A coordinate conversion method and device

Abstract

The application discloses a coordinate conversion method and device, comprising: when finding the minimum reference line interval of a target point on a reference line, starting from the initial reference line interval, if the currently detected reference line interval is not the minimum reference line interval of the target point, calculating the projection of the target point to the first discrete point of the reference interval, determining the advancing step and the advancing direction according to the projection, and determining the new reference line interval through the advancing step and the advancing direction, and cyclically executing the above steps until the minimum reference line interval of the target point on the reference line is found. Thus, the projection of the target point to the first discrete point of the reference interval can point to the direction of the minimum reference line interval and the length of moving to the minimum reference line interval, so that the updated reference line interval is closer to the minimum reference interval of the target point on the reference line, the searching efficiency is improved, the time for finding the minimum reference line interval of the target point on the reference line is shortened, and the coordinate conversion efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of unmanned driving, and in particular to a coordinate conversion method and device. BACKGROUND

[0002] With the development of unmanned driving technology, unmanned vehicles may become the mainstream of public travel in the future. In the driving process, Frenet coordinates are usually used to represent lane deviation and vehicle driving distance.

[0003] However, in general, the coordinates of an object are represented by a Cartesian coordinate system. In order to represent the Frenet coordinates, the Cartesian coordinates need to be converted into Frenet coordinates. However, the existing coordinate conversion technology usually has the problems of large amount of calculation and low calculation efficiency. SUMMARY

[0004] Therefore, the embodiments of the present application disclose a coordinate conversion method and device. The projection of a target point to a reference line interval is calculated to determine the step length and the forward direction, and the new reference line interval is determined based on the step length and the forward direction, so that the new reference line interval is closer to the minimum reference line interval of the target point on the reference line, improving the search efficiency and shortening the time to find the minimum reference line interval.

[0005] The embodiments of the present application disclose a coordinate conversion method, comprising:

[0006] determining the reference line of the vehicle and determining the starting reference line interval on the reference line; each two adjacent discrete points on the reference line form a reference line interval;

[0007] starting from the starting reference line interval, detecting and determining whether the reference line interval being detected is the minimum reference line interval corresponding to the target point; the target point is used to represent the obstacle detected by the vehicle, which affects the driving decision planning of the vehicle, and the normal line passing through the target point exists in the minimum reference line interval;

[0008] if the reference line interval being detected is not the minimum reference line interval of the target point, calculating the projection of the vector of the first discrete point to the target point on the tangent vector of the first discrete point; the first discrete point is the first discrete point in the driving direction of the vehicle; the projection includes the projection length and the direction;

[0009] calculating the step length and the forward direction based on the projection, and determining the new reference line interval based on the step length and the forward direction, until the minimum reference line interval of the target point on the reference line is found;

[0010] When the minimum reference line interval of the target point on the reference line is found, the transverse coordinate and the longitudinal coordinate of the target point on the Frenet coordinate system are calculated through the minimum reference line interval.

[0011] Optionally, the determining the initial reference line interval on the reference line comprises:

[0012] taking the discrete point on the reference line closest to the current position of the vehicle and located in front of the vehicle as a reference point;

[0013] taking the interval formed by the reference point and the next discrete point of the reference point as the initial reference interval for finding the minimum reference interval of the target point on the reference line.

[0014] Optionally, the judging whether the reference line interval being detected is the minimum reference line interval corresponding to the target point comprises:

[0015] judging whether the relationship between the discrete point on the reference line interval being detected and the target point satisfies a preset first condition;

[0016] the preset first condition is that the dot product of the vector from the first discrete point on the reference line interval being detected to the target point and the tangent vector of the first discrete point is greater than zero, and the dot product of the vector from the second discrete point on the reference line interval being detected to the target point and the tangent vector of the second discrete point is less than zero;

[0017] alternatively, the preset first condition is that the dot product of the vector from the first discrete point on the reference line interval being detected to the target point and the tangent vector of the first discrete point is equal to zero;

[0018] alternatively, the preset first condition is that the dot product of the vector from the second discrete point on the reference line interval being detected to the target point and the tangent vector of the second discrete point is equal to zero;

[0019] the second discrete point is the second discrete point on the reference line interval being detected;

[0020] if the relationship between the discrete point on the reference line interval being detected and the target point satisfies the preset first condition, it indicates that the reference line interval being detected is the minimum reference line interval corresponding to the target point.

[0021] Optionally, the calculating the forward step length through the projection length comprises:

[0022] taking the reference line interval being detected as the initial position, determining the total length of the reference line interval on the reference line smaller than the projection length and close to the projection length;

[0023] Determine the number of reference line intervals that have a total length less than the projection length and close to the projection length, and take the number of reference line intervals that have a total length less than the projection length and close to the projection length as the advancing step.

[0024] Optionally, the calculating the transverse coordinate and the longitudinal coordinate of the target point in the Frenet coordinate system through the minimum reference line interval comprises:

[0025] Construct a first coordinate system through the third discrete point and the fourth discrete point of the minimum reference line interval; the first coordinate system takes the third discrete point as the origin, takes the line connecting the third discrete point and the fourth discrete point as the transverse axis, and takes the direction perpendicular to the transverse axis as the longitudinal axis;

[0026] Determine the coordinates and tangent vectors of the third discrete point and the fourth discrete point in the first coordinate system, and calculate the coordinates of the target point in the first coordinate system;

[0027] Calculate the transverse coordinate and the longitudinal coordinate of the target point in the Frenet coordinate system through the coordinates of the target point in the first coordinate system, and the coordinates and tangent vectors of the third discrete point and the fourth discrete point in the first coordinate system.

[0028] Optionally, the calculating the transverse coordinate and the longitudinal coordinate of the target point in the Frenet coordinate system through the coordinates of the target point in the first coordinate system, and the coordinates and tangent vectors of the third discrete point and the fourth discrete point in the first coordinate system comprises:

[0029] Determine the projection point of the target point in the direction of the third discrete point and the fourth discrete point in the first coordinate system, and calculate the proportion value of the first length to the second length through the relationship between the normal vector of the projection point and the tangent vector of the projection point; the first length is the length from the projection point to the third discrete point, and the second length is the length from the third discrete point to the fourth discrete point;

[0030] Calculate the coordinates of the projection point through the relationship between the projection point, the third discrete point, the fourth discrete point, and the proportion value in the first coordinate system;

[0031] Calculate the coordinates of the tangent vector of the projection point through the relationship between the tangent vector of the projection point, the tangent vector of the third discrete point in the first coordinate system, the tangent vector of the fourth discrete point in the first coordinate system, and the proportion value in the first coordinate system;

[0032] Calculate the first length through the proportion value and the length from the third discrete point to the fourth discrete point in the first coordinate system;

[0033] calculating a length of the reference line from the starting point to a third discrete point in the first coordinate system;

[0034] taking a sum of the first length and the length of the reference line from the starting point to the third discrete point as a transverse coordinate of the target point in the Frenet coordinate system;

[0035] calculating coordinates of the normal vector of the projection point according to coordinates of the tangent vector of the projection point and a relationship between the tangent vector of the projection point and the normal vector of the projection point in the first coordinate system;

[0036] calculating a length of the target point to the projection point through the coordinates of the normal vector of the projection point, the coordinates of the projection point and the coordinates of the target point, and taking the length of the target point to the projection point as a longitudinal coordinate of the target point in the Frenet coordinate system.

