Truck lithium battery vibration impact active buffer protection method and system

Abstract

The invention relates to the technical field of battery protection, and discloses a truck lithium battery vibration impact active buffer protection method and system.The method comprises the steps that the three-axis vibration acceleration of a lithium battery box in a truck is collected, and the three-axis vibration acceleration comprises the vertical vibration acceleration, the longitudinal vibration acceleration and the transverse vibration acceleration; performing Fourier transform on the vertical vibration acceleration to obtain a frequency spectrum of the vertical vibration acceleration; calculating a high-frequency energy ratio of the frequency spectrum based on the low-frequency energy of the frequency spectrum and the high-frequency energy of the frequency spectrum; and judging whether the high-frequency energy ratio exceeds a preset ratio threshold value or not. According to the invention, reliable protection can be provided for the lithium battery in a complex vibration environment.

Description

Technical Field

[0001] The present invention relates to the technical field of battery protection, and in particular to a method and system for actively buffering vibration and impact protection of a truck lithium battery. Background Art

[0002] When a truck is driving, the lithium battery box will inevitably be subjected to vibration and impact. Existing technology often uses elastic materials such as rubber pads and springs to deal with this problem. Rubber pads are installed between the lithium battery box and the installation position, and their elastic deformation is used to absorb vibration energy, thereby reducing the impact force transmitted to the battery.

[0003] The existing technology has the following defects: the existing technology relies on a simple mechanical structure to achieve the buffering function, and lacks comprehensive monitoring and in-depth analysis of the vibration of the lithium battery box. On the one hand, the existing technology mainly considers the impact of vertical road bumps on the battery, and ignores the role of longitudinal and lateral vibrations during vehicle acceleration, braking, and turning, resulting in the inability to fully collect vibration acceleration data of the lithium battery box during truck driving, and the acquisition of vertical, longitudinal and lateral vibration information is incomplete; on the other hand, it is difficult to accurately determine the dominant frequency component of the vibration acceleration from the limited data collected. Due to the above shortcomings, when formulating buffering protection strategies, the existing technology lacks sufficient data support and scientific basis, and cannot formulate accurate and targeted protection measures for actual vibration conditions, such as vibration intensity, frequency characteristics, etc., which makes it difficult to meet the actual needs of lithium battery protection, thereby reducing the accuracy of lithium battery protection and making it difficult to provide reliable protection for lithium batteries in complex vibration environments. Summary of the Invention

[0004] The present invention provides a method and system for active vibration and impact buffering protection of truck lithium batteries, the main purpose of which is to solve the problem that the existing technology is difficult to provide reliable protection for lithium batteries in complex vibration environments.

[0005] To achieve the above objectives, the present invention provides a truck lithium battery vibration and impact active buffering protection method, comprising:

[0006] S1. Collecting triaxial vibration acceleration of a lithium battery box in a truck, wherein the triaxial vibration acceleration includes vertical vibration acceleration, longitudinal vibration acceleration, and lateral vibration acceleration;

[0007] S2. Performing Fourier transform on the vertical vibration acceleration to obtain a frequency spectrum of the vertical vibration acceleration;

[0008] S3. Calculating a high-frequency energy ratio of the spectrum based on the low-frequency energy of the spectrum and the high-frequency energy of the spectrum;

[0009] S4. Determine whether the high-frequency energy ratio exceeds a preset ratio threshold:

[0010] When the high-frequency energy proportion does not exceed the preset proportion threshold, a state estimation value of the lithium battery box is generated based on the Kalman filter, an active damping force of the lithium battery box is calculated based on the state estimation value, a buffering force of the damper in the truck is generated based on the active damping force, and the buffering force is used to provide buffering protection for the lithium battery box of the truck;

[0011] When the proportion of the high-frequency energy exceeds the preset proportion threshold, the vertical vibration acceleration, the longitudinal vibration acceleration and the lateral vibration acceleration are synthesized into the equivalent vertical vibration acceleration of the lithium battery box. When the equivalent vertical vibration exceeds the preset vibration threshold, the reserve energy of the piezoelectric drive in the truck is used to buffer and protect the truck's lithium battery box.

[0012] In a preferred embodiment, the calculating the high-frequency energy ratio of the spectrum based on the low-frequency energy of the spectrum and the high-frequency energy of the spectrum includes:

[0013] Performing low-frequency domain integration calculation on the spectrum to obtain the low-frequency energy;

[0014] Performing high-frequency domain integral calculation on the spectrum to obtain the high-frequency energy;

[0015] A ratio of the low-frequency energy to the high-frequency energy is calculated to obtain the high-frequency energy ratio.

[0016] In a preferred embodiment, the calculation formula of the active damping force is as follows:

[0017]

[0018] Where, F damp represents the active damping force, K p represents the displacement feedback gain, represents the vertical displacement estimate in the state estimate, K d represents the speed feedback gain, Indicates the vertical velocity estimate value in the state estimate value.

[0019] In a preferred embodiment, generating a buffering force of a damper in the truck based on the active damping force comprises:

[0020] The target current of the damper is calculated based on the active damping force, wherein the calculation formula of the target current is as follows:

[0021]

[0022] Where, I represents the target current, Fdamp represents the active damping force, c min represents the basic damping coefficient of the damper, v z represents the piston movement speed of the damper, k i represents the current-damping gain;

[0023] The buffering force of the damper in the truck is calculated based on the target current, wherein the calculation formula of the buffering force is as follows:

[0024] F buffer =(c min +k i ·I)·v z

[0025] Where, I represents the target current, F buffer represents the buffer force, c min represents the basic damping coefficient of the damper, v z represents the piston movement speed of the damper, k i represents the current-damping gain.

[0026] In a preferred embodiment, the calculation formula of the equivalent vertical vibration acceleration is as follows:

[0027]

[0028] Where, Denotes the equivalent vertical vibration acceleration, a z represents the vertical vibration acceleration, a x represents the longitudinal vibration acceleration, a1 represents the longitudinal coupling coefficient, a y represents the lateral vibration acceleration, and a2 represents the lateral coupling coefficient.

