CN112444803B - Target detection method and device of vehicle-mounted radar and vehicle - Google Patents

Target detection method and device of vehicle-mounted radar and vehicle Download PDF

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CN112444803B
CN112444803B CN201910806457.4A CN201910806457A CN112444803B CN 112444803 B CN112444803 B CN 112444803B CN 201910806457 A CN201910806457 A CN 201910806457A CN 112444803 B CN112444803 B CN 112444803B
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speed
modulation mode
vehicle
target vehicle
slow
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CN112444803A (en
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贺刚
农英雄
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BYD Co Ltd
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
    • G01S13/06—Systems determining position data of a target
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
    • G01S13/06—Systems determining position data of a target
    • G01S13/08—Systems for measuring distance only
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S13/00—Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified
    • G01S13/02—Systems using reflection of radio waves, e.g. primary radar systems; Analogous systems
    • G01S13/50—Systems of measurement based on relative movement of target
    • G01S13/58—Velocity or trajectory determination systems; Sense-of-movement determination systems
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
    • G01S7/02—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00
    • G01S7/41—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S13/00 using analysis of echo signal for target characterisation; Target signature; Target cross-section

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  • Engineering & Computer Science (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Radar Systems Or Details Thereof (AREA)

Abstract

The invention discloses a target detection method and device of a vehicle-mounted radar and a vehicle, wherein the method comprises the following steps: modulating a signal to be transmitted in a preset modulation mode, wherein the preset modulation mode comprises a fast frame modulation mode and a slow frame modulation mode; alternately transmitting a fast frame modulated signal and a slow frame modulated signal, and receiving a echo signal; and carrying out speed dimension analysis on the echo signal to obtain the relative speed of the target vehicle, wherein the relative speed of the target vehicle is obtained based on the first speed of the target vehicle in the fast frame modulation mode and the second speed of the target vehicle in the slow frame modulation mode. Therefore, the maximum speed measuring range can be effectively expanded, the speeds of various driving states of the comprehensive road conditions are analyzed, the operation amount of a high-order data processing algorithm is reduced, the efficiency of the whole data processing process can be improved, and the false alarm rate is reduced. Moreover, the method is easy to realize and has high execution efficiency.

Description

Target detection method and device of vehicle-mounted radar and vehicle
Technical Field
The present invention relates to the field of vehicle technologies, and in particular, to a target detection method for a vehicle-mounted radar, a target detection device for a vehicle-mounted radar, and a vehicle.
Background
According to the target detection method of the vehicle-mounted radar in the related art, firstly, signals in the form of multi-order frequency stepping continuous wave MS-FSCW are transmitted, and parameters of the MS-FSCW transmitting waveforms are determined, wherein the waveform parameters comprise sweep frequency bandwidth, sweep frequency period, sampling rate, the number of the frequency stepping continuous wave signals and initial frequency difference among the frequency stepping continuous wave signals, and then received echo signals are processed to obtain distance and speed information of a target.
However, the related art has the problems that the maximum speed measurement range is small, the oncoming vehicles are easy to cause speed error measurement and error alarm is easy to be caused, and in order to avoid the error alarm, the oncoming vehicles need to be processed by a target order algorithm, and then extra operation amount is brought to a later high-order data processing algorithm.
Disclosure of Invention
The present invention aims to solve at least one of the technical problems in the related art to some extent.
Therefore, a first object of the present invention is to provide a target detection method for a vehicle radar, which can effectively expand a maximum speed measurement range, reduce the operand of a higher-order data processing algorithm, and reduce the false alarm rate.
A second object of the present invention is to provide an object detection device for a vehicle-mounted radar.
A third object of the present invention is to propose a vehicle.
In order to achieve the above object, an embodiment of a first aspect of the present invention provides a target detection method for a vehicle radar, including: modulating a signal to be transmitted in a preset modulation mode, wherein the preset modulation mode comprises a fast frame modulation mode and a slow frame modulation mode; alternately transmitting a fast frame modulated signal and a slow frame modulated signal, and receiving a echo signal; and carrying out speed dimension analysis on the echo signal to obtain the relative speed of the target vehicle, wherein the relative speed of the target vehicle is obtained based on the first speed of the target vehicle in the fast frame modulation mode and the second speed of the target vehicle in the slow frame modulation mode.
According to the target detection method of the vehicle-mounted radar provided by the embodiment of the invention, firstly, a signal to be transmitted is modulated in a preset modulation mode, wherein the preset modulation mode comprises a fast frame modulation mode and a slow frame modulation mode, then, the signal modulated by the fast frame and the signal modulated by the slow frame are alternately transmitted, an echo signal is received, speed dimension analysis is carried out on the echo signal, so that the relative speed of a target vehicle is obtained, and the relative speed of the target vehicle is obtained based on the first speed of the target vehicle in the fast frame modulation mode and the second speed of the target vehicle in the slow frame modulation mode. Therefore, the target detection method of the vehicle-mounted radar can effectively expand the maximum speed measurement range, analyze the speed of various driving states of comprehensive road conditions, reduce the operand of a high-order data processing algorithm, and further improve the efficiency of the whole data processing process and reduce the false alarm rate. Moreover, the method is easy to realize and has high execution efficiency.
