Example one
The embodiment of the invention provides a method for detecting an upper obstacle. Hereinafter, the inventive concept of the upper obstacle detection method provided in the embodiment of the present invention will be briefly described.
Specifically, referring to fig. 3, fig. 3 shows a right view of a road in the driving scene of the vehicle shown in fig. 1, which shows a driving diagram between the vehicle and an obstacle above the right side of the road.
As shown in fig. 3, R represents a straight line distance between the scattering center U2 of the obstacle above the right side of the road and the vehicle, and a side angle between the straight line distance and the Y axis direction in the radar coordinate system is denoted as "a", which may be simply referred to as an elevation angle between the obstacle above the right side of the road and the vehicle.
As can be seen from the schematic diagram shown in fig. 3, as the vehicle travels forward along the Y-axis direction, the obstacle on the right side of the road is closer to the vehicle, and the elevation angle a is larger, whereas in the fixed elevation antenna pattern of the radar, the larger the elevation angle is, the weaker the signal energy of the radar signal reflected by the obstacle on the right side of the road is. In contrast, for a ground obstacle located on the same plane as the vehicle, the closer the vehicle is to the ground obstacle, the stronger the energy of the radar signal reflected by the ground obstacle.
Therefore, whether the target to be detected is an upper obstacle or not can be determined based on the relative position relationship between the vehicle and the target to be detected and the variation trend between the signal energy of the radar signal reflected by the target to be detected.
Based on this, referring to fig. 4, the method for detecting an upper obstacle according to the embodiment of the present invention includes the following steps:
s402, in a target time interval in the vehicle running process, signal parameters of radar signals reflected by the target to be detected are obtained.
Therefore, the radar can externally transmit a detection radar signal, when the radar meets an obstacle, the detection radar signal can be reflected to the radar through the blocking of the obstacle, and therefore if the radar receives the reflected radar signal, the fact that the obstacle exists in the front can be determined. Therefore, the radar signal according to the embodiment of the present invention is: the signal is sent by the radar and is received by the radar after being reflected by the target to be detected.
Hereinafter, for convenience of explanation, a signal emitted by a radar is referred to as a detection radar signal, and a signal reflected by an obstacle (an object to be detected according to an embodiment of the present invention) and received by the radar is referred to as a radar signal.
In a specific implementation process, the start frame of the target period may be a sending time of the detection radar signal or a receiving time of the radar signal, and the end frame may be a current frame.
In one possible scenario, the ending frame of the target period is the current frame, and the starting frame of the target period is a frame of the radar which initially receives the reflected radar signal.
In another possible scenario, the ending frame of the target period is the current frame, and the starting frame of the target period is a frame from which the radar starts tracking the reflected radar signal after the radar initially sends out the detection radar signal.
It should be noted that a frame of a radar signal emitted by the radar (referred to as a transmission frame for short) may be different from a frame of a radar signal that starts tracking (referred to as a tracking frame for short).
Specifically, if the radar starts to track the radar signal in a certain frame after sending the detection radar signal, the start frame is a frame after sending the detection radar signal and starts to track the radar signal, at this time, the radar may not record the frame interval between the transmission frame and the tracking frame, and the frame interval is generally fixed, and may be preset in an execution device of the method for detecting the obstacle above the radar (hereinafter, referred to as an upper obstacle detection device for short) or in a radar or other readable storage locations.
Or, if the radar starts to track the radar signal in the same frame as the detection radar signal is sent out, the transmission frame is the same as the tracking frame.
In another possible scenario, the starting frame of the target period may also be a frame of the radar signal emitted by the radar. And will not be described in detail.
It should be noted that the aforementioned target time period may be a time period formed by transmitting, reflecting and receiving one or more radar signals. For example, if the target time interval includes the transmission of a plurality of radar signals, the start frame of the target time interval is the start frame of the first radar signal in the plurality of radar signals (the foregoing at least three methods are not described again). In addition, considering that the radar continuously sends out radar signals to the outside during normal operation, the embodiment of the present invention is directed to detection of an object to be detected, and therefore, the plurality of radar signals may be radar signals reflected by the object to be detected.