[0029] In a preferred embodiment, it is characterized in that the steps of generating the reserve energy of the piezoelectric driver are as follows:

[0030] Get the impact point and average height of the current section in the truck;

[0031] Calculating the height difference between the impact point and the average height;

[0032] When the travel distance between the truck and the impact point reaches a preset distance value, calculating the predicted energy of the piezoelectric actuator based on the travel distance, the height difference, and the travel speed of the truck;

[0033] The piezoelectric drive in the truck is charged in stages based on the predicted energy until the reserve energy in the piezoelectric drive reaches the predicted energy, wherein the stage charging includes a first charging stage and a second charging stage.

[0034] In a preferred embodiment, it is characterized in that the calculation formula of the predicted energy is as follows:

[0035]

[0036] Where, E represents the predicted energy, d represents the driving distance, and v k represents the driving speed, represents the equivalent vertical vibration acceleration, g represents the acceleration due to gravity, h avg represents the average height, Δh represents the height difference, k p represents the correction factor of the piezoelectric actuator.

[0037] In a preferred embodiment, it is characterized in that the steps of the first charging stage are as follows:

[0038] collecting the temperature of the piezoelectric actuator in real time;

[0039] Determining whether the temperature exceeds a reference temperature of the piezoelectric driver:

[0040] When the temperature does not exceed the reference temperature of the piezoelectric driver, performing conventional charging on the piezoelectric driver;

[0041] When the temperature exceeds a reference temperature of the piezoelectric driver, the piezoelectric driver is charged at a reduced capacity.

[0042] In a preferred embodiment, the steps of the second charging stage are as follows:

[0043] After the first energy charging stage is completed, obtaining the first stage energy of the piezoelectric driver;

[0044] Calculating the difference between the first-stage energy and the predicted energy to obtain the second-stage energy of the piezoelectric actuator;

[0045] Determine whether the second stage energy exceeds the preset stage energy:

[0046] When the second stage energy exceeds the preset stage energy, the piezoelectric driver is charged with additional energy;

[0047] When the second stage energy does not exceed the preset stage energy, the piezoelectric driver is normally charged.

[0048] In order to solve the above problems, the present invention also provides a truck lithium battery vibration and impact active buffering protection system, the system comprising:

[0049] A vibration acceleration acquisition module is used to acquire the three-axis vibration acceleration of the lithium battery box in the truck, wherein the three-axis vibration acceleration includes vertical vibration acceleration, longitudinal vibration acceleration and lateral vibration acceleration;

[0050] a spectrum acquisition module, configured to perform Fourier transform on the vertical vibration acceleration to obtain a spectrum of the vertical vibration acceleration;

[0051] a high-frequency energy ratio calculation module, configured to calculate the high-frequency energy ratio of the spectrum based on the low-frequency energy of the spectrum and the high-frequency energy of the spectrum;

[0052] The judgment module is used to judge whether the high-frequency energy ratio exceeds a preset ratio threshold:

[0053] When the proportion of high-frequency energy does not exceed the preset proportion threshold, a state estimation value of the lithium battery box of the truck is generated based on the Kalman filter, an active damping force of the lithium battery box is calculated based on the state estimation value, a buffering force of the damper in the truck is generated based on the active damping force, and the buffering force is used to provide buffering protection for the lithium battery box of the truck;

[0054] When the proportion of the high-frequency energy exceeds the preset proportion threshold, the vertical vibration acceleration, the longitudinal vibration acceleration and the lateral vibration acceleration are synthesized into the equivalent vertical vibration acceleration of the lithium battery box. When the equivalent vertical vibration exceeds the preset vibration threshold, the reserve energy of the piezoelectric drive in the truck is used to buffer and protect the truck's lithium battery box.

[0055] Compared with the prior art, the present invention has the following beneficial effects:

[0056] 1. This invention achieves comprehensive vibration data collection by collecting the triaxial vibration acceleration of the truck's lithium battery box. This layout and technical principle ensures that complete triaxial vibration acceleration data can be obtained in real time while the truck is in motion, providing a sufficient data foundation for subsequent analysis and protection strategy formulation.

[0057] 2. The present invention analyzes vibration characteristics by performing a Fourier transform on the collected vertical vibration acceleration to understand the energy distribution of vertical vibration acceleration at different frequencies. Different strategies are adopted based on whether the high-frequency energy ratio exceeds a preset ratio threshold. When the high-frequency energy ratio does not exceed the ratio threshold, indicating that the low-frequency vibration component is dominant, a state estimate is generated based on the Kalman filter, and the active damping force and the damper buffering force are calculated. When the low frequency component is dominant, the damper can function relatively stably, continuously offsetting the energy brought by the low-frequency vibration, effectively suppressing the shaking and displacement of the housing. Moreover, when the damper is used during low-frequency vibration, the damper does not need to reserve a large amount of additional energy, avoiding unnecessary energy consumption. When the high-frequency energy ratio exceeds the ratio threshold, the three-axis vibration acceleration is synthesized into an equivalent vertical vibration acceleration. Depending on whether it exceeds the preset vibration threshold, the piezoelectric driver's reserved energy is used for buffering protection. The piezoelectric driver can release a large amount of energy in a short period of time, meeting the demand for strong buffering force under high-frequency vibration, better protecting the lithium battery housing, and providing reliable protection for lithium batteries in complex vibration environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 A schematic flow chart of a method for actively buffering and protecting truck lithium batteries from vibration and shock, provided by one embodiment of the present invention;

[0059] Figure 2 This is a functional module diagram of a truck lithium battery vibration and impact active buffering protection system provided by one embodiment of the present invention;

[0060] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0061] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0062] The embodiment of the present application provides a method for actively buffering and protecting truck lithium batteries from vibration and shock. The execution subject of the method for actively buffering and protecting truck lithium batteries from vibration and shock includes but is not limited to at least one of the electronic devices such as a server and a terminal that can be configured to execute the method provided by the embodiment of the present application. In other words, the method for actively buffering and protecting truck lithium batteries from vibration and shock can be executed by software or hardware installed on a terminal device or a server device. The server includes but is not limited to: a single server, a server cluster, a cloud server or a cloud server cluster, etc. The server can be an independent server, or it can be a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, content delivery networks (CDNs), and big data and artificial intelligence platforms.