[0037] The embodiment of the present application discloses a coordinate conversion device, comprising:

[0038] a starting reference line interval determination unit configured to determine a reference line of the vehicle and determine a starting reference line interval on the reference line; each two adjacent discrete points on the reference line form a reference line interval;

[0039] a minimum reference line interval searching unit configured to start detection from the starting reference line interval, and determine whether a reference line interval being detected is a minimum reference line interval corresponding to a target point; the target point is used to represent an obstacle detected by the vehicle and affecting driving decision planning of the vehicle, and a normal line passing through the target point exists in the minimum reference line interval;

[0040] a calculation unit configured to calculate a projection of a vector from a first discrete point to the target point on a tangent vector of the first discrete point if the reference line interval being detected is not the minimum reference line interval corresponding to the target point; the first discrete point is a first discrete point in a driving direction of the vehicle; the projection includes a projection length and a direction;

[0041] a reference line interval updating unit configured to calculate a step length and a forward direction through the projection, and determine a new reference line interval based on the step length and the forward direction until the minimum reference line interval of the target point on the reference line is found;

[0042] a coordinate conversion unit configured to calculate a transverse coordinate and a longitudinal coordinate of the target point in a Frenet coordinate system through the minimum reference line interval when the minimum reference line interval of the target point on the reference line is found.

[0043] Optionally, the starting reference line interval determination unit comprises:

[0044] The reference point first determining sub-unit is configured to determine a discrete point closest to the current position of the vehicle and located in front of the vehicle on the reference line as a reference point.

[0045] The starting reference line interval first determining sub-unit is configured to determine an interval formed by the reference point and a next discrete point of the reference point as a starting reference interval for searching for the minimum reference interval of the target point on the reference line.

[0046] Optionally, the minimum reference line interval searching unit comprises:

[0047] The judging sub-unit is configured to judge whether a relationship between the discrete point on the reference line interval being detected and the target point satisfies a preset first condition.

[0048] The preset first condition is that a dot product of a vector from a first discrete point of the reference line interval being detected to the target point and a tangent vector of the first discrete point is greater than zero, and a dot product of a vector from a second discrete point of the reference line interval being detected to the target point and a tangent vector of the second discrete point is less than zero.

[0049] Alternatively, the preset first condition is that the dot product of the vector from the first discrete point of the reference line interval being detected to the target point and the tangent vector of the first discrete point is equal to zero.

[0050] Alternatively, the preset first condition is that the dot product of the vector from the second discrete point of the reference line interval being detected to the target point and the tangent vector of the second discrete point is equal to zero.

[0051] The second discrete point is a second discrete point of the reference line interval being detected.

[0052] The first determining sub-unit is configured to, if the relationship between the discrete point on the reference line interval being detected and the target point satisfies the preset first condition, represent that the reference line interval being detected is the minimum reference line interval corresponding to the target point.

[0053] Embodiments of the present application disclose an electronic device, comprising:

[0054] a memory and a processor;

[0055] The memory is configured to store a program.

[0056] The memory stores the program.

[0057] The processor is configured to execute the program stored in the memory.

[0058] The embodiment of the present application discloses a coordinate conversion method, comprising: when searching for the minimum reference line interval of a target point on a reference line, starting from a starting reference line interval, if the currently detected reference line interval is not the minimum reference line interval of the target point, calculating the projection of the target point to the first discrete point of the reference interval, determining the advancing step and the advancing direction according to the projection, and determining the new reference line interval through the advancing step and the advancing direction, and cyclically executing the above steps until the minimum reference line interval of the target point on the reference line is found. Thus, the projection of the target point to the first discrete point of the reference interval can point to the direction of the minimum reference line interval and the length of moving to the minimum reference line interval, and the reference line interval is updated through the projection of the target point to the first discrete point of the reference interval as the step, so that the updated reference line interval is closer to the minimum reference interval of the target point on the reference line, the searching efficiency is improved, the time for finding the minimum reference line interval of the target point on the reference line is shortened, and the coordinate conversion efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS

[0059] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor based on the provided drawings.

[0060] Figure 1 A flowchart of a coordinate conversion method provided by the embodiment of the present application is shown;

[0061] Figure 2 A schematic diagram of the relationship between a reference line, a target point and a vehicle position disclosed by the embodiment of the present application is shown;

[0062] Figure 3 A schematic diagram of the minimum reference line interval corresponding to the target point is shown;

[0063] Figure 4 A schematic diagram of the projection of the vector from the first discrete point to the target point on the tangent vector of the first discrete point is shown;

[0064] Figure 5 A schematic diagram of the special position of the target point in a special scenario is shown;

[0065] Figure 6 Another flowchart of a coordinate conversion method disclosed in the embodiment is shown;

[0066] Figure 7 A schematic diagram of the starting reference line interval is shown;

[0067] Figure 8A flow chart of a method for calculating the horizontal coordinate and the vertical coordinate of the target point in the Frenet coordinate by the minimum reference line interval is shown;

[0068] Figure 9 A preliminary coordinate conversion schematic diagram is shown;

[0069] Figure 10 A schematic diagram of the relationship between the target point, the projection point and the two discrete points of the minimum reference line interval is shown;

[0070] Figure 11 A structural schematic diagram of a coordinate conversion device provided by an embodiment of the present application is shown;

[0071] Figure 12 A structural schematic diagram of an electronic device provided by an embodiment of the present application is shown. DETAILED DESCRIPTION

[0072] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without any creative work fall within the protection scope of the present application.

[0073] Reference Figure 1 A flow chart of a coordinate conversion method provided by an embodiment of the present application is shown, and in the present embodiment, the method comprises:

[0074] S101: determining a reference line of the vehicle and determining a starting reference line interval on the reference line; each two adjacent discrete points on the reference line form a reference line interval.

[0075] In the present embodiment, the reference line of the vehicle can be obtained by sampling a global path, wherein the global path is a path planned according to the starting point and the ending point of the travel of the unmanned vehicle. The sampling step length for sampling the global path can be set according to the requirement, which is not limited in the present embodiment, and the sampling step length can be equidistant or non-equidistant.

[0076] As known from the above introduction, the reference line can comprise a plurality of discrete points, and each two adjacent discrete points form a reference line interval.

[0077] In this embodiment, the initial reference line interval is a starting interval for searching the minimum reference line interval, wherein the initial reference line interval can be preset, for example, an interval formed by a starting point of the reference line and an adjacent discrete point, wherein the starting point of the reference line can be a starting point of global path planning; or can also be set according to a preset rule, for example, determined according to an actual driving position of the vehicle, which is not limited in this embodiment. The method for determining according to the actual driving position of the vehicle will be described in detail below, and will not be repeated in this embodiment.

[0078] S102: Starting from the starting reference line interval, it is judged whether the reference line interval being detected is the minimum reference line interval corresponding to the target point; the target point is used to represent an obstacle detected by the host vehicle that affects driving decision planning of the host vehicle, and the normal line passing through the target point exists in the minimum reference line interval.

[0079] In this embodiment, the target point is an obstacle that affects driving decision planning of the host vehicle, wherein the target point can be another participant on a road of interest of the host vehicle, for example, a vehicle in front of the host vehicle, a signboard, a pedestrian, etc.

