A data compression transmission method for measuring a parabolic motion trajectory

Abstract

The application discloses a kind of parabolic trajectory measurement data compression transmission methods, including obtaining initial trajectory measurement data;Calculate the initial reference parabola;Obtain the trajectory measurement data of actual sampling point, calculate the deviation of the trajectory data of the reference sampling point of actual sampling point trajectory measurement data and the same time reference parabola, obtain deviation data, and transmit compressed deviation data, and the actual trajectory measurement data is restored by the trajectory data of the reference sampling point of reference parabola and decompressed deviation data, in receiving end.The application uses reference parabola and reference sampling point as the benchmark of data compression;The deviation between actual parabolic trajectory and reference parabolic trajectory is described by calculating the data deviation between actual sampling point data and reference sampling point;The sample data of actual parabola at actual sampling point is restored without deviation by the trajectory of reference parabola and deviation data, and the restoration of parabolic trajectory measurement data is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to a data compression transmission method, in particular to a data compression transmission method for measuring parabolic motion trajectory. BACKGROUND

[0002] After the missile is launched, it will present a complex motion curve under the combined action of gravity, Coriolis force and atmospheric resistance, with high dynamic characteristics of high speed and large acceleration. Precise measurement of the motion trajectory of the missile after launch helps to improve the bomb calculation of the aircraft, the design and manufacture of the missile, the inspection and testing of weapon equipment, and helps to strengthen national defense.

[0003] In the trajectory measurement of the missile launch, there is a contradiction between large amount of trajectory measurement data and low communication transmission bandwidth. If the trajectory data is not compressed, it will inevitably affect the spatial sampling density of the trajectory measurement, and further affect the accuracy of the trajectory measurement.

[0004] Both the accuracy and spatial sampling density of the trajectory measurement must be ensured, and the data must not be lost, which puts higher requirements on data compression in the trajectory measurement data transmission.

[0005] The commonly used encoding methods of lossless compression mainly include Shannon-Fano coding, Huffman Coding, Arithmetic Coding, Run-length coding and LZW (Lempel-Ziv-Welch) coding.

[0006] Shannon-Fano coding is a technique based on a set of symbols and their occurrence probabilities (estimated or measured) to construct a prefix code.

[0007] Huffman Coding is an entropy coding (weight coding) algorithm, which is a kind of variable length coding (VLC).

[0008] LZW (Lempel-Ziv-Welch) coding belongs to the second type of dictionary encoding, which creates a phrase dictionary from the input data.

[0009] Huffman Coding has fast processing speed, but low compression rate; Arithmetic Coding requires a large amount of calculation.

[0010] The method needs to obtain a piece of data first, then make statistics, and finally encode, which is not suitable for data compression of single track measurement point. For continuous curve, the data can be compressed by using differential encoding to eliminate redundant information, but the encoding method is extremely sensitive to data packet loss and data packet transmission error. If error retransmission and packet retransmission are used, it cannot be guaranteed to be error-free. Therefore, it is necessary to design a lossless data compression transmission method to improve data compression rate. SUMMARY

[0011] The technical problem to be solved by the present application is to provide a data compression transmission method for parabolic motion trajectory measurement, which solves the problem of low data compression rate of existing compression methods, affecting transmission efficiency and measurement accuracy.

[0012] The technical solution adopted by the present application to solve the above technical problem is to provide a data compression transmission method for parabolic motion trajectory measurement, comprising the following steps: S1: obtaining initial trajectory measurement data, transmitting the initial trajectory measurement data; calculating the initial reference parabola according to the initial trajectory measurement data, and transmitting the reference parabola parameters; S2: obtaining the trajectory measurement data of the actual sampling point, calculating the deviation of the actual sampling point trajectory measurement data from the reference sampling point trajectory data of the reference parabola at the same time to obtain the deviation data, and comparing the deviation data with the set threshold; S3: if the deviation data is greater than the set threshold, transmitting the actual sampling point trajectory measurement data; calculating the updated reference parabola according to the actual sampling point trajectory measurement data, and transmitting the updated reference parabola parameters; S4: if the deviation data is less than or equal to the set threshold, transmitting the compressed deviation data; S5: repeating steps S2-S4 to obtain the trajectory measurement data of the actual parabola at all actual sampling points until the end.

