Right-turn vehicle and straight non-motor vehicle track prediction and conflict early warning method

Abstract

The invention provides a right-turn vehicle and straight-going non-motor vehicle track prediction and conflict early warning method. The method comprises the following steps: determining the positions of right-turn motor vehicles and straight-going non-motor vehicles according to signals output by pressure sensors in a right-turn area of a right-turn lane and a right-turn area of a non-motor vehicle lane; the positions of the motor vehicles and the non-motor vehicles are numbered based on the time interval t, and motor vehicle driving information and non-motor vehicle driving information are determined; a random number is introduced into the motor vehicle driving information to update the motor vehicle driving information, the positions of all moments are updated according to the updated motor vehicle driving information and the non-motor vehicle driving information, and the driving tracks of the motor vehicle and the non-motor vehicle are obtained through fitting based on the updated positions; and predicting the time when the motor vehicle and the non-motor vehicle arrive at the potential conflict area based on the driving tracks of the motor vehicle and the non-motor vehicle, determining the difference absolute value of the time when the motor vehicle and the non-motor vehicle arrive at the potential conflict area, determining the conflict level according to the difference absolute value, and carrying out early warning according to the conflict level.

Description

Technical Field

[0001] The present invention relates to the field of intelligent traffic prediction and control, and in particular to a method for predicting and warning the trajectories of right-turning vehicles and straight-moving non-motor vehicles and for early warning of conflicts. Background Art

[0002] As urban traffic becomes increasingly congested and complex, the conflict between right-turning vehicles and straight-moving non-motorized vehicles has become increasingly prominent. At many urban intersections, right-turning vehicles and straight-moving or left-turning non-motorized vehicles (such as bicycles and electric vehicles) often cross paths, increasing the risk of traffic accidents. This conflict not only threatens road traffic safety, but also affects the smoothness of urban traffic.

[0003] First, there are significant differences in the motion characteristics of right-turning vehicles and straight-moving non-motorized vehicles. Right-turning vehicles are usually faster, and their driving trajectories are affected by many factors such as intersection geometry and traffic signals. Straight-moving non-motorized vehicles are more flexible and their trajectories are more difficult to predict. Therefore, how to accurately predict the trajectories of these two types of traffic participants is the key to conflict warning.

[0004] Secondly, existing conflict warning methods are often based on static intersection geometry and traffic rules, while ignoring the dynamic changes in actual traffic flow. For example, when a right-turning vehicle stops and waits at a red light, its subsequent driving trajectory and speed will change. This dynamic change is crucial to the accuracy of trajectory prediction and conflict warning.

[0005] Therefore, in order to solve the above technical problems, it is urgent to propose a new technical means. Summary of the invention

[0006] In view of this, the purpose of the present invention is to provide a method for predicting the trajectories of right-turning vehicles and straight-moving non-motor vehicles and for warning of conflicts. The method can timely discover the conflict area between right-turning motor vehicles and straight-moving non-motor vehicles based on the initial positions of motor vehicles and non-motor vehicles and the motion information during the moving process, and make intelligent and accurate warnings in combination with the current intersection aggregation form, thereby effectively reducing the conflicts between right-turning motor vehicles and straight-moving non-motor vehicles and reducing the incidence of traffic accidents at intersections.

[0007] The present invention provides a method for predicting and warning the trajectories of a right-turning vehicle and a straight-moving non-motor vehicle and for early warning of a conflict, comprising the following steps:

[0008] S1. Establish a rectangular coordinate system with the end point of the left solid line of the right-turn lane in the motor vehicle lane as the origin, the forward direction of the motor vehicle as the x-axis direction, and the direction perpendicular to the x-axis and located on the right side of the motor vehicle lane as the y-axis direction;

[0009] S2. A pressure sensor is provided in the right-turn area of ​​the right-turn lane of the motor vehicle lane and the non-motor vehicle lane corresponding to the right-turn area, and the position of the right-turning motor vehicle and the straight non-motor vehicle is determined according to the signal output by the pressure sensor;

[0010] S3. Determine the time interval △t, and number the positions of motor vehicles and non-motor vehicles based on the time interval △t, and determine the driving information of motor vehicles and non-motor vehicles, wherein the driving information of motor vehicles includes speed, deflection angle, acceleration; the driving information of non-motor vehicles includes speed and acceleration;

