Radar systems with paired one-dimensional and two-dimensional antenna arrays

Abstract

This document describes the techniques and systems for radar systems with paired one-dimensional (1D) and two-dimensional (2D) antenna arrays. Even with fewer antenna elements compared to conventional radar systems, the paired arrays allow the example radar system to achieve comparable angular resolution at a lower cost. For example, a 1D array includes antenna elements positioned in a first direction (e.g., azimuth direction) and spaced apart by a first and a second distance. A 2D array includes at least four additional antenna elements positioned in a first and a second direction (e.g., elevation direction). The additional antenna elements are spaced apart by a third distance in the second direction and by the sum of the first and second directions in the first direction. A processor can use a shared angle estimate to correlate the angles of corresponding objects in the first and second directions.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 142,434, filed January 27, 2021, pursuant to 35U.SC119(e), the disclosure of which is incorporated herein by reference in its entirety. Background Technology

[0003] Radar systems use antennas to transmit and receive electromagnetic (EM) signals for detecting and tracking objects. In automotive applications, radar antennas may comprise a two-dimensional (2D) array of elements to measure the azimuth and elevation angles associated with an object. The resolution of azimuth and elevation angles is roughly proportional to the aperture size of the array. Achieving a large aperture using a 2D array could require many antenna elements, increasing cost. Maintaining the angular resolution of the radar system for both azimuth and elevation estimation with minimal antenna elements and cost is desirable. Summary of the Invention

[0004] This document describes the techniques and systems for radar systems with paired one-dimensional (1D) and 2D antenna arrays. Even with far fewer antenna elements compared to conventional radar systems, the paired arrays allow the example radar system to achieve comparable angular resolution at a lower cost and with lower complexity. For example, the radar system includes a processor and antennas that receive electromagnetic energy reflected by one or more objects. The antennas include 1D (e.g., linear) and 2D arrays. The 1D array includes antenna elements positioned in a first direction (e.g., azimuth direction) and spaced apart by a first and a second distance in that direction. The 2D array includes at least four additional antenna elements positioned in the first direction and a second direction orthogonal to the first direction (e.g., elevation direction). The additional antenna elements are spaced apart by a third distance in the second direction and by the sum of the first and second directions in the first direction. The processor can use the electromagnetic energy received by the 1D array to determine a first and a second angle associated with one or more objects in the first direction. The processor can also use the electromagnetic energy received by the 2D array to determine a third and a fourth angle associated with one or more objects. The third angle is in the first direction, and the fourth angle is in the second direction. The processor can then use the second and third angles to associate the first and fourth angles with corresponding objects in one or more objects.

[0005] This document also describes the methods performed by the systems summarized above and other configurations of the radar systems described herein, as well as the apparatus for performing these methods.

[0006] This invention provides a simplified concept related to radar systems having paired 1D and 2D antenna arrays, which is further described in the detailed description and accompanying drawings. This invention is not intended to identify essential features of the claimed subject matter, nor is it intended to define the scope of the claimed subject matter. Attached Figure Description

[0007] In this document, details of one or more aspects of a radar system having paired 1D and 2D antenna arrays are described with reference to the following figures. The same numbers are generally used throughout the figures to refer to similar features and components:

[0008] Figure 1 An example environment is shown where a radar system with paired 1D and 2D antenna arrays can be implemented;

[0009] Figure 2A and Figure 2B An example antenna with paired 1D and 2D antenna arrays is shown;

[0010] Figure 3 An example conceptual diagram of a radar system with paired 1D and 2D antenna arrays is shown;

[0011] Figure 4 An example conceptual diagram is shown, illustrating an angle-finding module that uses paired 1D and 2D antenna arrays to correlate azimuth and elevation angles to the corresponding objects.

[0012] Figure 5 Another example concept diagram of a radar system with paired 1D and 2D antenna arrays is shown;

[0013] Figure 6 Another example conceptual diagram shows an angle determination module that uses paired 1D and 2D antenna arrays to correlate azimuth and elevation angles to corresponding objects; and

[0014] Figure 7 An example method for a radar system with paired 1D and 2D antenna arrays and an angle determination module is shown. Detailed Implementation

[0015] Overview

[0016] Radar systems can be configured as a crucial sensing technology that vehicle-based systems can use to acquire information about their surroundings. For example, vehicle-based systems can use radar systems to detect objects in or near a road and take necessary actions (e.g., reduce speed, change lanes) to avoid collisions. Radar systems typically include at least two antennas to transmit and receive EM radiation. Some radar systems include a receiving antenna with a one-dimensional (1D) linear array of antenna elements to measure the azimuth or elevation angle associated with an object. Such radar systems can estimate a single angle (e.g., elevation or azimuth) associated with an object. Larger apertures in the azimuth or elevation directions can increase the number of antenna elements and cost to provide sufficient angular resolution.

[0017] Some other radar systems include a receiving antenna with a two-dimensional (2D) planar array of antenna elements to estimate both the azimuth and elevation angles of an object. In such radar systems, digital beamforming can be used to estimate the angular position of the object. In digital beamforming, the radar system characterizes the angular information of the object by analyzing the relative phase across the antenna elements using a 2D Fast Fourier Transform (FFT). The angular resolution of such radar systems typically depends on the aperture size of the 2D planar array. A larger aperture size improves angular resolution but requires additional antenna elements and increases cost.

[0018] Other radar systems include receiving antennas in sparse 2D arrays with antenna elements. Such systems can use azimuth linear arrays and elevation linear arrays to estimate the azimuth and elevation angles of an object, respectively. These systems use matching algorithms to associate azimuth and elevation angles for each object. Although such systems typically include fewer antenna elements than planar 2D arrays, the increased aperture size often introduces grating lobes into the radiation pattern, especially when the array spacing is greater than half the wavelength of the EM signal. For many applications, including automotive applications, angle determination using these systems can also be overly complex.