[0080] For example, refer to Figure 2 , a schematic diagram of a relationship among a reference line, a target point and a host vehicle position disclosed by an embodiment of the present application is shown, wherein the reference line is formed by a plurality of discrete points, a position where the reference line starts represents a starting point of the reference line, the host vehicle drives according to a planned path, so that the host vehicle position is located on the reference line, and the target point can be detected by the host vehicle and is an obstacle that affects decision planning of the host vehicle.

[0081] In this embodiment, in the scenario where the target point exists, the minimum reference line interval can be understood as a reference line interval on the reference line of the host vehicle that has a greater impact on driving of the host vehicle, and in this embodiment, the reference line interval in which the normal line passing through the target point exists on the reference line is taken as the minimum reference line interval, so that it can be judged on the reference line whether the reference line interval being detected is the minimum reference line interval corresponding to the target point based on this principle.

[0082] For example, refer to Figure 3 , a schematic diagram of the minimum reference line interval corresponding to the target point is shown, wherein a point exists in the minimum reference line interval, and a line connecting the point and the target point is perpendicular to a tangent direction of the point (for example, a line connecting the point and the target point is perpendicular to the tangent direction of the point in the figure). Figure 3If the line connecting the point and the target point is perpendicular to the tangent vector of the point (i.e., the normal line passing through the target point exists in the minimum reference line interval), the reference line interval in which the point is located is the minimum reference line interval corresponding to the target point. In addition, the projection point of the target point on the minimum reference line interval to the starting point of the reference line is taken as the longitudinal coordinate S in the Frenet coordinate system, and the distance between the target point P and the projection point is taken as the transverse coordinate L in the Frenet coordinate system. The longitudinal coordinate S and the transverse coordinate L will be described in detail below, and will not be described again in this embodiment.

[0083] In this embodiment, the method for determining whether the reference line interval being detected is the minimum reference line interval corresponding to the target point can include various methods, which are not limited in this embodiment. The principle followed is that the normal line passing through the target point exists on the minimum reference line interval.

[0084] In one embodiment, the process of determining whether the reference line interval being detected is the minimum reference line interval corresponding to the target point can include:

[0085] determining whether the relationship between the discrete point on the reference line interval being detected and the target point satisfies a preset first condition;

[0086] The preset first condition is that the dot product of the vector from the first discrete point on the reference line interval being detected to the target point and the tangent vector of the first discrete point is greater than zero, and the dot product of the vector from the second discrete point on the reference line interval being detected to the target point and the tangent vector of the second discrete point is less than zero.

[0087] Alternatively, the preset first condition is that the dot product of the vector from the first discrete point on the reference line interval being detected to the target point and the tangent vector of the first discrete point is equal to zero.

[0088] Alternatively, the preset first condition is that the dot product of the vector from the second discrete point on the reference line interval being detected to the target point and the tangent vector of the second discrete point is equal to zero.

[0089] The second discrete point is the second discrete point on the reference line interval being detected.

[0090] If the relationship between the discrete point on the reference line interval being detected and the target point satisfies the preset first condition, it indicates that the reference line interval being detected is the minimum reference line interval corresponding to the target point.

[0091] In this embodiment, the direction of the tangent vector of a certain discrete point on the reference line interval is consistent with the direction of the vehicle.

[0092] For example, assuming that the currently detected reference line interval is AB, point A is the first discrete point of the currently detected reference line interval, and point B is the second discrete point of the currently detected reference line interval, the tangent vector of point A is represented as The tangent vector of point B is represented as The target point is P, the vector from point A to point P is represented as The vector from point B to point P is represented as Then, when any one of the following three conditions is met, it means that the currently detected reference line interval is the minimum reference line interval corresponding to the target point:

[0093] Condition 1:

[0094] Condition 2:

[0095] Condition 3:

[0096] Then, condition 1 means that there is a point in interval AB such that the product of the vector from the point to point P and the tangent vector of the point is zero, that is, there is a normal line passing through the target point in the reference line interval AB; condition 2 means that the product of the vector from point A to point P and the tangent vector of point A is zero, that is, there is a normal line passing through the target point in the reference line interval AB, and the normal line passes through point A; condition 3 means that the product of the vector from point B to point P and the tangent vector of point B is zero, that is, there is a normal line passing through the target point in the reference line interval AB, and the normal line passes through point B. Wherein, in the case of meeting any one of the above three conditions, it means that interval AB is the minimum reference line interval corresponding to the target point.

[0097] When the relationship between the discrete points on the currently detected reference line interval and the target point meets the preset first condition, it means that the currently detected reference line interval is the minimum reference line interval corresponding to the target point, or in other words, it means that the currently detected reference line interval is the minimum reference line interval corresponding to the target point on the reference line.

[0098] S103: If the currently detected reference line interval is not the minimum reference line interval of the target point, calculate the projection of the vector from the first discrete point to the target point on the tangent vector of the first discrete point; the first discrete point is the first discrete point of the currently detected reference line interval in the driving direction of the vehicle; the projection includes the projection length and the projection direction.

[0099] In this embodiment, the reference line is a pre-planned path, which includes the driving direction of the vehicle. For a reference line interval on the reference line, there are two discrete points. In the driving direction of the vehicle, the vehicle will pass through the two discrete points constituting a certain reference line interval respectively.

[0100] In this embodiment, the projection direction is related to the product of the vector from the first discrete point to the target point and the tangent vector of the first discrete point. When the product is greater than zero, it means that the projection direction is the same as the direction of the tangent vector of the first discrete point. When the product is less than zero, it means that the projection direction is opposite to the direction of the tangent vector of the first discrete point.

[0101] In existing technologies, when searching for the minimum reference line interval, the calculation is usually performed on each reference point on the reference line to find the minimum reference line interval. However, this method involves a large amount of computation and has low computational efficiency.

[0102] In order to find a suitable reference line interval more quickly, reduce the amount of calculation, and improve the efficiency of calculation, the applicant uses an appropriate step size to find a new reference line interval that is close to the minimum reference line interval.

[0103] In order to find the minimum reference line interval more quickly, this embodiment determines the step length by projecting the target point onto the reference line interval, as shown in S104 below:

[0104] S104: Calculate the forward step length and forward direction through the projection, and determine a new reference line interval based on the forward step length and forward direction, until the smallest reference line interval of the target point on the reference line is found.

[0105] In this embodiment, the projection of the vector from the first discrete point to the target point onto the tangent vector of the first discrete point includes the length and direction of the projection. The forward step length can be determined by the projection length and direction, which also includes the forward direction and the forward length.

[0106] The forward direction is the same as the projection direction. When the projection direction is the same as the tangent vector of the first discrete point, the forward direction is the same as the tangent vector of the first discrete point. When the projection direction is opposite to the tangent vector of the first discrete point, the forward direction is opposite to the tangent vector of the first discrete point.

[0107] For example: Figure 4 As shown, assuming the reference line interval AB is the reference line interval being detected, then point A is the first discrete point on the reference line interval being detected, and the target point is P. Then the tangent vector of the vector from point A to point P at point A is... The projection on the surface, due to and If the product of is greater than zero, then the direction of travel is the vehicle's direction of travel, and the projected length is d in the figure.

[0108] In this embodiment, the process of calculating the step length through projection is not limited, but preferably, the following method can be used:

[0109] determining the total length of the reference line interval corresponding to the projection length on the reference line from the starting position of the reference line interval being detected in the advancing direction;

[0110] determining the number of reference line intervals through which the total length of the reference line interval corresponding to the projection length on the reference line passes, and taking the number of reference line intervals through which the total length of the reference line interval corresponding to the projection length on the reference line passes as the advancing step.

