Relay performance evaluation method, device, electrical equipment, medium and program product

Abstract

The present application discloses a relay performance evaluation method, device, electrical equipment, medium and program product, the method comprising: determining a first characteristic parameter characterizing mechanical performance degradation according to a first acoustic signal of the contact of the relay during the closing process and a second acoustic signal of the contact during the breaking process, the first characteristic parameter comprising a first motion parameter of the closing process and a second motion parameter of the breaking process; determining a second characteristic parameter characterizing the electrical wear state of the contact according to the first acoustic signal; determining the healthy residual value of the relay based on the first characteristic parameter and the second characteristic parameter. Without damaging the relay, the acoustic signal generated during the contact movement of the relay is analyzed to quantitatively characterize the mechanical performance degradation and the electrical wear state of the contact, that is, to obtain the first characteristic parameter and the second characteristic parameter, and then to obtain the healthy residual value of the relay based on these two characteristic parameters, thereby realizing non-contact performance evaluation and avoiding the drawbacks of contact evaluation.

Description

Technical Field

[0001] The present application relates to the field of electrical appliance detection technology, and in particular to a relay performance evaluation method, device, electrical equipment, medium and program product. Background Art

[0002] Relay is an important component in electronic equipment. During the operation of the equipment, as the number of relay operations increases, the closing and breaking performances of the relay contacts will gradually deteriorate, causing the overall performance of the relay to deteriorate. Therefore, the performance evaluation of the relay is directly related to the normal operation of electronic equipment that relies on the relay for operation.

[0003] At present, the performance evaluation of relays is basically analyzed based on electrical parameters as characteristic parameters. Although electrical parameters can intuitively reflect the current operating status of the relay and are easy to make performance evaluation, the measurement of electrical parameters requires the relay to be disassembled or destroyed, which is a relatively complicated process and can easily cause damage to the relay. Therefore, there are disadvantages in practical applications.

[0004] The above statements are only used to provide background information related to the present application and do not necessarily constitute prior art. Summary of the invention

[0005] In view of the above problems, the present application proposes a relay performance evaluation method, device, electrical equipment, medium and program product to solve the problem that there are certain disadvantages in using electrical parameters as characteristic parameters for relay performance evaluation.

[0006] The first aspect of the present application provides a relay performance evaluation method, the method comprising:

[0007] Determining, according to the acoustic signal generated during the contact action of the relay, a first characteristic parameter characterizing the degradation of mechanical performance and a second characteristic parameter characterizing the electrical wear state of the contact;

[0008] Based on the first characteristic parameter and the second characteristic parameter, a health residual value of the relay is determined.

[0009] In the technical solution of the embodiment of the present application, without damaging the relay, the acoustic signal generated during the contact movement of the relay is collected and analyzed to quantitatively characterize the mechanical performance degradation and contact electrical wear state of the relay, that is, to obtain the first characteristic parameter and the second characteristic parameter, and then based on these two characteristic parameters, the health residual value of the relay is obtained, thereby realizing non-contact performance evaluation and avoiding the disadvantages of contact evaluation.

[0010] In some embodiments, determining the first characteristic parameter characterizing the degradation of mechanical performance and the second characteristic parameter characterizing the electrical wear state of the contact according to the acoustic signal generated during the contact action of the relay includes:

[0011] The first characteristic parameter is determined based on a first acoustic signal during the contact's closing process and a second acoustic signal during the contact's opening process; the first characteristic parameter includes a first motion parameter during the closing process and a second motion parameter during the opening process; the second characteristic parameter is determined based on the first acoustic signal.

[0012] In this embodiment, since the contact action of the relay includes a closing process and a breaking process, and both processes will generate sound, the motion parameters of the two processes are obtained respectively by analyzing the acoustic signals of the two processes to fully characterize the degradation of mechanical properties. At the same time, since the contact closing is affected by the roughness of the contact surface and local protrusions, the second characteristic parameter characterizing the electrical wear state of the contact can be obtained by using the acoustic signal of the closing process.

[0013] In some embodiments, the first motion parameter includes at least one of a pull-in time, an overtravel time, a first bounce time, and a bounce end time; and determining the first characteristic parameter according to a first acoustic signal of the contact pull-in process and a second acoustic signal of the contact disconnection process includes:

[0014] The first acoustic signal and the second acoustic signal are converted into a first energy signal and a second energy signal respectively; based on the first energy signal, the pull-in time, the overtravel time and the first bounce time are determined; using the target modal component with the highest frequency among the multiple modal components obtained by decomposing the first acoustic signal, the bounce end time is determined; based on the second energy signal, the second motion parameter is determined.

[0015] In this embodiment, since the movement of the contacts during the closing process is a manifestation of energy, it is easier to obtain the closing time, overtravel time and first bounce time of the contacts by using the first energy signal of the first acoustic signal. Since the acoustic signal contains more noise, its energy signal is difficult to directly reflect the bounce end time, and the bounce of the contacts will produce more high-frequency signals. Therefore, the acoustic signal is modally decomposed and the high-frequency modal components are used to calculate the bounce end time. Since the separation of the contacts during the disconnection process also manifests energy, the second energy signal of the second acoustic signal is used to determine the motion parameters of the disconnection process.

[0016] In some embodiments, determining the pull-in time, the overtravel time, and the first bounce time based on the first energy signal includes:

[0017] According to the energy peak of the first energy signal and the time point corresponding to the energy peak, the contact first collision moment, the iron core collision moment, and the contact first bounce end moment are determined; the pull-in time is obtained by using the time point when the relay receives the closing command and the contact first collision moment; the overtravel time is obtained by using the iron core collision moment and the contact first collision moment; the first bounce time is obtained by using the contact first collision moment and the contact first bounce end moment.

[0018] In this embodiment, since the collision of the contacts and the contact of the core during the attraction process are both moments of rapid energy increase, the energy peak of the first energy signal is analyzed to obtain the moment of the first contact collision, the moment of the core collision, and the moment when the first contact bounces ends. The attraction time is obtained using the moment of the first contact collision and the time point of the closing instruction, the overtravel time is obtained using the moment of the core collision and the moment of the first contact collision, and the first bounce time of the contact is obtained using the moment of the first contact collision and the moment when the first contact bounces ends.

[0019] In some embodiments, determining the bounce end time by using a target modal component having the highest frequency among a plurality of modal components obtained by decomposing the first acoustic signal comprises:

[0020] A third energy signal within the over-travel time range is intercepted from the energy signal obtained by converting the target modal component; the time point corresponding to the minimum value of the third energy signal is determined as the end time of the contact bounce; and the end time of the contact bounce is obtained by using the end time of the contact bounce and the first collision time of the contacts.

[0021] In this embodiment, since the contact will bounce multiple times during the attraction process and these bounces all occur within the over-travel time, the energy signal of the high-frequency modal component within the over-travel time range is intercepted to reduce signal interference. Taking into account the time when the contact bounces end and the minimum energy value, the time point corresponding to the minimum value of the intercepted third energy signal is used as the bounce end time, thereby obtaining the bounce end time using the contact bounce end time and the contact first collision time.

[0022] In some embodiments, the second motion parameter includes at least one of a release time and a separation travel time; and determining the second motion parameter based on the second energy signal includes:

[0023] According to the maximum energy value in the second energy signal, the moment of hitting the yoke iron plate is determined; the kurtosis sequence corresponding to the second acoustic signal is determined; the kurtosis sequence is used to describe the sharpness of the peak of the second acoustic signal; according to the moment of hitting the yoke iron plate and the kurtosis peak in the kurtosis sequence, the contact disconnection moment is determined; the release time is obtained by using the time point when the relay receives the disconnection instruction and the contact disconnection moment; the disconnection distance travel time is obtained by using the contact disconnection moment and the moment of hitting the yoke iron plate.

[0024] In this embodiment, during the disconnection process, when the contact bracket collides with the yoke plate, it indicates that the disconnection is completed, and the collision with the yoke plate will generate a lot of energy. Therefore, the moment of collision with the yoke plate is determined by using the maximum energy value in the second energy signal. Considering that the signal of contact separation in the disconnection process is weak, the threshold value based on energy analysis is not easy to determine. Therefore, by detecting the kurtosis of the second sound signal, the contact disconnection moment is obtained according to the kurtosis peak value in the kurtosis sequence generated by the detection and combined with the moment of collision with the yoke plate, so as to obtain the disconnection distance travel time using the contact disconnection moment and the moment of collision with the yoke plate, and obtain the release time using the time point of the disconnection instruction and the contact disconnection moment.

