Radar calibration system and method thereof

Abstract

A radar calibration system is set on a vehicle and includes a sensing unit and a housing. The sensing unit includes a receiving antenna array, the receiving antenna array includes at least four receiving antennas, the receiving antennas are arranged on an antenna plane and have a receiving antenna center, the distance between the receiving antenna center and the ground is greater than 40 cm, and the distance between any two adjacent receiving antennas is a receiving antenna interval, the ratio of the receiving antenna interval is 1:3:2 in sequence. The housing includes a bottom surface attached to the outer surface of the vehicle, the sensing unit is arranged in the housing, the antenna plane and the antenna plane angle of the outer surface of the vehicle are between 0 degrees and 90 degrees, and the vertical distance between the receiving antenna center and the bottom surface is less than or equal to 2 cm. Therefore, it is beneficial to reduce the sensing error caused by the virtual mirror target.

Description

Technical Field

[0001] This invention relates to a radar correction system and method, and more particularly to a radar correction system and method for use in vehicles. Background Technology

[0002] With the rapid development of Advanced Driver Assistance Systems (ADAS) and autonomous driving technologies, radar systems installed in vehicles are used to sense the position of targets or objects relative to the vehicle, in order to achieve BSD (Blind Spot Detection), LCA (Lane Change Assist), LDW (Lane Departure Warning), RCTA (Rear Cross Traffic Alert), FCW (Front Collision Warning), and prevent accidents caused by the radius difference between inner wheels. However, for existing radar systems, the accuracy and correctness of target position sensing are affected by echo or multipath signals.

[0003] In ideal or general circumstances, a vehicle's radar detects a target by emitting an electromagnetic wave signal to the target. The signal reflected from the target then returns along the original path of the emitted signal and is received by the radar. The radar then uses the received signal to determine information about the target, such as distance, speed, and angle. In this case, the angle at which the radar emits the signal and the angle at which it receives the signal are the same.

[0004] Figure 4 Please refer to the diagram illustrating the current operational status of the radar system 400. Figure 4 However, in some other cases, the same assumption is made regarding a target object (e.g.) Figure 4 In the case of the actual target t1, the vehicle's existing radar system 400 may receive signals other than those returned from the original transmission path of the actual target t1. These other signals are electromagnetic waves reflected from the actual target t1 and then reflected by other reflective surfaces, and are received by the existing radar system 400 almost simultaneously. This is the so-called multipath problem.

[0005] The path length of these signals reflected by other reflective surfaces (e.g., sub-path s21 plus sub-path s22, the length of which is the same as sub-path s21 plus the virtual sub-path s22m) will be longer than the path length of the signal returning from the original transmission path (i.e., the actual target path s1), while the speed will be very close to the speed of the signal returning from the original transmission path. Due to the limited accuracy of the range and velocity detected by the existing radar system 400, these multipath signals will fall within the same range-Doppler bin on the existing radar system 400 and cannot be distinguished. In this case, in addition to sensing the actual target t1 at the same transmission angle as the original, the existing radar system 400 will also sense a virtual mirror target t2 (mirror target, i.e., ghost target) at a different angle, such as... Figure 4 As shown. Since the path lengths of the mirror target t2 and the actual target t1 are different, the phase received by the antenna will also be different. However, the presence of the mirror target t2 will disrupt the phase distribution of the actual target t1 on the antenna, causing the existing radar system 400 to distort the angle judgment of the actual target t1. For example, the mirror target t2 may be formed relative to the actual target t1 through reflective surfaces such as the divider (or guardrail) 490, the vehicle surface, etc., and is not limited to this.

[0006] Therefore, there is an urgent need in today's radar system market to develop an integrated solution that effectively reduces sensing errors caused by mirror targets. Summary of the Invention

[0007] This invention provides a radar correction system and method. The angle between the antenna plane of the radar system and the antenna plane of the vehicle's outer surface is between 0 degrees and 90 degrees. The vertical distance between the center of the receiving antenna and the bottom surface of the outer casing is less than or equal to 2 cm, which helps to reduce sensing errors caused by virtual mirror targets. Furthermore, the storage medium of the radar correction system can be used to provide radar sensing programs and target angle forms, which include actual target angles or mirror target angles.

[0008] According to one embodiment of the present invention, a radar correction system is provided for installation in a vehicle and includes a sensing unit and a housing. The sensing unit includes a receiving antenna array comprising at least four receiving antennas, each antenna being disposed on an antenna plane and having a receiving antenna center. The distance between the receiving antenna center and the ground is greater than 40 cm. The receiving antennas are asymmetrical relative to their centers, and there is a receiving antenna spacing between any two adjacent receiving antennas in a ratio of 1:3:2. The housing includes a bottom surface attached to the outer surface of the vehicle. The sensing unit is disposed within the housing. The angle between the antenna plane and the antenna plane of the vehicle's outer surface is between 0 degrees and 90 degrees. The vertical distance between the receiving antenna center and the bottom surface is less than or equal to 2 cm. The sensing unit is used to sense actual targets, and the distance between the receiving antenna center and the actual target along the longitudinal direction of the vehicle is greater than 30 m and less than 100 m.

[0009] In an embodiment of the radar correction system according to the foregoing embodiments, the sensing unit may further include a transmitting antenna array, the transmitting antenna array including at least one transmitting antenna, the transmitting antenna being disposed on the antenna plane, and the outer surface of the vehicle being located on the left or right side of the vehicle.

[0010] In an embodiment of the radar correction system according to the foregoing implementation, the receiving antennas can be arranged sequentially on the horizontal plane of the vehicle, and the ratio of the distance between the receiving antennas from the direction away from the outer surface to the direction closer to the outer surface is 1:3:2.

[0011] In an embodiment of the radar correction system according to the foregoing implementation, the antenna plane angle may be between 30 degrees and 50 degrees.

[0012] According to another embodiment of the present invention, a radar correction system is provided for installation in a vehicle and includes a sensing unit, a housing, and at least one shielding unit. The sensing unit includes a receiving antenna array comprising at least three receiving antennas, each antenna being disposed on an antenna plane and having a receiving antenna center. The receiving antennas are symmetrical with respect to the receiving antenna center, and there is an equal distance between any two adjacent receiving antennas. The housing includes a bottom surface attached to the outer surface of the vehicle. The sensing unit is disposed within the housing. The angle between the antenna plane and the antenna plane of the vehicle's outer surface is between 0 degrees and 90 degrees. The vertical distance between the receiving antenna center and the bottom surface is less than or equal to 2 cm. The shielding unit is disposed on the outer surface of the vehicle and is used to shield the reflected signal of a virtual mirror target. The average surface roughness of the shielding unit is less than 5 cm. The sensing unit is used to sense the actual target. The distance between the receiving antenna center and the actual target along the lateral direction of the vehicle is between 1 m and 5 m.

[0013] In an embodiment of the radar correction system according to the foregoing implementation, the sensing unit and the masking unit may be arranged sequentially from the front to the rear of the vehicle on the horizontal plane of the vehicle.

[0014] In the embodiment of the radar correction system according to the foregoing implementation, the vertical distance between each receiving antenna and the outer surface of the vehicle is h, and the vertical height of the shielding unit relative to the outer surface is hb, which can satisfy the following condition: 0 <hb / h<0.4。

[0015] In the embodiments of the radar correction system according to the foregoing implementation, the distance between each receiving antenna and the shielding unit can be between 5cm and 70cm, and the shielding unit is made of at least one of a wave-absorbing material and a metal material.