[0111] In this embodiment, the starting position mentioned here is specifically the first discrete point on the reference line interval being detected (the first discrete point on the reference line interval being detected passed through in the vehicle travel direction).

[0112] In this embodiment, the total length of the reference line interval corresponding to the projection length on the reference line is determined in the advancing direction from the first discrete point on the reference line interval being detected, and in order to avoid skipping the minimum reference line interval, the total length of the reference line interval corresponding to the projection length on the reference line determined based on the projection length is less than the projection length, and in order to improve the efficiency of finding the minimum reference line interval, the total length of the reference line interval corresponding to the projection length on the reference line determined based on the projection length approaches the projection length.

[0113] In this embodiment, the lengths of the reference line intervals on the reference line can be the same or different, and in the case where the lengths of the reference line intervals are the same, the advancing step can be calculated by the following formula 4):

[0114]

[0115] wherein, represents the floor value, that is, when the result of is not an integer, the integer close to the result and less than the result is taken as the final result of Step.

[0116] wherein, Line_arc is the interval length of the two adjacent points of the reference line.

[0117] In this embodiment, as can be known from the above introduction, the reference line is composed of a plurality of discrete points, and each discrete point can be provided with a number. By determining the number of the discrete points on the reference line, a new reference line interval can be determined. For example, taking the first discrete point of the reference line interval being currently detected as the starting point, a new reference line interval is found in combination with the advancing step and the advancing direction.

[0118] For example, it is assumed that the first discrete point of the reference line interval being detected is A, and the number is ID AThe forward step is Step, and the new reference line interval number is ID update , and the calculation process of the new reference line interval number can be represented as shown in the following formula 5):

[0119] ID update = ID A + Step 5);

[0120] S105: When the minimum reference line interval of the target point on the reference line is found, the transverse coordinate and the longitudinal coordinate of the target point on the Frenet coordinate system are calculated through the minimum reference line interval.

[0121] In this embodiment, the transverse coordinate and the longitudinal coordinate of the target point on the Frenet coordinate system can be calculated in various ways, which are not limited in this embodiment.

[0122] In this embodiment, when the minimum reference line interval of the target point on the reference line is found, the projection of the target point to the first discrete point of the reference interval is calculated from the starting reference line interval, the forward step and the forward direction are determined according to the projection, and the new reference line interval is determined through the forward step and the forward direction, and the above steps are repeatedly executed until the minimum reference line interval of the target point on the reference line is found. Therefore, the projection of the target point to the first discrete point of the reference interval can point to the direction of the minimum reference line interval and the length of the movement to the minimum reference line interval. The reference line interval is updated by the projection of the target point to the first discrete point of the reference interval as the step, so that the updated reference line interval is closer to the minimum reference interval of the target point on the reference line, improving the efficiency of the search and shortening the time to find the minimum reference line interval of the target point on the reference line, thereby improving the coordinate conversion efficiency.

[0123] The applicant finds that when the target point is at a special position on the reference line interval, for example, the first special position: the target point is at the intersection position of the perpendicular lines of the two straight lines of the reference line (refer to Figure 5 (a)), or the second special position: the target point is at the curvature center position of the curve of the reference line (refer to Figure 5 (b)), the minimum reference line interval of the target point on the reference line cannot be accurately determined. For the first special position, the minimum reference line interval corresponding to the target point may be considered as the area in front of the vehicle 1, or as the area in front of the vehicle 2; for the second special position, the distance from the target point to any position in the reference line interval is the same, so any reference line interval will be considered as the minimum reference line interval of the target point. Therefore, based on the above problems, the minimum reference line interval of the target point on the reference line cannot be determined.

[0124] To solve the above problems, with reference to Figure 6 , another flowchart of a coordinate conversion method disclosed in the embodiment is shown, which includes the following steps:

[0125] S401: A discrete point on the reference line closest to the current position of the vehicle and located in front of the vehicle is taken as a reference point on the reference line.

[0126] In the embodiment, when the vehicle travels along the reference line (planned path), at a certain moment, when the vehicle travels to a certain position on the reference line, there will be a point on the reference line in front of the vehicle closest to the current position of the vehicle in the travel direction of the vehicle. For example, the front of the vehicle or the travel direction of the vehicle.

[0127] For example, as shown in Figure 7 , the position o of the vehicle on the reference line is the current position of the vehicle, and as can be seen from the enlarged view, the point K closest to the vehicle and located in front of the vehicle is the first reference point.

[0128] S402: An interval formed by the reference point and the next discrete point of the reference point is taken as a starting reference interval for finding the minimum reference line interval of the target point on the reference line.

[0129] With reference to Figure 7 , the interval formed by the reference point K and the reference point I adjacent to the reference point K is the starting reference line interval.

[0130] S403: Starting from the starting reference line interval, it is determined whether the reference line interval being detected is the minimum reference line interval corresponding to the target point; the target point represents an obstacle detected by the vehicle that affects the driving decision planning of the vehicle, and the normal line passing through the target point exists in the minimum reference line interval.

[0131] S404: If the reference line interval being detected is not the minimum reference line interval of the target point, the projection of the vector from the first discrete point to the target point on the tangent vector at the first discrete point is calculated; the first discrete point is the first discrete point in the travel direction of the vehicle; the projection includes the length and direction of the projection.

[0132] S405: The advancing step and the advancing direction are calculated through the projection, and a new reference line interval is determined based on the advancing step and the advancing direction, until the minimum reference line interval of the target point on the reference line is found.

[0133] S406: When the minimum reference line interval of the target point on the reference line is found, the horizontal coordinate and the vertical coordinate of the target point in the Frenet coordinate system are calculated through the minimum reference line interval.

[0134] In this embodiment, the steps of S403-S406 are consistent with S102-S105 described above, and will not be described again in this embodiment.

[0135] In this embodiment, by taking the interval formed by the reference line and the next discrete point of the reference point as the starting reference line interval of the minimum reference line interval of the target point on the reference line, if the reference line interval being detected is not the minimum reference line interval of the target point, the projection of the vector from the first discrete point to the target point on the tangent vector at the first discrete point is calculated; the first discrete point is the first discrete point of the reference line interval being detected in the driving direction of the vehicle; the projection includes the projection length and direction; the advancing step and advancing direction are calculated based on the projection, and a new reference line interval is determined based on the advancing step and advancing direction until the minimum reference line interval of the target point on the reference line is found; when the minimum reference line interval of the target point on the reference line is found, the horizontal coordinate and vertical coordinate of the target point on the Frenet coordinate system are calculated based on the minimum reference line interval.

[0136] Thus, by taking the interval formed by the reference line and the next discrete point of the reference point as the starting reference line interval of the minimum reference line interval of the target point on the reference line, and by determining the advancing step and advancing direction, a new reference line interval is continuously determined for detecting whether it is the minimum reference line interval. Then, only one minimum reference line interval will be determined in the calculated advancing direction, avoiding the problem that multiple minimum reference line intervals exist and thus the minimum reference line interval cannot be determined.

