Vehicle speed control method and system, electronic equipment and storage medium

Abstract

The invention relates to a vehicle speed control method and system, electronic equipment and a storage medium, and belongs to the technical field of vehicle control, and the method comprises the steps: obtaining a current road surface grade, and determining a vehicle speed range meeting a preset condition according to the current road surface grade; wherein the preset condition is that the vertical acceleration weighted root-mean-square value of the vehicle is smaller than a vertical acceleration weighted root-mean-square threshold value; according to the current vehicle speed, determining a vehicle speed enabling the longitudinal acceleration of the vehicle to be minimum from the vehicle speed range as a target vehicle speed; and controlling the vehicle to run according to the target speed. The vehicle speed range meeting the vertical comfort is obtained according to the current road surface grade and the preset vertical acceleration weighted root-mean-square threshold value, then the target vehicle speed with the optimal longitudinal comfort is found out from the vehicle speed range, the influence of the vehicle speed on the vertical and longitudinal riding comfort is fully considered, and the vehicle speed control accuracy is improved. And when the vehicle runs according to the target vehicle speed, passengers have better experience feeling.

Description

Technical Field

[0001] The present invention relates to the field of vehicle control technology, and in particular to a vehicle speed control method, system, electronic equipment and storage medium. Background Art

[0002] During driving, the vehicle mainly relies on the tracking and adjustment capabilities of the active suspension or semi-active suspension to compensate for the impact of road excitation. However, changes in vehicle speed during driving will also affect the riding comfort of the passengers. Therefore, when the adjustment function of the vehicle suspension system cannot meet the comfort needs of the passengers, the riding comfort performance can also be improved by appropriately adjusting the speed.

[0003] The Chinese patent "Comfort control method for unmanned vehicles with integrated vehicle speed planning and preview semi-active suspension" (CN202010080594.7) discloses a comfort control method for unmanned vehicles with integrated vehicle speed planning and preview semi-active suspension, which coordinates the suspension with the vehicle speed to ensure ride comfort. However, this method does not fully consider the impact of vehicle speed on ride comfort. Summary of the invention

[0004] In view of this, it is necessary to provide a vehicle speed control method, system, electronic device and storage medium to solve the problem that the prior art does not fully consider the impact of vehicle speed on ride comfort when controlling vehicle speed.

[0005] In order to solve the above problems, in a first aspect, the present invention provides a vehicle speed control, comprising: Get the current road grade and current vehicle speed; Determining a vehicle speed range that meets a preset condition according to the current road surface grade; wherein the preset condition is that a weighted root mean square value of a vertical acceleration of the vehicle is less than a weighted root mean square threshold value of a vertical acceleration; According to the current vehicle speed, determining a vehicle speed from the vehicle speed range that minimizes the longitudinal acceleration of the vehicle as a target vehicle speed; The vehicle is controlled to travel according to the target vehicle speed.

[0006] Optionally, determining a vehicle speed range that meets a preset condition according to the current road surface grade includes: Obtain the mapping relationship between the vehicle speed and the weighted root mean square value of the vehicle vertical acceleration and the weighted root mean square threshold of the vertical acceleration under different road surface grades; Determining a target mapping relationship and a target vertical acceleration weighted root mean square threshold according to the current road surface grade; A vehicle speed range that is less than the target vertical acceleration weighted root mean square threshold is determined according to the target mapping relationship.

[0007] Optionally, the obtaining of a mapping relationship between a vehicle speed and a weighted root mean square value of a vehicle vertical acceleration under different road surface grades includes: Obtaining detection data of vehicle speed and weighted root mean square value of vehicle vertical acceleration under different road surface grades; The detection data is fitted based on the polynomial interpolation fitting method to obtain the function expression between the vehicle speed and the weighted root mean square value of the vehicle vertical acceleration under different road grades:

[0008] in, represents the weighted RMS value of the vehicle vertical acceleration, Indicates vehicle speed. Represents polynomial coefficients.

