Spacecraft autonomous navigation method under random noise and dynamic interference

Abstract

The invention belongs to the technical field of spacecraft navigation methods, and particularly relates to a spacecraft autonomous navigation method under random noise and dynamic interference. Comprising the following steps: S1, establishing a spacecraft kinetic equation under dynamic disturbance force, and establishing a spacecraft position measurement equation under random noise; s2, constructing a spacecraft augmented state system; s3, designing a forecasting module of a spacecraft augmented state system, wherein the forecasting module comprises a spacecraft augmented state forecasting value and a spacecraft augmented state forecasting error covariance matrix; calculating a spacecraft estimation gain coefficient matrix; s4, giving a spacecraft augmented state estimation value according to the spacecraft augmented state forecast value, the spacecraft augmented state forecast error covariance matrix and the estimation gain coefficient matrix; and S5, according to the augmented state estimation value of the spacecraft, obtaining estimation values of the position, the speed and the received dynamic interference force of the spacecraft. The influence of the dynamic disturbing force on the navigation precision of the spacecraft is reduced, and the autonomous perception of the dynamic disturbing force is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of spacecraft navigation methods, and particularly relates to a spacecraft autonomous navigation method under random noise and dynamic interference. Background Art

[0002] Spacecraft navigation is the basis for a spacecraft to perform various tasks and is a key prerequisite for ensuring the safe, accurate, and stable operation of the spacecraft. Spacecraft navigation refers to obtaining information such as the current position of the spacecraft through measurement data with noise. In the problem of spacecraft navigation, how to process the noise in the measurement data is a long-term problem, and existing solutions such as Kalman filtering, extended Kalman filtering, unscented Kalman filtering, etc. are adopted. However, the above methods can only handle the measurement data noise problem under known non-linear dynamic conditions, and cannot solve the navigation problem of the spacecraft under unknown disturbing forces, nor can they autonomously identify the magnitude of the unknown disturbing forces.

[0003] The current space environment where the spacecraft is located is becoming increasingly complex, and it is affected by various complex dynamic interferences such as unknown impacts and unknown force disturbances. How to achieve autonomous perception of the disturbing force and accurate navigation under the disturbing force is a hot research direction. Under the current spacecraft structure design, installing a disturbing force sensor is a method to sense the disturbing force, but this design will increase the complexity of the spacecraft's hardware assembly and also increase the overall production cost of the spacecraft.

[0004] How to achieve autonomous perception of the external dynamic disturbing force of the spacecraft and high-precision navigation under the disturbing force without installing a disturbing force sensor is an important problem in current spacecraft navigation. If a set of spacecraft autonomous navigation methods, including spacecraft position estimation, velocity estimation, and disturbing force estimation, can be given when the spacecraft measurement data has noise and the spacecraft is affected by unknown dynamic disturbing forces, it has important practical significance. Summary of the Invention

[0005] In order to solve the technical problem of "how to achieve autonomous perception of the external dynamic disturbing force of the spacecraft and the influence of the dynamic disturbing force on the spacecraft navigation accuracy without installing a disturbing force sensor when the spacecraft measurement data has noise and the spacecraft is affected by unknown dynamic disturbing forces", the present invention provides the following technical solutions:

[0006] A spacecraft autonomous navigation method under random noise and dynamic interference, comprising the following steps:

[0007] S1. Establish the spacecraft dynamics equation under dynamic interference forces. The spacecraft dynamics equation involves variables such as the spacecraft position, spacecraft velocity, and dynamic interference forces acting on the spacecraft; and based on the influence of random noise in spacecraft position measurement, establish the spacecraft position measurement equation under random noise.

[0008] S2. Construct the augmented state system of the spacecraft: Based on the actual sampling process, establish the discrete equations of spacecraft dynamics and spacecraft position measurement under dynamic interference; and by introducing the augmented state of the spacecraft including the spacecraft position, spacecraft velocity, and dynamic interference forces acting on the spacecraft, establish the discrete equation of the augmented state of the spacecraft.

