Self-adaptive obstacle avoidance trajectory planning method

Abstract

The invention discloses a self-adaptive obstacle avoidance trajectory planning method. Obstacle avoidance trajectory information is obtained through the self-adaptive obstacle avoidance trajectory planning method; the obstacle avoidance track information comprises a vehicle obstacle avoidance track, a critical safety distance and a current lane passable margin; the adaptive obstacle avoidance trajectory planning method comprises the following steps: dividing safety threshold information into comfortable obstacle avoidance safety threshold information, stable obstacle avoidance safety threshold information and emergency obstacle avoidance safety threshold information; based on the vehicle obstacle avoidance trajectory fitting formula and in combination with safety threshold information, a comfortable obstacle avoidance vehicle obstacle avoidance trajectory, a stable obstacle avoidance vehicle obstacle avoidance trajectory and an emergency obstacle avoidance vehicle obstacle avoidance trajectory are obtained; a current lane passable margin is constructed, a steering obstacle avoidance strategy is judged in an auxiliary mode, and detour obstacle avoidance or lane changing obstacle avoidance is confirmed to be implemented; the method comprehensively considers the influence of the vehicle speed, the road surface state and the obstacle size, and generates a reasonable obstacle avoidance planning track under different driving conditions.

Description

Technical Field

[0001] The present invention relates to the field of vehicle obstacle avoidance, and in particular to the field of an adaptive obstacle avoidance trajectory planning method. Background Art

[0002] Assisted driving and autonomous driving have gradually become part of our daily lives. Obstacle avoidance trajectory planning is particularly important in autonomous driving. Traditional obstacle avoidance trajectory planning methods fail to fully consider factors such as vehicle speed, road conditions, and obstacle size. They suffer from a single steering behavior and fail to effectively guarantee the feasibility of the obstacle avoidance trajectory.

[0003] Therefore, how to invent an adaptive obstacle avoidance trajectory planning method that comprehensively considers the influence of vehicle speed, road conditions, and obstacle size, and generates a reasonable obstacle avoidance planning trajectory under different driving conditions has become a difficult problem that needs to be solved urgently in this field. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides an adaptive obstacle avoidance trajectory planning method, which comprehensively considers the influence of vehicle speed, road conditions, and obstacle size, and generates a reasonable obstacle avoidance planning trajectory under different driving conditions.

[0005] According to the present invention, an adaptive obstacle avoidance trajectory planning method is provided, wherein obstacle avoidance trajectory information is obtained by the adaptive obstacle avoidance trajectory planning method; the obstacle avoidance trajectory information includes the vehicle obstacle avoidance trajectory, the critical safety distance, and the current lane passability margin;

[0006] The adaptive obstacle avoidance trajectory planning method comprises the following steps:

[0007] Obtain vehicle status information, road status information, size information, and safety threshold information;

[0008] The safety threshold information is divided into comfortable obstacle avoidance safety threshold information, stable obstacle avoidance safety threshold information, and emergency obstacle avoidance safety threshold information;

[0009] Combining vehicle status information, road status information, and size information, a vehicle obstacle avoidance trajectory fitting formula is established based on a fifth-order polynomial, and a critical safety distance formula is established through the vehicle obstacle avoidance trajectory fitting formula;

[0010] Based on the vehicle obstacle avoidance trajectory fitting formula and combined with the safety threshold information, the comfortable obstacle avoidance vehicle obstacle avoidance trajectory, the stable obstacle avoidance vehicle obstacle avoidance trajectory, and the emergency obstacle avoidance vehicle obstacle avoidance trajectory are obtained;

[0011] The critical safety distance is obtained by combining the vehicle obstacle avoidance trajectory fitting formula with the critical safety distance formula;

[0012] Construct the current lane's passable margin to assist in determining the steering obstacle avoidance strategy, and confirm the implementation of detour or lane change to avoid obstacles based on the current lane's passable margin.

