Automobile bumper parameter determination method and device, and storage medium

Abstract

The application discloses a kind of automobile bumper parameter determination method, device and storage medium, the method comprises: the curvature radius range and radar size of vehicle bumper are determined;According to the simulation test of the radar angle measurement accuracy in a plurality of curvature radii of curvature radius range, and according to the simulation result, the curve change relationship between curvature radius and angle measurement accuracy is determined;According to the minimum available radius corresponding to radar size determined by curve change relationship, and according to the minimum curvature radius of bumper under different radar size calculated by radar-bumper included angle corresponding to minimum available radius.The technical scheme provided in the application can solve the technical problems of high cost and low precision in the prior art that require experimental methods to obtain bumper size.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and in particular to a method, apparatus and storage medium for determining automobile bumper parameters. Background Technology

[0002] In the automotive field, Advanced Driving Assistance Systems (ADAS) are a fundamental feature of autonomous driving, requiring devices such as millimeter-wave radar, cameras, and lidar sensors to function. Among these, millimeter-wave radar sensors have become one of the mainstream sensors due to their moderate cost, strong environmental adaptability, and good long-range detection capabilities.

[0003] Millimeter-wave radars are categorized into forward-facing radars and corner radars based on their performance. Forward-facing radars are installed in the center front of the vehicle, offering a longer detection range and capable of detecting vehicles in front of the car; they are often installed behind the vehicle's emblem or grille. Corner radars have a wider detection angle, capable of detecting vehicles or obstacles on the left and right sides of the vehicle, and are installed at the four corners of the car. When installing corner radars, considering the appearance and impact of the car bumper, the main installation methods are currently the low-ground placement under the bumper and the bumper-window placement. However, the low-ground placement under the bumper has the disadvantage of the radar sensor being too close to the ground, reducing radar performance; the bumper-window placement exposes the radar, affecting the vehicle's aesthetics and the radar's environmental adaptability. According to actual measurements, the bumper does affect radar performance. For example, near the 77GHz frequency band where millimeter-wave radars operate, the reflection energy of electromagnetic waves perpendicularly incident on certain bumpers can reach up to 35%. At this point, the bumper causes significant transmission attenuation and reflection of the electromagnetic waves emitted by the 77GHz automotive millimeter-wave radar, resulting in a reduced detection range. Furthermore, excessive reflection of electromagnetic waves can cause radar to generate false targets, or even lead to system saturation and radar failure to detect targets.

[0004] The design and material selection of bumpers not only require harmony with the vehicle's styling, lightweight construction, and impact resistance, but also, if a rear radar device is to be added, its electromagnetic performance must be considered. Currently, in the automotive design process, to select a suitable bumper for use with millimeter-wave radar, it is usually necessary to first manufacture a physical bumper, then assemble the millimeter-wave radar onto the bumper, and conduct physical testing. If the experimental results are unsatisfactory, the bumper needs to be modified. Typically, numerous and repeated experiments are required to obtain a bumper structure that meets design requirements. This process is costly, cumbersome, and difficult to determine an accurate bumper structure, making it unsuitable for widespread adoption. Summary of the Invention

[0005] This invention provides a method, device, and storage medium for determining automobile bumper parameters, aiming to effectively solve the technical problems of high cost and low accuracy in the prior art, which requires experimental methods to obtain bumper dimensions.

[0006] According to one aspect of the present invention, a method for determining automobile bumper parameters is provided, the method comprising:

[0007] Determine the range of the vehicle bumper's radius of curvature and the radar size;

[0008] The radar angle measurement accuracy is simulated and tested based on multiple radii of curvature within the range of the stated radius of curvature, and the curve relationship between the radius of curvature and the angle measurement accuracy is determined based on the simulation results.

[0009] The minimum usable radius corresponding to the radar size is determined based on the curve variation relationship, and the minimum radius of curvature of the bumper under different radar sizes is calculated based on the radar-bumper angle corresponding to the minimum usable radius.

[0010] Furthermore, the simulation test of radar angle measurement accuracy based on multiple radii of curvature within the curvature radius range includes:

[0011] The minimum and maximum threshold values ​​of the radius of curvature are determined based on the radius of curvature range, and the step size for adjusting the radius of curvature is determined.

[0012] Determine the current radius of curvature to be the minimum threshold, and perform the following loop operation:

[0013] (1) The radar sends a pulse signal to the test target and receives the echo signal returned by the test target;

[0014] (2) Calculate the test azimuth angle of the test target based on the pulse signal and the echo signal;

[0015] (3) Increase the current radius of curvature by the step amount to obtain the updated current radius of curvature, and determine whether the updated current radius of curvature is greater than the maximum threshold; if the updated current radius of curvature is not greater than the maximum threshold, return to step (1); if the updated current radius of curvature is greater than the maximum threshold, terminate the loop.

