Finite-Time Sliding Mode Fault-Tolerant Safe Control Method and System Based on Observer Method

Abstract

The present invention relates to the technical field of sliding mode fault-tolerant safety control, and particularly relates to a finite-time sliding mode fault-tolerant safety control method and system based on an observer method. The method includes: establishing a dynamic model of a discrete cyber-physical system with parameter uncertainties and actuator faults; performing mathematical modeling for periodic DoS interference attacks and packet losses to obtain the packet loss situation; designing state and fault observers based on the packet loss situation and the dynamic model to obtain estimation information; designing a linear sliding mode surface based on the estimation information; designing a sliding mode fault-tolerant safety controller based on the linear sliding mode surface; and performing finite-time sliding mode fault-tolerant safety control on the discrete cyber-physical system with periodic DoS interference attacks and packet losses based on the sliding mode fault-tolerant safety controller. The present invention combines sliding mode control technology with a fault-tolerant control method, and it has very important practical significance to consider the finite-time sliding mode fault-tolerant safety control of a cyber-physical system with periodic DoS interference attacks and packet losses.

Description

Technical Field

[0001] The present invention relates to the technical field of sliding mode fault-tolerant safety control, and particularly to a finite-time sliding mode fault-tolerant safety control method and system based on an observer method. Background Art

[0002] Cyber-physical systems based on communication, computer, and control technologies have attracted much attention due to their advanced sensing, computing, and communication capabilities. As a new type of intelligent system, cyber-physical systems closely integrate the physical space and the information space and have extensive applications in industrial automation systems and other large-scale infrastructures. In this structure, the openness of the communication network improves the efficiency of the physical system but also brings technical challenges in system integration and security. In cyber-physical systems, DoS attacks can interrupt data transmission without requiring comprehensive information about the system, posing a serious threat to the security of cyber-physical systems. Therefore, considering the impact of DoS attacks on the system, the security of cyber-physical systems has received more and more extensive attention.

[0003] In a network environment, in addition to malicious network attacks, inherent factors of the wireless channel, such as channel aging, packet congestion, etc., can also cause random packet loss, resulting in a decline in system performance or even instability.

[0004] The existing research on sliding mode fault-tolerant safety control problems mainly considers the packet loss phenomenon caused by reasons such as channel aging and packet congestion, and then the periodic DoS attack will also cause packet loss. In addition to packet loss, physical faults may occur in the physical layer of cyber-physical systems, and most research results mainly focus on the infinite behavior of the system. In this regard, there is currently no finite-time sliding mode fault-tolerant safety control scheme for cyber-physical systems that simultaneously considers periodic DoS interference attacks and packet loss. Summary of the Invention

[0005] To solve the technical problem that there is currently no finite-time sliding mode fault-tolerant safety control scheme for cyber-physical systems that simultaneously considers periodic DoS interference attacks and packet loss, an embodiment of the present invention provides a finite-time sliding mode fault-tolerant safety control method and system based on an observer method. The technical solution is as follows:

[0006] On the one hand, a finite-time sliding mode fault-tolerant safety control method based on an observer method is provided, characterized in that the method includes:

[0007] S1. Establish a dynamic model of a discrete cyber-physical system with parameter uncertainties and actuator faults;

[0008] S2. Perform mathematical modeling for periodic DoS interference attacks and packet loss to obtain the packet loss situation;

[0009] S3. According to the packet loss situation, design a state observer and a fault observer in combination with the dynamic model to obtain estimation information;

[0010] S4. Design a linear sliding mode surface based on the estimation information; design a sliding mode fault-tolerant safety controller based on the linear sliding mode surface;

[0011] S5. Based on the sliding mode fault-tolerant safety controller, perform finite-time sliding mode fault-tolerant safety control on the discrete cyber-physical system with periodic DoS interference attacks and packet losses.

