Method for rear collision early warning processing of vehicle, auxiliary driving system, vehicle and computer program product

Abstract

The present application relates to a method for rear collision early warning processing of a vehicle, comprising: detecting motion state information of a rear target object (2) located on the same lane as a vehicle (1), the motion state information comprising acceleration information and speed information and distance information between the rear target object and the vehicle (S1); evaluating a risk of collision between the vehicle and the rear target on the basis of the motion state information of the vehicle and the motion state information of the rear target (S2); and if there is a risk of collision between the vehicle and the rear target object, detecting motion state information of the surrounding target object within a predetermined distance range from the vehicle, and controlling a running state of the vehicle at least based on the motion state information of the surrounding target object to prevent collision between the vehicle and the rear target object (S3). According to the invention, the active avoidance function of the auxiliary driving system can be optimized, the occurrence of rear collision accidents is effectively reduced, and the driving experience and safety of a user are improved.

Description

Technical Field

[0001] The present application relates to the field of assisted driving, and in particular to a method for rear-end collision warning processing for a vehicle, an assisted driving system, a vehicle including the assisted driving system 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] In current vehicles, only one millimeter-wave radar is usually installed at each of the two rear corners of the vehicle body to detect the driving environment information of the adjacent lane on the corresponding side. Figure 1 The following is a schematic diagram of the detection range of the lateral millimeter-wave radar according to the prior art. The two lateral millimeter-wave radars 113 and 114 are respectively installed at the rear corners of the left and right sides of the vehicle body to detect the driving environment information of the left adjacent lane and the right adjacent lane respectively. As shown in the detection range of the lateral millimeter-wave radars 113 and 114 marked by dotted lines, the two lateral millimeter-wave radars 113 and 114 cannot detect the radar blind area B (at the rear of the vehicle 1) behind the rear body. Figure 1 Considering that the current assisted driving systems are usually designed for normal driving behavior, the rear vehicle 2 that is accelerating and approaching the vehicle 1 from behind the vehicle 1 cannot be detected in time by the vehicle 1 because it is in the radar blind spot B, which leads to a rear-end collision between the rear vehicle 2 and the vehicle 1.

[0003] Therefore, how to avoid rear collision of the rear vehicle as much as possible has become a technical problem that needs to be solved. Summary of the invention

[0004] The purpose of the present application is to provide a method for rear-end collision warning processing for a vehicle, an assisted driving system, a vehicle including the assisted driving system 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 rear collision warning processing of a vehicle is provided, the method comprising:

[0006] - Step S1: Detecting motion state information of a target object behind the vehicle in the same lane as the vehicle, wherein the motion state information includes acceleration information and speed information as well as distance information between the target object behind the vehicle;

[0007] - Step S2: evaluating the collision risk between the vehicle and the rear target based on the motion state information of the vehicle and the motion state information of the rear target; and

[0008] - Step S3: in the case where there is a risk of collision between the vehicle and the rear target, detecting motion state information of surrounding targets within a predetermined distance range from the vehicle, and controlling the running state of the vehicle at least based on the motion state information of the surrounding targets,

[0009] Used to prevent the vehicle from colliding with the rear target.

[0010] The core concept of the present application includes at least: using a new control method of millimeter-wave radar to measure the motion state information of the rear target in the same lane in real time and accurately - including acceleration information, speed information and distance information, thereby evaluating the collision risk between the vehicle and the rear target, and obtaining the motion state information of the vehicle's surrounding targets when there is a collision risk, thereby determining whether the vehicle should accelerate forward, change lanes, or issue an alarm, thereby optimizing the active avoidance function of the assisted driving system, effectively reducing the occurrence of rear collision accidents, and improving the user's driving experience and safety.

[0011] According to an optional embodiment of the present application, step S1 may include:

[0012] - Step S11: 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 rear target object after the first linear frequency modulation signal is received, wherein the rear target object and the vehicle are located in the same lane, and the first time interval T1 is a linear function of time;

[0013] - Step S12: 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

[0014] - Step S13: Obtain acceleration information of the rear target object by performing a two-dimensional Fourier transform on the first discrete intermediate frequency signal.

[0015] According to another optional embodiment of the present application, two or more first linear frequency modulation signals may be transmitted at the first time interval T1 in each frame of millimeter wave transmission period.

[0016] According to another optional embodiment of the present application, step S1 may further include:

[0017] - Step S14: 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 target object behind, wherein the second time interval T2 is a predetermined constant;

[0018] - Step S15: 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;

[0019] - Step S16: Obtaining the speed information of the rear target object by performing a two-dimensional Fourier transform on the second discrete intermediate frequency signal; and

[0020] -Step S17: Calculate the distance information between the rear target object and the vehicle based on at least the time difference between the first linear frequency modulation signal and the first echo signal, and / or calculate the distance information between the rear target object and the vehicle based on at least the time difference between the second linear frequency modulation signal and the second echo signal.