To achieve the above object, a second aspect of the present invention provides an object detection device for a vehicle radar, including: the modulation module is used for modulating the signal to be transmitted in a preset modulation mode, wherein the preset modulation mode comprises a fast frame modulation mode and a slow frame modulation mode; the receiving and transmitting module is used for alternately transmitting the signals modulated by the fast frames and the signals modulated by the slow frames and receiving the echo signals; the speed analysis module is used for carrying out speed dimension analysis on the echo signals so as to obtain the relative speed of the target vehicle, wherein the relative speed of the target vehicle is obtained based on the first speed of the target vehicle in the fast frame modulation mode and the second speed of the target vehicle in the slow frame modulation mode; the time for the fast frame modulated signal to drop from the highest frequency point to the lowest frequency point is smaller than the time for the slow frame modulated signal to drop from the highest frequency point to the lowest frequency point.
According to the target detection device of the vehicle-mounted radar provided by the embodiment of the invention, the signal to be transmitted is modulated in a preset modulation mode through the modulation module, wherein the preset modulation mode comprises a fast frame modulation mode and a slow frame modulation mode, the signal after the fast frame modulation and the signal after the slow frame modulation are alternately transmitted through the transceiver module, the echo signal is received, the speed dimension analysis is carried out on the echo signal through the speed analysis module, so that the relative speed of the target vehicle is obtained based on the first speed of the target vehicle in the fast frame modulation mode and the second speed of the target vehicle in the slow frame modulation mode, and the time for the signal after the fast frame modulation to drop from the highest frequency point to the lowest frequency point is smaller than the time for the signal after the slow frame modulation to drop from the highest frequency point to the lowest frequency point. Therefore, the target detection device of the vehicle-mounted radar can effectively expand the maximum speed measurement range, analyze the speed of various driving states of comprehensive road conditions, reduce the operand of a high-order data processing algorithm, and further improve the efficiency of the whole data processing process and reduce the false alarm rate. Moreover, the method is easy to realize and has high execution efficiency.
In order to achieve the above object, an embodiment of a third aspect of the present invention provides a vehicle, including an object detection device of an on-board radar according to an embodiment of the second aspect of the present invention.
According to the vehicle provided by the embodiment of the invention, the maximum speed measuring range can be effectively expanded through the target detection device of the vehicle-mounted radar, the speeds of various driving states of the comprehensive road conditions are analyzed, the operand of a high-order data processing algorithm is reduced, and therefore, the efficiency of the whole data processing process can be improved, and the false alarm rate is reduced. Moreover, the method is easy to realize and has high execution efficiency.
Drawings
Fig. 1 is a flowchart of a target detection method of a vehicle-mounted radar according to an embodiment of the present invention;
FIG. 2 is a flow chart of a method for detecting an object of a vehicle radar according to an embodiment of the present invention;
FIG. 3 is a flow chart of a target detection method of an on-board radar according to another embodiment of the present invention;
FIG. 4 is a flow chart of a method for detecting an object of a vehicle radar according to an embodiment of the present invention;
FIG. 5 is a schematic diagram of an alternate modulation mode of fast frames and slow frames in a target detection method of a vehicle radar according to an embodiment of the present invention;
FIG. 6 is a schematic diagram of a blind spot detection area in a target detection method of a vehicle radar according to an embodiment of the present invention;
FIG. 7 is a schematic diagram of a lane change auxiliary detecting area in a target detecting method of a vehicle-mounted radar according to an embodiment of the present invention;
FIG. 8 is a block diagram of an object detection apparatus of a vehicle radar according to an embodiment of the present invention;
fig. 9 is a block diagram schematically illustrating an object detection apparatus of a vehicle-mounted radar according to an embodiment of the present invention.
Detailed Description
Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative and intended to explain the present invention and should not be construed as limiting the invention.
The following describes a target detection method and a detection device of a vehicle-mounted radar and a vehicle according to an embodiment of the present invention with reference to the accompanying drawings.
Fig. 1 is a flowchart of a target detection method of a vehicle radar according to an embodiment of the present invention. As shown in fig. 1, the target detection method of the vehicle radar according to the embodiment of the invention includes the following steps:
s1, modulating a signal to be transmitted in a preset modulation mode, wherein the preset modulation mode comprises a fast frame modulation mode and a slow frame modulation mode.
It can be understood that the preset modulation mode may be a triangle wave combined fast frame and slow frame alternative modulation mode, or a sawtooth wave combined fast frame and slow frame alternative modulation mode, which does not make a unique limitation on the carrier wave of the preset modulation mode. After the modulation mode is determined, modulation parameters may be determined, where the modulation parameters may include a modulation frequency, a modulation bandwidth, a transmission period, a number of periods of a modulation waveform, a time length of modulation, and the like.
