A method and system for safe deceleration of automatic driving

Abstract

The present invention discloses a method for safe deceleration in automatic driving, comprising the following steps: S1, obtaining lane line information; S2, judging the quality of the lane line according to the lane line information, and controlling the vehicle to decelerate when the quality of the lane line meets a first preset condition. The present invention provides a method for actively and safely decelerating in automatic driving according to signals representing the quality of the lane line such as the lane line length and confidence output by a sensor in an automatic driving system. When the vehicle is in an automatic driving or assisted driving state, once the sensor senses that the quality of the lane line is poor, the system automatically decelerates safely to ensure the driving safety of the driver and passengers during the automatic driving of the vehicle.

Description

Technical Field

[0001] The present invention belongs to the technical field of autonomous driving, and more specifically relates to a method and system for safe deceleration of autonomous driving. Background Art

[0002] In recent years, with the continuous development and application of assisted driving / autonomous driving technology, the corresponding safety issues caused by autonomous driving technology have become more and more the focus of consumers' attention. Therefore, automobile manufacturers need to fully consider safety risks and complete safety strategies before developing and installing autonomous driving technology. The assisted driving functions currently installed in mass-produced vehicles of various OEMs mainly rely on the lane lines perceived by the visual sensor for trajectory planning and lateral tracking control. Since the lane lines output by the visual sensor are not ideal in some environments such as backlight, rain and snow, it is likely to cause unstable lateral control of autonomous driving. In addition, ordinary drivers and passengers do not have a sufficient understanding of the current autonomous driving technology. When the driver and passengers turn on the related functions of autonomous driving while driving an autonomous driving vehicle, it is very easy to cause major safety hazards. If the system cannot reduce the speed to a safe range in time, it will pose a huge threat to the life safety of the driver and passengers. Therefore, it is worth further research on how to safely reduce the speed of the autonomous driving system according to the surrounding environment of the vehicle and the quality of the current lane line to ensure driving safety when the sensor cannot accurately perceive the lane line conditions.

[0003] At present, the mass-produced automatic driving / assisted driving systems installed by major mainstream automobile manufacturers mainly remind the driver to take over when the sensor cannot accurately sense the lane line, the lane conditions are poor or even disappear, and the research on strategies to ensure safety such as active speed reduction of the system is not perfect. For example, my country's patent CN202011136705.8 discloses a vehicle lateral control method, a vehicle, and a computer-readable storage medium, the method comprising: after recognizing that the lane line disappears, obtaining the position information of the vehicle at a certain moment when it has a lane line and is automatically driven according to the lane line based on historical lane line data; determining the current posture that the vehicle should maintain based on the posture at the certain moment and through the track calculation algorithm; and controlling the vehicle laterally based on the current posture that should be maintained so that the vehicle maintains the posture that should be maintained. The invention can automatically drive on a driving route that is more in line with the expected driving route. The invention maintains lateral stability control through an algorithm when the lane line disappears, and does not safely control the vehicle speed. Summary of the invention

[0004] To solve the above problems, the present invention provides an automatic driving safe deceleration method and system, which ensures that the automatic driving vehicle reduces to a safe speed when the sensor recognizes that the lane line quality is poor or even disappears.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows: a method for safe deceleration of an automatic driving vehicle comprises the following steps:

[0006] S1. Obtain lane line information;

[0007] S2. Determine the quality of the lane line according to the lane line information, and when the quality of the lane line meets a first preset condition, control the vehicle to slow down.

[0008] As an optimization, the lane line information includes the lane line length and / or lane line confidence and / or lane line curvature value on the left and / or right side of the vehicle.

[0009] As an optimization, step S1 also includes obtaining the vehicle status information, and when the vehicle status information meets the second preset condition, step S2 is executed.

[0010] As an optimization, the vehicle status information includes the vehicle speed and / or the on / off status of the vehicle's automatic driving function.

[0011] As an optimization, the second preset condition includes that the vehicle speed exceeds a set threshold, and / or the vehicle's automatic driving function is turned on.

[0012] As an optimization, the first preset condition includes that the difference between the time distance and the lane line length is greater than the lane line length deceleration threshold for multiple consecutive cycles.

[0013] As an optimization, the first preset condition also includes that the lane line confidence is lower than a preset value.

[0014] As an optimization, the first preset condition also includes that the lane line curvature value is less than a preset value.

[0015] As an optimization, step S2 further includes, when the quality of the lane line does not meet the first preset condition, exiting the speed reduction control of the vehicle.

