Method and apparatus for controlling travelling speed of autonomous vehicle

Abstract

A method and apparatus for controlling the travelling speed of an autonomous vehicle, which relate to the technical field of autonomous driving. The method comprises: in response to detecting an obstacle vehicle, acquiring ego-vehicle center coordinates of an autonomous vehicle, and the azimuth angle, turning radius and front outer steering wheel coordinates of the obstacle vehicle; calculating the coordinates of circle center of a cut-in region of the obstacle vehicle, wherein the cut-in region is a region which uses as a cut-in boundary a steering circle formed by the obstacle vehicle when moving according to the maximum turning angle; determining whether the autonomous vehicle is located in the cut-in region of the obstacle vehicle; when the autonomous vehicle is located in the cut-in region of the obstacle vehicle, calculating the minimum distance between the autonomous vehicle and the cut-in region of the obstacle vehicle, and on the basis of the minimum distance, determining a deceleration strategy; and on the basis of the deceleration strategy, controlling the travelling speed of the autonomous vehicle. The method implements safer autonomous driving, and avoids rear-end collision problems caused by irrational braking or emergency braking.

Description

Method and device for controlling driving speed of autonomous vehicle

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202410082572.2, filed on January 19, 2024, entitled “Method and device for controlling the driving speed of an autonomous driving vehicle.” The disclosure of the above-mentioned Chinese patent application is hereby incorporated by reference in its entirety as part or all of this application. Technical Field

[0003] The present disclosure relates to the field of autonomous driving technology, and in particular to a method and device for controlling the driving speed of an autonomous driving vehicle. Background Art

[0004] When an autonomous vehicle (the main vehicle) encounters an oncoming vehicle while driving, it determines whether there is a collision risk based on the planned trajectory output by the planning module and the predicted trajectories of surrounding vehicles (obstacle vehicles) obtained from the prediction module. If the predicted trajectory of the oncoming vehicle conflicts with the planned trajectory of the main vehicle, the main vehicle will brake suddenly to avoid the collision and ensure safe driving. When the main vehicle encounters an oncoming obstacle vehicle, existing methods generally determine whether the two vehicles will collide based on the distance between the main vehicle and the obstacle vehicle. If the distance is less than the safe distance, the main vehicle will brake suddenly to avoid the collision.

[0005] In the process of implementing the present disclosure, the inventors discovered that the prior art has at least the following problems:

[0006] In existing technologies, the distance calculation between two vehicles often results in large errors due to the varying sizes of obstacle vehicles and the large variations in the azimuth of the obstacle vehicle about to cut into the main vehicle. This results in inaccurate calculation of the safe distance, leading to collisions and seriously affecting the driving safety of autonomous vehicles. Summary of the Invention

[0007] In view of this, the embodiments of the present disclosure provide a method and device for controlling the driving speed of an autonomous vehicle, which can calculate the minimum distance from the autonomous vehicle to the obstacle vehicle's entry area based on the turning radius and turning circle of the obstacle vehicle, and further calculate the corresponding autonomous vehicle speed decision conditions based on this minimum distance, so that the speed planning of the autonomous vehicle is safer and more reasonable, thereby achieving safer autonomous driving and avoiding rear-end collisions caused by unreasonable braking or sudden braking.

[0008] To achieve the above objectives, according to one aspect of an embodiment of the present disclosure, a method for controlling the driving speed of an autonomous driving vehicle is provided, comprising:

[0009] In response to detecting an obstacle vehicle, obtaining the center coordinates of the main vehicle of the autonomous driving vehicle, the azimuth angle, the turning radius, and the front outer steering wheel coordinates of the obstacle vehicle;

[0010] Calculating the center coordinates of the barrier vehicle's entry area based on the barrier vehicle's azimuth angle, turning radius, and front outer steering wheel coordinates, wherein the entry area is defined by the turning circle formed when the barrier vehicle moves at its maximum turning angle;

[0011] Determining whether the autonomous vehicle is within the barrier vehicle's cut-in area based on the main vehicle's center coordinates, the barrier vehicle's center coordinates, the barrier vehicle's turning radius, and the distance from the autonomous vehicle's center to the vehicle's forward vertex;

[0012] When the autonomous vehicle is within the cut-in area of ​​the barrier vehicle, a minimum distance between the autonomous vehicle and the cut-in area is calculated based on the center coordinates of the main vehicle and the center coordinates of the barrier vehicle's cut-in area, and a deceleration strategy is determined based on the minimum distance, the braking distance required for the autonomous vehicle to brake at maximum deceleration, and a preset buffer distance.

[0013] The driving speed of the autonomous driving vehicle is controlled according to the deceleration strategy.

[0014] According to one or more embodiments, whether the autonomous driving vehicle is located in the cut-in area of ​​the obstacle vehicle is determined based on the center coordinates of the main vehicle, the center coordinates of the cut-in area of ​​the obstacle vehicle, the turning radius, and the distance from the center of the autonomous driving vehicle to the forward vertex of the vehicle body, including: calculating a first distance between the center of the autonomous driving vehicle and the center of the cut-in area of ​​the obstacle vehicle based on the center coordinates of the main vehicle and the center coordinates of the cut-in area of ​​the obstacle vehicle; if the first distance is not greater than the turning radius and the distance from the center of the autonomous driving vehicle to the forward vertex of the vehicle body, determining that the autonomous driving vehicle is located in the cut-in area of ​​the obstacle vehicle; if the first distance is greater than the turning radius and the distance from the center of the autonomous driving vehicle to the forward vertex of the vehicle body, determining that the autonomous driving vehicle is not located in the cut-in area of ​​the obstacle vehicle.