[0013] Further, the step S3 of calculating the updated reference parabola according to the actual sampling point trajectory measurement data comprises:

[0014] S31: obtaining the trajectory measurement data of 4 sampling points in 3 consecutive time periods, obtaining the position d, velocity v and acceleration a information in 3 consecutive time periods; S32: calculating the function parameters position d, velocity v and acceleration a in X axis, Y axis and Z axis directions of 3 time periods respectively, constructing the function (a x t 2 +v x t+d x ,a y t 2 +v y t+d y ,a z t 2 +v z t+dz ); 6 parabolas are obtained; S33: fitting the reference parabola by the obtained 6 parabolas, removing the parabola with the largest deviation, calculating the expected value of the parabola with the smallest root mean square error of the remaining 5 parabolas, as the reference parabola, obtaining the updated reference parabola equation:

[0015]

[0016] Further, the step S1 comprises: obtaining initial spatial position d0(d x0 ,d y0 ,d z0 ), initial velocity v0(v x0 ,v y0 ,v z0 ) and initial acceleration a0(a x0 ,a y0 ,a z0 ), defining the initial reference parabola (a x t 2 +v x t+d x ,a y t 2 +v y t+d y ,a z t 2 +v z t+d z ).

[0017] Further, the calculation of the trajectory data of the reference sampling point of the reference parabola comprises: obtaining the actual sampling sampling period T, recording the time deviation Δtm of the mth actual sampling, determining the time of the mth reference sampling as the time tm of the actual sampling, tm=m×T+Δtm; the trajectory data of the mth reference sampling point is the theoretical spatial position and the theoretical spatial velocity of the reference parabola at the time tm.

[0018] Further, the trajectory measurement data comprises: time stamp milliseconds, time stamp UTC seconds, latitude, longitude, height and XYZ three-axis speed; the trajectory measurement data comprises 22 bytes, wherein the time stamp milliseconds is 11 bits; the time stamp UTC seconds is 4 bytes; the latitude is 4 bytes; the longitude is 4 bytes; the height is 2 bytes; and the XYZ three-axis speed is 6 bytes.

[0019] Further, the compressed deviation data comprises: a compression flag, a reference parabola number, a sampling time deviation, a sampling serial number, XYZ three-axis position deviation values, and XYZ three-axis speed deviation values; wherein the compression flag is 2 bits; the reference parabola number is 3 bits; the sampling time deviation is 11 bits; the sampling serial number is 16 bits; the XYZ three-axis position deviation values are 15 bits plus 1 bit of "0" padding; the XYZ three-axis speed deviation values are 15 bits plus 1 bit of "0" padding; and a total of 8 bytes.

[0020] Further, the reference parabola parameters are transmitted by a special frame, and the special frame comprises: a compression flag, a reference parabola number, a sampling time deviation, a sampling serial number, a UTC time of a parabola position starting point, a sampling serial number corresponding to the UTC time of the parabola position starting point, a longitude of the parabola position starting point, a latitude of the parabola position starting point, an elevation of the parabola position starting point, an X-axis speed of the parabola position starting point, a Y-axis speed of the parabola position starting point, and a Z-axis speed of the parabola position starting point; wherein the compression flag is 2 bits and is fixed as binary 01; the reference parabola number is 3 bits; the sampling time deviation is 11 bits; the sampling serial number is 16 bits; the UTC time of the parabola position starting point is 8 bytes; the sampling serial number corresponding to the UTC time of the parabola position starting point is 2 bytes; the longitude of the parabola position starting point is 4 bytes; the latitude of the parabola position starting point is 4 bytes; the elevation of the parabola position starting point is 2 bytes; the X-axis speed of the parabola position starting point is 2 bytes; the Y-axis speed of the parabola position starting point is 2 bytes; and the Z-axis speed of the parabola position starting point is 2 bytes.

[0021] Further, the obtaining of the trajectory measurement data comprises: obtaining track data including latitude, longitude and height by satellite positioning, and converting the latitude, longitude and height from a geodetic coordinate system to a spatial rectangular coordinate system to obtain XYZ three-axis position information; and measuring acceleration and angular velocity by an accelerometer and a gyroscope, and calculating XYZ three-axis speed and relative displacement after coordinate rotation transformation.

[0022] Further, the comparison of the deviation data with the set threshold comprises: comparing the XYZ three-axis position deviation values of the deviation data with a set position threshold, and comparing the XYZ three-axis speed deviation values with a set speed threshold; any deviation value greater than the set threshold indicates that the deviation data is greater than the set threshold, and all deviation values less than or equal to the set threshold indicates that the deviation data is less than or equal to the set threshold.

