Safe decentralized control method and system under switching event triggered control strategy

Abstract

The present invention discloses a method and system for secure decentralized control under a switching event-triggered control strategy, and is a method for secure decentralized control of a large-scale networked interconnected system under a switching event-triggered control strategy. The event trigger mechanism effectively alleviates the communication pressure of the system, ensuring that the system can maintain stable operation and security when subjected to external disturbances or denial of service attacks. Due to the nature of the event trigger mechanism, the present invention constructs a switchable event trigger mechanism and applies it to each interconnected subsystem; and then collaboratively designs event-triggered communication parameters and safety controller control rules. The present invention enables large-scale interconnected systems to have performance levels in dealing with denial of service and disturbances, can guarantee control performance, and obtain higher communication efficiency. The present invention can be applied to unmanned interconnected systems, security control and communication optimization of smart grids, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of network communication and system control, and in particular to a control method based on a switching event trigger mechanism and a network interconnection system. Background Art

[0002] In recent years, the popularity of large-scale systems has made network communications more complex and critical. However, with the development of the network, network security issues have become increasingly prominent, including DoS (Denial of Service) attacks. DoS attacks may cause system communication interruptions and seriously affect the operation and stability of the system. Therefore, how to effectively combat DoS attacks has become one of the important challenges in today's network communication field.

[0003] In actual engineering, this technology can be widely used in various large-scale systems, especially those facing severe network security threats. For example, in intelligent transportation systems, this technology can be used to improve the communication efficiency of intelligent transportation systems and enhance the system's resistance to DoS attacks, thereby ensuring the stable operation of transportation systems. In intelligent power systems, this technology can be used to improve the communication efficiency of the system and ensure the stability of the system, thereby improving the operating efficiency and safety of the power system. Summary of the invention

[0004] This paper proposes a communication scheme (SETC) based on an event trigger mechanism, which is designed to handle DoS attacks in large-scale systems with network interconnection. The scheme adopts a decentralized control strategy and uses an event trigger mechanism to improve communication efficiency while ensuring the security and stability of the system under DoS attacks. Switching the event trigger mechanism enables the system to respond to DoS attacks more quickly and accurately, reduce the communication burden, improve efficiency, and ensure the stable operation of large-scale systems.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A control method based on a switching event trigger mechanism and a networked interconnection system control method, comprising the following steps:

[0007] S100, establish a state space model for each subsystem of a large networked interconnected system;

[0008] S200, establishing a mathematical model of energy-limited denial-of-service attacks that each subsystem may be subjected to;

[0009] S300, based on the system model with switching event triggering strategy parameters and random network communication delays and packet loss caused by denial of service attacks, the constraint matrix of the controller with robust stability performance is designed using the Lyapunov stability analysis method ; Then the matrix Decouple and convert into linear matrix inequality form so that it can be solved in computer software to calculate the event trigger strategy parameters and controller rules that meet the system performance;

[0010] S400 , finally collaboratively designing controller input and trigger strategy parameters, solving them based on the conditions of steps S100 - S300 , and thereby achieving safe decentralized control under the switching event triggered control strategy.

[0011] On the other hand, the present invention discloses a safe distributed control system based on a switching event triggered control strategy, based on an interconnected network system, including the following modules:

[0012] A switching event triggering unit based on character confirmation detection technology is used to determine whether a data packet is lost during transmission, thereby determining whether to switch the event triggering mechanism in S301;

[0013] The system calculation unit is used to calculate the controller gain and event trigger parameters that can keep the system stable based on the switching event trigger mechanism when the system is attacked by denial of service, and then calculate the controller gain and event trigger parameters of the system based on the state space equation of the networked interconnected large system and the switching event trigger mechanism;

[0014] The distributed control unit of the networked interconnected large system is used to finally design the distributed controller input and the secure distributed control based on the switching event triggering control strategy under the denial of service attack.

[0015] It can be seen from the above technical solution that the safe decentralized control method based on the switching event triggered control strategy of the present invention has the following advantages over the prior art:

[0016] First, the present invention establishes a detailed state space model for each subsystem of the interconnected large system and takes into account the influencing factors of the interconnection between subsystems, so that these models can more accurately reflect the dynamic characteristics and state changes of the large networked system.