[0012] Optionally, in S1, establish a dynamic model of a discrete cyber-physical system with parameter uncertainties and actuator faults, including:

[0013] Establish a dynamic model of a discrete cyber-physical system with parameter uncertainties and actuator faults. The state equation of the dynamic model is shown in the following formula (1):

[0014] (1)

[0015] Where, represents the state signal, represents the control input signal, represents the measured output signal; represents the actuator fault, represents the external disturbance; the real matrix refers to the bounded parameter uncertainty that satisfies , where satisfies ; and are known constant matrices with appropriate dimensions.

[0016] Optionally, in S2, perform mathematical modeling for periodic DoS interference attacks and packet losses to obtain the packet loss situation, including:

[0017] Define the variable through the following formula (2) to describe the periodic DoS interference attack strategy:

[0018] (2)

[0019] Where, is the number of periods; when , it represents the attack dormant time; when , it represents the attack time in the nth period; let be the action period of the attacker, be the duration of the silent period, where is a set of positive integers;

[0020] According to the periodic attack strategy of the DoS attacker, when the attacker is in the dormant state, only the random packet loss caused by the inherent factors of the wireless channel is considered. During the attack period, the DoS attacker selects the interference power according to the total energy it possesses to attack the wireless channel. Therefore, when occurs, the packet loss is caused by the inherent factors of the wireless channel, and when occurs, the packet loss is caused by the periodic DoS attack.

[0021] Let represent whether the observer can successfully receive the data packet under the influence of the DoS attack and the inherent factors of the channel as shown in the following formula (3)

[0022] (3)

[0023] Replace the lost measurement value with the latest received data to obtain the actual measurement value :

[0024] (4).

[0025] Optionally, in S3, according to the packet loss situation, design a state observer and a fault observer in combination with the dynamic model to obtain the estimation information, including:

[0026] The actual measurement value , construct an observer as shown in the following formula (5):

[0027] (5)

[0028] where, is the estimated value of , is the estimated value of ; is the state observer gain matrix to be determined, is the fault observer gain matrix to be determined.

[0029] Optionally, in S4, design a linear sliding mode surface based on the estimation information, including:

[0030] Design the sliding mode surface function according to the state estimation of the cyber-physical system, and design the reaching law according to the sliding mode surface function, and then design a finite-time sliding mode fault-tolerant safety control method based on the observer method.

[0031] Optionally, in S4, design a sliding mode fault-tolerant safety controller based on the linear sliding mode surface, including:

[0032] The sliding mode fault-tolerant safety controller is designed as shown in the following formula (6)

[0033] (6)

[0034] Among them, .

[0035] On the other hand, a finite-time sliding mode fault-tolerant safety control system based on the observer method is provided. This system is applied to the finite-time sliding mode fault-tolerant safety control method based on the observer method. The system includes:

[0036] A dynamic model establishment module for establishing a dynamic model of a discrete cyber-physical system with parameter uncertainties and actuator faults;

[0037] A mathematical modeling module for performing mathematical modeling for periodic DoS interference attacks and packet losses to obtain the packet loss situation;

[0038] An observer design module for designing a state observer and a fault observer according to the packet loss situation and in combination with the dynamic model to obtain estimation information;

[0039] A sliding mode fault-tolerant safety controller design module for designing a linear sliding mode surface based on the estimation information; designing a sliding mode fault-tolerant safety controller based on the linear sliding mode surface;

[0040] A sliding mode fault-tolerant safety control module for performing finite-time sliding mode fault-tolerant safety control on a discrete cyber-physical system with periodic DoS interference attacks and packet losses based on the sliding mode fault-tolerant safety controller.

[0041] On the other hand, a finite-time sliding mode fault-tolerant safety controller based on the observer method is provided. The finite-time sliding mode fault-tolerant safety controller based on the observer method is used to implement the above-mentioned finite-time sliding mode fault-tolerant safety control method based on the observer method.

[0042] On the other hand, a finite-time sliding mode fault-tolerant safety control device based on the observer method is provided. The finite-time sliding mode fault-tolerant safety control device based on the observer method includes: a processor; a memory, and computer-readable instructions are stored on the memory. When the computer-readable instructions are executed by the processor, any one of the methods in the above-mentioned finite-time sliding mode fault-tolerant safety control method based on the observer method is implemented.

