A gravitational wave detection platform digital twin fault detection method based on interval observer

Abstract

The application discloses a kind of based on interval observer's gravitational wave detection platform digital twin fault detection method, belong to spacecraft operation fault diagnosis field.The application provides a kind of gravitational wave detection platform digital twin fault detection method, in the upper link of digital twin system, the limited dimension real measurement data of gravitational wave detection platform is reconstructed into the dynamic estimation envelope of full-dimensional state variable using interval observer.Make that digital twin system can detect the fault of real gravitational wave detection platform not directly measurable signal, improve the detectability to platform fault.The application expands the range of state variable that can be monitored by digital twin system to on-orbit gravitational wave detection platform.The application provides a kind of computer equipment and storage medium of gravitational wave detection platform digital twin fault detection method, for realizing the specific steps of the above working method.

Description

Technical Field

[0001] This invention belongs to the field of spacecraft operation fault diagnosis, and in particular, a digital twin fault detection method for a gravitational wave detection platform based on an interval observer. Background Technology

[0002] A space-based gravitational wave detection system is a unique multi-body spacecraft system spanning over 20 orders of magnitude across macroscopic and microscopic scales. This involves three gravitational wave detection platforms maintaining stable formation at a baseline ranging from tens to millions of kilometers, requiring the test masses within all six platforms to achieve nanometer-scale relative motion. Therefore, fault diagnosis of the gravitational wave detection platforms can monitor their on-orbit operational status and assist in fault-tolerant control to recover from fault conditions, thereby extending the on-orbit lifespan of the gravitational wave detection system and ensuring the overall performance of the gravitational wave detection mission.

[0003] Digital twins, as an advanced mirroring system that fully utilizes data from physical models, sensor updates, and operational history, have been widely used for spacecraft on-orbit operational status monitoring and fault diagnosis. The concept of digital twins was initially termed "Information Mirroring Model" by Michael Grieves of the University of Michigan, later evolving into the term "digital twin." In 2012, NASA provided a conceptual description of digital twins: Digital twins refer to a simulation process that fully utilizes data from physical models, sensors, and operational history, integrating multiple disciplines and scales. As a virtual mirror of a physical product, it reflects the entire lifecycle of the corresponding physical entity. The U.S. Department of Defense was the first to propose using Digital Twin technology for the health maintenance and support of aerospace vehicles. First, a model of the real aircraft is established in digital space, and sensors are used to achieve complete synchronization with the aircraft's actual state. After each flight, based on the current structural condition and past loads, timely analysis and assessment can be conducted to determine if maintenance is needed and whether the aircraft can withstand the loads of the next mission. However, traditional digital twin technology, by connecting the upper-layer link to the monitored entity, can only receive real signals from the entity's sensors and perform health assessments or fault diagnoses by comparing them with simulated signals from a ground-based numerical simulation model. This significantly limits the range of state variables that a digital twin system can monitor, potentially overlooking potential faults in the real system. Therefore, it is necessary to expand the range of state variables that a digital twin system can monitor. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a digital twin fault detection method for a gravitational wave detection platform based on an interval observer.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] A digital twin fault detection method for a gravitational wave detection platform based on an interval observer includes the following steps:

[0007] Step 1: Establish a dynamic simulation model of the gravitational wave detection platform included in the ground link, select the state variables describing the gravitational wave detection platform, and extract the accurate numerical solution of the signal to be detected from the selected model state variables;

[0008] Step 2: Based on the platform dynamics simulation model established in Step 1, and using the actual measurement data of the signal to be detected transmitted by the on-orbit gravitational wave detection platform via the downlink, construct an interval observer to provide a dynamic upper bound estimation envelope of the signal to be detected. and dynamic lower bound estimation envelope

[0009] Step 3: Based on the precise numerical solution x of the signal under test derived in Step 1 and the dynamic upper bound estimation envelope of the signal under test calculated in Step 2. The dynamic lower bound estimation envelope is used to determine whether the on-orbit gravitational wave detection platform has malfunctioned. If the precise numerical solution x of the detected signal falls within the dynamic upper bound estimation envelope of the detected signal... and dynamic lower bound estimation envelope If the signal is within the range, there is no fault; otherwise, the gravitational wave detection platform malfunctions.