[0021] According to another optional embodiment of the present application, the collision risk between the vehicle and the rear target may be evaluated based at least on the speed difference Δv, the acceleration difference Δa, and the distance d between the vehicle and the rear target, wherein it is evaluated that there is a collision risk between the vehicle and the rear target when the following formula is satisfied:

[0022]

[0023] Among them, T s Indicates a predetermined duration threshold.

[0024] According to another optional embodiment of the present application, step S3 may include:

[0025] - Step S31: When there is a risk of collision between the vehicle and the rear target, it can be detected whether there is a front target within a predetermined distance range in front of the vehicle;

[0026] - Step S32: When there is no target object in front of the vehicle within a predetermined distance range, the vehicle may be controlled to accelerate forward until the following formula is satisfied:

[0027]

[0028] Among them, T s Indicates a predetermined duration threshold;

[0029] - Step S33: When there is a target object in front of the vehicle within a predetermined distance range, or when the vehicle accelerates for a predetermined time threshold t and still does not satisfy the formula In the case of a vehicle, acceleration information and speed information of a side rear target object in a rear blind spot of the vehicle can be detected, wherein the rear blind spot of the vehicle includes a rearview mirror blind spot of the vehicle and / or an extended area extending rearward from the rearview mirror blind spot; and

[0030] -Step S34: evaluating the collision risk between the vehicle and the side rear target at least based on the speed information of the vehicle and the acceleration information and speed information of the side rear target, and controlling the operating state of the vehicle at least based on the evaluated collision risk to prevent the vehicle from colliding with the rear target.

[0031] According to another optional embodiment of the present application, step S33 may include:

[0032] - Step S331: transmitting a third number of third linear frequency modulation signals at a third time interval T3 in each frame of millimeter wave transmission cycle, and receiving a third echo signal of the third linear frequency modulation signal reflected by a target object at the rear side, wherein the rear blind spot of the vehicle includes a rearview mirror blind spot of the vehicle and / or an extended area extending backward from the rearview mirror blind spot, and the third time interval T3 is a linear function of time;

[0033] - Step S332: Mixing the third echo signal with the third linear frequency modulation signal to obtain a third intermediate frequency signal, and converting the third intermediate frequency signal into a third discrete intermediate frequency signal; and

[0034] - Step S333: Obtain acceleration information of the side rear target object by performing a two-dimensional Fourier transform on the third discrete intermediate frequency signal.

[0035] According to another optional embodiment of the present application, step S33 may further include:

[0036] - Step S334: transmitting a fourth number of fourth linear frequency modulation signals at a fourth time interval T4 in each frame of the millimeter wave transmission cycle, and receiving a fourth echo signal of the fourth linear frequency modulation signal reflected by a target object at the side and rear, wherein the fourth time interval T4 is a predetermined constant;

[0037] - Step S335: Mixing the fourth echo signal with the fourth linear frequency modulation signal to obtain a fourth intermediate frequency signal, and converting the fourth intermediate frequency signal into a fourth discrete intermediate frequency signal; and

[0038] - Step S336: Obtain the speed information of the side rear target by performing a two-dimensional Fourier transform on the fourth discrete intermediate frequency signal.

[0039] According to another optional embodiment of the present application, step S34 may include:

[0040] - Step S341: when the acceleration of the target object behind the side 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 using the Ackerman steering model at least based on the speed information of the vehicle;

[0041] - Step S342: Calculating a second longitudinal travel distance X2 traveled by the side rear object within the first time t1 based on the speed information and acceleration information of the side rear object;

[0042] -Step S343: 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 ;

[0043] -Step S344: When the difference is greater than or equal to the preset safety distance threshold value X s , assessing that there is no risk of collision between the side rear target and the vehicle, and controlling the vehicle to change lanes and drive into the lane where the side rear target is located; and

[0044] -Step S345: when the difference is less than the preset safety distance threshold value X s In the case of a collision between the side rear target and the vehicle, the vehicle is controlled to send an alarm message to the rear target to prompt the rear target to slow down or maintain a safe distance.

[0045] According to another optional embodiment of the present application, the side rear target may include a left rear target in the left blind spot of the vehicle and / or a right rear target in the right blind spot of the vehicle, wherein, when there is no risk of collision between the vehicle and the left rear target, the vehicle can be controlled to change lanes and drive into the left adjacent lane, and / or when there is no risk of collision between the vehicle and the right rear target, the vehicle can be controlled to change lanes and drive into the right adjacent lane, and / or when there is a risk of collision between the vehicle and both the left rear target and the right rear target, the vehicle can be controlled to send an alarm message to the rear target to prompt the rear target to slow down or maintain a safe distance.

[0046] According to another optional 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.

[0047] According to a second aspect of the present application, an assisted driving system is provided, and the assisted driving system may include:

[0048] - a millimeter wave radar configured to detect motion state information of surrounding targets of the vehicle, wherein the motion state information includes acceleration information and velocity information of the surrounding targets and distance information between the surrounding targets and the vehicle; and

[0049] - A control unit configured to perform the method according to the application.