[0043] On the other hand, a computer-readable storage medium is provided. At least one instruction is stored in the storage medium, and the at least one instruction is loaded and executed by a processor to implement any one of the methods in the above-mentioned finite-time sliding mode fault-tolerant safety control method based on the observer method.

[0044] The beneficial effects brought by the technical solutions provided in the embodiments of the present invention at least include:

[0045] In the embodiments of the present invention, for a cyber-physical system with periodic DoS interference attacks and packet losses, a finite-time sliding mode fault-tolerant security control method based on an observer method is provided. By considering the packet loss phenomenon caused by periodic DoS interference attacks and internal channel factors within a unified framework, an update strategy is proposed. Then, an observer is designed under the update strategy to estimate the system state and fault information. Based on the estimated information, a sliding mode surface and a sliding mode fault-tolerant security controller are designed, which can ensure the finite-time reachability of the sliding mode surface during the approaching phase, and deduce the finite-time boundedness of the closed-loop system during the approaching phase and the sliding phase. There has been no technical research on the finite-time sliding mode fault-tolerant security control problem for discrete cyber-physical systems with periodic DoS interference attacks and packet losses. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0047] Figure 1 is a flowchart of a finite-time sliding mode fault-tolerant security control method based on an observer method provided by the embodiments of the present invention;

[0048] Figure 2 is a block diagram of a finite-time sliding mode fault-tolerant security control system provided by the embodiments of the present invention;

[0049] Figure 3 is a schematic structural diagram of an electronic device provided by the embodiments of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0050] The following describes the technical solutions in the present invention with reference to the drawings.

[0051] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to represent examples, illustrations, or explanations. Any embodiment or design solution described as "example" in the present invention should not be construed as being more preferred or having more advantages than other embodiments or design solutions. Exactly, the use of the word "example" is intended to present concepts in a specific way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or either one of the two.

[0052] In the embodiments of the present invention, "image" and "picture" can sometimes be used interchangeably. It should be noted that when not emphasizing the difference, they have the same meaning. "of", "corresponding", and "corresponding" can sometimes be used interchangeably. It should be noted that when not emphasizing the difference, they have the same meaning.

[0053] In the embodiments of the present invention, sometimes subscripts such as W 1 may be written in a non-subscript form such as W1. When not emphasizing the difference, they have the same meaning.

[0054] To make the technical problems, technical solutions, and advantages to be solved by the present invention clearer, the following will be described in detail with reference to the accompanying drawings and specific embodiments.

[0055] The embodiments of the present invention provide a finite-time sliding mode fault-tolerant safety control method based on an observer method. This method can be implemented by a finite-time sliding mode fault-tolerant safety control device based on an observer method. The finite-time sliding mode fault-tolerant safety control device based on an observer method can be a terminal or a server. As Figure 1 shown in the flowchart of the finite-time sliding mode fault-tolerant safety control method based on an observer method, the processing flow of this method can include the following steps:

[0056] S1. Establish a dynamic model of a discrete cyber-physical system with parameter uncertainties and actuator faults;

[0057] S2. Conduct mathematical modeling for periodic DoS interference attacks and packet losses to obtain the packet loss situation;

[0058] S3. According to the packet loss situation, design a state observer and a fault observer in combination with the dynamic model to obtain estimation information;

[0059] S4. Design a linear sliding mode surface based on the observer estimation information; design a sliding mode fault-tolerant safety controller based on the linear sliding mode surface;

[0060] S5. Based on the sliding mode fault-tolerant safety controller, perform finite-time sliding mode fault-tolerant safety control on the discrete cyber-physical system with periodic DoS interference attacks and packet losses.

[0061] In a feasible implementation, since the attacker has limited energy, the DoS jammer needs to replenish energy during the sleep period of each cycle. During this period, only the inherent random packet loss caused by wireless channel attenuation or congestion is considered. First, the periodic DoS jamming attack involves injecting jamming signals into the wireless channel, which may cause data loss on the sensor-to-observer channel. Second, the packet loss phenomenon caused by attacks and internal channel factors is considered within a unified framework, and an update strategy is proposed to describe the transmission of signals from the sensor to the observer. Subsequently, a discrete linear sliding surface is constructed, and the proposed reaching law ensures the finite-time reachability of the sliding surface during the reaching phase. Based on the estimated information, a sliding-mode fault-tolerant security controller is designed, and the derived sufficient criterion can ensure that the closed-loop system is stochastically finite-time bounded during the reaching phase and the sliding phase.

