Intelligent networked automobile formation distributed pulse control method based on event triggering

Abstract

The invention belongs to the technical field of intelligent networked automobiles, and particularly relates to an event triggering-based intelligent networked automobile formation distributed pulse control method, which comprises the following steps of: setting a vehicle team with connectivity, and setting a target path of the vehicle team and initial positions of a leading vehicle and each following vehicle; communication connection is established between the vehicles; checking whether the real-time state of the vehicle reaches a triggering condition or a checking period, if so, triggering a pulse signal, updating a controller, and spreading the information of the event to other vehicles through a communication link; and if not, continuously checking until the formation target is realized. According to the method, the second-order model is adopted, the pulse control technology is introduced into intelligent network connection automobile formation control, compared with an existing continuous control method, due to the fact that a communication channel is not occupied all the time through pulse control, communication network blocking and network jamming can be avoided, resources can be more effectively saved, and the control efficiency is improved. And the formation control target can be quickly realized, and the safety of following vehicles is guaranteed.

Description

Technical Field

[0001] This invention relates to the field of intelligent connected vehicle platooning control technology, specifically to an event-triggered distributed pulse control method for intelligent connected vehicle platooning. Background Technology

[0002] Vehicle platooning control arranges multiple vehicles into a designated formation and structure, ensuring that vehicles within the platoon maintain small and relatively stable distances and travel at the same speed along the road. Intelligent connected vehicle platooning is a key technology for next-generation intelligent transportation systems, offering competitive advantages in fuel savings, reduced road occupancy, and lower transportation costs. The use of C-V2X wireless communication technology enables real-time dynamic information exchange between vehicles, fully realizing efficient collaboration and significantly contributing to ensuring driving safety and improving traffic efficiency.

[0003] Traditional platoon communication uses periodic sampling, which consumes significant system resources and can lead to communication delays and data packet loss. Later, due to the limited processing power of processors, event-triggered control strategies were proposed. Event-triggered mechanisms are communication strategies that trigger data transmission based on the occurrence of events. In event-triggered control, sampling only occurs when the state-related control error exceeds the allowable range. Compared to periodic sampling, event-triggered control strategies have a lower probability of redundant information transmission and can reduce the frequency of communication between vehicles.

[0004] While the aforementioned continuous control methods are relatively effective, their constant occupation of the communication channel can clog the communication network and cause network congestion. In contrast, pulse control, as a discontinuous control method, typically has a simpler structure. When the ability to collect, compute, and communicate information is limited, pulse control, due to its occasional occupation of the communication channel, can more effectively save resources, reduce costs, improve system efficiency, and quickly achieve platooning control objectives, ensuring the safety of following vehicles. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides an event-triggered distributed pulse control method for intelligent connected vehicle platooning. This method overcomes the drawback of existing continuous control methods that constantly occupy communication channels, effectively saves resources, and can quickly achieve platooning control objectives while ensuring the safety of following vehicles.

[0007] (II) Technical Solution

[0008] A distributed pulse control method for intelligent connected vehicle platooning based on event triggering includes the following steps:

[0009] Step 1: Set up a convoy of N connected vehicles, and set the target path for the convoy and the initial positions of the lead vehicle and each following vehicle.

[0010] Step 2: Establish a communication connection between the vehicles to exchange information in real time.

[0011] Step 3: Monitor the status information of each vehicle.

[0012] The longitudinal dynamics model of the vehicle is constructed as follows: Where, x i (t)=[p i (t), v i (t)] T Let p be the state vector. i (t) represents the position, v i (t) represents velocity, u i (t) represents the control signal. Vehicle i (i = 1...N) at control input u i Under the influence of (t), state x i (t) follows the state x0(t) of the lead vehicle, and the longitudinal dynamic model of x0(t) is expressed as: Where x0(t) represents the state of the lead vehicle, and u0(t) represents the control input for the lead vehicle. x0(t) is controlled by adjusting u0(t). The lead vehicle is the object that all vehicles in the platoon are tracking. The goal of all vehicles is to match the speed of the lead vehicle and maintain a safe distance from it. That is, for any initial value of a second-order intelligent vehicle platooning system, if:

[0013]

[0014] This means that the second-order intelligent vehicle platooning system has achieved the platooning control objective; where d i，0 =i(l+t) h *v0) represents the safe distance between the voluntary vehicle and the lead vehicle, where t h is the headway, and l is the minimum safe distance.

