阅读说明：本技术 自适应巡航系统弯道车速控制方法、存储介质及电子设备 (Curve vehicle speed control method of adaptive cruise system, storage medium and electronic equipment ) 是由 李作文 刘晓楠 李迎弟 樊密丽 李君� 于 2021-07-30 设计创作，主要内容包括：本发明提供一种自适应巡航系统弯道车速控制方法、存储介质及电子设备,该方法包括获取前方道路的车道线,并根据所述车道线计算出第一道路曲率；获取当前车辆的车辆运行状态信息,并根据所述车辆运行状态信息计算出第二道路曲率；根据所述第一道路曲率、所述第二道路曲率和预设的道路曲率速度表获得安全车速；当自适应巡航系统正常启动时,根据所述安全车速和所述车辆运行状态信息计算出目标车速；根据所述目标车速控制所述当前车辆。实施本发明,能够精准地计算出目标车速,从而提高车辆在弯道行驶的安全性和稳定性。(The invention provides a curve vehicle speed control method of an adaptive cruise system, a storage medium and electronic equipment, wherein the method comprises the steps of obtaining a lane line of a front road, and calculating a first road curvature according to the lane line; acquiring vehicle running state information of a current vehicle, and calculating a second road curvature according to the vehicle running state information; obtaining a safe vehicle speed according to the first road curvature, the second road curvature and a preset road curvature speed meter; when the adaptive cruise system is normally started, calculating a target speed according to the safe speed and the vehicle running state information; and controlling the current vehicle according to the target vehicle speed. By implementing the method and the device, the target speed can be accurately calculated, so that the safety and the stability of the vehicle running on the curve are improved.)

1. A method for controlling the speed of an adaptive cruise system curve vehicle is characterized by comprising the following steps:

acquiring a lane line of a front road, and calculating the curvature of the front road according to the lane line;

acquiring vehicle running state information of a current vehicle, and calculating a second road curvature according to the vehicle running state information;

obtaining a safe vehicle speed according to the first road curvature, the second road curvature and a preset road curvature speed meter;

when the adaptive cruise system is normally started, calculating a target speed according to the safe speed and the vehicle running state information;

and controlling the current vehicle according to the target vehicle speed.

2. A curve vehicle speed control method of an adaptive cruise system as claimed in claim 1, wherein said calculating a first road curvature from a lane line comprises:

if no valid lane line is identified, setting the first road curvature to 0;

and if the effective lane line is identified, acquiring a third road curvature and a road curvature change rate at the position of the camera, and calculating the first road curvature according to the third road curvature and the road curvature change rate.

3. A curve vehicle speed control method of an adaptive cruise system as claimed in claim 1, wherein said vehicle operation state information includes longitudinal vehicle speed, front wheel turning angle, vehicle wheel base, lateral acceleration, right rear wheel vehicle speed, left rear wheel vehicle speed and rear wheel base, said obtaining vehicle operation state information and calculating a second road curvature according to said vehicle operation state information, specifically comprising:

if the longitudinal speed is less than or equal to a preset first speed threshold value, calculating the second road curvature according to the front wheel corner and the vehicle wheelbase;

and if the longitudinal vehicle speed is greater than or equal to a preset second vehicle speed threshold value, calculating the yaw rate of the current vehicle according to the longitudinal vehicle speed, the lateral acceleration, the right rear wheel vehicle speed, the left rear wheel vehicle speed and the rear wheel track, and calculating the second road curvature according to the yaw rate and the longitudinal vehicle speed.

4. A curve vehicle speed control method of an adaptive cruise system according to claim 3, wherein if the longitudinal vehicle speed is less than or equal to a preset first vehicle speed threshold, calculating the second road curvature according to the front wheel rotation angle and the vehicle wheel base, specifically comprises:

and if the longitudinal speed is less than or equal to a preset first speed threshold value, calculating the second road curvature according to the ratio of the front wheel corner to the vehicle wheelbase.