[0015] According to the one or more embodiments, the minimum distance between the autonomous driving vehicle and the barrier vehicle's cut-in area is calculated based on the main vehicle center coordinates and the circle center coordinates, including: obtaining a vector representation formed by the center of the autonomous driving vehicle and the center of the barrier vehicle's cut-in area based on the main vehicle center coordinates and the circle center coordinates; calculating a first distance between the center of the autonomous driving vehicle and the center of the barrier vehicle's cut-in area based on the vector representation; calculating a projection distance of the vector representation in the driving direction of the autonomous driving vehicle and a straight-line distance from the center of the barrier vehicle's cut-in area to the driving direction of the autonomous driving vehicle based on a unit vector in the driving direction of the autonomous driving vehicle and a vector representation formed by the center of the autonomous driving vehicle and the center of the barrier vehicle's cut-in area; and calculating the minimum distance between the autonomous driving vehicle and the barrier vehicle's cut-in area based on the distance, the straight-line distance, the turning radius of the barrier vehicle, the distance between the center of the autonomous driving vehicle and the front boundary of the vehicle body, and the diameter of the circumscribed circle of the barrier vehicle.

[0016] According to the one or more embodiments, the method further includes: determining that the deceleration strategy is a slow braking strategy when the autonomous driving vehicle is not located in the cutting-in area of ​​the obstacle vehicle.

[0017] According to the one or more embodiments, the deceleration strategy is determined based on the minimum distance, the braking distance required for the autonomous driving vehicle to brake at maximum deceleration and the preset buffer distance, including: when the minimum distance is greater than the sum of the braking distance required for the autonomous driving vehicle to brake at maximum deceleration and the preset buffer distance, determining the deceleration strategy to be a slow braking strategy; when the minimum distance is not greater than the sum of the braking distance required for the autonomous driving vehicle to brake at maximum deceleration and the preset buffer distance, determining the deceleration strategy to be an emergency braking strategy.

[0018] According to the one or more embodiments, the driving speed of the autonomous driving vehicle is controlled according to the deceleration strategy, including: when the deceleration strategy is a gentle braking strategy, the driving speed of the autonomous driving vehicle is controlled according to the current driving speed of the autonomous driving vehicle and the first deceleration; when the deceleration strategy is a sudden braking strategy, the driving speed of the autonomous driving vehicle is controlled according to the current driving speed of the autonomous driving vehicle and the maximum deceleration; wherein the first deceleration is less than the maximum deceleration.

[0019] According to another aspect of the present disclosure, a device for controlling the driving speed of an autonomous vehicle is provided, comprising:

[0020] a vehicle data acquisition module, configured to acquire, in response to detecting an obstacle vehicle, the center coordinates of the main vehicle of the autonomous driving vehicle, the azimuth angle, turning radius, and front outer steering wheel coordinates of the obstacle vehicle;

[0021] a center coordinate calculation module for calculating the center coordinates of the barrier vehicle's entry area based on the barrier vehicle's azimuth angle, turning radius, and front outer steering wheel coordinates, wherein the entry area is defined by the turning circle formed when the barrier vehicle moves at its maximum turning angle;

[0022] an area distance determination module, configured to determine whether the autonomous driving vehicle is within the barrier vehicle's entry area based on the center coordinates of the main vehicle, the center coordinates of the barrier vehicle's entry area, the barrier vehicle's turning radius, and the distance from the center of the autonomous driving vehicle to the forward vertex of the vehicle body;

[0023] a deceleration strategy determination module, configured to calculate, when the autonomous vehicle is within the cut-in area of ​​the obstacle vehicle, a minimum distance between the autonomous vehicle and the cut-in area based on the center coordinates of the main vehicle and the center coordinates of the cut-in area of ​​the obstacle vehicle, and determine a deceleration strategy based on the minimum distance, a braking distance required for the autonomous vehicle to brake at maximum deceleration, and a preset buffer distance;

[0024] A driving speed control module is used to control the driving speed of the autonomous driving vehicle according to the deceleration strategy.

[0025] According to one or more embodiments, the area distance judgment module is also used to: calculate the first distance between the center of the autonomous driving vehicle and the center of the obstacle vehicle's cut-in area based on the center coordinates of the main vehicle and the center coordinates of the obstacle vehicle's cut-in area; if the first distance is not greater than the turning radius and the distance from the center of the autonomous driving vehicle to the forward vertex of the vehicle body, determine that the autonomous driving vehicle is within the cut-in area of ​​the obstacle vehicle; if the first distance is greater than the turning radius and the distance from the center of the autonomous driving vehicle to the forward vertex of the vehicle body, determine that the autonomous driving vehicle is not within the cut-in area of ​​the obstacle vehicle.

[0026] According to another aspect of an embodiment of the present disclosure, an electronic device is provided, comprising: one or more processors; a storage device for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement the method for controlling the driving speed of an autonomous driving vehicle provided in an embodiment of the present disclosure.

[0027] According to another aspect of an embodiment of the present disclosure, a computer-readable medium is provided, on which a computer program is stored. When the program is executed by a processor, the method for controlling the driving speed of an autonomous driving vehicle provided by an embodiment of the present disclosure is implemented.

[0028] The further effects of the above-mentioned non-conventional optional manner will be described below in conjunction with specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are used to better understand the present disclosure and do not constitute an improper limitation of the present disclosure.

[0030] FIG1 is a schematic diagram of the main steps of a method for controlling the driving speed of an autonomous driving vehicle according to an embodiment of the present disclosure;

[0031] FIG2 is a schematic diagram of the positional relationship between the autonomous driving vehicle and the obstacle vehicle according to an embodiment of the present disclosure;

[0032] FIG3 is a schematic diagram of rectangular parameters of an autonomous driving vehicle according to an embodiment of the present disclosure;

[0033] FIG4 is a schematic diagram of a control flow of a driving speed according to an embodiment of the present disclosure;

[0034] FIG5 is a schematic diagram of main modules of a device for controlling the driving speed of an autonomous driving vehicle according to an embodiment of the present disclosure;

[0035] FIG6 is a diagram of an exemplary system architecture in which embodiments of the present disclosure may be applied;

[0036] FIG7 is a schematic diagram of the structure of a computer system of a terminal device or a server suitable for implementing an embodiment of the present disclosure. DETAILED DESCRIPTION

[0037] The following description of exemplary embodiments of the present disclosure is made in conjunction with the accompanying drawings, including various details of the embodiments of the present disclosure to facilitate understanding. These details should be considered as merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present disclosure. Similarly, for the sake of clarity and conciseness, descriptions of well-known functions and structures are omitted in the following description.