The signal parameters related to the embodiments of the present invention may include, but are not limited to: the time of transmission of the radar signal (which may be represented by a frame), the time of reception of the radar signal (which may also be represented by a frame), and the signal energy of the radar signal. Wherein the signal energy can pass through P
iThe unit is decibel (dB), where i represents the frame number, the start frame of the frame number is a frame from which the radar transmits a probe radar signal and starts tracking the radar signal, and the end frame is a frame from which the radar receives the radar signal.
The signal parameters of the radar signals are recorded during the process of detecting the obstacles by the radar, so that the step can be realized by acquiring data from a radar processor.
At this time, the specific implementation manner of acquiring the signal parameter of the radar signal is related to the relationship between the detection device of the obstacle above the radar and the radar.
In one possible design, the upper obstacle detection device may be disposed inside the radar, and may be implemented as one or more processors (or processing modules) inside the radar, independent from the main processor, or may be implemented as one or more processing modules in the main processor. In this implementation scenario, the upper obstacle detection device may perform information interaction with a main processor of the radar, and request the main processor to obtain the signal parameters.
In another possible design, the upper obstacle detecting device may be provided independently of the radar, and in this case, data interaction may be implemented between the upper obstacle detecting device and the processor of the radar through wired or wireless communication. The wireless communication method may include, but is not limited to: Wireless-Fidelity (WiFi), bluetooth, Near Field Communication (NFC). In a specific implementation scene, the upper obstacle detection device can send a request to a processor of the radar in a wired or wireless mode, and the processor of the radar feeds data back to the upper obstacle detection device according to the request to achieve acquisition of signal parameters; alternatively, an automatic transmission rule, for example, a periodic transmission method, a real-time transmission method, or the like may be provided in the processor of the radar, and the upper obstacle detecting device may be configured to receive only the signal parameter transmitted by the processor of the radar by a wired or wireless method.
S404, acquiring the relative position relation between the target to be detected and the vehicle according to the signal parameters.
Based on the aforementioned inventive concept, the relative position relationship is used to represent the distance relationship between the target to be detected and the vehicle. Specifically, the relative positional relationship according to the embodiment of the present invention may include: a first distance between the vehicle and the object to be detected. I.e. the distance R shown in fig. 3.
In particular, this step can be realized by the transmission time of the detection radar signal and the reception time of the radar signal in the signal parameters.
For example, if the transmitting time of the detection radar signal is t1, the receiving time of the radar signal is t2, and the signal propagation speed is v, the propagation time of the radar signal between the radar and the target to be detected is (t2-t1), and thus the product of the propagation time and the signal propagation speed is obtained and divided by 2, and the first distance is obtained, which can be specifically expressed as: (t2-t1) v/2.
And S406, determining whether the target to be detected is an upper obstacle of the vehicle according to the relative position relationship and the change trend of the signal energy in the signal parameter in the target time period.
Based on the inventive concept shown in fig. 3, when the step of S406 in the scheme is implemented, it can be implemented in a manner as shown in fig. 5:
s4062, acquiring a trend parameter between the first distance and the signal energy in the target time period.
The embodiment of the invention provides a trend parameter, and the change trend between the first distance and the signal energy is represented by the trend parameter. Specifically, the trend parameter may be determined according to the variation of the first distance and the variation of the signal energy.
Specifically, the embodiment of the present invention provides two realizable ways for obtaining the trend parameter:
first, a trend parameter may be obtained over successive frames. The method can be realized by the following specific means:
1.1) acquiring a distance deviation value corresponding to each frame in a target time interval, wherein the distance deviation value is the difference between a first distance corresponding to the frame and a first distance average value in continuous multiple frames in the target time interval;
1.2) acquiring a signal energy deviation value corresponding to each frame in a target time period, wherein the signal energy deviation value is the difference between the signal energy corresponding to the frame and the average value of the signal energy in continuous multiple frames in the target time period;
1.3) acquiring a first change parameter and a second change parameter, wherein the first change parameter is the sum of products of distance deviation values and energy deviation values of frames in continuous multiple frames in a target time period; the second change parameter is the square sum of the distance deviation value of each frame in continuous multiple frames in the target time interval;
1.4) obtaining the ratio of the first variation parameter to the second variation parameter to be used as the trend parameter corresponding to the continuous multiframes.
