A method for testing safety performance of new energy vehicle parts

Abstract

The present invention discloses a method for detecting the safety performance of new energy vehicle parts, and relates to the technical field of parts safety detection, including obtaining the number of brakes, the total braking time and the total driving time of the new energy vehicle to be tested, calculating the first safety factor of the brake pad, and issuing the first brake pad safety warning; after receiving the first brake pad safety warning, using a microphone to capture the noise signal generated when the brake pad is braked, according to the energy of each frame of the noise signal generated when the brake pad is braked and the short-time zero-crossing rate, calculating the braking stability coefficient and the braking abnormality coefficient of the brake pad, and calculating the comprehensive safety factor of the brake pad; calculating the predicted number of driving times of the brake pad of the new energy vehicle, and issuing the second brake pad safety warning. It can be known in advance that the brake pad is about to reach the replacement standard, so as to avoid accidents caused by the failure of the brake pad during driving.

Description

Technical Field

[0001] The present invention relates to the technical field of component safety detection, and in particular to a method for detecting the safety performance of new energy vehicle components. Background Art

[0002] With the rapid development of the new energy vehicle industry, its safety performance has attracted more and more attention from all walks of life. As the core component of the braking system of new energy vehicles, the safety performance of brake pads is directly related to the driving safety of the vehicle and the life safety of passengers. Therefore, it is particularly important to conduct strict safety performance testing on brake pads of new energy vehicles. New energy vehicles, especially electric vehicles, have higher performance requirements for brake pads due to the uniqueness of their power systems and braking systems. During the braking process, electric vehicles not only need to convert vehicle kinetic energy into heat energy, but also need to recover part of the energy to improve energy efficiency. In this process, brake pads need to withstand higher temperatures and more complex working conditions, and are prone to problems such as increased wear, thermal decay, and increased noise, which in turn affects braking performance and safety.

[0003] In a Chinese invention application with application publication number CN116989081A, a brake pad automatic monitoring method and system are disclosed, including obtaining a default warning wear degree A of a brake pad wear indicator; obtaining the number of braking times L of the vehicle, and setting the life level of the brake pad according to the number of braking times; obtaining the total use time T and the braking time P of the brake pad, and obtaining a decay index G based on the relationship between the total use time T and the braking time P of the brake pad and the life level, and performing a first correction on the default warning wear degree A according to the decay index G, and the corrected default warning wear degree is A1; obtaining the driving speed B, and performing a second correction on the default warning wear degree, and the corrected default warning wear degree is A2; and obtaining the brake pad temperature K, and performing a third correction on the default warning wear degree, and the corrected default warning wear degree is A3.

[0004] In the above invention application, by obtaining parameters such as the total usage time of the brake pad, the braking time, and the number of brakes, combined with the relationship between the life level and the attenuation index, the monitoring accuracy of the brake pad life and wear status is improved. However, concepts such as life level and attenuation index may be relatively abstract for non-professionals, and are not easy to understand and grasp, and may have certain limitations in adapting to different driving habits.

[0005] To this end, the present invention provides a method for detecting the safety performance of new energy vehicle parts. Summary of the invention

[0006] 1. Technical issues to be resolved

[0007] In view of the shortcomings of the prior art, the present invention provides a method for detecting the safety performance of new energy vehicle parts. The present invention obtains the number of brakes Sc, the total braking time Ls and the total driving time Xs of the new energy vehicle to be tested, calculates the first safety factor Dq of the brake pad, and issues a first brake pad safety warning. After receiving the first brake pad safety warning, a microphone is used to capture the noise signal generated by the brake pad during braking. According to the energy of each frame of the noise signal generated by the brake pad during braking, the noise factor Dq of the brake pad is calculated. and short-time zero-crossing rate , calculate the brake stability coefficient Wd and the brake abnormality coefficient Yc of the brake pad, calculate the comprehensive safety coefficient Zh of the brake pad, calculate the predicted driving number Xy of the brake pad of the new energy vehicle, and issue a second brake pad safety warning to the outside, so that you can know in advance that the brake pad is about to reach the replacement standard, avoid accidents caused by brake pad failure during driving, and avoid damage to the brake disc or other components due to excessive wear of the brake pad, thereby reducing maintenance costs, ensuring that the brake system is always in good condition, and improving driving safety, thereby solving the technical problems recorded in the background technology.