[0009] S3. Design the prediction module of the augmented state system of the spacecraft, including the predicted value of the augmented state of the spacecraft and the predicted error covariance matrix of the augmented state of the spacecraft; calculate the estimated gain coefficient matrix of the spacecraft according to the predicted error covariance matrix of the augmented state of the spacecraft.

[0010] S4. Give the updated result of the estimated value of the augmented state of the spacecraft according to the predicted value of the augmented state of the spacecraft, the predicted error covariance matrix of the augmented state of the spacecraft, and the estimated gain coefficient matrix.

[0011] S5. Obtain the estimated values of the spacecraft position, spacecraft velocity, and dynamic interference forces acting on the spacecraft according to the estimated value of the augmented state of the spacecraft.

[0012] Further, in step S1, the spacecraft dynamics equation under dynamic interference is established, expressed as

[0013]

[0014] where \(X(t)\in R\) 3 is the spacecraft position at time \(t\), \(V(t)\in R\) 3 is the spacecraft velocity at time \(t\), \(M\in R\) is the mass of the spacecraft, \(F(t)\in R\) 3 is the active driving force of the spacecraft at time \(t\), \(D(t)\in R\) 3 is the dynamic interference force acting on the spacecraft at time \(t\), and \(R\) is the set composed of all real numbers.

[0015] Further, in step S1, based on the influence of random noise in spacecraft position measurement, the spacecraft position measurement equation is established, expressed as

[0016] \(Y(t)=X(t)+N(t)\ (2)\),

[0017] where \(Y(t)\in R\) 3 is the measured value of the spacecraft position at time \(t\), \(N(t)\in R\) 3 is the random noise in spacecraft position measurement at time \(t\).

[0018] Furthermore, in step S2, based on the actual sampling process, discrete equations of spacecraft dynamics and spacecraft position measurement under dynamic disturbances are established, expressed as

[0019]

[0020] where \(h\in\mathbb{R}\) is the sampling step, \(\mathbf{X}\) k+1 \(\in\mathbb{R}\) 3 is the spacecraft position at the \((k + 1)\)-th sampling step, \(\mathbf{X}\) k \(\in\mathbb{R}\) 3 is the spacecraft position at the \(k\)-th sampling step; \(\mathbf{V}\) k+1 \(\in\mathbb{R}\) 3 is the spacecraft velocity at the \((k + 1)\)-th sampling step, \(\mathbf{V}\) k \(\in\mathbb{R}\) 3 is the spacecraft velocity at the \(k\)-th sampling step; \(\mathbf{F}\) k \(\in\mathbb{R}\) 3 is the active driving force of the spacecraft at the \(k\)-th sampling step; \(\mathbf{D}\) k \(\in\mathbb{R}\) 3 is the dynamic disturbance force acting on the spacecraft at the \(k\)-th sampling step; \(\mathbf{Y}\) k \(\in\mathbb{R}\) 3 is the spacecraft position measurement value at the \(k\)-th sampling step; \(\mathbf{N}\) k \(\in\mathbb{R}\) 3 is the random noise of the spacecraft position measurement at the \(k\)-th sampling step.

[0021] Furthermore, in step S2, an augmented state including the spacecraft position, spacecraft velocity, and dynamic disturbance force acting on the spacecraft is introduced, and a discrete equation of the spacecraft augmented state is established, expressed as

[0022]

[0023] where \(\mathbf{Z}\) k+1 \(\in\mathbb{R}\) 9 is the spacecraft augmented state at the \((k + 1)\)-th sampling step, \(\mathbf{Z}\) k \(\in\mathbb{R}\) 9 is the spacecraft augmented state at the \(k\)-th sampling step, \(\mathbf{A}\in\mathbb{R}\) 9×9 is the spacecraft augmented state system matrix, \(\mathbf{B}\in\mathbb{R}\) 9×3 is the external input matrix of the spacecraft augmented state system, \(\mathbf{C}\in\mathbb{R}\) 3×9 is the measurement matrix of the spacecraft augmented state system.