[0015] Step 4: Check if the real-time status of the vehicle has reached the trigger condition or the check cycle. If yes, proceed to step 5; otherwise, continue to step 3.

[0016] Step 5: Trigger the pulse signal and update the controller.

[0017] This invention uses control signals to represent:

[0018]

[0019] in, γ represents the impulse control intensity, and δ represents the Dirac function. Therefore, the intelligent connected vehicle platooning system can be rewritten in impulse control form, as follows:

[0020]

[0021] Let e i =(ξ i η i ) T =(p0-p i -d i，0 v0-v i ) T Then there is

[0022]

[0023] From this we can obtain

[0024]

[0025] Vector c = (1, 1), When σ i When (k) = 1, it indicates that the i-th following vehicle is at t k Constantly controlled, otherwise, σ i (k) = 0. Therefore, at any given triggering moment, at least one controller of a following vehicle is triggered, and at most all controllers of following vehicles are triggered simultaneously;

[0026] For the following vehicle i, check whether the triggering condition formed by the motion state at the current time t and the previous triggering time is met, and set a checking cycle based on this condition. If the triggering condition is not met and the inspection cycle has not been reached, then following vehicle i will not send status information x to its neighboring vehicles at the current time t. i (t); If the triggering condition is met or the inspection cycle is reached, the vehicle sends its current motion status information to its neighboring vehicles. The triggering condition is defined as:

[0027]

[0028] in,

[0029]

[0030] L is the Laplacian matrix of the communication topology graph G between following vehicles, where make For a connected graph consisting of a lead vehicle and N following vehicles, matrix B = diag(b1, b2, ..., b...). N) is a diagonal matrix. If the lead vehicle and the following vehicle are connected by an edge, then b i >0, otherwise, b i =0.

[0031] For any μ>0, ζ>0, the following condition is satisfied by calculation: and Event triggering matrix σ i (k), symmetric positive definite matrix P and constants To achieve the goal of intelligent connected vehicle platoon control and eliminate Zeno behavior, where λ1 and λ2 are the minimum and maximum eigenvalues ​​of P, respectively, and β1 is... The largest eigenvalue, and β1≥0.

[0032] Proof: For any t∈(t k , t k+1 Construct the following Lyapunov function:

[0033]

[0034] Then V k The derivative of (e) is calculated as follows:

[0035]

[0036] but

[0037] On the other hand, when t = t k hour,

[0038]

[0039] make Then there is

[0040] The corresponding comparison system is:

[0041]

[0042] Solving the system of equations, we can obtain...

[0043]

[0044] Depend on We can obtain (lnβ2) / ε+β1=-β<0

[0045] Then there is

[0046] Due to V k (e(t))=e(t) T If Pe(t)≤ω(t), then:

[0047] And function V k (e(t)) satisfies λ1||e(t)|| 2 ≤V k (e(t))≤λ2||e(t)|| 2

[0048] but

[0049] Right now

[0050] As t→∞ That is, the convoy achieves the formation control objective. Furthermore, when u0(t) = 0, calculations show that... In other words, when the lead vehicle is moving at a constant speed in a straight line, the system is exponentially stable under this control action. Next, we will prove that the system does not exhibit Zeno behavior:

[0051] Case 1: The trigger time sequence is all from get

[0052] At any given time, define but because Then there is

[0053]

[0054]

[0055] in

[0056] Because at the trigger time χ i (t)=f i (t) = 0, that is Solving the differential equation yields the following:

[0057]

[0058] Because there is at the trigger time

[0059]

[0060] Therefore, for any t∈(t) k , t k+1 All of them are available.