[0009] Optionally, obtaining the current road surface grade includes: When the current road surface is a continuous random road surface, the current road surface grade is determined.

[0010] Optionally, determining the current road surface grade includes: The current road surface grade is determined according to the road surface spatial power spectrum density of the current road surface.

[0011] Optionally, the method further includes: When the current road surface is a discrete impact road surface, guidance prompt information is generated; the prompt information includes elevation information and length information of the impact object.

[0012] Optionally, the method further includes: When there is a special situation that there is no road ahead, a landslide or pedestrians intruding on the current road surface, a deceleration prompt message is generated, and a braking distance is determined according to the current vehicle speed; If the driver does not brake the vehicle within the braking distance, the vehicle is controlled to brake.

[0013] In a second aspect, the present invention further provides a vehicle speed control system, comprising: An information acquisition module is used to obtain the current road surface grade and the current vehicle speed; An information acquisition module is used to obtain the current road surface grade and the current vehicle speed; an information processing module, configured to determine a vehicle speed range that satisfies a preset condition according to the current road surface grade; wherein the preset condition is that a weighted root mean square value of a vertical acceleration of the vehicle is less than a weighted root mean square threshold of a vertical acceleration; and, according to the current vehicle speed, determine a vehicle speed from the vehicle speed range that minimizes the longitudinal acceleration of the vehicle as a target vehicle speed; The vehicle speed control module is used to control the vehicle to travel according to the target vehicle speed.

[0014] In a third aspect, the present invention also provides an electronic device comprising a memory and a processor, wherein the memory is used to store programs; and the processor is coupled to the memory and is used to execute the programs stored in the memory to implement the steps in any one of the vehicle speed control methods described above.

[0015] In a fourth aspect, the present invention further provides a computer-readable storage medium for storing a computer-readable program, wherein the program or instruction, when executed by a processor, can implement the steps in any one of the above-mentioned vehicle speed control methods.

[0016] The beneficial effects of the present invention are: In the present invention, the current road surface grade is obtained, and the speed range that meets the preset conditions is determined according to the current road surface grade; wherein the preset condition is that the weighted root mean square value of the vertical acceleration of the vehicle is less than the weighted root mean square threshold of the vertical acceleration; according to the current vehicle speed, a vehicle speed with the minimum longitudinal acceleration is determined from the vehicle speed range as the target vehicle speed; and the vehicle is controlled to travel according to the target vehicle speed. The smaller the acceleration, the higher the comfort. The present invention obtains the vehicle speed range that meets the vertical comfort according to the current road surface grade and the preset vertical acceleration weighted root mean square threshold, and then finds the target vehicle speed with the best longitudinal comfort from the vehicle speed range, fully considering the influence of the vehicle speed on the vertical and longitudinal riding comfort, so that when the vehicle travels according to the target vehicle speed, the passengers have a better experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic flow chart of an embodiment of a vehicle speed control method provided by the present invention; Figure 2 A schematic diagram of a fitting curve of the relationship between vehicle speed and weighted root mean square value of vehicle vertical acceleration on a Class C road provided by the present invention; Figure 3 A schematic diagram of a nine-degree-of-freedom passive suspension model of a whole vehicle provided by the present invention; Figure 4 A schematic structural diagram of an embodiment of a vehicle speed control system provided by the present invention; Figure 5 A schematic structural diagram of another embodiment of a vehicle speed control system provided by the present invention; Figure 6 A schematic diagram of a control process flow of a vehicle speed control system provided by the present invention. DETAILED DESCRIPTION

[0018] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0019] In the description of the embodiments of the present invention, unless otherwise specified, "plurality" means two or more. "First", "second", etc. involved in the embodiments of the present invention are used to distinguish similar objects, and are not used to describe a specific order or sequence, nor are they used to indicate or imply their relative importance or implicitly indicate the number of technical features indicated. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more.

