System and method for detecting a risk of collision between a motor vehicle and a second object located in a lane adjacent to the vehicle when changing lanes

Abstract

The invention relates to a method for detecting the risk of collision between a motor vehicle and a second object located in a lane adjacent to the main lane of the motor vehicle in the event of a lane change, the method involving detecting the presence of an object in a predetermined danger zone (Z) and estimating a time to collision (TTC) between the vehicle and the detected object. Detecting the presence of an object in the danger zone (Z) involves calculating an actual distance (L) between the motor vehicle and each object detected by the radar, given by transforming a distance (X) transmitted by the radar corresponding to the straight-line distance between the motor vehicle and each object detected by the radar. AB ), the actual distance (L AB ) corresponds to the arc length between two points; determining the danger zone (Z) according to the main lane line and the width of the main lane; and checking the coordinates (L) of each object detected by the radar AB , Y) is within the predetermined danger zone (Z).

Description

Technical Field

[0001] The present invention relates to the field of motor vehicle driving assistance, and in particular to an obstacle avoidance assistance system.

[0002] More specifically, the present invention relates to a method and a system for detecting the risk of an imminent collision between a vehicle located in a main traffic lane and a moving or stationary object located in a traffic lane adjacent to the main lane in the event of a vehicle changing lanes. Background Art

[0003] Specifically, many accidents are caused by the driver leaving the lane unintentionally after his / her attention is reduced, or intentionally leaving the lane when the driver wants to overtake a preceding vehicle that is traveling at a lower speed than his / her own speed.

[0004] However, even when leaving a lane intentionally, the driver may miscalculate the distance between his vehicle and a moving or stationary object located in an adjacent lane, potentially leading to a head-on collision with the object.

[0005] Today, some motor vehicles are equipped with active safety devices that are able to assess the trajectory of the motor vehicle and recognize the surrounding environment in order to determine the risk of collision depending on the situation. Some actions can then be taken automatically or in conjunction with the vehicle driver to keep the vehicle in its lane.

[0006] So-called Lane Keeping Assist (LKA in the abbreviation) systems are known, which make it possible to automatically reposition the vehicle in its lane, or so-called Lane Departure Warning (LDW in the abbreviation) systems which make it possible to warn the driver about leaving the lane.

[0007] Reference may be made in this regard to document EP 2 042 399-A1, which proposes a system for assisting the driver of a host vehicle by calculating the risk of collision with a second vehicle located in the surroundings of the host vehicle.

[0008] Document US 2015 149 039-A1 is also known, which describes a lane keeping assistance system capable of calculating the risk of collision with nearby vehicles.

[0009] However, in the case of curves, such systems cannot calculate the time to collision with nearby vehicles in real time.

[0010] There is a need for improved driver assistance methods and systems to provide the driver with detection of an impending collision with a neighboring vehicle that is as safe as possible by taking lane shape into account by differentiating between straights and curves. Summary of the invention

[0011] It is therefore an object of the present invention to provide a method and a system for detecting the risk of an imminent collision with a moving or stationary object located in a lane adjacent to a main lane.

[0012] A subject of the present invention is a system for detecting the risk of collision between a motor vehicle and a second object located in a lane adjacent to the main lane of the motor vehicle when the motor vehicle changes lanes, the motor vehicle comprising a detection device, which in particular comprises: at least one perception sensor, such as an infrared camera, which is directed toward the main lane in front of the vehicle so that the coefficients of the lane boundary line required for virtually reconstructing the main lane can be obtained; and at least one front or side radar, which is used to detect the coordinates of each second object located in the radar field of view.

[0013] The system for detecting collision risks includes a module for detecting objects in a determined danger zone and transmitting a mark value of each object detected in the danger zone to a computer, the module having: a module for calculating the actual distance between the motor vehicle and each object detected by the radar, the actual distance corresponding to the length of a line segment between two points, regardless of the shape of the lane, whether in straight or curved form; a module for determining the danger zone based on the main lane line and the width of the main lane; and a module for checking, for each object detected by the radar, whether its coordinates are located in the previously determined danger zone.