[0137] Reference Figure 8 , a flowchart of a method for calculating the horizontal coordinate and vertical coordinate of the target point on the Frenet coordinate based on the minimum reference line interval is shown, and in this embodiment, the method comprises:

[0138] S601: constructing a first coordinate system based on the third discrete point and the fourth discrete point of the minimum reference line interval; the first coordinate system takes the third discrete point as the origin, takes the line connecting the third discrete point and the fourth discrete point as the horizontal axis, and takes the direction perpendicular to the horizontal axis as the vertical axis.

[0139] For example, reference Figure 9 , assuming that the first discrete point of the minimum reference line interval is point A and the second discrete point is point B, then in the constructed first coordinate system, point A is taken as the origin, AB is taken as the horizontal axis, and the direction perpendicular to AB is taken as the vertical axis.

[0140] S602: determining the coordinates and tangent vector of the third discrete point and the fourth discrete point in the first coordinate system, and calculating the coordinates of the target point in the first coordinate system.

[0141] As Figure 9 shown, assuming the third discrete point is point A, the fourth discrete point is point B, and the third discrete point is the origin of the first coordinate system, then the coordinates of point A are (0, 0), and the coordinates of point B are (|AB|, 0).

[0142] In this embodiment, the tangent vectors of the third discrete point and the fourth discrete point in the first coordinate system can be calculated by the heading angle of the third discrete point, the heading angle of the fourth discrete point, and the angle between the horizontal coordinate of the first coordinate system and the horizontal coordinate of the global coordinate system.

[0143] For example, as shown in Figure 10 , assuming the third discrete point on the minimum reference line interval is represented as point A, the fourth discrete point is represented as point B, and the tangent vector of the third discrete point in the global coordinate system is represented as After conversion to the first coordinate system, it is represented as The tangent vector of the fourth discrete point in the global coordinate system is represented as After conversion to the first coordinate system, it is represented as Then wherein the converted m1 and m2 can be calculated by the following formula 6):

[0144]

[0145] wherein θ a represents the path heading angle of point A, θ b represents the path heading angle of point B, and θ represents the angle between the AB line and the horizontal axis in the global coordinate system.

[0146] In this embodiment, after the first coordinate system is constructed, the coordinates of the third discrete point in the first coordinate system and the coordinates of the fourth discrete point in the first coordinate system can be determined, and the coordinates of the target point in the first coordinate system are calculated based on the coordinates of the third discrete point and the fourth discrete point in the first coordinate system and the relationship between the target point and the third discrete point and the fourth discrete point.

[0147] For example, the coordinates of the target point in the first coordinate system can be calculated by the following formula 7):

[0148]

[0149] wherein the coordinates of point A in the first coordinate system are (0, 0), and the coordinates of point B are (|AB|, 0).

[0150] S603: Calculate the horizontal coordinate and the vertical coordinate of the target point in the Frenet coordinate system by the coordinates of the target point in the first coordinate system, and the coordinates and tangent vectors of the third discrete point and the fourth discrete point in the first coordinate system.

[0151] In the embodiment, the method for calculating the horizontal coordinate and the vertical coordinate of the target point in the Frenet coordinate system includes multiple methods, which are not limited in the embodiment. However, the operation amount of many methods in the prior art is large, and the operation efficiency is low. In order to solve the problem, preferably, the method of S701-S708 is used to determine in the embodiment, including:

[0152] S701: In the first coordinate system, the projection point of the target point in the direction of the third discrete point and the fourth discrete point is determined, and the proportion value of the first length to the second length is calculated through the relationship between the normal vector of the projection point and the tangent vector of the projection point; the first length is the length from the projection point to the third discrete point, and the second length is the length from the third discrete point to the fourth discrete point.

[0153] In the embodiment, the dot product of the normal vector of the projection point and the tangent vector of the projection point is equal to zero, the coordinates of the projection point can be represented by the third discrete point, the fourth discrete point and the length proportion, the normal vector of the projection point can be represented by the coordinates of the target point and the coordinates of the projection point, and the tangent vector of the projection point can be represented by the tangent vector of the third discrete point and the tangent vector of the fourth discrete point:

[0154] For example, as shown in the above Figure 10 , it is assumed that the third discrete point is represented as point A, the fourth discrete point is represented as point B, the target point is P, λ represents the proportion value of the first length to the second length, and the projection point is P λ , P λ can be represented by the following formula 8), the tangent vector t λ of the projection point is represented by the following formula 9), and the normal vector n λ of the projection point is represented by the following formula 10), and the relationship between the normal vector and the tangent vector of the projection point is represented by the following formula 11):

[0155] P λ =λB+(1-λ)A 8);

[0156] t λ =λt2+(1-λ)t1 9);

[0157] n λ =P-P λ 10);

[0158] n λ ·t λ =0 11);

[0159] In the embodiment, based on the above formula 8)-formula 11), the proportion value of the first length to the second length can be calculated.

[0160] S702: calculating the coordinate of the projection point in the first coordinate system according to the relationship between the projection point, the third discrete point, the fourth discrete point and the scale value;

[0161] As shown in the above formula 8) to formula 11), after the scale value λ is calculated, the coordinate of the projection point P λ may be calculated by formula 8).

[0162] S703: calculating the coordinate of the tangent vector of the projection point in the first coordinate system according to the relationship between the tangent vector of the projection point, the tangent vector of the third discrete point in the first coordinate system, the tangent vector of the fourth discrete point in the first coordinate system and the scale value;

[0163] As shown in the above formula 8) to formula 11), after the scale value λ is calculated, the coordinate of the tangent vector t λ of the projection point may be calculated by formula 9).

[0164] S704: calculating the first length in the first coordinate system according to the scale value and the length from the third discrete point to the fourth discrete point;

[0165] For example, as shown in the above formula 10), the first length is represented as A λ P Figure 10 may be represented by the following formula 12):

[0166] Ap λ = λ|AB| 12);

[0167] S705: calculating the length from the reference line starting point to the third discrete point in the first coordinate system;

[0168] As introduced above, the reference line starting point is the starting point of the entire reference line, as shown in the above formula 10, the reference line starting point is the first point of the reference line. Figure 2

[0169] S706: taking the sum of the first length and the length from the reference line starting point to the third discrete point as the abscissa of the target point in the Frenet coordinate system;

[0170] For example, assuming that the length from the starting point of the reference line to the third discrete point is represented as A offst , and the first length is λ·|AB|, then the sum of the first length and the length from the reference line starting point to the third discrete point is represented as the following formula 13):

[0171] S = A offst + λ·|AB| 13);

[0172] ​S707: In the first coordinate system, according to the coordinates of the tangent vector of the projection point and the relationship between the tangent vector of the projection point and the normal vector of the projection point, the coordinates of the normal vector are calculated;

[0173] Wherein, since the product of the normal vector of the projection point and the tangent vector of the projection point is equal to zero, after the normal vector of the projection point has been calculated, the coordinates of the normal vector of the projection point can be calculated based on the relationship between the normal vector of the projection point and the tangent vector of the projection point, such as the formula 11) shown above.

[0174] S708: The length from the target point to the projection point is calculated by the coordinates of the normal vector of the projection point, the coordinates of the projection point and the coordinates of the target point, and the length from the target point to the projection point is taken as the longitudinal coordinate of the target point on the Frenet coordinate system.

[0175] For example, the longitudinal coordinate of the target point on the Frenet coordinate can be represented by the following formula 14):

[0176]

[0177] Wherein, represents the vector from the target point to the projection point, represents the unit normal vector of P λ .

