Device used to determine the angular resolution of radar

Abstract

An apparatus and method are provided for determining the angular resolution of a radar (111). The apparatus includes: a first corner reflector (103a) and a second corner reflector (103b) for reflecting electromagnetic waves from the radar along a reflection direction toward the radar; a first motor (105a) for adjusting the first corner reflector and / or the second corner reflector to change a first distance between the first corner reflector and the second corner reflector in a direction of movement perpendicular to the reflection direction; a second motor (105b) for adjusting the first corner reflector and / or the second corner reflector to change a second distance between the first corner reflector and the second corner reflector in a direction of movement along the reflection direction; and a controller (101) for receiving reflection measurements of a plurality of first distances and / or a plurality of second distances from the radar and determining the angular resolution of the radar based on the reflection measurements.

Description

Technical Field

[0001] This invention generally relates to radar technology. For example, this invention relates to a device for determining and verifying the angular resolution of a radar under test. Background Technology

[0002] Automotive radar systems need to offer enhanced performance to detect different objects on the street and create high-quality traffic maps accordingly. Among various scenarios, resolving stationary objects is particularly critical, as state-of-the-art radar systems often cannot distinguish between two stationary adjacent objects at the same distance, potentially leading to hazardous situations.

[0003] Modern radar needs improved performance to achieve autonomous driving capabilities. Especially for imaging radar, one of the most crucial capabilities is angular resolution—the ability to detect two objects at the same distance and speed. Significant resources are currently being invested in developing radar systems with outstanding angular performance. In fact, such radar systems require a stable and accurate verification process to determine their angular resolution. If this verification process begins early in the radar development process, it will be far more efficient.

[0004] Because modern automotive imaging radar requires high performance, especially in the angular domain, a complex process is needed to validate the angular resolution of automotive imaging radar.

[0005] The traditional method for verifying the angular resolution of automotive imaging radar is to place two corner reflectors in a parking area or in an anechoic chamber at the same distance from the radar under test (RUT). The two corner reflectors are laterally spaced according to the required angular interval, and a person moves the angle according to the desired scene.

[0006] However, a drawback of this method is that the angular performance of the radar system under test cannot be consistently evaluated. Manually moving the corner reflector closer to or further away from the RUT does not provide sufficient performance because the accuracy required to position the reflector at several phase differences is on the micrometer scale, which is impractical for manual setup.

[0007] Furthermore, traditional methods do not allow for reproducible verification setups because it is nearly impossible to accurately replicate previous settings or to position the corner reflector in exactly the same location as before. Additionally, traditional methods are very time-consuming, as positioning the corner reflector at a specific distance requires considerable manpower to move it accordingly, resulting in poor accuracy, as mentioned above.

[0008] In view of the above, it is necessary to address the aforementioned technical deficiencies in existing equipment regarding radar angular resolution. Summary of the Invention

[0009] The apparatus and method according to the present invention facilitate the determination of radar angular resolution in a stable and efficient manner.

[0010] The above and other objectives are achieved through the subject matter claimed in the independent claims. Other implementations are apparent from the dependent claims, the specification, and the drawings.

[0011] Typically, the implementation described in this invention provides an improved device comprising multiple corner reflectors, several motors, and a controller for determining the angular resolution of the radar under test (RUT).

[0012] To validate the Direction of Arrival (DoA) algorithm and the radar's antenna layout, the radar separates two targets (i.e., reflectors) located within the same range at the same speed. The phase difference between the targets is a key parameter. The phase difference varies with λ, which, for some radar applications, is measured in millimeters and depends on the detection range from the target to the RUT.

[0013] In practice, since the amplitude of λ is very short, this parameter cannot be controlled; therefore, it is considered random and uniformly distributed. However, to verify the stability of the DoA algorithm, a device based on the implementation disclosed herein is able to evaluate the angular resolution capability of the RUT across multiple potential phase differences.

[0014] In this regard, the device according to the implementation disclosed herein can locate corner reflectors with phase differences of several micrometers, which is completely impractical for manual setup. Furthermore, the device according to the implementation disclosed herein can measure many different scenarios (defined as setups with different distances between corner reflectors). In contrast, conventional methods for verifying the angular resolution of radar systems are extremely time-consuming because each displacement between corner reflectors requires considerable manual intervention to move them accordingly, resulting in very low accuracy.

[0015] According to a first aspect, an apparatus for determining the angular resolution of a radar includes: a plurality of corner reflectors, including a first corner reflector and a second corner reflector, for reflecting electromagnetic waves from the radar along a reflection direction toward the radar; a first motor for adjusting the position of at least one of the first corner reflector and the second corner reflector to change a first distance between the first corner reflector and the second corner reflector in a first direction of movement perpendicular to the reflection direction toward the radar; and a second motor for adjusting the position of at least one of the first corner reflector and the second corner reflector to change a second distance between the first corner reflector and the second corner reflector in a second direction of movement parallel to the reflection direction toward the radar.

[0016] The device further includes a controller for controlling the first motor and the second motor to position the first corner reflector and / or the second corner reflector, and for receiving reflection measurement information of a plurality of first distances and / or a plurality of second distances from the radar. The controller is also configured to determine the angular resolution of the radar based on the reflection measurement information received from the radar.

[0017] Therefore, an improved device is provided that helps to determine the angular resolution of radar in a stable and efficient manner with significantly higher accuracy.

[0018] In another possible implementation, the controller determines the radar's angular resolution by determining the phase difference between a first reflected signal from the first corner reflector and a second reflected signal from the second corner reflector for the plurality of first distances and / or the plurality of second distances. This helps to determine the radar's angular resolution in an accurate and stable manner.

[0019] In another possible implementation, the controller is used to generate a verification report, wherein the verification report includes information about the determined angular resolution. Thus, the result of the determined angular resolution is provided effectively.