[0010] Furthermore, specifically:

[0011] Step 1: Establish a dynamic simulation model of the gravitational wave detection platform included in the ground link:

[0012]

[0013] in:

[0014] as well as:

[0015]

[0016] The gravitational wave detection platform is selected as the state variable X, and the dynamic simulation model of the gravitational wave detection platform is reorganized into dynamic equations containing the state variables. The state-space form of the output equation y:

[0017]

[0018] y = H 16×19 X (5)

[0019] At the same time, the precise numerical solution x of the signal to be detected is derived from the selected model state variables X;

[0020] in, This represents the coordinate transformation matrix from coordinate system X to coordinate system Y; m (·) Indicates the mass of the corresponding component of the gravitational wave detection platform; I (·) Represents the inertia of the corresponding component of the gravitational wave detection platform; I3 represents a 3×3 identity matrix; O3 represents a 3×3 zero matrix; [r (·) ×] represents the position vector r (·) The cross product matrix of elements; f (·)_e T represents all external forces acting on the corresponding components of the gravitational wave detection platform. (·)_e This should represent all external torques acting on the corresponding components of the gravitational wave detection platform;

[0021] Step 2: Using the platform dynamics simulation model established in Step 1, and based on the actual measurement data yr of the signal to be detected transmitted by the downlink from the on-orbit gravitational wave detection platform, construct an interval observer to provide a dynamic upper bound estimation envelope for the signal to be detected x. and dynamic lower bound estimation envelope

[0022]

[0023] in, and These represent the lower bound envelope observer and the upper bound envelope observer of the signal to be tested, x, respectively. d (k) and Let y represent the lower and upper boundaries of the known noise signal d at time k, respectively; r (k) represents the actual measurement data of the signal to be detected transmitted by the downlink from the on-orbit gravitational wave detection platform; A and H are the system matrix and output matrix of the dynamic simulation model of the gravitational wave detection platform in step one, respectively; B + B - Let B represent the nonnegation of the control mapping matrix B in the dynamic simulation model of the gravitational wave detection platform in step one. + =max{0,B} and B - =B + -B;L, These represent the gain matrices of the lower bound envelope observer and the upper bound envelope observer, respectively.

[0024] Step 3: Based on the precise numerical solution x of the signal under test obtained in Step 1 and the dynamic estimation envelope of the signal under test calculated in Step 2... and The criteria for determining whether an on-orbit gravitational wave detection platform has malfunctioned are as follows:

[0025]

[0026] Furthermore, in step one, the selected state variables X describing the gravitational wave detection platform include: the linear motion position vector rB and the velocity vector of the gravitational wave detection platform. Angular motion position vector Θ of gravitational wave detection platform B and angular velocity vector The platform includes the T / M1 line motion position vector for inspection quality. With velocity vector and its angular motion position vector With velocity vector The position vector of the test mass T / M2 line motion contained within the gravitational wave detection platform With velocity vector and its angular motion position vector With velocity vector The rotational angular displacement α and rotational angular velocity of the rotatable electrode cage C contained within the gravitational wave detection platform. The signal to be detected, x, consists of the elements contained in the state variables of the gravitational wave detection platform selected above.

[0027] Furthermore, in step one, in the state-space form of the dynamic simulation model of the gravitational wave detection platform, u represents the active control force and torque acting on the corresponding component of the gravitational wave detection platform, including: the active control force f of the gravitational wave detection platform thruster. FEEP and torque T FEEP The platform includes the T / M1 active electrostatic levitation control force for inspection quality. and torque T / M2 Active Electrostatic Suspension Control Force and torque The platform includes a rotatable electrode cage with active control torque T. C ;d represents the interference force and torque experienced by the corresponding component of the gravitational wave detection platform, including: the noise force f of the gravitational wave detection platform thruster. FEEP,d and torque T FEEP,d The solar radiation pressure interference force f experienced by the gravitational wave detection platform sol,d With torque T sol,d The inspection quality T / M1 contained within the platform is subject to interference. and disturbance torque T / M2 is subject to interference force and disturbance torque The platform includes a rotatable electrode cage with an interference torque T. C,d The sum of the active control force and torque u acting on the gravitational wave detection platform and the disturbance force and torque d acting on the corresponding components of the gravitational wave detection platform, plus all the external forces f mentioned above. (·)_e With external torque T (·)_e The sum is consistent.

