System and method for sensing surroundings of a vehicle

Abstract

A system and method for sensing a vehicle's surroundings via an on-board radar sensor. A directional transmitter array transmits radiation into an area surrounding the vehicle, and a receiver array receives the reflected radiation. A controller can derive useful information, such as the vehicle's relative speed and the identification of hazards in the vehicle's surroundings, using a self-speed calculation module, a wall detection module, a dynamic range enhancement module, a dual-reflection detection module, and the like.

Description

[Technical Field]

[0001] This application claims the benefit of priority from U.S. Provisional Patent Application No. 62 / 932,511, filed November 8, 2019, U.S. Provisional Patent Application No. 62 / 955,487, filed December 31, 2019, U.S. Provisional Patent Application No. 63 / 037,021, filed June 10, 2020, and U.S. Provisional Patent Application No. 63 / 037,026, filed June 10, 2020, the contents of which are incorporated by reference in their entireties.

[0002] The present disclosure herein relates to systems and methods for sensing the surroundings of a vehicle. In particular, systems and methods are described for providing an on-board radar sensor operable to detect objects in an area surrounding a moving vehicle. [Background technology]

[0003] A variety of sensors may be used to detect objects. In fact, with the increasing use of autonomous vehicles, such as self-driving cars and the like, a plethora of sensors are used to detect objects near a moving vehicle. For example, sensors such as video cameras, ultrasonic sensors, infrared, LIDAR sensors, and the like may be used to provide information about the environment in which the vehicle is traveling.

[0004] The use of radar is becoming more and more widespread with the development of RFIC and signal technology. Radar sensors have the advantage of operating in complete darkness, fog, mist, and rain. Radar is an electronic system with the advantages of low cost, low power consumption, and high accuracy. It can be significantly used in various applications, including space shuttle topographic missions, optical systems, geotechnical mapping, meteorological detection, etc. The working efficiency of radar systems is based on reliable and stable radar signals with wide coverage, high directivity, high gain, and low signal-to-noise ratio.

[0005] The usefulness of radar as an onboard sensor depends on its resolution and accuracy in determining direction, range, and speed. The directivity achievable by an antenna depends on its physical size relative to the wavelength at the operating frequency. This applies to both mechanically and electronically steered beams. Electronic beam steering involves aligning the phase of signals to and from the antenna elements in a given direction. The beam shape of an antenna array depends on the phase shift applied to each antenna element in the array. Typically, each antenna element has an a priori implementation-dependent phase shift associated with the transmission lines and amplifiers along the signal path to the antenna element. If no additional phase shift is applied, the resulting beam typically does not have a well-defined beam shape, and the direction from which the reflected beam is received is difficult to determine.

[0006] A well-known method for achieving highly directional beams is to apply a phase shift along each path to the corresponding antenna elements so that transmissions from different elements combine coherently in a given propagation direction. Nevertheless, applying arbitrary phase shifts introduces implementation complexity and sometimes requires resorting to coarse phase control. An example of coarse phase control is selecting one of two or four possible phases, while finer control may allow the selection of eight or sixteen phase values ​​in each phase control path.

[0007] Directivity to the transmitted beam can be achieved through binary phase shift keying (BPSK)-based beamforming. This can be achieved by applying a 0-degree or 180-degree phase shift to the signal transmitted through the selected antenna. Nevertheless, BPSK beamforming carriers typically suffer from coarse phase quantization and a large difference between the optimal desired phase and the actual phase. BPSK beamforming typically produces significant sidelobes that can waste approximately 60% of the transmitted energy. Sidelobe reduction requires finer control of the phase, for example, every 90 degrees instead of 180 degrees. With a 90-degree granularity of phase control, only 20% of the energy is lost to the sidelobes.

[0008] As an illustration, in the imaging context, a transmitting antenna may be scanned with various code sequences over several time intervals (e.g., by switching between antennas over time, or by coding the antenna with a Hadamard code, or by beamforming toward a specific direction). The directional characteristics can be recreated by recursive beamforming combined with inversion of the encoding matrix. Reflections from moving targets can produce phase rotations across these time intervals in a manner detrimental to imaging. The rationale for creating a good beamformer comes from concentrating energy in different directions in each time interval, reducing the effects of phase rotation. Furthermore, when a transmit sweep across a range of frequencies, such as an up-chirp or down-chirp, is transmitted over a time period, the delay between time intervals is further increased.

[0009] As a result, it can be very difficult to pinpoint the location of a target. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] U.S. Patent Publication No. 16 / 802,610 [Patent Document 2] U.S. Provisional Patent Application No. 62 / 955,482 Summary of the Invention [Problem to be solved by the invention]

[0011] Therefore, there remains a need for an effective radar sensor that can be used to accurately detect objects in the area surrounding a moving vehicle. The invention described herein addresses the above-mentioned need. [Means for solving the problem]

[0012] According to one aspect of the presently disclosed subject matter, a system for sensing surroundings of a vehicle is introduced. The system may include an on-board radar unit including a radar transmission unit having an array of transmission antennas connected to an oscillator and configured to transmit electromagnetic waves into an area surrounding the vehicle, and a radar receiving unit having at least one receiving antenna configured to receive the electromagnetic waves reflected by objects within the area surrounding the vehicle, the radar receiving unit operable to generate raw data.

[0013] The system may further include a processor unit in communication with the radar receiving unit, configured to receive raw data from the radar unit, and operable to generate environmental information based on the received data.

[0014] Optionally, the processor may comprise various additional modules, such as a self-speed calculation module operable to calculate the speed of the vehicle from the raw data, a wall detection module operable to detect flat surfaces in the area surrounding the vehicle, a dynamic range enhancement module operable to distinguish weakly reflecting objects from strongly reflecting objects in the same vicinity, and a double-reflection identification module operable to distinguish single-reflected electromagnetic waves reflected directly by an object towards the radar receiving unit from double-reflected electromagnetic waves reflected indirectly from the object towards the radar receiving unit via an intermediate reflective surface.

[0015] In some systems, the radar transmission unit further comprises a polarizer configured and operable to generate circularly polarized electromagnetic waves, and / or the radar receiving unit further comprises a polarization detector configured and operable to detect the polarization of the received electromagnetic waves. Thus, the dual-reflection identification module may comprise a circular polarizer and a polarization detector.

[0016] If necessary, the system may include an ego-velocity calculation module comprising an image generation unit and a memory unit, wherein the image generation unit may be configured and operable to construct a three-dimensional image representing an area surrounding the vehicle comprising a matrix of voxels, each voxel representing a horizontal spatial coordinate (x) of a reflecting object along an axis parallel to the path of the vehicle, a vertical spatial coordinate (y) of the reflecting object along a vertical axis perpendicular to the path of the vehicle, a radial spatial coordinate (R) of the reflecting object along an axis radially diverging from the vehicle, an intensity value, and an apparent radial velocity v of the reflecting object. R The memory unit may be configured to store data relating to at least a first three-dimensional image representing an area surrounding the vehicle at a first instant in time and a second three-dimensional image representing an area surrounding the vehicle at a second instant in time after a delay time (dt).

