Elastic memory event trigger control system and method for switching system under DoS attack

Abstract

The invention relates to the field of switching system control, and discloses an elastic memory event trigger control system and method for a switching system under DoS attack, and the system comprises a switching system, a sampler, an event trigger with a buffer, a local controller, an edge cloud, and an attack detector. The event trigger with the buffer is used for judging whether sampling data can be released or not; the edge cloud is composed of a cloud controller with a buffer and a switching identifier; the attack detector is used for detecting whether DOS attacks exist or not, and scheduling the cloud controller when the DoS attacks are not detected; and when the DoS attack is detected, stopping detecting the event triggering condition, and scheduling the local controller. According to the control system and method disclosed by the invention, an elastic memory event triggering scheme is adopted, and system data with small errors and large state values can be released, so that transient response is greatly shortened, a large number of network resources are saved, and good control performance is ensured.

Description

Technical Field

[0001] The present invention relates to the field of switching system control, and in particular to a flexible memory event triggering control system and method for a switching system under DoS attack. Background Art

[0002] With the rapid development of network communication technologies, research on network switching systems has garnered widespread attention in applications such as unmanned ground vehicles, smart grids, and water distribution systems. Network switching systems consist of traditional switching systems and network control technologies. A unique aspect of network switching systems is their ability to share sampled information between sensors, controllers, and actuators via network channels. However, as the amount of information collected from networked sensors increases, network switching systems require significant computational resources to achieve control objectives, leading to insufficient performance of network controllers.

[0003] Because the cloud controller is located in the cloud, its openness makes it susceptible to malicious attacks on network channels. Among various types of network attacks, denial of service (DoS) attacks are particularly harmful because the initiator does not require in-depth knowledge of the switching system. DoS attacks can cut off the connection between the cloud controller and the system, resulting in slow system convergence, severe system jitter, and even instability. Furthermore, cloud-controlled switching systems face the challenge of limited communication resources. Appropriate event-triggered solutions can effectively reduce data transmission times.

[0004] Various triggering technologies have been proposed to address this issue. These include periodic event triggering, dynamic event triggering, time triggering, and adaptive triggering. However, these technologies all make triggering decisions based on the error between the current signal and the most recently released signal. If the error is large, new packets are more likely to be released, while if the error is small, they are not released. This results in data with large status values ​​being unable to be released, failing to shorten the system response time.

[0005] As control performance requirements become increasingly stringent, researchers are conducting in-depth research on how to reduce convergence time and system chatter amplitude. Therefore, designing efficient trigger mechanisms and controllers to improve system control performance while ensuring exponential stability is a challenging task. Summary of the Invention

[0006] To solve the above technical problems, the present invention provides a flexible memory event triggering control system and method for a switching system under a DoS attack, so as to achieve the purpose of saving a large amount of network resources while ensuring good control performance.

[0007] To achieve the above object, the technical solution of the present invention is as follows: A resilient memory event-triggered control system for a switching system under DoS attacks, comprising a switching system, a sampler, an event trigger with a buffer, a local controller, an edge cloud, and an attack detector; The switching system is composed of multiple subsystems and corresponding switching instructions; The sampler is used to sample the state of the switching system and transmit the sampled data to an event trigger with a buffer; The event trigger with a buffer is used to determine whether the sampled data can be released, and the buffer is used to store trigger data that meets the event triggering conditions; The local controller is used to control the switching system to ensure that the system does not have a large chattering amplitude; The edge cloud consists of a cloud controller with a buffer and a switch identifier. The switch identifier is used to identify the occurrence of switches between different modes of the switching system and the system mode based on trigger data, thereby selecting the corresponding cloud controller. The cloud controller is used to control the switching system to ensure system stability. The attack detector is used to detect whether there is a DOS attack, and when no DoS attack is detected, the cloud controller is dispatched; when a DoS attack is detected, the detection of event triggering conditions is stopped and the local controller is dispatched.