5. The adaptive cruise system curve vehicle speed control method according to claim 4, wherein if the longitudinal vehicle speed is greater than or equal to a preset second vehicle speed threshold value, calculating a yaw rate of the current vehicle from the longitudinal vehicle speed, the lateral acceleration, the right rear wheel vehicle speed, the left rear wheel vehicle speed, and the rear wheel track, and calculating the second road curvature from the yaw rate and the longitudinal vehicle speed, specifically comprises:

if the longitudinal vehicle speed is greater than or equal to a preset second vehicle speed threshold value, calculating a first sub-yaw velocity according to the vehicle speed of the right rear wheel, the vehicle speed of the left rear wheel and the wheel distance of the rear wheels;

calculating a second sub yaw rate according to the lateral acceleration and the longitudinal vehicle speed;

calculating the yaw rate according to the first sub yaw rate and the second yaw rate;

and calculating the second road curvature according to the ratio of the yaw angular velocity to the longitudinal vehicle speed.

6. A curve vehicle speed control method of an adaptive cruise system according to any one of claims 1-5, characterized in that said obtaining a safe vehicle speed from said first road curvature, said second road curvature and a preset road curvature speedometer comprises:

taking a minimum value of the first road curvature and the second road curvature as a target road curvature;

and obtaining the safe vehicle speed according to the target road curvature and the road curvature speed table.

7. A curve vehicle speed control method for an adaptive cruise system as claimed in claim 1, wherein said vehicle operating state information further includes a steering wheel angle and a steering wheel angle speed, and said calculating a target vehicle speed from said safe vehicle speed and said vehicle operating state information comprises:

if no effective vehicle following target is identified, acquiring the steering wheel speed limited by the steering wheel steering angle, the steering wheel speed limited by the steering wheel speed and the cruising speed set by an adaptive cruising system, and taking the minimum value of the safe vehicle speed, the steering wheel speed and the cruising speed as the target vehicle speed;

and if an effective following target is identified, acquiring the following speed of the following target, and taking the minimum value of the safe vehicle speed, the corner speed and the following speed as the target vehicle speed.

8. A curve vehicle speed control method as claimed in claim 7, wherein said calculating a target vehicle speed based on said safe vehicle speed and said vehicle operating condition information previously comprises:

if a new target is detected in the front lane, identifying an effective following target;

and if no new target is detected in the front lane, no effective following target is identified.

9. A storage medium storing computer instructions for performing all the steps of the adaptive cruise system curve vehicle speed control method according to any one of claims 1-8, when the computer instructions are executed by a computer.

10. An electronic device, comprising:

at least one processor; and the number of the first and second groups,

a memory communicatively coupled to the at least one processor; wherein the content of the first and second substances,

the memory stores instructions executable by the at least one processor to enable the at least one processor to perform the adaptive cruise system curve vehicle speed control method of any one of claims 1-8.

Technical Field

The invention relates to the technical field of automobiles, in particular to a curve vehicle speed control method of an adaptive cruise system, a storage medium and electronic equipment.

Background

An Adaptive Cruise Control (ACC) system is an intelligent automatic Control system. During the running process of the vehicle, a vehicle distance sensor (radar) arranged at the front part of the vehicle continuously scans a road in front of the vehicle, meanwhile, a wheel speed sensor collects a vehicle speed signal, when the distance between the ACC control unit and the front vehicle is too small, the ACC control unit can be coordinated with a brake anti-lock system and an engine control system to act so as to brake wheels properly, and the output power of an engine is reduced, so that the vehicle and the front vehicle can keep a safe distance all the time.

Currently, the following two main logic control schemes are adopted in the existing ACC system:

1) the curvature of the estimated road is recognized and predicted by an Electronic Scanning Radar (ESR), whether the vehicle is running in a curve is determined, and the maximum curve running speed is calculated.

2) The method comprises the steps of utilizing a carrier phase differential technology (RTK) -Global Positioning System (GPS) and an electronic map to obtain front road information and curve information, calculating the safe vehicle speed when passing through a curve according to the curve information, and detecting whether a lane enters the curve in Real Time to control the vehicle speed.

However, in the process of implementing the invention, the inventor finds that the target of the front vehicle may be lost due to turning in the curve steering control process in the existing ACC system logic control scheme, so that the calculated maximum curve running vehicle speed is relatively high, safety accidents are easy to occur, and the safety and stability of the vehicle running in the curve are reduced.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a curve vehicle speed control method, a storage medium and an electronic device of an adaptive cruise system, which can accurately calculate a target vehicle speed so as to improve the safety and stability of the vehicle running in a curve.