[0017] Additionally or alternatively, the system may include a wall detection module comprising a processing unit and a memory unit storing executable code for comparing the energy profile in the virtual box to a reference energy profile having properties indicative of a two-dimensional reflector.

[0018] It is therefore another aspect of the present disclosure to teach a method for sensing surroundings of a vehicle by providing an on-board radar unit comprising a radar transmission unit comprising an array of transmit antennas connected to an oscillator, and a radar receiving unit comprising at least one receive antenna; providing a processor unit in communication with the radar receiving unit; transmitting electromagnetic radiation into an area surrounding the vehicle; receiving the electromagnetic radiation reflected from objects in the area surrounding the vehicle; detecting polarization of the received electromagnetic waves; detecting targets extending in two dimensions within the area surrounding the vehicle; distinguishing weakly reflecting objects from strongly reflecting objects in the same vicinity by applying a combination of dynamic range enhancing filters; constructing a series of three-dimensional images of the area surrounding the vehicle; and analyzing the series of three-dimensional images to determine the speed of the vehicle.

[0019] If appropriate, detecting two-dimensional targets in an area surrounding the vehicle may include detecting spectral reflection points in the reflected radiation, constructing a virtual box around a volume containing candidate wall-like objects, calculating an energy profile of the radar image within the virtual box, and applying a classification function to the energy profile.

[0020] Additionally or alternatively, the method may include applying a classification function that includes calculating at least one wall-indicating parameter selected from the group consisting of: total energy reflected from within the virtual box; a profile of energy reflected from within segments of the virtual box; a number of voxels within the virtual box that have energy values ​​above a threshold; and combinations thereof.

[0021] If necessary, constructing a series of three-dimensional images includes at least constructing a first three-dimensional image representing the area surrounding the vehicle at a first instant in time, waiting for a delay time (dt), and constructing a second three-dimensional image representing the area surrounding the vehicle at a second instant in time.

[0022] Thus, analyzing the series of three-dimensional images to determine the vehicle's speed may include detecting a common reflective object in the first three-dimensional image and the second three-dimensional image, determining a horizontal shift (dx) of the detected common reflective object, and calculating the slope of a plot of apparent radial velocity vR as a function of the horizontal shift dx of the reflective object. Where appropriate, determining the horizontal shift (dx) includes determining the x-coordinate (xn) of the reflective object, determining the y-coordinate (yn) of the reflective object, finding the co-latitude angle (θn) of the reflective object by calculating the arctangent of the ratio of the x-coordinate of the reflective object to the y-coordinate of the reflective object (xn / yn), and calculating the sine of the co-latitude angle, such that dx=sin(arctan(xn / yn)).

[0023] In yet another aspect, a method is taught for simulating quadrature phase-shift keying (QPSK) beamforming in an antenna array, where each antenna of the array is connected to a common transmitter through a binary phase shifter. The method can include determining a required complex QPSK steering vector for each transmitting antenna of the array. The steering vector typically has a real component selected from 0 and 180 degrees and an imaginary component selected from 90 and 270 degrees.

[0024] Thus, the transmitter generates an oscillating signal. During a first time interval, for each transmit antenna having a guide vector associated with a real component of 180 degrees, the biphasic adjuster applies a 180-degree phase shift to the transmitted signal. During a second time interval, for each transmit antenna having a guide vector associated with an imaginary component of 180 degrees, the biphasic adjuster applies a 180-degree phase shift to the transmitted signal. A post-processor may be used to apply a 90-degree phase shift to the signal received during the second time interval, and the post-processor may sum the signal received during the first time interval with the 90-degree phase-shifted signal received during the second time interval. Optionally, the transmitter may sweep the oscillating signal over a range of frequencies during each time interval.

[0025] For a better understanding of the embodiments, and to show how they may be carried into effect, reference will now be made, purely by way of example, to the accompanying drawings in which:

[0026] With specific reference now to the drawings in detail, it is emphasized that the details shown are presented by way of example and for illustrative discussion only of selected embodiments, to provide what is believed to be the most useful and easily understood explanation of principles and conceptual aspects. In this regard, no attempt is made to show structural details in more detail than necessary for a fundamental understanding, and the description taken together with the drawings will make clear to those skilled in the art how various selected embodiments may be practiced. [Brief explanation of the drawings]

[0027] [Figure 1A] 1 is a schematic representation of an on-board radar unit configured to detect objects in an area surrounding a vehicle. [Figure 1B] FIG. 1 is a block diagram illustrating selected elements of a possible system for sensing the surroundings of a vehicle. [Figure 2A] 3 is a flow chart showing selected steps in a possible method for sensing the surroundings of a vehicle. [Figure 2B] 3 is a flow chart showing selected steps in a possible method for sensing the surroundings of a vehicle. [Figure 2C] 3 is a flow chart showing selected steps in a possible method for sensing the surroundings of a vehicle. [Figure 3A] 1 is a diagram illustrating a schematic representation of a radar unit of the present disclosure mounted on a moving vehicle detecting apparent movement of objects in the area surrounding the vehicle. [Figure 3B] 1 is a diagram illustrating a schematic representation of a radar unit of the present disclosure mounted on a moving vehicle detecting apparent movement of objects in the area surrounding the vehicle. [Figure 3C] 1 is a diagram illustrating a schematic representation of a radar unit of the present disclosure mounted on a moving vehicle detecting apparent movement of objects in the area surrounding the vehicle. [Figure 3D]1 is a diagram illustrating a schematic representation of a radar unit of the present disclosure mounted on a moving vehicle detecting apparent movement of objects in the area surrounding the vehicle. [Figure 4A] Figure 1 shows three example plots of apparent radial velocity vR as a function of the horizontal displacement dx of a reflecting object, as measured by a radar unit mounted on a vehicle traveling at different speeds. [Figure 4B] Figure 1 shows three example plots of apparent radial velocity vR as a function of the horizontal displacement dx of a reflecting object, as measured by a radar unit mounted on a vehicle traveling at different speeds. [Figure 4C] Figure 1 shows three example plots of apparent radial velocity vR as a function of the horizontal displacement dx of a reflecting object, as measured by a radar unit mounted on a vehicle traveling at different speeds. [Figure 5] 1 is a diagram that shows a schematic representation of a radar unit of the present disclosure mounted on a moving vehicle detecting two-dimensional wall-type targets in the area surrounding the vehicle. [Figure 6A] FIG. 10 illustrates how guidance vectors can be generated by BPSK phase shifting the phase of a selected antenna by 0 or 180 degrees. [Figure 6B] FIG. 1 illustrates a possible BPSK mechanism for phase shifting the signal to the antenna by 180 degrees. [Figure 6C] FIG. 10 illustrates how a guiding vector can be generated by QPSK phase shifting the phase of a selected antenna by 0, 90, 180, or 270 degrees. [Figure 6D] FIG. 1 illustrates possible quadrature modulation mechanisms for phase shifting the signal to the antenna by 0, 90, 180, or 270 degrees. [Figure 7A] 1 is a block diagram that schematically represents selected elements of a first embodiment of a system for simulating quadrature phase shift keying (QPSK) beamforming. [Figure 7B]10 is a set of graphs illustrating a possible set of profiles illustrating how the phase of the signal transmitted from each transmit antenna of the first embodiment may vary over time. [Figure 7C] 4 is a flowchart illustrating selected steps in a method for simulating quadrature phase shift keying (QPSK) beamforming in a first embodiment system. [Figure 8A] FIG. 10 is a block diagram that schematically represents selected elements of a second embodiment of a system for simulating quadrature phase shift keying (QPSK) beamforming, with each antenna connected to a gain control unit. [Figure 8B] 10 is a set of graphs illustrating a possible set of profiles illustrating how the phase of the signal transmitted from each transmit antenna of the second embodiment may vary over time. [Figure 8C] 10 is a flowchart illustrating selected steps in a method for simulating quadrature phase shift keying (QPSK) beamforming in a second embodiment system. [Figure 9A] FIG. 10 is a block diagram of a system including a common, shifted dual phase shared by all antennas according to a third embodiment. [Figure 9B] 10 is a set of graphs illustrating a possible set of profiles illustrating how the phase of the signal transmitted from each transmit antenna of the third embodiment may vary over time. DETAILED DESCRIPTION OF THE INVENTION