[0025] In some embodiments, the second characteristic parameter includes at least one of a permutation entropy partial mean and a cosine similarity, and determining the second characteristic parameter according to the first acoustic signal includes:

[0026] Reconstruct the other modal components except the modal component with the lowest frequency among the multiple modal components obtained by decomposing the first acoustic signal to obtain a reconstructed signal; determine the permutation entropy partial mean using the reconstructed signal within the first bounce time range; the permutation entropy partial mean characterizes the degree of change of the permutation entropy of the signal; determine the cosine similarity based on the first acoustic signal and a preset reference acoustic signal; the reference acoustic signal is an acoustic signal generated by the contact attraction process of the reference sample at the beginning of its life.

[0027] In this embodiment, by reconstructing the modal components of the acoustic signal, low-frequency environmental noise in the acoustic signal can be eliminated, and by using the reconstructed signal within the first bounce time range to calculate the partial mean of the permutation entropy, a characterization of the degree of degradation of the contact's macroscopic morphology is obtained, so as to avoid nonlinear superposition of the acoustic signal caused by multiple bounces of the contact, which interferes with the analysis. In addition, by using the reference acoustic signal of the reference sample as a reference, the cosine similarity of the first acoustic signal relative to the reference is calculated to obtain a characterization of the degree of degradation of the contact's microscopic morphology.

[0028] In some embodiments, determining the cosine similarity according to the first acoustic signal and a preset reference acoustic signal includes:

[0029] A first modal component located within the first bounce time range is intercepted from the modal component with the highest frequency among the two modal components obtained by decomposing the first acoustic signal; a second modal component located within the first bounce time range is intercepted from the modal component with the highest frequency among the two modal components obtained by decomposing the reference acoustic signal; and the cosine similarity between the first modal component and the second modal component is determined.

[0030] In this embodiment, since the acoustic signal of contact collision is reflected in the high-frequency region, the high-frequency modal component of the acoustic signal is selected as the effective mode, and the cosine similarity is calculated by using the high-frequency modal component within the first bounce time range to avoid nonlinear superposition of the acoustic signal caused by multiple contact bounces, which would interfere with the analysis.

[0031] In some embodiments, determining the health residual value of the relay based on the first characteristic parameter and the second characteristic parameter includes:

[0032] Based on the first characteristic parameter and the second characteristic parameter obtained multiple times, determine the first weight of the first characteristic parameter obtained each time and the second weight of the second characteristic parameter obtained each time; according to the preset initial parameters and the preset final parameters, determine the first degradation percentage of the first characteristic parameter obtained each time and the second degradation percentage of the second characteristic parameter obtained each time; the initial parameters and the final parameters are the characteristic parameters of the benchmark sample at the initial life and the characteristic parameters at the end of the life, respectively; using the first characteristic parameter, the first weight and the first degradation percentage obtained multiple times, obtain the mechanical property residual value; using the second characteristic parameter, the second weight and the second degradation percentage obtained multiple times, obtain the contact electrical wear residual value; determine the mechanical property residual value and the contact electrical wear residual value as healthy residual values.

[0033] In this embodiment, the health residual value is evaluated by using the characteristic parameters obtained multiple times to reduce the accidental influence of a single characteristic parameter, and the weight and degradation percentage of the characteristic parameters obtained each time are calculated to measure the importance and change trend of different characteristics respectively. Finally, the characteristic parameters, weights and degradation percentages obtained multiple times are fused to obtain the mechanical property residual value and the contact electrical wear residual value.

[0034] In some embodiments, the determining, based on the first characteristic parameter and the second characteristic parameter obtained multiple times, a first weight of the first characteristic parameter obtained each time and a second weight of the second characteristic parameter obtained each time, comprises:

[0035] Based on the first characteristic parameter and the second characteristic parameter obtained multiple times, determine the basic weight of the first characteristic parameter and the basic weight of the second characteristic parameter; according to the initial parameters, determine the first variation degree of the first characteristic parameter obtained each time and the second variation degree of the second characteristic parameter obtained each time; the first variation degree reflects the difference of the first characteristic parameter relative to the benchmark sample at the initial life, and the second variation degree reflects the difference of the second characteristic parameter from the benchmark sample at the initial life; use the basic weight of the first characteristic parameter and the first variation degree to determine the first weight of the first characteristic parameter obtained each time; use the basic weight of the second characteristic parameter and the second variation degree to determine the first weight of the first characteristic parameter obtained each time.

[0036] In this embodiment, basic weights of different features are obtained by using characteristic parameters obtained multiple times to measure the stability of different types of characteristic parameters, and by using initial parameters, the degree of variation of the characteristic parameters obtained each time relative to the benchmark sample at the beginning of life is calculated, and the final weight of the characteristic parameters obtained each time is calculated using the degree of variation and the basic weight.

[0037] A second aspect of the present application provides a relay performance evaluation device, the device comprising:

[0038] A parameter analysis module, used to determine a first characteristic parameter characterizing mechanical performance degradation and a second characteristic parameter characterizing electrical wear state of the contact according to an acoustic signal generated during the contact action of the relay;

[0039] An evaluation module is used to determine a healthy residual value of the relay based on the first characteristic parameter and the second characteristic parameter.

[0040] The third aspect of the present application proposes an electrical device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method described in the first aspect when executing the program.

[0041] The fourth aspect of the present application proposes a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described in the first aspect above.

[0042] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0044] Figure 1 is a flow chart of an embodiment of a relay performance evaluation method according to an exemplary embodiment;

[0045] Figure 2 A flowchart of a relay performance evaluation implementation according to an exemplary embodiment is shown;

[0046] Figure 3 is a waveform diagram of a first acoustic signal and a first energy signal according to an exemplary embodiment;

[0047] Figure 4 is a waveform diagram of a first energy signal within an over-travel time according to an exemplary embodiment;

[0048] Figure 5 is a waveform diagram of the inverse number of the third energy signal of the high frequency mode according to an exemplary embodiment;

[0049] Figure 6 is a waveform diagram of a second acoustic signal and a second energy signal according to an exemplary embodiment;

[0050] Figure 7 is a waveform diagram of a second acoustic signal and a kurtosis sequence according to an exemplary embodiment;

[0051] Figure 8 4 are diagrams of four modal components of a first acoustic signal according to an exemplary embodiment;

[0052] Fig. 9 is a flow chart showing the calculation of the partial mean of permutation entropy according to an exemplary embodiment;

[0053] Fig.10 2 are diagrams of two modal components of a reference acoustic signal according to an exemplary embodiment;

[0054] Fig.11 2 are diagrams of two modal components of a first acoustic signal according to an exemplary embodiment;

[0055] Fig.12 is a diagram of a second modal component of a reference acoustic signal according to an exemplary embodiment;

[0056] Fig.13 is a flow chart of calculating cosine similarity according to an exemplary embodiment;

[0057] Fig.14 is a structural schematic diagram of a relay performance evaluation device according to an exemplary embodiment;

[0058] Fig.15 is a schematic diagram of a hardware structure of an electric device according to an exemplary embodiment;

[0059] Fig.16 The figure is a schematic diagram of the structure of a storage medium according to an exemplary embodiment. DETAILED DESCRIPTION

[0060] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0061] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0062] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0063] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0064] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0065] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0066] At present, more and more electric vehicles are on the market. Relays, as important switching devices, are widely used in automobile control systems. In actual operation, the relay's performance gradually deteriorates due to long-term working heat or abnormal up and down high voltage processes and voltage and current fluctuations. Therefore, real-time performance evaluation of relays is directly related to the normal operation of equipment that relies on relays for operation.

[0067] The existing solution is to measure the electrical parameters of the relay in a contact manner to predict the electrical life of the relay. Since it involves the measurement of specific parameters, it is easy to damage the finished relay, which has disadvantages in actual engineering applications.

[0068] After research, it was found that the existing relay performance evaluation basically uses electrical parameters (such as contact resistance, arcing time, etc.) as input. There are few studies on the dynamic characteristics and degradation mechanism of the relay mechanical structure, and the electrical wear state of the relay contacts has not been characterized.