It should be noted that, the target detection method of the vehicle radar according to the embodiment of the present invention may also use other derived modulation modes of alternately modulating fast frames and slow frames.
S2, alternately transmitting a fast frame modulated signal and a slow frame modulated signal, and receiving a echo signal.
Wherein, according to one embodiment of the invention, the time that the fast frame modulated signal falls from the highest frequency point to the lowest frequency point is less than the time that the slow frame modulated signal falls from the highest frequency point to the lowest frequency point.
It will be appreciated that, as shown in fig. 5, the time for the fast frame modulated signal to drop from the highest frequency point, e.g., point a in the graph, to the lowest frequency point, e.g., point B in the graph, is t1, and the time for the slow frame modulated signal to drop from the highest frequency point, e.g., point C in the graph, to the lowest frequency point, e.g., point D in the graph, is t2, with t1 < t2 being apparent. Preferably, in embodiments of the present invention, 3t1 < t2.
S3, carrying out speed dimension analysis on the echo signals to obtain the relative speed v of the target vehicle, wherein the relative speed v of the target vehicle is obtained based on the first speed v1 of the target vehicle in a fast frame modulation mode and the second speed v2 of the target vehicle in a slow frame modulation mode.
According to one embodiment of the present invention, as shown in fig. 2, the velocity-dimensional analysis of the echo signal further includes the steps of:
s30, carrying out spectrum analysis on the echo signals to respectively obtain a fast frame spectrum corresponding to the fast frame modulation mode and a slow frame spectrum corresponding to the slow frame modulation mode.
S31, determining the position d of the target vehicle in the fast frame frequency spectrum respectively v1 And position d of slow frame spectrum v2 。
S32, obtaining the speed resolution V corresponding to the fast frame modulation mode res1 And obtain the velocity resolution V corresponding to the slow frame modulation mode res2 。
Understandably, radar speed resolution V res The method comprises the following steps:
wherein V is res For radar speed resolution, lambda is the operating wavelength of the radar, T f For the length of the modulation time.
Radar maximum speed measuring range V max The method comprises the following steps:
wherein V is max Is the maximum speed measuring range of the radar, lambda is the working wavelength of the radar, T c Is the period of the modulated waveform, i.e., the time between adjacent peaks of the modulated waveform.
The fast frame modulation time T shown in fig. 5 will be f1 Substituting the fast frame modulation mode into the formula (1) to obtain the corresponding speed resolution V res1 Period T of the fast frame modulation waveform shown in fig. 5 will be c1 Substituting the formula (2) to obtain the maximum speed measurement range V corresponding to the fast frame modulation mode max1 Slow frame modulation time T shown in fig. 5 f2 Substituting formula (1) can obtain slowSpeed resolution V corresponding to frame modulation mode res2 Period T of the slow frame modulation waveform shown in fig. 5 will be c2 Substituting the formula (2) to obtain the maximum speed measurement range V corresponding to the slow frame modulation mode max2 。
Here, the speed resolution V corresponding to the fast frame modulation scheme is described res1 Speed resolution V corresponding to slow frame modulation scheme res2 There is no multiple relationship, i.e. V res1 ≠NV res2 Wherein N is a positive integer. In addition, since the time t1 for the fast frame modulated signal to drop from the highest frequency point to the lowest frequency point is smaller than the time t2 for the slow frame modulated signal to drop from the highest frequency point to the lowest frequency point, i.e., t1 < t2, the speed resolution V corresponding to the fast frame modulation scheme res1 Is greater than the speed resolution V corresponding to the slow frame modulation mode res2 Maximum speed measuring range V corresponding to fast frame modulation mode max1 Is larger than the maximum speed measuring range V corresponding to the slow frame modulation mode max2 I.e. V res1 ＞V res2 ，V max1 ＞V max2 。
S33, according to the position d of the target vehicle in the fast frame frequency spectrum v1 Speed resolution V corresponding to fast frame modulation scheme res1 Obtaining a first speed v1 of the target vehicle in a fast frame modulation mode, and according to a position d of the target vehicle in a slow frame frequency spectrum v2 Speed resolution V corresponding to slow frame modulation scheme res2 And obtaining a second speed v2 of the target vehicle in the slow frame modulation mode.
It can be understood that the following formula:
where v is the relative speed of the target vehicle, d v For the position of the target vehicle in the velocity-dimensional spectrum of the echo signal, V res For the speed resolution of the target vehicle, M is 1/2 of the number of speed dimension Fourier transform points.
At the position d of the known target vehicle in the fast frame spectrum v1 Corresponding to fast frame modulation modeSpeed resolution V res1 On the premise of (1), the first speed v1 of the target vehicle in the fast frame modulation mode can be obtained. Specifically, at decision d v1 When M is less than or equal to M, d v1 And V res1 Substitution v=d v V res In the step (d), a first speed v1 of the target vehicle in a fast frame modulation mode is obtained, and a judgment is made v1 At > M, d will be v1 And V res1 Substitution v= (d v -2M)V res In the first speed v1 of the target vehicle in the fast frame modulation method is obtained.