[0028] Aspects of the present disclosure relate to systems and methods for sensing the surroundings of a vehicle. In particular, systems and methods are described for providing an on-board radar sensor operable to detect objects in an area surrounding a moving vehicle. Further, a directional radar array having a wide field of view is described.

[0029] Presented herein is an on-board radar unit operable to detect objects surrounding a vehicle, the on-board radar unit being mounted on the vehicle. The radar unit can be used to obtain information about the environment in which the radar unit is traveling. This disclosure teaches various techniques by which the radar unit can analyze received data to glean useful information, such as the relative speed of the vehicle and the identification of hazards in the vehicle's surroundings.

[0030] Reducing sidelobes can provide a radar unit with sufficient directionality. To reduce sidelobes, the signals transmitted by each antenna in the array can be biphase shifted according to a required time phase shift profile. For example, to simulate multiple phase shift beamforming, such as quadrature phase shift keying (QPSK) beamforming, post-processing methods can be applied to the received reflected signals over multiple time periods. Typically, the receiver and transmitter can be synchronized to produce consistent results during the time interval in which the signals are combined.

[0031] Where necessary, detailed embodiments of the present invention are disclosed herein, however, it will be understood that the disclosed embodiments are merely illustrative of the invention, which may be embodied in various and alternative forms. The figures are not necessarily drawn to scale, and some features may be exaggerated or minimized to show details of particular components. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but merely as a representative basis for teaching those skilled in the art to various uses of the present invention.

[0032] In various embodiments of the present disclosure, one or more tasks as described herein may be performed by a data processor, such as a computing platform or distributed computing system for executing a plurality of instructions. Optionally, the data processor includes or has access to volatile memory for storing instructions, data, or the like. Additionally or alternatively, the data processor may have access to non-volatile storage, such as, for example, a magnetic hard disk, flash drive, removable media, or the like, for storing instructions and / or data.

[0033] It is expressly noted that the systems and methods of the present disclosure herein may not be limited in their application to the details of construction and the arrangements of components or methods set forth in the Detailed Description or illustrated in the drawings and examples. The systems and methods of the present disclosure may be capable of other embodiments or of being practiced and carried out in various ways and techniques.

[0034] Alternative methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure. Nevertheless, specific methods and materials are described herein for illustrative purposes only. The materials, methods, and examples are not necessarily intended to be limiting.

[0035] Alternative methods and materials similar or equivalent to those described herein may be used in the practice or testing of embodiments of the present disclosure. Nevertheless, certain methods and materials are described herein for illustrative purposes only. The materials, methods, and examples are not necessarily intended to be limiting. Thus, various embodiments may omit, substitute, or add various procedures or components, as appropriate. For example, methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. Furthermore, aspects and components described with respect to certain embodiments may be combined in various other embodiments.

[0036] 1A, which schematically illustrates an example of an automotive radar unit 100 configured to detect objects in an area 120 surrounding the vehicle, the automotive radar unit 100 being mounted on the vehicle. The radar unit 100 may be mounted on a variety of vehicles as required, including road vehicles such as cars, trucks, motorbikes, trailers, caravans and the like, work vehicles such as diggers, cranes and the like, and, where appropriate, aircraft and ships.

[0037] By way of illustration, the radar unit 100 may be mounted on a vehicle and used to detect various objects in the vicinity of the radar unit 100, such as other vehicles 121, bicycles 122, pedestrians 123, road signs 124, walls 125, curbs 126, trees 127, and the like.

[0038] Thus, radar unit 100 can be used to obtain information about the environment that a vehicle is traveling in. This disclosure teaches various techniques by which the radar unit can analyze the received data to glean useful information, such as the relative speed of the vehicle and the identification of hazards in the vehicle's surroundings.

[0039] 1B, selected elements of a radar system for sensing a possible vehicle's surroundings are presented. The system includes a radar unit 110 and a controller 130. The radar unit 110 may include a radar transmission unit 112 and a radar receiving unit 114.

[0040] The radar transmission unit 112 includes an array of transmit antennas TX connected to an oscillator 116 and configured to transmit electromagnetic waves into an area surrounding the vehicle. The radar receiving unit 114 includes at least one receive antenna RX configured to receive electromagnetic waves reflected by objects in an area 120 surrounding the vehicle and may be operable to generate raw data.

[0041] The controller 130 may include various modules, such as a processor unit 132, an ego-velocity calculation module 134, a wall detection module 136, a dynamic range enhancement module 138, a dual reflection detection module 139, and the like.

[0042] The processor unit 132 may be in communication with the radar receiving unit 114 to receive raw data from the radar unit 114 and generate environmental information based on the received data. For example, an ego-speed calculation module 134 may be provided to calculate the speed of the vehicle from the raw data, a wall detection module 136 may be provided to detect flat surfaces in an area surrounding the vehicle, and a dynamic range enhancement module 138 may be provided to distinguish weakly reflective objects, such as pedestrians 123, from strongly reflective objects, such as walls 125 or curbs 126, within the same vicinity.

[0043] A dual-reflection discrimination module 139 may be provided to distinguish between a single-reflected electromagnetic wave reflected directly by an object toward the radar receiving unit 114 and a dual-reflected electromagnetic wave reflected indirectly from the object toward the radar receiving unit 114 via an intermediate reflective surface. For example, the radar transmitting unit 112 may include a circular polarizer configured and operable to generate a circularly polarized electromagnetic wave, such as that described in applicant's co-pending U.S. Patent Publication No. 16 / 802,610, which is incorporated herein in its entirety. Accordingly, the radar receiving unit 114 may include a polarization detector configured and operable to detect the polarization of the received electromagnetic wave.

[0044] Circularly polarized electromagnetic waves reverse their polarity upon reflection so that waves that reflect even times can be easily distinguished from waves that reflect odd times. If the polarization of the received wave matches the polarization of the transmitted wave, the received wave can be considered to have been received directly from the reflecting object. If the polarization of the received wave is reversed, the received wave can be considered to have been received indirectly via a secondary reflector.