[0008] (II) Technical solution

[0009] To achieve the above objectives, the present invention is implemented through the following technical solutions: A method for detecting the safety performance of new energy vehicle parts, comprising the following steps:

[0010] Obtain the number of brakes Sc, the total braking time Ls and the total driving time Xs of the new energy vehicle to be tested, calculate the first safety factor Dq of the brake pad, and issue a first brake pad safety warning;

[0011] After receiving the first brake pad safety warning, a microphone is used to capture the noise signal generated by the brake pad during braking. and short-time zero-crossing rate , calculate the brake pad's braking stability coefficient Wd and braking abnormality coefficient Yc, and calculate the brake pad's comprehensive safety factor Zh;

[0012] Get the comprehensive safety factor of the brake pads of the new energy vehicle each time it brakes after receiving the first brake pad safety warning , and count the average number of braking times Jz of the car each time it travels, calculate the predicted number of driving times Xy of the brake pads of new energy vehicles, and issue a second brake pad safety warning.

[0013] Furthermore, a pressure sensor is installed on the brake pad of the new energy vehicle. When the pressure sensor detects a pressure change, it automatically counts the number of brakes Sc, and calculates the duration of each pressure change, accumulates the total braking time Ls, and obtains the total driving time Xs of the new energy vehicle after replacing the brake pad.

[0014] Furthermore, the number of brake times Sc, the total braking time Ls and the total driving time Xs of the new energy vehicle to be tested are obtained, and the first safety factor Dq of the brake pad is calculated:

[0015]

[0016] in, Indicates the maximum number of brake times during the historical maintenance of the brake pad. Indicates the minimum number of brake times during the brake pad maintenance history. Indicates the maximum value of the total braking time during the historical maintenance of the brake pad. Indicates the minimum total braking time of the brake pad during historical maintenance. Indicates the maximum total driving time of the brake pad during historical maintenance. Indicates the minimum total driving time when the brake pads have been serviced in history.

[0017] Furthermore, when the first safety factor Dq of the brake pad is less than a first safety threshold, a first brake pad safety warning is issued, wherein the first safety threshold is the maximum value of the first safety factor when all brake pads are repaired.

[0018] Furthermore, after receiving the first brake pad safety warning, a microphone is used to capture the noise signal generated by the brake pad during braking, and the noise signal is divided into frames (or windows) of fixed length. For each frame, its energy is calculated. (i.e. the integral or summation of the square of the signal), and calculate the number of zero crossings, divided by the frame length, to get the short-time zero crossing rate .

[0019] In a continuous signal, a zero crossing means that the signal crosses the time axis; in a discrete signal, a zero crossing means that the sign of adjacent sampling points changes.

[0020] Furthermore, the energy of each frame of the noise signal generated by the brake pad during braking is obtained. and short-time zero-crossing rate , calculate the braking stability coefficient Wd of the brake pad:

[0021]

[0022] Where a represents the sequence number of each frame of the noise signal, a=1, 2, ..., N, and is the stable weight calculated according to the entropy weight method, and + , is the mean energy of each frame of the noise signal generated by the brake pad during braking. It is the mean value of the short-term zero-crossing rate of each frame of the noise signal generated by the brake pad during braking.

[0023] Furthermore, the mean energy of each frame of the noise signal generated by the brake pad during braking is and the mean of the short-time zero-crossing rate , calculate the brake pad's braking abnormality coefficient Yc:

[0024]

[0025] in, is the average energy of each frame of the standard noise signal generated by the brake pad during braking. It is the average value of the short-term zero-crossing rate of each frame of the standard noise signal generated by the brake pad during braking.

[0026] Furthermore, the braking stability coefficient Wd and the braking abnormality coefficient Yc of the brake pad to be tested are obtained, and the comprehensive safety factor Zh of the brake pad is calculated:

[0027]

[0028] in, The maximum braking stability factor for all brake pads when repairing, The minimum braking stability factor for all brake pads when repairing. The maximum braking abnormality coefficient for all brake pads during maintenance. Minimum brake abnormality factor for all brake pads when repairing.

[0029] Furthermore, the comprehensive safety factor of the brake pads of the new energy vehicle is obtained each time the brake is applied after the new energy vehicle receives the first brake pad safety warning. , calculate the rate of change of the comprehensive safety factor Bh:

[0030]

[0031] Among them, i represents the sequence number of each braking after the new energy vehicle receives the first brake pad safety warning, i=1, 2, ..., m, Indicates the comprehensive safety factor of the brake pads during the most recent brake application.

[0032] Furthermore, the driving habits of new energy vehicles are obtained, and the average number of braking times of the vehicle each time is counted, Jz, combined with the change rate of the comprehensive safety factor Bh and the comprehensive safety factor of the brake pads of the latest braking , calculate the predicted driving times Xy of the new energy vehicle brake pads:

[0033]

[0034] in, It represents the average value of the comprehensive safety factor for all brake pad repairs. is the rounding function.

