Ultrasonic probe coupling control parameter optimization method based on chemical reaction optimization

Abstract

The invention provides an ultrasonic probe coupling control parameter optimization method based on chemical reaction optimization, and aims to solve the problem of unstable coupling control of a wheel set and a probe in high-speed movement. According to the method, a kinematic model of an ultrasonic probe is established, and parameters such as the extension length, the mass and the spring stiffness coefficient of the probe are optimally designed by applying a CRO algorithm, so that the contact stability and the ultrasonic signal quality of the probe during the passing period of a wheel are maximized, and stable coupling of the probe and a wheel set under high-speed movement is realized. Moreover, according to the method, through simulation verification, the optimized probe system can keep long-time effective contact under different vehicle speed conditions, so that the detection precision is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of train automated flaw detection, and in particular relates to an ultrasonic probe coupling control parameter optimization method based on chemical reaction optimization (CRO), which is used to improve the coupling stability and detection accuracy between the ultrasonic probe and the wheel tread during wheelset detection. Background Art

[0002] With the widespread use of high-speed railways and EMUs, the safety of train operation has become the focus of attention of the global railway sector. As the core component of the train, the quality and operating status of the wheelset have an important impact on the kinematics, dynamics and safety of the train. In order to ensure the safe operation of the train, it is necessary to conduct regular flaw detection on the wheelset.

[0003] Automated ultrasonic flaw detection technology is an important means of current wheelset inspection, but the contact instability between the probe and the wheel tread during high-speed dynamic inspection is still the main factor affecting the inspection effect.

[0004] Traditional coupling control methods mostly use manual adjustment, but they cannot meet the detection requirements under high-speed operation conditions. Therefore, automated coupling control has become the key to improving the reliability of ultrasonic probe detection. Although the existing algorithms can solve the problem to a certain extent, they still have problems such as local optimality and slow convergence.

[0005] Therefore, a method is urgently needed to solve the coupling control problem between wheelsets and probes under high-speed conditions. Summary of the invention

[0006] The purpose of the present invention is to provide an ultrasonic probe coupling control parameter optimization method based on chemical reaction optimization CRO. The present invention improves the coupling stability and detection accuracy of the wheelset probe during high-speed detection by optimizing the parameters of the probe, thereby ensuring safe operation of the wheelset without defects.

[0007] To achieve the above purpose, the present invention provides a method for optimizing the coupling control parameters of an ultrasonic probe, and the specific scheme is as follows: The method for optimizing ultrasonic probe coupling control parameters based on chemical reaction optimization includes the following steps: (1) Establish the kinematic and dynamic models of the wheelset and ultrasonic probe, and analyze the dynamic response process of the probe at different speeds; (2) Using the chemical reaction optimization algorithm CRO to optimize the probe parameters such as probe mass, probe extension length and spring stiffness coefficient; (3) Adjust the probe parameters according to the optimization results to ensure that the probe and wheelset maintain a stable coupling state when the wheel moves at high speed.

[0008] Furthermore, the chemical reaction optimization algorithm CRO is used to optimize the design of these probe parameters: Step a: Initialize the molecular information, that is, initialize the individuals that perform chemical reactions in the CRO algorithm; and define the objective function and constraints of the probe parameter optimization problem to ensure that the state of each molecule corresponds to a set of solutions for the probe parameters; Step b: Select random molecules, calculate the molecular potential energy value, determine the molecular chemical reaction type and perform corresponding chemical reactions, including single molecule decomposition reaction, single molecule invalid collision, intermolecular combination reaction, and intermolecular invalid collision; Step c: Update the current molecular structure and determine whether the termination condition is met. If not, return to step b. If so, exit the loop. Step d: Output the optimal value and obtain the corresponding probe parameters.

[0009] Furthermore, the probe parameter optimization problem is: , The maximum time for the probe spring to be steadily compressed; The quality of the probe, is the probe extension length, is the spring elastic coefficient.

[0010] Furthermore, the initialization molecular information includes: molecular population size, initial kinetic energy, kinetic energy loss rate, and initial environmental energy.

[0011] Furthermore, the optimization goal of the method is to maximize the contact time between the probe and the wheel during the detection period to ensure the dynamic response stability of the probe when the wheel passes.

