Patent Publication Number: US-2023136923-A1

Title: Method and apparatus with vehicle radar control

Description:
This application is a continuation of U.S. patent application Ser. No. 16/166,905, filed on Oct. 22, 2018, which claims the benefit under 35 USC § 119(a) of Korean Patent Application No. 10-2018-0059849, filed on May 25, 2018 in the Korean Intellectual Property Office, the entire disclosures of which are incorporated herein by reference for all purposes. 
    
    
     BACKGROUND 
     1. Field 
     The following description relates to a method and apparatus with vehicle radar control. 
     2. Description of Related Art 
     Radar for a vehicle may be a device configured to measure at least a position or a velocity of an object in relation to the vehicle. The radar may be located on one or more of a front side, a lateral side, or a rear side of the vehicle, among other locations. The radar detects target objects within a field of view (FoV) and range of the radar. In general, the space in which the radar may be located on a vehicle is limited. In addition, cost and performance associated with the radar may further limit design and implementation of vehicle-based radar. As a result of these limitations, a target object may not be detected by the radar. 
     SUMMARY 
     This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
     In one general aspect, a vehicle radar control method includes collecting environmental information of the vehicle, determining radar mode of the vehicle based on the collected environmental information, and controlling a transmitting antenna array or a receiving antenna array of the vehicle based on the determined radar mode. 
     The determining may include determining the radar mode from among a plurality of radar modes defined based on a detectable azimuth, a detectable range, or a detectable elevation. 
     The determining may include determining the radar mode from among a plurality of radar modes defined based on a detection rate, a detection area, or an angular resolution. 
     The determining may include determining the radar mode from among a digital beamforming mode, an analog beamforming mode, and a hybrid beamforming mode based on the detectable elevation. 
     The controlling may include changing one or more of an elevation and an azimuth of a radiation pattern emitted by the transmitting antenna array in response to a determined mode. 
     In response to the digital beamforming mode being determined to be the radar mode, the controlling may include controlling the transmitting antenna array using a multiple-input and multiple-output (MIMO) method. 
     In response to the analog beamforming mode being determined to be the radar mode, the controlling may include controlling the transmitting antenna array using a phased array method. 
     In response to the hybrid beamforming mode being determined to be the radar mode, the controlling may include controlling the transmitting antenna array using a combined method that is a combination of the MIMO method and the phased array method. 
     The determining may include determining the radar mode from among a short-range radar (SRR) mode, a medium-range radar (MRR) mode, and a long-range radar (LRR) mode based on the detectable azimuth and the detectable range. 
     The method may further include collecting information regarding a result of controlling the radar; and determining a radar mode based on the environmental information and a result of controlling the radar. 
     The method may further include collecting information regarding a result of controlling the radar; determining a reliability of the result of controlling the radar; and determining a radar mode based on the environmental information and the reliability of the result of controlling the radar. 
     The determining may include determining the radar mode based on a reliability of the result of controlling the radar. 
     The environmental information may include road environment information and object environment information. 
     A non-transitory computer-readable storage medium may store instructions that, when executed by a processor, may cause the processor to perform the method described above. 
     In another general aspect, an apparatus with vehicle radar control includes at least one processor and a radio frequency (RF) transceiver including a transmitting antenna array and a receiving antenna array. The processor collects environmental information of the vehicle, determines a radar mode of the vehicle based on the collected environmental information, generates a control signal configured to control one or more of the transmitting antenna array and receiving antenna array based on the determined radar mode; and provides the generated control signal to the RF transceiver, wherein one or more of the transmitting antenna array and the receiving antenna array operate according to the generated control signal. 
     The transmitting antenna array may include at least three antennas forming a two-dimensional (2D) array. 
     The transceiver may include a phase shifter configured to adjust a phase of the transmitting antenna array. 
     Each of a plurality of antennas included in the transmitting antenna array and the receiving antenna array may be independently controlled to be turned on or off according to the control signal. 
     The apparatus may further include a memory. The memory may be configured to store a plurality of radar modes that are defined based on a detectable azimuth, a detectable range, or a detectable elevation. The processor may determine the radar mode from among the plurality of radar modes. The memory also may be configured to store a plurality of radar modes corresponding to a detection rate, a detection area, or an angular resolution, 
     The processor may determine the radar mode from among a digital beamforming mode, an analog beamforming mode, and a hybrid beamforming mode based on an azimuth or an elevation obtained from the environmental information. 
     The control signal may be configured to change one or more of an elevation and an azimuth of a radiation pattern emitted by the transmitting antenna array in response to a determined mode. 
     In response to the digital beamforming mode being determined to be the radar mode, the processor may control the transmitting antenna array using a MIMO method. 
     In response to the analog beamforming mode being determined to be the radar mode, the processor may control the transmitting antenna array using a phased array method. 
     In response to the hybrid beamforming mode being determined to be the radar mode, the processor may control the transmitting antenna array using a combined method that is a combination of a MIMO method and a phased array method. 
     The processor may be configured to determine the radar mode from among a short-range radar (SRR) mode, a medium-range radar (MRR) mode, and a long-range radar (LRR) mode based on the detectable azimuth and the detectable range. 
     The processor may be further configured to: collect information regarding a result of controlling the radar; and determine a radar mode based on the environmental information and a result of controlling the radar. 
     The processor may be further configured to: collect information regarding a result of controlling the radar; determine a reliability of the result of controlling the radar; and determine a radar mode based on the environmental information and the reliability of the result of controlling the radar. 
     In yet another general aspect, an apparatus for controlling a radar of a vehicle includes an RF transceiver including a first processor and a second processor. The first processor may collect environmental information of the vehicle and determine a radar mode of the vehicle based on the collected environmental information. The second processor may control a transmitting antenna array of the vehicle or a receiving antenna array of the vehicle based on the determined radar mode. 
     Other features and aspects will be apparent from the following detailed description, the drawings, and the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a diagram illustrating an example of the operation of an apparatus for controlling a radar of a vehicle. 
