CN115891992B - Speed planning algorithm and device for passenger car - Google Patents

Abstract

The invention relates to a speed planning algorithm and a speed planning device for a passenger car. The method comprises the steps of determining a maximum speed and an intermediate speed, comparing the current speed with the maximum speed if the intermediate speed is larger than or equal to the maximum speed, decelerating to the maximum speed in a first half section if the current speed is larger than the maximum speed, driving at a constant speed after decelerating to the platform speed in a second half section, accelerating to the maximum speed in the first half section if the current speed is smaller than the maximum speed, driving at a constant speed after decelerating to the platform speed in the second half section, comparing the intermediate speed with the platform speed if the intermediate speed is smaller than the maximum speed, accelerating to the intermediate speed in the first half section if the intermediate speed is larger than the platform speed, driving at a constant speed after decelerating to the platform speed in the second half section, accelerating to the intermediate speed in the first half section if the intermediate speed is smaller than the platform speed, and driving at a constant speed after accelerating to the platform speed in the second half section. The method has the advantages of simple calculation process of the intermediate speed and improvement of planning efficiency.

Description

Speed planning algorithm and device for passenger car

Technical Field

The invention relates to a speed planning algorithm and device for a passenger car, and belongs to the technical field of speed planning.

Background

In the running process of the automatic driving vehicle, the speed planning is required to be carried out according to the actual road condition and the scene so as to achieve the aim of rapidly, stably, safely and accurately reaching the target place when the vehicle is automatically driven.

Common speed planning algorithms include an S-type speed planning algorithm, an exponential type speed planning algorithm, and a trapezoidal type speed planning algorithm. The S-shaped speed planning has higher flexibility in acceleration and deceleration control, but has more sections and larger calculated amount, the exponential-shaped speed planning has discontinuous acceleration, is suitable for speed control of a stepping motor, and has the advantages of simplicity, small calculated amount, high response speed and the like, and is widely used.

For example, journal articles with the names of 'computer engineering' and publication numbers of 1000-3428 (201) 01-00-0 and 'intelligent vehicle trapezoidal speed planning method based on intermediate speed' disclose an intelligent vehicle trapezoidal speed planning method based on intermediate speed, wherein the speed planning method brings the speed of an obstacle into the speed planning process of a vehicle, and uses the proposed intermediate speed quantity as a reference quantity of speed decision control, thereby realizing vehicle speed advanced planning, ensuring the continuity of planning results, improving the stability of the planning speed process and solving the problem of fluctuation of the speed planning result when facing dynamic obstacles.

However, in the above speed planning process, the calculation process of the intermediate speed is complex, resulting in low planning efficiency.

Disclosure of Invention

The application aims to provide a speed planning algorithm and device for a passenger car, which are used for solving the problem of low planning efficiency of the existing mode.

In order to achieve the above purpose, the present application provides a technical solution for a speed planning algorithm for a passenger car, including the following steps:

1) Determining the maximum speed, the maximum acceleration and the maximum deceleration of the current road;

2) Determining the intermediate speed of the vehicle under the current road according to the current speed of the vehicle, the target distance, the minimum safe distance and the maximum acceleration;

3) Judging the intermediate speed and the maximum speed, if the intermediate speed is greater than or equal to the maximum speed, performing speed planning by taking the maximum speed as a limiting speed, and entering the step 4), and if the intermediate speed is less than the maximum speed, performing speed planning by taking the intermediate speed as the limiting speed, and entering the step 5);

4) Judging the current speed and the maximum speed, if the current speed is larger than the maximum speed, decelerating the vehicle from the current speed to the maximum speed at a first deceleration and then driving at the maximum speed at a constant speed, decelerating the vehicle from the maximum speed to the platform speed at a second deceleration and then driving at the platform speed at a constant speed at a second deceleration in the latter half of the target distance, accelerating the vehicle from the current speed to the maximum speed at the first acceleration and then driving at the maximum speed at the first acceleration in the first half of the target distance, decelerating the vehicle from the maximum speed to the platform speed at the third deceleration in the latter half of the target distance and then driving at the constant speed at the platform speed;

5) Judging the middle speed and the platform speed, if the middle speed is greater than the platform speed, accelerating the vehicle from the current speed to the middle speed at a second acceleration, then driving at a middle speed at a constant speed, and decelerating the vehicle from the middle speed to the platform speed at a fourth deceleration in the second half of the target distance, then driving at the platform speed at a constant speed;

The speed of the platform is the speed of an obstacle, the first acceleration, the second acceleration, the third acceleration and the fourth acceleration are all smaller than the maximum acceleration, and the first deceleration, the second deceleration, the third deceleration and the fourth deceleration are all smaller than the maximum deceleration.