[0063] Reference Figure 1 FIG. 1 is a flow chart of a method for actively buffering and protecting truck lithium batteries from vibration and shock according to an embodiment of the present invention. In this embodiment, the method for actively buffering and protecting truck lithium batteries from vibration and shock includes:

[0064] S1. Collecting triaxial vibration acceleration of a lithium battery box in a truck, wherein the triaxial vibration acceleration includes vertical vibration acceleration, longitudinal vibration acceleration, and lateral vibration acceleration;

[0065] In detail, a three-axis acceleration sensor is installed near the center of gravity of the lithium battery box in the truck or at the rigid connection part. The three-axis acceleration sensor can directly measure and output vertical vibration acceleration, longitudinal vibration acceleration and lateral vibration acceleration. The three-axis acceleration sensor uses the principles of piezoelectric effect, piezoresistive effect, etc. to convert the acceleration generated by vibration into an electrical signal for output.

[0066] Specifically, vertical vibration acceleration refers to the speed at which the lithium battery case changes in vertical velocity. When a truck travels over bumpy roads, such as speed bumps or potholes, it vibrates vertically, causing changes in vertical vibration acceleration and subjecting the lithium battery case to vertical forces.

[0067] Specifically, longitudinal vibration acceleration refers to the rate of change in the forward or reverse speed of the lithium battery box. Rapid acceleration, braking, or frequent starts and stops can produce significant longitudinal vibration acceleration, which can subject the lithium battery box to forward and backward forces. This can loosen battery connectors and affect the electrical connection between battery packs.

[0068] Specifically, lateral vibration acceleration indicates how quickly the lithium battery case's velocity changes perpendicular to the direction of travel. Transverse vibration acceleration is generated when a vehicle turns, avoids obstacles, or travels over uneven surfaces. This acceleration subjects the lithium battery case to left and right forces, potentially causing the batteries to shift or collide within the case, potentially damaging the battery casing or internal structure.

[0069] S2. Performing Fourier transform on the vertical vibration acceleration to obtain a frequency spectrum of the vertical vibration acceleration;

[0070] Specifically, when analyzing vertical vibration acceleration, it is necessary to preprocess the vertical vibration acceleration. This preprocessing involves using a high-pass filter to remove trend terms from the vertical vibration acceleration, which helps eliminate low-frequency drift or long-term trends in the signal and focus the signal on high-frequency vibration characteristics. Preprocessing also involves windowing the vertical vibration acceleration using a Hanning window function. This reduces spectral leakage caused by signal truncation and improves the accuracy of spectral analysis. After preprocessing, a fast Fourier transform (FFT) is performed on each segment of vertical vibration acceleration to convert the time domain signal into a frequency domain complex sequence, achieving signal feature conversion from the time dimension to the frequency dimension. The resulting frequency domain complex sequence is then modulo-squared to obtain the signal power value at each frequency point. This is then normalized to obtain the power spectral density (PSD). As a form of spectrum, the power spectral density (PSD) accurately characterizes the distribution of signal energy in the frequency domain, providing strong data support for subsequent frequency-based analysis and research.

[0071] Specifically, the main purpose of step S2 is to analyze vibration characteristics and provide a key basis for subsequent buffer protection decisions. The spectrum can be used to understand the energy distribution of vertical vibration acceleration at different frequencies and calculate the high-frequency energy proportion of the spectrum. Depending on whether the high-frequency energy proportion exceeds the preset proportion threshold, different buffer protection strategies can be adopted.

[0072] S3. Calculating a high-frequency energy ratio of the spectrum based on the low-frequency energy of the spectrum and the high-frequency energy of the spectrum;

[0073] In the embodiment of the present invention, the calculating the high-frequency energy ratio of the spectrum based on the low-frequency energy of the spectrum and the high-frequency energy of the spectrum includes:

[0074] Performing low-frequency domain integration calculation on the spectrum to obtain the low-frequency energy;

[0075] The calculation formula of the low-frequency energy is as follows:

[0076]

[0077] Where, E low represents the low-frequency energy, PSD(f)df represents the power spectral density function;

[0078] Performing high-frequency domain integral calculation on the spectrum to obtain the high-frequency energy;

[0079] The calculation formula of the high frequency energy is as follows:

[0080]

[0081] Where, E high represents the high frequency energy, PSD(f)df represents the power spectral density function;

[0082] The ratio of the low-frequency energy to the high-frequency energy is calculated to obtain the high-frequency energy ratio, wherein the calculation formula for the high-frequency energy ratio is as follows:

[0083]

[0084] Where, P represents the proportion of high frequency energy, E high Represents the high frequency energy, E low Represents the low-frequency energy.

[0085] Specifically, in vibration analysis, low-frequency energy and high-frequency energy are defined based on the energy distribution in different frequency ranges of the spectrum. Low-frequency energy is the energy value obtained by integrating the spectrum in the low-frequency domain. It reflects the energy carried by the low-frequency vibration component. Similarly, high-frequency energy is the result of integrating the spectrum in the high-frequency domain. It represents the energy contained in the high-frequency vibration component.

[0086] In detail, the proportion of high-frequency energy in the spectrum is calculated. The main purpose is to determine the vibration characteristics of the truck's lithium battery box during driving, and provide a decision-making basis for the buffering protection of the lithium battery box. When the high-frequency energy proportion does not exceed the preset proportion threshold, it indicates that the low-frequency vibration component is dominant. The active damping force is calculated based on the Kalman filter, and the damper is used to buffer and protect the lithium battery box. If the high-frequency energy proportion exceeds the preset threshold, it means that the high-frequency vibration component is prominent. The three-axis vibration acceleration is synthesized into an equivalent vertical vibration acceleration. When the equivalent vertical vibration exceeds the preset threshold, the piezoelectric driver is used to reserve energy to protect the lithium battery box.

