Error correction method of three-axis inertial sensor

Abstract

The invention provides an error correction method of a three-axis inertial sensor, and relates to the technical field of inertial navigation control, and the error correction method of the three-axis inertial sensor comprises the following steps: determining a non-orthogonal error source of the three-axis inertial sensor; constructing a comprehensive error model according to a non-orthogonal error source; measuring the actual output value of the three-axis inertial sensor; calculating a compensation parameter according to the actual output value and the comprehensive error model; and correcting the actual output value according to the compensation parameter. The comprehensive error model is constructed according to the non-orthogonal error source, and the compensation parameter is calculated according to the comprehensive error model to correct the actual output value, so that the measurement deviation can be effectively reduced, and the measurement accuracy of the sensor is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of inertial navigation control, and in particular to an error correction method for a three-axis inertial sensor. Background Art

[0002] At present, inertial sensors are mainly single-axis, but with the expansion of application fields, the demand for three-axis inertial sensors in the market is becoming increasingly strong. Due to the limitations of processing technology and factors such as the sensor's own parameters, three-axis inertial sensors have measurement errors during the measurement process due to factors such as incomplete orthogonality of sensitive axes and inconsistent sensitivity. These errors will greatly reduce the measurement accuracy of the sensor and limit its application range.

[0003] Therefore, how to propose a method to compensate for the errors of three-axis inertial sensors to avoid measurement errors caused by factors such as incomplete orthogonality of sensitive axes and inconsistent sensitivity has become a technical problem that needs to be solved urgently. Summary of the invention

[0004] In view of this, the present invention aims to solve the problem of measurement error of a three-axis inertial sensor caused by factors such as incomplete orthogonality of sensitive axes and inconsistent sensitivity.

[0005] Specifically, the present invention is achieved through the following technical solutions:

[0006] According to a first aspect of the present invention, a method for correcting an error of a three-axis inertial sensor is provided, which is used for the three-axis inertial sensor. The method for correcting the error of the three-axis inertial sensor comprises: determining a non-orthogonal error source of the three-axis inertial sensor; constructing a comprehensive error model according to the non-orthogonal error source; measuring an actual output value of the three-axis inertial sensor; calculating a compensation parameter according to the actual output value and the comprehensive error model; and correcting the actual output value according to the compensation parameter.

[0007] Optionally, in some technical schemes, the step of constructing a comprehensive error model based on the non-orthogonal error sources includes: obtaining the zero-position output voltage of the three-axis inertial sensor; applying a known standard input signal to the three-axis inertial sensor and calculating a scale factor matrix; determining the three-axis non-orthogonal error of the three-axis inertial sensor; and constructing a comprehensive error model based on the zero-position output voltage, the scale factor matrix and the three-axis non-orthogonal error.

[0008] Optionally, in some technical solutions, the step of obtaining the zero-position output voltage of the three-axis inertial sensor includes: determining that the three-axis inertial sensor has no external input signal; recording multiple voltage output values ​​on each axis of the three-axis inertial sensor within a preset time; respectively calculating the average value of the multiple voltage output values ​​on each axis, and recording the average value on each axis as the zero-position output voltage.

[0009] Optionally, in some technical solutions, the steps of applying a known standard input signal to the three-axis inertial sensor and calculating a scale factor matrix include: applying a known standard input signal to the three-axis inertial sensor; determining a standard output value of each axis according to the standard input signal; measuring the measurement value of each axis in the three-axis inertial sensor; calculating a voltage proportional coefficient of each axis in the three-axis inertial sensor according to the standard output value and the measurement value; and constructing a scale factor matrix according to the voltage proportional coefficient.

[0010] Optionally, in some technical solutions, the relationship between the standard output value and the measured value is expressed as:

[0011]

[0012] Among them, β x , β y , β z They represent the standard output values ​​of the X-axis, Y-axis, and Z-axis respectively, K represents the scale factor matrix, and U x , U y , U z Respectively represent the measurement values ​​of the X-axis, Y-axis, and Z-axis, k s , k y , k z Represents the voltage proportionality coefficients of the standard output values ​​and measured values ​​of the X-axis, Y-axis, and Z-axis respectively.