[0020] In another possible implementation, the plurality of corner reflectors further includes a third corner reflector and a fourth corner reflector for reflecting electromagnetic waves from the radar along a reflection direction toward the radar, wherein the first motor is further configured to change the position of at least one of the third corner reflector and the fourth corner reflector in a third motion direction perpendicular to the reflection direction toward the radar and perpendicular to the first motion direction; the second motor is further configured to change the position of at least one of the third corner reflector and the fourth corner reflector in a second motion direction parallel to the reflection direction toward the radar.

[0021] In one implementation, the first and second corner reflectors move horizontally, while the third and fourth corner reflectors move vertically. This facilitates accurate determination of the radar's angular resolution in a flexible and versatile manner.

[0022] In another possible implementation, the plurality of corner reflectors further includes a third corner reflector and a fourth corner reflector for reflecting electromagnetic waves from the radar along a reflection direction toward the radar. The device also includes a third motor for changing the position of at least one of the third corner reflector and the fourth corner reflector in a third motion direction perpendicular to the reflection direction toward the radar and perpendicular to the first motion direction; and a fourth motor for changing the position of at least one of the third corner reflector and the fourth corner reflector in a second motion direction parallel to the reflection direction toward the radar.

[0023] Therefore, it helps to accurately determine the angular resolution of the radar in a flexible, versatile and efficient manner.

[0024] In another possible implementation, at least some of the plurality of corner reflectors have different sizes. This makes it possible to measure the angular resolution of radars with different radar cross-sections in a stable manner.

[0025] In another possible implementation, the device further includes: an absorption plate having a front surface covered by an absorbing material for absorbing electromagnetic waves from the radar, wherein the plurality of corner reflectors are disposed on one side of the absorption plate having the front surface, and the first, second, third and / or fourth motors are disposed on the other opposite side of the absorption plate.

[0026] Therefore, it helps to limit clutter from the environment in measurement settings and determine the radar's angular resolution in an accurate and stable manner.

[0027] In another possible implementation, the absorber plate defines one or more slots, wherein each of the plurality of corner reflectors is configured to move along a corresponding one of the one or more slots. Therefore, the positions of the plurality of corner reflectors can be adjusted efficiently.

[0028] In another possible implementation, the device further includes a movable frame having casters disposed at the bottom of the movable frame, wherein the absorption plate, the plurality of corner reflectors, and the first, second, third, and / or fourth motors are mounted on the movable frame.

[0029] Therefore, this enables the device to measure the radar's angular resolution in a continuous and autonomous manner, and to efficiently determine the radar's angular resolution.

[0030] In another possible implementation, the device further includes one or more covers for shielding the plurality of corner reflectors in a parking position, wherein the one or more covers are made of a material for absorbing electromagnetic waves from the radar. The parking position refers to the location where the corner reflectors are physically shielded by the covers, so that the corner reflectors do not reflect electromagnetic waves back to the radar.

[0031] Therefore, the device avoids any potential interference from corner reflectors that are not involved in the measurement, and it can measure the radar's angular resolution in a stable manner. The device can also be placed in an anechoic chamber to avoid interfering with alternative measurements in case all corner reflectors are in the parking position.

[0032] In another possible implementation, the second motor and / or the fourth motor are used to change the position of at least one of the plurality of corner reflectors in a second direction parallel to the reflection direction toward the radar in steps of less than 100 micrometers, wherein the step size represents the distance between the position of at least one of the plurality of corner reflectors and a successive position.

[0033] Therefore, this makes it possible to measure the radar's angular resolution with extremely high accuracy in a fully reproducible measurement setup.

[0034] In another possible implementation, the first motor is used to adjust the position of at least one of the first corner reflector and the second corner reflector to change the first distance between the first corner reflector and the second corner reflector in a first direction perpendicular to the reflection direction toward the radar with a step size of at least 10 mm, and / or the first motor and / or the third motor is used to adjust the position of at least one of the third corner reflector and the fourth corner reflector to change the distance between the third corner reflector and the fourth corner reflector in a third movement direction perpendicular to the reflection direction toward the radar with a step size of at least 10 mm.

[0035] Therefore, this makes it possible to measure the radar's angular resolution with extremely high accuracy in a fully reproducible measurement setup.

[0036] In another possible implementation, the controller is configured to send a signal to the radar, wherein the signal triggers the radar to emit electromagnetic waves toward the plurality of corner reflectors and / or the signal further indicates one or more radar parameters that define the waveform of the electromagnetic waves to be emitted by the radar toward the plurality of corner reflectors.

[0037] Therefore, this enables the device to measure the angular resolution of the radar in a continuous and autonomous manner, and to efficiently determine the angular resolution of the radar.

[0038] According to a second aspect, a method for determining the angular resolution of a radar is provided. The method of the second aspect includes the following steps: controlling a first motor and a second motor to position a first corner reflector and / or a second corner reflector among a plurality of corner reflectors, wherein the first corner reflector and / or the second corner reflector is used to reflect electromagnetic waves from the radar along a reflection direction toward the radar; adjusting the position of at least one of the first corner reflector and the second corner reflector by the first motor to change a first distance between the first corner reflector and the second corner reflector in a first direction of movement perpendicular to the reflection direction toward the radar; adjusting the position of at least one of the first corner reflector and the second corner reflector by the second motor to change a second distance between the first corner reflector and the second corner reflector in a second direction parallel to the reflection direction toward the radar; receiving reflection measurement information of a plurality of first distances and / or a plurality of second distances from the radar; and determining the angular resolution of the radar based on the reflection measurement information received from the radar.

[0039] Therefore, an improved method is provided that helps to determine the angular resolution of radar in a stable and efficient manner with significantly higher accuracy.

