An Inertial Navigation Attitude Data Error Correction Method

Abstract

The present invention relates to a method for correcting the errors of inertial navigation attitude data. The core of this method lies in the combination of low-frequency recording and high-frequency calculation techniques: recording attitude data at a low frequency to reduce the system burden, and when accurate data is required, switching to the high-frequency calculation mode to calculate the carrier attitude angular rate based on the attitude data at the current moment and the previous moment. At the synchronization moment, the time difference between the internal clock's precise measurement and the external time synchronization signal is measured, and then, in combination with the current attitude data, attitude angular rate, and time difference, the attitude data at the synchronization moment is corrected in real time through high-frequency calculation. Finally, the corrected attitude data is output in the form of an efficient structured data packet. This method not only significantly improves the real-time performance and accuracy of the attitude information output, but also optimizes the data processing flow, reduces the transmission burden, and ensures the high-performance operation of inertial navigation devices.

Description

Technical Field

[0001] The present invention relates to the technical field of inertial navigation, and particularly to a method for correcting errors in inertial navigation attitude data. Background Art

[0002] In the technical field of inertial navigation, the accuracy and real-time performance of attitude data are crucial for navigation accuracy and system reliability. Due to advantages such as a wide measurement dynamic range, good linearity, stable performance, and all-weather navigation, inertial navigation products play an irreplaceable role in fields such as ship navigation. Its core function is to collect the angular motion information and apparent acceleration information of the carrier through sensitive devices, and use a mathematical model to calculate the angular velocity and acceleration of the carrier, and further deduce the attitude information, velocity information, and position information. However, the accuracy and reliability of inertial navigation products highly depend on the precise processing of inertial sensor errors.

[0003] In the practical application of the existing technology of inertial navigation products, a key technical challenge is how to ensure that the attitude data output by the inertial navigation device is kept in real-time synchronization with the external synchronization signal. Due to the accuracy difference between the system clock source and the internal clock source of the inertial navigation device, and the influence of factors such as the power-on sequence of the system synchronization device and the inertial navigation device, the internal calculation moment of the navigation device and the moment of the external synchronization timekeeping signal often cannot be fully synchronized. The time difference in data output caused by this asynchronization will seriously affect the real-time performance and accuracy of navigation data.

[0004] In the case of low-frequency recording of attitude data, although it can reflect the basic trend of the carrier's movement, it is difficult to capture the minute changes within a short period of time, thus affecting navigation accuracy. In addition, when the external system requests precise attitude data, if only relying on low-frequency recorded data for output, it may not meet the real-time requirements. For these problems, although the method in the authorized text has improved the real-time performance and accuracy of attitude data to a certain extent, it still faces challenges in practical applications. Summary of the Invention

[0005] The present invention provides a method for compensating synchronization errors of attitude data by combining low-frequency recording and high-frequency calculation for the technical problems existing in the prior art. Based on the low-frequency recording of attitude data, when the external system requests precise attitude data, the inertial navigation device switches to the high-frequency calculation mode, calculates the attitude angular rate using the attitude data at the latest low-frequency recording moment, and combines the time difference between the internal clock and the external time synchronization signal to perform real-time correction on the attitude data at the synchronization moment. This method not only retains the advantage of low-frequency recorded data reflecting the movement trend of the carrier, but also improves the real-time performance and accuracy of attitude data using high-frequency calculation, effectively making up for the deficiencies of the prior art.

[0006] The technical solution of the present invention to solve the above technical problems is as follows: An inertial navigation attitude data error correction method, including:

[0007] S101, the inertial navigation device records the attitude data of the carrier at each navigation solution moment at a low frequency;

[0008] S102, when the requesting device requests the current accurate attitude data, the inertial navigation device prepares for high-frequency calculation;

[0009] S103, the inertial navigation device switches to high-frequency calculation, and calculates the attitude angular rate of the carrier during this period according to the attitude data at the current moment and the previous moment of two low-frequency recording moments;

[0010] S104, at the synchronization moment, the inertial navigation device measures the time difference between the internal clock and the external time synchronization signal;

[0011] S105, according to the attitude data, attitude angular rate and synchronization time difference at the current navigation solution moment, use high-frequency calculation to correct the attitude data of the carrier at the synchronization moment;

[0012] S106, output the corrected attitude data to the requesting device.

[0013] Preferably, in S101, recording the attitude data of the carrier at each navigation solution moment at a low frequency includes:

[0014] Define the low frequency as recording the attitude data less than or equal to 10 Hz, that is, recording the attitude information of the carrier's heading, pitch angle, and roll angle at the current moment up to 10 times per second at most.