[0012] Furthermore, the kinematic and dynamic models of the wheelset and the ultrasonic probe are established: a coupled ultrasonic probe mechanism is designed, including a static platform and a dynamic platform parallel to each other, a double spring design is adopted between the static platform and the dynamic platform, and the double spring is used to make it a floating structure. During the detection process, the probe can perform real-time posture fine-tuning according to the changes in the wheel tread shape, thereby ensuring good coupling of the contact surface.

[0013] Furthermore, the spring stiffness coefficient is set according to different outer diameters and compression amounts, and the spring stiffness coefficient corresponding to the outer diameter ranges from 1000 to 2000.

[0014] Furthermore, the extension length of the probe ranges from 4 mm to 10 mm, and the mass of the probe ranges from 25 g to 40 g.

[0015] Furthermore, the method verifies the optimization scheme through simulation, ensures the coupling stability of the probe at different wheel speeds, and guarantees the transmission quality of the ultrasonic signal.

[0016] Furthermore, simulation experiments were performed to verify the dynamic response of the probe at different vehicle speeds, ranging from 15 km / h to 30 km / h.

[0017] The present invention adopts the chemical reaction optimization algorithm (CRO) to replace the traditional optimization method, which has the following advantages: (1) The present invention optimizes the probe parameters through a chemical reaction optimization algorithm (CRO) to solve the coupling control problem between the wheelset and the probe under high-speed conditions; (2) The present invention significantly improves the coupling stability between the probe and the wheelset when in contact by optimizing the probe parameters, thus ensuring the accuracy and reliability of flaw detection; (3) The present invention adopts a chemical reaction optimization algorithm for parameter optimization, which can quickly converge to the optimal solution under complex multivariable conditions, thereby improving the efficiency of parameter optimization; (4) The probe design optimized by the method of the present invention exhibits good dynamic response capability in actual detection, can adapt to the complex environment of high-speed wheel movement, and effectively improves the stability and anti-interference ability of the detection system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of the coupled ultrasonic probe mechanism.

[0019] Figure 2 Flowchart of the steps for solving the probe-wheel coupling optimization problem using CRO.

[0020] Figure 3 Schematic diagram of the compression changes at both ends of the probe spring corresponding to the initial parameters.

[0021] Figure 4 Schematic diagram of the fitness evolution curve.

[0022] Figure 5 Schematic diagram of the length change at both ends of the probe spring corresponding to the optimized parameters.

[0023] Among them, 1-moving platform, 2-static platform. DETAILED DESCRIPTION

[0024] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0025] The steps of this embodiment of the ultrasonic probe coupling control parameter optimization method based on chemical reaction optimization CRO are as follows: (1) A coupled ultrasonic probe mechanism is proposed and the kinematic model of the probe is established.

[0026] In combination with the specific process and relevant standards of wheel ultrasonic testing, this embodiment proposes a new coupled ultrasonic probe mechanism, which adopts a double spring design to have the characteristics of a floating structure. During the testing process, the probe can perform real-time posture fine-tuning according to the changes in the wheel tread shape. The mechanism consists of a static platform 2 and a dynamic platform 1 that are parallel to each other.

[0027] Figure 1 A simplified diagram of the coupled ultrasonic probe mechanism is given. It can be seen that the probe becomes a floating structure through double springs. During the detection process, the position and posture can be fine-tuned in real time according to the condition of the tread, thereby ensuring good coupling of the contact surface.

[0028] The spring end fixed to one end of the moving platform 1 is called , the spring end fixed to one end of the static platform 2 is called The central section of each spring is called , the center of the line connecting the two springs is used as the base point , base point lie in The branch topology consists of two branches. Because the base point lie in On the central axis, so Can be equivalent to , the orientation feature set of the end component: (1) Therefore, the ends of both branch chain 1 and branch chain 3 can realize three translations and three rotations, a total of 6 degrees of freedom. In the static coordinate system The homogeneous coordinates in are: (2) (3) According to the coordinate system transformation method of the space without common origin, in the moving coordinate system In In the static coordinate system The coordinates in can be expressed as: (4) in, Respectively represent the axis, axis, Angle of shaft rotation; Representative ; Representative ; Represents the distance between the moving platform 1 and the static platform 2. According to the probe structure modeling, the length change of the two spring rods can be obtained as follows: (5) (6) in, When the probe is actually moving, it represents the angle of the probe's forward and backward deflection, which is consistent with the angle in formula (4). Consistent.

[0029] r has already appeared in formulas (2) and (3), and according to Figure 1 As shown, r represents the distance from the spring to the base point O.