[0050] According to another optional embodiment of the present application, the assisted driving system may further include a rear collision warning unit, which is configured to control the vehicle to send an alarm message to the rear target when there is a risk of collision between the vehicle and the side rear target, so as to prompt the rear target to slow down or maintain a safe distance, wherein the rear collision warning unit includes, for example, double flash lights.

[0051] According to another optional embodiment of the present application, the millimeter wave radar may include:

[0052] - at least one rear-facing millimeter-wave radar configured to detect acceleration information, speed information, and distance information between a rear target object located in the same lane as the vehicle and the vehicle; and / or

[0053] - a forward millimeter-wave radar configured to detect whether there is a forward target within a predetermined distance range in front of the vehicle; and / or

[0054] - A side rear millimeter wave radar configured to detect acceleration information and speed information of a side rear target object in a rear blind spot of the vehicle.

[0055] According to a third aspect of the present application, a vehicle is provided, which may include an assisted driving system according to the present application.

[0056] According to a fourth 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

[0057] 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:

[0058] Figure 1 A schematic diagram showing the detection range of a lateral millimeter wave radar according to the prior art is shown;

[0059] Figure 2 A flowchart showing a method for rear collision warning processing of a vehicle according to an exemplary embodiment of the present application is shown;

[0060] Figure 3 A schematic diagram of a vehicle driving scenario according to an exemplary embodiment of the present application is shown;

[0061] Figure 4 A flowchart showing a method for rear collision warning processing of a vehicle according to another exemplary embodiment of the present application is shown;

[0062] Figure 5 A graph showing the relationship between the time interval of a millimeter wave radar transmitting signal and time according to the prior art;

[0063] Figure 6 A frequency-time relationship diagram of a transmission signal of a millimeter-wave radar according to the prior art is shown;

[0064] Figure 7 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;

[0065] Figure 8 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;

[0066] Fig. 9 A flowchart showing a method for rear collision warning processing of a vehicle according to another exemplary embodiment of the present application is shown;

[0067] Fig.10 A workflow diagram of step S33 according to another exemplary embodiment of the present application is shown;

[0068] Fig.11 A flowchart showing step S34 according to another exemplary embodiment of the present application is shown;

[0069] Fig.12 A driving scene diagram according to another exemplary embodiment of the present application is shown; and

[0070] Fig.13 A schematic block diagram of an assisted driving system according to an exemplary embodiment of the present application is shown. DETAILED DESCRIPTION

[0071] 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.

[0072] Figure 2 The following is a flowchart of a method for rear collision warning processing of a vehicle according to an exemplary embodiment of the present application. The following exemplary embodiments describe the method according to the present application in more detail.

[0073] like Figure 2 As shown, the method may include steps S1 to S3. In step S1, the motion state information of the rear target object 2 located in the same lane as the vehicle 1 may be detected, wherein the motion state information may include acceleration information and speed information as well as distance information between the rear target object 2 and the vehicle 1. In the current embodiment of the present application, the vehicle 1 is especially a vehicle equipped with an assisted driving system 10 of level L2 or above, and the assisted driving system 10 is especially equipped with an active avoidance function, and the present application is to improve the active avoidance function of the assisted driving system 10. At least four millimeter-wave radars may be installed in the vehicle 1, which are configured to detect the motion state information of the surrounding targets in different directions of the vehicle 1, wherein the motion state information may include acceleration information and speed information of the surrounding targets as well as distance information between the surrounding targets and the vehicle 1, etc.

[0074] like Figure 3 The schematic diagram of a vehicle driving scene according to an exemplary embodiment of the present application is shown. At least one rear-facing millimeter-wave radar 111 may be installed on the rear side of the vehicle 1, which is configured to detect the motion state information of a rear target 2 located in the same lane as the vehicle 1, wherein the motion state information may include acceleration information and speed information of the rear target 2 and distance information between the rear target 2 and the vehicle 1. The rear target 2 may include, for example, a vehicle or motorcycle traveling behind the vehicle 1 in the same lane. Figure 3 The figure shows by way of example a rearward millimeter-wave radar 111 installed on the left side of the rear body of the vehicle 1 and a rearward millimeter-wave radar 111 installed on the right side. As shown in the detection range of the millimeter-wave radars 111, 113, and 114 marked with dotted lines, most of the radar blind spots of these two lateral millimeter-wave radars 113 and 114 directly behind the rear body of the vehicle 1 can be covered by the detection range of these two rearward millimeter-wave radars 111, thereby minimizing the radar blind spot directly behind the vehicle 1.

[0075] Next, combine Figure 4 The workflow diagram showing a method for rear collision warning processing of a vehicle according to another exemplary embodiment of the present application elaborates on the detection process of the motion state information of the rear target 2 by the rearward millimeter wave radar 111 .