[0017] Furthermore, the present invention adopts a switching event triggering control strategy, which can achieve higher communication efficiency in non-DoS attack and reduce the impact of DoS attack during DoS attack while ensuring control performance, thus saving communication resources and achieving the desired control performance index.

[0018] By integrating SETC and networked interconnected systems into a unified time-delay system framework, more flexible and reliable safety control can be achieved, and it is suitable for various types of control systems and application scenarios, whether it is industrial control, robot control or intelligent transportation system.

[0019] Finally, the algorithm in the present invention is simple, easy to operate and implement, saves communication resources, and has strong resistance to network attacks. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a flow chart of the method of the present invention;

[0021] Figure 2 It is a mechanical system consisting of four interconnected vehicles according to an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of a simulation of tracking four cars in an embodiment of the present invention;

[0023] Figure 4 This is the data transmission situation under the switching event triggering mechanism in the embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0025] like Figure 1 As shown, the secure decentralized control method under the switching event triggered control strategy described in this embodiment includes:

[0026] S100. Establish a state space model for each subsystem of a large networked interconnected system.

[0027] S200. Establish a mathematical model of the energy-limited denial-of-service attack that each subsystem may be subject to.

[0028] S300, based on the system model with switching event triggering strategy parameters and random network communication delays and packet loss caused by denial of service attacks, the constraint matrix of the controller with robust stability performance is designed using the Lyapunov stability analysis method ; then The matrix is ​​decoupled and converted into a linear matrix inequality so that it can be solved in computer software to calculate the event trigger strategy parameters and controller rules that meet the system performance. For the specific calculation method, please see steps S301 and S302.

[0029] S400 , finally collaboratively designing controller input and trigger strategy parameters based on the conditions of steps S100 - S300 .

[0030] The following are specific instructions for the above steps:

[0031] First, define the state space model of each subsystem of the networked interconnected large system as follows:

[0032]

[0033]

[0034]

[0035] in, is the state of subsystem i; is the measured output of subsystem i; is the external disturbance of subsystem i; is the control input of subsystem i; is the controllable output of subsystem i, is a fixed coefficient matrix; It is the interconnection coupling function of a large networked interconnected system;

[0036] The embodiment of the present invention mainly considers the problem of realizing secure decentralized control of a control strategy triggered by a switching event of a networked large system under a denial of service attack.

[0037] Note: Symbol Represents the set of positive integers, symbol represents the symmetric term in a symmetric matrix, the symbol Representation Matrix The transpose of .

[0038] The specific steps are as follows:

[0039] S100, based on the interconnected system model, defines a constraint term of the interconnection coupling function, and its constraint inequality is ;

[0040] in, is the coupling strength, which is related to the actual system model.

[0041] S200 builds a mathematical model of the energy-limited denial-of-service attacks that each subsystem may be subject to.

[0042] First, we define that each subsystem of a large networked interconnected system may be subject to a limited energy denial of service attack. An energy-limited denial of service attack is an attack that starts at a specific time point and lasts for a certain period of time. An energy-limited denial of service attack can be described by the following mathematical model using a time interval:

[0043]

[0044] in Indicates the nth DoS attack interval, Indicates the moment when the DoS attacker is active, symbol Indicates duration.

[0045] For S300, the constraint matrix of the controller with robust stability performance is designed using the Lyapunov stability analysis method based on the system model with switching event triggering strategy parameters and random network communication delays and packet loss caused by denial of service attacks. Then The matrix is ​​decoupled and converted into a linear matrix inequality, so that it can be solved in computer software to calculate the event triggering strategy parameters and controller rules that meet the system performance.

[0046] The specific steps include:

[0047] S301, design a switching event trigger mechanism

[0048]

[0049] in It is the future trigger moment. is the most recent triggering moment, , is the current sampling time, ; The symbol inf represents the maximum lower bound of a set; the symbol Indicates the sampling interval of the current system; symbol Indicates the positive trigger parameter, represents the weight matrix; symbol is a given trigger parameter; this mechanism will use character confirmation detection technology to detect during data transmission. Assuming that data transmission is in progress at the current moment, when it is detected that the current moment is subject to a denial of service attack and packet loss, the packet loss flag parameter ACK is set to 1 to indicate that packet loss is detected, and the corresponding event trigger condition when ACK=0 is switched. When the current transmission is detected to be successful, the packet loss flag parameter ACK is set to 0 to indicate successful transmission, and the event trigger condition corresponding to ACK=1 is switched to .