[0062] Specifically, S101: Establish a dynamic model of a discrete cyber-physical system with parameter uncertainties and actuator faults;

[0063] In a feasible implementation, in S101, establishing a dynamic model of a discrete cyber-physical system with parameter uncertainties and actuator faults includes:

[0064] Establish a dynamic model of a discrete cyber-physical system with parameter uncertainties and actuator faults. The state equation of the dynamic model is shown in the following formula (1):

[0065] (1)

[0066] Where, represents the state signal, represents the control input signal, represents the measurement output signal; represents the actuator fault, represents the external disturbance; the real matrix refers to the bounded parameter uncertainty that satisfies where satisfies ; and are known constant matrices with appropriate dimensions.

[0067] S102: Conduct mathematical modeling for periodic DoS jamming attacks and packet loss to obtain the packet loss situation;

[0068] In a feasible implementation, even in the absence of malicious attacks by opponents, due to the limitations of current wireless communication technologies, inherent factors such as channel noise and channel fading in the wireless channel may still cause packet loss. Define the relationship between the signal-to-noise ratio SNR and the symbol error rate SER as: , where, , , represents the transmit power, represents the additive white Gaussian noise, is a parameter;

[0069] Define the variable through the following formula (2) to describe the periodic DoS interference attack strategy:

[0070] (2)

[0071] where is the number of periods; when , it represents the attack sleep time; when , it represents the attack time in the nth period; let be the action period of the attacker, be the duration of the silent period, where is a set of positive integers;

[0072] According to the periodic attack strategy of the DoS attacker, when the attacker is in the sleep state, only consider the random packet loss caused by the inherent factors of the wireless channel. During the attack period, the DoS attacker selects the interference power according to the total energy it has to attack the wireless channel;

[0073] At this time, the channel signal-to-noise ratio becomes the signal-to-noise ratio SINR. The relationship between SINR and SER is defined as , , is the interference power; based on the relationship between the signal-to-noise ratio SNR and the symbol error rate SER, refine SERP by combining the new SINR:

[0074] (2-1);

[0075] Formula (2-1) can uniformly represent the impact of inherent packet loss and periodic DoS interference attacks on the wireless channel. Let represent whether the observer can successfully receive the data packet under the influence of the DoS attack and the inherent factors of the channel as shown in the following formula (3)

[0076] (3)

[0077] Combining Equation (2-1) and Equation (3), we can get:

[0078]

[0079] where, . Replace the lost measurement value with the latest received data to obtain the actual measurement value :

[0080] (4).

[0081] S103. Design a state observer and a fault observer based on the packet loss situation in combination with the dynamic model, and obtain the estimation information;

[0082] In a feasible implementation manner, S103, designing a state observer and a fault observer based on the packet loss situation in combination with the dynamic model and obtaining the estimation information includes:

[0083] Based on the actual measurement value , construct an observer as shown in the following formula (5):

[0084] (5)

[0085] where, is 's estimated value, is 's estimated value; is the state observer gain matrix to be determined, is the fault observer gain matrix to be determined.

[0086] S104. Design a linear sliding mode surface based on the estimation information; design a sliding mode fault-tolerant safety controller based on the linear sliding mode surface;

[0087] In a feasible implementation manner, in S104, designing a linear sliding mode surface based on the estimation information includes:

[0088] Based on the estimation information, select a discrete-time sliding mode surface function as shown in the following formula (6-1):

[0089] (6-1)

[0090] where, , is an arbitrary matrix, define to ensure that is non-singular.

