Method for controlling millimeter-wave radar, millimeter-wave radar, method for lane change assistance of vehicle, lane change assistance system, vehicle and computer program product

Abstract

The present application relates to a method for controlling a millimeter wave radar, comprising: transmitting a first number of first chirp signals at a first time interval T1 in each frame of millimeter wave transmission period, and receiving a first echo signal of the first chirp signals reflected by a moving target, the first time interval T1 being a linear function about time (S1); performing frequency mixing processing on the first echo signal and the first linear frequency modulation signal to obtain a first intermediate frequency signal, and converting the first intermediate frequency signal into a first discrete intermediate frequency signal (S2); the acceleration information of the moving object is obtained by performing two-dimensional Fourier transform on the first discrete intermediate frequency signal (S3). According to the method and the device, the acceleration information of the moving target object is measured in a short time range by changing the time interval of the signal emission of the millimeter-wave radar, the acceleration of the rear vehicle in the visual blind area of the vehicle is accurately measured in real time, and a foundation is laid for optimizing the lane changing auxiliary function of the vehicle.

Description

Technical Field

[0001] The present application relates to the field of vehicles, and in particular to a method for controlling a millimeter-wave radar, a millimeter-wave radar, a method for lane change assistance for a vehicle, a lane change assistance system, a vehicle including a lane change assistance system according to the present application and / or a millimeter-wave radar according to the present application, and a computer program product for at least assisting in implementing the steps of the method described in the present application. Background Art

[0002] The current L2 and above assisted driving systems are usually equipped with a lane change assistance function. When a rear vehicle is detected in the blind spot behind the vehicle, a first-level alarm notification will be provided. If the driver still requests to change lanes despite the first-level alarm notification, a second-level alarm notification will be sent directly without distinguishing whether the rear vehicle has decelerated. In some actual driving scenarios, the rear vehicle may have continued to decelerate for a period of time to actively avoid the vehicle. At this time, the vehicle is able to perform a normal lane change. Therefore, this second-level alarm notification that does not distinguish the status of the rear vehicle will undoubtedly affect the user experience of the assisted driving function.

[0003] Therefore, there is room for improvement in the lane change assistance function of the current assisted driving system. Summary of the invention

[0004] The purpose of the present application is to provide a method for controlling a millimeter-wave radar, a millimeter-wave radar, a method for lane change assistance for a vehicle, a lane change assistance system, a vehicle including a lane change assistance system according to the present application and / or a millimeter-wave radar according to the present application, and a computer program product, so as to at least partially solve the problems in the prior art.

[0005] According to a first aspect of the present application, a method for controlling a millimeter wave radar is provided, the method comprising:

[0006] - Step S1: transmitting a first number of first linear frequency modulation signals at a first time interval T1 in each frame of millimeter wave transmission cycle, and receiving a first echo signal reflected by a moving target from the first linear frequency modulation signal, wherein the first time interval T1 is a linear function of time;

[0007] - Step S2: Mixing the first echo signal with the first linear frequency modulation signal to obtain a first intermediate frequency signal, and converting the first intermediate frequency signal into a first discrete intermediate frequency signal; and

[0008] - Step S3: Obtain acceleration information of the moving target by performing a two-dimensional Fourier transform on the first discrete intermediate frequency signal.

[0009] The core concept of the present application is to give acceleration measurement information to the radar point cloud data by changing the time interval of the millimeter-wave radar's transmission signal, thereby realizing the measurement of acceleration information of moving targets within a short time range, especially being able to measure the acceleration of rear vehicles in the vehicle's blind spot in real time and accurately, laying the foundation for optimizing various assisted driving functions of the vehicle, especially the lane change assistance function.

[0010] According to an optional embodiment of the present application, two or more first linear frequency modulation signals are transmitted at the first time interval T1 in each frame millimeter wave transmission period.

[0011] According to another optional embodiment of the present application, the method may further include:

[0012] - Step S4: transmitting a second number of second linear frequency modulation signals at a second time interval T2 in each frame of the millimeter wave transmission cycle, and receiving a second echo signal reflected by the second linear frequency modulation signal from the moving target, wherein the second time interval T2 is a predetermined constant;

[0013] - Step S5: Mixing the second echo signal with the second linear frequency modulation signal to obtain a second intermediate frequency signal, and converting the second intermediate frequency signal into a second discrete intermediate frequency signal; and

[0014] - Step S6: Obtain the speed information of the moving target by performing a two-dimensional Fourier transform on the second discrete intermediate frequency signal.

[0015] According to a second aspect of the present application, a millimeter wave radar is provided, which is used to perform the method according to the present application, wherein the millimeter wave radar includes the following components:

[0016] - a signal transmitting unit, configured to transmit a first number of first linear frequency modulation signals at a first time interval T1 in each frame of millimeter wave transmission cycle, wherein the first time interval T1 is a linear function of time;

[0017] - a signal receiving unit, configured to receive a first echo signal of the first linear frequency modulation signal reflected by a moving target;

[0018] - a mixing unit, configured to mix the first echo signal with the first linear frequency modulation signal to obtain a first intermediate frequency signal;

[0019] - an analog-to-digital conversion unit configured to convert the first intermediate frequency signal into a first discrete intermediate frequency signal; and

[0020] - an intermediate frequency signal processing unit, configured to obtain acceleration information of the moving target by performing a two-dimensional Fourier transform on the first discrete intermediate frequency signal.