[0040] The advantages of the method provided in the second aspect are the same as the advantages of the corresponding implementation method of the device provided in the first aspect.

[0041] According to a third aspect, a computer program product is provided, including a computer-readable storage medium for storing program code, which, when executed by a computer or processor, performs the method according to the second aspect described above. Therefore, an improved computer program product is provided that helps to determine the angular resolution of radar in a stable and efficient manner with significantly higher accuracy.

[0042] Details of one or more embodiments are set forth in the accompanying drawings and description. Other features, objectives, and advantages will be apparent from the description, drawings, and claims. Attached Figure Description

[0043] The embodiments are described in more detail below with reference to the accompanying drawings and schematic diagrams.

[0044] Figure 1 A diagram of an apparatus for determining the angular resolution of a radar, provided as an embodiment.

[0045] Figure 2 A diagram of another device for determining the angular resolution of a radar, provided for one embodiment.

[0046] Figure 3An exemplary corner reflector among a plurality of corner reflectors provided in one embodiment.

[0047] Figure 4 A flowchart illustrating the process by which a device determines the angular resolution of a radar, as provided in one embodiment.

[0048] Figure 5 An example of a verification report generated for a device provided in one embodiment.

[0049] Figure 6 A flowchart illustrating a method for determining the angular resolution of a radar, provided as an embodiment.

[0050] In the following text, the same reference numerals refer to the same or at least functionally equivalent features. Detailed Implementation

[0051] In the following description, reference is made to the accompanying drawings, which form part of this invention, and which illustrate specific aspects of embodiments of the invention or aspects in which embodiments of the invention may be used. It should be understood that embodiments may be used in other aspects and include structural or logical variations not depicted in the drawings. Therefore, the following detailed description should not be construed in a limiting sense, and the scope of the invention is defined by the appended claims.

[0052] For example, it should be understood that disclosures relating to a described method may also apply to corresponding devices or systems used to perform the method, and vice versa. For instance, if one or more specific method steps are described, the corresponding device may include one or more units, such as functional units, for performing the described one or more method steps (e.g., a unit performing the one or more steps, or multiple units each performing one or more of the plurality of steps), even if such units are not explicitly described or illustrated in the figures. On the other hand, for example, if a particular apparatus is described according to one or more units (e.g., functional units), the corresponding method may include a step to perform the function of one or more units (e.g., a step performing the function of the one or more units, or multiple steps each performing the function of one or more of the plurality of units), even if such steps are not explicitly described or illustrated in the figures. Furthermore, it should be understood that, unless otherwise indicated, features of the various exemplary embodiments and / or aspects described herein may be combined with each other.

[0053] The automotive industry requires an extremely intensive validation process during the development of radar systems, which may require significant resources to provide a clear assessment of the radar system's angular resolution.

[0054] In this regard, the embodiments provide a verification setup in an anechoic chamber to evaluate the angular resolution performance of a radar under test (RUT) by placing corner reflectors at different angular distances in two dimensions, such as azimuth and elevation, where the two corner reflectors are located within the same range and have the same relative velocity as the RUT. This verification setup can be fully automated and can be configured to any desired angular position.

[0055] Furthermore, it is necessary to resolve two objects of different sizes as separate entities, which is especially important when one object is significantly larger than the other. The implementation allows for the assembly of corner reflectors of different sizes to evaluate this critical use case.

[0056] Therefore, the embodiment provides a device with a controller that configures and monitors mechanical components for verifying the angular performance of a radar under test (RUT).

[0057] In one embodiment, the mechanical component is a housing equipped with four motors. In another embodiment, the housing is made of aluminum or plastic. A plastic housing reduces reflected energy. Each motor adjusts the position of a separate corner reflector, the exact position of which is determined by a controller. In another embodiment, two additional motors are installed that move with high accuracy over a very short displacement range to adjust the corner reflectors toward the RUT and to configure a precise phase difference between the corner reflectors.

[0058] In one embodiment, the mechanical settings of the device are monitored by a controller, which includes a software framework running in a general-purpose computer and is responsible for the following functions:

[0059] 1. Motor configuration: The controller sets each motor to its proper position and defines its required longitudinal displacement according to the angular distance to verify and accurately coordinate the complete cycle of the phase difference between the corner reflectors (in terms of setting the correct values ​​and proper timing);

[0060] 2. Radar Under Test (RUT) Configuration: The controller sets appropriate radar parameters (such as waveforms), triggers radar measurements, and collects the detection list generated by the RUT for each radar cycle time;

[0061] 3. Generation of verification report: Based on the received radar detection list and the different angular distances to be verified, the controller calculates the corresponding detection probability for each phase difference and generates the required graphs and figures to create a verification report.

[0062] Figure 1The figure shows an exemplary device 100 provided in one embodiment, which includes a plurality of corner reflectors 103a to 103d for reflecting electromagnetic waves from radar 111 along a reflection direction toward radar 111. In one embodiment, the plurality of corner reflectors 103a to 103d includes a first corner reflector 103a, a second corner reflector 103b, a third corner reflector 103c, and a fourth corner reflector 103d for reflecting electromagnetic waves from radar 111 along a reflection direction toward radar 111.

[0063] If possible Figure 1 As seen in the diagram, device 100 also includes a controller 101 for determining the angular resolution of radar 111 based on reflection measurement information received from radar 111. In one embodiment, the reflection measurement information includes a point cloud detection list generated by processing reflected electromagnetic waves from a plurality of corner reflectors 103a to 103d. This processing is typically performed by radar 111 itself. In one embodiment, controller 101 evaluates the point cloud detection list provided by radar 111 to determine the angular resolution of radar 111.