         FIG.  2    is a flowchart illustrating an example of a method of controlling a radar of a vehicle. 
         FIG.  3    is a diagram illustrating an example of an apparatus for controlling a radar of a vehicle. 
         FIG.  4 A  is a diagram illustrating an example of a virtual multiple-input and multiple-output (MIMO) array based on digital beamforming. 
         FIG.  4 B  is a diagram illustrating an example of a virtual MIMO array based on analog beamforming. 
         FIG.  5 A  is a diagram illustrating an example of an unsuccessful detection of a target object on a curved road. 
         FIG.  5 B  is a diagram illustrating an example of a successful detection of a target object on a curved road using an apparatus for controlling a radar of a vehicle. 
         FIG.  6 A  is a diagram illustrating an example of failure to detect a target object on flat ground above a vehicle traveling uphill. 
         FIG.  6 B  is a diagram illustrating an example of failure to detect a target object downhill from a vehicle traveling on flat ground. 
         FIG.  6 C  is a diagram illustrating an example of failure to detect a target object uphill from a vehicle traveling on flat ground. 
         FIG.  6 D  is a diagram illustrating an example of successfully detecting a target object on flat ground above a vehicle traveling uphill using an apparatus for controlling a radar of a vehicle. 
         FIG.  6 E  is a diagram illustrating an example of successfully detecting a target object uphill from a vehicle traveling on flat ground using an apparatus for controlling a radar of a vehicle. 
         FIG.  6 F  is a diagram illustrating an example of successfully detecting a target object on a flat ground above a vehicle traveling up an incline using an apparatus for controlling a radar of a vehicle. 
     
    
    
     Throughout the drawings and the detailed description, unless otherwise described or provided, the same drawing reference numerals refer to the same elements, features, and structures. The drawings may not be to scale, and the relative size, proportions, and depiction of elements in the drawings may be exaggerated for clarity, illustration, and convenience. 
     DETAILED DESCRIPTION 
     The following detailed description is provided to assist the reader in gaining a comprehensive understanding of the methods, apparatuses, and/or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatuses, and/or systems described herein will be apparent after obtaining an understanding of the disclosure of this application. For example, the sequences of operations described herein are merely examples, and are not limited to those set forth herein, but may be changed as will be apparent after gaining an understanding of the disclosure of this application, with the exception of operations necessarily occurring in a certain order. Also, descriptions of features that are known after gaining an understanding of the disclosure of this application may be omitted for increased clarity and conciseness. 
     The features described herein may be embodied in different forms and are not to be construed as being limited to the examples described herein. Rather, the examples described herein have been provided merely to illustrate some of the many possible ways of implementing the methods, apparatuses, and/or systems described herein that will be apparent after gaining an understanding of the disclosure of this application. 
     Throughout the specification, when an element, such as a layer, a region, or a substrate, is described as being “on,” “connected to,” or “coupled to” another element, the element may be directly “on,” “connected to,” or “coupled to” the other element, or there may be one or more other intervening elements. In contrast, when an element is described as being “directly on,” “directly connected to,” or “directly coupled to” another element, there are no other intervening elements. As used herein, the term “and/or” includes any one of the associated listed items and any combination of any two or more of the associated listed items. 
     Although terms such as “first,” “second,” and “third” may be used herein to describe various members, components, regions, layers, or sections, these members, components, regions, layers, or sections are not to be limited by these terms. Rather, these terms are only used to distinguish one member, component, region, layer, or section from another member, component, region, layer, or section. Thus, a first member, component, region, layer, or section referred to in some examples described herein may also be referred to as a second member, component, region, layer, or section in other examples without departing from the teachings described herein. 
     The terminology used herein describes various examples only and is not intended to limit the disclosure. The articles “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise. The terms “comprises,” “includes,” and “has” specify the presence of stated features, numbers, operations, members, elements, and/or combinations thereof, but do not preclude the presence or addition of one or more other features, numbers, operations, members, elements, and/or combinations thereof. 
     Unless otherwise defined, all terms, including technical and scientific terms, used herein have the meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains and/or a meaning based on an understanding of the disclosure of the detailed description. Terms, such as those defined in commonly used dictionaries, are to be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the disclosure provided herein, and the terms are not to be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
     After gaining an understanding of the disclosure, if any one example of the detailed description of structures or functions are deemed to result in an ambiguous interpretation of an embodiment, such disclosure may be otherwise omitted for clarity. 
       FIG.  1    is a diagram illustrating an example of the operation of a vehicle radar controlling apparatus for a vehicle including radar. The radar detects target objects within a field of view (FoV) and range of the radar. However, there is a tradeoff between detection coverage (e.g., the range and/or the area of detection) and resolution when radar resources of the vehicle are limited. As a result of these constraints, target objects may not be detected by the radar. Therefore, the following description provides methods and systems that overcome or mitigate such limitations to provide more effective detection of target objects using the limited radar resources that may be available for the vehicle. 
     Referring to the example of  FIG.  1   , an environment  100  includes a vehicle  101  and target objects  102 ,  103 ,  104 , and  105  shown in relation to the vehicle  101  traveling on a multi-lane road  107 . The vehicle  101  includes a vehicle radar controlling apparatus  110 . The vehicle radar controlling apparatus  110  may adaptively determine a radar mode based on the environment  100  in which a vehicle  101  is located. By using a radar mode determined to be best suited to the environment  100 , the vehicle radar controlling apparatus  110  provides for more effective target detection than would otherwise be available from the limited resources of the vehicle  101 . 
     In one example, the vehicle radar controlling apparatus  110  may select a radar mode from a number of pre-defined profiles that the radar controlling apparatus determines to be suitable for the environment  100  in which the vehicle  101  is located. For example, the vehicle radar controlling apparatus  110  may change a radiation pattern of the radar based on one or more factors, such as an elevation of a radar beam. In this example, the beam may include a radio frequency (RF) signal. The vehicle radar controlling apparatus  110  uses the one or more factors, such as elevation to determine a radiation pattern that is suitable for the environment  100  around the vehicle  101 . As a result, the radar may more effectively detect a target object than would be possible using the unadjusted radiation pattern. 