[0087] S4. Determine whether the high-frequency energy ratio exceeds a preset ratio threshold:

[0088] When the high-frequency energy proportion does not exceed the preset proportion threshold, generating a state estimation value of the lithium battery box based on Kalman filtering;

[0089] Specifically, the researchers established a theoretical model of truck lithium battery box vibration, simulating vibrations under various road conditions and driving speeds. Using mechanical vibration theory and dynamic equations, they analyzed the distribution of high-frequency and low-frequency energy within the vertical vibration acceleration spectrum. In an ideal, simple vibration model, assuming a truck traveling at a typical speed on a smooth but slightly bumpy road, multiple simulations revealed that when the proportion of high-frequency energy exceeds 50%, the vibration characteristics change significantly, with low-frequency vibrations gradually becoming dominant, followed by high-frequency vibrations. To account for the discrepancy between the simplified model and actual conditions, the threshold for this proportion was set at 40%.

[0090] In detail, Kalman filtering is an algorithm that uses linear system state equations and system input and output observation data to optimally estimate the system state. The specific implementation steps for generating the state estimation value of the lithium battery box based on Kalman filtering are as follows: first, a dynamic model with the vertical displacement, velocity and acceleration of the lithium battery box as state variables is constructed, and the vertical vibration acceleration measured by the three-axis acceleration sensor is used as the observation input. Through real-time iteration of the time update step (predicting the state based on Newton's kinematic equations) and the measurement update step (correcting the prediction by fusing sensor data), the Kalman gain matrix is dynamically calculated to optimally weight the predicted value and the measured data, and finally a high-precision vertical displacement estimation value and a vertical velocity estimation value are output, and the vertical displacement estimation value and the vertical velocity estimation value are combined into the state estimation value of the lithium battery box.

[0091] In detail, the time update step is based on Newton's kinematic equations, and the state estimate at the previous moment is used to predict the prior estimate of the state at the current moment; the measurement update step is to fuse the vertical vibration acceleration measured by the three-axis accelerometer with the predicted value, dynamically calculate the Kalman gain matrix, and correct the predicted value in an optimal weighted manner to obtain the posterior estimate of the state at the current moment.

[0092] Calculating an active damping force of the lithium battery box based on the state estimation value, generating a buffering force of the damper in the truck based on the active damping force, and utilizing the buffering force to provide buffering protection for the lithium battery box of the truck;

[0093] In an embodiment of the present invention, it is characterized in that the calculation formula of the active damping force is as follows:

[0094]

[0095] Where, F damp represents the active damping force, K p represents the displacement feedback gain, represents the vertical displacement estimate in the state estimate, K d represents the speed feedback gain, Indicates the vertical velocity estimate value in the state estimate value.

[0096] In detail, the calculation formula of the active damping force is essentially the classical control force of the second-order vibration system. Indicates the elastic force, which "pulls back" the lithium battery box that deviates from the equilibrium position. Represents the damping force, which is used to consume vibration energy and suppress oscillation. p Indicates the sensitivity to position offset, which is essentially a virtual spring stiffness. Its basic value is usually 1.2 to 1.5 times the natural frequency of the lithium battery box. d It represents the intensity of the suppression of the movement speed, which is essentially the virtual damper coefficient.

[0097] In an embodiment of the present invention, it is characterized in that generating the buffering force of the damper in the truck based on the active damping force includes:

[0098] The target current of the damper is calculated based on the active damping force, wherein the calculation formula of the target current is as follows:

[0099]

[0100] Where, I represents the target current, F damp represents the active damping force, c min represents the basic damping coefficient of the damper, v z represents the piston movement speed of the damper, k i represents the current-damping gain;

[0101] In detail, c min The basic damping coefficient of the damper reflects the basic damping characteristics of the damper itself that are independent of current control and is an inherent parameter of the damper. i It indicates the change in damping force caused by a unit current change, and is a coefficient that describes the conversion relationship between current and damping force. The damper itself has a basic damping force, which is determined by c min ·v z This part of the basic damping force is naturally generated by the damper and needs to be subtracted from the active damping force to obtain the damping force generated only by current control. The remaining damping force after deducting the basic damping force is divided by k i , the target current required for buffering force can be obtained.

[0102] The buffering force of the damper in the truck is calculated based on the target current, wherein the calculation formula of the buffering force is as follows:

[0103] F buffer =(c min +k i ·I)·vz

[0104] Where, I represents the target current, F buffer represents the buffer force, c min represents the basic damping coefficient of the damper, v z represents the piston movement speed of the damper, k i represents the current-damping gain.

[0105] In detail, the calculation formula of the buffer force is constructed based on the working principle of the damper. The buffer force generated by the damper consists of two parts. One part is the basic damping force, which is composed of c min ·v z The other part is the damping force generated by the target current control, and the two parts of the damping force are added together (c min +k i I), then multiplied by the piston speed v z , we get the final buffering force generated by the damper. The buffering force is opposite to the vibration direction of the lithium battery box. Finally, the buffering force is applied to the lithium battery box through the movement of the piston, realizing dynamic offset of the impact energy and ensuring that the displacement and acceleration of the lithium battery box are always within the safety threshold.

[0106] In general: when the proportion of high-frequency energy does not exceed the threshold, it indicates that the vibration is mainly composed of low-frequency components. The state estimation value generated based on the Kalman filter can utilize its filtering characteristics to effectively eliminate sensor noise interference and accurately obtain state information such as the vertical displacement and speed of the lithium battery box. The buffering force generated by the damper is adapted to the actual vibration state of the lithium battery box, avoiding insufficient or excessive buffering, ensuring the stable operation of the lithium battery box in a low-frequency vibration environment, and extending its service life.

[0107] When the proportion of the high-frequency energy exceeds the preset proportion threshold, the vertical vibration acceleration, the longitudinal vibration acceleration and the lateral vibration acceleration are synthesized into the equivalent vertical vibration acceleration of the lithium battery box. When the equivalent vertical vibration exceeds the preset vibration threshold, the reserve energy of the piezoelectric drive in the truck is used to buffer and protect the truck's lithium battery box.