[0038] It should be noted that the collection, collection, updating, analysis, processing, use, transmission, and storage of user personal information involved in the technical solutions disclosed in this application all comply with relevant laws and regulations, are used for legitimate purposes, and do not violate public order and good morals. Necessary measures will be taken with respect to user personal information to prevent unauthorized access to user personal information data and to maintain the security of user personal information, network security, and national security.

[0039] In order to avoid collisions, the present disclosure takes the turning radius of the obstacle vehicle into consideration, and defines the turning circle formed by the maximum turning angle movement of the obstacle vehicle as the entry boundary. The minimum distance from the autonomous driving vehicle (i.e., the main vehicle) to the entry boundary is the minimum distance between the autonomous driving vehicle (i.e., the main vehicle) and the entry area of ​​the obstacle vehicle. The conditions for the main vehicle's braking strategy are calculated based on the minimum distance, so that the main vehicle can make more reasonable predictions to achieve safer autonomous driving and avoid rear-end collisions caused by unreasonable braking or sudden braking. The present disclosure calculates the minimum distance from the main vehicle to the entry area of ​​the obstacle vehicle based on the turning radius and turning circle of the obstacle vehicle, and further calculates the corresponding main vehicle speed decision conditions based on this minimum distance, so that the main vehicle's speed planning is safer and more reasonable.

[0040] FIG1 is a schematic diagram of the main steps of a method for controlling the driving speed of an autonomous vehicle according to an embodiment of the present disclosure. As shown in FIG1 , the method for controlling the driving speed of an autonomous vehicle according to an embodiment of the present disclosure mainly includes the following steps S101 to S105.

[0041] Step S101: In response to detecting an obstacle vehicle, the main vehicle center coordinates, the azimuth angle, turning radius, and front outer steering wheel coordinates of the autonomous driving vehicle are obtained. The main vehicle center coordinates generally refer to the rear wheel center coordinates of the main vehicle (in the subsequent embodiments of this disclosure, the main vehicle refers to the autonomous driving vehicle); the azimuth angle of the obstacle vehicle refers to the angle between the 0-degree azimuth angle (e.g., due north or due east) set in the map coordinate system and the driving direction of the obstacle vehicle; the turning radius of the obstacle vehicle can be calculated based on the length of the obstacle vehicle, which can be obtained based on the model of the obstacle vehicle; the front outer steering wheel of the obstacle vehicle refers to the front wheel on the outside of the vehicle's turning direction. For example, if the vehicle turns right, the front left wheel is the front outer steering wheel, and the front right wheel is the front inner steering wheel.

[0042] Step S102: Calculating the center coordinates of the barrier vehicle's entry area based on the barrier vehicle's azimuth angle, turning radius, and front outer steering wheel coordinates. The entry area is an area with the turning circle formed when the barrier vehicle moves at the maximum turning angle as the entry boundary.

[0043] Step S103: Determine whether the autonomous driving vehicle is within the entry area of ​​the obstacle vehicle based on the main vehicle center coordinates, the circle center coordinates, the turning radius, and the distance from the center of the autonomous driving vehicle to the forward vertex of the vehicle body.

[0044] According to one embodiment of the present disclosure, whether the autonomous driving vehicle is located in the cut-in area of ​​the obstacle vehicle is determined based on the main vehicle center coordinates, the circle center coordinates, the turning radius, and the distance from the center of the autonomous driving vehicle to the forward vertex of the vehicle body. Specifically, the method may include: calculating a first distance between the center of the autonomous driving vehicle and the center of the cut-in area of ​​the obstacle vehicle based on the main vehicle center coordinates and the circle center coordinates; if the first distance is not greater than the turning radius and the distance from the center of the autonomous driving vehicle to the forward vertex of the vehicle body, determining that the autonomous driving vehicle is located in the cut-in area of ​​the obstacle vehicle; if the first distance is greater than the turning radius and the distance from the center of the autonomous driving vehicle to the forward vertex of the vehicle body, determining that the autonomous driving vehicle is not located in the cut-in area of ​​the obstacle vehicle.

[0045] Step S104: When the autonomous vehicle is within the barrier vehicle's cut-in zone, the minimum distance between the autonomous vehicle and the barrier vehicle's cut-in zone is calculated based on the host vehicle's center coordinates and the circle's center coordinates. A deceleration strategy is then determined based on the minimum distance, the braking distance required for the autonomous vehicle to brake at maximum deceleration, and a preset buffer distance. Deceleration refers to the rate of change of an object's momentum, which is the opposite of acceleration and represents the object's deceleration. It can generally be expressed using the following formula: deceleration a = -|dV / dt|, where dV / dt is the rate of change of the object's velocity.

[0046] According to another embodiment of the present disclosure, calculating the minimum distance between the autonomous driving vehicle and the barrier vehicle's cut-in area based on the main vehicle center coordinates and the circle center coordinates may specifically include: obtaining a vector representation formed by the center of the autonomous driving vehicle and the center of the barrier vehicle's cut-in area based on the main vehicle center coordinates and the circle center coordinates; calculating a first distance between the center of the autonomous driving vehicle and the center of the barrier vehicle's cut-in area based on the vector representation; calculating a projection distance of the vector representation in the autonomous driving vehicle's travel direction and a straight-line distance from the center of the barrier vehicle's cut-in area to the autonomous driving vehicle's travel direction based on a unit vector in the autonomous driving vehicle's travel direction and a vector representation formed by the center of the autonomous driving vehicle and the center of the barrier vehicle's cut-in area; and calculating the minimum distance between the autonomous driving vehicle and the barrier vehicle's cut-in area based on the distance, the straight-line distance, the barrier vehicle's turning radius, the distance between the center of the autonomous driving vehicle and the front boundary of the vehicle body, and the circumscribed circle diameter of the barrier vehicle.

[0047] Step S105: Control the driving speed of the autonomous driving vehicle according to the deceleration strategy.