[0015] Preferably, in S103, high-frequency calculation includes:

[0016] Define the high-frequency calculation as greater than or equal to 100 Hz, that is, calculating at least 100 times per second.

[0017] Preferably, S102 further includes:

[0018] S201, on the inertial navigation device, select the data within a specific time range before and after the request moment according to the request moment;

[0019] S202, pack the selected data into a structured data packet according to a predetermined format;

[0020] S203, the requesting device receives the data packet from the inertial navigation device and parses the data packet;

[0021] S204, extract the count, the time node of the count, and the original data for specific error correction calculation.

[0022] Preferably, in step S201, the data within a specific time range before and after the request moment is selected, including:

[0023] Based on the request moment, a time range is defined, that is, 3 seconds before and after the request moment. Within the set time range, relevant data points are screened out from the storage medium of the inertial navigation device.

[0024] Preferably, step S202 includes:

[0025] S301, classify the motion laws of the carrier, assign a unique number to each calculation formula for classification, and output it as a law calculation list;

[0026] S302, utilize the high-frequency calculation area of the carrier to compare data changes;

[0027] S303, send a data packet including the calculation formula number and the endpoint data of the corresponding time period to the requesting device;

[0028] S304, the requesting device calls the calculation formula for calculation to correct data errors.

[0029] Preferably, in step S301, classifying the motion laws of the carrier includes:

[0030] When the carrier loaded with inertial navigation attitude executes a new action, there will be fixed state characteristics in terms of speed, trajectory, and angle. According to the laws of historical carrier motion, various indicators during the carrier's motion are collected, the data sampling frequency is set, and the key change points and change laws during the carrier's motion are captured and defined as motion mode laws.

[0031] Preferably, the motion mode laws include:

[0032] In motion mode recognition, observe the change trends of the angular velocity and acceleration change factors in different motion modes;

[0033] Obtain the change relationships between the change factors and time and spatial positions;

[0034] According to the change relationships, construct calculation formulas and error correction models for describing the motion mode and organize them into a list;

[0035] Assign a unique number to each calculation formula and error correction model to form a list containing multiple motion modes and their corresponding calculation formulas and error correction models. Each model has a unique number, and this list serves as the law calculation list.

[0036] Preferably, the data packet format in step S303 includes:

[0037] Start symbol | Data packet length | Calculation formula number | Start time and end time | Start position and end position | Error correction model code | Motion mode | Check code | End symbol.

[0038] Preferably, the S301 includes:

[0039] S401, refine the motion law calculation list of the carrier;

[0040] S402, limit the range of parameter thresholds of the calculation formula.

[0041] The beneficial effects of the present invention are:

[0042] 1. In the low-frequency recording stage, the system stores data at a lower frequency, reducing the burden of data storage and processing, thereby reducing system energy consumption and extending the service life of the device. At the same time, when the requesting device requests accurate data, the system can quickly switch to the high-frequency calculation mode, capture the minute changes in data within a short period of time, ensuring the real-time and accuracy of the data. This flexible calculation method not only improves the response speed of the system but also optimizes the resource utilization efficiency.

[0043] 2. By carefully selecting and only sending data within the critical time period, this solution greatly reduces the burden of data transmission. This not only reduces the time and resources required for data transmission but also enables the requesting device to receive the required data more quickly. Therefore, the timeliness of the data is significantly improved, and the requesting device can almost real-time obtain the latest status information of the carrier, providing a strong guarantee for quickly responding to the actions of the carrier.

[0044] 3. By carefully classifying the motion law of the carrier and generating corresponding calculation formulas and threshold change intervals, the data processing process is significantly optimized. The core lies in reducing the amount of unnecessary transmitted data, which not only reduces the delay in the data transmission process but also effectively reduces the risk of data being stolen or tampered with, thereby greatly enhancing the security of data transmission. In addition, through the real-time comparison and matching technology in the high-frequency calculation area, the accuracy and integrity of the data are further ensured, providing a solid guarantee for the subsequent application of the data.

[0045] 4. The setting of the range of core parameter thresholds makes the calculation formula highly flexible and adaptable. This innovation not only allows the calculation formula to be dynamically adjusted in the actual motion environment of the carrier to accurately match various complex scenarios but also greatly enhances the accuracy and practicality of the data. In addition, through the carefully set parameter range, this technology can effectively filter out abnormal data, ensuring the stability and reliability of the calculation results. Description of the Drawings

[0046] Figure 1Schematic flowchart of an inertial navigation attitude data error correction method according to an embodiment of the present invention. Detailed implementation manners

[0047] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are only a part rather than all of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0048] In the description of the present application, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present application, "a plurality" means two or more unless otherwise specifically defined.

