A gyro plus table raw data transmission method for an inertial navigation system

Abstract

The present application belongs to the technical field of inertial navigation, and is an inertial navigation original data transmission method based on unsigned integer accumulation principle, comprising the following steps: step 1, converting gyro angle increment sampling value and accelerometer velocity increment sampling value into unsigned integer inertial navigation original data increment according to conversion dimension at the sampling end; step 2, adding the unsigned integer inertial navigation original data increment and the historical sampling data accumulation of the corresponding item at the inertial navigation data sampling end to obtain the accumulated unsigned integer form of inertial navigation original data; step 3, transmitting the accumulated unsigned integer form of inertial navigation original data from the sampling end to the receiving end through a hardware communication channel; step 4, restoring the accumulated unsigned integer form of inertial navigation original data into inertial navigation increment data at the receiving end; and step 5, calculating the lost gyro angle increment and accelerometer velocity increment based on the received inertial navigation increment data and corresponding sampling time stamp, and filling in the missing part of the angular motion and linear motion information.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of inertial navigation, in particular to a gyro plus table raw data transmission method for an inertial navigation system. BACKGROUND

[0002] In the field of high-precision inertial navigation, inertial navigation raw data is generally output in the form of gyro angular increment and plus table velocity increment at a high frequency. In the case of high-frequency output, data signals are more susceptible to external interference and loss. Moreover, due to the integral characteristics of inertial navigation, when the gyro angular increment and plus table velocity increment sampling values are lost, the inertial navigation integral calculation will be incorrect, and effective inertial navigation information cannot be provided. SUMMARY

[0003] The present application addresses the contradiction between the requirement for continuity of inertial navigation raw data and the susceptibility of data signals to interference and loss in the case of high-frequency output, and proposes an inertial navigation raw data transmission method based on the principle of unsigned integer accumulation, to improve the reliability of the navigation system.

[0004] Specifically, the present application provides an inertial navigation raw data transmission method based on the principle of unsigned integer accumulation, which comprises the following steps:

[0005] Step 1: At the sampling end, the corresponding conversion dimension is determined according to the gyro angular increment data and the plus table velocity increment data, and the gyro angular increment sampling value and the plus table velocity increment sampling value are converted into unsigned integer inertial navigation raw data increments according to the conversion dimension;

[0006] Step 2: At the inertial navigation data sampling end, the unsigned integer inertial navigation raw data increments are added to the historical sampling data of the corresponding item to obtain inertial navigation raw data in the form of accumulated unsigned integers;

[0007] Step 3: The inertial navigation raw data in the form of accumulated unsigned integers is transmitted from the sampling end to the receiving end through a hardware communication channel;

[0008] Step 4: At the receiving end, the inertial navigation raw data in the form of accumulated unsigned integers is restored to inertial navigation increment data;

[0009] Step 5: Based on the received inertial navigation increment data and the corresponding sampling time stamp, the lost gyro angular increment and plus table velocity increment are calculated, and the missing angular motion and linear motion information are completed.

[0010] Furthermore, in step 1, the conversion dimension of the gyro angular increment data and the conversion dimension of the plus table velocity increment data are determined respectively; the number of significant digits N after the decimal point of the increment sampling value is g , and the conversion dimension is

[0011]

[0011] The gyro angle increment sampling value and the accelerometer velocity increment sampling value are multiplied by corresponding conversion dimensions to obtain unsigned integer inertial navigation original data increments.

[0012] Further, in step 3, the information transmitted from the sampling end to the receiving end includes a current sampling count timestamp, gyro angle increment unsigned integer accumulated sum data and accelerometer velocity increment unsigned integer accumulated sum data.

[0013] Further, in step 4, the accumulated unsigned integer form inertial navigation original data of the previous frame and the next frame are subtracted, the subtraction result is assigned to a signed integer variable, and then converted into an increment form through corresponding conversion dimensions.

[0014] Further, in step 5, based on the subtraction of the sampling count timestamps of the previous two times, the sampling interval number between the two received samplings is obtained.

[0015] The gyro angle increment and the accelerometer velocity increment in the inertial navigation increment data are respectively divided by the sampling interval number to obtain increment data used for navigation solution.

[0016] Further, in step 3, during the transmission process, the conversion dimensions of the gyro angle increment data and the conversion dimensions of the accelerometer velocity increment data are agreed by the transmission protocol.