[0014] This actual distance is given by transforming the distance transmitted by the radar corresponding to the straight-line distance between the motor vehicle and each object detected by the radar.

[0015] The label is, for example, a binary true or false value associated with the lane in question, true indicating the presence of an object in the adjacent lane and false indicating the absence of an object in the adjacent lane.

[0016] The collision detection system also includes a collision time estimation module.

[0017] Therefore, the system is able to detect objects in adjacent lanes to the right and left of a main lane in which the motor vehicle is traveling and calculate the actual distance between the motor vehicle and the objects, regardless of whether the lane is in a straight or curved shape.

[0018] The collision time estimation module advantageously comprises: a module for calculating the angle between the motor vehicle and the detected object, assuming that the trajectory of the object is parallel to the main lane; a module for projecting the relative speed transmitted by the radar onto the road axis, regardless of the shape of the road, in order to obtain the relative speed along the road and thus exploit these data; and a module for calculating the collision time of each detected object detected by the radar based on the actual distance and the relative speed.

[0019] For example, the danger zone includes: a first zone portion defined by two substantially parallel lines along the lane and spaced laterally apart by a first distance, the first distance being calculated based on the width of the adjacent lane given by the camera or based on the width of the reference lane; and a second zone portion defined by two lines inclined toward each other relative to the first lines and spaced laterally apart by a second distance less than the first distance, so that the detection error of the radar at a long distance can be reduced. Specifically, by reducing the distance between the lines of the second danger zone, the lateral offset of the detected object before the detected object is considered to be located in the danger zone is increased.

[0020] The total length of the danger zone is fixed (regardless of the shape of the vehicle's lane) and is predetermined by the manufacturer in the computer.

[0021] Advantageously, the system also comprises a module for filtering the objects detected by the radar in order to identify the most critical of these objects based on the signature indicating the presence of the objects in the danger zone and the collision time.

[0022] For example, the module for filtering detected objects includes: a first filter that retains only detected objects whose flag is true (i.e., objects located in the danger zone); a module for determining the most critical object located in the danger zone based on the distance from the vehicle and / or the collision time; and a module for comparing the collision time with the most critical object to a threshold. As a non-limiting example, the module for filtering detected objects may include a module for retaining only moving objects.

[0023] The system may further include a warning module that transmits a signal to the driver warning of the presence of a critical object by indicating the collision time with the most critical object when the collision time with the most critical object is less than or equal to the threshold.

[0024] The system thus makes it possible to isolate objects that are considered to be critical and to output warning signals and / or intervention signals if there is a risk of a critical object and therefore a risk of an imminent collision with the target object.

[0025] A module may also be provided which is capable of controlling the vehicle controls in order to reposition the vehicle in its main lane. However, such a module will not be described further.

[0026] According to a second aspect, the invention relates to a motor vehicle comprising a computer and a system as described above for detecting a risk of collision between the motor vehicle and a second object located in a lane adjacent to a main lane of the motor vehicle in the event of a lane change by the motor vehicle.

[0027] According to a third aspect, the present invention relates to a method for detecting the risk of collision between a motor vehicle and a second object located in a lane adjacent to the main lane of the motor vehicle, the motor vehicle comprising a detection device, which in particular comprises: at least one perception sensor, such as an infrared camera, the at least one perception sensor pointing to the main lane in front of the vehicle so that the coefficients of the lane boundary line required to virtually reconstruct the main lane can be obtained; and at least one front or side radar, the at least one front or side radar being used to detect the coordinates of each second object located in the radar field of view.

[0028] According to the method, the presence of an object in a determined danger zone is detected and a time to collision between the vehicle and the detected object is estimated.