The speed planning algorithm for the passenger car has the beneficial effects that the method and the system have the advantages that by combining road conditions, under the condition that the maximum speed and the maximum acceleration under the current road are obtained, the middle speed under the current road is calculated, the limiting speed of the vehicle under the current road is determined according to the middle speed and the maximum speed, trapezoidal speed planning is carried out according to the limiting speed, and the front half section and the rear half section of the target distance are adopted for sectional planning during planning, so that the vehicle can safely travel to an obstacle in the shortest time. The method has the advantages that the calculation process of the intermediate speed is simple, and the planning efficiency of the speed is improved.

Further, in the step 2), the intermediate speed is calculated as follows:

Wherein V_mid is the intermediate speed, a_{acc_max} is the maximum acceleration, s is the target distance, s_{safe_min} is the minimum safe distance, and V_cur is the current speed.

Further, the road includes a straight road and a curved road.

Further, in the straight road, the maximum speed is obtained according to road speed limit information.

Further, in the curved road, the maximum speed is obtained according to road speed limit information, the maximum acceleration is obtained according to a curvature radius, and the maximum deceleration is obtained according to vehicle parameters.

In addition, the application also provides a technical scheme of the speed planning device for the passenger car, which comprises a processor, a memory and a computer program which is stored in the memory and can run on the processor, wherein the processor realizes the following steps when executing the computer program:

1) Acquiring the maximum speed, the maximum acceleration and the maximum deceleration of the vehicle under the current road, and simultaneously acquiring the current speed, the target distance and the minimum safe distance of the vehicle;

2) Determining the intermediate speed of the vehicle under the current road according to the current speed of the vehicle, the target distance, the minimum safe distance and the maximum acceleration;

3) Judging the intermediate speed and the maximum speed, if the intermediate speed is greater than or equal to the maximum speed, performing speed planning by taking the maximum speed as a limiting speed, and entering the step 4), and if the intermediate speed is less than the maximum speed, performing speed planning by taking the intermediate speed as the limiting speed, and entering the step 5);

4) Judging the current speed and the maximum speed, if the current speed is larger than the maximum speed, decelerating the vehicle from the current speed to the maximum speed at a first deceleration and then driving at the maximum speed at a constant speed, decelerating the vehicle from the maximum speed to the platform speed at a second deceleration and then driving at the platform speed at a constant speed at a second deceleration in the latter half of the target distance, accelerating the vehicle from the current speed to the maximum speed at the first acceleration and then driving at the maximum speed at the first acceleration in the first half of the target distance, decelerating the vehicle from the maximum speed to the platform speed at the third deceleration in the latter half of the target distance and then driving at the constant speed at the platform speed;

5) Judging the middle speed and the platform speed, if the middle speed is greater than the platform speed, accelerating the vehicle from the current speed to the middle speed at a second acceleration, then driving at a middle speed at a constant speed, and decelerating the vehicle from the middle speed to the platform speed at a fourth deceleration in the second half of the target distance, then driving at the platform speed at a constant speed;

The speed of the platform is the speed of an obstacle, the first acceleration, the second acceleration, the third acceleration and the fourth acceleration are all smaller than the maximum acceleration, and the first deceleration, the second deceleration, the third deceleration and the fourth deceleration are all smaller than the maximum deceleration.

The speed planning device for the passenger car has the beneficial effects that the method and the device have the advantages that the road condition is combined, the middle speed under the current road is calculated under the condition that the maximum speed and the maximum acceleration under the current road are obtained, the limiting speed of the vehicle under the current road is determined according to the middle speed and the maximum speed, the trapezoid speed planning is carried out according to the limiting speed, and the front half section and the rear half section of the target distance are adopted for the subsection planning during the planning, so that the vehicle can safely travel to an obstacle in the shortest time. The method has the advantages that the calculation process of the intermediate speed is simple, and the planning efficiency of the speed is improved.