[0013] Compared with the existing technology, the present invention has the following beneficial effects: combining vehicle state information, road state information, and size information, and establishing a vehicle obstacle avoidance trajectory fitting formula based on a quintic polynomial, thereby achieving adaptive obstacle avoidance trajectory planning under multiple working conditions;

[0014] By dividing the safety threshold information into comfortable obstacle avoidance safety threshold information, stable obstacle avoidance safety threshold information, and emergency obstacle avoidance safety threshold information, it is possible to obtain comfortable obstacle avoidance vehicle obstacle avoidance trajectories, stable obstacle avoidance vehicle obstacle avoidance trajectories, and emergency obstacle avoidance vehicle obstacle avoidance trajectories, thereby achieving the goal of generating hierarchical obstacle avoidance trajectories that take into account both obstacle avoidance safety and comfort requirements, and selecting a reasonable obstacle avoidance planning trajectory based on actual obstacle avoidance conditions;

[0015] By constructing the current lane traversability margin η f Based on information such as the vehicle's speed, obstacle size, and actual road width, it assists in steering obstacle avoidance decisions and flexibly switches between detour obstacle avoidance mode and lane change obstacle avoidance mode, making the obstacle avoidance trajectory closer to actual driving behavior and enhancing the continuity of obstacle avoidance actions. This not only enables the selection of the safest obstacle avoidance method, but also minimizes interference with adjacent lanes.

[0016] Furthermore, the vehicle obstacle avoidance trajectory is the moving trajectory of the vehicle's center of mass (X(t), Y(t)) during the obstacle avoidance process;

[0017] The critical safety distance D ss Y is the lateral position of the right front corner of the vehicle and the lateral boundary position of the obstacle in front of it during vehicle steering and obstacle avoidance c When the vehicle is aligned, it still maintains a longitudinal safety distance Δd from the obstacle in front. ss Under the condition of , the distance between the first measurement line where the right front corner of the vehicle is located and the second measurement line where the left rear corner of the front obstacle is located when the vehicle starts to turn;

[0018] The first measurement line is parallel to the second measurement line, and the first measurement line is perpendicular to the vehicle axis when the vehicle is turning.

[0019] Furthermore, the vehicle state information includes the initial vehicle speed V x ;

[0020] The road surface state information includes a road surface adhesion coefficient μ;

[0021] The size information includes the vehicle width W v , the distance d between the center of mass of the vehicle and the front of the vehicle f , obstacle lateral boundary position Y c ;

[0022] The safety threshold information includes the maximum lateral acceleration a ymax , longitudinal safety distance Δd ss .

[0023] Furthermore, the maximum lateral acceleration a ymax Including the maximum lateral acceleration for comfortable obstacle avoidance, the maximum lateral acceleration for smooth obstacle avoidance, and the maximum lateral acceleration for emergency obstacle avoidance;

[0024] The maximum lateral acceleration for comfortable obstacle avoidance is 0.22*μ*g; the maximum lateral acceleration for smooth obstacle avoidance is 0.4*μ*g; and the maximum lateral acceleration for emergency obstacle avoidance is 0.5*μ*g.

[0025] The g is the acceleration due to gravity.

[0026] The beneficial effect of adopting the previous step is that the maximum value of the comfortable obstacle avoidance lateral acceleration is 0.22*μ*g; the maximum value of the smooth obstacle avoidance lateral acceleration is 0.4*μ*g; the maximum value of the emergency obstacle avoidance lateral acceleration is 0.5*μ*g; and the obstacle avoidance trajectory of the comfortable obstacle avoidance vehicle, the obstacle avoidance trajectory of the smooth obstacle avoidance vehicle, and the obstacle avoidance trajectory of the emergency obstacle avoidance vehicle are obtained.

[0027] Furthermore, the vehicle obstacle avoidance trajectory fitting formula is:

[0028] X(t)=V x *t

[0029] Y(t)=a5*t 5 +a4*t 4 +a3*t 3 +a2*t 2 +a1*t+a0

[0030] X f =V x *t f

[0031]

[0032] The a0, a1, a2, a3, a4, and a5 are the curve fitting coefficients to be determined;

[0033] Δd ys To reserve a safe distance for the side, Y w Lateral displacement to avoid obstacles.

[0034] The beneficial effect of the previous step is that the vehicle obstacle avoidance trajectory fitting formula is established based on the fifth-order polynomial, and the calculation method of the fitting coefficient a1 includes the initial vehicle speed V xThe calculation method of fitting coefficients a3, a4, and a5 includes the lateral boundary position Y of the obstacle c , obstacle avoidance lateral displacement Y w , Lateral safety distance Δd ys ; At the same time, by combining the longitudinal vehicle speed information V x and the lateral boundary position Y of the obstacle c , estimate the lateral displacement Y of the obstacle avoidance w , which is conducive to achieving adaptive steering and obstacle avoidance at different vehicle speeds and obstacle sizes;

[0035] It is conducive to achieving detour obstacle avoidance for small obstacles, and lane change obstacle avoidance for large obstacles, and adaptively changing the lateral safety distance according to the vehicle speed to ensure obstacle avoidance safety. Compared with the traditional lane change-only obstacle avoidance operation, it is relatively flexible and closer to actual driving decisions.