[0020] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0021] Reference Figure 1 , shows a flow chart of an embodiment of a vehicle speed control method provided by the present invention, the method comprising: S101, obtaining the current road surface grade and the current vehicle speed.

[0022] S102, determining a vehicle speed range that meets a preset condition according to the current road surface grade; wherein the preset condition is that the weighted root mean square value of the vertical acceleration of the vehicle is less than a weighted root mean square threshold value of the vertical acceleration.

[0023] S103: According to the current vehicle speed, determine a vehicle speed in the vehicle speed range that minimizes the longitudinal acceleration of the vehicle as a target vehicle speed.

[0024] S104, controlling the vehicle to travel according to the target vehicle speed.

[0025] The road surface grade is used to characterize the flatness of the road surface. The road surface grade may include 6 grades from AF. As the road surface grade increases, the flatness of the road surface decreases, that is, the road surface becomes more and more bumpy. The current road surface grade may be the road surface grade of the current road surface.

[0026] The weighted root mean square vertical acceleration (RMS) of the vehicle is an important parameter in vehicle vibration analysis and comfort evaluation. It processes the vertical acceleration signal of the vehicle by frequency weighting and calculates its root mean square value to reflect the human body's perception of vertical vibration. The RMS of the vehicle is related to factors such as the road surface grade and the vehicle speed. Therefore, after obtaining the current road surface grade, the vehicle speed range that meets the preset conditions can be determined according to the current road surface grade; wherein the preset condition is that the RMS of the vehicle is less than the weighted root mean square threshold of the vertical acceleration. That is, under the current road surface grade, when the vehicle speed remains in this speed range, the RMS of the vehicle can be made less than the weighted root mean square threshold of the vertical acceleration. Because the smaller the RMS, the higher the vertical comfort, therefore, under the current road surface grade, when the vehicle speed remains in this speed range, the user's vertical comfort requirements are met.

[0027] Then, according to the current vehicle speed, a vehicle speed that minimizes the longitudinal acceleration of the vehicle can be determined from the above speed range as the target vehicle speed. Specifically, the longitudinal acceleration can be calculated in sequence by the following formulas:

[0028] in, is the longitudinal acceleration, is the current vehicle speed, is the vehicle speed within the above speed range.

[0029] Make Smallest Similarly, the smaller the longitudinal acceleration, the higher the longitudinal comfort. In the above speed range, using the target speed can make the longitudinal comfort of the user the best.

[0030] After the target speed is determined, the driver can be prompted to drive according to the target speed, or the vehicle can be automatically controlled to drive according to the target speed.

[0031] The present invention obtains a vehicle speed range that satisfies vertical comfort based on the current road surface grade and a preset vertical acceleration weighted root mean square threshold, and then finds a target vehicle speed with optimal longitudinal comfort within the vehicle speed range, fully considering the influence of vehicle speed on vertical and longitudinal ride comfort, so that passengers have a better experience when the vehicle travels according to the target vehicle speed.

[0032] In one embodiment, S102 may specifically include: obtaining the mapping relationship between the vehicle speed and the weighted root mean square value of the vehicle's vertical acceleration and the weighted root mean square threshold of the vertical acceleration under different road surface grades; determining the target mapping relationship and the target vertical acceleration weighted root mean square threshold according to the current road surface grade; and determining the vehicle speed range that is less than the target vertical acceleration weighted root mean square threshold according to the target mapping relationship.

[0033] One road surface grade may correspond to a mapping relationship and a vertical acceleration weighted root mean square threshold. After the current road surface grade is obtained, the target mapping relationship and the target vertical acceleration weighted root mean square threshold may be determined according to the current road surface grade.