[0016] Furthermore, determining the curve relationship between the radius of curvature and the angular measurement accuracy based on the simulation results includes:

[0017] Obtain the true azimuth angle of the test target;

[0018] Calculate the angle difference between the true azimuth and the test azimuth to obtain the azimuth error corresponding to the current radius of curvature;

[0019] Curve fitting is performed on multiple radii of curvature and their corresponding azimuth errors to obtain the curve variation relationship.

[0020] Furthermore, determining the minimum usable radius corresponding to the radar size based on the curve variation relationship includes:

[0021] When the azimuth error is less than a preset error threshold, the minimum value of the current radius of curvature is obtained as the minimum usable radius.

[0022] Furthermore, the step of calculating the minimum radius of curvature of the bumper under different radar sizes based on the radar-bumper angle corresponding to the minimum usable radius includes:

[0023] Construct the geometric relationship between the radar-bumper angle, radius of curvature, and radar dimensions;

[0024] Substituting the minimum usable radius into the geometric relationship yields the maximum included angle threshold of the radar-bumper included angle.

[0025] Substituting the maximum included angle threshold into the geometric relationship yields the minimum radius of curvature of the bumper under different radar sizes.

[0026] Furthermore, the method also includes:

[0027] Set the radar-bumper distance between the radar and the bumper to an integer multiple of half the air wavelength;

[0028] The minimum installation radius of the bumper is calculated based on the radar size and the radar-bumper distance.

[0029] Furthermore, the method also includes:

[0030] After calculating the minimum radius of curvature, it is determined whether the minimum radius of curvature is less than the minimum installation radius. If it is less, the value of the minimum radius of curvature is updated to the value of the minimum installation radius.

[0031] Furthermore, the method also includes:

[0032] Determine the dielectric constant of the bumper;

[0033] Acquire the signal frequency of the radar transmitted signal;

[0034] The dielectric wavelength of the bumper is calculated based on the dielectric constant and the signal frequency;

[0035] The thickness of the bumper is determined to be an integer multiple of half the wavelength of the medium.

[0036] According to another aspect of the present invention, the present invention also provides a vehicle bumper parameter determining device, the device comprising:

[0037] The data determination module is used to determine the range of the curvature radius of the vehicle bumper and the radar size;

[0038] The simulation test module is used to simulate and test the radar angle measurement accuracy based on multiple radii of curvature within the range of the curvature radius, and to determine the curve relationship between the curvature radius and the angle measurement accuracy based on the simulation results;

[0039] The radius determination module is used to determine the minimum usable radius corresponding to the radar size based on the curve variation relationship, and to calculate the minimum radius of curvature of the bumper under different radar sizes based on the radar-bumper angle corresponding to the minimum usable radius.

[0040] According to another aspect of the invention, the invention also provides a storage medium storing a plurality of instructions adapted to be loaded by a processor to execute any of the automobile bumper parameter determination methods described above.

[0041] Through one or more embodiments of the above embodiments of the present invention, at least the following technical effects can be achieved:

[0042] In the technical solution disclosed in this invention, simulation is performed based on the range of the curvature radius of the bumper and the radar size to obtain the angular measurement accuracy of the radar under different curvature radii, and the curve variation relationship between the curvature radius and the angular measurement accuracy is determined; then, the minimum usable radius of the bumper under the radar size is determined based on the curve variation relationship, and then the minimum curvature radius of the bumper is calculated based on the corresponding radar-bumper angle.

[0043] This solution utilizes simulation software to model and study the impact of bumpers with different curvatures on radar. Given a fixed radar size, it determines the minimum radius of curvature for the bumper. Calculating this minimum radius of curvature in this way satisfies the radar's angle measurement accuracy requirements while reducing costs and workload. Furthermore, this solution also determines the bumper thickness and the distance between the bumper and the radar. Combined with the minimum radius of curvature, this provides a reference for the early design of the bumper, shortening the development and verification cycle. Attached Figure Description

[0044] The technical solution and other beneficial effects of the present invention will become apparent from the following detailed description of specific embodiments of the invention, in conjunction with the accompanying drawings.

[0045] Figure 1 A flowchart illustrating the steps of a method for determining automobile bumper parameters provided in an embodiment of the present invention;

[0046] Figure 2 This is a schematic diagram of a first type of bumper-radar provided in an embodiment of the present invention;

[0047] Figure 3 A curve diagram showing the relationship between radius of curvature and angular measurement accuracy is provided for an embodiment of the present invention.

[0048] Figure 4 A second type of bumper-radar schematic diagram provided for an embodiment of the present invention.