[0019] In contrast, this document describes techniques and systems for providing receiving antennas with paired 1D and 2D arrays to support angle measurement features. For example, a radar system may include antenna arrays with a first sparse 1D array and a sparse 2D array. The 1D array is positioned in a first direction (e.g., an elevation or azimuth direction) and includes multiple antenna elements spaced apart by a first and a second distance. The 2D array includes multiple antenna elements spaced apart by the sum of the first and second distances in the first direction, and spaced apart by a third and / or a fourth distance in the second direction (e.g., an azimuth or elevation direction). The second direction is orthogonal to the first direction. In this way, the described systems and techniques reduce the number of antenna elements while maintaining angular resolution that can otherwise be achieved using rectangular 2D arrays with similar aperture sizes.

[0020] The radar system uses the EM energy received from paired 1D and 2D arrays to estimate the elevation and azimuth angles associated with one or more nearby objects. The radar system can then associate the elevation and azimuth angles with corresponding objects among the one or more objects. In this way, the computational complexity of the described radar system in associating azimuth and elevation angles with corresponding objects is similar to that of a conventional radar system with a conventional 2D planar array. The described angle determination technique can be applied to various configurations of the described paired 1D and 2D arrays.

[0021] This example is merely one illustration of the technology and systems used in a radar system with paired 1D and 2D antenna arrays. Other examples and implementations are described in this document.

[0022] Operating environment

[0023] Figure 1 An example environment 100 is shown, in which a radar system 102 with paired 1D and 2D antenna arrays can be implemented. In the depicted environment 100, the radar system 102 is mounted to or integrated into a vehicle 104. The radar system 102 can detect one or more objects 120 in the vicinity of the vehicle 104. Although shown as a car, the vehicle 104 can represent other types of motorized vehicles (e.g., cars, motorcycles, buses, tractors, semi-trailers), non-motorized vehicles (e.g., bicycles), rail vehicles (e.g., trains), water vehicles (e.g., boats), aircraft (e.g., airplanes), or spacecraft (e.g., satellites). Typically, manufacturers can mount the radar system 102 to any mobile platform, including mobile machinery or robotic equipment.

[0024] In the depicted implementation, radar system 102 is mounted on the front of vehicle 104 and illuminates object 120. Radar system 102 can detect object 120 from any external surface of vehicle 104. For example, radar system 102 can be integrated into a bumper, side mirror, headlight, taillight, or any other internal or external location where object 120 needs to be detected. In some cases, vehicle 104 includes multiple radar systems 102, such as a first radar system 102 and a second radar system 102 providing a larger field of view. Typically, radar system 102 can be designed with portions of radar system 102 distributed at different locations on vehicle 104 to provide a specific field of view encompassing the region of interest. Example fields of view include 360-degree fields of view, one or more 180-degree fields of view, one or more 90-degree fields of view, etc., which may overlap or be combined into a field of view of a specific size.

[0025] Object 120 is made of one or more materials that reflect radar signals. Depending on the application, object 120 may represent a target of interest. In some cases, object 120 may be a moving object (e.g., another vehicle) or a stationary object (e.g., a roadside sign).

[0026] Radar system 102 emits EM radiation by transmitting EM signals or waveforms via antenna elements. In environment 100, radar system 102 can detect and track object 120 by transmitting and receiving one or more radar signals. For example, radar system 102 may transmit EM signals between 100 and 400 GHz, between 4 and 100 GHz, or between approximately 70 and 80 GHz.

[0027] Radar system 102 may include a transmitter 106 and at least one antenna 110 for transmitting EM signals. Radar system 102 may also include a receiver 108 and at least one antenna 110 for receiving a reflected version of the EM signal. Transmitter 106 includes one or more components for transmitting EM signals. Receiver 108 includes one or more components for detecting reflected EM signals. Transmitter 106 and receiver 108 may be integrated together on the same integrated circuit (e.g., a transceiver integrated circuit) or separately on different integrated circuits. In other implementations, radar system 102 does not include a separate antenna 110, but transmitter 106 and receiver 108 each include an antenna or antenna element.

[0028] The radar system 102 also includes one or more processors 112 (e.g., energy processing units) and a computer-readable storage medium (CRM) 114. The processor 112 may be a microprocessor or a system-on-a-chip. The processor 112 can execute instructions stored in the CRM 114. For example, the processor 112 can process EM energy received by the antenna 110 and use the angle determination module 116 to determine the position of the object 120 relative to the radar system 102. The processor 112 can also generate radar data for at least one vehicle system. For example, the processor 112 can control an autonomous or semi-autonomous driving system of the vehicle 104 based on the processed EM energy from the antenna 110.

[0029] Angle determination module 116 acquires the EM energy received by antenna 110 or receiver 108 and determines the azimuth and elevation angles associated with object 120. Angle determination module 116 may be implemented as instructions, hardware, software, or a combination thereof in CRM 114 executed by processor 112.

[0030] Radar system 102 can determine the distance to object 120 based on the time taken for EM signals to travel from radar system 102 to object 120 and back from object 120 to radar system 102. Radar system 102 can also use angle determination module 116 to determine the position of object 120 based on azimuth angle 128 and elevation angle 130 based on the direction of the maximum amplitude echo signal received by radar system 102.

[0031] As an example, Figure 1 A vehicle 104 traveling on road 118 is shown. A radar system 102 detects an object 120 in front of the vehicle 104. The radar system 102 may define a coordinate system having an x-axis 122 (e.g., in the direction of travel along road 118), a y-axis 124 (e.g., perpendicular to the x-axis 122 and along the surface of road 118), and a z-axis 126 (e.g., perpendicular to the surface of road 118). The radar system 102 may locate the object 120 based on an azimuth angle 128 and an elevation angle 130. The azimuth angle 128 may represent the horizontal angle from the x-axis 122 to the object 120. The elevation angle 130 may represent the vertical angle from the surface of road 118 (e.g., the plane defined by the x-axis 122 and y-axis 124) to the object 120.

[0032] Vehicle 104 may also include at least one vehicle system that relies on data from radar system 102, such as a driver assistance system, autonomous driving system, or semi-autonomous driving system. Radar system 102 may include an interface that interfaces with the data-dependent vehicle system. For example, processor 112 outputs a signal based on EM energy received by receiver 108 or antenna 110 via this interface.