[0064] As in Figure 1 As can be further seen, the device 100 also includes: a first motor 105a for adjusting the position of at least one of the first corner reflector 103a and the second corner reflector 103b to change a first distance between the first corner reflector 103a and the second corner reflector 103b in a first direction of movement perpendicular to the reflection direction toward the radar 111; and a second motor 105b for adjusting the position of at least one of the first corner reflector 103a and the second corner reflector 103b to change a second distance between the first corner reflector 103a and the second corner reflector 103b in a second direction of movement parallel to the reflection direction toward the radar 111.

[0065] In one embodiment, controller 101 controls a first motor 105a and a second motor 105b to position a first corner reflector 103a and / or a second corner reflector 103b, and receives reflection measurement information for a plurality of first distances and / or a plurality of second distances from radar 111. In one embodiment, controller 101 determines the angular resolution of radar 111 by determining the phase difference between a first reflection signal from the first corner reflector 103a and a second reflection signal from the second corner reflector 103b for the plurality of first distances and / or the plurality of second distances.

[0066] In one embodiment, the first motor 105a is further configured to change the position of at least one of the third corner reflector 103c and the fourth corner reflector 103d in a third motion direction perpendicular to the reflection direction toward the radar 111 and perpendicular to the first motion direction, and the second motor 105b is further configured to change the position of at least one of the third corner reflector 103c and the fourth corner reflector 103d in a second motion direction parallel to the reflection direction toward the radar 111.

[0067] Additionally, the device 100 includes a third motor 105c for changing the position of at least one of the third corner reflector 103c and the fourth corner reflector 103d in a third motion direction perpendicular to the reflection direction toward the radar 111 and perpendicular to the first motion direction; and a fourth motor 105d for changing the position of at least one of the third corner reflector 103c and the fourth corner reflector 103d in a second motion direction parallel to the reflection direction toward the radar 111.

[0068] In one embodiment, the first corner reflector 103a and the second corner reflector 103b are used for horizontal movement, and the third corner reflector 103c and the fourth corner reflector 103d are used for vertical movement. That is, the first direction of movement extends horizontally along a plane perpendicular to the reflection direction toward the radar 111, and the third direction of movement extends vertically along a plane perpendicular to the reflection direction toward the radar 111.

[0069] It should be noted that the second motor 105b and / or the fourth motor 105d are used to change the position of at least one of the plurality of corner reflectors 103a to 103d in a second direction parallel to the reflection direction toward the radar 111 with a step size of less than 100 micrometers, wherein the step size represents the distance between the position of at least one of the plurality of corner reflectors and consecutive positions. Therefore, this enables the measurement of the angular resolution of the radar 111 with extremely high accuracy.

[0070] In one embodiment, the first motor 105a is used to adjust the position of at least one of the first corner reflector 103a and the second corner reflector 103b to change the first distance between the first corner reflector 103a and the second corner reflector 103b in a first direction perpendicular to the reflection direction toward the radar 111 in steps of at least 10 mm.

[0071] Similarly, the first motor 105a and / or the third motor 105c are used to adjust the position of at least one of the third corner reflector 103c and the fourth corner reflector 103d to change the distance between the third corner reflector 103c and the fourth corner reflector 103d in a third motion direction perpendicular to the reflection direction toward the radar 111 in steps of at least 10 mm.

[0072] In another embodiment, the device 100 includes a total of six motors 105a to 105f, wherein two motors 105b and 105c are used to move the first corner reflector 103a and the second corner reflector 103b in a first direction of motion, wherein two motors 105d and 105e are used to move the third corner reflector 103c and the fourth corner reflector 103d in a third direction of motion, and wherein two motors 105a and 105f are used to move at least one of the plurality of corner reflectors 103a to 103d in a second direction of motion.

[0073] In one embodiment, controller 101 is configured to send a signal to radar 111 to trigger radar 111 to emit electromagnetic waves toward a plurality of corner reflectors 103a to 103d. Furthermore, the signal indicates one or more radar parameters, such as the waveform of the electromagnetic waves to be emitted by radar 111 toward the plurality of corner reflectors 103a to 103d.

[0074] In another embodiment, one or more radar parameters for radar configuration are provided by the radar supplier to evaluate radar performance when radar 111 is operating in normal operating mode.

[0075] The controller 101 can be configured to position all motors 105a to 105f at any specific location to place multiple corner reflectors 103a to 103d, providing the device 100 with great versatility and enabling verification of radar power at any angular interval with high accuracy. Furthermore, the controller 101 can define the sequential addition of positions along the direction of motion for any corner reflector 103a to 103d, resulting in fully automated continuous testing.

[0076] In one embodiment, to perform a verification test on radar 111, it may be necessary to input only the minimum and maximum angular intervals to be evaluated, as well as the angular interval steps. With these parameters, controller 101 can automatically transmit the required position and timing displacement to motors 105a to 105f and should detail verification report 107, which includes information about the determined angular resolution of the radar under test.

[0077] The ability to distinguish between two stationary objects within the same range and RUTs of different sizes (i.e., δ radar cross-section; δRCS) is a critical requirement for automotive imaging radar. δRCS is defined as the size difference between two laterally adjacent objects being detected, measured in decibels (dB). Pedestrians standing next to large objects such as buildings, buses, or trucks are a very common use case in urban scenarios.

[0078] To this end, in one embodiment, a verification system is provided with corner reflectors 103a to 103d of different sizes mounted thereon, wherein the corner reflectors 103a to 103d are connected to motors 105a to 105f via mechanical adapters, which are effective for the different sized corner reflectors 103a to 103d. Enabling a setup where a weaker object (of smaller size) is close to a primary object (of larger size) is a key requirement for evaluating the angular resolution performance of radar 111.

[0079] Therefore, these embodiments enable the verification setup to accurately measure whether the radar under test (RUT) can resolve two static targets, such as corner reflectors 103a to 103d, at a given angular distance from the RUT.

