Emergency braking parking auxiliary method and system based on laser radar and vehicle

Abstract

The invention provides an emergency braking parking assisting method and system based on a laser radar and a vehicle, the emergency braking parking assisting method comprises the steps that when the emergency braking parking assisting system is started, the retreating track of the vehicle is obtained, and the retreating track is an arc with the first curvature center as the circle center and the first curvature radius as the radius; obtaining a trajectory range of the vehicle according to the backward trajectory and vehicle characteristics of the vehicle; judging whether a collision obstacle exists in the track range or not; acquiring a target obstacle collision point and a target self-vehicle collision point under the condition that the collision obstacle exists in the track range; calculating collision time according to the target obstacle collision point and the target self-vehicle collision point; and controlling the braking time of the vehicle according to the collision time. The technical problems that the sensitivity of a traditional strategy to the environment is low, the parking position cannot be controlled in the automatic parking process, and the safety of the vehicle is low are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile assisted driving, and in particular to a laser radar-based emergency braking and parking assistance method, a laser radar-based emergency braking and parking assistance system, and a vehicle. Background Art

[0002] Given that the automatic parking function has been widely used in the automotive field and is well known to the majority of users, many manufacturers at home and abroad as well as emerging car manufacturers have the ability to develop and mass-produce vehicles equipped with fully automatic parking functions.

[0003] Existing emergency brake parking assistance systems still use radar sensors and wide-angle cameras as sources of obstacle information. However, radar itself has limitations as an obstacle perception medium, and is prone to false alarms and missed reports of obstacles; strong light, reflections, and dark light may affect the detection function of wide-angle cameras. LiDAR uses high-frequency laser beams as a measurement medium, which has better accuracy and anti-interference. At the same time, with the popularization of autonomous driving, the number of vehicles equipped with LiDAR is increasing, which also brings greater application breadth to the stability, safety, and scalability of basic driving assistance functions.

[0004] However, in actual use, there is a problem: traditional strategies have low sensitivity to the environment, cannot control the parking position during automatic parking, and have low vehicle safety. Summary of the invention

[0005] The present invention solves the technical problems that the traditional strategy has low sensitivity to the environment, cannot control the parking position during the automatic parking process, and has low vehicle safety.

[0006] To solve the above problems, the present invention provides an emergency braking parking assistance method based on laser radar, which is applied to an emergency braking parking assistance system based on laser radar. The emergency braking parking assistance method includes: when the emergency braking parking assistance system is started, obtaining the backward trajectory of the vehicle, wherein the backward trajectory is: an arc with a first curvature center as the center and a first curvature radius as the radius; obtaining the trajectory range of the vehicle according to the backward trajectory and the vehicle characteristics of the vehicle; judging whether there is a collision obstacle within the trajectory range; if there is a collision obstacle within the trajectory range, obtaining the target obstacle collision point and the target self-vehicle collision point; calculating the collision time according to the target obstacle collision point and the target self-vehicle collision point; and controlling the braking moment of the vehicle according to the collision time.

[0007] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: the present invention can effectively obtain the possible collision points of the vehicle and the collision obstacles of the vehicle by calculating the vehicle's backward trajectory and performing collision detection analysis; that is to say, there is no possibility of accidental touch on the obstacles on the side of the vehicle.

[0008] In one embodiment of the present invention, when the emergency braking parking assistance system is activated, the backward trajectory of the vehicle is obtained, including: when the emergency braking parking assistance system is activated, the front wheel steering angle, the rear wheel steering angle, and the center of the front axle and the center of the rear axle of the vehicle are obtained in the world coordinate system; according to the front wheel steering angle, the rear wheel steering angle, and the center of the front axle and the center of the rear axle of the vehicle, a first curvature center and a first curvature radius are obtained; wherein, in the world coordinate system, the coordinates of the first curvature center are , the coordinates of the center of the front axle of the vehicle are , the coordinates of the rear axle center of the vehicle are ; The backward trajectory is: the trajectory of the center of the rear axle of the vehicle.