[0033] Typically, automotive systems use radar data provided by radar system 102 to perform functions. For example, a driver assistance system may provide blind spot monitoring and generate an alert indicating a potential collision with object 120 detected by radar system 102. In such implementations, radar data from radar system 102 indicates when changing lanes is safe or unsafe. An autonomous driving system may move vehicle 104 to a specific location on road 118 while avoiding a collision with object 120 detected by radar system 102. The radar data provided by radar system 102 can provide information about the distance to object 120 and the position of object 110, enabling the autonomous driving system to perform emergency braking, lane changes, or adjust the speed of vehicle 104.

[0034] Figure 2A and Figure 2B An example antenna 200 with paired 1D and 2D arrays is shown. Antenna 200 (e.g., antenna 200-1 and antenna 200-2) is... Figure 1 An example of an antenna 110 in radar system 102 has similar components. Antenna 200 includes multiple antenna elements 208. Antenna elements 208 represent the physical location or phase center location of the elements of 1D array 204 and 2D array 206. Antenna elements 208 can also represent the combined location or phase center location of the elements of antenna 200 formed by multiple-input multiple-output (MIMO) technology.

[0035] Fixed to a printed circuit board (PCB) 202, the antenna 200 includes a 1D array 204 (e.g., an azimuth array) in a first direction and a 2D array 206 (e.g., 2D array 206-1 and 2D array 206-2) in the first direction (e.g., the azimuth direction) and a second direction orthogonal to the first direction (e.g., the elevation direction). In other implementations, the antenna 200 may be manufactured using different materials, components, and techniques. For example, the antenna 200 may include a lens antenna, a metallized plastic antenna, a dish antenna, a horn antenna, or a combination thereof.

[0036] In operation, antenna 200 can receive EM energy reflected by one or more objects 120. In the depicted implementation, 1D array 204 is positioned in the azimuth direction. In other implementations, 1D array 204 may be positioned in the elevation direction or another direction. In the depicted implementation, 1D array 204 is positioned below 2D arrays 206-1 and 206-2. In other implementations, 1D array 204 may be positioned above or to the side of 2D arrays 206-1 or 206-2. For example, 1D array 204 and 2D arrays 206-1 or 2D array 206-2 may be configured or arranged in an approximately T-shape (e.g., 1D array 204 is above 2D array 206-1), an approximately inverted T-shape (e.g., 1D array 204 is below 2D array 206-1), or an approximately cross-shaped configuration (e.g., 1D array 204 is positioned through approximately the center of 2D array 206-1).

[0037] The 1D array 204 is a sparse linear array comprising multiple antenna elements 208. The antenna elements 208 are alternately spaced apart by a first distance d1 210 and a second distance d2 212. For Figure 2A The antenna 200-1 shown is moved from left to right, and the antenna elements 208 of the 1D array 204 are separated by a first distance 210, a second distance 212, a third distance 210, a fourth distance 212, and so on. Every other antenna element 208 of the 1D array 204 is separated by a third distance d3 214, where the third distance d3 214 represents the sum of the first distance 210 and the second distance 212. In other words, the 1D array 204 can be formed by two uniform linear arrays, both of which include antenna elements 208 spaced apart by the third distance 214 and are offset by the first distance 210.

[0038] The antenna elements 208 of the 2D array 206 can be arranged in an approximately rectangular shape, such as... Figure 2A and Figure 2B As shown. These antenna elements 208 can be positioned close to the antenna elements 208 of the 1D array (e.g., as shown). Figure 2A and Figure 2B (As shown). In other implementations, the antenna elements 208 of the 2D array 206 may overlap with the antenna elements 208 of the 1D array 204 (e.g., the 1D array may be positioned at the lateral ends of the 2D array 206 or between the lateral ends of the 2D array 206), or may be separated from the antenna elements 208 of the 1D array 204. The antenna elements 208 of the 2D array 206 may be arranged in a two-dimensional sparse array, such as... Figure 2A and Figure 2B As shown. The specific arrangement of the 1D array 204 and the 2D array 206 can be selected based on the position and arrangement of other components in the radar system 102.

[0039] The 2D array 206 is a sparse 2D array comprising at least four antenna elements 208. The antenna elements 208 are spaced apart by a third distance 214 in the azimuth direction (or the same direction as the 1D array 204). Figure 2A The antenna elements 208 of the 2D array 206-1 in the antenna 200-1 are spaced apart by a fourth distance d4 214 in the elevation direction (or in a direction orthogonal to the direction of the 1D array 204). Figure 2B The antenna elements 208 of the 2D array 206-2 in antenna 200-2 are alternately spaced at a fourth distance 216 and a fifth distance d5 218 in the elevation direction (or in a direction orthogonal to the direction of the 1D array 204). For Figure 2B The antenna 200-2 shown is moved from top to bottom. The antenna elements 208 of the 2D array 206-2 are separated by a fourth distance 216, a fifth distance 218, a fourth distance 216, a fifth distance 218, and so on, in the elevation direction. Every other antenna element 208 of the 2D array 204 is separated by a sixth distance d6 220 in the elevation direction, where the sixth distance d6 220 represents the sum of the fourth distance 216 and the fifth distance 218. In other words, the 2D array 206-2 can be formed by two uniform 2D arrays, both of which include antenna elements 208 spaced apart by a sixth distance 220 in the elevation direction, and these two uniform 2D arrays are offset by a fourth distance 216. (See also: Regarding...) Figures 3 to 6 The angle measurement module 116 uses a first distance 210, a second distance 212, a third distance 214, a fourth distance 216, a fifth distance 218 and / or a sixth distance 220 to associate the elevation angle with the azimuth angle for the corresponding object 120.

[0040] 1D array 204 and 2D array 206 include multiple antenna elements 208. 1D array 204 may include M antenna elements 208. 2D array 206 may include N antenna elements 208 not included in 1D array 204 (e.g., at least four). In automotive applications, the number of antenna elements 208 in 2D array 206 may be larger than the maximum expected number of objects 120 to be detected by radar system 102. The number N of antenna elements 208 in 2D array 206 is typically less than the product of M and P, where P represents the number of antenna elements 208 in the elevation direction of 2D array 206. In some implementations, N is less than half the product of M and P (e.g., ...). The total number of antenna elements 208 in antenna 200 is typically equal to M+N. The number of antenna elements 208 in antenna 200 (e.g., M+N) is typically much smaller than the number of antenna elements 208 in a rectangular array (e.g., M×P) with the same aperture size.