[0076] like Figure 4As shown, step S1 may include steps S11 to S17. In the prior art, millimeter wave radar uses millimeter waves as electromagnetic waves to send signals, and can obtain information such as the distance, speed, azimuth and / or height of the target by capturing and processing the echo signal reflected by the target, but it is still unable to measure the acceleration of the moving target in real time, but 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 target 2 accelerates, and it is difficult to provide reliable and effective support for the assisted driving system 10. The present application proposes a new control method for millimeter wave radar, which is used to measure the acceleration of a moving target in real time and accurately.

[0077] In step S11, a first number of first linear frequency modulation signals are transmitted at a first time interval T1 in each frame of millimeter wave transmission cycle, and a first echo signal reflected by the first linear frequency modulation signal from the rear target 2 is received, wherein the rear target 2 and the vehicle 1 are located in the same lane, and the first time interval T1 is a linear function of time. In the meaning of the present application, a "linear frequency modulation signal (Chirp)" refers to a signal whose frequency continuously changes linearly within the radar signal cycle, 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.

[0078] In the prior art, the time interval T for the millimeter wave radar to transmit the linear frequency modulation signal is always equal. Figure 5 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 6 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.

[0079] 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 6 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 S 10 That is the first linear frequency modulation signal. Figure 7 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.

[0080] exist Figure 3 In the driving scene diagram according to an exemplary embodiment of the present application, a first linear frequency modulation signal transmitted by the signal transmitting unit of the rear millimeter-wave radar 111 is reflected by the rear target object 2 (here, a moving rear vehicle) located in the same lane as the vehicle 1, and is received as a first echo signal by the signal receiving unit of the rear millimeter-wave radar 111.

[0081] In step S12, 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 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, that is, the first discrete intermediate frequency signal is obtained.

[0082] In step S13, the acceleration information of the rear 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 rear target 2 can be used to obtain the acceleration information of the rear target 2. d and the electromagnetic wave propagation speed c to calculate the distance d of the rear target 2 relative to the rearward millimeter-wave radar 111, which is expressed as:

[0083] d=t d c / 2 (Formula 1)

[0084] Therefore, the frequency f of the linear frequency modulation signal c It can be expressed as follows:

[0085] f c =2dk / c (Formula 2)

[0086] Therefore, the distance information of the target 2 behind 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:

[0087]

[0088] 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.

[0089] Therefore, the velocity v of the target object 2 behind can be calculated as

[0090]

[0091] 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 rear target 2 can be calculated as:

[0092]

[0093] In the embodiment of steps S11 to S13, the time interval of the transmission signal of the millimeter-wave radar is changed to give the radar point cloud data acceleration measurement information, thereby realizing the measurement of the acceleration information of the moving target within a short time range, especially the acceleration of the rear target traveling in the same lane as the vehicle 1 can be measured in real time and accurately, laying the foundation for optimizing various auxiliary driving functions of the vehicle, especially the active avoidance function.

[0094] The step S1 may further include steps S14 to S16, for determining the speed information of the rear target object 2. In step S14, 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 rear target object 2 of the second linear frequency modulation signal is received, wherein the second time interval T2 is a predetermined constant.

[0095] like Figure 8The 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 7 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 .

[0096] In step S15, 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 the mixing unit 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, that is, a second discrete intermediate frequency signal is obtained.

[0097] In step S16, the speed information of the rear target object 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 rear target 2 can be calculated as

[0098]

[0099] Here, the second time interval T2 is equal to the predetermined constant T c , thereby the speed information of the target object 2 behind can be obtained quickly and accurately.

[0100] The step S1 may further include a step S17. In step S17, the distance information between the rear target object 2 and the vehicle 1 is calculated based on at least the time difference between the first linear frequency modulation signal and the first echo signal, and / or the distance information between the rear target object 2 and the vehicle 1 is calculated based on at least the time difference between the second linear frequency modulation signal and the second echo 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 rear target object 2 can be used to calculate the distance information between the rear target object 2 and the vehicle 1. dand the electromagnetic wave propagation speed c to calculate the distance d of the rear target object 2 relative to the rear millimeter-wave radar 111, which can be considered to be approximately equal to the distance from the rear target object 2 to the vehicle 1, and its expression is:

[0101] d=t d c / 2 (Formula 1)

[0102] The above describes a novel control method for the millimeter wave radar used in step S1, which measures the motion state information of the rear target 2 within a short time range by changing the time interval of the transmission signal of the millimeter wave radar, including acceleration measurement, speed measurement and distance measurement.

[0103] In step S2, the collision risk between the vehicle 1 and the rear target 2 can be evaluated based on the motion state information of the vehicle 1 and the motion state information of the rear target 2. Here, "collision risk" is used to characterize the possibility of collision between the vehicle 1 and the rear target 2. Specifically, the collision risk between the vehicle 1 and the rear target 2 can be evaluated based on at least the speed difference Δv, the acceleration difference Δa and the distance d between the vehicle 1 and the rear target 2, wherein, if the following formula is satisfied, it means that the rear target 2 is accelerating and will collide with the rear target 2 within a time period T s If a rear-end collision occurs with the vehicle 1, it can be assessed that there is a risk of collision between the vehicle 1 and the rear target object 2:

[0104]

[0105] Among them, T s represents a predetermined time threshold, which can be set to 30 seconds or 60 seconds, for example.