[0050] S302, design the following controller based on the event trigger mechanism

[0051]

[0052] in is the trigger state of the ith subsystem, is the controller gain to be designed, , It is communication-induced delay;

[0053] S303, Divide into smaller sections and further design the controller

[0054]

[0055] in , ,when When, conditions Established, when When, conditions Establishment; Symbol , is a communication delay function and satisfies the relationship , is the lower bound of the communication delay, Upper limit on communication delay;

[0056] S304, according to the event trigger mechanism and controller rules designed in S301-S303, when there is a positive definite matrix and a positive constant , we can design a conditional matrix Satisfies the following relationship:

[0057] ,

[0058] in,

[0059]

[0060]

[0061]

[0062]

[0063] S305, based on the conditional matrix given in 304 , decouple it, when there is a positive definite matrix , and a positive constant , so that it satisfies the following relationship: ,

[0064]

[0065] in,

[0066]

[0067]

[0068]

[0069]

[0070]

[0071]

[0072]

[0073]

[0074] .

[0075] For S400, the controller input is finally designed, based on the conditions of steps S100-S300, to achieve safe decentralized control under the switching event triggered control strategy;

[0076] The specific steps include:

[0077] S401, according to the required performance indicators, based on steps S100-S300, the given event trigger parameters and constant Substituting the decoupled condition matrix given in S305 (see S305 matrix), the controller gains of each subsystem can be obtained , the weight matrix of the event triggering mechanism .

[0078] On the other hand, the embodiment of the present invention also discloses a safe distributed control system under a switching event triggering control strategy, based on an interconnected network system, including the following modules:

[0079] A switching event triggering unit based on character confirmation detection technology is used to determine whether a data packet is lost during transmission, thereby determining whether to switch the event triggering mechanism in S301;

[0080] The system calculation unit is used to calculate the controller gain and event trigger parameters that can keep the system stable based on the switching event trigger mechanism when the system is attacked by denial of service, and then calculate the controller gain and event trigger parameters of the system based on the state space equation of the networked interconnected large system and the switching event trigger mechanism;

[0081] The distributed control unit of the networked interconnected large system is used to finally design the distributed controller input and the secure distributed control based on the switching event triggering control strategy under the denial of service attack.

[0082] The switching event triggering unit based on the character confirmation detection technology is:

[0083] S301, design a switching event trigger mechanism

[0084]

[0085] Wherein, the system computing unit, the processing steps include:

[0086] S305, based on the conditional matrix given in 304 , decouple it, when there is a positive definite matrix , and a positive constant , so that it satisfies the following relationship:

[0087] ,

[0088] The given event trigger parameter and constant Substituting the decoupled condition matrix given in S305 (see S305 matrix), the controller gains of each subsystem can be obtained , the weight matrix of the event triggering mechanism .

[0089] The specific processing steps of the networked interconnected large system distributed control unit include:

[0090] S302, design the following controller based on the event trigger mechanism

[0091]

[0092] S303, Divide into smaller sections and further design the controller

[0093]

[0094] The present invention can be applied in many related fields, such as smart grids, unmanned systems, and large-scale networked control systems. It can effectively alleviate communication pressure when there are external disturbances and communication channels are attacked by denial of service, and can maintain the stability and security of the system.

[0095] In this embodiment, an experimental example is used to verify the proposed design method. Figure 2 The mechanical system consists of four interconnected vehicles. Considering the disturbance, the i-th vehicle model is:

[0096]

[0097] Combined with the actual physical meaning, the following state space matrix parameters are given:

[0098]

[0099] Assume that the current sampling time, communication delay lower limit, and communication delay upper limit of the system are .