[0049] In the description of the present application, the term "for example" is used to mean "serving as an example, illustration, or explanation". Any embodiment described as "for example" in the present application is not necessarily construed as being more preferred or having more advantages than other embodiments. In order for any person skilled in the art to implement and use the present invention, the following description is given. In the following description, details are set forth for purposes of explanation. It should be understood that those of ordinary skill in the art can recognize that the present invention can be implemented without the use of these specific details. In other instances, well-known structures and processes are not elaborated in detail to avoid obscuring the description of the present invention with unnecessary details. Therefore, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed in the present application.

[0050] Embodiment 1:

[0051] Figure 1 Schematic flowchart of an inertial navigation attitude data error correction method according to an embodiment of the present invention. As Figure 1 shown, an inertial navigation attitude data error correction method according to an embodiment of the present invention includes the following steps:

[0052] S101, the inertial navigation device records the attitude data of the carrier at each navigation solution moment at a low frequency.

[0053] Wherein, the low frequency in the above step refers to that the inertial navigation system records the attitude data of the carrier on which the inertial navigation device is installed at a lower frequency. The data recorded at this frequency is not continuous, but is sufficient to reflect the basic trend of the carrier's movement. In the text, the carrier is the carrier on which the inertial navigation device is installed;

[0054] Define the low frequency as less than or equal to 10 Hz to record the attitude data, that is, record the heading, pitch angle, roll angle and other information at the current moment up to 10 times per second, and record the attitude data corresponding to the first attitude data at time t1. The attitude data corresponding to the second attitude data at time t2. ......, and record it as the attitude data corresponding to the Nth attitude data at time tn. .

[0055] Among them, the current navigation solution time and the corresponding vehicle attitude information are obtained through navigation solution using the carrier angular motion and visual acceleration information, and the gyroscope and accelerometer that are maturely used in the existing technology are used to obtain the carrier angular motion and visual acceleration information.

[0056] S102. When the requesting device requests the current accurate attitude data, the inertial navigation device prepares for high-frequency calculation.

[0057] Among them, the requesting device is the device that sends an attitude data request to the inertial navigation system.

[0058] Specifically, the requesting device sends a request signal to the inertial navigation system through the communication interface. After the system receives the request signal, it immediately prepares to switch to the high-frequency calculation mode.

[0059] S103. The inertial navigation device switches to high-frequency calculation, and calculates the attitude angular rate of the carrier during this period according to the attitude data at the current moment and the attitude data at the two low-frequency recording moments of the previous moment.

[0060] Among them, the high frequency in the above steps refers to the calculation frequency higher than the normal recording frequency used by the inertial navigation system for attitude angular rate calculation and attitude data correction. The calculation of this frequency can capture the minute changes in attitude data in a short period of time;

[0061] Define the high-frequency calculation as greater than or equal to 100 Hz, that is, calculate at least 100 times per second.

[0062] The formula for calculating the attitude angular rate is as follows:

[0063]

[0064] Among them, Ω1 and Ω2 are the attitude angles at times t1 and t2 respectively, and Δt is the time interval (t2 - t1).

[0065] S104. At the synchronization moment, the inertial navigation device measures the time difference between the internal clock and the external time synchronization signal.

[0066] Specifically, in an inertial navigation system, the internal clock and the external time synchronization signal together constitute the system's time reference system. The internal clock is responsible for recording the time within the system, providing the basis for data recording, processing, and error correction; while the external time synchronization signal is used to calibrate and correct the deviation of the internal clock, ensuring that the system time is consistent with the external time.

[0067] For example, in the inertial navigation system of a ship, the internal clock may record the timestamp of the attitude data at a frequency of 1 Hz, and the external time synchronization signal comes from the GPS satellite navigation system. When the ship is sailing, the system will regularly receive GPS signals and compare the time information in them with the internal clock. If a deviation is found, the system will accordingly adjust the frequency or phase of the internal clock to ensure that the internal time is consistent with the GPS time. In this way, the ship can obtain more accurate attitude data and thus perform more accurate navigation and positioning.