[0008] A method for triggering and controlling a switching system's elastic memory event under a DoS attack, using the control system described above, includes the following steps: Step 1: Based on the signal transmission process of the networked closed-loop control system under the elastic memory event triggering mechanism, a switching system dynamics model is established; Step 2: Build a DoS attack model and construct an elastic memory event trigger mechanism and cloud / local controller model based on the DoS attack detection method; Step 3: Combine the switching system dynamics model, elastic memory event triggering mechanism, and cloud / local controller model to establish a closed-loop control dynamics model for the switching system. Step 4, performing stability analysis on the closed-loop control dynamics model of the switching system to obtain the stability condition of the closed-loop control dynamics model of the switching system; Step 5: Using a solver to solve the stability condition of the closed-loop control dynamics model of the switching system, and obtaining the event-triggered control parameters of the switching system under DoS attack.

[0009] In the above scheme, in step 1, the switching system dynamics model established is as follows: ; in, is the state vector that changes with time t, is the derivative of the state vector with respect to time t, is the control input that varies with time t; , is the system parameter of the switching system, It is a switch instruction.

[0010] In the above scheme, in step 2, the DOS attack model established is as follows: ; in, is the end time of the nth DoS attack detected, , is the ideal time when the nth DoS attack occurs, is the duration of the nth DoS attack, is the maximum detection time of the attack detector, Indicates the detected DoS attack interval, Indicates the detected DoS attack sleep interval. The minimum detection time of the attack detector.

[0011] In the above solution, in step 2, the DoS attack detection method is as follows: First, the average data traffic volume q when there is no DoS attack is recorded and stored; then, during normal operation, the observed data traffic volume value Compare with q, and the comparison result is used as the output of the attack detector , which is also used to turn on or off event triggers and is defined as follows: ; Among them, the output of the attack detector , indicating that a DoS attack has occurred; the output of the attack detector is , indicating that no DoS attack has occurred.

[0012] In the above solution, in step 2, the elastic memory event triggering mechanism established is as follows: ; When DoS occurs, the attack detector outputs a signal , then the event trigger mechanism stops working immediately; once the DoS attack is detected to be over, the event trigger will be Forced release of data; When there is no DoS attack, the attack detector outputs a signal If the event triggers the condition If true, the latest sampling data can be released successfully; in, is the sampling error, for The transpose of is the historical output signal, is the maximum number of memory items stored in the cache, is the weight of the released data, which satisfies the requirement that the sum of the weights of the historical signals is 1, that is , is the system state vector at the latest sampling moment; Stored in cache The average value of the system state vector, for The transpose of For the Trigger moment The system state vector, is the trigger matrix, It is Trigger moment The switching instruction is , f is the trigger parameter, The end time of the nth DoS attack detected.

[0013] In the above solution, in step 2, the cloud / local controller model established is as follows: ; in, For control input, when no DoS attack occurs, the attack detector outputs a signal , calling the cloud controller , which is the sum of the historical output signal r when it takes different values, For cloud controller gain, For the Trigger moment When the switch instruction, is the historical output signal, is the maximum number of memory items stored in the cache, is the weight of the released data, which satisfies the requirement that the sum of the weights of the historical signals is 1, that is , For the Trigger moment The system state vector; when the maximum number of memory items stored in the buffer is When, the cloud controller is a memoryless controller; When a DoS attack occurs, the attack detector outputs a signal , calling the local controller , is the local controller gain, which is the sum of the local controller gains of the p subsystems, is the local controller gain of the ith subsystem, is the system state vector that changes with time t.

[0014] In the above solution, in step 3, the closed-loop control dynamics model of the switching system is divided into three states: Closed-loop control dynamics model of switching system under asynchronous control state: ; Closed-loop control dynamics model of the switching system under synchronous control: ; Closed-loop control dynamics model of the switching system under DOS attack state: ; in, is the sampling error, is the state vector that changes with time t, is the derivative of the state vector with respect to time t, is the historical output signal, is the maximum number of memory items stored in the cache, is the weight of the released data, which satisfies the requirement that the sum of the weights of the historical signals is 1, that is ; For the asynchronous cloud control matrix, , and is the system parameter of the ith subsystem, is the cloud controller gain of the jth subsystem when the historical output signal is r; To synchronize the cloud control matrix, , is the cloud controller gain of the i-th subsystem when the historical output signal is r; is the local control matrix, , is the local controller gain, which is the sum of the local controller gains of the p subsystems, is the local controller gain of the ith subsystem.