[0091] In a feasible implementation manner, in S104, designing a sliding mode fault-tolerant safety controller based on the linear sliding mode surface includes:

[0092] Design an approaching law as follows:

[0093] (6-2)

[0094] where, is the convergence parameter, represents the sampling time, is a switching parameter, is about sign function;

[0095] From formulas (5), (6-1) and (6-2), we can get:

[0096] (6-3)

[0097] According to the above formula, the sliding mode fault-tolerant safety controller is designed as the following formula (6):

[0098] (6)

[0099] where, .

[0100] S105. Based on the sliding mode fault-tolerant safety controller, perform finite-time sliding mode fault-tolerant safety control on the discrete cyber-physical system with periodic DoS interference attacks and packet losses.

[0101] In a feasible implementation, use the designed sliding mode fault-tolerant safety controller to achieve finite-time sliding mode fault-tolerant safety control of the discrete cyber-physical system considering periodic DoS interference attacks and packet losses, so as to ensure the finite-time reachability of the sliding surface in the approaching stage, and at the same time ensure the finite-time boundedness of the closed-loop system in the approaching stage and the sliding stage.

[0102] In the embodiment of the present invention, the finite-time sliding mode fault-tolerant safety control problem of the cyber-physical system under periodic DoS interference attacks and packet losses is mainly studied. Periodic DoS interference attacks involve injecting interference signals into the wireless channel, which may cause data loss on the sensor-to-observer channel. In addition, packet loss phenomena caused by interference attacks and internal channel factors are considered within a unified framework, and an update strategy is proposed to describe the transmission of signals from sensors to observers. A discrete-time sliding surface is constructed, and the finite-time reachability of the sliding surface is ensured in the approaching stage by using the proposed reaching law. On this basis, a sliding mode fault-tolerant safety controller is designed to ensure that the closed-loop system has stochastic finite-time boundedness in both the reaching motion stage and the sliding motion stage. Therefore, the present invention provides a finite-time sliding mode fault-tolerant safety control method for the cyber-physical system with periodic DoS interference attacks and packet losses.

[0103] Figure 2 is a block diagram of a finite-time sliding mode fault-tolerant safety control system 300 based on an observer method shown according to an exemplary embodiment. This system is used for the finite-time sliding mode fault-tolerant safety control method based on the observer method. Refer to Figure 2, the system includes a dynamic model establishment module 310, a mathematical modeling module 320, an observer design module 330, a sliding mode fault-tolerant safety controller design module 340, and a sliding mode fault-tolerant safety control module 350. Among them:

[0104] The dynamic model establishment module 310 is used to establish a dynamic model of a discrete cyber-physical system with parameter uncertainties and actuator faults;

[0105] The mathematical modeling module 320 is used to perform mathematical modeling for periodic DoS interference attacks and packet losses to obtain the packet loss situation;

[0106] The observer design module 330 is used to design a state observer and a fault observer according to the packet loss situation in combination with the dynamic model to obtain estimation information;

[0107] The sliding mode fault-tolerant safety controller design module 340 is used to design a linear sliding mode surface based on the estimation information; and design a sliding mode fault-tolerant safety controller based on the linear sliding mode surface;

[0108] The sliding mode fault-tolerant safety control module 350 is used to perform finite-time sliding mode fault-tolerant safety control on a discrete cyber-physical system with periodic DoS interference attacks and packet losses based on the sliding mode fault-tolerant safety controller.

[0109] Optionally, the dynamic model establishment module 310 is used to establish a dynamic model of a discrete cyber-physical system with parameter uncertainties and actuator faults, and the state equation of the dynamic model is shown in the following formula (1):

[0110] (1)

[0111] Wherein, represents the state signal, represents the control input signal, represents the measured output signal; represents the actuator fault, represents the external disturbance; the real matrix refers to the bounded parameter uncertainty that satisfies , where satisfies ; and are known constant matrices with appropriate dimensions.

[0112] Optionally, the mathematical modeling module 320 is used to define a variable through the following formula (2) to describe the periodic DoS interference attack strategy:

[0113] (2)

[0114] Among them, is the number of periods; when it represents the attack sleep time; when it represents the attack time in the nth period; let be the action period of the attacker, be the duration of the silent period, where is a set of positive integers;

[0115] According to the periodic attack strategy of the DoS attacker, when the attacker is in the sleep state, only the random packet loss caused by the inherent factors of the wireless channel is considered. During the attack time period, the DoS attacker selects the interference power according to the total energy it has to attack the wireless channel; therefore, when the packet loss is caused by the inherent factors of the wireless channel, and when the packet loss is caused by the periodic DoS attack.