[0028] Furthermore, in step one, the state variable X describing the gravitational wave detection platform, the active control force and torque u acting on the corresponding component of the gravitational wave detection platform, and the disturbance force and torque d acting on the corresponding component of the gravitational wave detection platform, Ω in the state space form of the dynamic simulation model of the gravitational wave detection platform... 19×19 M 19×19 , The various forms are as follows:

[0029]

[0030]

[0031]

[0032] The first stiffness coupling coefficient Ω1 and the second stiffness coupling coefficient Ω2 are determined by the dynamic simulation model of the gravitational wave detection platform.

[0033] Furthermore, the system matrix of the dynamic simulation model of the gravitational wave detection platform in step one... Control mapping matrix

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] This invention provides a digital twin fault detection method for gravitational wave detection platforms. In the upper-layer link of the digital twin system, an interval observer is used to reconstruct the finite-dimensional real measurement data of the gravitational wave detection platform into a dynamic estimation envelope of full-dimensional state variables. This enables the digital twin system to detect faults in signals that cannot be directly measured from the real gravitational wave detection platform, improving the detectability of platform faults. This invention expands the range of state variables that can be monitored by the digital twin system for on-orbit gravitational wave detection platforms.

[0036] This invention provides a computer device and storage medium for a digital twin fault detection method for a gravitational wave detection platform, which are used to implement the specific steps of the above-mentioned working method. Attached Figure Description

[0037] Figure 1 This is a flowchart of a digital twin fault detection method for a gravitational wave detection platform based on an interval observer, according to the present invention.

[0038] Figure 2 This is an abstract diagram of the components and coordinate system of the gravitational wave detection platform described in this invention;

[0039] Figure 3 This is a fault diagnosis logic diagram provided by the digital twin system when the signal under test does not have a fault in the embodiment;

[0040] Figure 4 This is a fault diagnosis logic diagram provided by the digital twin system when the signal under test fails in the embodiment. Detailed Implementation

[0041] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0042] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0043] The present invention will now be described in further detail with reference to the accompanying drawings:

[0044] See Figures 1-4 This invention provides a digital twin fault detection method for a gravitational wave detection platform based on interval observers. Fault diagnosis is implemented by reconstructing the dynamic estimation envelope of the full-dimensional state variables of the gravitational wave detection platform through an interval observer introduced into the upper-layer link of the digital twin. Simulation examples verify the effectiveness of the proposed method.

[0045] A digital twin fault detection method for a gravitational wave detection platform based on an interval observer includes the following steps:

[0046] Step 1: Establish a dynamic simulation model of the gravitational wave detection platform included in the ground link:

[0047]

[0048] In formula (1):

[0049]

[0050] as well as:

[0051]

[0052] The gravitational wave detection platform is selected as the state variable X, and the dynamic simulation model of the gravitational wave detection platform is reorganized into dynamic equations containing the state variables. The state-space form of the output equation y:

[0053]

[0054] y = H 16×19 X (5)

[0055] At the same time, the precise numerical solution x of a certain signal to be detected is derived from the selected model state variables X.

[0056] Step Two: Using the platform dynamics simulation model established in Step One, based on the actual measurement data y of the signal to be detected transmitted by the downlink from the on-orbit gravitational wave detection platform. r Constructing an interval observer provides a dynamic upper bound estimate of the envelope of the signal to be detected, x. and dynamic lower bound estimation envelope

[0057]

[0058] Step 3: Estimate the dynamic upper bound envelope of the detected signal x based on the precise numerical solution x obtained in Step 1 and the detected signal x calculated in Step 2. and dynamic lower bound estimation envelope Construct fault detection logic:

[0059]

[0060] Based on fault detection logic, it is determined whether the on-orbit gravitational wave detection platform has malfunctioned.

[0061] Example

[0062] In this embodiment, the inertial parameters in the dynamic model of the gravitational wave detection platform are set as follows: the test mass is... Electrode cage mass The mass m of the gravitational wave detection platform (excluding the two test masses and two electrode cages contained within the platform) sc =700kg. Inspect the moment of inertia of the mass. Electrode cage moment of inertia The moment of inertia I of the gravitational wave detection platform (excluding the two test masses and two electrode cages included in the platform). sc = 450 kg·m 2 .

[0063] set up Figure 2 The structural parameters of the gravitational wave detection platform shown are: |r BO1|=0m,|r CT1 |=0m,|r BC |=|r O1C |=0.4m, and The test quality values ​​T / M1 and T / M2 are calculated from the measurement signals of the gravitational wave detection platform.