Specifically, the method can be implemented by the following formula (formula one):
wherein,
wherein S represents a trend parameter corresponding to a plurality of continuous frames, and R
iIndicating a first distance, R, between the object to be detected and the vehicle at the i-th frame
·Mean value, P, representing a first distance between the object to be detected and the vehicle within successive frames
iRepresenting the signal energy between the object to be detected and the vehicle at the i-th frame, P
*Representing the average value of the signal energy between the object to be detected and the vehicle in successive frames i
0Representing the start of successive multiframes, i
eIndicating the end frame of consecutive multiframes.
In one possible design, the consecutive multiframes may be specified as a target time period, at which time i
0Start frame, i, representing a target period
eAn end frame indicating a target period.
Further, the aforementioned consecutive multiframes within the target period refer to at least two consecutive frames within the target period.
Second, a trend parameter within a single frame may be obtained. The method can be realized by the following specific means:
2.1) acquiring a distance deviation value corresponding to each frame except for the initial frame in the target time period, wherein the distance deviation value is the difference between a first distance corresponding to the frame and a first distance corresponding to the initial frame;
2.2) acquiring a signal energy deviation value corresponding to each frame except the initial frame in the target time period, wherein the signal energy deviation value is the difference between the signal energy corresponding to the frame and the signal energy corresponding to the initial frame;
and 2.3) acquiring the ratio of the signal energy deviation value to the distance deviation value in each frame except the initial frame in the target time interval to serve as a trend parameter corresponding to the frame.
Specifically, the method can be realized by the following formula (expressed as formula two):
wherein S is
iIndicates a trend parameter, R, corresponding to the ith frame
iIndicating a first distance, R, between the object to be detected and the vehicle at the i-th frame
jA first distance, P, between the object to be detected and the vehicle corresponding to a start frame representing a target period
iRepresenting the signal energy between the object to be detected and the vehicle at the i-th frame, P
jIndicating the signal energy between the object to be detected and the vehicle corresponding to the start frame, and i indicating any frame except the start frame in the object period.
In addition to this, other variants of the second implementation are possible. For example, in one possible design, for any frame except the starting frame, when the signal energy deviation value and the distance deviation value corresponding to the frame are obtained, the signal energy and the distance corresponding to the starting frame may be replaced by: after the signal energy and the distance corresponding to the frame (or the specified number of frames, wherein the specified book number is an integer greater than 1) before the frame are obtained, the signal energy deviation value and the distance deviation value are obtained, and then the ratio of the signal energy deviation value to the distance deviation value is obtained to be used as the trend parameter corresponding to the frame.
It should be noted that, when the trend parameter is obtained through the first formula or the second formula, the obtaining sequence between the distance deviation value and the energy deviation value in the embodiment of the present invention is not particularly limited, and the two steps may be executed simultaneously or sequentially.
S4064, determining whether the target to be detected is an upper obstacle of the vehicle according to the trend parameter and a preset trend threshold value.
Specifically, in the foregoing steps, different trend parameters can be obtained, and based on the inventive concept shown in fig. 3, the determination of whether the target to be detected is an obstacle above the vehicle can be achieved by comparing the trend parameters with a preset trend threshold.
Specifically, if the detection is implemented through the first formula in S4062, the trend parameter corresponding to the consecutive multiple frames may be compared with a preset trend threshold, and if the trend parameter corresponding to the consecutive multiple frames is smaller than the trend threshold, it is determined that the target to be detected is an obstacle above the vehicle. Otherwise, if the trend parameter corresponding to the continuous multiple frames is larger than or equal to the trend threshold, determining that the target to be detected is not the obstacle above the vehicle.
Because the first formula is a trend parameter in a plurality of continuous frames, the detection can be realized by a direct comparison mode, and the first formula has higher accuracy and is beneficial to improving the detection accuracy.