The technical scheme of the invention provides a curve vehicle speed control method of an adaptive cruise system, which comprises the following steps:

acquiring a lane line of a front road, and calculating a first road curvature according to the lane line;

acquiring vehicle running state information of a current vehicle, and calculating a second road curvature according to the vehicle running state information;

obtaining a safe vehicle speed according to the first road curvature, the second road curvature and a preset road curvature speed meter;

when the adaptive cruise system is normally started, calculating a target speed according to the safe speed and the vehicle running state information;

and controlling the current vehicle according to the target vehicle speed.

Further, the calculating the curvature of the first road according to the lane line specifically includes:

if no valid lane line is identified, setting the first road curvature to 0;

and if the effective lane line is identified, acquiring a third road curvature and a road curvature change rate at the position of the camera, and calculating the first road curvature according to the third road curvature and the road curvature change rate.

Further, the vehicle running state information includes a longitudinal vehicle speed, a front wheel corner, a vehicle wheel base, a lateral acceleration, a right rear wheel vehicle speed, a left rear wheel vehicle speed and a rear wheel base, the vehicle running state information is acquired, and a second road curvature is calculated according to the vehicle running state information, and the method specifically includes:

if the longitudinal speed is less than or equal to a preset first speed threshold value, calculating the second road curvature according to the front wheel corner and the vehicle wheelbase;

and if the longitudinal vehicle speed is greater than or equal to a preset second vehicle speed threshold value, calculating the yaw rate of the current vehicle according to the longitudinal vehicle speed, the lateral acceleration, the right rear wheel vehicle speed, the left rear wheel vehicle speed and the rear wheel track, and calculating the second road curvature according to the yaw rate and the longitudinal vehicle speed.

Further, if the longitudinal vehicle speed is less than or equal to a preset first vehicle speed threshold, calculating the second road curvature according to the front wheel rotation angle and the vehicle wheel base, specifically including:

and if the longitudinal speed is less than or equal to a preset first speed threshold value, calculating the second road curvature according to the ratio of the front wheel corner to the vehicle wheelbase.

Further, if the longitudinal vehicle speed is greater than or equal to a preset second vehicle speed threshold, calculating a yaw rate of the current vehicle according to the longitudinal vehicle speed, the lateral acceleration, the right rear wheel vehicle speed, the left rear wheel vehicle speed, and the rear wheel track, and calculating the second road curvature according to the yaw rate and the longitudinal vehicle speed, specifically including:

if the longitudinal vehicle speed is greater than or equal to a preset second vehicle speed threshold value,

calculating a first sub yaw velocity according to the right rear wheel speed, the left rear wheel speed and the rear wheel track;

calculating a second sub yaw rate according to the lateral acceleration and the longitudinal vehicle speed;

calculating the yaw rate according to the first sub yaw rate and the second yaw rate;

and calculating the second road curvature according to the ratio of the yaw angular velocity to the longitudinal vehicle speed.

Further, obtaining a safe vehicle speed according to the first road curvature, the second road curvature and a preset road curvature speed meter specifically comprises:

taking a minimum value of the first road curvature and the second road curvature as a target road curvature;

and obtaining the safe vehicle speed according to the target road curvature and the road curvature speed table.

Further, the vehicle operating state information further includes a steering wheel angle and a steering wheel angular speed, and the calculating the target vehicle speed according to the safe vehicle speed and the vehicle operating state information specifically includes:

if no effective vehicle following target is identified, acquiring the steering wheel speed limited by the steering wheel steering angle, the steering wheel speed limited by the steering wheel speed and the cruising speed set by an adaptive cruising system, and taking the minimum value of the safe vehicle speed, the steering wheel speed and the cruising speed as the target vehicle speed;

and if an effective following target is identified, acquiring the following speed of the following target, and taking the minimum value of the safe vehicle speed, the corner speed and the following speed as the target vehicle speed.

Further, the calculating a target vehicle speed according to the safe vehicle speed and the vehicle operation state information includes:

if a new target is detected in the front lane, identifying an effective following target;

and if no new target is detected in the front lane, no effective following target is identified.