     In an example, the vehicle radar controlling apparatus  110  includes a sensor, a processor, and an RF transceiver (not shown in  FIG.  1   ). The vehicle radar controlling apparatus  110  may further include a memory (also not shown in  FIG.  1   ). Various components of the vehicle radar controlling apparatus  110  are shown in  FIG.  3    and described in further detail in the following paragraphs. 
     The sensor obtains sensor data of an internal environment and/or an external environment of the vehicle  101 . The sensor may include an internal sensor and/or an external sensor. The internal sensor detects an internal state of the vehicle  101 . For example, the internal sensor may detect one or more of: a control signal of the vehicle  101 ; a rotation angle of the vehicle  101  through a steering wheel of the vehicle  101 . The internal sensor may include, for example, an inertial measurement unit (IMU) configured to detect acceleration of the vehicle  101 . The external sensor detects an external state of the vehicle  101 . The external sensor may include, for example, a camera, a radar, a light detection and ranging (LIDAR) device or system, an ultrasonic sensor, and the like. 
     The processor is configured to determine environmental information of the vehicle  101  based on the sensor data obtained from a sensor. The environmental information determined by the processor may include road environment information and object environment information. Road environment information may include information associated with one or more of a width, a slope, a rotation radius, and/or information about a road on which the vehicle is traveling, such as the lanes of a road. Object environment information may include information associated with one or more of a position, a size, a speed, and/or a direction of an object. The object may include a target object and an occluded object. A target object refers to a target to be detected, and an occluded object refers to an object that may hinder detection of a target object. 
     For example, the processor may calculate a curvature and a slope of a road based on internal sensor data, such as a rotation angle of the steering wheel of the vehicle  101  and an acceleration detected from the IMU. The processor may calculate a width of the road and obtain lane information using data received from an external sensor, such as a camera. For example, the processor may process an image obtained from the camera to identify the road and an object (e.g., target or occluded). 
     The memory is configured to store a number of distinct radar modes. In one example, each radar mode may correspond to specific environmental information determined by the processor. A number of different radar modes may be defined for storage by the memory. For example, a radar mode may be based on one or more of: FoV, an azimuth, a range, and an elevation of a radiation pattern of a radar beam. For example, the FoV may refer to angle in within a horizontal plane that indicates the spread of the radar beams within the plane. The azimuth may refer to angle (positive or negative) formed between a reference direction (e.g., the direction of travel of the vehicle in a horizontal plane) and a line from the radar to a point of interest projected in the horizontal plane at which beams are directed. The range may refer to the maximum distance at which an object may be detected by the radar. The elevation may refer to an angle (positive or negative) in a vertical plane measured from the horizontal plane in which beams are directed. As described herein, selecting, determining, or changing the radar mode causes one or more of a detection rate, a detection area, or an angular resolution to change. In one example, the detection area may be defined by: 1) a FoV and a range, or 2) an azimuth, a range, and/or an elevation. Changing the radar mode can change: 1) only an azimuth; 2) only an elevation; or 3) both the azimuth and the elevation. 
     As describe above, the vehicle radar controlling apparatus  110  may determine or select a radar mode from a number of specific or pre-defined radar modes. For example, a digital beamforming mode, an analog beamforming mode, and a hybrid beamforming mode may be defined with regard to a detectable elevation and/or a detectable azimuth. In another example, a short-range radar (SRR) mode, a medium-range radar (MRR) mode, and a long-range radar (LRR) mode may be defined with regard to a detectable azimuth and a detectable range. The digital beamforming mode, the analog beamforming mode, the hybrid beamforming mode, the SRR mode, the MRR mode, and the LRR mode may be used in combination. However, the radar modes described above are provided merely as examples and various other types of radar modes also may be defined for use according to the teachings provided herein. 
     As described above, the processor is configured to determine or select a radar mode based on or corresponding to the determined environmental information. For example, the processor may determine the radar mode of the vehicle  101  from among a plurality of radar modes defined in advance. In one example, the processor may determine the radar mode that is best suited for the environment based on one or more factors determined from the environmental information including: a detectable azimuth, a detectable range, or a detectable elevation. 
     For example, when the slope of a road on which a vehicle  101  is traveling changes, the vehicle radar controlling apparatus  110  determines the radar mode of the vehicle  101  based on a detected elevation. In this example, the vehicle radar controlling apparatus  110  may choose from among the digital beamforming mode, the analog beamforming mode, and the hybrid beamforming mode that is best suited for the detected elevation. In another example, when the curvature of a road on which a vehicle  101  is traveling changes, the vehicle radar controlling apparatus  110  may determine the radar mode based on a detected azimuth. In this example, the vehicle radar controlling apparatus  110  may choose from among the digital beamforming mode, the analog beamforming mode, and the hybrid beamforming mode that is best suited for the detected azimuth. In another example, when the curvature of a road on which a vehicle  101  is traveling changes, the vehicle radar controlling apparatus  110  may determine the radar mode based on a detected azimuth and range. In this example, the vehicle radar controlling apparatus  110  may choose from among the SRR mode, the MRR mode, and the LRR mode that is best suited for the detected azimuth and range. In a non-limiting example, an SRR mode may have a scan range of 0.2 m to 30 m and an example field of view angle of 80°, an MRR mode may have a scan range of 0.2 m to 60 m and an example field of view angle of 60°, and an LRR mode may have a range of 0.2 m to 200 m and an example field of view angle of 18°. 
     The RF transceiver may include a plurality of antennas. In one example, the plurality of antennas forms a transmitting antenna array and a receiving antenna array. A plurality of antennas included in the transmitting antenna array may be arranged two-dimensionally to form a two-dimensional (2D) array. The vehicle radar controlling apparatus  110  may use the transmitting antenna array in which the antennas are arranged two-dimensionally to implement a number of beamforming modes allowing the direction of the radar to be changed by azimuth, elevation, and various combinations of azimuths and elevations. 