[0021] According to a third aspect of the present application, a method for lane change assistance for a vehicle is provided, the method comprising:

[0022] - Step S1': monitoring the driver's lane-changing intention when a moving target is detected in the rear blind spot of the vehicle;

[0023] - Step S2': when the driver's intention to change lanes is detected, the acceleration information of the moving target is obtained by the method for controlling the millimeter-wave radar according to the present application, and the speed information of the moving target is obtained by the method for controlling the millimeter-wave radar according to the present application; and

[0024] - Step S3': evaluating the collision risk between the vehicle and the moving object based at least on the speed information of the vehicle and the acceleration information and speed information of the moving object,

[0025] And sending lane change instruction information to the driver at least based on the assessed collision risk.

[0026] The concept of the present application also includes: when a second-level alarm occurs in the assisted driving system, the vehicle's lane change success rate is evaluated based on the speed information and acceleration information of the rear vehicle measured according to the method for controlling the millimeter-wave radar of the present application, and the corresponding lane change instruction information is displayed to the driver, thereby effectively improving the vehicle's lane change success rate and lane change safety, thereby enhancing the user experience of the assisted driving system.

[0027] According to another embodiment of the present application, when a moving target is detected in a rear blind spot of a vehicle, a first-level alarm signal is sent to the driver of the vehicle, and when the driver's intention to change lanes is monitored, a second-level alarm signal is sent to the driver of the vehicle, wherein the rear blind spot of the vehicle includes the blind spot of the rearview mirror of the vehicle and / or an extended area extending backward from the blind spot of the rearview mirror.

[0028] According to another embodiment of the present application, step S3' may include:

[0029] - Step S31': when the acceleration of the moving target object continues to decrease within the millimeter wave transmission period exceeding the preset frame number N, obtaining the first time t1 and the first longitudinal driving distance X1 required for the vehicle to complete the lane change by means of the Ackerman steering model at least based on the speed information of the vehicle;

[0030] - Step S32': Calculating a second longitudinal travel distance X2 traveled by the moving object within the first time t1 based on the speed information and acceleration information of the moving object;

[0031] - Step S33': Determine whether the difference between the first longitudinal driving distance X1 and the second longitudinal driving distance X2 is greater than or equal to a preset safety distance threshold value X s ;

[0032] - Step S34': when the difference is greater than or equal to the preset safety distance threshold value X s In the case of a lane change, sending first lane change instruction information regarding permission for a lane change operation to a driver of the vehicle;

[0033] and

[0034] - Step S35': when the difference is less than the preset safety distance threshold value X s In the case of

[0035] Second lane change instruction information regarding stopping the lane change operation is sent to a driver of the vehicle.

[0036] According to another embodiment of the present application, the preset frame number N of the millimeter wave transmission cycle can be adjusted based on the aggressiveness of the driver's lane changing strategy, wherein the more aggressive the driver's lane changing strategy is, the smaller the preset frame number N of the millimeter wave transmission cycle is.

[0037] According to another embodiment of the present application, a green lane change response can be displayed by the lane change indication module to send a first lane change indication message about allowing the lane change operation to the driver of the vehicle, and / or a red lane change response can be displayed by the lane change indication module to send a second lane change indication message about stopping the lane change operation to the driver of the vehicle, wherein the lane change indication module is configured as an on-board display, and the on-board display includes a head-up display, a central control display and / or an instrument panel, etc.

[0038] According to a fourth aspect of the present application, a lane change assistance system is provided, which is used to execute the lane change assistance method for a vehicle according to the present application, wherein the lane change assistance system may include the following components:

[0039] -Millimeter wave radar according to the present application;

[0040] - a blind spot detection module, which is configured to detect a moving target in a rear blind spot of the vehicle;

[0041] - a lane change intention monitoring module configured to monitor a lane change intention of a driver of the vehicle;

[0042] - a vehicle speed detection module, which is configured to detect speed information of the vehicle;

[0043] - a collision risk assessment module configured to assess the collision risk between the vehicle and the moving object based at least on the speed information of the vehicle and the acceleration information and speed information of the moving object; and

[0044] A lane change indication module is configured to send lane change indication information to the driver based at least on the assessed collision risk.

[0045] According to another embodiment of the present application, the lane change assistance system may further include an alarm module, which is configured to send a primary alarm signal to the driver of the vehicle when a moving target is detected in the rear blind spot of the vehicle, and send a secondary alarm signal to the driver of the vehicle when the driver's intention to change lanes is monitored.

[0046] According to a fifth aspect of the present application, a vehicle is provided, comprising a lane change assistance system according to the present application and / or a millimeter wave radar according to the present application.