[0049] Figure 5 This is a schematic diagram of a vehicle bumper parameter determination device provided in an embodiment of the present invention. Detailed Implementation

[0050] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0051] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the term "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, the character " / " in this document, unless otherwise specified, generally indicates that the preceding and following related objects have an "or" relationship.

[0052] Figure 1 The diagram shows a flowchart of the steps in a method for determining car bumper parameters according to an embodiment of the present invention. According to one aspect of the present invention, a method for determining car bumper parameters is provided, the method comprising:

[0053] Step 101: Determine the range of the vehicle bumper's radius of curvature and the radar size;

[0054] Step 102: Simulate and test the radar angle measurement accuracy based on multiple radii of curvature within the range of the stated radius of curvature, and determine the curve relationship between the radius of curvature and the angle measurement accuracy based on the simulation results;

[0055] Step 103: Determine the minimum usable radius corresponding to the radar size based on the curve variation relationship, and calculate the minimum radius of curvature of the bumper under different radar sizes based on the radar-bumper angle corresponding to the minimum usable radius.

[0056] In vehicles, bumpers can affect radar signals. In overall vehicle design, the radius of curvature of the bumper should be as large as possible, meaning the bumper's curvature should be as small as possible, and it should be as flat as possible. However, angular radars are installed at the four corners of the car and require a certain angle. Therefore, it is necessary to balance the relationship between the vehicle's shape angles and the radar's influence, so that the bumper can match the vehicle's corners while meeting the requirements for radar signal measurement accuracy. Furthermore, sharp edges increase the reflection and refraction of electromagnetic wave energy, significantly increasing multipath effects. Multipath reflected incident waves are reflected between the components and the radar panel. If the transmitted wave reaches the radar and is absorbed by the receiving antenna, radar performance may degrade.

[0057] Given that current mainstream bumper designs still focus on mechanical performance, there is no mature and clear solution for improving the transmission attenuation and reflection of millimeter waves in terms of electromagnetic performance design. This solution simulates and tests the impact of bumper curvature on the overall electromechanical performance of the radar, and determines the minimum curvature radius of the bumper, which can reduce the impact of the bumper on the accuracy of radar signal measurement and improve the performance of the radar system.

[0058] The following is a detailed description of steps 101 to 103 above.

[0059] In step 101, the curvature radius range of the vehicle bumper and the radar size are determined.

[0060] For example, vehicle bumpers have their own common ranges of curvature radii, which can be set in advance according to application requirements. The curvature radius of an arc is the radius of the circle formed when the arc is part of a larger circle. A larger curvature radius results in a smoother arc, while a smaller radius results in a steeper arc. The reciprocal of the curvature radius is the curvature. Curvature k = (angle rotated / corresponding arc length). When both the angle and arc length approach 0, this is the standard definition of curvature for a smooth curve of any shape. For a circle, the curvature does not change with position.

[0061] Radar dimensions vary significantly depending on the radar model. Before designing the bumper, the dimensions of the specific radar model need to be measured. In this application, the required radar dimension is the radar length along the length of the bumper. This solution requires calculating the optimal bumper dimensions, including the bumper's radius and thickness, given the radar dimension.

[0062] In step 102, the radar angle measurement accuracy is simulated and tested based on multiple radii of curvature within the range of the curvature radius, and the curve relationship between the curvature radius and the angle measurement accuracy is determined based on the simulation results.

[0063] For example, within the radius of curvature, simulation tests are performed with a preset step size. The smaller the step size, the more tests are performed and the higher the test accuracy; conversely, the larger the step size, the fewer tests are performed, but the test efficiency is higher. In specific applications, the optimal step size can be selected based on both accuracy and efficiency.

[0064] After determining the step size, while keeping the bumper's thickness and height constant, the radius of curvature of the bumper is gradually changed to simulate the radar's radiation pattern and angle measurement performance. Simulation tests are conducted at each radius of curvature, and the angle of the test target is calculated using the radar signal. After the tests, the relationship between the radius of curvature and angle measurement accuracy is determined based on the simulation results.

[0065] In step 103, the minimum usable radius corresponding to the radar size is determined according to the curve variation relationship, and the minimum radius of curvature of the bumper under different radar sizes is calculated according to the radar-bumper angle corresponding to the minimum usable radius.

[0066] For example, bumpers can affect radar performance. For instance, near the 77GHz frequency band where millimeter-wave radar operates, the reflected energy of electromagnetic waves incident perpendicularly to a bumper can reach up to 35%. The bumper causes transmission attenuation and reflection of electromagnetic waves, resulting in a reduced detection range and the generation of false targets. Furthermore, the impact of the bumper on the radar's angle measurement accuracy varies depending on its radius of curvature. Generally, a larger bumper curvature and a smaller radius of curvature lead to a larger radar angle measurement error. As the radius of curvature increases, the radar ranging error gradually decreases and the output measurement angle stabilizes.