[0017] The present application has the following beneficial effects:

[0018] The conventional inertial navigation original data is transmitted in an increment form at a high frequency. When the transmission communication is disturbed to cause data loss, the integral solution of the inertial navigation is prone to be incorrect due to the lack of part of the angular motion and linear motion information. The present application proposes a new inertial navigation original data transmission method. The inertial navigation increment original data is converted into unsigned integer accumulated original data form based on the unsigned integer accumulation principle and then transmitted. When the data transmission is lost due to hardware transmission interference, the average of the angular motion and linear motion data of the missing part can be calculated and filled in through the latest received accumulated data, so as to ensure the correct navigation integral solution.

[0019] The unsigned integer adopted in the present application can carry more effective data than the conventional decimal with positive and negative signs under the same data length. Meanwhile, the accumulated form data adopted in the present application can be filled in through the received complete data before and after the frame and the interval frame number even if the frame is lost during data transmission, so that the angular motion and linear motion data have recoverability. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a sampling end flowchart of the inertial navigation original data transmission method based on the unsigned integer accumulation principle.

[0021] Figure 2It is a receiving end flow chart of an inertial navigation original data transmission method based on unsigned integer accumulation principle. DETAILED DESCRIPTION

[0022] The technical solutions of the present application will be described in more detail below with reference to the accompanying drawings. The present application includes but is not limited to the following embodiments.

[0023] The present application provides an inertial navigation original data transmission method based on unsigned integer accumulation principle. The method includes the following steps:

[0024] Step 1: At the inertial navigation original data sampling end, the dimension is determined according to the gyro and table measurement, and the gyro angle increment and the table velocity increment sampling value are converted into unsigned integers according to the dimension.

[0025] N is set g The number of effective digits after the decimal point of the gyro data is ensured to be , and the dimension is defined as The gyro increment sampling value Δθ is multiplied by the dimension and the calculation result is stored as unsigned integer data. The table data dimension definition and conversion method are the same.

[0026] Step 2: The unsigned integer inertial navigation original data increment is accumulated at the inertial navigation data sampling end to obtain the accumulated unsigned integer form of the inertial navigation original data. When the data value reaches the maximum value that can be stored by the unsigned integer data, the accumulation continues, and the unsigned integer data will naturally overflow without worrying about the data exceeding the unsigned integer representation range.

[0027] Example of unsigned integer natural overflow principle:

[0028] Suppose there is an accumulated unsigned integer 0xFFFFFFFE, and the unsigned integer inertial navigation original data increment is 0x00000002. The result of their addition exceeds the maximum value that can be represented by the unsigned integer, causing the unsigned integer to naturally overflow. In the computer, the sum of 0xFFFFFFFE and 0x00000002 is 0x00000000. When the accumulated value exceeds the maximum value that can be stored by the unsigned integer, the value will start to accumulate from 0x00000000 again. However, the increment 0x00000002 can still be calculated by 0x00000000 minus 0xFFFFFFFE. Therefore, there is no need to worry about the data exceeding the unsigned integer representation range.

[0029] Step 3: The inertial navigation original data is transmitted from the sampling end to the receiving end through a hardware communication channel.

[0030] Step 4: At the inertial navigation original data receiving end, the original data is restored to the gyro angle increment and table velocity increment form.

[0031] Step 5, calculate the missing gyro angle increment and table velocity increment based on the accumulated original number, and fill in the missing part of the angular motion and linear motion information.

[0032] Specifically, in an embodiment, the specific implementation scheme of the inertial navigation original data transmission method is as follows:

[0033] Step 1, open a static or global six-dimensional double-precision floating-point array for storing the accumulated sum of three-dimensional gyro and three-dimensional table historical sampling data, and initialize the array element initial value to 0.

[0034] In this embodiment, the gyro angle increment data is converted to 1e8, and the table velocity increment data is converted to 1e6.

[0035] The three-dimensional gyro angle increment data of the current sampling period is multiplied by 1e8, and the three-dimensional table velocity increment data is multiplied by 1e6.

[0036] Step 2, add the three-dimensional gyro angle increment data and the three-dimensional table velocity increment data after dimension conversion to the corresponding historical sampling data accumulation sum to obtain new accumulation sum data containing the current sampling period data.

[0037] The integer part of the double-precision floating-point type accumulation sum data is assigned to an unsigned integer variable to obtain unsigned integer inertial navigation accumulation sum original data, which is as follows:

[0038] Taking C language as an example, the double-precision floating-point type accumulation sum data is first converted to unsigned integer type, and then assigned to an unsigned integer variable using the assignment symbol, so as to realize the operation of "assigning the integer part of the double-precision floating-point type accumulation sum data to an unsigned integer variable".

[0039] Step 3, send the original data packet to the receiving end through hardware communication, and the information contained in one transmission includes: current sampling count timestamp, three-dimensional gyro unsigned integer accumulation sum data and three-dimensional table unsigned integer accumulation sum data.