[0035] Furthermore, when the predicted number of driving times Xy is less than 10, a second brake pad safety warning is issued.

[0036] (III) Beneficial effects

[0037] The present invention provides a method for detecting the safety performance of new energy vehicle parts, which has the following beneficial effects:

[0038] 1. Obtain the number of brakes Sc, total braking time Ls and total driving time Xs of the new energy vehicle to be tested, calculate the first safety factor Dq of the brake pad, and issue the first brake pad safety warning to the outside, which can promote further analysis of the actual operation of the brake pad, so as to take measures in advance to avoid failure of the brake system and prevent safety accidents caused by brake system problems.

[0039] 2. After receiving the first brake pad safety warning, use the microphone to capture the noise signal generated by the brake pad during braking. and short-time zero-crossing rate , calculate the brake pad's braking stability coefficient Wd and braking abnormality coefficient Yc, and calculate the brake pad's comprehensive safety factor Zh. It can monitor the working status of the brake pad in real time, and can more accurately evaluate the brake pad's braking stability and whether there are abnormalities, reminding car owners to replace the brake pads in time or perform other necessary maintenance, thereby extending the service life of the brake system and reducing maintenance costs.

[0040] 3. Obtain the comprehensive safety factor of the brake pads of the new energy vehicle each time it brakes after receiving the first brake pad safety warning , and count the average number of braking times Jz of the car each time it drives, calculate the predicted number of driving times Xy of the brake pads of new energy vehicles, and issue a second brake pad safety warning to the outside, so that you can know in advance that the brake pads are about to reach the replacement standard, avoid accidents caused by brake pad failure during driving, and avoid damage to the brake disc or other components due to excessive wear of the brake pads, thereby reducing maintenance costs, ensuring that the brake system is always in good condition, and improving driving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 The present invention is a schematic flow chart of a method for detecting safety performance of new energy vehicle parts. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] See also Figure 1 The present invention provides a method for detecting the safety performance of new energy vehicle parts, comprising the following steps:

[0044] Step 1: Obtain the number of brake times Sc, total brake time Ls and total driving time Xs of the new energy vehicle to be tested, calculate the first safety factor Dq of the brake pad, and issue a first brake pad safety warning.

[0045] The step 1 includes the following contents:

[0046] Step 101, install a pressure sensor on the brake pad of the new energy vehicle. When the pressure sensor detects a pressure change, it automatically counts the number of brakes Sc, and counts the duration of each pressure change, accumulates the total braking time Ls, and obtains the total driving time Xs of the new energy vehicle after the brake pad is replaced.

[0047] Step 102: Obtain the number of braking times Sc, the total braking time Ls and the total driving time Xs of the new energy vehicle to be tested, and calculate the first safety factor Dq of the brake pad:

[0048]

[0049] in, Indicates the maximum number of brake times during the historical maintenance of the brake pad. Indicates the minimum number of brake times during the brake pad maintenance history. Indicates the maximum value of the total braking time during the historical maintenance of the brake pad. Indicates the minimum total braking time of the brake pad during historical maintenance. Indicates the maximum total driving time of the brake pad during historical maintenance. Indicates the minimum total driving time when the brake pads have been serviced in history.

[0050] Step 103: When the first safety factor Dq of the brake pad is less than a first safety threshold, a first brake pad safety warning is issued, wherein the first safety threshold is the maximum value of the first safety factor when all brake pads are repaired.

[0051] When using, combine the contents in steps 101 to 103:

[0052] The number of brakes Sc, total braking time Ls and total driving time Xs of the new energy vehicle to be tested are obtained, the first safety factor Dq of the brake pad is calculated, and the first brake pad safety warning is issued to the outside, which can prompt further analysis of the actual operation of the brake pad, so as to take measures in advance to avoid failure of the brake system and prevent safety accidents caused by brake system problems.

[0053] Step 2: After receiving the first brake pad safety warning, use a microphone to capture the noise signal generated by the brake pad during braking. and short-time zero-crossing rate , calculate the braking stability coefficient Wd and braking abnormality coefficient Yc of the brake pad, and calculate the comprehensive safety factor Zh of the brake pad.

[0054] The step 2 includes the following contents:

[0055] Step 201: After receiving the first brake pad safety warning, use a microphone to capture the noise signal generated by the brake pad during braking, divide the noise signal into frames (or windows) of fixed length, and calculate the energy of each frame. (i.e. the integral or summation of the square of the signal), and calculate the number of zero crossings, divided by the frame length, to get the short-time zero crossing rate .