[0009] Compared with the existing technology, the technical effect achieved by adopting this technical solution is: Obtain the obstacle matrix with the center of the rear axle of the vehicle as the center of the matrix, and use the coordinates of the center of the rear axle of the vehicle , transform the obstacle matrix into an obstacle matrix containing coordinates in the world system. When the emergency brake parking assist system is activated, the vehicle is at a low speed. At low speed, the vehicle can be simplified to a two-wheel model. According to the kinematic principle, the center of curvature and the radius of curvature (that is, the first center of curvature and the first radius of curvature in this embodiment) can be obtained according to the front wheel angle and the rear wheel angle of the vehicle; the coordinates of the first center of curvature are .

[0010] In one embodiment of the present invention, ; ; The first radius of curvature is: ;in, is the front wheel turning angle of the vehicle, is the rear wheel turning angle of the vehicle; is the abscissa of the first center of curvature, is the ordinate of the first center of curvature; is the horizontal coordinate of the center of the front axle of the vehicle, is the ordinate of the center of the front axle of the vehicle; is the horizontal coordinate of the rear axle center of the vehicle, is the ordinate of the rear axle center of the vehicle; is the first radius of curvature.

[0011] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: the first curvature center can be calculated and determined according to the front wheel turning angle, the rear wheel turning angle, and the coordinates of the front axle center and the rear axle center of the vehicle. Since the backward trajectory can be considered as the movement of the vehicle around a circle center, the first curvature radius can be calculated by the coordinates of the first curvature center and the coordinates of the rear axle center of the vehicle, which is specifically obtained by the Pythagorean theorem of a right triangle. The backward trajectory of the vehicle can be obtained by the first curvature center and the first curvature radius.

[0012] In one example of the present invention, when there is a collision obstacle within a trajectory range, a target obstacle collision point and a target ego-vehicle collision point are obtained, including: obtaining the target obstacle within the trajectory range; obtaining the target obstacle collision point of the target obstacle; and calculating the target ego-vehicle collision point based on the target obstacle collision point.

[0013] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: the target obstacle collision point is the target point where the ego vehicle collides within the trajectory range, and the target ego vehicle collision point can be calculated based on the target obstacle collision point, thereby obtaining the collision time and collision distance.

[0014] In one example of the present invention, obtaining a target obstacle within a trajectory range includes: obtaining a collision obstacle within the trajectory range; when there are multiple collision obstacles, defining a collision obstacle closest to the vehicle among the multiple collision obstacles as a target obstacle; and / or when there is one collision obstacle, defining the collision obstacle as a target obstacle.

[0015] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: there may be one or more obstacles within the trajectory range. In order to determine the target obstacle, when there are multiple collision obstacles, the distance between each collision obstacle and the vehicle is obtained, and multiple distances are compared. The collision obstacle closest to the vehicle is regarded as the target obstacle, and its coordinates in the world coordinate system are obtained as the basis for subsequent steps; when there is only one collision obstacle, the collision obstacle is directly regarded as the target obstacle.

[0016] In one example of the present invention, a target self-vehicle collision point is calculated based on a target obstacle collision point, including: obtaining a first collision point of the vehicle based on the target obstacle collision point; when there are multiple first collision points, defining the first collision point closest to the target obstacle collision point among the multiple first collision points as the target self-vehicle collision point; and / or when the number of first collision points is one, defining the first collision point as the target self-vehicle collision point.

[0017] Compared with the prior art, the technical effects achieved by adopting the technical solution are as follows: after determining the target obstacle, the target obstacle collision point can be obtained; after obtaining the target obstacle collision point, the vehicle may have one or more self-vehicle collision points (that is, the first collision point), and for all possible self-vehicle collision points, the corresponding distances between each self-vehicle collision point and the target obstacle collision point are calculated, and the self-vehicle collision point with the smallest distance is obtained as the actual self-vehicle collision point, and the actual self-vehicle collision point is also the target self-vehicle collision point; when the number of the first collision point is one, the first collision point is directly regarded as the target self-vehicle collision point.

[0018] In one embodiment of the present invention, the collision time is calculated according to the target obstacle collision point and the target ego vehicle collision point, including: obtaining a first vector from the first curvature center to the target ego vehicle collision point as ; Get the second vector from the first curvature center to the target obstacle collision point as ; Calculate the collision time based on the first vector and the second vector; where the collision time is: ; is the safe distance between the collision point of the target vehicle and the collision point of the target obstacle, v is the linear speed of the vehicle, is the second radius of curvature.