[0048] According to another embodiment of the present disclosure, the autonomous driving vehicle speed control method of the present disclosure further includes: when the autonomous driving vehicle is not located in the cut-in area of ​​the obstacle vehicle, determining that the deceleration strategy is a slow braking strategy.

[0049] According to another embodiment of the present disclosure, the deceleration strategy is determined based on the minimum distance, the braking distance required for the autonomous driving vehicle to brake at maximum deceleration, and a preset buffer distance. Specifically, it may include: when the minimum distance is greater than the sum of the braking distance required for the autonomous driving vehicle to brake at maximum deceleration and the preset buffer distance, determining the deceleration strategy to be a slow braking strategy; when the minimum distance is not greater than the sum of the braking distance required for the autonomous driving vehicle to brake at maximum deceleration and the preset buffer distance, determining the deceleration strategy to be an emergency braking strategy.

[0050] According to another embodiment of the present disclosure, controlling the driving speed of the autonomous driving vehicle according to the deceleration strategy may specifically include: when the deceleration strategy is a gentle braking strategy, controlling the driving speed of the autonomous driving vehicle according to the current driving speed of the autonomous driving vehicle and a first deceleration; when the deceleration strategy is an emergency braking strategy, controlling the driving speed of the autonomous driving vehicle according to the current driving speed of the autonomous driving vehicle and the maximum deceleration; wherein the first deceleration is less than the maximum deceleration.

[0051] The specific implementation process of the present disclosure is described below in conjunction with specific embodiments.

[0052] In the disclosed embodiment, the turning circle formed by the obstacle vehicle's maximum turning angle is first defined as the entry boundary of the entry zone. The minimum distance between the host vehicle and the entry boundary is then defined as the minimum distance between the host vehicle and the obstacle vehicle's entry zone. The maximum turning angle refers to the maximum steering angle of the front wheels. This maximum turning angle may vary for different vehicles, typically ranging from 30 to 40 degrees. This maximum turning angle can be pre-set for different vehicles.

[0053] As shown in Figure 2, the geometric relationship between the main vehicle and the obstacle vehicle defined in the embodiment of the present disclosure is shown. Figure 2 is a schematic diagram of the positional relationship between the autonomous driving vehicle and the obstacle vehicle in one embodiment of the present disclosure. For the convenience of calculation, the body of the vehicle is generally represented by a rectangle. In the figure, Ego is the body rectangle of the main vehicle, Obs is the body rectangle of the obstacle vehicle, A is the center of the main vehicle (generally the center of the rear wheel), B is the center of the obstacle vehicle, and C is the contact point between the front outer steering wheel of the obstacle vehicle and the ground. When the obstacle vehicle cuts in front of the main vehicle, assuming that the obstacle vehicle always cuts in at the maximum turning angle, the closest cutting-in boundary to the main vehicle can be represented by the turning circle with O as the center in Figure 2. The radius r of the turning circle is the turning radius of the obstacle vehicle. If the length of the obstacle vehicle body rectangle is given as L, the empirical algorithm for the turning radius is generally:

[0054] r=2.4*L (1)

[0055] Taking Figure 2 as an example, the coordinates of point C can generally be directly obtained from the obstacle vehicle body rectangle, using (x c ,y c ) represents the coordinates of the center O (x o ,y o ) can be calculated based on the azimuth angle θ of the obstacle vehicle Obs The relationship between the turning radius r and the center of the circle O can be obtained from Figure 2. The specific calculation formula is as follows:

[0056] x o =x c +r*sin(θ Obs ), y o =y c +r*cos(θ Obs ) (2)

[0057] The coordinates of point A can be directly obtained from the main vehicle information, using (x a ,y a ), then the vector formed by the center of the rear wheel of the main vehicle and the center O of the turning circle of the cut-in area is expressed as:

[0058] Then we can get:

[0059] in, It represents the unit vector in the direction of the main vehicle's travel, which can be obtained by intercepting two points on the main vehicle's travel path and normalizing them. d1 and d2 are the lengths of the AD and DO segments shown in Figure 2. The calculation of d1 can be obtained by formula (5), which represents the dot product of two vectors. The result is the vector In the direction of the main vehicle The projection distance on is the length of d1. The calculation of d2 can be obtained by formula (6), which represents the cross product of two vectors. The calculation result is the distance from point O to vector The distance of the straight line in the direction (the direction of travel of the autonomous driving vehicle) (denoted as: the straight line distance from point O to the direction of travel of the autonomous driving vehicle), that is, the size of d2.

[0060] According to the geometric relationship of triangles, we can get:

[0061] Here, d3 refers to the length of the line segment DE shown in Figure 2, and E is the intersection of the driving direction of the autonomous driving vehicle and the cutting boundary.

[0062] In conjunction with FIG3 , which is a schematic diagram of rectangular parameters of an autonomous driving vehicle according to an embodiment of the present disclosure, based on the above relationship and the geometric relationship in FIG2 , and taking into account the uncertainties of the main vehicle's body rectangle, the obstacle vehicle's body rectangle, and the obstacle vehicle's azimuth, the minimum distance between the main vehicle and the obstacle vehicle's entry boundary is calculated as follows:

[0063] d min =d1+d3-l f -R Obs *2 (8)

[0064] Among them, use l f R represents the distance from the center of the vehicle (i.e., the center of the rear wheel) to the front edge of the vehicle body shown in Figure 3. Obs *2 is the circumscribed circle diameter of the obstacle vehicle. Since the azimuth angle of the obstacle vehicle is not constant during the cutting process and is subject to uncertainty due to various random factors, to ensure safety, the circumscribed circle diameter of the obstacle vehicle must be subtracted when calculating the minimum distance between the main vehicle and the obstacle vehicle cutting area.

[0065] Combining Figures 2 and 3, the minimum distance between the autonomous driving vehicle and the obstacle vehicle in the cut-in area can be calculated.