Further, in the step 2), the intermediate speed is calculated as follows:

Wherein V_mid is the intermediate speed, a_{acc_max} is the maximum acceleration, s is the target distance, s_{safe_min} is the minimum safe distance, and V_cur is the current speed.

Further, the road includes a straight road and a curved road.

Further, in the straight road, the maximum speed is obtained according to road speed limit information.

Further, in the curved road, the maximum speed is obtained according to road speed limit information, the maximum acceleration is obtained according to a curvature radius, and the maximum deceleration is obtained according to vehicle parameters.

Drawings

FIG. 1 is a flow chart of the speed planning algorithm for a passenger vehicle of the present invention;

FIG. 2 is a graph of a speed plan for the present invention with maximum speed limiting and a current speed greater than maximum speed;

FIG. 3 is a graph of a speed plan for the present invention with maximum speed limiting and current speed less than maximum speed;

FIG. 4 is a graph illustrating a speed plan for a platform speed greater than an intermediate speed, with the present invention limiting the speed to the intermediate speed;

FIG. 5 is a graph illustrating a speed plan for a platform speed less than an intermediate speed, with the intermediate speed limiting the speed according to the present invention;

fig. 6 is a block diagram of a speed planning apparatus for a passenger car according to the present invention.

Detailed Description

Speed planning algorithm embodiment for passenger car:

The speed planning algorithm for the passenger car mainly aims at solving the problem that the calculation of the intermediate speed is complex in the prior art, and on the basis of determining the maximum speed, the maximum acceleration and the maximum deceleration of the current road, the intermediate speed is calculated according to the maximum acceleration and the target distance and the minimum safety distance, and the speed planning is carried out by taking a small value as the limiting speed of the current road through the comparison of the intermediate speed and the maximum speed, so that the planning efficiency is improved.

Specifically, the speed planning algorithm for the passenger car is shown in fig. 1, and comprises the following steps:

1) The maximum speed V_max, the maximum acceleration a_{acc_max}, and the maximum deceleration a_{dec_max} under the current road are determined.

In this step, the road includes a straight road and a curved road, wherein:

In a straight road, the maximum speed V_max is obtained from speed limit information of the road (speed limit information can be obtained through a map), the maximum acceleration a_{acc_max} and the maximum deceleration a_{dec_max} are limited by hardware conditions of the vehicle, and are parameters of the vehicle, and the acceleration limit and the deceleration limit of the vehicle are generally taken. Of course, the maximum acceleration a_{acc_max} can also be obtained according to the distance of the obstacle ahead and the current speed.

In a curved road, the minimum turning radius of the vehicle is obtained according to the curvature radius of the current road (curvature radius=1/minimum turning radius), the maximum acceleration a_{acc_max}(a_{acc_max} =current speed is determined according to the minimum turning radius and the current speed, the current speed/minimum turning radius), the maximum deceleration a_{dec_max} is obtained by taking the deceleration limit of the vehicle, and the maximum speed V_max is obtained according to the speed limit information of the road.

The maximum speed V_max is the speed limit of the vehicle running on the current road, the maximum acceleration a_{acc_max} is the acceleration limit of the vehicle during acceleration, the maximum deceleration a_{dec_max} is the deceleration limit of the vehicle during deceleration, the acceleration is positive number, the deceleration is negative number, the acceleration and the deceleration are both numerical values, and the acceleration and the deceleration are irrelevant to the positive and negative. For example, the deceleration is-10 m/s² is greater than the deceleration is-8 m/s². In the speed planning, the acceleration or deceleration is between the maximum acceleration a_{acc_max} and the maximum deceleration a_{dec_max}, and this range is not exceeded.

2) The intermediate speed V_mid of the vehicle under the current road is determined based on the current speed V_cur of the vehicle, the target distance s, the minimum safe distance s_{safe_min}, and the maximum acceleration a_{acc_max}.

The calculation process is as follows:

the target distance s is the distance from the vehicle to the obstacle (here, the obstacle may be an intersection, a station, a moving vehicle, a moving pedestrian, a stationary obstacle, etc.), s-s_{safe_min} represents the safe distance that the vehicle can travel, so the meaning of the intermediate speed is that the vehicle accelerates to the speed when the maximum acceleration is half of the safe distance at the current speed, so that the vehicle can reach half of the target distance in the shortest time and reach the target speed.