[0024] Furthermore, \(\mathbf{Z}\) k , \(\mathbf{A}\), \(\mathbf{B}\), \(\mathbf{C}\) satisfy the following expressions:

[0025]

[0026] where \(\mathbf{I}\)3 ∈R 3×3 is the 3×3 identity matrix, 0 3 ∈R 3×3 is the 3×3 zero matrix.

[0027] Furthermore, in step S3, design a prediction module for the augmented spacecraft state system, including the predicted value of the augmented spacecraft state and the predicted error covariance matrix of the augmented spacecraft state, expressed as

[0028]

[0029] where is the predicted value of the augmented spacecraft state at the (k + 1)-th sampling step, is the estimated value of the augmented spacecraft state at the k-th sampling step, is the predicted error covariance matrix of the augmented spacecraft state at the (k + 1)-th sampling step, P k ∈R 9×9 is the estimated error covariance matrix of the augmented spacecraft state at the k-th sampling step.

[0030] Furthermore, in step S3, calculate the spacecraft estimation gain coefficient matrix according to the predicted error covariance matrix of the augmented spacecraft state, expressed as

[0031]

[0032] where K k+1 ∈R 9×3 is the spacecraft estimation gain coefficient matrix at the (k + 1)-th sampling step,

[0033] Q k+1 ∈R 3×3 is the spacecraft measurement noise covariance matrix at the (k + 1)-th sampling step.

[0034] Furthermore, in step S4,

[0035] Based on the predicted value of the augmented spacecraft state, the predicted error covariance matrix of the augmented spacecraft state, and the estimation gain coefficient matrix, give the updated result of the estimated value of the augmented spacecraft state, expressed as

[0036]

[0037] where I 9 ∈R 9×9 is the 9×9 identity matrix, is the estimated value of the augmented spacecraft state at the (k + 1)-th sampling step, P k+1 ∈R 9×9 is the estimated error covariance matrix of the augmented spacecraft state at the (k + 1)-th sampling step.

[0038] Further, in step S5,

[0039] Based on the augmented state estimate of the spacecraft, the estimated values of the spacecraft position, spacecraft velocity, and dynamic disturbance force acting on the spacecraft are obtained, expressed as:

[0040]

[0041] where is the estimated value of the spacecraft position at the (k + 1)-th sampling step, is the estimated value of the spacecraft velocity at the (k + 1)-th sampling step, is the estimated value of the dynamic disturbance force acting on the spacecraft at the (k + 1)-th sampling step.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] The present invention provides a set of spacecraft autonomous navigation methods, including the design of the augmented state of the spacecraft under sampling scenarios and its discrete equation representation, the prediction module of the augmented state system of the spacecraft, the calculation process of the estimated gain coefficient matrix, and the update of the estimated value of the augmented state of the spacecraft. It realizes high-precision estimation of the position, velocity, and dynamic disturbance force of the spacecraft. During the spacecraft navigation process, it reduces the influence of the dynamic disturbance force on the navigation accuracy of the spacecraft, realizes the autonomous perception of the dynamic disturbance force, and high-precision estimation of the position, velocity, and dynamic disturbance force of the spacecraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 is the flow chart of the method of the present invention.

[0045] Figure 2a is one of the spacecraft position estimation result diagrams under the method of the present invention.

[0046] Figure 2b is the second spacecraft position estimation result diagram under the method of the present invention.

[0047] Figure 2c is the third spacecraft position estimation result diagram under the method of the present invention.

[0048] Figure 3a is one of the spacecraft velocity estimation result diagrams under the method of the present invention.

[0049] Figure 3b is the second spacecraft velocity estimation result diagram under the method of the present invention.

[0050] Figure 3c is the third spacecraft velocity estimation result diagram under the method of the present invention.

[0051] Figure 4a It is one of the estimated result diagrams of the dynamic interference force received by the spacecraft under the method of the present invention.

[0052] Figure 4b It is the second of the estimated result diagrams of the dynamic interference force received by the spacecraft under the method of the present invention.

[0053] Figure 4c It is the third of the estimated result diagrams of the dynamic interference force received by the spacecraft under the method of the present invention. Specific implementation manners

[0054] The technical solution of the present invention will be clearly described below in conjunction with the accompanying drawings. Obviously, the described embodiments are not all embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0055] The symbol descriptions involved in the present invention are as follows.

