Methods of determining a degree of battery pack breach, controllers, systems, trolleys, and media

Abstract

A method, controller, system, electric vehicle and medium for determining the damage degree of a battery pack, the method comprising: acquiring an elastic wave signal generated by an impact through a plurality of elastic wave sensors arranged in a battery chassis; calculating an impact position and an impact energy according to the elastic wave signal; and determining the damage degree of the battery pack according to at least the impact energy and a maximum bearable energy at the impact position, so that the damage degree of the battery pack can be determined in a timely and accurate manner after the vehicle is impacted.

Description

Technical Field

[0001] This article relates to battery protection technology, and more particularly to a method for determining the extent of damage to a battery pack, a controller, a system, an electric vehicle, and a medium. Background Technology

[0002] Battery packs in new energy vehicles are prone to fire and explosion when subjected to impacts or compression, posing a significant risk to the safety of the vehicle and its occupants. Therefore, timely assessment of battery pack damage levels can improve battery pack safety, extend battery pack lifespan, and reduce maintenance costs, significantly contributing to the overall performance of the electric vehicle and enhancing user safety.

[0003] Existing methods for determining the extent of battery pack damage include visual inspection and electrochemical performance testing. Visual inspection can detect obvious damage, deformation, or leakage on the battery pack surface. Electrochemical performance testing can assess the performance changes of the battery pack under specific conditions, such as capacity testing, internal resistance testing, charge-discharge testing, and cycle life testing. However, these existing methods all require the vehicle to be in a specific scenario (such as a repair shop) or under specific conditions. They cannot determine the extent of damage in a timely manner when the vehicle is in normal use, resulting in delayed damage assessment and failing to provide timely protection for the safety of the electric vehicle and its occupants. Summary of the Invention

[0004] This application provides a method, controller, system, electric vehicle, and medium for determining the degree of damage to a battery pack, which can determine the degree of damage to the battery pack in a timely and accurate manner after the vehicle is subjected to an impact.

[0005] The method for determining the degree of damage to the battery pack in the battery chassis provided in this application embodiment includes:

[0006] Multiple elastic wave sensors installed in the battery chassis acquire elastic wave signals generated by the impact.

[0007] The impact location and impact energy are calculated based on the elastic wave signal.

[0008] The extent of damage to the battery pack is determined based at least on the impact energy and the maximum tolerable energy at the impact location.

[0009] The non-transient computer-readable storage medium provided in this application embodiment stores one or more program instructions, which can be executed by one or more processors to implement the method for determining the degree of damage to the battery pack in the battery chassis as described above.

[0010] The controller provided in this application embodiment includes:

[0011] A storage module is configured to store computer program instructions that can be executed on a processor;

[0012] The processing module is configured to execute the computer program instructions to implement the method for determining the degree of damage to the battery pack in the battery chassis as described above.

[0013] The control system provided in this application includes:

[0014] Battery chassis including the battery pack;

[0015] Multiple elastic wave sensors are installed in the battery chassis;

[0016] And the controller as described above.

[0017] The tram provided in this application includes the control system described above.

[0018] The technical solution described in this embodiment can promptly determine the degree of damage to the battery pack in the battery chassis by utilizing the elastic wave signal generated by the impact when the vehicle is subjected to an impact; and by borrowing the material damage measurement mechanism, the impact energy and the maximum withstandable energy at the impact location are taken into account as factors in determining the degree of damage to the battery pack, thus ensuring the accuracy of the determined degree of damage to the battery pack.

[0019] Other features and advantages of this application will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the application. Other advantages of this application can be realized and obtained by means of the embodiments described in the description and the accompanying drawings. Attached Figure Description

[0020] The accompanying drawings are used to provide an understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0021] Figure 1 A flowchart illustrating the method for determining the degree of damage to the battery pack in a battery chassis provided in this application embodiment;

[0022] Figure 2 A schematic diagram of the frequency points corresponding to the maximum amplitude of the frequency-domain elastic wave signal provided in the embodiments of this application;

[0023] Figure 3 A schematic diagram of the maximum frequency point in the frequency domain elastic wave signal whose amplitude is equal to a preset amplitude threshold provided in the embodiments of this application;

[0024] Figure 4 A flowchart illustrating the method for determining material factors provided in this application embodiment;

[0025] Figure 5A plan view of a battery pack is provided in this application embodiment;

[0026] Figure 6 This is a flowchart of a method for obtaining impact energy from elastic wave signals, provided in an embodiment of this application.