[0040] Step 4, the receiving end receives and caches the inertial navigation original number data packet, and subtracts the front and rear frame unsigned integer inertial navigation original data, assigns the difference result to a signed integer variable, and then converts it to an increment form through dimension conversion.

[0041] Suppose there is an accumulated unsigned integer number 0xFFFFFFFE, and the increment data -2e-6 is converted to -2 after dimension conversion 1e6. Assigning -2 to an unsigned integer number will convert -2 to 0xFFFFFFFE. 0xFFFFFFFE is added to the existing accumulated unsigned integer number 0xFFFFFFFE, and the result is 0xFFFFFFFC.

[0042] The calculation method of the incremental data recovered at the receiving end is as follows:

[0043] (1) Difference between the unsigned integer inertial navigation original data of the previous and next frames, i.e. 0xFFFFFFFC-0xFFFFFFFE=0xFFFFFFFE.

[0044] (2) Assignment of the calculation result in (1) by a signed integer variable, 0xFFFFFFFE is -2 of the signed integer.

[0045] (3) Dimension conversion to the final required incremental data, the dimension is agreed by the transmission protocol and need not be contained in the transmission data. Namely, -2 is divided by the agreed dimension 1e6 to obtain the required incremental data -2e-6.

[0046] Step 5, subtract the data time stamp count values in the previous and next data packets to obtain the sampling interval number between the received data packets.

[0047] Divide the incremental data by the sampling interval number to obtain the incremental data used for navigation solution. The obtained incremental data is stored in the navigation solution incremental data buffer area and used for navigation integral solution.

[0048] The application is not limited to the above specific embodiments, and those skilled in the art can implement the application in other various specific embodiments according to the embodiments and the disclosure of the drawings. Therefore, any design using the design structure and idea of the application and making some simple changes or modifications falls within the protection scope of the application.

Claims

1. An inertial navigation original data transmission method based on the principle of unsigned integer number accumulation, characterized in that, The inertial navigation original data transmission method based on the unsigned integer accumulation principle comprises the following steps: Step 1: at the sampling end, according to the gyro angle increment data and the accelerometer velocity increment data, corresponding conversion dimensions are determined respectively, and the gyro angle increment sampling value and the accelerometer velocity increment sampling value are converted into unsigned integer inertial navigation original data increments according to the conversion dimensions; Step 2: at the inertial navigation data sampling end, the unsigned integer inertial navigation original data increments are added to the historical sampling data of the corresponding items to obtain accumulated unsigned integer form inertial navigation original data; Step 3: the accumulated unsigned integer form inertial navigation original data is transmitted from the sampling end to the receiving end through a hardware communication channel; Step 4: at the receiving end, the accumulated unsigned integer form inertial navigation original data is restored into inertial navigation increment data; Step 5: based on the received inertial navigation increment data before and after and the corresponding sampling count time stamps, the missing gyro angle increment and the missing accelerometer velocity increment are calculated, and the missing part of the angular motion and linear motion information is filled in.

2. The inertial navigation raw data transmission method based on the unsigned integer accumulation principle according to claim 1, characterized in that, In step 1, the conversion dimension of the gyro angle increment data and the conversion dimension of the table speed increment data are determined respectively; the effective number of digits after the decimal point of the increment sampling value N g , the conversion dimension is The gyro angle increment sampling value and the accelerometer velocity increment sampling value are multiplied by the corresponding conversion dimensions to obtain unsigned integer inertial navigation original data increments.

3. The inertial navigation raw data transmission method based on the unsigned integer accumulation principle according to claim 1, characterized in that, In step 3, the information transmitted from the sampling end to the receiving end includes the current sampling count time stamp, the gyro angle increment unsigned integer accumulation sum data and the accelerometer velocity increment unsigned integer accumulation sum data.

4. The inertial navigation raw data transmission method based on the unsigned integer accumulation principle according to claim 1, characterized in that, In step 4, the accumulated unsigned integer form inertial navigation original data of the previous and next frames is subtracted, the subtraction result is assigned to a signed integer variable, and then converted into increment form through the corresponding conversion dimension.

5. The inertial navigation raw data transmission method based on the unsigned integer accumulation principle according to claim 1, characterized in that, In step 5, based on the subtraction of the sampling count time stamps before and after, the sampling interval number between the two received samplings is obtained; The gyro angle increment and the accelerometer velocity increment in the inertial navigation increment data are divided by the sampling interval number respectively to obtain the increment data used for navigation solution.

6. The inertial navigation raw data transmission method based on the unsigned integer accumulation principle according to claim 1, characterized in that, In step 3, during the transmission process, the conversion dimension of the gyro angle increment data and the conversion dimension of the accelerometer velocity increment data are agreed by the transmission protocol.

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