[0041] exist Figure 2A In the depicted implementation, the 1D array 204 includes 14 antenna elements 208, and the 2D array 206 includes 16 antenna elements 208 not included in the 1D array 204. Antenna 200-1 includes 30 antenna elements 208, significantly smaller than the 80 antenna elements included in a rectangular array with the same aperture size. In other implementations, the 1D array 204 and 2D array 206 may include fewer or additional antenna elements 208. The 2D array 206 typically includes at least four antenna elements 208 not included in the 1D array 204.

[0042] 1D array 204 and 2D array 206 can be planar arrays providing high gain and low loss. Planar arrays are well-suited for vehicle integration due to their small size. For example, antenna element 208 can be a slot etched or otherwise formed in an electroplated material on one surface of PCB 206 for use as a substrate-integrated waveguide (SIW) antenna. As another example, antenna element 208 can be a radiating slot of a waveguide antenna constructed of metallized plastic and / or metal. Antenna element 208 can also be part of an aperture antenna, microstrip antenna, or dipole antenna. For example, 1D array 204 and 2D array 206 can include subarrays of patch elements (e.g., microstrip patch antenna subarrays) or dipole elements.

[0043] Figure 3 An example concept diagram 300 shows a radar system with paired 1D and 2D arrays and an angle measurement module 116. Figure 3 The radar system can be, for example, Figure 1 The radar system 102 includes a pair of 1D arrays and 2D arrays. In the depicted implementation, the radar system 102 includes a 1D array 204 and a 2D array 206-1 of antennas 200-1, which can be arranged in various positions, including... Figure 2A The arrangement shown.

[0044] At 304, the angle determination module 116 obtains the EM energy 302 received by the 1D array 204 and determines azimuth estimates 306 and 308 associated with one or more objects 120. For example, the angle determination module 116 can determine the azimuth estimate 306, θ1, θ2, ..., θ8 based on a first distance d1210. N Where N represents the estimated number of targets. The angle determination module 116 can also determine the azimuth estimate 308 based on the third distance d3214. The third distance d3214 represents the sum of the first distance 210 and the second distance 212.

[0045] At 312, the angle determination module 116 acquires the EM energy 310 received by the 2D array 206-1 and determines an azimuth estimate 314 and an elevation estimate 316 associated with one or more objects 120. For example, the angle determination module 116 can determine the azimuth estimate 314 based on a third distance d1210. The angle measurement module 116 can also determine the elevation angle estimate 316, φ1, φ2, ..., φ based on the fourth distance 216d4. N .

[0046] The angle determination module 116 can use various angle determination functions to determine azimuth estimates 306, azimuth estimates 308, azimuth estimates 314, and elevation estimates 316 based on EM energies 302 and EM energies 310. As a non-limiting example, the angle determination module 116 can use pseudospectral functions (including Spatial Alternating Generalized Expectation-Maximization (SAGE), Delayed Sum (DS), Minimum Variance Distortionless Response (MVDR), and / or functions based on Multi-Signal Classification (MUSIC)) to calculate the direction of arrival of the EM signals received by the 1D array 204 and the 2D array 206-1. As another example, the angle determination module 116 can use the Estimation of Signal Parameters via Rotational Invariance Technique (ESPRIT) or FFT beamforming to calculate the azimuth estimates 306, azimuth estimates 308, azimuth estimates 314, and elevation estimates 316. The angle determination module 116 can determine the azimuth and elevation angle estimates with relatively low processing complexity and cost.

[0047] At 318, the angle determination module 116 associates an azimuth estimate 306 and an elevation estimate 316 for object 120 based on common (e.g., shared) azimuth estimates 308 and 314. Specifically, the angle determination module 116 determines an azimuth estimate 306 and an elevation estimate 316 associated with each of one or more objects 120. (Refer to...) Figure 4 A more detailed description of an example of concept diagram 300.

[0048] Figure 4 An example conceptual diagram 400 illustrates how azimuth estimation 306 and elevation estimation 316 are associated with the angle determination module of the corresponding object 120. For example, Figure 4 Angle measurement module can be Figures 1 to 3 Angle measurement module 116. (Refer to...) Figure 3 As described, the angle measurement module 116 determines the azimuth estimate 306 and elevation estimate 316 associated with the object 120.

[0049] At position 402, the angle measurement module 116 can form or generate a complex covariance matrix based on the EM energy 302 and EM energy 310 received by the 1D array 204 and 2D array 206-1, respectively. For example, the angle measurement module 116 can form the complex covariance matrix R using equation (1):

[0050] R = xx H (1)

[0051] Where x represents the measurements from EM energies 302 and 310, and H represents the Hermitian matrix of x (e.g., a self-adjoint matrix). The Hermitian matrix is ​​a complex square matrix equal to its own conjugate transpose (e.g., the element in the i-th row and j-th column is equal to the complex conjugate of the element in the j-th row and i-th column).

[0052] At 404, the angle determination module 116 can use eigenvalue decomposition to estimate the number of targets N (e.g., detected object 120) and the signal subspace E from the complex covariance matrix R. s .

[0053] At position 406, the angle measurement module 116 can select the signal subspace E. s The elements corresponding to the 1D array 204 are used to determine the azimuth estimates 306, θ1, θ2, ..., θ6. N And the azimuth estimate is 308. Where N represents the estimated number of objects 120. The angle determination module 116 can, for example, apply a single two-dimensional signal parameter estimation (ESPRIT) using rotation-invariant techniques to estimate the azimuth angle. Azimuth angle estimation 306 is based on a first distance 210, and azimuth angle estimation 308 is based on a third distance 214. In other implementations, the angle determination module 116 can use other pseudospectral functions (including Spatial Alternating Generalized Expectation-Maximization (SAGE), Delayed Sum (DS), Minimum Variance Distortionless Response (MVDR), and / or functions based on Multi-Signal Classification (MUSIC)) to calculate the direction of arrival of the EM signal received by the 1D array 204. The angle determination module 116 can determine azimuth angle estimates 306 and 308 with relatively low processing complexity and cost.