[0027] Figure 7 A flowchart illustrating a method for calculating the impact location based on elastic wave signals, provided in an embodiment of this application.

[0028] Figure 8 A schematic diagram of the signal after normalization processing of sub-band signals of multiple channels, provided in an embodiment of this application;

[0029] Figure 9 This is a flowchart of a battery warning method provided in an embodiment of this application;

[0030] Figure 10 A block diagram of controller components provided in the embodiments of this application;

[0031] Figure 11 This is a schematic diagram illustrating the arrangement of multiple elastic wave sensors in a battery chassis according to an embodiment of this application. Detailed Implementation

[0032] This application describes several embodiments, but these descriptions are exemplary and not limiting, and it will be apparent to those skilled in the art that many more embodiments and implementations are possible within the scope of the embodiments described herein. Although many possible combinations of features are shown in the drawings and discussed in the detailed description, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with, or may replace, any feature or element of any other embodiment.

[0033] This application includes and contemplates combinations of features and elements known to those skilled in the art. The embodiments, features, and elements disclosed in this application can also be combined with any conventional features or elements to form unique inventive solutions. Any feature or element of any embodiment can also be combined with features or elements from other inventive solutions to form another unique inventive solution. Therefore, it should be understood that any feature shown and / or discussed in this application can be implemented individually or in any suitable combination. Therefore, the embodiments are not limited except by the limitations imposed by the appended claims and their equivalents. Furthermore, various modifications and changes can be made within the scope of the appended claims.

[0034] Furthermore, in describing representative embodiments, the specification may have presented methods and / or processes as a specific sequence of steps. However, the method or process should not be limited to the specific order of steps described herein, to the extent that it does not depend on such a specific order. As will be understood by those skilled in the art, other sequences of steps are also possible. Therefore, the specific order of steps set forth in the specification should not be construed as a limitation of the claims. Moreover, the claims concerning the method and / or process should not be limited to the steps performed in the written order, and those skilled in the art will readily understand that these orders can be varied and still remain within the spirit and scope of the embodiments of this application.

[0035] This application provides a method for determining the degree of damage to a battery pack in a battery chassis, such as... Figure 1 The method includes:

[0036] Step S101 acquires the elastic wave signal generated by the impact by multiple elastic wave sensors installed in the battery chassis;

[0037] Step S102 calculates the impact location and impact energy based on the elastic wave signal;

[0038] Step S103 determines the degree of damage to the battery pack based at least on the impact energy and the maximum tolerable energy at the impact location.

[0039] The method described in this embodiment can promptly determine the degree of damage to the battery pack in the battery chassis by utilizing the elastic wave signal generated by the impact when the vehicle is subjected to an impact; and by using the material damage measurement mechanism, the impact energy and the maximum withstandable energy at the impact location are taken into account as factors in determining the degree of damage to the battery pack, thus ensuring the accuracy of the determined degree of damage to the battery pack.

[0040] In an exemplary embodiment, determining the degree of damage to the battery pack based at least on the impact energy and the maximum tolerable energy at the impact location includes:

[0041] The degree of damage to the battery pack is determined by comparing the impact energy with the maximum tolerable energy at the impact location.

[0042] In an exemplary embodiment, determining the degree of damage to the battery pack by comparing the impact energy with the maximum tolerable energy at the impact location includes:

[0043] If the impact energy is greater than or equal to the maximum tolerable energy at the impact location, the damage level of the battery pack is determined to be 1, i.e., complete damage has occurred.

[0044] If the impact energy is less than the maximum tolerable energy at the impact location, the degree of damage to the battery pack is determined as the ratio of the impact energy to the maximum tolerable energy at the impact location.

