Vehicle speed planning and control method and device, medium and equipment

Abstract

The embodiment of the invention discloses a vehicle speed planning and control method and device, a medium and equipment, relates to the technical field of automatic driving, and aims to solve the problem that an automatic driving speed planning scheme in the prior art is difficult to meet different requirements of passengers at different stages. According to the method, the maximum value of deceleration and the corresponding moment are calculated according to the information of the relative distance, the speed and the deceleration which can be collected by a vehicle, a deceleration curve is planned to comprise at least four sections of curves, and the front two sections and the rear two sections of curves are in central symmetry; the continuous deceleration and deceleration slope between two adjacent front and back curves is ensured, and the deceleration and slope of the middle curve can be ensured to be continuous due to the fact that the deceleration in the initial stage and the deceleration in the final stage are basically zero, so that the continuity and the differentiable property of the whole curve are ensured; different requirements of passengers for comfort and efficiency in different acceleration and deceleration stages are met, and the passengers have better comfort experience.

Description

Technical Field

[0001] The present application relates to the field of autonomous driving technology, and specifically to a vehicle speed planning and control method, device, medium and equipment. Background Art

[0002] Compared with human drivers, autonomous driving technology can avoid accidents caused by misoperation, fatigue driving, etc., and is more efficient and safer. The speed planning module is an important module in the autonomous driving algorithm. Generally, a high-order polynomial or a high-order Bezier curve is used to generate a smooth trajectory, and quadratic planning is used to find the optimal solution that meets expectations. However, when following a stationary vehicle at a long distance, the initial requirements of the driver and passengers for comfort are lower than the expectations for the timeliness of braking. An earlier braking feeling will make people feel more secure, while in the middle of braking, the requirements for comfort are higher, which is reflected in the autonomous driving algorithm level as a small acceleration change rate. The polynomial curve or Bezier curve generated by only one polynomial has poor flexibility and is difficult to meet different needs at different stages. It is more troublesome to adjust, resulting in poor passenger comfort. Summary of the invention

[0003] The main purpose of this application is to provide a vehicle speed planning and control method, device, medium and equipment, aiming to solve the problem that the existing automatic driving speed planning scheme is difficult to meet the different needs of passengers at different stages.

[0004] To achieve the above objectives, the technical solutions adopted in the embodiments of the present application are as follows: In a first aspect, an embodiment of the present application provides a vehicle speed planning method, which is applied to following a static obstacle and includes the following steps: According to the distance between the target vehicle and the target obstacle, the speed of the target vehicle and the deceleration of the target vehicle, a target time and a target speed are obtained; wherein the target time is the time corresponding to the point with the maximum deceleration on the deceleration curve, the target speed is the speed of the target vehicle at the target time, and the deceleration curve includes at least four segmented curves, and the first two segmented curves are centrosymmetric, and the last two segmented curves are centrosymmetric; According to the target time, target speed, and the distance between the target vehicle and the target obstacle, the target deceleration time, the maximum deceleration, the end time of the first segmented curve, and the polynomial coefficients of the first two segmented curves are obtained by iterative solution; According to the maximum deceleration and the target deceleration time, the end points of the remaining segment curves and the polynomial coefficients of the last two segment curves are obtained; According to the end points of the four segmented curves and the polynomial coefficients, the target deceleration curve is obtained to realize speed planning.

[0005] In a possible implementation of the first aspect, before obtaining the target deceleration curve to implement speed planning according to the end points of the four segmented curves and the polynomial coefficients, the vehicle speed planning method further includes: Determine whether the target vehicle reaches the expected speed at the end point of the second segmented curve. If the result of the determination is no, set the holding curve and holding time; wherein the holding curve corresponds to the maximum deceleration within the holding time; According to the end points of the four segmented curves and the polynomial coefficients, the target deceleration curve is obtained to achieve speed planning, including: According to the end time and polynomial coefficients of the four segmented curves, the holding curve and the holding time, the target deceleration curve is obtained to realize speed planning; wherein the holding curve is between the first two segmented curves and the last two segmented curves.

[0006] In a possible implementation of the first aspect, obtaining a target time and a target speed according to a distance between a target vehicle and a target obstacle, a speed of the target vehicle, and a deceleration of the target vehicle includes: The target speed is obtained according to the speed of the target vehicle and the speed attenuation coefficient.