[0036] Furthermore, the process of obtaining the vehicle obstacle avoidance trajectory based on the vehicle obstacle avoidance trajectory fitting formula combined with the safety threshold information is as follows: substituting the safety threshold information into the vehicle obstacle avoidance trajectory fitting formula to calculate the vehicle obstacle avoidance trajectory;

[0037] The vehicle obstacle avoidance trajectory formula is:

[0038]

[0039] X(t) is the longitudinal position of the vehicle's center of mass at time t during the obstacle avoidance process, and Y(t) is the lateral position of the vehicle's center of mass at time t during the obstacle avoidance process;

[0040] t f The obstacle avoidance time can be calculated by the following formula

[0041]

[0042] The beneficial effect of the above step is that the vehicle center of mass (X(t), Y(t)) obstacle avoidance trajectory is realized through the obstacle avoidance time t by the vehicle obstacle avoidance trajectory formula. f It is expressed that, and the lateral acceleration a y Constraints determine the obstacle avoidance time t f, can quickly determine the obstacle avoidance trajectory and corresponding critical safety distance under different conditions such as vehicle speed, road adhesion conditions, and obstacle size, helping to improve response speed in emergency obstacle avoidance scenarios. It also avoids the reliance of traditional obstacle avoidance trajectory planning methods on sampling interval settings, and can effectively and adaptively adjust the obstacle avoidance planning trajectory based on actual driving conditions. The obstacle avoidance trajectory planning process avoids tedious steps such as obstacle avoidance trajectory cluster generation, obstacle avoidance trajectory multi-objective evaluation and screening, and obstacle avoidance trajectory smoothing, saving required storage space and computational effort. In the obstacle avoidance trajectory generation stage, it avoids over-reliance on pre-set sampling intervals, alleviates the computational burden caused by unnecessary sampling, and avoids the problem of invalid obstacle avoidance trajectory planning caused by problems with sampling accuracy and representativeness.

[0043] Furthermore, the autonomous driving vehicle autonomously switches between comfortable obstacle avoidance vehicle trajectory, stable obstacle avoidance vehicle trajectory or emergency obstacle avoidance vehicle trajectory according to the driver's personal habits and actual obstacle avoidance conditions;

[0044] When comfortable obstacle avoidance vehicle trajectory is selected, a ymax is the maximum lateral acceleration for comfortable obstacle avoidance, specifically 0.22*μ*g, which is substituted into the vehicle obstacle avoidance trajectory formula to obtain the comfortable obstacle avoidance vehicle obstacle avoidance trajectory;

[0045] When a stable obstacle avoidance vehicle trajectory is selected, a ymax is the maximum lateral acceleration for smooth obstacle avoidance, specifically 0.4*μ*g, which is substituted into the vehicle obstacle avoidance trajectory formula to obtain the smooth obstacle avoidance vehicle obstacle avoidance trajectory;

[0046] When the emergency obstacle avoidance vehicle avoidance trajectory is selected, a ymax is the maximum lateral acceleration for emergency obstacle avoidance, specifically 0.5*μ*g. Substitute it into the vehicle obstacle avoidance trajectory formula to obtain the emergency obstacle avoidance vehicle obstacle avoidance trajectory.

[0047] The beneficial effect of adopting the previous step is that the above technical solution can achieve the obstacle avoidance trajectory of the comfortable obstacle avoidance vehicle, the obstacle avoidance trajectory of the smooth obstacle avoidance vehicle, and the obstacle avoidance trajectory of the emergency obstacle avoidance vehicle, which is conducive to comprehensively considering the influence of vehicle speed, road surface conditions, and obstacle size, and generating reasonable obstacle avoidance planning trajectories under different driving conditions, so that the vehicle obstacle avoidance trajectory is closer to actual needs.

[0048] Furthermore, the critical safety distance formula is:

[0049]

[0050] The t c The critical collision moment is the moment when the vehicle turns to avoid the obstacle and the lateral position of the right front corner of the vehicle is at the lateral boundary position Y of the obstacle in front of it. c moments of agreement;

[0051] (X(t c ),Y(t c )) is the center of mass position of the vehicle at the critical collision moment; θ c is the vehicle heading angle at the critical collision;

[0052] The X(t c ) by the formula X(t c )=V x *t c Calculated;

[0053] The θ c Calculated by the following formula:

[0054]

[0055]