     The processor may control the antennas of the RF transceiver based on the determined radar mode. The RF transceiver transmits an RF signal based on a radiation pattern of a beam defined by the corresponding radar mode. The RF transceiver also receives RF signals reflected from objects that are external to the vehicle. The processor is configured to process a received RF signal to detect a target object. 
     Referring to  FIG.  1   , the vehicle  101  may use the vehicle radar controlling apparatus  110  to select one or more radar modes. For example, the vehicle  101  may use the vehicle radar controlling apparatus  110  to select a first radar mode, a second radar mode, or a third radar mode. 
     In one example, the first radar mode has a coverage characteristic of a medium azimuth, a medium range, and a medium elevation, and includes a combined mode that is a combination of the MRR mode and the hybrid beamforming mode. The second radar mode has a coverage characteristic of a small azimuth, a long range, and a small elevation, and includes a combined mode that is a combination of the LRR mode and the analog beamforming mode. The third radar mode has a coverage characteristic of a wide azimuth, a short range, and a wide elevation, and includes a combined mode that is a combination of the SRR mode and the digital beamforming mode. 
     The vehicle radar controlling apparatus  110  is configured to determine a radar mode based on a signal detected from the environment associated with the vehicle  101 . For example, the vehicle radar controlling apparatus  110  may obtain speed information of the vehicle  101  from a speed sensor of the vehicle  101 . The vehicle radar controlling apparatus  110  may calculate a curvature and a slope of a road based on a rotation angle of the steering wheel of the vehicle  101  and an acceleration detected from the IMU. In this example, when the speed information of the vehicle  101  is greater than or equal to a first threshold value, the vehicle radar controlling apparatus  110  determines a long-range detection is suitable for the vehicle environment. As a result, the vehicle radar controlling apparatus  110  selects the second radar mode which causes the RF transceiver to transmit an RF signal having a detection coverage area  123 . The vehicle radar controlling apparatus  110  is configured to receive an RF signal reflected from any target objects within the coverage area, such as target objects  103  and  104 . Therefore, the vehicle radar controlling apparatus  110  detects the target object  104  separated from the vehicle  101  by a long range. 
     In another example, when the speed of the vehicle  101  is between the first threshold value and a third threshold value, the vehicle radar controlling apparatus  110  determines a medium-range detection is suitable for the environment. As a result, the vehicle radar controlling apparatus  110  selects the first radar mode, which causes the RF transceiver to transmit an RF signal having a detection coverage area  121 . The vehicle radar controlling apparatus  110  is configured to receive an RF signal reflected from any target objects within the coverage area  121 , such as a target object  102 . Therefore, the vehicle radar controlling apparatus  110  detects the target object  102  separated from the vehicle  101  by a medium range. 
     In another example, when a speed of the vehicle  101  is less than the third threshold value, the vehicle radar controlling apparatus  110  determines a short-range detection is suitable for the environment. As a result, the vehicle radar controlling apparatus  110  selects the second radar mode, which causes the RF transceiver to transmit an RF signal having a detection coverage  125 . The vehicle radar controlling apparatus  110  is configured to receive an RF signal reflected from any target objects with the coverage area  124 , such a target object  105 . Therefore, the vehicle radar controlling apparatus  110  is able to determine whether the target object  105  comes closer to the vehicle  101  or not. 
       FIG.  2    is a flowchart illustrating an example of a method of controlling a radar of a vehicle. 
     Referring to  FIG.  2   , in operation  201 , a vehicle radar controlling apparatus determines environmental information about a vehicle. The vehicle radar controlling apparatus may receive sensor data from the vehicle sensor, including the internal sensor and the external sensor of the vehicle. The vehicle radar controlling apparatus is configured to determine the environmental information of the vehicle based on the received sensor data. For example, the vehicle radar controlling apparatus processes the sensor data to classify the environmental information as road environment information and object environment information. The road environment information may include information associated with one or more of a width, a slope, a rotation radius, and/or information about a road on which the vehicle is traveling, such as the lanes of a road. The object environment information may include information associated with one or more of a position, a size, a speed, and/or a direction of an object, including a target object and an occluded object. 
     In operation  203 , the vehicle radar controlling apparatus determines a radar mode of the vehicle based on the determined environmental information. As described herein, various radar modes may be defined in advance to correspond to different and/or specific road environment information and object environment information. For example, the vehicle radar controlling apparatus may determine the radar mode from a number of specific or pre-defined radar modes, such as the digital beamforming mode, the analog beamforming mode, and the hybrid beamforming mode. 
     In one example, in response to the vehicle radar controlling apparatus determining the digital beamforming mode as the radar mode, the vehicle radar controlling apparatus controls the transmitting antenna array using a multiple-input and multiple-output (MIMO) method. The MIMO method uses orthogonality of signals to distinguish between a plurality of RF signals transmitted from a plurality of antennas. The vehicle radar controlling apparatus causes the transmitting antenna array to radiate a plurality of beams at a desired elevation. In addition, the receiving antenna array receives reflected beans, and the controlling apparatus processes the signals received from the antenna array to determine an angular resolution corresponding to an elevated direction. For example, the vehicle radar controlling apparatus may obtain the angular resolution corresponding to the elevated direction by forming a virtual array between the transmitting antenna array and the receiving antenna array using the MIMO method. Thus, the vehicle radar controlling apparatus can cause the antenna array to radiate a plurality of beams having an elevation range greater than or equal to a predetermined value. In addition, the vehicle radar controlling apparatus may estimate an elevation of a target object based on a beam that is reflected and received by the antenna array. 