[0068] At the synchronization moment tout, latch the data and performance of the buffer counter Counter, and calculate the time difference between the synchronization moment and the current navigation solution moment ; the time difference between the synchronization moment and the current navigation solution moment It is calculated by the following formula:

[0069]

[0070] where Counter is the value of the buffer counter corresponding to the time difference between the internal clock and the external time synchronization signal, which is cleared at each navigation solution moment, is the timing frequency, is the time difference between the synchronization moment and the current navigation solution moment.

[0071] S105, according to the attitude data, attitude angular rate, and synchronization time difference at the current navigation solution moment, use high-frequency calculation to correct the attitude data of the carrier at the synchronization moment.

[0072] Among them, the formula for correcting the attitude information of the carrier at the synchronization moment is as follows:

[0073]

[0074] Among them is the corrected attitude data, is the attitude data at the current navigation solution moment, is the attitude angular rate, is the time difference between the synchronization moment and the current navigation solution moment.

[0075] S106, output the corrected attitude data to the requesting device.

[0076] For example, a practical application case of a ship inertial navigation system is simulated. A low frequency of 1 Hz is defined, that is, the attitude data is recorded once per second;

[0077] At t1 = 0 seconds, the attitude data is: heading = 0 degrees, pitch angle = 0 degrees, roll angle = 0 degrees;

[0078] At t2 = 1 second, the attitude data is: heading = 5 degrees, pitch angle = 1 degree, roll angle = 0.5 degrees... (and so on, recorded once per second);

[0079] Suppose at t = 1.5 seconds, the autopilot system sends a request signal to the inertial navigation system through the communication interface;

[0080] Switch to a high frequency of 100 Hz, that is, calculate 100 times per second. Use the attitude data at t1 = 1 second and t2 = 2 seconds for calculation (because at t = 1.5 seconds, the latest low-frequency data is at t2 = 2 seconds);

[0081] Attitude angle rate calculation formula: , heading angle rate = (5 degrees - 0 degrees) / 1 second = 5 degrees / second, pitch angle rate = (1 degree - 0 degrees) / 1 second = 1 degree / second, roll angle rate = (0.5 degrees - 0 degrees) / 1 second = 0.5 degrees / second;

[0082] The internal clock is assumed to record timestamps at 1 Hz, and the external time synchronization signal comes from GPS. Suppose a GPS signal is received at t = 1.5 seconds;

[0083] The internal clock records a timestamp at t = 1 second and will record the next timestamp at t = 2 seconds. At t = 1.5 seconds, the time difference between the internal clock and GPS time is seconds (because the internal clock's most recent record was at t = 1 second);

[0084] The current navigation solution time is t = 1 second (because this is the time point of the latest low-frequency data); formula for correcting the attitude information of the carrier at the synchronization moment: , the corrected attitude data = current attitude data + attitude angle rate ; the corrected heading = 0 degrees + 5 degrees / second 0.5 seconds = 2.5 degrees, the corrected pitch angle = 0 degrees + 1 degree / second 0.5 seconds = 0.5 degrees, the corrected roll angle = 0 degrees + 0.5 degrees / second 0.5 seconds = 0.25 degrees;

[0085] Output the corrected heading = 2.5 degrees, the corrected pitch angle = 0.5 degrees, the corrected roll angle = 0.25 degrees, the output time t = 1.5 seconds (synchronization moment), and define the above corrected data as error correction model number E001.

[0086] The technical solutions in the embodiments of the present application at least have the following technical effects or advantages:

[0087] 1. In the low-frequency recording stage, the system stores data at a lower frequency, reducing the burden of data storage and processing, thereby reducing system energy consumption and extending the service life of the device. At the same time, when the requesting device requests precise data, the system can quickly switch to the high-frequency calculation mode, capturing the minute changes in data within a short period of time, ensuring the real-time and accuracy of the data. This flexible calculation method not only improves the system's response speed but also optimizes the resource utilization efficiency.

[0088] Embodiment 2:

[0089] By combining low-frequency data recording with high-frequency calculation, efficient utilization of resources is achieved. To address the problem of reduced data timeliness caused by the carrier moving too fast, technical time nodes are now sent to the requesting device, along with various types of data. The requesting device calculates the specific values of the required time nodes, and the data sent is the data within a specific time range before and after the request moment, improving data timeliness to cope with the rapid movement of the carrier.

[0090] Now, further improvements are made based on step S102 of Embodiment 1, specifically:

[0091] S201. On the inertial navigation device, according to the request moment, select the data within a specific time range before and after the request moment.

[0092] Among them, the data within the specific time range includes the count, i.e., the serial number of each data point, the time node of the count, i.e., the time stamp corresponding to each data point, and the angular velocity, acceleration, position, etc. of the original data.