[0034] In one embodiment, the step of obtaining the mapping relationship between the vehicle speed and the weighted root mean square value of the vehicle vertical acceleration under different road surface grades may specifically include: first obtaining the detection data of the vehicle speed and the weighted root mean square value of the vehicle vertical acceleration under different road surface grades; the detection data of the vehicle speed and the weighted root mean square value of the vehicle vertical acceleration under different road surface grades may be the data detected when the vehicle is actually on the road, or may be simulation test data. Then, the detection data is fitted based on the polynomial interpolation fitting method to obtain the function expression between the vehicle speed and the weighted root mean square value of the vehicle vertical acceleration under different road surface grades:

[0035] in, represents the weighted RMS value of the vehicle vertical acceleration, Indicates vehicle speed. represents the polynomial coefficients, which are determined by fitting.

[0036] Reference Figure 2 , showing a schematic diagram of a fitting curve of the relationship between vehicle speed and weighted root mean square value of vertical acceleration of a vehicle on a C-class road provided by the present invention. Figure 2 For example, if the target vertical acceleration weighted RMS threshold is selected as 0.14, the vehicle speed range is 35-42 km / h.

[0037] In one embodiment, the step of obtaining the current road surface grade may specifically include: when the current road surface is a continuous random road surface, determining the current road surface grade.

[0038] Continuous random road surface refers to a random function of the road surface height z(x) varying with position xx or time t. It has the following characteristics: ① Randomness: the road surface height is random and cannot be described by a deterministic function. ② Stationarity: the statistical characteristics of the road surface height (such as mean, variance, autocorrelation function, etc.) are stationary in space or time. ③ Isotropy: Under the isotropy assumption, the statistical characteristics of the road surface height are independent of direction.

[0039] In this embodiment, when the current road surface is determined to be a continuous random road surface, the current road surface grade is determined and executed. Figure 1 The various steps of the embodiment in FIG.

[0040] In one embodiment, the step of determining the current road surface grade may specifically include: determining the current road surface grade according to the road surface spatial power spectrum density of the current road surface. The road surface spatial power spectrum density is expressed by the following formula:

[0041] in, is the road surface spatial power spectrum density, is the road roughness coefficient; is the spatial frequency; is the reference spatial frequency, ; W is the frequency index, and in general, its value is selected as 2. According to the road surface spatial power spectrum density, the road surface roughness is usually divided into 8 levels, including AH.

[0042] The road surface spatial power spectral density Converted into road surface time power spectrum density , the vehicle has a speed Driving over an uneven road with spatial frequency n, temporal frequency , the road surface time power spectrum density can be expressed as:

[0043] By taking the first-order derivative, we can get the expressions of the power spectrum density of the vertical velocity and the power spectrum density of the vertical acceleration of the road surface:

[0044]

[0045] The white noise method is used to simulate the time domain road roughness model. Assuming that w(t) is a Gaussian white noise with a unit intensity of 1 and setting the vehicle speed v at a certain moment, the simulated road surface time domain model can be obtained:

[0046] Where: is the vertical velocity of the road surface roughness. Introduce the lower cutoff time frequency , we can get the time-domain random road surface excitation simulated by the filtered white noise method:

[0047] Where: For road excitation, ,in is the lower spatial cutoff frequency, which is substituted into the above formula to obtain:

[0048] in, Based on the above formula, the road random model can be built in Simulink, and the time domain random road excitation model is used as the input of the vehicle suspension system. The vehicle dynamics adopts the dynamic modeling method of the whole vehicle with nine degrees of freedom, so as to realize the vehicle suspension system simulation based on the road random model in Simulink, so as to obtain the simulation test data of the weighted root mean square value of the vehicle speed and the vehicle vertical acceleration under different road grades.