[0019] Compared with the prior art, the technical effects achieved by adopting this technical solution are as follows: the collision time can be used to determine when a vehicle will collide during reverse parking, thereby predicting in advance and reacting to the vehicle to avoid a collision; the present invention can accurately obtain the actual arc-shaped driving distance of the vehicle and the obstacle, can accurately predict the corresponding nonlinear distance, and then control the parking position, thereby improving the safety of the entire vehicle as much as possible without affecting manual driving.

[0020] In one example of the present invention, vehicle characteristics include: the length and width of the vehicle; obtaining the trajectory range of the vehicle based on the backward trajectory and the vehicle characteristics of the vehicle, including: obtaining the coordinates of the vehicle corners of the vehicle based on the vehicle characteristics and the center of the front axle of the vehicle and the center of the rear axle of the vehicle, wherein the vehicle corners are: left front corner, right front corner, right rear corner and right left corner; obtaining the angular distance from the first center of curvature to each vehicle corner; obtaining the trajectory range based on multiple angular distances and the first center of curvature.

[0021] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: when the coordinates of the center of the front axle and the center of the rear axle of the vehicle are known, the trajectory range of the vehicle can be obtained according to the length, width and size of the rearview mirror of the vehicle, that is, the maximum movement range of the vehicle in which a collision may occur during the backward movement of the vehicle.

[0022] On the other hand, an embodiment of the present invention further provides an emergency braking parking assistance system based on laser radar, which applies the emergency braking parking assistance method based on laser radar as any of the above embodiments, and the emergency braking parking assistance system includes: a first acquisition module, the first acquisition module is used to acquire the backward trajectory of the vehicle when the emergency braking parking assistance system is started, wherein the backward trajectory is: an arc with a first curvature center as the center and a first curvature radius as the radius; a second acquisition module, the second acquisition module is used to obtain the trajectory range of the vehicle according to the backward trajectory and the vehicle characteristics of the vehicle; a first judgment module, the first judgment module is used to determine whether there is a collision obstacle within the trajectory range; a third acquisition module, the third acquisition module is used to acquire the target obstacle collision point and the target self-vehicle collision point when there is a collision obstacle within the trajectory range; a calculation module, the calculation module is used to calculate the collision time according to the target obstacle collision point and the target self-vehicle collision point; an execution module, the execution module is used to control the braking moment of the vehicle according to the collision time.

[0023] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: the laser radar-based emergency braking parking assistance system in this embodiment is used to implement the laser radar-based emergency braking parking assistance method as in any embodiment of the present invention, so it has all the beneficial effects of the laser radar-based emergency braking parking assistance method as in any embodiment of the present invention, which will not be repeated here.

[0024] On the other hand, an embodiment of the present invention further provides a vehicle, comprising: a processor, a memory, and a program or instruction stored in the memory and executable on the processor, wherein when the program or instruction is executed by the processor, the steps of the laser radar-based emergency braking parking assistance method as described in any one of the above embodiments are implemented.

[0025] Compared with the prior art, the technical effect achieved by adopting this technical solution is as follows: the vehicle operation in this embodiment is like the laser radar-based emergency braking parking assistance method in any embodiment of the present invention, so it has all the beneficial effects of the laser radar-based emergency braking parking assistance method in any embodiment of the present invention, which will not be repeated here.

[0026] After adopting the technical solution of the present invention, the following technical effects can be achieved: (1) By calculating the vehicle's backward trajectory and performing collision detection analysis, the possible collision points and collision obstacles of the ego vehicle can be effectively obtained. In other words, there is no possibility of accidental contact with obstacles on the side of the vehicle. (2) The collision time can be used to determine when a collision will occur during reverse parking, thereby predicting in advance and reacting to the vehicle to avoid a collision. The present invention can accurately obtain the actual arc-shaped driving distance of the vehicle and the obstacle, accurately predict the corresponding nonlinear distance, and then control the parking position, thereby improving the safety of the entire vehicle as much as possible without affecting manual driving. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A flowchart of a laser radar-based emergency braking parking assistance method provided in Embodiment 1 of the present invention; Figure 2 It is a schematic diagram of the structure of a vehicle during parking; Figure 3 A schematic structural block diagram of a laser radar-based emergency braking and parking assistance system provided in Embodiment 2 of the present invention; Figure 4 A block diagram of the composition of a vehicle provided in Embodiment 3 of the present invention.