[0056] R: The set composed of all real numbers;

[0057] t: The system operation time of the spacecraft, t ∈ [0, ∞);

[0058] X(t): The position of the spacecraft at time t, X(t) ∈ R 3 ;

[0059] V(t): The velocity of the spacecraft at time t, V(t) ∈ R 3 ;

[0060] M: The mass of the spacecraft, M ∈ R;

[0061] F(t): The active driving force of the spacecraft at time t, F(t) ∈ R 3 ;

[0062] D(t): The dynamic interference force received by the spacecraft at time t, D(t) ∈ R 3 ;

[0063] Y(t): The measured value of the spacecraft position at time t, Y(t) ∈ R 3 ;

[0064] N(t): The random noise of the spacecraft position measurement at time t, N(t) ∈ R 3 ;

[0065] h: Sampling step size, h ∈ R;

[0066] X k : The position of the spacecraft at the k-th sampling step, X k ∈ R 3 ;

[0067] X k+1 : The position of the spacecraft at the (k + 1)-th sampling step, X k+1 ∈R 3 ;

[0068] V k : The velocity of the spacecraft at the k-th sampling step, V k ∈R 3 ;

[0069] V k+1 : The velocity of the spacecraft at the (k + 1)-th sampling step, V k+1 ∈R 3 ;

[0070] F k : The active driving force of the spacecraft at the k-th sampling step, F k ∈R 3 ;

[0071] D k : The dynamic interference force acting on the spacecraft at the k-th sampling step, D k ∈R 3 ;

[0072] Y k : The measured value of the spacecraft position at the k-th sampling step, Y k ∈R 3 ;

[0073] N k : The random noise of the spacecraft position measurement at the k-th sampling step, N k ∈R 3 ;

[0074] Z k : The augmented state of the spacecraft at the k-th sampling step, Z k ∈R 9 ;

[0075] Z k+1 : The augmented state of the spacecraft at the (k + 1)-th sampling step, Z k+1 ∈R 9 ;

[0076] A: The augmented state system matrix of the spacecraft, A ∈ R 9×9 ;

[0077] B: The external input matrix of the spacecraft augmented state system, B ∈ R 9×3 ;

[0078] C: The measurement matrix of the spacecraft augmented state system, C ∈ R 3×9 ;

[0079] I3 : The 3×3 identity matrix, I 3 ∈R 3×3 ;

[0080] 0 3 : The 3×3 zero matrix, 0 3 ∈R 3×3 ;

[0081] The predicted value of the augmented state of the spacecraft at the (k + 1)-th sampling step

[0082] The estimated value of the augmented state of the spacecraft at the k-th sampling step

[0083] The estimated value of the augmented state of the spacecraft at the (k + 1)-th sampling step

[0084] The predicted error covariance matrix of the augmented state of the spacecraft at the (k + 1)-th sampling step

[0085]

[0086] P k : The estimated error covariance matrix of the augmented state of the spacecraft at the k-th sampling step, P k ∈R 9×9 ;

[0087] P k+1 : The estimated error covariance matrix of the augmented state of the spacecraft at the (k + 1)-th sampling step

[0088] P k+1 ∈R 9×9 ;

[0089] K k+1 : The estimation gain coefficient matrix of the spacecraft at the (k + 1)-th sampling step, K k+1 ∈R 9×3 ;

[0090] Q k+1 : The measurement noise covariance matrix of the spacecraft at the (k + 1)-th sampling step, Q k+1 ∈R 3×3 ;

[0091] I 9 : The 9×9 identity matrix, I 9 ∈R 9×9 ;

[0092] The estimated value of the spacecraft position at the (k + 1)-th sampling step,

[0093] The estimated value of the spacecraft velocity at the (k + 1)-th sampling step,

[0094] The estimated value of the dynamic disturbance force acting on the spacecraft at the (k + 1)-th sampling step,

[0095]

[0096] Embodiment

[0097] As Figure 1 shown, the present invention provides a spacecraft autonomous navigation method under random noise and dynamic disturbance, including the following steps:

[0098] S1. Establish the spacecraft dynamics equation under the action of dynamic disturbance force, where the spacecraft dynamics equation involves variables such as spacecraft position, spacecraft velocity, and dynamic disturbance force acting on the spacecraft; and based on the influence of random noise in spacecraft position measurement, establish the spacecraft position measurement equation;

[0099] S2. Construct the spacecraft augmented state system: based on the actual sampling process, establish the discrete equations of spacecraft dynamics and spacecraft position measurement under dynamic disturbance; and by introducing the spacecraft augmented state including spacecraft position, spacecraft velocity, and dynamic disturbance force acting on the spacecraft, establish the spacecraft augmented state discrete equation;

[0100] S3. Design the prediction module of the spacecraft augmented state system, including the predicted value of the spacecraft augmented state and the predicted error covariance matrix of the spacecraft augmented state; calculate the spacecraft estimation gain coefficient matrix according to the predicted error covariance matrix of the spacecraft augmented state.

[0101] S4. Give the updated result of the spacecraft augmented state estimation value according to the predicted value of the spacecraft augmented state, the predicted error covariance matrix of the spacecraft augmented state, and the estimation gain coefficient matrix.

[0102] S5. Obtain the estimated values of spacecraft position, spacecraft velocity, and dynamic disturbance force acting on the spacecraft according to the estimated value of the spacecraft augmented state.

[0103] Specifically,

[0104] In step S1, establish the spacecraft dynamics equation under dynamic disturbance, expressed as

[0105]

[0106] where X(t) ∈ R3 is the position of the spacecraft at time t, represents the derivative of X(t); V(t) ∈ R 3 is the velocity of the spacecraft at time t, where represents the derivative of V(t); M ∈ R is the mass of the spacecraft, F(t) ∈ R 3 is the active driving force of the spacecraft at time t, where R is the set consisting of all real numbers; D(t) ∈ R 3 is the dynamic interference force acting on the spacecraft at time t, R 3 represents three-dimensional real space.

[0107] In step S1, since sensors are installed on the spacecraft to measure its position, the measured values often carry noise. Therefore, based on the influence of the random noise in the spacecraft position measurement, the spacecraft position measurement equation is expressed as Y(t) = X(t) + N(t) (2),

[0108] where Y(t) ∈ R 3 is the measured value of the spacecraft position at time t, N(t) ∈ R 3 is the random noise in the spacecraft position measurement at time t.

[0109] In step S2, based on the actual sampling process, the discrete equations of the spacecraft dynamics and the spacecraft position measurement under dynamic interference are established, expressed as

[0110]

[0111] where h ∈ R is the sampling step size, X k+1 ∈ R 3 is the position of the spacecraft at the (k + 1)-th sampling step, X k ∈ R 3 is the position of the spacecraft at the k-th sampling step; V k+1 ∈ R 3 is the velocity of the spacecraft at the (k + 1)-th sampling step, V k ∈ R 3 is the velocity of the spacecraft at the k-th sampling step; F k ∈ R 3 is the active driving force of the spacecraft at the k-th sampling step; D k ∈ R 3 is the dynamic interference force acting on the spacecraft at the k-th sampling step; Y k ∈ R 3 is the measured value of the spacecraft position at the k-th sampling step; N k ∈ R 3 is the random noise in the spacecraft position measurement at the k-th sampling step.

[0112] In step S2, an augmented state including the spacecraft position, spacecraft velocity, and dynamic disturbance force acting on the spacecraft is introduced to obtain the discrete equation of the spacecraft augmented state, expressed as

[0113]

[0114] where Z k+1 ∈R 9 is the spacecraft augmented state at the (k + 1)-th sampling step, Z k ∈R 9 is the spacecraft augmented state at the k-th sampling step, A ∈ R 9×9 is the system matrix of the spacecraft augmented state, B ∈ R 9×3 is the external input matrix of the spacecraft augmented state system, C ∈ R 3×9 is the measurement matrix of the spacecraft augmented state system, where R 9 represents a 9-dimensional physical space, R 9×9 represents a 9×9 physical space matrix; R 9×3 represents a 9×3 physical space matrix; R 3×9 represents a 3×9 physical space matrix. Z k , A, B, and C satisfy the following expressions:

[0115]

[0116] where I 3 ∈R 3×3 is a 3×3 identity matrix, 0 3 ∈R 3×3 is a 3×3 zero matrix.

