A tunnel entrance area heterogeneous vehicle event triggering strategy

Abstract

The present application belongs to the field of intelligent transportation, and discloses a tunnel entrance area heterogeneous vehicle event triggering strategy, comprising: S1. establishing a tunnel entrance area network-connected human-driven vehicle driving model; S2. establishing a tunnel entrance area heterogeneous vehicle cooperative driving model; S3. designing a heterogeneous vehicle event triggering strategy. According to the characteristics of the tunnel entrance area, the differences in communication and perception between CHV and HV are considered, the tunnel entrance area heterogeneous vehicle cooperative driving model is established, so that the proposed model can better depict the driving law of heterogeneous vehicles in the tunnel entrance area. On the basis of the tunnel entrance area heterogeneous vehicle cooperative driving model, the present application further proposes a tunnel entrance area heterogeneous vehicle event triggering strategy, which provides theoretical guidance for improving the traffic condition of the tunnel entrance area while saving the computing and communication resources of the roadside equipment.

Description

Technical Field

[0001] The present invention belongs to the field of intelligent transportation, and in particular relates to a heterogeneous vehicle event triggering strategy in a tunnel entrance area. Background Art

[0002] Due to the rapidly changing driving environment and conditions inside and outside the tunnel, vehicle behavior at the entrance of a highway tunnel is complex, leading to significant traffic problems. With the development of connected vehicle (IoV) technology, roadside equipment (ROE) can send control information to connected human-driven vehicles (CHVs), enabling coordinated vehicle movement at the tunnel entrance, thereby improving traffic conditions. However, due to economic constraints and other factors, mixed traffic consisting of traditional human-driven vehicles (HVs) and CHVs will continue to exist. Differences between HVs and CHVs in communication and perception make the interaction between vehicles in this area even more complex. Furthermore, the CHVs' ability to improve traffic conditions at the tunnel entrance largely stems from the connected control exerted by the RSE on the CHVs, a process that consumes significant computational and communication resources. In reality, not all CHVs require real-time control from RSEs. Therefore, establishing a model for heterogeneous vehicle cooperative driving at the tunnel entrance and proposing corresponding event-triggered strategies can improve traffic efficiency at the tunnel entrance while conserving computational and communication resources of RSEs.

[0003] A review of relevant patents and papers revealed that few patents currently address control strategies for mixed traffic consisting of traditional and connected vehicles at tunnel entrances. Patent CN117236017A discloses a method for modeling the coordinated operation of connected vehicles at tunnel entrances based on a social force model. This method establishes a model for the coordinated operation of connected vehicles at tunnel entrances. However, this method fails to capture the driving patterns of heterogeneous vehicles at tunnel entrances and fails to conserve computing and communication resources for roadside equipment. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a heterogeneous vehicle event triggering strategy in the tunnel entrance area. The present invention aims to solve the problem that the existing method consumes large computing and communication resources and is difficult to characterize the driving patterns of heterogeneous vehicles in the tunnel entrance area.

[0005] The present invention provides a heterogeneous vehicle event triggering strategy in a tunnel entrance area, comprising the following steps:

[0006] S1. Establish a connected human driving model in the tunnel entrance area;

[0007] S2. Establish a cooperative driving model for heterogeneous vehicles in the tunnel entrance area;

[0008] S3. Design a triggering strategy for heterogeneous vehicle events.

[0009] Furthermore, the specific content of step S1 is: constructing a connected human driving model in the tunnel entrance area from the perspective of social forces, that is, describing the dynamic behavior of the connected human driving in the tunnel entrance area through the self-driving force, the repulsive force between vehicles, the potential field force of the tunnel, and the network control force during the vehicle driving process;

[0010] I. The calculation expression of self-driving force is:

[0011]

[0012] Where, The positive direction is from outside the tunnel to inside the tunnel; m n is the mass of the nth car; a n is the maximum acceleration expected of the vehicle; is the position of the nth vehicle at time t; v max is the speed limit of the road. When the vehicle is outside the tunnel, v max is the speed limit outside the tunnel. When the vehicle is inside the tunnel, v max is the speed limit in the tunnel;

[0013] II. The calculation expression of the repulsive force between vehicles is:

[0014]

[0015] s n,CHV (t) = x n-1 (t)-x n (t)

[0016]

[0017] Where, The positive direction is from outside the tunnel to inside the tunnel; s n (t) is the distance between the nth vehicle and the preceding vehicle n-1; is the expected distance between the nth vehicle; T n is the expected headway; x n (t) is the position of the nth vehicle at time t; s0 is the minimum headway; b is the minimum desired deceleration of the vehicle; Δv n (t) = v n (t)-v n-1 (t), is the speed difference between the nth car and the n-1th car; and are the communication delays of CHV for inter-vehicle distance and speed difference, respectively;

