Decision-making method for automatic driving vehicle passing through yellow light at intersection

Abstract

The invention relates to a decision-making method for an automatic driving vehicle passing through an intersection yellow light. The method comprises the following steps: S1, acquiring a signal light state of an intersection; s2, if it is detected that the signal lamp is changed from green to yellow, whether a slow brake can stop driving at the position in front of an intersection stop line or not is judged, and the speed of the slow brake is smaller than or equal to a preset acceleration threshold value; s3, if slow braking can make the vehicle stop driving at the position in front of the intersection stop line, a slow braking decision is given; and S4, if the slow brake cannot enable the vehicle to stop driving at the position in front of the intersection stop line, judging whether the vehicle can be accelerated to pass through the intersection stop line within the specified time, and if so, issuing a decision of accelerating to pass through the intersection stop line. By adopting the steps, under the condition that the signal lamp is a yellow lamp, the current road condition and the vehicle condition are comprehensively analyzed and judged, a reasonable driving strategy is given, the accident occurrence probability is reduced, and the driving of the automatic driving vehicle is safer and smoother.

Description

Technical Field

[0001] The present invention relates to the field of autonomous driving technology, and in particular to a decision-making method for an autonomous driving vehicle when passing a yellow light at an intersection. Background Art

[0002] The development of autonomous driving technology has brought revolutionary changes to the transportation sector. Its application has not only changed people's travel methods, but also improved traffic safety and efficiency. However, autonomous driving vehicles still need to make accurate and safe decisions when facing complex traffic environments. When passing through intersections, the existing autonomous driving systems usually treat yellow lights as red lights and make emergency braking decisions when the yellow light is on. They do not analyze and judge the current road conditions, which causes autonomous driving cars to often brake suddenly at intersections, which is prone to traffic accidents such as rear-end collisions and congestion.

[0003] Therefore, there is an urgent need to provide a decision-making method for an autonomous driving vehicle when passing a yellow light at an intersection to solve the above problems. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings and defects of the prior art and to provide a decision-making method for an autonomous driving vehicle when passing through a yellow light at an intersection. When the signal light is yellow, a comprehensive analysis and judgment is made on the road conditions and the situation of the vehicle at that time, and a reasonable driving strategy is given to reduce the probability of accidents, so that the driving of the autonomous driving vehicle is safer and smoother.

[0005] The objective of the present invention is achieved through the following technical solutions:

[0006] A decision-making method for an autonomous driving vehicle when passing a yellow light at an intersection, characterized by comprising:

[0007] S1: Get the traffic light status at the intersection;

[0008] S2: If it is detected that the traffic light changes from green to yellow, it is determined whether the vehicle can stop driving at the position before the stop line of the intersection by slow braking, and the speed of the slow braking is less than or equal to the preset acceleration threshold;

[0009] S3: If slow braking can stop the vehicle before the stop line at the intersection, a slow braking decision is issued;

[0010] S4: If slow braking cannot stop the vehicle in front of the stop line at the intersection, determine whether the vehicle can accelerate through the stop line at the intersection within the specified time. If so, make a decision to accelerate through the stop line at the intersection.

[0011] Optionally, before judging whether the vehicle can accelerate through the stop line of the intersection within a specified time, the process further includes:

[0012] S31: If the vehicle cannot stop at the position before the stop line of the intersection by slow braking, determine whether the vehicle can pass the stop line of the intersection at the current speed within a specified time;

[0013] S32: If the vehicle can pass the stop line of the intersection at the current speed within the specified time, a decision is made to pass the stop line of the intersection at the current speed;

[0014] S33: If the vehicle cannot pass the stop line of the intersection at the current speed within the specified time, determine whether the vehicle can accelerate to pass the stop line of the intersection, and the maximum speed after acceleration does not exceed 10% of the maximum speed limit of the intersection.

[0015] Optionally, it also includes:

[0016] S5: If the slow brake cannot stop the vehicle at the position before the stop line of the intersection, and the vehicle cannot pass the intersection at the current speed or accelerate within the specified time, an emergency brake decision is issued, and the acceleration of the emergency brake is greater than the specified acceleration threshold.

[0017] Optionally, the prescribed time is set to 3s.

[0018] Optionally, it also includes:

[0019] S6: If the traffic light is detected to be yellow at the first time, a decision to slow down the brakes is issued to control the vehicle to stop at a position before the stop line at the intersection.

[0020] Optionally, it also includes:

[0021] S7: If the traffic light is blocked by the vehicle ahead after entering the detection range and the state of the traffic light at the intersection cannot be obtained, a stop decision is issued.

