A vehicle speed control method based on automatic deceleration of traffic on both sides

Abstract

The present invention relates to a vehicle speed control method based on automatic deceleration of traffic on both sides, comprising the following steps: 1) obtaining the driving speed of the vehicle and the driving information of each vehicle in front of the adjacent lane; 2) judging whether the vehicle needs to decelerate, if yes, executing step 3); 3) calculating the deceleration required for the vehicle; 4) controlling the vehicle to decelerate according to the deceleration. The vehicle speed control method based on automatic deceleration of traffic on both sides of the present invention judges whether the vehicle needs to decelerate based on the driving speed of the vehicle and the driving speed of the vehicle in front of the adjacent lane and the longitudinal distance from the vehicle, and calculates the deceleration required for the vehicle; when the vehicle is too fast relative to the surrounding vehicles, the deceleration will be automatically controlled to reduce the sense of oppression on the driver of the vehicle and the passengers in the vehicle, avoid panic, and improve the safety and comfort of automatic driving.

Description

Technical Field

[0001] The present invention belongs to the technical field of automatic driving, and in particular relates to a vehicle speed control method based on automatic deceleration of traffic on both sides. Background Art

[0002] With the rapid development of automobile intelligence, more and more cars are equipped with automatic driving systems. In the process of automatic driving, the automatic driving system generally obtains the speed limit and traffic congestion of the current road on the map through positioning information to determine the speed of automatic driving. Affected by the real-time nature of the map and human factors, the driving speed determined by the automatic driving system is likely to be significantly different from the driving speed of surrounding vehicles; when the driving speed determined by the automatic driving system is much higher than the driving speed of surrounding vehicles, the slower traffic in the side lanes will cause a sense of oppression to the driver of the vehicle, causing the driver to panic, distrust the automatic driving system, and even hastily control the system manually, resulting in an accident.

[0003] Existing patents for the control of the speed of automatic driving are basically aimed at cruise driving. The speed of the vehicle is controlled by obtaining the speed of the vehicle in front, so as to make the following vehicle driving smoother and more comfortable while maintaining a certain distance, such as Chinese patent CN201711205382.1 Adaptive vehicle speed control method and adaptive vehicle speed control device. Therefore, it is necessary to propose a vehicle speed control method based on automatic deceleration of traffic on both sides, so as to automatically adjust the speed of the automatic driving according to the speed of the surrounding vehicles, reduce the sense of oppression, and improve the safety of automatic driving. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is to provide a vehicle speed control method based on automatic deceleration of traffic on both sides, so as to solve the problem that drivers may panic due to slower traffic in the side lanes during current autonomous driving, thereby achieving the effect of improving the comfort and safety of autonomous driving.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A vehicle speed control method based on automatic deceleration of traffic on both sides comprises the following steps:

[0007] 1) Obtain the driving speed of the vehicle and the driving information of the vehicles ahead in the adjacent lanes;

[0008] 2) Determine whether the vehicle needs to slow down. If yes, execute step 3); if no, the vehicle keeps driving in the original state;

[0009] 3) Calculate the required deceleration of the vehicle;

[0010] 4) Control the vehicle to decelerate according to the deceleration rate.

[0011] Furthermore, the driving information in step 1) includes the driving speed of the preceding vehicle and the longitudinal distance between the preceding vehicle and the vehicle.

[0012] Furthermore, step 1) also includes the following:

[0013] The vehicle in front of the adjacent lane is defined as the preceding vehicle, and the preceding vehicle closest to the vehicle is defined as the nearest preceding vehicle; when the longitudinal distance between the preceding vehicle and the nearest preceding vehicle is less than 30m and the difference between the driving speed of the preceding vehicle and the driving speed of the preceding vehicle is greater than 10m / s, a count constant value is accumulated.

[0014] Furthermore, the conditions for determining that the vehicle needs to slow down in step 2) are as follows:

[0015] The count constant value is greater than or equal to 2, the vehicle's speed is greater than 50 km / h, and the longitudinal distance between the nearest preceding vehicle and the vehicle is less than 50 m.