[0030] d has already appeared in formula (4), and if Figure 1 As shown, d represents the distance between the moving platform 1 and the static platform 2.

[0031] and Respectively and , which is consistent with formula (4).

[0032] The dynamic change of the spring rod length is constrained by the mass of the probe. , Probe extension length and spring constant .

[0033] (2) Apply the chemical reaction optimization algorithm (CRO) to optimize the probe parameters.

[0034] The CRO algorithm solves complex optimization problems by simulating the behavior of molecules in a container during a chemical reaction. Each molecule represents a possible solution, and the energy of the molecule corresponds to the objective function value of the optimization problem. and Represent the molecules before and after the reaction The potential energy, and represent the kinetic energy of the molecules before and after the reaction, and represents the total energy in the container before and after the reaction, and They represent the number of molecules before and after the reaction, respectively. (7) In CRO, represents the objective function value of the optimization problem, so the optimization goal is to achieve the minimum value. The energy of mutual conversion between molecules and container energy is expressed as In the process of simulating chemical reactions, it is assumed that there is no conversion of other energy loss forms such as heat energy. The four basic chemical reaction processes are defined as follows: (a) Single molecule invalid collision: This means that the molecule collides slightly with the container wall. The molecule loses some energy and transfers it to the container. This reaction can be understood as a local search of the algorithm in a smaller space: (8) (b) Single-molecule decomposition reaction: This indicates a violent collision between a molecule and the container wall. The molecule is split into two and needs to obtain some energy from the container. This reaction can be understood as a local search of the algorithm in a larger space: (9) (c) Multi-molecule invalid collision: refers to the collision between molecules moving at a low speed. Energy exchange occurs between molecules. This reaction is similar to the single-molecule invalid collision. It can also be understood as a local search of the algorithm in a smaller space, but no energy is obtained from the container: (10) (d) Multi-molecular chemical reaction: It means that the molecules collide with each other and the energy of the molecules after the reaction is the sum of the energy of the original molecules. The container energy does not participate in the reaction. This reaction can be understood as a global search of the algorithm: (11) The steps of solving the probe-wheel coupling optimization problem using the CRO algorithm are as follows: Figure 2 As shown, including the following: Step a: Initialize the molecular information (initialize the individuals that perform chemical reactions in the CRO algorithm); and define the objective function and constraints of the probe parameter optimization problem to ensure that the state of each molecule corresponds to a set of solutions for the probe parameters; Step b: Select random molecules, calculate the molecular potential energy value, determine the type of molecular chemical reaction and perform the corresponding chemical reaction (single molecule decomposition reaction, single molecule invalid collision, intermolecular combination reaction, intermolecular invalid collision); Step c: Update the current molecular structure and determine whether the termination condition is met. If not, return to step b. If so, exit the loop. Step d: Output the optimal value and obtain the corresponding probe parameters.

[0035] Through the global search capability of the CRO algorithm, it is possible to find the optimal solution in a complex, multi-dimensional design space to ensure that the probe has the best dynamic response performance at different speeds. The search range and initial values ​​of the probe parameters are set as shown in Table 1: Table 1 Optimization parameter range and initial value , Among them, the parameter initialization settings (initialization molecule information) of the CRO algorithm are shown in Table 2: Table 2 CRO algorithm parameter initialization settings , Since the probe spring itself has a certain width, the compression changes at both ends of the spring in the direction of the wheel passing need to be considered separately during the optimization process. , Figure 3 The initial compression changes at both ends of the spring based on the initial parameter settings of the algorithm are given.

[0036] The maximum time for the probe spring to be compressed steadily is defined as , which represents the time in formula (5) and formula (6) that the spring rod length compression remains within the acceptable range. , Probe extension length and spring constant The probe parameter optimization problem can be simplified to the following model: (12) Using the CRO algorithm to achieve optimization, the optimal solution is ,The optimal fitness value is 26.0417, Figure 4 The fitness change during the optimization process is given. Figure 5 The optimized results are given.

[0037] (3) Adjust the design parameters of the probe based on the optimization results to ensure that the probe and wheelset maintain a stable coupling state when the wheel moves at high speed; (4) The optimization scheme is verified through simulation to ensure the coupling stability of the probe at different wheel speeds and the transmission quality of the ultrasonic signal.

