1. A curve speed limiting method is characterized by comprising the following steps:

according to the curvatures respectively corresponding to N positions in a preset curve road section in the advancing direction of a vehicle, obtaining N upper limit speeds corresponding to the curvatures; wherein N is a natural number greater than 0;

evaluating the N upper limit speeds according to the current running information of the vehicle to obtain a target upper limit speed;

acquiring an acceleration curve corresponding to the target upper limit speed;

and controlling the vehicle to run according to the acceleration curve in the preset curve section.

2. The method of claim 1, wherein the evaluating the N upper limit speeds according to current driving information of the vehicle to obtain a target upper limit speed comprises:

determining the current upper limit speed to be evaluated from the N upper limit speeds, and performing at least one evaluation step on the current upper limit speed to be evaluated according to the current running information of the vehicle;

if the number of times of the evaluation step executed on the current upper limit speed to be evaluated does not reach the number of times corresponding to the first preset duration, taking the next upper limit speed as a new upper limit speed to be evaluated, and continuously executing the evaluation step of at least one time on the current upper limit speed to be evaluated according to the current running information of the vehicle;

and if the number of times of the evaluation step executed on the current to-be-evaluated upper limit speed reaches the number of times corresponding to the first preset time length, and the predicted position of the vehicle after the first preset time length is the tail end of the preset curved road section, determining that the current to-be-evaluated upper limit speed is the target upper limit speed.

3. The method of claim 2, wherein the N upper velocities are arranged in order from the near to the far of the N positions, the method further comprising:

and if the number of times of the evaluation step executed on the current upper limit speed to be evaluated reaches the number of times corresponding to the first preset time length, and the predicted position of the vehicle after the first preset time length is not the tail end of the preset curved road section, taking the next upper limit speed as a new upper limit speed to be evaluated, and continuously executing the evaluation step of at least one time on the current upper limit speed to be evaluated according to the current driving information of the vehicle until the target upper limit speed is determined from the N upper limit speeds.

4. The method according to claim 2 or 3, characterized in that the current travel information of the vehicle includes a speed, an acceleration, and a position at the current time, and the acceleration at the current time is related to an upper limit speed to be currently evaluated;

wherein, the step of evaluating the current upper limit speed to be evaluated at least once according to the current running information of the vehicle comprises the following steps:

obtaining the predicted speed and the predicted position at the next moment according to the current running information of the vehicle;

acquiring the curvature speed corresponding to the predicted position at the next moment;

when the predicted speed at the next moment is greater than the curvature speed corresponding to the predicted position at the next moment, determining that the current upper limit speed to be evaluated is not the target upper limit speed;

when the predicted speed at the next moment is less than or equal to the curvature speed corresponding to the predicted position at the next moment, taking the minimum one of the curvature speed corresponding to the predicted position at the next moment and the current upper limit speed to be evaluated as a first speed;

obtaining the predicted acceleration at the next moment according to the first speed and the speed at the current moment;

and taking the predicted speed, the predicted acceleration and the predicted position at the next moment as new current running information of the vehicle, and continuing to execute the step of obtaining the predicted speed and the predicted position at the next moment according to the current running information of the vehicle until the number of times of executing the evaluation step on the current upper limit speed to be evaluated reaches the number of times corresponding to the first preset time length.

5. The method of claim 4, wherein deriving the predicted acceleration for the next time based on the first velocity and the velocity for the current time comprises:

obtaining a first acceleration according to the first speed and the speed at the current moment;

when the absolute value of the first acceleration is smaller than or equal to an acceleration threshold, determining that the first acceleration is a predicted acceleration at the next moment;

and when the absolute value of the first acceleration is larger than the acceleration threshold, determining the predicted acceleration at the next moment according to the acceleration threshold.

6. The method according to claim 4, wherein when the current upper limit speed to be evaluated is the target upper limit speed, M predicted positions are obtained after the first preset time period, the M predicted positions respectively correspond to M moments, and the obtaining of the acceleration curve corresponding to the target upper limit speed includes:

and obtaining an acceleration curve according to the predicted acceleration corresponding to each moment in the M moments.

7. The method according to any one of claims 1 to 6, wherein the obtaining of the N upper limit speeds corresponding to the curvatures according to the curvatures respectively corresponding to the N positions in the preset curve section in the vehicle advancing direction includes:

acquiring N positions in a preset curve section from near to far from a preset electronic map according to the advancing direction of a vehicle;

obtaining N curvature speeds corresponding to the curvatures according to the curvatures respectively corresponding to the N positions;

and obtaining N upper limit speeds according to the N curvature speeds.

8. A vehicle-mounted terminal characterized by comprising:

the sampling unit is used for obtaining N upper limit speeds corresponding to curvatures according to the curvatures respectively corresponding to N positions in a preset curve road section in the advancing direction of the vehicle; wherein N is a natural number greater than 0;

the evaluation unit is used for evaluating the N upper limit speeds according to the current running information of the vehicle to obtain a target upper limit speed; acquiring an acceleration curve corresponding to the target upper limit speed;

and the control unit is used for controlling the vehicle to run according to the acceleration curve in the preset curve road section.