[0016] Furthermore, step 3) includes the following sub-steps:

[0017] 31) Calculate the average speed by dividing the sum of the speeds of the preceding vehicles by the count constant value;

[0018] 32) Calculate the relative speed by subtracting the vehicle's speed from the average speed;

[0019] 33) Calculate the deceleration by dividing the square of the relative speed by twice the longitudinal distance between the nearest preceding vehicle and the vehicle.

[0020] Furthermore, before step 32), it is also necessary to perform speed compensation on the average vehicle speed by subtracting the average vehicle speed from the speed compensation value, and the compensation value is 5 m / s.

[0021] Furthermore, before step 33), it is also necessary to perform distance compensation on the longitudinal distance between the nearest preceding vehicle and the vehicle, by subtracting the longitudinal distance between the nearest preceding vehicle and the vehicle from the distance compensation value, and the distance compensation value is 2m.

[0022] Furthermore, step 4) includes the following sub-steps:

[0023] 41) Limit the amplitude of deceleration;

[0024] 42) Limit the deceleration slope;

[0025] 43) Controlling the vehicle to decelerate according to the deceleration outputted through the processing of steps 41) and 42).

[0026] Furthermore, the content of limiting the amplitude of the deceleration in step 41) is as follows:

[0027] Define the amplitude as [-0.5, 0]. When the deceleration value belongs to [-0.5, 0], the deceleration is directly output; when the deceleration value is less than -0.5, -0.5m / s is output. 2 As deceleration; when the deceleration value is greater than 0, 0 m / s is output 2 as deceleration.

[0028] Furthermore, the content of limiting the slope of deceleration in step 42) is as follows:

[0029] The current deceleration of the vehicle is taken as the basis and the deceleration is 0.5 m / s per second. 2 Approach the deceleration after amplitude limitation and output continuously.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] 1. The vehicle speed control method based on automatic deceleration of traffic on both sides of the present invention determines whether the vehicle needs to decelerate based on the driving speed of the vehicle and the driving speed of the vehicle in front of the adjacent lane and the longitudinal distance from the vehicle, and calculates the deceleration required for the vehicle; when the speed of the vehicle is too fast relative to the surrounding vehicles, the deceleration is automatically controlled to reduce the sense of oppression on the driver of the vehicle and the passengers in the vehicle, avoid panic, and improve the safety and comfort of automatic driving.

[0032] 2. The vehicle speed control method based on automatic deceleration of traffic on both sides of the present invention, after calculating the deceleration, needs to be subject to amplitude limitation and slope limitation before outputting the control vehicle deceleration. The amplitude limitation controls the output deceleration within a certain range to avoid excessive vehicle deceleration and affecting normal driving; the slope limitation controls the deceleration to be continuously output in a gradually increasing form to avoid sudden output of a large deceleration causing a sudden drop in vehicle speed, making the controlled vehicle deceleration smoother, thereby improving the safety and comfort of automatic driving. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A flow chart of a vehicle speed control method based on automatic deceleration of traffic on both sides according to an embodiment;

[0034] Figure 2 Schematic diagram of an application scenario of the vehicle speed control method described in the embodiment. DETAILED DESCRIPTION

[0035] The specific implementation modes of the present invention will be further described in detail below in conjunction with the accompanying drawings.

[0036] Example:

[0037] See also Figure 1 , a vehicle speed control method based on automatic deceleration of traffic on both sides, comprising the following steps:

[0038] 1) Obtain information, including the driving speed of the vehicle and the driving information of the vehicles ahead in the adjacent lanes;

[0039] The driving information includes the driving speed of the preceding vehicle and the longitudinal distance between the preceding vehicle and the vehicle; step 1) also includes the following contents:

[0040] The vehicle in front of the adjacent lane is defined as the preceding vehicle, and the preceding vehicle closest to the vehicle is defined as the nearest preceding vehicle; when the longitudinal distance between the preceding vehicle and the nearest preceding vehicle is less than 30m and the difference between the driving speed of the preceding vehicle and the driving speed of the preceding vehicle is greater than 10m / s, a count constant value is accumulated.