[0056] In a continuous signal, a zero crossing means that the signal crosses the time axis; in a discrete signal, a zero crossing means that the sign of adjacent sampling points changes.

[0057] Step 202: Obtain the energy of each frame of the noise signal generated by the brake pad during braking. and short-time zero-crossing rate , calculate the braking stability coefficient Wd of the brake pad:

[0058]

[0059] Where a represents the sequence number of each frame of the noise signal, a=1, 2, ..., N, and is the stable weight calculated according to the entropy weight method, and + , is the mean energy of each frame of the noise signal generated by the brake pad during braking. It is the mean value of the short-term zero-crossing rate of each frame of the noise signal generated by the brake pad during braking.

[0060] Step 203: The average value of each frame energy of the noise signal generated by the brake pad during braking and the mean of the short-time zero-crossing rate , calculate the brake pad's braking abnormality coefficient Yc:

[0061]

[0062] in, is the average energy of each frame of the standard noise signal generated by the brake pad during braking. It is the average value of the short-term zero-crossing rate of each frame of the standard noise signal generated by the brake pad during braking.

[0063] Step 204: Obtain the braking stability coefficient Wd and the braking abnormality coefficient Yc of the brake pad to be tested, and calculate the comprehensive safety factor Zh of the brake pad:

[0064]

[0065] in, The maximum braking stability factor for all brake pads when repairing, The minimum braking stability factor for all brake pads when repairing. The maximum braking abnormality coefficient for all brake pads during maintenance. Minimum brake abnormality factor for all brake pads when repairing.

[0066] When using, combine the contents in steps 201 to 204:

[0067] After receiving the first brake pad safety warning, a microphone is used to capture the noise signal generated by the brake pad during braking. and short-time zero-crossing rate , calculate the brake pad's braking stability coefficient Wd and braking abnormality coefficient Yc, and calculate the brake pad's comprehensive safety factor Zh. It can monitor the working status of the brake pad in real time, and can more accurately evaluate the brake pad's braking stability and whether there are abnormalities, reminding car owners to replace the brake pads in time or perform other necessary maintenance, thereby extending the service life of the brake system and reducing maintenance costs.

[0068] Step 3: Obtain the comprehensive safety factor of the brake pads for each braking after the new energy vehicle receives the first brake pad safety warning , and count the average number of braking times Jz of the car each time it travels, calculate the predicted number of driving times Xy of the brake pads of new energy vehicles, and issue a second brake pad safety warning.

[0069] The step three includes the following contents:

[0070] Step 301: Obtain the comprehensive safety factor of the brake pad each time the new energy vehicle brakes after receiving the first brake pad safety warning , calculate the rate of change of the comprehensive safety factor Bh:

[0071]

[0072] Among them, i represents the sequence number of each braking after the new energy vehicle receives the first brake pad safety warning, i=1, 2, ..., m, Indicates the comprehensive safety factor of the brake pads during the most recent brake application.

[0073] Step 302: Obtain the driving habits of new energy vehicles, calculate the average number of braking times of the vehicle each time, and combine the comprehensive safety factor change rate Bh and the comprehensive safety factor of the brake pads of the latest braking. , calculate the predicted driving times Xy of the new energy vehicle brake pads:

[0074]

[0075] in, It represents the average value of the comprehensive safety factor for all brake pad repairs. is the rounding function.

[0076] Step 303: When the predicted number of driving times Xy is less than 10, a second brake pad safety warning is issued to indicate that the brake pad needs maintenance.

[0077] When using, combine the contents in steps 301 to 303:

[0078] Get the comprehensive safety factor of the brake pads of the new energy vehicle each time it brakes after receiving the first brake pad safety warning , and count the average number of braking times Jz of the car each time it drives, calculate the predicted number of driving times Xy of the brake pads of new energy vehicles, and issue a second brake pad safety warning to the outside, so that you can know in advance that the brake pads are about to reach the replacement standard, avoid accidents caused by brake pad failure during driving, and avoid damage to the brake disc or other components due to excessive wear of the brake pads, thereby reducing maintenance costs, ensuring that the brake system is always in good condition, and improving driving safety.

[0079] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination thereof. When implemented using software, the above embodiments may be implemented in whole or in part in the form of a computer program product. A person of ordinary skill in the art may appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein may be implemented in electronic hardware, or in a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution.

[0080] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0081] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be covered by the protection scope of the present application.