The technical solution of the present invention also provides a storage medium storing computer instructions for executing all the steps of the curve vehicle speed control method of the adaptive cruise system as described above when the computer executes the computer instructions.

The technical solution of the present invention also provides an electronic device, including:

at least one processor; and the number of the first and second groups,

a memory communicatively coupled to the at least one processor; wherein the content of the first and second substances,

the memory stores instructions executable by the at least one processor to enable the at least one processor to perform the adaptive cruise system curve vehicle speed control method as previously described.

After adopting above-mentioned technical scheme, have following beneficial effect: the method comprises the steps of obtaining lane lines and vehicle running state information, respectively calculating a first road curvature and a second road curvature according to the lane lines and the vehicle running state information, obtaining a safe vehicle speed according to the first road curvature, the second road curvature and a preset road curvature speed meter, calculating a target vehicle speed according to the safe vehicle speed and the vehicle running state information, controlling a current vehicle according to the target vehicle speed, and improving the accuracy of calculating the target vehicle speed, so that the safety and the stability of the vehicle running on a curve are improved.

Drawings

The disclosure of the present invention will become more readily understood by reference to the drawings. It should be understood that: these drawings are for illustrative purposes only and are not intended to limit the scope of the present disclosure. In the figure:

FIG. 1 is a flowchart illustrating a method for controlling a vehicle speed at a curve of an adaptive cruise control system according to an embodiment of the present invention;

FIG. 2 is a chart of the predetermined road curvature speed relationship of FIG. 1;

FIG. 3 is a flowchart illustrating a method for controlling a vehicle speed at a curve of an adaptive cruise control system according to a second embodiment of the present invention;

FIG. 4 is a chart of steering wheel angle versus vehicle speed at the steering angle of FIG. 2;

FIG. 5 is a graph of the steering wheel angular velocity versus vehicle angular velocity correspondence of FIG. 2;

fig. 6 is a schematic hardware structure diagram of an electronic device for controlling a vehicle speed of a curve of an adaptive cruise system according to a fourth embodiment of the present invention.

Detailed Description

The following further describes embodiments of the present invention with reference to the accompanying drawings.

It is easily understood that according to the technical solution of the present invention, those skilled in the art can substitute various structures and implementation manners without changing the spirit of the present invention. Therefore, the following detailed description and the accompanying drawings are merely illustrative of the technical aspects of the present invention, and should not be construed as limiting or restricting the technical aspects of the present invention.

The terms of orientation of up, down, left, right, front, back, top, bottom, and the like referred to or may be referred to in this specification are defined relative to the configuration shown in the drawings, and are relative terms, and thus may be changed correspondingly according to the position and the use state of the device. Therefore, these and other directional terms should not be construed as limiting terms.

Example one

As shown in fig. 1, fig. 1 is a flowchart of an adaptive cruise system curve vehicle speed control method according to an embodiment of the present invention, including:

step S101: acquiring a lane line of a front road, and calculating a first road curvature according to the lane line;

step S102: acquiring vehicle running state information of a current vehicle, and calculating a second road curvature according to the vehicle running state information;

step S103: obtaining a safe vehicle speed according to the first road curvature, the second road curvature and a preset road curvature speed meter;

step S104: when the adaptive cruise system is normally started, calculating a target speed according to the safe speed and the vehicle running state information;

step S105: and controlling the current vehicle according to the target vehicle speed.