[0013] Optionally, in some technical schemes, the steps of determining the three-axis non-orthogonal error of the three-axis inertial sensor include: establishing an ideal orthogonal coordinate system; performing Euler rotation on the ideal orthogonal coordinate system to obtain a virtual orthogonal coordinate system; determining the transformation relationship between the ideal orthogonal coordinate system and the virtual orthogonal coordinate system; calculating the three-axis non-orthogonal error based on the rotation angle and transformation relationship of the Euler rotation; wherein the ideal orthogonal coordinate system includes an X-axis, a Y-axis and a Z-axis.

[0014] Optionally, in some technical solutions, the comprehensive error model is expressed as:

[0015]

[0016] Among them, R represents the transformation relationship between the ideal orthogonal coordinate system and the virtual orthogonal coordinate system, β x , β y , β z Respectively represent the standard output values ​​of the X-axis, Y-axis, and Z-axis, k x , k y , k z Respectively represents the voltage proportional coefficient of the standard output value and the measured value of the X-axis, Y-axis, and Z-axis, U x ′、U y ′、U z ′ represents the true value of the X-axis, Y-axis, and Z-axis respectively, Ux0 , U y0 , U z0 Respectively represent the zero position output voltage of the X-axis, Y-axis, and Z-axis.

[0017] Optionally, in some technical solutions, the three-axis inertial sensor includes an accelerometer, a gyroscope, a magnetometer and an inertial device.

[0018] The technical solution provided by the present invention brings at least the following beneficial effects:

[0019] The present invention provides an error correction method for a three-axis inertial sensor. A comprehensive error model is constructed according to non-orthogonal error sources, and compensation parameters are calculated according to the comprehensive error model to correct the actual output value, which can effectively reduce the measurement deviation, thereby improving the measurement accuracy of the sensor. At the same time, by analyzing and compensating the measurement deviation of the three-axis inertial sensor, the problem of insufficient compensation caused by only considering a single error factor and ignoring other factors is avoided. In addition, by calculating the compensation parameters according to the actual output value and the comprehensive error model, the output of the three-axis inertial sensor can be corrected in real time, which can ensure that in various complex practical application scenarios, the three-axis inertial sensor can provide relatively accurate measurement data, thereby increasing the reliability of the three-axis inertial sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or related technical descriptions are briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0022] Figure 1 A schematic flow chart of an error correction method for a three-axis inertial sensor provided by an embodiment of the present invention;

[0023] Figure 2 A schematic diagram of a process for constructing a comprehensive error model provided by an embodiment of the present invention;

[0024] Figure 3 A schematic diagram of a process for obtaining the zero-position output voltage of a three-axis inertial sensor provided in an embodiment of the present invention;

[0025] Figure 4 A schematic diagram of a process for determining a scale factor matrix of a three-axis inertial sensor provided by an embodiment of the present invention;

[0026] Figure 5 A schematic diagram of a process for determining a non-orthogonal error of a three-axis inertial sensor provided by an embodiment of the present invention;

[0027] Figure 6 One of the schematic diagrams of coordinate transformation of an orthogonal coordinate system provided by an embodiment of the present invention;

[0028] Figure 7 A second schematic diagram of coordinate transformation of an orthogonal coordinate system provided by an embodiment of the present invention;

[0029] Figure 8 The third schematic diagram of coordinate transformation of an orthogonal coordinate system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] like Figure 1 As shown, an error correction method for a three-axis inertial sensor applicable to an embodiment of the present invention includes:

[0032] S101: Determine the source of non-orthogonal error of the three-axis inertial sensor;

[0033] S102: construct a comprehensive error model based on non-orthogonal error sources;

[0034] S103: measuring the actual output value of the three-axis inertial sensor;

[0035] S104: Calculating compensation parameters according to the actual output value and the comprehensive error model;

[0036] S105: Correcting the actual output value according to the compensation parameter.

