阅读说明：本技术 一种基于斥力场模型的特种车辆避让方法和系统 (Special vehicle avoidance method and system based on repulsive force field model ) 是由 闫海宁 王孟 陈佳玲 吴炫儒 李彪 于 2021-10-09 设计创作，主要内容包括：本发明提供了一种基于斥力场模型的特种车辆避让方法,包括,以当前车辆的行驶方向构建行驶坐标系,构建障碍边界的斥力函数；以特种车辆的行驶方向构建特种坐标系,构建特种车辆边界斥力函数；计算障碍物边界斥力函数和特种车辆边界斥力函数在行驶坐标系的两个坐标轴上的合力；基于车辆行驶方向的合力控制当前车辆的速度,基于垂直行驶方向的横向合力控制当前车辆的转向角度。本发明还提供了特种车辆避让系统。本发明的优点在于：以当前车辆位置为基点构建两个坐标系以分析当前车辆周边的障碍物以及特种车辆的斥力场函数,基于斥力的合力做出避让特种车辆的决策,在及时避让特种车辆的同时确保能够安全的躲避障碍物。(The invention provides a special vehicle avoidance method based on a repulsive force field model, which comprises the steps of constructing a running coordinate system according to the running direction of a current vehicle and constructing a repulsive force function of an obstacle boundary; constructing a special coordinate system according to the running direction of the special vehicle, and constructing a special vehicle boundary repulsion function; calculating the resultant force of the barrier boundary repulsion function and the special vehicle boundary repulsion function on two coordinate axes of a driving coordinate system; the speed of the current vehicle is controlled based on the resultant force of the traveling directions of the vehicles, and the steering angle of the current vehicle is controlled based on the lateral resultant force of the vertical traveling directions. The invention also provides a special vehicle avoidance system. The invention has the advantages that: two coordinate systems are constructed by taking the current vehicle position as a base point to analyze the barriers around the current vehicle and the repulsion field function of the special vehicle, a decision for avoiding the special vehicle is made based on the resultant force of repulsion, and the barriers can be safely avoided while the special vehicle is avoided in time.)

1. A special vehicle avoiding method based on a repulsive force field model is characterized by comprising the following steps: comprises the steps of (a) preparing a mixture of a plurality of raw materials,

constructing a driving coordinate system according to the driving direction of the current vehicle, acquiring boundary coordinates of the obstacle, calculating an obstacle avoidance safety distance, and constructing a repulsion function of the obstacle boundary;

constructing a special coordinate system by taking the current vehicle as a base point and the driving direction of the special vehicle, acquiring boundary coordinates of the special vehicle, and constructing a boundary repulsion function of the special vehicle;

when a special vehicle needs to be avoided, calculating resultant forces of the barrier boundary repulsion function and the special vehicle boundary repulsion function on two coordinate axes of a driving coordinate system;

the speed of the current vehicle is controlled based on the resultant force of the traveling directions of the vehicles, and the steering angle of the current vehicle is controlled based on the lateral resultant force of the vertical traveling directions.

2. A special vehicle avoidance method based on a repulsive force field model according to claim 1, wherein: the method for constructing the traveling coordinate system is that,

and constructing an XOY plane coordinate system as a running coordinate system by taking the geometric center of the current vehicle as an O point, the running direction as a Y axis and the direction parallel to the axle as an X axis.

3. A special vehicle avoidance method based on a repulsive force field model according to claim 2, wherein: the method for calculating the obstacle avoidance safe distance comprises the following steps

Calculating obstacle boundaries P_i(x_i，y_i) Distance to the current vehicle:

wherein B is the width of the current vehicle, L is the length of the current vehicle,satisfies the following formula,

introducing the relative speed v of the current vehicle and the obstacle,

v＝v₀-v_i

wherein v is₀Is the current vehicle speed, v_iIs the speed of the obstacle.

The obstacle avoidance safety distance of the obstacle is as follows,

wherein k is₁>And 0 is a safety factor.