[0028] Description of reference numerals: 100-emergency braking parking assist system; 101-first acquisition module; 102-second acquisition module; 103-first judgment module; 104-third acquisition module; 105-calculation module; 106-execution module; 200-vehicle; 210-memory; 211-computer program; 220-processor; 300-readable storage medium; 310-computer executable instructions. DETAILED DESCRIPTION

[0029] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and understandable, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] [Example 1] See also Figure 1 , which is a flow chart of an emergency braking parking assistance method based on laser radar provided in the first embodiment of the present invention. The emergency braking parking assistance method based on laser radar includes: Step S100: when the emergency braking parking assistance system is activated, obtaining a backward trajectory of the vehicle, wherein the backward trajectory is: an arc with a first curvature center as a circle center and a first curvature radius as a radius; Step S200: obtaining a trajectory range of the vehicle according to the backward trajectory and the vehicle characteristics of the vehicle; Step S300: Determine whether there is a collision obstacle within the trajectory range; Step S400: when there is a collision obstacle within the trajectory range, obtaining a target obstacle collision point and a target vehicle collision point; Step S500: Calculating the collision time according to the target obstacle collision point and the target vehicle collision point; Step S600: Control the braking moment of the vehicle according to the collision time.

[0031] In a specific embodiment, briefly speaking, the present invention first calculates the backward trajectory of the vehicle. The backward trajectory can be considered as the movement of the vehicle around a circle. Since the steering wheel angle is fixed during emergency braking and parking, the front wheel angle of the vehicle After obtaining the first curvature center (that is, the center of the circle) and the first curvature radius (that is, the radius), the backward trajectory of the vehicle can be obtained. The backward trajectory in this embodiment is specifically the motion trajectory of the center of the rear axle of the vehicle; according to the backward trajectory of the vehicle and the vehicle characteristics of the vehicle (in this embodiment, specifically the length, width and size of the rearview mirror of the vehicle), the maximum and minimum values ​​of the backward trajectory can be calculated, so as to obtain the trajectory range of the vehicle during the backward process (which can also be expressed as the collision area of ​​the vehicle), and the trajectory range is the area where the vehicle passes during the backward process; perform collision detection analysis: according to the trajectory range, if there is a collision obstacle, Obstacles can be obtained, and the target obstacle collision point and the target self-vehicle collision point can be obtained. The target obstacle collision point is the position of the collision obstacle closest to the vehicle within the trajectory range, and the target self-vehicle collision point is the self-vehicle collision point closest to the target obstacle collision point; after obtaining the target obstacle collision point and the target self-vehicle collision point, the collision time and collision distance can be obtained; finally, the collision distance, collision time and coordinates of the target obstacle collision point are given to the control, and the control can control the braking moment of the vehicle according to the calibration data, and specifically send the corresponding collision time to the emergency braking parking assist system state machine as a state jump standard and braking force calculation parameter.

[0032] Specifically, the vehicle characteristics, front axle center, and rear axle center data in the present invention can be obtained through laser radar. After having the laser radar-based data, the present invention can effectively obtain the possible collision points and collision obstacles of the vehicle through calculation of the vehicle's backward trajectory and collision detection analysis; that is, there is no accidental contact with obstacles on the side of the vehicle.

[0033] Furthermore, step S100 includes: Step S110: when the emergency brake parking assist system is activated, the front wheel steering angle, rear wheel steering angle, front axle center and rear axle center of the vehicle are obtained in the world coordinate system; Step S120: obtaining a first curvature center and a first curvature radius according to the front wheel turning angle, the rear wheel turning angle, the center of the front axle of the vehicle, and the center of the rear axle of the vehicle; Among them, in the world coordinate system, the coordinates of the first curvature center are , the coordinates of the center of the front axle of the vehicle are , the coordinates of the rear axle center of the vehicle are ; The backward trajectory is: the trajectory of the center of the rear axle of the vehicle.

[0034] Specifically, obtain the obstacle matrix with the center of the rear axle of the vehicle as the center of the matrix, through the coordinates of the center of the rear axle of the vehicle , transform the obstacle matrix into an obstacle matrix containing coordinates in the world system. When the emergency brake parking assist system is activated, the vehicle is at a low speed. At low speed, the vehicle can be simplified to a two-wheel model. According to the kinematic principle, the center of curvature and the radius of curvature (that is, the first center of curvature and the first radius of curvature in this embodiment) can be obtained according to the front wheel angle and the rear wheel angle of the vehicle; the coordinates of the first center of curvature are .