[0023] The present application has the following advantages over the prior art: the data compression transmission method for parabolic trajectory measurement provided by the present application uses a reference parabola and a reference sampling point as the datum for data compression; the deviation between the actual sampling point data and the reference sampling point is calculated to describe the deviation between the actual parabolic trajectory and the reference parabolic trajectory; the sample data of the actual parabolic trajectory at the actual sampling point is restored without deviation by using the reference parabolic trajectory and the deviation data, thereby realizing the restoration of the parabolic trajectory measurement data; the deviation value of the parabolic trajectory sampling point relative to the reference sampling point is transmitted, which is equivalent to transmitting the complete trajectory sampling point information, thereby realizing information compression; the bandwidth requirement of the wireless communication system is reduced, the wireless communication distance is increased, and the reliability of wireless data transmission is improved. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The flow chart of the data compression transmission method for parabolic trajectory measurement in the embodiment of the present application is shown in FIG. 1.

[0025] Figure 2 The schematic diagram of the compressed deviation data in the embodiment of the present application is shown in FIG. 2.

[0026] Figure 3 The flow chart of the data compression transmission method for parabolic trajectory measurement in the embodiment of the present application is shown in FIG. 1. DETAILED DESCRIPTION

[0027] The present application will be further described below in conjunction with the drawings and embodiments.

[0028] Figure 1 The flow chart of the data compression transmission method for parabolic trajectory measurement in the embodiment of the present application is shown in FIG. 1.

[0029] Please refer to Figure 1 The data compression transmission method for parabolic trajectory measurement in the embodiment of the present application calculates the deviation between the actual sampling point data and the reference sampling point to describe the deviation between the actual parabolic trajectory and the reference parabolic trajectory; restores the sample data of the actual parabolic trajectory at the actual sampling point without deviation by using the reference parabolic trajectory and the deviation data, thereby realizing the restoration of the parabolic trajectory measurement data, and transmits the deviation value of the parabolic trajectory sampling point relative to the reference sampling point, which is equivalent to transmitting the complete trajectory sampling point information, thereby realizing information compression; and specifically includes the following steps:

[0030] S1: obtaining the initial trajectory measurement data and transmitting the initial trajectory measurement data; calculating the initial reference parabola according to the initial trajectory measurement data and transmitting the parameters of the reference parabola;

[0031] The initial spatial position d0(d x0 ,d y0 ,dz0 ), initial velocity v0(v x0 , v y0 , v z0 ) and initial acceleration a0(a x0 , a y0 , a z0 ), define the initial reference parabola (a x t 2 +v x t+d x , a y t 2 +v y t+d y , a z t 2 +v z t+d z ).

[0032] The reference parabola parameters are transmitted by using a special frame, and the special frame includes: a compression flag, a reference parabola number, a sampling time deviation, a sampling serial number, a UTC time of a parabola position starting point, a sampling serial number corresponding to the UTC time of the parabola position starting point, a longitude of the parabola position starting point, a latitude of the parabola position starting point, an elevation of the parabola position starting point, an X-axis velocity of the parabola position starting point, a Y-axis velocity of the parabola position starting point, and a Z-axis velocity of the parabola position starting point; wherein the compression flag is 2 bits and is fixed as binary 01; the reference parabola number is 3 bits; the sampling time deviation is 11 bits; the sampling serial number is 16 bits; the UTC time of the parabola position starting point is 8 bytes; the sampling serial number corresponding to the UTC time of the parabola position starting point is 2 bytes; the longitude of the parabola position starting point is 4 bytes; the latitude of the parabola position starting point is 4 bytes; the elevation of the parabola position starting point is 2 bytes; the X-axis velocity of the parabola position starting point is 2 bytes; the Y-axis velocity of the parabola position starting point is 2 bytes; and the Z-axis velocity of the parabola position starting point is 2 bytes.

[0033] S2: obtaining trajectory measurement data of an actual sampling point, calculating a deviation between the trajectory measurement data of the actual sampling point and trajectory data of a reference sampling point of a reference parabola at the same time to obtain deviation data, and comparing the deviation data with a set threshold value;

[0034] The calculation of the trajectory data of the reference sampling point of the reference parabola includes: obtaining an actual sampling period T, recording a time deviation Δtm of the mth actual sampling, determining a time tm of the mth reference sampling as a time of the actual sampling, tm=m×T+Δtm; and the trajectory data of the mth reference sampling point is a theoretical spatial position and a theoretical spatial velocity of the reference parabola at the time tm.