[0007] In a possible implementation of the first aspect, obtaining a target deceleration curve to implement speed planning according to the end points of the four segmented curves and the polynomial coefficients includes: According to the end points of the four segmented curves and the polynomial coefficients, the target deceleration curve is obtained; According to the speed of the target vehicle and the deceleration corresponding to each moment on the target deceleration curve, the speed information of the target vehicle at each moment within the target deceleration time is obtained to realize speed planning.

[0008] In a second aspect, an embodiment of the present application provides a vehicle control method, comprising the following steps: In response to the deceleration instruction, the vehicle speed is planned according to the deceleration curve; wherein the deceleration curve is obtained according to the vehicle speed planning method provided in any one of the first aspects above; According to the result of speed planning, the vehicle is controlled to slow down.

[0009] In a possible implementation manner of the second aspect, after controlling the vehicle to decelerate according to a result of the speed planning, the vehicle control method further includes: Determine whether the real-time speed of the vehicle reaches the expected speed at the end point of the second segment curve of the deceleration curve; When the result of the judgment is no, the speed of the vehicle in the holding time period is controlled according to the holding curve of the deceleration curve; wherein the holding curve corresponds to the maximum deceleration in the holding time period.

[0010] In a third aspect, an embodiment of the present application provides a vehicle speed planning device, which is applied to following and stopping around a static obstacle, comprising: An acquisition module, the acquisition module is used to obtain a target time and a target speed according to the distance between the target vehicle and the target obstacle, the speed of the target vehicle and the deceleration of the target vehicle; wherein the target time is the time corresponding to the point with the maximum deceleration on the deceleration curve, the target speed is the speed of the target vehicle at the target time, and the deceleration curve includes at least four segmented curves, and the first two segmented curves are centrosymmetric, and the last two segmented curves are centrosymmetric; An iteration module is used to iteratively solve the target deceleration time, the maximum deceleration, the end time of the first segmented curve, and the polynomial coefficients of the first two segmented curves according to the target time, the target speed, and the distance between the target vehicle and the target obstacle; The target module is used to obtain the end points of the remaining segmented curves and the polynomial coefficients of the last two segmented curves according to the maximum deceleration and the target deceleration time; The planning module is used to obtain the target deceleration curve according to the end points of the four segmented curves and the polynomial coefficients to realize speed planning.

[0011] In a fourth aspect, an embodiment of the present application provides a vehicle control device, including: A speed planning module, the speed planning module is used to plan the speed of the vehicle according to a deceleration curve in response to a deceleration instruction; wherein the deceleration curve is obtained according to the vehicle speed planning method provided in any one of the first aspects above; The control module is used to control the vehicle to decelerate according to the result of speed planning.

[0012] In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium storing a computer program. When the computer program is loaded and executed by a processor, it implements a vehicle speed planning method as provided in any one of the first aspects above or a vehicle control method as provided in any one of the second aspects above.

[0013] In a sixth aspect, an embodiment of the present application provides an electronic device, including a processor and a memory, wherein: The memory is used to store computer programs; The processor is used to load and execute a computer program so that the electronic device executes a vehicle speed planning method as provided in any one of the first aspects above or a vehicle control method as provided in any one of the second aspects above.

[0014] Compared with the prior art, the beneficial effects of this application are: The vehicle speed planning and control method, device, medium and equipment proposed in the embodiments of the present application, the vehicle speed planning method includes: obtaining a target time and a target speed according to the distance between the target vehicle and the target obstacle, the speed of the target vehicle and the deceleration of the target vehicle; wherein the target time is the time corresponding to the point with the largest deceleration on the deceleration curve, the target speed is the speed of the target vehicle at the target time, and the deceleration curve includes at least four segmented curves, and the first two segmented curves are centrally symmetrical, and the last two segmented curves are centrally symmetrical; according to the target time, the target speed and the distance between the target vehicle and the target obstacle, iteratively solving to obtain the target deceleration time, the maximum deceleration, the end time of the first segmented curve and the polynomial coefficients of the first two segmented curves; according to the maximum deceleration and the target deceleration time, obtaining the end time of the remaining segmented curves and the polynomial coefficients of the last two segmented curves; according to the end time and the polynomial coefficients of the four segmented curves, obtaining the target deceleration curve to achieve speed planning. The present application first uses the information of relative distance, speed and deceleration that can be collected by the vehicle, the maximum deceleration value and the corresponding time, and plans the deceleration curve to include at least four curves, so that the first two curves and the last two curves are respectively centrally symmetrical, thereby ensuring the continuity of the deceleration and the deceleration slope between the two adjacent curves. In addition, since the initial and final decelerations are basically zero, the continuity of the deceleration and the slope of the middle curve can be guaranteed, thereby ensuring the continuity and differentiability of the overall curve, meeting the different needs of passengers for comfort and efficiency at different stages of acceleration and deceleration, and giving passengers a better comfort experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of the structure of an electronic device of a hardware operating environment involved in an embodiment of the present application; Figure 2 A schematic diagram of a vehicle speed planning method according to an embodiment of the present application; Figure 3 A schematic diagram of a deceleration curve in a vehicle speed planning method provided in an embodiment of the present application; Figure 4 A schematic diagram of a vehicle control method according to an embodiment of the present application; Figure 5 A schematic diagram of a flow chart of a vehicle control method provided in an embodiment of the present application in one implementation manner; Figure 6 A schematic diagram of a module of a vehicle speed planning device provided in an embodiment of the present application; Figure 7 A schematic diagram of a module of a vehicle control device provided in an embodiment of the present application; Markings in the figure: 101 - processor, 102 - communication bus, 103 - network interface, 104 - user interface, 105 - memory. DETAILED DESCRIPTION