Similarly, the position d of the target vehicle in the slow frame frequency spectrum is known v2 Speed resolution V corresponding to slow frame modulation scheme res2 On the premise of (2), the second speed v2 of the target vehicle in the slow frame modulation mode can be obtained. Specifically, at decision d v2 When M is less than or equal to M, d v2 And V res2 Substitution v=d v V res In the step (d), a second speed v2 of the target vehicle in the slow frame modulation mode is obtained, and the judgment is made v2 At > M, d will be v2 And V res2 Substitution v= (d v -2M)V res In (2), a second speed v2 of the target vehicle in the slow frame modulation scheme is obtained.
Thus, the first speed v1 of the target vehicle in the fast frame modulation mode and the second speed v2 of the target vehicle in the slow frame modulation mode can be obtained through simple algebraic operation, so that the execution efficiency is high and the implementation is easy. In addition, the target detection method of the vehicle-mounted radar of the embodiment of the invention adopts the modulation mode of alternating fast frames and slow frames, so that the maximum speed measurement range corresponding to the modulation mode of the fast frames can be expanded by 3 times, and the final speed measurement range can be 3V max1 。
According to one embodiment of the present invention, as shown in fig. 3, the velocity-dimensional analysis of the echo signal further includes the steps of:
s40, traversing the first speed formula to obtain a plurality of first traversing speeds, wherein the first speed formula is used for obtaining a maximum speed measuring range V corresponding to a first speed V1 and a fast frame modulation mode max1 And a first parameter N1 is constructed, the first parameter N1 belonging to the first set of values.
It can be understood that according to the radar speed measurement principleIt is known that the speed of the target vehicle has a periodic character, i.e. f (v+2v max ) =f (V), where V max Is the maximum speed measurement range of the target vehicle. Thus, a first speed formula can be obtained
v＝v1+2N1V max1 (4)
For example, the first parameter N1 may belong to the first set of values { -2, -1,0,1,2}. 5 values of the first parameter N1, the known first speed V1 and the maximum speed measuring range V corresponding to the fast frame modulation mode are taken max1 And (3) respectively substituting the first traversal speeds into the formula (4) to obtain the first traversal speeds corresponding to the 5 numerical values respectively.
S41, traversing the second velocity formula to obtain a plurality of second traversing speeds, wherein the second velocity formula is used for obtaining a maximum velocity measuring range V corresponding to a slow frame modulation mode at a second velocity V2 max2 And a second parameter N2 is constructed, the second parameter N2 belonging to a second set of values.
It can be appreciated that the speed of the target vehicle has a periodic characteristic, i.e., f (v+2v) max ) =f (V), where V max Is the maximum speed measurement range of the target vehicle. Thereby, a second velocity formula can be obtained
v＝v2+2N2V max2 (5)
For example, the second parameter N2 may belong to the first set of values { -2, -1,0,1,2}. 5 values of the second parameter N2, and a known second speed V2 and a maximum speed measurement range V corresponding to a slow frame modulation mode max2 And (5) respectively substituting the values into the formula to obtain second traversal speeds corresponding to the 5 values respectively.
S42, comparing each first traversing speed in the first traversing speeds with each second traversing speed in the second traversing speeds in turn, and calculating the relative speed v of the target vehicle according to the first traversing speed and the second traversing speed with the smallest difference.
It will be appreciated that when the first traverse speed and the second traverse speed with the smallest difference are obtained, the smaller value of the first traverse speed and the second traverse speed may be taken as the relative speed of the target vehicle, the larger value of the first traverse speed and the second traverse speed may be taken as the relative speed of the target vehicle, or the average value of the first traverse speed and the second traverse speed may be taken as the relative speed of the target vehicle, which is not limited in the embodiment of the present invention.
Therefore, the target detection method of the vehicle-mounted radar provided by the embodiment of the invention has the advantages of easiness in implementation and high execution efficiency, and only involves simple linear transformation by utilizing the characteristic that the speed is periodic. In addition, the speed of various driving states in the comprehensive road conditions can be analyzed, so that the occurrence of false alarm of the oncoming vehicles at high speed can be effectively avoided.
For example, taking a blind area radar with a frequency of 77GHz as an example, the radar antenna adopts 2-transmit and 4-receive, adopts a sawtooth wave modulation mode and combines a fast frame and a slow frame alternating modulation mode to modulate a signal to be transmitted. Wherein, the modulation parameters are as follows: modulation frequency f 0 The modulation bandwidth b=375m is 76GHz, the fast frame has 64 modulation periods, the frequency modulation time of the fast frame is 52us, and the time between the highest points of adjacent frequencies is the modulation period T c1 Time length T of fast frame modulation =3us f1 =3584 us. The slow frame has 64 modulation periods, the frequency modulation time of the slow frame is 52us, and the time of the adjacent highest frequency point is the modulation period T c2 Time length T of slow frame modulation=14.8us f2 Idle time tidle=3 ms between fast frame modulation and slow frame modulation= 4275.2 us.