[0054] At position 408, the angle determination module 116 can select the element in the signal subspace corresponding to the 2D array 206-1 and determine the azimuth estimate 314. And elevation angle estimation 316, φ1, φ2, ..., φ NWhere N represents the estimated number of objects 120. The angle determination module 116 can, for example, apply a single two-dimensional ESPRIT to estimate the azimuth and elevation angles. The azimuth estimate 314 is based on a third distance 214 in the 2D array 206-1, and the elevation estimate 316 is based on a fourth distance 216 in the 2D array 206-1. The angle determination module 116 can use other pseudospectral functions, including SAGE, delay summation, MVDR, and / or MUSIC-based functions, in other implementations to calculate the direction of arrival of the EM signal received by the 2D array 206-1. The angle determination module 116 can determine the azimuth estimate 314 and elevation estimate 316 with relatively low processing complexity and cost.

[0055] At 410, the angle determination module 116 can unfold the azimuth angles from azimuth estimates 306, 308, and 314, and pair the unfolded azimuth estimate 306 with the elevation estimate 316. The elevation estimate 316 can be paired with the azimuth estimate 306 using common or shared angles in the azimuth estimates 308 and 314. For example, the angle determination module 116 can automatically pair multiple angle pairs from the elevation estimate 316 and the azimuth estimate 306 estimated using 2D ESPRIT. As mentioned above, both azimuth estimates 308 and 314 are based on a third distance 214 in the azimuth direction.

[0056] Figure 5 Another example concept diagram 500 shows a radar system with paired 1D and 2D arrays and an angle measurement module 116. Figure 5 The radar system can be, for example, Figure 1 The radar system 102 includes a pair of 1D arrays and 2D arrays. In the depicted implementation, the radar system 102 includes a 1D array 204 and a 2D array 206-2 of antennas 200-2, which can be arranged in various positions, including... Figure 2B The arrangement shown.

[0057] At 504, the angle determination module 116 obtains the EM energy 502 received by the 1D array 204 and determines azimuth estimates 506 and 508 associated with one or more objects 120. For example, the angle determination module 116 can determine the azimuth estimate 506, θ1, θ2, ..., θ8 based on a first distance d1210. N Where N represents the estimated number of targets. The angle determination module 116 can also determine the azimuth estimate 508 based on the third distance d3214. The third distance d3214 represents the sum of the first distance 210 and the second distance 212.

[0058] At 512, the angle measurement module 116 obtains the EM energy 510 received by the 2D array 206-2 and determines the elevation angle estimate 514 and elevation angle estimate 516 associated with one or more objects 120. For example, the angle measurement module 116 can determine the elevation angle estimate 514, φ1, φ2, ..., φ based on the sixth distance d6220. N The angle measurement module 116 can also determine the elevation angle estimate 516, β1, β2, ..., β based on the fourth distance 216d4. N .

[0059] The angle determination module 116 can use various angle determination functions to determine azimuth estimate 506, azimuth estimate 510, elevation estimate 514, and elevation estimate 516 based on EM energy 502 and EM energy 510. As described above, the angle determination module 116 can use pseudospectral functions, including SAGE, DS, MVDR, and / or MUSIC-based functions, to calculate the direction of arrival of the EM signals received by the 1D array 204 and the 2D array 206-2. As another example, the angle determination module 116 can use ESPRIT technology or FFT beamforming to calculate azimuth estimate 506, azimuth estimate 508, elevation estimate 514, and elevation estimate 516. The angle determination module 116 can determine the azimuth and elevation estimates with relatively low processing complexity and cost.

[0060] At 518, the angle determination module 116 associates the azimuth estimate 506 and elevation estimate 516 with the object 120 based on a common azimuth estimate 508 and elevation estimate 514. Specifically, the angle determination module 116 determines the azimuth estimate 506 and elevation estimate 516 associated with each of one or more objects 120. (Refer to...) Figure 6 A more detailed description of an example of concept diagram 500.

[0061] Figure 6 Another example concept diagram 600 shows how azimuth estimation 506 and elevation estimation 516 are associated with the angle determination module of the corresponding object 120. For example, Figure 6 Angle measurement module can be Figures 1 to 3 Angle measurement module 116. (Refer to...) Figure 5 As described, the angle measurement module 116 determines the azimuth estimate 506 and elevation estimate 516 associated with the object 120.

[0062] At position 602, the angle measurement module 116 can form or generate a complex covariance matrix based on the EM energy 502 and EM energy 510 received by the 1D array 204 and 2D array 206-2, respectively. For example, the angle measurement module 116 can form the complex covariance matrix R using equation (2):

[0063] R = xx H (2)

[0064] Where x represents the measurements from EM energies 502 and 510, and H represents the Hermitian matrix of x (e.g., a self-adjoint matrix). The Hermitian matrix is ​​a complex square matrix equal to its own conjugate transpose (e.g., the element in the i-th row and j-th column is equal to the complex conjugate of the element in the j-th row and i-th column).

[0065] At 604, the angle determination module 116 can use eigenvalue decomposition to estimate the number of targets N (e.g., detected object 120) and the signal subspace E from the complex covariance matrix R. s .

[0066] At position 606, the angle determination module 116 can select the element in the signal subspace corresponding to the 1D array 204 and determine the azimuth estimate 506, θ1, θ2, ..., θ N And the azimuth estimate is 508. Where N represents the estimated number of objects 120. The angle determination module 116 can, for example, apply a single two-dimensional ESPRIT to estimate the azimuth. Azimuth estimation 506 is based on a first distance 210, and azimuth estimation 508 is based on a third distance 214. In other implementations, the angle determination module 116 can use other pseudospectral functions, including SAGE, DS, MVDR, and / or MUSIC-based functions, to calculate the direction of arrival of the EM signal received by the 1D array 204. The angle determination module 116 can determine azimuth estimates 506 and 508 with relatively low processing complexity and cost.

[0067] At position 608, the angle determination module 116 can select the element in the signal subspace corresponding to the 2D array 206-2, and determine the elevation angle estimate 514, φ1, φ2, ..., φ N And elevation angle estimation 516, β1,β2,…,β N Where N represents the estimated number of objects 120. The angle determination module 116 can, for example, apply a single two-dimensional ESPRIT to estimate the elevation angle. The elevation angle estimation 514 is based on the sixth distance 220 in the 2D array 206-2, and the elevation angle estimation 516 is based on the fourth distance 216 in the 2D array 206-2. In other implementations, the angle determination module 116 can use other pseudospectral functions, including SAGE, DS, MVDR, and / or MUSIC-based functions, to calculate the direction of arrival of the EM signal received by the 2D array 206-2. The angle determination module 116 can determine the possible elevation angle estimates 514 and 516 with relatively low processing complexity and cost.