[0106] In step S3, when there is a risk of collision between the vehicle 1 and the rear target 2, the motion state information of the surrounding targets within a predetermined distance from the vehicle 1 can be detected, and the running state of the vehicle 1 can be controlled based on at least the motion state information of the surrounding targets to prevent the vehicle 1 from colliding with the rear target 2. Figure 3 In the schematic diagram of vehicle driving scene shown, the surrounding targets may include not only the rear target 2 located in the same lane as the vehicle 1, but also the front target 3 located in the same lane as the vehicle 1 within a predetermined distance range in front of the vehicle 1, and optionally may also include the side rear targets 4 and 5 in the adjacent lanes of the lane where the vehicle 1 is located. According to different driving scenes, the operating state of the controlled vehicle 1 may include accelerating forward, changing lanes and / or warning prompts, etc., so as to avoid collision accidents with the rear target 2 as much as possible.

[0107] Next, the control process of the operating state of the vehicle 1 is described in detail in combination with different embodiments. Fig. 9 The following is a flowchart of a method for rear collision warning processing of a vehicle according to another exemplary embodiment of the present application. Figure 2 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.

[0108] The step S3 may include steps S31 to S34. In step S31, when there is a risk of collision between the vehicle 1 and the rear target 2, it may be detected whether there is a front target 3 within a predetermined distance range in front of the vehicle 1. Figure 3 As shown, a forward millimeter-wave radar 112 may be installed on the front side of the vehicle 1, which is configured to detect whether there is a front target 3 within a predetermined distance range in front of the vehicle 1. Alternatively, a vehicle-mounted camera and / or a laser radar installed on the front side of the vehicle 1 may be used to detect whether there is a front target 3 within a predetermined distance range in front of the vehicle 1.

[0109] In step S32, when there is no target object 3 in front of the vehicle 1 within a predetermined distance range, the vehicle 1 may be controlled to accelerate forward until the following formula is satisfied and then the acceleration is stopped:

[0110]

[0111] Among them, T s represents a predetermined time threshold, which means that the target object 2 behind is within the time T s The vehicle 1 will not be overtaken by the vehicle 1, and the risk of rear collision with the rear target object 2 is avoided.

[0112] In step S33, when there is a front target object 3 within a predetermined distance range in front of the vehicle 1, or when the vehicle 1 accelerates for the predetermined time threshold t and still does not satisfy Formula 7, which means that the vehicle 1 cannot escape the risk of collision with the rear target object 2 by accelerating forward, the acceleration information and speed information of the side rear targets in the rear blind spot of the vehicle 1, including the left rear target object 4 in the left blind spot of the vehicle 1 and / or the right rear target object 5 in the right blind spot of the vehicle 1, can be detected, wherein the rear blind spot of the vehicle 1 can include the rearview mirror blind spot of the vehicle and / or an extended area extending backward from the rearview mirror blind spot.

[0113] like Figure 3In the schematic diagram of the vehicle driving scene shown, a left-side millimeter-wave radar 113 and a right-side millimeter-wave radar 114 are respectively installed at the rear corners on the left and right sides of the body of the vehicle 1, which are used to detect the acceleration information and speed information of the side rear targets in the rear blind spot of the vehicle 1. 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 side rear targets in the extended area will quickly approach the vehicle 1 and enter the rearview mirror blind spot of the vehicle 1. The distance range of the extended area is based on the ability to detect the left rear target 4 or the right rear target 5 and timely warn the driver to achieve a safe lane change.

[0114] Here, the acceleration information and speed information of the side and rear targets 4 and 5 can also be measured in real time and accurately by means of the novel control method of the millimeter wave radar described above, and the detection process is similar to the process of detecting the acceleration information and speed information of the rear target 2 by the rear millimeter wave radar 111 described above. Fig.10 A workflow diagram of step S33 according to another exemplary embodiment of the present application is shown, and step S33 may include steps S331 to S336.

[0115] In step S331, a third number of third linear frequency modulation signals are respectively transmitted at a third time interval T3 in each frame of millimeter wave transmission cycle, and a third echo signal of the third linear frequency modulation signal reflected by the side rear target is received, wherein the rear blind spot of the vehicle 1 includes the rearview mirror blind spot of the vehicle 1 and / or the extended area extending backward from the rearview mirror blind spot, and the third time interval T3 is a linear function of time. Here, two or more third linear frequency modulation signals can be respectively transmitted at the third time interval T3 in each frame of millimeter wave transmission cycle. In step S332, the third echo signal is mixed with the third linear frequency modulation signal to obtain a third intermediate frequency signal, and the third intermediate frequency signal is converted into a third discrete intermediate frequency signal. In step S333, the acceleration information of the side rear targets 4 and 5 can be obtained by performing a two-dimensional Fourier transform on the third discrete intermediate frequency signal.