If the detection is implemented by the formula two in S4062, since the formula two obtains the trend parameter in a single frame, in order to adapt to different detection requirements, the following three possible implementation manners are provided in the embodiment of the present invention:
in the first mode, in any frame except the initial frame in the target time period, the trend parameter corresponding to the frame is compared with the trend threshold, and if the trend parameter corresponding to the frame is smaller than the trend threshold, the target to be detected is determined to be an obstacle above the vehicle. Otherwise, if the trend parameter corresponding to the frame is larger than or equal to the trend threshold, determining that the target to be detected is not the obstacle above the vehicle.
The realization mode has less data processing amount and is beneficial to improving the detection efficiency.
In a second mode, in any frame except the initial frame in the target time period, if the trend parameter corresponding to the frame is smaller than the trend threshold, the number of continuous frames with the trend parameter smaller than the trend parameter threshold is obtained, and therefore, if the number of the continuous frames is larger than or equal to the preset frame threshold, the target to be detected is determined to be an obstacle above the vehicle, wherein the frame threshold is at least two frames.
It can be known that, if the number of the aforementioned consecutive frames is smaller than the preset frame threshold, it is determined that the object to be detected is not an obstacle above the vehicle.
That is, if the determination result of a single frame is yes, in order to further ensure that the determination result is not an accidental situation, the target to be detected is determined as an obstacle above the vehicle only when at least two frames are both determined as yes. Compared with the first mode, the implementation mode is equivalent to the addition of a secondary inspection process, so that the accidental situations can be further avoided, and the detection accuracy is further improved.
And thirdly, acquiring the average value of the trend parameters corresponding to the frames except the initial frame in the target time period, and determining that the target to be detected is the upper obstacle of the vehicle if the average value of the trend parameters is smaller than a trend threshold value.
In the implementation mode, the average value of the trend parameter of the whole target time interval can represent the relative position relation and the change trend of the signal energy in the target time interval, and the detection accuracy is improved.
By the scheme, the detection of the target to be detected can be realized.
In addition, it should be noted that the trend threshold in each of the foregoing implementations may be set as needed, and the trend threshold in each of the different implementations may be set to the same value, or may be set to different thresholds in combination with different detection requirements.
For example, in one possible design, the aforementioned trend threshold may be set to the same value, e.g., to 0.05.
In addition, as can be seen from fig. 1 and 2, the upper obstacle above the road is generally closer to the boundary line of the road, that is, the lateral distance in the X-axis direction is generally within a certain distance threshold range, and therefore, the characteristic can be used as an auxiliary characteristic in the detection step.
At this time, the relative position relationship in the embodiment of the present invention may further include a second distance in addition to the first distance, where the second distance is a distance between the target to be detected and the radar pointing line. For example, the second distance of the upper left obstacle shown in fig. 1 is the distance between the upper left obstacle and the radar pointing line; the second distance of the upper right obstacle shown in fig. 1 is the distance between the upper right obstacle and the radar pointing line.
In particular, the method may be implemented with reference to the method shown in fig. 6. As shown in fig. 6, before executing S406, the method further includes the steps of:
s4052, a first distance and a second distance are respectively obtained for each frame in the target time interval.
The first distance is a linear distance between the target to be detected and the vehicle, and is not described in detail.
S4054, judging whether the target to be detected is an obstacle to be detected above according to the first distance and the second distance.
If so, S406 is executed, that is, the step of determining whether the target to be detected is an upper obstacle of the vehicle according to the relative position relationship and the variation trend of the signal energy in the target time period is executed, which is not described again.
If not, executing S408, and determining that the target to be detected is not the upper obstacle of the vehicle.
Specifically, the determination process may be: and if the first distance is greater than the first distance threshold value and the second distance is less than a preset second distance threshold value, determining that the target to be detected is an obstacle to be detected above. Otherwise, if the first distance is smaller than or equal to the first distance threshold value and/or the second distance is larger than or equal to a preset second distance threshold value, determining that the target to be detected is not the obstacle to be detected.
