WO2021147307A1 - Vehicle adaptive cruise control method and apparatus - Google Patents

Abstract

Disclosed is a vehicle adaptive cruise control method, comprising: acquiring the vehicle speed before speed changing, the vehicle speed after speed changing and a speed changing distance of a vehicle at each speed changing position; calculating a variable speed at each speed changing position according to the vehicle speed before speed changing, the vehicle speed after speed changing and the speed changing distance; calculating a first numerical value according to the variable speed and the speed changing distance; determining a vehicle following time distance of the vehicle at each speed changing position according to the correlation between first numerical values and vehicle following time distances, and determining a vehicle following time distance corresponding to the most first numerical values as the vehicle following time distance of the vehicle; and adjusting a travelling speed by using the vehicle following time distance of the vehicle.

Description

Vehicle adaptive cruise control method and device Technical field

The invention relates to the technical field of vehicle automatic control, in particular to a vehicle adaptive cruise control method and device.

Background technique

Adaptive Cruise Control (ACC) is an intelligent automatic control technology, which combines safe distance keeping control on the basis of traditional cruise control, and monitors the forward driving environment through the environmental information perception module. When the vehicle or the vehicle in front is far beyond the safe distance to cruise at a preset speed, and the vehicle in front is within the monitoring range and the speed of the vehicle in front is less than the cruising speed, it will automatically follow the vehicle in front by a certain control strategy. Among them, when following the preceding vehicle, it is mainly used to adjust the vehicle speed according to the following time distance when the safety distance of the vehicle is certain, so as to realize the control of the vehicle speed. In the prior art, the follow-up time is usually a preset fixed value. During specific operations, the driver can input by himself. This makes the setting of the follow-up time not take into account the changes in the performance of the vehicle itself. The impact of the vehicle effect, which in turn leads to vehicle control that does not meet the actual operation needs, and there is a safety risk.

Summary of the invention

In order to solve the problems of the prior art, embodiments of the present invention provide a vehicle adaptive cruise control method and device. The technical solution is as follows:

In one aspect, a vehicle adaptive cruise control method is provided, and the method includes:

Obtain the vehicle speed before shifting, the speed after shifting, and the shifting distance of the vehicle at each shifting position;

Calculating the variable speed of each of the shift positions according to the vehicle speed before the shift, the vehicle speed after the shift, and the shift distance;

Calculating a first value according to the variable speed and the variable speed distance;

Determine the following time distance of the vehicle at each of the shift positions according to the corresponding relationship between the first value and the following time distance, and determine the following time distance corresponding to the first value at most as the vehicle's following time distance. Car time

The driving speed is adjusted by using the following time distance of the vehicle.

Further, the first value is a weighted sum of the variable speed and the variable speed distance.

Further, each of the shift positions includes position information when the shift is started and position information when the shift is ended on different road sections.

Further, the method further includes: when the number of the first values greater than the preset threshold exceeds the preset number, sending a prompt message to remind the user to turn off the automatic transmission function.

In another aspect, an adaptive cruise control device for a vehicle is provided, and the device includes:

The parameter acquisition module is used to acquire the vehicle speed before shifting, the vehicle speed after shifting and the shifting distance of the vehicle at each shifting position;

A calculation module, configured to calculate the variable speed of each of the shift positions according to the vehicle speed before the shift, the vehicle speed after the shift, and the shift distance, and to calculate the first value based on the variable speed and the shift distance;

The vehicle-following time distance determination module is used to determine the vehicle-following time distance at each of the shifting positions according to the corresponding relationship between the first value and the vehicle-following time distance, and follow the vehicle corresponding to the most first value The time distance is determined as the following time distance of the vehicle;

The speed control module is used to adjust the driving speed by using the following time distance of the vehicle.

Further, the first value is a weighted sum of the variable speed and the variable speed distance.

Further, each of the shift positions includes position information when the shift is started and position information when the shift is ended on different road sections.

Further, the device further includes:

The prompt module is configured to send a prompt message to remind the user to turn off the automatic transmission function when the number of the first numerical values that are greater than the preset threshold exceeds the preset number.

The beneficial effects brought about by the technical solutions provided by the embodiments of the present invention are:

1. The vehicle adaptive cruise control method and device disclosed in the present invention obtain the following time distance of the vehicle at different shift positions, and determine the following time distance corresponding to the first value at the most shift position as the current following vehicle of the vehicle Time distance, in determining the time distance to follow the car, taking into account the impact of vehicle performance changes on the following effect, adjust the vehicle speed according to the current time distance to follow the car, improving the safety and driving experience of the user's driving;

2. The vehicle adaptive cruise control method and device disclosed in the present invention judge the warning signal by the number of the first value greater than the preset threshold. When the vehicle condition is not suitable for the adaptive cruise system, other vehicle users can be reminded in time Turn off adaptive cruise and change to manual control.