[0069] Based on this, the present application proposes a relay performance evaluation method, which realizes performance evaluation in a closed state without damaging the product, that is, by collecting the acoustic signal generated during the action of the relay contact and analyzing the acoustic signal, a first characteristic parameter characterizing the degradation of the mechanical performance and a second characteristic parameter characterizing the electrical wear state of the contact are obtained, and then based on these two characteristic parameters, the health residual value of the relay is obtained, thereby realizing the performance evaluation of the relay in a non-contact manner and avoiding the disadvantages of contact evaluation.

[0070] The relay performance evaluation method disclosed in the embodiment of the present application can be applied to the VCU (vehicle control unit) of electrical equipment, and of course can also be used in other electrical equipment that relies on relays for operation, to achieve performance evaluation of the relays used on the equipment in a non-contact manner.

[0071] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0072] Figure 1 This is a flow chart of an embodiment of a relay performance evaluation method according to an exemplary embodiment of the present application. The relay performance evaluation method includes the following steps:

[0073] Step 101: determining a first characteristic parameter characterizing mechanical performance degradation and a second characteristic parameter characterizing electrical wear state of the contact according to an acoustic signal generated during the contact action process of the relay;

[0074] Step 102: Determine the health residual value of the relay based on the first characteristic parameter and the second characteristic parameter.

[0075] The contact action process can be understood as the closing and opening actions of the relay during operation, such as Figure 2 For the relay structure shown, the closing action refers to that after the relay receives the closing command, the coil of the relay is energized, and the current passes through the coil to generate an electromagnetic field. Under the action of the electromagnetic field, the static iron core attracts the moving iron core, and the moving iron core overcomes the elastic force of the reaction spring, compresses the reaction spring to move toward the static iron core and contacts with the static iron core, and the moving iron core drives the bracket to move, and the bracket drives the moving contact to move and contact with the static contact, thereby realizing the closure of the relay; the disconnecting action refers to that after the relay receives the disconnecting command, the coil loses power, the electromagnetic induction disappears, the reaction spring pushes the moving iron core back to its position, the moving iron core drives the bracket, and the bracket drives the moving contact back to its original position, the bracket contacts with the yoke iron plate, the moving contact separates from the static contact, and the relay disconnects.

[0076] Acoustic signals can be understood as the sound signals generated by the contact and collision between mechanical structures when the relay performs closing and opening actions. In practical applications, the acoustic signals can be collected by placing an acoustic sensor around the relay or sticking it on the surface of the relay. Since the collection of acoustic signals does not require the disassembly or destruction of the relay, non-contact performance evaluation of the relay can be achieved.

[0077] The first characteristic parameter is a parameter used to characterize the degradation of the mechanical performance of the relay. Due to the wear or fatigue of the mechanical parts of the relay (such as contacts, iron core, etc.), the mechanical performance degradation refers to the degradation of the performance of the mechanical parts of the relay. As the number of relay switching operations increases, the performance of the mechanical parts of the relay will gradually degrade, and thus the first characteristic parameter characterizing the performance degradation of the machine obtained based on the acoustic signal analysis will change.

[0078] The second characteristic parameter is a parameter used to characterize the electrical wear state of the relay contact. The electrical wear state of the contact refers to the surface roughness and oxidation caused by the attraction of the contact during long-term use. As the number of relay switching operations increases, the contact surface will gradually lose its smoothness and experience oxidation, ablation or burning. Therefore, the second characteristic parameter characterizing the electrical wear state of the contact obtained based on the acoustic signal analysis will change.

[0079] The health residual value can be understood as the degree to which the relay can still work normally and meet specific performance requirements, which affects the reliability and maintenance cost of the equipment. By monitoring the health residual value of the relay in real time, the working performance of the relay can be understood. The higher the health residual value, the more reliable and stable the working performance of the relay.

[0080] At this point, the above Figure 1 The relay performance evaluation process shown in the figure collects the acoustic signals generated during the operation of the relay contacts and analyzes the acoustic signals to obtain a first characteristic parameter characterizing the degradation of mechanical properties and a second characteristic parameter characterizing the electrical wear state of the contacts, and then obtains the healthy residual value of the relay based on these two characteristic parameters, thereby realizing the performance evaluation of the relay in a non-contact manner and avoiding the disadvantages of contact evaluation.

[0081] In an optional implementation, determining the first characteristic parameter characterizing the degradation of mechanical performance and the second characteristic parameter characterizing the electrical wear state of the contact according to the acoustic signal generated during the contact action of the relay in the above step 101 includes:

[0082] According to the first acoustic signal of the contact's closing process and the second acoustic signal of the contact's opening process, the first characteristic parameter is determined, and the first characteristic parameter includes the first motion parameter of the closing process and the second motion parameter of the opening process; according to the first acoustic signal, the second characteristic parameter is determined.

[0083] The pull-in process can be understood as the process in which the moving contact and the static contact are in stable contact after the relay receives the closing command. This pull-in process represents the closing process of the relay.

[0084] The first sound signal can be understood as the sound signal generated during the closing process of the relay. When the closing command is detected, the sound signal generated by the closing action of the relay can be collected and collected for a period of time, for example, for 2 seconds. Therefore, the first sound signal is a signal waveform composed of a group of signal values ​​at different time points, and the intervals between the time points are determined by the sampling frequency of the sound sensor.

[0085] The disconnection process can be understood as the process in which the moving contact and the static contact separate after the relay receives the disconnection command. The disconnection process represents the disconnection process of the relay.

[0086] The second sound signal can be understood as the sound signal generated during the relay disconnection process. When the disconnection command is detected, the sound signal generated by the relay disconnection action can be collected and collected for a period of time. Therefore, the second sound signal is also a signal waveform composed of a group of signal values ​​at different time points, and the interval between the time points is determined by the sampling frequency of the sound sensor.

[0087] It should be noted here that due to the degradation of the mechanical properties of the relay, both the closing process and the breaking process of the contact will be affected. Therefore, the first motion parameter of the closing process can be determined according to the first sound signal, and the second motion parameter of the breaking process can be determined according to the second sound signal. Among them, the first motion parameter can be understood as the motion parameter of the contact during the closing process, and the second motion parameter can be understood as the motion parameter of the contact during the breaking process.

[0088] In this embodiment, since the contact action of the relay includes a closing process and a breaking process, and both processes will generate sound, the motion parameters of the two processes are obtained respectively by analyzing the acoustic signals of the two processes to fully characterize the degradation of mechanical properties. At the same time, since the contact closing is affected by the roughness of the contact surface and local protrusions, the second characteristic parameter characterizing the electrical wear state of the contact can be obtained by using the acoustic signal of the closing process.

[0089] In an optional implementation, the first motion parameter included in the first characteristic parameter includes at least one of the pull-in time, overtravel time, first bounce time and bounce end time. Among them, the pull-in time refers to the time length from the relay receiving the closing instruction to the first contact collision, which is used to indicate the time from the coil power-on to the first pull-in of the moving contact and the static contact of the relay; the overtravel time refers to the time length from the first contact collision to the iron core collision, which is used to indicate the time from the first pull-in to the complete pull-in of the moving contact and the static contact of the relay; the first bounce time refers to the time length from the first contact collision to the end of the first contact bounce, which is used to indicate the time from the first pull-in of the moving contact and the static contact of the relay to the end of the first bounce of the moving contact; the bounce end time refers to the time length from the first contact collision to the end of the contact bounce, which is used to indicate the time from the first pull-in of the moving contact and the static contact of the relay to the end of the moving contact bounce.

[0090] Determining a first characteristic parameter according to a first acoustic signal during a contact closing process and a second acoustic signal during a contact breaking process includes:

[0091] The first acoustic signal and the second acoustic signal are converted into a first energy signal and a second energy signal respectively. Based on the first energy signal, the pull-in time, the overtravel time and the first bounce time are determined. Then, the bounce end time is determined by using the target modal component with the highest frequency among the multiple modal components obtained by decomposing the first acoustic signal. Based on the second energy signal, the second motion parameter is determined.

[0092] The first energy signal is an energy signal corresponding to the first acoustic signal, and the second energy signal is an energy signal corresponding to the second acoustic signal.

[0093] The first sound signal and the second sound signal are respectively converted into the first energy signal and the second energy signal. The conversion can be performed in a short-energy manner. The conversion process includes:

[0094] First, the acoustic signal is framed using a window function of a preset length. The expression for the frame processing is:

[0095]

[0096] In the above formula, is the acoustic signal of the nth sampling point in the i-th frame, i=1, 2...v, v is the total number of frames of the acoustic signal, For sound signal, is the window function, n=1, 2...L, L represents the frame length (such as 10 sampling points as one frame), The frame movement step size (for example, the window function moves every 2 sample points).