[0016] It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0017] See attached Figure 1 , attached Figure 1 This is a schematic diagram of the structure of an electronic device of the hardware operating environment involved in the embodiment of the present application. The electronic device may include: a processor 101, such as a central processing unit (CPU), a communication bus 102, a user interface 104, a network interface 103, and a memory 105. Among them, the communication bus 102 is used to realize the connection and communication between these components. The user interface 104 may include a display (Display), an input unit such as a keyboard (Keyboard), and the user interface 104 may also include a standard wired interface and a wireless interface. The network interface 103 may optionally include a standard wired interface and a wireless interface (such as a wireless fidelity (WIreless-FIdelity, WI-FI) interface). The memory 105 may optionally be a storage device independent of the aforementioned processor 101. The memory 105 may be a high-speed random access memory (RAM) memory, or it may be a stable non-volatile memory (NVM), such as at least one disk storage. The processor 101 may be a general-purpose processor, including a central processing unit, a network processor, etc., or it may be a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component.

[0018] Those skilled in the art will appreciate that Figure 1 The structure shown in the figure does not constitute a limitation on the electronic device, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.

[0019] As attached Figure 1 As shown, the memory 105 as a storage medium may include an operating system, a network communication module, a user interface module, and a vehicle speed planning device or a vehicle control device.

[0020] In the attached Figure 1In the electronic device shown, the network interface 103 is mainly used for data communication with the network server; the user interface 104 is mainly used for data interaction with the user; the processor 101 and the memory 105 in the present application can be set in the electronic device, and the electronic device calls the vehicle speed planning device or the vehicle control device stored in the memory 105 through the processor 101, and executes the vehicle speed planning method or the vehicle control method provided in the embodiment of the present application.

[0021] Compared with human drivers, autonomous driving technology can avoid accidents caused by misoperation, fatigue driving, etc., and is more efficient and safer. Currently, autonomous driving has end-to-end solutions and traditional modular solutions. Although the end-to-end solution is more concise at the code level, it requires a large number of training samples, and the algorithm is less interpretable. It takes a long time to train complex working conditions, and commercialization is more difficult. The modular solution has strong interpretability, more flexible algorithm adjustment, and is easier to commercialize. The planning module is a relatively important module in the autonomous driving algorithm. It inherits the results of the upstream perception, positioning and prediction module, and sends the planned trajectory to the downstream control module. In the time-space separation algorithm, path planning and speed planning are performed separately.

[0022] The speed planning module generally uses high-order polynomials or high-order Bezier curves to generate a smooth trajectory, and uses quadratic programming to find the optimal solution that meets expectations. However, humans have different requirements for different stages of vehicle acceleration and deceleration. For example, when following a stationary vehicle at a long distance, in the initial stage of recognition, the driver and passengers' requirements for comfort are lower than their expectations for the timeliness of braking. An earlier braking feeling will make the driver and passengers feel safer. In the middle of braking, people have higher requirements for comfort, which is reflected in the level of autonomous driving algorithms as a small rate of change of acceleration. The polynomial curve or Bezier curve generated by only one polynomial has poor flexibility and is difficult to meet different requirements at different stages. It is more troublesome to adjust and the planning time period is short.