[0011] S4. Introducing random numbers into the motor vehicle driving information, and updating the motor vehicle driving information, updating the positions of each moment with the updated motor vehicle driving information and non-motor vehicle driving information, and fitting the driving trajectories of motor vehicles and non-motor vehicles based on the updated positions;

[0012] S5. Predict the time when the motor vehicle and the non-motor vehicle arrive at the potential conflict area based on the driving trajectories of the motor vehicle and the non-motor vehicle, and calculate the absolute value PET of the difference between the time when the motor vehicle and the non-motor vehicle arrive at the potential conflict area, determine the conflict level according to the absolute value PET, and issue an early warning based on the conflict level.

[0013] Further, determining the positions of the right-turning motor vehicle and the straight-moving non-motor vehicle according to the signal output by the pressure sensor specifically includes:

[0014] The positions of the four wheels of the motor vehicle are determined based on the pressure sensor outputting the pressure signal, and are expressed as:

[0015] (x moi ,y moi ), i = 1, 2, 3, 4, when i = 1, 2, 3, 4, when i is 1 and 2, it represents the left front wheel and the right front wheel respectively, and when i is 3 and 4, it represents the left rear wheel and the right rear wheel respectively; the positions of the two wheels of the non-motor vehicle are determined according to the pressure sensor that outputs the pressure signal, and are expressed as: (x nmoj ,y nmoj ), j = 1, 2;

[0016] Determine the position of the vehicle as (x mo ,y mo ):

[0017] or

[0018]

[0019] Determine the position of the non-motor vehicle as (x nmo ,y nmo ):

[0020]

[0021] Further, step S3 specifically includes:

[0022] The speed, acceleration and deflection angle of the vehicle are:

[0023]

[0024] Where: v MO represents the speed of the motor vehicle, a MO represents the acceleration of the motor vehicle; θ is the deflection angle of the motor vehicle, (x mo,n ,y mo,n ) represents the coordinates of the motor vehicle in the coordinate system at the nth time interval △t.

[0025] Further, updating the position at each time with the updated driving information of the motor vehicle and the driving information of the non-motor vehicle specifically includes:

[0026] Introduce random numbers into the acceleration and deflection angle of the motor vehicle, and determine the acceleration and deflection angle after the random numbers are introduced:

[0027]

[0028] θ up =θ+ξ θ ;

[0029] in: is the acceleration after the introduction of random numbers, θ up is the vehicle deflection angle after the introduction of random numbers, ξ a is the acceleration random number, ξ θ is the random number of the deflection angle of the motor vehicle;

[0030] Determine the displacement of the vehicle:

[0031]

[0032] Among them, t is the time length set to determine the displacement;

[0033] Determine the components △x and △y of the displacement S in the x-axis and y-axis directions of the coordinate system:

[0034] △x=S×cosθ up ;

[0035] △y=S×sinθ up ;

[0036] Update the position of the vehicle to (x' mo ,y' mo )

[0037] x'mo,n = x mo,n-1 + Δx;

[0038] y' mo,n = y mo,n-1 + Δy.

[0039] Furthermore, determine the conflict level according to the absolute value of the difference PET and give an early warning based on the conflict level, which specifically includes:

[0040] Determine the absolute value of the difference PET:

[0041] PET = |T mo - T nmo |;

[0042] Where: T mo is the time when the right-turning motor vehicle arrives at the potential conflict area, and T nmo is the time when the non-motor vehicle arrives at the potential conflict area;

[0043] Set the early warning thresholds T1 and T2, and T1 < T2;

[0044] When PET ≤ T1, at this time, it is a high risk of conflict between the right-turning motor vehicle and the straight-going non-motor vehicle. If T mo ≥ T nmo , then the red light of the right-turning lane is always on and a deceleration voice prompt is given to the motor vehicle; when T mo < T nmo , then the red light of the non-motor vehicle lane is always on and a deceleration voice prompt is given to the non-motor vehicle;

[0045] When T1 < PET < T2, at this time, it is a medium risk of conflict between the right-turning motor vehicle and the straight-going non-motor vehicle. If T mo ≥ T nmo , then the yellow light of the right-turning lane flashes and a voice prompt of "pay attention to observation" is given to the motor vehicle; when T mo < T nmo , then the yellow light of the non-motor vehicle lane flashes and a voice prompt of "pay attention to observation" is given to the non-motor vehicle;

[0046] When PET > T2, at this time, it is a low risk of conflict between the right-turning motor vehicle and the straight-going non-motor vehicle, and no early warning prompt is turned on.