[0080] For scenarios with only one target, Direction of Arrival (DoA) estimation is much simpler than for scenarios with multiple targets in the same Doppler cell. However, DoA estimation methods are entirely dependent on the antenna layout of the RUT, and processing must be consistent with the location of the physical components. The geometry of the antenna array directly affects the phase shift caused by the electromagnetic wave propagation path. In fact, DoA estimation differs in uniform linear arrays from that in sparse antenna configurations, to give a concrete example.

[0081] The problem to be solved is to estimate the direction of arrival of the incident target based on the measured array response. This assumes the target reflects light from a uniform linear array.

[0082] For a plane wave sampled on the receiving antenna, the relative phase shift at the m-th element corresponds to:

[0083] Where d represents the distance between the two antennas, and λ is the wavelength of the signal at the corresponding frequency.

[0084] When only one target exists, accuracy depends on: wavelength, signal-to-noise ratio (SNR) before DoA (Doppler), number of channels and their location distribution.

[0085] Using the simplified formula of =sin(), the Cramer-Rao lower limit is given by the following expression:

[0086]

[0087] If there are two targets (such as a reflector), the DoA estimate will be affected as follows:

[0088] 1. Power difference between targets (primarily defined by radar cross-section);

[0089] 2. The angular interval between two targets; and / or

[0090] 3. The phase difference between the two targets.

[0091] To validate the Direction of Arrival (DoA) algorithm and the radar's antenna layout, the radar separates two targets within the same range with the same velocity relative to the radar; the phase difference between the two targets is a key parameter. Since the radar's resolution capability depends on this phase difference, the implementation allows validation of the RUT's DoA algorithm along different (as many desired) phase differences, resulting in stable evaluations and excellent overall performance.

[0092] The embodiment implements a device 100 with a controller 101 that defines the motor displacement and the positions of reflectors 103a to 103d, thus enabling the configuration of the phase difference between reflectors 103a to 103d with very high accuracy and reproducibility, where high accuracy refers to the accuracy of the motor displacement. If a specific position of reflectors 103a to 103d is required for a defined setup, motors 105a to 105f place reflectors 103a to 103d in the accurate position. Reproducibility is the ability of device 100 to set reflectors 103a to 103d in exactly the same position they have previously been placed when a specific scene needs to be repeated.

[0093] The phase value from the received signal varies in the manner of λ, which corresponds to 3.9 mm in the application of automotive radar for transmitting electromagnetic waves at 77 GHz according to the embodiment. This is why so many tiny movement steps, on the order of 10 μm, are required, making accuracy challenging (<1 μm). Such a setup is typically not achievable by manually moving reflectors 103a to 103d.

[0094] Evaluating any angular performance based solely on a single physical setting between targets will lead to erroneous conclusions. Instead, embodiments enable a device 100 with a unique architecture to properly evaluate the angular performance of radar 111. Specifically, these embodiments may include assemblies of two reflectors 103a to 103d with different sizes (e.g., different radar cross-sections) to verify whether radar 111 can separate two reflectors 103a to 103d with different sizes. This scenario is crucial regarding angular detection performance.

[0095] These embodiments can also serve as a standard for evaluating mmWave radar performance in the industry because they significantly simplify the verification process for Radar 111 in terms of its angular resolution. They are adaptable to laboratory environments, saving considerable resources and even improving the safety of the verification process.

[0096] Furthermore, the embodiments may enable industry-related entities to formulate benchmarks based on the performance evaluated by device 100 using the embodiments. Applying the embodiments within the mmWave scope, automakers can validate several Layer 1 systems to obtain clear comparisons between all radars. This information is highly relevant during the project grant phase.

[0097] In another embodiment, Figure 2 As shown in the diagram of an exemplary device 100, the device 100 includes a controller 101 and a plurality of corner reflectors 103a to 103d for reflecting electromagnetic waves from radar 111 along a reflection direction toward radar 111. The plurality of corner reflectors 103a to 103d includes a first corner reflector 103a, a second corner reflector 103b, a third corner reflector 103c, and a fourth corner reflector 103d.

[0098] The device 100 also includes two or more motors 211, 213 ( Figure 2 (Not all shown) wherein at least one motor 211, 213 is used to move the first corner reflector 103a and the second corner reflector 103b in a first direction of motion perpendicular to the reflection direction toward the radar 111; at least one motor 211, 213 is used to move at least one of a plurality of corner reflectors 103a to 103d in a second direction of motion parallel to the reflection direction toward the radar 111; and at least one motor is used to move the third corner reflector 103c and the fourth corner reflector 103d upward in a third direction perpendicular to the reflection direction toward the radar 111. The first direction of motion extends horizontally along a plane perpendicular to the reflection direction toward the radar 111, and the third direction of motion extends vertically along a plane perpendicular to the reflection direction toward the radar 111.

[0099] from Figure 2 As can be seen, the device 100 also includes an absorption plate 201 having a front surface covered by an absorbing material for absorbing electromagnetic waves from the radar 111, wherein a plurality of corner reflectors 103a to 103d are disposed on one side of the absorption plate 201 having the front surface, and two or more motors 211, 213 are disposed on the other opposite side of the absorption plate 201.

[0100] In one embodiment, the absorber plate defines one or more slots 205a, 205b, and each of the plurality of corner reflectors 103a to 103d is for moving along a corresponding one of the one or more slots 205a, 205b.

[0101] In one embodiment, the device 100 further includes a movable frame (also referred to as a chassis) 207 having casters 209a to 209c disposed at the bottom of the movable frame 207, wherein an absorption plate 201, a plurality of corner reflectors 103a to 103d, and two or more motors 211, 213 are mounted on the frame 207. In one embodiment, the device 100 further includes a plurality of motor controllers 221 for controlling the two or more motors 211, 213. In one embodiment, the movable frame 207 may have a height of approximately 194 cm, a width of approximately 144 cm, and a depth of approximately 88 cm.