9. A vehicle-mounted terminal characterized by comprising:

a memory storing executable program code;

and a processor coupled to the memory;

the processor calls the executable program code stored in the memory, which when executed by the processor causes the processor to implement the method of any one of claims 1-7.

10. A computer-readable storage medium having executable program code stored thereon, wherein the executable program code, when executed by a processor, implements the method of any of claims 1-7.

11. A vehicle characterized in that it comprises the in-vehicle terminal of claim 8 or 9.

Background

Because the high-precision map can provide abundant information, especially the geometric information of the lane line, the automatic driving can deal with more problems, such as various complicated curve speed limits, based on the high-precision map.

In practice, the current curve speed limiting method generally determines the minimum driving speed on a future curve to drive, and the curve speed limiting mode is not flexible enough.

Disclosure of Invention

The embodiment of the application provides a curve speed limiting method, a vehicle-mounted terminal, a vehicle and a computer readable storage medium, which can realize flexible curve speed limiting.

The first aspect of the embodiment of the application provides a method for limiting speed of a curve, which comprises the following steps:

according to the curvatures respectively corresponding to N positions in a preset curve road section in the advancing direction of a vehicle, obtaining N upper limit speeds corresponding to the curvatures; wherein N is a natural number greater than 0;

evaluating the N upper limit speeds according to the current running information of the vehicle to obtain a target upper limit speed;

acquiring an acceleration curve corresponding to the target upper limit speed;

and controlling the vehicle to run according to the acceleration curve in the preset curve section.

As an optional implementation manner, in the first aspect of the embodiment of the present application, the evaluating the N upper limit speeds according to the current driving information of the vehicle to obtain the target upper limit speed includes:

determining the current upper limit speed to be evaluated from the N upper limit speeds, and performing at least one evaluation step on the current upper limit speed to be evaluated according to the current running information of the vehicle;

if the number of times of the evaluation step executed on the current upper limit speed to be evaluated does not reach the number of times corresponding to the first preset duration, taking the next upper limit speed as a new upper limit speed to be evaluated, and continuously executing the evaluation step of at least one time on the current upper limit speed to be evaluated according to the current running information of the vehicle;

and if the number of times of the evaluation step executed on the current to-be-evaluated upper limit speed reaches the number of times corresponding to the first preset time length, and the predicted position of the vehicle after the first preset time length is the tail end of the preset curved road section, determining that the current to-be-evaluated upper limit speed is the target upper limit speed.

As an optional implementation manner, in the first aspect of this embodiment of the present application, the N upper limit speeds are sequentially arranged from near to far according to the N positions, and the method further includes:

and if the number of times of the evaluation step executed on the current upper limit speed to be evaluated reaches the number of times corresponding to the first preset time length, and the predicted position of the vehicle after the first preset time length is not the tail end of the preset curved road section, taking the next upper limit speed as a new upper limit speed to be evaluated, and continuously executing the evaluation step of at least one time on the current upper limit speed to be evaluated according to the current driving information of the vehicle until the target upper limit speed is determined from the N upper limit speeds.

As an optional implementation manner, in the first aspect of the embodiment of the present application, the current driving information of the vehicle includes a speed, an acceleration, and a position at the current time, and the acceleration at the current time is related to an upper limit speed to be currently evaluated;

wherein, the step of evaluating the current upper limit speed to be evaluated at least once according to the current running information of the vehicle comprises the following steps:

obtaining the predicted speed and the predicted position at the next moment according to the current running information of the vehicle;

acquiring the curvature speed corresponding to the predicted position at the next moment;

when the predicted speed at the next moment is greater than the curvature speed corresponding to the predicted position at the next moment, determining that the current upper limit speed to be evaluated is not the target upper limit speed;

when the predicted speed at the next moment is less than or equal to the curvature speed corresponding to the predicted position at the next moment, taking the minimum one of the curvature speed corresponding to the predicted position at the next moment and the current upper limit speed to be evaluated as a first speed;

obtaining the predicted acceleration at the next moment according to the first speed and the speed at the current moment;

and taking the predicted speed, the predicted acceleration and the predicted position at the next moment as new current running information of the vehicle, and continuing to execute the step of obtaining the predicted speed and the predicted position at the next moment according to the current running information of the vehicle until the number of times of executing the evaluation step on the current upper limit speed to be evaluated reaches the number of times corresponding to the first preset time length.

As an optional implementation manner, in the first aspect of the embodiment of the present application, the obtaining a predicted acceleration at a next time according to the first speed and the speed at the current time includes:

obtaining a first acceleration according to the first speed and the speed at the current moment;

when the absolute value of the first acceleration is smaller than or equal to an acceleration threshold, determining that the first acceleration is a predicted acceleration at the next moment;

and when the absolute value of the first acceleration is larger than the acceleration threshold, determining the predicted acceleration at the next moment according to the acceleration threshold.

As an optional implementation manner, in the first aspect of the embodiment of the present application, when the current upper limit speed to be evaluated is the target upper limit speed, obtaining M predicted positions after the first preset time period, where the M predicted positions respectively correspond to M times, and the obtaining an acceleration curve corresponding to the target upper limit speed includes:

and obtaining an acceleration curve according to the predicted acceleration corresponding to each moment in the M moments.