[0047] Furthermore, determine the times T mo and T nmo when the right-turning motor vehicle and the non-motor vehicle arrive at the potential conflict area according to the following method:

[0048] Where π is the pi, d is the arc radius of the traveling trajectory when the vehicle turns right to the conflict area, and θ1 is the central angle turned when the vehicle turns right to the conflict area; v MOSThe speed of the motor vehicle at the starting point of the right turn;

[0049] Among them, L nmo is the distance from the current position of the non-motor vehicle to the conflict area when it is going straight, v nmo The speed of non-motor vehicles.

[0050] The beneficial effects of the present invention are as follows: Through the present invention, the conflict area between right-turning motor vehicles and straight-moving non-motor vehicles can be timely discovered based on the initial positions of motor vehicles and non-motor vehicles and the movement information during the travel process, and intelligent and accurate early warning can be performed in combination with the current intersection aggregation form, thereby effectively reducing the conflict between right-turning motor vehicles and straight-moving non-motor vehicles and reducing the incidence of traffic accidents at intersections. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0052] Figure 1 It is a flow chart of the present invention.

[0053] Figure 2 It is a schematic diagram of the conflict between a right-turning vehicle and a straight-moving non-motor vehicle at an intersection in the present invention. DETAILED DESCRIPTION

[0054] The present invention is further described in detail below:

[0055] The present invention provides a method for predicting and warning the trajectories of a right-turning vehicle and a straight-moving non-motor vehicle and for early warning of a conflict, comprising the following steps:

[0056] S1. Take the left solid line end point of the right turn lane in the motor vehicle lane as the origin, take the forward direction of the motor vehicle as the x-axis direction, and take the direction perpendicular to the x-axis and located on the right side of the motor vehicle lane as the y-axis direction to establish a rectangular coordinate system; Figure 2 As shown, if there are two or more right-turn lanes, the end point of the left solid line of the leftmost right-turn lane is taken as the origin. The left and right sides in the present invention are both based on the forward direction of the motor vehicle as a reference;

[0057] S2. A pressure sensor is set in the right-turn area of ​​the right-turn lane of the motor vehicle lane and the non-motor vehicle lane corresponding to the right-turn area, and the position of the right-turning motor vehicle and the straight-going non-motor vehicle is determined according to the signal output by the pressure sensor; the position of the pressure sensor in the coordinate system is determined, and when a certain pressure sensor or several pressure sensors output a pressure signal, the current wheel position coordinate position can be determined, and the coordinate position corresponds to the coordinate position of the pressure sensor being pressed;

[0058] S3. Determine the time interval △t, and number the positions of motor vehicles and non-motor vehicles based on the time interval △t, and determine the motor vehicle driving information and non-motor vehicle driving information, wherein the motor vehicle driving information includes speed, deflection angle, acceleration;

[0059] Specifically: determining the positions of the right-turning motor vehicle and the straight-moving non-motor vehicle according to the signal output by the pressure sensor specifically includes:

[0060] The positions of the four wheels of the motor vehicle are determined based on the pressure sensor outputting the pressure signal, and are expressed as:

[0061] (x moi ,y moi ), i = 1, 2, 3, 4, when i = 1, 2, 3, 4, when i is 1 and 2, it represents the left front wheel and the right front wheel respectively, and when i is 3 and 4, it represents the left rear wheel and the right rear wheel respectively; the positions of the two wheels of the non-motor vehicle are determined according to the pressure sensor that outputs the pressure signal, and are expressed as: (x nmoj ,y nmoj ), j = 1, 2;

[0062] Determine the position of the vehicle as (x mo ,y mo ):

[0063] or

[0064]

[0065] Determine the position of the non-motor vehicle as (x nmo ,y nmo ):

[0066]