[0061]

[0062] We ordered Then there is

[0063] Prove by contradiction: Assume the system exhibits Zeno behavior, i.e., it has The calculation based on the above formula yields ζ≤0, which contradicts the previous statement that ζ>0. Therefore... The system does not exhibit Zeno behavior;

[0064] Case 2: The trigger time sequence is all composed of t k +ε is obtained because Obviously That is, the system does not have Zeno behavior;

[0065] Case 3: The trigger time sequence already contains t k +ε, and also Based on the above proof, the system also does not exhibit Zeno behavior;

[0066] This completes the proof.

[0067] Step 6: The vehicle that triggered the control will transmit the event information to other vehicles through the communication link. After receiving the event information, the other vehicles will update their status and target path.

[0068] Step 7: The vehicles plan according to the new target path and adjust their speed according to the path planning and status update to maintain the stability and safety of the formation; repeat the above steps until the convoy achieves the formation control target.

[0069] Furthermore, the aforementioned connected convoy refers to a path consisting of multiple one-way channels at any given time, pointing from the lead vehicle i=0 to the tail vehicle i=N.

[0070] Furthermore, the triggering conditions in the event-triggered communication module and the event-triggered control module are distributed, related only to the vehicle's own status information and unrelated to the status information of neighboring vehicles, and use pulse control with high system efficiency and low energy consumption.

[0071] (III) Beneficial Effects:

[0072] Compared with existing technologies, this invention provides a distributed pulse control method for intelligent connected vehicle platooning based on event triggering, which has the following beneficial effects:

[0073] 1. This invention introduces pulse control technology into intelligent connected vehicle platooning control. Compared with existing continuous control methods, pulse control avoids continuously occupying the communication channel, thus preventing communication network congestion and network lag. Therefore, it can more effectively save resources and increase the economic benefits of the platooning system.

[0074] 2. The event triggering conditions adopted in this invention are distributed structures. The event triggering conditions are only related to the status information of the vehicle itself and are not related to the information of neighboring vehicles. By checking whether the triggering conditions formed by the motion state at the current time t and the previous triggering time are met or whether the checking cycle has been reached, it is determined whether to send status information. When the information processing capabilities of mobile phones, computing and communication are limited, it can more effectively save the network bandwidth of the vehicle network and the energy consumption of terminal devices. Moreover, this method can quickly achieve the formation control target and ensure the safety of following vehicles. Attached Figure Description

[0075] Figure 1 This is a schematic diagram of the process of the present invention;

[0076] Figure 2 This is an example diagram of the vehicle communication topology of the present invention;

[0077] Figure 3 This is the trigger pulse control circuit diagram of the present invention;

[0078] Figure 4 This is a diagram showing the displacement and speed deviation between the first vehicle and the lead vehicle under the event-triggered strategy of this invention.

[0079] Figure 5 This is a diagram showing the displacement and speed deviation between the second vehicle and the lead vehicle under the event-triggered strategy of this invention.

[0080] Figure 6 This is a diagram showing the displacement and speed deviation between the third vehicle and the lead vehicle under the event-triggered strategy of this invention.

[0081] Figure 7 This is a diagram showing the displacement and speed deviation between the fourth vehicle and the lead vehicle under the event-triggered strategy of this invention.

[0082] Figure 8 This is a diagram showing the triggering times of the pulse controllers for each vehicle under the event-triggered strategy of this invention. Detailed Implementation

[0083] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0084] Reference Figures 1-3 This embodiment describes a distributed pulse control method for intelligent connected vehicle platooning based on event triggering, comprising the following steps:

[0085] Step 1: Set up a convoy of N connected vehicles, and set the target path for the convoy and the initial positions of the lead vehicle and each following vehicle.