[0022] Optionally, it also includes:

[0023] S71: If the vehicle ahead moves forward and eventually passes the stop line at the intersection, the vehicle stops before the stop line at the intersection until the traffic light turns green;

[0024] S72: If the front vehicle moves forward and eventually does not pass the stop line of the intersection, the vehicle moves along with the front vehicle and stops behind the front vehicle.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] In the present invention, the status of the traffic lights at the intersection is obtained first, and subsequent decisions are made according to the detected status of the traffic lights; if it is detected that the traffic light changes from green to yellow, it is determined whether the slow braking can stop the vehicle at the position before the stop line of the intersection, and the speed of the slow braking is less than or equal to the preset acceleration threshold; if the slow braking can stop the vehicle at the position before the stop line of the intersection, a slow braking decision is issued; if the slow braking cannot stop the vehicle at the position before the stop line of the intersection, it is determined whether the vehicle can accelerate through the stop line of the intersection within the specified time, and if so, a decision to accelerate through the stop line of the intersection is issued. Through the comprehensive analysis and judgment of the detection of the traffic lights at the intersection, the status of the vehicle and the road condition information, different decisions are made in advance, and reasonable driving strategies are given, thereby reducing the probability of accidents. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The flowchart of making a slow braking decision in the present invention.

[0028] Figure 2 The flowchart of the present invention is to make a decision on passing the stop line at the intersection.

[0029] Figure 3 Another flow chart of making slow braking decision in the present invention.

[0030] Figure 4 This is a flow chart for making parking decisions in the present invention. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below in conjunction with embodiments and drawings, but the embodiments of the present invention are not limited thereto.

[0032] The technical solution of the present invention proposes a decision-making method for an autonomous driving vehicle when passing a yellow light at an intersection.

[0033] Reference Figures 1 to 4 , in this embodiment, includes:

[0034] S1: Get the traffic light status at the intersection;

[0035] S2: If it is detected that the traffic light changes from green to yellow, it is determined whether the vehicle can stop driving at the position before the stop line of the intersection by slow braking, and the speed of the slow braking is less than or equal to the preset acceleration threshold;

[0036] S3: If slow braking can stop the vehicle before the stop line at the intersection, a slow braking decision is issued;

[0037] S4: If slow braking cannot stop the vehicle in front of the stop line at the intersection, determine whether the vehicle can accelerate through the stop line at the intersection within the specified time. If so, make a decision to accelerate through the stop line at the intersection.

[0038] Optionally, refer to Figure 1 and Figure 2 In this embodiment, in the traffic signal, the role of the yellow light is to warn vehicles and buffer traffic. When the autonomous driving vehicle is driving to the intersection, if the yellow light is on, it is necessary to make a timely response decision to the yellow light; when the autonomous driving vehicle passes through the intersection, the signal light status of the intersection is first obtained, that is, the vehicle performs signal light detection in the process of approaching the intersection. If the light is detected as green at the first time, and it turns to yellow when driving close to the intersection, it is determined whether the slow braking can stop the vehicle at the position before the stop line of the intersection. According to the current speed of the vehicle and the distance from the current position of the vehicle to the stop line, according to the kinematic formula, it can be determined whether the slow braking method can stop the vehicle at the position before the stop line. Among them, the slow braking method includes the absolute value of the braking acceleration (indicating the magnitude of the acceleration) being less than or equal to the preset acceleration threshold. In one example, the acceleration threshold a=2m / s can be preset. 2 In the above step S2, if the vehicle accelerates at a speed of a≤2m / s 2 If the vehicle can stop at the position in front of the stop line under the condition of slow braking, a decision to slow down the braking is made. If slow braking cannot make the vehicle stop at the position in front of the stop line of the intersection, it is determined whether the vehicle can accelerate through the stop line of the intersection within the specified time, wherein the absolute value of the acceleration is less than or equal to the preset acceleration threshold. If the acceleration is less than or equal to the threshold, the vehicle can accelerate through the stop line of the intersection before the yellow light turns red, then a decision to accelerate through the stop line of the intersection is made. Through the above steps, when the traffic light is yellow, a comprehensive analysis and judgment is made on the road conditions and the vehicle's situation at the time, and a reasonable driving strategy is given for the yellow light, giving priority to slow braking to reduce the probability of accidents, making the driving of the autonomous driving vehicle safer and smoother.