As an alternative implementation, in the first aspect of the embodiments of the present application, the obtaining, according to curvatures respectively corresponding to N positions in a preset curve section in a vehicle advancing direction, N upper limit speeds corresponding to the curvatures includes:

acquiring N positions in a preset curve section from near to far from a preset electronic map according to the advancing direction of a vehicle;

obtaining N curvature speeds corresponding to the curvatures according to the curvatures respectively corresponding to the N positions;

and obtaining N upper limit speeds according to the N curvature speeds.

A second aspect of the embodiments of the present application provides a vehicle-mounted terminal, including:

the sampling unit is used for obtaining N upper limit speeds corresponding to curvatures according to the curvatures respectively corresponding to N positions in a preset curve road section in the advancing direction of the vehicle; wherein N is a natural number greater than 0;

the evaluation unit is used for evaluating the N upper limit speeds according to the current running information of the vehicle to obtain a target upper limit speed; acquiring an acceleration curve corresponding to the target upper limit speed;

and the control unit is used for controlling the vehicle to run according to the acceleration curve in the preset curve road section.

A third aspect of the embodiments of the present application provides a vehicle-mounted terminal, which may include:

a memory storing executable program code;

and a processor coupled to the memory;

the processor calls the executable program code stored in the memory, and when executed by the processor, the executable program code causes the processor to implement the method according to the first aspect of the embodiments of the present application.

A fourth aspect of embodiments of the present application provides a computer-readable storage medium, on which executable program code is stored, and when the executable program code is executed by a processor, the method according to the first aspect of embodiments of the present application is implemented.

A fifth aspect of embodiments of the present application discloses a computer program product, which, when run on a computer, causes the computer to perform any one of the methods disclosed in the first aspect of embodiments of the present application.

A sixth aspect of the present embodiment discloses an application publishing platform, configured to publish a computer program product, where when the computer program product runs on a computer, the computer is caused to execute any of the methods disclosed in the first aspect of the present embodiment.

A seventh aspect of embodiments of the present application discloses a vehicle that includes any of the in-vehicle terminals disclosed in the second and third aspects.

According to the technical scheme, the embodiment of the application has the following advantages:

in the embodiment of the application, firstly, according to the curvatures respectively corresponding to the N positions in the preset curve section in the advancing direction of the vehicle, N upper limit speeds corresponding to the curvatures are obtained, then, the N upper limit speeds are evaluated according to the current running information of the vehicle, a target upper limit speed is obtained, an acceleration curve corresponding to the target upper limit speed is obtained, and finally, in the preset curve section, the vehicle is controlled to run according to the acceleration curve. By implementing the method, the target upper limit speed can be obtained according to the current running information of the vehicle and the curvature of the preset curve road section, and then the vehicle is controlled to change speed to pass the curve by taking the target upper limit speed as the speed reference.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the embodiments and the drawings used in the description of the prior art, and obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained according to the drawings.

FIG. 1 is a schematic diagram of a scenario disclosed in an embodiment of the present application;

FIG. 2 is a flow chart diagram illustrating a curve speed limiting method disclosed in an embodiment of the present application;

FIG. 3 is a flow chart illustrating another method for limiting speed of a curve according to an embodiment of the present disclosure;

FIG. 4 is a schematic flowchart illustrating at least one evaluation step performed on the current upper limit speed to be evaluated according to an embodiment of the present disclosure;

FIG. 5 is a block diagram of an exemplary vehicle mounted terminal according to the disclosure;

fig. 6 is a block diagram of still another structure of the in-vehicle terminal disclosed in the embodiment of the present application;

fig. 7 is a block diagram of a vehicle according to an embodiment of the present application.

Detailed Description

The embodiment of the application provides a curve speed limiting method, a vehicle-mounted terminal, a vehicle and a computer readable storage medium, which can realize flexible curve speed limiting.

For a person skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments of the present application, and not all embodiments. The embodiments in the present application shall fall within the protection scope of the present application.

Referring to fig. 1, fig. 1 is a scene schematic diagram of a curve speed limiting method disclosed in an embodiment of the present application. The scene diagram shown in fig. 1 includes a vehicle 10 and a preset curve segment 20, before the vehicle 10 enters the preset curve segment 20, firstly, according to curvatures respectively corresponding to N positions in the preset curve segment 20 in a forward direction of the vehicle 10, N upper limit speeds corresponding to the curvatures are obtained, then, according to current driving information of the vehicle 10, the N upper limit speeds are evaluated, a target upper limit speed is obtained, an acceleration curve corresponding to the target upper limit speed is obtained, and finally, the vehicle 10 is controlled to drive on the preset curve segment 20 with an indication of the acceleration curve. By implementing the method, the vehicle 10 is controlled to run on the preset curve road section 20 at variable speed according to the current running information of the vehicle 10 and the curvatures of a plurality of position points on the preset curve road section 20, which is beneficial to improving the flexibility of curve speed limit.

Referring to fig. 2, fig. 2 is a schematic flow chart illustrating a curve speed limiting method according to an embodiment of the present application. The curve speed limiting method can be applied to a vehicle-mounted terminal on the vehicle 10, and can comprise the following steps:

201. and obtaining N upper limit speeds corresponding to the curvatures according to the curvatures respectively corresponding to N positions in the preset curve road section in the advancing direction of the vehicle.