[0016] According to another embodiment of the present invention, a radar correction method is provided for a radar correction system of a vehicle. The radar correction system includes a sensing unit disposed on the outer surface of the vehicle and includes a receiving antenna array. The receiving antenna array includes a plurality of receiving antennas, which are configured on an antenna plane. The angle between the antenna plane and the antenna plane of the outer surface of the vehicle is between 0 degrees and 90 degrees. The radar correction method includes a guidance matrix establishment step, a sensing step, a normalization step, and a target angle table generation step. The guidance matrix establishment step includes establishing a guidance matrix based on the complex first path group coefficients, complex second path group coefficients, complex third path group coefficients, and complex fourth path group coefficients of the receiving antenna and their corresponding complex guidance vectors, and defining the received signal received by the receiving antenna as a function of the guidance matrix. For the receiving antenna, the actual target path is a straight line path between the receiving antenna and the actual target, and the mirror target path is a straight line path between the receiving antenna and a virtual mirror target. The sensing step includes enabling the receiving antenna to receive the received signal. The normalization step includes normalizing the guiding matrix using the component corresponding to the reference antenna (one of the receiving antennas) to obtain a normalized guiding matrix, and normalizing the received signal using the component corresponding to the reference antenna to obtain a normalized received signal, defining that the normalized guiding matrix and the normalized received signal are equal. The target angle form generation step includes generating a target angle form based on the normalized guiding matrix. The target angle form includes the guiding matrix and its corresponding actual target angle or mirrored target angle, where the actual target angle is the angle between the normal to the antenna plane and the actual target path, and the mirrored target angle is the angle between the normal to the antenna plane and the mirrored target path.

[0017] In an embodiment of the radar correction method according to the foregoing implementation, the radar correction method may further include a post-correction sensing step, which includes calculating the corresponding guidance matrix from the received signal and determining the actual target angle or mirror target angle corresponding to the guidance matrix based on the target angle table, so as to reduce the sensing error caused by the mirror target.

[0018] In an embodiment of the radar correction method according to the foregoing implementation, the radar correction method may further include an angle relationship deriving step, which includes deriving the angle relationship based on the vertical distance of each receiving antenna relative to the outer surface of the vehicle, the antenna plane angle, and the actual target path. The angle relationship is the relationship between the actual target angle and the mirrored target angle.

[0019] In an embodiment of the radar correction method according to the foregoing implementation, in the step of deriving the angle relationship, the vertical distance of the receiving antenna relative to the outer surface of the vehicle is h, and the antenna plane angle is θ. p Given that the actual target path is s1, the actual target angle is θ1 degrees, and the mirrored target angle is θ2 degrees, it can satisfy the following conditions:

[0020] .

[0021] In an embodiment of the radar correction method according to the foregoing implementation, the radar correction method may further include a reflection coefficient deriving step, which includes deriving the reflection coefficient of each receiving antenna based on a normalized guiding matrix. Each reflection coefficient includes an amplitude coefficient and a phase coefficient, and the reflection coefficient of each receiving antenna is an analytical solution. The target angle form generation step further includes generating a target angle form based on the reflection coefficients corresponding to the receiving antennas.

[0022] In an embodiment of the radar correction method according to the foregoing implementation, the step of deriving the reflection coefficient may further include defining the amplitude coefficient and phase coefficient of the reflection coefficient of the reference antenna as constants. Attached Figure Description

[0023] Figure 1A A block diagram illustrating a radar correction system according to a first embodiment of the present invention;

[0024] Figure 1B A schematic diagram of the radar correction system of the first embodiment is shown;

[0025] Figure 1C A schematic diagram illustrating the operational status of the radar correction system of the first embodiment is shown.

[0026] Figure 1D A schematic diagram illustrating another usage state of the radar correction system of the first embodiment is shown;

[0027] Figure 2A A flowchart illustrating the radar correction method according to the second embodiment of the present invention is shown;

[0028] Figure 2B A schematic diagram illustrating the relationship between the actual target angle and the actual target path in the radar correction method of the second embodiment is shown.

[0029] Figure 2CA comparison chart showing the sensing results of existing radar systems for actual targets that are corner reflectors;

[0030] Figure 2D A schematic diagram illustrating the sensing results of the radar correction method of the second embodiment for an actual target that is a corner reflector is shown.

[0031] Figure 2E A comparative diagram showing the sensing results of existing radar systems for a bicycle as an actual target is presented.

[0032] Figure 2F A schematic diagram illustrating the sensing results of the radar correction method of the second embodiment for the actual target being a bicycle is shown.

[0033] Figure 2G A comparative diagram showing the sensing results of existing radar systems for a vehicle as the actual target is presented.

[0034] Figure 2H A schematic diagram illustrating the sensing results of the radar correction method of the second embodiment for a vehicle as the actual target is shown.

[0035] Figure 2I A comparison chart showing the sensing results of an existing radar system for a vehicle as the actual target is presented.

[0036] Figure 2J A schematic diagram illustrating another sensing result for a vehicle as the actual target of the radar correction method of the second embodiment is shown.

[0037] Figure 2K A comparison chart showing the sensing results of an existing radar system for a vehicle as the actual target is presented.

[0038] Figure 2L A schematic diagram illustrating the radar correction method of the second embodiment for a second sensing result with the actual target being a car is shown.

[0039] Figure 3A A block diagram illustrating a radar correction system according to a third embodiment of the present invention;

[0040] Figure 3B A schematic diagram illustrating the operational status of the radar correction system according to the third embodiment is shown;

[0041] Figure 3C A schematic diagram of the shielding unit in the radar correction system of the third embodiment is shown;

[0042] Figure 3D Plot a comparison of the sensing results of existing radar correction systems;

[0043] Figure 3E , Figure 3F , Figure 3G and Figure 3HSchematic diagrams illustrating the sensing results of the radar correction system of the third embodiment with different shielding configurations are shown respectively; and

[0044] Figure 4 Draw a schematic diagram showing the operational status of the existing radar system. Detailed Implementation

[0045] Embodiments of the present invention will now be described with reference to the drawings. For clarity, many practical details will be described in the following description. However, it should be understood that these practical details are not intended to limit the invention. That is, these practical details are not essential in the embodiments of the present invention. Furthermore, for the sake of simplicity, some conventional structures and elements will be shown in the drawings in a simple schematic manner; and repeated elements may be represented by the same number.

[0046] Furthermore, the terms "first," "second," and "third" are used only to describe different components and do not limit the components themselves. Therefore, the first component can also be referred to as the second component. Moreover, the combinations of components / units / circuits in this article are not combinations generally known, conventional, or existing in this field. Whether the components / units / circuits themselves are prior art cannot be used to determine whether their combination relationships are easily accomplished by a person skilled in the art.

[0047] Figure 1A A block diagram illustrating a radar correction system 100 according to a first embodiment of the present invention is shown. Figure 1B A schematic diagram of the radar correction system 100 according to the first embodiment is shown. Figure 1C A schematic diagram illustrating the operational status of the radar correction system 100 according to the first embodiment is shown (not drawn to scale). Please refer to... Figures 1A to 1C The radar correction system (i.e., radar system, radar sensing system) 100 is installed in the vehicle 500 and includes a sensing unit 140, a control unit 110, and a housing 170. The sensing unit 140 includes a receiving antenna array 160, which includes a plurality of receiving antennas 167. The receiving antennas 167 are disposed on the antenna plane 144 and have a receiving antenna center c1, which is the geometric center of the plurality of receiving antennas 167. The distance between the receiving antenna center c1 and the ground is greater than 40 cm. Furthermore, the vehicle 500 can be a single vehicle or a trailer connected to a trailer. The sensing unit 140 and the control unit 110 can be integrated into a single device housed in the housing 170, or they can be two separate devices. For example, the control unit 110 is part of the control system of the vehicle 500. The outer surface 544 can be made of materials such as metal or plastic that easily or poorly reflect signals.