[0035] Furthermore, ; ; The first radius of curvature is: ; in, is the front wheel turning angle of the vehicle, is the rear wheel turning angle of the vehicle; is the abscissa of the first center of curvature, is the ordinate of the first center of curvature; is the horizontal coordinate of the center of the front axle of the vehicle, is the ordinate of the center of the front axle of the vehicle; is the horizontal coordinate of the rear axle center of the vehicle, is the ordinate of the rear axle center of the vehicle; is the first radius of curvature.

[0036] Specifically, the first curvature center can be calculated and determined according to the front wheel turning angle, the rear wheel turning angle, and the coordinates of the front axle center and the rear axle center of the vehicle. Since the backward trajectory can be considered as the movement of the vehicle around a circle center, the first curvature radius can be calculated by the coordinates of the first curvature center and the coordinates of the rear axle center of the vehicle, which can be obtained specifically by the Pythagorean theorem of a right triangle. The backward trajectory of the vehicle can be obtained by the first curvature center and the first curvature radius.

[0037] Furthermore, step S400 includes: Step S410: Acquire target obstacles within the trajectory range; Step S420: obtaining a target obstacle collision point of the target obstacle; Step S430: Calculate the target vehicle collision point based on the target obstacle collision point.

[0038] Specifically, possible obstacles are screened within the trajectory range. The specific operation is as follows: traverse the gripmap, and if there is a possible obstacle collision point within the trajectory range , calculate the corresponding radius of curvature ; Traverse each edge of the vehicle's border to obtain the collision point of the vehicle Among them, in the world coordinate system, the coordinates of the target obstacle collision point are , the coordinates of the target vehicle collision point are .

[0039] Furthermore, step S410 includes: Step S411: Obtain collision obstacles within the trajectory range; Step S412: when there are multiple collision obstacles, define the collision obstacle closest to the vehicle among the multiple collision obstacles as the target obstacle; and / or Step S413: When the number of the collision obstacle is one, define the collision obstacle as a target obstacle.

[0040] Specifically, there may be one or more obstacles within the trajectory range. In order to determine the target obstacle, if there are multiple collision obstacles, the distance between each collision obstacle and the vehicle is obtained, and multiple distances are compared. The collision obstacle closest to the vehicle is regarded as the target obstacle, and its coordinates in the world coordinate system are obtained as the basis for subsequent steps; if there is only one collision obstacle, the collision obstacle is directly regarded as the target obstacle.

[0041] Further, step S430 includes: Step S431: acquiring a first collision point of the vehicle according to a target obstacle collision point; Step S432: when there are multiple first collision points, define the first collision point closest to the target obstacle collision point among the multiple first collision points as the target vehicle collision point; and / or Step S433: When the number of the first collision point is one, define the first collision point as the target vehicle collision point.

[0042] Specifically, after determining the target obstacle, the target obstacle collision point can be obtained; after obtaining the target obstacle collision point, the vehicle may have one or more self-vehicle collision points (that is, the first collision point), and for all possible self-vehicle collision points , calculate the corresponding distances between each ego vehicle collision point and the target obstacle collision point, and obtain the ego vehicle collision point with the smallest distance as the actual ego vehicle collision point , the actual self-vehicle collision point is also the target self-vehicle collision point; when the number of the first collision point is one, the first collision point is directly regarded as the target self-vehicle collision point.

[0043] In a specific embodiment, the specific operations of step S300 are: Screen possible obstacles within the trajectory range. The specific operation is: traverse the gripmap, if there is a possible obstacle collision point within the trajectory range , calculate the corresponding radius of curvature ; Traverse each edge of the vehicle's border to obtain the collision point of the vehicle .

[0044] The two points of the vehicle frame are recorded as: ,in are the four corner points of the vehicle marked clockwise from the vehicle frame. To explain, this expression is a custom expression. One side of the vehicle frame can be simplified into a line segment, and the line segment can be directly represented by two endpoints. In this way, each frame is modeled separately to form an edge set. Among them, is the coordinate of a point on the vehicle’s border, is the coordinate of another point on the vehicle’s bounding box, is the set of two points on a certain border of the vehicle. , , and They are brief descriptions of the four vehicle angles, , , and are brief descriptions of the four borders of the vehicle. Preferably, is the coordinate of the front left corner of the vehicle, is the coordinate of the front right corner of the vehicle in world coordinates, is the coordinate of the rear right corner of the vehicle in world coordinates, is the coordinate of the rear left corner of the vehicle in world coordinates.