[0097] Then, the short-time energy of each frame of the sound signal is calculated. The short-time energy calculation formula is as follows:

[0098]

[0099] In the above formula, is the short-time energy of the sound signal of the i-th frame.

[0100] The modal component can be understood as using variational mode decomposition (VMD) to decompose the acoustic signal into sub-signals with specific frequencies and limited bandwidths. The first acoustic signal is decomposed into multiple modal components, each with a different frequency. Since the original acoustic signal contains a lot of low-frequency noise and the energy signal is difficult to reflect the end of the contact bounce, the bounce end time is determined by selecting the target modal component with the highest frequency. Among them, the number of modal components decomposed from the first acoustic signal can be set in advance based on practical experience, for example, set to 4 modal numbers.

[0101] In this embodiment, since the movement of the contacts during the closing process is a manifestation of energy, it is easier to obtain the closing time, overtravel time and first bounce time of the contacts by using the first energy signal of the first acoustic signal. However, since the acoustic signal contains more low-frequency noise, its energy signal is difficult to directly reflect the bounce end time, and the bounce of the contacts will produce more high-frequency signals. Therefore, the acoustic signal is modally decomposed and the high-frequency modal components are used to calculate the bounce end time. Since the separation of the contacts during the disconnection process also manifests energy, the second energy signal of the second acoustic signal is used to determine the motion parameters of the disconnection process.

[0102] In an optional embodiment, determining the pull-in time, the overtravel time and the first bounce time based on the first energy signal includes:

[0103] According to the energy peak contained in the first energy signal and the time point corresponding to the energy peak, the moment of the first contact collision, the moment of the iron core collision, and the moment when the first contact bounce ends are determined. The pull-in time is obtained by using the time point when the relay receives the closing command and the moment of the first contact collision. The overtravel time is obtained by using the moment of the iron core collision and the moment of the first contact collision. The first bounce time is obtained by using the moment of the first contact collision and the moment when the first contact bounce ends.

[0104] Among them, the first contact collision moment refers to the time point when the moving contact and the static contact of the relay first contact during the attraction process; the iron core collision moment refers to the time point when the moving iron core and the static iron core of the relay contact during the attraction process, which indicates that the moving contact and the static contact are stably attracted; the first contact bounce end moment refers to the time point when the moving contact jumps back after the moving contact collides with the static contact for the first time.

[0105] It should be noted that both contact collision and core collision are moments of energy surge, so the first contact collision moment and core collision moment can be obtained by determining the position of energy surge. The position of energy surge can be understood as the energy peak point contained in the energy signal, that is, the wave crest point.

[0106] For the process of determining the first contact collision moment, an energy threshold may be preset, and starting from the first energy peak point of the first energy signal, the time point corresponding to the first energy peak point exceeding the energy threshold is sought as the first contact collision moment.

[0107] Regarding the process of determining the core collision moment, considering that not all core collision moments are energy maximums, the minimum value of the energy peak can be pre-set, and the minimum value is a multiple of the maximum energy value, and the multiple ranges from 0.1 to 1. To prevent interference caused by too many energy peaks, the minimum number of acoustic signal frames between energy peaks can be pre-set, that is, the first frame number threshold, and to avoid misidentification caused by the energy peak point being too short to the energy peak point corresponding to the first contact collision moment, the minimum number of acoustic signal frames required to be spaced from the energy peak point corresponding to the first contact collision moment can be pre-set, that is, the second frame number threshold. Since the first contact collision occurs before the core collision, starting from the energy peak point corresponding to the first contact collision moment of the first energy signal, the time point corresponding to the energy peak point that meets the minimum value, the first frame number threshold, and the second frame number threshold is searched as the core collision moment. Furthermore, if the energy peaks after the energy peak point corresponding to the first contact collision moment in the first energy signal cannot meet the minimum value requirement, the multiple of the maximum energy value can be appropriately reduced to reduce the minimum value, and then search again.

[0108] Exemplarily, assuming that the minimum value of the energy peak is set to 0.6*max (En), the first frame number threshold is 20 frames, and the second frame number threshold is 100 frames, starting from the energy peak point corresponding to the first contact collision moment of the first energy signal En, look for energy peak points that satisfy the energy value greater than 0.6*max (En), the number of frames between the previous energy peak is greater than 20 frames, and the interval between the energy peak point corresponding to the first contact collision moment is greater than 100 frames. If the energy peak points after the energy peak point corresponding to the first contact collision moment in the first energy signal cannot reach 0.6*max (En), then adjust the minimum value to 0.4*max (En) and search again. If it still cannot be found, adjust the minimum value to 0.2*max (En) and search again.

[0109] like Figure 3 The waveform of the first acoustic signal and the waveform of the first energy signal are shown, wherein the energy peak point indicated by T1 is the moment of the first contact collision, and the energy peak point indicated by T2 is the moment of the iron core collision.

[0110] Furthermore, the calculation formula of the pull-in time is as follows:

[0111] Closing time = the time when the contacts first collide T1-the time of the closing command

[0112] The calculation formula of overtravel time is as follows:

[0113] Overtravel time = core collision time T2 - contact first collision time T1

[0114] After determining the moment of the first contact collision and the moment of the core collision, the process of determining the end moment of the first contact bounce is that since the first bounce after the first contact collision lasts the longest in the entire bounce interval, its energy is also relatively large, and the maximum energy value can be found within the over-travel time range. Since the first bounce occurs immediately after the first contact collision, the first collision corresponds to the first energy peak of the energy signal, and the first bounce should be close to the position of the second energy peak of the energy signal. Based on this, the minimum number of sound signal frames of the energy peak interval, that is, the third frame number threshold, can be pre-set, and the second energy peak whose interval with the first energy peak is greater than the third frame number threshold can be found within the over-travel time range, and the time point corresponding to the second energy peak found is used as the end moment of the first contact bounce.

[0115] For example, assuming that the third frame number threshold is 10 frames, Figure 4From the waveform of the first energy signal within the overtravel time shown, it can be seen that the local energy is relatively simple. By calling the preset peak search function to find the second energy peak with an interval of more than 10 frames from the first energy peak, the time point T3 corresponding to the second energy peak is used as the end moment of the first contact bounce.

[0116] By the above Figure 4 It can be seen that the complete process of the first contact bounce starts from the first contact collision and ends at the second contact collision.

[0117] Furthermore, the calculation formula for the first bounce time is as follows:

[0118] First bounce time = contact first bounce end time T3 - contact first collision time T1

[0119] It should be noted that the above-mentioned analysis of the first contact collision moment, the core collision moment and the first contact bounce end moment based on the first energy signal is only an exemplary description, and can also be analyzed and determined by other methods based on the contact movement principle, which does not constitute a limitation on the scope of protection of the present application.

[0120] In this embodiment, since the collision of the contacts and the contact of the core during the attraction process are both moments of rapid energy increase, the energy peak of the first energy signal is analyzed to obtain the moment of the first contact collision, the moment of the core collision, and the moment when the first contact bounces ends. The attraction time is obtained using the moment of the first contact collision and the time point of the closing instruction, the overtravel time is obtained using the moment of the core collision and the moment of the first contact collision, and the first bounce time of the contact is obtained using the moment of the first contact collision and the moment when the first contact bounces ends.

[0121] In an optional embodiment, determining the bounce end time for a target modal component having the highest frequency among a plurality of modal components obtained by decomposing the first acoustic signal comprises:

[0122] The third energy signal within the over-travel time range is intercepted from the energy signal obtained by converting the target modal component, and the time point corresponding to the minimum value of the third energy signal is determined as the end time of the contact bounce. Then, the end time of the contact bounce and the first contact collision time are used to obtain the end time of the bounce.

[0123] The third energy signal refers to the energy signal of the high-frequency modal component within the overtravel time, and the minimum value refers to the trough point in the third energy signal. Since the end time of contact bounce refers to the position where the last bounce of the moving contact ends during multiple bounces, when the last bounce of the moving contact ends, the energy at this time is the minimum, so the end time of contact bounce is close to the minimum energy value of the energy signal.