[0015] In the above scheme, in step 4, the stability condition of the closed-loop control dynamic model of the switching system is: ; in, is the asynchronous cloud control algebra matrix, , asynchronous cloud control coefficient , subscript 0 represents the attack detector output signal when there is no DoS attack , is the historical output signal, is the maximum number of memory items stored in the cache, is the weight of the released data, which satisfies the requirement that the sum of the weights of the historical signals is 1, that is ; is the cloud controller algebraic gain, is a matrix The transpose of , is the cloud controller gain of the jth subsystem when the historical output signal is r; is the matrix P of the jth subsystem when there is no DoS attack j0 The inverse matrix of , f is the event trigger parameter, is the event trigger algebraic matrix, , is the event trigger matrix of the jth subsystem; is the system parameter A of the i-th subsystem i The transpose of is the system parameter B of the i-th subsystem i The transpose of ; in, is the synchronization cloud control algebra matrix, , Synchronous Cloud Control Coefficient , subscript 0 represents the attack detector output signal when there is no DoS attack , is the historical output signal, is the maximum number of memory items stored in the cache, is the weight of the released data, which satisfies the requirement that the sum of the weights of the historical signals is 1, that is ; is the cloud controller algebraic gain, is a matrix The transpose of , is the cloud controller gain of the i-th subsystem when the historical output signal is r; is the matrix P of the i-th subsystem when there is no DoS attack i0 The inverse matrix of , f is the event trigger parameter, is the event trigger algebraic matrix, , is the trigger matrix of the i-th subsystem; is the system parameter A of the i-th subsystem i The transpose of is the system parameter B of the i-th subsystem i The transpose of ; in, is the local control algebra matrix, , local control coefficient , subscript 1 represents the output signal of the attack detector when there is a DoS attack , is the local controller algebraic gain, which is the sum of the local controller algebraic gains of the p subsystems, is the local controller algebraic gain of the ith subsystem, , K i is the local controller gain of the ith subsystem, is the matrix P of the i-th subsystem when a DoS attack occurs i1 The inverse matrix of is the system parameter A of the i-th subsystem i The transpose of is the system parameter B of the i-th subsystem i The transpose of ; ; ; ; ; in, is the matrix of the jth subsystem when there is no DoS attack The inverse matrix of is the matrix of the i-th subsystem when there is no DoS attack The inverse matrix of is the matrix of the jth subsystem when a DoS attack occurs The inverse matrix of is the matrix of the i-th subsystem when a DoS attack occurs The inverse matrix of the system switching point transition parameter , the transition parameter from DoS attack interval to DoS attack sleep interval >0, the transition parameter from the DoS attack dormant period to the DoS attack period >0, transition parameter product ; Synchronous cloud control coefficient , asynchronous cloud control coefficient , local control coefficient , is the maximum asynchronous time, and is the DoS attack parameter, is the average dwell time of the switching system.

[0016] In the above solution, in step 5, the event triggering control parameters of the switching system are as follows: Cloud Controller Gains: ; Local controller gain: ; Event trigger matrix: ; in, is the algebraic gain of the cloud controller of the i-th subsystem when the historical output signal is r, is the matrix of the i-th subsystem when no DoS attack occurs; is the sum of the local controller gains of the p subsystems, is the local controller algebraic gain of the ith subsystem, is the matrix of the i-th subsystem when a DoS attack occurs, is the event trigger algebraic matrix of the i-th subsystem.

[0017] Through the above technical solution, the elastic memory event triggering control system and method of the switching system under DoS attack provided by the present invention have the following beneficial effects: 1. Edge clouds offer low latency and can provide a wealth of computing and storage resources. By migrating computing to the cloud, control systems can reduce their energy costs. Therefore, this invention employs a cloud controller with a cache. Unlike other network controllers, the cloud controller's gain is related not only to the number of subsystems but also to the amount of stored data. 2. This invention designs a scheduling mechanism for the local controller and the cloud / local controller based on the attack detector's output signal. This mechanism schedules the cloud controller when there is no DoS attack; it schedules the local controller when a DoS attack occurs, thus ensuring better system control performance. 3. The present invention adopts a flexible memory event triggering scheme, which can release system data with small errors but large state values, thereby greatly shortening the transient response. By increasing the trigger parameters, the system can save a lot of network resources and ensure good control performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for describing the embodiments or the prior art.