The minimum safe distance s_{safe_min} is determined according to the relative position of the vehicle and the obstacle, if the vehicle runs in the same direction, the calculation mode is s_{safe_min}＝V_cur²/(2 a), if the vehicle runs in the opposite direction, the calculation mode is s_{safe_min}＝(V_cur+v_obs)²/(2a),V_cur (scalar) is the current speed of the vehicle, v_obs (scalar) is the speed of the obstacle, and a is the maximum deceleration limited by the vehicle and is the same as the maximum deceleration a_{dec_max}.

3) Determining the sizes of V_mid and V_max, if V_mid≥V_max, performing speed planning by taking V_max as a limiting speed, and entering step 4), and if V_mid＜V_max, performing speed planning by taking V_mid as a limiting speed, and entering step 5).

4) Judging the sizes of V_cur and V_max:

As shown in fig. 2, if V_cur＞V_max, the vehicle is decelerating from V_cur to V_max at a first deceleration and then traveling at a constant velocity of V_max in the first half of the target distance s, decelerating from V_max to a platform velocity V_flat at a second deceleration and then traveling at a constant velocity of V_flat in the second half of the target distance s, V_flat being the velocity of an obstacle, if the obstacle is a platform, V_flat =0, and if the obstacle is a moving vehicle, V_flat being the velocity of a moving vehicle;

As shown in fig. 3, if V_cur＜V_max, the vehicle accelerates from V_cur to V_max at a first acceleration and then travels at a constant velocity at V_max in the first half of the target distance s, and decelerates from V_max at a third deceleration to V_flat in the second half of the target distance s and then travels at a constant velocity at V_flat;

of course, if V_cur＝V_max, the vehicle travels at a constant speed of V_cur in the first half of the target distance s, and then at a constant speed of V_flat after the vehicle decelerates from V_max at a third deceleration of V_flat in the second half of the target distance s;

In the case of V_flat＜V_max, the vehicle is decelerated to V_flat in the latter half of the target distance s, and in the case of V_flat≥V_max, V_max is a speed limit, and the vehicle is not allowed to exceed the speed limit, so that the vehicle can directly travel at a constant speed according to V_max in the latter half of the target distance s.

In step 4), the first deceleration, the second deceleration, the first acceleration, and the third deceleration are set according to the following:

Assuming that the vehicle is decelerating from V_cur to V_max at a certain deceleration to just travel s/2, then this deceleration is the minimum deceleration a_{dec_min1} at the first half of the deceleration in figure 2,Therefore, the first deceleration can be any value between a_{dec_min1} and a_{dec_max}, and can be specifically set according to actual requirements;

Assuming that the vehicle is decelerating from V_max to V_flat at a certain deceleration to just travel s/2, then this deceleration is the minimum deceleration a_{dec_min2} at the second-half deceleration in figure 2,The second deceleration can be any value between a_{dec_min2} and a_{dec_max}, and can be set according to actual requirements, and the third deceleration can be any value between a_{dec_min2} and a_{dec_max};

assuming that the vehicle is accelerating from V_cur to V_max at a certain acceleration to just travel s/2, then this deceleration is the minimum acceleration a_{acc_min1} at the first half acceleration in figure 3,Therefore, the first acceleration may be any value between a_{acc_min1} and a_{acc_max}, and may specifically be set according to the actual requirement.

5) In the case of V_mid＜V_max, in combination with the calculation process of V_mid, V_cur does not exceed V_mid, so the sizes of V_mid and V_flat are directly determined:

As shown in fig. 4, if V_mid＞V_flat, the vehicle accelerates from V_cur to V_mid at a second acceleration and then travels at a constant velocity of V_mid in the first half of the target distance s, and decelerates from V_mid to V_flat at a fourth deceleration in the second half of the target distance s and then travels at a constant velocity of V_flat;

as shown in fig. 5, if V_mid＜V_flat, the vehicle is accelerated from V_cur to V_mid at a third acceleration and then travels at a constant velocity of V_mid in the first half of the target distance s, and the vehicle is accelerated from V_mid to V_flat at a fourth acceleration and then travels at a constant velocity of V_flat in the second half of the target distance s;

Of course, if V_mid＝V_flat, the vehicle accelerates from V_cur to V_mid at the third acceleration and then travels at a constant speed of V_mid in the first half of the target distance s, and the vehicle travels at a constant speed of V_mid in the second half of the target distance s.