[0049] Reference Figure 3 , showing a schematic diagram of a nine-degree-of-freedom passive suspension model of a whole vehicle provided by the present invention. The vehicle is a six-wheel vehicle, and the vehicle suspension selects a passive suspension. The nine degrees of freedom include the movement of the vehicle in three directions of vertical, pitch, and roll and the movement of six wheels. The nine-degree-of-freedom model of the whole vehicle is established in the following way: Vertical movement:

[0050] Pitch movement:

[0051] Rolling motion:

[0052] The vertical kinematic equations of the six wheels are:

[0053] In the above formula, is the total mass of the vehicle body, For the i The unsprung mass of a suspension unit, , is the moment of inertia of the vehicle body around the Y-axis and the X-axis; is the vertical displacement of the center of mass of the vehicle body, is the pitch angle of the vehicle body, is the inclination angle of the vehicle body; For the i The vertical displacement of the suspension unit at the hinge point with the vehicle body, For the i The vertical displacement of the unsprung mass of a suspension unit, For the i The input displacement of the road surface at the wheel of each suspension unit; No. i The spring stiffness of each suspension subsystem, No. iThe tire spring rate, For the i The damping coefficient of the suspension subsystem. i = 1, 2, 3, 4, 5, 6 correspond to the left front, right front, left center, right center, left rear, and right rear suspension units respectively. The dot on the symbol in the formula represents a single differential, and two dots represent a double differential.

[0054] For the convenience of calculation and analysis, it is assumed that the pitch angle of the vehicle body and roll angle If the change is small, , The vertical displacements of the six wheels are derived from this and the vertical displacement at the center of mass of the vehicle body , Pitch angle and roll angle The relationship is expressed as follows:

[0055] The road roughness model describes the performance of the road surface conditions transmitted to the wheel vibration input into the vehicle body. The road surface excitation at the tire contact point of the vehicle model is as follows: Figure 3 In , , , which can be regarded as an indicator for evaluating vehicle comfort. The nine-degree-of-freedom model describes the motion law of the vehicle in space. By simulating the motion characteristics of the vehicle suspension, the vehicle's driving smoothness, handling, comfort and other performance can be evaluated.

[0056] In one embodiment, after the target vehicle speed is determined, the comprehensive comfort of the target vehicle speed can be determined based on the above two models.

[0057] In one embodiment, the vehicle speed control method further includes: when the current road surface is a discrete impact road surface, generating guidance prompt information; the prompt information includes elevation information and length information of the impact object.

[0058] Discrete impact pavement refers to the presence of obvious, discrete obstacles or uneven areas on the pavement surface. These obstacles are usually isolated and discontinuous, which will cause instantaneous impact or vibration to the vehicle. Unlike continuous random pavement, the excitation of discrete impact pavement is local and sudden, which usually produces a large instantaneous impact force on the vehicle's suspension system, tires and body. For example, pavement containing speed bumps, continuous undulating pavement, pothole pavement, etc. are all discrete impact pavements.

[0059] When it is detected that the current road surface is a discrete impact road surface, the elevation information and length information of the impact object, that is, the road obstacle, can be further obtained to remind the driver to slow down appropriately through the vehicle speed control system based on his own experience.

[0060] In one embodiment, the vehicle speed control method also includes: when there is a special situation where there is no road ahead, a landslide, or pedestrians intruding on the current road surface, generating a deceleration prompt message, and determining a braking distance based on the current vehicle speed; if the driver does not brake the vehicle within the braking distance, controlling the vehicle to brake.

[0061] When a vehicle encounters pedestrians intruding or landslides, the minimum braking distance in the current state can be calculated based on the current vehicle speed and vehicle parameters. , first remind the driver to slow down to ensure the safety of vehicle driving. No deceleration is performed ( ), the brake actuator is controlled to decelerate and stop urgently.

[0062] Reference Figure 4 , shows a schematic structural diagram of an embodiment of a vehicle speed control system provided by the present invention, the vehicle speed control system 40 comprises: The information acquisition module 401 is used to obtain the current road surface grade and the current vehicle speed; The information processing module 402 is used to determine a vehicle speed range that meets a preset condition according to the current road surface grade; wherein the preset condition is that the weighted root mean square value of the vertical acceleration of the vehicle is less than the weighted root mean square threshold of the vertical acceleration; and according to the current vehicle speed, determine a vehicle speed from the vehicle speed range that minimizes the longitudinal acceleration of the vehicle as a target vehicle speed; The vehicle speed control module 403 is used to control the vehicle to travel according to the target vehicle speed.