     In another example, in response to the vehicle radar controlling apparatus determining the analog beamforming mode as the radar mode, the vehicle radar controlling apparatus may control the transmitting antenna array using a phased array method. Using the phased array method, the vehicle radar controlling apparatus is configured to perform beamforming or beamsteering on a plurality of RF signals transmitted from the transmitting array. For example, the vehicle radar controlling apparatus is configured cause the transmitting array to form an integrated beam by adjusting the phase of a plurality of antennas included in the transmitting antenna array using a phase shifter. The vehicle radar controlling apparatus may thus cause the array to radiate a beam having an elevation range less than or equal to a predetermined value. In this example, the analog beamforming mode provides a relatively higher detection rate, gain, or resolution as compared to the digital beamforming mode of the previously described example. 
     In response to the vehicle radar controlling apparatus determining the hybrid beamforming mode as the radar mode, the vehicle radar controlling apparatus may control the transmitting antenna array using a combination of the MIMO method and the phased array method. For example, in the hybrid beamforming mode, the vehicle radar controlling apparatus is configured to select antennas from a plurality of antennas of the array to form a plurality of sub-arrays. In this example, one or more of the sub arrays are controlled using the phased array method, and one or more of the sub arrays are controlled using the MIMO method. According to this example, the hybrid beamforming mode provides: a relatively higher gain as compared to the digital beamforming mode described above, and a relatively higher angular resolution as compared to the analog beamforming mode described above. The proportion of the digital beamforming mode and the analog beamforming mode used in the hybrid beamforming mode may be adjusted to vary the gain and the resolution as desired for any particular application, conditions, or environmental information or the like. 
     In one example, the vehicle radar controlling apparatus controls the receiving antenna array using the MIMO method. Although the MIMO method may be generally used to receive a reflected signal, reception of signals is not limited thereto. For example, the receiving antenna array also may be controlled using the phased array method or a combination of the MIMO method and the phased array method. 
     In operation  205 , the vehicle radar controlling apparatus controls the transmitting antenna array and/or the receiving antenna array of the vehicle based on the determined radar mode. 
     Although  FIG.  2    is shown as one sequential process, it will be appreciated that the process may be performed iteratively by the vehicle radar controlling apparatus to continually collect and monitor environmental information and determine radar modes based on updated or changing information to periodically or continually control the radar based on the determined radar mode. Furthermore, in operation  203 , the vehicle radar controlling apparatus may make further determinations based on one or more of feedback, changing environmental conditions, results of controlling the radar, and other factors such as reliability of results or control of radar. 
     In one example, the vehicle radar controlling apparatus may determine a single mode corresponding to the road environment information and the object environment information, or the vehicle radar controlling apparatus may change between multiple modes in sequential order. For example, the vehicle radar controlling apparatus may determine whether an object is present using a radar mode with a coverage characteristic having a wide radiation angle. When the object is determined to be present, the vehicle radar controlling apparatus may then change the radar mode to a radar mode with a coverage characteristic having a small radiation angle and perform high-resolution beamforming in a direction of the detected object. 
     In another example, the vehicle radar controlling apparatus may determine the radar mode of the vehicle based on the environmental information and as a result of controlling the radar. The result may be used as feedback by the vehicle radar controlling apparatus to change the radar mode of the vehicle. For example, when resolution is reduced by an environmental condition (e.g., due to precipitation, such as rain or snow), the vehicle radar controlling apparatus may process this condition as feedback to change from a radar mode that has a lower resolution to a different radar mode that provides a higher resolution. 
     In another example, the vehicle radar controlling apparatus determine a reliability of the result of controlling the radar. The vehicle radar controlling apparatus may use the determined reliability to change the radar mode. For example, when the reliability of a detection result associated with a portion of a beam radiation area is less than or equal to a threshold value, the vehicle radar controlling apparatus may scan the corresponding portion using a high-resolution radar mode with a small radiation coverage. 
     In another example, a processor may determine a difference between a detection result obtained from detection of an object using a vehicle sensor and a result of controlling the radar to detect the object. In one example, the processor measures a reliability by comparing the difference with a threshold value. As a result, the processor may calculate the disparity between a detection result obtained by the radar of the vehicle and a detection result obtained by another sensor of the vehicle, and measure reliability by comparing the disparity with a threshold value. 
     In another example, the processor may calculate a fluctuation value as a result of controlling the radar. The reliability of a determination may be measured by the processor by comparing the fluctuation value to a threshold value. That is, the processor may measure a fluctuation in a detection result obtained by the radar and measure a reliability by comparing the fluctuation with a threshold value. 
       FIG.  3    is a diagram illustrating an example of a vehicle radar controlling apparatus. 
     Referring to  FIG.  3   , a vehicle radar controlling apparatus  110  includes a sensor  301 , a processor  303 , an optional memory  305 , and an RF transceiver  307 . 
     The RF transceiver  307  includes a transmitting antenna array and a receiving antenna array. In the example show in  FIG.  3   , the transmitting antenna array includes at least three antennas forming a 2D array, such as, for example, antennas  311 ,  312 , and  313 . In this example, the antenna  313  may be arranged outside a line that is formed by the antenna  311  and the antenna  312 . The RF transceiver  307  may change an azimuth and an elevation of a beam via the two-dimensionally arranged antennas. The receiving antenna array may include a plurality of antennas, for example, the antennas  321 ,  322 , and  323 . The antennas  321 ,  322 , and  323  may form a one-dimensional (1D) array or a 2D array. The antennas  311 ,  312 , and  313  that form the transmitting antenna array, and the antennas  321 ,  322 , and  323  that form the receiving antenna array may be controlled independently to be turned on or off. 
     In one example, the RF transceiver  307  includes the phase shifter (not shown). The phase shifter may change a phase of each antenna included in the transmitting antenna array. 
     In one example, the RF transceiver  307  includes at least one radio frequency integrated circuit (RFIC) (not shown), and a transmitting antenna and a receiving antenna connected to the RFIC. 
     In one example, the RF transceiver  307  also includes a processor (not shown). For example, the RF transceiver  307  may include a microcontroller unit (MCU) or a field-programmable gate array (FPGA). In one example, the RF transceiver  307  also includes an interface (not shown), for example, a controller area network (CAN) and a local area network (LAN) interface. The RF transceiver  307  may control the antennas  311 ,  312 ,  313 ,  321 ,  322 , and  323  by synchronizing them. 