[0047] According to a sixth aspect of the present application, a computer program product, such as a computer-readable program carrier, is provided, which contains or stores computer program instructions, and when the computer program instructions are executed by a processor, they at least assist in implementing the steps of the method described in the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The principles, features and advantages of the present application may be better understood by describing the present application in more detail below with reference to the accompanying drawings. The accompanying drawings show:

[0049] Figure 1 A flowchart showing a method for controlling a millimeter wave radar according to an exemplary embodiment of the present application is shown;

[0050] Figure 2 A graph showing the relationship between the time interval of a millimeter wave radar transmitting signal and time according to the prior art;

[0051] Figure 3 A frequency-time relationship diagram of a transmission signal of a millimeter-wave radar according to the prior art is shown;

[0052] Figure 4 A diagram showing the relationship between the time interval of a millimeter wave radar transmitting signal and time according to an exemplary embodiment of the present application;

[0053] Figure 5 A frequency-time relationship diagram of a transmission signal of a millimeter wave radar according to an exemplary embodiment of the present application is shown;

[0054] Figure 6A driving scene diagram according to an exemplary embodiment of the present application is shown;

[0055] Figure 7 A flowchart showing a method for controlling a millimeter wave radar according to another exemplary embodiment of the present application is shown;

[0056] Figure 8 A schematic block diagram of a millimeter wave radar according to an exemplary embodiment of the present application is shown;

[0057] Fig. 9 A flowchart showing a method for lane change assistance for a vehicle according to an exemplary embodiment of the present application is shown;

[0058] Fig.10 A flowchart showing a method for lane change assistance for a vehicle according to another exemplary embodiment of the present application is shown;

[0059] Fig.11 A driving scene diagram according to another exemplary embodiment of the present application is shown;

[0060] Fig.12 A schematic block diagram showing a lane change assistance system according to an exemplary embodiment of the present application; and

[0061] Fig.13 A schematic block diagram of a vehicle according to an exemplary embodiment of the present application is shown. DETAILED DESCRIPTION

[0062] In order to make the technical problems, technical solutions and beneficial technical effects to be solved by the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and multiple exemplary embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, rather than to limit the scope of protection of the present application.

[0063] In the prior art, millimeter-wave radar uses millimeter waves as electromagnetic waves to send signals. It can obtain information such as the distance, speed, azimuth and / or altitude of the target by capturing and processing the echo signal reflected by the target. However, it is still impossible to measure the acceleration of the moving target in real time. Instead, it mainly calculates the acceleration information of the target indirectly through the target tracking method. However, the target tracking method has a large calculation error in scenarios where the acceleration of the moving target is unstable, especially in driving scenarios where the rear vehicle decelerates, and it is difficult to provide reliable and effective support for the assisted driving system. The present application proposes a method for controlling a millimeter-wave radar to measure the acceleration of a moving target in real time and accurately.

[0064] Figure 1A flowchart of a method for controlling a millimeter wave radar according to an exemplary embodiment of the present application is shown. The following exemplary embodiments describe the method according to the present application in more detail.

[0065] like Figure 1 As shown, the method may include steps S1 to S3. In step S1, a first number of first linear frequency modulation signals are transmitted at a first time interval T1 in each frame of millimeter wave transmission period, and a first echo signal reflected by the first linear frequency modulation signal through the moving target 2 is received, wherein the first time interval T1 is a linear function of time. In the meaning of the present application, "linear frequency modulation signal (Chirp)" refers to a signal whose frequency changes continuously and linearly within the radar signal period, which increases the transmission width of the signal by modulating the carrier frequency and realizes pulse compression when receiving. Exemplarily, the time domain expression of the linear frequency modulation signal can be Where A represents the amplitude of the linear frequency modulation signal, f represents the frequency of the linear frequency modulation signal, and t represents the time. Indicates the phase of the linear frequency modulation signal.

[0066] In the prior art, the time interval T for the millimeter wave radar to transmit the linear frequency modulation signal is always equal. Figure 2 The relationship between the time interval T of the millimeter wave radar transmitting signal and the time t according to the prior art is shown. In a 50ms millimeter wave transmitting cycle T cycle The time interval T between each linear frequency modulation signal emitted by the millimeter wave radar is always equal to the constant T c , that is 5ms. Figure 3 The frequency-time relationship diagram of the transmission signal of the millimeter wave radar according to the prior art is shown. In a 50ms millimeter wave transmission period T cycle At a fixed time interval of 5ms c 10 linear frequency modulation signals S1 to S are transmitted respectively 10 , the frequency of the linear frequency modulation signal f c The relationship with time t can be expressed as f c =kt+p, wherein k represents the linear waveform slope of the linear frequency modulation signal, and p represents a constant which is different for each linear frequency modulation signal.