[0178] In this embodiment, the proportion of the first length to the second length is calculated by the relationship between the tangent vector of the projection point and the normal vector of the projection point, and the method for calculating the transverse coordinate based on the proportion value simplifies the calculation process, reduces the operation amount in the calculation process, and improves the processing efficiency.

[0179] In addition to the above method of calculating the transverse coordinate and the longitudinal coordinate of the target point on the Frenet coordinate by the minimum reference line interval, other methods can also be used for calculation, which are not limited in this embodiment, for example, the projection point coordinates of the target point on the third discrete point and the fourth discrete point constituting the minimum reference line interval are directly calculated, and the transverse coordinate and the longitudinal coordinate of the target point on the Frenet coordinate are calculated by the projection point coordinates.

[0180] Reference Figure 11 , shows a structure schematic diagram of a coordinate conversion device provided by an embodiment of the application, in this embodiment, the device comprises:

[0181] A starting reference line interval determination unit 1101 is configured to determine a reference line of the vehicle and determine a starting reference line interval on the reference line; each two adjacent discrete points on the reference line constitute a reference line interval;

[0182] The minimum reference line interval searching unit 1102 is configured to start detection from the starting reference line interval, and determine whether the reference line interval being detected is the minimum reference line interval corresponding to the target point; the target point is used to represent an obstacle detected by the ego vehicle, which affects the driving decision planning of the ego vehicle, and the reference line passes through the normal line of the target point in the minimum reference line interval;

[0183] The calculation unit 1103 is configured to, if the reference line interval being detected is not the minimum reference line interval of the target point, calculate a projection of a vector from a first discrete point to the target point on a tangent vector of the first discrete point; the first discrete point is the first discrete point of the reference line interval being detected in the driving direction of the ego vehicle; the projection includes a projection length and a direction;

[0184] The reference line interval updating unit 1104 is configured to calculate a forward step length and a forward direction based on the projection, and determine a new reference line interval based on the forward step length and the forward direction, until the minimum reference line interval of the target point on the reference line is found;

[0185] The coordinate conversion unit 1105 is configured to, when the minimum reference line interval of the target point on the reference line is found, calculate a transverse coordinate and a longitudinal coordinate of the target point in the Frenet coordinate system based on the minimum reference line interval.

[0186] Optionally, the starting reference line interval determining unit comprises:

[0187] The reference point first determining sub-unit is configured to take a discrete point on the reference line closest to the current position of the ego vehicle and located in front of the ego vehicle as a reference point;

[0188] The starting reference line interval first determining sub-unit is configured to take an interval formed by the reference point and a next discrete point of the reference point as a starting reference interval for searching the minimum reference interval of the target point on the reference line.

[0189] Optionally, the minimum reference line interval searching unit comprises:

[0190] The judging sub-unit is configured to judge whether a relationship between a discrete point on the reference line interval being detected and the target point satisfies a preset first condition;

[0191] The preset first condition is that a dot product of a vector from a first discrete point of the reference line interval being detected to the target point and a tangent vector of the first discrete point is greater than zero, and a dot product of a vector from a second discrete point of the reference line interval being detected to the target point and a tangent vector of the second discrete point is less than zero;

[0192] Or, the preset first condition is that the dot product of the vector from the first discrete point of the reference line interval being detected to the target point and the tangent vector of the first discrete point is equal to zero.

[0193] Or, the preset first condition is that the dot product of the vector from the second discrete point of the reference line interval being detected to the target point and the tangent vector of the second discrete point is equal to zero.

[0194] The second discrete point is a second discrete point of the reference line interval being detected.

[0195] The first determination sub-unit is configured to, if the relationship between the discrete point on the reference line interval being detected and the target point satisfies the preset first condition, determine that the reference line interval being detected is the minimum reference line interval corresponding to the target point.

[0196] Optionally, the reference line interval updating unit comprises:

[0197] The second determination sub-unit is configured to determine the total length of the reference line interval smaller than the projection length and close to the projection length, starting from the reference line interval being detected.

[0198] The third determination sub-unit is configured to determine the number of reference line intervals through which the total length of the reference line interval smaller than the projection length and close to the projection length passes, and take the number of reference line intervals through which the total length of the reference line interval smaller than the projection length and close to the projection length passes as the forward step.

[0199] Optionally, the coordinate conversion unit comprises:

[0200] The coordinate system construction sub-unit is configured to construct a first coordinate system through the third discrete point and the fourth discrete point of the minimum reference line interval; the first coordinate system takes the third discrete point as the origin, takes the line connecting the third discrete point and the fourth discrete point as the horizontal axis, and takes the direction perpendicular to the horizontal axis as the vertical axis.

[0201] The first calculation sub-unit is configured to determine the coordinates and tangent vectors of the third discrete point and the fourth discrete point in the first coordinate system, and calculate the coordinates of the target point in the first coordinate system.

[0202] The second calculation sub-unit is configured to calculate the horizontal coordinates and vertical coordinates of the target point in the Frenet coordinate system through the coordinates of the target point in the first coordinate system, and the coordinates and tangent vectors of the third discrete point and the fourth discrete point in the first coordinate system.

[0203] Optionally, the second calculation sub-unit is configured to:

[0204] Determine a projection point of the target point in the direction of the third discrete point and the fourth discrete point under the first coordinate system, and calculate a proportion value of a first length to a second length through the relationship between a normal vector of the projection point and a tangent vector of the projection point; the first length is the length from the projection point to the third discrete point, and the second length is the length from the third discrete point to the fourth discrete point;

[0205] Calculate the coordinates of the projection point through the relationship between the projection point, the third discrete point, the fourth discrete point and the proportion value under the first coordinate system;

[0206] Calculate the coordinates of the tangent vector of the projection point through the relationship between the tangent vector of the projection point, the tangent vector of the third discrete point in the first coordinate system, the tangent vector of the fourth discrete point in the first coordinate system and the proportion value under the first coordinate system;

[0207] Calculate the first length through the proportion value and the length from the third discrete point to the fourth discrete point under the first coordinate system;

[0208] Calculate the length from the reference line starting point to the third discrete point under the first coordinate system;

[0209] Take the sum of the first length and the length from the reference line starting point to the third discrete point as the horizontal coordinate of the target point in the Frenet coordinate system;

[0210] Calculate the coordinates of the normal vector of the projection point through the coordinates of the tangent vector of the projection point and the relationship between the tangent vector of the projection point and the normal vector of the projection point under the first coordinate system;

[0211] Calculate the length from the target point to the projection point through the coordinates of the normal vector of the projection point, the coordinates of the projection point and the coordinates of the target point, and take the length from the target point to the projection point as the vertical coordinate of the target point in the Frenet coordinate system.

[0212] The device of the embodiment discloses a coordinate conversion method, which comprises the following steps: when searching for a minimum reference line interval of a target point on a reference line, starting from a starting reference line interval, if the currently detected reference line interval is not the minimum reference line interval of the target point, calculating a projection of the target point to a first discrete point of the reference interval, determining an advancing step and an advancing direction according to the projection, and determining a new reference line interval through the advancing step and the advancing direction, and cyclically executing the above steps until the minimum reference line interval of the target point on the reference line is found. Thus, the projection of the target point to the first discrete point of the reference interval can point to the direction of the minimum reference line interval and the length of moving to the minimum reference line interval, so that the reference line interval is updated through the projection of the target point to the first discrete point of the reference interval as a step, so that the updated reference line interval is closer to the minimum reference interval of the target point on the reference line, the searching efficiency is improved, the time for finding the minimum reference line interval of the target point on the reference line is shortened, and the coordinate conversion efficiency is improved.

