050] In one embodiment, the main control unit is further configured to determine the real-time offset state of the robot through the following steps: First, by judging the numerical signs and magnitudes of the pressure differences of the front-side mobile wheels and the pressure differences of the rear-side mobile wheels, judge the validity of the pressure data (i.e., the first position pressure, the second position pressure, the third position pressure, and the fourth position pressure) collected at the current moment; then, when the currently collected data is in a valid state, determine the current offset state and the attitude to be corrected according to the numerical signs and magnitudes of the pressure differences of the front-side mobile wheels and the pressure differences of the rear-side mobile wheels. Among them, the pressure difference of the front-side mobile wheels is the difference between the first position pressure and the third position pressure, and the pressure difference of the rear-side mobile wheels is the difference between the fourth position pressure and the second position pressure.

[0051] Specifically, feature extraction is performed on the pressure data after filtering output to obtain the pressure difference of the front-side mobile wheels and the pressure difference of the rear-side mobile wheels, so as to judge whether the robot attitude has shifted and calculate the corresponding offset state. Among them, the following expressions are used to calculate the pressure difference of the front-side mobile wheels and the pressure difference of the rear-side mobile wheels:

[0052] D1 = Pressure L1OUT - Pressure R1OUT

[0053] D2 = Pressure R2OUT - Pressure L1OUT

[0054] Among them, D1 represents the pressure difference of the front-side mobile wheels, D2 represents the pressure difference of the rear-side mobile wheels, Pressure L1OUTIndicates the pressure at the first position, Pressure L1OUT Indicates the pressure at the second position, Pressure R1OUT Indicates the pressure at the third position, Pressure R2OUT Indicates the pressure at the fourth position.

[0055] After calculating the pressure difference between the front moving wheels and the rear moving wheels of the current robot, the main control unit is further configured to first determine the validity of the currently collected pressure data according to the numerical signs and magnitudes of the calculated pressure differences between the front moving wheels and the rear moving wheels.

[0056] In one embodiment, when the numerical signs of the calculated pressure differences between the front moving wheels and the rear moving wheels are the same and the magnitudes are equal, the currently collected voltage data is valid, and in the valid state, the offset state of the current robot is continuously determined; otherwise, the currently collected pressure data is in an invalid state.

[0057] Further, when it is determined that the currently collected data is in a valid state, the main control unit is further configured to determine the current offset state and the posture to be corrected according to the numerical signs and magnitudes of the calculated pressure differences between the front moving wheels and the rear moving wheels.

[0058] In the first embodiment, when the numerical signs of the calculated pressure differences between the front moving wheels and the rear moving wheels are both positive, the current robot posture is biased to the left of the weld center position and needs to be corrected to the right (it is necessary to control the robot posture to correct to the right).

[0059] In the second embodiment, when the numerical signs of the calculated pressure differences between the front moving wheels and the rear moving wheels are both negative, the current robot posture is biased to the right of the weld center position and needs to be corrected to the left (it is necessary to control the robot posture to correct to the left).

[0060] In the third embodiment, when the numerical signs of the calculated pressure differences between the front moving wheels and the rear moving wheels are both zero, the current robot posture has no offset (it is not necessary to correct the robot posture currently).

[0061] In one embodiment of the present invention, the motor drive unit generally uses a differential steering mechanism to control the movement of the magnetic particle flaw detection robot, so as to complete the weld tracking task.

[0062] Therefore, when calculating the desired speeds of the respective moving wheel motors required for robot posture correction, the main control unit described in the embodiment of the present invention is further configured to calculate the desired speeds of the respective moving wheel motors according to the pressure difference of the front moving wheels or the pressure difference of the rear moving wheels representing the offset amount currently.

[0063] In one embodiment, the master control unit is further configured to calculate the desired speed of each mobile wheel motor by using the following expression:

[0064] V d = K × D1

[0065] V L = V + V d

[0066] V R = V - V d

[0067] Wherein, V represents the desired rotational speed of the mobile wheels of the robot as a whole (this parameter is a preset value), K represents the proportional coefficient of the corresponding relationship between the offset and the rotational speed difference, V L represents the desired rotational speed to be provided to the left mobile wheel motor, and V R represents the desired rotational speed to be provided to the right mobile wheel motor.