[0108] In an embodiment of the present invention, it is characterized in that the calculation formula of the equivalent vertical vibration acceleration is as follows:

[0109]

[0110] Where, Denotes the equivalent vertical vibration acceleration, a z represents the vertical vibration acceleration, a x represents the longitudinal vibration acceleration, a1 represents the longitudinal coupling coefficient, a yrepresents the lateral vibration acceleration, and a2 represents the lateral coupling coefficient.

[0111] Specifically, the lithium battery case is considered a multi-degree-of-freedom vibration system. Based on Newton's laws of motion and vibration theory, the interaction between vibration accelerations in different directions is considered, and the coupling coefficient is determined by deriving the system's motion equations. Assuming a certain correlation between the vertical, longitudinal, and lateral vibration equations of the case, mathematical derivation is used to derive the coefficient expressions for the influence of longitudinal and lateral vibrations on vertical vibration, thereby determining a1 and a2. The range of a1 and a2 values will be affected by various factors, including the lithium battery case structure, installation method, and truck driving conditions. If the truck lithium battery case structure is designed so that longitudinal or lateral vibration has minimal effect on vertical vibration, or if good vibration isolation measures are installed to weaken the transmission of vibration between directions, a1 and a2 will approach 0. If the case structure is rigid, and the longitudinal, lateral, and vertical vibrations are strongly correlated, vibrations are easily transmitted to each other, and a1 and a2 will approach 1.

[0112] Specifically, when a truck is driving, the vibrations to which the lithium battery box is subjected are not solely vertical. Longitudinal and lateral vibrations also affect the box's vertical vibrations, as the truck's mechanical structure is not completely rigid and there are elastic connections between the various components. When longitudinal vibrations occur, the elastic deformation and displacement transmission of the structure can cause deformation or displacement of the components connected to the lithium battery box. For example, if the frame bends or twists under longitudinal vibration, this deformation can be transmitted to the lithium battery box through the supporting structure, causing the box to generate additional vibrations in the vertical direction. z +a1·a x +a2·a y It can comprehensively consider the interaction of vibrations in three directions. This combination is to quantify and superimpose the effects of vibrations in different directions on the vertical direction, thereby obtaining an equivalent vertical vibration acceleration that can fully reflect the comprehensive vibration situation in the vertical direction. Based on this equivalent value, the vibration state of the lithium battery box can be judged more accurately, so that when it exceeds the preset threshold, the piezoelectric driver's reserved energy can be reasonably used for buffering protection.

[0113] In detail, when the equivalent vertical vibration acceleration is monitored When the preset vibration threshold is exceeded, the energy release mechanism of the piezoelectric driver is triggered, and the energy previously stored in the piezoelectric driver begins to be converted into mechanical force. This mechanical force is transmitted to the lithium battery box through the buffer structure connected to the lithium battery box (such as elastic brackets, connectors, etc.). The direction of the mechanical force is opposite to the vibration direction of the box, offsetting or weakening the vibration energy of the lithium battery box, suppressing the vibration amplitude of the box, and reducing the adverse effects of vibration on the internal structure of the lithium battery box and battery performance, thereby achieving buffering protection for the truck's lithium battery box.

[0114] In general: when the proportion of high-frequency energy exceeds the threshold, it means that the vibration is mainly composed of high-frequency components. At this time, only focusing on vertical vibration is not comprehensive. By synthesizing the equivalent vertical vibration acceleration, the coupling effects of longitudinal and lateral vibrations on the vertical direction are comprehensively considered, which can accurately capture the true vibration state of the lithium battery box in a complex high-frequency vibration environment, and provide a more accurate basis for buffering protection; because the piezoelectric driver has limited reserve energy, it decides whether to enable it by judging whether the equivalent vertical vibration acceleration exceeds the preset threshold, avoiding unnecessary energy consumption. The energy buffer is only released when the vibration intensity is sufficient to threaten the safety of the lithium battery box, ensuring that the energy is used in key places and improving energy utilization efficiency; according to the high-frequency vibration characteristics and the equivalent vertical vibration acceleration, the piezoelectric driver reserve energy buffer is used in a targeted manner. Compared with a single strategy, this method can better cope with high-frequency vibration scenarios, provide more adaptive and effective protection for the lithium battery box, reduce the risk of damage to the lithium battery box due to vibration, and ensure its stability and service life.

[0115] In an embodiment of the present invention, it is characterized in that the steps of generating the reserve energy of the piezoelectric driver are as follows:

[0116] Get the impact point and average height of the current section in the truck;

[0117] In detail, the current road section refers to the section of road on which the truck is traveling; the impact point refers to the location on the current road section where the truck may be subjected to greater impact force during driving, such as potholes, bumps and speed bumps on the road. The truck will be impacted when passing by, and these locations are the impact points; the average height refers to the average vertical height of the road surface of the current road section relative to a certain reference plane (road design elevation plane). Road surfaces at different heights have different geological conditions, slopes, etc., which in turn affect the vibration of the truck during driving and the stress condition of the lithium battery box.

[0118] In detail, the distance information of the truck's driving section is pre-marked on the high-precision map. The distance information includes the locations of possible impact points such as potholes and speed bumps, as well as the road design elevation surface data of each section of the road. The real-time position of the truck is obtained through the truck's built-in navigation system and matched with the map data to obtain the impact point and average height information of the current section.

[0119] Calculating the height difference between the impact point and the average height;

[0120] Specifically, after obtaining the data on the truck's impact point on the current road section and the average height data of the current road section, the height of the road surface at the impact point relative to the reference plane (road design elevation plane) is subtracted from the average height of the current road section. The difference obtained is the height difference between the impact point and the average height. This height difference can reflect the degree of deviation between the impact point and the average height of the current road section. If the height difference is positive, it indicates that the impact point is higher than the average height, which may be a bump; if it is negative, the impact point is lower than the average height, which may be a pothole. The greater the height difference, the more severe the impact of bumps and vibrations on the vehicle when passing the impact point, and the greater the impact force on the lithium battery box. By calculating and paying attention to this height difference, it can provide a key basis for subsequent predictions of the energy required to be stored by the piezoelectric actuator and judgment of the risk of impact on the lithium battery box.

