Distinguishing method for angular velocity maximum value of single-set ten-meter inertial measurement unit gyroscope based on inclined meter information fusion

Abstract

The invention relates to a single-set ten-meter inertial measurement unit gyro angular velocity maximum value discrimination method based on oblique meter information fusion, which comprises the following steps: 1, calculating the increment value of each path of pulse according to the total eight paths of information of three-orthogonal and one-oblique positive and negative pulses of a gyro; 2, calculating the angular velocity of each axis of the inertial measurement unit gyroscope at present; 3, the x-axis gyroscope maximum value fault judgment method comprises the following steps: if the angular velocity of the x-axis gyroscope is greater than the threshold value and the angular velocity combined by other tables is less than the threshold value, determining that the x-axis gyroscope has a maximum value fault; otherwise, the operation is normal; 4, performing y-axis gyroscope maximum value fault judgment by adopting a method similar to an x-axis method; 5, performing z-axis gyroscope maximum value fault judgment by adopting a method similar to an x-axis method; according to the method, only through optimization of the algorithm, the problems of erroneous judgment and erroneous switching existing in the gyro angular velocity maximum value fault of an existing single-set ten-meter inertial measurement unit are solved, and when one oblique meter breaks down, maximum value fault diagnosis can still be carried out on the gyro orthogonal meter.

Description

Technical Field

[0001] The present invention relates to the technical field of redundant technology for inertial units of launch vehicles, and particularly to a method for discriminating the maximum value of gyro angular velocity of a single set of ten-table inertial units based on the information fusion of inclined tables. Background Art

[0002] Inertial unit measurement devices are mainly used to sense the angular velocity and apparent velocity information during the flight of launch vehicles, and send them to the on-board computer as inputs for navigation, guidance, and control calculations. Their reliability is directly related to the success or failure of flight missions. Therefore, in order to improve the reliability of launch vehicles, it is necessary to perform redundant design on this device to enhance the reliability of the inertial navigation system.

[0003] There are various common redundant design schemes for inertial units of launch vehicles, including: two sets of eight-table, three sets of six-table, single set of "ten-table", and two sets of "ten-table" and other inertial measurement combinations. Among these inertial combination schemes, the single set of "ten-table" inertial measurement combination shows certain advantages in terms of reliability, economy, and simplicity, and has increasingly become the mainstream application of launch vehicles. It is composed of 5 gyros and 5 accelerometers, and both the gyros and accelerometers adopt a mounting method of 3 orthogonal and 2 inclined.

[0004] However, in the existing methods for judging the maximum value of gyro angular velocity of single set of "ten-table" inertial units, it is judged whether the maximum value of the angular velocity of the corresponding axis is greater than the threshold value. If it holds, it is a gyro angular velocity maximum value fault; otherwise, the output of the inertial unit is normal. This inertial unit redundant design method is extremely likely to regard the phenomenon of angular velocity exceeding the threshold as an inertial unit fault when the angular velocity increases due to faults or poor control effects, resulting in problems of misjudgment and mis-switching of the gyro angular velocity maximum value fault for this mode.

[0005] Therefore, a method for discriminating the maximum value of gyro angular velocity of a single set of ten-table inertial units based on the information fusion of inclined tables is proposed, that is, first calculate the angular velocities of the three orthogonal and one inclined inertial units, then perform information fusion on these 4 angular velocities, and perform fault judgment on the maximum value of the gyro angular velocity of the orthogonal axis according to the information fusion of the orthogonal and inclined axis angular velocities. Summary of the Invention

[0006] The purpose of the present invention is to overcome the problem of misjudgment of the maximum value of gyro angular velocity fault for the flight angular velocity exceeding the threshold in the existing redundant technology of single set of ten-table inertial units, and propose a method for discriminating the maximum value of gyro angular velocity of a single set of ten-table inertial units based on the information fusion of inclined tables. According to the calculation and fusion of the output information of the three orthogonal and one inclined inertial units, and then based on the information fusion of the orthogonal and inclined axis angular velocities, the fault judgment of the maximum value of the gyro angular velocity of the orthogonal axis of the single set of ten-table inertial units is realized.