[0018] III. The calculation expression of the potential field force of the tunnel is:

[0019]

[0020]

[0021] Where, the tunnel potential field The positive direction is from outside the tunnel to inside the tunnel; k tun is the potential field coefficient of the tunnel entrance area; d is the coordinate of the vehicle; d0 is the coordinate when the vehicle has the maximum deceleration in the deceleration section at the tunnel entrance; σ x is a coefficient related to the length of the vehicle's deceleration distance; v n (t) is the speed of the vehicle; v limit is the speed limit inside the tunnel;

[0022] IV. The calculation expression of the network control force is:

[0023]

[0024]

[0025] Where, α l represents the weight coefficient of the influence of the nlth vehicle on the target vehicle. The sum of the weight coefficients of the k vehicles in front of the target vehicle is 1, and the closer to the target vehicle, the larger the weight coefficient; c is the control coefficient; k represents the number of vehicles whose preceding vehicle information the target vehicle can obtain; Δv n-l,n (t) = v n-l (t)-v n (t) represents the speed difference between the nlth car and the nth car; It is the communication delay of CHV to multiple preceding vehicle speed difference information.

[0026] Furthermore, step S2 includes the following sub-steps:

[0027] S2.1 Establish a model of traditional human driving;

[0028]

[0029]

[0030]

[0031]

[0032]

[0033] Where, and They represent the speed of the vehicle, the distance between the vehicle and the preceding vehicle, and the speed difference perceived by the driver respectively; and They are the HV’s perception delay of the inter-vehicle distance and speed difference;

[0034] S2.2 For a heterogeneous vehicle queue with N vehicles, use the adjacency matrix Characterizing the communication topology between heterogeneous vehicles, the expression is as follows:

[0035]

[0036]

[0037] Where, I N is the N-dimensional identity matrix; N =diag{ξ 11 ,ξ 22 ,…,ξ NN} represents the vehicle type in the heterogeneous vehicle, ξ nn =1 means the nth vehicle is a CHV, ξ nn =0 means the nth vehicle is a HV;

[0038] S2.3 Based on the communication topology relationship between heterogeneous vehicles, a cooperative driving model of heterogeneous vehicles in the tunnel entrance area is established;

[0039]

[0040] Where, ξ nn represents the vehicle type of heterogeneous vehicles, ξ nn =1 means the nth vehicle is a CHV, ξ nn =0 indicates that the nth vehicle is an HV.

[0041] Furthermore, the heterogeneous vehicle event triggering strategy in step S3 is as follows: vehicle information on the road is collected by roadside equipment, and based on the difference between the distance between the CHV and the preceding vehicle and the distance between the balancing vehicles, whether to perform network control on the target CHV is determined. Only when the difference is greater than a set threshold does the roadside equipment perform network control on the target CHV.

[0042] If the nth vehicle is a CHV, the event triggering conditions are as follows:

[0043]

[0044] Where n is the vehicle number; is the time when the nth vehicle is controlled for the u+1th time; x n-1 (t) and x n (t) represents the position of the nth vehicle and the n-1th vehicle at time t; se is the distance between balancing vehicles, and thr is the triggering threshold.

[0045] Furthermore, the trigger threshold thr=3m.

[0046] Beneficial effects:

[0047] 1. Based on the characteristics of the tunnel entrance area and taking into account the differences in communication and perception between CHVs and HVs, this paper establishes a cooperative driving model for heterogeneous vehicles in the tunnel entrance area. This model can better characterize the driving patterns of heterogeneous vehicles in the tunnel entrance area.

[0048] 2. Based on the model of cooperative driving of heterogeneous vehicles in the tunnel entrance area, this paper further proposes a strategy for triggering heterogeneous vehicle events in the tunnel entrance area, providing theoretical guidance for saving computing and communication resources of roadside equipment while improving traffic conditions in the tunnel entrance area.