[0048] Please refer to Figure 1B and Figure 1CThe housing 170 includes a bottom surface 177, which is directly attached to the outer surface 544 of the vehicle 500 (e.g., the housing 170 is fixed to the outer surface 544 of the vehicle 500 via a power connector 178 thereon). That is, the vertical distance (i.e., the gap) between the bottom surface 177 and the outer surface 544 is essentially zero. The sensing unit 140 is disposed within the housing 170. The antenna plane angle θ between the antenna plane 144 and the outer surface 544 of the vehicle 500 is... p Between 0 degrees and 90 degrees (inclusive, the following descriptions are equally applicable), the vertical distance hc between the center c1 of the receiving antenna and the bottom surface 177 of the housing 170 is less than or equal to 2 cm. The sensing unit 140 is used to sense the actual target t1. The distance between the center c1 of the receiving antenna and the actual target t1 along the longitudinal direction y of the vehicle 500 can be greater than 30 m and less than 100 m, and it should be understood that the distance between the center c1 of the receiving antenna and the actual target t1 along the longitudinal direction y of the vehicle 500 can be less than or equal to 30 m.

[0049] Please refer to Figure 1A The control unit 110 is communicatively coupled to the receiving antenna 167. The control unit 110 includes a processor 120 and a storage medium 130. The storage medium 130 is communicatively coupled to the processor 120 and can be used to provide a radar sensing program 133 and a target angle form 134. The target angle form 134 includes the actual target angle θ1 or the mirror target angle θ2, or other angles corresponding to the two angles. The storage medium 130 is specifically a non-transitory computer-readable storage medium, and the radar sensing program 133 is specifically program code. The control unit 110 uses the radar sensing program 133 and the target angle form 134 to reduce the sensing error caused by the virtual mirror target (i.e., the mirror object) t2. Therefore, the received signal of the receiving antenna 167 is synthesized from the signals reflected by the actual target t1 and the mirror target t2. The target angle form 134 can effectively eliminate or reduce the proportion of the received signal corresponding to the mirror target t2, so that the radar correction system 100 can more accurately sense the actual target t1.

[0050] In detail, the sensing unit 140 may further include a transmitting antenna array 150 (such as...). Figure 1A As shown, and in Figure 1B and Figure 1C (omitted), the transmitting antenna array 150 includes at least one transmitting antenna 157, which is disposed on the antenna plane 144. Furthermore, the sensing unit 140 also includes radio frequency components and baseband components. The transmitting antenna 157 and each receiving antenna 167 can be a circuit board antenna, and the antenna plane 144 can be, but is not limited to, the side of the circuit board 143 away from the outer surface 544 of the vehicle 500. Specifically, please refer to... Figure 1B and Figure 1CThe sensing unit 140 may further include an antenna plane 144f configured with another transmitting antenna array and another receiving antenna array. The antenna plane 144f is the side of the circuit board 143f that is away from the outer surface 544 of the vehicle 500. The circuit boards 143 and 143f have an included angle. The circuit boards 143 and 143f are rigid printed circuit boards to meet the reliability requirements when the parts are glued to the surface of the circuit board. The circuit board 145 is physically and electrically connected between the circuit boards 143 and 143f. The circuit board 145 may be a flexible printed circuit board (e.g., a flexible conductive multilayer film). The circuit boards 143, 143f, and 145 all meet the material requirements for high-frequency communication.

[0051] Please refer to Figure 1C The outer surface 544 of vehicle 500 can be located on the left side 530 or the right side 540 of vehicle 500. The vertical distance between the bottom surface 177 of housing 170 and outer surface 544 can be substantially zero or non-zero, and the vertical distance between the center c1 of receiving antenna and outer surface 544 is less than or equal to 6.5 cm. This allows the radar correction system 100 to conform to the appearance requirements of vehicle 500, while also improving the accuracy of left or right target detection when vehicle 500 is moving forward, backward, or turning, and effectively preventing accidents caused by inner wheel differential. Furthermore, the vertical distance between the center c1 of receiving antenna and outer surface 544 can be greater than or equal to 1.0 cm and less than or equal to 6.5 cm.

[0052] The number of receiving antennas 167 can be at least four. The receiving antennas 167 can be symmetrical or asymmetrical with respect to the receiving antenna center c1. Any two adjacent receiving antennas 167 are separated by a receiving antenna spacing a1, which can be equal or unequal. Furthermore, the receiving antennas 167 can include at least two different receiving antenna spacings a1. One receiving antenna spacing a1 can be an integer multiple or non-integer multiple of the other receiving antenna spacing a1. For example, if the receiving antennas 167 are asymmetrical with respect to the receiving antenna center c1, the ratio of the receiving antenna spacings a1 is 1:3:2. In the first embodiment, the receiving antennas 167 are arranged sequentially on the horizontal plane of the vehicle 500, and the receiving antennas 167 include at least two different receiving antenna spacings a1, and the antenna plane angle θ... p Between 30 and 50 degrees. Therefore, the radar correction system 100 can accurately sense actual target angles θ1 between -30 and 60 degrees or between -60 and 30 degrees, and the actual target angle θ1 range is essentially the same whether the sensing unit 140 is mounted on the left 530 or right 540 of the vehicle 500. Specifically, the sensing unit 140 is in the form of a multi-input multi-output (MIMO) system including two transmitting antennas 157 and four receiving antennas 167. Figure 1B and Figure 1C Only four receiving antennas 167 are shown in the figure. The four receiving antennas 167 are asymmetrical with respect to the center c1 of the receiving antenna. The ratio of the distance a1 between the four receiving antennas 167 from the direction away from the outer surface 544 to the direction close to the outer surface 544 is 1:3:2 in sequence. The distance a1 between each receiving antenna can be an integer multiple of half the wavelength of the radar signal (which can be a millimeter wave, for example, with a frequency of 77 GHz, but is not limited thereto). Therefore, the receiving antennas 167 contain three different receiving antenna distances a1, and are not limited thereto.

[0053] Figure 1D A schematic diagram of another usage state of the radar correction system 100 of the first embodiment (not drawn to scale) is shown, illustrating the geometric relationship between the receiving antenna 167, the actual target t1, and the reflection point 545 of the outer surface 544 of the vehicle 500 as follows: Figure 1D And as shown in equations (1) to (5), where r1 is the distance between the receiving antenna 167 and the reflection point 545 along the longitudinal direction y of the vehicle 500, the outer surface 544 of the vehicle 500 can be parallel to the longitudinal direction y, r2 is the distance between the reflection point 545 and the actual target t1 along the longitudinal direction y, R is the distance between the receiving antenna 167 and the actual target t1 along the longitudinal direction y, θ r Let θ be the angle between subpath s22 and the normal n2 of reflection point 545 on outer surface 544 (i.e., the incident angle and reflection angle of the reflected signal at reflection point 545). g The angle between subpath s21 and the vertical direction y is equal to 90 - θ. r (degrees), θ i Let be the angle between the actual target path s1 and the longitudinal direction y, and h be the vertical distance of the receiving antenna 167 relative to the outer surface 544 of the vehicle 500 (i.e., the height along the lateral direction x of the vehicle 500). T Let t1 be the vertical distance between the actual target t1 and the outer surface 544 of the vehicle 500. Equations (1) to (5) are as follows:

[0054]

[0055]

[0056]

[0057]

[0058] .