[0007] The above object of the present invention is achieved by the following technical solutions:

[0008] Provide a discrimination method for the maximum gyro angular velocity of a single set of ten-axis inertial units based on the information fusion of the skew table, including the following steps:

[0009] (1) Calculate the positive and negative pulse increment information of 8 channels, including three orthogonal and one skew, according to the positive and negative pulse full amount information of the three orthogonal and one skew of the gyro.

[0010] (2) Calculate the angular velocity of each axis of the gyro of the inertial unit at the current beat for the three orthogonal and one skew of the gyro.

[0011] (3) Judge the maximum angular velocity fault of the x-axis gyro according to the information fusion of the orthogonal and skew tables. The judgment method is: if the angular velocity of the x-axis gyro is greater than the threshold value and the reference angular velocity in the x-axis direction fused by the orthogonal and skew tables is less than the threshold value, then the x-axis gyro has a maximum angular velocity fault; otherwise, the output of the inertial unit is normal.

[0012] (4) Judge the maximum angular velocity fault of the y-axis gyro according to the information fusion of the orthogonal and skew tables. The judgment method is: if the angular velocity of the y-axis gyro is greater than the threshold value and the reference angular velocity in the y-axis direction fused by the orthogonal and skew tables is less than the threshold value, then the y-axis gyro has a maximum angular velocity fault; otherwise, the output of the inertial unit is normal.

[0013] (5) Judge the maximum angular velocity fault of the z-axis gyro according to the information fusion of the orthogonal and skew tables. The judgment method is: if the angular velocity of the z-axis gyro is greater than the threshold value and the reference angular velocity in the z-axis direction fused by the orthogonal and skew tables is less than the threshold value, then the z-axis gyro has a maximum angular velocity fault; otherwise, the output of the inertial unit is normal.

[0014] Preferably, the calculation method of step (1) for calculating the positive and negative pulse increment information of 8 channels, including three orthogonal and one skew, according to the positive and negative pulse full amount information of the three orthogonal and one skew of the gyro is as follows:

[0015] ΔN gx+ =N gx+,n -N gx+,n-1

[0016] ΔN gx- =N gx-,n -N gx-,n-1

[0017] ΔN gy+ =N gy+,n -N gy+,n-1

[0018] ΔN gy- =N gy-,n -N gy-,n-1

[0019] ΔNgz+ = N gz+,n -N gz+,n-1

[0020] ΔN gz- = N gz-,n -N gz-,n-1

[0021] ΔN gi+ = N gi+,n -N gi+,n-1

[0022] ΔN gi- = N gi-,n -N gi-,n-1

[0023] Where: N gx+,n , N gx-,n , N gy+,n , N gy-,n , N gz+,n , N gz-,n , N gi+,n , N gi-,n are respectively the full pulse quantities of the positive and negative channels of the gyroscope in the current cycle for a single set of ten tables with three orthogonal axes (x-axis, y-axis, z-axis) and an inclined axis (s-axis or t-axis); N gx+,n-1 , N gx-,n-1 , N gy+,n-1 , N gy-,n-1 , N gz+,n-1 , N gz-,n-1 , N gi+,n-1 , N gi-,n-1 respectively represent the full pulse quantities of the positive and negative channels of the gyroscope in the previous cycle for a single set of ten tables with three orthogonal axes (x-axis, y-axis, z-axis) and an inclined axis (s-axis or t-axis); When calculating for the first time, ΔN gx+ , ΔN gx- , ΔN gy+ , ΔN gy- , ΔN gz+ , ΔN gz- , ΔN gi+ , ΔN gi- are all 0.

[0024] Preferably, the x-axis, y-axis, and z-axis are the three-axis coordinates of the inertial unit orthogonal coordinate system o-xyz, and their definitions are as follows: The origin o is located at the centroid of the inertial unit; ox - draw a straight line ox through o perpendicular to the installation reference plane, with the upward direction being positive; oz - draw a straight line oz through o perpendicular to the positioning reference plane, and the direction away from this reference plane is positive; o-xyz is a right-handed rectangular orthogonal coordinate system.