[0121] When the travel distance between the truck and the impact point reaches a preset distance value, calculating the predicted energy of the piezoelectric actuator based on the travel distance, the height difference, and the travel speed of the truck;

[0122] In an embodiment of the present invention, it is characterized in that the calculation formula of the predicted energy is as follows:

[0123]

[0124] Where, E represents the predicted energy, d represents the driving distance, and v k represents the driving speed, represents the equivalent vertical vibration acceleration, g represents the acceleration due to gravity, h avg represents the average height, Δh represents the height difference, k p represents the correction factor of the piezoelectric actuator.

[0125] In detail, the technical specifications of the piezoelectric actuator, such as material type (piezoelectric ceramic, piezoelectric polymer or other new materials), structural design (size, shape, number of layers, etc.), and expected application scenarios, are submitted to technical experts in this field. The experts analyze how these factors affect the performance of the piezoelectric actuator based on their research results or actual project experience, and then provide k p The recommended value of

[0126] In detail, It reflects the impact of driving distance and speed on predicted energy. The longer the distance and the faster the speed, the greater the energy demand may be. The equivalent vertical vibration acceleration combines the effects of vertical, longitudinal and lateral vibrations on the vertical direction. It is a key indicator for measuring the actual vibration intensity of the lithium battery box at the impact point. Dividing it by the acceleration of gravity is to normalize the vibration acceleration and highlight its relative size.

[0127] Specifically, the greater the vibration acceleration, the more severe the impact on the box, and the piezoelectric driver needs to provide more energy to offset the impact. This term is used to quantify the effect of vibration intensity on energy demand.

[0128] In detail, It means that based on benchmark 1, the energy demand is increased according to the relative size of the height difference. That is, the larger the height difference relative to the average height, the more energy the piezoelectric driver needs to reserve to cope with the impact. Piezoelectric drivers themselves have various characteristics, such as different energy conversion efficiency and aging degree during use. The correction factor k p It is used to adjust and correct the previously calculated energy value according to the actual characteristics of the piezoelectric driver, so that the final predicted energy is more in line with the actual energy demand of the piezoelectric driver in actual work.

[0129] Overall, by combining these factors, we comprehensively consider multiple aspects such as the truck's driving state, the vibration characteristics of the impact point, and the characteristics of the piezoelectric actuator itself, thereby reasonably calculating the predicted energy required by the piezoelectric actuator when the truck passes the impact point.

[0130] The piezoelectric drive in the truck is charged in stages based on the predicted energy until the reserve energy in the piezoelectric drive reaches the predicted energy, wherein the stage charging includes a first charging stage and a second charging stage.

[0131] In an embodiment of the present invention, it is characterized in that the steps of the first charging stage are as follows:

[0132] collecting the temperature of the piezoelectric actuator in real time;

[0133] Determining whether the temperature exceeds a reference temperature of the piezoelectric driver:

[0134] When the temperature does not exceed the reference temperature of the piezoelectric driver, performing conventional charging on the piezoelectric driver;

[0135] When the temperature exceeds a reference temperature of the piezoelectric driver, the piezoelectric driver is charged at a reduced capacity.

[0136] In detail, the first charging stage is the preliminary link for stage-by-stage charging of the truck's piezoelectric drive based on the predicted energy. The main purpose is to charge it safely and effectively under the premise of considering the temperature state of the piezoelectric drive, so that its reserve energy approaches the predicted energy. In the first charging stage, the temperature of the piezoelectric drive is continuously and dynamically obtained through temperature sensors and other equipment. Because the temperature has a significant impact on the performance and safety of the piezoelectric drive, excessively high temperature may reduce its efficiency and even damage the device, so real-time temperature monitoring is the basis for subsequent charging strategy adjustments; afterward, the collected temperature is compared with the pre-set reference temperature for judgment. The reference temperature is a comprehensive consideration of factors such as the material properties and working performance of the piezoelectric drive. It is certain that the piezoelectric driver can work well within this temperature range; when the temperature does not exceed the reference temperature, it indicates that the piezoelectric driver is in a relatively safe and stable operating temperature range. At this time, conventional charging is adopted. Conventional charging is generally operated according to standard charging current, voltage and other parameters, which can ensure that the piezoelectric driver stores energy stably and efficiently, so that it gradually approaches the predicted energy value; if the real-time temperature exceeds the reference temperature, it means that the operating temperature of the piezoelectric driver is too high, and continuing conventional charging may bring risks. Derating charging means reducing the charging power, current and other parameters to reduce the heat generated during the charging process, avoid further temperature increase, and slowly increase its reserve energy while ensuring the safety of the piezoelectric driver.

[0137] In an embodiment of the present invention, the steps of the second charging stage are as follows:

[0138] After the first energy charging stage is completed, obtaining the first stage energy of the piezoelectric driver;

[0139] Calculating the difference between the first-stage energy and the predicted energy to obtain the second-stage energy of the piezoelectric actuator;

[0140] Determine whether the second stage energy exceeds the preset stage energy:

[0141] When the second stage energy exceeds the preset stage energy, the piezoelectric driver is charged with additional energy;

[0142] When the second stage energy does not exceed the preset stage energy, the piezoelectric driver is normally charged.

[0143] Specifically, the preset stage energy is derived based on expert rules. Based on the key factors identified by experts as influencing the preset stage energy, such as the type of piezoelectric actuator and the structure and quality of the lithium battery housing, these key influencing factors are categorized and quantified. For example, the energy conversion efficiency of piezoelectric actuators is classified into three levels: high, medium, and low. Truck driving conditions are also categorized into smooth roads, moderately bumpy roads, and severely bumpy roads. Based on these factors, for piezoelectric actuators with high energy conversion efficiency, the preset stage energy is 40% of the total energy requirement when driving on smooth roads. For piezoelectric actuators with low energy conversion efficiency, the preset stage energy is 60% of the total energy requirement when driving on severely bumpy roads.