[0116] Let indicate whether the observer can successfully receive the data packet under the influence of the DoS attack and the channel inherent factors as shown in the following formula (3)

[0117] (3)

[0118] Replace the lost measurement value with the latest received data to obtain the actual measurement value :

[0119] (4).

[0120] Optionally, the observer design module 330 is used for the actual measurement value to construct an observer as shown in the following formula (5):

[0121] (5)

[0122] Among them, is the estimated value of, is the estimated value of; is the state observer gain matrix to be determined, is the fault observer gain matrix to be determined.

[0123] Optionally, the sliding mode fault-tolerant safety controller design module 340 is used to design a sliding mode surface function according to the state estimation of the cyber-physical system, design an approaching law according to the sliding mode surface function, and further design a finite-time sliding mode fault-tolerant safety control method based on the observer method.

[0124] Optionally, a sliding mode fault-tolerant safety controller design module 340 is used to design a sliding mode fault-tolerant safety controller as shown in the following formula (6).

[0125] (6)

[0126] Wherein, .

[0127] In the embodiment of the present invention, for the finite-time sliding mode fault-tolerant safety control problem of a cyber-physical system with periodic DoS jamming attacks and packet losses. By injecting periodic high-energy interference signals into the wireless channel, a periodic attack strategy affecting data transmission is studied. Under the condition of limited energy, the packet loss problem caused by the inherent factors of the channel and periodic DoS jamming attacks is considered. On this basis, the reaching law proposed is used to analyze the finite-time reachability of the sliding surface in the reaching stage. In addition, the designed sliding mode fault-tolerant safety control law can ensure that the obtained closed-loop system is stochastically finite-time bounded in both the reaching stage and the sliding stage.

[0128] Figure 3 is a schematic structural diagram of a finite-time sliding mode fault-tolerant safety control device based on an observer method provided by an embodiment of the present invention. As Figure 3 shown, the finite-time sliding mode fault-tolerant safety control device based on an observer method may include the above-mentioned Figure 2 shown finite-time sliding mode fault-tolerant safety control system based on an observer method. Optionally, the finite-time sliding mode fault-tolerant safety control device 410 based on an observer method may include a first processor 2001.

[0129] Optionally, the finite-time sliding mode fault-tolerant safety control device 410 based on an observer method may further include a memory 2002 and a transceiver 2003.

[0130] Wherein, the first processor 2001, the memory 2002, and the transceiver 2003 may be connected through a communication bus, for example.

[0131] Next, in combination with Figure 3 each component of the finite-time sliding mode fault-tolerant safety control device 410 based on an observer method will be specifically introduced:

[0132] Among them, the first processor 2001 is the control center of the finite-time sliding mode fault-tolerant safety control device 410 based on the observer method, which can be a single processor or a collective term for multiple processing elements. For example, the first processor 2001 is one or more central processing units (CPUs), or can be an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present invention, such as: one or more digital signal processors (DSPs), or one or more field programmable gate arrays (FPGAs).

[0133] Optionally, the first processor 2001 can execute various functions of the finite-time sliding mode fault-tolerant safety control device 410 based on the observer method by running or executing software programs stored in the memory 2002 and calling data stored in the memory 2002.

[0134] In a specific implementation, as an embodiment, the first processor 2001 can include one or more CPUs, such as Figure 3 the CPU0 and CPU1 shown in

[0135] In a specific implementation, as an embodiment, the finite-time sliding mode fault-tolerant safety control device 410 based on the observer method can also include multiple processors, such as Figure 3 the first processor 2001 and the second processor 2004 shown in

[0136] Each of these processors can be a single-core processor (single-CPU) or a multi-core processor (multi-CPU). Here, the processor can refer to one or more devices, circuits, and / or processing cores for processing data (such as computer program instructions).

