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CN-121978218-A - TOFD probe posture adjustment system and method

CN121978218ACN 121978218 ACN121978218 ACN 121978218ACN-121978218-A

Abstract

The invention belongs to the technical field of nondestructive testing, and discloses a TOFD probe posture adjustment system and a TOFD probe posture adjustment method, wherein the TOFD probe posture adjustment system comprises a first rotating motor and a controller which are fixedly installed; the first rotating motor is fixedly connected with a first connecting piece, the second rotating motor is fixedly arranged on the first connecting piece, the central axis of the output shaft of the first rotating motor is intersected with the central axis of the output shaft of the second rotating motor at one point, the intersection point is defined as a fixed intersection point, the second rotating motor is fixedly connected with a second connecting piece, the second connecting piece is used for being connected with a TOFD probe unit, the TOFD probe unit comprises a force measuring part used for monitoring the contact force between the TOFD probe unit and a measured object in real time, the sound beam incident point of the TOFD probe unit coincides with the fixed intersection point, and the problem that in the prior art, the sound beam incident point of the probe is difficult to adjust in a two-dimensional posture and is kept stable, so that harmful translation and interference force sensing signals are generated in the posture adjusting process is effectively solved.

Inventors

  • TU CHUNLEI
  • LI JIE
  • SUN HAOXIANG
  • TAO QIANNAN
  • ZHENG YU

Assignees

  • 江苏省特种设备安全监督检验研究院

Dates

Publication Date
20260505
Application Date
20260122

Claims (9)