Description of the drawings

In order to explain the technical solutions in the embodiments of the present invention more clearly, the following will briefly introduce the drawings needed in the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work.

Fig. 1 is a flowchart of a vehicle adaptive cruise control method provided by an embodiment of the present invention;

Fig. 2 is a schematic diagram of a module structure of a vehicle adaptive cruise control device provided by an embodiment of the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only Part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

Adaptive cruise is a vehicle automatic control technology that allows the vehicle cruise control system to adjust the speed of the vehicle to adapt to the traffic conditions. The main principle is: the travel speed of the vehicle in front is detected by the radar installed in front of the vehicle, and the travel speed of the self-vehicle is adjusted according to the preset safety distance and the following distance. The following time distance, also known as the headway time, refers to the time interval between two consecutive car head ends passing through a certain end surface in a queue of vehicles driving in the same lane, and the relationship between the following time distance, the following distance and the vehicle speed Expressed by the following formula:

Following distance = following distance × vehicle speed

According to the above formula, in the prior art, the vehicle speed is adjusted by the following distance and the preset following time distance. However, it is difficult to reflect the influence of the change in vehicle performance on the following effect by the preset fixed following time distance. The outgoing vehicle speed does not match the actual demand, resulting in a situation where the actual following distance is less than the safe following distance, and there is a risk of rear-end collision, or the following distance is too large, which affects the speed of the vehicle.

Therefore, in order to solve the above technical problems, the embodiments of the present invention disclose a vehicle adaptive cruise control method and device. The specific technical solutions are as follows.

Example 1

As shown in Figure 1, a vehicle adaptive cruise control method is provided, including:

S1. Obtain the vehicle speed before shifting, the speed after shifting and the shifting distance of the vehicle at each shift position;

S2. Calculate the variable speed of each shift position according to the vehicle speed before the shift, the vehicle speed after the shift and the shift distance;

S3. Calculate the first value according to the variable speed and the variable speed distance;

S4. Determine the following time distance of the vehicle at each shift position according to the corresponding relationship between the first value and the following time distance, and determine the following time distance corresponding to the most first value as the following time distance of the vehicle;

S5. Use the following time distance of the vehicle to adjust the driving speed.

In the above method, it should be noted that the vehicle speed before shifting in step S1 usually refers to the vehicle speed at the start of shifting, the vehicle speed after shifting usually refers to the vehicle speed at the end of shifting, and the shifting distance usually refers to the distance between the starting shifting position and the ending shifting position. The shift position usually includes: the vehicle position information when the shift is started and the vehicle position information when the shift is ended, two position information. The speed change in the method includes: acceleration or deceleration, and correspondingly, the speed change in step S2 includes: acceleration or deceleration. The first value is the weighted sum of the variable speed and the variable speed distance. Corresponding to the two situations of shifting, the calculation method of the first value in steps S3 and S4 and the determination method of the following time distance include two situations:

Case 1, the impact of vehicle deceleration performance on the following time distance on a certain road section

The calculation of the first value specifically includes the following formula:

s _minus = K ₁ a _minus + K ₂ x

Among them, s is _reduced to the first value when the vehicle is decelerating, a is _reduced to the variable speed, x is the variable speed distance, K ₁ and K ₂ are the weight values of variable speed a _minus and the variable speed distance x respectively. The value can be taken based on experience Value, or machine learning determination based on sample data, the specific determination method is not limited in the embodiment of the present invention, and the values of K ₁ and K ₂ may be (0, 1).

The corresponding relationship between the first value and the following time distance can be: a value range of the first value corresponds to one following time distance, for example, when s _minus ∈[s ₁ ,s ₂ ], the corresponding time distance τ Is τ ₁ , or when s _minus ∈ [s ₁ , s ₂ ], the corresponding following time distance is s _{1 and the} corresponding following time distance τ is τ ₁ , and so on.

Case two, the impact of vehicle acceleration performance on the following time distance on a certain road section

The calculation of the first value specifically includes the following formula:

s _plus = K ₃ a _plus + K ₄ x

Among them, s _plus is the first value when the vehicle is decelerating, a _plus is the variable speed, x is the variable speed distance, K ₃ and K ₄ are the weight values of variable speed a _plus and the variable speed distance x respectively, and the value can be taken based on experience Value, or machine learning determination based on sample data, the specific determination method is not limited in the embodiment of the present invention, and the values of K ₃ and K ₄ may be (0, 1).