[0045] The degree of damage to the aforementioned battery pack can be represented by D1. E abs E represents the impact energy. max This indicates the maximum energy that the battery pack can withstand at the impact location. For example, the battery pack is designed to withstand a maximum energy of 150 joules. When subjected to an energy impact of 60 joules, its damage level D1 = 60 / 150 = 0.4; when subjected to an energy impact of 180 joules, its damage level D1 = 1, that is, complete failure occurs.

[0046] In another exemplary embodiment, determining the degree of damage to the battery pack based at least on the impact energy and the maximum tolerable energy at the impact location includes:

[0047] The damage factor of the battery pack is determined by comparing the impact energy with the maximum tolerable energy at the impact location; the degree of damage to the battery pack is determined based on the damage factor and the material factor.

[0048] The material factor described in this embodiment is used to represent the hardness characteristics of the impacting object. The higher the hardness of the impacting object, the larger the material factor. Under the same external impact energy, the larger the material factor of the impacting object, the greater the damage to the battery pack and the greater the risk of battery pack damage. Conversely, the smaller the material factor of the impacting object, the less damage to the battery pack and the lower the risk of battery pack damage.

[0049] This embodiment incorporates the hardness of the impacting object as a factor in determining the extent of battery pack damage, thereby improving the accuracy of the battery pack damage assessment results.

[0050] Through repeated testing, this invention has shown that the increase in the material factor has a non-linear effect on the degree of damage to the battery pack. Therefore, in an exemplary embodiment, determining the degree of damage to the battery pack based on the damage factor and the material factor includes: determining the degree of damage to the battery pack based on the product of the damage factor and the material factor.

[0051] For example, in this embodiment, it can be As a damage factor, the degree of damage to the battery pack is represented by D2, where D2 = D1 * α, and α represents the material factor.

[0052] Because impactors with different material properties produce different elastic wave signals after striking a battery pack, the material properties in this embodiment can be determined using the elastic wave signals.

[0053] In one exemplary embodiment, the material factor is determined by the elastic wave signal in the following manner:

[0054] The final elastic wave signal is determined by receiving elastic wave signals from multiple channels. The material factor is calculated based on the final elastic wave signal. For example, the elastic wave signals from each channel are multiplied by the weight of the corresponding channel and then summed. The summation result is used as the final elastic wave signal.

[0055] or,

[0056] The material factor is calculated based on the elastic wave signals received from multiple channels. The final material factor is determined by the multiple material factors. Each channel corresponds to an elastic wave sensor, and different channels correspond to different elastic wave sensors. Each material factor can also be multiplied by the weight of the corresponding channel and then summed. The summation result is used as the final material factor.

[0057] The weights corresponding to each of the above channels can be equal or determined based on the energy of a single channel.

[0058] The weight determined based on single-channel energy can be the ratio of the single-channel energy to the sum of the energies of all channels. For example, the weight corresponding to channel j... j is the channel number, E j Let N be the energy of channel j, and N be the total number of channels. k represents the data points sampled by a discrete ADC for a single-channel elastic wave signal. The total length of the data points varies depending on the sampling rate, such as 2048 points or 1024 points. A refers to the amplitude of the elastic wave signal, which can be the amplitude of a frequency domain signal or the amplitude of a time domain signal.

[0059] In one exemplary embodiment, the method of calculating the material factor based on a specified elastic wave signal includes any of the following methods, wherein the specified elastic wave signal refers to the final elastic wave signal or the elastic wave signal of each channel:

[0060] Method 1: Determine the frequency point F corresponding to the maximum amplitude of the sampled elastic wave signal of a preset length in the frequency domain. max ,like Figure 2 As shown, the F max Divide by half the sampling rate to obtain the material factor.

[0061] Assuming α represents the material factor, then F s The sampling rate is indicated. The maximum amplitude of the frequency-domain specified elastic wave signal can be: the maximum absolute amplitude of the frequency-domain specified elastic wave signal, the maximum amplitude after windowing and smoothing the amplitude value of the frequency-domain specified elastic wave signal, or the maximum amplitude value after normalization of the frequency-domain specified elastic wave signal.

[0062] Method 2: Determine the frequency-weighted average value F of the sampled elastic wave signal with a preset length in the frequency domain. mean , to the F mean Divide by half the sampling rate to obtain the material factor.