[0100] Given parameters and system performance indicators Substituting into S305, the following controller gain can be obtained: and event trigger weight matrix :

[0101]

[0102]

[0103] The simulation results of the switching event trigger mechanism with denial of service attack are as follows: Figure 3 and Figure 4 As shown; it can be seen from the simulation data that under a denial of service attack, the use of a switching event trigger mechanism can reduce the amount of data packet transmission and save communication resources while maintaining the expected control performance.

[0104] In summary, the present invention has a clear idea, a more reasonable and scientific structure, and can achieve synchronization at an exponential rate, which can further shorten the convergence time. The algorithm designed by the present invention is fast, simple and easy to operate.

[0105] The embodiment of the present application also provides an electronic device, including a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus;

[0106] Memory, used to store computer programs;

[0107] The processor is used to implement the above-mentioned safe decentralized control method of the switching event triggering control strategy when executing the program stored in the memory, and the method includes:

[0108] Establish the state space model of each subsystem of the networked interconnected large system and constrain the interconnected items.

[0109] A mathematical model of the energy-limited denial-of-service attack that each subsystem may be subjected to is established.

[0110] According to the system model with switching event triggering strategy parameters and random network communication delays and packet loss caused by denial of service attacks, the constraint matrix of the controller with robust stability performance is designed using the Lyapunov stability analysis method. Then The matrix is ​​decoupled and converted into a linear matrix inequality, so that it can be solved in computer software to calculate the event triggering strategy parameters and controller rules that meet the system performance.

[0111] Finally, the controller input and trigger strategy parameters are collaboratively designed and solved based on the conditions of steps S100-S300, thereby achieving safe decentralized control under the switching event triggered control strategy.

[0112] It is understandable that the system provided by the embodiment of the present invention corresponds to the method provided by the embodiment of the present invention, and the explanation, examples and beneficial effects of the relevant contents can refer to the corresponding parts in the above method.

[0113] The communication bus mentioned in the above electronic device can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The communication bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, only one thick line is used in the figure, but it does not mean that there is only one bus or one type of bus.

[0114] The communication interface is used for communication between the above electronic device and other devices.

[0115] The memory may include a random access memory (RAM) or a non-volatile memory (NVM), such as at least one disk memory. Optionally, the memory may also be at least one storage device located away from the aforementioned processor.

[0116] The above-mentioned processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gates or transistor logic devices, and discrete hardware components.

[0117] In another embodiment provided in the present application, a computer-readable storage medium is also provided, in which a computer program is stored. When the computer program is executed by a processor, the steps of the safe decentralized control method under the above-mentioned switching event triggered control strategy are implemented.

[0118] In another embodiment provided in the present application, a computer program product including instructions is also provided, which, when executed on a computer, enables the computer to execute the safe decentralized control method under any switching event triggered control strategy in the above embodiments.

[0119] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state hard disk SoLid State Disk (SSD)), etc.

[0120] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0121] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A safe decentralized control method under a switching event-triggered control strategy, based on a networked large-scale interconnected system, characterized in that: The following steps are involved: S100, establish a state space model for each subsystem of a large networked interconnected system; S200, establishing a mathematical model of energy-limited denial-of-service attacks that each subsystem may be subjected to; S300, based on the system model with switching event triggering strategy parameters and random network communication delays and packet loss caused by denial of service attacks, the constraint matrix of the controller with robust stability performance is designed using the Lyapunov stability analysis method ; Then the matrix Decouple and convert into linear matrix inequality form so that it can be solved in computer software to calculate the event trigger strategy parameters and controller rules that meet the system performance; S400 , finally collaboratively designing controller input and trigger strategy parameters, solving them based on the conditions of steps S100 - S300 , and thereby achieving safe decentralized control under the switching event triggered control strategy.

2. The method for secure decentralized control under a switching event-triggered control strategy according to claim 1, characterized in that: The S100 specifically includes: First, define the state space model of each subsystem of the networked interconnected large system as follows: in, is the state of subsystem i; is the measured output of subsystem i; is the external disturbance of subsystem i; is the control input of subsystem i; is the controllable output of subsystem i, is a fixed coefficient matrix; It is the interconnection coupling function of a large networked interconnected system; Based on the state space model of each subsystem of the networked interconnected large system, a constraint term of the interconnection coupling function is defined, and its constraint inequality is: ; in, is the coupling strength, which is related to the actual system model.