[0124] It should be noted here that, considering that the energy minimum value is not easy to obtain, it is easier to find the energy peak value by taking the inverse of the third energy signal.

[0125] For example, Figure 5 The waveform of the inverse number of the third energy signal of the high frequency mode shown is composed of Figure 5 It can be seen that the energy peak point indicated by T4 is the end time of contact bounce.

[0126] Furthermore, the calculation formula for the bounce end time is as follows:

[0127] Bounce end time = contact bounce end time T4 - contact first collision time T1

[0128] In this embodiment, since the contact will bounce multiple times during the attraction process and these bounces all occur within the over-travel time, the energy signal of the high-frequency modal component within the over-travel time range is intercepted to reduce signal interference. Taking into account the time when the contact bounces end and the minimum energy value, the time point corresponding to the minimum value of the intercepted third energy signal is used as the bounce end time, thereby obtaining the bounce end time using the contact bounce end time and the contact first collision time.

[0129] In an optional embodiment, the second motion parameter in the first characteristic parameter includes at least one of the release time and the disconnection travel time. The release time refers to the time length from when the relay receives the disconnection command to when the moving contact and the static contact are separated; the disconnection travel time refers to the time length from when the moving contact and the static contact are separated to when the bracket hits the yoke iron plate, which is used to indicate the travel time from when the moving contact and the static contact are separated to when the moving contact stops moving.

[0130] The process of determining the second motion parameter based on the second energy signal includes:

[0131] According to the maximum energy value in the second energy signal, the moment of hitting the yoke iron plate is determined, the kurtosis sequence corresponding to the second sound signal is determined, and the contact disconnection moment is determined according to the moment of hitting the yoke iron plate and the kurtosis peak in the kurtosis sequence. The release time is obtained by using the time point when the relay receives the disconnection command and the contact disconnection moment, and the disconnection distance travel time is obtained by using the contact disconnection moment and the moment of hitting the yoke iron plate.

[0132] The maximum energy value may be understood as the maximum energy peak value among the energy peak values ​​included in the second energy signal, and the maximum energy peak value may represent the energy generated by the contact bracket impacting the yoke iron plate.

[0133] The moment of striking the yoke iron plate can be understood as the moment when the moving contact stops moving during the breaking process.

[0134] The method for determining the moment of impacting the yoke iron plate is as follows: the time point corresponding to the maximum energy value can be used as the moment of impacting the yoke iron plate, or an energy threshold can be obtained based on the maximum energy value (for example, 2 / 3 times the maximum energy value is used as the energy threshold), and the time point corresponding to the first energy value greater than the energy threshold is found in the second energy signal as the moment of impacting the yoke iron plate.

[0135] For example, Figure 6 The waveform of the second sound signal and the waveform of the second energy signal are shown, and the position indicated by T5 is the moment of impacting the yoke iron plate.

[0136] The kurtosis sequence can be understood as an ordered sequence composed of multiple kurtosis values ​​arranged in time order. The kurtosis sequence is used to describe the sharpness of the peak of the second acoustic signal, which can reflect the characteristics of the sudden change in the amplitude of the acoustic signal. Since the signal of contact separation during the breaking process is weak, it is not easy to determine by analyzing the energy threshold, and the kurtosis of the acoustic signal is conducive to analyzing the moment when the signal amplitude suddenly changes when the contact is broken. The contact breaking moment refers to the time point when the moving contact and the static contact of the relay are separated.

[0137] The process of determining the kurtosis sequence corresponding to the second sound signal includes: using a length of The sliding window of length N slides on the second sound signal Sound according to 1 moving step until the end of the sliding window coincides with the end of the sound signal. The kurtosis value is calculated once each time the sound signal in the sliding window is slid. The kurtosis value calculation formula is as follows:

[0138]

[0139] In the above formula, k represents the last sampling signal of the sliding window, k= , +1, +2…N, Sound[n] represents the nth sound signal value in the sliding window.

[0140] The contact breaking moment is determined according to the moment of striking the yoke iron plate and the kurtosis peak value in the kurtosis sequence, specifically, the candidate kurtosis peak values ​​before the moment of striking the yoke iron plate and with a peak interval greater than a preset interval are obtained, and then the contact breaking moment is determined according to the number of candidate kurtosis peak values. Exemplarily, if the number is greater than 2, the time point corresponding to the second kurtosis peak value is selected as the contact breaking moment, otherwise, the time point corresponding to one of the obtained candidate kurtosis peak values ​​is selected as the contact breaking moment.

[0141] For example, Figure 7 The waveform of the second acoustic signal and the waveform of the kurtosis sequence are shown, and the position indicated by T6 is the contact disconnection moment.

[0142] After obtaining the moment of striking the yoke iron plate and the moment of contact breaking, the calculation formula for the release time is as follows:

[0143] Release time = time point of disconnection command - contact disconnection moment

[0144] The calculation formula for the disconnection travel time is as follows:

[0145] Disconnection travel time = time of hitting yoke iron plate - time of contact disconnection

[0146] In this embodiment, during the disconnection process, when the contact bracket collides with the yoke plate, it indicates that the disconnection is completed, and the collision with the yoke plate will generate a lot of energy. Therefore, the moment of collision with the yoke plate is determined by using the maximum energy value in the second energy signal. Considering that the signal of contact separation in the disconnection process is weak, the threshold value based on energy analysis is not easy to determine. Therefore, by detecting the kurtosis of the second sound signal, the contact disconnection moment is obtained according to the kurtosis peak value in the kurtosis sequence generated by the detection and combined with the moment of collision with the yoke plate, so as to obtain the disconnection distance travel time using the contact disconnection moment and the moment of collision with the yoke plate, and obtain the release time using the time point of the disconnection instruction and the contact disconnection moment.

[0147] In an optional embodiment, the second characteristic parameter includes at least one of the permutation entropy partial mean and the cosine similarity. The permutation entropy partial mean characterizes the degree of change of the permutation entropy of the signal. As a characterization parameter of the electrical wear state of the contact, the permutation entropy partial mean can realize the characterization of the degree of degradation of the macroscopic morphology of the contact. The cosine similarity characterizes the degree of similarity between the signal and the signal of the reference sample at the beginning of the life. As a characterization parameter of the electrical wear state of the contact, the cosine similarity can realize the characterization of the degree of degradation of the microscopic morphology of the contact.

[0148] Determining a second characteristic parameter according to the first acoustic signal includes:

[0149] The modal components other than the modal component with the lowest frequency among the multiple modal components obtained by decomposing the first acoustic signal are reconstructed to obtain a reconstructed signal, and the partial mean of the permutation entropy is determined by using the reconstructed signal within the first bounce time range of the reconstructed signal, and the cosine similarity is determined according to the first acoustic signal and a preset reference acoustic signal.

[0150] The reconstructed signal can be understood as the acoustic signal after the low-frequency noise is removed. The reconstructed signal can better reflect the non-stationary characteristics of the acoustic signal at the moment of contact collision. By intercepting the bounce part of the reconstructed signal and calculating the partial mean of the permutation entropy, the nonlinear superposition of the acoustic signal caused by multiple bounces of the contact can be avoided.

[0151] For example, Figure 8The four modal components of the first acoustic signal shown are IMF1, IMF2, IMF3 and IMF4 from low frequency to high frequency. Among them, the time domain signal of IMF1 does not have the envelope of the impact signal. Combined with the experimental situation, it is believed that IMF1 is composed of low-frequency noise in the environment and does not contain effective information about contact collision. Therefore, IMF2, IMF3 and IMF4 are selected as effective modes and reconstructed.

[0152] The reconstructed signal within the first bounce time range in the reconstructed signal is used to determine the partial mean of the permutation entropy. Specifically, the reconstructed signal within the first bounce time range is divided into multiple signal sequences according to the length N. For each signal sequence, a phase space reconstruction matrix of the signal sequence is constructed, and the permutation entropy (PE) of the signal sequence is calculated according to the phase space reconstruction matrix. The skewness is calculated using the permutation entropy of each signal sequence, and the partial mean of the permutation entropy is calculated using the skewness and the average of the permutation entropy of each signal sequence. The partial mean of the permutation entropy is calculated as follows:

[0153]

[0154] In the above formula, is the permutation entropy skewness, is the mean of the permutation entropy.

[0155] Those skilled in the art can understand that the construction of the phase space reconstruction matrix, the calculation of the permutation entropy and the calculation of the skewness can be implemented with reference to relevant technologies, and this application does not make any specific limitations on this.