4. A special vehicle avoidance method based on a repulsive force field model, according to claim 3, characterized in that: the repulsive force function of the obstacle boundary is constructed in a manner that,

when rho₁＝D₁When the obstacle avoidance is started, the maximum range of the repulsion function of the safe obstacle avoidance is D₁The function of the repulsive force field is then,

wherein k is_pIs the coefficient of repulsion;

when in useIn the meantime, the repulsive force field acts only in the X-axis direction, and in other cases acts only in the Y-axis direction, and thus the repulsive force field function is improved as,

is marked as

5. A special vehicle avoidance method based on a repulsive force field model according to claim 4, wherein: the construction method of the special coordinate system comprises the following steps:

the geometric center of the current vehicle is taken as a coordinate origin O, the advancing direction of the special vehicle is taken as an axis Y ', and the direction vertical to the axis Y ' is taken as an axis X '.

6. A special vehicle avoidance method based on a repulsive force field model according to claim 5, wherein: construction of Special vehicle boundary q_iThe method of the point repulsion function is that,

calculating q_iThe distance of the point from the origin of coordinates O,

in the running coordinate system XOY, four of the current vehiclesThe coordinates of the vertex are respectively,

the special coordinate system X 'OY' rotates around the origin by the driving coordinate system XOY by an angle theta_iIs obtained where | θ_i|<π，θ_i>0 denotes rotation in the clockwise direction, theta_i<0 represents rotation in the counterclockwise direction;

the coordinate conversion formula from the driving coordinate system XOY to the special coordinate system X 'OY' is as follows,

the coordinates A, B, C, D of the current vehicle vertex are transformed into a coordinate system X 'OY', namely A (X)_A′,y_A′)、B(x_B′,y_B′)、C(x_C′,y_C′)、D(x_D′,y_D′)；

The maximum distance from the current vehicle boundary point to the Y' axis is,

d₀＝max{|y_A′|,|y_B′|,|y_C′|,|y_D′|}

the minimum distance of the feature vehicle to the Y' axis is,

d_min＝min{|y′_i|}

the current critical condition that the vehicle needs to avoid the special vehicle is,

d_min<d₀

to ensure a safety margin, the critical conditions are modified to,

d_min<γd₀

wherein γ >1 is a correction coefficient;

safe obstacle avoidance distance D of special vehicle₂In order to realize the purpose,

wherein k is₂>0 is a safety factor;

the boundary repulsive force model of the special vehicle is,

wherein k is_qIs the coefficient of repulsion;

considering only the boundary points q of the special vehicle_iThe repulsive force in the X' axis direction, the repulsive force function is,

7. a special vehicle avoidance method based on a repulsive force field model according to claim 6, wherein: the method for calculating the resultant force of the obstacle boundary and the special vehicle boundary on two coordinate axes of the formal coordinate system comprises the following steps,

the repulsion function of the special vehicle boundary is respectively decomposed on an X axis and a Y axis,

F_q(i)＝F_qx(i)+F_qy(i)

wherein the content of the first and second substances,

F_qx(i)＝F_q(i)cosθ_i

F_qy(i)＝F_q(i)sinθ_i

the resultant forces of the barrier boundary repulsive force function and the special vehicle boundary repulsive force function on the coordinate axis are respectively,

8. a special vehicle avoidance method based on a repulsive force field model according to claim 7, wherein: a method of controlling the steering angle alpha is,

α＝k₃|F_x|

wherein k is₃>0 is a constant number of times, and,

when F is present_xIn the positive half axis of the X axis, the steering direction is X axis square, when F_xIn the negative half axis of the X axis, the steering direction is the negative direction of the X axis.

9. A special vehicle avoidance method based on a repulsive force field model according to claim 8, wherein: the method of controlling the current vehicle speed is,

when a resultant force F_yAnd the velocity v before avoidance₀The vehicle speed v 'after avoidance with the same direction'₀In order to realize the purpose,

v′₀＝v₀+k₄|F_y|t

wherein k is₄>0 is a constant and t is time;

when a resultant force F_yAnd the velocity v before avoidance₀When the direction is opposite, the vehicle speed v 'after avoidance'₀In order to realize the purpose,

v′₀＝v₀+k₅|F_y|t

wherein k is₅<0 is a constant.