[0029] Advantageously, in order to detect the presence of an object in a danger zone, an actual distance between the motor vehicle and each object detected by the radar is calculated, given by transforming the distance transmitted by the radar corresponding to the straight-line distance between the motor vehicle and each object detected by the radar, the actual distance corresponding to the arc length between two points, regardless of the shape of the lane, whether in straight or curved form; the danger zone is determined based on the main lane line and the width of the main lane; and for each object detected by the radar, its coordinates are checked whether they are located in the determined danger zone; and the mark value of each object detected in the danger zone is transmitted to the computer.

[0030] This actual distance is given by transforming the distance transmitted by the radar corresponding to the straight-line distance between the motor vehicle and each object detected by the radar.

[0031] The label is, for example, a binary true or false value associated with the lane in question, true indicating the presence of an object in the adjacent lane and false indicating the absence of an object in the adjacent lane.

[0032] In the step of estimating the collision time, the angle between the motor vehicle and the detected object can be calculated assuming that the trajectory of the object is parallel to the main lane; the relative speed can be calculated based on the projection of the relative speed transmitted by the radar on the road axis regardless of the shape of the road in order to utilize these data; and the collision time of each detected object can be calculated for each object detected by the radar based on the actual distance and the relative speed.

[0033] Advantageously, the most critical detected object is determined by filtering detected objects whose flag is true (ie objects located in the danger zone); and determining the most critical of these objects based on distance to the vehicle and / or time to collision.

[0034] The collision time with the most critical object can also be compared with a threshold value, and when the collision time with the most critical object is less than or equal to the threshold value, a signal is output to warn the driver of the presence of a critical object and therefore a risk by indicating, for example, the collision time with the most critical object. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Other objects, characteristics and advantages of the present invention will become clear from a reading of the following description given by way of non-limiting example only and with reference to the accompanying drawings, in which:

[0036] - Figure 1 A system for detecting a risk of collision between a motor vehicle and a second object according to the invention is schematically shown;

[0037] - Figure 2 Schematically shows the Figure 1 Danger areas determined by the system for detecting the risk of collision; and

[0038] - Figure 3 Shown by Figure 1 The steps of the method for detecting a collision risk according to the present invention are implemented by a system. DETAILED DESCRIPTION

[0039] Figure 1 Very schematically, a system is shown for detecting a risk of collision between a motor vehicle and a second object located in a lane adjacent to the main lane of the motor vehicle in the event of a lane change, ie when the vehicle moves from a main lane to an adjacent lane.

[0040] A "second object" is understood to mean an immovable object, such as a safety barrier, or a moving object, such as a second motor vehicle moving in the same direction or in the opposite direction to the host vehicle.

[0041] The system 10 for detecting a risk of collision comprises a module 12 for recovering data originating from a detection device (not shown) provided on board the motor vehicle.

[0042] The detection device particularly includes at least one perception sensor (eg, an infrared camera), which points to the main lane in front of the vehicle so that coefficients a, b, c, d of the lane boundary line required for virtually reconstructing the main lane can be obtained.

[0043] The detection device further comprises at least one front or side radar (not shown), which is used to detect the coordinates X, Y of each second object located in the field of view of the radar.

[0044] The system 10 for detecting a risk of collision further comprises a module 20 for detecting an object located in a determined danger zone Z and a module 30 for estimating a time to collision.

[0045] like Figure 1 As shown, the module 20 for detecting objects in a determined danger zone Z comprises a module 22 for reconstructing the equation of the road Y from the coefficients a, b, c, d using the following equation:

[0046] Y 道线 =dx 3 +cx 2 +b.x+a (Equation 1)

[0047] in:

[0048] a, b, c, d are coefficients representing lane lines transmitted by the camera; and

[0049] x is the vertical distance.

[0050] The module 20 for detecting objects located in the determined danger zone Z then comprises a method for calculating the actual distance L between the motor vehicle and each object detected by the radar. AB Module 24.

[0051] The actual distance L AB is given by transforming the distance X transmitted by the radar and corresponding to the straight-line distance between the motor vehicle and each object detected by the radar.