[0067] In the current embodiment of the present application, two or more first linear frequency modulation signals are transmitted at the first time interval T1 in each frame millimeter wave transmission cycle. Figure 5 The frequency-time relationship diagram of the transmission signal of the millimeter wave radar according to an exemplary embodiment of the present application is shown in a 50ms millimeter wave transmission period T cycle The last two linear frequency modulation signals S9 and S10 That is the first linear frequency modulation signal. Figure 4 FIG. 1 shows a relationship diagram of the time interval of the millimeter wave radar transmission signal according to an exemplary embodiment of the present application, the linear frequency modulation signal S8 and S9, and the linear frequency modulation signal S9 and S 10 The first time interval T1 between the two is a linear function of time t, which can be expressed as T1=-t+m, for example, wherein the slope of the linear function is -1, and m represents a constant of the linear function.

[0068] exist Figure 6 In a driving scene diagram according to an exemplary embodiment of the present application, a first linear frequency modulation signal transmitted by a signal transmitting unit 11 of a millimeter-wave radar 10 is reflected by a moving target object 2 (here, a moving rear vehicle) located in a blind spot of the field of view of a vehicle 1, and is received as a first echo signal by a signal receiving unit 12 of the millimeter-wave radar 11.

[0069] In step S2, the first echo signal and the first linear frequency modulation signal are mixed to obtain a first intermediate frequency signal, and the first intermediate frequency signal is converted into a first discrete intermediate frequency signal. The frequency of the first intermediate frequency signal generated by mixing by the mixing unit 13 is equal to the frequency difference between the first echo signal and the corresponding first linear frequency modulation signal, and its phase is equal to the phase difference between the first echo signal and the corresponding first linear frequency modulation signal. Since the first intermediate frequency signal obtained by mixing is an analog signal, the input first intermediate frequency signal can be analyzed and converted into a discrete digital signal by the analog-to-digital conversion unit 14, that is, the first discrete intermediate frequency signal is obtained.

[0070] In step S3, the acceleration information of the moving target 2 is obtained by performing a two-dimensional Fourier transform on the first discrete intermediate frequency signal. According to the operating principle of the millimeter wave radar, the time difference t between the transmitted linear frequency modulation signal and the echo signal reflected by the moving target 2 can be used to obtain the acceleration information of the moving target 2. d and electromagnetic wave propagation speed c to calculate the distance d of the moving target 2 relative to the millimeter wave radar 10, which is expressed as:

[0071] d=t d c / 2 (Formula 1)

[0072] Therefore, the frequency f of the linear frequency modulation signal c It can be expressed as follows:

[0073] f c =2dk / c (Formula 2)

[0074] Therefore, the distance information of the moving target 2 can be obtained based on the frequency information of the radar point cloud data. The phase difference between the transmitted linear frequency modulation signal and the received echo signal It can be calculated by substituting into formula 2 as follows:

[0075]

[0076] Where λ represents the wavelength of the linear frequency modulation signal, and Δd represents the time difference t d The phase difference between the first linear frequency modulation signal and the first echo signal can be obtained by performing a two-dimensional Fourier transform on the first discrete intermediate frequency signal.

[0077] Therefore, the velocity v of the moving target 2 can be calculated as

[0078]

[0079] Here, the first time interval T1 is a linear function T1=-t+m about time t, thereby providing acceleration measurement information to the radar point cloud data. The acceleration a of the moving target 2 can be calculated as:

[0080]

[0081] According to the embodiments of the present application, the acceleration measurement information is given to the radar point cloud data by changing the time interval of the transmission signal of the millimeter-wave radar, thereby realizing the measurement of the acceleration information of the moving target within a short time range, and especially being able to measure the acceleration of the rear vehicle in the blind spot of the vehicle's field of view in real time and accurately, laying the foundation for optimizing various assisted driving functions of the vehicle, especially the lane change assistance function.

[0082] Figure 7 FIG. 1 shows a flowchart of a method for controlling a millimeter wave radar according to another exemplary embodiment of the present application. Figure 1 The differences between the embodiments shown in FIG. 1 and FIG. 2 are shown in FIG. 3 , and the same steps are not described repeatedly for the sake of brevity.

[0083] like Figure 7 As shown, the method may further include steps S4 to S6. In step S4, a second number of second linear frequency modulation signals are respectively transmitted at a second time interval T2 in each frame of the millimeter wave transmission cycle, and a second echo signal reflected by the moving target 2 from the second linear frequency modulation signal is received, wherein the second time interval T2 is a predetermined constant.

[0084] like Figure 5 The frequency-time relationship diagram of the transmission signal of the millimeter wave radar according to an exemplary embodiment of the present application is shown in a 50ms millimeter wave transmission period T cycle The first eight linear frequency modulation signals S1 to S8 transmitted in the internal are the second linear frequency modulation signals. Figure 4 The relationship between the time interval of the millimeter wave radar transmission signal and time according to an exemplary embodiment of the present application is shown, and the second time interval T2 between each second linear frequency modulation signal S1 to S8 is always equal to the predetermined constant T c .

