Zero offset change compensation method and device for accelerometer
By predicting and compensating for accelerometer bias variations in real time using a square root function model, the problem of zero bias drift in flexible accelerometers was solved, thus improving the long-term accuracy and stability of the inertial navigation system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-27
- Publication Date
- 2026-04-07
AI Technical Summary
The zero bias of a flexible accelerometer is easily affected by environmental factors, leading to long-term drift, increasing the need for periodic calibration, and reducing the accuracy and reliability of the inertial navigation system.
The square root function model is used to predict the zero bias change, and the accelerometer output value is compensated in real time to reduce the dependence on periodic calibration.
This improves the long-term stability of the flexible accelerometer, reduces calibration workload, extends calibration cycle, and enhances the accuracy and stability of the inertial navigation system.
Smart Images
Figure CN121804533A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of inertial sensor technology, and in particular to an accelerometer zero bias change compensation method and device, which is applicable to high-precision inertial navigation systems, aerospace attitude control and other fields. Background Technology
[0002] Flexible accelerometers operate based on the principle of torque balance. Their core characteristic is that the output signal should be zero when there is no acceleration input; this value is commonly referred to as "zero bias." However, in practical applications, zero bias is easily affected by various environmental and temporal factors such as temperature fluctuations, mechanical vibrations, and material aging, leading to zero-point drift. During long-term service, this zero-point drift accumulates over time, increasing acceleration measurement errors and reducing the accuracy and reliability of the entire inertial navigation system.
[0003] To maintain the system's accuracy within acceptable limits, the zero bias of the inertial navigation system needs to be calibrated and adjusted periodically during actual use. However, the frequent calibration requirements throughout the product's lifecycle not only increase maintenance costs and workload but may also cause equipment downtime, affecting the continuity of use and ease of operation, thus placing a significant burden on the maintenance of practical engineering applications.
[0004] Therefore, improving the long-term stability of flexible accelerometers and reducing their dependence on periodic calibration has become one of the key issues that urgently need to be addressed in the field of inertial navigation. Summary of the Invention
[0005] In view of this, the present invention provides an accelerometer zero bias change compensation method and apparatus, which aims to improve the long-term stability of flexible accelerometers and reduce their dependence on periodic calibration.
[0006] The first aspect of this invention provides a method for compensating for zero bias variation in an accelerometer, comprising the following steps: Get the cumulative working time; Based on the cumulative working time, the zero bias change is predicted using a preset square root function model; The accelerometer output value is compensated in real time based on the predicted zero bias change. The square root function model takes the following form: ; in, This represents the change in zero bias of the accelerometer, in units of... , This represents the cumulative working time in days, and a and b are the fitting parameters.
[0007] Optionally, obtaining the preset square root function model includes: S1. Perform multiple zero-bias tests on the accelerometer under consistent test conditions within a preset time period. S2. Based on the results of multiple zero bias tests, calculate the deviation between the zero bias value of the accelerometer and the initial zero bias value in each test to obtain the zero bias change sequence. S3. Using time as the independent variable and the zero-bias change as the dependent variable, a square root function model is used for fitting to establish the functional relationship between the accelerometer's zero-bias change and time.
[0008] Optionally, the zero bias test described in S1 is performed using a four-point roll test method to obtain zero bias data of the accelerometer in various directions.
[0009] Optionally, the zero bias change mentioned in S2 is the difference between the zero bias value obtained in this test and the initial zero bias value, in units of... .
[0010] Optionally, the accelerometer output value can be compensated in real time based on the predicted zero bias change, including: Based on the current cumulative running time, the zero bias change is predicted by substituting it into a preset square root function model, and the predicted zero bias change is subtracted from the original output of the accelerometer to achieve dynamic compensation of the zero bias error.
[0011] Optionally, the method is applicable to accelerometer zero-bias error correction in inertial navigation systems, unmanned aerial vehicle navigation systems, vehicle navigation systems, or spacecraft attitude control systems.
[0012] A second aspect of the present invention provides an accelerometer zero bias change compensation device for performing the accelerometer zero bias change compensation method as described in any one of the first aspects.
[0013] A third aspect of the present invention provides a computer-readable storage medium storing one or more preset programs, which, when executed by a processor, implement the steps of the accelerometer zero bias change compensation method as described in any one aspect of the first aspect.