The speed resolution V corresponding to the fast frame modulation mode can be calculated by the formula (1) and the formula (2) res1 =0.55m/s, maximum speed measurement range V corresponding to fast frame modulation mode max1 Speed resolution V corresponding to slow frame modulation mode res2 =0.46 m/s, maximum velocity measurement range V corresponding to slow frame modulation mode max2 ＝53km/h。
Peak position d in fast frame modulation at a relative speed of the target vehicle of 100km/h v1 =51, the number of velocity-dimensional fourier transform points m1=64, then m=1/2m1=32, according to formula (3), the first velocity v1= (51-64) 0.55 x 3.6= -25.74km/h. Peak position d in slow frame modulation v2 And similarly, the second speed v2= (60-64) 0.46 x 3.6= -6.624km/h. Then obtaining the target according to the formula (4) and the formula (5)The relative speeds v= -25.74+2×n1×63, v= -6.624+2×n2×53 of the vehicle, where N1 and N2 are { -2, -1,0,1,2}, after traversing the relative speeds of the target vehicle, it is known that when n1=n2=1, the difference between the first traversing speed and the second traversing speed is the smallest, and at this time, the smaller value of the first traversing speed and the second traversing speed is taken as the relative speed of the target vehicle, i.e. the relative speed of the target vehicle is v= 99.376km/h.
According to one embodiment of the present invention, before the velocity-dimensional analysis of the echo signal, the method further comprises: and carrying out distance dimension analysis on the echo signals to obtain the distance d between the target vehicle and the host vehicle.
It can be understood that the distance dimension analysis can be performed according to the distance dimension spectrum peak position of the echo signal, and the distance d between the target vehicle and the host vehicle is as follows:
d＝R res *d v ’ (6)
wherein d is the distance between the target vehicle and the host vehicle, R res For distance resolution, d v ' the position of the target vehicle in the range dimension spectrum peak of the echo signal, which is specifically represented by the target vehicle being at the d-th position v ' at the location of the spectral lines.
Preferably, the embodiment of the invention can use a constant false alarm detection algorithm (CFAR) to obtain the position d of the range-dimensional spectrum peak value of the target vehicle in the echo signal v ’。
Further, according to an embodiment of the present invention, after the velocity-dimensional analysis of the echo signal, the method further includes: and carrying out angle dimension analysis on the echo signals to obtain the included angle between the target vehicle and the host vehicle.
It can be appreciated that an algorithm of beam forming or a method of angle dimension fourier transform may be used to perform angle dimension analysis on the echo signal to obtain an included angle between the target vehicle and the host vehicle.
The echo signal velocity dimension analysis result, the distance dimension analysis result and the angle dimension analysis result can be processed through a high-order data processing algorithm, wherein the high-order data processing algorithm generally comprises a clustering algorithm and a tracking algorithm, and preferably, a Kalman filtering tracking algorithm can be adopted. In addition, the target detection method of the vehicle-mounted radar can expand the maximum speed measurement range, so that when the speed dimension analysis is carried out on the echo signal, the larger negative speed of the oncoming vehicle at high speed can be accurately analyzed, and the target detection method can be directly kicked out from the potential threat target queue, thereby reducing the potential threat target input of a high-order data algorithm, greatly reducing the operation amount of the high-order data processing algorithm, improving the efficiency of the whole data processing process and reducing the false alarm rate.
According to an embodiment of the present invention, the target detection method of the vehicle-mounted radar further includes: and detecting a backward blind area according to at least one of the distance d between the target vehicle and the host vehicle, the relative speed v of the target vehicle and the included angle between the target vehicle and the host vehicle.
It is understood that the host vehicle may be subjected to a backward blind spot detection according to at least one of the distance d between the target vehicle and the host vehicle, the relative speed v of the target vehicle, and the angle between the target vehicle and the host vehicle, wherein the backward blind spot detection may include a Blind Spot Detection (BSD) and a curve assist (LCA) detection.
As shown in fig. 6, h, e, f, g is a lane line, and a, b, and c are horizontal lines perpendicular to the lane line h, e, f, g, where a is 0 m from the tail of the vehicle, b is 8 m from the tail of the vehicle, and c is 70 m from the tail of the vehicle. When blind spot detection is performed, when the target vehicle is in an adjacent lane behind the host vehicle and the target vehicle is judged to be in a range of 0-8 meters behind the host vehicle according to the obtained distance d between the target vehicle and the host vehicle, as shown by a hatched area in fig. 6, an alarm is started.
In addition, in the blind spot detection, when it is determined that the obtained relative speed of the target vehicle is a positive value, wherein the relative speed of the target vehicle=the speed of the target vehicle-the own vehicle speed, that is, when the speed of the target vehicle is greater than the own vehicle speed, an alarm is started.
As shown in fig. 7, h, e, f, g is a lane line, and a, b, and c are horizontal lines perpendicular to the lane line h, e, f, g, where a is 0 m from the vehicle tail, b is 8 m from the vehicle tail, and c is 70 m from the vehicle tail. When the target vehicle is in the adjacent lane behind the A column of the vehicle and the target vehicle is judged to be in the range of 0-70 meters behind the vehicle according to the distance d between the target vehicle and the vehicle during curve auxiliary detection, as shown by the hatched area in fig. 7, an alarm is started.