[0116] In step S334, a fourth number of fourth linear frequency modulation signals are transmitted at a fourth time interval T4 in each frame of the millimeter wave transmission cycle, and a fourth echo signal reflected by the fourth linear frequency modulation signal from the side and rear target is received, wherein the fourth time interval T4 is a predetermined constant. In step S335, the fourth echo signal is mixed with the fourth linear frequency modulation signal to obtain a fourth intermediate frequency signal, and the fourth intermediate frequency signal is converted into a fourth discrete intermediate frequency signal. In step S336, the velocity information of the side and rear targets 4 and 5 is obtained by performing a two-dimensional Fourier transform on the fourth discrete intermediate frequency signal.

[0117] Here, the speed measurement advantage of millimeter-wave radar is fully utilized, and the acceleration measurement within a short time range is realized by changing the time interval of the millimeter-wave radar's transmission signal, so as to measure the speed information and acceleration information of the side and rear targets in the blind spot of the vehicle's field of view in real time and accurately.

[0118] Next, in step S34, the collision risk between the vehicle 1 and the rear target is evaluated based at least on the speed information of the vehicle 1 and the acceleration information and speed information of the rear target, and the running state of the vehicle 1 is controlled based at least on the evaluated collision risk to prevent the vehicle 1 from colliding with the rear target 2. Here, the speed information of the vehicle 1 can be obtained through the wheel speed sensor of the vehicle 1, and the acceleration of the rear targets 4 and 5 can be detected periodically by millimeter wave transmission, and the collision risk between the vehicle 1 and the rear targets 4 and 5 can be evaluated, for example, with the help of the Ackerman steering model, so as to determine whether the vehicle 1 can change lanes to an adjacent lane and to which adjacent lane the vehicle 1 can change lanes.

[0119] like Fig.11 The flowchart of step S34 according to another exemplary embodiment of the present application is shown, and the step S34 may include steps S341 to S345. In step S341, when the acceleration of the side rear target object continues to decrease within the millimeter wave transmission cycle exceeding the preset frame number N (for example, 5 frames) - that is, the side rear target object 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 can be obtained based on at least the speed information of the vehicle 1, for example, with the help of the Ackerman steering model. 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.

[0120] exist Fig.12The driving scene diagram according to another embodiment of the present application shown 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 driving speed v1 of vehicle 1 can be detected by a wheel speed sensor, and the inner wheel turning angle θ (which corresponds to the driving direction) of vehicle 1 can be detected by a 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 turning 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:

[0121]

[0122] 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:

[0123]

[0124]

[0125] In step S342, the second longitudinal distance X2 traveled by the side rear target within the first time t1 is calculated based on the speed information and acceleration information of the side rear target. cycle For a linear frequency modulation signal, the frame number n is calculated as follows:

[0126] n=t1 / T cycle (Formula 11)

[0127] In order to simplify the calculation process, the driving process of the target object at the rear side 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 target object at the rear side within each frame of millimeter wave transmission cycle:

[0128]

[0129] Among them, v i represents the velocity of the target object at the beginning of the millimeter wave transmission cycle in the i-th frame, a i It represents the acceleration of the target object at the side and rear during the millimeter wave transmission period of the i-th frame.

[0130] In step S343, 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 the vehicle 1 toward the adjacent lane on the corresponding side. When the difference is greater than or equal to the preset safety distance threshold value X s In the case of , in step S344, it can be assessed that there is no risk of collision between the side rear target and the vehicle, and the vehicle 1 is controlled to change lanes and drive into the lane where the side rear target is located, thereby avoiding a rear collision accident with the rear target 2. Figure 3 In the driving scenario shown, when there is no risk of collision between the vehicle 1 and the left rear target 4, the vehicle 1 can be controlled to change lanes into the left adjacent lane, and / or when there is no risk of collision between the vehicle 1 and the right rear target 5, the vehicle 1 can be controlled to change lanes into the right adjacent lane.

[0131] When the difference is less than the preset safety distance threshold value X s In this case, in step S345, it can be assessed that there is a risk of collision between the side rear target and the vehicle 1 - that is, there is a risk of collision between the vehicle 1 and both the left rear target 4 and the right rear target 5, which means that the vehicle 1 cannot change lanes to the adjacent lanes on the left or right sides for active avoidance, thereby controlling the vehicle 1 to send an alarm message to the rear target 2 - for example, turning on the hazard lights of the vehicle 1 to prompt the rear target 2 to slow down or maintain a safe distance.

[0132] According to the present application, a new control method using millimeter-wave radar is used to measure the motion state information of the rear target in the same lane in real time and accurately, including acceleration information, speed information and distance information, thereby evaluating the collision risk between the vehicle and the rear target, and obtaining the motion state information of the vehicle's surrounding targets when there is a collision risk, thereby determining whether the vehicle should accelerate forward, change lanes, or issue an alarm, thereby optimizing the active avoidance function of the assisted driving system, effectively reducing the occurrence of rear collision accidents, and improving the user's driving experience and safety.