In step 5), the second acceleration, the fourth deceleration, the third acceleration and the fourth acceleration are set according to the following steps:

Assuming that the vehicle is accelerating from V_cur to V_mid at a certain acceleration just to travel s/2, then this acceleration is the minimum acceleration a_{acc_min2} at the first half acceleration in figure 4,Combining the calculation formula of the intermediate speed to obtainThe second acceleration can be any value between a_{acc_min2} and a_{acc_max}, and can be specifically set according to actual requirements, and the third acceleration can be any value between a_{acc_min2} and a_{acc_max} in the same way;

Assuming that the vehicle is decelerating from V_mid to V_flat at a certain deceleration to just travel s/2, then this deceleration is the minimum deceleration a_{dec_min3} at the second-half deceleration in figure 4,Therefore, the fourth deceleration can be any value between a_{dec_min3} and a_{dec_max}, and can be specifically set according to the actual requirement;

Assuming that the vehicle is accelerating from V_mid to V_flat at a certain acceleration just to travel s/2, then this acceleration is the minimum acceleration a_{acc_min3} at the second half of the acceleration in figure 5,Therefore, the fourth acceleration may be any value between a_{acc_min3} and a_{acc_max}, and may be specifically set according to the actual requirement.

In the above embodiment, in order to better meet the actual situation of the road, the maximum speed V_max, the maximum acceleration a_{acc_max}, and the maximum deceleration a_{dec_max} are determined according to the road situation and the scene, and as other embodiments, the values of the maximum speed V_max, the maximum acceleration a_{acc_max}, and the maximum deceleration a_{dec_max} under different roads may be directly calibrated empirically, regardless of the straight road or the curved road.

The invention calculates the intermediate speed, compares the intermediate speed with the maximum speed, takes a smaller value as a limiting speed, performs trapezoidal speed planning, can ensure that the vehicle safely reaches a target point (i.e. an obstacle) in the shortest time, and is a universal process in the trapezoidal speed planning process, thus being applicable to various scenes such as lane changing, following, conventional driving, crossing, entering, obstacle avoidance and the like.

Speed planning apparatus embodiment for passenger car:

a speed planning apparatus for a passenger vehicle, as shown in fig. 6, comprises a processor, a memory and a computer program stored in the memory and executable on the processor, which processor, when executing the computer program, implements a speed planning algorithm for the passenger vehicle.

The specific implementation process and effect of the speed planning algorithm for the passenger car are described in the speed planning algorithm embodiment for the passenger car, and are not described herein.

That is, the algorithm in the speed planning algorithm embodiment for a passenger vehicle above should be understood that the flow of the speed planning algorithm for a passenger vehicle may be implemented by computer program instructions. These computer program instructions may be provided to a processor, such as a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus, etc., such that execution of the instructions by the processor results in the implementation of the functions specified in the algorithm flow described above.

The processor in this embodiment refers to a microprocessor MCU or a processing device such as a programmable logic device FPGA;

The memory referred to in this embodiment is used to store computer program instructions that are formed to implement a speed planning algorithm for a passenger vehicle, and includes physical means for storing information, typically by digitizing the information and then storing the information in a medium that uses electrical, magnetic, or optical means. For example, various memories for storing information by electric energy, RAM, ROM, etc., various memories for storing information by magnetic energy, hard disk, floppy disk, magnetic tape, magnetic core memory, bubble memory, U disk, various memories for storing information by optical means, CD or DVD. Of course, there are other ways of storing, such as quantum storing, graphene storing, etc.

The speed planning device for the passenger car, which is formed by the memory and the processor and is formed by storing the computer program instructions for realizing the speed planning algorithm for the passenger car, is realized by executing the corresponding program instructions by the processor in the computer, and the computer can be realized in an intelligent terminal by using a windows operating system, a linux system or other program languages, such as android and iOS system programming languages, and is realized by processing logic based on a quantum computer.

As other embodiments, the speed planning apparatus for a passenger car may further include other processing hardware, such as a database or a multi-level cache, a GPU, etc., and the present invention is not limited to the structure of the speed planning apparatus for a passenger car.