[0039] Furthermore, in step S4, in the process of judging whether to accelerate through the stop line of the intersection, it is necessary to consider the vehicle's own information, that is, the vehicle's instantaneous speed and the vehicle's own length information, etc. The vehicle's own length information can be entered through an input device, or it can be obtained according to the vehicle's own model; when judging whether the vehicle can accelerate through the stop line of the intersection, it is actually to judge whether the rear end of the vehicle can cross the stop line of the intersection before the yellow light turns red, that is, the vehicle's own length needs to be considered; at the same time, when the yellow light just turns on, start to make real-time decisions on the yellow light situation. Since some states may change at any time during the driving process of the vehicle, it is necessary to make real-time decisions based on each time period of the vehicle's driving. For example, the original yellow light response decision may be to continue driving through the intersection, but during the driving process, due to the obstruction of the obstacle vehicle, the vehicle is forced to slow down or stop and cannot pass through the intersection. In this case, it is necessary to make a new decision based on the current situation.

[0040] Reference Figure 2 , in this embodiment, before judging whether the vehicle can accelerate through the stop line of the intersection within the specified time, it also includes step S31: if the slow brake cannot stop the vehicle at the position before the stop line of the intersection before the yellow light turns red, then judging whether the vehicle can pass the stop line of the intersection at the current speed within the specified time, that is, judging whether the vehicle is calculated at the moment when the green light turns yellow;

[0041] Step S32: If the rear of the vehicle can cross the stop line of the intersection at the current speed within the specified time, a decision is made to travel through the stop line of the intersection at a constant speed; that is, the distance between the rear of the vehicle and the stop line of the intersection is set to S, the current speed is v, the specified time is t, S≤vt, then the vehicle can cross the stop line of the intersection at a constant speed, therefore, the vehicle makes a decision to pass the stop line of the intersection at the current speed.

[0042] Step S33: If the vehicle cannot pass the stop line of the intersection at the current speed within the specified time, that is, S>vt, then proceed to step S4: determine whether the vehicle can accelerate through the stop line of the intersection within the specified time. If the vehicle can accelerate through the stop line of the intersection, then a decision is made to accelerate through the stop line of the intersection. The absolute value of the acceleration during acceleration must be less than or equal to the preset acceleration threshold. At the same time, the maximum speed after acceleration must not exceed 10% of the maximum speed limit of the intersection. If both the acceleration and the maximum speed meet the requirements, a decision can be made to accelerate across the stop line of the intersection.

[0043] In this embodiment, step S5 is also included: if both steps S3 and S4 are not satisfied, that is, the slow brake cannot stop the vehicle at the position before the stop line of the intersection, and the rear end of the vehicle cannot pass the stop line of the intersection at the current speed or accelerate within the specified time, an emergency braking decision is made, and the acceleration of the emergency braking is greater than the specified acceleration threshold to ensure the driving safety of the vehicle; wherein the specified time is set to 3s, that is, the yellow light is on for 3s by default, and the yellow light time varies from place to place, but the minimum is 3s, which is set to 3s to prevent congestion or traffic safety caused by vehicles passing through intersections.

[0044] Reference Figure 3In this embodiment, step S6 is also included: if the signal light is detected as a yellow light at the first time, a slow braking decision is issued to control the vehicle to stop at a position before the stop line of the intersection; that is, when the vehicle approaches the signal light, when the signal light enters the detection range, it is displayed as a yellow light, then there is no need to consider it, and the yellow light is directly treated as a red light, and a slow braking decision is made; for an autonomous driving vehicle, the detection range of the signal light is usually greater than 50m, or even more than 100m. The detection range can be used as a deceleration buffer to avoid any emergency braking. When the signal light enters the detection range, it is a yellow light, and it is unknown how many seconds the yellow light is left, that is, the yellow light may turn red in the next second. If the vehicle does not make any decision or makes a decision to accelerate according to step S4, it may cause emergency braking or running a red light; the setting of the detection range and the decision of step S6 are sufficient for the vehicle to slow down the brakes before reaching the intersection, thereby avoiding emergencies or accidents.