[0085] In step S5, the second echo signal and the second linear frequency modulation signal are mixed to obtain a second intermediate frequency signal, and the second intermediate frequency signal is converted into a second discrete intermediate frequency signal. The frequency of the second intermediate frequency signal generated by mixing by the mixing unit 13 is equal to the frequency difference between the second echo signal and the corresponding second linear frequency modulation signal, and its phase is equal to the phase difference between the second echo signal and the corresponding second linear frequency modulation signal. Since the second intermediate frequency signal obtained by mixing is an analog signal, the input second intermediate frequency signal can be analyzed and converted into a discrete digital signal by the analog-to-digital conversion unit 14, that is, a second discrete intermediate frequency signal is obtained.

[0086] In step S6, the speed information of the moving target 2 is obtained by performing a two-dimensional Fourier transform on the second discrete intermediate frequency signal. Here, the phase difference between the second linear frequency modulation signal and the second echo signal can be obtained by performing a two-dimensional Fourier transform on the second discrete intermediate frequency signal. According to the above-mentioned radar millimeter wave operating principle, the speed v of the moving target 2 can be calculated as

[0087]

[0088] Here, the second time interval T2 is equal to the predetermined constant T c , thereby the speed information of the moving target 2 can be obtained quickly and accurately.

[0089] Figure 8 A schematic block diagram of a millimeter wave radar according to an exemplary embodiment of the present application is shown.

[0090] like Figure 8 As shown, the millimeter wave radar 10 may include the following components:

[0091] - a signal transmitting unit 11, which is configured to transmit a first number of first linear frequency modulation signals at a first time interval T1 in each frame of millimeter wave transmission cycle, wherein the first time interval T1 is a linear function of time, and optionally further configured to transmit a second number of second linear frequency modulation signals at a second time interval T2, wherein the second time interval T2 is a predetermined constant;

[0092] a signal receiving unit 12, configured to receive a first echo signal of the first linear frequency modulation signal reflected by the moving target 2, and optionally also receive a second echo signal of the second linear frequency modulation signal reflected by the moving target 2;

[0093] a mixing unit 13, configured to mix the first echo signal with the first linear frequency modulation signal to obtain a first intermediate frequency signal, and optionally to mix the second echo signal with the second linear frequency modulation signal to obtain a second intermediate frequency signal;

[0094] - an analog-to-digital conversion unit 14, which is configured to convert the first intermediate frequency signal into a first discrete intermediate frequency signal, and optionally also convert the second intermediate frequency signal into a second discrete intermediate frequency signal; and

[0095] - An intermediate frequency signal processing unit 15, which is configured to obtain the acceleration information of the moving target 2 by performing a two-dimensional Fourier transform on the first discrete intermediate frequency signal, and optionally also obtain the speed information of the moving target 2 by performing a two-dimensional Fourier transform on the second discrete intermediate frequency signal.

[0096] The above describes the operating principle of the improved millimeter wave radar, that is, the acceleration measurement and velocity measurement within a short time range are achieved by changing the time interval of the millimeter wave radar's transmission signal. Fig. 9 A flowchart showing a method for lane change assistance for a vehicle according to an exemplary embodiment of the present application explains in detail the application of such a millimeter wave radar 10 in a lane change assistance process of the vehicle.

[0097] like Fig. 9 As shown, the method for lane change assistance for a vehicle may include steps S1' to S3'. In step S1', when a moving target 2 is detected in the rear blind spot of the vehicle 1, the lane change intention of the driver of the vehicle 1 is monitored. In the current embodiment of the present application, the vehicle 1 refers to a vehicle with an assisted driving system of level L2 or above, and the assisted driving system particularly has an assisted lane change function. The present application is to improve the assisted lane change function of the assisted driving system.

[0098] In the meaning of this application, "the rear blind spot of the vehicle" means the area behind the vehicle 1 that the driver of the vehicle 1 cannot observe through the rearview mirror of the vehicle 1 during driving, especially including the rearview mirror blind spot of the vehicle 1, and optionally also including the extended area extending backward from the rearview mirror blind spot, considering that the rear vehicle in the extended area will quickly approach the vehicle 1 and enter the rearview mirror blind spot of the vehicle 1, and the distance range of the extended area is based on the ability to detect the moving target 2 and timely warn the driver to achieve a safe lane change. The moving target 2 in the rear blind spot of the vehicle 1 can be detected by the blind spot detection module 101, which includes, for example, sensors such as a vehicle-mounted camera, a millimeter-wave radar, a laser radar and / or an ultrasonic radar. According to the operating principle of the above-mentioned millimeter-wave radar 10, the distance d of the moving target 2 relative to the millimeter-wave radar 10 can be calculated by formula 1, and based on the calculated distance d, it is determined whether the moving target is located in the rear blind spot of the vehicle 1.

[0099] During the lane change process of vehicle 1, there is a certain risk of collision between vehicle 1 and a moving target 2 located in the rear blind spot of vehicle 1. Therefore, when the moving target 2 in the rear blind spot of vehicle 1 is detected, a first-level alarm signal can be sent to the driver of vehicle 1 through the alarm module 106, and the driver's lane change intention can be monitored through the lane change intention monitoring module 102. Exemplarily, the driver's lane change intention can be monitored based on the state of the turn signal of vehicle 1 and / or the steering wheel angle. If the turn signal is turned on or the steering wheel angle is greater than a preset angle, the driver's lane change intention is detected. In the case where the driver's lane change intention is detected, a second-level alarm signal can also be sent to the driver of vehicle 1.