The corresponding relationship between the first value and the following time distance can be: a value range of the first value corresponds to one following time distance, for example, when s is _{added to} ∈[s ₁ ,s ₂ ], the corresponding following time distance τ Is τ ₁ , or when s is _{added to} ε[s ₁ ,s ₂ ], the corresponding time _{distance τ is s 1 and} the time distance τ is τ ₁ , and so on.

After calculating the first value of each road segment and the corresponding time distance for the vehicle, the following time distance corresponding to the first value with the largest number is determined to be the time distance for the vehicle. For example: calculated the first value of the vehicle at 10 shift positions and its corresponding follow-up time. Among them, 8 of the first values correspond to the follow-up time τ ₁ , then determine τ ₁ as the vehicle’s follow-up time. Car time.

In step S5, the driving speed is adjusted by using the following time distance of the vehicle, which can be adjusted according to the following formula:

c=τv

Among them, c is the following distance, τ is the following time, and v is the speed of the vehicle.

When a certain following distance c is satisfied, the vehicle speed v is adjusted according to the following time distance τ.

Further, there is a situation when the number of the first values greater than the preset threshold exceeds the preset number. At this time, the performance of the vehicle is poor, which may cause the vehicle to lose control. Therefore, the method disclosed in the embodiment of the present invention further includes:

S6. When the number of the first values greater than the preset threshold exceeds the preset number, a prompt message is sent to remind the user to turn off the automatic transmission function and change to manual control. For example, assuming that the preset number is 5, the first value of the vehicle at 10 shift positions and its corresponding follow-up time are calculated. Among them, there are 8 first values corresponding to the pre-determined follow-up time exceeding the first value. Set the threshold s _n , and then send a prompt message.

Example 2

As shown in Figure 2, this embodiment discloses an adaptive cruise control device for a vehicle on the basis of Embodiment 1, including:

The parameter acquisition module is used to acquire the vehicle speed before shifting, the vehicle speed after shifting and the shifting distance of the vehicle at each shifting position;

The calculation module is used to calculate the variable speed of each variable speed position according to the vehicle speed before the shift, the vehicle speed after the shift and the shift distance, and to calculate the first value according to the variable speed and the shift distance;

The following time distance determination module is used to determine the following time distance of the vehicle at each shift position according to the corresponding relationship between the first value and the following time distance, and determine the following time distance corresponding to the most first value as the following time distance of the vehicle Time span

The speed control module is used to adjust the driving speed by using the following time distance of the vehicle.

In the above device, it should be noted that the parameter acquisition module includes: a speed measurement module, a positioning module, and a distance measurement module. The acquired vehicle speed before shifting usually refers to the vehicle speed at the start of shifting, and the vehicle speed after shifting usually refers to the vehicle speed at the end of shifting. Distance usually refers to the distance between the start and end shift positions, and the shift position usually includes: vehicle position information when starting the shift and vehicle position information when ending the shift, two position information.

The calculation module includes two situations when calculating the variable speed and the first value:

Case 1, the impact of vehicle deceleration performance on the following time distance on a certain road section

The calculation of the first value specifically includes the following formula:

s _minus = K ₁ a _minus + K ₂ x

Among them, s is _reduced to the first value when the vehicle is decelerating, a is _reduced to the variable speed, x is the variable speed distance, K ₁ and K ₂ are the weight values of variable speed a _minus and the variable speed distance x respectively. The value can be taken based on experience Value, or machine learning determination based on sample data, the specific determination method is not limited in the embodiment of the present invention, and the values of K ₁ and K ₂ may be (0, 1).

The corresponding relationship between the first value and the following time distance can be: a value range of the first value corresponds to one following time distance, for example, when s _minus ∈[s ₁ ,s ₂ ], the corresponding time distance τ Is τ ₁ , or when s _minus ∈ [s ₁ , s ₂ ], the corresponding following time distance is s _{1 and the} corresponding following time distance τ is τ ₁ , and so on.

Case two, the impact of vehicle acceleration performance on the following time distance on a certain road section

The calculation of the first value specifically includes the following formula:

s _plus = K ₃ a _plus + K ₄ x

Among them, s _plus is the first value when the vehicle is decelerating, a _plus is the variable speed, x is the variable speed distance, K ₃ and K ₄ are the weight values of variable speed a _plus and the variable speed distance x respectively, and the value can be taken based on experience Value, or machine learning determination based on sample data, the specific determination method is not limited in the embodiment of the present invention, and the values of K ₃ and K ₄ may be (0, 1).

The corresponding relationship between the first value and the following time distance can be: a value range of the first value corresponds to one following time distance, for example, when s is _{added to} ∈[s ₁ ,s ₂ ], the corresponding following time distance τ Is τ ₁ , or when s is _{added to} ε[s ₁ ,s ₂ ], the corresponding time _{distance τ is s 1 and} the time distance τ is τ ₁ , and so on.