10. The utility model provides a special vehicle dodges system based on repulsion field model which characterized in that: comprises the steps of (a) preparing a mixture of a plurality of raw materials,

the obstacle repulsion function calculation module is used for constructing a driving coordinate system according to the driving direction of the current vehicle, acquiring boundary coordinates of obstacles, calculating obstacle avoidance safe distance and constructing a repulsion function of the obstacle boundary;

the special vehicle repulsion function calculation module is used for constructing a special coordinate system by taking the current vehicle as a base point and the running direction of the special vehicle, acquiring boundary coordinates of the special vehicle and constructing a special vehicle boundary repulsion function;

the resultant force calculation module is used for calculating resultant forces of the barrier boundary repulsion function and the special vehicle boundary repulsion function on two coordinate axes of a driving coordinate system when a special vehicle needs to be avoided;

and the avoidance decision module controls the speed of the current vehicle based on the resultant force in the vehicle running direction and controls the steering angle of the current vehicle based on the transverse resultant force in the vertical running direction.

Technical Field

The invention relates to the technical field of intelligent driving, in particular to a special vehicle avoidance method and system based on a repulsive force field model.

Background

With the popularization and development of the automatic driving technology, more and more problems need to be solved by the automatic driving technology, for example, when special vehicles such as police cars, fire trucks, ambulances, engineering wreckers and the like exist on lanes, the special vehicles need to be identified in time and give way actively.

The invention patent application with publication number CN110733499A discloses an autonomous vehicle and a control method thereof, which determine the priority of the special vehicle demand information by receiving and analyzing the information sent by the special vehicle, and control the automatic vehicle to avoid the special vehicle according to the priority sequence of the special vehicle, however, the method needs the special vehicle to establish a communication relationship with the autonomous vehicle, and only considers the relative position relationship between the autonomous vehicle and the special vehicle and other autonomous vehicles during avoiding, which is not suitable for the current actual road condition and cannot be used on the road at the present stage.

The invention patent application with publication number CN112060089A discloses an avoidance method for a special vehicle, which judges the current surrounding environment and the state of the special vehicle by obtaining audio signals and image information, when the special vehicle meets the preset conditions, obtains the motion parameters of the special vehicle and judges the motion trend of the special vehicle according to the motion parameters, and then determines an avoidance path according to the motion trend and the image information. The prior art is a typical obstacle avoidance mode, and the specific steps are to identify a special vehicle, judge whether avoidance needs to be carried out, and select an avoidance path. In the prior art, research on special vehicle identification is relatively complete, but the states of other surrounding vehicles cannot be actively analyzed and obstacles cannot be avoided in advance in judging whether avoidance is needed or not and planning of an avoidance path, so that the method has certain limitations.

Disclosure of Invention

The invention aims to provide a method and a system for making a decision of avoiding a special vehicle based on a repulsive force field model.

The invention solves the technical problems through the following technical scheme: a special vehicle avoiding method based on a repulsive force field model comprises the following steps,

constructing a driving coordinate system according to the driving direction of the current vehicle, acquiring boundary coordinates of the obstacle, calculating an obstacle avoidance safety distance, and constructing a repulsion function of the obstacle boundary;

constructing a special coordinate system by taking the current vehicle as a base point and the driving direction of the special vehicle, acquiring boundary coordinates of the special vehicle, and constructing a boundary repulsion function of the special vehicle;

when a special vehicle needs to be avoided, calculating resultant forces of the barrier boundary repulsion function and the special vehicle boundary repulsion function on two coordinate axes of a driving coordinate system;

the speed of the current vehicle is controlled based on the resultant force of the traveling directions of the vehicles, and the steering angle of the current vehicle is controlled based on the lateral resultant force of the vertical traveling directions.