In the embodiment of the application, N is a natural number greater than 0.

In some embodiments, the vehicle-mounted terminal may obtain, through a preset electronic map or by accessing a server, curvatures corresponding to N positions in a preset curved road section, where the curvatures refer to radians corresponding to the positions, and then obtain N upper limit speeds according to the curvatures corresponding to the N positions, respectively.

In some embodiments, a curvature speed table may be preset on the in-vehicle terminal, and the curvature speed table may include a plurality of curvature ranges and a curvature speed corresponding to each curvature range. Optionally, the vehicle-mounted terminal may first search target curvature ranges in which the curvatures of the N positions are located in the curvature speed table, and then use the curvature speed corresponding to the target curvature range as the upper limit speed of the corresponding position.

202. And evaluating the N upper limit speeds according to the current running information of the vehicle to obtain the target upper limit speed.

In the embodiment of the present application, the target upper limit speed is determined from the N upper limit speeds by evaluating the N upper limit speeds. The current traveling information of the vehicle may include at least a current speed, acceleration, position, and the like of the vehicle. The target upper limit speed may indicate an upper speed limit of the vehicle, that is, a maximum speed at which the vehicle travels on the preset curve section is less than or equal to the target upper limit speed.

In this embodiment of the application, the vehicle-mounted terminal may preset an evaluation condition, and if it is determined that any one of the N upper limit speeds meets the preset evaluation condition according to the current driving information of the vehicle, it is determined that the upper limit speed is the target upper limit speed, and otherwise, it is determined that the upper limit speed is not the target upper limit speed. Wherein the preset evaluation condition indicates that the vehicle can safely exit the preset curve section within a first preset time period.

203. And acquiring an acceleration curve corresponding to the target upper limit speed.

In the embodiment of the application, the acceleration curve reflects the speed change of the vehicle within the first preset time period when the target upper limit speed is taken as a reference. It should be noted that the first preset time length may be matched with a route of the preset curve road section, and may be determined based on the operation capability of the vehicle-mounted terminal, and it can be understood that the stronger the operation capability of the vehicle-mounted terminal is, the longer the first preset time length is, the longer the length of the preset curve road section is correspondingly.

In some embodiments, the first preset time period may include a plurality of acceleration periods, and the acceleration curve includes an acceleration corresponding to each acceleration period. For example, if the first preset time period is 5s and the acceleration period is 1s, the acceleration curve may include 5 acceleration periods, which are 0s-1s, 1s-2s, 2s-3s, 3s-4s, and 4s-5s, respectively. Wherein the acceleration of 0s-1s is a, the acceleration of 1s-2s is b, the acceleration of 2s-3s is c, the acceleration of 3s-4s is d, and the acceleration of 4s-5s is e.

204. And controlling the vehicle to run according to the acceleration curve in the preset curve section.

In some embodiments, the vehicle-mounted terminal may determine a target acceleration curve according to the acceleration corresponding to each acceleration period in the acceleration curve, and control the vehicle to run according to the corresponding acceleration in each acceleration period of the target acceleration curve. The number of acceleration cycles of the target acceleration curve is less than the number of cycles corresponding to the acceleration curve, the cycle duration of each acceleration cycle corresponding to the target acceleration curve is greater than the cycle duration of each acceleration cycle corresponding to the acceleration curve, and the second preset duration corresponding to the target acceleration curve is greater than the first preset duration. Illustratively, the second preset time period is 6s, wherein the acceleration of 0s-2s is f, the acceleration of 2s-4s is g, and the acceleration of 4s-6s is h. For example, the vehicle is controlled to travel at an acceleration f within 0s-2s, at an acceleration g within 2s-4s, and at an acceleration h within 4s-6 s.

In some embodiments, the in-vehicle terminal may control the vehicle to travel at a corresponding acceleration in each acceleration period of the above-described acceleration curve. Illustratively, the vehicle is controlled to run with an acceleration a within 0s-1s, an acceleration b within 1s-2s, an acceleration c within 2s-3s, an acceleration d within 3s-4s, and an acceleration e within 4s-5 s.

By implementing the method, different preset curve road sections can correspond to the same or different target upper limit speeds, and the target upper limit speed of each preset curve road section can be obtained by calculation according to the curvatures of N position points on the preset curve road sections. By dividing a curve into a plurality of preset curve road sections, the target upper limit speed can be adjusted in real time according to the specific conditions of the curve, so that the curve speed limiting mode is more flexible and more accurate.

Referring to fig. 3, fig. 3 is a schematic flow chart illustrating another curve speed limiting method disclosed in the embodiment of the present application. The curve speed limiting method can comprise the following steps:

301. and acquiring N positions in the preset curve road section from the near to the far from the preset electronic map according to the advancing direction of the vehicle.

In the embodiment of the application, the curvatures corresponding to the N positions in the preset curve road section obtained from near to far are gradually increased. For example, referring to fig. 1, the predetermined curve segment in fig. 1 includes a position a0, a position a1, and a position A3, wherein the curvature of the position a0 is smaller than the curvature of the position a1, and the curvature of the position a1 is smaller than the curvature of the position A3.