In addition, it should be noted that the implementation shown in fig. 6 is a possible design, and the execution order of the lateral feature detection and the trend parameter detection implemented by the embodiment of the present invention is not particularly limited. That is, if the transverse characteristic detection is used as an auxiliary detection step for detecting the trend parameter, the target to be detected can be finally determined to be the obstacle to be detected only if the detection results of the transverse characteristic detection and the detection results of the trend parameter detection are both yes; otherwise, if the detection result of at least one detection step is negative, determining that the target to be detected is not the obstacle to be detected.
Therefore, in other possible designs, the detection of the trend parameter may be performed first, and if the detection result is yes, the transverse characteristic detection as shown in fig. 6 is performed, and at this time, if the detection result is yes, it may be determined that the target to be detected is the obstacle to be detected above
In addition to the foregoing flow, as shown in fig. 3, the embodiment of the present invention further provides a possible detection method: the detection of the target to be detected is realized by using the elevation angle a shown in fig. 3. In this case, the detection method may be used as an auxiliary solution to any of the above-mentioned realizable solutions, so that, on the premise that the inspection results of the above-mentioned solutions are all yes, if the elevation angle detection result is also yes, it is determined that the target to be detected is an obstacle to be detected above. Otherwise, if the detection result of any detection step is negative, determining that the target to be detected is not the obstacle to be detected.
Specifically, if the elevation angle is used as a detection basis for the above obstacle, the variation trend between the elevation angle and the signal energy may be obtained in a manner similar to the implementation manner of the first distance, and the detection of the target to be detected may be implemented by comparing a second trend parameter capable of representing the variation trend with a second trend threshold. The implementation is the same as above, and is not described in detail.
In addition, considering that the conventional radar may not have a measurement tool for an elevation angle, if the elevation angle is used as a detection basis for an obstacle above, the elevation angle measurement tool needs to be provided, which increases the hardware equipment cost to some extent.
Besides detecting the target to be detected based on the scheme to determine whether the target to be detected is an obstacle above the vehicle, the radar can also detect the obstacle in front of the vehicle, and the detection mode can be realized by adopting a similar means of the detection method provided by the embodiment of the invention besides the existing mode.
Specifically, as described in the implementation scenario shown in fig. 3, as the vehicle travels forward, the signal energy of the radar signal reflected by the ground obstacle is higher, and thus, in a manner similar to fig. 1, according to the relative positional relationship and the trend of the signal energy of the radar signal in the target period, if the signal energy of the radar signal increases as the first distance decreases, it may be determined as the ground obstacle of the vehicle.
In addition, the scheme can be realized only by the radar capable of realizing the transmission and the reception of the radar signals, so that the embodiment of the invention has no special limitation on the type of the radar.
In one possible implementation scenario, such as the background art automatic driving or assisted driving scenario, the radar involved in the foregoing implementation steps may be a millimeter wave radar.
It is to be understood that some or all of the steps or operations in the above-described embodiments are merely examples, and other operations or variations of various operations may be performed by the embodiments of the present invention. Further, the various steps may be performed in a different order presented in the above-described embodiments, and it is possible that not all of the operations in the above-described embodiments are performed.
Based on the above-mentioned method for detecting an obstacle, the embodiment of the present invention further provides an embodiment of an apparatus for implementing the steps and methods of the above-mentioned method embodiment.
An embodiment of the present invention provides an upper obstacle detection device, referring to fig. 7, the upper obstacle detection device 700 includes:
a memory 710;
a processor 720; and
a computer program;
wherein the computer program is stored in the memory 710 and configured to be executed by the processor 720 to implement the methods as described in the above embodiments.
In addition, as shown in fig. 7, a transceiver 730 is further disposed in the upper obstacle detecting device 700 for data transmission or communication with other devices, which is not described herein again.
As shown in fig. 7, the memory 710, the processor 720 and the transceiver 730 are connected via a bus and communicate with each other.
The number of the processors 720 in the upper obstacle detection device 700 may be one or more, and the processors 720 may also be referred to as a processing unit, which may implement a certain control function. The processor 720 may be a general purpose processor, a special purpose processor, or the like.
In an alternative design, the processor 720 may also store instructions that can be executed by the processor to cause the upper obstacle detection apparatus 700 to perform the method described in the above method embodiment.