[0067] Simulation tests can determine the minimum usable radius for the current radar size. Based on this minimum usable radius and the radar size, the angle between the radar and the bumper can be calculated, ultimately determining the minimum radius of curvature for the radar size. When the bumper material is fixed, the optimal angle between the radar and the bumper is also relatively fixed. Therefore, this solution first obtains the minimum usable radius of the bumper using simulation results for a radar of one size, then determines the optimal radar-bumper angle for that material, and finally, based on the relationship between the radar size and the bumper radius, obtains the minimum radius of curvature that satisfies the application requirements for angle measurement error. This approach allows for obtaining the bumper radius at a relatively low cost while meeting the radar's angle measurement accuracy requirements.

[0068] Furthermore, the simulation test of radar angle measurement accuracy based on multiple radii of curvature within the curvature radius range includes:

[0069] The minimum and maximum threshold values ​​of the radius of curvature are determined based on the radius of curvature range, and the step size for adjusting the radius of curvature is determined.

[0070] Determine the current radius of curvature to be the minimum threshold, and perform the following loop operation:

[0071] (1) The radar sends a pulse signal to the test target and receives the echo signal returned by the test target;

[0072] (2) Calculate the test azimuth angle of the test target based on the pulse signal and the echo signal;

[0073] (3) Increase the current radius of curvature by the step amount to obtain the updated current radius of curvature, and determine whether the updated current radius of curvature is greater than the maximum threshold; if the updated current radius of curvature is not greater than the maximum threshold, return to step (1); if the updated current radius of curvature is greater than the maximum threshold, terminate the loop.

[0074] For example, to study the impact of vehicle bumper curvature on antenna radiation patterns and other performance characteristics, a simulation of radar angular measurement accuracy is performed using a preset radar size. For instance, using the simulation software HFSS, bumper structures with different curvatures are created within the software. An angular radar with a 150° azimuth detection range is selected, and simulation tests are conducted at different radii of curvature. The relationship between the radius of curvature R and the curvature k is as follows:

[0075] ,

[0076] Where k represents the curvature of the bumper, and R represents the radius of curvature of the bumper.

[0077] Figure 2 This is a schematic diagram of a first type of bumper-radar provided in an embodiment of the present invention. In the simulation, a standard sphere with center O and radius R is selected to simulate the shape of the bumper under ideal conditions. The model is established as follows: Figure 2 It should be noted that in practical engineering applications, Figure 2 The bumper model shown is defined as a radar mounting area. Outside of this area, the shape and size of the bumper can be freely designed for integration with the vehicle body.

[0078] Parametric modeling was used for the bumper model. The simulation used a radar with dimensions of 55mm*55mm as an example. When the radar size is other than standard, the maximum angle threshold between the radar and the bumper is relatively fixed. Therefore, the maximum angle threshold between the radar and the bumper can be determined based on one or more radar sizes.

[0079] In the specific simulation process, the minimum and maximum thresholds of the radius of curvature are first determined. For example, when the radius of curvature is in the range of 100mm-500mm, the minimum threshold is 100mm and the maximum threshold is 500mm.

[0080] Then, it is necessary to determine the adjustment range of the bumper curvature radius for each simulation. For example, adjust the step size to 50mm or 100mm. If higher curvature radius accuracy is required, the step size can be reduced. If efficiency is required, the step size can be increased.

[0081] With the radar size fixed, the radius of curvature of the bumper is gradually increased, and the angle measurement accuracy under different radii of curvature is calculated through simulation tests.

[0082] For example in Figure 2 The radar azimuth angle of 60° is selected, and the test target is set at the azimuth angle of 60°. Then, the process of calculating the radar azimuth angle is simulated, and the azimuth angle of the test target is calculated based on the simulation results.

[0083] Specifically, assuming the radius of curvature ranges from 100mm to 500mm, starting from the minimum threshold, the current radius of curvature is 100mm. The radar sends a pulse signal to the test target and receives the corresponding echo signal. Then, the first test azimuth angle of the test target is calculated based on the pulse signal and the echo signal. Next, the radius of curvature is increased by a step size. For example, when the step size is 100mm, the current radius of curvature is increased by another 100mm, resulting in an updated current radius of curvature of 200mm. The same process is simulated again to calculate the second test azimuth angle. This process is repeated continuously to obtain the third test azimuth angle corresponding to a radius of curvature of 300mm and the fourth test azimuth angle corresponding to a radius of curvature of 400mm. This loop is repeated until the current radius of curvature reaches 500mm, at which point the fifth test azimuth angle is calculated. After further increasing the step size, the current radius of curvature becomes 600mm, which is greater than the maximum threshold, and the loop exits.