[0045] Reference is now made to the flowchart of Figure 2A, which illustrates selected steps in a possible method 200 for sensing surroundings of a vehicle. The method may include any or all of the following steps: providing an on-board radar unit 210, the on-board radar unit including a radar transmission unit having an array of transmit antennas connected to an oscillator, and a radar reception unit having at least one receive antenna, and a processor unit in communication with the radar reception unit; transmitting electromagnetic radiation into an area surrounding the vehicle 220; receiving electromagnetic radiation reflected from objects in the area surrounding the vehicle 230; detecting polarization of the received electromagnetic radiation 240; detecting targets extending in two dimensions within the area surrounding the vehicle 250; and optionally, distinguishing weakly reflecting objects from strongly reflecting objects in the same vicinity by applying a combination of dynamic range enhancing filters 260; constructing a series of three-dimensional images of the area surrounding the vehicle 270; and analyzing the series of three-dimensional images to determine the speed of the vehicle 280.

[0046] It should be noted that the above steps of the method 200 for detecting the surroundings of a vehicle may be performed in various combinations and in various orders according to suitable requirements. If necessary, those skilled in the art may include additional steps.

[0047] 2B and 2C present substeps of a possible method for carrying out the steps of constructing a series of three-dimensional images 280 and detecting targets spread in two dimensions in the area surrounding the vehicle 250.

[0048] 2B, substeps of a possible method for performing the step 280 of constructing a series of 3D images are detailed, including at least constructing 281 a first 3D image representing the area surrounding the vehicle at a first instant in time, waiting a delay time (dt) and constructing 282 a second 3D image representing the area surrounding the vehicle at a second instant in time, detecting 283 common reflective objects in the first and second 3D images, determining 284 a horizontal shift (dx) of the detected common reflective objects, and calculating an apparent radial velocity v as a function of the horizontal shift dx of the reflective objects. R and calculating 285 the slope of the trend line through the plot of

[0049] Thus, the ego-velocity calculation module may include an image generation unit configured and operable to construct a three-dimensional image representing an area surrounding the vehicle, and a memory unit configured and operable to store data relating to a sequence including at least a first three-dimensional image representing an area surrounding the vehicle at a first instant in time and a second three-dimensional image representing an area surrounding the vehicle at a second instant in time after a delay time (dt).

[0050] To better illustrate the method of self-velocity determination, reference is now made to Figures 3A-3D, which schematically illustrate a radar unit 300 of the present disclosure mounted on a moving vehicle 310 detecting apparent movement of objects 322, 324 in the area surrounding the vehicle 310.

[0051] As shown in Figures 3A and 3B, which show side and top views of a vehicle, the position 320 of a reflective object can be defined by at least a horizontal spatial coordinate (x), a vertical spatial coordinate (y), and a radial spatial coordinate (R).

[0052] Thus, a three-dimensional image of the area surrounding the vehicle can be constructed by constructing a matrix of voxels, each characterized by a set of voxel parameters, including the horizontal spatial coordinate of the reflecting object along an axis parallel to the vehicle's path (x), the vertical spatial coordinate of the reflecting object along a vertical axis perpendicular to the vehicle's path (y), and the radial spatial coordinate of the reflecting object along an axis radially diverging from the vehicle (R). Each voxel also contains an intensity value indicating the energy of the radiation reflected from each voxel, and the apparent radial velocity v of any reflecting object located at these coordinates in the area around the vehicle. R It may further be associated with a Doppler shift value that may be indicative of the radial velocity of the object. Note that even a stationary object will typically have an apparent radial velocity when detected by a sensor mounted on a moving vehicle.

[0053] The corresponding 3D images may contain clusters or shapes of high intensity voxels characteristic of reflective objects in the area surrounding the vehicle. Thus, the x-coordinate (x n ) and y-coordinate (y n ) can be determined.

[0054] Once a series of such 3D images have been generated and each 3D image is stored in a local memory unit, a common reflective object can be identified at different coordinates in two or more 3D images. Thus, the horizontal shift dx between a pair of 3D images is the ratio of the x coordinate of the reflective object to the y coordinate of the reflective object (x n / y n ) to determine the co-latitude angle (θ n ) and find dx=sin(arctan(x n / y n )) and calculating the sine of the co-latitude angle.

[0055] Therefore, the horizontal shift is

number

[0056] 3C and 3D, a stationary reflective object located at point 321 relatively close to radar unit 300 will typically have a large horizontal shift dx1, while a stationary reflective object located at point 322 relatively far from radar unit 300 will typically have a larger horizontal shift dx2. Each reflective object has an apparent radial speed v R1 , v R2 It is further noted that the .lamda.

[0057] For each stationary reflecting object, the apparent radial speed is a function v R =v car It can be shown that the horizontal shift by dx is related to the radial speed of the vehicle. Thus, when a graph is plotted representing the radial speed values ​​of all detected objects against their corresponding horizontal shifts, a trend line can be constructed, for example using the method of least squares, and the slope of the resulting trend line will be related to the vehicle's speed v car can be shown.

[0058] By way of illustration, Figures 4A-4C show the apparent radial velocity v as a function of the horizontal displacement dx of a reflecting object, as measured by a radar unit mounted on a vehicle traveling at different speeds. R Here are three examples of such plots: Figure 4A shows a plot of radial speed against horizontal displacement, as recorded by a stationary vehicle. The slope of the resulting line is flat, indicating no vehicle motion.

[0059] FIG. 4B shows a plot of radial speed versus horizontal displacement as recorded by a vehicle traveling at 20 kph, and FIG. 4C shows a plot of radial speed versus horizontal displacement as recorded by a vehicle traveling at 40 kph. car Note that as increases, the slope of the trend line increases proportionally.

[0060] 2C, substeps of a possible method for performing step 250 of detecting two-dimensional targets in an area surrounding a vehicle are detailed. The substeps include detecting spectral reflection points in reflected radiation 251, constructing a virtual box around a volume containing candidate wall-like objects 252, calculating an energy profile of the radar image within the virtual box 253, and applying a classification function to the energy profile 254. Illustratively, the classification function may involve calculating at least one wall-indicating parameter selected from the group consisting of the total energy reflected from within the virtual box, a profile of energy reflected from within a segment of the virtual box, the number of voxels within the virtual box that have energy values ​​above a threshold, and combinations thereof.

[0061] It is important that a vehicle be able to detect very long objects such as walls and the like within the vehicle's perimeter, but it should be noted that radar-based far-field sensors may encounter problems when representing such vast or complex geometric dimensions.

[0062] As an illustration, a signal reflected from an extensive wall may consist of a dominant reflection from a single reflecting point, as well as much weaker diffracted and "diffuse" reflections that may be difficult to detect. Nevertheless, being able to estimate the size of a detected object can be very important for various radar applications, and particularly in automotive radar applications, where very long obstacle edges can be relevant to determining and maintaining safe driving routes.

[0063] Accordingly, the systems described herein may include a wall detection module operable to detect flat surfaces in the area of ​​the vehicle by applying a method for detecting and classifying very long two-dimensional obstacles such as walls, fences, curbs, and the like. The module may further be operable to distinguish such obstacles from single, localized objects such as pedestrians, poles, road signs, and the like. Specifically, the wall detection module may include a processing unit and a memory unit storing executable code for comparing an energy profile within the virtual box to a reference energy profile having properties indicative of a two-dimensional reflector.