[0019] Figure 1 Schematic diagram of a flexible memory event triggering control system for a switching system under DoS attack disclosed in an embodiment of the present invention; Figure 2 The maximum asynchronous time disclosed in the embodiment of the present invention Schematic diagram of switching instructions between the switching system and the controller; Figure 3 This is a schematic diagram of the time zone of a DOS attack and the triggering moment of an elastic memory event changing over time under the cloud control and local control disclosed in an embodiment of the present invention; Figure 4 A schematic diagram of the change of the state vector of the switching system over time under the cloud control and local control disclosed in an embodiment of the present invention; Figure 5 This is a schematic diagram of the time zone of DOS attacks and the triggering moment of elastic memory events changing over time under cloud control; Figure 6 Schematic diagram of the time-varying state vector of the switching system under cloud control. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0021] The present invention provides a flexible memory event triggering control system for switching systems under DoS attacks, such as Figure 1 As shown, it includes a switching system, a sampler, an event trigger with a buffer, a local controller, an edge cloud, and an attack detector; The switching system consists of multiple subsystems and corresponding switching instructions; The sampler is used to sample the state of the switching system and transmit the sampled data to the event trigger with a buffer; An event trigger with a buffer is used to determine whether the sampled data can be released. The buffer is used to store the trigger data that meets the event trigger conditions. The local controller is used to control the switching system to ensure that the system does not have a large chattering amplitude; The edge cloud consists of a cloud controller with a buffer and a switch identifier. The switch identifier is used to identify the switch occurrence and system mode between different modes of the switching system based on trigger data, and then select the corresponding cloud controller. The cloud controller is used to control the switching system to ensure system stability. The attack detector is used to detect whether there is a DoS attack. When no DoS attack is detected, the cloud controller is dispatched. When a DoS attack is detected, the detection of event triggering conditions is stopped and the local controller is dispatched.

[0022] The present invention also discloses a method for triggering and controlling an elastic memory event of a switching system under a DoS attack, which adopts the above control system and includes the following steps:

[0023] Step 1: Based on the signal transmission process of the networked closed-loop control system under the elastic memory event triggering mechanism, a switching system dynamics model is established.

[0024] The established switching system dynamics model is as follows: ; in, is the state vector that changes with time t, is the derivative of the state vector with respect to time t, is the control input that varies with time t; , is the system parameter of the switching system, It is a switch instruction.

[0025] Step 2: Build a DoS attack model and construct an elastic memory event trigger mechanism and cloud / local controller model based on the DoS attack detection method.

[0026] The established DOS attack model is as follows: ; in, is the end time of the nth DoS attack detected, , is the ideal time when the nth DoS attack occurs, is the duration of the nth DoS attack, is the maximum detection time of the attack detector, Indicates the detected DoS attack interval, Indicates the detected DoS attack sleep interval. The minimum detection time of the attack detector.

[0027] DoS attack detection methods are as follows: First, the average data traffic volume q when there is no DoS attack is recorded and stored; then, during normal operation, the observed data traffic volume value Compare with q, and the comparison result is used as the output of the attack detector , which is also used to turn on or off event triggers and is defined as follows: ; Among them, the output of the attack detector , indicating that a DoS attack has occurred; the output of the attack detector is , indicating that no DoS attack has occurred.

[0028] The established elastic memory event triggering mechanism is as follows: ; When DoS occurs, the attack detector outputs a signal , then the event trigger mechanism stops working immediately; once the DoS attack is detected to be over, the event trigger will be Forced release of data; When there is no DoS attack, the attack detector outputs a signal If the event triggers the condition If true, the latest sampling data can be released successfully; in, is the sampling error, for The transpose of is the historical output signal, is the maximum number of memory items stored in the cache, is the weight of the released data, which satisfies the requirement that the sum of the weights of the historical signals is 1, that is , is the system state vector at the latest sampling moment; Stored in cache The average value of the system state vector, for The transpose of For the Trigger moment The system state vector, is the trigger matrix, It is Trigger moment The switching instruction is , f is the trigger parameter, The end time of the nth DoS attack detected.