[0093] Specifically, based on the request moment, a time range is defined, that is, 3 seconds before and after the request moment. Within the set time range, relevant data points are screened out from the storage medium of the inertial navigation device.

[0094] S202. Pack the screened data into a structured data packet according to a predetermined format.

[0095] Among them, the structured data packet format is as follows:

[0096] Start symbol | Data packet length | Count 1 | Time node 1 | Angular velocity 1 | Acceleration 1 | Position 1 |... | Check code | End symbol;

[0097] The start symbol represents a special character or character sequence used to identify the start of the data packet;

[0098] The data packet length represents the total length of the data in the data packet (excluding the start symbol, end symbol, and checksum).

[0099] The count represents the serial number or index of each data point, used to identify the order of the data.

[0100] The time node represents the timestamp corresponding to each data point, used to identify the time information of the data.

[0101] The angular velocity, acceleration, and position represent the original data, indicating the motion state of an object at a specific time node.

[0102] The checksum represents the check value used to check the integrity and correctness of the data packet.

[0103] The end symbol represents a special character or character sequence used to identify the end of the data packet.

[0104] For example, taking a specific data packet as an example: START|120|001|20230401120000|0.01|0.02|X1, Y1, Z1|...|010|20230401120009|0.10|0.20|X10, Y10, Z10|CHECKSUM|END;

[0105] START is the start symbol, indicating the start of the data packet.

[0106] 120 is the data packet length, representing the total length of the data in the data packet (assuming each data point occupies a certain number of bytes and the total length of all data has been calculated).

[0107] 001 to 010 is the count, indicating that these are the 1st to 10th data points.

[0108] 20230401120000 to 20230401120009 are the time nodes, indicating the timestamps corresponding to these data points from 12:00:00 on April 1, 2023 to 12:00:09 on April 1, 2023.

[0109] 0.01, 0.02, X1, Y1, Z1 to 0.10, 0.20, X10, Y10, Z10 are the original data, representing the angular velocity from 0.01 rad / s to 0.10 rad / s, the acceleration from 0.02 m / s² to 0.20 m / s², and the position information longitude X1, latitude Y1, altitude Z1 (where X1, Y1, Z1 are specific values, replaced by letters for simplicity of explanation) to longitude X10, latitude Y10, altitude Z10.

[0110] CHECKSUM is the checksum, used to check the integrity and correctness of the data packet.

[0111] END is the end symbol, indicating the end of the data packet.

[0112] S203, The requesting device receives the data packet from the inertial navigation device and parses the data packet.

[0113] Specifically, the requesting device parses the data packet according to a pre - defined format and extracts the attitude data information therein.

[0114] S204, Extract the count, the time node of the count, and the raw data for specific error correction calculation.

[0115] The technical solutions in the embodiments of the present application at least have the following technical effects or advantages:

[0116] 1. By carefully selecting and only sending the data within the critical time period, this solution greatly reduces the burden of data transmission. This approach not only reduces the time and resources required for data transmission, but also enables the requesting device to receive the required data more quickly. Therefore, the timeliness of the data is significantly improved, and the requesting device can almost real - time obtain the latest status information of the carrier, providing a strong guarantee for quickly responding to the actions of the carrier.

[0117] 2. This solution also makes full use of the computing power of the requesting device to process the received data through real - time calculation. This method avoids complex pre - processing before data transmission, thereby improving the efficiency of data processing. At the same time, since the calculation is performed in real - time on the requesting device, it can more accurately reflect the current state of the carrier, timely detect and correct errors in the data. This real - time calculation method ensures the accuracy and reliability of the data, providing more accurate data support for applications such as navigation and control.

[0118] Embodiment 3:

[0119] By selecting and sending the data within the critical time period, and using the computing power of the requesting device for real - time calculation, the timeliness of the data is improved, enabling the requesting device to more accurately obtain and respond to the rapid actions of the carrier. In the high - frequency high - speed movement and change of the carrier, for the transmission of such a large amount of data, there are still risks of delay and transmission delay, as well as the risk of information being stolen. Based on this, by classifying the movement laws of the carrier and generating corresponding calculation formulas, and using the high - frequency calculation area for real - time comparison and matching, the amount of data to be transmitted is reduced.

[0120] Now, on the basis of step S202 in Embodiment 2, further improvements are made, specifically:

[0121] S301. Classify the motion laws of the carrier, match a unique number to each calculation formula for classification, and output it as a law calculation list.