[0064] The method may include detecting the strongest reflection from an object and estimating the size of the object from an energy profile in the radar image along the object, where the strongest reflection is detected from a specular point on the object.

[0065] Referring now to FIG. 5, a radar unit 500 of the present disclosure mounted on a moving vehicle 510 may detect a two-dimensional, wall-type target 520 in an area surrounding the vehicle by identifying a reflection point 530. Note in particular that the specular reflection point of a two-dimensional object is typically tangent to the reflection point 530 and perpendicular to the normal between the sensor and the reflection point. For radar in the millimeter-wave range, multiple weak reflections along the vast surface of a two-dimensional object are expected. Therefore, a virtual box 540 may be constructed to contain the expected volume of the wall, and the energy profile of the radar image within the virtual box may be calculated.

[0066] Once the energy profile of the radar image within the virtual box is calculated, a classification function can be applied to determine the likelihood that the object is a wall-like object. For example, the classification function may calculate and combine various wall-indicating parameters, such as the integrated total energy of all reflections within the volume containing the virtual box, the integrated energy of all reflections within a segment within the virtual box, the number of voxels within the box that exceed a certain threshold, or the use of voxel clustering within the box, such as K-means, DBSCAN, or similar. Various classification methods, such as hard thresholding, SVM, NN\CNN, etc., can be applied to the extracted features.

[0067] It should be noted that the dimensions of candidate wall-like objects can be assessed by various methods, such as the following examples: Root mean square values ​​can be calculated for the energy distribution within the box, possibly excluding specular reflections themselves; Additionally or alternatively, the continuity of voxels exceeding a certain threshold can be determined; furthermore, the dimensions of the main clusters can be determined after applying a clustering algorithm to the voxels within the box.

[0068] Where appropriate, for example, if a wide field of view along the horizontal axis is provided, the velocity profile of reflections along very long targets may be determined using self-velocity determination techniques such as those described herein. Thus, by referring to the history and relative velocity of specular reflections for the sensor, it may be possible to improve the reliability of wall-like object detection. For example, a constant zero relative velocity of a strong reflection detected by a moving sensor may indicate the presence of a very long object parallel to the vehicle's motion.

[0069] It should be further noted that different objects may reflect electromagnetic radiation with different intensities. Thus, there is a risk that a weaker reflecting object may be obscured by a more dominant reflection from a strongly reflecting object in the same vicinity. For example, a parked vehicle may be more reflective than a pedestrian, and plastic piping may be less reflective than a structural wall through which it protrudes; in such cases, it may be difficult to distinguish the weaker reflection from the stronger reflection.

[0070] Accordingly, the systems described herein may include a dynamic range enhancement module configured and operable to distinguish weakly reflective objects from strongly reflective objects within the same vicinity.

[0071] One way to enhance weak targets may be by applying specialized filters to match the expected properties of a particular target, yet this may come at the expense of other targets of interest, potentially reducing and worsening their detectability.

[0072] Surprisingly, it turns out that the dynamic range can be enhanced by combining several filters on the same image: for example, an unfiltered image can be merged with a filtered image to enhance weak reflections.

[0073] According to one possible combination, finite impulse response (FIR) or infinite impulse response (IIR) filtering can be merged with unfiltered radar images across multiple frames. Such a combination can be useful for enhancing weak but dynamic objects. Such dynamic objects include pedestrians, cyclists, or other vehicles whose motion may be inherent. Other dynamic objects can be stationary objects whose apparent motion is induced by a moving on-board detector, such as thin, localized objects like plastic pipes, versus large surfaces like semi-static walls that may appear stationary relative to the vehicle.

[0074] According to another possible enhancement technique, various high-pass or band-pass filters may be applied to multiple frames to generate several images, each of which is expected to correspond to different time scales.

[0075] Yet another enhancement technique may involve Doppler-domain filtering. If Doppler resolution allows, the expected Doppler histogram associated with the motion of large, static objects can be removed over their predicted volume. This may leave behind weaker, but more dynamic, micro-Doppler signatures of targets (e.g., pedestrians).

[0076] Thus, a multi-layer image including multiple layers may be introduced, with each layer corresponding to a different filter. Accordingly, layers may be combined in various combinations. It is further noted that, if desired, feature extraction may be performed separately for each layer, such as by generating a point cloud image and detecting features therein, such as that described in applicant's co-pending U.S. Provisional Patent Application No. 62 / 955,482, which is incorporated herein by reference in its entirety. Additionally or alternatively, if preferred, a common feature extraction procedure may be performed simultaneously on multiple layers. Similarly, data from one layer may be used to support data processing from other layers as needed, for example, for target detection enhancement.

[0077] Reference is now made to Figures 6A and 6B. Figure 1A shows how a guidance vector can be generated by BPSK phase shifting. Without artificial phase shifting, an array of antennas can produce a range of phase shifts due to the nature of electronic circuits and the like, in addition to the phase produced by wave propagation in the desired guidance direction (called the "array factor"). This range of phases is represented by the circled area in Figure 6A(i). The phasors shown in the figure do not consistently add up. By selectively adding a 180-degree phase shift to all antennas producing phases within the left side of the circle, these phasors can be partially aligned, as shown in Figure 6A(ii), thereby radiating energy toward the desired guidance direction. Therefore, each antenna 1116 in the array may be connected to a signal-generating oscillator 1112 via a dual-phase adjuster 1114, as shown in Figure 6B. While the BPSK mechanism can actually generate guidance vector 1110, the resulting beam suffers from significant sidelobes and significant loss.

[0078] By providing additional phase shift options, more efficient guidance vectors can be generated. Referring to Figures 6C and 6D, a range of phases such as that shown in Figure 6C(iii) can be converted to a net guidance vector 1130, such as that shown in Figure 1C(iv), by selectively shifting each transmit signal by 0, 90, 180, or 270 degrees (QPSK), as needed.

[0079] 6D shows a possible hardware arrangement 1140 for producing such a phase shift in the antennas 1148 of the array. Each antenna 1148 of the array may be connected to a signal generating oscillator 1142 via a phase shift mechanism having two parallel arms: an in-phase arm (Re) and a quadrature arm (Im).

[0080] The in-phase arm (Re) includes a first bi-phase adjuster 1144 that can be selectively activated to add a 180 degree phase shift to the oscillating signal, if desired. Alternatively, by not activating the first bi-phase adjuster, the signal is transferred in phase to the transmit antenna.

[0081] The quadrature arm (Im) includes a second bi-phase adjuster 1146 and a quarter-cycle phase adjuster 1145. The quarter-cycle phase adjuster 1145 is configured to add a 90-degree phase shift to the oscillating signal. Thus, when the second bi-phase adjuster 1146 is not activated, a 90-degree phase shift is applied to the signal transferred to the antenna. Alternatively, when the second bi-phase adjuster is activated to add an additional 180-degree phase shift, a total phase shift of 270 degrees is applied to the signal transferred to the antenna, as needed.