Specifically, when the ACC system detects an entrance into a curve, the electronic control unit ECU executes steps S101 to S102, acquires the lane line and the vehicle running state information of the road ahead, and calculates the first road curvature ρ from the lane line and the vehicle running state information, respectively₁And a second road curvature ρ₂. The lane line of the front road can be acquired through a camera arranged on the vehicle body, and the vehicle running state information comprises longitudinal vehicle speed, front wheel turning angle, vehicle wheelbase, lateral acceleration, right rear wheel vehicle speed, left rear wheel vehicle speed, rear wheel wheelbase, steering wheel turning angle and steering wheel turning angle speed. Then, step S103 is executed, according to the first road curvature, the second road curvature and the preset road curvature speedometerObtaining a safe vehicle speed, wherein the road curvature speed meter is a curvature-speed relation graph set according to road standards, the larger the road curvature is, the smaller the safe vehicle speed is, as shown in FIG. 2, the abscissa is the road curvature rho, and the ordinate is the safe vehicle speed V_limitFor convenience of visual inspection, the numerical values shown in fig. 2 are schematic diagrams, specific numerical values can be set according to requirements, safe vehicle speeds corresponding to corresponding road curvatures can be inquired through a preset road curvature speedometer, so that the safe vehicle speeds meet road standards, safety is improved, and compared with the method for calculating the safe vehicle speeds by adopting lateral acceleration in the prior art, the calculated safe vehicle speeds are inaccurate due to the fact that the lateral acceleration detected by a sensor is unstable, the safe vehicle speeds exceed the vehicle speeds specified by the road standards easily, and the vehicle is unstable. And step S104 is executed to judge whether the adaptive cruise system is normally started or not, and when the adaptive cruise system is normally started, the target speed is calculated according to the safe speed and the vehicle running state information. And finally, executing the step S105 to control the current vehicle according to the target vehicle speed.

The sequence of step S101 and step S102 in this embodiment is only for convenience of description, and does not limit the claims, and a person skilled in the art should understand that step S101 and step S102 can be interchanged or performed synchronously without affecting the actual effect.

According to the curve vehicle speed control method of the adaptive cruise system, the lane line and the vehicle running state information are obtained, the first road curvature and the second road curvature are calculated according to the lane line and the vehicle running state information respectively, the safe vehicle speed is obtained according to the first road curvature, the second road curvature and a preset road curvature speed table, the target vehicle speed is calculated according to the safe vehicle speed and the vehicle running state information, the current vehicle is controlled according to the target vehicle speed, the accuracy of calculating the target vehicle speed is improved, and therefore the safety and the stability of the vehicle running on the curve are improved.

In one embodiment, in order to further improve the accuracy of the target vehicle speed and improve the safety and stability of the vehicle running on a curve, the step S101 specifically includes:

acquiring a lane line of a front road through a camera;

if no valid lane line is identified, setting the first road curvature to 0;

and if the effective lane line is identified, acquiring a third road curvature and a road curvature change rate at the position of the camera, and calculating the first road curvature according to the third road curvature and the road curvature change rate.

Specifically, the ECU acquires a lane line of the road ahead through the camera, and if no valid lane line is identified, the curvature ρ of the first road is determined₁And if not, acquiring a third road curvature and a road curvature change rate at the position of the camera, and calculating the first road curvature by using the following formula:

ρ₁＝2*C_ur+6*dC_ur(1) formula

Where ρ is₁Is the first road curvature; c_urA third road curvature; dC (direct current)_urIs the rate of change of curvature of the road.

The identification of the lane line and the judgment of the effectiveness can be obtained by adopting the existing method, which is not an improvement point of the application, and therefore, the description is omitted.

Example two

As shown in fig. 3, fig. 3 is a flowchart of an adaptive cruise system curve vehicle speed control method according to a second embodiment of the present invention, including:

step S301: acquiring a lane line of a front road;

step S302: judging whether a valid lane line is identified;

step S303: setting the first road curvature to 0;

step S304: acquiring a third road curvature and a road curvature change rate at the position of the camera, and calculating a first road curvature according to the third road curvature and the road curvature change rate;

step S305: acquiring vehicle running state information of a current vehicle;

step S306: judging whether the longitudinal vehicle speed is less than or equal to a preset first vehicle speed threshold value or not;

step S307: calculating a second road curvature according to the front wheel corner and the vehicle wheelbase;

step S308: judging whether the longitudinal vehicle speed is greater than or equal to a preset second vehicle speed threshold value or not;

step S309: calculating the yaw velocity of the current vehicle according to the longitudinal vehicle speed, the lateral acceleration, the right rear wheel vehicle speed, the left rear wheel vehicle speed and the rear wheel track, and calculating the second road curvature according to the yaw velocity and the longitudinal vehicle speed;

step S310: taking the minimum value of the first road curvature and the second road curvature as a target road curvature;