[0023] Therefore, refer to the attached Figure 2 Based on the hardware device of the aforementioned embodiment, the embodiment of the present application provides a vehicle speed planning method to solve the above problem, and is applied to following and stopping static obstacles during the automatic driving process, including the following steps: S10: Obtain a target time and a target speed according to the distance between the target vehicle and the target obstacle, the speed of the target vehicle, and the deceleration of the target vehicle; wherein the target time is the time corresponding to the point with the maximum deceleration on the deceleration curve, and the target speed is the speed of the target vehicle at the target time. The deceleration curve includes at least four segmented curves, and the first two segmented curves are centrally symmetrical, and the last two segmented curves are centrally symmetrical.

[0024] In the specific implementation process, the target vehicle is the vehicle that currently needs to plan its speed. The obstacle is a static obstacle, such as a stationary vehicle, a warning sign, or other obstacles. The target obstacle is an obstacle that is stationary in front of the target vehicle and requires the target vehicle to brake and stop. The relevant parameter information can be obtained through the perception module on the target vehicle, such as obtaining the relative distance between the target vehicle and the target obstacle through radar. , obtain the current speed of the target vehicle through the speed sensor And deceleration Set the point where the maximum deceleration is achieved on the entire deceleration curve to At this moment, the relative distance between the target vehicle and the target obstacle , set the vehicle speed at this time, that is, the target speed , where is the distance attenuation coefficient, is the speed attenuation coefficient. That is, according to the distance between the target vehicle and the target obstacle, the speed of the target vehicle and the deceleration of the target vehicle, the target time and target speed are obtained, including: The target speed is obtained according to the speed of the target vehicle and the speed attenuation coefficient.

[0025] The planned deceleration curve can be as shown in the attached Figure 3 As shown, the end point of each segmented curve corresponds to the horizontal axis. , , , , , , The deceleration magnitude of the ordinate corresponding to the time is a1, a4, and the first two segmented curves are about ( , a1) is centrally symmetrical, and the latter two segmented curves are about ( , a4) Central symmetry, this symmetry ensures the continuity of deceleration and deceleration slope between two adjacent sections.

[0026] S20: According to the target time, the target speed, and the distance between the target vehicle and the target obstacle, iteratively solve to obtain the target deceleration time, the maximum deceleration, the end time of the first segmented curve, and the polynomial coefficients of the first two segmented curves.

[0027] In the specific implementation process, the target deceleration time is the time required for the entire deceleration process. The maximum deceleration is as shown in the attached Figure 3 As shown, set in When the time is reached, calculate the overall deceleration time :

[0028] In the formula, To plan the time to reach maximum deceleration, = ,as well as:

[0029] In the formula, is the coefficient of the first curve, is the coefficient of the second curve, and the time of the first integral is from 0 to , the time of the second integral is arrive Since the first curve and the second curve are about ( , a1) is centrally symmetric, we can get: ,

[0030] In the formula, is the actual deceleration of the vehicle when it starts to decelerate, for The deceleration rate of the time plan, It is the maximum deceleration value achieved for the entire trajectory. It is also the terminal deceleration of the second trajectory. When adjustment is required, it is also the fixed deceleration of the third trajectory.

[0031] Calculate the end time of the first curve segment :

[0032] in, It is the time coefficient, generally ranging from 0.35 to 0.45.

[0033] Calculate the polynomial for the first curve segment, and the coefficients are:

[0034] Where da0 is the current state of the vehicle, that is, the acceleration slope at the planning starting point; Then the polynomial coefficients of the second curve are:

[0035] The distance to the maximum deceleration value And the value of speed is iteratively calculated:

[0036]

[0037]

[0038]

[0039] In the formula is the iteration coefficient, For time The planned vehicle speed at is the actual speed of the vehicle when it starts to decelerate. and Substitute the value of into the above calculation and iterate five times to get the final result.

[0040] S30: According to the maximum deceleration and the target deceleration time, the end points of the remaining segment curves and the polynomial coefficients of the last two segment curves are obtained.

[0041] In the specific implementation process, the coefficient of the deceleration curve and the end time of each curve segment are calculated. As attached Figure 3 The polynomial coefficients for the last segment of the curve shown are:

[0042]

[0043] , determined according to the actual vehicle movement; ) .

[0044] S40: Obtain a target deceleration curve according to the end points of the four segmented curves and the polynomial coefficients to achieve speed planning.