[0102] In one embodiment, the device 100 further includes one or more covers 203a to 203d for covering a plurality of corner reflectors 103a to 103d at a parking position, wherein the one or more covers 203a to 203d are made of a material for absorbing electromagnetic waves from radar 111.

[0103] The parking position is where corner reflectors 103a to 103d are physically covered by cover plates 203a to 203d, thus preventing them from reflecting their transmitted signals back to the radar and greatly reducing the reflections from their transmitted signals back to the radar, which can be considered negligible. In one embodiment, if a free line of sight exists, i.e., if all reflectors are visible, the radar 111 receives reflected signals from all corner reflectors 103a to 103d because multipath trajectories have been carefully suppressed in the anechoic chamber environment. If none of the reflectors 103a to 103d are in the parking position, the radar 111 detects all four reflectors 103a to 103d.

[0104] In one embodiment, in order to verify the radar's angular resolution in a stable manner and to avoid any potential coupling between the two dimensions (e.g., azimuth and elevation) during the estimation of the direction of arrival from reflectors 103a to 103d, it is recommended to use only two corner reflectors 103a to 103d that move along the azimuth or elevation dimension at the same time, wherein the other two corner reflectors 103a to 103d may be positioned at the parking position.

[0105] In one embodiment, such as Figure 2 The illustrated device 100 can be applied to determine the angular resolution of an automotive radar emitting electromagnetic waves in the 76 GHz to 81 GHz range. Each of the plurality of corner reflectors 103a to 103d moves only in a single direction (azimuth or elevation). The dynamic range of the displacement among the plurality of corner reflectors 103a to 103d is monitored by a controller 101. In one embodiment, the plurality of corner reflectors 103a to 103d move longitudinally (horizontally or vertically) by 400 mm, moving in 10 mm increments.

[0106] The corner reflectors cannot physically reach or exceed the intersection center point to prevent collisions between them. At the bottom of the rack 207, a plurality of motor controllers 221 are mounted and configured to connect to motors 211, 213, and the plurality of motor controllers 221 send control signals to motors 211, 213, which accordingly adjust the positions of the plurality of corner reflectors 103a to 103d.

[0107] Simultaneously, the phase motor can move the corner reflectors 103a to 103d with a shorter span but greater resolution. In one embodiment, the phase motor, triggered by the controller 101, can move the corner reflectors 103a to 103d over a span of 30 mm, moving 100 μm at a time. This resolution sequence is necessary because the phase is very sensitive and depends on λ.

[0108] from Figure 2 As can be seen, each of the multiple corner reflectors 103a to 103d is in the parking position and is covered by plexiglass plates 203a to 203d connected to an absorber plate 201 with four rods. For clarity, the cover plates 203a to 203d are... Figure 2 The covers are shown as transparent, but they should be covered by an absorbent material to ensure that the corner reflectors 103a to 103d do not interfere with any measurements in the anechoic chamber when placed in the parking position. In one embodiment, the size of the covers 203a to 203d may be adapted to potentially cover the largest corner reflectors 103a to 103d.

[0109] The physical dimensions of the multiple corner reflectors 103a to 103d depend, for example, on the operating frequency band and the required verification dynamic range (e.g., the set of angles to be tested).

[0110] In one embodiment, a plurality of corner reflectors 103a to 103d are used to reflect electromagnetic waves from the radar in a frequency range of about 60 GHz to about 90 GHz along a reflection direction toward the radar.

[0111] Figure 3 An exemplary corner reflector 300 comprising a plurality of corner reflectors 103a to 103d provided in one embodiment is shown, wherein the corner reflector 300 is a trihedral corner reflector 300 having a side length "a". In one embodiment, the plurality of corner reflectors 103a to 103d of device 100 have the same or different side lengths, wherein the radar cross-section of one or more of the plurality of corner reflectors 103a to 103d is in the range of 5 dBsm to 20 dBsm or L is in the range of approximately 80 mm to approximately 250 mm for corner reflectors, where L corresponds to the side length multiplied by 80 mm.

[0112] In one embodiment, corner reflectors 103a to 103d are placed at a distance of 9.2 meters (referred to as "D") from the radar under test (RUT).

[0113] In one embodiment, at least some of the corner reflectors 103a to 103d have different sizes. For example, the corner reflectors 103a to 103d used in the reconstructed scene are 5dBsm corner reflectors at 77GHz with L = 83 mm; 10dBsm corner reflectors at 77GHz with L = 110 mm; 15dBsm corner reflectors at 77GHz with L = 146 mm; and 20dBsm corner reflectors at 77GHz with L = 195 mm.

[0114] Since the closest possible location for the two trihedral corner reflectors 103a to 103d is corner to corner, the minimum distance between their phase centers is L. The minimum angular resolution of this configuration is arcsin(L / D) = arcsin(82.3 mm / 9200 mm) = 0.51°, where “L” represents the minimum distance between the phase centers of the two corner reflectors 103a to 103d, and “D” represents the distance between the radar and the corner reflectors 103a to 103d.

[0115] Figure 4 A flowchart of a process 400 for determining the angular resolution of a radar under test (RUT) by device 100 is provided for one embodiment, wherein the controller 101 of device 100 is used to evaluate the angular resolution performance of the RUT (at the level of 1 μm as described above) by setting different phase difference values ​​between the two corner reflectors 103a to 103d of device 100 with outstanding accuracy.

[0116] Specifically, Figure 4 A verification procedure for evaluating the angular resolution performance of the RUT is shown, where the input parameters are the maximum and minimum angular resolution locations (specifically between 4° and 1°) and the measurement step size (e.g., 1°). It should be noted that the values ​​of 4° and 1° are examples.