[0067] The non-motor vehicle driving information includes speed and acceleration; of course, when determining the time interval △t, the initial position of the current motor vehicle and non-motor vehicle must be determined first, and the initial position is the basis for subsequent position updates; starting from the initial position A, when driving to the current moment, the motor vehicle has continuously driven for t1 time, then the t1 time is divided according to △t to form multiple time intervals, and then each time price has a position point, so the position is numbered;

[0068] S4. Introducing random numbers into the motor vehicle driving information, and updating the motor vehicle driving information, updating the position of each moment with the updated motor vehicle driving information and non-motor vehicle driving information, and fitting the driving trajectories of motor vehicles and non-motor vehicles based on the updated position; specifically:

[0069] The speed, acceleration and deflection angle of the vehicle are:

[0070]

[0071] Where: v MO represents the speed of the motor vehicle, a MO represents the acceleration of the motor vehicle; θ is the deflection angle of the motor vehicle, (x mo,n ,y mo,n ) represents the coordinates of the motor vehicle in the coordinate system at the nth time interval △t.

[0072] Updating the position at each time with the updated driving information of motor vehicles and non-motor vehicles specifically includes:

[0073] Introduce random numbers into the acceleration and deflection angle of the motor vehicle, and determine the acceleration and deflection angle after the random numbers are introduced:

[0074]

[0075] in: is the acceleration after the introduction of random numbers, θ up is the vehicle deflection angle after the introduction of random numbers, ξ a is the acceleration random number, ξ θ is the random number of the deflection angle of the motor vehicle; the random number of the acceleration and the random number of the deflection angle of the motor vehicle are determined based on the existing empirical estimation method. When estimating empirically, factors such as the shape of the intersection and the traffic flow status are referred to. The shape of the intersection is fixed, and the traffic flow status is dynamic. Different random numbers are estimated under different traffic conditions and stored accordingly. When in use, the current traffic flow status is obtained, and then the corresponding random number is found.

[0076] Determine the displacement of the vehicle:

[0077]

[0078] Among them, t is the time length set to determine the displacement;

[0079] Determine the components △x and △y of the displacement S in the x-axis and y-axis directions of the coordinate system:

[0080] △x=S×cosθ up (10);

[0081] △y=S×sinθ up (11);

[0082] Update the position of the vehicle to (x' mo ,y' mo )

[0083] x' mo,n =xmo,n-1 +△x(12);

[0084] y' mo,n =y mo,n-1 +△y(13).

[0085] In this step, the purpose is to predict the movement trajectory of the vehicle after the current moment. From the current moment, the conflict position between the motor vehicle and the straight-moving non-motor vehicle when turning right is a position. Therefore, the above process is used for prediction. At the current moment T+△t, the position of the motor vehicle can be determined through the above process. After the position is determined, the position of T+2△t is predicted by the above process, and then the positions at each future moment are fitted to obtain the predicted trajectory. For the non-motor vehicle, it is moving straight, so its trajectory is a straight line (the non-motor vehicle does not strictly travel in a straight line on the road during driving. When processing, it is directly equivalent to a straight line). The intersection of the straight line and the trajectory of the motor vehicle is the conflict point. However, generally, a conflict area is defined according to a set range with the intersection as the center of the range. Then, the time when the motor vehicle and the non-motor vehicle arrive at the conflict area is predicted based on the current speed of the vehicle.

[0086] S5. Predict the time when the motor vehicle and the non-motor vehicle arrive at the potential conflict area based on the driving trajectories of the motor vehicle and the non-motor vehicle, and calculate the absolute value PET of the difference between the time when the motor vehicle and the non-motor vehicle arrive at the potential conflict area, determine the conflict level according to the absolute value PET, and issue an early warning based on the conflict level.

[0087] The conflict level is determined based on the absolute value of the difference PET, and an early warning is issued based on the conflict level, including:

[0088] Determine the absolute value of the difference PET:

[0089] PET=|T mo -T nmo |(14);

[0090] Where: T mo T is the time it takes for a right-turning vehicle to reach the potential conflict area. nmo The time it takes for non-motor vehicles to reach the potential conflict area;

[0091] Set warning thresholds T1 and T2, and T1 <T2;

[0092] When PET≤T1, there is a high risk of conflict between right-turning motor vehicles and straight-moving non-motor vehicles. mo ≥T nmo , the red light in the right-turn lane stays on and a voice prompt is given to vehicles to slow down; when T mo <T nmoWhen this occurs, the red light on the non-motor vehicle lane remains constantly on and voice prompts for deceleration are given to non-motor vehicles.