[0045] In the specific implementation process, after obtaining the polynomial coefficients and the end time of each segment, the entire deceleration curve is determined, and each segment is clearly divided. Then, the deceleration of any point on the curve is calculated according to time: When time t is (0, ) Time: ; When time t is ( , ) Time: ; When time t is ( , ) Time:

[0046] When time t is ( , ) Time:

[0047] In the formula, is the terminal deceleration, generally 0; When time t is ( , ), check whether the vehicle reaches the expected speed. If so, ,otherwise That is, the maximum deceleration is maintained, and the vehicle speed planning method further includes: Determine whether the target vehicle reaches the expected speed at the end point of the second segmented curve. If the result of the determination is no, set the holding curve and holding time; wherein the holding curve corresponds to the maximum deceleration within the holding time; According to the end points of the four segmented curves and the polynomial coefficients, the target deceleration curve is obtained to achieve speed planning, including: According to the end time and polynomial coefficients of the four segmented curves, the holding curve and the holding time, the target deceleration curve is obtained to realize speed planning; wherein the holding curve is between the first two segmented curves and the last two segmented curves.

[0048] In the specific implementation process, by setting the segmentation of the holding curve as an adjustment, the braking distance caused by delay and other reasons that is shorter than the planned braking distance is corrected, as shown in the attached Figure 3 The third curve shown in Maintain maximum deceleration for a period of time , this period of time is the holding time, which is adjusted according to the actual situation, that is, according to the current speed and maximum deceleration, how much time is needed to decelerate to the expected speed. At the same time, since the deceleration of the initial and final sections is basically zero, the deceleration and slope of the two ends of the middle holding curve segment and other segmented curves can be kept continuous, ensuring the continuity of the overall trajectory. And it can be adjusted in real time according to the operation of the vehicle, avoiding re-planning, consuming less computing power, and being more flexible.

[0049] The deceleration curve can be used to quickly obtain the deceleration required by the vehicle at each moment, and then control the vehicle from the initial state to control its speed according to the deceleration corresponding to the deceleration curve, and obtain the speed information of the vehicle at each moment in the entire deceleration period, so as to realize the planning of vehicle speed. That is: according to the end time of the four segmented curves and the polynomial coefficients, the target deceleration curve is obtained to realize speed planning, including: According to the end points of the four segmented curves and the polynomial coefficients, the target deceleration curve is obtained; According to the speed of the target vehicle and the deceleration corresponding to each moment on the target deceleration curve, the speed information of the target vehicle at each moment within the target deceleration time is obtained to realize speed planning.

[0050] In this embodiment, firstly, the information of relative distance, speed and deceleration, the maximum deceleration value and the corresponding time that can be collected by the vehicle are used, and the deceleration curve is planned to include at least four curves, so that the first two curves and the last two curves are respectively symmetrical with each other, thereby ensuring the continuity of the deceleration and the deceleration slope between the two adjacent curves. In addition, since the initial and final decelerations are basically zero, the continuity of the deceleration and the slope of the middle curve can be ensured, thereby ensuring the continuity and differentiability of the overall curve, meeting the different needs of passengers for comfort and efficiency at different stages of acceleration and deceleration, and giving passengers a better comfort experience.

[0051] See attached Figure 4 Based on the same inventive concept as in the above-mentioned embodiment, the embodiment of the present application further provides a vehicle control method, comprising the following steps: S50: In response to the deceleration instruction, planning the speed of the vehicle according to the deceleration curve; wherein the deceleration curve is obtained according to the vehicle speed planning method provided in the embodiment of the present application; S60: Control the vehicle to decelerate according to the result of the speed planning.

[0052] In the specific implementation process, during the automatic driving process, when there is a stationary obstacle in front of the vehicle's perception module, the vehicle system issues a warning and prompts that braking and stopping are required, and then the vehicle speed planning method provided in the embodiment of the present application is performed to obtain the deceleration curve, and the result is sent to the vehicle's control module to control the vehicle to start braking. The deceleration planning can directly send the deceleration to the control module, so the trajectory can be represented by acceleration as the independent variable.

[0053] In one embodiment, after controlling the vehicle to decelerate according to the result of the speed planning, the vehicle control method further includes: Determine whether the real-time speed of the vehicle reaches the expected speed at the end point of the second segment curve of the deceleration curve; When the result of the judgment is no, the speed of the vehicle in the holding time period is controlled according to the holding curve of the deceleration curve; wherein the holding curve corresponds to the maximum deceleration in the holding time period.