[0049] Other advantages, objects, and features of the present invention will be described in part in the following description and, in part, will be apparent to those skilled in the art upon examination of the following description or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is a flow chart of a heterogeneous vehicle event triggering strategy for a tunnel entrance area according to the present invention;

[0051] Figure 2 Schematic diagram of heterogeneous vehicle communication topology in the tunnel entrance area;

[0052] Figure 3 The speed curves of heterogeneous vehicle queues passing through the tunnel entrance area under different penetration rates;

[0053] Figure 4 The inter-vehicle distance curves of heterogeneous vehicle queues passing through the tunnel entrance area under different penetration rates;

[0054] Figure 5 When N=21, the number of times the roadside equipment sends control information to the CHV. DETAILED DESCRIPTION

[0055] To make the technical solutions, advantages, and purposes of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0056] like Figure 1 As shown, the present invention provides a heterogeneous vehicle event triggering strategy in the tunnel entrance area, including the following steps:

[0057] S1. Establish a connected human driving model in the tunnel entrance area;

[0058] At the tunnel entrance area, the driving of the connected human driver will be affected by the environment of the tunnel entrance area and the vehicle in front. In addition, in the connected environment, the connected human driver can obtain information about the surrounding vehicles through roadside equipment, thereby achieving cooperative driving. Based on the above analysis, a connected human driver driving model in the tunnel entrance area can be constructed from the perspective of social forces. By considering virtual forces such as the self-driving force, the repulsive force between vehicles, the potential field force of the tunnel, and the connected control force during vehicle driving, the dynamic behavior of the connected human driver in the tunnel entrance area is characterized. The expressions of these social forces are as follows:

[0059] (1) Self-driving force:

[0060]

[0061] in, The positive direction is from outside the tunnel to inside the tunnel, m n is the mass of the nth car, a n is the maximum acceleration expected of the vehicle, is the position of the nth vehicle at time t, v max is the speed limit of the road. When the vehicle is outside the tunnel, v max is the speed limit outside the tunnel. When the vehicle is inside the tunnel, v max This is the speed limit in the tunnel.

[0062] (2) Repulsive force between vehicles: In the case of a single lane, a vehicle is only affected by the vehicle in front. This means that the vehicle will only experience repulsive force from the vehicle in front. The magnitude of this repulsive force is related to the distance between the two vehicles and the speed difference, and its direction is opposite to the direction of travel of the vehicle. The expression of the repulsive force between vehicles is as follows:

[0063]

[0064] s n,CHV (t) = x n-1(t)-x n (t)

[0065]

[0066] in, The positive direction is from outside the tunnel to inside the tunnel, s n (t) is the distance between the nth vehicle and the preceding vehicle n-1, is the expected distance between the nth vehicle, T n is the expected headway, x n (t) is the position of the nth vehicle at time t, s0 is the minimum headway, b is the minimum deceleration expected by the vehicle, Δv n (t) = v n (t)-v n-1 (t) is the speed difference between the nth vehicle and the n-1th vehicle. The communication between the roadside equipment and the CHV will have a certain delay time. and are the communication delays of CHV for inter-vehicle distance and speed difference, respectively.

[0067] (3) Network control force: In a networked environment, roadside equipment can send speed adjustment instructions to the CHV through vehicle-road communication based on the collected vehicle information on the road, such as position, speed, acceleration, etc., to adjust the driving state of the networked driver. This effect can be regarded as a virtual force, namely the network control force. Considering the information of multiple leading vehicles can improve the quality of the vehicle's driving decision, and when the vehicle can better follow the speed of the leading vehicle, it can effectively reduce the speed disturbance in the traffic flow, thereby suppressing the formation of traffic congestion. Based on the above analysis, the following network control force is proposed:

[0068]

[0069]

[0070] Among them, α l Represents the weight coefficient of the impact of the nlth vehicle on the target vehicle, and α1<α2<…<α k This is because the closer the vehicle is to the target vehicle, the greater its influence on it, and the greater its weight coefficient. c is the control coefficient, and k represents the number of vehicles whose preceding vehicle information the target vehicle can obtain. Δv n-l,n (t) = v n-l (t)-v n (t) represents the speed difference between the nlth car and the nth car. It is the communication delay of CHV to multiple preceding vehicle speed difference information.

[0071] (4) Tunnel potential force: When a vehicle enters the tunnel entrance area, due to the speed limit and environmental changes inside and outside the tunnel, the driver will slow down in this area. The tunnel potential force is:

[0072]

[0073]

[0074] Among them, the tunnel potential field The positive direction is from outside the tunnel to inside the tunnel, k tun is the potential field coefficient of the tunnel entrance area, d is the coordinate of the vehicle, d0 is the coordinate when the vehicle has the maximum deceleration in the deceleration section at the tunnel entrance, σ x is the coefficient related to the length of the vehicle deceleration distance, v n (t) is the speed of the vehicle, v limit It is the speed limit inside the tunnel.