[0122] Specifically, when a carrier equipped with inertial navigation attitude executes a new action, it will have fixed state characteristics in terms of speed, trajectory, and angle. According to the laws of historical carrier motion, collect various indicators of the carrier during the motion process, set the data sampling frequency, and capture the key change points and change laws of the carrier motion, which are defined as motion mode laws.

[0123] Preprocess the collected data, such as filtering and denoising, to improve the data quality.

[0124] Perform pattern recognition on the processed data to divide different motion modes, such as uniform linear motion, uniformly accelerated linear motion, circular motion, etc.

[0125] For each motion mode, analyze its data characteristics (such as the change laws of angular velocity, acceleration, etc.), and derive mathematical calculation formulas that can accurately describe the motion. These formulas usually include the relationships between variables such as error time (t), start time (tr), end time (te), start longitude and latitude (λ0, φ0), end longitude and latitude (longitude and latitude (λt, φt) after te - tr), speed (v), acceleration (a), etc.

[0126] Organize all motion modes and their corresponding calculation formulas (in motion mode recognition, observe the change trends of other change factors such as angular velocity and acceleration in different motion modes, obtain the change relationships between the change factors and time and spatial positions, and thus construct the calculation formulas describing these motion modes) and error correction models into a list, assign a unique number to each calculation formula and error correction model, and finally form a list containing multiple motion modes and their corresponding calculation formulas and error correction models. Each model has a unique number, and this list serves as the law calculation list for subsequent quick retrieval and invocation.

[0127] For example, the derivation process of the simulation formula for uniform linear forward movement is as follows:

[0128] Definition of speed: The speed v is the ratio of displacement s to time t: v = t / s.

[0129] Definition of acceleration: In uniform linear motion, the acceleration a is zero: a = 0.

[0130] Relationship between displacement and time: If an object moves in uniform linear motion with speed v, then the relationship between displacement s and time t is: s = vt.

[0131] To determine whether an object is in uniform linear motion, the following conditions can be used:

[0132] At any two time points \(t_1\) and \(t_2\) with a constant speed, the measured speeds \(v_1\) and \(v_2\) should be equal: \(v_1 = v_2\);

[0133] The acceleration is zero: the measured acceleration \(a\) should be close to zero (within a small threshold range considering the errors in actual measurement): , where is a small positive number representing the allowable acceleration error range;

[0134] Combining the above conditions, a formula for judging uniform linear motion can be simulated. Assuming there is a starting time \(t_0\), an ending time \(t_f\), a starting speed \(v_0\), an ending speed \(v_f\), and a measured acceleration \(a_{measured}\), the following logic can be used for judgment:

[0135] Calculate the time interval: ;

[0136] Check if the speed is constant: , where \(\delta\) is a small positive number representing the allowable speed change range;

[0137] Check if the acceleration is zero: ;

[0138] If both of the above two conditions are met, it can be considered that the object is in uniform linear motion;

[0139] The above conditions can be combined into a judgment formula: ;

[0140] If \(IUSM\) is true (i.e., both conditions are met), the object is in uniform linear motion, and this calculation formula is defined as number \(AE01\).

[0141] S302. Use the high - frequency calculation area of the carrier to compare data changes.

[0142] Specifically, set up a high - frequency calculation area on the carrier, equipped with an ARMCortex - A series embedded processor computing device to support fast data processing and analysis. Use the high - frequency calculation area to quickly process the received data and extract data features;

[0143] Compare the extracted data features with the pre - stored regular calculation list to find the calculation formula number and error correction model number that best match the current carrier state.

[0144] S303. Send a data packet containing the calculation formula number and the endpoint data of the corresponding time period to the requesting device.

[0145] Specifically, after determining the calculation formula number, the carrier does not need to transmit all the original data, but only sends the calculation formula number, the endpoint data (start time and end time) of the corresponding period, and the endpoint values (start position and end position) of the corresponding category data;

[0146] The data packet format sent to the requesting device is updated to:

[0147] Start character | Packet length | Calculation formula number | Start time and end time | Start position and end position | Error correction model code | Motion mode | Check code | End character.

[0148] S304. The requesting device calls the calculation formula to calculate and perform data error correction.

[0149] Specifically, after receiving the endpoint data of the calculation formula number, the requesting device calculates according to the rule calculation list stored in it, calls the corresponding calculation formula, and combines the endpoint data for calculation, so as to obtain each data point within the required time node.