[0066] After obtaining the minimum distance between the main vehicle and the obstacle vehicle in the cut-in area, the driving speed can be controlled in conjunction with Figure 4. Figure 4 is a schematic diagram of the driving speed control process of an embodiment of the present disclosure. As shown in Figure 4, first determine according to formula (9):

[0067] in, is the distance from the rear wheel center of the main vehicle to the forward vertex of the vehicle body, as shown in Figure 3. If the condition in (9) is met, it means that the main vehicle is not within the cut-in range of the obstacle vehicle. At this time, the main vehicle can first adopt a slow braking strategy to interact, that is, decelerate at a smaller deceleration (i.e., the first deceleration).

[0068] If the condition in (9) is not met, it is necessary to continue to determine whether the condition (10) is met:

[0069] d min >d safe +d buffer (10)

[0070] in, The current speed of the main vehicle is v cur The maximum deceleration a max The braking distance required for braking. It should be noted that there is a time delay t between the main vehicle issuing the braking command and the chassis executing it. delay , so when calculating the braking distance d safe This delay needs to be considered. In addition, considering the uncertainty of the dynamic obstacle vehicle, the buffer distance d needs to be considered. buffer , where the buffer distance is a pre-set parameter, that is, the main vehicle needs to maintain a buffer distance with the obstacle vehicle after braking at the maximum deceleration to ensure safety. If the conditions shown in formula (10) are met, a slow braking strategy can be adopted to decelerate at a smaller deceleration (i.e., the first deceleration); if not, the main vehicle's speed planning module needs to adopt an emergency braking strategy to slow down at the maximum deceleration a max Slow down and brake to avoid collision with obstacle vehicles.

[0071] The maximum deceleration of the main vehicle can be pre-set, or calculated based on the minimum distance between the main vehicle and the obstacle vehicle, or based on the current speed v of the main vehicle. cur The specific calculation method can be flexibly set according to needs.

[0072] Figure 5 is a schematic diagram of the main modules of a device for controlling the speed of an autonomous vehicle according to an embodiment of the present disclosure. As shown in Figure 5 , the device 500 for controlling the speed of an autonomous vehicle according to an embodiment of the present disclosure primarily includes a vehicle data acquisition module 501, a circle center coordinate calculation module 502, a zone distance determination module 503, a deceleration strategy determination module 504, and a speed control module 505.

[0073] The vehicle data acquisition module 501 is configured to acquire the center coordinates of the main vehicle of the autonomous driving vehicle, the azimuth angle, turning radius, and front outer steering wheel coordinates of the obstacle vehicle in response to detecting the obstacle vehicle;

[0074] A center coordinate calculation module 502 is configured to calculate the center coordinates of the barrier vehicle's entry area based on the barrier vehicle's azimuth angle, turning radius, and front outer steering wheel coordinates. The entry area is defined as an area defined by the turning circle formed when the barrier vehicle moves at its maximum turning angle.

[0075] The area distance determination module 503 is configured to determine whether the autonomous driving vehicle is within the barrier vehicle's cut-in area based on the main vehicle center coordinates, the circle center coordinates, the turning radius, and the distance from the center of the autonomous driving vehicle to the forward vertex of the vehicle body;

[0076] a deceleration strategy determination module 504 for calculating, when the autonomous vehicle is within the cut-in zone of the obstacle vehicle, a minimum distance between the autonomous vehicle and the cut-in zone based on the center coordinates of the host vehicle and the center coordinates of the circle, and determining a deceleration strategy based on the minimum distance, a braking distance required for the autonomous vehicle to brake at maximum deceleration, and a preset buffer distance;

[0077] The driving speed control module 505 is used to control the driving speed of the autonomous driving vehicle according to the deceleration strategy.

[0078] According to one embodiment of the present disclosure, the area distance judgment module 503 can also be used to: calculate the first distance between the center of the autonomous driving vehicle and the center of the circle of the obstacle vehicle based on the center coordinates of the main vehicle and the center coordinates of the circle; when the first distance is not greater than the turning radius and the distance from the center of the autonomous driving vehicle to the forward vertex of the vehicle body, determine that the autonomous driving vehicle is within the obstacle vehicle's cut-in area; when the first distance is greater than the turning radius and the distance from the center of the autonomous driving vehicle to the forward vertex of the vehicle body, determine that the autonomous driving vehicle is not within the obstacle vehicle's cut-in area.

[0079] According to another embodiment of the present disclosure, when calculating the minimum distance between the autonomous driving vehicle and the obstacle vehicle's cut-in area based on the main vehicle center coordinates and the circle center coordinates, the deceleration strategy determination module 504 may further be configured to: obtain a vector representation formed by the center of the autonomous driving vehicle and the center of the obstacle vehicle's cut-in area based on the main vehicle center coordinates and the circle center coordinates; calculate a first distance between the center of the autonomous driving vehicle and the center of the obstacle vehicle's cut-in area based on the vector representation; calculate a projection distance of the vector representation in the autonomous driving vehicle's travel direction and a straight-line distance from the center of the obstacle vehicle's cut-in area to the autonomous driving vehicle's travel direction based on a unit vector in the autonomous driving vehicle's travel direction and a vector representation formed by the center of the autonomous driving vehicle and the center of the obstacle vehicle's cut-in area; and calculate the minimum distance between the autonomous driving vehicle and the obstacle vehicle's cut-in area based on the distance, the straight-line distance, the obstacle vehicle's turning radius, the distance between the center of the autonomous driving vehicle and the front boundary of the vehicle body, and the diameter of the circumscribed circle of the obstacle vehicle.

[0080] According to another embodiment of the present disclosure, the deceleration strategy determination module 504 may also be used to determine that the deceleration strategy is a slow braking strategy when the autonomous driving vehicle is not located in the cut-in area of ​​the obstacle vehicle.

[0081] According to another embodiment of the present disclosure, when determining the deceleration strategy based on the minimum distance, the braking distance required for the autonomous driving vehicle to brake at maximum deceleration and the preset buffer distance, the deceleration strategy determination module 504 can also be used to: determine that the deceleration strategy is a slow braking strategy when the minimum distance is greater than the sum of the braking distance required for the autonomous driving vehicle to brake at maximum deceleration and the preset buffer distance; and determine that the deceleration strategy is an emergency braking strategy when the minimum distance is not greater than the sum of the braking distance required for the autonomous driving vehicle to brake at maximum deceleration and the preset buffer distance.