[0082] It will be appreciated that such a hardware quadrature modulation mechanism, such as that shown in Figure 6D, can significantly improve the overall guidance vector. Nevertheless, the arrangement requires significantly more hardware elements than the simple two-phase adjuster 1120 of Figure 6B. The addition of a quadrature arm for each antenna, including a quarter-cycle phase adjuster that may need to be located physically close to the antenna itself, places significant hardware limitations on the designer of the antenna array circuit.

[0083] A possible solution for generating an improved guidance vector using only two phase regulator elements is now described.

[0084] 7A, there is shown selected elements of a first embodiment of a system for simulating quadrature phase shift keying (QPSK) beamforming in an antenna array 1200. The system includes a transmitter 1250, an antenna array 1210, a bi-phase adjuster 1220 associated with each transmit antenna, a controller 1230, a receive antenna 1240, and a post processor 1260.

[0085] Transmitter 1250 is configured and operable to generate an oscillating signal for transmission by antenna array 1210. It should be noted that, if appropriate, transmitter 1250 may be further operable to generate a signal that sweeps through a range of frequencies, or a chirp.

[0086] The antenna array 1210 includes several antennas A1 to An, each operable to transmit a signal generated by an oscillator 1270 with a required phase shift. It will be noted that the superposition of the signals transmitted from all of the antennas in the array results in a general signal beam having a characteristic shape.

[0087] The bi-phase adjuster 1220 associated with each transmit antenna An is configured and operable to selectively apply a 180 degree phase shift to the oscillating signal as needed. Alternatively, if the bi-phase adjuster 1220 is not activated, no phase shift is applied to the oscillating signal. Thus, the signal transmitted by the associated antenna is in phase or out of phase with the oscillating signal produced by the oscillator 1270 as needed.

[0088] The controller 1230 is configured to send activation commands to the bi-phase adjuster 1220 so that only the required antennas transmit phase-shifted signals.

[0089] The receive antenna(s) 1240 are configured to receive return signals reflected from the target.

[0090] The post processor 1260 is operable to manipulate the received signals and includes a memory 1280 element and a processing unit 1290. The memory element 1280 is operable to store the received signals. The processing unit is operable to apply a phase shift to selected received signals stored in the memory 1280 and is further operable to sum the received signals stored in the memory 1280.

[0091] In a particular example, the processing unit may apply a 90 degree phase shift to selected received signals and sum these with other received signals to produce the required output signal.

[0092] Thus, the controller may be operable to determine a complex guidance vector C=R+jI required for each antenna of the array. The complex guidance vector C includes a binary real component R selected from +1 and −1, and a binary imaginary component I selected from +1 and −1. A value of +1 indicates no phase shift is required, and a component of −1 indicates a phase shift is required. Thus, the real component may represent a required phase shift selected from 0 and 180 degrees, and the imaginary component may represent a required phase shift selected from 90 and 270 degrees, all associated with the combination R=+1, I=+1.

[0093] Referring now to the graph of FIG. 7B, there is shown a possible set of profiles illustrating how the phases S1 to Sn of the signals transmitted from each of the transmit antennas A1 to An in the first embodiment may vary over time.

[0094] Note that the phase shift of each antenna remains fixed for a given time interval Δt. Each antenna An receives a unique profile determined by the required guidance vector C at that time. Each complex guidance vector C can determine the required phase shift between two consecutive time intervals Δt, Δt+1.

[0095] During a first time interval Δti, the controller commands the bi-phase adjusters 1220 of antennas A1-An having a guidance vector Ci associated with a real component Ri of −1 to apply a 180 degree phase shift to the transmitted signal.

[0096] During a second time interval Δti+1, the controller commands the bi-phase adjuster 1220 of the antenna having the guidance vector Ci associated with an imaginary I component of −1 to apply a 180 degree phase shift to the transmitted signal.

[0097] Thus, the post processor 1260 may be operable to store in memory the reflected signals received during the first time interval and the second time interval, and the processor unit may then apply a 90 degree phase shift to the signal received during the second time interval before summing the signal received during the first time interval with the 90 degree phase shifted signal received during the second time interval.

[0098] The resulting output signal from the post processor will have the characteristics of a quadrature-shifted signal.

[0099] Referring now to the flowchart of FIG. 7C, selected steps of a method 1400 for simulating quadrature phase shift keying (QPSK) beamforming in the system of FIG. 7A in which the antennas of the array 1210 are connected to a common transmitter via respective bi-phase adjusters 1220 are shown.

[0100] For each transmit antenna of the array, a required complex QPSK guidance vector C is determined 1410, comprising a real component R selected from +1 and −1, and a binary imaginary component I selected from +1 and −1.

[0101] The transmitter generates an oscillating signal that is transmitted to each antenna via a two-phase modulator 1420. Optionally, each transmitted signal may sweep over a range of frequencies during each time interval.

[0102] During the first time interval 1430, for each transmitting antenna having a guidance vector associated with a real component R of +1, the associated bi-phase adjuster applies a 180 degree phase shift to the transmitted signal 1432, the antenna transmits the signal 1434, and the received signal is stored in a post processor memory 1436.

[0103] During a second time interval 1440, for each transmitting antenna having an induction vector associated with an imaginary component I of +1, the associated biphasor applies a 180 degree phase shift to the transmitted signal 1442, the antenna transmits the signal 1444, and the received signal is stored in a post processor memory 1446.

[0104] The post processor may then apply 1450 a 90 degree phase shift to the signal received during the second time interval 1440 and sum 1460 the signal received during the first time interval to the 90 degree phase shifted signal received during the second time interval.

[0105] A particular feature of the systems and methods described herein is the linear combination of signals received over several time intervals in order to simulate and benefit from the advantages of an enhanced beamformer in a simulated manner. This feature can be extended in various ways that will be apparent to those skilled in the art and are mentioned here as examples.

[0106] In one extension, if the transmitter already supports beamforming using a particular choice of phases (e.g., 4-phase QPSK, 8-phase 8-PSK, etc.) or gain, then a combination of M codewords (two or more) over M time intervals can be used to generate a larger choice of phases by a factor M (e.g., using four time intervals with BPSK or two time intervals with QPSK to generate simulated 8-PSK).

[0107] The simulated QPSK scheme can alternatively be calculated by taking the desired phasor C for each transmit antenna and calculating X = Sgn(Re{C·e -jφ}), where φ is 0 during the first interval and 90 degrees during the second interval, and then jφIn another extension of the invention, the sequence of "modulation" phases φ can be chosen in different ways over time, for example at different scanned frequencies or frames.

[0108] In another extension of the present invention, the signal received over M intervals may be modulated with arbitrary phasors a1,..a2 that do not necessarily have unit gain (rather than a1=1, a2=j as in the QPSK case as described herein). M The beamforming codewords over these M intervals are a1,..a M These linear combinations, weighted by , are chosen in a way that produces the desired characteristics (such as high peak to sidelobe levels).

[0109] The above-described method for implementing QPSK (quadrature) beamforming by using two phase adjusters and two time intervals is presented for illustrative purposes only. This method can be further generalized to implement any even number 2n of phases over n time intervals. For example, with three time intervals, 6-PSK modulation can be realized.