[0150] For example, continuing with the example in step S301, the requesting device receives the calculation formula number AE01 sent by the carrier, finds its corresponding calculation formula, substitutes data such as the endpoint data (start time and end time) of the corresponding period and the endpoint values (start position and end position) of the corresponding category data into the calculation formula, and obtains the corresponding error correction model number E001 and error data. Assuming that the error of uniform linear motion for 20s passes through the time difference between the synchronization moment and the current navigation solution moment in step S104 , after matching the error correction model with the calculation formula number, the error correction data under this model is obtained.

[0151] The technical solutions in the embodiments of the present application at least have the following technical effects or advantages:

[0152] 1. By classifying the motion laws of the carrier in detail and generating corresponding calculation formulas and threshold change intervals, the data processing flow is significantly optimized. The core lies in reducing the amount of data transmitted unnecessarily, which not only reduces the delay in the data transmission process, but also effectively reduces the risk of data being stolen or tampered with, thus greatly improving the security of data transmission. In addition, through the real-time comparison and matching technology in the high-frequency calculation area, the accuracy and integrity of the data are further ensured, providing a solid guarantee for the subsequent application of the data.

[0153] 2. This technical solution can still demonstrate excellent performance in a complex environment with high-frequency, high-speed movement and changes. The real-time comparison and matching in the high-frequency computing area, as the core means of the technology, not only achieve the instant processing and verification of data, but also ensure the efficiency and accuracy of data during transmission. This real-time processing ability, combined with the effective reduction of data volume, jointly contributes to the ultimate goal of the technical solution: even under extreme conditions, it can provide timely, accurate, and secure data support for various applications, thus meeting various high-demand application scenarios.

[0154] Embodiment 4:

[0155] By classifying the movement laws of the carrier and constructing calculation formulas, setting the threshold range of the variation factor, and combining the real-time comparison in the high-frequency computing area, the data transmission volume is significantly reduced. Due to the influence of the operation mode of external factors, the current airflow, and other real-world environmental problems on the carrier, it cannot perfectly match the parameters of the pre-set calculation formula. Therefore, by limiting the specific threshold variation range of the core parameters in the calculation formula for data comparison and matching, the reduction of data transmission volume and the improvement of calculation accuracy are further achieved.

[0156] Now, on the basis of step S301 of Embodiment 3, further improvements are made, specifically as follows:

[0157] S401, refine the movement law calculation list of the carrier.

[0158] S402, limit the threshold variation range of the parameters of the calculation formula.

[0159] Specifically, conduct in-depth research on the possible movement laws of the carrier, and limit the threshold variation range of the parameters (such as speed, acceleration, steering angle, etc.) for each parameter of the calculation formula. The threshold variation range should be determined based on the design parameters of the carrier, historical movement data, and possible changes in the actual environment.

[0160] For example, in the movement classification law calculation list of the unmanned submersible shown in Table 1 (this table is only used for illustrative purposes and does not serve as an actual application law table), if the collected parameters such as error time (t), start time (tr), end time (te), start longitude and latitude (λ0, φ0), end longitude and latitude (longitude and latitude (λt, φt) after te - tr), speed (v), acceleration (a), etc. meet the threshold range under the calculation formula number, then the parameters can be matched and calculated, and the appropriate error correction model number can be matched.

[0161] Table 1 Movement Classification Law Calculation List of Unmanned Submersible

[0162]

[0163] The technical solutions in the embodiments of the present application at least have the following technical effects or advantages:

[0164] 1. The setting of the change range of the core parameter threshold makes the calculation formula highly flexible and adaptable. This innovation not only allows the calculation formula to be dynamically adjusted in the actual motion environment of the carrier to accurately match various complex scenarios, but also greatly enhances the accuracy and practicality of the data. In addition, through the carefully set parameter range, this technology can effectively filter abnormal data and ensure the stability and reliability of the calculation results.

[0165] 2. This technology ensures the accuracy and adaptability of the calculation results through data comparison and matching in the high-frequency calculation area and the application of an adaptable calculation formula. This high-precision calculation ability provides reliable data support for the motion control of the carrier, thereby improving the performance and stability of the entire system. Finally, these technical means work together to enable the technical solution to provide accurate and adaptable carrier motion data support while ensuring data security and efficiency, meeting the requirements of various complex application scenarios. This comprehensive technical advantage makes the present technical solution have broad application prospects and significant market value in the field of carrier motion data processing.