[0056] The beneficial effect of adopting the previous step is that the critical safety distance D is obtained by the formula 1 ss , achieving the critical safety distance is when the lateral position of the right front corner of the vehicle is consistent with the lateral boundary position of the obstacle in front, while still maintaining a certain safety distance from the obstacle in the longitudinal direction, thus ensuring obstacle avoidance safety;

[0057] Passing critical safety distance D ss During the calculation process, the obstacle avoidance trajectory passes the obstacle avoidance time t f It is expressed that, and the lateral acceleration a y Constraints determine the obstacle avoidance time t f The system quickly determines obstacle avoidance trajectories and corresponding critical safety distances under different vehicle speeds, road adhesion conditions, and obstacle sizes, helping to improve response speed in emergency obstacle avoidance scenarios. It also avoids the reliance of traditional obstacle avoidance trajectory planning methods on sampling interval settings, effectively and adaptively adjusting obstacle avoidance planning trajectories based on actual driving conditions. The obstacle avoidance trajectory planning process avoids tedious steps such as obstacle avoidance trajectory cluster generation, multi-objective evaluation and screening of obstacle avoidance trajectories, and smoothing of obstacle avoidance trajectories, saving required storage space and computational effort. In the obstacle avoidance trajectory cluster generation phase, it avoids over-reliance on pre-set sampling intervals, alleviating the computational burden of unnecessary sampling and preventing invalid obstacle avoidance trajectory planning due to issues with sampling accuracy and representativeness.

[0058] Furthermore, the critical safety distance includes a comfortable obstacle avoidance critical safety distance, a smooth obstacle avoidance critical safety distance, and an emergency obstacle avoidance critical safety distance.

[0059] The autonomous driving vehicle autonomously switches obstacle avoidance plans based on actual obstacle avoidance conditions and the critical safety distance for comfortable obstacle avoidance, the critical safety distance for smooth obstacle avoidance, and the critical safety distance for emergency obstacle avoidance. When the longitudinal distance between the vehicle and the obstacle ahead is less than the critical safety distance for comfortable obstacle avoidance, the vehicle automatically switches to the smooth obstacle avoidance plan; when the longitudinal distance between the vehicle and the obstacle ahead is less than the critical safety distance for smooth obstacle avoidance, the vehicle automatically switches to the emergency obstacle avoidance plan.

[0060] a ymax When the maximum lateral acceleration for comfortable obstacle avoidance is 0.22*μ*g, substitute it into the critical safety distance formula to obtain the critical safety distance for comfortable obstacle avoidance.

[0061] a ymax When the maximum lateral acceleration for smooth obstacle avoidance is 0.4*μ*g, substitute it into the first formula to obtain the critical safety distance for smooth obstacle avoidance.

[0062] a ymax When the maximum lateral acceleration for emergency obstacle avoidance is 0.5*μ*g, the critical safety distance for emergency obstacle avoidance is obtained by substituting it into the critical safety distance formula.

[0063] The effects of the previous step are that the critical safety distance for comfortable obstacle avoidance, the critical safety distance for smooth obstacle avoidance, and the critical safety distance for emergency obstacle avoidance are obtained, which is conducive to selecting a reasonable obstacle avoidance planning trajectory under different driving conditions.

[0064] Furthermore, the current lane passability margin η is obtained by formula 1 f ;

[0065] The formula 1 is:

[0066]

[0067] W * =W v +Δd ys

[0068] W=W r -Y c

[0069]

[0070] V x is the vehicle speed, W r is the lane width, Y c is the lateral boundary position of the obstacle, W * is the expected passable space threshold, Δd ys Reserve a safe distance for the side, and W is the actual passable lateral space;

[0071] When η f<1, implement detour to avoid obstacles; when η f ≥1, implement lane change to avoid obstacles.

[0072] The effect of the previous step is to construct the current lane passability margin based on the information such as the vehicle speed, obstacle size, actual road width, etc., and use the current lane passability margin η f , assisting in steering obstacle avoidance decisions, flexibly switching between detour and lane change modes, making the obstacle avoidance trajectory closer to actual driving behavior and enhancing the continuity of obstacle avoidance actions. This not only achieves the selection of the safest obstacle avoidance method, but also minimizes interference with adjacent lanes. When the obstacle directly ahead has a small degree of road encroachment and there is sufficient lateral space in the current lane, that is, η f <1, then the obstacle avoidance is implemented to minimize the interference to the adjacent lanes, which is conducive to safe driving in scenes with continuous and dense multiple obstacles. When the obstacle in front of the vehicle occupies a large degree of road and the lateral space of the current lane is insufficient, that is, η f ≥1, then change lanes to avoid obstacles and minimize the risk of collision. BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Figure 1 This is a comparison diagram of the comfortable obstacle avoidance trajectory, the stable obstacle avoidance trajectory, and the emergency obstacle avoidance trajectory in Example 1;