[0014] This invention provides a method and apparatus for compensating for zero-bias variation in accelerometers, aiming to improve the long-term stability of flexible accelerometers, reduce their dependence on periodic calibration, and decrease the calibration workload required throughout the product's service life. This method can predict the long-term drift characteristics of the device based on short-term test data, thereby effectively extending the calibration cycle and providing reliable technical support for practical engineering applications. Attached Figure Description
[0015] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments of the present invention will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0016] Figure 1 This is a schematic diagram illustrating the change in zero bias of an accelerometer over time according to an embodiment of the present invention; Figure 2 It is a comparison chart of short-term data prediction results and actual long-term test results using the method of this invention; Figure 3 This is a flowchart illustrating an embodiment of an accelerometer zero bias change compensation method according to the present invention. Detailed Implementation
[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0018] The features and illustrative embodiments of various aspects of the present invention will now be described in detail. Numerous specific details are set forth in the following detailed description to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention. The invention is by no means limited to any specific setups and methods set forth below, but covers any improvements, substitutions, and modifications to structures, methods, and devices without departing from the spirit of the invention. Well-known structures and techniques are not shown in the drawings and the following description to avoid unnecessarily obscuring the invention.
[0019] In the description of this invention, it should be noted that the directions or positional relationships indicated by terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing and simplifying the invention, and should not be construed as limiting the invention. Furthermore, the use of ordinal numbers (e.g., "first and second," etc.) is for distinguishing objects and is not limited to this order, and should not be construed as indicating or implying relative importance.
[0020] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly, encompassing both direct connection and indirect connection via an intermediate medium. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.
[0021] It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other, and the various embodiments can be referenced and cited in each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.
[0022] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.
[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0024] The features and illustrative embodiments of various aspects of the present invention will now be described in detail. Numerous specific details are set forth in the following detailed description in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention. The invention is by no means limited to any specific setups and methods set forth below, but covers any improvements, substitutions, and modifications to the methods without departing from the spirit of the invention. In the accompanying drawings and the following description, well-known techniques are not shown to avoid unnecessarily obscuring the invention.
[0025] It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other, and the various embodiments can be referenced and cited in each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.
[0026] Figure 1 This is a schematic diagram illustrating the change in zero bias of an accelerometer over time according to an embodiment of the present invention. Figure 2 It is a comparison chart of short-term data prediction results and actual long-term test results using the method of this invention. Figure 3 This is a flowchart illustrating an embodiment of the accelerometer zero bias change compensation method of the present invention.
[0027] like Figure 3 As shown, the present invention provides a method for compensating for zero bias variation in an accelerometer, comprising the following steps: 1) Within one to two months, the accelerometer shall be subjected to no less than six zero-bias tests. Each test shall be conducted under environmental and operating conditions that are as close as possible to minimize the error introduced by external interference. 2) Based on the multiple zero-bias test data obtained in step 1), calculate the deviation between each zero-bias value and the initial zero-bias value to obtain the zero-bias change sequence; 3) Using time as the independent variable and the zero-bias change as the dependent variable, based on the data sequence obtained in step 2), fit the model using the square root function to establish the functional relationship between the accelerometer zero-bias change and time. 4) The zero-bias change-time function relationship fitted in step 3) is written into the navigation system as a compensation model. In actual operation, the accelerometer output value is automatically compensated for zero bias based on the cumulative working time, thereby improving the long-term accuracy and stability of the navigation system.
[0028] Furthermore, in step 1), the accelerometer is subjected to at least six zero-bias tests using a four-point roll test over a period of one to two months, and the zero-bias of the accelerometer is calculated. K 0i .
[0029] Furthermore, step 2) specifically involves: Based on the zero bias of the accelerometer obtained in step 1), calculate the change in zero bias of the accelerometer during the i-th test. The zero-biased change sequence is obtained. .
[0030] Furthermore, in step 3), the time change sequence is as follows:
[0031] Using the time-varying series as the independent variable and the zero-biased series as the dependent variable, a regression analysis was performed using the square root function as the model:
[0032] in, Let be the zero bias change of the accelerometer, and a and b be the parameters to be fitted. This represents the change over time.
[0033] Further, step 4) specifically involves: Based on the zero bias change-time function relationship of the accelerometer obtained in step 3), predict the zero bias change of the accelerometer after t days, and compensate for the zero bias of the accelerometer based on this change, as shown in the following formula:
[0034] In the formula This is the predicted zero bias value of the accelerometer after day t.