[0068] At 610, the angle determination module 116 can expand the azimuth angle from azimuth estimates 506 and 508. The angle determination module 116 can also expand the elevation angle from elevation estimates 514 and 516. The angle determination module 116 can then pair the expanded azimuth estimate 506 with the elevation estimate 516. The elevation estimate 516 can be paired with the azimuth estimate 506 using common or shared angle pairs from the azimuth estimate 508 and the elevation estimate 514.

[0069] Example Method

[0070] Figure 7 An example method 700 of a radar system 102 with paired 1D and 2D antenna arrays and an angle determination module 116 is shown. Method 700 is shown as multiple sets of operations (or actions) performed, but is not necessarily limited to the order or combination of operations shown herein. Furthermore, any one or more of the operations may be repeated, combined, or recombined to provide other methods. References may be made in the various sections discussed below. Figure 1 Environment 100 and Figures 1 to 6 The entities detailed herein are for illustrative purposes only. This technique is not limited to being performed by one or more entities.

[0071] At 702, the radar system's antenna receives EM energy reflected by one or more objects at a 1D array. The 1D array includes first antenna elements positioned in a first direction and spaced apart by a first distance and a second distance in that direction. For example, antenna 200-1 or antenna 200-2 of radar system 102 may receive EM energy 302 or 502 reflected by one or more objects 120 at a 1D array 204. The 1D array 204 may include a plurality of antenna elements 208 positioned in the azimuth direction. In other implementations, the antenna elements 208 of the 1D array 204 may be positioned in the elevation direction or other directions. The antenna elements 208 of the 1D array 204 are alternately spaced apart by a first distance d1210 and a second distance d2212.

[0072] At 704, the radar system's antenna receives EM energy reflected by one or more objects at a 2D array. The 2D array includes at least four second antenna elements not included in the 1D array. Second antenna elements are positioned in a first direction and in a second direction orthogonal to the first direction. The second antenna elements are spaced apart in the first direction by the sum of a first distance and a second distance. At least some of the second antenna elements are spaced apart in the second direction by a third distance. For example, antenna 200-1 or antenna 200-2 of radar system 102 may receive EM energy 310 or 510 reflected by one or more objects 120 at 2D array 206-1 or 2D array 206-2, respectively. 2D array 206 may include a plurality of antenna elements 208 positioned in the azimuth and elevation directions. Specifically, 2D array 206 includes at least four antenna elements 208 not included in the 1D array 204. In other implementations, the antenna elements 208 of 2D array 206 may be positioned in other directions orthogonal to each other. The antenna elements 208 of the 2D array 206 are spaced apart by a third distance d3214 in the azimuth direction. The third distance 214 represents the sum of the first distance 210 and the second distance 212. The antenna elements 208 of the 2D array 206-1 are spaced apart by a fourth distance d4216 in the elevation direction. The antenna elements 208 of the 2D array 206-2 are alternately spaced apart by the fourth distance d4216 and the fifth distance d5218 in the elevation direction.

[0073] At 706, a first angle and a second angle associated with one or more objects are determined based on the EM energy received at the 1D array. The first angle and the second angle are in a first direction. For example, the processor 112 of the radar system 102 can use the angle determination module 116 and the EM energy 302 received by the 1D array 204 to determine azimuth estimates 306 and 308 associated with one or more objects 120.

[0074] At 708, the EM energy received by the 2D array is used to determine a third and fourth angle associated with one or more objects. The third angle is in the first direction, and the fourth angle is in the second direction. For example, the processor 112 can use the angle determination module 116 and the EM energy 310 received by the 2D array 206-1 to determine the azimuth estimate 314 and elevation estimate 316 associated with one or more objects 120.

[0075] At 710, the first and fourth angles are associated with corresponding objects in one or more objects using the second and third angles. For example, processor 112 can use angle determination module 116, along with azimuth estimate 308 and azimuth estimate 314, to associate azimuth estimate 306 and elevation estimate 316 with corresponding objects in one or more objects 120.

[0076] Example

[0077] Examples are provided in the following sections.

[0078] Example 1: A radar system includes: an antenna configured to receive electromagnetic (EM) energy reflected by one or more objects, the antenna comprising: a one-dimensional (1D) array including a first antenna element positioned in a first direction, the first antenna elements being spaced apart by a first distance and a second distance in the first direction; a two-dimensional (2D) array including at least four second antenna elements not included in the 1D array and positioned in the first and second directions, the second direction being orthogonal to the first direction, at least some of the second antenna elements being spaced apart by a third distance in the second direction and spaced apart by the sum of the first distance and the second distance in the first direction; and one or more processors configured to: determine a first angle and a second angle associated with one or more objects using the EM energy received at the 1D array, the first angle and the second angle being in the first direction; determine a third angle and a fourth angle associated with one or more objects using the EM energy received at the 2D array, the third angle being in the first direction and the fourth angle being in the second direction; and associate the first angle and the fourth angle with corresponding objects among the one or more objects using the second angle and the third angle.

[0079] Example 2: The radar system of Example 1, wherein: the first angle is determined based on a first distance; the second angle is determined based on the sum of the first distance and the second distance; and the third angle is determined based on a third distance.

[0080] Example 3: The radar system of Example 1 or 2, wherein the second radar element is spaced apart at a third and a fourth distance in a second direction.

[0081] Example 4: The system of Example 3, wherein one or more processors are further configured to: determine a fifth angle associated with one or more objects using EM energy received by a 2D array, the fifth angle being in a second direction, wherein one or more processors are configured to: associate the first angle and the third angle with corresponding objects in one or more objects by using the second angle, the fourth angle and the fifth angle to associate the first angle and the third angle with corresponding objects in one or more objects.

[0082] Example 5: The radar system of Example 4, wherein: the first angle is determined based on a first distance; the second and fourth angles are determined based on the sum of the first and second distances; the third angle is determined based on a third distance; and the fifth angle is determined based on the sum of the third and fourth distances.