The method and the system construct two coordinate systems by taking the current vehicle position as a base point respectively to analyze the barriers around the current vehicle and the repulsion field function of the special vehicle, make a decision for avoiding the special vehicle based on the resultant force of repulsion, ensure that the barriers can be safely avoided while the special vehicle is avoided in time, and ensure a safe and efficient traffic environment.

Preferably, the method for constructing the coordinate system of travel is,

and constructing an XOY plane coordinate system as a running coordinate system by taking the geometric center of the current vehicle as an O point, the running direction as a Y axis and the direction parallel to the axle as an X axis.

Preferably, the method for calculating the obstacle avoidance safety distance comprises

Calculating obstacle boundaries P_i(x_i，y_i) Distance to the current vehicle:

wherein B is the width of the current vehicle, L is the length of the current vehicle,satisfies the following formula,

introducing the relative speed v of the current vehicle and the obstacle,

v＝v₀-v_i

wherein v is₀Is the current vehicle speed, v_iIs the speed of the obstacle.

The obstacle avoidance safety distance of the obstacle is as follows,

wherein k is₁>And 0 is a safety factor.

Preferably, the repulsive force function of the obstacle boundary is constructed by,

when rho₁＝D₁When the obstacle avoidance is started, the maximum range of the repulsion function of the safe obstacle avoidance is D₁The function of the repulsive force field is then,

wherein k is_pIs the coefficient of repulsion;

when in useIn the meantime, the repulsive force field acts only in the X-axis direction, and in other cases acts only in the Y-axis direction, and thus the repulsive force field function is improved as,

is marked as

Preferably, the construction method of the special coordinate system comprises the following steps:

the geometric center of the current vehicle is taken as a coordinate origin O, the advancing direction of the special vehicle is taken as an axis Y ', and the direction vertical to the axis Y ' is taken as an axis X '.

Preferably, a special vehicle boundary q is constructed_iThe method of the point repulsion function is that,

calculating q_iThe distance of the point from the origin of coordinates O,

in the travel coordinate system XOY, the coordinates of the four vertexes of the current vehicle are respectively,

the special coordinate system X 'OY' rotates around the origin by the driving coordinate system XOY by an angle theta_iIs obtained where | θ_i|<π，θ_i>0 denotes rotation in the clockwise direction, theta_i<0 represents rotation in the counterclockwise direction;

the coordinate conversion formula from the driving coordinate system XOY to the special coordinate system X 'OY' is as follows,

the coordinates A, B, C, D of the current vehicle vertex are transformed into a coordinate system X 'OY', namely A (X)_A′,y_A′)、B(x_B′,y_B′)、C(x_C′,y_C′)、D(x_D′,y_D′)；

The maximum distance from the current vehicle boundary point to the Y' axis is,

d₀＝max{|y_A′|,|y_B′|,|y_C′|,|y_D′|}

the minimum distance of the feature vehicle to the Y' axis is,

d_min＝min{|y′_i|}

the current critical condition that the vehicle needs to avoid the special vehicle is,

d_min<d₀

to ensure a safety margin, the critical conditions are modified to,

d_min<γd₀

wherein γ >1 is a correction coefficient;

safe obstacle avoidance distance D of special vehicle₂In order to realize the purpose,

wherein k is₂>0 is a safety factor;

the boundary repulsive force model of the special vehicle is,

wherein k is_qIs the coefficient of repulsion;

considering only the boundary points q of the special vehicle_iThe repulsive force in the X' axis direction, the repulsive force function is,

preferably, the method for calculating the resultant force of the obstacle boundary and the special vehicle boundary on two coordinate axes of the formal coordinate system is,

the repulsion function of the special vehicle boundary is respectively decomposed on an X axis and a Y axis,

F_q(i)＝F_qx(i)+F_qy(i)

wherein the content of the first and second substances,

F_qx(i)＝F_q(i)cosθ_i

F_qy(i)＝F_q(i)sinθ_i

the resultant forces of the barrier boundary repulsive force function and the special vehicle boundary repulsive force function on the coordinate axis are respectively,

preferably, the steering angle a is controlled by,

α＝k₃|F_x|

wherein k is₃>0 is a constant number of times, and,

when F is present_xIn the positive half axis of the X axis, the steering direction is X axis square, when F_xIn the negative half axis of the X axis, the steering direction is the negative direction of the X axis.