[0117] In one embodiment, the controller 101 of device 100 uses the motor of device 100 to place the corner reflectors 103a to 103d in their appropriate positions (corresponding to a 4° angular distance), determining the initial positions of the corner reflectors 103a to 103d, where the distance between the two corner reflectors 103a to 103d and the RUT is exactly the same (0° phase difference). In a static scene, the controller 101 triggers the radar to begin measurement.

[0118] Once the radar has processed the reflected signals from the corner reflectors and / or the corresponding detection list within a given cycle, the controller moves the motor toward the radar to set the next phase difference value accordingly. When the phase motor has moved toward the radar by at least a displacement corresponding to 720° of phase (meaning that each individual position between the reflectors has been evaluated twice), the controller 101 calculates the reflected signals from the corner reflectors and / or the detection list for each cycle and generates a metric of "detection probability per phase difference".

[0119] Once the metric is defined, the specific angular position is evaluated, and controller 101 establishes a continuous angular interval between corner reflectors 103a to 103d, initializing the phase difference between the corner reflectors to 0°. This complete process is repeated until a new metric for that angular position is generated. The loop ends when the minimum distance to be verified is reached; the number of iterations depends on the defined angle measurement step size.

[0120] Once the controller 101 has collected all periodic reflected signals from corner reflectors 103a to 103d and / or the detection list, and generated corresponding metrics up to the minimum angular interval, it generates a complete verification report that includes all detection probabilities for each phase difference value at all angular positions. When such a report is available, evaluating the radar's angular resolution performance is highly accurate because it has been characterized across the entire position span between corner reflectors 103a and 103d.

[0121] Process 400 includes the following steps: First, controller 101 adjusts the positions of corner reflectors 103a to 103d according to the required angular intervals. Figure 4 Step 401). Next, the controller 101 triggers the radar to start measurement by emitting electromagnetic waves to the corner reflectors 103a to 103d. Figure 4 Step 403), and the radar receives the reflected electromagnetic waves and processes the received data from the corner reflector. Figure 4 Step 405). After the radar sends the processed measurement information to the controller 101, the controller 101 determines the probability of individually detecting corner reflectors 103a to 103d based on the phase difference of a specific angular interval between corner reflectors 103a to 103d. Figure 4 Step 407). Finally, the controller 101 generates a verification report including the detection probability as a function of the phase difference for all possible angular interval values ​​between the corner reflectors 103a and 103d. Figure 4 Step 409).

[0122] Figure 5An example of a verification report 500 generated by the device is shown in one embodiment, wherein the device 100 has performed the complete verification process as described above. The verification report 500 includes information about the determined angular resolution of the radar, and in particular about the probability of individually detecting the plurality of corner reflectors 103a to 103d as a function of phase difference.

[0123] from Figure 5 As can be seen, the solid lines show the detection probabilities of two corner reflectors 103a to 103d spaced apart as a function of their phase difference, at given angular intervals (4°, 3°, 2°, and 1°, respectively). On the other hand, Figure 5 The dashed line shown illustrates the average detection probability measured by a simple but incomplete performance evaluation.

[0124] All depiction values ​​are configurable, offering high flexibility and stability to verify any desired angular interval. Given the above, the embodiments may be adapted to meet industry standards based on unique verification quality.

[0125] Figure 6 A flowchart of a method 600 for determining the angular resolution of a radar is provided for one embodiment. Method 600 includes the following steps: controlling 601 a first motor and a second motor to position a first corner reflector and / or a second corner reflector among a plurality of corner reflectors, wherein the first corner reflector and / or the second corner reflector is used to reflect electromagnetic waves from the radar along a reflection direction toward the radar; adjusting 603 the position of at least one of the first corner reflector and the second corner reflector by the first motor to change a first distance between the first corner reflector and the second corner reflector in a first direction of movement perpendicular to the reflection direction toward the radar; adjusting 605 the position of at least one of the first corner reflector and the second corner reflector by the second motor to change a second distance between the first corner reflector and the second corner reflector in a second direction parallel to the reflection direction toward the radar; receiving 607 reflection measurement information of a plurality of first distances and / or a plurality of second distances from the radar; and determining 609 the angular resolution of the radar based on the reflection measurement information received from the radar.

[0126] Several embodiments are provided in this application, and it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely exemplary. For example, the unit division is merely a logical functional division and may be other divisions in actual implementation. For example, multiple units or components may be merged or integrated into another system, or some features may be ignored or not performed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be implemented through some interface. Direct coupling or communication connection between apparatuses or units may be implemented electronically, mechanically, or otherwise.

[0127] The units described as discrete parts may or may not be physically separate. The parts shown as units may or may not be physical units; they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0128] In addition, the functional units in the embodiments may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

Claims

1. A device (100) for determining the angular resolution of a radar (111), characterized in that, include: Multiple corner reflectors (103a to 103d), including a first corner reflector (103a) and a second corner reflector (103b), are used to reflect electromagnetic waves from the radar (111) along a reflection direction toward the radar (111); A first motor (105a) is used to adjust the position of at least one of the first corner reflector (103a) and the second corner reflector (103b) to change a first distance between the first corner reflector (103a) and the second corner reflector (103b) in a first movement direction perpendicular to the reflection direction toward the radar (111); A second motor (105b) is used to adjust the position of at least one of the first corner reflector (103a) and the second corner reflector (103b) to change a second distance between the first corner reflector (103a) and the second corner reflector (103b) in a second movement direction along the reflection direction toward the radar (111); A controller (101) is configured to control the first motor (105a) and the second motor (105b) to position the first corner reflector (103a) and / or the second corner reflector (103b), and to receive reflection measurement information of multiple first distances and / or multiple second distances from the radar (111). The controller (101) is further configured to determine the angular resolution of the radar (111) based on the reflection measurement information received from the radar (111).