[0052] According to the following Cartesian equation, the actual distance L AB Corresponding to the arc length between two points A and B:

[0053]

[0054] in:

[0055] Taking the longitudinal axis of the vehicle radar as a reference,

[0056] x A is the longitudinal position of the vehicle relative to the radar origin,

[0057] x B is the position of the object detected by the radar on that same axis, and

[0058] YLine' is the derivative of YLine.

[0059] By writing:

[0060]

[0061] in:

[0062] and

[0063] o.((x-x0) n =ε(x), where

[0064] Therefore, the actual distance L is obtained using the following equation AB :

[0065]

[0066] The actual distance L calculated in this way AB Corresponds to the length of the line segment between two points A and B, regardless of the shape of the lane, whether it is in the form of a straight line or a curve.

[0067] The module 20 for detecting an object located in a determined danger zone Z comprises a module 26 for determining the danger zone Z.

[0068] exist Figure 2 The danger zone Z shown in detail in comprises a first zone portion Z1 defined by two lines L1 which are substantially parallel and along the lane and which are laterally spaced apart by a distance D1 calculated based on the width of the adjacent lane given by the camera or based on a reference lane width.

[0069] The danger zone Z includes a second zone portion Z2 defined by two lines L2 inclined toward each other relative to the first line L1 so as to form a chamfered shape. The two lines L2 are laterally spaced apart by a distance D2, so that the detection error of the radar at a long distance can be reduced. Specifically, by reducing the distance between the lines of the second danger zone Z2, the lateral offset Y2 of the detected object before the detected object is considered to be located in the danger zone Z is increased.

[0070] The total length of the danger zone Z is fixed (regardless of the shape of the vehicle's lane) and is predetermined by the manufacturer in a computer.

[0071] The object detection module 20 includes a module for checking the coordinates (L) of each object detected by the radar. AB , Y) whether the module 28 is located in a predetermined danger zone Z.

[0072] For each object detected in the danger zone Z, a label F is generated. This label is, for example, a binary true or false value associated with the lane in question, true indicating the presence of an object in an adjacent lane and false indicating the absence of an object in an adjacent lane.

[0073] As in Figure 1 As shown in FIG. 1 , the module 30 for estimating the collision time TTC includes a module for calculating the angle α between the motor vehicle and the detected object under the assumption that the trajectory of the object is parallel to the main lane. 物体 Module 32. Angle α 物体 It is defined by the following equation:

[0074] α 物体 =dx 2 +c.x+b (Equation 5)

[0075] The module 30 also includes a module 34 for: regardless of the shape of the road, the relative speed V transmitted by the radar 相对x 、V 相对y (expressed as x and y) to make use of this data.

[0076] Therefore, the relative velocity V of the detected object transmitted by the radar is 相对x 、V 相对y (expressed in x and y) onto the road axis to obtain the relative speed V along the road using the following equation 相对x_道路 :

[0077] V 相对X_道路 = cos(α 物体 ).V 相对x +sin(α 物体 ).V 相对y (Equation 6)

[0078] Finally, the module 30 for estimating the TTC comprises a module 34 for calculating, for each object detected by the radar, the time to collision TTC of each detected object using the following equation:

[0079]

[0080] The collision detection system 10 also comprises a module 40 for filtering the objects detected by the radar in order to identify the most critical of these objects.

[0081] Thus, the module 40 for filtering detected objects receives a set of marker vectors F marking the presence of objects in the danger zone Z. i and the time to collision TTC with the detected object i , where i is an integer between 1 and n.

[0082] The filtering module 40 comprises a first filter 42 which retains only detected objects whose flag is true, ie objects located in the danger zone Z.

[0083] As a non-limiting example, the means 40 for filtering detected objects may include a means for retaining only moving objects.

[0084] The filtering module 40 includes a module 44 for filtering the vehicle based on the distance L AB and / or time to collision TTC to determine the most critical object located in the danger zone Z.

[0085] Then, the filtering module 40 comprises a module 46 for comparing the collision time TTC with the most critical object with the threshold S TTC If the collision time TTC with the most critical object is less than or equal to the threshold S TTC , the warning module 50 transmits a signal to the driver warning of the existence of a dangerous object by indicating the collision time TTC with the most dangerous object.