[0093] When T1 < PET < T2, this is a medium risk of conflict between right-turning motor vehicles and straight-going non-motor vehicles. If T mo ≥ T nmo , then the yellow light on the right-turn lane flashes and voice prompts for motor vehicles to pay attention and observe are given; when T mo < T nmo , then the yellow light on the non-motor vehicle lane flashes and voice prompts for non-motor vehicles to pay attention and observe are given.

[0094] When PET > T2, this is a low risk of conflict between right-turning motor vehicles and straight-going non-motor vehicles, and no warning prompts are activated.

[0095] Determine the arrival times T mo and T nmo of right-turning motor vehicles and non-motor vehicles at the potential conflict area according to the following method:

[0096] Among them, π is the pi, d is the arc radius of the traveling trajectory when the vehicle turns right and moves to the conflict area, and θ1 is the central angle turned when the vehicle turns right and moves to the conflict area; v MOS is the vehicle speed of the motor vehicle at the starting point of the right turn. The starting point of the right turn is the end of the straight section of the right-turn lane and the starting point of the arc-shaped lane during the right turn. Generally, it is at the traffic light stop limit line. This speed is calculated through the motor vehicle speed determination formula (4).

[0097] Among them, L nmo is the distance from the current position of the non-motor vehicle going straight to the conflict area, and v nmo is the speed of the non-motor vehicle.

[0098] Through the above method, based on the initial positions of motor vehicles and non-motor vehicles and the movement information during the traveling process, the conflict area between right-turning motor vehicles and straight-going non-motor vehicles can be discovered in a timely manner, and intelligent and accurate warnings can be carried out in combination with the current intersection set form, so as to effectively reduce the conflict between right-turning motor vehicles and straight-going non-motor vehicles and reduce the incidence of traffic accidents at intersections.

[0099] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A method for predicting and warning the trajectories of right-turning vehicles and straight-moving non-motor vehicles, characterized in that: The following steps are involved: S1. Establish a rectangular coordinate system with the end point of the left solid line of the right-turn lane in the motor vehicle lane as the origin, the forward direction of the motor vehicle as the x-axis direction, and the direction perpendicular to the x-axis and located on the right side of the motor vehicle lane as the y-axis direction; S2. A pressure sensor is provided in the right-turn area of ​​the right-turn lane of the motor vehicle lane and the non-motor vehicle lane corresponding to the right-turn area, and the position of the right-turning motor vehicle and the straight non-motor vehicle is determined according to the signal output by the pressure sensor; S3. Determine the time interval △t, and number the positions of motor vehicles and non-motor vehicles based on the time interval △t, and determine the driving information of motor vehicles and non-motor vehicles, wherein the driving information of motor vehicles includes speed, deflection angle, acceleration; the driving information of non-motor vehicles includes speed and acceleration; S4. Introducing random numbers into the motor vehicle driving information, and updating the motor vehicle driving information, updating the positions of each moment with the updated motor vehicle driving information and non-motor vehicle driving information, and fitting the driving trajectories of motor vehicles and non-motor vehicles based on the updated positions; S5. Predict the time when the motor vehicle and the non-motor vehicle arrive at the potential conflict area based on the driving trajectories of the motor vehicle and the non-motor vehicle, and calculate the absolute value PET of the difference between the time when the motor vehicle and the non-motor vehicle arrive at the potential conflict area, determine the conflict level according to the absolute value PET, and issue an early warning based on the conflict level.