[0059] Furthermore, the target angle form 134 may include a steering matrix and its corresponding actual target angle θ1 or mirrored target angle θ2. For the receiving antenna 167, the actual target path s1 is the straight-line path between the receiving antenna 167 and the actual target (i.e., the actual target object) t1, and the actual target angle θ1 is the angle between the normal n1 of the antenna plane 144 and the actual target path s1. Figure 1C In the diagram, normal n1 is zero degrees, counterclockwise direction of normal n1 is a positive angle, and clockwise direction of normal n1 is a negative angle. The mirror target path s2 is the straight-line path between the receiving antenna 167 and the virtual mirror target t2. The mirror target angle θ2 is the angle between the normal n1 of the antenna plane 144 and the mirror target path s2. The control unit 110 is also used to calculate the corresponding guidance matrix from the received signal of the receiving antenna 167, and determine the actual target angle θ1 or the mirror target angle θ2 corresponding to the guidance matrix according to the target angle table 134. Therefore, the target angle table 134 provided in the storage medium 130 helps to calculate and look up the table from the received signal to obtain sensing results that exclude or reduce the influence of the mirror target t2. It should be noted that the radar correction system 100 of the present invention considers multiple path groups (such as the first to fourth path groups described in the second embodiment below) to correct angle sensing errors. However, in the physical environment, there are only actual targets and no mirror targets. Signals traveling along the actual target path and the mirror target path are both reflected by the actual target and received by the receiving antenna. However, the actual target path and the mirror target path are different. Therefore, existing radar systems tend to judge the received signals that travel along the mirror target path as being reflected by the mirror target. That is, existing radar algorithms regard all received signals as signals reflected by the actual target path, thus generating sensing errors.

[0060] Based on the vertical distance h of each receiving antenna 167 relative to the outer surface 544 of the vehicle 500 and the antenna plane angle θ p The angle relationship can be derived from the actual target path s1, which is the relationship between the actual target angle θ1 and the mirrored target angle θ2. Therefore, by reducing the computational dimensionality, the accuracy of the radar correction system 100 can be improved, while simultaneously reducing the computational load.

[0061] Furthermore, the radar correction system 100 of the first embodiment can be used to execute the radar correction method 200 of the second embodiment below. Therefore, for other details regarding the radar correction system 100, please refer to the content of the radar correction method 200 of the second embodiment below, which will not be described in detail here.

[0062] Figure 2A A flowchart illustrating the radar correction method 200 of the second embodiment of the present invention is provided, and the radar correction system 100 of the first embodiment of the present invention is used as an aid and example to illustrate the radar correction method 200 of the second embodiment. Please refer to... Figure 1A , Figure 1B and Figure 2A The radar correction method 200 is used in the radar correction system 100 of the vehicle 500. The radar correction system 100 includes a sensing unit 140, which is disposed on the outer surface 544 of the vehicle 500 and includes a receiving antenna array 160. The receiving antenna array 160 includes a plurality of receiving antennas 167, which are disposed on the antenna plane 144. The angle θ between the antenna plane 144 and the antenna plane of the outer surface 544 of the vehicle 500 is [θ]. p Between 0 degrees and 90 degrees, the radar correction method 200 includes a guidance matrix establishment step 220, a sensing step 230, a normalization step 240, and a target angle form generation step 260.

[0063] Step 220 of establishing the guidance matrix includes establishing a guidance matrix based on the complex first path group coefficients, complex second path group coefficients, complex third path group coefficients, complex fourth path group coefficients of the receiving antenna 167 and their corresponding complex guidance vectors, and defining the received signal received by the receiving antenna 167 as a function of the guidance matrix. For the receiving antenna 167, the actual target path s1 is the straight line path between the receiving antenna 167 and the actual target t1, and the mirror target path s2 is the straight line path between the receiving antenna 167 and the virtual mirror target t2. The coefficients of the first path group are derived from the actual target path s1, and the coefficients of the second and third path groups are derived from the actual target path s1 and the mirror target path s2, and the coefficients of the fourth path group are derived from the mirror target path s2. Furthermore, the mirror target path s2 contains sub-paths s21 and s22, or the mirror target path s2 contains sub-path s21 and a virtual sub-path s22m, wherein the sub-paths s22 and s22m have the same length and are mirror images of each other relative to the outer surface 544 of the vehicle 500.

[0064] Sensing step 230 includes causing receiving antenna 167 to receive a received signal. Normalization step 240 includes normalizing the guiding matrix with the component corresponding to the reference antenna, which is one of the receiving antennas 167, to obtain a normalized guiding matrix, and normalizing the received signal with the component corresponding to the reference antenna to obtain a normalized received signal, and defining the normalized guiding matrix as equal to the normalized received signal.

[0065] Step 260 of generating the target angle form includes generating a target angle form 134 based on a normalized guidance matrix. The target angle form 134 includes the guidance matrix and its corresponding actual target angle θ1 or mirrored target angle θ2. The actual target angle θ1 is the angle between the normal n1 of the antenna plane 144 and the actual target path s1, and the mirrored target angle θ2 is the angle between the normal n1 of the antenna plane 144 and the mirrored target path s2. This reduces the sensing error caused by the mirrored target t2.

[0066] Furthermore, the radar correction method 200 establishes a multipath model or multipath group model, that is, the received signal from the transmitting antenna 157 to the receiving antenna 167 is established as a multipath model including a first path group, a second path group, a third path group, and a fourth path group, so as to obtain the correct actual target angle θ1. The first path group is from the transmitting antenna 157 through the actual target path s1 to the actual target t1, and then through the actual target path s1 to the receiving antenna 167. Therefore, the coefficients of the first path group are derived based on the actual target path s1 or the actual target angle θ1. The second path group is from the transmitting antenna 157 through the actual target path s1 to the actual target t1, and then through the mirror target path s2 (i.e., reflected at the reflection point 545 on the outer surface 544) to the receiving antenna 167. Therefore, the coefficients of the second path group are derived based on the actual target path s1 or the actual target angle θ1 and the mirror target path s2 or the mirror target angle θ2. The third path group is from the transmitting antenna 157 via the mirror target path s2 to the actual target t1, and then via the actual target path s1 to the receiving antenna 167. Therefore, the coefficients of the third path group are derived based on the actual target path s1 or the actual target angle θ1 and the mirror target path s2 or the mirror target angle θ2. The fourth path group is from the transmitting antenna 157 via the mirror target path s2 to the actual target t1, and then via the mirror target path s2 to the receiving antenna 167. Therefore, the coefficients of the fourth path group are derived based on the mirror target path s2 or the mirror target angle θ2. The phases of the four path groups are different, not only because of the different path group lengths, but also because of the phase change caused by reflection from the reflecting surface (actual target t1 or outer surface 544 and its reflection point 545). In addition, the energy (or amplitude) of the four path groups will be different, which will also affect the phase of the synthesized signal. In the case of multipath, the received signal of the receiving antenna 167 of the multipath model of the present invention is the sum of the four path groups.