[0084] Furthermore, determining the curve relationship between the radius of curvature and the angular measurement accuracy based on the simulation results includes:

[0085] Obtain the true azimuth angle of the test target;

[0086] Calculate the angle difference between the true azimuth and the test azimuth to obtain the azimuth error corresponding to the current radius of curvature;

[0087] Curve fitting is performed on multiple radii of curvature and their corresponding azimuth errors to obtain the curve variation relationship.

[0088] For example, Figure 3 This invention provides a curve diagram showing the relationship between radius of curvature and angular measurement accuracy, which is relevant to embodiments of the invention. Figure 2The bumper and radar were simulated, and the angular accuracy results at the radar azimuth angle of 60° were selected. For example, when the current curvature radius of the bumper is 100mm, the radar test determined the test azimuth angle to be 65.7°, then the azimuth angle error is 65.7° - 60° = 5.7°. Other azimuth angle errors were calculated sequentially, and the results were plotted. Figure 3 The graph shows that after adding bumpers with different radii of curvature, the angular accuracy at large angles gradually approaches the ideal value as the radius of curvature increases. When the radius of curvature exceeds 300mm, the curve changes gradually and tends to stabilize. Figure 3 The dashed line represents the inherent error of the radar itself, such as 2.8°. This means that the radar itself inevitably has an angle measurement error. However, after adding a bumper, the angle measurement error will increase due to the influence of the bumper. The difference between the two is the error caused by the influence of the bumper.

[0089] Furthermore, determining the minimum usable radius corresponding to the radar size based on the curve variation relationship includes:

[0090] When the azimuth error is less than a preset error threshold, the minimum value of the current radius of curvature is obtained as the minimum usable radius.

[0091] For example, Figure 3 In the process, after the radius of curvature reaches 300mm, the curve gradually slows down and stabilizes, reducing the error fluctuation caused by the bumper. In this case, the inflection point where the curve becomes less volatile can be determined first. The radius of curvature corresponding to this inflection point is the minimum usable radius. If it is smaller than this minimum usable radius, the resulting error will be larger. In practical applications, the actual radius of curvature of the bumper can be determined to be a value greater than this minimum usable radius. While meeting measurement accuracy requirements, the final radius of curvature of the bumper can be determined by combining it with the actual angles of the vehicle. This allows the bumper to match the vehicle's edges and corners while minimizing its impact on the radar.

[0092] Furthermore, the step of calculating the minimum radius of curvature of the bumper under different radar sizes based on the radar-bumper angle corresponding to the minimum usable radius includes:

[0093] Construct the geometric relationship between the radar-bumper angle, radius of curvature, and radar dimensions;

[0094] Substituting the minimum usable radius into the geometric relationship, we obtain the maximum included angle threshold of the radar-bumper included angle.

[0095] Substituting the maximum included angle threshold into the geometric relationship yields the minimum radius of curvature of the bumper under different radar sizes.

[0096] For example, Figure 4This is a schematic diagram of a second type of bumper-radar provided in an embodiment of the present invention. Figure 4 In the middle, above the radar cross-section are two bumpers with different curvatures, with radii of curvature R1 and R2 respectively. The radar dimensions are... , The values ​​are the dimensions of the radar housing (excluding connectors), with the centers of the bumper curvature circles being O1 and O2, and the corresponding central angles at the bumper edges being 2α and 2θ. According to the geometric tangent-chord angle theorem, angles α and θ are simultaneously the angles between the radar edge and the bumper, i.e., the radar-bumper angle. Figure 4 The following relationship can be obtained:

[0097] Formula 1:

[0098] Where α represents the radar-bumper angle, Indicates radar size, This indicates the radius of curvature of the bumper.

[0099] The above formulas can be used to construct the geometric relationship between the radar-bumper angle, the radius of curvature, and the radar dimensions. The radar-bumper angle can be calculated using the following formula:

[0100] Formula 2:

[0101] by Figure 3 For example, the simulation uses a radar with dimensions of 55mm*55mm. According to the simulation results, when the radar size is 55mm and the radius of curvature is 300mm, the azimuth error reaches an inflection point, and the minimum usable radius is 300mm. Substituting 300mm as the minimum usable radius into the above geometric relationship (Formula 2), the maximum angle threshold of the radar-bumper angle is obtained as follows: Furthermore, the maximum included angle threshold can be obtained. Approximately 6°.

[0102] As can be seen from Formula 2, the larger the radius of curvature, the smaller the radar-bumper angle. In practical applications, the larger the radius of curvature, the better, provided that the vehicle's cornering angle is met. Therefore, the smaller the radar-bumper angle, the better.