     The sensor  301  may obtain sensor data of an internal environment and an external environment of a vehicle. The sensor  301  may detect an internal state of the vehicle, such as, for example, a control signal of the vehicle, a current speed of the vehicle, and a steering angle of a steering wheel of the vehicle. In one example, the sensor  301  may include or obtain sensor data from one or more internal sensors, for example, an IMU. The sensor  301  also may detect an external state of the vehicle via one or more external sensors, such as, for example, a radar, a LIDAR system or device, a camera, and an ultrasonic sensor, and the like. 
     The processor  303  is configured to determine environmental information of the vehicle based on the sensor data obtained from a sensor  301 . The environmental information determined by the processor  303  may include road environment information and object environment information. Road environment information may include information associated with one or more of a width, a slope, a rotation radius, and/or information about a road on which the vehicle is traveling, such as the lanes of a road. Object environment information may include information associated with one or more of a position, a size, a speed, and/or a direction of an object. The object may include a target object and an occluded object. A target object refers to a target to be detected, and an occluded object refers to an object that may hinder detection of a target object. 
     The processor  303  may estimate or determine road environment information including information associated with a shape of the road or a type of road. For example, the processor  303  may calculate a curvature and a slope of a road based on internal sensor data, such as a rotation angle of the steering wheel of the vehicle and or an acceleration detected from the IMU. The processor  303  may calculate a width of the road and obtain lane information using data received from an external sensor, such as a camera. For example, the processor may process an image obtained from the camera to identify the road and an object (e.g., target or occluded). 
     The processor  303  may determine a radar mode of the vehicle based on the environmental information. For example, the processor  303  may determine or select a radar mode from a number of specific or pre-defined radar modes, such as the digital beamforming mode, the analog beamforming mode, the hybrid beamforming mode, the SRR mode, the MRR mode, and the LRR mode corresponding to the environmental information, as described in detail above. The processor  303  generates a control signal based on the determined radar mode. The processor  303  controls a transmitting antenna array and/or a receiving antenna array using the control signal provided to the RF transceiver  307 . The control signal indicates whether an antenna of an array operates in an “on” or and “off” state. In the “on” state, an antenna of the transmitting array may transmit an RF signal and an antenna of the receiving array may receive an RF signal. 
     In one example, the processor  303  controls a phase of each of the antennas using the phased array method described above according to the determined radar mode. For example, using the phased array method the processor  303  is configured to perform beamforming or beamsteering on a plurality of RF signals transmitted from the transmitting array. In this example, the processor  303  is configured generate a control signal corresponding to the radar mode. The control signal provided to the RF transceiver to control the phase shifter. The phase shifter adjusts the phase of the plurality of antennas included in the transmitting antenna as indicated by the control signal. 
     In one example, the vehicle radar controlling apparatus  110  includes the memory  305 . The memory  305  may store information associated with a radiation beam pattern or a beam pattern. The pattern determines whether an antenna included in the transmitting antenna array is turned on or off and the operation of the. The memory  305  also may store a plurality of radar modes defined based on a detectable azimuth, a detectable range, or a detectable elevation. The processor  303  may determine a radar mode of the vehicle among the radar modes stored in the memory  305 . 
     In another example, a vehicle radar controlling apparatus includes a first processor and the RF transceiver includes a second processor. In this example, the first processor collects environmental information of a vehicle using sensor data and determines a radar mode of the vehicle based on the environmental information. The second processor controls the transmitting antenna array of the vehicle or the receiving antenna array of the vehicle based on the radar mode determined by the first processor. 
       FIG.  4 A  is a diagram illustrating an example of a virtual MIMO array based on digital beamforming.  FIG.  4 B  is a diagram illustrating an example of a virtual MIMO array based on analog beamforming. 
     The example shown in  FIG.  4 A  includes a vehicle  401  having a transmitting antenna array  411  and a receiving antenna array  413 . In this example, the antennas included in the transmitting antenna array  411  are arranged in a vertical direction, and antennas included in a receiving antenna array  413  are arranged in a horizontal direction. Transmitting antenna array  411  and the receiving antenna array  413  may be combined to form the virtual MIMO array  415 . 
     The vehicle radar controlling apparatus transmits an RF signal using digital beamforming via a transmitting antenna array  411 . In this example, the vehicle radar controlling apparatus controls the transmitting antenna array  411  to emit RF signals from the antennas that are orthogonal to each other. For example, the vehicle radar controlling apparatus may control the transmitting antenna array  411  to emit RF signals having phases, codes, times, and/or frequencies, and the like, that are orthogonal to each other. The orthogonality of signals may be used to distinguish between a plurality of RF signals transmitted from different antennas of the transmitting array  411 . 
     The vehicle radar controlling apparatus causes the transmitting antenna array  411  to radiate a plurality of beams at a desired elevation. In addition, the receiving antenna array  413  receives reflected beans, and the vehicle radar controlling apparatus processes the signals received from the antenna array to determine an angular resolution corresponding to an elevated direction. The virtual MIMO array  415  may be combined in a range direction to form a three-dimensional (3D) detection coverage volume  419  to detect a target object  420 . 
     The example shown in  FIG.  4 B  includes a vehicle  401  having a transmitting antenna array  421  and a receiving antenna array  423 . In this example, the antennas included in the transmitting antenna array  421  are arranged in a vertical direction, and antennas included in a receiving antenna array  423  are arranged in a horizontal direction. Transmitting antenna array  421  and the receiving antenna array  423  may be combined to form the virtual MIMO array  425 . In this example, the virtual MIMO array  425  may be formed with a single row of antennas in the transmitting array  421  and combined in a range direction to form a 2D detection range. 