Preferably, the method of controlling the current vehicle speed is,

when a resultant force F_yAnd the velocity v before avoidance₀The vehicle speed v 'after avoidance with the same direction'₀In order to realize the purpose,

v′₀＝v₀+k₄|F_y|t

wherein k is₄>0 is a constant and t is time;

when a resultant force F_yAnd the velocity v before avoidance₀Phase of directionReverse, the vehicle speed v 'after avoidance'₀In order to realize the purpose,

v′₀＝v₀+k₅|F_y|t

wherein k is₅<0 is a constant.

The invention also provides a special vehicle avoiding system based on the repulsive force field model, which comprises,

the obstacle repulsion function calculation module is used for constructing a driving coordinate system according to the driving direction of the current vehicle, acquiring boundary coordinates of obstacles, calculating obstacle avoidance safe distance and constructing a repulsion function of the obstacle boundary;

the special vehicle repulsion function calculation module is used for constructing a special coordinate system by taking the current vehicle as a base point and the running direction of the special vehicle, acquiring boundary coordinates of the special vehicle and constructing a special vehicle boundary repulsion function;

the resultant force calculation module is used for calculating resultant forces of the barrier boundary repulsion function and the special vehicle boundary repulsion function on two coordinate axes of a driving coordinate system when a special vehicle needs to be avoided;

and the avoidance decision module controls the speed of the current vehicle based on the resultant force in the vehicle running direction and controls the steering angle of the current vehicle based on the transverse resultant force in the vertical running direction.

The special vehicle avoidance method and system based on the repulsive force field model have the advantages that: two coordinate systems are respectively constructed by taking the current vehicle position as a base point to analyze the barriers around the current vehicle and the repulsion field function of the special vehicle, a decision for avoiding the special vehicle is made based on the resultant force of repulsion, the barriers can be safely avoided while the special vehicle is avoided in time, and a safe and efficient traffic environment is ensured.

Drawings

Fig. 1 is a flowchart of a special vehicle avoidance method based on a repulsive force field model according to an embodiment of the present invention;

fig. 2 is a schematic diagram of an obstacle boundary repulsion function construction of a special vehicle avoidance method based on a repulsion field model according to an embodiment of the present invention;

fig. 3 is a schematic diagram of a special vehicle boundary repulsion function construction of a special vehicle avoidance method based on a repulsion field model according to an embodiment of the present invention;

fig. 4 is one of schematic diagrams of an avoidance process of a special vehicle avoidance method based on a repulsive field model according to an embodiment of the present invention;

fig. 5 is a second schematic view of an avoidance process of the special vehicle avoidance method based on the repulsive field model according to the embodiment of the present invention;

fig. 6 is a schematic diagram of a special vehicle avoidance system based on a repulsive field model according to an embodiment of the present invention.

Detailed Description

To make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention are described below in detail and completely with reference to the accompanying drawings, and it is apparent that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1, the present embodiment provides a special vehicle avoidance method based on a repulsive force field model, including,

constructing a driving coordinate system according to the driving direction of the current vehicle, acquiring boundary coordinates of the obstacle, calculating an obstacle avoidance safety distance, and constructing a repulsion function of the obstacle boundary;

constructing a special coordinate system by taking the current vehicle as a base point and the driving direction of the special vehicle, acquiring boundary coordinates of the special vehicle, and constructing a boundary repulsion function of the special vehicle;

when a special vehicle needs to be avoided, calculating resultant forces of the barrier boundary repulsion function and the special vehicle boundary repulsion function on two coordinate axes of a driving coordinate system;

the speed of the current vehicle is controlled based on the resultant force of the traveling directions of the vehicles, and the steering angle of the current vehicle is controlled based on the lateral resultant force of the vertical traveling directions.