[0037] According to the error correction method of the three-axis inertial sensor provided by the present invention, it is used for the three-axis inertial sensor, and the error correction method of the three-axis inertial sensor includes: determining the non-orthogonal error source of the three-axis inertial sensor; constructing a comprehensive error model according to the non-orthogonal error source; measuring the actual output value of the three-axis inertial sensor; calculating the compensation parameter according to the actual output value and the comprehensive error model; correcting the actual output value according to the compensation parameter. That is to say, constructing a comprehensive error model according to the non-orthogonal error source, and calculating the compensation parameter according to the comprehensive error model to correct the actual output value can effectively reduce the measurement deviation, thereby improving the measurement accuracy of the sensor. At the same time, by analyzing and compensating the measurement deviation of the three-axis inertial sensor, the problem of insufficient compensation caused by only considering a single error factor and ignoring other factors is avoided. In addition, by calculating the compensation parameter according to the actual output value and the comprehensive error model, the output of the three-axis inertial sensor can be corrected in real time, which can ensure that the three-axis inertial sensor can provide relatively accurate measurement data in various complex practical application scenarios, thereby increasing the reliability of the three-axis inertial sensor.

[0038] Optionally, in some embodiments, Figure 2 As shown in FIG. 1 , the steps of constructing a comprehensive error model based on non-orthogonal error sources include:

[0039] S201: Obtain the zero position output voltage of the three-axis inertial sensor;

[0040] S202: applying a known standard input signal to the three-axis inertial sensor and calculating a scaling factor matrix;

[0041] S203: Determine three-axis non-orthogonal errors of the three-axis inertial sensor;

[0042] S204: Constructing a comprehensive error model according to the zero-position output voltage, the scale factor matrix and the three-axis non-orthogonal errors.

[0043] In this embodiment, a comprehensive error model is constructed by combining the zero-position output voltage, the scale factor matrix and the three-axis non-orthogonal error, which can effectively reduce the measurement deviation, thereby improving the measurement accuracy of the sensor. It is understandable that due to the limitations of the manufacturing process, even when there is no external input (i.e., the ideal output should be zero in theory), the three-axis inertial sensor will have a smaller output value, and this output value is the zero-point voltage. In actual measurement, the output of the sensor not only includes the ideal output voltage, but also the zero-point voltage. This is because the sensor cannot completely eliminate the influence of the zero-point voltage, and the zero-point voltage always exists and is superimposed on the ideal output voltage. So the voltage actually measured is the sum of the zero-point voltage and the ideal output voltage.

[0044] Optionally, in some embodiments, Figure 3As shown, the steps of obtaining the zero position output voltage of the three-axis inertial sensor include:

[0045] S301: Determine that the three-axis inertial sensor has no external input signal;

[0046] S302: Record multiple voltage output values ​​of each axis of the three-axis inertial sensor within a preset time;

[0047] S303: Calculate the average value of multiple voltage output values ​​on each axis respectively, and record the average value on each axis as the zero-position output voltage.

[0048] In this embodiment, when there is no external input signal to the three-axis inertial sensor, multiple voltage output values ​​on each axis within a preset time are recorded, that is, multiple measurements are performed within a period of time. Since the voltage output fluctuation caused by factors such as internal noise of the three-axis inertial sensor is random, the noise of electronic components (including sensitive axes) can cause the voltage output to change randomly within a certain range. By averaging multiple voltage output values, these random fluctuations can be offset, thereby more accurately obtaining the zero-position output voltage of each axis. At the same time, the zero-position output voltage of each axis is calculated separately, and independent zero-position calibration can be performed for each axis of the three-axis inertial sensor, and then personalized zero-position compensation parameters are provided for each corresponding axis according to the zero-position output voltage of each axis, thereby more effectively eliminating the zero-position error on each axis and improving the measurement accuracy of the entire sensor.

[0049] Optionally, in some embodiments, Figure 4 As shown in FIG. 1 , the steps of applying a known standard input signal to the three-axis inertial sensor and calculating the scale factor matrix include:

[0050] S401: applying a known standard input signal to the three-axis inertial sensor;

[0051] S402: Determine a standard output value of each axis according to a standard input signal;

[0052] S403: measuring the measurement value of each axis of the three-axis inertial sensor;

[0053] S404: Calculate the voltage proportional coefficient of each axis in the three-axis inertial sensor according to the standard output value and the measured value;

[0054] S405: Construct a scaling factor matrix according to the voltage proportional coefficient.