[0103] When electromagnetic waves are incident on a medium interface, reflection, refraction, and scattering occur. The angle of reflection equals the angle of incidence. When the maximum included angle threshold α is large, the reflected and scattered electromagnetic waves interfere more strongly with the radar, thus affecting the amplitude and phase of the antenna operation and reducing the directional stability of each antenna channel. Figure 1 To the point of being responsive.

[0104] Based on the characteristics of the bumper, if the bumper material is fixed, the corresponding radar-bumper angle is relatively fixed. Therefore, to ensure that the electromagnetic waves reflected by the bumper do not affect the entire radar system, the maximum angle threshold for the bumper of this material can be determined to be 6°. Then, this maximum angle threshold is substituted into the geometric formula to obtain the minimum radius of curvature of the bumper under different radar sizes.

[0105] In this example, the minimum radius of curvature of the bumper under different radar sizes can be calculated using the following formula:

[0106] ≈5 .

[0107] Where R represents the minimum radius of curvature for different radar sizes, and α represents the radar-bumper angle. Indicates the radar size.

[0108] Therefore, in this embodiment of the bumper, the radius of curvature of the bumper and the size of the radar exist. ≈5 Based on the relationship between the radar size and the minimum radius of curvature of the bumper, when the radar size is different, the minimum radius of curvature of the bumper can be calculated directly based on the current radar size. The calculation is simple, which greatly improves the calculation efficiency and reduces the cost.

[0109] Furthermore, the method also includes:

[0110] Set the radar-bumper distance between the radar and the bumper to an integer multiple of half the air wavelength;

[0111] The minimum installation radius of the bumper is calculated based on the radar size and the radar-bumper distance.

[0112] Furthermore, the method also includes:

[0113] After calculating the minimum radius of curvature, it is determined whether the minimum radius of curvature is less than the minimum installation radius. If it is less, the value of the minimum radius of curvature is updated to the value of the minimum installation radius.

[0114] For example, according to Figure 4 In addition to Formulas 1 and 2, the geometric relationships between the bumper and the radar also include the following:

[0115] Formula 3:

[0116] Where R1 represents the radius of curvature, α represents the radar-bumper angle, and L represents the radar-bumper distance.

[0117] according to The following relationship can be derived between radar size and radius of curvature:

[0118] Formula 4:

[0119] in, This indicates the minimum installation radius, and L represents the radar-bumper distance. Indicates the radar size.

[0120] In practical applications, the radius of curvature of the bumper must be greater than the minimum installation radius; otherwise, the radar cannot be completely encapsulated inside the bumper. Therefore, after calculating the minimum radius of curvature, it is necessary to determine whether the minimum radius of curvature is less than the minimum installation radius. If it is less, the value of the minimum radius of curvature is updated to the value of the minimum installation radius; if it is greater, the original minimum radius of curvature remains unchanged. This operation ensures that the radar can be installed inside the bumper.

[0121] Specifically, the radar-bumper distance between the radar and the bumper is set to an integer multiple of half the air wavelength. This range is determined by the radar's operating wavelength, and theoretically, it is chosen to be an integer multiple of half the air wavelength of the radar's center frequency. For example, the radar-bumper distance L between the bumper center and the radar height can be set to twice the air wavelength.

[0122] Furthermore, the method also includes:

[0123] Determine the dielectric constant of the bumper;

[0124] Acquire the signal frequency of the radar transmitted signal;

[0125] The dielectric wavelength of the bumper is calculated based on the dielectric constant and the signal frequency;

[0126] The thickness of the bumper is determined to be an integer multiple of half the wavelength of the medium.

[0127] For example, the goal of this solution is to determine multiple parameters of the bumper, including the minimum radius of curvature and radar-bumper distance L, as well as the bumper thickness H.

[0128] Based on the characteristics and penetrating power of electromagnetic waves, the thickness H of the bumper should be half a wavelength or an integer multiple of half a wavelength to minimize performance degradation.

[0129] First, the dielectric constant of the bumper material is obtained. Then, the wavelength of the medium corresponding to this dielectric constant at the radar signal frequency is calculated. Finally, the thickness of the bumper is determined to be an integer multiple of half the wavelength of the medium at the radar's operating center frequency.

[0130] For example, the bumper thickness H can be one times the wavelength of the medium. The formula for calculating the wavelength of the medium is as follows:

[0131] ,

[0132] in, Here, λ represents the wavelength of the medium, c is the speed of light in a vacuum, and f is the radar operating frequency. is the dielectric constant of the bumper material.

[0133] Additionally, when designing the bumper, it is necessary to use materials with a low dielectric constant at 77GHz. and low dielectric loss angle The material should be of uniform thickness, and it is not recommended to use compounds that include glass fiber, carbon fiber, or metal particles.