[0029] The cloud / local controller model is established as follows: ; in, For control input, when no DoS attack occurs, the attack detector outputs a signal , calling the cloud controller , which is the sum of the historical output signal r when it takes different values, For cloud controller gain, For the Trigger moment When the switch instruction, is the historical output signal, is the maximum number of memory items stored in the cache, is the weight of the released data, which satisfies the requirement that the sum of the weights of the historical signals is 1, that is , For the Trigger moment The system state vector; when the maximum number of memory items stored in the buffer is When, the cloud controller is a memoryless controller; When a DoS attack occurs, the attack detector outputs a signal , calling the local controller , is the local controller gain, which is the sum of the local controller gains of the p subsystems, is the local controller gain of the ith subsystem, is the system state vector that changes with time t.

[0030] Step 3: Combine the switching system dynamics model, elastic memory event triggering mechanism and cloud / local controller model to establish a closed-loop control dynamics model of the switching system.

[0031] The closed-loop control dynamics model of the switching system is divided into three states: (1) Closed-loop control dynamics model of switching system under asynchronous control state: ; (2) Closed-loop control dynamics model of the switching system under synchronous control: ; (3) Dynamic model of closed-loop control of switching system under DOS attack state: ; in, is the sampling error, is the state vector that changes with time t, is the derivative of the state vector with respect to time t, is the historical output signal, is the maximum number of memory items stored in the cache, is the weight of the released data, which satisfies the requirement that the sum of the weights of the historical signals is 1, that is ; For the asynchronous cloud control matrix, , and is the system parameter of the ith subsystem, is the cloud controller gain of the jth subsystem when the historical output signal is r; To synchronize the cloud control matrix, , is the cloud controller gain of the i-th subsystem when the historical output signal is r; is the local control matrix, , is the local controller gain, which is the sum of the local controller gains of the p subsystems, is the local controller gain of the ith subsystem.

[0032] Step 4: Perform stability analysis on the closed-loop control dynamics model of the switching system to obtain the stability condition of the closed-loop control dynamics model of the switching system.

[0033] The stability condition of the closed-loop control dynamics model of the switching system is: ; in, is the asynchronous cloud control algebra matrix, , asynchronous cloud control coefficient , subscript 0 represents the attack detector output signal when there is no DoS attack , is the historical output signal, is the maximum number of memory items stored in the cache, is the weight of the released data, which satisfies the requirement that the sum of the weights of the historical signals is 1, that is ; is the cloud controller algebraic gain, is a matrix The transpose of , is the cloud controller gain of the jth subsystem when the historical output signal is r; is the matrix P of the jth subsystem when there is no DoS attack j0 The inverse matrix of , f is the event trigger parameter, is the event trigger algebraic matrix, , is the event trigger matrix of the jth subsystem; is the system parameter A of the i-th subsystem i The transpose of is the system parameter B of the i-th subsystem i The transpose of ; in, is the synchronization cloud control algebra matrix, , Synchronous Cloud Control Coefficient , subscript 0 represents the attack detector output signal when there is no DoS attack , is the historical output signal, is the maximum number of memory items stored in the cache, is the weight of the released data, which satisfies the requirement that the sum of the weights of the historical signals is 1, that is . is the cloud controller algebraic gain, is a matrix The transpose of , is the cloud controller gain of the i-th subsystem when the historical output signal is r; is the matrix P of the i-th subsystem when there is no DoS attack i0 The inverse matrix of , f is the event trigger parameter, is the event trigger algebraic matrix, , is the trigger matrix of the i-th subsystem; is the system parameter A of the i-th subsystem i The transpose of is the system parameter B of the i-th subsystem i The transpose of ; in, is the local control algebra matrix, , local control coefficient , subscript 1 represents the output signal of the attack detector when there is a DoS attack , is the local controller algebraic gain, which is the sum of the local controller algebraic gains of the p subsystems, is the local controller algebraic gain of the ith subsystem, , K i is the local controller gain of the ith subsystem, is the matrix P of the i-th subsystem when a DoS attack occurs i1 The inverse matrix of is the system parameter A of the i-th subsystem i The transpose of is the system parameter B of the i-th subsystem i The transpose of ; ; ; ; ; in, is the matrix of the jth subsystem when there is no DoS attack The inverse matrix of is the matrix of the i-th subsystem when there is no DoS attack The inverse matrix of is the matrix of the jth subsystem when a DoS attack occurs The inverse matrix of is the matrix of the i-th subsystem when a DoS attack occurs The inverse matrix of the system switching point transition parameter , the transition parameter from DoS attack interval to DoS attack sleep interval >0, the transition parameter from the DoS attack dormant period to the DoS attack period >0, transition parameter product ; Synchronous cloud control coefficient , asynchronous cloud control coefficient , local control coefficient , is the maximum asynchronous time, and is the DoS attack parameter, is the average dwell time of the switching system.