[0054] The embodiment of the present application adopts a multi-segment polynomial splicing method to plan the deceleration curve at different stages, which can meet the different requirements of the driver and passengers for comfort and efficiency at different stages of acceleration and deceleration, and the planning time can be long. The entire deceleration process is divided into four to five segments, as shown in the attached figure. Figure 3The figure shows a situation divided into five sections, of which the third section is an adjustment section with a fixed deceleration to correct the braking distance that is less than the planned braking distance due to delays and other reasons. Since the speed in the first half of the braking section is relatively high, the braking time in the first half is given to be 0.35 to 0.45 times the total time, and the speed reached is reduced to about 0.45 times the initial speed. After determining the time and speed parameters, the distance from the target vehicle, the relative speed, the acceleration of the vehicle, and the acceleration slope of the vehicle in the initial state can be used as the constraint conditions of the first section of the trajectory to solve, so that the acceleration between the final multi-segment curves is continuous and the acceleration slope is continuous, so that the vehicle comfort is better.

[0055] As attached Figure 5 As shown, when planning and controlling vehicle speed, first obtain the distance between the vehicle and the target vehicle at the current moment, the speed, acceleration and acceleration slope of the vehicle. The target vehicle referred to here is also the target obstacle in the above-mentioned embodiment. Then calculate the deceleration curve. First, calculate the time required and the rough solution of the maximum deceleration according to the values ​​of the speed change and the distance change of the first two sections of the curve set. Then, use five iterative calculations to obtain the exact solution of the coefficient of each section of the deceleration curve. The trajectory of each section of the deceleration is represented by a quadratic equation of acceleration, and the entire curve is represented as a splicing of quartic polynomials of multiple distances.

[0056] The vehicle can be controlled according to the deceleration corresponding to different times. When the time reaches T2, the vehicle is detected. By comparing whether the current speed of the vehicle reaches the expected speed, it is determined whether a curve needs to be planned. Figure 3 If the planned speed, that is, the expected speed mentioned in the above embodiment, is reached in the third segment of the trajectory shown in the figure, the planning of the third segment of the trajectory is canceled, and the planning of the fourth and fifth segments of the trajectory is sent to control the vehicle; if the expected speed is not reached, the third segment of the trajectory is sent for speed planning until the vehicle speed reaches the planned speed, so as to adjust the trajectory curve according to the real-time operating status of the vehicle and avoid re-planning, thereby meeting the different needs of passengers for comfort and efficiency at different stages.

[0057] See attached Figure 6 Based on the same inventive concept as in the above-mentioned embodiment, the embodiment of the present application further provides a vehicle speed planning device, which is applied to following and stopping around a static obstacle, comprising: An acquisition module, the acquisition module is used to obtain a target time and a target speed according to the distance between the target vehicle and the target obstacle, the speed of the target vehicle and the deceleration of the target vehicle; wherein the target time is the time corresponding to the point with the maximum deceleration on the deceleration curve, the target speed is the speed of the target vehicle at the target time, and the deceleration curve includes at least four segmented curves, and the first two segmented curves are centrosymmetric, and the last two segmented curves are centrosymmetric; An iteration module is used to iteratively solve the target deceleration time, the maximum deceleration, the end time of the first segmented curve, and the polynomial coefficients of the first two segmented curves according to the target time, the target speed, and the distance between the target vehicle and the target obstacle; The target module is used to obtain the end points of the remaining segmented curves and the polynomial coefficients of the last two segmented curves according to the maximum deceleration and the target deceleration time; The planning module is used to obtain the target deceleration curve according to the end points of the four segmented curves and the polynomial coefficients to realize speed planning.

[0058] Refer to the attached Figure 7 Based on the same inventive concept as in the above-mentioned embodiment, the embodiment of the present application further provides a vehicle control device, including: A speed planning module, the speed planning module is used to respond to the deceleration instruction and plan the speed of the vehicle according to the deceleration curve; wherein the deceleration curve is obtained according to the vehicle speed planning method provided in the embodiment of the present application; The control module is used to control the vehicle to decelerate according to the result of speed planning.

[0059] Those skilled in the art should understand that the division of the various modules in the embodiment is only a division of logical functions, and can be fully or partially integrated into one or more actual carriers in actual application, and these modules can be all implemented in the form of software called by the processing unit, or all implemented in the form of hardware, or implemented in the form of a combination of software and hardware. It should be noted that the modules in the vehicle speed planning device / vehicle control device in this embodiment correspond one-to-one to the steps in the vehicle speed planning method / vehicle control method in the aforementioned embodiment. Therefore, the specific implementation of this embodiment can refer to the aforementioned implementation, which will not be repeated here.