[0110] A method may be implemented in which the transmitter selectively applies a 180 degree phase shift to a particular antenna during N time intervals according to the following condition: if in the nth time interval the real value of the guidance vector rotated by n*180 / N degrees is negative, then the 180 degree phase shift is applied to the kth antenna. Thus, a 180 degree phase shift is applied to the kth antenna if the following formula is true: Real(C k *e -j*φ[n] )<0 where C k is the k-th component of the induction vector, and φ n =πn / N is the rotation sequence.

[0111] Therefore, if appropriate, in a post-processor, a rotation of φn radians for the nth time interval can be applied before summing the signals received in all time intervals.

[0112] Methods such as those described herein can be extended to incorporate additional measures for the desired beamformer by choosing a set of N phase shift sequences such that the median value of the signal transmitted over N time intervals meets the desired measure. For example, effective attenuation for each unique transmit antenna may be required for gain control for apodization and transmitter gain equalization. This can be achieved without analog gain control by using a unique rotation sequence for each unique transmit antenna, e.g., the steering vector for each antenna may be rotated by, for example, an angle step (1-a)*φn, where the value of a is specifically chosen to suit each transmit antenna.

[0113] The multiple time intervals necessary to apply the described method may also be used for other purposes. In one possible embodiment, multiple time intervals may be used to allow for Doppler processing within each frame, to allow for integration times that may be longer than the channel coherence time, and to obtain information about target velocities. Each spatial transmitter direction to be scanned may include N time intervals, and Doppler post-processing may search for a linear phase shift between the intervals that may correspond to the radial velocity. This may be implemented, for example, using a Fast Fourier Transform (FFT) over the time intervals.

[0114] Note that, if appropriate, each time interval may itself involve sweeping the transmitted signal over multiple frequencies using a stepped frequency continuous wave, chirp, or some other frequency function over time during the time interval. Thus, by varying the beamformer between time intervals as described above, sidelobe levels should typically be reduced by phase quantization at any given rate. However, associated beamforming quantization errors may still produce sidelobes at other rates.

[0115] Another feature of the present method is that the spectral shape of the generated sidelobes can be controlled by selecting a specific order for the time intervals so that the quantization noise that generates the sidelobes is largely confined to high frequencies corresponding to higher radial velocities than expected in the particular application. If desired, the phase rotation φn for the nth time interval (where n can take any integer value from 0 to N-1) can be selected as follows: φ n =π * [(n * (N-1) / 2)mod N] Here, "mod" is the modulo operation that returns the remainder when divided by a given integer, and it is assumed that N is an integer multiple of 4. As mentioned above, a 180 degree rotation is calculated by dividing Real(Ck * ej * The post-processor applies a rotation by φn only if φ[n]<0. With this reordering of the time intervals, most of the sidelobe power resides at the Nyquist frequency of the Doppler.

[0116] It will be appreciated that other structures may be used to select the phase rotation sequence, or the order in the sequence of guiding vectors, to optimize the spectral shape of the quantization noise, as appropriate.

[0117] In the above structure, the known required guidance vector is φ for two-phase selection. nAn alternative approach is to use Real(H({b k}) * exp(j * φ n ))) at the maximum value l, where H({b k}) is the unique phase selection b k is a phasor representing the combination of all transmitting antennas in the desired spatial direction. Such a maximization can be done, for example, by K H can be implemented in various ways, such as by an exhaustive search over all two-phase combinations (with K transmit antennas with the option of H = 1). H can be obtained, for example, by analysis of direct measurements of electromagnetic waves reflected by a reference target located in the desired spatial direction.

[0118] The number of time intervals may be selected to achieve the required beamforming accuracy, for example, in terms of sidelobe level, signal-to-noise ratio (SNR) (possibly using longer integration times with additional intervals), and Doppler estimation resolution. On the other hand, the number of time intervals may be limited by other factors, such as the memory capacity and processing power of the electronic components and the avoidance of blurring within the frame. Therefore, the actual number of time intervals selected may be a compromise between all these considerations.

[0119] Since some spatial directions may be more important than others, in terms of the required SNR and Doppler resolution, it may be preferable to allocate more time intervals to these preferred directions and fewer time intervals to other lower priority directions.

[0120] This scanning method may be used in a variety of applications, such as external car radar sensors used for ADAS (Advanced Driver Assistance Systems) or autonomous driving. It will be appreciated that in such applications, the horizontal angular range of interest (azimuth range) is typically wider than the vertical angular range of interest (altitude range). This is because car radar sensors generally do not need to scan below the road surface. Therefore, it may be preferable to align the transmitter antenna in a vertical linear array so that the side lobes are outside the high preferred altitude range. The receiver antenna may be arranged in a horizontal linear array oriented at right angles.

[0121] Other possible applications may include monitoring enclosed spaces such as rooms, stadiums, goal lines, or the like. Still other applications may involve tracking objects within a target area, possibly using large arrays for body scanning. Still other applications will occur to those skilled in the art.

[0122] Reference is now made to the block diagram of FIG. 8A, which schematically illustrates selected elements of a second embodiment of a system in which each antenna is connected to a gain control unit 1550 such that quadrature amplitude modulation (QAM) beamforming can be simulated.

[0123] In addition to the components shown in the first example system of Figure 7A, a dedicated gain control unit 1530 is associated with each transmit antenna, and the controller is therefore further configured to instruct the gain control unit to amplify the transmitted signal by a required gain determined by the complex guidance vector.

[0124] The controller may also be operable to determine the complex guidance vector C=R+jI required for each antenna of the array, where the guidance vector may still have a continuous real component R selected from the range +1>R>-1 and a continuous imaginary component I selected from the range +1>I>-1.

[0125] Thus, the controller may be further operable to select a required amplitude R for the real component of the associated guidance vector and to instruct the associated gain control unit to apply the associated first gain GR to the transmitted signal during a first time interval. Similarly, the controller is operable to select a required amplitude I for the imaginary component of the associated guidance vector and to instruct the associated gain control unit to apply a second gain GI to the transmitted signal during a second time interval, the second gain GI being equal to the product of GR and the absolute ratio of I to R.

[0126] Referring to the set of graphs shown in FIG. 8B, the resulting signal produced by each antenna during each time period may therefore be amplitude modulated and phase modulated.

[0127] Referring now to the flowchart of FIG. 8C, selected steps of a method for simulating quadrature amplitude modulation (QAM) beamforming in the system of FIG. 8A in which the antennas of the array are each connected to a common transmitter via associated binary phase adjusters and gain control units 1530 are shown.

[0128] For each transmit antenna of the array, a required complex QPSK guidance vector C is determined 1610, with a real component R selected from the range +1>R>-1 and an imaginary component I selected from the range +1>I>-1.

[0129] The transmitter generates an oscillating signal that is transmitted to each antenna via a two-phase modulator 1620. Optionally, each transmitted signal may sweep over a range of frequencies during each time interval.

[0130] During a first time interval 1630, for each transmit antenna having a guidance vector associated with a negative real component R, an associated bi-phase adjuster applies a 180 degree phase shift to the transmitted signal 1632. An associated gain control unit amplifies the signal by a first value GR=|R|G0 1633, the antenna transmits the amplified signal 1634, and the received signal is stored 1636 in a post processor memory.