     Referring to  FIG.  4 B , the vehicle radar controlling apparatus causes the transmitting antenna array  421  to transmit an RF signal using analog beamforming. In this example, the vehicle radar controlling apparatus performs beamforming with a single beam  427  by changing a phase of each of the RF signals transmitted from the antennas using the phased array method. A beam formed by phased array increases the intensity of the beam resulting in a relatively higher reception gain from the intensified beam. However, in this example, the beam does have an angular resolution in an elevated direction. As a result, the virtual MIMO array  425  may not have an angular resolution in a vertical or an elevated direction that is provided by the virtual MIMO array  415   
     The vehicle radar controlling apparatus may determine whether a detection in an elevated direction is needed based on the environmental information. In response to a determination that an elevated direction detection is needed, the vehicle radar controlling apparatus is configured to control a radar using the digital beamforming as described with reference to  FIG.  4 A . In response to a determination that no elevation direction detection is needed, the vehicle radar controlling apparatus is configured to control the radar using the analog beamforming as described with reference to  FIG.  4 B . Although a detection coverage volume/area is reduced, the analog beamforming may obtain a greater gain as compared with the digital beamforming enabling detection of a target object at a longer range. 
       FIG.  5 A  is a diagram illustrating an example of an unsuccessful detection of a target object on a curved road.  FIG.  5 B  is a diagram illustrating an example of a successful detection of a target object on a curved road using a vehicle radar controlling apparatus. 
     As shown in  FIG.  5 A , a vehicle  511  having a set or fixed detection coverage does not detect a target object  513  on a sharp curved road.  FIG.  5 A  illustrates the trade-off between the detection coverage and a gain of the radar due to the limited resources of the vehicle  511 . For example, a first radar mode may have a narrow detection coverage  515  and a relatively higher gain, and a second radar mode may have a wide detection coverage  516  and a relatively lower gain. Thus, a blind spot  517  occurs on the curved road regardless of the radar mode provided as illustrated in  FIG.  5 A . As a result, a target object  513  located in the blind spot  517  may not be detected. 
     As shown in  FIG.  5 B , a vehicle  521  having variable detection coverage detects a target object  523  on a sharp curved road eliminating the blind spot  517  shown in  FIG.  5 A . In this example, the vehicle  521  is equipped with a vehicle radar controlling apparatus. The vehicle radar controlling apparatus collects environmental information including information associated with a shape or a type of a road or a location of the target object  523  based on sensor data. The vehicle radar controlling apparatus determines a radar mode enabling an effective detection of the target object  523  based on the collected environmental information. As illustrated, the vehicle radar controlling apparatus detects the target object  523  using radar mode having a detection coverage  527  optimized for the vehicle&#39;s environment. For example, the direction and range of the radar beams are changed to account for the curvature of the road and speed at which the vehicle  521  is traveling. 
       FIG.  6 A  is a diagram illustrating an example of failure to detect a target object on flat ground above a vehicle traveling uphill.  FIG.  6 B  is a diagram illustrating an example of failure to detect a target object downhill from a vehicle traveling on flat ground.  FIG.  6 C  is a diagram illustrating an example of failure to detect a target object uphill from a vehicle traveling on flat ground. These examples illustrate that a vehicle  601  having a fixed elevation detection coverage may not detect a target object  603  when a slope of a road the vehicle  601  is travelling on changes. 
     Referring to  FIG.  6 A , a vehicle  601  travels on an uphill road. Ahead of the vehicle  601 , the slope of the uphill road becomes flat, and a target object  603  located on the flat ground is in a blind spot outside of the coverage area  610  of the vehicle&#39;s radar. 
     Referring to  FIG.  6 B , a vehicle  601  travels on a flat road. Ahead of the vehicle  601 , the slope of the road changes to a downhill road, and a target object  603  located on the downhill portion of the road is in a blind spot outside of the coverage area  610  of the vehicle&#39;s radar. 
     Referring to  FIG.  6 C , a vehicle  601  travels on a flat road. Ahead of the vehicle  601 , the slope of the road changes to an uphill road, and a target object  603  located on the uphill road is in a blind spot outside of the coverage area  610  of the vehicle&#39;s radar. 
       FIG.  6 D  is a diagram illustrating an example of successfully detecting a target object on flat ground above a vehicle traveling uphill using an apparatus for controlling a radar of a vehicle.  FIG.  6 E  is a diagram illustrating an example of successfully detecting a target object uphill from a vehicle traveling on flat ground using an apparatus for controlling a radar of a vehicle.  FIG.  6 F  is a diagram illustrating an example of successfully detecting a target object on a flat ground above a vehicle traveling up an incline using an apparatus for controlling a radar of a vehicle. 
     Referring to  FIG.  6 D , a vehicle  601  travels on an uphill road. Ahead of the vehicle  601 , the slope of the uphill road becomes flat, and a target object  603  is located on the flat ground. The vehicle radar controlling apparatus of the vehicle  601  collects environmental information including information associated with a change in slope of the road and estimates a change in the slope of the road using data collected from a sensor. In response to the estimated road slope, the vehicle radar controlling apparatus of the vehicle  601  determines a radar mode having a detection coverage  625  with an increased elevated direction to detect the target object  603 . 
     Referring to  FIG.  6 E , a vehicle  601  travels on a flat road. Ahead of the vehicle  601 , the slope of the road becomes downhill, and a target object  603  is located on the downhill road. The vehicle radar controlling apparatus of the vehicle  601  collects environmental information including information associated with a change in slope of the road and estimates a change in the slope of the road using data collected from a sensor. In response to the estimated road slope, the vehicle radar controlling apparatus of the vehicle  601  determines a radar mode having a detection coverage  625  with a decreased elevation direction to detect the target object  603  downhill from the vehicle  601 . 
     Referring to  FIG.  6 F , a vehicle  601  travels on a flat ground. Ahead of the vehicle  601 , the slope of the flat road becomes uphill, and a target object  603  is located on the uphill road. The vehicle radar controlling apparatus of the vehicle  601  collects environmental information including information associated with a change in slope of the road and estimates a change in the slope of the road using data collected from a sensor. In response to the estimated road slope, the vehicle radar controlling apparatus of the vehicle  601  determines a radar mode having a detection coverage  627  with an increased elevated direction to detect the target object  603 . 