[0034] Step 5: Use the solver to solve the stability conditions of the closed-loop control dynamics model of the switching system and obtain the event-triggered control parameters of the switching system under DoS attack.

[0035] The event trigger control parameters of the switching system are as follows: Cloud Controller Gains: ; Local controller gain: ; Event trigger matrix: ; in, is the algebraic gain of the cloud controller of the i-th subsystem when the historical output signal is r, is the matrix of the i-th subsystem when no DoS attack occurs; is the sum of the local controller gains of the p subsystems, is the local controller algebraic gain of the ith subsystem, is the matrix of the i-th subsystem when a DoS attack occurs, is the event trigger algebraic matrix of the i-th subsystem.

[0036] Simulation comparison:

[0037] In a specific embodiment, a switching system with two subsystems is adopted, and the parameter values ​​are as follows: , , , ; f=0.27, , , , , , , , , , , h=0.1s, s, , , =1.6.

[0038] The stability conditions of the closed-loop control dynamics model of the switching system can be solved using LMI to obtain the control parameters.

[0039] Applying a flexible memory event-triggered control method for a switching system under DOS attack, the control parameters of the closed-loop control dynamics model of the switching system are as follows: ; .

[0040] The above control parameters are simulated and the results are as follows: Figures 2 to 4 The results shown.

[0041] In order to reflect the advantages of the control method of the present invention, a comparison is made from two major aspects.

[0042] Compared with the memoryless event trigger control method, the maximum number of stored data in the buffer is set. , the stability condition described in step 4 above is unsolvable, so the memoryless event trigger control method cannot stabilize the system. Figure 3 and Figure 4 It can be seen that when the elastic memory event trigger control method is used, a large amount of network resources can be saved while ensuring good control performance of the switching system.

[0043] Compared with setting only the cloud controller without setting the local controller, the local controller gain Substitute the local control algebra matrix described in step 4 above , and then solve the stability condition in step 4 to obtain the control parameters of the closed-loop control dynamic model of the switching system as follows: ; .

[0044] By simulating the above control parameters, we can get the following Figure 5~Figure 6 The results shown in the figure. Figures 3 to 6 It is found that when the local controller is set, the switching system converges faster and the system chattering amplitude is smaller, resulting in better control performance of the system.

[0045] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A flexible memory event trigger control system for switching systems under DoS attacks, characterized in that: Includes switching system, sampler, event trigger with buffer, local controller, edge cloud and attack detector; The switching system is composed of multiple subsystems and corresponding switching instructions; The sampler is used to sample the state of the switching system and transmit the sampled data to the event trigger with a buffer; The event trigger with a buffer is used to determine whether the sampled data can be released, and the buffer is used to store the trigger data that meets the event trigger condition; The local controller is used to control the switching system to ensure that the system does not have a large amplitude of chattering; The edge cloud is composed of a cloud controller with a buffer and a switching identifier; the switching identifier is used to identify the switching occurrence and system mode between different modes of the switching system according to the trigger data, so as to select the corresponding cloud controller, and the cloud controller is used to control the switching system to ensure the stability of the system; The attack detector is used to detect whether there is a DOS attack. When no DoS attack is detected, the cloud controller is dispatched; when a DoS attack is detected, the detection of event triggering conditions is stopped and the local controller is dispatched.