302. Obtaining N curvature speeds corresponding to the curvatures according to the curvatures respectively corresponding to the N positions, and obtaining N upper limit speeds according to the N curvature speeds, wherein the N upper limit speeds are sequentially arranged according to the sequence of the N positions from near to far.

In some embodiments, the N curvature speeds may be taken as the N upper limit speeds. The curvature and the curvature speed can be in a negative correlation relationship, and the larger the curvature of the position, the smaller the corresponding curvature speed. Since the curvature corresponding to the N positions is gradually increased, and the N upper limit speeds are sequentially arranged from near to far according to the N positions, the N upper limit speeds are gradually decreased.

303. And determining the current upper limit speed to be evaluated from the N upper limit speeds.

In some embodiments, the vehicle-mounted terminal may sequentially evaluate the N upper limit speeds from a larger upper limit speed, and this evaluation may make the determined target upper limit speed as large as possible. Since the speed of the vehicle in the preset curve road section is determined by taking the target upper limit speed as a reference speed, the target upper limit speed is ensured to be as large as possible, and the driving speed of the vehicle in the preset curve road section is favorably improved.

304. And performing at least one evaluation step on the upper limit speed to be evaluated currently according to the current running information of the vehicle.

It should be noted that, if the current upper limit speed to be evaluated does not meet the preset evaluation condition in any evaluation step, the next upper limit speed may be used as the current upper limit speed to be evaluated. The preset evaluation condition is used for evaluating whether the vehicle can safely drive out of the preset curve road section within a first preset time length when the running speed of the vehicle is controlled by taking the upper limit speed to be evaluated at present as a target upper limit speed.

305. And judging whether the number of times of the evaluation step executed on the current upper limit speed to be evaluated reaches the number of times corresponding to the first preset time length, if so, executing a step 307, and if not, executing a step 306.

In the embodiment of the present application, the number of times corresponding to the first preset time period is the same as the number of acceleration cycles, that is, one evaluation step may determine the acceleration corresponding to one acceleration cycle. It is understood that the time interval between the current time and the next time corresponding to one evaluation step may be the cycle time of the acceleration cycle.

In some embodiments, when the evaluation number of times does not reach the number of times corresponding to the first preset duration, if the acceleration corresponding to the next time is obtained through one evaluation step, it is determined that the upper limit speed to be evaluated currently can be subjected to the next evaluation step, and otherwise, step 306 is executed.

306. The next upper limit speed is taken as the new upper limit speed to be evaluated, and the process continues to step 304.

307. Judging whether the predicted position of the vehicle after the first preset time length is the tail end of the preset curve road section or not, if so, executing a step 308; if not, go to step 306.

In some embodiments, the step of successfully performing the evaluation once on the current upper limit speed to be evaluated may obtain a predicted position of the vehicle at the next time, in addition to the acceleration at the next time, that is, if the step of successfully performing the evaluation for the number of times corresponding to the first preset duration on the current upper limit speed to be evaluated is performed, the predicted position of the vehicle after the first preset duration may be determined, and if the predicted position of the vehicle after the first preset duration is the end of the preset curved road segment, it is determined that the vehicle may safely drive out of the preset curved road segment by using the current upper limit speed to be evaluated as the target upper limit speed.

308. And determining the current upper limit speed to be evaluated as the target upper limit speed.

309. And acquiring an acceleration curve corresponding to the target upper limit speed.

In the examples of the present application. When the number of times of the evaluation step executed for the current upper limit speed to be evaluated reaches the number of times corresponding to the first preset time length, the number of the accelerated speeds determined by the vehicle-mounted terminal through executing the evaluation step is the same as the number of times corresponding to the first preset time length. Because the curvatures corresponding to the N positions in the preset curve section are gradually increased, in order to ensure that the vehicle can safely pass a curve at a high speed, the vehicle needs to be decelerated continuously in the process of running on the preset curve section, that is, the acceleration curve reflects the deceleration condition of the vehicle within the first preset duration when the target upper limit speed is taken as a reference.

310. And controlling the vehicle to run according to the acceleration curve in the preset curve section.

For the description of step 310, please refer to the introduction of step 204 in fig. 2, which is not described herein again.

In the embodiment of the application, on one hand, the vehicle-mounted terminal sequentially evaluates the N upper limit speeds from a larger upper limit speed, so that the determined target upper limit speed is as large as possible, which is favorable for improving the running speed of the vehicle in the preset curve road section. On the other hand, when the number of times of the evaluation step executed for the current upper limit speed to be evaluated reaches the number of times corresponding to the first preset time length, and the predicted position of the vehicle after the first preset time length is the end of the preset curve section, it can be ensured that the vehicle safely drives out of the preset curve section. Therefore, the safe and high-speed curve speed limit can be realized by implementing the method.

In some embodiments, the acceleration at the present time included in the current running information of the vehicle is correlated with the upper limit speed to be currently evaluated; the step of performing, by the vehicle-mounted terminal, at least one evaluation on the current upper limit speed to be evaluated according to the current driving information of the vehicle may include the steps of:

401. and obtaining the predicted speed and the predicted position at the next moment according to the current running information of the vehicle.