[0035] The comparison of the deviation data with the set threshold value comprises: comparing XYZ three-axis position deviation values of the deviation data with a set position threshold value, and comparing XYZ three-axis velocity deviation values with a set velocity threshold value; any deviation value greater than the set threshold value indicates that the deviation data is greater than the set threshold value, and all deviation values less than or equal to the set threshold value indicates that the deviation data is less than or equal to the set threshold value.

[0036] S3: if the deviation data is greater than the set threshold value, transmitting the trajectory measurement data of the actual sampling points, at this time, the receiving end receives the uncompressed trajectory measurement data; calculating an updated reference parabola according to the trajectory measurement data of the actual sampling points, and transmitting the updated reference parabola parameters;

[0037] Calculating the updated reference parabola according to the trajectory measurement data of the actual sampling points comprises:

[0038] S31: obtaining trajectory measurement data of 4 sampling points in 3 continuous time periods, obtaining position d, velocity v and acceleration a information in 3 continuous time periods;

[0039] S32: calculating function parameters position d, velocity v and acceleration a in X axis, Y axis and Z axis directions of 3 time periods respectively, constructing functions (a x t 2 +v x t+d x ,a y t 2 +v y t+d y ,a z t 2 +v z t+d z ); obtaining 6 parabolas;

[0040] S33: fitting a reference parabola through the obtained 6 parabolas, removing the parabola with the largest deviation, calculating the parabola determined by the expected value of the root mean square error of the remaining 5 parabolas as the reference parabola, obtaining an updated reference parabola equation:

[0041] S4: if the deviation data is less than or equal to the set threshold value, transmitting the compressed deviation data; at this time, the receiving end restores the trajectory measurement data of the actual parabola at the actual sampling points through the trajectory data of the reference sampling points of the reference parabola and the decompressed deviation data;

[0042] The trajectory measurement data includes: time stamp milliseconds, time stamp UTC seconds, latitude, longitude, height, and XYZ three-axis speed; the trajectory measurement data includes 22 bytes, wherein the time stamp milliseconds are 2 bytes; the time stamp UTC seconds are 4 bytes; the latitude is 4 bytes; the longitude is 4 bytes; the height is 2 bytes; and the XYZ three-axis speed is 6 bytes.

[0043] The compressed deviation data includes: a compression flag, a reference parabola number, a sampling time deviation, a sampling serial number, XYZ three-axis position deviation values, and XYZ three-axis speed deviation values; wherein the compression flag is 2 bits; the reference parabola number is 3 bits; the sampling time deviation is 11 bits; the sampling serial number is 16 bits; the XYZ three-axis position deviation values are 15 bits plus 1 bit of '0' padding; the XYZ three-axis speed deviation values are 15 bits plus 1 bit of '0' padding; and the total is 8 bytes. Figure 2

[0044] The trajectory measurement data is 22 bytes, the compressed deviation data is 8 bytes, the compression rate is 2.75, and the transmission of the reference parabola parameters makes the compression rate slightly lower than 2.75, thereby improving the compression rate of data transmission.

[0045] S5: repeating steps S2-S4 to obtain trajectory measurement data of the actual parabola at all actual sampling points until the end.

[0046] Specifically, the trajectory measurement data is obtained by acquiring the flight path data through satellite positioning, including latitude, longitude and height, and converting the latitude, longitude and height from the geodetic coordinate system to the spatial rectangular coordinate system to obtain XYZ three-axis position information; the acceleration and angular velocity are measured through the accelerometer and gyroscope, and after coordinate rotation transformation, the XYZ three-axis speed and relative displacement are calculated.