     The vehicle radar controlling apparatuses, the vehicle  101 , the vehicle radar controlling apparatus  110 , sensor  301 , processor  303 , memory  305 , RF transceiver  307 , antennas  3111 ,  312 ,  313 ,  321 ,  322 ,  323 , transmitters, receivers, and other apparatuses, units, modules, and components described herein with respect to  FIGS.  1 - 6 F  are implemented by hardware components. Examples of hardware components that may be used to perform the operations described in this application where appropriate include controllers, sensors, generators, drivers, memories, comparators, arithmetic logic units, adders, subtractors, multipliers, dividers, integrators, and any other electronic components configured to perform the operations described in this application. In other examples, one or more of the hardware components that perform the operations described in this application are implemented by computing hardware, for example, by one or more processors or computers. A processor or computer may be implemented by one or more processing elements, such as an array of logic gates, a controller and an arithmetic logic unit, a digital signal processor, a microcomputer, a programmable logic controller, a field-programmable gate array, a programmable logic array, a microprocessor, or any other device or combination of devices that is configured to respond to and execute instructions in a defined manner to achieve a desired result. In one example, a processor or computer includes, or is connected to, one or more memories storing instructions or software that are executed by the processor or computer. Hardware components implemented by a processor or computer may execute instructions or software, such as an operating system (OS) and one or more software applications that run on the OS, to perform the operations described in this application. The hardware components may also access, manipulate, process, create, and store data in response to execution of the instructions or software. For simplicity, the singular term “processor” or “computer” may be used in the description of the examples described in this application, but in other examples multiple processors or computers may be used, or a processor or computer may include multiple processing elements, or multiple types of processing elements, or both. For example, a single hardware component or two or more hardware components may be implemented by a single processor, or two or more processors, or a processor and a controller. One or more hardware components may be implemented by one or more processors, or a processor and a controller, and one or more other hardware components may be implemented by one or more other processors, or another processor and another controller. One or more processors, or a processor and a controller, may implement a single hardware component, or two or more hardware components. A hardware component may have any one or more of different processing configurations, examples of which include a single processor, independent processors, parallel processors, single-instruction single-data (SISD) multiprocessing, single-instruction multiple-data (SIMD) multiprocessing, multiple-instruction single-data (MISD) multiprocessing, and multiple-instruction multiple-data (MIMD) multiprocessing. 
     The methods illustrated in  FIGS.  1 - 6 F  that perform the operations described in this application are performed by computing hardware, for example, by one or more processors or computers, implemented as described above executing instructions or software to perform the operations. For example, a single operation or two or more operations may be performed by a single processor, or two or more processors, or a processor and a controller. One or more operations may be performed by one or more processors, or a processor and a controller, and one or more other operations may be performed by one or more other processors, or another processor and another controller. One or more processors, or a processor and a controller, may perform a single operation, or two or more operations. 
     Instructions or software to control computing hardware, for example, one or more processors or computers, to implement the hardware components and perform the methods as described above may be written as computer programs, code segments, instructions or any combination thereof, for individually or collectively instructing or configuring the one or more processors or computers to operate as a machine or special-purpose computer to perform the operations that are performed by the hardware components and the methods as described above. In one example, the instructions or software include machine code that is directly executed by the one or more processors or computers, such as machine code produced by a compiler. In another example, the instructions or software includes higher-level code that is executed by the one or more processors or computer using an interpreter. The instructions or software may be written using any programming language based on the block diagrams and the flow charts illustrated in the drawings and the corresponding descriptions in the specification, which disclose algorithms for performing the operations that are performed by the hardware components and the methods as described above. 
     The instructions or software to control computing hardware, for example, one or more processors or computers, to implement the hardware components and perform the methods as described above, and any associated data, data files, and data structures, may be recorded, stored, or fixed in or on one or more non-transitory computer-readable storage media. 
     Examples of a non-transitory computer-readable storage medium include read-only memory (ROM), random-access programmable read only memory (PROM), electrically erasable programmable read-only memory (EEPROM), random-access memory (RAM), dynamic random access memory (DRAM), static random access memory (SRAM), flash memory, non-volatile random access memory, CD-ROMs, CD-Rs, CD+Rs, CD-RWs, CD+RWs, DVD-ROMs, DVD-Rs, DVD+Rs, DVD-RWs, DVD+RWs, DVD-RAMs, BD-ROMs, BD-Rs, BD-R LTHs, BD-REs, blue-ray or optical disk storage, hard disk drive (HDD), solid state drive (SSD), flash memory, a card type memory such as multimedia card micro or a card (for example, secure digital (SD) or extreme digital (XD)), magnetic tapes, floppy disks, magneto-optical data storage devices, optical data storage devices, hard disks, solid-state disks, and any other device that is configured to store the instructions or software and any associated data, data files, and data structures in a non-transitory manner and provide the instructions or software and any associated data, data files, and data structures to one or more processors or computers so that the one or more processors or computers can execute the instructions. In one example, the instructions or software and any associated data, data files, and data structures are distributed over network-coupled computer systems so that the instructions and software and any associated data, data files, and data structures are stored, accessed, and executed in a distributed fashion by the one or more processors or computers. 
     While this disclosure includes specific examples, it will be apparent after an understanding of the disclosure of this application that various changes in form and details may be made in these examples without departing from the spirit and scope of the claims and their equivalents. The examples described herein are to be considered in a descriptive sense only, and not for purposes of limitation. Descriptions of features or aspects in each example are to be considered as being applicable to similar features or aspects in other examples. Suitable results may be achieved if the described techniques are performed in a different order, and/or if components in a described system, architecture, device, or circuit are combined in a different manner, and/or replaced or supplemented by other components or their equivalents. Therefore, the scope of the disclosure is defined not by the detailed description, but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents are to be construed as being included in the disclosure.