[0083] Example 6: Any radar system of the prior examples, wherein the one or more processors are configured to associate a first angle and a fourth angle with corresponding objects of one or more objects in such a way as to generate a complex covariance matrix using EM energy received at a 1D array and a 2D array; to determine an estimate of the number of one or more objects using eigenvalue decomposition of the complex covariance matrix; to expand the first angle and the fourth angle; and to pair the expanded fourth angle with the expanded first angle using the common value of the second angle and the third angle.

[0084] Example 7: The radar system of Example 4, wherein the one or more processors are configured to associate a first angle and a fourth angle with corresponding objects among one or more objects in such a way as to generate a complex covariance matrix using EM energy received at a 1D array and a 2D array; to determine an estimate of the number of one or more objects using eigenvalue decomposition of the complex covariance matrix; to unfold the first angle, a second angle, a third angle, a fourth angle, and a fifth angle; and to pair the unfolded fourth angle with the unfolded first angle using the common value of the second angle and the fifth angle.

[0085] Example 8: Any radar system in the previous example, where the 1D array is positioned in the azimuth direction and the 2D array is positioned in both the azimuth and elevation directions.

[0086] Example 9: Any radar system in the previous example where the 1D array is a linear array.

[0087] Example 10: Any radar system in the preceding examples, wherein the 1D array and 2D array are configured in an approximate T-shape, an approximate inverted T-shape, or an approximate cross shape.

[0088] Example 11: Any radar system in the preceding example, wherein the 1D array includes a first number of antenna elements and the 2D array includes a second number of antenna elements in a first direction, the first number of antenna elements being greater than the second number of antenna elements.

[0089] Example 12: Any radar system in the previous example, where the second antenna element of the 2D array is configured in an approximately rectangular shape.

[0090] Example 13: Any radar system in the previous example, where the second antenna element of the 2D array is located in a sparse array.

[0091] Example 14: Any radar system in the preceding example, wherein the first angle, second angle, third angle, and fourth angle are determined using at least one of the following: signal parameter estimation via rotation-invariant technique (ESPRIT), spatial alternation generalized expectation maximization (SAGE), delay summation (DS), minimum variance distortionless response (MVDR), multiple signal classification (MUSIC), or a function based on fast Fourier transform (FFT) beamforming.

[0092] Example 15: Any radar system in the previous example, wherein the radar system is configured for installation on a vehicle.

[0093] Example 16: A computer-readable storage medium comprising computer-executable instructions, which, when executed, cause a processor of a radar system to: receive electromagnetic (EM) energy reflected by one or more objects from an antenna of the radar system; determine a first angle and a second angle associated with the one or more objects using the EM energy received by a one-dimensional (1D) array of the antenna, the 1D array including a first antenna element positioned in a first direction, the first antenna element being spaced apart by a first distance and a second distance in the first direction, the first angle and the second angle being in the first direction; determine a third angle and a fourth angle associated with the one or more objects using the EM energy received by a two-dimensional (2D) array of the antenna, the 2D array including at least four second antenna elements not included in the 1D array and positioned in the first and second directions, the second direction being orthogonal to the first direction, at least some of the second antenna elements being spaced apart by a third distance in the second direction and spaced apart by the sum of the first distance and the second distance in the first direction, the third angle being in the first direction and the fourth angle being in the second direction; and associate the first angle and the fourth angle with corresponding objects among the one or more objects using the second angle and the third angle.

[0094] Example 17: A computer-readable storage medium of Example 16, wherein: a first angle is determined based on a first distance; a second angle is determined based on the sum of the first distance and the second distance; and a third angle is determined based on a third distance.

[0095] Example 18: A computer-readable storage medium of Example 16 or 17, wherein the second antenna element is spaced apart by a third and a fourth distance in a second direction.

[0096] Example 19: A computer-readable storage medium of Example 18, the computer-readable storage medium including further computer-executable instructions, which, when executed, cause a processor of a radar system to: determine a fifth angle associated with one or more objects using EM energy received by a 2D array, the fifth angle being in a second direction, wherein the association of a first angle and a third angle with a corresponding object among the one or more objects includes: associating the first angle and the third angle with the corresponding object among the one or more objects using a second angle, a fourth angle, and a fifth angle.

[0097] Example 20: A method comprising: receiving electromagnetic (EM) energy reflected by one or more objects by an antenna of a radar system; determining a first angle and a second angle associated with the one or more objects using the EM energy received by a one-dimensional (1D) array of the antenna, the 1D array including a first antenna element positioned in a first direction, the first antenna element being spaced apart by a first distance and a second distance in the first direction, the first angle and the second angle being in the first direction; determining a third angle and a fourth angle associated with the one or more objects using the EM energy received by a two-dimensional (2D) array of the antenna, the 2D array including at least four second antenna elements not included in the 1D array and positioned in the first and second directions, the second direction being orthogonal to the first direction, at least some of the second antenna elements being spaced apart by a third distance in the second direction and spaced apart by the sum of the first distance and the second distance in the first direction, the third angle being in the first direction and the fourth angle being in the second direction; and associating the first angle and the fourth angle with corresponding objects among the one or more objects using the second angle and the third angle.

[0098] Example 21: A computer-readable storage medium including computer-executable instructions that, when executed, cause a processor to perform radar operations of a processor using a radar system of any one of Examples 1 to 15.

[0099] Example 22: A method comprising performing radar operations using a processor of a radar system as described in any one of claims 1 to 15.

[0100] Conclusion

[0101] While various embodiments of the present disclosure have been described in the foregoing description and illustrated in the accompanying drawings, it should be understood that the present disclosure is not limited thereto, but can be practiced in various ways within the scope of the following claims. It will be apparent from the foregoing description that various modifications can be made without departing from the scope of the present disclosure as defined by the appended claims.