[0025] Preferably, the installation reference plane refers to the reference plane used to determine the installation position and geometric relationship of the inertial assembly during mechanical design and manufacturing; the positioning reference plane refers to the surface of the inertial assembly that contacts the positioning element when the inertial assembly is positioned in the fixture during machining; the definition of the o-xyz coordinate system is not unique and can be defined according to user needs.

[0026] Preferably, the following method is used in step (2) to calculate the angular velocity of each axis of the gyroscopes of the inertial assembly in three orthogonal and one skew positions at the current beat:

[0027] The angular velocities Δω x , Δω y , Δω z and Δω i of the gyroscopes of the inertial assembly in three orthogonal and one skew positions are calculated in detail as follows:

[0028]

[0029] Δω i = ΔN gi+ ·K gi+ - ΔN gi- ·K gi- - D 0i

[0030] where: K gx+ , K gx- , K gy+ , K gy- , K gz+ , K gz- , K gi+ , K gi- are the positive and negative pulse conversion coefficients of the gyroscopes of the x-axis, y-axis, z-axis, and s-axis or t-axis; D 0x , D 0y , D 0z , D 0i are the zero-order term coefficients of the gyroscopes of the x-axis, y-axis, z-axis, and s-axis or t-axis, with the unit of rad / s.

[0031] Preferably, the pulse conversion coefficient refers to the proportional coefficient for the gyroscope to convert the measured pulse signal into a rotational speed signal; the zero-order term error refers to the non-zero output voltage of the gyroscope due to manufacturing errors when the acceleration input is zero. Both the pulse conversion coefficient and the zero-order term error are obtained through single-unit calibration.

[0032] Preferably, the following calculation method is used in step (3) to diagnose the maximum value fault of the angular velocity of the gyroscopes of the inertial assembly in the x-axis direction based on the fusion of orthogonal and skew-axis angular velocity information:

[0033]

[0034] θ i1 、θi2 , θ i3 are respectively the angles between the s-axis or t-axis gyroscope and the x-axis, y-axis, and z-axis in the attached drawings of the specification, which are given by inertial assembly calibration measurement; Figure 2 In is the gyroscope maximum threshold value.

[0035] Preferably, the calculation method for the maximum gyroscope angular velocity fault diagnosis in the y-axis direction of the inertial assembly according to the orthogonal and skew-axis angular velocity information fusion in step (4) is as follows:

[0036]

[0037] Preferably, the calculation method for the maximum gyroscope angular velocity fault diagnosis in the z-axis direction of the inertial assembly according to the orthogonal and skew-axis angular velocity information fusion in step (5) is as follows:

[0038]

[0039] The present invention has the following advantages compared with the prior art:

[0040] (1) The present invention can improve the reliability of redundancy technology without adding single-machine equipment;

[0041] (2) The present invention solves the problem that misjudgment or mis-switching may occur in the existing single-set ten-instrument inertial assembly redundancy judgment method when the flight angular velocity exceeds the threshold;

[0042] (3) The present invention has stronger adaptability and can be applied to the working conditions of single-set ten-instrument inertial assembly one-degree faults and even some two-degree faults;

[0043] (4) The present invention only adds a reference angular velocity according to the orthogonal and skew-axis angular velocity information fusion, with less modification of the flight software code and less testing work. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 is a flow chart of a method for discriminating the maximum gyroscope angular velocity of a single-set ten-instrument inertial assembly based on skew-table information fusion according to the present invention

[0045] Figure 2 is a schematic diagram of the gyroscope installation of the inertial assembly according to the present invention DETAILED DESCRIPTION OF THE EMBODIMENTS

[0046] The present invention will be further described in detail below with reference to the attached drawings and specific embodiments:

[0047] Refer to Figure 1 which is a flow chart of a method for discriminating the maximum gyroscope angular velocity of a single-set ten-instrument inertial assembly based on skew-table information fusion according to the present invention, and specifically includes:

[0048] (1) Calculate the incremental information of the positive and negative pulses of these 8 channels based on the full amount information of the positive and negative pulses of the three orthogonal axes (x-axis, y-axis, z-axis) and one obliquely placed axis (take the s-axis) of the gyroscope.