In addition, when the curve assist detection is performed, when it is determined that the obtained relative speed of the target vehicle is a positive value, wherein the relative speed of the target vehicle=the speed of the target vehicle-the own vehicle speed, that is, when the speed of the target vehicle is greater than the own vehicle speed and the collision time is less than 3.5 seconds, wherein the collision time=the distance between the target vehicle and the own vehicle/the relative speed of the target vehicle, an alarm is started, for example, a warning that the vehicle owner has a lane change risk is presented. Preferably, the length of the collision time can be segmented, and multi-level alarm prompts are given according to the segmentation.
It should be noted that, the target detection method of the vehicle-mounted radar according to the embodiment of the invention is not only suitable for Blind Spot Detection (BSD) and lane change auxiliary detection (LCA) in blind spot detection, but also suitable for other applications based on collision time, such as an automobile door opening anti-collision early warning system, an automobile reversing intersection transverse anti-collision early warning system, an adaptive cruise (ACC) and other similar applications.
As described above, according to an embodiment of the present invention, as shown in fig. 4, the target detection method of the vehicle-mounted radar of the embodiment of the present invention includes the steps of:
s101, modulating a signal to be transmitted in a preset modulation mode, wherein the preset modulation mode comprises a fast frame modulation mode and a slow frame modulation mode.
S102, determining modulation parameters.
S103, alternately transmitting a fast frame modulated signal and a slow frame modulated signal, and receiving a echo signal.
S104, performing distance dimension analysis on the echo signals to obtain the distance d between the target vehicle and the host vehicle.
S105, carrying out speed dimension analysis on the echo signal to obtain the relative speed v of the target vehicle, wherein the relative speed v of the target vehicle is obtained based on the first speed v1 of the target vehicle in a fast frame modulation mode and the second speed v2 of the target vehicle in a slow frame modulation mode.
S106, carrying out angle dimension analysis on the echo signals to obtain the included angle between the target vehicle and the host vehicle.
And S107, detecting a backward blind area according to at least one of the distance d between the target vehicle and the host vehicle, the relative speed v of the target vehicle and the included angle between the target vehicle and the host vehicle.
In summary, according to the target detection method for the vehicle-mounted radar provided by the embodiment of the invention, a signal to be transmitted is modulated in a preset modulation mode, wherein the preset modulation mode comprises a fast frame modulation mode and a slow frame modulation mode, then a signal modulated by a fast frame and a signal modulated by a slow frame are alternately transmitted, an echo signal is received, and speed dimension analysis is performed on the echo signal to obtain the relative speed of the target vehicle, wherein the relative speed of the target vehicle is obtained based on the first speed of the target vehicle in the fast frame modulation mode and the second speed of the target vehicle in the slow frame modulation mode. Therefore, the target detection method of the vehicle-mounted radar can effectively expand the maximum speed measurement range, analyze the speed of various driving states of comprehensive road conditions, reduce the operand of a high-order data processing algorithm, and further improve the efficiency of the whole data processing process and reduce the false alarm rate. Moreover, the method is easy to realize and has high execution efficiency.
Corresponding to the target detection method of the vehicle-mounted radar in the embodiment, the embodiment of the invention further provides a target detection device of the vehicle-mounted radar.
Fig. 8 is a block diagram schematically illustrating an object detection apparatus of a vehicle-mounted radar according to an embodiment of the present invention. As shown in fig. 8, the object detection device of the vehicle-mounted radar according to the embodiment of the present invention includes: a modulation module 10, a transceiver module 20 and a speed resolution module 30.
The modulation module 10 is configured to modulate a signal to be transmitted in a preset modulation mode, where the preset modulation mode includes a fast frame modulation mode and a slow frame modulation mode; the transceiver module 20 is configured to alternately transmit a fast frame modulated signal and a slow frame modulated signal, and receive a echo signal; the speed analysis module 30 performs speed dimension analysis on the echo signal to obtain a relative speed v of the target vehicle, wherein the relative speed v of the target vehicle is obtained based on a first speed v1 of the target vehicle in a fast frame modulation mode and a second speed v2 of the target vehicle in a slow frame modulation mode; the time t1 that the signal after fast frame modulation drops from the highest frequency point to the lowest frequency point is smaller than the time t2 that the signal after slow frame modulation drops from the highest frequency point to the lowest frequency point.
According to an embodiment of the present invention, the speed analysis module 30 is further configured to perform spectrum analysis on the echo signal to obtain a fast frame spectrum corresponding to the fast frame modulation mode and a slow frame spectrum corresponding to the slow frame modulation mode, and determine the position d of the target vehicle in the fast frame spectrum, respectively v1 And position d of slow frame spectrum v2 And obtaining the speed resolution V corresponding to the fast frame modulation mode res1 And obtain the velocity resolution V corresponding to the slow frame modulation mode res2 According to the position d of the target vehicle in the fast frame frequency spectrum v1 Speed resolution V corresponding to fast frame modulation scheme res1 Obtaining a first speed v1 of the target vehicle in a fast frame modulation mode, and according to a position d of the target vehicle in a slow frame frequency spectrum v2 Speed resolution V corresponding to slow frame modulation scheme res2 And obtaining a second speed v2 of the target vehicle in the slow frame modulation mode.