In the embodiment of the present application, the current driving information of the vehicle-mounted terminal may include a speed V0, an acceleration a0, and a position a1 at the current time of the vehicle, where the interval duration between the current time and the next time is t, the predicted speed V1 at the next time is V0+ a0 × t, the position a2 at the next time may be obtained from the position a1 at the current time and the distance S1 traveled by the vehicle within the duration t, and the distance S1 traveled by the vehicle within the duration t is V0 × t +1/2 × a0 × t ^ 2.

402. And acquiring the curvature speed corresponding to the predicted position at the next moment.

In some embodiments, a position curve table may be preset in the vehicle-mounted terminal, where coordinates and curvatures corresponding to respective positions in a preset curve section are recorded in the position curve table, and the vehicle-mounted terminal obtains a target coordinate corresponding to a predicted position at a next time, and then searches the curvature corresponding to the target coordinate in the position curve table, so as to search a curvature speed corresponding to the predicted position at the next time from a curvature speed table.

403. And when the predicted speed at the next moment is greater than the curvature speed corresponding to the predicted position at the next moment, determining that the current upper limit speed to be evaluated is not the target upper limit speed.

It should be noted that, if the vehicle needs to safely pass through the predicted position at the next time, the predicted speed of the vehicle at the next time needs to be less than or equal to the curvature speed corresponding to the predicted position at the next time, and if the predicted speed is greater than the curvature speed, the vehicle cannot safely pass through the predicted position at the next time, and the overbending with the upper limit speed to be currently evaluated as the speed limit reference fails.

404. And when the predicted speed at the next moment is less than or equal to the curvature speed corresponding to the predicted position at the next moment, taking the minimum of the curvature speed corresponding to the predicted position at the next moment and the current upper limit speed to be evaluated as the first speed.

405. And obtaining the predicted acceleration at the next moment according to the first speed and the speed at the current moment.

For example, if V2 is equal to or less than V1, the first speed is V2, and the predicted acceleration a1 at the next time is (V2-V0)/t, of the curvature speed V2 corresponding to the predicted position at the next time. If V2 is greater than V1, the first speed is V1, and the predicted acceleration a1 at the next time is (V1-V0)/t.

It should be noted that steps 401 to 405 are a single evaluation step.

406. Judging whether the number of times of the evaluation step executed on the current upper limit speed to be evaluated reaches the number of times corresponding to the first preset time length, if so, ending the circulation; if not, go to step 407.

407. The predicted speed, the predicted acceleration, and the predicted position at the next time are taken as new current traveling information of the vehicle, and the process proceeds to step 401.

The current curve speed limiting method usually determines a fixed driving speed according to the maximum curvature of the curve to drive, that is, when the existing curve speed limiting method is used to control the vehicle to drive out of the preset curve section, the vehicle is controlled to drive at a constant speed at the minimum upper limit speed of the N upper limit speeds, which often results in that the speed of the vehicle in the preset curve section is too low, and the user experience is not good.

In the embodiment of the present invention, the speed reduction amount of the vehicle in the next deceleration cycle is determined based on the smallest one of the target upper limit speed and the curvature speed corresponding to the predicted position at the present time, and since the target upper limit speed is as large as possible, the smallest one of the target upper limit speed and the curvature speed corresponding to the predicted position at the present time is usually larger than the smallest upper limit speed among the N upper limit speeds, and thus the speed reduction amount of the vehicle in the next deceleration cycle is often small. Therefore, compared with the constant speed curve passing at the minimum upper limit speed, the vehicle-mounted terminal periodically adjusts the running speed of the vehicle according to the curvature of the preset curve road section and the target upper limit speed, so that the running speed of the vehicle is ensured to be as large as possible on the premise of safe running, and the safe and high-speed curve speed limit is realized.

Furthermore, the curve speed limiting method is simple in calculation method and occupies relatively few calculation resources, so that the vehicle-mounted terminal is high in calculation efficiency and high in real-time performance, and the success rate of safe and high-speed bending is further improved.

In some embodiments, obtaining the predicted acceleration at the next time according to the first speed and the speed at the current time by the vehicle-mounted terminal may include: obtaining a first acceleration according to the first speed and the speed at the current moment; when the absolute value of the first acceleration is smaller than or equal to the acceleration threshold, determining that the first acceleration is the predicted acceleration at the next moment; and when the absolute value of the first acceleration is larger than the acceleration threshold, determining the predicted acceleration at the next moment according to the acceleration threshold.

In summary, in the embodiment of the present application, the first acceleration is a negative value, and in some embodiments, when the absolute value of the first acceleration is greater than the acceleration threshold, the negative acceleration threshold may be used as the predicted acceleration at the next time.

In the embodiment of the present application, the acceleration threshold may be a positive number, and the acceleration threshold may be used to measure whether the first acceleration is comfortable acceleration, specifically, if the absolute value of the first acceleration is less than or equal to the acceleration threshold, the first acceleration is a comfortable acceleration, otherwise, the first acceleration is an uncomfortable acceleration. Alternatively, the acceleration threshold may be measured by a number of experiments.

In this application embodiment, when calculating the acceleration at the next moment, regard the comfort level of acceleration as one of the considerations, can make the vehicle slow down when crossing the curve more laminate user's actual demand, be favorable to further improving user's the experience of crossing the curve.