In the embodiment, two coordinate systems are respectively constructed by taking the current vehicle position as a base point to analyze the barriers around the current vehicle and the repulsion field function of the special vehicle, a decision for avoiding the special vehicle is made based on the resultant force of repulsion, the barriers can be safely avoided while the special vehicle is avoided in time, and a safe and efficient traffic environment is ensured.

Specifically, the method for avoiding the special vehicle based on the repulsive force field model provided by the embodiment includes the following steps:

s1: constructing a driving coordinate system according to the driving direction of the current vehicle, acquiring boundary coordinates of the obstacle, calculating an obstacle avoidance safety distance, and constructing a repulsion function of the obstacle boundary;

referring to fig. 2, the method for constructing the driving coordinate system is,

and constructing an XOY plane coordinate system as a running coordinate system by taking the geometric center of the current vehicle as an O point, the running direction as a Y axis and the direction parallel to the axle as an X axis.

The method for calculating the obstacle avoidance safe distance comprises the following steps

Calculating obstacle boundaries P_i(x_i，y_i) Distance to the current vehicle:

wherein B is the width of the current vehicle, L is the length of the current vehicle,satisfies the following formula,

introducing the relative speed v of the current vehicle and the obstacle,

v＝v₀-v_i

wherein v is₀Is the current vehicle speed, v_iIs the speed of the obstacle.

The conditions to be considered when performing obstacle avoidance determination are as follows:

when the obstacle is positioned in front of the current vehicle in the Y direction and v is greater than zero, the larger v is, the larger the required obstacle avoidance safe distance is,

when the obstacle is positioned in front of the current vehicle in the Y direction and v is less than zero, the obstacle does not collide with the current vehicle, and the obstacle avoidance safety distance does not need to be considered;

when the barrier is positioned behind the current vehicle in the Y direction and v is greater than zero, the v barrier does not collide with the current vehicle, and the obstacle avoidance safety distance does not need to be considered;

when the obstacle is located behind the current vehicle in the Y direction and v is smaller than zero, the larger v is, the larger the required obstacle avoidance safety distance is.

Based on the above analysis, the calculation formula of the obstacle avoidance safety distance provided by the embodiment is as follows,

wherein k is₁>0 is a safety factor and is an empirical value.

The repulsive force function of the obstacle boundary is constructed in a manner that,

when rho₁＝D₁When the obstacle avoidance is started, the maximum range of the repulsion function of the safe obstacle avoidance is D₁The function of the repulsive force field is then,

wherein k is_pIs the coefficient of repulsion;

when in useIn the meantime, the repulsive force field acts only in the X-axis direction, and in other cases acts only in the Y-axis direction, and thus the repulsive force field function is improved as,

is marked as

S2: constructing a special coordinate system by taking the current vehicle as a base point and the driving direction of the special vehicle, acquiring boundary coordinates of the special vehicle, and constructing a boundary repulsion function of the special vehicle;

referring to fig. 3, the method for constructing the special coordinate system includes:

the geometric center of the current vehicle is taken as a coordinate origin O, the advancing direction of the special vehicle is taken as an axis Y ', and the direction vertical to the axis Y ' is taken as an axis X '.