[0038] Through multiple simulations and tests, the various parameters of the probe array were optimized and adjusted to achieve stable coupling between the probe and the wheel tread, and the signal reception and transmission during the flaw detection process were significantly improved.

[0039] The experimental results show that the probe's extension length, spring stiffness coefficient and other parameters have an important influence on the system's dynamic response and coupling stability. Through optimization, the probe's response time and signal stability when in contact with the wheel tread are significantly improved.

[0040] The above description is only a preferred embodiment of the present invention and does not constitute a limitation on the protection scope of the present invention. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. An ultrasonic probe coupling control parameter optimization method based on chemical reaction optimization, characterized in that: The method comprises the following steps: (1) Establish the kinematic and dynamic models of the wheelset and ultrasonic probe, and analyze the dynamic response process of the probe at different speeds; (2) Using the chemical reaction optimization algorithm CRO to optimize the probe parameters such as probe mass, probe extension length and spring stiffness coefficient; (3) Adjust the probe parameters according to the optimization results to ensure that the probe and wheelset maintain a stable coupling state when the wheel moves at high speed.

2. The method for optimizing ultrasonic probe coupling control parameters based on chemical reaction optimization according to claim 1, characterized in that: The step (2) uses the chemical reaction optimization algorithm CRO to optimize the design of these probe parameters: Step a: Initialize the molecular information, that is, initialize the individuals that perform chemical reactions in the CRO algorithm; and define the objective function and constraints of the probe parameter optimization problem to ensure that the state of each molecule corresponds to a set of solutions for the probe parameters; Step b: Select random molecules, calculate the molecular potential energy value, determine the molecular chemical reaction type and perform corresponding chemical reactions, including single molecule decomposition reaction, single molecule invalid collision, intermolecular combination reaction, and intermolecular invalid collision; Step c: Update the current molecular structure and determine whether the termination condition is met. If not, return to step b. If so, exit the loop. Step d: Output the optimal value and obtain the corresponding probe parameters.

3. The method for optimizing ultrasonic probe coupling control parameters based on chemical reaction optimization according to claim 2, characterized in that: The probe parameter optimization problem: ， The maximum time for the probe spring to be steadily compressed; The quality of the probe, is the probe extension length, is the spring elastic coefficient.

4. The method for optimizing ultrasonic probe coupling control parameters based on chemical reaction optimization according to claim 2, characterized in that: The initialization molecular information includes: molecular population size, initial kinetic energy, kinetic energy loss rate, and initial environmental energy.

5. The method for optimizing ultrasonic probe coupling control parameters based on chemical reaction optimization according to any one of claims 1 to 4, characterized in that: The optimization goal of the method is to maximize the contact time between the probe and the wheel during the detection period and ensure the dynamic response stability of the probe when the wheel passes.

6. The method for optimizing ultrasonic probe coupling control parameters based on chemical reaction optimization according to any one of claims 1 to 4, characterized in that: The kinematic and dynamic models of the wheelset and the ultrasonic probe are established: a coupled ultrasonic probe mechanism is designed, including a static platform and a dynamic platform parallel to each other, a double spring design is adopted between the static platform and the dynamic platform, and the double spring makes it a floating structure. During the detection process, the probe can perform real-time posture fine-tuning according to the changes in the wheel tread shape, thereby ensuring good coupling of the contact surface.

7. The method for optimizing ultrasonic probe coupling control parameters based on chemical reaction optimization according to any one of claims 1 to 4, characterized in that: The spring stiffness coefficient is set according to different outer diameters and compression amounts, and the spring stiffness coefficient corresponding to the outer diameter ranges from 1000 to 2000.

8. The method for optimizing ultrasonic probe coupling control parameters based on chemical reaction optimization according to any one of claims 1 to 4, characterized in that: The extension length of the probe ranges from 4 mm to 10 mm, and the mass of the probe ranges from 25 g to 40 g.

9. The method for optimizing ultrasonic probe coupling control parameters based on chemical reaction optimization according to any one of claims 1 to 4, characterized in that: The method verifies the optimization scheme through simulation, ensures the coupling stability of the probe at different wheel speeds, and guarantees the transmission quality of the ultrasonic signal.

10. The method for optimizing ultrasonic probe coupling control parameters based on chemical reaction optimization according to claim 9, characterized in that: The dynamic response of the probe under different vehicle speeds is verified through simulation experiments, and the vehicle speed range is 15 km / h to 30 km / h.

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