[0063] For example, F i P is the sampling frequency value. i For F i The corresponding weights, where len is the preset length of the elastic wave signal specified in the frequency domain. Frequency weight P i The calculation method can be frequency point F i Amplitude value A i The proportion in the sum of frequency domain amplitude values, i.e.

[0064] Method 3: Determine the maximum frequency point F in the frequency domain of the sampled elastic wave signal of a preset length that corresponds to an amplitude value greater than or equal to a preset amplitude threshold A0. i ,like Figure 3 As shown, the maximum frequency point F i Divide by half the sampling rate to obtain the material factor.

[0065] Figure 4 A flowchart for determining material factors is shown.

[0066] In one exemplary implementation, the maximum tolerable energy at the impact location is obtained in the following manner:

[0067] The maximum withstandable energy is obtained at multiple first designated locations on the surface of the battery pack subjected to impact, and the maximum withstandable energy at the impact location is determined based on the maximum withstandable energy at the first designated locations adjacent to the impact location.

[0068] When the impact location is the first designated location, the maximum withstandable energy at the impact location is the maximum withstandable energy at the first designated location. When the impact location is different from the first designated location, the maximum withstandable energy at the impact location is determined based on the maximum withstandable energy of one or more first designated locations adjacent to the impact location. For example, the maximum withstandable energy of the first designated location closest to the impact location can be used as the maximum withstandable energy of the impact location; or, the average value of the maximum withstandable energies of multiple first designated locations adjacent to the impact location can be used as the maximum withstandable energy of the impact location; or, interpolation can be performed on the maximum withstandable energies of multiple first designated locations adjacent to the impact location to obtain the maximum withstandable energy of the impact location.

[0069] In an exemplary embodiment, the maximum tolerable energy at a plurality of first designated locations on the surface of the battery pack is obtained by the following method:

[0070] For each first designated position, the preset impact energy E is gradually increased, and the impact energy received by each of the multiple preset points of the battery pack under the condition that the preset impact energy E is received at the first designated position is obtained. If it is determined that the impact energy received by at least one of the multiple preset points is greater than or equal to the known yield energy of that point, the maximum tolerable energy at the first designated position is determined to be the preset impact energy E at this time.

[0071] For example, the first designated location is a grid point on the surface of the battery pack. When impact energy is applied to any of the grid points on the surface of the battery pack, the impact energy can be measured at any preset point on the battery pack. The preset points can be set not only on the surface of the battery pack but also inside the battery pack. The preset points on the surface of the battery pack can be all the same as, partially the same as, or different from the first designated location.

[0072] The yield energy at the preset point is related to factors such as the battery pack material and structure, and can be considered as a property parameter of the battery pack. When the impact energy received at a preset point is greater than or equal to the yield energy at that point, the material at that point begins to undergo plastic deformation. This means that the deformation of the material will become persistent and irreversible after the applied stress is removed. In this case, the point may break.

[0073] Figure 5 A plan view of a battery pack is shown, in which six elastic wave sensors are arranged. Point E represents a first designated position, and the other points represent preset positions. Impact energy is applied to point E, and the impact energy E'(i,j) received by each preset position is obtained through deformation field transmission. For each preset position, E'(i,j) is compared with its own yield energy E(i,j). If E'(i,j) < E(i,j), the impact energy applied to point E is increased. If E'(i,j) ≥ E(i,j), the maximum withstandable energy at point E is determined, which is the impact energy received by point E at this time.

[0074] When a certain location on the surface of the battery pack is impacted, the battery pack may not necessarily break at that location because there are supporting structures such as crossbeams and longitudinal beams inside the location. Instead, the other side of the crossbeams or other locations may break. Therefore, according to the solution described in the embodiments of this application, the battery pack can be damaged when the impact energy applied to any first designated location is greater than the maximum withstand energy of the first designated location (the damage may occur at any location of the battery pack). This makes the calculated maximum withstand energy of the first designated location more consistent and accurate with the definition of battery damage.