Further, according to an embodiment of the present invention, the speed analysis module 30 is further configured to traverse a first speed formula to obtain a plurality of first traversed speeds, where the first speed formula is used for a first speed V1 and a maximum speed measurement range V corresponding to a fast frame modulation mode max1 Constructing a first parameter N1, wherein the first parameter N1 belongs to a first numerical value set, and traversing a second speed formula to obtain a plurality of second traversing speeds, wherein the second speed formula is in a maximum speed measuring range V corresponding to a second speed V2 and a slow frame modulation mode max2 And a second parameter N2 is constructed, the second parameter N2 belongs to a second value set, and each first traversing speed in the plurality of first traversing speeds and each second traversing speed in the plurality of second traversing speeds are sequentially advancedAnd comparing the rows, and calculating the relative speed v of the target vehicle according to the first traversing speed and the second traversing speed with the smallest difference value.
According to an embodiment of the present invention, as shown in fig. 9, the target detection apparatus of the vehicle radar further includes a distance resolving module 40, configured to perform distance dimension resolving on the echo signal to obtain a distance d between the target vehicle and the host vehicle.
Further, according to an embodiment of the present invention, as shown in fig. 9, the target detection apparatus of the vehicle radar further includes an angle resolving module 50, configured to perform angle dimension resolving on the echo signal, so as to obtain an included angle between the target vehicle and the host vehicle.
Further, according to an embodiment of the present invention, as shown in fig. 9, the target detection apparatus of the vehicle-mounted radar further includes an analysis module 60 for performing a backward blind area detection according to at least one of a distance d between the target vehicle and the host vehicle, a relative speed v of the target vehicle, and an angle between the target vehicle and the host vehicle.
It should be noted that the foregoing explanation of the embodiment of the target detection method of the vehicle radar is also applicable to the target detection device of the vehicle radar in the embodiment of the present invention, and will not be repeated here.
In summary, according to the target detection device for the vehicle-mounted radar provided by the embodiment of the invention, a signal to be transmitted is modulated by a modulation module in a preset modulation mode, wherein the preset modulation mode comprises a fast frame modulation mode and a slow frame modulation mode, a signal modulated by a fast frame and a signal modulated by a slow frame are alternately transmitted by a transceiver module, an echo signal is received, a speed dimension analysis is performed on the echo signal by a speed analysis module, so as to obtain the relative speed of a target vehicle, wherein the relative speed of the target vehicle is obtained based on the first speed of the target vehicle in the fast frame modulation mode and the second speed of the target vehicle in the slow frame modulation mode, and the time for the signal modulated by the fast frame to drop from the highest frequency point to the lowest frequency point is smaller than the time for the signal modulated by the slow frame to drop from the highest frequency point to the lowest frequency point. Therefore, the target detection device of the vehicle-mounted radar can effectively expand the maximum speed measurement range, analyze the speed of various driving states of comprehensive road conditions, reduce the operand of a high-order data processing algorithm, and further improve the efficiency of the whole data processing process and reduce the false alarm rate. Moreover, the method is easy to realize and has high execution efficiency.
Based on the target detection device of the vehicle-mounted radar in the embodiment, the embodiment of the invention also provides a vehicle, which comprises the target detection device of the vehicle-mounted radar.
According to the vehicle provided by the embodiment of the invention, the maximum speed measuring range can be effectively expanded through the target detection device of the vehicle-mounted radar, the speeds of various driving states of the comprehensive road conditions are analyzed, the operand of a high-order data processing algorithm is reduced, and therefore, the efficiency of the whole data processing process can be improved, and the false alarm rate is reduced. Moreover, the method is easy to realize and has high execution efficiency.
In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.
In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.
In the present invention, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.
In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.
While embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that variations, modifications, alternatives and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the invention.

Claims (10)

1. The target detection method of the vehicle-mounted radar is characterized by comprising the following steps of:
modulating a signal to be transmitted in a preset modulation mode, wherein the preset modulation mode comprises a fast frame modulation mode and a slow frame modulation mode;
alternately transmitting a fast frame modulated signal and a slow frame modulated signal, and receiving a echo signal;
performing speed dimension analysis on the echo signal to obtain the relative speed of a target vehicle, wherein the relative speed of the target vehicle is obtained based on the first speed of the target vehicle in the fast frame modulation mode and the second speed of the target vehicle in the slow frame modulation mode; the time for the fast frame modulated signal to drop from the highest frequency point to the lowest frequency point is different from the time for the slow frame modulated signal to drop from the highest frequency point to the lowest frequency point.