2. The method for predicting and warning the trajectories of right-turning vehicles and straight-moving non-motor vehicles according to claim 1 is characterized in that: And determining the positions of the right-turning motor vehicle and the straight-moving non-motor vehicle according to the signal output by the pressure sensor specifically includes: The positions of the four wheels of the motor vehicle are determined based on the pressure sensor outputting the pressure signal, and are expressed as: (x moi ,y moi ), i = 1, 2, 3, 4, when i = 1, 2, 3, 4, when i is 1 and 2, it represents the left front wheel and the right front wheel respectively, and when i is 3 and 4, it represents the left rear wheel and the right rear wheel respectively; the positions of the two wheels of the non-motor vehicle are determined according to the pressure sensor that outputs the pressure signal, and are expressed as: (x nmoj ,y nmoj ), j = 1, 2; Determine the position of the vehicle as (x mo ,y mo ): or Determine the position of the non-motor vehicle as (x nmo ,y nmo ):

3. The method for predicting and warning the trajectories of right-turning vehicles and straight-moving non-motor vehicles according to claim 2 is characterized in that: Step S3 specifically includes: The speed, acceleration and deflection angle of the vehicle are: Where: v MO represents the speed of the motor vehicle, a MO represents the acceleration of the motor vehicle; θ is the deflection angle of the motor vehicle, (x mo,n ,y mo,n ) represents the coordinates of the motor vehicle in the coordinate system at the nth time interval △t.

4. The method for predicting and warning the trajectories of right-turning vehicles and straight-moving non-motor vehicles and for early warning of conflicts according to claim 3 is characterized in that: Updating the position at each time with the updated driving information of motor vehicles and non-motor vehicles specifically includes: Introduce random numbers into the acceleration and deflection angle of the motor vehicle, and determine the acceleration and deflection angle after the random numbers are introduced: i up =θ+ξ θ ; in: is the acceleration after the introduction of random numbers, θ up is the vehicle deflection angle after the introduction of random numbers, ξ a is the acceleration random number, ξ θ is the random number of the deflection angle of the motor vehicle; Determine the displacement of the vehicle: Among them, t is the time length set to determine the displacement; Determine the components △x and △y of the displacement S in the x-axis and y-axis directions of the coordinate system: △x=S×cosθ up ; △y=S×sinθ up ; Update the position of the vehicle to (x' mo ,y' mo ) x' mo,n =x mo,n-1 +△x; and' mo,n =and mo,n-1 +△y。 5. The method for predicting and warning the trajectories of right-turning vehicles and straight-moving non-motor vehicles and for early warning of conflicts according to claim 4 is characterized in that: The conflict level is determined based on the absolute value of the difference PET, and an early warning is issued based on the conflict level, including: Determine the absolute value of the difference PET: PET=|T mo -T nmo |; Where: T mo T is the time it takes for a right-turning vehicle to reach the potential conflict area. nmo The time it takes for non-motor vehicles to reach the potential conflict area; Set warning thresholds T1 and T2, and T1 <T2; When PET≤T1, there is a high risk of conflict between right-turning motor vehicles and straight-moving non-motor vehicles. mo ≥T nmo , the red light in the right turn lane is always on and a voice prompt is given to the motor vehicle to slow down; when T mo <T nmo When the red light of the non-motor vehicle lane is on, the non-motor vehicle lane will be prompted to slow down by voice; When T1 < PET < T2, this is the medium risk of conflict between right-turning motor vehicles and straight-going non-motor vehicles. If T mo ≥ T nmo , then the yellow light of the right-turn lane flashes and a voice prompt for motor vehicles to pay attention and observe is given; when T mo < T nmo , then the yellow light of the non-motor vehicle lane flashes and a voice prompt for non-motor vehicles to pay attention and observe is given; When PET>T2, there is a low risk of conflict between right-turning motor vehicles and straight-moving non-motor vehicles, and the early warning prompt is not activated.

6. The method for predicting and warning the trajectories of right-turning vehicles and straight-moving non-motor vehicles and for early warning of conflicts according to claim 5, characterized in that: The time T for right-turning motor vehicles and non-motor vehicles to arrive at the potential conflict area is determined according to the following method mo and T nmo : Where π is the circumference of a circle, d is the radius of the arc of the trajectory of the vehicle when it turns right and moves to the conflict area, θ1 is the central angle of the circle that the vehicle turns when it moves to the conflict area; v MOS The speed of the motor vehicle at the starting point of the right turn; Among them, L nmo is the distance from the current position of the non-motor vehicle to the conflict area when it is going straight, v nmo The speed of non-motor vehicles.

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