[0067] In detail, the radar correction method 200 may further include an angle relationship determination step 210, which includes determining the angle relationship based on the vertical distance h of each receiving antenna 167 relative to the outer surface 544 of the vehicle 500 and the antenna plane angle θ. pThe angle relationship is derived from the actual target path s1, which is the relationship between the actual target angle θ1 and the mirrored target angle θ2. By reducing the computational dimensionality, the accuracy of the radar correction method 200 can be improved, while simultaneously reducing the computational load.

[0068] In step 210, where the angle relationship is derived, the vertical distance between the receiving antenna 167 and the outer surface 544 of the vehicle 500 is h, and the antenna plane angle is θ. p The actual target path (length) is s1, the actual target angle is θ1 degrees, and the mirrored target angle is θ2 degrees. The unit of all angles is degrees, and they can satisfy the following condition (6):

[0069] .

[0070] In step 220 of establishing the guidance matrix, please refer to the following equations (7) to (11), where X is the received signal of all receiving antennas 167, represented by a matrix. In equation (7), the first four terms on the right side of the equation correspond to the signals of the first path group, the second path group, the third path group, and the fourth path group, respectively. s(t) is the form of the radar transmitted signal, a(θ1) and a(θ2) are guidance vectors and are functions of θ1 and θ2, respectively, and are related to the arrangement of the receiving antennas 167. noise is noise or other signals. For example, when there are eight receiving antennas 167 and their arrangement is [0,1,4,6,9,10,13,15]×0.5×λ, where λ is the wavelength of the radar signal, their guidance vectors a(θ1) and a(θ2) can be represented by equation (8). Furthermore, in equations (7) and (9), α1 is the coefficient of the first path group, α2 is the coefficient of the second path group and the coefficient of the third path group, and α3 is the coefficient of the fourth path group. The coefficients α1, α2, and α3 include the phase change of the signal from transmission to reception and the amplitude relationship between different path groups. s1 is the length of the actual target path, and s2 is the length of the mirrored target path. Equations (7) to (11) are as follows:

[0071] ;

[0072]

[0073] ;

[0074] ;

[0075]

[0076] .

[0077] In the aforementioned equations (10) and (11), β(θ1) is the phase coefficient and represents the phase change reflected by the reflection point 545 of the outer surface 544 of the vehicle 500. Although the theoretical value is π (i.e., 180 degrees), judging from the phase distribution of the received signal X in equation (7), β(θ1) is related to the actual target angle θ1. Γ(θ1) is the amplitude coefficient and represents the ratio of the amplitude of the second or third path group to the amplitude of the first path group in equation (7). Γ(θ1) is also related to the actual target angle θ1. The distribution of Γ(θ1) and β(θ1) with angle varies with different reflective surface environments. Currently, an analytical solution cannot be obtained; it can only be obtained by comparing the simulated and measured received signals X. Furthermore, equation (7) can be rearranged into equation (12), where A in equations (12) and (13) is a guiding matrix established based on the complex first path group coefficients, complex second path group coefficients, complex third path group coefficients, complex fourth path group coefficients of the receiving antenna 167 and their corresponding complex guiding vectors. Equations (12) and (13) are as follows:

[0078]

[0079] .

[0080] Next, in sensing step 230, the receiving antenna 167 receives the received signal. In normalization step 240, the guiding matrix is ​​normalized with the component corresponding to the reference antenna to obtain the normalized guiding matrix, and the noise in equation (7) is ignored, that is, the noise or other signals of the received signal X are ignored. The received signal X in equation (7) is normalized with the component corresponding to the reference antenna to obtain the normalized received signal. It can be seen that the normalized guiding matrix and the normalized received signal are equal vectors.

[0081] The radar correction method 200 may further include a reflection coefficient derivation step 250, which includes deriving the reflection coefficient of each receiving antenna 167 based on a normalized guiding matrix (e.g., by solving a system of equations). Each reflection coefficient includes an amplitude coefficient and a phase coefficient, and the reflection coefficient of each receiving antenna 167 is an analytical solution. In the subsequent target angle form generation step 260, a target angle form 134 is generated based on the reflection coefficients corresponding to each receiving antenna 167. Therefore, the analytical solution for the reflection coefficients of each receiving antenna 167 helps to improve sensing accuracy while calculating the position of the actual target t1 with controllable resources and time, thereby improving the sensing efficiency of the radar correction method 200 and the radar correction system 100.

[0082] Furthermore, in step 250 of deriving the reflection coefficient, the amplitude coefficient and phase coefficient of the reflection coefficient of the reference antenna may also be defined as constants, for example, defining the amplitude coefficient (e.g., the aforementioned Γ(θ1)) as 0.8 and the phase coefficient (e.g., the aforementioned β(θ1)) as 180 degrees (π). This helps to improve sensing accuracy while saving computational resources and time.

[0083] The radar correction method 200 may further include a target angle form storage step 270, which stores the target angle form 134 in the storage medium 130 of the control unit 110 of the radar correction system 100 (or another radar system), so that the radar correction system 100 reduces the sensing error caused by the virtual mirror target t2 when performing the subsequent correction sensing step 290.

[0084] After completing the target angle form storage step 270, the radar correction method 200 may further include a post-correction sensing step 290, which includes calculating the corresponding guidance matrix from the received signal and determining the actual target angle θ1 or the mirror target angle θ2 corresponding to the guidance matrix according to the target angle form 134, in order to reduce the sensing error caused by the mirror target t2. Therefore, by incorporating the lookup method of the target angle form 134 into the radar sensing calculation process, it is helpful to calculate and look up the target angle form from the received signal to obtain sensing results that exclude or reduce the influence of the mirror target t2.

[0085] In the post-calibration sensing step 290, the DML (Deterministic Maximum Likelihood) algorithm can be used, where X is the received signal, which is complex data, and A is the guiding matrix, where A = A(θ1,θ2), which is related to the arrangement of the receiving antenna 167. H Let A represent the complex conjugate transposed matrix of the received signal X. Theoretically, when the received signal X and A×s(t) are closest, the DML objective function (Cost Function) in Equation (14) can reach its maximum value. When the maximum value is reached, the angle corresponding to the guiding matrix A is the estimated actual target angle θ1. It should be noted that the angle relationship between the actual target angle θ1 and the mirror target angle θ2 has been obtained in the previous angle relationship derivation step 210 (for example, as shown in Equation (6)). Therefore, the mirror target angle θ2 can be represented by the actual target angle θ1. In this way, the problem can be simplified to the estimation of only one actual target angle θ1, that is, the two-dimensional DML objective function is transformed into a one-dimensional DML objective function, as shown in Equation (14) below:

[0086] .

[0087] Furthermore, in the post-correction sensing step 290, the range of the mirror target angle θ2 can be defined first, and then the actual target angle θ1 can be estimated. At this time, the accuracy of estimating the actual target angle θ1 will be improved. Thus, the radar correction method 200 using a one-dimensional DML objective function not only reduces the computational load but also achieves higher accuracy. In addition, the MUSIC (Multiple Signal Classification) algorithm can be used in the post-correction sensing step 290, and it is not limited to this.

[0088] Figure 2B A schematic diagram illustrating the relationship between the actual target angle θ1 and the actual target path s1 in the radar correction method 200 of the second embodiment is shown, wherein the antenna plane 144 faces the rear 520 of the vehicle 500, and the antenna plane angle θ p It is 40 degrees. Please refer to... Figure 2B On the horizontal plane of vehicle 50, the position of receiving antenna 167 is defined as the origin (i.e., both the horizontal x-direction and the vertical y-direction are 0m). The relationship between the distance of the actual target t1 from the receiving antenna 167 in the horizontal x-direction and the distance in the vertical y-direction and the actual target angle θ1 is as follows: Figure 2B Furthermore, the radar correction system 100 used to perform the radar correction method 200 can accurately sense the actual target t1 in the lateral direction x, which is between 1m and 5m (in fact, the maximum lateral sensing distance can be greater than 5m) and in the longitudinal direction y, which is between 0m and -100m.