[0075] It should be noted that the tunnel potential field exists only when the vehicle is within 200 m from the tunnel entrance and the speed is greater than the speed limit in the tunnel. In this embodiment, the relevant parameters in the model are set to the parameters in Table 1.

[0076] Table 1. Relevant parameters of the model

[0077]

[0078]

[0079] S2. Establish a cooperative driving model for heterogeneous vehicles in the tunnel entrance area;

[0080] With the development of connected vehicle technology, mixed traffic consisting of traditional human drivers and connected vehicles will continue to exist for a long time. The introduction of connected vehicles provides a new means of regulating traffic conditions at tunnel entrances, but it also complicates traffic conditions there. Compared to hybrid vehicles (HVs), hybrid vehicles (HVs) can only obtain information about the vehicle ahead through the driver's vision, and there is a difference between the perception latency of HVs and the communication latency of CHVs. Based on the above analysis, we first establish a model for traditional human drivers as follows:

[0081]

[0082] in,

[0083]

[0084]

[0085]

[0086]

[0087] in, and They are the speed of the vehicle, the distance between the vehicle and the preceding vehicle, and the speed difference information perceived by the driver. and They are the HV’s perception delay of the vehicle distance and speed difference.

[0088] For fleets consisting entirely of HVs and CHVs, the adjacency matrix can be used to and The communication topology between vehicles is described as follows:

[0089]

[0090] Therefore, for a heterogeneous vehicle queue with N vehicles, the adjacency matrix can be used Characterizing the communication topology between heterogeneous vehicles, its expression is as follows:

[0091]

[0092] Among them, I N is the N-dimensional identity matrix, N =diag{ξ 11 ,ξ 22 ,…,ξ NN} represents the vehicle type in the heterogeneous vehicle, ξ nn =1 means the nth vehicle is a CHV, ξ nn =0 indicates that the nth vehicle is an HV.

[0093] Combining the aforementioned communication topology between heterogeneous vehicles, a cooperative driving model of heterogeneous vehicles in the tunnel entrance area can be established:

[0094]

[0095] Where, ξ nn represents the vehicle type of heterogeneous vehicles, ξ nn =1 means the nth vehicle is a CHV, ξ nn =0 indicates that the nth vehicle is an HV.

[0096] In this embodiment, the HV perception delay is set and The schematic diagram of heterogeneous vehicle communication topology in the tunnel entrance area is as follows: Figure 2 shown.

[0097] S3. Design a triggering strategy for heterogeneous vehicle events;

[0098] While roadside equipment sending control information to a CHV can improve traffic conditions at tunnel entrances, real-time control by the roadside equipment is not necessary during the CHV's passage through the tunnel entrance. Real-time control of the CHV would waste the roadside equipment's computing and communication resources. Therefore, drawing on the concept of event-triggered control, we propose the following heterogeneous vehicle event triggering strategy: the roadside equipment collects vehicle information on the road and determines whether to initiate network control of the CHV based on the difference between the distance between the CHV and the preceding vehicle and the distance between the balancing vehicle and the preceding vehicle. Only when this difference exceeds a set threshold does the roadside equipment initiate network control of the CHV, thus reducing unnecessary computation and communication.

[0099] According to the above analysis, if the nth vehicle is a CHV, the event triggering conditions are as follows:

[0100]

[0101] Where n is the vehicle number, is the time when the nth vehicle is controlled for the u+1th time, x n-1 (t) and x n (t) are the positions of the nth vehicle and the n-1th vehicle at time t. e is the distance between balancing vehicles, and thr is the triggering threshold.

[0102] In this embodiment, the trigger threshold thr is set to 3m. The flow chart of the trigger strategy for heterogeneous vehicle events in the tunnel entrance area is as follows: Figure 1 As shown. Based on the proposed heterogeneous vehicle event triggering strategy, CHV is controlled through networking. Figure 3 The speed curves of heterogeneous vehicle queues passing through the tunnel entrance area at different penetration rates when N=21 are shown. Figure 4 The inter-vehicle distance curves of heterogeneous vehicle queues passing through the tunnel entrance area at different penetration rates are shown when N=21. Figure 5 The results show that when N=21, under the conditions of event-triggered control and real-time control, the number of times the roadside equipment sends control information to the CHV when a heterogeneous vehicle queue with different penetration rates passes through the tunnel entrance area.

[0103] It is hereby stated that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. 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 solutions of the present invention may be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions, which should all be included in the scope of the claims of the present invention.