[0086] Step 2: Establish a communication connection between the vehicles to exchange information in real time;

[0087] Step 3: Monitor the status information of each vehicle;

[0088] The longitudinal dynamics model of the vehicle is constructed as follows: Where, x i (t)=[p i (t), v i (t)] T Let p be the state vector. i (t) represents the position, v i (t) represents velocity, u i (t) represents the control signal. Vehicle i (i = 1...N) at control input u i Under the influence of (t), state x i (t) follows the state x0(t) of the lead vehicle, and the longitudinal dynamic model of x0(t) is expressed as: Where x0(t) is the state of the lead vehicle, u0(t) is the control input of the lead vehicle, and x0(t) is controlled by adjusting u0(t). The lead vehicle is the object that all vehicles in the convoy need to track. The goal of all vehicles is to have the same speed as the lead vehicle and to maintain a certain safe distance from the lead vehicle.

[0089] That is: for any initial value of a second-order intelligent vehicle platooning system, if:

[0090]

[0091] This means that the second-order intelligent vehicle platooning system has achieved the platooning control objective; where d i，0 =i(l+t) h *v0) represents the safe distance between the voluntary vehicle and the lead vehicle, where t h is the headway, and l is the minimum safe distance.

[0092] The specific values ​​are: N = 4, ε = 0.5, x0(0) = [0, 15] T x1(0) = [-15, 0] T x2(0) = [-56, 0] T x3(0) = [-83, 0] T x4(0) = [-110, 0] T u0(t)=0, l=4.5, t h =1.5.

[0093] Step 4: Check if the real-time status of the vehicle has reached the trigger condition or the check cycle. If yes, proceed to step 5; otherwise, continue to step 3.

[0094] Step 5: Trigger the pulse signal and update the controller.

[0095] This invention uses control signals to represent:

[0096]

[0097] in, γ represents the impulse control intensity, and δ represents the Dirac function. Therefore, the intelligent connected vehicle platooning system can be rewritten in impulse control form, as follows:

[0098]

[0099] Let e i =(ξ i η i ) T =(p0-p i -d i，0 v0-v i ) T Then there is

[0100]

[0101] From this we can obtain

[0102]

[0103] Vector c = (1, 1), When σ i When (k) = 1, it indicates that the i-th following vehicle is at t k Constantly controlled, otherwise, σ i (k) = 0. Therefore, at any given triggering moment, at least one controller of a following vehicle is triggered, and at most all controllers of following vehicles are triggered simultaneously;

[0104] For the following vehicle i, check whether the triggering condition formed by the motion state at the current time t and the previous triggering time is met, and set a checking cycle based on this condition. If the triggering condition is not met and the inspection cycle has not been reached, then following vehicle i will not send status information x to its neighboring vehicles at the current time t. i (t); If the triggering condition is met or the inspection cycle is reached, the vehicle sends its current motion status information to its neighboring vehicles. The triggering condition is defined as:

[0105]

[0106] in,

[0107]

[0108] L is the Laplacian matrix of the communication topology graph G between following vehicles, where make For a connected graph consisting of a lead vehicle and N following vehicles, matrix B = diag(b1, b2, ..., b...). N ) is a diagonal matrix. If the lead vehicle and the following vehicle are connected by an edge, then b i >0, otherwise, b i =0.

[0109] For any μ>0, ζ>0, the following condition is satisfied by calculation: and Event triggering matrix σ i (k), symmetric positive definite matrix P and constants To achieve the goal of intelligent connected vehicle platoon control and eliminate Zeno behavior, where λ1 and λ2 are the minimum and maximum eigenvalues ​​of P, respectively, and β1 is... The largest eigenvalue, and β1≥0.

[0110] The calculated values ​​are P = I8, δ = 0.7, γ = 0.3207, ζ = 0.2900, and μ = 0.0068.

[0111] Step 6: The vehicle that triggered the control will transmit the event information to other vehicles through the communication link. After receiving the event information, the other vehicles will update their own status and target path.

[0112] Step 7: The vehicles plan according to the new target path and adjust their speed according to the path planning and status update to maintain the stability and safety of the formation; repeat the above steps until the convoy achieves the formation control target.