[0075] In an exemplary embodiment, calculating the impact energy based on the elastic wave signal includes:

[0076] Calculate the initial energy based on the elastic wave signal;

[0077] The impact energy is obtained by multiplying the initial energy by the energy calibration coefficient;

[0078] The energy calibration coefficient is determined based on the energy coefficients of one or more pre-stored second designated locations on the surface of the battery pack. The energy coefficient for each second designated location is equal to the ratio of the unit impact energy applied to that location to the impact energy calculated using elastic wave signals. Ideally, the impact energy applied to the battery pack should equal the calculated impact energy. However, due to limitations in calculation accuracy and energy loss, the applied impact energy may not be equal to the actually calculated impact energy; therefore, calibration of the calculated impact energy is necessary. The second designated location and the first designated location may be the same or different.

[0079] In an exemplary embodiment, the energy coefficient at each second designated location can be obtained in the following manner:

[0080] After applying a unit impact energy to a second designated location on the surface of the battery pack, the impact energy E at that second designated location is calculated based on the elastic wave signals from each elastic wave sensor channel. p p is the label of the second specified position; 1 / E p This serves as the energy coefficient for the second designated location.

[0081] For example, the energy calibration coefficient is determined based on the energy coefficients at one or more pre-stored second specified locations on the surface of the battery pack, including: the energy calibration coefficient is the average of the energy coefficients at multiple pre-stored second specified locations on the surface of the battery pack. As an example, the energy calibration coefficient is the average of the energy coefficients at all pre-stored second specified locations on the surface of the battery pack.

[0082] To further improve the accuracy of impact energy calculation, the energy calibration coefficient can be precisely set to the energy calibration coefficient at the impact location during energy calibration. Therefore, in another embodiment, calculating the impact energy based on the elastic wave signal includes: calculating an initial energy based on the elastic wave signal; and multiplying the initial energy by the energy calibration coefficient at the impact location to obtain the impact energy received at the impact location. The impact location can be calculated from the elastic wave signal or obtained using other sensors (such as capacitive, infrared, or ultrasonic sensors).

[0083] For example, when the impact location is a second designated location, the energy calibration coefficient of the impact location is equal to the pre-stored energy coefficient of the second location; when the impact location is not a second designated location, the energy calibration coefficient of the impact location is obtained by interpolation based on the energy coefficients of a preset number of second designated locations on the battery pack surface. The preset number of second designated locations refers to second designated locations adjacent to the impact location.

[0084] The method for obtaining impact energy based on elastic wave signals described in the embodiments of this application can be referred to. Figure 6 . Figure 6 The area enclosed by the dashed line is used to obtain the energy coefficient. Without considering the impact location, a coarse calculation of the actual impact energy is performed based on the energy calibration coefficient determined from the average of the energy coefficients at multiple second specified locations. With the impact location considered, a fine calculation of the actual impact energy is performed by determining the energy calibration coefficient at the impact location.

[0085] In an exemplary embodiment, calculating the impact location based on the elastic wave signal includes:

[0086] The characteristics of the elastic wave signal from each channel are acquired, including one or more of the following: time characteristics, energy characteristics, and energy-time ratio characteristics; the time characteristics are used to characterize the time it takes for the elastic wave sensor of each channel to receive the elastic wave signal.

[0087] The impact location is obtained by comparing the feature with a pre-stored feature sample obtained after each third designated position on the surface of the battery pack is impacted.

[0088] For example, features from elastic wave signals from multiple channels are combined into a feature set;

[0089] The similarity between the feature set and the pre-stored feature samples obtained after each third designated position on the surface of the battery pack is impacted is judged, and the n feature samples with the highest similarity are found.

[0090] The similarity of the n feature samples is used as the weight, and the coordinates of the n third specified positions corresponding to the n feature samples are weighted and summed to obtain the impact position.

[0091] The third designated position and the second designated position may be the same or different.

[0092] In one exemplary embodiment, the characteristics of acquiring the elastic wave signal from each channel include one or more of the following:

[0093] The first moment when the absolute value of the elastic wave signal from each channel is greater than the preset threshold A1 is taken as the time feature of the elastic wave signal of the corresponding channel.