[0068] In the present invention, by placing the pressure sensor A on the suspension device corresponding to the mobile wheel, when there is a displacement of a certain wheel, the corresponding pressure value will change. When the robot posture has no offset from the weld position, all sensor values are the same. When the robot posture is biased to the left with respect to the weld position, the front left suspension device and the rear right suspension device have downward displacements, and the pressure at the corresponding pressure sensor position increases, that is, the Pressure L1 and Pressure R2 values become larger, while the rear left suspension device and the front right suspension device have upward displacements, and the pressure at the corresponding pressure sensor position decreases, that is, the Pressure L2 and Pressure R1 values become smaller, and then the calculation results of D1 and D2 are negative. Similarly, when the robot posture is biased to the right with respect to the weld position, the calculation results of D1 and D2 are positive.

[0069] In this way, after calculating the desired rotational speed V L for the left mobile wheel motor of the robot and the desired rotational speed V RAfter that, the main control unit will send these two desired rotational speeds to the motor drive unit, which will convert these two desired rotational speeds into a left motor drive signal for controlling the (at least two) left mobile wheel motors of the robot to reach the desired rotational speed, and a right motor drive signal for controlling the (at least two) right mobile wheel motors of the robot to reach the desired rotational speed respectively. Then, the interface unit will send these two motor drive signals to the corresponding mobile wheel motors respectively, so that each motor of the current robot reaches the corresponding desired rotational speed under the control of the corresponding motor drive signal, to correct the offset of the current robot, and thus, by implementing the attitude control of the robot, enable it to complete the accurate weld seam tracking task.

[0070] In addition, based on the above weld seam tracking system, an embodiment of the present invention further provides a weld seam tracking method for a magnetic particle flaw detection robot. This weld seam tracking method is implemented by using the weld seam tracking system as described above.

[0071] Figure 5 It is a schematic diagram of the step flow of the weld seam tracking method for a magnetic particle flaw detection robot according to an embodiment of the present application. As Figure 5 shown, the weld seam tracking method described in the embodiment of the present invention includes the following steps:

[0072] Step S501, measure the pressure at the corresponding position of the robot during tracking movement through a plurality of pressure sensors A respectively arranged on the suspension device of the robot mobile wheel;

[0073] Step S502, the data processing module B determines the offset state of the current robot attitude compared with the weld seam center according to the pressures measured at different positions, and based on this, generates a motor drive signal for correcting the offset, and thus sends the motor drive signal to the corresponding mobile wheel motor.

[0074] The present invention discloses a weld seam tracking system and method for a magnetic particle flaw detection robot. The system and method include a pressure sensor and a data processing module. Mainly, the data acquisition unit in the data processing module real-time obtains the pressure values of the pressure sensors distributed at 4 positions, and transmits these values to the data main control unit in the main control circuit board. The main control unit analyzes and gives the offset amount of the current robot attitude compared with the weld seam center position, and gives the rotational speed difference of the two motors required when correcting this offset amount through closed-loop operation, so as to achieve the purpose of the robot's weld seam tracking movement. The present invention can provide accurate and continuous path guidance for the flaw detection robot during the inspection of the circumferential weld seam of the storage tank, and the overall structure is simple and the volume is small, which is convenient for integration with the flaw detection robot.

[0075] As described above, only the preferred specific embodiments of the present invention are provided, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

[0076] In the description of the present invention, unless otherwise specified, "a plurality of" means two or more; the orientation or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0077] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "connected" and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0078] It should be understood that the embodiments disclosed by the present invention are not limited to the specific structures, processing steps or materials disclosed herein, but should extend to equivalent alternatives of these features understood by those of ordinary skill in the relevant art. It should also be understood that the terms used herein are only for the purpose of describing specific embodiments and do not mean to limit.

[0079] The phrase "an embodiment" or "embodiments" mentioned in the specification means that the specific features, structures or characteristics described in connection with the embodiments are included in at least one embodiment of the present invention. Therefore, the phrases "an embodiment" or "embodiments" that appear throughout the specification do not necessarily all refer to the same embodiment.

[0080] Although the embodiments disclosed by the present invention are as above, the content described is only an embodiment adopted for the convenience of understanding the present invention and is not intended to limit the present invention. Any person skilled in the technical field to which the present invention pertains can make any modifications and changes in the form of implementation and details without departing from the spirit and scope disclosed by the present invention. However, the patent protection scope of the present invention shall still be subject to the scope defined by the appended claims.