[0100] In step S2', when the driver's intention to change lanes is detected, the acceleration information of the moving target 2 is obtained through steps S1 to S3 of the method according to the present application, and the speed information of the moving target 2 is obtained through steps S4 to S6 of the method according to the present application. Here, the speed measurement advantage of the millimeter wave radar is fully utilized, and the acceleration measurement within a short time range is realized by changing the time interval of the transmission signal of the millimeter wave radar, so as to measure the speed information and acceleration information of the rear vehicle in the blind spot of the vehicle's field of view in real time and accurately.

[0101] In step S3', the collision risk between the vehicle 1 and the moving object 2 is evaluated based on at least the speed information of the vehicle 1 and the acceleration information and speed information of the moving object 2, and a lane change instruction message is sent to the driver based on at least the evaluated collision risk. Here, the acceleration of the moving object 2 can be detected periodically by the millimeter wave transmission, and the collision risk between the vehicle 1 and the moving object 2 can be evaluated, for example, with the aid of the Ackerman steering model, so as to guide the driver to complete the lane change safely. Fig.10 The illustrated workflow diagram of a method for lane change assistance for a vehicle according to another exemplary embodiment of the present application explains step S3 ′ in detail.

[0102] like Fig.10 As shown, the step S3' may include steps S31' to S35'. In step S31', when the acceleration of the moving target 2 continues to decrease within the millimeter wave transmission cycle exceeding the preset frame number N (e.g., 5 frames) - that is, the rear vehicle has been continuously decelerating - the first time t1 and the first longitudinal driving distance X1 required for the vehicle 1 to complete the lane change are obtained by using the Ackerman steering model at least based on the speed information of the vehicle 1. Here, the preset frame number N of the millimeter wave transmission cycle can be adjusted based on the aggressiveness of the driver's lane change strategy, wherein the more aggressive the driver's lane change strategy is, the smaller the preset frame number N of the millimeter wave transmission cycle is.

[0103] exist Fig.11 The driving scene diagram according to another embodiment of the present application shows the position of vehicle 1 before changing lanes and after completing the lane change. L represents the wheelbase of vehicle 1, and w represents the width of a single lane, which can be obtained by performing image recognition on the road surface image obtained by the on-board camera, or can be obtained from a high-precision map based on the current position information. The speed information of vehicle 1 can be detected by the vehicle speed detection module 103, including the driving speed v1 of vehicle 1 detected by the wheel speed sensor and the inner wheel angle θ (i.e., the driving direction) detected by the steering wheel angle sensor. The turning radius R of vehicle 1 can be calculated based on the wheelbase L of vehicle 1 and the inner wheel angle θ. According to the Ackerman steering model, the angle θ′ that vehicle 1 needs to travel to complete the lane change process can be calculated by the following formula:

[0104]

[0105] The first longitudinal travel distance X1 and the first time t1 required for the vehicle 1 to complete the lane change can be calculated as follows:

[0106]

[0107] In step S32', the second longitudinal distance X2 traveled by the moving object 2 within the first time t1 is calculated based on the speed information and acceleration information of the moving object 2. In the first time t1, n frames of millimeter waves can be transmitted with a transmission period of T cycle For a linear frequency modulation signal, the frame number n is calculated as follows:

[0108] n=t1 / T cycle (Formula 9)

[0109] In order to simplify the calculation process, the driving process of the moving target 2 within the first time t1 is decomposed into n driving processes within each frame of millimeter wave transmission cycle, so that the second longitudinal driving distance X2 can be calculated as the sum of the distances traveled by the moving target 2 within each frame of millimeter wave transmission cycle:

[0110]

[0111] Among them, v i represents the velocity of the moving target 2 at the beginning of the millimeter wave transmission cycle in the i-th frame, a i Represents the acceleration of the moving target 2 during the i-th frame millimeter wave transmission period.

[0112] In step S33', it is determined whether the difference between the first longitudinal driving distance X1 and the second longitudinal driving distance X2 is greater than or equal to a preset safety distance threshold value X s , used to determine the lane change success rate of vehicle 1.

[0113] When the difference is greater than or equal to the preset safety distance threshold value X s In the case of the first lane change indication information on allowing the lane change operation can be sent to the driver of the vehicle 1 in step S34'. Here, a green lane change response can be displayed by the lane change indication module 105 to send the first lane change indication information on allowing the lane change operation to the driver of the vehicle 1, and the lane change indication module 105 is particularly configured as an on-board display, and the on-board display includes, for example, a head-up display, a central control display and / or an instrument panel.

[0114] When the difference is less than the preset safety distance threshold value X s In the case of the second lane change instruction information about stopping the lane change operation can be sent to the driver of the vehicle 1 in step S35'. Here, the lane change instruction module 105 can display a red lane change response to send the second lane change instruction information about stopping the lane change operation to the driver of the vehicle 1.