[0213] Reference Figure 12 , a structure schematic diagram of an electronic device provided by an embodiment of the application is shown, in the embodiment, the electronic device comprises:

[0214] a memory 1201 and a processor 1202;

[0215] The memory is used for storing a program;

[0216] The memory stores the program;

[0217] The processor is used for executing the program stored in the memory, and executes the following coordinate conversion method:

[0218] determining a reference line of the vehicle, and determining a starting reference line interval on the reference line; each two adjacent discrete points on the reference line form a reference line interval;

[0219] starting from the starting reference line interval, judging whether the currently detected reference line interval is a minimum reference line interval corresponding to a target point; the target point is used for representing an obstacle detected by the vehicle and affecting driving decision planning of the vehicle, and a normal line passing through the target point exists in the minimum reference line interval;

[0220] if the currently detected reference line interval is not the minimum reference line interval of the target point, calculating a projection of a first discrete point to a vector of the target point on a tangent vector of the first discrete point; the first discrete point is a first discrete point of the currently detected reference line interval in the driving direction of the vehicle; the projection comprises a projection length and a direction;

[0221] The advancing step and advancing direction are calculated through the projection, and a new reference line interval is determined based on the advancing step and advancing direction until a minimum reference line interval of the target point on the reference line is found;

[0222] When the minimum reference line interval of the target point on the reference line is found, the transverse coordinate and longitudinal coordinate of the target point on the Frenet coordinate system are calculated through the minimum reference line interval.

[0223] Optionally, the determining of the initial reference line interval on the reference line comprises:

[0224] The discrete point on the reference line closest to the current position of the vehicle and located in front of the vehicle is taken as a reference point;

[0225] The interval formed by the reference point and the next discrete point of the reference point is taken as the initial reference interval for finding the minimum reference interval of the target point on the reference line.

[0226] Optionally, the judging whether the reference line interval being detected is the minimum reference line interval corresponding to the target point comprises:

[0227] The relationship between the discrete point on the reference line interval being detected and the target point is judged whether to satisfy a preset first condition;

[0228] The preset first condition is that the dot product of the vector from the first discrete point of the reference line interval being detected to the target point and the tangent vector of the first discrete point is greater than zero, and the dot product of the vector from the second discrete point of the reference line interval being detected to the target point and the tangent vector of the second discrete point is less than zero;

[0229] Alternatively, the preset first condition is that the dot product of the vector from the first discrete point of the reference line interval being detected to the target point and the tangent vector of the first discrete point is equal to zero;

[0230] Alternatively, the preset first condition is that the dot product of the vector from the second discrete point of the reference line interval being detected to the target point and the tangent vector of the second discrete point is equal to zero;

[0231] The second discrete point is the second discrete point of the reference line interval being detected;

[0232] If the relationship between the discrete point on the reference line interval being detected and the target point satisfies the preset first condition, it indicates that the reference line interval being detected is the minimum reference line interval corresponding to the target point.

[0233] Optionally, the calculating of the advancing step through the projection length comprises:

[0234] determining a total length of the reference line interval smaller than the projection length and close to the projection length on the reference line, starting from the reference line interval being detected;

[0235] determining a number of reference line intervals through which the total length of the reference line interval smaller than the projection length and close to the projection length passes, and taking the number of reference line intervals through which the total length of the reference line interval smaller than the projection length and close to the projection length passes as the advancing step. Optionally, the calculating the transverse coordinate and the longitudinal coordinate of the target point on the Frenet coordinate system through the minimum reference line interval comprises:

[0236] constructing a first coordinate system through the third discrete point and the fourth discrete point of the minimum reference line interval; the first coordinate system taking the third discrete point as the origin, taking the line connecting the third discrete point and the fourth discrete point as the transverse axis, and taking the direction perpendicular to the transverse axis as the longitudinal axis;

[0237] determining the coordinates and tangent vectors of the third discrete point and the fourth discrete point in the first coordinate system, and calculating the coordinates of the target point in the first coordinate system;

[0238] calculating the transverse coordinate and the longitudinal coordinate of the target point on the Frenet coordinate system through the coordinates of the target point on the first coordinate system, and the coordinates and tangent vectors of the third discrete point and the fourth discrete point on the first coordinate system.

[0239] Optionally, the calculating the transverse coordinate and the longitudinal coordinate of the target point on the Frenet coordinate system through the coordinates of the target point on the first coordinate system, and the coordinates and tangent vectors of the fourth discrete point and the fifth discrete point on the first coordinate system comprises:

[0240] determining a projection point of the target point in the direction of the third discrete point and the fourth discrete point in the first coordinate system, and calculating a proportion value of the first length to the second length through the relationship between the normal vector of the projection point and the tangent vector of the projection point; the first length being the length from the projection point to the third discrete point, and the second length being the length from the third discrete point to the fourth discrete point;

[0241] calculating the coordinates of the projection point through the relationship between the projection point, the third discrete point, the fourth discrete point and the proportion value in the first coordinate system;

[0242] calculating the coordinates of the tangent vector of the projection point through the relationship between the tangent vector of the projection point, the tangent vector of the third discrete point on the first coordinate system, the tangent vector of the fourth discrete point on the first coordinate system and the proportion value in the first coordinate system;

[0243] calculating the first length under the first coordinate system by the ratio value and the length from the third discrete point to the fourth discrete point;

[0244] calculating the length from the reference line start point to the third discrete point under the first coordinate system;

[0245] taking the sum of the first length and the length from the reference line start point to the third discrete point as the horizontal coordinate of the target point on the Frenet coordinate system;

[0246] calculating the coordinates of the normal vector of the projection point according to the coordinates of the tangent vector of the projection point and the relationship between the tangent vector of the projection point and the normal vector of the projection point under the first coordinate system;

[0247] calculating the length from the target point to the projection point by the coordinates of the normal vector of the projection point, the coordinates of the projection point and the coordinates of the target point, and taking the length from the target point to the projection point as the vertical coordinate of the target point on the Frenet coordinate system.

[0248] It should be noted that each of the embodiments in the specification adopts a progressive manner for description, and each embodiment focuses on the different places from other embodiments. The same and similar parts among the embodiments can be referred to each other.

[0249] The above description of disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A coordinate conversion method characterized by, The method comprises the following steps: determining a reference line of the vehicle, and determining a starting reference line interval on the reference line; each two adjacent discrete points on the reference line form a reference line interval; starting from the starting reference line interval, determining whether the reference line interval being detected is the minimum reference line interval corresponding to a target point; the target point is used to represent an obstacle detected by the vehicle, which affects the driving decision planning of the vehicle, and a normal line passing through the target point exists in the minimum reference line interval; if the reference line interval being detected is not the minimum reference line interval of the target point, calculating a projection of a vector from a first discrete point to the target point on a tangent vector of the first discrete point; the first discrete point is the first discrete point of the reference line interval being detected in the driving direction of the vehicle; the projection comprises a projection length and a direction; calculating an advancing step and an advancing direction through the projection, and determining a new reference line interval based on the advancing step and the advancing direction, until the minimum reference line interval of the target point on the reference line is found; when the minimum reference line interval of the target point on the reference line is found, calculating a transverse coordinate and a longitudinal coordinate of the target point on a Frenet coordinate system through the minimum reference line interval.