Claims

1. A weld seam tracking system for a magnetic particle flaw detection robot, characterized in that, Including: A plurality of pressure sensors respectively arranged on the suspension device of the robot moving wheels, which are used to measure the pressure at corresponding positions during the tracking movement of the robot; A data processing module, which is used to judge the offset state of the current robot posture relative to the weld center according to the pressures measured at different positions, and based on this, generate a motor drive signal for correcting the offset, so as to send the motor drive signal to the corresponding moving wheel motor.

2. The seam tracking system according to claim 1, wherein The data processing module includes: A main control unit, which is configured to extract the pressure difference of the front moving wheels and the pressure difference of the rear moving wheels according to the pressures at different positions, and determine the offset state and calculate the expected rotational speeds of the respective moving wheel motors when an offset occurs according to the pressure difference of the front moving wheels and the pressure difference of the rear moving wheels. Among them, based on the moving direction of the robot, the pressure obtained at the left front moving wheel of the robot is marked as the first position pressure, the pressure obtained at the left rear moving wheel is marked as the second position pressure, the pressure obtained at the right front moving wheel is marked as the third position pressure, and the pressure obtained at the right rear moving wheel is marked as the fourth position pressure; A motor drive unit, which is configured to convert the expected rotational speeds of the respective moving wheel motors into motor drive signals for different moving wheel motors, so that each motor outputs the expected rotational speed.

3. The seam tracking system according to claim 2, wherein, The main control unit is further configured to determine the offset state through the following steps: Judge the validity of the collected pressure data by judging the numerical signs and magnitudes of the pressure difference of the front moving wheels and the pressure difference of the rear moving wheels. Among them, the pressure difference of the front moving wheels is the difference between the first position pressure and the third position pressure, and the pressure difference of the rear moving wheels is the difference between the fourth position pressure and the second position pressure; When the collected data is valid, then determine the current offset state and the posture to be corrected according to the numerical signs and magnitudes of the pressure difference of the front moving wheels and the pressure difference of the rear moving wheels.

4. The weld tracking system according to claim 3, wherein When the numerical signs of the pressure difference of the front moving wheels and the pressure difference of the rear moving wheels are both positive, the current robot posture is biased to the left of the weld center position and needs to be corrected to the right; When the numerical signs of the pressure difference of the front moving wheels and the pressure difference of the rear moving wheels are both negative, the current robot posture is biased to the right of the weld center position and needs to be corrected to the left; When the numerical signs of the pressure difference of the front moving wheels and the pressure difference of the rear moving wheels are both zero, the current robot posture has no offset.

5. The weld tracking system according to claim 3 or 4, wherein When the numerical signs of the pressure difference of the front moving wheels and the pressure difference of the rear moving wheels are the same and the magnitudes are equal, the currently collected voltage data is valid.

6. The weld seam tracking system according to any one of claims 2 to 5, characterized in that, The main control unit is further configured to calculate the expected speeds of the respective moving wheel motors by using the following expression: V d = K × D1 V L = V + V d V R = V - V d Among them, V represents the expected rotational speed of the moving wheels of the whole robot, K represents the proportionality coefficient of the corresponding relationship between the offset and the rotational speed difference, D1 represents the pressure difference of the front moving wheels, V L represents the expected rotational speed provided to the left moving wheel motor, V R represents the expected rotational speed provided to the right moving wheel motor.

7. The weld seam tracking system according to any one of claims 2 to 6, characterized in that, The data processing module further includes: The data acquisition unit is used to receive the pressure data of each pressure sensor, convert the pressure data into a voltage signal that meets the voltage processing conditions of the main control unit, and then perform analog-to-digital conversion and noise reduction filtering on the voltage signal to obtain the pressure data to be transmitted to the main control unit.

8. The seam tracking system according to claim 7, wherein The data acquisition unit is also used to implement noise reduction filtering by using a moving average filtering algorithm.

9. The seam tracking system according to any one of claims 2 to 8, characterized in that, The data processing module further includes: The interface unit is used to receive the pressure data from multiple pressure sensors and send the motor drive signal to each mobile wheel motor.

10. A weld seam tracking method for a magnetic particle flaw detection robot, characterized in that, The weld tracking method is implemented by using the weld tracking system according to any one of claims 1 to 9, wherein the weld tracking method includes: Step 1, measuring the pressure at corresponding positions during the tracking movement of the robot by using a plurality of pressure sensors respectively arranged on the suspension devices of the robot mobile wheels; Step 2, the data processing module determines the offset state of the current robot posture relative to the weld center according to the pressures measured at different positions, and based on this, generates a motor drive signal for correcting the offset, and then sends the motor drive signal to the corresponding mobile wheel motor.

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