[0089] Figure 2C A comparison chart showing the sensing results of existing radar systems for actual targets that are corner reflectors is presented. Figure 2D A schematic diagram illustrating the sensing results of the radar correction system 100, which performs the radar correction method 200 of the second embodiment, for an actual target t1 as a corner reflector. Figure 2E A comparison chart showing the sensing results of existing radar systems for a bicycle as an actual target is presented. Figure 2F The diagram illustrates the sensing results of the radar correction system 100, which performs the radar correction method 200 of the second embodiment, for the actual target t1 being a bicycle. Figure 2G The diagram shows a comparison of sensing results for a vehicle as the actual target, with the bottom surface of the existing radar system's casing at a vertical distance of 0 cm from the outer surface of the vehicle. Figure 2H The diagram illustrates the sensing results for a vehicle, where the bottom surface 177 of the housing 170 of the radar correction system 100 used to perform the radar correction method 200 of the second embodiment is 0 cm from the outer surface 544 of the vehicle 500. Figure 2I The diagram illustrates a comparison of sensing results for a vehicle as the actual target, with the bottom surface of the existing radar system's casing at a vertical distance of 3 cm from the outer surface of the vehicle. Figure 2JThe diagram illustrates the sensing results for a radar correction system 100, used to perform the radar correction method 200 of the second embodiment, with a vertical distance of 3 cm between the bottom surface 177 and the outer surface 544, and the actual target t1 being a car. Figure 2K The diagram illustrates a comparison of sensing results for a vehicle as the actual target, with the bottom surface of the existing radar system's casing at a vertical distance of 5 cm from the outer surface of the vehicle. Figure 2L The diagram illustrates the sensing results for a vehicle as the actual target t1, with a vertical distance of 5 cm between the bottom surface 177 and the outer surface 544 of the radar correction system 100 used to perform the radar correction method 200 of the second embodiment. Specifically, Figures 2C to 2L On the horizontal plane of the vehicle, the position of the receiving antenna is defined as the origin. The horizontal direction (x) away from the vehicle's outer surface is positive, and the vertical direction (y) towards the rear of the vehicle (or toward the rear of the vehicle) is negative. The antenna plane faces the rear of the vehicle, and the angle of the antenna plane is 40 degrees. Furthermore, Figures 2C to 2L The vertical distance between the center of the receiving antenna and the bottom surface of the outer casing is 1.5cm, therefore Figures 2C to 2H The vertical distance between the center of the receiving antenna and the outer surface of the vehicle is 1.5 cm. Figure 2I , Figure 2J The vertical distance between the center of the receiving antenna and the outer surface of the vehicle is 4.5 cm. Figure 2K , Figure 2L The vertical distance between the center of the receiving antenna and the outer surface of the vehicle is 6.5 cm.

[0090] Please refer to Figure 2C and Figure 2D , Figure 2C and Figure 2D The actual target shown is a corner reflector, and its horizontal distance (x) from the receiving antenna (which serves as the origin) is 2m. Figure 2C The existing radar system shown has significant sensing errors, specifically, along the longitudinal direction y, the transverse direction x of multiple sensing positions is not 2m, and in particular, the sensing positions are less than 2m or 0m in the transverse direction x. Figure 2D The sensing results of the radar correction system 100 shown can effectively reduce the occurrence of the sensing error.

[0091] Please refer to Figure 2E and Figure 2F , Figure 2E and Figure 2F The actual target shown is a bicycle, and its horizontal distance (x) from the receiving antenna (which serves as the origin) is 2m. Figure 2E The existing radar system shown has significant sensing errors, specifically, along the longitudinal direction y, the transverse direction x of multiple sensing positions is not 2m, and in particular, the sensing positions are less than 2m or 0m in the transverse direction x. Figure 2F The sensing results of the radar correction system 100 shown can effectively reduce the occurrence of the sensing error.

[0092] Please refer to Figures 2G to 2L , Figures 2G to 2L The actual target shown is a car, and the horizontal distance (x) from the receiving antenna (which serves as the origin) is 5m. Figure 2G , Figure 2I , Figure 2K The existing radar system shown has significant sensing errors, specifically, along the longitudinal direction y, the lateral direction x of multiple sensing locations is not 5m, and in particular, the sensing locations are less than 5m or 0m from the lateral direction x. Figure 2H , Figure 2J , Figure 2L The sensing results of the radar correction system 100 shown can effectively reduce the occurrence of the sensing error.

[0093] Figure 3A A block diagram illustrating a radar correction system 300 according to a third embodiment of the present invention is shown. Figure 3B A schematic diagram illustrating the operational status of the radar correction system 300 according to the third embodiment is shown (not drawn to scale). Please refer to... Figure 3A and Figure 3B The radar correction system 300 is installed in the vehicle 600 and includes a sensing unit 340, a control unit 310, and a housing 370. The sensing unit 340 includes a receiving antenna array 360, which includes at least three receiving antennas 367. Each receiving antenna 367 is disposed on an antenna plane 344 and has a receiving antenna center c1. The receiving antennas 367 are symmetrical with respect to the receiving antenna center c1, and there is an equal receiving antenna spacing a1 between any two adjacent receiving antennas 367. The housing 370 includes a bottom surface 377, which is directly attached to the outer surface 644 of the vehicle 600, meaning the vertical distance between the bottom surface 377 and the outer surface 644 is substantially zero. The sensing unit 340 is disposed within the housing 370. The antenna plane angle θ between the antenna plane 344 and the outer surface 644 of the vehicle 600 is... p Between 0 degrees and 90 degrees, the vertical distance hc between the center c1 of the receiving antenna and the bottom surface 377 of the outer casing 370 is less than or equal to 2 cm. Furthermore, the distance between the center c1 of the receiving antenna and the ground can be greater than 40 cm.

[0094] The control unit 310 is communicatively coupled to the receiving antenna 367. The control unit 310 includes a processor 320 and a storage medium 330. The storage medium 330 is communicatively coupled to the processor 320 and can be used to provide a radar sensing program 333 and a target angle form 334. The target angle form 334 includes the actual target angle θ1 or the mirrored target angle. The control unit 310 uses the radar sensing program 333 and the target angle form 334 to reduce the sensing error caused by the virtual mirrored target.

[0095] Figure 3CSchematic diagram showing the shielding unit 380 in the radar calibration system 300 of the third embodiment. Please refer to Figures 3A to 3C , the radar calibration system 300 further includes at least one shielding unit 380, which is disposed on the outer surface 644 of the vehicle 600 and is used to shield the reflected signal of the mirror target. The average surface roughness of the shielding unit 380 is less than 5 cm. The sensing unit 340 and the shielding unit 380 are arranged in sequence from the front part 610 to the rear part 620 of the vehicle 600 on the horizontal plane of the vehicle 600. The sensing unit 340 is used to sense the actual target t1, and the distance between the receiving antenna center c1 and the actual target t1 along the transverse direction x of the vehicle 600 is between 1 m and 5 m. Thereby, it helps to improve the sensing accuracy of the rear target when the vehicle 600 moves forward, backward and turns, and can also effectively prevent accidents caused by the inner wheel difference. Furthermore, the vehicle 600 can be a single vehicle or a trailer connected to a trailer. The sensing unit 340 and the shielding unit 380 can be integrated into one device or two separate devices, such as Figure 3B and Figure 3C shown. In addition, the distance between the receiving antenna center c1 and the actual target t1 along the longitudinal direction y of the vehicle 600 can be greater than 30 m and less than 100 m.