[0041] 2) Determine whether the vehicle needs to slow down. If yes, execute step 3); if no, continue to drive at the current speed of the vehicle. The conditions for determining that the vehicle needs to slow down are as follows:

[0042] The count constant value is greater than or equal to 2, the vehicle's speed is greater than 50 km / h, and the longitudinal distance between the nearest preceding vehicle and the vehicle is less than 50 m;

[0043] 3) Calculate the required deceleration of the vehicle; including the following sub-steps:

[0044] 31) Calculate the average speed by dividing the sum of the speeds of the preceding vehicles by the count constant value;

[0045] 32) Calculate the relative speed by subtracting the vehicle's speed from the average speed;

[0046] 33) Calculate the deceleration by dividing the square of the relative speed by twice the longitudinal distance between the nearest preceding vehicle and the vehicle.

[0047] 4) Controlling the vehicle to decelerate according to the deceleration rate; including the following sub-steps:

[0048] 41) Limit the deceleration amplitude; the content is as follows:

[0049] Define the amplitude as [-0.5, 0]. When the deceleration value belongs to [-0.5, 0], the deceleration is directly output; when the deceleration value is less than -0.5, -0.5m / s is output. 2 As deceleration; when the deceleration value is greater than 0, 0 m / s is output 2 as deceleration.

[0050] 42) Limit the deceleration slope; the content is as follows:

[0051] The current deceleration of the vehicle is taken as the basis and the deceleration is 0.5 m / s per second. 2 Approach the deceleration after amplitude limitation and output continuously.

[0052] 43) Controlling the vehicle to decelerate according to the deceleration outputted through the processing of steps 41) and 42).

[0053] Furthermore, before step 32), it is also necessary to perform speed compensation on the average vehicle speed by subtracting the average vehicle speed from the speed compensation value, and the compensation value is 5 m / s.

[0054] Furthermore, before step 33), it is also necessary to perform distance compensation on the longitudinal distance between the nearest preceding vehicle and the vehicle, by subtracting the longitudinal distance between the nearest preceding vehicle and the vehicle from the distance compensation value, and the distance compensation value is 2m.

[0055] The vehicle speed control method based on automatic deceleration of traffic on both sides of the present invention determines whether the vehicle needs to decelerate based on the driving speed of the vehicle and the driving speed of the vehicle in front of the adjacent lane and the longitudinal distance from the vehicle, and calculates the deceleration required for the vehicle; when the speed of the vehicle is too fast relative to the surrounding vehicles, the deceleration will be automatically controlled to reduce the pressure on the driver of the vehicle and the passengers in the vehicle to avoid panic; in addition, after the deceleration is calculated, it needs to be output after amplitude limitation and slope limitation before the vehicle deceleration is controlled. The amplitude limitation controls the output deceleration within a certain range to avoid excessive vehicle deceleration and affecting normal driving; the slope limitation controls the deceleration to be continuously output in a gradually increasing form to avoid sudden output of a large deceleration causing a sudden drop in vehicle speed, so that the controlled vehicle deceleration is smoother, thereby improving the safety and comfort of automatic driving.

[0056] See also Figure 2 To facilitate understanding of this scheme, Figure 2 The following is an example of a scenario diagram:

[0057] Figure 2 In the equation, C1 is the vehicle, Vh is the speed of the vehicle, C2, C3, C4, and C5 represent the vehicles in front of the adjacent lanes of the vehicle, with corresponding speeds of V2, V3, V4, and V5, and longitudinal distances from the vehicle of D2, D3, D4, and D5, respectively; then C2 is the nearest preceding vehicle, C3, C4, and C5 are the preceding vehicles, and C3, C4, and C5 all meet the requirements of the cumulative count constant value.