Claims (10)

Translated fromChinese

1.一种用于客车的速度规划算法，其特征在于，包括以下步骤：1. A speed planning algorithm for a passenger car, characterized by comprising the following steps:1)确定当前道路下的最大速度、最大加速度、以及最大减速度；1) Determine the maximum speed, maximum acceleration, and maximum deceleration for the current road;2)根据车辆的当前速度V_cur、目标距离s、最小安全距离s_{safe_min}、以及所述最大加速度a_{acc_max}确定车辆在当前道路下的中间速度V_mid；中间速度V_mid的计算过程为：2) Determine the intermediate speed V_mid of the vehicle on the current road based on the current speed V_cur , the target distance s , the minimum safe distance s_{safe_min} , and the maximum acceleration a_{acc_max} ; the calculation process of the intermediate speed V_mid is:3)判断中间速度和最大速度的大小，若中间速度大于等于最大速度，则以最大速度作为限制速度进行速度规划，进入步骤4)；若中间速度小于最大速度，则以中间速度作为限制速度进行速度规划，进入步骤5)；3) Determine the size of the intermediate speed and the maximum speed. If the intermediate speed is greater than or equal to the maximum speed, use the maximum speed as the speed limit for speed planning and proceed to step 4); if the intermediate speed is less than the maximum speed, use the intermediate speed as the speed limit for speed planning and proceed to step 5);4)判断当前速度和最大速度的大小，若当前速度大于最大速度，则在目标距离的前半段，车辆以第一减速度从当前速度减速至最大速度后，以最大速度匀速行驶；在目标距离的后半段，车辆以第二减速度从最大速度减速至平台速度后，以平台速度匀速行驶；若当前速度小于最大速度，则在目标距离的前半段，车辆以第一加速度从当前速度加速至最大速度后，以最大速度匀速行驶；在目标距离的后半段，车辆以第三减速度从最大速度减速至平台速度后，以平台速度匀速行驶；4) Determine the difference between the current speed and the maximum speed. If the current speed is greater than the maximum speed, then in the first half of the target distance, the vehicle decelerates from the current speed to the maximum speed at a first deceleration, and then travels at a constant speed of the maximum speed. In the second half of the target distance, the vehicle decelerates from the maximum speed to the platform speed at a second deceleration, and then travels at a constant speed of the platform speed. If the current speed is less than the maximum speed, then in the first half of the target distance, the vehicle accelerates from the current speed to the maximum speed at a first acceleration, and then travels at a constant speed of the maximum speed. In the second half of the target distance, the vehicle decelerates from the maximum speed to the platform speed at a third deceleration, and then travels at a constant speed of the platform speed.5)判断中间速度和平台速度的大小，若中间速度大于平台速度，则在目标距离的前半段，车辆以第二加速度从当前速度加速至中间速度后，以中间速度匀速行驶；在目标距离的后半段，车辆以第四减速度从中间速度减速至平台速度后，以平台速度匀速行驶；若中间速度小于平台速度，则在目标距离的前半段，车辆以第三加速度从当前速度加速至中间速度后，以中间速度匀速行驶；在目标距离的后半段，车辆以第四加速度从中间速度加速至平台速度后，以平台速度匀速行驶；5) Determine the magnitude of the intermediate speed and the platform speed. If the intermediate speed is greater than the platform speed, then in the first half of the target distance, the vehicle accelerates from the current speed to the intermediate speed using the second acceleration, and then travels at a constant speed at the intermediate speed. In the second half of the target distance, the vehicle decelerates from the intermediate speed to the platform speed using the fourth deceleration, and then travels at a constant speed at the platform speed. If the intermediate speed is less than the platform speed, then in the first half of the target distance, the vehicle accelerates from the current speed to the intermediate speed using the third acceleration, and then travels at a constant speed at the intermediate speed. In the second half of the target distance, the vehicle accelerates from the intermediate speed to the platform speed using the fourth acceleration, and then travels at a constant speed at the platform speed.所述平台速度为障碍物的速度；所述第一加速度、第二加速度、第三加速度、第四加速度均小于最大加速度；所述第一减速度、第二减速度、第三减速度、第四减速度均小于最大减速度。