[0096] Please refer to Figure 3B , the vertical distance of each receiving antenna 367 relative to the outer surface 644 of the vehicle 600 is h, and the vertical height of the shielding unit 380 relative to the outer surface 644 is hb, which can satisfy the following condition: 0 < hb / h < 0.4. Thereby, the influence of the mirror target can be effectively excluded or reduced in the sensing result.

[0097] Please refer to Figure 3B and Figure 3C , the spacing between each receiving antenna 367 and the shielding unit 380 (such as Figure 3C the spacing g1, g2 in the middle) can be between 5 cm and 70 cm, and the shielding unit 380 is made of at least one of an absorbing material and a metal material. Thereby, the signal reflected by the actual target t1 passing through the path s2b can be effectively blocked by the shielding unit 380, so that the signal will not be received by the receiving antenna 367. Further, when the shielding unit 380 is an absorbing material, such as a radio frequency absorber (RFAbsorber) or an absorbing material with an average surface roughness less than 5 cm but without microstructures, the shielding unit 380 can absorb Figure 3BThe signal reflected from the actual target t1 to the shielding unit 380 via path s2b is absorbed. When the shielding unit 380 is made of metal, it can reflect or scatter the signal reflected from the actual target t1 to the shielding unit 380 via path s2b. The shielding unit 380 can also be surface-treated, such as with a multilayer film, to absorb, reflect, or scatter the signal reflected to the shielding unit 380 via path s2b. The shape of the shielding unit 380 can be a rectangular, triangular, circular, conical, or a combination thereof, and is not limited thereto.

[0098] Figure 3D Plot a comparison of the sensing results of existing radar systems. Figure 3E , Figure 3F , Figure 3G and Figure 3H Schematic diagrams illustrating the sensing results of the radar correction system 300 according to the third embodiment with different shielding configurations are shown. Please refer to... Figures 3D to 3H , Figures 3D to 3H The diagram shows the actual target t1 located at a sensing position with a horizontal x-axis of 4m, where the position of one receiving antenna 367 is the origin. Figure 3D Sensing map of an existing radar system without a shielding unit. Figure 3E The radar correction system 300 includes a sensing image of a masking unit 380, which is disposed on the receiving antenna 367 toward the rear 620 of the vehicle 600, and the distance between the receiving antenna 367 and the receiving antenna 367 along the longitudinal direction y is 7.5 cm. Figure 3F The radar correction system 300 includes a sensing image with two shielding units 380. The two shielding units 380 are positioned on the receiving antenna 367 facing the rear 620 of the vehicle 600, and their distances from the receiving antenna 367 along the longitudinal direction y are 7.5 cm and 15 cm, respectively. Figure 3C The spacings g1 and g2 shown are 7.5cm and 15cm, respectively. Figure 3G The radar correction system 300 includes a sensing map with three masking units 380. The three masking units 380 are disposed on the receiving antenna 367 in the direction of the rear 620 of the vehicle 600, and the distances between them and the receiving antenna 367 in the longitudinal direction y are 7.5cm, 15cm and 30cm respectively. Figure 3H The radar correction system 300 includes a sensing map with four masking units 380. The four masking units 380 are disposed on the receiving antenna 367 in the direction of the rear 620 of the vehicle 600, and the distances between them and the receiving antenna 367 in the longitudinal direction y are 7.5cm, 15cm, 30cm and 60cm respectively.

[0099] Figure 3DThe existing radar system shown exhibits significant sensing errors. Specifically, in the longitudinal direction (y) approximately -30m to -45m, the lateral direction (x) relative to the actual target t1 is greater than 4m. This may be related to the field of view (FOV) characteristics of the existing radar system. Furthermore, in the longitudinal direction (y) approximately -50m to -80m, the lateral direction (x) relative to the actual target t1 is less than 4m. Figures 3E to 3H The sensing results of the radar correction system 300 shown can effectively reduce the occurrence of the sensing error, especially effectively improve the accuracy of the lateral x-direction of the sensing position of the actual target t1 when the longitudinal direction y is less than -30m.

[0100] In addition, please refer to Figure 3A and Figure 3B The sensing unit 340 further includes a transmitting antenna array 350, which includes at least one transmitting antenna 357 disposed on the antenna plane 344. The outer surface 644 of the vehicle 600 may be located on the left side 630 or the right side 640 of the vehicle 600. The vertical distance between the bottom surface 377 of the housing 370 and the outer surface 644 may be substantially zero or non-zero, and the vertical distance between the center c1 of the receiving antenna and the outer surface 644 may be less than or equal to 6.5 cm. Furthermore, the vertical distance between the center c1 of the receiving antenna and the outer surface 644 may be greater than or equal to 1.0 cm and less than or equal to 6.5 cm.

[0101] Specifically, there are four receiving antennas 367 arranged sequentially on the horizontal plane of vehicle 600, with equal spacing a1 between them and an antenna plane angle θ. p Between 30 and 50 degrees Celsius. Figure 3B In the diagram, R represents the distance between the receiving antenna 367 and the actual target t1 along the longitudinal direction y, and θ represents the distance between them. i h is the angle between the actual target path s1 and the longitudinal direction y. T Let t1 be the vertical distance between the actual target t1 and the outer surface 644 of the vehicle 600.

[0102] For further details regarding the radar correction system 300 of the third embodiment, please refer to the contents of the radar correction system 100 of the first embodiment and the radar correction method 200 of the second embodiment, which will not be described in detail here.

[0103] Although the present invention has been disclosed above by way of embodiments, it is not intended to limit the present invention. Any person 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 claims.

[0104] [Symbol Explanation]

[0105] 100, 300: Radar correction system

[0106] 110, 310: Control Unit

[0107] 120,320: Processor

[0108] 130, 330: Storage media

[0109] 133,333: Radar sensing procedure

[0110] 134,334: Target Angle Form

[0111] 140, 340: Sensing Unit

[0112] 143, 143f, 145: Circuit Board

[0113] 144, 144f, 344: Antenna Plane

[0114] 150, 350: Transmit antenna array

[0115] 157,357: Transmitting antenna

[0116] 160, 360: Receiver antenna array

[0117] 167,367: Receiving antenna

[0118] 170, 370: Outer shell

[0119] 177,377: Bottom surface

[0120] 178: Power connector

[0121] 200: Radar Correction Methods

[0122] 210: Steps to derive angular relationships

[0123] 220: Steps for establishing the guiding matrix

[0124] 230: Sensing Steps

[0125] 240: Formalization Steps

[0126] 250: Steps for obtaining the reflection coefficient

[0127] 260: Steps to generate the target angle form

[0128] 270: Steps for storing the target angle form

[0129] 290: Post-calibration sensing steps

[0130] 380: Shielding Unit

[0131] 400: Existing radar systems

[0132] 490: Divider Island

[0133] 500, 600: Vehicles

[0134] 510, 610: Front

[0135] 520, 620: Rear

[0136] 530,630:Left

[0137] 540, 640: Right side

[0138] 544, 644: Outer surface

[0139] 545: Reflection point

[0140] a1: Spacing between receiving antennas

[0141] c1: Center of receiving antenna

[0142] t1: Actual target

[0143] t2: Mirror target

[0144] s1: Actual target path

[0145] s2: Mirror target path

[0146] s21,s22,s22m: Subpaths

[0147] s2b: path

[0148] θ1: Actual target angle

[0149] θ2: Mirror target angle

[0150] θ p Antenna plane angle

[0151] θ r The angle between the subpath and the normal to the reflection point on the outer surface.