[0144] Specifically, the second charging phase is a process that, after the first charging phase, further increases the piezoelectric driver's stored energy to the predicted energy. The specific steps are as follows: After the first charging phase, the piezoelectric driver's stored energy at the end of the first charging phase is obtained through monitoring equipment, i.e., the first-phase energy. The difference between the obtained first-phase energy and the previously calculated predicted energy is calculated. The predicted energy is determined based on truck driving parameters, and the final energy value required for the piezoelectric driver to store is the difference between the two, i.e., the energy required to be replenished in the second phase. If the calculated second-phase energy exceeds the preset stage energy, it means that the piezoelectric driver is significantly short of the target reserve energy. In this case, incremental charging is used, i.e., appropriately increasing charging parameters such as power and current to accelerate energy replenishment, so that the piezoelectric driver can reach the predicted energy level as quickly as possible and meet the subsequent buffer protection requirements of the lithium battery box. If the second-phase energy does not exceed the preset stage energy, it indicates that the piezoelectric driver's stored energy is relatively good and the difference from the predicted energy is small. Conventional charging is then continued, operating according to standard charging parameters, to steadily replenish the remaining energy and ensure that the piezoelectric driver safely and stably reaches the predicted energy level.

[0145] In general: the first charging stage adjusts the charging method according to the temperature, and conventional charging is performed when the temperature is normal to ensure charging efficiency; the second charging stage is based on the energy situation after the end of the first charging stage. When the energy difference is large, incremental charging is performed to quickly replenish energy, and when the energy difference is small, conventional charging is performed to smoothly replenish energy, making the entire charging process efficient and reasonable. By gradually charging in two charging stages, the piezoelectric driver's stored energy can be more accurately made to reach the predicted energy, meeting the energy requirements for the buffer protection of the lithium battery box, avoiding insufficient or excessive energy reserves, and improving energy utilization efficiency.

[0146] like Figure 2 1 is a functional module diagram of a truck lithium battery vibration and impact active buffering protection system provided by one embodiment of the present invention.

[0147] The truck lithium battery active vibration and shock buffering protection system 100 described in the present invention can be installed in an electronic device. Depending on the functionality to be implemented, the truck lithium battery active vibration and shock buffering protection system 100 may include a vibration acceleration acquisition module 101, a spectrum acquisition module 102, a high-frequency energy ratio calculation module 103, and a judgment module 104. A module, also referred to as a unit, is a series of computer program segments that can be executed by an electronic device processor and perform a fixed function. These are stored in the electronic device's memory.

[0148] In this embodiment, the functions of each module / unit are as follows:

[0149] A vibration acceleration acquisition module is used to acquire the three-axis vibration acceleration of the lithium battery box in the truck, wherein the three-axis vibration acceleration includes vertical vibration acceleration, longitudinal vibration acceleration and lateral vibration acceleration;

[0150] a spectrum acquisition module, configured to perform Fourier transform on the vertical vibration acceleration to obtain a spectrum of the vertical vibration acceleration;

[0151] a high-frequency energy ratio calculation module, configured to calculate the high-frequency energy ratio of the spectrum based on the low-frequency energy of the spectrum and the high-frequency energy of the spectrum;

[0152] The judgment module is used to judge whether the high-frequency energy ratio exceeds a preset ratio threshold:

[0153] When the proportion of high-frequency energy does not exceed the preset proportion threshold, a state estimation value of the lithium battery box of the truck is generated based on the Kalman filter, an active damping force of the lithium battery box is calculated based on the state estimation value, a buffering force of the damper in the truck is generated based on the active damping force, and the buffering force is used to provide buffering protection for the lithium battery box of the truck;

[0154] When the proportion of the high-frequency energy exceeds the preset proportion threshold, the vertical vibration acceleration, the longitudinal vibration acceleration and the lateral vibration acceleration are synthesized into the equivalent vertical vibration acceleration of the lithium battery box. When the equivalent vertical vibration exceeds the preset vibration threshold, the reserve energy of the piezoelectric drive in the truck is used to buffer and protect the truck's lithium battery box.

[0155] In the several embodiments provided by the present invention, it should be understood that the disclosed methods and systems can be implemented in other ways. For example, the system embodiments described above are merely illustrative. For example, the module division is merely a logical function division, and other division methods may be used in actual implementation.

[0156] The modules described as separate components may or may not be physically separate, and the components shown as modules may or may not be physical units, that is, they may be located in one place or distributed across multiple network elements. Some or all of the modules may be selected to achieve the purpose of the solution of this embodiment according to actual needs.

[0157] In addition, the functional modules in various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or hardware plus software functional modules.

[0158] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0159] The embodiments of the present application can acquire and process relevant data based on artificial intelligence technology. Artificial intelligence refers to the theories, methods, technologies, and application systems that use digital computers or machines controlled by digital computers to simulate, extend, and expand human intelligence, perceive the environment, acquire knowledge, and use knowledge to achieve optimal results.

[0160] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A truck lithium battery vibration impact active buffering protection method, characterized in that: The method comprises: S1. Collecting triaxial vibration acceleration of a lithium battery box in a truck, wherein the triaxial vibration acceleration includes vertical vibration acceleration, longitudinal vibration acceleration, and lateral vibration acceleration; S2. Performing Fourier transform on the vertical vibration acceleration to obtain a frequency spectrum of the vertical vibration acceleration; S3. Calculating a high-frequency energy ratio of the spectrum based on the low-frequency energy of the spectrum and the high-frequency energy of the spectrum; S4. Determine whether the high-frequency energy ratio exceeds a preset ratio threshold: When the high-frequency energy proportion does not exceed the preset proportion threshold, a state estimation value of the lithium battery box is generated based on the Kalman filter, an active damping force of the lithium battery box is calculated based on the state estimation value, a buffering force of the damper in the truck is generated based on the active damping force, and the buffering force is used to provide buffering protection for the lithium battery box of the truck; When the proportion of the high-frequency energy exceeds the preset proportion threshold, the vertical vibration acceleration, the longitudinal vibration acceleration and the lateral vibration acceleration are synthesized into the equivalent vertical vibration acceleration of the lithium battery box. When the equivalent vertical vibration exceeds the preset vibration threshold, the reserve energy of the piezoelectric drive in the truck is used to buffer and protect the truck's lithium battery box.