[0117] In step S3, a prediction module of the spacecraft augmented state system is designed, including the predicted value of the spacecraft augmented state and the predicted error covariance matrix of the spacecraft augmented state, expressed as

[0118]

[0119] where is the predicted value of the spacecraft augmented state at the (k + 1)-th sampling step, is the estimated value of the spacecraft augmented state at the k-th sampling step, is the predicted error covariance matrix of the spacecraft augmented state at the (k + 1)-th sampling step, P k ∈R 9×9 is the estimated error covariance matrix of the spacecraft augmented state at the k-th sampling step.

[0120] In step S3, according to the predicted error covariance matrix of the spacecraft augmented state, the estimated gain coefficient matrix of the spacecraft is calculated, expressed as

[0121]

[0122] where \(K\) k+1 \(\in R\) 9×3 is the spacecraft estimation gain coefficient matrix at the \((k + 1)\)-th sampling step,

[0123] \(Q\) k+1 \(\in R\) 3×3 is the spacecraft measurement noise covariance matrix at the \((k + 1)\)-th sampling step.

[0124] In step S4, according to the predicted value of the spacecraft augmented state, the predicted error covariance matrix of the spacecraft augmented state, and the estimation gain coefficient matrix (also known as the filtering gain coefficient matrix), the updated result of the estimated value of the spacecraft augmented state is given, expressed as

[0125]

[0126] where \(I\) 9 \(\in R\) 9×9 is a \(9\times9\) identity matrix, is the estimated value of the spacecraft augmented state at the \((k + 1)\)-th sampling step, \(P\) k+1 \(\in R\) 9×9 is the predicted error covariance matrix of the spacecraft augmented state at the \((k + 1)\)-th sampling step.

[0127] In step S5, according to the estimated value of the spacecraft augmented state, the estimated values of the spacecraft position, spacecraft velocity, and dynamic interference force acting on the spacecraft are obtained, expressed as:

[0128]

[0129] where is the estimated value of the spacecraft position at the \((k + 1)\)-th sampling step, is the estimated value of the spacecraft velocity at the \((k + 1)\)-th sampling step, is the estimated value of the dynamic interference force acting on the spacecraft at the \((k + 1)\)-th sampling step.

[0130] The present invention aims at the problem of spacecraft autonomous navigation under unknown dynamic interference forces, and provides a set of spacecraft autonomous navigation methods with the ability to actively sense interference forces, realizing the active estimation of spacecraft position, velocity, and interference force. The invention content includes the design of the spacecraft augmented state and its discrete equation representation in the sampling scenario, the prediction module of the spacecraft augmented state system, the calculation process of the estimation gain coefficient matrix, the updated module of the estimated value of the spacecraft augmented state, etc.

[0131] To verify the applicability of the method of the present invention, considering the case where the spacecraft is subjected to a triangular dynamic interference force, a spacecraft navigation simulation experiment was carried out. Hereinafter, an application example of a spacecraft navigation simulation experiment based on the spacecraft autonomous navigation method of the present invention is given.

[0132] Among them, the active driving force of the spacecraft, the dynamic interference force, and the spacecraft mass parameters are respectively:

[0133] M = 2000 (kg).