[0055] In this embodiment, a known standard input signal is first applied to the three-axis inertial sensor, and the standard output value of each axis is determined according to the standard input signal, so that the standard size of the real physical quantity corresponding to each axis can be clarified. Then, when the standard input signal is applied, the measured value of each axis of the three-axis inertial sensor is measured, and the difference between the actual output and the theoretical output of the sensor can be found by comparing the standard output value and the measured value. That is to say, the conversion efficiency or sensitivity of the sensitive element of each axis is different when converting the physical quantity into an electrical signal. The voltage proportional coefficient is introduced to describe this difference, thereby compensating for the error caused by the personalized difference of the sensitive element. When the standard angular velocity is applied, the actual voltage output of the three axes is measured, and the voltage proportional coefficient of each axis is calculated according to the standard output value and the measured value. The voltage proportional coefficient can accurately quantify the proportional relationship between the voltage measurement value and the standard output value on each axis. Finally, a scale factor matrix is ​​constructed according to the voltage proportional coefficient, which can comprehensively describe the proportional relationship between the three axes of the three-axis inertial sensor in the form of a matrix, thereby effectively calibrating the three-axis inertial sensor, thereby improving the measurement accuracy and reliability of the entire sensor.

[0056] Optionally, in some embodiments, the relationship between the standard output value and the measured value is expressed as:

[0057]

[0058] Among them, β x , β y , β z They represent the standard output values ​​of the X-axis, Y-axis, and Z-axis respectively, K represents the scale factor matrix, and U x , U y , U z Respectively represent the measurement values ​​of the X-axis, Y-axis, and Z-axis, k x , k y , k z Represents the voltage proportionality coefficients of the standard output values ​​and measured values ​​of the X-axis, Y-axis, and Z-axis respectively.

[0059] In this embodiment, the relationship between the standard output value and the measured value is represented in matrix form, which can provide a systematic and comprehensive perspective to describe the behavior of the three-axis inertial sensor. At the same time, it is more convenient and efficient to deal with the relationship between the standard output value and the measured value. The output of the three-axis inertial sensor under different input combinations can be simulated by matrix multiplication, and the compensation parameters can be solved by operations such as matrix inversion, so as to effectively calibrate the three-axis inertial sensor, thereby improving the measurement accuracy and reliability of the entire sensor.

[0060] Optionally, in some embodiments, Figure 5As shown, the steps of determining the three-axis non-orthogonality error of the three-axis inertial sensor include:

[0061] S501: Establishing an ideal orthogonal coordinate system;

[0062] S502: Performing Euler rotation on the ideal orthogonal coordinate system to obtain a virtual orthogonal coordinate system;

[0063] S503: Determine the conversion relationship between the ideal orthogonal coordinate system and the virtual orthogonal coordinate system;

[0064] S504: Calculate the three-axis non-orthogonality error according to the rotation angle and the transformation relationship of the Euler rotation.

[0065] In this embodiment, an ideal orthogonal coordinate system is established, and the ideal orthogonal coordinate system includes an X-axis, a Y-axis, and a Z-axis, which are perpendicular to each other. The ideal orthogonal coordinate system is subjected to Euler rotation to obtain a virtual orthogonal coordinate system, which simulates the change in the direction of the coordinate axis that may occur in actual situations. Due to manufacturing processes, installation errors, or external factors (such as vibration, collision), the actual coordinate axis of the sensor may undergo a slight rotation, forming a virtual orthogonal coordinate system that deviates from the ideal orthogonal coordinate system. That is, by generating a virtual orthogonal coordinate system through the mathematical means of Euler rotation, the deviation can be systematically studied, and the non-orthogonal error data can be calculated according to the rotation angle and conversion relationship of the Euler rotation, and the abstract coordinate axis non-orthogonality problem can be converted into specific and quantifiable data. The rotation angle and conversion relationship can accurately calculate the error size caused by non-orthogonality between each axis, and then calculate the non-orthogonal error data of the three-axis inertial sensor to correct the three-axis inertial sensor and avoid the deviation caused by the attitude perception error.