[0074] Figure 2 The obstacle avoidance trajectory diagram for implementing Example 1;

[0075] Figure 3 This is a trajectory diagram for lane change and obstacle avoidance implemented in Example 1;

[0076] Figure 4 The obstacle avoidance trajectory diagram under different road adhesion coefficients in Example 1;

[0077] Figure 5 The obstacle avoidance trajectory diagram at different initial vehicle speeds in Example 1. DETAILED DESCRIPTION

[0078] In order to better understand the technical solution of the present invention, the present invention is further described below in conjunction with specific embodiments and the accompanying drawings.

[0079] Example 1:

[0080] According to this embodiment, an adaptive obstacle avoidance trajectory planning method is provided, wherein obstacle avoidance trajectory information is obtained by the adaptive obstacle avoidance trajectory planning method; the obstacle avoidance trajectory information includes the vehicle obstacle avoidance trajectory, the critical safety distance, and the current lane passability margin;

[0081] The vehicle obstacle avoidance trajectory is the moving trajectory of the vehicle's center of mass (X(t), Y(t)) during the obstacle avoidance process;

[0082] The critical safety distance D ss Y is the lateral position of the right front corner of the vehicle and the lateral boundary position of the obstacle in front of it during vehicle steering and obstacle avoidance c When the vehicle is aligned, it still maintains a longitudinal safety distance Δd from the obstacle in front. ss Under the condition of , the distance between the first measurement line where the right front corner of the vehicle is located and the second measurement line where the left rear corner of the front obstacle is located when the vehicle starts to turn;

[0083] The first measurement line is parallel to the second measurement line, and the first measurement line is perpendicular to the vehicle axis when the vehicle is turning.

[0084] The adaptive obstacle avoidance trajectory planning method comprises the following steps:

[0085] Obtain vehicle status information, road status information, size information, and safety threshold information;

[0086] The vehicle state information includes the initial vehicle speed V x The road surface condition information includes the road adhesion coefficient μ; the size information includes the vehicle width W v , the distance d between the center of mass of the vehicle and the front of the vehicle f , obstacle lateral boundary position Y c The safety threshold information includes the maximum lateral acceleration a ymax , longitudinal safety distance Δd ss .

[0087] The safety threshold information is divided into comfortable obstacle avoidance safety threshold information, stable obstacle avoidance safety threshold information, and emergency obstacle avoidance safety threshold information;

[0088] Maximum lateral acceleration a ymax Including the maximum lateral acceleration for comfortable obstacle avoidance, the maximum lateral acceleration for smooth obstacle avoidance, and the maximum lateral acceleration for emergency obstacle avoidance;

[0089] The maximum value of the comfortable obstacle avoidance lateral acceleration is 0.22*μ*g; the maximum value of the smooth obstacle avoidance lateral acceleration is 0.4*μ*g; the maximum value of the emergency obstacle avoidance lateral acceleration is 0.5*μ*g; where g is the acceleration due to gravity.

[0090] Combining vehicle status information, road status information, and size information, a vehicle obstacle avoidance trajectory fitting formula is established based on a fifth-order polynomial, and a critical safety distance formula is established through the vehicle obstacle avoidance trajectory fitting formula;

[0091] The vehicle obstacle avoidance trajectory fitting formula is:

[0092] X(t)=V x *t

[0093] Y(t)=a5*t 5 +a4*t 4 +a3*t 3 +a2*t 2 +a1*t+a0

[0094] X f =V x *t f

[0095]

[0096] The a0, a1, a2, a3, a4, and a5 are the curve fitting coefficients to be determined;

[0097] Δd ys To reserve a safe distance for the side, Y w Lateral displacement to avoid obstacles.