In yet another possible design, the upper obstacle detecting device 700 may include circuitry that may perform the functions of transmitting or receiving or communicating in the foregoing method embodiments.
Optionally, the number of the memories 710 in the upper obstacle detection device 700 may be one or more, and the memories 710 have instructions or intermediate data stored thereon, and the instructions may be executed on the processor, so that the upper obstacle detection device 700 performs the method described in the above method embodiments. Optionally, other related data may also be stored in the memory 710. Optionally, processor 720 may also store instructions and/or data therein. The processor 720 and the memory 710 may be provided separately or may be integrated together.
Further, the processor 720 may be referred to as a processing unit. The transceiver 730 may be referred to as a transceiver unit, a transceiver circuit, a transceiver, or the like, and is used for implementing the transceiving function of the upper obstacle detecting device 700.
Specifically, in a possible implementation scenario, if the upper obstacle detection apparatus 700 is used to implement the operation corresponding to the upper obstacle detection method in the embodiment shown in fig. 4, the transceiver 730 is used to acquire the signal parameters of the radar signal reflected by the target to be detected.
The transceiver 730 may further perform other corresponding communication functions. And processor 720 is configured to perform the corresponding determination or control operations, and optionally, may store corresponding instructions in memory 710. The specific processing manner of each component can be referred to the related description of the previous embodiment.
The processor 720 and the transceiver 730 described in the embodiments of the present invention may be implemented on an Integrated Circuit (IC), an analog IC, a Radio Frequency Integrated Circuit (RFIC), a mixed signal IC, an Application Specific Integrated Circuit (ASIC), a Printed Circuit Board (PCB), an electronic device, or the like. The processor and transceiver may also be fabricated using various 1C process technologies, such as Complementary Metal Oxide Semiconductor (CMOS), N-type metal oxide semiconductor (NMOS), P-type metal oxide semiconductor (PMOS), Bipolar Junction Transistor (BJT), Bipolar CMOS (bicmos), silicon germanium (SiGe), gallium arsenide (GaAs), and the like.
Alternatively, the upper obstacle detecting device 700 may be a stand-alone device or may be part of a larger device.
Furthermore, an embodiment of the present invention provides a readable storage medium, on which a computer program is stored, the computer program being executed by a processor to implement the method described in the foregoing embodiment.
Furthermore, the embodiment of the present invention also provides a computer program product, which is used to execute the method described in the foregoing embodiment when the computer program is executed by a computer.
In a possible design, the program in the eighth aspect may be stored in whole or in part on a storage medium packaged with the processor, or in part or in whole on a memory not packaged with the processor.
Also, an embodiment of the present invention provides an overhead obstacle detection system, please refer to fig. 8, where the overhead obstacle detection system 800 includes:
upper obstacle detecting device 700;
and a radar 810 for emitting a detection radar signal and receiving the radar signal reflected by the target to be detected.
In one possible design, the radar is a millimeter wave radar.
In addition, an embodiment of the present invention further provides a vehicle, please refer to fig. 9, where the vehicle 900 includes: upper obstacle detection system 800. The vehicle 900 may be a conventional vehicle including the overhead obstacle detection system 800, or a vehicle equipped with an ADAS system, or an autonomous vehicle. In one possible embodiment, the radar 810 in the vehicle 900 may be disposed at the head or a front portion of the vehicle 900, thereby acquiring environmental information in front of the vehicle; the upper obstacle detecting device 700 may be disposed in the vehicle interior, for example, near the vehicle control device, and is not limited thereto. Communication between the radar 810 and the upper obstacle detection device 700 in the vehicle 900 may be through a CAN bus, an ethernet link, wireless communication, near field communication, etc., without limitation.
Those of ordinary skill in the art will understand that: all or part of the steps for implementing the method embodiments may be implemented by hardware related to program instructions, and the program may be stored in a computer readable storage medium, and when executed, the program performs the steps including the method embodiments; and the aforementioned storage medium includes: various media that can store program codes, such as ROM, RAM, magnetic or optical disks.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.