[0086] A module may also be provided which is capable of controlling the vehicle controls in order to reposition the vehicle in its main lane. However, such a module will not be described further.

[0087] Figure 3 A flow chart is shown for implementing a method 60 for detecting a risk of collision between a motor vehicle and a second object located in a lane adjacent to the main lane of the motor vehicle when the motor vehicle changes lanes from the main lane to an adjacent lane.

[0088] In a first step 62 , data originating from detection devices (not shown) provided on board the motor vehicle are retrieved.

[0089] The detection device particularly includes at least one perception sensor (eg, an infrared camera), which points to the main lane in front of the vehicle so that coefficients a, b, c, d of the lane boundary line required for virtually reconstructing the main lane can be obtained.

[0090] The detection device further comprises at least one front or side radar (not shown), which is used to detect the coordinates X, Y of each second object located in the field of view of the radar.

[0091] In parallel, in step 70 an object is detected in the danger zone Z and in step 80 a collision time between the vehicle and the detected object is estimated.

[0092] In step 90 , the most critical object detected is determined, and finally in step 100 , a warning signal is output if a critical object is present.

[0093] In the step 70 of detecting objects in the danger zone Z, an actual distance L is calculated between the motor vehicle and each object detected by the radar, given by transforming the distance X transmitted by the radar corresponding to the straight-line distance between the motor vehicle and each object detected by the radar. AB .

[0094] According to equation 2, the actual distance L AB Corresponding to the arc length between two points A and B:

[0095]

[0096] in:

[0097] Taking the longitudinal axis of the vehicle radar as a reference,

[0098] x A is the longitudinal position of the vehicle relative to the radar origin,

[0099] x B is the position of the object detected by the radar on that same axis, and

[0100] YLine' is the derivative of YLine determined using Equation 1.

[0101] By writing:

[0102]

[0103] in:

[0104] and

[0105] o.((x-x0) n =ε(x), where

[0106] Therefore, the actual distance L is obtained using the following equation AB :

[0107]

[0108] The actual distance L calculated in this way AB Corresponds to the length of the line segment between two points A and B, regardless of the shape of the lane, whether it is in the form of a straight line or a curve.

[0109] Next, in step 76, a danger zone Z is determined. Figure 2 As shown in detail in , the danger zone comprises a first zone portion Z1 defined by two substantially parallel lines L1 along the lane, the two lines L1 being laterally spaced apart by a distance D1 or offset calculated based on the width of the adjacent lane given by the camera or based on a reference lane width.

[0110] The danger zone Z includes a second zone portion Z2 defined by two lines L2 inclined toward each other relative to the first line L1 so as to form a chamfered shape. The two lines L2 are laterally spaced apart by a distance D2, so that the detection error of the radar at a long distance can be reduced. Specifically, by reducing the distance between the lines of the second danger zone Z2, the lateral offset Y2 of the detected object before the detected object is considered to be located in the danger zone Z is increased.

[0111] The total length of the danger zone Z is fixed (regardless of the shape of the vehicle's lane) and is predetermined by the manufacturer in a computer.

[0112] Then, in step 78, for each object detected by the radar, its coordinates (L AB , Y) is located in the danger zone Z previously determined in step 76.

[0113] For each object detected in the danger zone Z, a label F is generated. This label is, for example, a binary true or false value associated with the lane in question, true indicating the presence of an object in an adjacent lane and false indicating the absence of an object in an adjacent lane.

[0114] As in Figure 3 As shown in FIG. 8 , in step 80 of estimating the collision time TTC, in step 82, the angle α between the motor vehicle and the detected object is calculated under the assumption that the trajectory of the object is parallel to the main lane. 物体 Angle α 物体 It is defined by the following equation:

[0115] α 物体 =dx 2 +c.x+b (Equation 5)

[0116] Then, in step 84, regardless of the shape of the road, according to the relative speed V transmitted by the radar 相对x 、V 相对y(expressed in x and y) onto the road axis to calculate the relative speed V 相对x_道路 , in order to make use of this data.