2. A method for triggering control of elastic memory events of a switching system under DoS attack, using the control system as claimed in claim 1, characterized in that: The steps include: Step 1, based on the signal transmission process of the networked closed-loop control system under the elastic memory event triggering mechanism, a switching system dynamics model is established; Step 2: Build a DoS attack model, and build an elastic memory event trigger mechanism and a cloud / local controller model based on the DoS attack detection method; Step 3, combining the switching system dynamics model, elastic memory event triggering mechanism and cloud / local controller model to establish a closed-loop control dynamics model of the switching system; Step 4, performing stability analysis on the closed-loop control dynamics model of the switching system to obtain a stability condition of the closed-loop control dynamics model of the switching system; Step 5: Using a solver to solve the stability condition of the closed-loop control dynamics model of the switching system, and obtaining event-triggered control parameters of the switching system under DoS attack.

3. The elastic memory event triggering control method for switching system under DoS attack according to claim 2 is characterized in that: In step 1, the established switching system dynamics model is as follows: ； in, is the state vector that changes with time t, is the derivative of the state vector with respect to time t, is the control input that varies with time t; , is the system parameter of the switching system, It is a switching instruction.

4. The elastic memory event triggering control method for switching system under DoS attack according to claim 2 is characterized in that: In step 2, the DOS attack model established is as follows: ； in, is the end time of the nth DoS attack detected, , is the ideal time when the nth DoS attack occurs, is the duration of the nth DoS attack, is the maximum detection time of the attack detector, Indicates the detected DoS attack interval, Indicates the detected DoS attack sleep interval. It is the minimum detection time of the attack detector.

5. The elastic memory event triggering control method for switching system under DoS attack according to claim 2 is characterized in that: In step 2, the DoS attack detection method is as follows: First, the average data flow rate q when there is no DoS attack is recorded and stored; then, during normal operation, the observed data flow rate value Compare with q, and the comparison result is used as the output of the attack detector , which is also used to turn on or off event triggers, and is defined as follows: ； Among them, the output of the attack detector , indicating that a DoS attack has occurred; the output of the attack detector , indicating that no DoS attack has occurred.

6. The elastic memory event triggering control method for switching system under DoS attack according to claim 2 is characterized in that: In step 2, the elastic memory event triggering mechanism established is as follows: ； When DoS occurs, the attack detector outputs a signal , then the event trigger mechanism stops working immediately; once the DoS attack is detected to be over, the event trigger will be Forced release of data; When there is no DoS attack, the attack detector outputs a signal If the event triggers the condition If true, the latest sampling data can be released successfully; in, is the sampling error, for The transpose of is the historical output signal, is the maximum number of memory items stored in the cache, is the weight of the released data, and the sum of the weights of the historical signals is 1, that is , is the system state vector at the latest sampling moment; Store in cache The average value of the system state vector, for The transpose of For the Trigger moment The system state vector, To trigger the matrix, It is Trigger moment The switching instruction is, f is the trigger parameter, The end time of the nth DoS attack detected.

7. The elastic memory event triggering control method for switching system under DoS attack according to claim 2 is characterized in that: In step 2, the cloud / local controller model is established as follows: ； in, For control input, when no DoS attack occurs, the attack detector outputs a signal , calling the cloud controller , which is the sum of the historical output signal r when it takes different values, is the cloud controller gain, For the Trigger moment The switching instruction when is the historical output signal, is the maximum number of memory items stored in the cache, is the weight of the released data, and the sum of the weights of the historical signals is 1, that is , For the Trigger moment The system state vector; when the maximum number of memory items stored in the buffer is When, the cloud controller is a memoryless controller; When a DoS attack occurs, the attack detector outputs a signal , calling the local controller , is the local controller gain, which is the sum of the local controller gains of p subsystems, is the local controller gain of the ith subsystem, is the system state vector that changes with time t.