[0066] Optionally, in some embodiments, the comprehensive error model is expressed as:

[0067]

[0068] Among them, R represents the transformation relationship between the ideal orthogonal coordinate system and the virtual orthogonal coordinate system, β x , β y , β z Respectively represent the standard output values ​​of the X-axis, Y-axis, and Z-axis, k x , k y , k z Respectively represents the voltage proportional coefficient of the standard output value and the measured value of the X-axis, Y-axis, and Z-axis, U x ′、U y ′、U z ′ represents the true value of the X-axis, Y-axis, and Z-axis respectively, U x0 , U y0 , U z0Respectively represent the zero position output voltage of the X-axis, Y-axis, and Z-axis.

[0069] In this embodiment, the comprehensive error model includes the zero-position output voltage, the scale factor matrix and the non-orthogonal error data, which can comprehensively consider various factors affecting the accuracy of the three-axis inertial sensor. Among them, the zero-position output voltage reflects the self-offset of the three-axis inertial sensor when there is no input, the scale factor matrix involves the proportional relationship between the input signal and the output voltage, and the non-orthogonal error data reflects the error caused by the sensitive axis in the non-ideal orthogonal state. This application is based on the comprehensive error model and can provide an accurate basis for subsequent error compensation.

[0070] Optionally, in some embodiments, the three-axis inertial sensor includes an accelerometer, a gyroscope, a magnetometer, and an inertial device.

[0071] In this embodiment, the three-axis inertial sensor includes an accelerometer, a gyroscope, a magnetometer and an inertial device. The accelerometer can measure the acceleration of an object in three axes, and the accelerometer can detect the acceleration change of an object. The gyroscope is used to measure the angular velocity of an object. The magnetometer is used to measure the magnetic field strength. The inertial device usually combines the acceleration and angular velocity measurement functions. At the same time, the accelerometer, gyroscope, magnetometer and inertial device can work together to achieve more accurate positioning and attitude solution.

[0072] In a specific application, the measurement error of the three-axis inertial sensor can be divided into zero position error, scale factor error and three-axis non-orthogonality error.

[0073] Ideally, the output value of the three-axis inertial sensor is the actual value. Therefore, when there is no input, the ideal output should be zero. However, due to the limitations of the manufacturing process, when there is no input, the three-axis inertial sensor also has a small output value. This error is called zero error. Assume that the three axes of the actual three-axis inertial sensor have a stable zero point output voltage U0 = [U s0 ,U y0 ,U z0 ] T , the actual measured output voltage U m =[U x ′,U y ′,U z ′] T , then the model of zero error can be expressed as:

[0074]

[0075] Among them, U=[U x ,U y ,U z ] Tis the output voltage of the ideal three-axis inertial sensor. The symbol T represents transposition. After transposition, the shape of the vector is changed from row form to column form.

[0076] Assume that the voltage ratios of the standard output values ​​of the three axes and the actual output voltage of the three-axis inertial sensor are k x , k y , k z , then the relationship between the three-axis standard output values ​​and the ideal three-axis inertial sensor output can be expressed as:

[0077]

[0078] Among them, β x , β y , β z is the standard output value of each axis, and K is the scale factor matrix.

[0079] Single-axis inertial sensors can measure input in the direction of the sensitive axis. The internal structure of a three-axis inertial sensor is generally orthogonal to each other, that is, the directions of the three single-axis measurement units (sensitive axes) in an ideal three-axis inertial sensor should be orthogonal to each other. However, due to the limitations of the processing technology, the sensitive axes of the actual three-axis inertial sensor are not completely orthogonal and must be compensated.

[0080] like Figure 6 As shown, O-XYZ is an ideal three-axis orthogonal coordinate system. The ideal orthogonal coordinate system O-XYZ is rotated around the OZ axis by an angle φ xx Get the coordinate system OX x 'Y x ′Z x ',like Figure 7 As shown, the coordinate system OX x 'Y x ′Z x 'Go around OY x ′ axis rotation angle φ xy Get the coordinate system OX x ″Y x ″Z x ",like Figure 8 As shown, the coordinate system OX x ″Y x ″Z x ″Go around OZ again x ″Axis rotation angle φ xz Get the coordinate system OX x ″′Y x ″′Z x ″′, and finally obtain a virtual orthogonal coordinate system OX x ″′Y x ″′Z x ″′, where Xx The ″′ axis constitutes the X axis of the actual three-axis inertial sensor coordinate system.

