Patent Application
20190162836
The present disclosure generally relates to vehicles, and more particularly relates to methods and radar systems for tracking information based on adaptive detectors.
Certain vehicles today utilize radar systems. For example, certain vehicles utilize radar systems to detect other vehicles, pedestrians, or other objects on a road in which the vehicle is travelling. Radar systems may be used in this manner, for example, in implementing automatic braking systems, adaptive cruise control, and avoidance features, among other vehicle features. Conventional detectors are memory-less and not take into account the information from previous frame. These detectors employ detection thresholds based only in the signal-to-noise ratio (SNR) and its level doesn't depend on the targets surroundings both spatially and temporally. While these radar detectors are generally useful for such vehicle features, in certain situations existing radar systems may have certain limitations.
Accordingly, it is desirable to provide improved techniques for radar system performance in vehicles, for example to include the information of the previous frame to adaptively change the threshold and thus to increase the probability of detecting tracked targets. It is further desirable to increase the detectability of weaker backscatter radar signals. Furthermore, other desirable features and characteristics of the present invention will be apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.
In accordance with an exemplary embodiment, a method is provided for controlling a radar system of a vehicle, the radar system having a plurality of receivers. The method comprises receiving a first range Doppler map, detecting an object in response to the first range Doppler map to generate an object signal using a first threshold wherein the first threshold is determined in response to a signal to noise ratio, generating a cluster signal in response to the object signal, determining a track state in response to the cluster signal, updating the first threshold in response to the track state and the signal to noise ratio to generate an updated threshold, and detecting the object in response to a second range Doppler map in response to the updated threshold.
In accordance with an exemplary embodiment, a radar control system for a vehicle is provided. The apparatus comprises a detector for receiving a first range Doppler map and detecting an object in response to the first range Doppler map to generate an object signal using a first threshold wherein the first threshold is determined in response to a signal to noise ratio, a cluster processor for generating a cluster signal in response to the object signal, a tracking processor for determining a track state in response to the cluster signal and a threshold computer for updating the first threshold in response to the track state and the signal to noise ratio to generate an updated threshold wherein the updated threshold is used for detecting the object in a subsequent range Doppler map.
The present disclosure will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein:
The following detailed description is merely exemplary in nature and is not intended to limit the disclosure or the application and uses thereof. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description. As used herein, the term module refers to any hardware, software, firmware, electronic control component, processing logic, and/or processor device, individually or in any combination, including without limitation: application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that executes one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality.
In the depicted embodiment, the vehicle 10 also includes a chassis 112, a body 114, four wheels 116, an electronic control system 118, a steering system 150, and a braking system 160. The body 114 is arranged on the chassis 112 and substantially encloses the other components of the vehicle 10. The body 114 and the chassis 112 may jointly form a frame. The wheels 116 are each rotationally coupled to the chassis 112 near a respective corner of the body 114.
In the exemplary embodiment illustrated in
Still referring to
The steering system 150 is mounted on the chassis 112, and controls steering of the wheels 116. The steering system 150 includes a steering wheel and a steering column (not depicted). The steering wheel receives inputs from a driver of the vehicle 10. The steering column results in desired steering angles for the wheels 116 via the drive shafts 134 based on the inputs from the driver.
The braking system 160 is mounted on the chassis 112, and provides braking for the vehicle 10. The braking system 160 receives inputs from the driver via a brake pedal (not depicted), and provides appropriate braking via brake units (also not depicted). The driver also provides inputs via an accelerator pedal (not depicted) as to a desired speed or acceleration of the vehicle 10, as well as various other inputs for various vehicle devices and/or systems, such as one or more vehicle radios, other entertainment or infotainment systems, environmental control systems, lightning units, navigation systems, and the like (not depicted in
Also as depicted in
The radar control system 12 is mounted on the chassis 112. As mentioned above, the radar control system 12 classifies objects based upon a three dimensional representation of the objects using received radar signals of the radar system 103. In one example, the radar control system 12 provides these functions in accordance with the method 400 described further below in connection with
While the radar control system 12, the radar system 103, and the controller 104 are depicted as being part of the same system, it will be appreciated that in certain embodiments these features may comprise two or more systems. In addition, in various embodiments the radar control system 12 may comprise all or part of, and/or may be coupled to, various other vehicle devices and systems, such as, among others, the actuator assembly 120, and/or the electronic control system 118.
With reference to
As depicted in
With reference to
The radar system 103 generates the transmittal radar signals via the signal generator(s) 302. The transmittal radar signals are filtered via the filter(s) 304, amplified via the amplifier(s) 306, and transmitted from the radar system 103 (and from the vehicle 10 to which the radar system 103 belongs, also referred to herein as the “host vehicle”) via the antenna(e) 308. The transmitting radar signals subsequently contact other vehicles and/or other objects on or alongside the road on which the host vehicle 10 is travelling. After contacting the other vehicles and/or other objects, the radar signals are reflected, and travel from the other vehicles and/or other objects in various directions, including some signals returning toward the host vehicle 10. The radar signals returning to the host vehicle 10 (also referred to herein as received radar signals) are received by the antenna(e) 310, amplified by the amplifier(s) 312, mixed by the mixer(s) 314, and digitized by the sampler(s)/digitizer(s) 316.