Claims

1. A method for testing the safety performance of new energy vehicle parts, characterized in that: The steps include: Obtain the number of brakes Sc, the total braking time Ls and the total driving time Xs of the new energy vehicle to be tested, calculate the first safety factor Dq of the brake pad, and issue a first brake pad safety warning; Obtain the number of brakes Sc, total brake time Ls and total driving time Xs of the new energy vehicle to be tested, and calculate the first safety factor Dq of the brake pad: Wherein, max(Sc) represents the maximum number of brake times during the historical maintenance of the brake pad, min(Sc) represents the minimum number of brake times during the historical maintenance of the brake pad, max(Ls) represents the maximum value of the total brake braking time during the historical maintenance of the brake pad, min(Ls) represents the minimum value of the total brake braking time during the historical maintenance of the brake pad, max(Xs) represents the maximum value of the total driving time during the historical maintenance of the brake pad, and min(Xs) represents the minimum value of the total driving time during the historical maintenance of the brake pad; After receiving the first brake pad safety warning, a microphone is used to capture the noise signal generated by the brake pad during braking. The energy Nl of each frame of the noise signal generated by the brake pad during braking is calculated. a and short-time zero-crossing rate Gn a , calculate the brake pad's braking stability coefficient Wd and braking abnormality coefficient Yc, and calculate the brake pad's comprehensive safety factor Zh; Get the energy Nl of each frame of the noise signal generated by the brake pad during braking a and short-time zero-crossing rate Gn a , calculate the braking stability coefficient Wd of the brake pad: Where a represents the sequence number of each frame of the noise signal, a = 1, 2, ..., N, k1 and k2 are stable weights calculated according to the entropy weight method, and k1 + k2 = 1, is the mean energy of each frame of the noise signal generated by the brake pad during braking. It is the average value of the short-term zero-crossing rate of each frame of the noise signal generated by the brake pad during braking; The average energy of each frame of the noise signal generated by the brake pad during braking and the mean of the short-time zero-crossing rate Calculate the brake abnormality coefficient Yc of the brake pad: Among them, Nl b Gn is the mean value of the energy of each frame of the standard noise signal generated by the brake pad during braking. b It is the average value of the short-term zero-crossing rate of each frame of the standard noise signal generated by the brake pad during braking; Obtain the braking stability coefficient Wd and the braking abnormality coefficient Yc of the brake pad to be tested, and calculate the comprehensive safety factor Zh of the brake pad: Among them, max(Wd) is the maximum braking stability coefficient when all brake pads are repaired, min(Wd) is the minimum braking stability coefficient when all brake pads are repaired, max(Yc) is the maximum braking abnormality coefficient when all brake pads are repaired, and min(Yc) is the minimum braking abnormality coefficient when all brake pads are repaired; Get the comprehensive safety factor Zh of the brake pads of the new energy vehicle each time it brakes after receiving the first brake pad safety warning i , and count the average number of braking times Jz of the car each time it travels, calculate the predicted number of driving times Xy of the brake pads of new energy vehicles, and issue a second brake pad safety warning.

2. A method for detecting safety performance of new energy vehicle parts according to claim 1, characterized in that: A pressure sensor is installed on the brake pad of the new energy vehicle. When the pressure sensor detects a pressure change, it automatically counts the number of brakes Sc, and calculates the duration of each pressure change. The total braking time Ls is accumulated, and the total driving time Xs of the new energy vehicle after the brake pad is replaced is obtained.

3. A method for detecting safety performance of new energy vehicle parts according to claim 1, characterized in that: When the first safety factor Dq of the brake pad is less than the first safety threshold, a first brake pad safety warning is issued, wherein the first safety threshold is the maximum value of the first safety factor when all brake pads are repaired.

4. A method for detecting safety performance of new energy vehicle parts according to claim 1, characterized in that: Get the comprehensive safety factor Zh of the brake pads of the new energy vehicle each time it brakes after receiving the first brake pad safety warning i , calculate the rate of change of the comprehensive safety factor Bh: Where i represents the sequence number of each braking after the new energy vehicle receives the first brake pad safety warning, i = 1, 2, ..., m, Zh m Indicates the comprehensive safety factor of the brake pads during the most recent brake application.

5. A method for detecting safety performance of new energy vehicle parts according to claim 4, characterized in that: Obtain the driving habits of new energy vehicles, count the average number of brakes per trip Jz, and combine the comprehensive safety factor change rate Bh and the comprehensive safety factor Zh of the latest brake pad m , calculate the predicted driving times Xy of the new energy vehicle brake pads: Among them, Zh b It represents the mean value of the comprehensive safety factor of all brake pad repairs, and [] is the rounding function.

6. A method for detecting safety performance of new energy vehicle parts according to claim 5, characterized in that: When the predicted driving number Xy is less than 10, a second brake pad safety warning is issued.

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