In some embodiments, when the current upper limit speed to be evaluated is the target upper limit speed, obtaining M predicted positions after a first preset time period, where the M predicted positions correspond to M times, respectively, and the obtaining, by the vehicle-mounted terminal, an acceleration curve corresponding to the target upper limit speed may include: and obtaining an acceleration curve according to the predicted acceleration corresponding to each moment in the M moments. It should be noted that, what is indicated by M may be the number of times that the first preset duration corresponds to the execution of the evaluation step, one evaluation step may obtain a predicted position at a time and a predicted acceleration of the acceleration cycle with the time as a starting time point, and the mth predicted position is the end of the preset curved road segment.

By implementing the method, the vehicle-mounted terminal directly obtains the acceleration curve of the vehicle within the first preset time length according to each predicted acceleration obtained in the evaluation step, resampling and obtaining by the vehicle-mounted terminal are not needed, and the curve speed-limiting efficiency of the vehicle is improved.

Referring to fig. 5, fig. 5 is a block diagram of a structure of a vehicle-mounted terminal according to the disclosure. As shown in fig. 5, the in-vehicle terminal may include: a sampling unit 501, an evaluation unit 502 and a control unit 603. Wherein:

the sampling unit 501 is configured to obtain N upper limit speeds corresponding to curvatures according to the curvatures respectively corresponding to N positions in a preset curve road section in the vehicle advancing direction; wherein N is a natural number greater than 0;

an evaluation unit 502, configured to evaluate the N upper limit speeds according to current driving information of the vehicle, so as to obtain a target upper limit speed; acquiring an acceleration curve corresponding to the target upper limit speed;

a control unit 503 for controlling the vehicle to travel according to the acceleration curve in a preset curve section.

In some embodiments, the evaluation unit 502 is configured to evaluate the N upper limit speeds according to the current driving information of the vehicle, and the manner of obtaining the target upper limit speed may specifically include:

an evaluation unit 502, configured to determine a current upper limit speed to be evaluated from the N upper limit speeds, and perform at least one evaluation step on the current upper limit speed to be evaluated according to current driving information of the vehicle; if the number of times of the evaluation step executed on the current upper limit speed to be evaluated does not reach the number of times corresponding to the first preset duration, taking the next upper limit speed as a new upper limit speed to be evaluated, and continuously executing at least one evaluation step on the current upper limit speed to be evaluated according to the current running information of the vehicle; and if the number of times of the evaluation step executed on the current upper limit speed to be evaluated reaches the number of times corresponding to the first preset time length, and the predicted position of the vehicle after the first preset time length is the tail end of the preset curved road section, determining that the current upper limit speed to be evaluated is the target upper limit speed.

In some embodiments, the N upper limit speeds are arranged in order from near to far of the N positions;

further, the evaluation unit 502 is further configured to, if the number of times of the evaluation step performed on the current upper limit speed to be evaluated reaches the number of times corresponding to the first preset time duration, and the predicted position of the vehicle after the first preset time duration is not the end of the preset curved road segment, take the next upper limit speed as a new upper limit speed to be evaluated, and continue to perform the above-mentioned evaluation step at least once on the current upper limit speed to be evaluated according to the current driving information of the vehicle until the target upper limit speed is determined from the N upper limit speeds.

In some embodiments, the current travel information of the vehicle includes a speed, an acceleration, and a position at the current time, and the acceleration at the current time is related to an upper limit speed to be currently evaluated; the manner of the evaluation unit 502 for performing an evaluation step once on the current upper limit speed to be evaluated may specifically include: an evaluation unit 502, configured to obtain a predicted speed and a predicted position at a next time according to current driving information of the vehicle; acquiring curvature speed corresponding to the predicted position at the next moment; when the predicted speed at the next moment is greater than the curvature speed corresponding to the predicted position at the next moment, determining that the current upper limit speed to be evaluated is not the target upper limit speed; when the predicted speed at the next moment is less than or equal to the curvature speed corresponding to the predicted position at the next moment, taking the minimum one of the curvature speed corresponding to the predicted position at the next moment and the current upper limit speed to be evaluated as a first speed; obtaining the predicted acceleration at the next moment according to the first speed and the speed at the current moment; and taking the predicted speed, the predicted acceleration and the predicted position at the next moment as new current running information of the vehicle, and continuously executing the step of obtaining the predicted speed and the predicted position at the next moment according to the current running information of the vehicle until the number of times of executing the evaluation step on the current upper limit speed to be evaluated reaches the number of times corresponding to the first preset duration.

In some embodiments, the manner for the evaluation unit 502 to obtain the predicted acceleration at the next time according to the first speed and the speed at the current time may specifically include: an evaluation unit 502, configured to obtain a first acceleration according to the first speed and the speed at the current time; when the absolute value of the first acceleration is smaller than or equal to the acceleration threshold, determining that the first acceleration is the predicted acceleration at the next moment; and when the absolute value of the first acceleration is larger than the acceleration threshold, determining the predicted acceleration at the next moment according to the acceleration threshold.

In some embodiments, when the current upper limit speed to be evaluated is the target upper limit speed, M predicted positions are obtained after a first preset time period, where the M predicted positions correspond to M times, respectively, and a manner that the evaluation unit 502 is used to obtain an acceleration curve corresponding to the target upper limit speed may specifically include: the evaluation unit 502 is configured to obtain an acceleration curve according to the predicted acceleration corresponding to each of the M moments.