[0156] The reference acoustic signal is an acoustic signal generated by the contact closing process of the reference sample at the beginning of its life. The reference sample can be understood as an unused new relay whose life is in the beginning stage.

[0157] In this embodiment, by reconstructing the modal components of the acoustic signal, low-frequency environmental noise in the acoustic signal can be eliminated, and by using the reconstructed signal within the first bounce time range to calculate the partial mean of the permutation entropy, a characterization of the degree of degradation of the contact's macroscopic morphology is obtained, thereby avoiding nonlinear superposition of acoustic signals caused by multiple bounces of the contact, which interferes with the analysis. In addition, by using the reference acoustic signal of the reference sample as a reference, the cosine similarity of the first acoustic signal relative to the reference is calculated to obtain a characterization of the degree of degradation of the contact's microscopic morphology.

[0158] Based on the calculation method of the partial mean of the permutation entropy given in the above embodiment, as Fig. 9As shown, the calculation process of the partial mean of the permutation entropy includes: performing variational modal decomposition on the first acoustic signal to obtain four modal components, namely IMF1, IMF2, IMF3 and IMF4 from low frequency to high frequency, reconstructing IMF2, IMF3 and IMF4, and intercepting the part of the reconstructed signal within the time range of the first contact bounce, and using this intercepted part of the reconstructed signal to calculate the partial mean of the permutation entropy.

[0159] In an optional embodiment, determining the cosine similarity according to the first sound signal and a preset reference sound signal includes:

[0160] A first modal component located within a first bounce time range is intercepted from the modal component with the highest frequency among the two modal components obtained by decomposing the first acoustic signal, and a second modal component located within a first bounce time range is intercepted from the modal component with the highest frequency among the two modal components obtained by decomposing the reference acoustic signal, and then the cosine similarity between the first modal component and the second modal component is determined.

[0161] Among them, since the stable contact of the contact in the attraction process is achieved by the micro-protrusions on the contact surface of the contact to release the conductivity, micro-protrusions of different shapes and sizes will generate high-frequency signals during the collision process. Therefore, the first acoustic signal and the reference signal are decomposed into two modal components, and the high-frequency modal component is selected as the effective mode.

[0162] The first modal component can be understood as the result of intercepting a bounce portion of the high-frequency modal component of the first acoustic signal.

[0163] The second modal component can be understood as the result of intercepting a bounce portion of the high-frequency modal component of the reference sound signal.

[0164] For example, Fig.10 As shown, the reference acoustic signal of the reference sample is decomposed into two modal components IMF1 and IMF2. Since the frequency of IMF2 is higher than that of IMF1, IMF2 is taken as the effective mode.

[0165] like Fig.11 As shown, the first acoustic signal is decomposed into two modal components IMF1 and IMF2. Since the frequency of IMF2 is higher than that of IMF1, IMF2 is regarded as a valid mode.

[0166] Then, if Fig.12 As shown, the part within the first bounce time range of the high-frequency modal component of the reference sound signal is intercepted to obtain the waveform of the second modal component, and the part within the first bounce time range of the high-frequency modal component of the first sound signal is intercepted to obtain the waveform of the first modal component.

[0167] The first modal component is expressed as , the second modal component is expressed as , the cosine similarity calculation formula is as follows:

[0168]

[0169] In this embodiment, since the acoustic signal of contact collision is reflected in the high-frequency region, the high-frequency modal component of the acoustic signal is selected as the effective mode, and the cosine similarity is calculated by using the high-frequency modal component within the first bounce time range to avoid nonlinear superposition of the acoustic signal caused by multiple contact bounces, which would interfere with the analysis.

[0170] Based on the cosine similarity calculation method given in the above embodiment, Fig.13 As shown, the calculation process of cosine similarity includes: performing variational modal decomposition on the first acoustic signal and the reference acoustic signal of the reference sample to obtain the low-frequency modal component and the high-frequency modal component of the first acoustic signal and the low-frequency modal component and the high-frequency modal component of the reference acoustic signal, intercepting the part of the high-frequency modal component of the first acoustic signal that is within the time range of the first contact bounce to obtain the first modal component, and intercepting the part of the high-frequency modal component of the reference acoustic signal that is within the time range of the first contact bounce to obtain the second modal component, and calculating the cosine similarity between the first modal component and the second modal component.

[0171] In an optional embodiment, the process of determining the health residual value of the relay based on the first characteristic parameter and the second characteristic parameter in the above step 102 includes:

[0172] Based on the first characteristic parameters and the second characteristic parameters obtained multiple times, the first weight of each first characteristic parameter obtained and the second weight of each second characteristic parameter obtained are determined; according to the preset initial parameters and the preset final parameters, the first degradation percentage of each first characteristic parameter obtained and the second degradation percentage of each second characteristic parameter obtained are determined; then, the mechanical property residual value is obtained using the first characteristic parameters, the first weight and the first degradation percentage obtained multiple times; and the contact electrical wear residual value is obtained using the second characteristic parameters, the second weight and the second degradation percentage obtained multiple times; finally, the mechanical property residual value and the contact electrical wear residual value are determined as healthy residual values.

[0173] The first characteristic parameter and the second characteristic parameter obtained multiple times refer to characteristic parameters obtained from the acoustic signal generated by the multiple actions of the relay, that is, the first characteristic parameter and the second characteristic parameter are obtained once each time the relay is actuated. Among them, one action of the relay includes the contact closing process and the contact breaking process.

[0174] The first weight includes the weights corresponding to the parameters in the first feature parameters, and the second weight includes the weights corresponding to the parameters in the second feature parameters. By assigning weights to each parameter, the importance of each feature can be measured.

[0175] The first degradation percentage includes the degradation percentage corresponding to each parameter in the first characteristic parameter, and the second degradation percentage includes the degradation percentage corresponding to each parameter in the second characteristic parameter. By calculating the degradation percentage of each parameter, the change trend of each characteristic can be measured.

[0176] The initial parameters and the final parameters are the characteristic parameters of the reference sample at the initial life and the characteristic parameters at the end of life, respectively. That is, the sum of the number of parameters of the first characteristic parameter and the second characteristic parameter is the same as the number of parameters included in the initial parameters, and the sum of the number of parameters of the first characteristic parameter and the second characteristic parameter is the same as the number of parameters included in the final parameters.

[0177] The mechanical performance residual value can be understood as a quantitative representation of the working performance of the mechanical structure of the relay, which can reflect the degradation of the mechanical structure of the relay.

[0178] The residual value of electrical wear of the contacts can be understood as a quantitative representation of the contact performance of the relay contacts, which can reflect the electrical wear state of the relay contacts.

[0179] In this embodiment, the health residual value is evaluated by using the characteristic parameters obtained multiple times to reduce the accidental influence of a single characteristic parameter, and the weight and degradation percentage of the characteristic parameters obtained each time are calculated to measure the importance and change trend of different characteristics respectively. Finally, the characteristic parameters, weights and degradation percentages obtained multiple times are fused to obtain the mechanical property residual value and the contact electrical wear residual value.

[0180] In an optional embodiment, based on the first characteristic parameter and the second characteristic parameter obtained multiple times, determining the first weight of the first characteristic parameter obtained each time and the second weight of the second characteristic parameter obtained each time includes:

[0181] Based on the first characteristic parameters and the second characteristic parameters obtained multiple times, the basic weight of the first characteristic parameter and the basic weight of the second characteristic parameter are determined, and according to the initial parameters, the first variation degree of the first characteristic parameter obtained each time and the second variation degree of the second characteristic parameter obtained each time are determined, and then the first weight of the first characteristic parameter obtained each time is determined using the basic weight and the first variation degree of the first characteristic parameter, and the first weight of the first characteristic parameter obtained each time is determined using the basic weight and the second variation degree of the second characteristic parameter.

[0182] The basic weight is calculated using the characteristic parameters obtained multiple times, and is used to measure the stability of the characteristic parameters.

[0183] The first variation degree reflects the difference of the first characteristic parameter relative to the reference sample at the beginning of the life, and the second variation degree reflects the difference of the second characteristic parameter from the reference sample at the beginning of the life. Exemplarily, the first variation degree and the second variation degree can be represented by a prominent index (PI) and / or an alienation index (AI).