[0063] It should be noted that the implementation principle or implementation process of the above modules can refer to the embodiment of the above vehicle speed control method, and will not be described one by one here.

[0064] Reference Figure 5, showing a schematic diagram of the structure of another embodiment of a vehicle speed control system provided by the present invention. The information acquisition module 401 includes a front road surface scanning unit and a vehicle speed detection unit, and the front road surface scanning unit includes a laser radar and a monocular camera. When the vehicle is traveling on the road, the front road surface scanning unit scans the road surface through the laser radar and monocular camera installed in front of the vehicle, and then identifies the road surface through a recognition algorithm to determine the road condition. Road conditions include: AF-level continuous random road surfaces, discrete impact road surfaces (such as manhole covers, speed bumps, potholes, etc.) or special road surfaces (such as landslides, no road ahead, pedestrians breaking in, etc.). Afterwards, the front road surface scanning unit transmits the collected road conditions to the information processing module, and similarly, the vehicle speed detection unit also transmits the detected vehicle speed conditions to the information processing module.

[0065] The information processing module 402 includes a first electronic control unit (ECU), which is used to determine a target mapping relationship and a target vertical acceleration weighted root mean square threshold according to the road surface grade when the road condition is an AF-level continuous random road surface; determine a vehicle speed range that is less than the target vertical acceleration weighted root mean square threshold according to the target mapping relationship; and determine a vehicle speed that minimizes the longitudinal acceleration of the vehicle from the vehicle speed range as a target vehicle speed; and transmit the target vehicle speed to the vehicle speed control module.

[0066] The first ECU is also used to generate guidance prompt information when the road condition is a discrete impact road surface, and display the guidance prompt information to the driver for viewing; wherein the prompt information includes elevation information and length information of the impact object.

[0067] The first ECU is also used to calculate the minimum braking distance under the current state according to the current vehicle speed and vehicle parameters when the road condition is a special road surface, and generate a deceleration prompt message to remind the driver to slow down to ensure the safety of vehicle driving. If the vehicle still fails to decelerate, a deceleration emergency stop command is sent to the vehicle speed control module.

[0068] The vehicle speed control module 403 includes a second electronic control unit, a throttle actuator, a brake actuator, etc. The second ECU is used to control the vehicle to travel according to the target vehicle speed through the throttle actuator and the brake actuator after receiving the target vehicle speed, or control the vehicle to decelerate and stop suddenly through the brake actuator after receiving the deceleration and emergency stop command.

[0069] Reference Figure 6, showing a schematic flow chart of the control process of a vehicle speed control system provided by the present invention. The information acquisition module 401 scans the road surface information through the dual road surface scanning sensors (lidar and monocular camera) installed in front of the vehicle, and determines the road condition through the recognition algorithm after completing the road surface information scanning. The R&D personnel use the Lagrange interpolation method to functionally describe the relationship between the vehicle speed and the weighted root mean square value of the vertical acceleration of the vehicle body under different road surface grades, and then match the road surface grade with the function and enter it into the first electronic control unit of the information processing module 402. When the vehicle is traveling on continuous random roads of different grades, the information processing module 402 is used to obtain an optimal target vehicle speed and transmit the target vehicle speed to the driver, who accelerates or decelerates.

[0070] The system of the present invention can meet the requirements of vehicle speed regulation under different road conditions, such as continuous random road conditions, discrete excitation road conditions and special road conditions, and improve the riding comfort of passengers when heavy vehicles are driving. The optimal target speed that meets the two comfort requirements can be output, and the driver can make the decision whether to drive at the target speed, which provides a certain degree of reliability while achieving intelligence. Finally, in emergency road conditions, the minimum braking distance under the current driving condition is first obtained based on the driving speed and vehicle status, and then the driver is reminded to brake. If If the vehicle fails to brake within the minimum braking distance, it will automatically perform an emergency brake stop, which ensures the safety of heavy vehicle driving to a certain extent.