[0094] The calculated energy value of the elastic wave signal from each channel is used as the energy characteristic of the elastic wave signal of the corresponding channel.

[0095] The ratio of the energy characteristic of the elastic wave signal of each channel to the time characteristic of the corresponding channel is used as the energy-time ratio characteristic of the elastic wave signal of the corresponding channel.

[0096] The following is an example of calculating the impact location based on elastic wave signals, such as... Figure 7 As shown.

[0097] After the impact, the elastic wave signal of the effective time length is intercepted. Considering that the duration of a single impact is generally less than 50ms, the elastic wave signal of 50ms can be intercepted.

[0098] The captured elastic wave signal is subjected to noise reduction processing. Because the vibration signal obtained by the car is affected by various factors such as road conditions, weather, and engine during the driving process, there are often large fluctuations. Low-pass noise reduction filtering of the elastic wave signal can make the subsequent feature calculation results more accurate.

[0099] A bandpass filter is designed based on the frequency band where the wavefront signals of multiple channels are concentrated, and the sub-band signal S_subband of each channel is obtained. The bandpass filter can be a wavelet bandpass filter. The signal after (0-1) normalization of the sub-band signal of each channel is as follows: Figure 8 As shown;

[0100] Calculate the features of each sub-band signal after normalization, including: calculating the first time when the absolute value of each sub-band signal after normalization is greater than a preset threshold A1, and recording it as a vector T = (T sensor1 T sensor2 T sensor3 T sensor4 T sensor5 T sensor6 The time characteristic reflects the sequential timing of the elastic wave signals received by each sensor; the energy of each sub-band signal after normalization is calculated and recorded as a vector E = (E... sensor1 E sensor2 E sensor3 E sensor4 E sensor5 E sensor6 This refers to the energy characteristics, which reflect the energy level of the elastic wave signal received by each sensor. Generally, the closer the sensor is to the impact point, the greater the energy. (Calculation...) The energy-to-time ratio characteristics were obtained;

[0101] The feature set is composed of time characteristics, energy characteristics, and energy-time ratio characteristics.

[0102] The similarity between the feature set and the feature samples obtained after each third designated position on the surface of the pre-stored battery pack is impacted is judged to obtain the n feature samples with the highest similarity.

[0103] Wherein, the feature sample obtained after each third designated position j is impacted can be represented as j = 1: M, where M is the number of the third designated positions in the entire design. For example, if the entire design has 8 rows and 11 columns of third designated positions, then M = 8 * 11 = 88.

[0104] Using the similarity of the n feature samples as weights, the coordinates of the n third specified positions corresponding to the n feature samples are weighted and summed to obtain the coordinates of the impact position.

[0105] This application also provides a battery warning method, such as... Figure 9 As shown, the method includes:

[0106] Step S801 acquires the elastic wave signal generated by the impact by multiple elastic wave sensors installed in the battery chassis;

[0107] Step S802 calculates the impact location and impact energy based on the elastic wave signal, and determines the degree of damage to the battery pack based at least on the impact energy and the maximum tolerable energy at the impact location.

[0108] The implementation process of step S802 can be referred to the relevant content described in the foregoing embodiments;

[0109] Step S803 provides a battery warning based on at least one of the impact location, impact energy, and degree of damage.

[0110] In an exemplary embodiment, battery warning based on at least one of the impact location, impact energy, and degree of damage includes: displaying at least one of the impact location, impact energy, and degree of damage, and / or providing a warning based on the degree of damage.

[0111] For example, the step of providing an early warning based on the degree of damage includes:

[0112] When the damage level of the battery pack is equal to 1, meaning the battery pack is completely damaged, a battery pack replacement prompt will be issued.

[0113] When the damage degree is greater than B1 and less than 1, that is, the battery pack is moderately damaged, a battery pack maintenance prompt is issued;

[0114] When the damage degree is less than B2 (B2<B1) and greater than 0, that is, the battery pack is slightly damaged, only a battery pack damage prompt is issued.

[0115] The above embodiments for issuing warning prompts according to the damage degree are not unique, and the damage degree levels can be set according to actual conditions.