[0082] According to another embodiment of the present disclosure, the driving speed control module 505 can also be used to: when the deceleration strategy is a gentle braking strategy, control the driving speed of the autonomous driving vehicle according to the current driving speed of the autonomous driving vehicle and the first deceleration; when the deceleration strategy is an emergency braking strategy, control the driving speed of the autonomous driving vehicle according to the current driving speed of the autonomous driving vehicle and the maximum deceleration; wherein, the first deceleration is less than the maximum deceleration.

[0083] According to the technical solution of the embodiment of the present disclosure, in response to detecting an obstacle vehicle, the center coordinates of the main vehicle of the autonomous driving vehicle, the azimuth angle, turning radius and front outer steering wheel coordinates of the obstacle vehicle are obtained; the center coordinates of the circle of the obstacle vehicle's cut-in area are calculated based on the azimuth angle, turning radius and front outer steering wheel coordinates of the obstacle vehicle, and the cut-in area is an area with the turning circle formed when the obstacle vehicle moves at the maximum turning angle as the cut-in boundary; the autonomous driving vehicle is judged whether it is located in the cut-in area of ​​the obstacle vehicle based on the center coordinates of the main vehicle, the center coordinates of the circle, the turning radius and the distance from the center of the autonomous driving vehicle to the forward vertex of the vehicle body; if the autonomous driving vehicle is located in the cut-in area of ​​the obstacle vehicle, the center coordinates of the main vehicle are calculated based on the center coordinates of the main vehicle The minimum distance between the autonomous driving vehicle and the obstacle vehicle's entry area is calculated based on the coordinates and the center coordinates of the circle, and the deceleration strategy is determined based on the minimum distance, the braking distance required for the autonomous driving vehicle to brake at maximum deceleration, and the preset buffer distance; the technical solution for controlling the driving speed of the autonomous driving vehicle according to the deceleration strategy realizes the calculation of the minimum distance from the autonomous driving vehicle to the obstacle vehicle's entry area based on the turning radius and turning circle of the obstacle vehicle, and further calculates the corresponding autonomous driving vehicle speed decision conditions based on this minimum distance, making the speed planning of the autonomous driving vehicle safer and more reasonable, thereby achieving safer autonomous driving and avoiding rear-end collisions caused by unreasonable braking or sudden braking.

[0084] FIG6 shows an exemplary system architecture 600 to which the method for controlling the driving speed of an autonomous vehicle or the device for controlling the driving speed of an autonomous vehicle according to an embodiment of the present disclosure can be applied.

[0085] As shown in Figure 6, system architecture 600 may include terminal devices 601, 602, and 603, a network 604, and a server 605. Network 604 is used to provide a medium for communication links between terminal devices 601, 602, and 603 and server 605. Network 604 may include various connection types, such as wired or wireless communication links or fiber optic cables.

[0086] Users can use terminal devices 601, 602, and 603 to interact with server 605 via network 604 to receive or send messages, etc. Various communication client applications can be installed on terminal devices 601, 602, and 603, such as navigation applications, control applications, search applications, instant messaging tools, email clients, social platform software, etc. (only as examples).

[0087] The terminal devices 601 , 602 , and 603 may be various electronic devices having a display screen and supporting web browsing, including but not limited to smart phones, tablet computers, laptop computers, and desktop computers.

[0088] The server 605 may be a server that provides various services, such as a background management server that provides support for websites browsed by users using the terminal devices 601 , 602 , and 603 (only as an example). The backend management server may respond to received vehicle speed control requests and other data by detecting an obstructing vehicle and obtaining the center coordinates of the autonomous vehicle's main vehicle, the obstructing vehicle's azimuth, turning radius, and front outer steering wheel coordinates; calculate the center coordinates of a cut-in area for the obstructing vehicle based on the obstructing vehicle's azimuth, turning radius, and front outer steering wheel coordinates, where the cut-in area is defined by the turning circle formed when the obstructing vehicle moves at its maximum turning angle; determine whether the autonomous vehicle is within the obstructing vehicle's cut-in area based on the main vehicle's center coordinates, the circle's center coordinates, the turning radius, and the distance from the center of the autonomous vehicle to the forward vertex of the vehicle body; and, if the autonomous vehicle is within the obstructing vehicle's cut-in area, calculate the minimum distance between the autonomous vehicle and the obstructing vehicle's cut-in area based on the main vehicle's center coordinates and the circle's center coordinates, and determine a deceleration strategy based on the minimum distance, the braking distance required for the autonomous vehicle to brake at maximum deceleration, and a preset buffer distance; perform other processing on the autonomous vehicle's speed based on the deceleration strategy, and feed back the processing result (e.g., a target driving speed—for example only) to the terminal device.

[0089] It should be noted that the method for controlling the driving speed of the autonomous driving vehicle provided in the embodiment of the present disclosure is generally executed by the server 605. Accordingly, the device for controlling the driving speed of the autonomous driving vehicle is generally set in the server 605.

[0090] It should be understood that the number of terminal devices, networks, and servers in Figure 6 is merely illustrative and any number of terminal devices, networks, and servers may be provided as required.

[0091] 7, which shows a schematic diagram of a computer system 700 suitable for implementing a terminal device or server according to an embodiment of the present disclosure. The terminal device or server shown in FIG7 is merely an example and should not limit the functionality and scope of use of the embodiments of the present disclosure.

[0092] As shown in FIG7 , a computer system 700 includes a central processing unit (CPU) 701, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 702 or a program loaded from a storage unit 708 into a random access memory (RAM) 703. Various programs and data required for the operation of the system 700 are also stored in the RAM 703. The CPU 701, the ROM 702, and the RAM 703 are connected to each other via a bus 704. An input / output (I / O) interface 705 is also connected to the bus 704.