[0071] In one embodiment, the present invention further provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the steps of any of the above-mentioned vehicle speed control methods are implemented.

[0072] In one embodiment, the present invention further provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by the processor, the steps of any of the above-mentioned vehicle speed control methods are implemented.

[0073] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0074] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A vehicle speed control method, characterized in that: include: Get the current road grade and current vehicle speed; Determining a vehicle speed range that meets a preset condition according to the current road surface grade; wherein the preset condition is that a weighted root mean square value of a vertical acceleration of the vehicle is less than a weighted root mean square threshold value of a vertical acceleration; According to the current vehicle speed, determining a vehicle speed from the vehicle speed range that minimizes the longitudinal acceleration of the vehicle as a target vehicle speed; The vehicle is controlled to travel according to the target vehicle speed.

2. The vehicle speed control method according to claim 1, characterized in that: The determining of a vehicle speed range that meets a preset condition according to the current road surface grade includes: Obtain the mapping relationship between the vehicle speed and the weighted root mean square value of the vehicle vertical acceleration and the weighted root mean square threshold of the vertical acceleration under different road surface grades; Determining a target mapping relationship and a target vertical acceleration weighted root mean square threshold according to the current road surface grade; A vehicle speed range that is less than the target vertical acceleration weighted root mean square threshold is determined according to the target mapping relationship.

3. The vehicle speed control method according to claim 2, characterized in that: The mapping relationship between the vehicle speed and the weighted root mean square value of the vehicle vertical acceleration under different road surface grades is obtained, including: Obtaining detection data of vehicle speed and weighted root mean square value of vehicle vertical acceleration under different road surface grades; The detection data is fitted based on the polynomial interpolation fitting method to obtain the function expression between the vehicle speed and the weighted root mean square value of the vehicle vertical acceleration under different road grades: in, represents the weighted RMS value of the vehicle vertical acceleration, Indicates vehicle speed. Represents polynomial coefficients.

4. The vehicle speed control method according to claim 1, characterized in that: The obtaining of the current road surface grade includes: When the current road surface is a continuous random road surface, the current road surface grade is determined.

5. The vehicle speed control method according to claim 4, characterized in that: Determining the current road surface grade includes: The current road surface grade is determined according to the road surface spatial power spectrum density of the current road surface.

6. The vehicle speed control method according to claim 4, characterized in that: The method further comprises: When the current road surface is a discrete impact road surface, guidance prompt information is generated; the prompt information includes elevation information and length information of the impact object.

7. The vehicle speed control method according to claim 4, characterized in that: The method further comprises: When there is a special situation that there is no road ahead, a landslide or pedestrians intruding on the current road surface, a deceleration prompt message is generated, and a braking distance is determined according to the current vehicle speed; If the driver does not brake the vehicle within the braking distance, the vehicle is controlled to brake.

8. A vehicle speed control system, characterized in that: include: An information acquisition module is used to obtain the current road surface grade and the current vehicle speed; an information processing module, configured to determine a vehicle speed range that satisfies a preset condition according to the current road surface grade; wherein the preset condition is that a weighted root mean square value of a vertical acceleration of the vehicle is less than a weighted root mean square threshold of a vertical acceleration; and, according to the current vehicle speed, determine a vehicle speed from the vehicle speed range that minimizes the longitudinal acceleration of the vehicle as a target vehicle speed; The vehicle speed control module is used to control the vehicle to travel according to the target vehicle speed.

9. An electronic device, characterized in that: comprising a memory and a processor, wherein: The memory is used to store programs; The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps in the vehicle speed control method described in any one of claims 1 to 7 above.

10. A computer-readable storage medium, characterized in that: Used to store computer-readable programs, wherein the programs or instructions, when executed by a processor, can implement the steps of the vehicle speed control method described in any one of claims 1 to 7.

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