The platform speed is the speed of the obstacle; the first acceleration, the second acceleration, the third acceleration, and the fourth acceleration are all less than the maximum acceleration; and the first deceleration, the second deceleration, the third deceleration, and the fourth deceleration are all less than the maximum deceleration.2.根据权利要求1所述的用于客车的速度规划算法，其特征在于，2. The speed planning algorithm for a passenger car according to claim 1, characterized in that:最小安全距离s_{safe_min}根据车辆与障碍物的相对位置决定，如果是同向行驶，s_{safe_min}＝V_cur²/(2a_{dec_max})，如果是反向行驶，s_{safe_min}＝(V_cur+v_obs)²/(2a_{dec_max})，v_obs为障碍物速度，a_{dec_max}为车辆最大减速度。The minimum safe distance_{ssafe_min} is determined by the relative position of the vehicle and the obstacle. If the vehicles are traveling in the^same direction,_{ssafe_min} =_Vcur2 /(_{2adec_max} ); if the vehicles are traveling in the opposite direction,_{ssafe_min} = (_Vcur +_vobs )² /(_{2adec_max} ), where_vobs is the obstacle speed and_{adec_max} is the maximum deceleration of the vehicle.3.根据权利要求1所述的用于客车的速度规划算法，其特征在于，道路包括直线道路和曲线道路。3. The speed planning algorithm for a bus according to claim 1, wherein the road comprises a straight road and a curved road.4.根据权利要求3所述的用于客车的速度规划算法，其特征在于，所述直线道路中，最大速度根据道路限速信息得到。4. The speed planning algorithm for a passenger car according to claim 3, characterized in that, on the straight road, the maximum speed is obtained according to road speed limit information.5.根据权利要求3所述的用于客车的速度规划算法，其特征在于，所述曲线道路中，最大速度根据道路限速信息得到；所述最大加速度根据曲率半径得到；所述最大减速度根据车辆参数得到。5. The speed planning algorithm for a passenger car according to claim 3, characterized in that, on the curved road, the maximum speed is obtained according to the road speed limit information; the maximum acceleration is obtained according to the curvature radius; and the maximum deceleration is obtained according to vehicle parameters.6.一种用于客车的速度规划装置，其特征在于，包括处理器、存储器以及存储在所述存储器中并可在处理器上运行的计算机程序，所述处理器在执行所述计算机程序时实现以下步骤：6. A speed planning device for a passenger vehicle, comprising a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the processor implements the following steps when executing the computer program:1)获取当前道路下的最大速度、最大加速度、以及最大减速度；同时获取车辆的当前速度、目标距离、最小安全距离；1) Obtain the maximum speed, maximum acceleration, and maximum deceleration on the current road; also obtain the vehicle's current speed, target distance, and minimum safe distance;2)根据车辆的当前速度V_cur、目标距离s、最小安全距离s_{safe_min}、以及所述最大加速度a_{acc_max}确定车辆在当前道路下的中间速度V_mid；中间速度V_mid的计算过程为：2) Determine the intermediate speed V_mid of the vehicle on the current road based on the current speed V_cur , the target distance s , the minimum safe distance s_{safe_min} , and the maximum acceleration a_{acc_max} ; the calculation process of the intermediate speed V_mid is:3)判断中间速度和最大速度的大小，若中间速度大于等于最大速度，则以最大速度作为限制速度进行速度规划，进入步骤4)；若中间速度小于最大速度，则以中间速度作为限制速度进行速度规划，进入步骤5)；3) Determine the size of the intermediate speed and the maximum speed. If the intermediate speed is greater than or equal to the maximum speed, use the maximum speed as the speed limit for speed planning and proceed to step 4); if the intermediate speed is less than the maximum speed, use the intermediate speed as the speed limit for speed planning and proceed to step 5);4)判断当前速度和最大速度的大小，若当前速度大于最大速度，则在目标距离的前半段，车辆以第一减速度从当前速度减速至最大速度后，以最大速度匀速行驶；在目标距离的后半段，车辆以第二减速度从最大速度减速至平台速度后，以平台速度匀速行驶；若当前速度小于最大速度，则在目标距离的前半段，车辆以第一加速度从当前速度加速至最大速度后，以最大速度匀速行驶；在目标距离的后半段，车辆以第三减速度从最大速度减速至平台速度后，以平台速度匀速行驶；4) Determine the difference between the current speed and the maximum speed. If the current speed is greater than the maximum speed, then in the first half of the target distance, the vehicle decelerates from the current speed to the maximum speed at a first deceleration, and then travels at a constant speed of the maximum speed. In the second half of the target distance, the vehicle decelerates from