[0064] The control input and disturbance of the numerical simulation model of the gravitational wave detection platform dynamics included in the ground link are set to d=0.

[0065] The selected fault diagnosis signal is the linear displacement vector of the gravitational wave detection platform's test mass T / M1 relative to the electrode cage T1. The y-axis component. The signal to be detected by the on-orbit gravitational wave detection platform in the space-based link is set. The corresponding upper and lower bounds of the measurement noise are:

[0066]

[0067]

[0068] Signal to be detected on the on-orbit gravitational wave detection platform The fault occurred as follows:

[0069]

[0070] This invention utilizes real measurement signals from an on-orbit gravitational wave detection platform to reconstruct the dynamic estimation envelope of arbitrary state variables and implement fault diagnosis, such as... Figure 1 As shown, this enables fault detection of previously unmeasurable internal system state variables, expanding the monitorable scope of digital twin systems.

[0071] See Figure 3 and Figure 4 , Figure 3 and Figure 4 This means that when a fault occurs inside the on-orbit gravitational wave detection platform, it will be reflected in the reconstructed dynamic estimation envelope, which will deviate from the accurate numerical solution given by the simulation model of the gravitational wave detection platform contained in the ground link, thereby achieving effective fault diagnosis.

[0072] This invention employs a dynamic envelope estimation method for state variables based on an interval observer. It reconstructs the dynamic estimated envelope of the full-dimensional state variables using finite-dimensional measurement data from an on-orbit gravitational wave detection platform. This estimated envelope is then compared with the precise numerical solution of the signal to be detected derived from the dynamic simulation model of the digital twin gravitational wave detection platform to achieve fault diagnosis.

[0073] This invention relates to a digital twin fault detection method for a gravitational wave detection platform based on an interval observer. The method includes: establishing a digital twin fault detection framework using the on-orbit gravitational wave detection platform and downlink data as the space-based link, and a dynamic simulation model of the gravitational wave detection platform as the ground-based link; establishing a dynamic simulation model of the gravitational wave detection platform included in the ground-based link, and defining the required descriptive variables; constructing an interval observer with a specific structure included in the space-based link, and providing a dynamic estimation envelope of the signal to be detected by inputting the actual measured values ​​of the state variables to be detected output by the on-orbit gravitational wave platform; and constructing fault detection logic to compare the dynamic estimation envelope of the signal to be detected given by the space-based link with the precise numerical solution of the signal to be detected given by the ground-based link, thereby achieving fault diagnosis. This invention enables the digital twin system to detect faults in signals that cannot be directly measured from a real gravitational wave detection platform, improving the detectability of platform faults.