[0093] The following components are connected to the I / O interface 705: an input section 706 including a keyboard, a mouse, and the like; an output section 707 including devices such as a cathode ray tube (CRT), a liquid crystal display (LCD), and a speaker; a storage section 708 including a hard disk; and a communication section 709 including a network interface card such as a LAN card or a modem. The communication section 709 performs communication processing via a network such as the Internet. A drive 710 is also connected to the I / O interface 705 as needed. A removable medium 711, such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory, is installed in the drive 710 as needed, so that computer programs read therefrom can be installed into the storage section 708 as needed.

[0094] In particular, according to the embodiments disclosed in the present disclosure, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, the embodiments disclosed in the present application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program comprising program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network via the communication section 709, and / or installed from a removable medium 711. When the computer program is executed by the central processing unit (CPU) 701, the above-mentioned functions defined in the system of the present disclosure are executed.

[0095] It should be noted that the computer-readable medium described in the present disclosure may be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or component, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to, an electrical connection having one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present disclosure, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, device, or component. In the present disclosure, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, which carries computer-readable program code. This propagated data signal may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium that can transmit, propagate, or transport a program for use by or in conjunction with an instruction execution system, apparatus, or device. Program code embodied on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wireline, optical fiber cable, RF, or any suitable combination thereof.

[0096] The flowcharts and block diagrams in the accompanying drawings illustrate the possible implementation architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, program segment, or a part of code, and the above-mentioned module, program segment, or a part of code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, and the combination of boxes in the block diagram or flowchart, can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0097] The units or modules involved in the embodiments described in the present disclosure may be implemented by software or by hardware. The units or modules described may also be provided in a processor. For example, they may be described as follows: a processor including a vehicle data acquisition module, a circle center coordinate calculation module, an area distance judgment module, a deceleration strategy determination module, and a driving speed control module. The names of these units or modules do not, in certain cases, constitute a limitation on the units or modules themselves. For example, the driving speed control module may also be described as a "module for controlling the driving speed of the autonomous driving vehicle according to the deceleration strategy."

[0098] As another aspect, the present disclosure further provides a computer-readable medium, which may be included in the device described in the above embodiment; or may exist independently without being assembled into the device. The computer-readable medium carries one or more programs, which, when executed by a device, cause the device to: in response to detecting an obstacle vehicle, obtain the center coordinates of a main vehicle of the autonomous vehicle, the azimuth angle, turning radius, and front outer steering wheel coordinates of the obstacle vehicle; calculate the center coordinates of a cut-in area of ​​the obstacle vehicle based on the azimuth angle, turning radius, and front outer steering wheel coordinates of the obstacle vehicle, wherein the cut-in area is an area defined by a turning circle formed when the obstacle vehicle moves at a maximum turning angle; determine whether the autonomous vehicle is within the cut-in area of ​​the obstacle vehicle based on the center coordinates of the main vehicle, the center coordinates of the circle, the turning radius, and the distance from the center of the autonomous vehicle to the forward vertex of the vehicle body; if the autonomous vehicle is within the cut-in area of ​​the obstacle vehicle, calculate the minimum distance between the autonomous vehicle and the cut-in area of ​​the obstacle vehicle based on the center coordinates of the main vehicle and the center coordinates of the circle, determine a deceleration strategy based on the minimum distance, the braking distance required for the autonomous vehicle to brake at maximum deceleration, and a preset buffer distance; and control the driving speed of the autonomous vehicle based on the deceleration strategy.

[0099] According to the technical solution of the embodiment of the present disclosure, in response to detecting an obstacle vehicle, the center coordinates of the main vehicle of the autonomous driving vehicle, the azimuth angle, turning radius and front outer steering wheel coordinates of the obstacle vehicle are obtained; the center coordinates of the circle of the obstacle vehicle's cut-in area are calculated based on the azimuth angle, turning radius and front outer steering wheel coordinates of the obstacle vehicle, and the cut-in area is an area with the turning circle formed when the obstacle vehicle moves at the maximum turning angle as the cut-in boundary; the autonomous driving vehicle is judged whether it is located in the cut-in area of ​​the obstacle vehicle based on the center coordinates of the main vehicle, the center coordinates of the circle, the turning radius and the distance from the center of the autonomous driving vehicle to the forward vertex of the vehicle body; if the autonomous driving vehicle is located in the cut-in area of ​​the obstacle vehicle, the center coordinates of the main vehicle are calculated based on the center coordinates of the main vehicle The minimum distance between the autonomous driving vehicle and the obstacle vehicle's entry area is calculated based on the coordinates and the center coordinates of the circle, and the deceleration strategy is determined based on the minimum distance, the braking distance required for the autonomous driving vehicle to brake at maximum deceleration, and the preset buffer distance; the technical solution for controlling the driving speed of the autonomous driving vehicle according to the deceleration strategy realizes the calculation of the minimum distance from the autonomous driving vehicle to the obstacle vehicle's entry area based on the turning radius and turning circle of the obstacle vehicle, and further calculates the corresponding autonomous driving vehicle speed decision conditions based on this minimum distance, making the speed planning of the autonomous driving vehicle safer and more reasonable, thereby achieving safer autonomous driving and avoiding rear-end collisions caused by unreasonable braking or sudden braking.

[0100] The above specific embodiments do not constitute a limitation on the scope of protection of this disclosure. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may occur depending on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this disclosure shall be included within the scope of protection of this disclosure.

Claims

1. A control method for the driving speed of an autonomous vehicle, comprising: Upon detecting an obstacle vehicle, obtaining the center coordinates of the host vehicle of the autonomous vehicle, the azimuth angle, turning radius, and coordinates of the front outer steering wheel of the obstacle vehicle; Calculating the center coordinates of the intrusion area of the obstacle vehicle according to the azimuth angle, turning radius, and coordinates of the front outer steering wheel of the obstacle vehicle, where the intrusion area is an area with the steering circle formed when the obstacle vehicle moves at the maximum turning angle as the intrusion boundary; Judging whether the autonomous vehicle is located within the intrusion area of the obstacle vehicle according to the center coordinates of the host vehicle, the center coordinates of the circle, the turning radius, and the distance from the center of the autonomous vehicle to the front vertex of the vehicle body; When the autonomous vehicle is located within the intrusion area of the obstacle vehicle, calculating the minimum distance between the autonomous vehicle and the intrusion area of the obstacle vehicle according to the center coordinates of the host vehicle and the center coordinates of the circle, and determining a deceleration strategy according to the minimum distance, the braking distance required for the autonomous vehicle to brake at the maximum deceleration, and a preset buffer distance; Controlling the driving speed of the autonomous vehicle according to the deceleration strategy.