2. The device (100) according to claim 1, characterized in that, The controller (101) is configured to determine the angular resolution of the radar (111) by determining the phase difference between a first reflected signal from the first corner reflector (103a) and a second reflected signal from the second corner reflector (103b) for the plurality of first distances and / or the plurality of second distances.

3. The device (100) according to claim 1 or 2, characterized in that, The controller (101) is used to generate a verification report (107), which includes information about the determined angular resolution.

4. The device (100) according to claim 1 or 2, characterized in that, The plurality of corner reflectors (103a to 103d) further include a third corner reflector (103c) and a fourth corner reflector (103d) for reflecting electromagnetic waves from the radar (111) along a reflection direction toward the radar (111). The first motor (105a) is also used to change the position of at least one of the third corner reflector (103c) and the fourth corner reflector (103d) in a third motion direction that is perpendicular to the reflection direction toward the radar (111) and perpendicular to the first motion direction. The second motor (105b) is also used to change the position of at least one of the third corner reflector (103c) and the fourth corner reflector (103d) in a second movement direction along the reflection direction toward the radar (111).

5. The device (100) according to claim 1 or 2, characterized in that, The plurality of corner reflectors (103a to 103d) further include a third corner reflector (103c) and a fourth corner reflector (103d) for reflecting electromagnetic waves from the radar (111) along a reflection direction toward the radar (111); the device (100) further includes: a third motor (105c) for changing the position of at least one of the third corner reflector (103c) and the fourth corner reflector (103d) in a third motion direction perpendicular to the reflection direction toward the radar (111) and perpendicular to the first motion direction; and a fourth motor (105d) for changing the position of at least one of the third corner reflector (103c) and the fourth corner reflector (103d) in a second motion direction along the reflection direction toward the radar (111).

6. The device (100) according to claim 1 or 2, characterized in that, At least some of the plurality of corner reflectors (103a to 103d) have different sizes.

7. The device (100) according to claim 5, characterized in that, It also includes an absorption plate (201) having a front surface covered with an absorbing material for absorbing electromagnetic waves from the radar (111), wherein the plurality of corner reflectors (103a to 103d) are disposed on one side of the absorption plate (201) having the front surface, and the first, second, third and / or fourth motors (105a to 105d) are disposed on the other opposite side of the absorption plate (201).

8. The device (100) according to claim 7, characterized in that, The absorption plate (201) defines one or more slots (205a, 205b), each of the plurality of corner reflectors (103a to 103d) being movable along a corresponding one of the one or more slots (205a, 205b).

9. The device (100) according to claim 7 or 8, characterized in that, It also includes a movable frame (207), wherein the movable frame (207) has casters (209a to 209c) disposed at the bottom of the movable frame (207), and the absorption plate (201), the plurality of corner reflectors (103a to 103d) and the first, second, third and / or fourth motors (105a to 105d) are mounted on the movable frame (207).

10. The device (100) according to claim 1 or 2, characterized in that, It also includes one or more covers (203a to 203d) for covering the plurality of corner reflectors (103a to 103d) in the parking position, the one or more covers (203a to 203d) being made of a material for absorbing electromagnetic waves from the radar (111).

11. The device (100) according to claim 5, characterized in that, The second motor (105b) and / or the fourth motor (105d) are used to change the position of at least one of the plurality of corner reflectors (103a to 103d) in a second movement direction along the reflection direction toward the radar (111) in steps of less than 100 micrometers.

12. The device (100) according to claim 5, characterized in that, The first motor (105a) is used to adjust the position of at least one of the first corner reflector (103a) and the second corner reflector (103b) to change the first distance between the first corner reflector (103a) and the second corner reflector (103b) in a first direction perpendicular to the reflection direction toward the radar (111) with a step size of at least 10 mm, and / or the first motor (105a) and / or the third motor (105c) are used to adjust the position of at least one of the third corner reflector (103c) and the fourth corner reflector (103d) to change the distance between the third corner reflector (103c) and the fourth corner reflector (103d) in a third movement direction perpendicular to the reflection direction toward the radar (111) with a step size of at least 10 mm.

13. The device (100) according to claim 1 or 2, characterized in that, The controller (101) is used to send a signal to the radar (111), wherein the signal triggers the radar (111) to transmit electromagnetic waves to the plurality of corner reflectors (103a to 103d) and / or the signal also indicates one or more radar parameters, the one or more radar parameters defining the waveform of the electromagnetic waves to be transmitted by the radar (111) to the plurality of corner reflectors (103a to 103d).

14. A method (600) for determining the angular resolution of a radar (111), characterized in that, include: Control (601) a first motor (105a) and a second motor (105b) to position a first corner reflector (103a) and / or a second corner reflector (103b) among a plurality of corner reflectors (103a to 103d), wherein the first corner reflector (103a) and / or the second corner reflector (103b) are used to reflect electromagnetic waves from the radar (111) along a reflection direction toward the radar (111); The position of at least one of the first corner reflector (103a) and the second corner reflector (103b) is adjusted (603) by the first motor (105a) to change the first distance between the first corner reflector (103a) and the second corner reflector (103b) in a first movement direction perpendicular to the reflection direction toward the radar (111); The position of at least one of the first corner reflector (103a) and the second corner reflector (103b) is adjusted (605) by the second motor (105b) to change the second distance between the first corner reflector (103a) and the second corner reflector (103b) in a second direction along the reflection direction toward the radar (111); Receive (607) multiple first distance and / or multiple second distance reflection measurement information from the radar (111); Based on the reflection measurement information received from the radar (111), the angular resolution of the radar (111) is determined (609).

15. A computer program product, characterized in that, Includes a computer-readable storage medium for storing program code, which, when executed by a computer or processor, causes the computer or processor to perform the method (600) according to claim 14.

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