[0060] Based on the same inventive concept as in the aforementioned embodiments, an embodiment of the present application further provides a computer-readable storage medium storing a computer program. When the computer program is loaded and executed by a processor, a vehicle speed planning method or a vehicle control method as provided in the embodiments of the present application is implemented.

[0061] Based on the same inventive concept as in the above-mentioned embodiment, an embodiment of the present application further provides an electronic device, including a processor and a memory, wherein: The memory is used to store computer programs; The processor is used to load and execute a computer program so that the electronic device executes a vehicle speed planning method or a vehicle control method as provided in an embodiment of the present application.

[0062] In some embodiments, the computer readable storage medium may be a memory such as FRAM, ROM, PROM, EPROM, EEPROM, flash memory, magnetic surface memory, optical disk, or CD-ROM; or various devices including one or any combination of the above memories. The computer may be various computing devices including intelligent terminals and servers.

[0063] In some embodiments, executable instructions may be in the form of a program, software, software module, script or code, written in any form of programming language (including compiled or interpreted languages, or declarative or procedural languages), and may be deployed in any form, including as a stand-alone program or as a module, component, subroutine or other unit suitable for use in a computing environment.

[0064] As an example, executable instructions may, but need not, correspond to a file in a file system, may be stored as part of a file storing other programs or data, such as in one or more scripts in a HyperText Markup Language (HTML) document, in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files storing one or more modules, subroutines, or code portions).

[0065] By way of example, executable instructions may be deployed to be executed on one computing device, or on multiple computing devices located at one site, or on multiple computing devices distributed across multiple sites and interconnected by a communication network.

[0066] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or system including the element.

[0067] The serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0068] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as a read-only memory / random access memory, a magnetic disk, or an optical disk), and includes a number of instructions for enabling a multimedia terminal device (which can be a mobile phone, a computer, a television receiver, or a network device, etc.) to execute the methods described in each embodiment of the present application.

[0069] In summary, the vehicle speed planning and control method, device, medium and equipment provided by the present application, the vehicle speed planning method includes: obtaining the target time and target speed according to the distance between the target vehicle and the target obstacle, the speed of the target vehicle and the deceleration of the target vehicle; wherein the target time is the time corresponding to the point with the largest deceleration on the deceleration curve, the target speed is the speed of the target vehicle at the target time, and the deceleration curve includes at least four segmented curves, and the first two segmented curves are centrally symmetrical, and the last two segmented curves are centrally symmetrical; according to the target time, the target speed and the distance between the target vehicle and the target obstacle, iteratively solve to obtain the target deceleration time, the maximum deceleration, the end time of the first segmented curve and the polynomial coefficients of the first two segmented curves; according to the maximum deceleration and the target deceleration time, obtain the end time of the remaining segmented curves and the polynomial coefficients of the last two segmented curves; according to the end time and the polynomial coefficients of the four segmented curves, obtain the target deceleration curve to realize speed planning. The present application first uses the information of relative distance, speed and deceleration that can be collected by the vehicle, the maximum deceleration value and the corresponding time, and plans the deceleration curve to include at least four curves, so that the first two curves and the last two curves are respectively centrally symmetrical, thereby ensuring the continuity of the deceleration and the deceleration slope between the two adjacent curves. In addition, since the initial and final decelerations are basically zero, the continuity of the deceleration and the slope of the middle curve can be guaranteed, thereby ensuring the continuity and differentiability of the overall curve, meeting the different needs of passengers for comfort and efficiency at different stages of acceleration and deceleration, and giving passengers a better comfort experience.

[0070] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A vehicle speed planning method, characterized in that: Applied to static obstacle following and stopping, including the following steps: According to the distance between the target vehicle and the target obstacle, the speed of the target vehicle and the deceleration of the target vehicle, a target time and a target speed are obtained; wherein the target time is the time corresponding to the point with the maximum deceleration on the deceleration curve, and the target speed is the speed of the target vehicle at the target time, and the deceleration curve includes at least four segmented curves, and the first two segmented curves are symmetrical about the center, and the last two segmented curves are symmetrical about the center; According to the target time, the target speed, and the distance between the target vehicle and the target obstacle, iteratively solve to obtain the target deceleration time, the maximum deceleration, the end time of the first segmented curve, and the polynomial coefficients of the first two segmented curves; According to the maximum deceleration and the target deceleration time, the end points of the remaining segmented curves and the polynomial coefficients of the last two segmented curves are obtained; According to the end points of the four segmented curves and the polynomial coefficients, the target deceleration curve is obtained to realize speed planning.