[0016] Based on the above method, the present invention also provides an automatic driving safety deceleration system, comprising:

[0017] An information collection module is used to collect lane line information on the left and / or right side of the vehicle, and / or vehicle status information;

[0018] The vehicle speed control module is used to control the vehicle speed;

[0019] The judgment module is used to judge whether the quality of the lane line meets the first preset condition and / or whether the vehicle status information meets the second preset condition based on the lane line information and / or the vehicle status information. If so, a speed reduction instruction can be sent to the vehicle speed control module; otherwise, a speed exit control instruction can be sent to the vehicle speed control module.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] The present invention provides a method for actively and safely reducing the speed of an automatic driving system according to signals representing the quality of lane lines, such as lane line length and confidence, output by sensors in an automatic driving system. When the vehicle is in an automatic driving or assisted driving state, once the sensor senses that the quality of the lane line is poor, the system automatically reduces the speed safely to ensure the driving safety of the driver and passengers during automatic driving of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0024] Example: See Figure 1 ,

[0025] A method for safe deceleration of an automatic driving system comprises the following steps:

[0026] S1. Acquire lane line information; the lane line information includes the lane line length and / or lane line confidence and / or lane line curvature value on the left and / or right side of the vehicle. It also includes acquiring the vehicle status information. When the vehicle status information meets the second preset condition, execute step S2. The vehicle status information includes the vehicle speed and / or the on / off status of the vehicle's automatic driving function. The second preset condition includes that the vehicle speed exceeds the set threshold, and / or the vehicle's automatic driving function is in the on state.

[0027] Specifically, the present invention mainly determines whether the quality of the lane line of the road ahead has deteriorated or disappeared based on the length of the left and right lane lines, the confidence of the left and right lane lines, the curvature of the current lane, and the speed of the vehicle output by the sensor, and then adopts a safe speed reduction strategy. The specific signals and parameters are as follows:

[0028] 1) LaneLeftRange: the length of the left lane line;

[0029] 2) LaneRightRange: the length of the right lane line;

[0030] 3) LaneLeftCONF: left lane line confidence;

[0031] 4) LaneRightCONF: right lane line confidence;

[0032] 5) HstVhcSpd: vehicle speed;

[0033] 6) CurvatureLane: lane curvature value;

[0034] 7) ADS_AutoDriveState: automatic driving function status.

[0035] S2. Determine the quality of the lane line according to the lane line information, and when the quality of the lane line meets the first preset condition, control the vehicle to slow down. Specifically, the basic idea of ​​the judgment is: when the automatic driving function is turned on, when the vehicle speed is higher than a set threshold, if it is detected that the length of the left and right lane lines is continuously reduced to a certain range, and the confidence of the left and right lane lines is at a low level, then determine to activate the function of speed reduction based on lane line quality. The specific logic is as follows: When the following conditions are met at the same time or one of them is met, it can be set according to the actual road conditions, and the function of speed reduction based on lane line quality is activated:

[0036] 1) The vehicle speed is higher than a certain value:

[0037] HstVhcSpd > VhThres_kph; (vehicle speed is higher than a certain value, the default value in the present invention is 40km / h)

[0038] 2) The difference between the time headway and the length of the left lane line is greater than the lane line length deceleration threshold for multiple consecutive cycles:

[0039] a) T1* (HstVhcSpd / 3.6)- LaneLeftRange>T2* (HstVhcSpd / 3.6);

[0040] b) The condition is satisfied continuously for NumLaneDec cycles.

[0041] Among them, the time distance T1* (HstVhcSpd / 3.6) represents the normal output reference value of the lane line length when the vehicle is driving normally, and T2* (HstVhcSpd / 3.6) is the lane line length deceleration threshold, which is also based on the distance traveled by the vehicle in T2 time, and T1> T2;

[0042] 3) The difference between the time headway and the length of the right lane line is greater than the lane line length deceleration threshold for multiple consecutive cycles:

[0043] a) T1* (HstVhcSpd / 3.6)- LaneRightRange>T2* (HstVhcSpd / 3.6);

[0044] b) The condition is satisfied continuously for NumLaneDec cycles.

[0045] 4) The left lane line confidence is lower than a certain value:

[0046] The confidence of the left lane line, LaneLeftCONF < ConfThres_Active (the confidence value of the lane line ranges from 0 to 100. The larger the value, the better the quality of the lane line and the more reliable it is. In the present invention, the ConfThres value is 50, which can be calibrated according to different sensors).

[0047] 5) The confidence of the right lane line is lower than a certain value:

[0048] The confidence of the right lane line, LaneRightCONF < ConfThres_Active (the confidence value of the lane line ranges from 0 to 100. The larger the value, the better the quality of the lane line and the more reliable it is. In the present invention, the ConfThres value is 50, which can be calibrated according to different sensors).

[0049] 6) The curvature of the lane line is less than the curvature threshold:

[0050] CurvatureLane < CurvatureThres. Since the length of the lane line changes significantly when the curvature of the curve is large for the sensor on which the present invention is based, and this is not due to poor lane line quality, the discussion scope of the present invention is limited to straight road conditions only. Therefore, the curvature threshold CurvatureThres takes a relatively small value (reference value 0.0012).

[0051] 7) The autonomous driving function is activated:

[0052] ADS_AutoDriveState == 2. In the present invention, the value of this signal being 2 represents the activation of the autonomous driving function, that is, the activation of the lateral and longitudinal functions. Different systems can modify this condition according to the system definition.

[0053] In step S2, it further includes that when the quality of the lane line does not meet the first preset condition, the speed reduction control of the vehicle is exited.