[0113] Furthermore, the aforementioned connected convoy refers to a path consisting of multiple one-way channels at any given time, pointing from the lead vehicle i=0 to the tail vehicle i=N.

[0114] Furthermore, the triggering conditions in the event-triggered communication module and the event-triggered control module are distributed, related only to the vehicle's own status information and unrelated to the status information of neighboring vehicles, and use pulse control with high system efficiency and low energy consumption.

[0115] The calculation step size is set to 0.001s, according to Figures 4-8Simulation results show that within a 30-second simulation period, the number of triggers for vehicle controllers 1-4 are 69, 80, 105, and 63, respectively. Around 5.12 seconds, the displacement and speed errors of the convoy are both within 1, at which point the number of triggers for each vehicle is only 16, 28, 56, and 13. Around 8.54 seconds, the displacement and speed errors are both within 0.1, at which point the number of triggers for each vehicle is only 27, 37, 62, and 20.

[0116] Under a periodic transmission strategy, the speed and displacement difference curves between vehicles are generally smoother than those under an event-triggered strategy. This is mainly because when the event triggering condition is not met, the predicted state information of the vehicle regarding its neighbors is inaccurate. Although the control performance of the event-triggered strategy decreases slightly, it significantly reduces the number of communications and executions. If the number of communications and executions is increased, the state curve of the event-triggered strategy will become increasingly closer to that of the periodic transmission strategy. In practical applications, the total number of transmissions and executions can be adjusted by modifying parameters according to the actual system's control performance requirements.

[0117] Based on the parameters in this case, the safe distance between vehicles in the convoy and adjacent vehicles is 27m. It has been verified that when the safe distance between vehicles is further reduced, the convoy can still quickly achieve the formation control objective under this control strategy by appropriately adjusting the corresponding parameters.

[0118] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A distributed pulse control method for intelligent connected vehicle platooning based on event triggering, characterized in that, Includes the following steps: Step 1: Set up a convoy of N connected vehicles, and set the target path for the convoy and the initial positions of the lead vehicle and each following vehicle. Step 2: Establish a communication connection between the vehicles to exchange information in real time; Step 3: Monitor the status information of each vehicle; Step 4: Check if the real-time status of the vehicle has reached the trigger condition or the check cycle. If yes, proceed to step 5; otherwise, continue to step 3. Step 5: Trigger pulse signal to update controller; Step 6: The vehicle that triggered the control will transmit the event information to other vehicles through the communication link. After receiving the event information, the other vehicles will update their status and target path. Step 7: The vehicles plan according to the new target path and adjust their speed according to the path planning and status update to maintain the stability and safety of the formation; repeat the above steps until the formation control target is achieved.

2. The distributed pulse control method for intelligent connected vehicle platooning based on event triggering according to claim 1, characterized in that, The longitudinal dynamics model of the vehicle is constructed as follows: Where, x i (t)=[p i (t), v i (t)] T Let p be the state vector. i (t) represents the position, v i (t) represents velocity, u i (t) represents the control signal. Vehicle i (i = 1…N) at control input u i Under the influence of (t), state x i (t) follows the state x0(t) of the lead vehicle, and the longitudinal dynamic model of x0(t) is expressed as: Where x0(t) represents the state of the lead vehicle, and u0(t) represents the control input for the lead vehicle. x0(t) is controlled by adjusting u0(t). The lead vehicle is the object that all vehicles in the platoon are tracking. The goal of all vehicles is to match the speed of the lead vehicle and maintain a safe distance from it. That is, for any initial value of a second-order intelligent vehicle platooning system, if: This means that the second-order intelligent vehicle platooning system has achieved the platooning control objective; where d i，0 =i(l+t) h *v0) represents the safe distance between the voluntary vehicle and the lead vehicle, where t h is the headway, and l is the minimum safe distance.