[0049] For the inertial measurement unit gyroscope with three orthogonal axes and one obliquely placed axis, a total of 8 channels of positive and negative pulse increments, the detailed calculation method is as follows:

[0050] ΔN gx+ = N gx+,n - N gx+,n-1

[0051] ΔN gx- = N gx-,n - N gx-,n-1

[0052] ΔN gy+ = N gy+,n - N gy+,n-1

[0053] ΔN gy- = N gy-,n - N gy-,n-1

[0054] ΔN gz+ = N gz+,n - N gz+,n-1

[0055] ΔN gz- = N gz-,n - N gz-,n-1

[0056] ΔN gs+ = N gs+,n - N gs+,n-1

[0057] ΔN gs- = N gs-,n - N gs-,n-1

[0058] Where: N gx+,n 、N gx-,n 、N gy+,n 、N gy-,n 、N gz+,n 、N gz-,n 、N gs+,n 、N gs-,n are the full amount values of the positive and negative channel pulses of the gyroscope in the current cycle of the single set of ten meters on the x-axis, y-axis, z-axis, and s-axis respectively; N gx+,n-1 、N gx-,n-1 、N gy+,n-1 、N gy-,n-1 、N gz+,n-1 、N gz-,n-1 、N gs+,n-1 、N gs-,n-1respectively represent the full pulse values of the positive and negative channels of the gyroscope in one cycle on the x-axis, y-axis, z-axis, and s-axis of a single set of ten tables; during the first calculation, ΔN gx+ , ΔN gx- , ΔN gy+ , ΔN gy- , ΔN gz+ , ΔN gz- , ΔN gs+ , ΔN gs- are all 0.

[0059] The x-axis, y-axis, and z-axis refer to the three-axis coordinates of the inertial measurement unit coordinate system o-xyz, and their definitions are as follows: The origin o is located at the center of mass of the inertial measurement unit; ox - draw a straight line ox through o perpendicular to the installation reference plane, with the upward direction being positive; oz - draw a straight line oz through o perpendicular to the positioning reference plane, and the direction away from this reference plane is positive; o-xyz is a right-handed rectangular coordinate system.

[0060] Among them: The installation reference plane refers to the reference plane used to determine the installation position and geometric relationship of the inertial measurement unit during mechanical design and manufacturing; the positioning reference plane refers to the surface where the inertial measurement unit contacts the positioning element when the inertial measurement unit is positioned in the fixture during machining; the definition of the o-xyz coordinate system is not unique and can be defined according to user needs.

[0061] (2) Calculate the angular velocities of the gyroscopes on the x-axis, y-axis, z-axis, and s-axis of the inertial measurement unit for the current beat;

[0062] The angular velocities Δω x , Δω y , Δω z , Δω s of the gyroscopes on the x-axis, y-axis, z-axis, and s-axis of the inertial measurement unit are calculated in detail as follows:

[0063]

[0064] Δω s = ΔN gs+ ·K gs+ - ΔN gs- ·K gs- - D 0s

[0065] Among them: K gx+ , K gx- , K gy+ , K gy- , K gz+ , K gz- , K gs+ , K gs- are the positive and negative pulse conversion coefficients of the gyroscopes on the x-axis, y-axis, z-axis, and s-axis; D 0x , D 0y , D 0z , D0s They are the zero-order term coefficients of the x-axis, y-axis, z-axis, and s-axis gyros, with the unit of rad / s.