Claims

1. A radar system comprising: an antenna configured to receive electromagnetic (EM) energy reflected by one or more objects, the antenna comprising: a one-dimensional (ID) array comprising first antenna elements positioned in a first direction, the first antenna elements alternately spaced apart by a first distance and a second distance in the first direction; and a two-dimensional (2D) array comprising at least four second antenna elements not contained by the ID array and positioned in the first direction and a second direction, the second direction being orthogonal to the first direction, at least some of the second antenna elements being spaced apart by a fourth distance in the second direction and by a sum of the first distance and the second distance in the first direction; and one or more processors configured to: determine, using the EM energy received at the ID array, a pair of a first angle and a second angle associated with the one or more objects, the first angle and the second angle being relative to the first direction, the first angle being determined using the first distance, the second angle being determined using the sum of the first distance and the second distance; determine, using the EM energy received at the 2D array, a pair of a third angle and a fourth angle associated with the one or more objects, the third angle being relative to the first direction and the fourth angle being relative to the second direction, the third angle being determined using the sum of the first distance and the second distance, the fourth angle being determined using the fourth distance; and associate, from the pair of the first angle and the second angle and the pair of the third angle and the fourth angle for each of the one or more objects, a respective first angle with a respective fourth angle by matching the respective second angle with the respective third angle.

2. The radar system of claim 1, wherein, the second antenna elements are alternately spaced apart by the fourth distance and a fifth distance in the second direction.

3. The radar system of claim 2, wherein, the one or more processors are further configured to: determine, using the EM energy received by the 2D array, a pair of a fourth angle and a fifth angle associated with the one or more objects, the fifth angle being relative to the second direction, the fifth angle being determined using a sum of the fourth distance and the fifth distance, and wherein the one or more processors are configured to associate the respective first angle with the respective fourth angle by matching the respective second angle with the respective fifth angle of the pair of the fourth angle and the fifth angle.

4. The radar system of claim 1, wherein, the one or more processors are configured to associate the first angle and the fourth angle with the respective one of the one or more objects in a manner that: generates a complex covariance matrix using the EM energy received at the ID array and the 2D array by multiplying a measurement matrix of the EM energy received at the ID array and the 2D array by the Hermitian of the measurement matrix; and and determining an estimate of a number of the one or more objects using an eigenvalue decomposition of the co-covariance matrix; expanding the first angle and the fourth angle.

5. The radar system of claim 1, wherein, The 1D array is positioned in an azimuth direction and the 2D array is positioned in the azimuth direction and an elevation direction.

6. The radar system of claim 1, wherein, The 1D array is a linear array.

7. The radar system of claim 6, wherein, The 1D array and the 2D array are configured in a T-shape, an inverted T-shape, or a cross-shape.

8. The radar system of claim 1, wherein, The 1D array includes a first number of antenna elements and the 2D array includes a second number of antenna elements in the first direction, the first number of antenna elements being greater than the second number of antenna elements.

9. The radar system of claim 1, wherein, The second antenna elements of the 2D array are configured in a rectangular shape.

10. The radar system of claim 1, wherein, The second antenna elements of the 2D array are positioned in a sparse array.

11. The radar system of claim 1, wherein, The first angle, the second angle, the third angle, and the fourth angle are determined using at least one of: ESPRIT, SAGE, DS, MVDR, MUSIC, or a function based on FFT beamforming.

12. The radar system of claim 1, wherein, The radar system is configured for installation on an automobile.

13. A computer-readable storage medium comprising computer-executable instructions that, when executed, cause a processor of a radar system to: receive, by an antenna of the radar system, electromagnetic (EM) energy reflected by one or more objects; determine, using the EM energy received by a one-dimensional (1D) array of the antenna, a pair of a first angle and a second angle associated with the one or more objects, the 1D array including first antenna elements positioned in a first direction, the first antenna elements alternately spaced apart by a first distance and a second distance in the first direction, the first angle and the second angle being relative to the first direction, the first angle being determined using the first distance, the second angle being determined using a sum of the first distance and the second distance; determine, using the EM energy received by a two-dimensional (2D) array of the antenna, a pair of a third angle and a fourth angle associated with the one or more objects, the 2D array including at least four second antenna elements, the at least four second antenna elements not being included by the 1D array and positioned in the first direction and a second direction, the second direction being orthogonal to the first direction, at least some of the second antenna elements being spaced apart by a fourth distance in the second direction and by a sum of the first distance and the second distance in the first direction, the third angle being relative to the first direction and the fourth angle being relative to the second direction, the third angle being determined using the sum of the first distance and the second distance, the fourth angle being determined using the fourth distance; and The respective first angle is associated with a respective fourth angle from the pair of the first angle and the second angle and the pair of the third angle and the fourth angle for each of the one or more objects by matching the respective second angle with the respective third angle.

14. The computer-readable storage medium of claim 13, wherein, The second antenna elements are alternately spaced apart by a fourth distance and a fifth distance in the second direction.

15. The computer-readable storage medium of claim 14, wherein, The computer-readable storage medium includes further computer-executable instructions that, when executed, cause a processor of a radar system to: determine a pair of fourth and fifth angles associated with the one or more objects using the EM energy received by the 2D array, the fifth angle being relative to the second direction, the fifth angle being determined using a sum of the fourth distance and the fifth distance, and wherein the respective first angle is associated with the respective fourth angle by matching the respective second angle with the respective fifth angle of the pair of the fourth and fifth angles.

16. A method comprising: receiving, by an antenna of a radar system, electromagnetic (EM) energy reflected by one or more objects; determining a pair of first and second angles associated with the one or more objects using the EM energy received by a one-dimensional (ID) array of the antenna, the ID array including first antenna elements positioned in a first direction, the first antenna elements being alternately spaced apart by a first distance and a second distance in the first direction, the first and second angles being relative to the first direction, the first angle being determined using the first distance, the second angle being determined using a sum of the first distance and the second distance; determining a pair of third and fourth angles associated with the one or more objects using the EM energy received by a two-dimensional (2D) array of the antenna, the 2D array including at least four second antenna elements that are not contained by the ID array and are positioned in the first direction and a second direction, the second direction being orthogonal to the first direction, at least some of the second antenna elements being spaced apart by a fourth distance in the second direction and by a sum of the first distance and the second distance in the first direction, the third angle being relative to the first direction and the fourth angle being relative to the second direction, the third angle being determined using the sum of the first distance and the second distance, the fourth angle being determined using the fourth distance; and associating a respective first angle with a respective fourth angle from the pair of the first angle and the second angle and the pair of the third angle and the fourth angle for each of the one or more objects by matching the respective second angle with the respective third angle.

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