[0045] remember: ; is the distance between the first center of curvature and the possible obstacle collision point, obtained by the coordinates of the first center of curvature and the coordinates of the collision obstacle.

[0046] remember: ; If the conditions are met Exists, get the corresponding collision point of the vehicle, that is: ; represents the horizontal coordinate of the collision point of the vehicle, that is, , represents the ordinate of the collision point of the vehicle, that is, , the coordinates of the collision point of the ego vehicle can be obtained by It can also be expressed by Indicated by. Where M is a simplified formula. Refers to the proportional coefficient of the collision point of the vehicle on the side where the vehicle is located. Ensuring that [0, 1] is to ensure that the collision point of the vehicle is on the vehicle frame, otherwise it will be a ray that exceeds the vehicle frame, that is, there is no collision obstacle point within the trajectory range.

[0047] Since the emergency braking parking assistance system is a driving assistance function, it should not occupy too much computing resources. If the traditional collision detection algorithm is used, the time complexity will reach , and this algorithm can reduce the time complexity to , in terms of computing resources, an exponential reduction has been achieved.

[0048] Furthermore, step S500 includes: Get the first vector from the first curvature center to the target vehicle collision point as ; Get the second vector from the first curvature center to the target obstacle collision point as ; Calculate the collision time based on the first vector and the second vector; The collision time is: ; is the safe distance between the collision point of the target vehicle and the collision point of the target obstacle, v is the linear speed of the vehicle, is the second radius of curvature.

[0049] Specifically, the collision time can be used to determine when a collision will occur during reverse parking, thereby predicting in advance and reacting to the vehicle to avoid a collision. The present invention can accurately obtain the actual arc-shaped driving distance of the vehicle and the obstacle, and can accurately predict the corresponding nonlinear distance, thereby controlling the parking position, thereby improving the safety of the entire vehicle as much as possible without affecting manual driving.

[0050] Further, the vehicle characteristics include: the length and width of the vehicle; step S200 includes: Step S210: obtaining the coordinates of the vehicle angles of the vehicle according to the vehicle characteristics and the center of the front axle of the vehicle and the center of the rear axle of the vehicle, wherein the vehicle angles are respectively: left front angle, right front angle, right rear angle and right left angle; Step S220: respectively obtaining the angular distance from the first curvature center to each vehicle corner; Step S230: Obtaining a trajectory range according to a plurality of angular distances and the first curvature center.

[0051] Specifically, when the coordinates of the center of the front axle and the center of the rear axle of the vehicle are known, the trajectory range of the vehicle can be obtained according to the length, width and size of the rearview mirror of the vehicle, that is, the maximum movement range of the vehicle in which a collision may occur during the backward movement of the vehicle.

[0052] First, calculate and obtain the coordinates of the four corners of the vehicle, which are , , and ; Then, calculate the distance from the first curvature center to each vehicle corner, and record it as the angular distance. ; Then obtain the collision area (that is, trajectory range) of the vehicle during parking, that is, satisfy the obstacle : , from which the trajectory range of the vehicle can be obtained.

[0053] Among them, fl represents the front left corner of the vehicle, is the coordinate of the front left corner of the vehicle in the world coordinate system; fr represents the front right corner of the vehicle, is the coordinate of the front right corner of the vehicle in the world coordinate system; rr represents the rear right corner of the vehicle, is the coordinate of the rear right corner of the vehicle in the world coordinate system; rl represents the rear left corner of the vehicle, is the coordinate of the rear left corner of the vehicle in world coordinates. is the distance from the first center of curvature to the front left corner of the vehicle, The distance from the first center of curvature to the front right corner of the vehicle, is the distance from the first center of curvature to the rear right corner of the vehicle, is the distance from the first center of curvature to the rear left corner of the vehicle.