[0098] Based on the vehicle obstacle avoidance trajectory fitting formula and combined with the safety threshold information, the comfortable obstacle avoidance vehicle obstacle avoidance trajectory, the stable obstacle avoidance vehicle obstacle avoidance trajectory, and the emergency obstacle avoidance vehicle obstacle avoidance trajectory are obtained; the specific process is:

[0099] Substitute the safety threshold information into the vehicle obstacle avoidance trajectory fitting formula to calculate the vehicle obstacle avoidance trajectory;

[0100] The vehicle obstacle avoidance trajectory formula is:

[0101]

[0102] X(t) is the longitudinal position of the vehicle's center of mass at time t during the obstacle avoidance process, and Y(t) is the lateral position of the vehicle's center of mass at time t during the obstacle avoidance process;

[0103] t f The obstacle avoidance time can be calculated by the following formula

[0104]

[0105] The autonomous driving vehicle autonomously switches between a comfortable obstacle avoidance vehicle trajectory, a stable obstacle avoidance vehicle trajectory, or an emergency obstacle avoidance vehicle trajectory based on the driver's personal habits and actual obstacle avoidance conditions;

[0106] When comfortable obstacle avoidance vehicle trajectory is selected, a ymax is the maximum lateral acceleration for comfortable obstacle avoidance, specifically 0.22*μ*g, which is substituted into the vehicle obstacle avoidance trajectory formula to obtain the comfortable obstacle avoidance vehicle obstacle avoidance trajectory;

[0107] When a stable obstacle avoidance vehicle trajectory is selected, a ymaxis the maximum lateral acceleration for smooth obstacle avoidance, specifically 0.4*μ*g, which is substituted into the vehicle obstacle avoidance trajectory formula to obtain the smooth obstacle avoidance vehicle obstacle avoidance trajectory;

[0108] When the emergency obstacle avoidance vehicle avoidance trajectory is selected, a ymax is the maximum lateral acceleration for emergency obstacle avoidance, specifically 0.5*μ*g. Substitute it into the vehicle obstacle avoidance trajectory formula to obtain the emergency obstacle avoidance vehicle obstacle avoidance trajectory.

[0109] The critical safety distance is obtained by combining the vehicle obstacle avoidance trajectory fitting formula with the critical safety distance formula;

[0110] The critical safety distance formula is:

[0111]

[0112] The t c The critical collision moment is the moment when the vehicle turns to avoid the obstacle and the lateral position of the right front corner of the vehicle is at the lateral boundary position Y of the obstacle in front of it. c moments of agreement;

[0113] (X(t c ),Y(t c )) is the center of mass position of the vehicle at the critical collision moment; θ c is the vehicle heading angle at the critical collision;

[0114] The X(t c ) by the formula X(t c )=V x *t c Calculated;

[0115] The θ c Calculated by the following formula:

[0116]

[0117] Construct the current lane's passable margin to assist in determining the steering obstacle avoidance strategy, and confirm the implementation of detour or lane change to avoid obstacles based on the current lane's passable margin.

[0118] The current lane passability margin η is obtained by formula 1 f ;

[0119] The formula 1 is:

[0120]

[0121] W * =W v +Δd ys

[0122] W=Wr -Y c

[0123]

[0124] V x is the vehicle speed, W r is the lane width, Y c is the lateral boundary position of the obstacle, W * is the expected passable space threshold, Δd ys Reserve a safe distance for the side, and W is the actual passable lateral space;

[0125] When η f <1, implement detour to avoid obstacles; when η f ≥1, implement lane change to avoid obstacles.

[0126] Example 2:

[0127] The same contents as those in Example 1 are not described in detail here. The differences between this embodiment and Example 1 are as follows:

[0128] According to this embodiment, a method for adaptive obstacle avoidance trajectory planning is provided, comprising the following steps:

[0129] The critical safety distance includes a comfortable obstacle avoidance critical safety distance, a stable obstacle avoidance critical safety distance, and an emergency obstacle avoidance critical safety distance.

[0130] The autonomous vehicle compares actual obstacle avoidance conditions with the critical safety distance for comfortable obstacle avoidance, the critical safety distance for smooth obstacle avoidance, and the critical safety distance for emergency obstacle avoidance, and autonomously switches obstacle avoidance plans. When the longitudinal distance between the vehicle and the obstacle ahead is less than the critical safety distance for comfortable obstacle avoidance, the vehicle automatically switches to the smooth obstacle avoidance plan. When the longitudinal distance between the vehicle and the obstacle ahead is less than the critical safety distance for smooth obstacle avoidance, the vehicle automatically switches to the emergency obstacle avoidance plan.

[0131] a ymax When the maximum lateral acceleration for comfortable obstacle avoidance is 0.22*μ*g, substitute it into the first formula to obtain the critical safety distance for comfortable obstacle avoidance.

[0132] a ymax When the maximum lateral acceleration for smooth obstacle avoidance is 0.4*μ*g, substitute it into the first formula to obtain the critical safety distance for smooth obstacle avoidance.

[0133] a ymax When the maximum lateral acceleration for emergency obstacle avoidance is 0.5*μ*g, it is substituted into the first formula to obtain the critical safety distance for emergency obstacle avoidance.