[0134] Through one or more embodiments of the above embodiments of the present invention, at least the following technical effects can be achieved:

[0135] In the technical solution disclosed in this invention, simulation is performed based on the range of the curvature radius of the bumper and the radar size to obtain the angular measurement accuracy of the radar under different curvature radii, and the curve variation relationship between the curvature radius and the angular measurement accuracy is determined; then, the minimum usable radius of the bumper under the radar size is determined based on the curve variation relationship, and then the minimum curvature radius of the bumper is calculated based on the corresponding radar-bumper angle.

[0136] This solution utilizes simulation software to model and study the impact of bumpers with different curvatures on radar. Given a fixed radar size, it determines the minimum radius of curvature for the bumper. Calculating this minimum radius of curvature in this way satisfies the radar's angle measurement accuracy requirements while reducing costs and workload. Furthermore, this solution also determines the bumper thickness and the distance between the bumper and the radar. Combined with the minimum radius of curvature, this provides a reference for the early design of the bumper, shortening the development and verification cycle.

[0137] Based on the same inventive concept as the method for determining automobile bumper parameters in an embodiment of the present invention, an embodiment of the present invention provides an apparatus for determining automobile bumper parameters. Please refer to [link / reference]. Figure 5 The device includes:

[0138] The data determination module 201 is used to determine the curvature radius range of the vehicle bumper and the radar size;

[0139] The simulation test module 202 is used to perform simulation tests on the radar angle measurement accuracy based on multiple radii of curvature within the radius of curvature range, and to determine the curve variation relationship between the radius of curvature and the angle measurement accuracy based on the simulation results;

[0140] The radius determination module 203 is used to determine the minimum usable radius corresponding to the radar size based on the curve change relationship, and to calculate the minimum radius of curvature of the bumper under different radar sizes based on the radar-bumper angle corresponding to the minimum usable radius.

[0141] Furthermore, the simulation test module 202 is also used for:

[0142] The minimum and maximum threshold values ​​of the radius of curvature are determined based on the radius of curvature range, and the step size for adjusting the radius of curvature is determined.

[0143] Determine the current radius of curvature to be the minimum threshold, and perform the following loop operation:

[0144] (1) The radar sends a pulse signal to the test target and receives the echo signal returned by the test target;

[0145] (2) Calculate the test azimuth angle of the test target based on the pulse signal and the echo signal;

[0146] (3) Increase the current radius of curvature by the step amount to obtain the updated current radius of curvature, and determine whether the updated current radius of curvature is greater than the maximum threshold; if the updated current radius of curvature is not greater than the maximum threshold, return to step (1); if the updated current radius of curvature is greater than the maximum threshold, terminate the loop.

[0147] Furthermore, the simulation test module 202 is also used for:

[0148] Obtain the true azimuth angle of the test target;

[0149] Calculate the angle difference between the true azimuth and the test azimuth to obtain the azimuth error corresponding to the current radius of curvature;

[0150] Curve fitting is performed on multiple radii of curvature and their corresponding azimuth errors to obtain the curve variation relationship.

[0151] Furthermore, the radius determination module 203 is also used for:

[0152] When the azimuth error is less than a preset error threshold, the minimum value of the current radius of curvature is obtained as the minimum usable radius.

[0153] Furthermore, the radius determination module 203 is also used for:

[0154] Construct the geometric relationship between the radar-bumper angle, radius of curvature, and radar dimensions;

[0155] Substituting the minimum usable radius into the geometric relationship, we obtain the maximum included angle threshold of the radar-bumper included angle.

[0156] Substituting the maximum included angle threshold into the geometric relationship yields the minimum radius of curvature of the bumper under different radar sizes.

[0157] Furthermore, the device is also used for:

[0158] Set the radar-bumper distance between the radar and the bumper to an integer multiple of half the air wavelength;

[0159] The minimum installation radius of the bumper is calculated based on the radar size and the radar-bumper distance.

[0160] Furthermore, the device is also used for:

[0161] After calculating the minimum radius of curvature, it is determined whether the minimum radius of curvature is less than the minimum installation radius. If it is less, the value of the minimum radius of curvature is updated to the value of the minimum installation radius.

[0162] Furthermore, the device is also used for:

[0163] Determine the dielectric constant of the bumper;

[0164] Acquire the signal frequency of the radar transmitted signal;

[0165] The dielectric wavelength of the bumper is calculated based on the dielectric constant and the signal frequency;

[0166] The thickness of the bumper is determined to be an integer multiple of half the wavelength of the medium.

[0167] Other aspects and implementation details of the vehicle bumper parameter determination device are the same as or similar to the vehicle bumper parameter determination method described above, and will not be repeated here.