[0117] Therefore, the following equation is used to obtain the relative speed V along the road 相对x_道路 :

[0118] V 相对X_道路 = cos(α 物体 ).V 相对x +sin(α 物体 ).V 相对y (Equation 6)

[0119] Finally, the time to collision TTC for each detected object is calculated for each object detected by the radar using the following equation:

[0120]

[0121] In step 90 of determining the most critical detected object, detected objects whose flag is true, ie objects located in the danger zone Z, are filtered in step 92 .

[0122] As a non-limiting example, only moving objects may also be retained.

[0123] Then, in step 94, based on the distance L to the vehicle AB and / or collision time TTC to determine the most critical object located in the danger zone Z, and in step 96, the collision time TTC with the most critical object is equal to the threshold value S. TTC If the collision time TTC with the most critical object is less than or equal to the threshold S TTC , then in step 100 a signal is output to the driver warning of the presence of a dangerous object by indicating the time to collision TTC with the most dangerous object.

[0124] Thus, by means of the invention, objects can be detected in adjacent lanes to the right and to the left of a main lane in which the motor vehicle is travelling.

[0125] It is also possible to calculate the actual distance between the mobile vehicle and the object, regardless of whether the lane is straight or curved.

[0126] Finally, the invention makes it possible to isolate objects that are considered to be critical and to output warning signals and / or intervention signals in the presence of critical objects.

Claims

1. A system for detecting a risk of collision between a motor vehicle and a second object located in a traffic lane adjacent to a main lane of the motor vehicle in the event of a motor vehicle changing lanes, the motor vehicle comprising a detection device, the detection device comprising: At least one perception sensor, the at least one perception sensor is directed toward the main lane so as to obtain coefficients a, b, c, d of a lane boundary line required for virtually reconstructing the main lane; and at least one frontal or side radar for detecting the coordinates (X, Y) of each second object located in the field of view of the radar, The system for detecting a collision risk comprises a module (20) for detecting second objects in a determined danger zone (Z) and transmitting to a computer a marking value (F) for each second object detected in the danger zone (Z), the module having: a method for calculating an actual distance L between the motor vehicle and each second object detected by the radar; AB module (24), the actual distance L AB A module (26) for determining a danger zone (Z) based on the boundary line of the main lane and the width of the main lane; and a module (26) for checking the coordinates (L) of each second object detected by the radar. AB , Y) is located in the previously determined dangerous zone (Z) module (28); and the system for detecting the risk of collision includes a module (30) for estimating the time to collision (TTC), The module (20) for detecting a second object in the determined danger zone (Z) comprises a module for reconstructing the road Y according to the coefficients a, b, c, d using the following equation: 道线 The module of equation (22): Y 道线 = d.x 3 + c.x 2 + b.x + a (Equation 1) where x is the longitudinal distance; and According to the following Cartesian equation, the actual distance L AB Corresponding to the arc length between the two points A and B: in: Taking the longitudinal axis of the vehicle radar as a reference, x A is the longitudinal position of the vehicle relative to the radar origin, x B is the position of a second object detected by the radar on the longitudinal axis, and Y 道线 'It's Y 道线 The derivative of .

2. The system of claim 1, wherein: The time to collision (TTC) estimation module (30) includes: a module for calculating an angle (α) between the motor vehicle and the detected second object 物体 ) module (32); for transmitting the relative speed (V 相对x , V 相对y ) is projected onto the road axis to obtain the relative speed along the road (V 相对x_道路 ) module (34); and for based on the actual distance L AB and the relative speed (V 相对x_道路 ), a module (34) for calculating a time to collision (TTC) for each second object detected by the radar.

3. The system of claim 1 or 2, wherein: The danger zone (Z) comprises: a first zone portion (Z1) defined by two substantially parallel lines (L1) along the carriageway and laterally spaced apart by a first distance (D1); and a second zone portion (Z2) defined by two lines (L2) inclined towards each other relative to the first lines (L1) and laterally spaced apart by a second distance (D2) less than the first distance (D1).