Claims

1. A heterogeneous vehicle event triggering strategy in the tunnel entrance area, characterized by: The following steps are involved: S1. Establish a connected human driving model in the tunnel entrance area; The specific content of step S1 is: constructing a connected human driving model in the tunnel entrance area from the perspective of social forces, that is, describing the dynamic behavior of the connected human driving in the tunnel entrance area through the self-driving force, the repulsive force between vehicles, the potential field force of the tunnel, and the network control force during the vehicle driving process; I. The calculation expression of self-driving force is: Where, The positive direction is from outside the tunnel to inside the tunnel; m n is the mass of the nth car; a n is the maximum acceleration expected of the vehicle; is the position of the nth vehicle at time t; v max is the speed limit of the road. When the vehicle is outside the tunnel, v max is the speed limit outside the tunnel. When the vehicle is inside the tunnel, v max is the speed limit in the tunnel; II. The calculation expression of the repulsive force between vehicles is: s n,CHV (t)=x n-1 (t)-x n (t) Where, The positive direction is from outside the tunnel to inside the tunnel; s n (t) is the distance between the nth vehicle and the preceding vehicle n-1; is the expected distance between the nth vehicle; T n is the expected headway; x n (t) is the position of the nth vehicle at time t; s0 is the minimum headway; b is the minimum desired deceleration of the vehicle; Δv n (t) = v n (t)-v n-1 (t), is the speed difference between the nth car and the n-1th car; and are the communication delays of CHV for inter-vehicle distance and speed difference, respectively; III. The calculation expression of the potential field force of the tunnel is: Where, the tunnel potential field The positive direction is from outside the tunnel to inside the tunnel; k tun is the potential field coefficient in the tunnel entrance area; d is the coordinate of the vehicle; d0 is the coordinate when the vehicle has the maximum deceleration in the deceleration section at the tunnel entrance; σ x is a coefficient related to the length of the vehicle's deceleration distance; v n (t) is the speed of the vehicle; v limit is the speed limit inside the tunnel; IV. The calculation expression of the network control force is: Where, α l represents the weight coefficient of the influence of the nlth vehicle on the target vehicle. The sum of the weight coefficients of the k vehicles in front of the target vehicle is 1, and the closer to the target vehicle, the larger the weight coefficient; c is the control coefficient; k represents the number of vehicles whose preceding vehicle information the target vehicle can obtain; Δv n-l,n (t) = v n-l (t)-v n (t) represents the speed difference between the nlth car and the nth car; is the communication delay of CHV to multiple preceding vehicle speed difference information; S2. Establish a cooperative driving model for heterogeneous vehicles in the tunnel entrance area; S2.1 Establish a model of traditional human driving; Where, and They represent the speed of the vehicle, the distance between the vehicle and the preceding vehicle, and the speed difference perceived by the driver respectively; and They are the HV’s perception delay of the inter-vehicle distance and speed difference; S2.2 For a heterogeneous vehicle queue with N vehicles, use the adjacency matrix A N Characterizing the communication topology between heterogeneous vehicles, the expression is as follows: A N =(I N -X N )A HV +Ξ N A CHV Where, I N is the N-dimensional identity matrix; N =diag{ξ 11 ,ξ 22 ,…,ξ NN } represents the vehicle type in the heterogeneous vehicle, ξ nn =1 means the nth vehicle is a CHV, ξ nn =0 means the nth vehicle is a HV; S2.3 Based on the communication topology relationship between heterogeneous vehicles, a cooperative driving model of heterogeneous vehicles in the tunnel entrance area is established; Where, ξ nn represents the vehicle type of heterogeneous vehicles, ξ nn =1 means the nth vehicle is a CHV, ξ nn =0 means the nth vehicle is a HV; S3. Design a triggering strategy for heterogeneous vehicle events.

2. The heterogeneous vehicle event triggering strategy for a tunnel entrance area according to claim 1 is characterized by: The heterogeneous vehicle event triggering strategy in step S3 is as follows: the roadside equipment collects vehicle information on the road and determines whether to perform network control on the target CHV based on the difference between the distance between the CHV and the preceding vehicle and the distance between the balancing vehicles. The roadside equipment performs network control on the target CHV only when the difference is greater than a set threshold. If the nth vehicle is a CHV, the event triggering conditions are as follows: Where n is the vehicle number; is the time when the nth vehicle is controlled for the u+1th time; x n-1 (t) and x n (t) represents the position of the nth vehicle and the n-1th vehicle at time t; s e is the distance between balancing vehicles, and thr is the triggering threshold.

3. The heterogeneous vehicle event triggering strategy for a tunnel entrance area according to claim 2 is characterized by: The triggering threshold thr=3m.

Images