step S311: obtaining a safe vehicle speed according to the curvature of the target road and a road curvature speedometer;

step S312: judging whether the adaptive cruise system is normally started or not;

step S313: controlling the speed of the current vehicle according to manual driving;

step S314: judging whether a valid car following target is identified;

step S315: acquiring a steering wheel speed limited by a steering wheel steering angle, a steering wheel speed limited by the steering wheel speed and a cruising speed set by an adaptive cruising system, and taking the minimum value of the safe speed, the steering wheel speed and the cruising speed as a target speed;

step S316: acquiring the following speed of a following target, and taking the minimum value of the safe speed, the corner speed and the following speed as the target speed;

step S317: and controlling the current vehicle according to the target vehicle speed.

Specifically, when the ACC system detects an entrance into a curve, the ECU first performs steps S301 to S302, determines whether a valid lane line is recognized in step S302, and if so, performs step S304 to calculate the first road curvature ρ using the above expression (1)₁Otherwise, step S303 is performed. Secondly, executing the steps S305 to S306 to judge whether the longitudinal vehicle speed is less than or equal to a preset first vehicle speed threshold value, if so, executing the step S307 to calculate the second road curvature rho₂Otherwise, step S308 is executed. In step S308, the portrait is determinedAnd whether the vehicle speed is greater than or equal to a preset second vehicle speed threshold value, if so, executing the step S309-step S310, otherwise, continuing to execute the step S305. In performing step S310, the first road curvature ρ is compared₁And a second road curvature ρ₂The curvature rho of the first road₁And a second road curvature ρ₂The minimum value of (d) is taken as the target road curvature, i.e., ρ ═ min (ρ)₁，ρ₂) And step S311 is executed to obtain a safe vehicle speed V according to Table 1_limit. Step S312 is executed again to determine whether the ACC system is normally started (e.g., the ACC system is turned off or abnormal, etc.), and if so, step S313 is executed, otherwise, step S314 is executed. In step S314, it is determined whether a valid following target is identified, i.e., whether there is a following vehicle available on the road ahead, if so, step S315 is performed, otherwise, step S316 is performed. Finally, step S317 is executed according to the target vehicle speed V_{Eyes of a user}The current vehicle is controlled.

In step S315, the maximum steering angle vehicle speed V of the steering wheel angle limit is acquired_swMaximum turning speed vehicle speed V limited by steering wheel turning speed_dswAnd cruise vehicle speed V set by ACC system_setWill safely drive the vehicle speed V_limitTurning vehicle speed V_swAngular velocity vehicle speed V_dswAnd cruising speed V_setIs taken as the target vehicle speed V_{Eyes of a user}I.e. V_{Eyes of a user}＝min(V_limit，V_sw，V_dsw，V_set) Therefore, the lateral force of the vehicle is prevented from exceeding the maximum static friction force of the ground, the adhesive force between the vehicle tire and the ground is enhanced, and the safety is improved. Wherein the maximum steering angle vehicle speed V of the steering wheel angle limit_swMaximum angular velocity vehicle speed V limited by steering wheel angular velocity_dswThe system can be preset in the system according to the requirements of users and can be obtained by looking up the table. Preferably, the graph of the steering wheel angle-steering angle vehicle speed relationship is shown in fig. 4, the abscissa is the steering wheel angle S, and the ordinate is the steering angle vehicle speed V_swFor easy visual inspection, the numerical values shown in fig. 4 are schematic diagrams, and specific numerical values thereof can be set according to requirements; FIG. 5 is a graph showing the relationship between the steering wheel rotational speed and the vehicle rotational speedThe abscissa is the steering wheel angular velocity V_sThe ordinate is the speed V of the corner speed_dswFor easy visual inspection, the numerical values shown in fig. 5 are schematic diagrams, and specific numerical values thereof can be set according to requirements.