[0168] According to another aspect of the present invention, the present invention also provides a storage medium storing a plurality of instructions adapted to be loaded by a processor to execute any of the automobile bumper parameter determination methods described above.

[0169] In summary, although the present invention has been disclosed above with reference to preferred embodiments, the above preferred embodiments are not intended to limit the present invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope defined in the claims.

Claims

1. A method for determining parameters of a car bumper, characterized in that, The method includes: The radar angle measurement accuracy was simulated and tested based on multiple radii of curvature within the curvature radius range. The minimum and maximum threshold values ​​of the radius of curvature are determined based on the radius of curvature range, and the step size for adjusting the radius of curvature is determined. Determine the current radius of curvature to be the minimum threshold, and perform the following loop operation: (1) The radar sends a pulse signal to the test target and receives the echo signal returned by the test target; (2) Calculate the test azimuth angle of the test target based on the pulse signal and the echo signal; (3) Increase the current radius of curvature by the step amount to obtain the updated current radius of curvature, and determine whether the updated current radius of curvature is greater than the maximum threshold; if the updated current radius of curvature is not greater than the maximum threshold, return to step (1); if the updated current radius of curvature is greater than the maximum threshold, terminate the loop. The relationship between the radius of curvature and the angular measurement accuracy is determined based on the simulation results. Determine the correspondence between the vehicle bumper's radius of curvature and the radar size, including constructing the geometric relationship between the radar-bumper angle, radius of curvature, and radar size: Substituting the minimum usable radius into the geometric relationship, we obtain the maximum included angle threshold of the radar-bumper included angle. Substituting the maximum included angle threshold into the geometric relationship yields the minimum radius of curvature of the bumper under different radar sizes.

2. The method as described in claim 1, characterized in that, The determination of the curve relationship between the radius of curvature and the angular measurement accuracy based on simulation results includes: Obtain the true azimuth angle of the test target; Calculate the angle difference between the true azimuth and the test azimuth to obtain the azimuth error corresponding to the current radius of curvature; Curve fitting is performed on multiple radii of curvature and their corresponding azimuth errors to obtain the curve variation relationship.

3. The method as described in claim 2, characterized in that, The step of determining the minimum usable radius corresponding to the radar size based on the curve variation relationship includes: When the azimuth error is less than a preset error threshold, the minimum value of the current radius of curvature is obtained as the minimum usable radius.

4. The method as described in claim 1, characterized in that, The method further includes: Set the radar-bumper distance between the radar and the bumper to an integer multiple of half the air wavelength; The minimum installation radius of the bumper is calculated based on the radar size and the radar-bumper distance.

5. The method as described in claim 4, characterized in that, The method further includes: After calculating the minimum radius of curvature, it is determined whether the minimum radius of curvature is less than the minimum installation radius. If it is less, the value of the minimum radius of curvature is updated to the value of the minimum installation radius.

6. The method as described in claim 1, characterized in that, The method further includes: Determine the dielectric constant of the bumper; Acquire the signal frequency of the radar transmitted signal; The dielectric wavelength of the bumper is calculated based on the dielectric constant and the signal frequency; The thickness of the bumper is determined to be an integer multiple of half the wavelength of the medium.

7. A device for determining parameters of a car bumper, characterized in that, The device includes: The data determination module substitutes the minimum available radius into the formula to obtain the maximum angle threshold of the radar-bumper angle, and substitutes the maximum angle threshold into the formula to obtain the minimum radius of curvature of the bumper under different radar sizes, which is used to determine the range of the radius of curvature of the vehicle bumper and the radar size. The simulation testing module is used to simulate and test the radar angle measurement accuracy based on multiple curvature radii within the curvature radius range, determine the minimum threshold, maximum threshold, and curvature change step of the curvature radius, determine the current curvature radius as the minimum threshold, and execute the following loop operation: (1) The radar sends a pulse signal to the test target and receives the echo signal returned by the test target; (2) Calculate the test azimuth angle of the test target based on the pulse signal and the echo signal; (3) Increase the current radius of curvature by the step amount to obtain the updated current radius of curvature, and determine whether the updated current radius of curvature is greater than the maximum threshold; if the updated current radius of curvature is not greater than the maximum threshold, return to step (1); if the updated current radius of curvature is greater than the maximum threshold, terminate the loop; determine the curve change relationship between radius of curvature and angle measurement accuracy based on the simulation results; The radius determination module is used to determine the minimum usable radius corresponding to the radar size based on the curve variation relationship, and to calculate the minimum radius of curvature of the bumper under different radar sizes based on the radar-bumper angle corresponding to the minimum usable radius.

8. A storage medium, characterized in that, The storage medium stores a plurality of instructions adapted for loading by a processor to perform the method as described in any one of claims 1 to 6.

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