[0134] The specific implementation step S1 includes:

[0135] Establish the dynamic equation of the spacecraft under dynamic interference, expressed as:

[0136]

[0137] The measured value of the spacecraft position is:

[0138] Y(t) = X(t) + N(t) (11);

[0139] The specific implementation step S2 includes:

[0140] Considering the actual sampling process, establish the discrete equations of the spacecraft dynamics and spacecraft position measurement under dynamic interference:

[0141]

[0142] Introduce the augmented state including the spacecraft position, spacecraft velocity, and dynamic interference force received by the spacecraft, and obtain the discrete equation representation of the augmented state:

[0143]

[0144] Where Z k , the expressions of A, B, and C are:

[0145]

[0146] The specific implementation step S3 includes:

[0147] Design the prediction module of the spacecraft augmented state system, expressed as:

[0148]

[0149] According to the prediction error covariance matrix of the spacecraft augmented state, calculate the spacecraft estimation gain coefficient matrix, expressed as:

[0150]

[0151] The specific implementation step S4 includes:

[0152] Based on the predicted value of the augmented state of the spacecraft, the predicted error covariance matrix of the augmented state of the spacecraft, and the estimated gain coefficient matrix, the updated result of the estimated value of the augmented state of the spacecraft is given, expressed as

[0153]

[0154] The specific implementation steps S5 include:

[0155] Based on the estimated value of the augmented state of the spacecraft, the estimated values of the position of the spacecraft, the velocity of the spacecraft, and the dynamic disturbance force received by the spacecraft are obtained, expressed as

[0156]

[0157] The simulation test results of the method of the present invention are shown in FIGS. 2 to 4. Figures 2a - 2c The estimated result of the position of the spacecraft under the method of the present invention is given, Figures 3a - 3c The estimated result of the velocity under the method of the present invention is given, Figures 4a - 4c The estimated result of the dynamic disturbance force under the method of the present invention is given.

[0158] Figures 2a - 2c It shows that the estimation accuracy of the spacecraft position reaches 0.0002 m. Figures 3a - 3c It shows that the estimation accuracy of the spacecraft velocity reaches 0.006 m / s. Figures 4a - 4c It shows that the dynamic estimation trend of the dynamic disturbance force received by the spacecraft can be obtained, and the estimation accuracy is within 50 N.

[0159] The above technical features constitute the best embodiment of the present invention, which has strong adaptability and the best implementation effect. Non-essential technical features can be added or subtracted according to actual needs to meet the needs of different situations.

[0160] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than a limitation on the protection scope of the present invention. Any simple modification or equivalent replacement of the technical solution of the present invention by those of ordinary skill in the art shall not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A method for autonomous navigation of a spacecraft under random noise and dynamic interference, characterized in that: The steps include: S1. Establishing a spacecraft dynamics equation under dynamic interference force, the spacecraft dynamics equation involves variables including spacecraft position, spacecraft velocity, and dynamic interference force on the spacecraft; and establishing a spacecraft position measurement equation based on the influence of random noise on spacecraft position measurement; S2. Constructing the spacecraft augmented state system: Based on the actual sampling process, the discrete equations of spacecraft dynamics and spacecraft position measurement under dynamic interference are established; and the discrete equations of spacecraft augmented state are established by introducing the spacecraft augmented state including the spacecraft position, spacecraft velocity, and the dynamic interference force on the spacecraft; S3. Design a prediction module for the spacecraft augmented state system, including the spacecraft augmented state prediction value and the spacecraft augmented state prediction error covariance matrix; calculate the spacecraft estimated gain coefficient matrix according to the spacecraft augmented state prediction error covariance matrix; S4. According to the spacecraft augmented state prediction value, the spacecraft augmented state prediction error covariance matrix, and the estimated gain coefficient matrix, an updated result of the spacecraft augmented state estimation value is given; S5. Obtain estimated values ​​of the spacecraft position, spacecraft velocity, and dynamic disturbance force acting on the spacecraft based on the estimated value of the spacecraft augmented state.

2. The spacecraft autonomous navigation method according to claim 1, characterized in that: In step S1, the dynamic equation of the spacecraft under dynamic disturbance is established, which is expressed as where X(t)∈R 3 is the spacecraft position at time t, V(t)∈R 3 is the spacecraft velocity at time t, M∈R is the mass of the spacecraft, and F(t)∈R 3 is the active driving force of the spacecraft at time t, D(t)∈R 3 is the dynamic disturbance force on the spacecraft at time t, and R is the set of all real numbers.