In step S316, the following speed V of the following target is acquired_followWill safely drive the vehicle speed V_limitTurning vehicle speed V_swAngular velocity vehicle speed V_dswSpeed V of following vehicle_followIs taken as the target vehicle speed V_{Eyes of a user}I.e. V_{Eyes of a user}＝min(V_limit，V_sw，V_dsw，V_follow) Therefore, the situation that the calculated vehicle speed exceeds a safety value or the repeated fluctuation range of the speed is large due to the fact that certain parameters such as the road curvature estimation error or the estimation value is unstable and fluctuates greatly is avoided, the situation that the lateral force of the vehicle exceeds the maximum static friction force of the ground is prevented, the adhesive force between the tires of the vehicle and the ground is enhanced, the minimum vehicle speed is obtained through comparison, the large sudden change of the vehicle speed can be restrained, the repeated acceleration and deceleration of the vehicle is restrained, the riding comfort is improved, the stability is improved, and the safety is enhanced.

According to the curve vehicle speed control method of the adaptive cruise system, the lane line and the vehicle running state information are obtained, the first road curvature and the second road curvature are calculated according to the lane line and the vehicle running state information respectively, the safe vehicle speed is obtained according to the first road curvature, the second road curvature and a preset road curvature speed table, the target vehicle speed is calculated according to the safe vehicle speed and the vehicle running state information, the current vehicle is controlled according to the target vehicle speed, the accuracy of calculating the target vehicle speed is improved, and therefore the safety and the stability of the vehicle running on the curve are improved.

In one embodiment, in order to further accurately calculate the second road curvature, so as to improve the accuracy of the safe vehicle speed, step S306 specifically includes:

and when the longitudinal speed is less than or equal to a preset first speed threshold value, calculating the second road curvature according to the ratio of the front wheel rotation angle to the vehicle wheelbase.

Specifically, when the longitudinal vehicle speed is less than or equal to a preset first vehicle speed threshold value, the second road curvature is calculated by using the following formula:

ρ₂δ/L, (2) formula

Where ρ is₂A second road curvature; delta is a front wheel corner; and L is the vehicle wheel base.

In one embodiment, in order to accurately calculate the yaw rate and prevent deviation, the second road curvature is further accurately calculated, so as to improve the accuracy of the safe vehicle speed, step S307 specifically includes:

when the longitudinal speed is greater than or equal to a preset second vehicle speed threshold value, calculating a first sub-yaw velocity according to the speed of a right rear wheel, the speed of a left rear wheel and the wheel distance of a rear wheel;

calculating a second sub-yaw velocity according to the lateral acceleration and the longitudinal vehicle speed;

calculating a yaw velocity according to the first sub yaw velocity and the second yaw velocity;

the second road curvature is calculated from a ratio of the yaw rate to the longitudinal vehicle speed.

Specifically, when the longitudinal vehicle speed is greater than or equal to a preset second vehicle speed threshold, the second road curvature is calculated by using the following formula:

wherein phi is a yaw angular velocity; a is a coefficient; phi is a₁Is the first sub yaw rate; phi is a₂Is the second sub yaw rate; v_rrThe right rear wheel speed; v_rlLeft rear wheel speed; b_rIs the rear wheel track; a is_yIs the lateral acceleration.

The first vehicle speed threshold and the second vehicle speed threshold can be set according to user requirements, and the first vehicle speed threshold can be the same as the second vehicle speed threshold or different from the second vehicle speed threshold. Preferably, the first vehicle speed threshold is set to 1m/s and the second vehicle speed threshold is set to 1.5 m/s.

In one embodiment, in order to further accurately calculate the target vehicle speed, so as to improve the safety and stability of the vehicle traveling on a curve, step S312 specifically includes:

if a new target is detected in the front lane, identifying an effective following target;

and if no new target is detected in the front lane, no effective following target is identified.

EXAMPLE III

A third embodiment of the present invention provides a storage medium for storing computer instructions which, when executed by a computer, perform all the steps of the adaptive cruise system curve vehicle speed control method in any of the method embodiments described above.

Example four

As shown in fig. 6, a schematic hardware structure diagram of an electronic device for controlling a vehicle speed of a curve of an adaptive cruise system according to a fourth embodiment of the present invention includes:

at least one processor 601; and the number of the first and second groups,

a memory 602 communicatively coupled to the at least one processor 601; wherein the content of the first and second substances,

the memory 602 stores instructions executable by the at least one processor 601 to enable the at least one processor 601 to perform the adaptive cruise system curve vehicle speed control method as previously described.