[0184] In this embodiment, basic weights of different features are obtained by using characteristic parameters obtained multiple times to measure the stability of different types of characteristic parameters, and by using initial parameters, the degree of variation of the characteristic parameters obtained each time relative to the benchmark sample at the beginning of life is calculated, and the final weight of the characteristic parameters obtained each time is calculated using the degree of variation and the basic weight.

[0185] Based on the above-mentioned embodiment of determining the health residual value, it can be summarized that the main processes include: basic weight calculation, weight optimization, trend evaluation and parameter fusion. These processes are described in detail below:

[0186] 1. Basic weight calculation

[0187] First, in order to improve the computational efficiency, the first characteristic parameter and the second characteristic parameter obtained each time are constructed as a parameter vector: ,in f 1j , f 2j … f 8j They represent the eight parameters obtained for the jth time, namely, the pull-in time, overtravel time, first bounce time, bounce end time, release time, disconnection distance travel time, permutation entropy partial mean, and cosine similarity. Then, the parameter vectors of the first characteristic parameters and the second characteristic parameters obtained multiple times are constructed into a multi-dimensional parameter matrix, and the matrix structure is as follows:

[0188]

[0189] Among them, the matrix size is n*m, n represents the number of parameters, that is, n=8, and m represents the number of detections.

[0190] Then, F is normalized to normalize each parameter in the matrix to a uniform dimension. The normalization formula is:

[0191]

[0192] In the above formula, i=1,2...n is the parameter category, and j=1,2...m is the number of detections.

[0193] Finally, considering that different categories of parameters contain different amounts of information, information entropy is used to measure the importance of different features. The information entropy calculation formula is as follows:

[0194]

[0195] The basic weight calculation formula for each category parameter is as follows:

[0196]

[0197] In order to facilitate subsequent weight optimization, the basic weights of the n category parameters are combined into a weight vector, and then the weight vector is replicated m times to expand it into a basic weight matrix of the same size as the parameter matrix .

[0198] 2. Weight optimization

[0199] To facilitate subsequent calculations, the initial parameters of m tests on the benchmark sample and the final parameters of m tests on the benchmark sample are obtained, and the initial parameters of the m tests are used to construct an initial parameter matrix as a benchmark, and the final parameters of the m tests are used to construct a final parameter matrix as a benchmark.

[0200] In order to highlight the variability of the parameters, on the one hand, the discrete coefficient of the parameter sequence is used as the highlighting factor of the parameter, and the calculation formula is as follows:

[0201]

[0202] In the above formula, represents the normalized parameters of the parameter matrix, =1, 2, when k=1, = , when k=2, = It represents the normalized parameters of the initial parameter matrix. This formula comprehensively measures the degree of variation of the parameters relative to the initial parameters, and amplifies them in the form of exponents to highlight their changes.

[0203] On the other hand, the alienation factor using Mahalanobis distance as parameter is calculated as follows:

[0204]

[0205] In the above formula, represents the normalized parameters in the initial parameter matrix, Represents the covariance matrix obtained from the initial parameter matrix and the parameter matrix.

[0206] Use the salience factor and alienation factor to adjust the basic weight matrix The optimized formula is as follows:

[0207]

[0208] In the above formula, represents the elements in the optimized weight matrix, includes the first weight of the first characteristic parameter obtained each time and the second weight of the second characteristic parameter, represents the maximum value among the highlight factors, Indicates the maximum value among the alienation factors.

[0209] It should be noted here that the weight optimization method given above is only an exemplary description, and it is also possible to consider only the salient factor or only the alienation factor.

[0210] 3. Trend Assessment

[0211] Trend evaluation obtains the change trend of each parameter in the parameter matrix through the initial parameter matrix and the final parameter matrix constructed above, that is, the degradation percentage. The calculation formula of the degradation percentage is as follows:

[0212]

[0213] In the above formula, represents the elements in the initial parameter matrix, represents the elements in the final parameter matrix, Represents the elements in the normalized parameter matrix.

[0214] 4. Parameter Fusion

[0215] Based on the above parameter matrix, optimized weights, and degradation percentage, the calculation formulas for the mechanical property residual value and the contact electrical wear residual value are as follows:

[0216]

[0217]

[0218] In the above two formulas, and are the residual value of mechanical properties and the residual value of contact electrical wear, n is the parameter category, m is the number of tests, and is the weight set, , and Represent the weights set for each parameter.

[0219] The above description of various embodiments tends to emphasize the differences between the various embodiments. The same or similar aspects can be referenced to each other, and for the sake of brevity, they will not be repeated herein.

[0220] Those skilled in the art will appreciate that, in the above method of a specific embodiment, the order in which the steps are written does not imply a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of the steps should be determined by their functions and possible internal logic.

[0221] Corresponding to the above-mentioned embodiment of the relay performance evaluation method, the present application also provides an embodiment of a relay performance evaluation device.

[0222] Fig.14 : is a schematic diagram of a structure of a relay performance evaluation device according to an exemplary embodiment of the present application, the device is used to execute the relay performance evaluation method provided in any of the above embodiments, such as Fig.14 As shown, the relay performance evaluation device includes:

[0223] The parameter analysis module 610 is used to determine a first characteristic parameter representing the degradation of mechanical performance and a second characteristic parameter representing the electrical wear state of the contact according to the acoustic signal generated during the contact action of the relay;

[0224] The evaluation module 620 is used to determine the health residual value of the relay based on the first characteristic parameter and the second characteristic parameter.

[0225] The implementation process of the functions and effects of each unit in the above-mentioned device is specifically described in the implementation process of the corresponding steps in the above-mentioned method, and will not be repeated here.

[0226] For the device embodiment, since it basically corresponds to the method embodiment, the relevant parts can refer to the partial description of the method embodiment. The device embodiment described above is only schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the present application scheme. A person of ordinary skill in the art can understand and implement it without paying any creative work.

[0227] The embodiments of the present application also provide an electrical device corresponding to the relay performance evaluation method provided in the aforementioned embodiments, so as to execute the aforementioned relay performance evaluation method.

[0228] Fig.15This is a hardware structure diagram of an electric device according to an exemplary embodiment of the present application, and the electric device may include: a communication interface 601, a processor 602, a memory 603 and a bus 604; wherein the communication interface 601, the processor 602 and the memory 603 communicate with each other through the bus 604. The processor 602 can execute the relay performance evaluation method described above by reading and executing the machine executable instructions corresponding to the control logic of the relay performance evaluation method in the memory 603. The specific content of the method is referred to the above embodiment, and will not be repeated here.

[0229] The memory 603 mentioned in this application can be any electronic, magnetic, optical or other physical storage device, and can contain storage information, such as executable instructions, data, etc. Specifically, the memory 603 can be RAM (Random Access Memory), flash memory, storage drive (such as hard disk drive), any type of storage disk (such as optical disk, DVD, etc.), or similar storage medium, or a combination thereof. The communication connection between the system network element and at least one other network element is realized through at least one communication interface 601 (which can be wired or wireless), and the Internet, wide area network, local area network, metropolitan area network, etc. can be used.

[0230] The bus 604 may be an ISA bus, a PCI bus or an EISA bus, etc. The bus may be divided into an address bus, a data bus, a control bus, etc. The memory 603 is used to store programs, and the processor 602 executes the programs after receiving execution instructions.

[0231] The processor 602 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by the hardware integrated logic circuit or software instructions in the processor 602. The above processor 602 can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc. The steps of the method disclosed in the embodiments of the present application can be directly embodied as a hardware decoding processor to be executed, or the hardware and software modules in the decoding processor can be combined and executed.

[0232] The electrical equipment provided in the embodiment of the present application and the relay performance evaluation method provided in the embodiment of the present application are based on the same inventive concept and have the same beneficial effects as the methods adopted, operated or implemented therein.

[0233] The present application also provides a computer-readable storage medium corresponding to the relay performance evaluation method provided in the above embodiment. Fig.16 As shown, the computer-readable storage medium shown is a CD 30 on which a computer program (ie, a program product) is stored. When the computer program is executed by a processor, the relay performance evaluation method provided by any of the aforementioned embodiments will be executed.

[0234] It should be noted that examples of the computer-readable storage medium may also include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other optical or magnetic storage media, which are not listed here one by one.

[0235] The computer-readable storage medium provided in the above-mentioned embodiments of the present application and the relay performance evaluation method provided in the embodiments of the present application are based on the same inventive concept and have the same beneficial effects as the method adopted, run or implemented by the application program stored therein.