3. The method for secure decentralized control under a switching event-triggered control strategy according to claim 2, characterized in that: The S200 specifically includes: First, it is defined that each subsystem of a large networked interconnected system may be subject to a limited energy denial of service attack; an energy-limited denial of service attack is an attack that starts at a specific time point and lasts for a certain period of time. The energy-limited denial of service attack is described by the following mathematical model using a time interval: in Indicates the nth DoS attack interval, Indicates the moment when the DoS attacker is active, symbol Indicates duration.

4. The method for secure decentralized control under a switching event-triggered control strategy according to claim 3, characterized in that: The S300 specifically includes: S301, design a switching event trigger mechanism in It is the future trigger moment. is the most recent triggering moment, , is the current sampling time, ; The symbol inf represents the maximum lower bound of a set; the symbol Indicates the sampling interval of the current system; symbol Indicates the positive trigger parameter, represents the weight matrix; symbol is a given trigger parameter; this mechanism will use character confirmation detection technology to detect during data transmission. Assuming that data transmission is in progress at the current moment, when it is detected that the current moment is subject to a denial of service attack and packet loss, the packet loss flag parameter ACK is set to 1 to indicate that packet loss is detected, and the corresponding event trigger condition when ACK=0 is switched. When the current transmission is detected to be successful, the packet loss flag parameter ACK is set to 0 to indicate successful transmission, and the event trigger condition corresponding to ACK=1 is switched to ; S302, design the following controller based on the event trigger mechanism in is the trigger state of the ith subsystem, is the controller gain to be designed, , It is communication-induced delay; S303, Divide into smaller sections and further design the controller in , ,when When, conditions Established, when When, conditions Establishment; Symbol , is a communication delay function and satisfies the relationship , is the lower bound of the communication delay, Upper limit on communication delay; S304, according to the event trigger mechanism and controller rules designed in S301-S303, when there is a positive definite matrix and a positive constant , design a conditional matrix Satisfies the following relationship: ， in, ； S305, based on the conditional matrix given in 304 , decouple it, when there is a positive definite matrix , and a positive constant , so that it satisfies the following relationship: , in, 。 5. The method for secure decentralized control under a switching event-triggered control strategy according to claim 4, characterized in that: The S400 specifically includes: S401, according to the required performance indicators, based on steps S100-S300, the given event trigger parameters and constant Substitute the decoupled condition matrix given in S305 to obtain the controller gains of each subsystem , the weight matrix of the event triggering mechanism .

6. A safe decentralized control system under a switching event triggered control strategy, used to implement the safe decentralized control method under a switching event triggered control strategy according to claims 1-5, characterized in that: Includes the following modules: A switching event triggering unit based on character confirmation detection technology is used to determine whether a data packet is lost during transmission, thereby determining whether to switch the event triggering mechanism in S301; The system calculation unit is used to calculate the controller gain and event trigger parameters that can keep the system stable based on the switching event trigger mechanism when the system is attacked by denial of service, and then calculate the controller gain and event trigger parameters of the system based on the state space equation of the networked interconnected large system and the switching event trigger mechanism; The distributed control unit of the networked interconnected large system is used to finally design the distributed controller input and the secure distributed control based on the switching event triggering control strategy under the denial of service attack.

7. A safe distributed control system under a switching event triggered control strategy according to claim 6, characterized in that: The switching event triggering unit based on the character confirmation detection technology performs the following steps: S301, design a switching event trigger mechanism 8. The secure distributed control system under a switching event-triggered control strategy according to claim 6, characterized in that: The system computing unit processing steps include: According to the conditional matrix given in S304 , decouple it, when there is a positive definite matrix , and a positive constant , so that it satisfies the following relationship: ， The given event trigger parameter and constant Substituting the decoupled condition matrix given in S305, the controller gains of each subsystem can be obtained: , the weight matrix of the event triggering mechanism .

9. The secure distributed control system under a switching event-triggered control strategy according to claim 6, characterized in that: The specific processing steps of the distributed control unit of the networked interconnected large system include: S302, design the following controller based on the event trigger mechanism S303, Divide into smaller sections and further design the controller 。

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