8. The elastic memory event triggering control method for switching system under DoS attack according to claim 2 is characterized in that: In step 3, the closed-loop control dynamics model of the switching system is divided into three states: Closed-loop control dynamics model of switching system under asynchronous control state: ； Closed-loop control dynamics model of switching system under synchronous control state: ； Closed-loop control dynamics model of switching system under DOS attack state: ； in, is the sampling error, is the state vector that changes with time t, is the derivative of the state vector with respect to time t, is the historical output signal, is the maximum number of memory items stored in the cache, is the weight of the released data, and the sum of the weights of the historical signals is 1, that is ; For the asynchronous cloud control matrix, , and is the system parameter of the ith subsystem, is the cloud controller gain of the jth subsystem when the historical output signal is r; To synchronize the cloud control matrix, , is the cloud controller gain of the ith subsystem when the historical output signal is r; is the local control matrix, , is the local controller gain, which is the sum of the local controller gains of p subsystems, is the local controller gain of the ith subsystem.

9. The elastic memory event triggering control method for switching system under DoS attack according to claim 2 is characterized in that: In step 4, the stability condition of the closed-loop control dynamics model of the switching system is: ； in, is the asynchronous cloud control algebraic matrix, , asynchronous cloud control coefficient , subscript 0 represents the attack detector output signal when there is no DoS attack , is the historical output signal, is the maximum number of memory items stored in the cache, is the weight of the released data, and the sum of the weights of the historical signals is 1, that is ; is the cloud controller algebraic gain, For the matrix The transpose of , is the cloud controller gain of the jth subsystem when the historical output signal is r; is the matrix P of the jth subsystem when there is no DoS attack j0 The inverse matrix of , f is the event trigger parameter, is the event trigger algebraic matrix, , is the event trigger matrix of the jth subsystem; is the system parameter A of the ith subsystem i The transpose of is the system parameter B of the ith subsystem i The transpose of ； in, is the synchronization cloud control algebraic matrix, , Synchronous cloud control coefficient , subscript 0 represents the attack detector output signal when there is no DoS attack , is the historical output signal, is the maximum number of memory items stored in the cache, is the weight of the released data, and the sum of the weights of the historical signals is 1, that is ; is the cloud controller algebraic gain, For the matrix The transpose of , is the cloud controller gain of the ith subsystem when the historical output signal is r; is the matrix P of the ith subsystem when there is no DoS attack i0 The inverse matrix of , f is the event trigger parameter, is the event trigger algebraic matrix, , is the trigger matrix of the i-th subsystem; is the system parameter A of the ith subsystem i The transpose of is the system parameter B of the ith subsystem i The transpose of ； in, is the local control algebra matrix, , local control coefficient , subscript 1 represents the output signal of the attack detector when there is a DoS attack , is the local controller algebraic gain, which is the sum of the local controller algebraic gains of p subsystems, is the local controller algebraic gain of the ith subsystem, , K i is the local controller gain of the ith subsystem, is the matrix P of the i-th subsystem when a DoS attack occurs i1 The inverse matrix of is the system parameter A of the ith subsystem i The transpose of is the system parameter B of the ith subsystem i The transpose of ； ； ； ； ； in, is the matrix of the jth subsystem when there is no DoS attack The inverse matrix of is the matrix of the ith subsystem when there is no DoS attack The inverse matrix of is the matrix of the jth subsystem when a DoS attack occurs The inverse matrix of is the matrix of the ith subsystem when a DoS attack occurs The inverse matrix of the system switching point transition parameter , transition parameters from DoS attack interval to DoS attack sleep interval >0, transition parameter from DoS attack sleep interval to DoS attack interval >0, transition parameter product ; Synchronous cloud control coefficient , asynchronous cloud control coefficient , local control coefficient , is the maximum asynchronous time, and is the DoS attack parameter, is the average dwell time of the switching system.

10. The elastic memory event triggering control method for switching system under DoS attack according to claim 2, characterized in that: In step 5, the event triggering control parameters of the switching system are as follows: Cloud Controller Gains: ; Local controller gain: ; Event trigger matrix: ; in, is the algebraic gain of the cloud controller of the ith subsystem when the historical output signal is r, is the matrix of the i-th subsystem when no DoS attack occurs; is the sum of the local controller gains of the p subsystems, is the local controller algebraic gain of the ith subsystem, is the matrix of the ith subsystem when a DoS attack occurs, is the event trigger algebraic matrix of the ith subsystem.

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