[0115] According to the present application, when a secondary alarm occurs in the assisted driving system, the lane change success rate of vehicle 1 is evaluated based on the speed information and acceleration information of the rear vehicle measured by the method for controlling the millimeter-wave radar according to the present application, and the corresponding lane change instruction information is displayed to the driver, thereby effectively improving the vehicle's lane change success rate and lane change safety, thereby enhancing the user experience of the assisted driving system.

[0116] In addition, it should be noted that the step numbers described herein do not necessarily represent a chronological order, but are merely a figure mark. The order can be changed according to specific circumstances as long as the technical purpose of the present application can be achieved.

[0117] Fig.12 1 shows a schematic block diagram of a lane change assistance system 100 according to an exemplary embodiment of the present application. Fig.12 As shown, the lane change assistance system 100 may include the following components:

[0118] - The millimeter wave radar 10 according to the present application;

[0119] - a blind spot detection module 101, which is configured to detect a moving target 2 in a rear blind spot of the vehicle 1;

[0120] A lane change intention monitoring module 102 configured to monitor the lane change intention of the driver of the vehicle 1;

[0121] - a vehicle speed detection module 103, which is configured to detect speed information of the vehicle 1, for example, including a wheel speed sensor for detecting the driving speed of the vehicle 1 and a steering wheel angle sensor for detecting the inner wheel angle θ (i.e., the driving direction) of the vehicle 1;

[0122] - a collision risk assessment module 104, which is configured to assess the collision risk between the vehicle 1 and the moving object 2 based at least on the speed information of the vehicle 1 and the acceleration information and speed information of the moving object 2, wherein the collision risk assessment module 104 is particularly configured with an Ackerman steering model; and

[0123] - A lane change indication module 105, which is configured to send lane change indication information to the driver at least based on the assessed collision risk, wherein the lane change indication module 105 is particularly configured as an on-board display, and the on-board display includes, for example, a head-up display, a central control display and / or an instrument panel.

[0124] Optionally, the lane change assist system 100 may further include an alarm module 106, which is configured to send a primary alarm signal to the driver of the vehicle 1 when a moving target 2 is detected in the rear blind spot of the vehicle 1, and to send a secondary alarm signal to the driver of the vehicle 1 when the driver's intention to change lanes is monitored.

[0125] Fig.13 1 shows a schematic block diagram of a vehicle 1 according to an exemplary embodiment of the present application. Fig.13 As shown, the vehicle 1 includes a lane change assistance system 100 according to the present application and / or a millimeter wave radar 10 according to the present application.

[0126] It should be understood that, in this document, the expressions "first", "second", "third", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance, nor should they be understood as implicitly indicating the number of the indicated technical features.

[0127] If an embodiment includes an “and / or” relationship between a first feature and a second feature, it should be interpreted as follows: according to one embodiment, the embodiment has both the first feature and the second feature, and according to another embodiment, the embodiment has either only the first feature or only the second feature.

[0128] Although specific embodiments have been described above, these embodiments are not intended to limit the scope of the present disclosure, even when only a single embodiment is described with respect to specific features. The feature examples provided in the present disclosure are intended to be illustrative, not restrictive, unless otherwise stated. In specific implementations, multiple features may be combined with each other, where technically feasible, according to actual needs. Various substitutions, changes, and modifications may also be conceived without departing from the spirit and scope of the present application.

Claims

1. A method for controlling a millimeter wave radar (10), the method comprising: Step S1: transmitting a first number of first linear frequency modulation signals at a first time interval T1 in each frame of millimeter wave transmission cycle, and receiving a first echo signal reflected by the first linear frequency modulation signal from a moving target (2), wherein the first time interval T1 is a linear function of time; Step S2: Mixing the first echo signal with the first linear frequency modulation signal to obtain a first intermediate frequency signal, and converting the first intermediate frequency signal into a first discrete intermediate frequency signal; and Step S3: Obtain acceleration information of the moving target (2) by performing a two-dimensional Fourier transform on the first discrete intermediate frequency signal.

2. The method according to claim 1, wherein: Two or more first linear frequency modulation signals are transmitted at the first time interval T1 in each frame millimeter wave transmission period.

3. The method according to claim 1 or 2, wherein: The method further comprises: Step S4: transmitting a second number of second linear frequency modulation signals at a second time interval T2 in each frame of the millimeter wave transmission cycle, and receiving a second echo signal reflected by the moving target (2) from the second linear frequency modulation signal, wherein the second time interval T2 is a predetermined constant; Step S5: mixing the second echo signal with the second linear frequency modulation signal to obtain a second intermediate frequency signal, and converting the second intermediate frequency signal into a second discrete intermediate frequency signal; and Step S6: Obtain the speed information of the moving target (2) by performing a two-dimensional Fourier transform on the second discrete intermediate frequency signal.