[0058] Corresponding to step 1), assuming that D5 minus D2 is greater than 30m, D4 minus D2 is less than 30m, and the difference between Vh and V2, V3 and V4 is greater than 10m / s, that is, the front vehicles C3 and C4 meet the conditions, then the cumulative count constant value is 2;

[0059] Corresponding to step 2), assuming that Vh is greater than 50km / h and D2 is less than 50m, it is determined that the vehicle needs to slow down;

[0060] Corresponding to step 31), the sum of V3 and V4 is divided by 2 to obtain the average vehicle speed V0;

[0061] In step 32), the relative speed Vc is calculated by subtracting 5 m / s from the average speed V0 and then subtracting Vh;

[0062] Corresponding to step 33), the deceleration a is calculated by dividing the square of the relative vehicle speed Vc by D2 minus 2m.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A vehicle speed control method based on automatic deceleration of traffic on both sides, characterized in that: The steps include: 1) Obtain the driving speed of the vehicle and the driving information of the vehicles ahead in the adjacent lanes; 2) Determine whether the vehicle needs to slow down, if yes, go to step 3); 3) Calculate the required deceleration of the vehicle; 4) Control the vehicle to decelerate according to the deceleration rate; The driving information in step 1) includes the driving speed of the preceding vehicle and the longitudinal distance between the preceding vehicle and the vehicle; Step 1) also includes the following: The vehicle in front of the adjacent lane is defined as the preceding vehicle, and the preceding vehicle closest to the vehicle is defined as the nearest preceding vehicle; when the longitudinal distance between the preceding vehicle and the nearest preceding vehicle is less than 30m and the difference between the driving speed of the preceding vehicle and the driving speed of the preceding vehicle is greater than 10m / s, a count constant value is accumulated.

2. The vehicle speed control method based on automatic deceleration of traffic on both sides according to claim 1, characterized in that: The conditions for judging that the vehicle needs to slow down in step 2) are as follows: The count constant value is greater than or equal to 2, the vehicle's speed is greater than 50 km / h, and the longitudinal distance between the nearest preceding vehicle and the vehicle is less than 50 m.

3. The vehicle speed control method based on automatic deceleration of traffic on both sides according to claim 2, characterized in that: Step 3) includes the following sub-steps: 31) Calculate the average speed by dividing the sum of the speeds of the preceding vehicles by the count constant value; 32) Calculate the relative speed by subtracting the vehicle's speed from the average speed; 33) Calculate the deceleration by dividing the square of the relative speed by twice the longitudinal distance between the nearest preceding vehicle and the vehicle.

4. The vehicle speed control method based on automatic deceleration of traffic on both sides according to claim 3, characterized in that: Before step 32), it is also necessary to perform speed compensation on the average vehicle speed by subtracting the average vehicle speed from the speed compensation value, which is 5 m / s.

5. The vehicle speed control method based on automatic deceleration of traffic on both sides according to claim 4, characterized in that: Before step 33), it is also necessary to perform distance compensation on the longitudinal distance between the nearest preceding vehicle and the vehicle. The longitudinal distance between the nearest preceding vehicle and the vehicle is subtracted from the distance compensation value. The distance compensation value is 2m.

6. The vehicle speed control method based on automatic deceleration of traffic on both sides according to claim 1, characterized in that: Step 4) includes the following sub-steps: 41) Limit the amplitude of deceleration; 42) Limit the deceleration slope; 43) Controlling the vehicle to decelerate according to the deceleration outputted through the processing of steps 41) and 42).

7. The vehicle speed control method based on automatic deceleration of traffic on both sides according to claim 6, characterized in that: The content of limiting the amplitude of deceleration in step 41) is as follows: Define the amplitude as [-0.5, 0]. When the deceleration value belongs to [-0.5, 0], the deceleration is directly output; when the deceleration value is less than -0.5, -0.5m / s is output. 2 As deceleration; when the deceleration value is greater than 0, 0 m / s is output 2 as deceleration.

8. The vehicle speed control method based on automatic deceleration of traffic on both sides according to claim 7, characterized in that: Step 42) The content of limiting the deceleration slope is as follows: The current deceleration of the vehicle is taken as the basis and the deceleration is 0.5 m / s per second. 2 Approach the deceleration after amplitude limitation and output continuously.

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