3. The spacecraft autonomous navigation method according to claim 2, characterized in that: In step S1, based on the influence of random noise in the spacecraft position measurement, the spacecraft position measurement equation is established, which is expressed as Y(t)=X(t)+N(t) (2), where Y(t)∈R 3 is the measured value of the spacecraft position at time t, N(t)∈R 3 is the random noise of the spacecraft position measurement at time t.

4. The spacecraft autonomous navigation method according to claim 3, characterized in that: In step S2, based on the actual sampling process, the discrete equations of spacecraft dynamics and spacecraft position measurement under dynamic interference are established, which are expressed as Where h∈R is the sampling step, X k+1 ∈R 3 is the spacecraft position at the k+1th sampling step, X k ∈R 3 is the spacecraft position at the kth sampling step; V k+1 ∈R 3 is the spacecraft velocity at the k+1th sampling step, V k ∈R 3 is the spacecraft velocity at the kth sampling step; F k ∈R 3 is the active driving force of the spacecraft at the kth sampling step; D k ∈R 3 is the dynamic disturbance force on the spacecraft at the kth sampling step; Y k ∈R 3 is the measured value of the spacecraft position at the kth sampling step; N k ∈R 3 is the random noise of the spacecraft position measurement at the kth sampling step.

5. The spacecraft autonomous navigation method according to claim 4, characterized in that: In step S2, an augmented state including the spacecraft position, spacecraft velocity, and dynamic disturbance force on the spacecraft is introduced to establish a discrete equation of the spacecraft augmented state, which is expressed as Where Z k+1 ∈R 9 is the spacecraft augmented state at the k+1th sampling step, Z k ∈R 9 is the augmented state of the spacecraft at the kth sampling step, A∈R 9×9 is the spacecraft augmented state system matrix, B∈R 9×3 is the external input matrix of the spacecraft augmented state system, C∈R 3×9 Augment the measurement matrix of the spacecraft state system.

6. The spacecraft autonomous navigation method according to claim 5, characterized in that: Z k ,A,B,C satisfy the following expression: where I3∈R 3×3 is a 3×3 identity matrix, 03∈R 3×3 is a 3×3 zero matrix.

7. The spacecraft autonomous navigation method according to claim 6, characterized in that: In step S3, a prediction module of the spacecraft augmented state system is designed, including the spacecraft augmented state prediction value and the spacecraft augmented state prediction error covariance matrix, which is expressed as in is the spacecraft augmented state prediction value at the k+1th sampling step, is the estimated value of the spacecraft augmented state at the kth sampling step, is the spacecraft augmented state prediction error covariance matrix at the k+1th sampling step, P k ∈R 9×9 is the spacecraft augmented state estimation error covariance matrix at the kth sampling step.

8. The spacecraft autonomous navigation method according to claim 7, characterized in that: In step S3, the spacecraft estimated gain coefficient matrix is ​​calculated based on the spacecraft augmented state prediction error covariance matrix, which is expressed as Where K k+1 ∈R 9×3 is the spacecraft estimated gain coefficient matrix at the k+1th sampling step, Q k+1 ∈R 3×3 is the spacecraft measurement noise covariance matrix at the k+1th sampling step.

9. The spacecraft autonomous navigation method according to claim 8, characterized in that: In step S4, According to the spacecraft augmented state prediction value, the spacecraft augmented state prediction error covariance matrix, and the estimated gain coefficient matrix, the spacecraft augmented state estimation value update result is given, which is expressed as where I9∈R 9×9 is a 9×9 identity matrix, is the estimated value of the spacecraft augmented state at the k+1th sampling step, P k+1 ∈R 9×9 is the spacecraft augmented state estimation error covariance matrix at the k+1th sampling step.

10. The spacecraft autonomous navigation method according to claim 9, characterized in that: In step S5, According to the estimated value of the spacecraft augmented state, the estimated values ​​of the spacecraft position, spacecraft velocity, and dynamic disturbance force on the spacecraft are obtained, which are expressed as: in is the estimated value of the spacecraft position at the k+1th sampling step, is the estimated value of the spacecraft velocity at the k+1th sampling step, is the estimated value of the dynamic disturbance force on the spacecraft at the k+1th sampling step.

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