[0166] It should be noted that in the above embodiments, the descriptions of each embodiment have their own emphases. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0167] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0168] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present invention. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of flows and / or blocks in the flowcharts and / or block diagrams, can be realized by computer program instructions. These computer program instructions can be provided to the processors of general-purpose computers, special-purpose computers, embedded computers, or other programmable data processing devices to generate a machine, so that the instructions executed by the processors of the computer or other programmable data processing devices generate means for realizing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0169] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to operate in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including an instruction means that implements the functions specified in one or more of the processes and / or blocks Figure 1 one or more of the processes and / or blocks Figure 1 specified in the block or blocks.

[0170] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable apparatus provide steps for implementing the functions specified in one or more of the processes and / or blocks Figure 1 one or more of the processes and / or blocks Figure 1 specified in the block or blocks.

[0171] Although the preferred embodiments of the present invention have been described, additional changes and modifications can be made by those skilled in the art once they learn of the basic inventive concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0172] It is obvious that those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. An inertial navigation attitude data error correction method, characterized in that Specifically include: S101, The inertial navigation device records the attitude data of the carrier at each navigation solution moment at a low frequency; S102, When the requesting device requests the current accurate attitude data, the inertial navigation device prepares for high-frequency calculation; S103, The inertial navigation device switches to high-frequency calculation, and calculates the attitude angular rate of the carrier during this period according to the attitude data at two low-frequency recording moments of the current moment and the previous moment; S104, At the synchronization moment, the inertial navigation device measures the time difference between the internal clock and the external time synchronization signal; S105, According to the attitude data, attitude angular rate and synchronization time difference at the current navigation solution moment, use high-frequency calculation to correct the attitude data of the carrier at the synchronization moment; S106, Output the corrected attitude data to the requesting device; The S102 further includes: S201, On the inertial navigation device, according to the request moment, select the data within a specific time range before and after the request moment; S202, Pack the selected data into a structured data packet according to a predetermined format; S203, The requesting device receives the data packet from the inertial navigation device and parses the data packet; S204, Extract the count, time nodes of the count, and raw data for specific error correction calculation; The S202 includes: S301, Classify the motion laws of the carrier, match a unique number to each calculation formula for classification, and output it as a list of law calculations; S302, Use the high-frequency calculation area of the carrier to compare data changes; S303, Send a data packet containing the calculation formula number and the endpoint data of the corresponding period to the requesting device; S304, The requesting device calls the calculation formula for calculation to perform data error correction.

2. The inertial navigation attitude data error correction method according to claim 1, characterized in that The S101, recording the attitude data of the carrier at each navigation solution moment at a low frequency, includes: Define the low frequency as recording attitude data less than or equal to 10Hz, that is, record the attitude information of the carrier's heading, pitch angle, and roll angle at the current moment up to 10 times per second at most.

3. A method for correcting the error of inertial navigation attitude data according to claim 1, characterized in that, The S103, high-frequency calculation, includes: Define the high-frequency calculation as greater than or equal to 100Hz, that is, calculate at least 100 times per second.

4. A method for correcting the error of inertial navigation attitude data according to claim 1, characterized in that, The S201, selecting the data within a specific time range before and after the request moment, includes: Based on the request moment, limit a time range, that is, 3 seconds before and after the request moment. Within the set time range, filter out the relevant data points from the storage medium of the inertial navigation device.

5. A method for correcting the error of inertial navigation attitude data according to claim 1, characterized in that, The S301, classifying the motion laws of the carrier, includes: When the carrier carrying the inertial navigation attitude performs a new action, there will be fixed state characteristics in terms of speed, trajectory, and angle. According to the laws of historical carrier motion, collect various indicators during the carrier's motion, set the data sampling frequency, and capture the key change points and change laws of the carrier's motion, which are defined as motion mode laws.

6. A method for correcting the error of inertial navigation attitude data according to claim 5, characterized in that The motion mode laws include: In motion mode recognition, observe the change trends of the change factors of angular velocity and acceleration in different motion modes; Obtain the change relationships between the change factors and time and spatial positions; Construct calculation formulas and error correction models describing the motion mode according to the change relationships and organize them into a list; A unique number is assigned to each calculation formula and error correction model to form a list containing various motion patterns and their corresponding calculation formulas and error correction models. Each model has a unique number, and this list serves as the regular calculation list.

7. A method for correcting the error of inertial navigation attitude data according to claim 1, characterized in that The S303, data packet format, includes: Start symbol | Data packet length | Calculation formula number | Start time and end time | Start position and end position | Error correction model code | Motion pattern | Check code | End symbol.

8. A method for correcting errors in inertial navigation attitude data according to claim 1, characterized in that, The S301 includes: S401, refine the motion law calculation list of the carrier; S402, limit the change range of the parameter threshold of the calculation formula.

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