[0116] The embodiments of the present application further provide a non-transitory computer-readable storage medium, where the non-transitory computer-readable storage medium stores one or more program instructions, and the one or more program instructions can be executed by one or more processors to implement the method for determining the damage degree of the battery pack in the battery chassis as described in any of the preceding embodiments.

[0117] The embodiments of the present application further provide a controller, as shown in Figure 10 , the controller includes:

[0118] a storage module 901, configured to store computer program instructions executable on a processor;

[0119] a processing module 902, configured to execute the computer program instructions to implement the method for determining the damage degree of the battery pack in the battery chassis as described in any of the preceding embodiments.

[0120] The embodiments of the present application further provide a control system, where the control system includes:

[0121] a battery chassis;

[0122] a plurality of elastic wave sensors arranged in the battery chassis;

[0123] and the controller as described in the preceding embodiments.

[0124] In an exemplary embodiment, the arrangement manner of the plurality of elastic wave sensors in the battery chassis includes one or more of the following, as shown in Figure 11 :

[0125] In the first solution, the plurality of elastic wave sensors are arranged on the upper and lower sides of the underbody guard plate in the battery chassis; the underbody guard plate is a rigid material directly interacting with impact, such as metal, wood material, and plastic material; the sensors arranged on the upper and lower sides of the underbody guard plate can directly receive the elastic wave signal generated by the impact;

[0126] Option 2: The multiple elastic wave sensors are installed on the upper and lower sides of any one or more interlayers in the battery chassis, excluding the battery pack; as shown in the figure, the multiple elastic sensors are installed on the upper and lower sides of the water-cooling plate; the elastic wave signal generated by the impact is transmitted through the bottom protective plate to one or more interlayers, and then received by the elastic wave sensors installed on the upper and lower sides of the interlayers.

[0127] Option 3 involves placing the multiple elastic wave sensors inside the battery pack within the battery chassis; the elastic wave signal generated by the impact then propagates through one or more interlayers to the battery pack, where it is received by the elastic wave sensors located inside the battery pack.

[0128] This application also provides a tram, which includes the control system described in the previous embodiments.

[0129] It will be understood by those skilled in the art that all or some of the steps, systems, or apparatuses disclosed above, and their functional modules / units, can be implemented as software, firmware, hardware, or suitable combinations thereof. In hardware implementations, the division between functional modules / units mentioned above does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed collaboratively by several physical components. Some or all components may be implemented as software executed by a processor, such as a digital signal processor or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit (ASIC). Such software may be distributed on a computer-readable medium, which may include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term "computer storage medium" includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and can be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

Claims

1. A method for determining the degree of damage to a battery pack in a battery chassis, the method comprising: Multiple elastic wave sensors installed in the battery chassis acquire elastic wave signals generated by the impact. The impact location and impact energy are calculated based on the elastic wave signal. The extent of damage to the battery pack is determined based at least on the impact energy and the maximum tolerable energy at the impact location.

2. The method according to claim 1, characterized in that, Determining the extent of damage to the battery pack based at least on the impact energy and the maximum tolerable energy at the impact location includes: The degree of damage to the battery pack is determined by comparing the impact energy with the maximum tolerable energy at the impact location; or, The damage factor of the battery pack is determined by comparing the impact energy with the maximum tolerable energy at the impact location; the degree of damage to the battery pack is determined based on the damage factor and the material factor; the material factor is used to represent the hardness characteristics of the impacting object, the higher the hardness, the larger the material factor, and the material factor is determined by the elastic wave signal.

3. The method according to claim 2, characterized in that, Determining the degree of damage to the battery pack based on the damage factor and material factor includes: The degree of damage to the battery pack is determined based on the product of the damage factor and the material factor.

4. The method according to claim 2 or 3, characterized in that, The material factor is determined by the elastic wave signal in the following ways: The final elastic wave signal is determined by receiving elastic wave signals from multiple channels, and the material factor is calculated based on the final elastic wave signal: or The material factor is calculated based on the received elastic wave signals from multiple channels, and the final material factor is determined by the multiple material factors.