[0045] Reference Figure 4 In this embodiment, step S7 is also included: if the signal light is blocked by the vehicle in front after entering the detection range, and the state of the signal light at the intersection cannot be obtained, a parking decision is issued; that is, due to the obstruction of the large vehicle, the vehicle cannot detect the state of the signal light in time, and even if the state of the signal light can be detected later, it cannot make a decision change in time, so a parking decision is directly issued to avoid accidents; further, in this embodiment, step S7 includes S71 and S72, S71: if the vehicle in front drives forward and eventually passes the stop line of the intersection, that is, the vehicle stops in front of the stop line of the intersection until the signal light turns green, that is, the vehicle follows the vehicle at a slow speed until the stop line of the intersection, and no sudden braking will be caused; S72: if the vehicle in front drives forward and eventually does not pass the stop line of the intersection, the vehicle moves with the vehicle in front and stops behind the vehicle in front or other stationary obstacles, thereby avoiding sudden braking; it should be noted that in order to prevent a collision, the vehicle should keep a certain safe distance from the vehicle in front and follow the vehicle at a slow speed to prevent the sudden braking of the vehicle in front from causing sudden braking or collision of the vehicle.

[0046] When a vehicle is passing the stop line of an intersection at a constant speed or accelerating, if the yellow light suddenly turns red when the front of the vehicle has crossed the stop line, and the vehicle is too fast to stop before the rear of the vehicle crosses the stop line, the traffic light will be ignored according to the situation; if there is no high-risk obstacle in front of the vehicle that will intersect with the vehicle, a red light run will be performed to prevent the vehicle from stopping at the intersection and causing traffic jams; if there is a high-risk obstacle in front of the vehicle that will intersect with the vehicle, emergency braking and avoidance are required. Under normal circumstances, this situation will not occur under the operation of steps S3, S4 and S5, but if the traffic light suddenly becomes abnormal or the vehicle's traffic light detection module is abnormal, resulting in missed detection and other emergencies, this solution will be used as a backup decision to prevent accidents.

[0047] The above-mentioned embodiments only express the implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A decision-making method for an autonomous driving vehicle when passing a yellow light at an intersection, characterized in that: include: S1: Get the traffic light status at the intersection; S2: If it is detected that the traffic light changes from green to yellow, it is determined whether the vehicle can stop driving at the position before the stop line of the intersection by slow braking, and the speed of the slow braking is less than or equal to the preset acceleration threshold; S3: If slow braking can stop the vehicle before the stop line at the intersection, a slow braking decision is issued; S4: If slow braking cannot stop the vehicle in front of the stop line at the intersection, determine whether the vehicle can accelerate through the stop line at the intersection within the specified time. If so, make a decision to accelerate through the stop line at the intersection.

2. The decision-making method for an autonomous driving vehicle passing a yellow light at an intersection according to claim 1, characterized in that: Before judging whether the vehicle can accelerate through the stop line of the intersection within the specified time, it also includes: S31: If the vehicle cannot stop at the position before the stop line of the intersection by slow braking, determine whether the vehicle can pass the stop line of the intersection at the current speed within a specified time; S32: If the vehicle can pass the stop line of the intersection at the current speed within the specified time, a decision is made to pass the stop line of the intersection at the current speed; S33: If the vehicle cannot pass the stop line of the intersection at the current speed within the specified time, determine whether the vehicle can accelerate to pass the stop line of the intersection, and the maximum speed after acceleration does not exceed 10% of the maximum speed limit of the intersection.

3. The decision-making method for an autonomous driving vehicle passing a yellow light at an intersection according to claim 2, characterized in that: Also includes: S5: If the slow brake cannot stop the vehicle at the position before the stop line of the intersection, and the vehicle cannot pass the intersection at the current speed or accelerate within the specified time, an emergency brake decision is issued, and the acceleration of the emergency brake is greater than the specified acceleration threshold.

4. The decision-making method for an autonomous driving vehicle when passing a yellow light at an intersection according to claim 3, characterized in that: The prescribed time is set to 3s.

5. The decision-making method for an autonomous driving vehicle passing a yellow light at an intersection according to claim 3, characterized in that: Also includes: S6: If the traffic light is detected to be yellow at the first time, a decision to slow down the brakes is issued to control the vehicle to stop at a position before the stop line at the intersection.

6. The decision-making method for an autonomous driving vehicle passing a yellow light at an intersection according to claim 1, characterized in that: Also includes: S7: If the traffic light is blocked by the vehicle ahead after entering the detection range and the state of the traffic light at the intersection cannot be obtained, a stop decision is issued.

7. The decision-making method for an autonomous driving vehicle passing a yellow light at an intersection according to claim 6, characterized in that: Also includes: S71: If the vehicle ahead moves forward and eventually passes the stop line at the intersection, the vehicle stops before the stop line at the intersection until the traffic light turns green; S72: If the front vehicle moves forward and eventually does not pass the stop line of the intersection, the vehicle moves along with the front vehicle and stops behind the front vehicle.

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