2. The method for detecting an object of a vehicle-mounted radar according to claim 1, wherein a time for which the fast frame modulated signal falls from a highest frequency point to a lowest frequency point is smaller than a time for which the slow frame modulated signal falls from the highest frequency point to the lowest frequency point.
3. The target detection method of the vehicle-mounted radar according to claim 1, wherein performing velocity-dimensional analysis on the echo signal includes:
performing spectrum analysis on the echo signals to respectively obtain a fast frame spectrum corresponding to the fast frame modulation mode and a slow frame spectrum corresponding to the slow frame modulation mode;
determining the position of the target vehicle in the fast frame frequency spectrum and the position of the slow frame frequency spectrum respectively;
acquiring the speed resolution corresponding to the fast frame modulation mode and the speed resolution corresponding to the slow frame modulation mode;
obtaining a first speed of the target vehicle in the fast frame modulation mode according to the position of the target vehicle in the fast frame frequency spectrum and the speed resolution corresponding to the fast frame modulation mode, and obtaining a second speed of the target vehicle in the slow frame modulation mode according to the position of the target vehicle in the slow frame frequency spectrum and the speed resolution corresponding to the slow frame modulation mode.
4. The target detection method of the vehicle-mounted radar according to claim 1, wherein performing velocity-dimensional analysis on the echo signal includes:
traversing a first speed formula to obtain a plurality of first traversing speeds, wherein the first speed formula is constructed by the first speed, a maximum speed measuring range corresponding to the fast frame modulation mode and a first parameter, and the first parameter belongs to a first numerical value set;
traversing a second speed formula to obtain a plurality of second traversing speeds, wherein the second speed formula is constructed by the second speed, a maximum speed measuring range corresponding to the slow frame modulation mode and a second parameter, and the second parameter belongs to a second numerical value set;
and comparing each first traversing speed in the first traversing speeds with each second traversing speed in the second traversing speeds in turn, and calculating the relative speed of the target vehicle according to the first traversing speed and the second traversing speed with the smallest difference.
5. The target detection method of an in-vehicle radar according to claim 1, characterized in that before the velocity-dimensional analysis of the echo signal, the method further comprises:
and carrying out distance dimension analysis on the echo signals to obtain the distance between the target vehicle and the host vehicle.
6. The method for detecting an object of an in-vehicle radar according to claim 5, wherein after the velocity-dimensional analysis of the echo signal, the method further comprises:
and carrying out angle dimension analysis on the echo signals to obtain the included angle between the target vehicle and the host vehicle.
7. The target detection method of the vehicle-mounted radar according to claim 6, characterized by further comprising:
and detecting a backward blind area according to at least one of the distance between the target vehicle and the host vehicle, the relative speed of the target vehicle and the included angle between the target vehicle and the host vehicle.
8. An object detection device of a vehicle-mounted radar, characterized by comprising:
the modulation module is used for modulating the signal to be transmitted in a preset modulation mode, wherein the preset modulation mode comprises a fast frame modulation mode and a slow frame modulation mode;
the receiving and transmitting module is used for alternately transmitting the signals modulated by the fast frames and the signals modulated by the slow frames and receiving the echo signals;
the speed analysis module is used for carrying out speed dimension analysis on the echo signals so as to obtain the relative speed of the target vehicle, wherein the relative speed of the target vehicle is obtained based on the first speed of the target vehicle in the fast frame modulation mode and the second speed of the target vehicle in the slow frame modulation mode; the time for the signal after fast frame modulation to drop from the highest frequency point to the lowest frequency point is smaller than the time for the signal after slow frame modulation to drop from the highest frequency point to the lowest frequency point; the time for the fast frame modulated signal to drop from the highest frequency point to the lowest frequency point is different from the time for the slow frame modulated signal to drop from the highest frequency point to the lowest frequency point.
9. The apparatus according to claim 8, wherein the speed analysis module is further configured to perform spectrum analysis on the echo signal to obtain a fast frame spectrum corresponding to the fast frame modulation mode and a slow frame spectrum corresponding to the slow frame modulation mode, determine a position of the target vehicle in the fast frame spectrum and a position of the slow frame spectrum, obtain a speed resolution corresponding to the fast frame modulation mode, obtain a speed resolution corresponding to the slow frame modulation mode, obtain a first speed of the target vehicle in the fast frame modulation mode according to the position of the target vehicle in the fast frame spectrum and the speed resolution corresponding to the fast frame modulation mode, and obtain a second speed of the target vehicle in the slow frame modulation mode according to the position of the target vehicle in the slow frame spectrum and the speed resolution corresponding to the slow frame modulation mode, respectively.
10. A vehicle characterized by comprising the object detection device of the in-vehicle radar according to any one of claims 8 to 9.
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CN105074497A (en) * 2013-04-03 2015-11-18 罗伯特·博世有限公司 Radar device and method having an antenna array with two switching states of different modulation
CN104730522A (en) * 2013-12-18 2015-06-24 株式会社万都 Method and device for sensing road environment based on frequency modulated continuous wave radar
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