[0137] Optionally, the memory 2002 may be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a random access memory (RAM) or other type of dynamic storage device that can store information and instructions, or may also be an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM), or other optical disc storage, optical disc storage (including compact discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), magnetic disk storage media, or any other medium that can be used to carry or store the desired program code in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory 2002 may be integrated with the first processor 2001 or may exist independently and be coupled to the first processor 2001 through an interface circuit ( Figure 3 not shown) of the finite-time sliding mode fault-tolerant safety control device 410 based on the observer method. The embodiments of the present invention do not make specific limitations thereto.

[0138] The transceiver 2003 is used to communicate with a network device or with a terminal device.

[0139] Optionally, the transceiver 2003 may include a receiver and a transmitter ( Figure 3 not shown separately). Among them, the receiver is used to implement the receiving function, and the transmitter is used to implement the transmitting function.

[0140] Optionally, the transceiver 2003 may be integrated with the first processor 2001 or may exist independently and be coupled to the first processor 2001 through an interface circuit ( Figure 3 not shown) of the finite-time sliding mode fault-tolerant safety control device 410 based on the observer method. The embodiments of the present invention do not make specific limitations thereto.

[0141] It should be noted that Figure 3 the structure of the finite-time sliding mode fault-tolerant safety control device 410 based on the observer method shown does not constitute a limitation to the router. The actual knowledge structure recognition device may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0142] In addition, the technical effects of the finite-time sliding mode fault-tolerant safety control device 410 based on the observer method may refer to the technical effects of the finite-time sliding mode fault-tolerant safety control method based on the observer method described in the above method embodiments, and will not be elaborated here.

[0143] It should be understood that the first processor 2001 in the embodiments of the present invention may be a central processing unit (CPU), and the processor may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0144] It should also be understood that the memory in the embodiments of the present invention may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of random access memory (RAM) are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchlink dynamic random access memory (SLDRAM), and direct rambus random access memory (DR RAM).

[0145] The above embodiments can be implemented in whole or in part by software, hardware (such as circuits), firmware, or any combination thereof. When implemented using software, the above embodiments 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 or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the processes or functions described in the embodiments of the present invention are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by wired (such as infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or a data center that contains one or more collections of available media. The available media can be magnetic media (such as floppy disks, hard disks, magnetic tapes), optical media (such as DVDs), or semiconductor media. The semiconductor media can be a solid-state drive.

[0146] It should be understood that the term "and / or" in this document is merely a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Here, A and B can be singular or plural. In addition, the character " / " in this document generally represents an "or" relationship between the associated objects before and after, but it may also represent an "and / or" relationship, which can be specifically understood by referring to the context.

[0147] It should be understood that in various embodiments of the present invention, the sequence numbers of the above processes do not imply the order of execution. The order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

[0148] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed in this document can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the present invention.

[0149] The unit described as a separation component may or may not be physically separated. The component shown as a unit may or may not be a physical unit, that is, it may be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0150] In addition, in each embodiment of the present invention, each functional unit may be integrated in a processing unit, may exist separately physically for each unit, or two or more units may be integrated in one unit.

[0151] If the above-mentioned function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or a part of this technical solution can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in each embodiment of the present invention.