[0054] is the coordinate of the vehicle's angle ab in the world coordinate system. When a is f, it represents the front angle of the vehicle; when a is r, it represents the rear angle of the vehicle; when b is l, it represents the left angle of the vehicle; when b is r, it represents the right angle of the vehicle. is the coordinate of the front left corner of the vehicle in world coordinates, represents the horizontal coordinate of the front left corner of the vehicle, Indicates the ordinate of the front left corner of the vehicle; is the coordinate of the front right corner of the vehicle in world coordinates, represents the horizontal coordinate of the front right corner of the vehicle, Indicates the ordinate of the front right corner of the vehicle; is the coordinate of the rear right corner of the vehicle in world coordinates, Represents the horizontal coordinate of the rear right corner of the vehicle, Indicates the ordinate of the rear right corner of the vehicle; is the coordinate of the rear left corner of the vehicle in world coordinates, Represents the horizontal coordinate of the rear left corner of the vehicle, Indicates the vertical coordinate of the rear left corner of the vehicle.

[0055] This embodiment also provides a schematic diagram of the structure of the vehicle during parking. Figure 2 : O is the first curvature center; D1 is the front left corner of the vehicle, D2 is the front right corner of the vehicle, D3 is the rear right corner, and D4 is the rear left corner of the vehicle; Z1 is the center of the front axle of the vehicle, and Z2 is the center of the rear axle of the vehicle; P1 is the target obstacle collision point, and P2 is the target vehicle collision point.

[0056] [Example 2] See also Figure 3 The present embodiment further provides an emergency braking parking assistance system 100 based on laser radar, which uses the emergency braking parking assistance method based on laser radar as in the first embodiment. The emergency braking parking assistance system 100 includes: a first acquisition module 101, a second acquisition module 102, a first judgment module 103, a third acquisition module 104, a calculation module 105 and an execution module 106. The first acquisition module 101 is used to acquire the backward trajectory of the vehicle when the emergency braking parking assistance system is started, wherein the backward trajectory is: an arc with the first curvature center as the center and the first curvature radius as the radius; the second acquisition module 102 is used to obtain the trajectory range of the vehicle according to the backward trajectory and the vehicle characteristics of the vehicle; the first judgment module 103 is used to determine whether there is a collision obstacle within the trajectory range; the third acquisition module 104 is used to acquire the target obstacle collision point and the target self-vehicle collision point when there is a collision obstacle within the trajectory range; the calculation module 105 is used to calculate the collision time according to the target obstacle collision point and the target self-vehicle collision point; the execution module 106 is used to control the braking moment of the vehicle according to the collision time.

[0057] In a specific embodiment, the first acquisition module 101, the second acquisition module 102, the first judgment module 103, the third acquisition module 104, the calculation module 105 and the execution module 106 of the laser radar-based emergency braking parking assistance system 100 cooperate to implement the laser radar-based emergency braking parking assistance method of the first embodiment as described above, which will not be repeated here.

[0058] [Example 3] See also Figure 4This embodiment provides a structural schematic diagram of a vehicle 200, wherein the vehicle 200 includes a processor 220 and a memory 210 electrically connected to the processor 220, wherein a computer program 211 is stored on the memory 210, and the processor 220 loads the computer program 211 to implement the emergency braking parking assistance method based on laser radar as in the first embodiment.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A laser radar-based emergency braking parking assistance method, wherein the emergency braking parking assistance method is applied to a laser radar-based emergency braking parking assistance system, characterized in that: The emergency braking parking assistance method comprises: When the emergency braking parking assistance system is activated, a backward trajectory of the vehicle is obtained, wherein the backward trajectory is: an arc with a first curvature center as a circle center and a first curvature radius as a radius; Obtaining a trajectory range of the vehicle according to the backward trajectory and vehicle characteristics of the vehicle; Determine whether there is a collision obstacle within the trajectory; When the collision obstacle exists within the trajectory range, obtaining a target obstacle collision point and a target ego-vehicle collision point; Calculating the collision time according to the target obstacle collision point and the target ego-vehicle collision point; The braking moment of the vehicle is controlled according to the collision time.

2. The emergency braking parking assistance method according to claim 1, characterized in that: When the emergency brake parking assistance system is activated, obtaining the backward trajectory of the vehicle includes: When the emergency brake parking assist system is activated, obtaining the front wheel steering angle, rear wheel steering angle, front axle center and rear axle center of the vehicle in the world coordinate system; Obtaining the first curvature center and the first curvature radius according to the front wheel turning angle, the rear wheel turning angle, the center of the front axle of the vehicle, and the center of the rear axle of the vehicle; Among them, in the world coordinate system, the coordinates of the first curvature center are , the coordinates of the center of the front axle of the vehicle are , the coordinates of the rear axle center of the vehicle are ; The backward trajectory is: the trajectory of the center of the rear axle of the vehicle.