[0066] The pulse conversion coefficient refers to the proportional coefficient for the gyro to convert the measured pulse signal into a rotational speed signal; the zero-order term error means that when the acceleration input is zero, due to manufacturing errors, the gyro will have a certain non-zero output voltage. Both the pulse conversion coefficient and the zero-order term error are obtained through single-unit calibration.

[0067] (3) Judging the x-axis gyro angular velocity maximum value fault based on the information fusion of the orthogonal and skew tables: If the angular velocity of the x-axis gyro is greater than the threshold value, and the reference angular velocity in the x-axis direction combined by other orthogonal and skew axes is less than the threshold value, then the x-axis has an angular velocity maximum value fault; otherwise, the output is normal.

[0068] The calculation method for diagnosing the x-axis inertial group gyro angular velocity maximum value fault for navigation calculation based on the information fusion of the orthogonal and skew tables is as follows:

[0069]

[0070] θ s1 、θ s2 、θ s3 They are the angles between the s-axis gyro and the x-axis, y-axis, and z-axis in the attached drawings of the specification, respectively, given by inertial group calibration measurement. Figure 2 ; It is the gyro maximum value threshold. Generally, it can be taken as 0.698 (about 40° / s).

[0071] (4) Similarly, judging the y-axis gyro angular velocity maximum value fault based on the information fusion of the orthogonal and skew tables: If the angular velocity of the y-axis gyro is greater than the threshold value, and the reference angular velocity in the y-axis direction combined by other orthogonal and skew axes is less than the threshold value, then the y-axis has an angular velocity maximum value fault; otherwise, the output is normal.

[0072] The calculation method for diagnosing the y-axis inertial group gyro angular velocity maximum value fault for navigation calculation based on the information fusion of the orthogonal and skew tables is as follows:

[0073]

[0074] (5) Similarly, judging the z-axis gyro angular velocity maximum value fault based on the information fusion of the orthogonal and skew tables: If the angular velocity of the z-axis gyro is greater than the threshold value, and the reference angular velocity in the z-axis direction combined by other orthogonal and skew axes is less than the threshold value, then the z-axis has an angular velocity maximum value fault; otherwise, the output is normal.

[0075] According to the information fusion of orthogonal and skew tables, the calculation method for the maximum gyro angular velocity fault diagnosis in the z-axis direction for navigation calculation is as follows:

[0076]

[0077] The method for diagnosing the maximum gyro angular velocity fault of a single set of ten-table inertial units in the present invention can well solve the problems of misjudgment and mis-switching of the maximum gyro fault caused by excessive angular velocity of the aircraft in the existing redundancy methods in the case of a single-degree fault of the inertial unit or even partial two-degree faults, and has a wider scope of adaptation.

[0078] As mentioned above, only the best specific implementation mode of the present invention is described, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

[0079] The content not detailedly described in the specification of the present invention belongs to the well-known technology of those skilled in the art.

Claims

1. A method for determining the maximum value of gyro angular velocity of a single set of ten-meter inertial group based on the fusion of tilt table information, characterized in that: The steps include: (1) Based on the full amount information of the gyroscope's three orthogonal and one oblique positive and negative pulses, calculate the three orthogonal and one oblique, a total of 8 positive and negative pulse increment information; (2) Calculate the current angular velocity of the three orthogonal and one oblique gyroscope on each axis of the inertial group gyroscope; (3) The x-axis gyro angular velocity maximum fault is judged based on the fusion of the orthogonal and oblique table information. The judgment method is: if the angular velocity of the x-axis gyro is greater than the threshold value, and the reference angular velocity in the x-axis direction obtained by the fusion of the orthogonal and oblique table information is less than the threshold value, then the x-axis gyro has an angular velocity maximum fault; otherwise, the output of the inertial group is normal; (4) The maximum angular velocity fault of the y-axis gyro is judged based on the fusion of the orthogonal and oblique table information. The judgment method is as follows: if the angular velocity of the y-axis gyro is greater than the threshold value, and the reference angular velocity of the y-axis direction obtained by the fusion of the orthogonal and oblique table information is less than the threshold value, then the y-axis gyro has a maximum angular velocity fault; otherwise, the output of the inertial group is normal; (5) The maximum angular velocity fault of the z-axis gyro is judged based on the fusion of the orthogonal and oblique table information. The judgment method is: if the angular velocity of the z-axis gyro is greater than the threshold value, and the reference angular velocity in the z-axis direction obtained by the fusion of the orthogonal and oblique table information is less than the threshold value, then the z-axis gyro has a maximum angular velocity fault; otherwise, the output of the inertial group is normal.