In fig. 6, one processor 601 is taken as an example.

The Electronic device is preferably an Electronic Control Unit (ECU).

The electronic device may further include: an input device 603 and an output device 604.

The processor 601, the memory 602, the input device 603, and the output device 604 may be connected by a bus or other means, and are illustrated as being connected by a bus.

The memory 602, which is a non-volatile computer-readable storage medium, may be used to retrieve non-volatile software programs, non-volatile computer-executable programs, and modules, such as program instructions/modules corresponding to the adaptive cruise system curve vehicle speed control method in the embodiments of the present application, for example, the method flows shown in fig. 1 and 3. The processor 601 executes various functional applications and data processing by running the nonvolatile software programs, instructions and modules obtained in the memory 602, so as to implement the adaptive cruise system curve vehicle speed control method in the above embodiment.

The memory 602 may include an acquisition program area and an acquisition data area, wherein the acquisition program area may acquire an operating system, an application program required for at least one function; the acquisition data region may acquire data created according to use of the adaptive cruise system curve vehicle speed control method, or the like. Further, the memory 602 may include high speed random access memory, and may also include non-volatile memory, such as at least one magnetic disk storage device, flash memory device, or other non-volatile solid state storage device. In some embodiments, memory 602 optionally includes memory remotely located from processor 601, and such remote memory may be connected over a network to a device that implements the adaptive cruise system curve vehicle speed control method. Examples of such networks include, but are not limited to, the internet, intranets, local area networks, mobile communication networks, and combinations thereof.

The input device 603 may receive input from a user click and generate signal inputs related to user settings and function control of the adaptive cruise system curve vehicle speed control method. The output device 604 may include a display device such as a display screen.

The method of adaptive cruise system curve vehicle speed control in any of the method embodiments described above is performed when the one or more modules retrieve in the memory 602 and are executed by the one or more processors 301.

The product can execute the method provided by the embodiment of the application, and has the corresponding functional modules and beneficial effects of the execution method. For technical details that are not described in detail in this embodiment, reference may be made to the methods provided in the embodiments of the present application.

The electronic device of embodiments of the present invention exists in a variety of forms, including but not limited to:

(1) an Electronic Control Unit (ECU) is also called a "traveling computer" or a "vehicle-mounted computer". The digital signal processor mainly comprises a microprocessor (CPU), a memory (ROM and RAM), an input/output interface (I/O), an analog-to-digital converter (A/D), a shaping circuit, a driving circuit and other large-scale integrated circuits.

(2) Mobile communication devices, which are characterized by mobile communication capabilities and are primarily targeted at providing voice and data communications. Such terminals include smart phones (e.g., iphones), multimedia phones, functional phones, and low-end phones, among others.

(3) The ultra-mobile personal computer equipment belongs to the category of personal computers, has calculation and processing functions and generally has the characteristic of mobile internet access. Such terminals include PDA, MID, and UMPC devices, among others.

(4) Portable entertainment devices such devices may display and play multimedia content. Such devices include audio and video players (e.g., ipods), handheld game consoles, electronic books, as well as smart toys and portable car navigation devices.

(5) The server is similar to a general computer architecture, but has higher requirements on processing capability, stability, reliability, safety, expandability, manageability and the like because of the need of providing highly reliable services.

(6) And other electronic devices with data interaction functions.

In addition, the logic instructions in the memory 602 may be implemented in software functional units and may be acquired from a computer readable storage medium when the logic instructions are sold or used as a stand-alone product. Based on such understanding, the technical solution of the present invention or a part thereof, which essentially contributes to the prior art, can be embodied in the form of a software product, which is obtained from a storage medium and includes instructions for causing a mobile terminal (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: various media capable of acquiring program codes, such as a usb disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk, or an optical disk.

The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the embodiment of the present invention. One of ordinary skill in the art can understand and implement it without inventive effort.

Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware. With this understanding in mind, the above-described technical solutions may be embodied in the form of a software product, which can be obtained from a computer-readable storage medium, such as ROM/RAM, magnetic disk, optical disk, etc., and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the methods described in the embodiments or some parts of the embodiments.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the embodiments of the present invention, and not to limit the same; although embodiments of the present invention have been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.