[0035] Further, step 5) specifically involves: The functional relationship obtained by fitting in step 4) is used as a compensation model and embedded into the navigation system. During the operation of the system, the zero bias change is automatically predicted based on the cumulative working time, and the output value of the accelerometer is compensated in real time, thereby improving the long-term accuracy and stability of the navigation system.
[0036] This invention provides a method for compensating for zero bias variation in accelerometers, which can be used in accelerometers capable of zero bias compensation. The method may include the following steps: S101: Within one to two months, under the same temperature conditions, measure the zero bias of the photoelectric accelerometer using the four-point flipping method, with no fewer than six tests performed. ; S102: Calculation of accelerometer Change over time : ; in, i The value of is a positive integer from 1 to N.
[0037] Table 1 Accelerometer Zero-Bias Test Data
[0038] S103: Using the time-varying sequence as the independent variable and the zero-partial variation sequence as the dependent variable, the relationship between the time variation and the zero-partial variation is fitted using the square root function as the model, and the parameters a=3.265 and b=0.253 are obtained.
[0039] S104: Based on the fitting results, calculate the accelerometer zero bias as... ,
[0040] in Initially zero bias, Due to changes over time, This is the zero bias after compensation.
[0041] S105: The fitted functional relationship is embedded into the navigation system as a compensation model. During system operation, the zero bias change is automatically predicted based on the cumulative working time, and the output value of the accelerometer is compensated in real time, thereby improving the long-term accuracy and stability of the navigation system.
[0042] The above-described embodiments of the invention can compensate for the zero bias of the accelerometer throughout its entire lifespan. This ensures that the zero bias of the accelerometer remains relatively small during use, reducing accuracy loss in inertial navigation systems.
[0043] The above detailed embodiments are a description of the present invention. It should not be considered that the specific embodiments of the present invention are limited to these descriptions. For those skilled in the art, several simple deductions and substitutions can be made without departing from the concept of the present invention, and all of these should be considered to fall within the protection scope of the present invention.
Claims
1. A method for compensating for zero bias variation in an accelerometer, characterized in that, Includes the following steps: Get the cumulative working time; Based on the cumulative working time, the zero bias change is predicted using a preset square root function model; The accelerometer output value is compensated in real time based on the predicted zero bias change. The square root function model takes the following form: ； in, This represents the change in zero bias of the accelerometer, in units of... , This represents the cumulative working time in days, and a and b are the fitting parameters.
2. The accelerometer zero bias compensation method according to claim 1, characterized in that, Obtaining the preset square root function model includes: S1. Perform multiple zero-bias tests on the accelerometer under consistent test conditions within a preset time period. S2. Based on the results of multiple zero bias tests, calculate the deviation between the zero bias value of the accelerometer and the initial zero bias value in each test to obtain the zero bias change sequence. S3. Using time as the independent variable and the zero-bias change as the dependent variable, a square root function model is used for fitting to establish the functional relationship between the accelerometer's zero-bias change and time.
3. The accelerometer zero bias change compensation method according to claim 2, characterized in that, The zero-bias test described in S1 is conducted using a four-point roll test method to obtain zero-bias data of the accelerometer in various directions.
4. The accelerometer zero bias compensation method according to claim 2, characterized in that, The zero bias change mentioned in S2 is the difference between the zero bias value obtained in this test and the initial zero bias value, in units of... .
5. The accelerometer zero bias change compensation method according to claim 2, characterized in that, The accelerometer output value is compensated in real time based on the predicted change in zero bias, including: Based on the current cumulative running time, the zero bias change is predicted by substituting it into a preset square root function model, and the predicted zero bias change is subtracted from the original output of the accelerometer to achieve dynamic compensation of the zero bias error.
6. The accelerometer zero bias change compensation method according to claim 2, characterized in that, The method is applicable to accelerometer zero bias error correction in inertial navigation systems, UAV navigation systems, vehicle navigation systems, or spacecraft attitude control systems.
7. An accelerometer zero bias change compensation device, characterized in that, Used to perform the accelerometer zero bias change compensation method as described in any one of claims 1-6.
8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores one or more preset programs, which, when executed by a processor, implement the steps of the accelerometer zero bias change compensation method as described in any one of claims 1-6.