3. The emergency braking parking assistance method according to claim 2, characterized in that: ； ； The first radius of curvature is: ; in, is the front wheel turning angle of the vehicle, is the rear wheel turning angle of the vehicle; is the abscissa of the first center of curvature, is the ordinate of the first center of curvature; is the horizontal coordinate of the center of the front axle of the vehicle, is the ordinate of the center of the front axle of the vehicle; is the horizontal coordinate of the rear axle center of the vehicle, is the ordinate of the rear axle center of the vehicle; is the first radius of curvature.

4. The emergency braking parking assistance method according to claim 1, characterized in that: When the collision obstacle exists within the trajectory range, obtaining the target obstacle collision point and the target vehicle collision point includes: Acquire target obstacles within the trajectory range; Acquire the target obstacle collision point of the target obstacle; The target vehicle collision point is obtained by calculation according to the target obstacle collision point.

5. The emergency braking parking assistance method according to claim 4, characterized in that: The obtaining of the target obstacle within the trajectory range includes: Acquire the collision obstacle within the trajectory range; When there are multiple collision obstacles, defining the collision obstacle closest to the vehicle among the multiple collision obstacles as the target obstacle; and / or When the number of the collision obstacle is one, the collision obstacle is defined as the target obstacle.

6. The emergency braking parking assistance method according to claim 4, characterized in that: The step of calculating the target vehicle collision point according to the target obstacle collision point includes: Acquire a first collision point of the vehicle according to the target obstacle collision point; When there are multiple first collision points, define the first collision point closest to the target obstacle collision point among the multiple first collision points as the target vehicle collision point; and / or When the number of the first collision point is one, the first collision point is defined as the target vehicle collision point.

7. The emergency braking parking assistance method according to claim 1, characterized in that: The calculating the collision time according to the target obstacle collision point and the target vehicle collision point includes: Get the first vector from the first curvature center to the target vehicle collision point as ; Get the second vector from the first curvature center to the target obstacle collision point as ; Calculating the collision time according to the first vector and the second vector; Wherein, the collision time is: ; is the safe distance between the target vehicle collision point and the target obstacle collision point, v is the linear speed of the vehicle, is the second radius of curvature.

8. The emergency braking parking assistance method according to claim 2, characterized in that: The vehicle characteristics include: the length and width of the vehicle; The step of obtaining a trajectory range of the vehicle according to the backward trajectory and the vehicle characteristics of the vehicle includes: Obtaining the coordinates of the vehicle angles of the vehicle according to the vehicle characteristics and the center of the front axle of the vehicle and the center of the rear axle of the vehicle, wherein the vehicle angles are: left front angle, right front angle, right rear angle and right left angle; respectively obtaining the angular distance from the first center of curvature to each of the vehicle corners; The trajectory range is obtained according to a plurality of the angular distances and the first curvature center.

9. An emergency braking parking assistance system based on laser radar, characterized in that: The emergency braking parking assistance system applies the laser radar-based emergency braking parking assistance method according to any one of claims 1 to 8, and the emergency braking parking assistance system includes: a first acquisition module, the first acquisition module being used to acquire a backward trajectory of the vehicle when the emergency parking assistance system is activated, wherein the backward trajectory is: an arc with a first curvature center as a circle center and a first curvature radius as a radius; a second acquisition module, the second acquisition module being used to obtain a trajectory range of the vehicle according to the backward trajectory and vehicle characteristics of the vehicle; A first judgment module, the first judgment module is used to judge whether there is a collision obstacle within the trajectory range; A third acquisition module, the third acquisition module is used to acquire a target obstacle collision point and a target vehicle collision point when the collision obstacle exists within the trajectory range; A calculation module, the calculation module is used to calculate the collision time according to the target obstacle collision point and the target vehicle collision point; An execution module is used to control the braking moment of the vehicle according to the collision time.

10. A vehicle, characterized in that: The vehicle includes: a processor, a memory, and a program or instruction stored in the memory and executable on the processor, wherein the program or instruction, when executed by the processor, implements the steps of the laser radar-based emergency braking parking assistance method as described in any one of claims 1 to 8.

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