[0133] 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.

[0134] Fig.13 A schematic block diagram of an auxiliary driving system 10 according to an exemplary embodiment of the present application is shown.

[0135] like Fig.13 As shown, the driver assistance system 10 is constructed in the vehicle 1, and can especially perform an active avoidance function. The driver assistance system 10 may include:

[0136] - a millimeter wave radar configured to detect motion state information of surrounding targets of the vehicle 1, wherein the motion state information may include acceleration information and speed information of the surrounding targets and distance information between the surrounding targets and the vehicle 1;

[0137] A control unit 12 configured to carry out the method according to the present application.

[0138] Exemplarily, the assisted driving system 10 may include at least one rear millimeter-wave radar 111, which is configured to detect acceleration information, speed information of a rear target 2 located in the same lane as the vehicle 1, and distance information between the rear target 2 and the vehicle 1. Optionally, the assisted driving system 10 may also include a forward millimeter-wave radar 112, which is configured to detect whether there is a front target 3 within a predetermined distance range in front of the vehicle 1. Optionally, the assisted driving system 10 may also include side and rear millimeter-wave radars 113 and 114, which are configured to detect acceleration information and speed information of side and rear targets 4 and 5 in the rear blind spot of the vehicle 1.

[0139] Optionally, the assisted driving system 10 may also include a rear collision warning unit 13, which is configured to control the vehicle 1 to send an alarm message to the rear target 2 when there is a risk of collision between the vehicle 1 and the side and rear targets 4 and 5, so as to prompt the rear target 2 to slow down or maintain a safe distance, wherein the rear collision warning unit 13 includes, for example, double flash lights.

[0140] 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.

[0141] 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.

[0142] 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 rear collision warning processing of a vehicle (1), the method comprising: Step S1: Detecting motion state information of a rear target object (2) located in the same lane as the vehicle (1), wherein the motion state information includes acceleration information and speed information as well as distance information between the rear target object (2) and the vehicle (1); Step S2: evaluating the collision risk between the vehicle (1) and the rear target object (2) based on the motion state information of the vehicle (1) and the motion state information of the rear target object (2); and Step S3: When there is a risk of collision between the vehicle (1) and the target object (2) behind, detecting the motion state information of the surrounding targets within a predetermined distance range from the vehicle (1), and controlling the running state of the vehicle (1) at least based on the motion state information of the surrounding targets, so as to prevent the vehicle (1) from colliding with the target object (2) behind.

2. The method according to claim 1, wherein: The step S1 comprises: Step S11: 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 rear target object (2), wherein the rear target object (2) and the vehicle (1) are located in the same lane, and the first time interval T1 is a linear function of time; Step S12: 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 S13: Obtain acceleration information of the rear target object (2) by performing a two-dimensional Fourier transform on the first discrete intermediate frequency signal.

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

4. The method according to claim 2, wherein: The step S1 further comprises: Step S14: 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 rear target object (2), wherein the second time interval T2 is a predetermined constant; Step S15: 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; Step S16: performing a two-dimensional Fourier transform on the second discrete intermediate frequency signal to obtain the speed information of the rear target object (2); and Step S17: Calculate the distance information between the rear target object (2) and the vehicle (1) based at least on the time difference between the first linear frequency modulation signal and the first echo signal, and / or calculate the distance information between the rear target object (2) and the vehicle (1) based at least on the time difference between the second linear frequency modulation signal and the second echo signal.

5. The method according to any one of claims 1 to 4, wherein: The risk of collision between the vehicle (1) and the rear target (2) is evaluated based at least on the speed difference Δv, the acceleration difference Δa and the distance d between the vehicle (1) and the rear target (2), wherein the risk of collision between the vehicle (1) and the rear target (2) is evaluated to exist when the following formula is satisfied: Among them, T s Indicates a predetermined duration threshold.

6. The method according to any one of claims 1 to 4, wherein: The step S3 comprises: Step S31: When there is a risk of collision between the vehicle (1) and the rear target object (2), detecting whether there is a front target object (3) within a predetermined distance range in front of the vehicle (1); Step S32: When there is no target object (3) in front of the vehicle (1) within a predetermined distance range, the vehicle (1) is controlled to accelerate forward until the following formula is satisfied and then the acceleration is stopped: Among them, T s Indicates a predetermined time threshold; Step S33: When there is a target object (3) in front of the vehicle (1) within a predetermined distance range, or when the vehicle (1) accelerates for a predetermined time threshold t and still does not satisfy the formula , detecting acceleration information and speed information of a rearward target object (4, 5) in a rearward blind spot of a vehicle (1), wherein the rearward blind spot of the vehicle (1) includes a rearview mirror blind spot of the vehicle and / or an extended area extending rearward from the rearview mirror blind spot; and Step S34: Evaluate the collision risk between the vehicle (1) and the side rear target object (4, 5) at least based on the speed information of the vehicle (1) and the acceleration information and speed information of the side rear target object (4, 5), and control the operating state of the vehicle (1) at least based on the evaluated collision risk to prevent the vehicle (1) from colliding with the rear target object (2).