Referring to fig. 6, fig. 6 is a block diagram of another structure of the in-vehicle terminal disclosed in the embodiment of the present application. The in-vehicle terminal shown in fig. 6 includes: a processor 601 and a memory 602.

The processor 601 has the following functions:

according to the curvatures respectively corresponding to N positions in a preset curve road section in the advancing direction of the vehicle, obtaining N upper limit speeds corresponding to the curvatures; wherein N is a natural number greater than 0;

evaluating the N upper limit speeds according to the current running information of the vehicle to obtain a target upper limit speed; acquiring an acceleration curve corresponding to the target upper limit speed;

and controlling the vehicle to run according to the acceleration curve in a preset curve section.

In some embodiments, the processor 601 also has the following functions:

determining the current upper limit speed to be evaluated from the N upper limit speeds, and performing at least one evaluation step on the current upper limit speed to be evaluated according to the current running information of the vehicle;

if the number of times of the evaluation step executed on the current upper limit speed to be evaluated does not reach the number of times corresponding to the first preset duration, taking the next upper limit speed as a new upper limit speed to be evaluated, and continuously executing the evaluation step of at least one time on the current upper limit speed to be evaluated according to the current running information of the vehicle;

and if the number of times of the evaluation step executed on the current upper limit speed to be evaluated reaches the number of times corresponding to the first preset time length, and the predicted position of the vehicle after the first preset time length is the tail end of the preset curved road section, determining that the current upper limit speed to be evaluated is the target upper limit speed.

In some embodiments, the N upper limit speeds are arranged in order from near to far of the N positions;

the processor 601 also has the following functions:

and if the number of times of the evaluation step executed on the current upper limit speed to be evaluated reaches the number of times corresponding to the first preset time length, and the predicted position of the vehicle after the first preset time length is not the tail end of the preset curved road section, taking the next upper limit speed as the new current upper limit speed to be evaluated, and continuously executing the evaluation step for at least one time on the current upper limit speed to be evaluated according to the current running information of the vehicle until the target upper limit speed is determined from the N upper limit speeds.

In some embodiments, the current driving information of the vehicle may include a speed, an acceleration, and a position at the current time, and the acceleration at the current time is related to an upper limit speed to be currently evaluated; the processor 601 also has the following functions:

obtaining the predicted speed and the predicted position at the next moment according to the current running information of the vehicle; acquiring curvature speed corresponding to the predicted position at the next moment; when the predicted speed at the next moment is greater than the curvature speed corresponding to the predicted position at the next moment, determining that the current upper limit speed to be evaluated is not the target upper limit speed; when the predicted speed at the next moment is less than or equal to the curvature speed corresponding to the predicted position at the next moment, taking the minimum one of the curvature speed corresponding to the predicted position at the next moment and the current upper limit speed to be evaluated as a first speed; obtaining the predicted acceleration at the next moment according to the first speed and the speed at the current moment; and taking the predicted speed, the predicted acceleration and the predicted position at the next moment as new current running information of the vehicle, and continuously executing the step of obtaining the predicted speed and the predicted position at the next moment according to the current running information of the vehicle until the number of times of executing the evaluation step on the current upper limit speed to be evaluated reaches the number of times corresponding to the first preset duration.

In some embodiments, the processor 601 also has the following functions:

obtaining a first acceleration according to the first speed and the speed at the current moment; when the absolute value of the first acceleration is smaller than or equal to the acceleration threshold, determining that the first acceleration is the predicted acceleration at the next moment; and when the absolute value of the first acceleration is larger than the acceleration threshold, determining the predicted acceleration at the next moment according to the acceleration threshold.

In some embodiments, when the current upper limit speed to be evaluated is the target upper limit speed, obtaining M predicted positions after the first preset time period, where the M predicted positions correspond to M moments respectively; the processor 601 also has the following functions:

and obtaining an acceleration curve according to the predicted acceleration corresponding to each moment in the M moments.

The memory 602 has the following functions:

the processing procedure and the processing result of the processor 601 are stored.

An embodiment of the application discloses a computer-readable storage medium storing a computer program, which when executed by a processor implements any one of the above-described method embodiments.

Embodiments of the present application disclose a computer program product comprising a non-transitory computer readable storage medium storing a computer program, and the computer program is operable to cause a computer to perform any of the above method embodiments.

The embodiment of the application discloses an application publishing platform, wherein the application publishing platform is used for publishing a computer program product, and when the computer program product runs on a computer, the computer is enabled to execute any method in the method embodiments.

The embodiment of the application discloses a vehicle, and the vehicle comprises the vehicle-mounted terminal.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product.

The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the application to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website site, computer, server, or data center to another website site, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that a computer can store or a data storage device, such as a server, a data center, etc., that is integrated with one or more available media. The usable medium may be a magnetic medium (e.g., floppy Disk, hard Disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

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 units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be substantially implemented or contributed to by the prior art, or all or part of the technical solution may be embodied in a software product, which is stored in a storage medium and includes instructions for causing a computer device (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 application. And the aforementioned storage medium includes: various media capable of storing 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 embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.