[0047] Referring to Figure 3 , the data compression transmission method for parabolic motion trajectory measurement of the embodiment of the application specifically includes the following steps in actual use:

[0048] Step 1: monitor the accelerometer and gyroscope to obtain acceleration and angular velocity, and judge whether the missile has separated from the aircraft carrier; when the missile separates from the carrier, go to step 2 to start parabolic position measurement, and assign the initial value of the sampling serial number m as 0;

[0049] Step 2: the trajectory data of the missile with the sampling serial number m, judge whether the satellite positioning data is available for 3 consecutive samplings; if available, go to step 4, otherwise go to step 3;

[0050] Step 3: the parameters of the parabola cannot be obtained at present, the trajectory measurement data is transmitted first, and then step 2 is continued to sample;

[0051] ​Step 4: Since the parameters of the parabola have not been calculated, the trajectory measurement data is transmitted first, and then step 5 is turned to calculate the parameters of the parabola;

[0052] Step 5: The initial spatial position, initial velocity and initial acceleration are obtained, the initial reference parabola is calculated, the parabola ID number is set as n=1, and then step 6 is turned;

[0053] Step 6: The parabola parameters of the parabola ID n are transmitted by using a special frame, and then step 7 is turned;

[0054] Step 7: The trajectory measurement data of the missile with the sampling number m is obtained, the position difference and the velocity difference between the current position and velocity and the position and velocity of the reference measurement point of the reference parabola with the number m are calculated, whether the difference is out of limit is judged, if not, step 8 is entered, and if yes, step 9 is entered;

[0055] Step 8: The deviation data after compression of the trajectory measurement data is transmitted, and then step 7 is turned to be iterated circularly until the missile is destroyed by touching the ground;

[0056] Step 9: Since the difference is out of limit, the uncompressed parabola trajectory measurement data is transmitted first, and then step 10 is turned to calculate the new parabola parameters;

[0057] Step 10: More than 5 parabola parameters are calculated in 3 continuous time periods selected from the current time, the parabola parameters are optimally estimated to make the root mean square error in the detection time period minimum, the reference parabola parameters of the n+1th are calculated, the parabola ID number is set as n+1, and then step 6 is turned to transmit the new reference parabola parameters to the receiving party.

[0058] In summary, the data compression transmission method of the parabola motion trajectory measurement in the embodiment of the application uses the reference parabola and the reference sampling point as the datum of data compression, the data deviation between the actual sampling point data and the reference sampling point is calculated to describe the deviation between the actual parabola trajectory and the reference parabola trajectory, the sample data of the actual parabola at the actual sampling point is restored from the reference parabola trajectory and the deviation data without deviation, the restoration of the parabola trajectory measurement data is realized, the deviation value of the parabola trajectory sampling point relative to the reference sampling point is transmitted, which is equivalent to transmitting the complete trajectory sampling point information, so that the information compression is realized, the bandwidth requirement of the wireless communication system is reduced, the wireless communication distance is increased, and the reliability of the wireless data transmission is improved.

[0059] Although the application has been disclosed as above with the preferred embodiments, it is not used to limit the application, any person skilled in the art can make some modifications and improvements without departing from the spirit and scope of the application, therefore the protection scope of the application should be defined by the claims.

Claims

1. A data compression and transmission method for measuring parabolic motion trajectories, characterized in that, Includes the following steps: S1: Acquire initial trajectory measurement data and transmit the initial trajectory measurement data; calculate the initial reference parabola based on the initial trajectory measurement data and transmit the reference parabola parameters; S2: Obtain the trajectory measurement data of the actual sampling points, calculate the deviation between the actual sampling point trajectory measurement data and the trajectory data of the reference sampling points of the reference parabola at the same time to obtain the deviation data, and compare the deviation data with the set threshold. S3: If the deviation data is greater than the set threshold, transmit the trajectory measurement data of the actual sampling points; calculate the updated reference parabola based on the trajectory measurement data of the actual sampling points, and transmit the updated reference parabola parameters. S4: If the deviation data is less than or equal to the set threshold, then transmit the compressed deviation data; S5: Repeat steps S2-S4 to obtain the trajectory measurement data of the actual parabola at all actual sampling points until the end; The updated reference parabola calculated based on the trajectory measurement data of the actual sampling points in step S3 includes: S31: Obtain trajectory measurement data from 4 sampling points in 3 consecutive time periods, and obtain position d, velocity v and acceleration a information for 3 consecutive time periods; S32: Calculate the function parameters position d, velocity v, and acceleration a in the X, Y, and Z axes for three time periods respectively, and construct the function (a x t 2 +v x t+d x ,a y t 2 +v y t+d y ,a z t 2 +v z t+d z ); 6 parabolas were obtained; S33: By fitting a reference parabola to the obtained 6 parabolas, removing the parabola with the largest deviation, and calculating the parabola with the smallest expected value of the remaining 5 parabolas, the updated reference parabola equation is obtained: .