7. The method according to claim 6, wherein: The step S33 comprises: Step S331: transmitting a third number of third linear frequency modulation signals at a third time interval T3 in each frame of millimeter wave transmission cycle, and receiving a third echo signal of the third linear frequency modulation signal reflected by a side rear target object (4, 5), 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, and the third time interval T3 is a linear function of time; Step S332: Mixing the third echo signal with the third linear frequency modulation signal to obtain a third intermediate frequency signal, and converting the third intermediate frequency signal into a third discrete intermediate frequency signal; and Step S333: Obtain acceleration information of the side and rear target object (4, 5) by performing a two-dimensional Fourier transform on the third discrete intermediate frequency signal.

8. The method according to claim 7, wherein: The step S33 further comprises: Step S334: transmitting a fourth number of fourth linear frequency modulation signals at a fourth time interval T4 in each frame of the millimeter wave transmission cycle, and receiving a fourth echo signal of the fourth linear frequency modulation signal reflected by the side and rear target object (4, 5), wherein the fourth time interval T4 is a predetermined constant; Step S335: mixing the fourth echo signal with the fourth linear frequency modulation signal to obtain a fourth intermediate frequency signal, and converting the fourth intermediate frequency signal into a fourth discrete intermediate frequency signal; and Step S336: Obtain the speed information of the side and rear target object (4, 5) by performing a two-dimensional Fourier transform on the fourth discrete intermediate frequency signal.

9. The method according to claim 6, wherein: The step S34 comprises: Step S341: when the acceleration of the target object (4, 5) at the side and rear continues to decrease within the millimeter wave transmission period exceeding the preset frame number N, the first time t1 and the first longitudinal travel distance X1 required for the vehicle (1) to complete the lane change are calculated by using the Ackerman steering model at least based on the speed information of the vehicle (1); Step S342: Calculating a second longitudinal travel distance X2 traveled by the side rear target object (4, 5) within the first time t1 based on the speed information and acceleration information of the side rear target object (4, 5); Step S343: 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 S344: When the difference is greater than or equal to the preset safety distance threshold value X s , assessing that there is no risk of collision between the side rear target object (4, 5) and the vehicle (1), and controlling the vehicle (1) to change lanes and drive into the lane where the side rear target object (4, 5) is located; and Step S345: When the difference is less than the preset safety distance threshold value X s In the case of a collision between the side rear target object (4, 5) and the vehicle (1), the vehicle (1) is evaluated as having a risk of collision, and the vehicle (1) is controlled to send an alarm message to the rear target object (2) to prompt the rear target object to slow down or maintain a safe distance.

10. The method according to claim 9, wherein: The side rear targets (4, 5) include a left rear target (4) in the left blind spot of the vehicle (1) and / or a right rear target (5) in the right blind spot of the vehicle (1), wherein, when there is no risk of collision between the vehicle (1) and the left rear target (4), the vehicle (1) is controlled to change lanes and drive into a left adjacent lane, and / or when there is no risk of collision between the vehicle (1) and the right rear target (5), the vehicle (1) is controlled to change lanes and drive into a right adjacent lane, and / or when there is a risk of collision between the vehicle (1) and both the left rear target (4) and the right rear target (5), the vehicle (1) is controlled to send an alarm message to the rear target (2) to prompt the rear target (2) to slow down or maintain a safe distance.

11. The method according to claim 9, 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.

12. An assisted driving system (10), the assisted driving system (10) comprising: A millimeter wave radar configured to detect motion state information of surrounding targets of a vehicle (1), wherein the motion state information includes acceleration information and velocity information of the surrounding targets and distance information between the surrounding targets and the vehicle (1); and A control unit (12) configured to execute the method according to any one of claims 1 to 11.

13. The driving assistance system (10) according to claim 12, wherein: The auxiliary driving system (10) further comprises a rear collision warning unit (13), which is configured to control the vehicle (1) to send an alarm message to the rear target (2) when there is a risk of collision between the vehicle (1) and the side rear target (4, 5), so as to prompt the rear target (2) to slow down or maintain a safe distance, wherein the rear collision warning unit (13) comprises, for example, a double flash light.

14. The driving assistance system (10) according to claim 12 or 13, wherein: The millimeter wave radar comprises: at least one rearward millimeter-wave radar (111) configured to detect acceleration information, speed information, and distance information between a rearward target object (2) located in the same lane as the vehicle (1) and the vehicle (1); and / or a forward millimeter-wave radar (112) configured to detect whether there is a forward target object (3) within a predetermined distance range in front of the vehicle (1); and / or A side rear millimeter wave radar (113, 114) is configured to detect acceleration information and speed information of a side rear target object (4, 5) in a rear blind spot of a vehicle (1).

15. A vehicle (1), comprising the assisted driving system (10) according to any one of claims 12 to 14. 16 . 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 claim 1 .

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