[0236] The embodiments of the present application also provide a computer program product corresponding to the relay performance evaluation method provided in the aforementioned embodiments, including a computer program, which is executed by a processor to implement the relay performance evaluation method provided in any of the aforementioned embodiments.

[0237] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The specification and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

[0238] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0239] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A relay performance evaluation method, characterized in that: The method comprises: Determining, according to the acoustic signal generated during the contact action of the relay, a first characteristic parameter characterizing the degradation of mechanical performance and a second characteristic parameter characterizing the electrical wear state of the contact; Determining a health residual value of a relay based on the first characteristic parameter and the second characteristic parameter; The method of determining the first characteristic parameter characterizing the degradation of mechanical performance and the second characteristic parameter characterizing the electrical wear state of the contact according to the acoustic signal generated during the contact action of the relay includes: The first characteristic parameter is determined according to a first acoustic signal of the contact's closing process and a second acoustic signal of the contact's opening process, the first characteristic parameter including a first motion parameter of the closing process and a second motion parameter of the opening process; wherein the closing process is a process in which the moving contact and the stationary contact are in stable contact after the relay receives a closing instruction, and the opening process is a process in which the moving contact and the stationary contact are separated after the relay receives a disconnection instruction, the first motion parameter is obtained according to an energy signal of the first acoustic signal and / or a multimodal component of the first acoustic signal, the second motion parameter is obtained according to an energy signal of the second acoustic signal, the first motion parameter includes at least one of a closing time, an overtravel time, a first bounce time and a bounce end time, and the second motion parameter includes at least one of a release time and a disconnection distance travel time; The second characteristic parameter is determined according to the first acoustic signal.

2. The method according to claim 1, characterized in that The determining of the first characteristic parameter according to the first acoustic signal of the contact during the closing process and the second acoustic signal of the contact during the opening process includes: Converting the first acoustic signal and the second acoustic signal into a first energy signal and a second energy signal respectively; Determine the pull-in time, the overtravel time, and the first bounce time based on the first energy signal; Determine the bounce end time by using a target modal component with the highest frequency among a plurality of modal components obtained by decomposing the first acoustic signal; Based on the second energy signal, the second motion parameter is determined.

3. The method according to claim 2, characterized in that The determining the pull-in time, the overtravel time and the first bounce time based on the first energy signal comprises: Determine the first contact collision moment, the core collision moment, and the first contact bounce end moment according to the energy peak value included in the first energy signal and the time point corresponding to the energy peak value; The pull-in time is obtained by using the time point when the relay receives the closing instruction and the time when the contacts first collide; The overtravel time is obtained by using the core collision moment and the contact first collision moment; The first bounce time is obtained by using the first collision moment of the contacts and the first bounce end moment of the contacts.

4. The method according to claim 3, characterized in that The determining the bounce end time by using a target modal component having the highest frequency among a plurality of modal components obtained by decomposing the first acoustic signal comprises: intercepting a third energy signal within the over-range time range from the energy signal obtained by converting the target modal component; Determining the time point corresponding to the minimum value of the third energy signal as the contact bounce end time; The bounce end time is obtained by using the contact bounce end time and the contact first collision time.

5. The method according to claim 2, characterized in that: The determining the second motion parameter based on the second energy signal includes: Determine the time of impacting the yoke iron plate according to the maximum energy value in the second energy signal; Determine a kurtosis sequence corresponding to the second acoustic signal; the kurtosis sequence is used to describe the sharpness of a peak value of the second acoustic signal; Determining the contact breaking time according to the impact time of the yoke iron plate and the kurtosis peak value in the kurtosis sequence; The release time is obtained by using the time point when the relay receives the disconnection instruction and the contact disconnection moment; The disconnection stroke time is obtained by using the contact disconnection time and the impact yoke iron plate time.

6. The method according to claim 2, characterized in that The second characteristic parameter includes at least one of a permutation entropy partial mean and a cosine similarity; and determining the second characteristic parameter according to the first acoustic signal includes: Reconstructing the other modal components except the modal component with the lowest frequency among the multiple modal components obtained by decomposing the first acoustic signal to obtain a reconstructed signal; Determine the permutation entropy partial mean by using the reconstructed signal in the first bounce time range among the reconstructed signals; the permutation entropy partial mean represents the degree of change of the permutation entropy of the signal; The cosine similarity is determined according to the first acoustic signal and a preset reference acoustic signal; the reference acoustic signal is an acoustic signal generated during the contact closing process of the reference sample at the beginning of its life.

7. The method according to claim 6, characterized in that The determining the cosine similarity according to the first acoustic signal and a preset reference acoustic signal includes: Intercepting a first modal component located within the first bounce time range from the modal component with the highest frequency among the two modal components obtained by decomposing the first acoustic signal; Intercepting a second modal component located within the first bounce time range from the modal component with the highest frequency among the two modal components obtained by decomposing the reference acoustic signal; A cosine similarity between the first modal component and the second modal component is determined.

8. The method according to any one of claims 1 to 7, characterized in that: The determining the health residual value of the relay based on the first characteristic parameter and the second characteristic parameter includes: Based on the first characteristic parameter and the second characteristic parameter obtained multiple times, determining a first weight of the first characteristic parameter obtained each time and a second weight of the second characteristic parameter obtained each time; Determine a first degradation percentage of the first characteristic parameter obtained each time and a second degradation percentage of the second characteristic parameter obtained each time according to a preset initial parameter and a preset final parameter; the initial parameter and the final parameter are characteristic parameters of the reference sample at the initial life and at the end of life, respectively; Obtaining a mechanical property residual value using the first characteristic parameter, the first weight, and the first degradation percentage obtained multiple times; Obtaining a contact electrical wear residual value using the second characteristic parameter, the second weight and the second degradation percentage obtained multiple times; The mechanical property residual value and the contact electrical wear residual value are determined as healthy residual values.

9. The method according to claim 8, characterized in that The determining, based on the first characteristic parameter and the second characteristic parameter obtained multiple times, a first weight of the first characteristic parameter obtained each time and a second weight of the second characteristic parameter obtained each time, comprises: Determining a basic weight of the first characteristic parameter and a basic weight of the second characteristic parameter based on the first characteristic parameter and the second characteristic parameter obtained multiple times; Determine, according to the initial parameters, a first variation degree of the first characteristic parameter obtained each time and a second variation degree of the second characteristic parameter obtained each time; the first variation degree reflects the difference of the first characteristic parameter relative to the reference sample at the initial stage of life, and the second variation degree reflects the difference of the second characteristic parameter from the reference sample at the initial stage of life; Determine a first weight of each obtained first feature parameter by using a basic weight of the first feature parameter and the first variation degree; The second weight of the second characteristic parameter obtained each time is determined by using the basic weight of the second characteristic parameter and the second variation degree.

10. A relay performance evaluation device, characterized in that: The device comprises: A parameter analysis module, used to determine a first characteristic parameter characterizing mechanical performance degradation and a second characteristic parameter characterizing electrical wear state of the contact according to an acoustic signal generated during the contact action of the relay; An evaluation module, configured to determine a health residual value of a relay based on the first characteristic parameter and the second characteristic parameter; Among them, the parameter analysis module is specifically used to determine the first characteristic parameter according to the first acoustic signal of the contact's attraction process and the second acoustic signal of the contact's breaking process, the first characteristic parameter including the first motion parameter of the attraction process and the second motion parameter of the breaking process; wherein the attraction process is the process in which the moving contact and the static contact are in stable contact after the relay receives a closing command, and the breaking process is the process in which the moving contact and the static contact are separated after the relay receives a breaking command, the first motion parameter is obtained according to the energy signal of the first acoustic signal and the second acoustic signal and / or the multimodal component of the first acoustic signal, the second motion parameter is obtained according to the energy signal of the second acoustic signal, the first motion parameter includes at least one of the attraction time, the overtravel time, the first bounce time and the bounce end time, and the second motion parameter includes at least one of the release time and the breaking distance travel time; the second characteristic parameter is determined according to the first acoustic signal.

11. An electric device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps of the method according to any one of claims 1 to 9 are implemented.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method according to any one of claims 1 to 9 are implemented.

13. A computer program product, comprising a computer program, characterized in that The computer program is executed by a processor to implement the method according to any one of claims 1 to 9.

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