5. The method according to claim 4, characterized in that, Methods for calculating material factors based on a specified elastic wave signal include: Determine the frequency point F corresponding to the maximum amplitude of the sampled elastic wave signal of a preset length in the frequency domain. max , to the F max Divide by half the sampling rate to obtain the material factor; or Determine the frequency-weighted average value F of the sampled elastic wave signal with a preset length in the frequency domain. mean , to the F mean Divide by half the sampling rate to obtain the material factor; or The maximum frequency point corresponding to the amplitude of the sampled elastic wave signal of a preset length that is greater than or equal to a preset amplitude threshold A0 is determined, and the maximum frequency point is divided by half of the sampling rate to obtain the material factor. The specified elastic wave signal is either the final elastic wave signal or the elastic wave signal of each channel.

6. The method according to claim 1, characterized in that, The maximum tolerable energy at the impact location is determined in the following way: The maximum tolerable energy at a plurality of first specified locations on the surface of the battery pack is obtained; and the maximum tolerable energy at the impact location is determined based on the maximum tolerable energy at the first specified locations adjacent to the impact location.

7. The method according to claim 6, characterized in that, The maximum withstandable energy at multiple first designated locations on the surface of the battery pack is obtained by the following method: For each first designated position, the preset impact energy E is gradually increased to obtain the impact energy received by each of the multiple preset points of the battery pack when the preset impact energy E is received at the first designated position. If it is determined that the impact energy received by at least one of the multiple preset points is greater than or equal to the known yield energy of that point, the maximum tolerable energy at the first designated position is determined to be the preset impact energy E at this time.

8. The method according to claim 1, characterized in that, Calculating the impact energy based on the elastic wave signal includes: Calculate the initial energy based on the elastic wave signal; The impact energy is obtained by multiplying the initial energy by the energy calibration coefficient; The energy calibration coefficient is determined based on the energy coefficients of one or more second designated locations on the surface of the battery pack, and the energy coefficient of each second designated location is equal to the ratio of the unit impact energy applied to that location to the impact energy received at that location calculated using the elastic wave signal.

9. The method according to claim 8, characterized in that, The energy calibration coefficient is determined based on the energy coefficients at one or more second designated locations on the surface of the battery pack, including: The energy calibration coefficient is the average of the energy coefficients at multiple second specified locations on the surface of the battery pack, stored in advance; or, When the impact position is the second designated position, the energy calibration coefficient of the impact position is equal to the pre-stored energy coefficient of the second designated position; when the impact position is not the second designated position, the energy calibration coefficient of the impact position is obtained by interpolation based on the pre-stored energy coefficients of the second designated positions on the surface of the battery pack of a preset number of pre-stored energy coefficients.

10. The method according to claim 1, characterized in that, The calculation of the impact location based on the elastic wave signal includes: The characteristics of the elastic wave signal from each channel are acquired, including one or more of the following: time characteristics, energy characteristics, and energy-time ratio characteristics; the time characteristics are used to characterize the time it takes for the elastic wave sensor of each channel to receive the elastic wave signal. The impact location is obtained by comparing the feature with a pre-stored feature sample obtained after each third specified position on the surface of the battery pack is impacted.

11. A non-transient computer-readable storage medium storing one or more program instructions that can be executed by one or more processors to implement the method as described in any one of claims 1-10.

12. A controller, characterized in that, The controller includes: A storage module is configured to store computer program instructions that can be executed on a processor; The processing module is configured to execute the computer program instructions to implement the method as described in any one of claims 1-10.

13. A control system, characterized in that, The control system includes: Battery chassis including the battery pack; Multiple elastic wave sensors are installed in the battery chassis; And the controller as described in claim 14.

14. The control system according to claim 13, characterized in that... ； The multiple elastic wave sensors are installed in the battery chassis in one or more of the following ways: the multiple elastic wave sensors are installed on the upper and lower sides of the bottom guard plate in the battery chassis. The plurality of elastic wave sensors are installed on the upper and lower sides of any one or more layers in the battery chassis, excluding the battery pack. The plurality of elastic wave sensors are installed inside the battery pack in the battery chassis.

15. An electric vehicle comprising the control system as described in claim 13 or 14.

Images