After the vehicle-following time distance determination module calculates the first value of each road segment and the corresponding vehicle-following time distance, it determines that the vehicle-following time distance corresponding to the most numerous first value is the vehicle's follow-up time distance. For example: calculated the first value of the vehicle at 10 shift positions and its corresponding follow-up time. Among them, 8 of the first values correspond to the follow-up time τ ₁ , then determine τ ₁ as the vehicle’s follow-up time. Car time.

The speed control module uses the following time distance of the vehicle to adjust the driving speed, which can be adjusted according to the following formula:

c=τv

Among them, c is the following distance, τ is the following time, and v is the speed of the vehicle.

When a certain following distance c is satisfied, the vehicle speed v is adjusted according to the following time distance τ.

Further, the vehicle adaptive cruise control device disclosed in the embodiment of the present invention further includes:

The prompt module is configured to send a prompt message to remind the user to turn off the automatic transmission function when the number of the first numerical values that are greater than the preset threshold exceeds the preset number. For example, assuming that the preset number is 5, the first value of the vehicle at 10 shift positions and its corresponding follow-up time are calculated. Among them, there are 8 first values corresponding to the pre-determined follow-up time exceeding the first value. Set the threshold s _n , and then send a prompt message.

The beneficial effects brought about by the technical solutions provided by the embodiments of the present invention are:

1. The vehicle adaptive cruise control method and device disclosed in the present invention obtain the following time distance of the vehicle at different shift positions, and determine the following time distance corresponding to the first value at the most shift position as the current following vehicle of the vehicle Time distance, in determining the time distance to follow the car, taking into account the impact of vehicle performance changes on the following effect, adjust the vehicle speed according to the current time distance to follow the car, improving the safety and driving experience of the user's driving;

2. The vehicle adaptive cruise control method and device disclosed in the present invention judge the warning signal by the number of the first value greater than the preset threshold. When the vehicle condition is not suitable for the adaptive cruise system, other vehicle users can be reminded in time Turn off adaptive cruise and change to manual control.

All the above-mentioned optional technical solutions can be combined in any way to form an optional embodiment of the present invention, which will not be repeated here.

The above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection of the present invention Within range.

Claims (8)

1. An adaptive cruise control method for a vehicle, which is characterized in that it includes:

   Obtain the vehicle speed before shifting, the speed after shifting, and the shifting distance of the vehicle at each shift position;

   Calculating the variable speed of each of the shift positions according to the vehicle speed before the shift, the vehicle speed after the shift, and the shift distance;

   Calculating a first value according to the variable speed and the variable speed distance;

   Determine the following time distance of the vehicle at each of the shift positions according to the corresponding relationship between the first value and the following time distance, and determine the following time distance corresponding to the first value at most as the vehicle's following time distance. Car time

   The driving speed is adjusted by using the following time distance of the vehicle.
2. The method for adaptive cruise control of a vehicle according to claim 1, wherein the first value is a weighted sum of the variable speed and the variable speed distance.
3. The method for adaptive cruise control of a vehicle according to claim 1, wherein each of the shift positions includes position information when the shift is started and position information when the shift is ended on different road sections.
4. A vehicle adaptive cruise control method according to any one of claims 1 to 3, wherein the method further comprises:

   When the number of the first values greater than the preset threshold exceeds the preset number, a prompt message is sent to remind the user to turn off the automatic transmission function.
5. An adaptive cruise control device for a vehicle, which is characterized in that it comprises:

   The parameter acquisition module is used to acquire the vehicle speed before shifting, the vehicle speed after shifting and the shifting distance of the vehicle at each shifting position;

   A calculation module, configured to calculate the variable speed of each of the variable speed positions according to the vehicle speed before the variable speed, the vehicle speed after the variable speed, and the variable speed distance, and to calculate a first value according to the variable speed and the variable speed distance;

   The vehicle-following time distance determination module is used to determine the vehicle-following time distance of the vehicle at each of the shift positions according to the corresponding relationship between the first value and the vehicle-following time distance, and follow the vehicle corresponding to the first value at most The time distance is determined as the following time distance of the vehicle;

   The speed control module is used to adjust the driving speed by using the following time distance of the vehicle.
6. The vehicle adaptive cruise control device of claim 5, wherein the first value is a weighted sum of the variable speed and the variable speed distance.
7. The vehicle adaptive cruise control device according to claim 5, wherein each of the shift positions includes position information when the shift is started and position information when the shift is ended on different road sections.
8. A vehicle adaptive cruise control device according to any one of claims 5-7, wherein the device further comprises:

   The prompt module is configured to send a prompt message to remind the user to turn off the automatic transmission function when the number of the first values greater than the preset threshold exceeds the preset number.

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