[0074] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A digital twin fault detection method for a gravitational wave detection platform based on an interval observer, characterized in that, Includes the following steps: Step 1: Establish a dynamic simulation model of the gravitational wave detection platform included in the ground link, select the state variables describing the gravitational wave detection platform, and extract the accurate numerical solution of the signal to be detected from the selected model state variables; Step 2: Based on the platform dynamics simulation model established in Step 1, and using the actual measurement data of the signal to be detected transmitted by the on-orbit gravitational wave detection platform via the downlink, construct an interval observer to provide a dynamic upper bound estimation envelope of the signal to be detected. and dynamic lower bound estimation envelope ; Step 3: Determine the precise numerical solution of the signal to be detected based on the information obtained in Step 1. The dynamic upper bound estimation envelope of the signal to be detected calculated in step two. And the dynamic lower bound estimation envelope, to determine whether the on-orbit gravitational wave detection platform has malfunctioned, if the precise numerical solution of the signal to be detected... Estimating the envelope of the dynamic upper bound of the signal to be detected. and dynamic lower bound estimation envelope If the signal is within the range, there is no fault; otherwise, the gravitational wave detection platform has malfunctioned. Specifically: Step 1: Establish a dynamic simulation model of the gravitational wave detection platform included in the ground link: （1） in: （2） as well as: （3） The selected gravitational wave detection platform describes the state variables as follows: The dynamic simulation model of the gravitational wave detection platform is organized into dynamic equations including state variables. With output equation State-space form: （4） （5） At the same time, from the selected model state variables The precise numerical solution of the signal to be detected is derived from the middle. ; in, This represents the coordinate transformation matrix projected from coordinate system X to coordinate system Y; This indicates the mass of the corresponding component of the gravitational wave detection platform; This indicates the inertia of the corresponding component of the gravitational wave detection platform. Represents a 3×3 identity matrix. Represents a zero matrix of size 3×3; Represents position vector A cross product matrix composed of elements; This represents all external forces acting on the corresponding components of the gravitational wave detection platform; This should represent all external torques acting on the corresponding components of the gravitational wave detection platform; Step 2: Using the platform dynamics simulation model established in Step 1, and based on the actual measurement data of the signal to be detected transmitted by the downlink from the on-orbit gravitational wave detection platform. Construct an interval observer to provide the signal to be detected. Dynamic upper bound estimation envelope and dynamic lower bound estimation envelope ; （6） in, and They represent the signals to be detected. The lower bound envelope observer and the upper bound envelope observer; and Representing known noise signals respectively At any moment The lower and upper boundaries; This represents the actual measurement data of the signal to be detected transmitted by the downlink from the on-orbit gravitational wave detection platform; , These are the system matrix and output matrix of the dynamic simulation model of the gravitational wave detection platform in step one, respectively; , These represent the control mapping matrices of the dynamic simulation model of the gravitational wave detection platform in step one. The nonnegative matrix, and ; , These represent the gain matrices of the lower bound envelope observer and the upper bound envelope observer, respectively. Step 3: Determine the precise numerical solution of the signal to be detected based on the information obtained in Step 1. The dynamic estimation envelope of the signal to be detected calculated in step two and The criteria for determining whether an on-orbit gravitational wave detection platform has malfunctioned are as follows: 。 2. The digital twin fault detection method for a gravitational wave detection platform based on an interval observer as described in claim 1, characterized in that, In step one, the selected state variables describing the gravitational wave detection platform Includes: the linear motion position vector of the gravitational wave detection platform and velocity vector ; angular motion position vector of the gravitational wave detection platform and angular velocity vector The platform includes the motion position vector of the inspection quality T / M1 line. With velocity vector and its angular motion position vector With velocity vector The position vector of the test mass T / M2 line motion contained within the gravitational wave detection platform. With velocity vector and its angular motion position vector With velocity vector The rotational angular displacement of the rotatable electrode cage C contained within the gravitational wave detection platform. With rotational angular velocity ;Signal to be checked These are the elements included in the state variables of the selected gravitational wave detection platform.

3. The digital twin fault detection method for a gravitational wave detection platform based on an interval observer according to claim 2, characterized in that, In step one, in the state-space form of the dynamic simulation model of the gravitational wave detection platform, This represents the active control forces and torques acting on corresponding components of the gravitational wave detection platform, including: the active control force of the gravitational wave detection platform's thrusters. and torque The platform includes the T / M1 active electrostatic levitation control force for inspection quality. and torque T / M2 active electrostatic levitation control force and torque The platform includes a rotatable electrode cage with active control torque. ; This represents the interference forces and torques experienced by corresponding components of the gravitational wave detection platform, including: the noise force of the gravitational wave detection platform's thrusters. and torque The solar radiation pressure interference force experienced by the gravitational wave detection platform With torque The inspection quality T / M1 contained within the platform is subject to interference. and disturbance torque T / M2 is subject to interference force and disturbance torque The platform contains a rotatable electrode cage with interfering torque. Active control forces and torques experienced by the gravitational wave detection platform Interference forces and torques experienced by components corresponding to the gravitational wave detection platform The sum of all external forces mentioned With external torque The sum is consistent.

4. The digital twin fault detection method for a gravitational wave detection platform based on an interval observer according to claim 3, characterized in that, In step one, the state variables describing the gravitational wave detection platform The active control force and torque experienced by the corresponding component of the gravitational wave detection platform And the interference forces and torques experienced by the corresponding components of the gravitational wave detection platform. The state-space form of the dynamic simulation model of the gravitational wave detection platform The various forms are as follows: ， ， , Among them, the first stiffness coupling coefficient Second stiffness coupling coefficient The results were determined by the dynamic simulation model of the gravitational wave detection platform.

5. The digital twin fault detection method for a gravitational wave detection platform based on an interval observer according to claim 1, characterized in that, In step two, the system matrix of the dynamic simulation model of the gravitational wave detection platform. Control mapping matrix .

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