[0131] During a second time interval 1640, for each transmit antenna having a guidance vector associated with a negative imaginary component I, the associated bi-phase adjuster applies a 180 degree phase shift to the transmitted signal 1642. The associated gain control unit amplifies the signal by a second value GI = |I|G0 1643. The antenna then transmits the amplified signal 1644, and the received signal is also stored 1646 in the post processor memory.

[0132] Thus, if the post processor applies 1650 a 90 degree phase shift to the signals received during the second time interval 1640 and sums 1660 these signals with the signals received during the first time interval, the resulting signal can have a virtual phase shift of any value desired.

[0133] It is further noted that while the system described herein includes a dedicated dual phase adjuster for each antenna, an alternative system without phase adjusters may operate by utilizing additional time intervals, as shown in FIG. 9A.

[0134] The use of such a system can be enabled by activating only those antennas with a real component of +1 during a first time period with no phase shift, activating only those antennas with a real component of −1 during a second time period with a 180 degree phase shift applied at the receiver, activating only those antennas with an imaginary component of +1 during a third time period with no phase shift, and activating only those antennas with an imaginary component of −1 during a fourth time period with a 180 degree phase shift applied at the receiver.

[0135] It should be further noted that if each antenna in the system has an independently controllable connection switch 1740, such as that shown in Figure 9A, it may be possible to apply such a phase shift directly from the oscillator 1770 or during post-processing. Additionally or alternatively, a common bi-phase adjuster may be connected to multiple transmit antennas, if desired.

[0136] An example signal profile produced by such an example system is presented in Figure 4B. The post processor may store in memory the received signals from each of the first time period, the second time period, the third time period, and the fourth time period.

[0137] The four signals can be summed by the receiver after applying 0, 180, 90, and 270 degree phase shifts in the first, second, third, and fourth steps, respectively. By summing all these signals, a simulated QPSK guide vector without a phase adjuster can be realized in the system.

[0138] Further extensions of linear combinations of signals received over multiple time intervals will occur to those skilled in the art.

[0139] Technical Notes Technical and scientific terms used herein should have the same meaning as commonly understood by those skilled in the art to which this disclosure pertains. Nevertheless, it is expected that many related systems and methods will be developed during the life of the patent that matures from this application. Accordingly, the scope of terms such as computing unit, network, display, memory, server, and the like is intended to deductively include all such new technologies.

[0140] As used herein, the term "about" refers to at least ±10%.

[0141] The terms "comprises," "comprising," "includes," "including," "having," and their cognates mean "including but not limited to" and indicate the inclusion of the listed elements but not the exclusion of other elements as a whole. Such terms encompass the terms "consisting of" and "consisting essentially of."

[0142] The phrase "consisting essentially of" means that the composition or method may include additional components and / or steps, but only if the additional components and / or steps do not materially alter the basic and novel characteristics of the claimed composition or method.

[0143] As used herein, the singular forms "a," "an," and "the" can include plural references unless the context clearly dictates otherwise. For example, the term "a compound" or "at least one compound" can include multiple compounds and mixtures thereof.

[0144] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment described as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments, or to exclude the incorporation of features from other embodiments.

[0145] The word "optionally" is used herein to mean "provided in some embodiments and not provided in others." Any particular embodiment of the present disclosure may include multiple "optional" features, so long as such features do not conflict.

[0146] Whenever a range of numerical values ​​is given herein, it is intended to include any recited number (fractional or integer) within the given range. The phrases "ranging / range between" a first and a second designated number, and "from" a first designated number and "to" a second designated number, are used interchangeably herein and are intended to include the first and second designated numbers and all fractional and integer numbers therebetween. It should therefore be understood that expressions in range format are merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the present disclosure. Thus, expressions in range format should be considered to have specifically disclosed all possible subranges and individual numerical values ​​within that range. For example, a range such as 1 to 6 should be considered to have specifically disclosed subranges such as 1 to 3, 1 to 4, 1 to 5, 7 to 4, 7 to 6, 3 to 6, etc., as well as individual numbers and non-integer intermediate values ​​within that range, e.g., 1, 7, 3, 4, 5, and 6. This applies regardless of the broadness of the range.

[0147] It is understood that certain features of the present disclosure that are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the present disclosure that are, for brevity, described in the context of a single embodiment, may also be provided separately, or in any suitable subcombination, or as suitable in any other described embodiment of the present disclosure. Certain features described in the context of various embodiments should not be considered essential features of those embodiments, unless the embodiment is invalid without those elements.

[0148] While this disclosure has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications, and variations that fall within the spirit and broad scope of the appended claims.

[0149] All publications, patents, and patent applications mentioned herein are herein incorporated by reference in their entirety to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference herein. Furthermore, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present disclosure. To the extent section headings are used, they should not be construed as necessarily limiting.

[0150] The scope of the disclosed subject matter is defined by the appended claims and includes both combinations and subcombinations of the various features described above, as well as variations and modifications thereof, which will occur to those skilled in the art upon reading the foregoing description.

Claims

1. 1. A system for detecting surroundings of a vehicle, comprising: a radar transmission unit comprising an array of transmitting antennas connected to an oscillator and configured to transmit electromagnetic waves into an area surrounding the vehicle; and a radar receiving unit comprising at least one receiving antenna configured to receive electromagnetic waves reflected by objects in the area surrounding the vehicle, the radar receiving unit being operable to generate raw data; an on-board radar unit comprising: a processor unit in communication with the radar receiving unit, configured to receive raw data from the radar unit, and operable to generate environmental information based on the received data; Equipped with the processor: an auto-speed calculation module operable to calculate a speed of the vehicle from the raw data; the self-velocity calculation module comprises an image generation unit and a memory unit; The image generation unit is configured and operable to construct a three-dimensional image representing the area surrounding the vehicle comprising a matrix of voxels, each voxel comprising: the horizontal spatial coordinate (x) of the reflecting object along an axis parallel to the path of the vehicle; the vertical spatial coordinate (y) of the reflecting object along a vertical axis perpendicular to the path of the vehicle; the radial space coordinate (R) of the reflecting object along an axis radially diverging from the vehicle; Intensity value, and The apparent radial velocity of the reflecting object, v Ｒ Doppler shift values ​​indicating characterized by a set of voxel parameters including The memory unit comprises at least: a first three-dimensional image representing the area surrounding the vehicle at a first instant in time; and a second three-dimensional image representing the area surrounding the vehicle at a second instant in time after a delay time (dt); A system configured to store data relating to:

2. 1. A system for detecting surroundings of a vehicle, comprising: a radar transmission unit comprising an array of transmitting antennas connected to an oscillator and configured to transmit electromagnetic waves into an area surrounding the vehicle; and a radar receiving unit comprising at least one receiving antenna configured to receive electromagnetic waves reflected by objects in the area surrounding the vehicle, the radar receiving unit being operable to generate raw data; an on-board radar unit comprising: a processor unit in communication with the radar receiving unit, configured to receive raw data from the radar unit, and operable to generate environmental information based on the received data; Equipped with the processor unit: a wall detection module operable to detect flat surfaces in the area surrounding the vehicle; The system, wherein the wall detection module comprises a memory unit storing executable code for comparing an energy profile within a virtual box to a reference energy profile having properties indicative of a two-dimensional reflector.

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