2. The truck lithium battery vibration impact active buffering protection method according to claim 1, characterized in that: The calculating the high-frequency energy proportion of the spectrum based on the low-frequency energy of the spectrum and the high-frequency energy of the spectrum includes: Performing low-frequency domain integration calculation on the spectrum to obtain the low-frequency energy; Performing high-frequency domain integral calculation on the spectrum to obtain the high-frequency energy; A ratio of the low-frequency energy to the high-frequency energy is calculated to obtain the high-frequency energy ratio.

3. The truck lithium battery vibration and impact active buffering protection method according to claim 1, characterized in that: The calculation formula of the active damping force is as follows: Where, F damp represents the active damping force, K p represents the displacement feedback gain, represents the vertical displacement estimate in the state estimate, K d represents the speed feedback gain, Indicates the vertical velocity estimate value in the state estimate value.

4. The truck lithium battery vibration and impact active buffering protection method according to claim 1, characterized in that: Generating a buffering force of a damper in the truck based on the active damping force includes: The target current of the damper is calculated based on the active damping force, wherein the calculation formula of the target current is as follows: Where, I represents the target current, F damp represents the active damping force, c min represents the basic damping coefficient of the damper, v z represents the piston movement speed of the damper, k i represents the current-damping gain; The buffering force of the damper in the truck is calculated based on the target current, wherein the calculation formula of the buffering force is as follows: F buffer =(c min +k i ·I)·v z Where, I represents the target current, F buffer represents the buffer force, c min represents the basic damping coefficient of the damper, v z represents the piston movement speed of the damper, k i represents the current-damping gain.

5. The truck lithium battery vibration and impact active buffering protection method according to claim 1, characterized in that: The calculation formula of the equivalent vertical vibration acceleration is as follows: Where, Denotes the equivalent vertical vibration acceleration, a z represents the vertical vibration acceleration, a x represents the longitudinal vibration acceleration, a1 represents the longitudinal coupling coefficient, a y represents the lateral vibration acceleration, and a2 represents the lateral coupling coefficient.

6. The truck lithium battery vibration and impact active buffering protection method according to claim 1, characterized in that: The steps for generating the stored energy of the piezoelectric actuator are as follows: Get the impact point and average height of the current section in the truck; Calculating the height difference between the impact point and the average height; When the travel distance between the truck and the impact point reaches a preset distance value, calculating the predicted energy of the piezoelectric actuator based on the travel distance, the height difference, and the travel speed of the truck; The piezoelectric drive in the truck is charged in stages based on the predicted energy until the reserve energy in the piezoelectric drive reaches the predicted energy, wherein the stage charging includes a first charging stage and a second charging stage.

7. The truck lithium battery vibration and impact active buffering protection method according to claim 6, characterized in that: The calculation formula of the predicted energy is as follows: Where, E represents the predicted energy, d represents the driving distance, and v k represents the driving speed, represents the equivalent vertical vibration acceleration, g represents the acceleration due to gravity, h avg represents the average height, Δh represents the height difference, k p represents the correction factor of the piezoelectric actuator.

8. The truck lithium battery vibration and impact active buffering protection method according to claim 6, characterized in that: The steps of the first charging stage are as follows: collecting the temperature of the piezoelectric actuator in real time; Determining whether the temperature exceeds a reference temperature of the piezoelectric driver: When the temperature does not exceed the reference temperature of the piezoelectric driver, performing conventional charging on the piezoelectric driver; When the temperature exceeds a reference temperature of the piezoelectric driver, the piezoelectric driver is charged at a reduced capacity.

9. The truck lithium battery vibration and impact active buffering protection method according to claim 8, characterized in that: The steps of the second charging stage are as follows: After the first energy charging stage is completed, obtaining the first stage energy of the piezoelectric driver; Calculating the difference between the first-stage energy and the predicted energy to obtain the second-stage energy of the piezoelectric actuator; Determine whether the second stage energy exceeds the preset stage energy: When the second stage energy exceeds the preset stage energy, the piezoelectric driver is charged with additional energy; When the second stage energy does not exceed the preset stage energy, the piezoelectric driver is normally charged.

10. A truck lithium battery vibration impact active buffer protection system, characterized in that: The system comprises: A vibration acceleration acquisition module is used to acquire the three-axis vibration acceleration of the lithium battery box in the truck, wherein the three-axis vibration acceleration includes vertical vibration acceleration, longitudinal vibration acceleration and lateral vibration acceleration; a spectrum acquisition module, configured to perform Fourier transform on the vertical vibration acceleration to obtain a spectrum of the vertical vibration acceleration; a high-frequency energy ratio calculation module, configured to calculate the high-frequency energy ratio of the spectrum based on the low-frequency energy of the spectrum and the high-frequency energy of the spectrum; The judgment module is used to judge whether the high-frequency energy ratio exceeds a preset ratio threshold: When the proportion of high-frequency energy does not exceed the preset proportion threshold, a state estimation value of the lithium battery box of the truck is generated based on the Kalman filter, an active damping force of the lithium battery box is calculated based on the state estimation value, a buffering force of the damper in the truck is generated based on the active damping force, and the buffering force is used to provide buffering protection for the lithium battery box of the truck; When the proportion of the high-frequency energy exceeds the preset proportion threshold, the vertical vibration acceleration, the longitudinal vibration acceleration and the lateral vibration acceleration are synthesized into the equivalent vertical vibration acceleration of the lithium battery box. When the equivalent vertical vibration exceeds the preset vibration threshold, the reserve energy of the piezoelectric drive in the truck is used to buffer and protect the truck's lithium battery box.

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