2. The vehicle speed planning method according to claim 1, characterized in that: Before obtaining the target deceleration curve according to the end points of the four segmented curves and the polynomial coefficients to implement the speed planning, the vehicle speed planning method further includes: Determine whether the target vehicle reaches the expected speed at the end point of the second segmented curve, and if the result of the determination is no, set a holding curve and a holding time; wherein the holding curve corresponds to the maximum deceleration within the holding time; The method of obtaining a target deceleration curve according to the end points of the four segmented curves and the polynomial coefficients to realize speed planning includes: According to the end points and polynomial coefficients of the four segmented curves, the holding curve and the holding time, a target deceleration curve is obtained to realize speed planning; wherein the holding curve is between the first two segmented curves and the last two segmented curves.

3. The vehicle speed planning method according to claim 1, characterized in that: The step of obtaining a target time and a target speed according to the distance between the target vehicle and the target obstacle, the speed of the target vehicle, and the deceleration of the target vehicle comprises: The target speed is obtained according to the speed of the target vehicle and the speed attenuation coefficient.

4. The vehicle speed planning method according to claim 1, characterized in that: The method of obtaining a target deceleration curve according to the end points of the four segmented curves and the polynomial coefficients to realize speed planning includes: According to the end points of the four segmented curves and the polynomial coefficients, the target deceleration curve is obtained; According to the speed of the target vehicle and the deceleration corresponding to each moment on the target deceleration curve, the speed information of the target vehicle at each moment within the target deceleration time is obtained to achieve speed planning.

5. A vehicle control method, characterized in that: The following steps are involved: In response to the deceleration instruction, the vehicle speed is planned according to the deceleration curve; wherein the deceleration curve is obtained according to the vehicle speed planning method according to any one of claims 1 to 4; According to the result of speed planning, the vehicle is controlled to decelerate.

6. The vehicle control method according to claim 5, characterized in that: After controlling the vehicle to decelerate according to the result of the speed planning, the vehicle control method further includes: Determining whether the real-time speed of the vehicle reaches the expected speed at the end point of the second segment curve of the deceleration curve; When the result of the judgment is no, the speed of the vehicle in the holding time period is controlled according to the holding curve of the deceleration curve; wherein the holding curve corresponds to the maximum deceleration in the holding time period.

7. A vehicle speed planning device, characterized in that: Applicable to static obstacle following and stopping, including: An acquisition module, the acquisition module is used to obtain a target time and a target speed according to the distance between the target vehicle and the target obstacle, the speed of the target vehicle and the deceleration of the target vehicle; wherein the target time is the time corresponding to the point with the maximum deceleration on the deceleration curve, the target speed is the speed of the target vehicle at the target time, and the deceleration curve includes at least four segmented curves, and the first two segmented curves are symmetrical about the center, and the last two segmented curves are symmetrical about the center; An iteration module, the iteration module is used to iteratively solve and obtain a target deceleration time, a maximum deceleration, an end time of the first segmented curve, and polynomial coefficients of the first two segmented curves according to the target time, the target speed, and the distance between the target vehicle and the target obstacle; A target module, the target module is used to obtain the end points of the remaining segmented curves and the polynomial coefficients of the last two segmented curves according to the maximum deceleration and the target deceleration time; A planning module is used to obtain a target deceleration curve according to the end points of the four segmented curves and polynomial coefficients to achieve speed planning.

8. A vehicle control device, characterized in that: include: A speed planning module, the speed planning module is used to plan the speed of the vehicle according to a deceleration curve in response to a deceleration instruction; wherein the deceleration curve is obtained according to the vehicle speed planning method according to any one of claims 1 to 4; A control module is used to control the vehicle to decelerate according to a result of speed planning.

9. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is loaded and executed by the processor, the vehicle speed planning method as described in any one of claims 1 to 4 or the vehicle control method as described in any one of claims 5 to 6 is implemented.

10. An electronic device, characterized in that: comprising a processor and a memory, wherein: The memory is used to store computer programs; The processor is used to load and execute the computer program so that the electronic device executes the vehicle speed planning method as described in any one of claims 1-4 or the vehicle control method as described in any one of claims 5-6.

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