Returning to
The processing unit 226 processes the information obtained by the receivers 222 for classification of objects based upon a three dimensional representation of the objects using received radar signals of the radar system 103. The processing unit 226 of the illustrated embodiment is capable of executing one or more programs (i.e., running software) to perform various tasks instructions encoded in the program(s). The processing unit 226 may include one or more microprocessors, microcontrollers, application specific integrated circuits (ASICs), or other suitable device as realized by those skilled in the art, such as, by way of example, electronic control component, processing logic, and/or processor device, individually or in any combination, including without limitation: application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that executes one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality.
In certain embodiments, the radar system 103 may include multiple memories 224 and/or processing units 226, working together or separately, as is also realized by those skilled in the art. In addition, it is noted that in certain embodiments, the functions of the memory 224, and/or the processing unit 226 may be performed in whole or in part by one or more other memories, interfaces, and/or processors disposed outside the radar system 103, such as the memory 242 and the processor 240 of the controller 104 described further below.
As depicted in
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As depicted in
The memory 242 can be any type of suitable memory. This would include the various types of dynamic random access memory (DRAM) such as SDRAM, the various types of static RAM (SRAM), and the various types of non-volatile memory (PROM, EPROM, and flash). In certain examples, the memory 242 is located on and/or co-located on the same computer chip as the processor 240. In the depicted embodiment, the memory 242 stores the above-referenced program 250 along with one or more stored values 252 (such as, by way of example, information from the received radar signals and the spectrograms therefrom).
The bus 248 serves to transmit programs, data, status and other information or signals between the various components of the computer system 232. The interface 244 allows communication to the computer system 232, for example from a system driver and/or another computer system, and can be implemented using any suitable method and apparatus. The interface 244 can include one or more network interfaces to communicate with other systems or components. In one embodiment, the interface 244 includes a transceiver. The interface 244 may also include one or more network interfaces to communicate with technicians, and/or one or more storage interfaces to connect to storage apparatuses, such as the storage device 246.
The storage device 246 can be any suitable type of storage apparatus, including direct access storage devices such as hard disk drives, flash systems, floppy disk drives and optical disk drives. In one exemplary embodiment, the storage device 246 comprises a program product from which memory 242 can receive a program 250 that executes one or more embodiments of one or more processes of the present disclosure, such as the method 400 (and any sub-processes thereof) described further below in connection with
The bus 248 can be any suitable physical or logical means of connecting computer systems and components. This includes, but is not limited to, direct hard-wired connections, fiber optics, infrared and wireless bus technologies. During operation, the program 250 is stored in the memory 242 and executed by the processor 240.
It will be appreciated that while this exemplary embodiment is described in the context of a fully functioning computer system, those skilled in the art will recognize that the mechanisms of the present disclosure are capable of being distributed as a program product with one or more types of non-transitory computer-readable signal bearing media used to store the program and the instructions thereof and carry out the distribution thereof, such as a non-transitory computer readable medium bearing the program and containing computer instructions stored therein for causing a computer processor (such as the processor 240) to perform and execute the program. Such a program product may take a variety of forms, and the present disclosure applies equally regardless of the particular type of computer-readable signal bearing media used to carry out the distribution. Examples of signal bearing media include: recordable media such as floppy disks, hard drives, memory cards and optical disks, and transmission media such as digital and analog communication links. It will similarly be appreciated that the computer system 232 may also otherwise differ from the embodiment depicted in
Turning now to
The currently disclosed tracking algorithm predicts the power of the cluster for the next frame and uses this information with the SNR. Initially a Range-Doppler map is the input for the detector 405 running the detector algorithm and the threshold is calculated on the SNR conditions or the radar noise floor.
The clustering processor 410 is operative to compute the cluster power Pk by adding the power from each detector that belongs to a cluster. A method determines the cluster center, for example, the center of mass of the detection in a four dimensional space (x,y,z,Doppler) using energy as weight. Power Pk is then associated with the cluster centroid. The power of cluster in frame (k−1) is known as Pk-1. To update the power for frame k, the method is operative to predict the power P′k=Pk-1. The method then performs the power measurement Pmeas_k and then computes Pk=f(SNRk,P′k, Pmeas_k).
The updated power is a function of the predicted power, the current power measured and the SNR of the environment. Power of cluster is computed taking into account the energy backscattered by each detection inside it. By using the power information we increase the reliability of the tracking algorithm. It is possible to separate clusters that are on the same position and Doppler by making use of the cluster power. It is possible to sort targets according to their power
By using the power information to compute the cluster power, the method increases the reliability of the tracking algorithm. It is possible to separate clusters that are on the same position and Doppler by making use of the cluster power and to targets according to their power. After the clustering processor 410 computes clusters and the tracking processor 415 processes track states, the information about each detection is used to define the threshold that will be used for the detector in the next frame and the location which this detection will be applied.
Turning now to
It will be appreciated that the disclosed methods, systems, and vehicles may vary from those depicted in the Figures and described herein. For example, the vehicle 10, the radar control system 12, the radar system 103, the controller 104, and/or various components thereof may vary from that depicted in
While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the disclosure in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary embodiment or exemplary embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the appended claims and the legal equivalents thereof.