[0134] The above description is merely a preferred embodiment of the present application and an illustration of the technical principles employed. Those skilled in the art should understand that the scope of the invention herein is not limited to the technical solutions formed by the specific combination of the above-mentioned technical features, but also encompasses other technical solutions formed by any combination of the above-mentioned technical features or their equivalents without departing from the inventive concept. For example, the above-mentioned features may have similar functions to (but not limited to) those disclosed in this application.

Claims

1. An adaptive obstacle avoidance trajectory planning method, characterized in that: Obtaining obstacle avoidance trajectory information through an adaptive obstacle avoidance trajectory planning method; the obstacle avoidance trajectory information includes the vehicle's obstacle avoidance trajectory, critical safety distance, and current lane passability margin; The adaptive obstacle avoidance trajectory planning method comprises the following steps: Obtain vehicle status information, road status information, size information, and safety threshold information; The safety threshold information is divided into comfortable obstacle avoidance safety threshold information, stable obstacle avoidance safety threshold information, and emergency obstacle avoidance safety threshold information; Combining vehicle status information, road status information, and size information, a vehicle obstacle avoidance trajectory fitting formula is established based on a fifth-order polynomial, and a critical safety distance formula is established through the vehicle obstacle avoidance trajectory fitting formula; Based on the vehicle obstacle avoidance trajectory fitting formula and combined with the safety threshold information, the comfortable obstacle avoidance vehicle obstacle avoidance trajectory, the stable obstacle avoidance vehicle obstacle avoidance trajectory, and the emergency obstacle avoidance vehicle obstacle avoidance trajectory are obtained; The critical safety distance is obtained by combining the vehicle obstacle avoidance trajectory fitting formula with the critical safety distance formula; Construct the current lane's passable margin to assist in determining the steering obstacle avoidance strategy, and confirm the implementation of detour or lane change to avoid obstacles based on the current lane's passable margin.

2. The adaptive obstacle avoidance trajectory planning method according to claim 1, characterized in that: The vehicle obstacle avoidance trajectory is the moving trajectory of the vehicle's center of mass (X(t), Y(t)) during the obstacle avoidance process; The critical safety distance D ss Y is the lateral position of the right front corner of the vehicle and the lateral boundary position of the obstacle in front of it during vehicle steering and obstacle avoidance c When the vehicle is aligned, it still maintains a longitudinal safety distance Δd from the obstacle in front. ss Under the condition of , the distance between the first measurement line where the right front corner of the vehicle is located and the second measurement line where the left rear corner of the front obstacle is located when the vehicle starts to turn; The first measurement line is parallel to the second measurement line, and the first measurement line is perpendicular to the vehicle axis when the vehicle is turning.

3. The adaptive obstacle avoidance trajectory planning method according to claim 2, characterized in that: The vehicle state information includes the initial vehicle speed V x ; The road surface state information includes a road surface adhesion coefficient μ; The size information includes the vehicle width W v , the distance d between the vehicle's center of mass and the vehicle's front f , obstacle lateral boundary position Y c ; The safety threshold information includes the maximum lateral acceleration a ymax , longitudinal safety distance Δd ss .

4. The adaptive obstacle avoidance trajectory planning method according to claim 3, characterized in that: Maximum lateral acceleration a ymax Including the maximum lateral acceleration for comfortable obstacle avoidance, the maximum lateral acceleration for smooth obstacle avoidance, and the maximum lateral acceleration for emergency obstacle avoidance; The maximum lateral acceleration for comfortable obstacle avoidance is 0.22*μ*g; the maximum lateral acceleration for smooth obstacle avoidance is 0.4*μ*g; and the maximum lateral acceleration for emergency obstacle avoidance is 0.5*μ*g. The g is the acceleration due to gravity.

5. The adaptive obstacle avoidance trajectory planning method according to claim 3, characterized in that: The vehicle obstacle avoidance trajectory fitting formula is: X(t)=V x *t Y(t)=a5*t 5 +a4*t 4 +a3*t 3 +a2*t 2 +a1*t+a0 X f =V x *t f <h2 style=";text-align:left;direction:ltr">a0=0,a1=V<h2 style=";text-align:left;direction:ltr"> x <h2 style=";text-align:left;direction:ltr"> ,a2=0,<h2 style=";text-align:left;direction:ltr"> The a0, a1, a2, a3, a4, and a5 are the curve fitting coefficients to be determined; The Δd ys To reserve a safe distance for the side, Y w Lateral displacement to avoid obstacles.