Construction of Special vehicle boundary q_iThe method of the point repulsion function is that,

calculating q_iThe distance of the point from the origin of coordinates O,

in the travel coordinate system XOY, the coordinates of the four vertexes of the current vehicle are respectively,

the special coordinate system X 'OY' rotates around the origin by the driving coordinate system XOY by an angle theta_iIs obtained where | θ_i|<π，θ_i>0 denotes rotation in the clockwise direction, theta_i<0 represents rotation in the counterclockwise direction;

the coordinate conversion formula from the driving coordinate system XOY to the special coordinate system X 'OY' is as follows,

the coordinates A, B, C, D of the current vehicle vertex are transformed into a coordinate system X 'OY', namely A (X)_A′,y_A′)、B(x_B′,y_B′)、C(x_C′,y_C′)、D(x_D′,y_D′)；

The maximum distance from the current vehicle boundary point to the Y' axis is,

d₀＝max{|y_A′|,|y_B′|,|y_C′|,|y_D′|}

the minimum distance of the feature vehicle to the Y' axis is,

d_min＝min{|y′_i|}

the current critical condition that the vehicle needs to avoid the special vehicle is,

d_min<d₀

to ensure a safety margin, the critical conditions are modified to,

d_min<γd₀

wherein γ >1 is a correction coefficient;

imitating D in S1₁Determination method for determining safe obstacle avoidance distance D₂，

Wherein k is₂>0 is a safety factor and is an empirical value.

The boundary repulsive force model of the special vehicle is,

wherein k is_qIs the coefficient of repulsion;

considering only the boundary points q of the special vehicle_iThe repulsive force in the X' axis direction, the repulsive force function is,

s3: when a special vehicle needs to be avoided, calculating resultant forces of the barrier boundary repulsion function and the special vehicle boundary repulsion function on two coordinate axes of a driving coordinate system;

firstly, the repulsion function F of the boundary of the special vehicle_q(i)Are respectively decomposed on an X axis and a Y axis,

F_q(i)＝F_qx(i)+F_qy(i)

wherein the content of the first and second substances,

F_qx(i)＝F_q(i)cosθ_i

F_qy(i)＝F_q(i)sinθ_i

the resultant forces of the barrier boundary repulsive force function and the special vehicle boundary repulsive force function on the coordinate axis are respectively,

s4: controlling the speed of the current vehicle based on the resultant force of the vehicle driving direction, and controlling the steering angle of the current vehicle based on the transverse resultant force vertical to the driving direction;

specifically, the steering angle α is controlled by,

α＝k₃|F_x|

wherein k is₃>0 is a constant number of times, and,

when F is present_xIn the positive half axis of the X axisThe direction of rotation is X-axis square when F_xWhen the axis of the X-axis is a negative half axis, the steering direction is the negative direction of the X-axis;

the method of controlling the current vehicle speed is,

when a resultant force F_yAnd the velocity v before avoidance₀The vehicle speed v 'after avoidance with the same direction'₀In order to realize the purpose,

v′₀＝v₀+k₄|F_y|t

wherein k is₄>0 is a constant and t is time;

when a resultant force F_yAnd the velocity v before avoidance₀When the direction is opposite, the vehicle speed v 'after avoidance'₀In order to realize the purpose,

v′₀＝v₀+k₅|F_y|t

wherein k is₅<0 is a constant.

Fig. 4 and 5 show the process of the vehicle avoiding the special vehicle, and in order to adapt to the driving track, the reading sequence of fig. 4 and 5 is from bottom to top.

Further, referring to fig. 6, the embodiment also provides a special vehicle avoidance system based on a repulsive force field model, including,

the obstacle repulsion function calculation module is used for constructing a driving coordinate system according to the driving direction of the current vehicle, acquiring boundary coordinates of obstacles, calculating obstacle avoidance safe distance and constructing a repulsion function of the obstacle boundary;

the special vehicle repulsion function calculation module is used for constructing a special coordinate system by taking the current vehicle as a base point and the running direction of the special vehicle, acquiring boundary coordinates of the special vehicle and constructing a special vehicle boundary repulsion function;

the resultant force calculation module is used for calculating resultant forces of the barrier boundary repulsion function and the special vehicle boundary repulsion function on two coordinate axes of a driving coordinate system when a special vehicle needs to be avoided;

and the avoidance decision module controls the speed of the current vehicle based on the resultant force in the vehicle running direction and controls the steering angle of the current vehicle based on the transverse resultant force in the vertical running direction.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.