the maximum speed to the platform speed at a second deceleration, and then travels at a constant speed of the platform speed. If the current speed is less than the maximum speed, then in the first half of the target distance, the vehicle accelerates from the current speed to the maximum speed at a first acceleration, and then travels at a constant speed of the maximum speed. In the second half of the target distance, the vehicle decelerates from the maximum speed to the platform speed at a third deceleration, and then travels at a constant speed of the platform speed.5)判断中间速度和平台速度的大小，若中间速度大于平台速度，则在目标距离的前半段，车辆以第二加速度从当前速度加速至中间速度后，以中间速度匀速行驶；在目标距离的后半段，车辆以第四减速度从中间速度减速至平台速度后，以平台速度匀速行驶；若中间速度小于平台速度，则在目标距离的前半段，车辆以第三加速度从当前速度加速至中间速度后，以中间速度匀速行驶；在目标距离的后半段，车辆以第四加速度从中间速度加速至平台速度后，以平台速度匀速行驶；5) Determine the magnitude of the intermediate speed and the platform speed. If the intermediate speed is greater than the platform speed, then in the first half of the target distance, the vehicle accelerates from the current speed to the intermediate speed using the second acceleration, and then travels at a constant speed at the intermediate speed. In the second half of the target distance, the vehicle decelerates from the intermediate speed to the platform speed using the fourth deceleration, and then travels at a constant speed at the platform speed. If the intermediate speed is less than the platform speed, then in the first half of the target distance, the vehicle accelerates from the current speed to the intermediate speed using the third acceleration, and then travels at a constant speed at the intermediate speed. In the second half of the target distance, the vehicle accelerates from the intermediate speed to the platform speed using the fourth acceleration, and then travels at a constant speed at the platform speed.所述平台速度为障碍物的速度；所述第一加速度、第二加速度、第三加速度、第四加速度均小于最大加速度；所述第一减速度、第二减速度、第三减速度、第四减速度均小于最大减速度。The platform speed is the speed of the obstacle; the first acceleration, the second acceleration, the third acceleration, and the fourth acceleration are all less than the maximum acceleration; and the first deceleration, the second deceleration, the third deceleration, and the fourth deceleration are all less than the maximum deceleration.7.根据权利要求6所述的用于客车的速度规划装置，其特征在于，7. The speed planning device for a passenger vehicle according to claim 6, characterized in that:最小安全距离s_{safe_min}根据车辆与障碍物的相对位置决定，如果是同向行驶，s_{safe_min}＝V_cur²/(2a_{dec_max})，如果是反向行驶，s_{safe_min}＝(V_cur+v_obs)²/(2a_{dec_max})，v_obs为障碍物速度，a_{dec_max}为车辆最大减速度。The minimum safe distance_{ssafe_min} is determined by the relative position of the vehicle and the obstacle. If the vehicles are traveling in the^same direction,_{ssafe_min} =_Vcur2 /(_{2adec_max} ); if the vehicles are traveling in the opposite direction,_{ssafe_min} = (_Vcur +_vobs )² /(_{2adec_max} ), where_vobs is the obstacle speed and_{adec_max} is the maximum deceleration of the vehicle.8.根据权利要求6所述的用于客车的速度规划装置，其特征在于，道路包括直线道路和曲线道路。8. The speed planning device for a bus according to claim 6, wherein the road comprises a straight road and a curved road.9.根据权利要求8所述的用于客车的速度规划装置，其特征在于，所述直线道路中，最大速度根据道路限速信息得到。9 . The speed planning device for a passenger car according to claim 8 , wherein the maximum speed on the straight road is obtained according to road speed limit information.10.根据权利要求8所述的用于客车的速度规划装置，其特征在于，所述曲线道路中，最大速度根据道路限速信息得到；所述最大加速度根据曲率半径得到；所述最大减速度根据车辆参数得到。10. The speed planning device for a passenger car according to claim 8, characterized in that, on the curved road, the maximum speed is obtained according to road speed limit information; the maximum acceleration is obtained according to the curvature radius; and the maximum deceleration is obtained according to vehicle parameters.