2. The method according to claim 1, wherein Judging whether the autonomous vehicle is located within the intrusion area of the obstacle vehicle according to the center coordinates of the host vehicle, the center coordinates of the circle, the turning radius, and the distance from the center of the autonomous vehicle to the front vertex of the vehicle body, including: Calculating a first distance between the center of the autonomous vehicle and the center of the intrusion area of the obstacle vehicle according to the center coordinates of the host vehicle and the center coordinates of the circle; Determining that the autonomous vehicle is located within the intrusion area of the obstacle vehicle when the first distance is not greater than the sum of the turning radius and the distance from the center of the autonomous vehicle to the front vertex of the vehicle body; Determining that the autonomous vehicle is not located within the intrusion area of the obstacle vehicle when the first distance is greater than the sum of the turning radius and the distance from the center of the autonomous vehicle to the front vertex of the vehicle body.

3. The method according to claim 1 or 2, wherein Calculating the minimum distance between the autonomous vehicle and the intrusion area of the obstacle vehicle according to the center coordinates of the host vehicle and the center coordinates of the circle, including: Obtaining a vector representation formed by the center of the autonomous vehicle and the center of the intrusion area of the obstacle vehicle according to the center coordinates of the host vehicle and the center coordinates of the circle; Calculating a first distance between the center of the autonomous vehicle and the center of the intrusion area of the obstacle vehicle according to the vector representation; Calculating the projection distance of the vector representation in the driving direction of the autonomous vehicle and the straight-line distance from the center of the intrusion area of the obstacle vehicle to the driving direction of the autonomous vehicle according to the unit vector in the driving direction of the autonomous vehicle and the vector representation formed by the center of the autonomous vehicle and the center of the intrusion area of the obstacle vehicle; Calculating the minimum distance between the autonomous vehicle and the intrusion area of the obstacle vehicle according to the distance, the straight-line distance, the turning radius of the obstacle vehicle, the distance between the center of the autonomous vehicle and the front boundary of the vehicle body, and the outer diameter of the circumscribed circle of the obstacle vehicle.

4. The method according to claim 1, wherein The method further includes: When the autonomous vehicle is not located within the cut-in area of the obstacle vehicle, determine that the deceleration strategy is a gentle braking strategy.

5. The method according to claim 1, wherein, Determine the deceleration strategy according to the minimum distance, the braking distance required for the autonomous vehicle to brake at the maximum deceleration, and a preset buffer distance, including: When the minimum distance is greater than the sum of the braking distance required for the autonomous vehicle to brake at the maximum deceleration and the preset buffer distance, determine that the deceleration strategy is a gentle braking strategy; When the minimum distance is not greater than the sum of the braking distance required for the autonomous vehicle to brake at the maximum deceleration and the preset buffer distance, determine that the deceleration strategy is an emergency braking strategy.

6. The method according to claim 4 or 5, wherein, Control the driving speed of the autonomous vehicle according to the deceleration strategy, including: When the deceleration strategy is a gentle braking strategy, control the driving speed of the autonomous vehicle according to the current driving speed and the first deceleration of the autonomous vehicle; When the deceleration strategy is an emergency braking strategy, control the driving speed of the autonomous vehicle according to the current driving speed and the maximum deceleration of the autonomous vehicle; Wherein, the first deceleration is less than the maximum deceleration.

7. A control device for the driving speed of an autonomous vehicle, comprising: A vehicle data acquisition module, configured to obtain the center coordinates of the host vehicle of the autonomous vehicle, the azimuth angle, turning radius, and the coordinates of the front outer steering wheel of the obstacle vehicle in response to detecting the obstacle vehicle; A center coordinate calculation module, configured to calculate the center coordinates of the cut-in area of the obstacle vehicle according to the azimuth angle, turning radius, and the coordinates of the front outer steering wheel of the obstacle vehicle, where the cut-in area is an area with the steering circle formed when the obstacle vehicle moves at the maximum turning angle as the cut-in boundary; A regional distance judgment module, configured to judge whether the autonomous vehicle is located within the cut-in area of the obstacle vehicle according to the center coordinates of the host vehicle, the center coordinates, the turning radius, and the distance from the center of the autonomous vehicle to the front vertex of the vehicle body; A deceleration strategy determination module, configured to calculate the minimum distance between the autonomous vehicle and the cut-in area of the obstacle vehicle according to the center coordinates of the host vehicle and the center coordinates when the autonomous vehicle is located within the cut-in area of the obstacle vehicle, and determine the deceleration strategy according to the minimum distance, the braking distance required for the autonomous vehicle to brake at the maximum deceleration, and a preset buffer distance; A driving speed control module, configured to control the driving speed of the autonomous vehicle according to the deceleration strategy.

8. The apparatus according to claim 7, wherein, The regional distance judgment module is further configured to: Calculate a first distance between the center of the autonomous vehicle and the center of the cut-in area of the obstacle vehicle according to the center coordinates of the host vehicle and the center coordinates; When the first distance is not greater than the sum of the turning radius and the distance from the center of the autonomous vehicle to the front vertex of the vehicle body, determine that the autonomous vehicle is located within the cut-in area of the obstacle vehicle; When the first distance is greater than the turning radius plus the distance from the center of the autonomous vehicle to the front vertex of the vehicle body, it is determined that the autonomous vehicle is not within the cut-in area of the obstacle vehicle.

9. An electronic device, comprising: One or more processors; A storage device for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors implement the method according to any one of claims 1-6.

10. A computer-readable medium having a computer program stored thereon, the program implementing the method according to any one of claims 1-6 when executed by a processor.

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