[0152] As described above, the above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A finite-time sliding mode fault-tolerant safety control method based on an observer method, characterized in that: The method comprises: S1. Build dynamic models of discrete cyber-physical systems with parameter uncertainties and actuator failures; A dynamic model of a discrete cyber-physical system with parameter uncertainty and actuator failure is established. The state equation of the dynamic model is shown in the following formula (1): in, Indicates the status signal, Represents the control input signal, Indicates the measurement output signal; Indicates an actuator failure. represents external disturbance; real matrix It means satisfying The bounded parameter uncertainty of satisfy A, B, C, F a , M, E1 and E2 are known constant matrices of appropriate dimensions; S2. Perform mathematical modeling for periodic DoS interference attacks and packet loss to obtain packet loss information; The variable α(k) is defined by the following formula (2) to describe the periodic DoS interference attack strategy: Where n∈{1, 2, …} is the number of cycles; when α(k)=0, it indicates the attack sleep time; when α(k)=1, it indicates the attack time in the nth cycle; let T dos (T dos ∈Z + ) is the attacker’s action cycle, T off (T off ∈Z + ,T off <T dos ) is the duration of the silent period, where Z + is a set of positive integers; According to the periodic attack strategy of the DoS attacker, when the attacker is in a dormant state, only the random packet loss caused by the inherent factors of the wireless channel is considered. During the attack period, the DoS attacker selects the interference power to attack the wireless channel according to the total energy it has. Therefore, when α(k) = 0, the packet loss is caused by the inherent factors of the wireless channel, and when α(k) = 1, the packet loss is caused by the periodic DoS attack. Let β α(k) (k)∈{0,1} indicates whether the observer can successfully receive the data packet under the influence of DoS attack and channel inherent factors as shown in the following formula (3): Replace the lost measurement value with the latest received data to get the actual measurement value y a (k): y a (k)=β α(k) (k)y(k)+(1-β α(k) (k))y a (k-1) (4); S3. According to the packet loss situation, a state observer and a fault observer are designed in combination with the dynamic model to obtain estimation information; S4, designing a linear sliding surface based on the estimated information; designing a sliding mode fault-tolerant safety controller based on the linear sliding surface; S5. Based on the sliding mode fault-tolerant security controller, a finite-time sliding mode fault-tolerant security control is performed on a discrete information-physical system with periodic DoS interference attacks and packet loss.

2. The finite-time sliding mode fault-tolerant safety control method based on the observer method according to claim 1 is characterized in that: The S3, according to the packet loss situation, designs a state observer and a fault observer in combination with the dynamic model to obtain estimation information, including: Based on the actual measured value y a (k), construct the observer as follows: in, is the estimated value of x(k), Yes a (k) estimated value; is the state observer gain matrix to be determined, is the fault observer gain matrix to be determined.

3. The finite-time sliding mode fault-tolerant safety control method based on the observer method according to claim 2 is characterized in that: In S4, a linear sliding surface is designed based on the estimated information, including: A sliding surface function is designed according to the state estimation of the information-physical system, and a reaching law is designed according to the sliding surface function, and then a finite-time sliding mode fault-tolerant safety control method based on an observer method is designed.

4. A finite-time sliding mode fault-tolerant safety control system based on an observer method, wherein the finite-time sliding mode fault-tolerant safety control system based on an observer method is used to implement the finite-time sliding mode fault-tolerant safety control method based on an observer method as claimed in any one of claims 1 to 3, characterized in that: The system comprises: Dynamic model building module, used to build dynamic models of discrete cyber-physical systems with parameter uncertainties and actuator failures; Mathematical modeling module, used to perform mathematical modeling on periodic DoS interference attacks and packet loss to obtain packet loss information; An observer design module is used to design a state observer and a fault observer according to the packet loss situation and in combination with the dynamic model to obtain estimation information; A sliding mode fault-tolerant safety controller design module is used to design a linear sliding surface based on the estimated information; and to design a sliding mode fault-tolerant safety controller based on the linear sliding surface; The sliding mode fault-tolerant safety control module is used to perform finite-time sliding mode fault-tolerant safety control on discrete information-physical systems with periodic DoS interference attacks and packet loss based on the sliding mode fault-tolerant safety controller.

5. A finite-time sliding mode fault-tolerant safety controller based on an observer method, characterized in that: The finite-time sliding mode fault-tolerant safety controller based on the observer method is used to implement the finite-time sliding mode fault-tolerant safety control method based on the observer method as described in any one of claims 1-3.

6. A finite-time sliding mode fault-tolerant safety control device based on an observer method, characterized in that: The finite-time sliding mode fault-tolerant safety control device based on the observer method comprises: processor; A memory having computer-readable instructions stored thereon, wherein when the computer-readable instructions are executed by the processor, the method according to any one of claims 1 to 3 is implemented.

7. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores program codes, which can be called by a processor to execute the method according to any one of claims 1 to 3.

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