2. The data compression and transmission method for measuring parabolic motion trajectories as described in claim 1, characterized in that, Step S1 includes: obtaining the initial spatial position d0(d x0 ,d y0 ,d z0 ), initial velocity v0(v x0 ,v y0 ,v z0 ) and initial acceleration a0(a x0 ,a y0 ,a z0 Define the initial reference parabola (a) x t 2 +v x t+d x ,a y t 2 +v y t+d y ,a z t 2 +v z t+d z ).

3. The data compression and transmission method for measuring parabolic motion trajectories as described in claim 1, characterized in that, The calculation of the trajectory data of the reference sampling point of the reference parabola includes: obtaining the sampling period T of the actual sampling, recording the time deviation Δtm of the m-th actual sampling, determining the time of the m-th reference sampling as the actual sampling time tm, tm = m×T + Δtm; the trajectory data of the m-th reference sampling point is the theoretical spatial position and theoretical spatial velocity of the reference parabola at time tm.

4. The data compression and transmission method for measuring parabolic motion trajectories as described in claim 1, characterized in that, The trajectory measurement data includes: timestamp milliseconds, timestamp UTC seconds, latitude, longitude, altitude, and XYZ three-axis velocity; the trajectory measurement data includes 22 bytes, of which the timestamp milliseconds is 11 bits; the timestamp UTC seconds is 4 bytes; the latitude is 4 bytes; the longitude is 4 bytes; the altitude is 2 bytes; and the XYZ three-axis velocity is 6 bytes.

5. The data compression and transmission method for measuring parabolic motion trajectories as described in claim 1, characterized in that, The compressed deviation data includes: compression flag, reference parabola number, sampling time deviation, sampling sequence number, XYZ three-axis position deviation value, and XYZ three-axis velocity deviation value; wherein, the compression flag is 2 bits; the reference parabola number is 3 bits; the sampling time deviation is 11 bits; the sampling sequence number is 16 bits; the XYZ three-axis position deviation value is 15 bits plus 1 bit "0" padding; the XYZ three-axis velocity deviation value is 15 bits plus 1 bit "0" padding; totaling 8 bytes.

6. The data compression and transmission method for measuring parabolic motion trajectories as described in claim 1, characterized in that, The reference parabola parameters are transmitted using special frames, which include: a compression flag, a reference parabola number, a sampling time offset, a sampling sequence number, the UTC time of the parabola's starting point, the sampling sequence number corresponding to the UTC time of the parabola's starting point, the longitude of the parabola's starting point, the latitude of the parabola's starting point, the elevation of the parabola's starting point, the X-axis velocity of the parabola's starting point, the Y-axis velocity of the parabola's starting point, and the Z-axis velocity of the parabola's starting point; wherein, the compression flag is 2 bits, fixed as binary 0. 1; The reference parabola number is 3 bits; the sampling time deviation is 11 bits; the sampling sequence number is 16 bits; the UTC time of the parabola's starting point is 8 bytes; the sampling sequence number corresponding to the UTC time of the parabola's starting point is 2 bytes; the longitude of the parabola's starting point is 4 bytes; the latitude of the parabola's starting point is 4 bytes; the elevation of the parabola's starting point is 2 bytes; the X-axis velocity of the parabola's starting point is 2 bytes; the Y-axis velocity of the parabola's starting point is 2 bytes; the Z-axis velocity of the parabola's starting point is 2 bytes.

7. The data compression and transmission method for measuring parabolic motion trajectories as described in claim 1, characterized in that, The acquisition of trajectory measurement data includes: obtaining trajectory data, including latitude, longitude and altitude, through satellite positioning; converting latitude, longitude and altitude from the geodetic coordinate system to the spatial rectangular coordinate system to obtain XYZ three-axis position information; measuring acceleration and angular velocity through accelerometers and gyroscopes; and calculating XYZ three-axis velocity and relative displacement after coordinate rotation transformation.

8. The data compression and transmission method for measuring parabolic motion trajectories as described in claim 1, characterized in that, The comparison between the deviation data and the set thresholds includes: comparing the XYZ three-axis position deviation values ​​of the deviation data with the set position thresholds, and comparing the XYZ three-axis speed deviation values ​​with the set speed thresholds; if any deviation value is greater than the set threshold, it means that the deviation data is greater than the set threshold, and if all deviation values ​​are less than or equal to the set threshold, it means that the deviation data is less than or equal to the set threshold.

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