[0152] θ g Angle between the sub-path and the longitudinal direction

[0153] θ i The angle between the actual target path and the longitudinal direction.

[0154] g1, g2: Spacing between the receiving antenna and the shielding element

[0155] h: Vertical distance of the receiving antenna relative to the outer surface of the vehicle

[0156] hb: Vertical height of the shading unit relative to the outer surface

[0157] hc: Vertical distance between the center of the receiving antenna and the bottom surface of the casing.

[0158] h T The actual vertical distance of the target relative to the vehicle's outer surface.

[0159] r1: Distance between the receiving antenna and the reflection point along the longitudinal direction

[0160] r2: Distance between the reflection point and the actual target along the longitudinal direction.

[0161] R: Distance between the receiving antenna and the actual target along the longitudinal direction

[0162] x: horizontal direction

[0163] y: Vertical direction

[0164] n1, n2: Normals.

Claims

1. A radar correction system, characterized in that, Used to be installed on a vehicle and includes: A sensing unit includes a receiving antenna array comprising at least four receiving antennas disposed on an antenna plane and having a receiving antenna center. The distance between the receiving antenna center and the ground is greater than 40 cm. The receiving antennas are asymmetrical relative to the receiving antenna center, and there is a receiving antenna spacing between any two adjacent receiving antennas in a ratio of 1:3:

2. The housing includes a bottom surface that is attached to the outer surface of the vehicle. The sensing unit is disposed inside the housing. The angle between the antenna plane and the antenna plane of the outer surface of the vehicle is between 0 degrees and 90 degrees. The vertical distance between the center of the receiving antenna and the bottom surface is less than or equal to 2 cm. The sensing unit is used to sense the actual target, and the distance between the center of the receiving antenna and the actual target along the longitudinal direction of the vehicle is greater than 30m and less than 100m.

2. The radar correction system according to claim 1, characterized in that, The sensing unit also includes a transmitting antenna array, which includes at least one transmitting antenna disposed on the antenna plane, and the outer surface of the vehicle is located on the left or right side of the vehicle.

3. The radar correction system according to claim 1, characterized in that, The receiving antennas are arranged sequentially on the horizontal plane of the vehicle, and the spacing between the receiving antennas is in the ratio of 1:3:2 from the direction away from the outer surface to the direction close to the outer surface.

4. The radar correction system according to claim 1, characterized in that, The antenna's plane angle is between 30 and 50 degrees.

5. A radar correction system, characterized in that, Used to be installed on a vehicle and includes: The sensing unit includes a receiving antenna array, which includes at least three receiving antennas, which are arranged on an antenna plane and have a receiving antenna center. The receiving antennas are symmetrical with respect to the receiving antenna center, and there is a receiving antenna spacing between any two adjacent receiving antennas. The receiving antenna spacings are equal. The housing includes a bottom surface attached to the outer surface of the vehicle. The sensing unit is disposed within the housing. The angle between the antenna plane and the antenna plane of the vehicle's outer surface is between 0 degrees and 90 degrees. The vertical distance between the center of the receiving antenna and the bottom surface is less than or equal to 2 cm. At least one shielding unit is disposed on the outer surface of the vehicle and used to shield the reflected signal of the virtual mirror target, wherein the average surface roughness of the shielding unit is less than 5 cm; The sensing unit is used to sense the actual target, and the distance between the center of the receiving antenna and the actual target along the lateral direction of the vehicle is between 1m and 5m.

6. The radar correction system according to claim 5, characterized in that, The sensing unit and the shielding unit are arranged sequentially from the front to the rear of the vehicle on the horizontal plane of the vehicle.

7. The radar correction system according to claim 5, characterized in that, The vertical distance between each receiving antenna and the outer surface of the vehicle is h, and the vertical height of the shielding unit relative to the outer surface is hb, satisfying the following conditions: 0 <hb / h<0.4。 8. The radar correction system according to claim 5, characterized in that, The distance between each receiving antenna and the shielding unit is between 5cm and 70cm, and the shielding unit is made of at least one of a wave-absorbing material and a metal material.

9. A radar correction method, characterized in that, A radar correction system for a vehicle includes a sensing unit disposed on the outer surface of the vehicle and including a receiving antenna array comprising a plurality of receiving antennas arranged in an antenna plane. The angle between the antenna plane and the antenna plane of the outer surface of the vehicle is between 0 degrees and 90 degrees. The radar correction method includes: The guidance matrix establishment step involves establishing a guidance matrix based on the complex first path group coefficients, complex second path group coefficients, complex third path group coefficients, complex fourth path group coefficients, and their corresponding complex guidance vectors for the receiving antennas. The received signals received by the receiving antennas are defined as a function of the guidance matrix. For the receiving antenna, the actual target path is the straight-line path between the receiving antenna and the actual target, and the mirror target path is the straight-line path between the receiving antenna and the virtual mirror target. The sensing step causes the receiving antennas to receive the received signal; The normalization step involves normalizing the guiding matrix with the component corresponding to the reference antenna, which is one of the receiving antennas, and normalizing the received signal with the component corresponding to the reference antenna to obtain the normalized received signal, and defining the normalized guiding matrix as equal to the normalized received signal. as well as The target angle form generation step generates a target angle form based on the normalized guidance matrix. The target angle form includes the guidance matrix and its corresponding actual target angle or mirror target angle, wherein the actual target angle is the angle between the normal of the antenna plane and the actual target path, and the mirror target angle is the angle between the normal of the antenna plane and the mirror target path.

10. The radar correction method according to claim 9, characterized in that, Also includes: The calibration sensing step calculates the corresponding guidance matrix from the received signal and determines the actual target angle or the mirror target angle corresponding to the guidance matrix based on the target angle table, so as to reduce the sensing error caused by the mirror target.

11. The radar correction method according to claim 9, characterized in that, Also includes: The angle relationship is derived by taking into account the vertical distance of each receiving antenna relative to the outer surface of the vehicle, the antenna plane angle, and the actual target path. The angle relationship is the relationship between the actual target angle and the mirrored target angle.

12. The radar correction method according to claim 11, characterized in that, In the step of deriving this angular relationship, the vertical distance between the receiving antenna and the outer surface of the vehicle is h, and the antenna plane angle is θ. p Given that the actual target path is s1, the actual target angle is θ1 degrees, and the mirrored target angle is θ2 degrees, the following conditions must be met: 。 13. The radar correction method according to claim 9, characterized in that, Also includes: The reflection coefficient is obtained by deriving the reflection coefficient of each receiving antenna based on the normalized guiding matrix. Each reflection coefficient includes an amplitude coefficient and a phase coefficient, and the reflection coefficient of each receiving antenna is an analytical solution. The target angle form generation step further includes generating the target angle form based on the reflection coefficients corresponding to the receiving antennas.

14. The radar correction method according to claim 13, characterized in that, The step of deriving the reflection coefficient also includes defining the amplitude coefficient and the phase coefficient of the reflection coefficient of the reference antenna as constants.

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