2. The method for determining the maximum value of the gyro angular velocity of a single set of ten-meter inertial group based on the fusion of tilt table information according to claim 1 is characterized by: In step (1), the calculation method of the 8-way positive and negative pulse increments is as follows: 、 、 、 、 、 、 、 3. Among them: , , , , , , , The full value of the current cycle gyro positive and negative channel pulses of a single set of ten meters, three orthogonal (x-axis, y-axis, z-axis) and oblique (s-axis or t-axis) respectively read; , , , , , , , Respectively represent the full value of the gyro positive and negative channel pulses in the previous cycle of a single set of ten tables, three orthogonal (x-axis, y-axis, z-axis) and oblique (s-axis or t-axis); when calculating for the first time, , , , , , , , All are 0; the x-axis, y-axis and z-axis are the orthogonal coordinate system of the inertial group The three-axis coordinates are defined as follows: the origin o is located at the center of mass of the inertia group; ox—through o, a straight line ox is perpendicular to the installation reference plane, with upward being positive; oz—through o, a straight line ox is perpendicular to the installation reference plane, with upward being positive; Draw a straight line oz perpendicular to the positioning reference plane, and the direction away from the reference plane is positive; It is a right-hand rectangular orthogonal coordinate system; the installation reference plane refers to the reference plane used to determine the installation position and geometric relationship of the inertial group during mechanical design and manufacturing; the positioning reference plane refers to the surface where the inertial group contacts the positioning element when the inertial group is positioned in the fixture during mechanical processing; The definition of the coordinate system is not unique and can be defined according to user needs.

4. The method for determining the maximum value of the gyro angular velocity of a single set of ten-meter inertial group based on the fusion of tilt table information according to claim 1, characterized in that: In step (2), the current angular velocity of the gyro with three orthogonal and one oblique corresponding axes of the inertial group gyro is calculated as follows: 、 5. Among them: , , , , , , , is the positive and negative pulse conversion coefficient of the x-axis, y-axis, z-axis and s-axis or t-axis gyroscope; , , , It is the zero-order coefficient of the x-axis, y-axis, z-axis and s-axis or t-axis gyro, in rad / s; the pulse conversion coefficient refers to the proportional coefficient of the gyro converting the measured pulse signal into the speed signal; the zero-order error refers to the non-zero volt output voltage of the gyro due to manufacturing error when the acceleration is zero input. Both the pulse conversion coefficient and the zero-order error are obtained through single-machine calibration.

6. The method for determining the maximum value of the gyro angular velocity of a single set of ten-meter inertial group based on the fusion of tilt table information according to claim 1, characterized in that: In step (3), the method for judging the maximum value fault of the x-axis gyro angular velocity used for navigation calculation is as follows: 、 7. , , The angles between the s-axis or t-axis gyro and the x-axis, y-axis, and z-axis in FIG. 2 of the accompanying drawings of the specification are respectively given by the calibration measurement of the inertial group; is the gyroscope maximum threshold.

8. The method for determining the maximum value of the gyro angular velocity of a single set of ten-meter inertial group based on the fusion of tilt table information according to claim 1 is characterized by: In step (4), the method for judging the maximum value fault of the y-axis gyro angular velocity used for navigation calculation is as follows: 、 9. The method for determining the maximum value of the gyro angular velocity of a single set of ten-meter inertial group based on the fusion of tilt table information according to claim 1, characterized in that: In step (5), the method for judging the maximum value fault of the z-axis gyro angular velocity used for navigation calculation is as follows: 、

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