  1. 1. A TOFD probe pose adjustment system comprising a fixedly mounted first rotary motor (100) and a controller, characterized in that: the output shaft of the first rotating motor (100) is fixedly connected with a first connecting piece (200), and a second rotating motor (300) is fixedly arranged on the first connecting piece (200); The central axis of the output shaft of the first rotating motor (100) and the central axis of the output shaft of the second rotating motor (300) intersect at a point, and the intersection point is defined as a fixed intersection point; the output shaft of the second rotating motor (300) is fixedly connected with a second connecting piece (400), the second connecting piece (400) is used for being connected with a TOFD probe unit (500), and the TOFD probe unit (500) comprises a force measuring part for monitoring the contact force between the TOFD probe unit (500) and a measured object in real time; the sound beam incidence point of the TOFD probe unit (500) coincides with the fixed intersection point; the signal input end of the controller is in communication connection with the signal output end of the TOFD probe unit (500) and is used for receiving the contact force signal; the control output end of the controller is respectively connected with the first rotating motor (100) and the second rotating motor (300) in a communication way so as to control the first rotating motor (100) to work cooperatively with the second rotating motor (300) and drive the TOFD probe unit (500) to adjust the gesture around the fixed intersection point.
  2. 2. The TOFD probe posture adjustment system according to claim 1, wherein the TOFD probe unit (500) further comprises a wedge (501), the wedge (501) is fixedly provided with a probe body (502) for transmitting ultrasonic waves, the wedge (501) is made of an elastic material, and the wedge (501) can be elastically deformed when being subjected to an external force; the wedge block (501) is of a frame structure with hollowed-out interior, a first beam (503) and a second beam (504) which are perpendicular to each other are arranged in the wedge block (501), and a plane where the axis of the first beam (503) is located and a plane where the second beam (504) is located are parallel to each other; the force measuring part comprises a first FBG sensor (505) and a second FBG sensor (506); the first FBG sensor (505) is arranged on the first beam (503), and is used for measuring the component of the contact force along the axial direction of the first beam (503); A second FBG sensor (506) is arranged on the second beam (504), the second FBG sensor (506) being arranged for measuring a component of the contact force in the axial direction of the second beam (504).
  3. 3. The TOFD probe posture adjustment system of claim 2, wherein a third FBG sensor (507) is further provided on the wedge (501) for monitoring the ambient temperature for temperature compensation of the measured calculation of contact force.
  4. 4. A TOFD probe posture adjustment system according to claim 3, wherein the number of the first beam (503) and the second beam (504) is set to be plural, and the total number of the first FBG sensors (505) and the second FBG sensors (506) is smaller than or equal to the total number of the first beam (503) and the second beam (504).
  5. 5. A method of TOFD probe pose adjustment performed by the TOFD probe pose adjustment system of claim 3 or 4, comprising the steps of: Acquiring the contact force between the TOFD probe unit (500) and the measured object in real time; calculating a target attitude angle adjustment amount of the TOFD probe unit (500) to be adjusted around the fixed intersection point by taking the contact force smaller than or equal to a preset threshold value as a control target; Determining a mapping relation between a target attitude angle adjustment amount and target rotation angles corresponding to the first rotation motor (100) and the second rotation motor (300) based on the spatial geometrical relation of sound beam incidence points of the first rotation motor (100), the second rotation motor (300) and the TOFD probe unit (500), and resolving the target attitude angle adjustment amount into the target rotation angles of the first rotation motor (100) and the second rotation motor (300); The controller controls the first rotating motor (100) and the second rotating motor (300) to rotate to corresponding target rotation angles respectively so as to adjust the TOFD probe unit (500) to adjust the gesture.
  6. 6. The method for adjusting the posture of the TOFD probe according to claim 5, wherein the contact force between the TOFD probe unit (500) and the object to be measured is obtained in real time, specifically comprising the steps of: The corresponding wavelength variation in the monitoring process of the first FBG sensor (505) and the second FBG sensor (506) is respectively obtained; Compensating the corresponding wavelength variation of the first FBG sensor (505) and the second FBG sensor (506) by taking the wavelength variation of the third FBG sensor (507) as temperature reference data to obtain the compensated wavelength variation; Based on the mapping relation between the wavelength variation and the acting force, the component of the contact force along the axial direction of the first beam (503) and the component of the contact force along the axial direction of the second beam (504) are respectively calculated and obtained.
  7. 7. The method for adjusting the posture of a TOFD probe according to claim 6, wherein the target posture angle adjustment amount of the TOFD probe unit (500) to be adjusted around the fixed intersection is calculated with the contact force less than or equal to a preset threshold as a control target, by the following specific calculation formula: Wherein e represents a preset threshold; representing a component of the contact force in the axial direction of the first beam (503); Representing a component of the contact force in an axial direction of the second beam (504); A target attitude angle adjustment amount indicating the axial direction of the first cross member (503); a target attitude angle adjustment amount indicating an axial direction of the second cross member (504); representing the proportional gain; representing the integral gain.
  8. 8. The method for adjusting the posture of a TOFD probe according to claim 7, wherein the mapping relationship between the target posture angle adjustment amount and the target rotation angle corresponding to the first rotation motor (100) and the second rotation motor (300) is determined based on the spatial geometrical relationship between the first rotation motor (100), the second rotation motor (300) and the sound beam incidence point of the TOFD probe unit (500), specifically comprising the steps of: Establishing a first coordinate system by taking an acoustic beam incidence point of the TOFD probe unit (500) as a first origin , wherein, The axis is vertically upwards and is provided with a plurality of grooves, The shaft extends axially along a first transverse beam (503), The shaft extends axially along the second cross beam (504); A second coordinate system is established by taking the intersection point of the rotation axis of the output shaft of the second rotating motor (300) and the end face of the output end of the second rotating motor as a second origin The second coordinate system is wound by the first coordinate system The shaft rotates by a first angle Then translate until the origin of coordinates coincides with the second origin, and The shaft coincides with the central axis of the output shaft of the second rotating motor (300); A third coordinate system is established by taking the intersection point of the rotation axis of the output shaft of the first rotating motor (100) and the end face of the output end as a third origin The third coordinate system is surrounded by the second coordinate system The shaft rotates by a second angle Then translating until the origin of coordinates coincides with the third origin, and The shaft coincides with the central axis of the output shaft of the first rotating motor (100); Based on the first angle Second angle And respectively calculating rotation transformation matrixes from the first coordinate system to the second coordinate system and the third coordinate system, and further deriving the mapping relation between the target attitude angle adjustment quantity and the target rotation angles corresponding to the first rotating motor (100) and the second rotating motor (300).
  9. 9. The method of claim 8, wherein the first angle is at a first angle 45 DEG, a second angle 65 °; The rotation transformation matrix between the first coordinate system and the second coordinate system is as follows The specific mathematical expression is as follows: the rotation transformation matrix between the first coordinate system and the third coordinate system is as follows The specific mathematical expression is as follows: Wherein, the Representing a rotation transformation matrix between the second coordinate system and the third coordinate system; based on the rotation change matrix, a mapping model of the target attitude angle adjustment quantity and the target turning angle is constructed as follows: further deriving the transformation to obtain the following mapping relation: In the formula, Representing a target rotation angle of the first rotation motor (100); indicating a target rotation angle of the second rotating electric machine (300).