6. The adaptive obstacle avoidance trajectory planning method according to claim 5, characterized in that: The process of obtaining the vehicle obstacle avoidance trajectory based on the vehicle obstacle avoidance trajectory fitting formula combined with the safety threshold information is as follows: substituting the safety threshold information into the vehicle obstacle avoidance trajectory fitting formula to calculate the vehicle obstacle avoidance trajectory; The vehicle obstacle avoidance trajectory formula is: X(t) is the longitudinal position of the vehicle's center of mass at time t during the obstacle avoidance process, and Y(t) is the lateral position of the vehicle's center of mass at time t during the obstacle avoidance process; t f The obstacle avoidance time can be calculated by the following formula 7. The adaptive obstacle avoidance trajectory planning method according to claim 6, characterized in that: The autonomous driving vehicle autonomously switches between a comfortable obstacle avoidance vehicle trajectory, a stable obstacle avoidance vehicle trajectory, or an emergency obstacle avoidance vehicle trajectory based on the driver's personal habits and actual obstacle avoidance conditions; When comfortable obstacle avoidance vehicle trajectory is selected, a ymax is the maximum lateral acceleration for comfortable obstacle avoidance, specifically 0.22*μ*g, which is substituted into the vehicle obstacle avoidance trajectory formula to obtain the comfortable obstacle avoidance vehicle obstacle avoidance trajectory; When a stable obstacle avoidance vehicle trajectory is selected, a ymax is the maximum lateral acceleration for smooth obstacle avoidance, specifically 0.4*μ*g, which is substituted into the vehicle obstacle avoidance trajectory formula to obtain the smooth obstacle avoidance vehicle obstacle avoidance trajectory; When the emergency obstacle avoidance vehicle avoidance trajectory is selected, a ymax is the maximum lateral acceleration for emergency obstacle avoidance, specifically 0.5*μ*g. Substitute it into the vehicle obstacle avoidance trajectory formula to obtain the emergency obstacle avoidance vehicle obstacle avoidance trajectory.

8. The adaptive obstacle avoidance trajectory planning method according to claim 7, characterized in that: The critical safety distance formula is: The t c The critical collision moment is the moment when the vehicle turns to avoid the obstacle and the lateral position of the right front corner of the vehicle is at the lateral boundary position Y in front of the obstacle. c moments of agreement; (X(t c ),Y(t c )) is the center of mass position of the vehicle at the critical collision moment; θ c is the vehicle heading angle at the critical collision; The X(t c ) by the formula X(t c )=V x *t c Calculated; The θ c Calculated by the following formula:

9. The adaptive obstacle avoidance trajectory planning method according to claim 8, characterized in that: The critical safety distance includes the critical safety distance for comfortable obstacle avoidance, the critical safety distance for stable obstacle avoidance, and the critical safety distance for emergency obstacle avoidance; The autonomous driving vehicle autonomously switches obstacle avoidance plans based on actual obstacle avoidance conditions and the critical safety distance for comfortable obstacle avoidance, the critical safety distance for smooth obstacle avoidance, and the critical safety distance for emergency obstacle avoidance. When the longitudinal distance between the vehicle and the obstacle ahead is less than the critical safety distance for comfortable obstacle avoidance, the vehicle automatically switches to the smooth obstacle avoidance plan; when the longitudinal distance between the vehicle and the obstacle ahead is less than the critical safety distance for smooth obstacle avoidance, the vehicle automatically switches to the emergency obstacle avoidance plan. a ymax When the maximum lateral acceleration for comfortable obstacle avoidance is 0.22*μ*g, substitute it into the critical safety distance formula to obtain the critical safety distance for comfortable obstacle avoidance. a ymax When the maximum lateral acceleration for smooth obstacle avoidance is 0.4*μ*g, substitute it into the first formula to obtain the critical safety distance for smooth obstacle avoidance. a ymax When the maximum lateral acceleration for emergency obstacle avoidance is 0.5*μ*g, the critical safety distance for emergency obstacle avoidance is obtained by substituting it into the critical safety distance formula.

10. The adaptive obstacle avoidance trajectory planning method according to claim 9, characterized in that: The current lane passability margin η is obtained by formula 1 f ; The formula 1 is: IN * =In v +Δd ys W=W r -Y c V x is the vehicle speed, W r is the lane width, Y c is the lateral boundary position of the obstacle, W * is the expected passable space threshold, Δd ys Reserve a safe distance for the side, and W is the actual passable lateral space; When η f <1, implement detour to avoid obstacles; when η f ≥1, implement lane change to avoid obstacles.

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