4. A millimeter wave radar (10), which is used to perform the method according to any one of claims 1 to 3, wherein: The millimeter wave radar (10) comprises the following components: A signal transmitting unit (11) configured to transmit a first number of first linear frequency modulation signals at a first time interval T1 in each frame of millimeter wave transmission cycle, wherein the first time interval T1 is a linear function of time; A signal receiving unit (12) configured to receive a first echo signal reflected by the first linear frequency modulation signal from a moving target (2); A frequency mixing unit (13), configured to perform frequency mixing processing on the first echo signal and the first linear frequency modulation signal to obtain a first intermediate frequency signal; an analog-to-digital conversion unit (14), configured to convert the first intermediate frequency signal into a first discrete intermediate frequency signal; and An intermediate frequency signal processing unit (15) is configured to obtain acceleration information of the moving target (2) by performing a two-dimensional Fourier transform on the first discrete intermediate frequency signal.

5. A method for lane change assistance for a vehicle (1), the method comprising: Step S1': when a moving target (2) is detected in a rear blind spot of the vehicle (1), monitoring the lane-changing intention of the driver of the vehicle (1); Step S2': when the driver's intention to change lanes is detected, the acceleration information of the moving object (2) is obtained by the method according to claim 1 or 2, and the speed information of the moving object (2) is obtained by the method according to claim 3; and Step S3': assessing the collision risk between the vehicle (1) and the moving object (2) based at least on the speed information of the vehicle (1) and the acceleration information and speed information of the moving object (2), and sending lane change instruction information to the driver based at least on the assessed collision risk.

6. The method according to claim 5, wherein: When a moving target (2) is detected in a rear blind spot of a vehicle (1), a first-level alarm signal is sent to the driver of the vehicle (1), and when the driver's intention to change lanes is monitored, a second-level alarm signal is sent to the driver of the vehicle (1), wherein the rear blind spot of the vehicle (1) includes a rearview mirror blind spot of the vehicle (1) and / or an extended area extending backward from the rearview mirror blind spot.

7. The method according to claim 5 or 6, wherein: The step S3' comprises: Step S31': when the acceleration of the moving target (2) continues to decrease within the millimeter wave transmission period exceeding the preset frame number N, at least based on the speed information of the vehicle (1) and using the Ackerman steering model, obtain the first time t1 and the first longitudinal driving distance X1 required for the vehicle (1) to complete the lane change; Step S32': calculating a second longitudinal travel distance X2 traveled by the moving object (2) within the first time t1 based on the speed information and acceleration information of the moving object (2); Step S33': Determine whether the difference between the first longitudinal driving distance X1 and the second longitudinal driving distance X2 is greater than or equal to a preset safety distance threshold value X s ; Step S34': When the difference is greater than or equal to the preset safety distance threshold value X s In the case of a lane change, sending first lane change instruction information regarding permission for a lane change operation to a driver of the vehicle (1); and Step S35': When the difference is less than the preset safety distance threshold value X s In the case of a vehicle (1), second lane change instruction information regarding stopping the lane change operation is sent to the driver of the vehicle (1).

8. The method according to claim 7, wherein: The preset frame number N of the millimeter wave transmission cycle is adjusted based on the aggressiveness of the driver's lane changing strategy, wherein the more aggressive the driver's lane changing strategy is, the smaller the preset frame number N of the millimeter wave transmission cycle is.

9. The method according to claim 7, wherein: A lane change indication module (105) displays a green lane change response to send a first lane change indication message about allowing a lane change operation to a driver of the vehicle (1), and / or a lane change indication module (105) displays a red lane change response to send a second lane change indication message about stopping the lane change operation to the driver of the vehicle (1), wherein the lane change indication module (105) is configured as an on-board display, and the on-board display includes a head-up display, a central control display and / or an instrument panel.

10. A lane change assistance system (100), for executing the method according to any one of claims 5 to 9, wherein: The lane change assistance system (100) comprises the following components: The millimeter wave radar (10) according to claim 4; A blind spot detection module (101) configured to detect a moving target object (2) in a rear blind spot of a vehicle (1); a lane change intention monitoring module (102) configured to monitor the lane change intention of the driver of the vehicle (1); A vehicle speed detection module (103), which is configured to detect speed information of the vehicle (1); A collision risk assessment module (104) configured to assess the collision risk between the vehicle (1) and the moving object (2) based at least on the speed information of the vehicle (1) and the acceleration information and speed information of the moving object (2); and A lane change indication module (105) is configured to send lane change indication information to the driver based at least on the assessed collision risk.

11. The lane change assistance system (100) according to claim 10, wherein: The lane change assistance system (100) further comprises an alarm module (106) configured to send a primary alarm signal to the driver of the vehicle (1) when a moving target (2) is detected in a rear blind spot of the vehicle (1), and to send a secondary alarm signal to the driver of the vehicle (1) when the driver's intention to change lanes is detected.

12. A vehicle (1), comprising the lane change assistance system (100) according to claim 10 or 11 and / or the millimeter wave radar (10) according to claim 4.

13. A computer program product, such as a computer-readable program carrier, comprising or storing computer program instructions, which, when executed by a processor, at least assist in implementing the steps of the method according to any one of claims 1 to 3 and 5 to 9.

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