2. The method of claim 1, wherein, The step of determining the starting reference line interval on the reference line comprises the following steps: taking a discrete point on the reference line closest to the current position of the vehicle and located in front of the vehicle as a reference point; taking an interval formed by the reference point and a next discrete point of the reference point as a starting reference interval for finding the minimum reference interval of the target point on the reference line.

3. The method of claim 1, wherein, The step of determining whether the reference line interval being detected is the minimum reference line interval corresponding to the target point comprises the following steps: determining whether a relationship between a discrete point on the reference line interval being detected and the target point satisfies a preset first condition; the preset first condition is that a dot product of a vector from a first discrete point of the reference line interval being detected to the target point and a tangent vector of the first discrete point is greater than zero, and a dot product of a vector from a second discrete point of the reference line interval being detected to the target point and a tangent vector of the second discrete point is less than zero; or, the preset first condition is that the dot product of the vector from the first discrete point of the reference line interval being detected to the target point and the tangent vector of the first discrete point is equal to zero; or, the preset first condition is that the dot product of the vector from the second discrete point of the reference line interval being detected to the target point and the tangent vector of the second discrete point is equal to zero; the second discrete point is the second discrete point of the reference line interval being detected; if the relationship between the discrete point on the reference line interval being detected and the target point satisfies the preset first condition, it indicates that the reference line interval being detected is the minimum reference line interval corresponding to the target point.

4. The method of claim 1, wherein, The step of calculating the advancing step through the projection comprises the following steps: determining a total length of a reference line interval smaller than the projection length and close to the projection length on the reference line, with the reference line interval being detected as a starting position; Determine the number of reference line intervals that the total length of the reference line intervals less than the projection length and close to the projection length has passed, and take the number of reference line intervals that the total length of the reference line intervals less than the projection length and close to the projection length has passed as the advancing step.

5. The method of claim 1, wherein, The calculating the transverse coordinate and the longitudinal coordinate of the target point on the Frenet coordinate system through the minimum reference line interval comprises: A first coordinate system is constructed through the third discrete point and the fourth discrete point of the minimum reference line interval; the first coordinate system takes the third discrete point as the origin, takes the line connecting the third discrete point and the fourth discrete point as the transverse axis, and takes the direction perpendicular to the transverse axis as the longitudinal axis; Determine the coordinates and tangent vectors of the third discrete point and the fourth discrete point in the first coordinate system, and calculate the coordinates of the target point in the first coordinate system; The calculating the transverse coordinate and the longitudinal coordinate of the target point on the Frenet coordinate system through the coordinates of the target point on the first coordinate system, and the coordinates and tangent vectors of the third discrete point and the fourth discrete point on the first coordinate system comprises:

6. The method of claim 5, wherein, Determine the projection point of the target point in the direction of the third discrete point and the fourth discrete point in the first coordinate system, and calculate the ratio value of the first length to the second length through the relationship between the normal vector of the projection point and the tangent vector of the projection point; the first length is the length from the projection point to the third discrete point, and the second length is the length from the third discrete point to the fourth discrete point; In the first coordinate system, the coordinates of the projection point are calculated through the relationship between the projection point, the third discrete point, the fourth discrete point and the ratio value; In the first coordinate system, the coordinates of the tangent vector of the projection point are calculated through the relationship between the tangent vector of the projection point, the tangent vector of the third discrete point on the first coordinate system, the tangent vector of the fourth discrete point on the first coordinate system and the ratio value; In the first coordinate system, the first length is calculated through the ratio value and the length from the third discrete point to the fourth discrete point; In the first coordinate system, the length from the starting point of the reference line to the third discrete point is calculated; The sum of the first length and the length from the starting point of the reference line to the third discrete point is taken as the transverse coordinate of the target point on the Frenet coordinate system; In the first coordinate system, the coordinates of the normal vector of the projection point are calculated according to the coordinates of the tangent vector of the projection point and the relationship between the tangent vector of the projection point and the normal vector of the projection point; The length from the target point to the projection point is calculated through the coordinates of the normal vector of the projection point, the coordinates of the projection point and the coordinates of the target point, and the length from the target point to the projection point is taken as the longitudinal coordinate of the target point on the Frenet coordinate system. Comprise:

7. A coordinate conversion apparatus characterized by comprising: A starting reference line interval determination unit is configured to determine a reference line of the vehicle and determine a starting reference line interval on the reference line; ​ Each two adjacent discrete points on the reference line form a reference line interval; A minimum reference line interval searching unit is configured to start detection from the starting reference line interval, and determine whether the reference line interval being detected is a minimum reference line interval corresponding to the target point; the target point is used to represent an obstacle detected by the ego vehicle and affecting driving decision planning of the ego vehicle, and a normal line passing through the target point exists in the minimum reference line interval; A calculation unit is configured to, if the reference line interval being detected is not the minimum reference line interval of the target point, calculate a projection of a vector from a first discrete point to the target point on a tangent vector of the first discrete point; the first discrete point is a first discrete point of the reference line interval being detected in a driving direction of the ego vehicle; the projection includes a projection length and a direction; A reference line interval updating unit is configured to calculate a step length and a forward direction through the projection, and determine a new reference line interval based on the step length and the forward direction, until the minimum reference line interval of the target point on the reference line is found; A coordinate conversion unit is configured to, when the minimum reference line interval of the target point on the reference line is found, calculate a transverse coordinate and a longitudinal coordinate of the target point on a Frenet coordinate system through the minimum reference line interval.

8. The apparatus of claim 7, wherein, The starting reference line interval determining unit comprises: A reference point first determining subunit is configured to take a discrete point on the reference line closest to a current position of the ego vehicle and located in front of the ego vehicle as a reference point; A starting reference line interval first determining subunit is configured to take an interval formed by the reference point and a next discrete point of the reference point as a starting reference interval for searching the minimum reference interval of the target point on the reference line.

9. The apparatus of claim 7, wherein, The minimum reference line interval searching unit comprises: A judging subunit is configured to determine whether a relationship between a discrete point on the reference line interval being detected and the target point satisfies a preset first condition; The preset first condition is that a dot product of a vector from a first discrete point of the reference line interval being detected to the target point and a tangent vector of the first discrete point is greater than zero, and a dot product of a vector from a second discrete point of the reference line interval being detected to the target point and a tangent vector of the second discrete point is less than zero; Or, the preset first condition is that the dot product of the vector from the first discrete point of the reference line interval being detected to the target point and the tangent vector of the first discrete point is equal to zero; Or, the preset first condition is that the dot product of the vector from the second discrete point of the reference line interval being detected to the target point and the tangent vector of the second discrete point is equal to zero; The second discrete point is a second discrete point of the reference line interval being detected; A first determining subunit is configured to, if the relationship between the discrete point on the reference line interval being detected and the target point satisfies the preset first condition, indicate that the reference line interval being detected is the minimum reference line interval corresponding to the target point.

10. An electronic device, comprising: Comprise: A memory and a processor; The memory is configured to store a program; The memory stores the program; The processor is configured to execute the coordinate conversion method in any one of claims 1-6 when executing a program stored in the memory.

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