3. The control signals used in this invention are represented as follows: in, γ represents the impulse control intensity, and δ represents the Dirac function. Therefore, the intelligent connected vehicle platooning system can be rewritten in impulse control form, as follows: Let e i =(ξ i η i ) T =(p0-p i -d i，0 v0-v i ) T Then there is From this we can obtain Vector c = (1, 1), When σ i When (k) = 1, it indicates that the i-th following vehicle is at t k Constantly controlled, otherwise, σ i (k) = 0; Therefore, at any given triggering moment, at least one controller of the following vehicle is triggered, and at most all controllers of the following vehicles are triggered simultaneously. For the following vehicle i, check whether the triggering condition formed by the motion state at the current time t and the previous triggering time is met, and set a checking cycle based on this condition. If the triggering condition is not met and the inspection cycle has not been reached, then following vehicle i will not send status information x to its neighboring vehicles at the current time t. i (t); If the triggering condition is met or the inspection cycle is reached, the vehicle sends its current motion status information to its neighboring vehicles. The triggering condition is defined as: in, L is the Laplacian matrix of the communication topology graph G between following vehicles, where make For a connected graph consisting of the lead vehicle v0 and N following vehicles, matrix B = diag(b1, b2, ..., b...). N ) is a diagonal matrix, if the leading vehicle and the following vehicle are connected by an edge b i >0, otherwise, b i =0.

4. The distributed pulse control method for intelligent connected vehicle platooning based on event triggering according to claim 3, characterized in that, For any μ>0, ζ>0, the following condition is satisfied by calculation: and Event triggering matrix σ i (k), symmetric positive definite matrix P and constants To achieve the goal of intelligent connected vehicle platoon control and eliminate Zeno behavior, where λ1 and λ2 are the minimum and maximum eigenvalues ​​of P, respectively, and β1 is... The largest eigenvalue, and β1≥0.

5. Proof: For any t∈(t k , t k+1 Construct the following Lyapunov function: Then V k The derivative of (e) is calculated as follows: but On the other hand, when t = t k hour, make Then there is The corresponding comparison system is: Solving the system of equations, we can obtain... From it can be obtained that (lnβ2) / ε + β1 = -β<0 Then there is Due to V k (e(t))=e(t) T If Pe(t)≤ω(t), then: And function V k (e(t)) satisfies λ1||e(t)|| 2 ≤V k (e(t))≤λ2||e(t)|| 2 but Right now As t→∞ That is, the convoy achieves the formation control objective; furthermore, when u0(t)=0, calculations show that... In other words, when the lead vehicle is moving at a constant speed in a straight line, the system is exponentially stable under this control action. Next, we will prove that the system does not exhibit Zeno behavior: Case 1: The trigger time sequence is all from get At any given time, define but because Then there is in Because at the trigger time χ i (t)=f i (t) = 0, that is Solving the differential equation yields Because there is at the trigger time Therefore, for any t∈(t) k , t k+1 All of them are available. We ordered Then there is Prove by contradiction: Assume the system exhibits Zeno behavior, i.e., it has The calculation based on the above formula yields ζ≤0, which contradicts the previous statement that ζ>

0. Therefore... The system does not exhibit Zeno behavior; Case 2: The trigger time sequence is all composed of t k +ε is obtained because Obviously That is, the system does not have Zeno behavior; Case 3: The trigger time sequence already contains t k +ε, and also Based on the above proof, the system also does not exhibit Zeno behavior; This completes the proof.

6. The distributed pulse control method for intelligent connected vehicle platooning based on event triggering according to claim 1, characterized in that, The aforementioned connected convoy refers to a path consisting of multiple one-way channels at any given time, from the lead vehicle i=0 to the tail vehicle i=N.

7. The distributed pulse control method for intelligent connected vehicle platooning based on event triggering according to claim 1, characterized in that, The triggering conditions in the event-triggered communication module and the event-triggered control module are distributed, related only to the real-time status information of the vehicle itself, and unrelated to the status information of neighboring vehicles. Furthermore, they utilize pulse control, which is highly efficient and energy-saving.

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