Description

TOFD probe posture adjustment system and method Technical Field The invention belongs to the technical field of nondestructive testing, and particularly relates to a TOFD probe posture adjustment system and method. Background In the detection of the time-of-flight diffraction (TOFD), accurate control of the probe attitude is a key to ensuring the quality of the detected signal. The existing commonly used posture adjustment modes are mainly divided into two types, namely manual adjustment depending on experience of an operator and auxiliary adjustment adopting passive compliant structures such as springs, floating brackets and the like. Manual adjustment is low in efficiency and poor in consistency, while the passive flexible structure can provide a certain degree of adaptability, the passive flexible structure is basically a passive deformation with fixed rigidity, and cannot be used for actively and dynamically adjusting the gesture according to the real-time contact force change between the probe and the workpiece. When the two methods are used for dealing with workpieces with complex curved surfaces or uneven surface states, stable coupling of the incidence points of the probe acoustic beams is difficult to maintain, uneven probe pressure and poor couplant distribution are easily caused, and detection accuracy is easily affected. To improve the automation level, the prior art also attempts to actively control the probe posture by using a multi-axis motion mechanism. However, in achieving two-dimensional attitude adjustment of the probe (i.e., having both pitch and roll degrees of freedom), such a generic mechanism faces an inherent limitation of structural rationality in that its mechanical configuration results in the probe's center of rotation (or instantaneous center of rotation) being difficult to always coincide with its substantial point of detection action (point of beam incidence) in order to provide two degrees of rotational freedom. In the conventional scheme (such as a serial joint robot, a cross sliding table matched with a rotary table and the like), the position of an acoustic beam incidence point of a probe relative to a driving axis of a mechanism is changed in the moving process, so that the incidence point of the probe is unnecessarily and jointly displaced (namely, harmful translation) on the surface of a workpiece when the angle of the probe is adjusted, the translation can directly interfere an established ultrasonic coupling layer, and further, extra sliding friction force which is irrelevant to the gesture change is introduced to the contact surface of the probe and the workpiece, so that the measurement signal of a contact force sensor is seriously polluted, therefore, the problem that the stability of the acoustic beam incidence point of the probe is difficult to realize two-dimensional gesture adjustment and the harmful translation and interference force sensing signal is generated in the gesture adjustment process exists in the prior art. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide a TOFD probe posture adjustment system and method, which solve the problems that in the prior art, harmful translation and interference force sensing signals are generated in the posture adjustment process because the stability of the incidence point of a probe sound beam is difficult to realize while the two-dimensional posture adjustment is maintained. The aim of the invention can be achieved by the following technical scheme: A TOFD probe attitude adjustment system includes a first rotary motor and a controller fixedly mounted; The output shaft of the first rotating motor is fixedly connected with a first connecting piece, and a second rotating motor is fixedly arranged on the first connecting piece; The central axis of the output shaft of the first rotating motor and the central axis of the output shaft of the second rotating motor intersect at a point, and the intersection point is defined as a fixed intersection point; The output shaft of the second rotating motor is fixedly connected with a second connecting piece, the second connecting piece is used for connecting a TOFD probe unit, and the TOFD probe unit comprises a force measuring part for monitoring the contact force between the TOFD probe unit and a measured object in real time; The sound beam incidence point of the TOFD probe unit coincides with the fixed intersection point; The signal input end of the controller is in communication connection with the signal output end of the TOFD probe unit and is used for receiving the contact force signal; the control output end of the controller is respectively connected with the first rotating motor and the second rotating motor in a communication way so as to control the first rotating motor and the second rotating motor to cooperatively work and drive the TOFD probe unit to adjust the gesture around the fixed intersection point. Further, the TOFD