[0054] Specifically, the basic idea of exiting the speed reduction function: After the speed reduction function according to the lane line quality is activated, when it is detected that the length of the lane line returns to the normal range for consecutive multiple cycles and the confidence of the lane line is higher than a certain value, that is, the condition for exiting the speed reduction function according to the lane line is met. The specific logic is as follows. If any of the following conditions is met, the speed reduction function according to the lane line quality exits:

[0055] 1) The exit conditions of the length and confidence of the left lane line are met simultaneously.

[0056] a) The difference between the time interval and the length of the left lane line is less than the lane line length exit threshold for consecutive multiple cycles:

[0057] T1 * (HstVhcSpd / 3.6) - LaneLeftRange < T3 * (HstVhcSpd / 3.6);

[0058] b) The confidence level of the left lane line is higher than a certain value:

[0059] LaneLeftCONF > ConfThres_InActive.

[0060] Among them, T3 < T2 < T1, and the value of ConfThres_InActive ranges from 70 to 100;

[0061] 2) Simultaneously meet the exit conditions for the length and confidence level of the right lane line

[0062] a) The difference between the time interval and the length of the right lane line is less than the lane line length exit threshold for multiple consecutive cycles:

[0063] T1 * (HstVhcSpd / 3.6) - LaneRightRange < T3 * (HstVhcSpd / 3.6);

[0064] b) The confidence level of the right lane line is higher than a certain value:

[0065] LaneRightCONF > ConfThres_InActive.

[0066] Among them, T3 < T2 < T1, and the value of ConfThres_InActive ranges from 70 to 100.

[0067] After determining the activation of deceleration according to the lane line in the above steps, the target acceleration is output to the vehicle actuator through acceleration planning for deceleration control, ensuring that the vehicle can decelerate safely in a timely manner when the lane line quality is poor, and ensuring the reliability and safety of the autonomous driving system.

[0068] Based on the above method, the present invention also provides an autonomous driving safety deceleration system, including

[0069] An information acquisition module, configured to acquire the lane line information on the left and / or right sides of the vehicle, and / or the vehicle state information;

[0070] A vehicle speed control module, configured to control the vehicle speed;

[0071] A judgment module, configured to judge whether the quality of the lane line meets the first preset condition according to the lane line information and / or the vehicle state information, and / or whether the vehicle state information meets the second preset condition. If so, it can send a deceleration instruction to the vehicle speed control module, otherwise it can send an exit vehicle speed control instruction to the vehicle speed control module.

[0072] The present invention provides a method for actively and safely reducing the speed of an automatic driving system according to signals representing the quality of lane lines, such as lane line length and confidence, output by sensors in an automatic driving system. When the vehicle is in an automatic driving or assisted driving state, once the sensor senses that the quality of the lane line is poor, the system automatically reduces the speed safely to ensure the driving safety of the driver and passengers during automatic driving of the vehicle.

[0073] 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 the technical solution. Those skilled in the art should understand that those modifications or equivalent substitutions of the technical solution of the present invention that do not depart from the purpose and scope of the technical solution should be included in the scope of the claims of the present invention.

Claims

1. A method for safe deceleration of an automatic driving, characterized in that: The following steps are included: S1. Acquire lane line information; the lane line information includes the lane line length and / or lane line confidence and / or lane line curvature value on the left and / or right side of the vehicle; S2. determining the quality of the lane line according to the lane line information, and controlling the vehicle to slow down when the quality of the lane line meets a first preset condition; The first preset condition includes that the difference between the time headway and the lane line length is greater than the lane line length deceleration threshold for multiple consecutive cycles, and / or the lane line confidence is lower than a preset value, and / or the lane line curvature value is less than a preset value; When the quality of the lane line does not meet the first preset condition, the vehicle speed reduction control is exited.

2. The method for safe deceleration of an automatic driving vehicle according to claim 1, characterized in that: Step S1 also includes obtaining vehicle status information. When the vehicle status information meets a second preset condition, step S2 is executed.

3. The method for safe deceleration of automatic driving according to claim 2, characterized in that: The vehicle status information includes the vehicle speed and / or the on / off status of the vehicle's automatic driving function.

4. The method for safe deceleration of automatic driving according to claim 3, characterized in that: The second preset condition includes that the vehicle speed exceeds a set threshold, and / or the automatic driving function of the vehicle is turned on.

5. An automatic driving safety deceleration system, characterized in that: include, An information collection module is used to collect lane line information on the left and / or right side of the vehicle, and / or vehicle status information; the lane line information includes the lane line length and / or lane line confidence and / or lane line curvature value on the left and / or right side of the vehicle; The vehicle speed control module is used to control the vehicle speed; A judgment module is used to judge whether the quality of the lane line meets a first preset condition and / or whether the vehicle status information meets a second preset condition based on the lane line information and / or the vehicle status information. If so, a speed reduction instruction can be sent to the vehicle speed control module; otherwise, an exit speed control instruction can be sent to the vehicle speed control module. The first preset condition includes that the difference between the time distance and the lane line length is greater than the lane line length deceleration threshold for multiple consecutive cycles, and / or the lane line confidence is lower than a preset value, and / or the lane line curvature value is less than a preset value.

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