4. The system as claimed in any one of the preceding claims further comprises a filtering module (40) for filtering the second objects detected by the radar in order to identify the most critical second object among the second objects based on a mark (F) for marking the presence of a second object in the danger zone (Z) and the collision times (TTC).

5. The system of claim 4, wherein: The filtering module (40) comprises: a first filter (42) that only retains the detected second object located in the danger zone (Z); and a filter for filtering the detected second object based on the actual distance L. AB and / or the collision time (TTC) to determine the most critical second object (44); and a module for comparing the collision time (TTC) with the most critical second object with a threshold value (S TTC ) for comparison module (46).

6. The system of claim 5, comprising a warning module (50) that warns when the time to collision (TTC) with the most critical second object is less than or equal to the threshold value (S TTC ), the warning module transmits a signal to the driver warning of the existence of a critical second object by indicating a time to collision (TTC) with the most critical second object.

7. A motor vehicle comprising a computer and a system as claimed in any one of the preceding claims for detecting a risk of collision between the motor vehicle and a second object located in a lane adjacent to the main lane of the motor vehicle when the motor vehicle changes lanes.

8. A method for detecting a risk of collision between a motor vehicle and a second object located in a traffic lane adjacent to a main lane of the motor vehicle in the event of a motor vehicle changing lanes, the motor vehicle comprising a detection device comprising: At least one perception sensor, the at least one perception sensor is directed toward the main lane so as to obtain coefficients a, b, c, d of a lane boundary line required for virtually reconstructing the main lane; and at least one frontal or side radar for detecting the coordinates (X, Y) of each second object located in the field of view of the radar, characterized in that the presence of the second object in the determined danger zone (Z) is detected and a time to collision (TTC) between the vehicle and the detected second object is estimated, and in order to detect the presence of the second object in the danger zone (Z): - calculating the actual distance L between the motor vehicle and each second object detected by the radar, given by transforming the distance (X) transmitted by the radar corresponding to the straight-line distance between the motor vehicle and each second object detected by the radar AB , the actual distance L AB corresponds to the length of the arc between two points A, B, said point A being the motor vehicle itself and said point B being the second object, - determining a danger zone (Z) based on the lines of the main lane and the width of the main lane, and - for each second object detected by the radar, check its coordinates (L AB , Y) is located in the determined dangerous area (Z), and the marking value (F) of each second object detected in the dangerous area (Z) is transmitted to the computer, The following equation is used to reconstruct the road Y according to the coefficients a, b, c, d: 道线 : Y 道线 = d.'x 3 + c.x 2 + b.x + a (Equation 1) where x is the longitudinal distance; and According to the following Cartesian equation, the actual distance L AB Corresponding to the arc length between the two points A and B: in: Taking the longitudinal axis of the vehicle radar as a reference, x A is the longitudinal position of the vehicle relative to the radar origin, x B is the position of a second object detected by the radar on the longitudinal axis, and Y 道线 'It's Y 道线 The derivative of .

9. The method of claim 8, wherein: In the step of estimating the time to collision (TTC), the angle (α) between the motor vehicle and the detected second object is calculated. 物体 ); according to the relative speed (V 相对x , V 相对y ) onto the road axis to calculate the relative speed (V 相对x_道路 ); and based on the actual distance L AB and the relative speed (V 相对x_道路 ), and for each second object detected by the radar, a time to collision (TTC) for each second object detected is calculated.

10. The method according to any one of claims 8 and 9, wherein: The most critical second object detected is determined by filtering the detected second objects located in the danger zone (Z); and based on the actual distance L AB and / or the time to collision (TTC) to determine the most critical second object among the second objects.

11. The method of claim 10, wherein: The collision time (TTC) with the most critical second object is equal to the threshold (S TTC ) is compared, and when the collision time (TTC) with the most critical second object is less than or equal to the threshold (S TTC ), a signal is output to the driver to warn the driver of the presence of a dangerous second object.

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