[0081] The rotation matrix is ​​obtained by performing Euler rotation on the ideal orthogonal coordinate system Rotation Matrix It is expressed as:

[0082]

[0083] The rotation matrix is ​​obtained by performing Euler rotation on the ideal orthogonal coordinate system Rotation Matrix It is expressed as:

[0084]

[0085] The rotation matrix is ​​obtained by performing Euler rotation on the ideal orthogonal coordinate system Rotation Matrix It is expressed as:

[0086]

[0087] After three rotations, the transformation relationship between the ideal three-axis orthogonal coordinate system and the virtual orthogonal coordinate system is:

[0088]

[0089] Transformation Matrix It is expressed as:

[0090]

[0091] Extract the X of the virtual orthogonal coordinate system x The ″′ axis serves as the X axis of the actual three-axis inertial sensor measurement coordinate system.

[0092] Similarly, the ideal orthogonal coordinate system O-XYZ is rotated around the OZ axis by an angle φ yx Get the coordinate system OX y 'Y y ′Z y ′, then go around OY y ′ axis rotation angle φ yy Get the coordinate system OX y ″Y y ″Z y ″, then go around OZ y ″Axis rotation angle φ yz Get the coordinate system OX y ″′Y y ″′Z y ″′, the final virtual orthogonal coordinate system OX y ″′Y y ″′Zy ″′, extract Y y The ″′ axis is used as the Y axis of the actual three-axis inertial sensor measurement coordinate system. The ideal orthogonal coordinate system O-XYZ is rotated around the OZ axis by an angle φ zx Get the coordinate system OX z 'Y z ′Z z ′, then go around OY z ′ axis rotation angle φ zy Get the coordinate system OX z ″Y z ″Z z ″, then go around OZ z ″Axis rotation angle φ zz Get the coordinate system OX z ″′Y z ″′Z z ″′, the final virtual orthogonal coordinate system OX z ″′Y z ″′Z z ″′, extract Z z The ″′ axis serves as the Z axis of the actual three-axis inertial sensor measurement coordinate system.

[0093] In summary, the ideal orthogonal coordinate system O-XYZ undergoes three independent groups of three Euler rotations to obtain three virtual orthogonal measurement coordinate systems. The real axes in the virtual orthogonal coordinate systems are extracted to form the measurement coordinate system of the actual three-axis inertial sensor. Through the coordinate transformation relationship, the relationship between the measurement value of the three-axis inertial sensor and the standard output values ​​of the three axes can be expressed as:

[0094]

[0095] The transformation matrix R is:

[0096]

[0097] Among them, β x0 , β y0 , β z0 is the measurement value of the three-axis inertial sensor.

[0098] By analyzing the zero position error, scale factor error and three-axis non-orthogonality error of the three-axis inertial sensor, the error model of the three-axis inertial sensor can be obtained:

[0099]

[0100] The relationship between the standard output value of each axis and the output of the three-axis inertial sensor:

[0101]

[0102] It can be seen that as long as R -1 , K and U0, that is, the conversion matrix, scale factor matrix and the stable zero-point output voltage of the three axes can be obtained to correct the measurement error of the three-axis inertial sensor. After the error model is established, the output value and actual value of the three-axis inertial sensor can be measured by a high-precision calibration platform, and the compensation parameters can be determined in combination with the error model to compensate for the error of the three-axis inertial sensor.

[0103] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0104] The above is only a specific embodiment of the present invention, so that those skilled in the art can understand or implement the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but should conform to the widest scope consistent with the principles and novel features applied herein.

Claims

1. A method for error correction of a three-axis inertial sensor, characterized in that: For a three-axis inertial sensor, the error correction method of the three-axis inertial sensor includes: Determining sources of non-orthogonal errors of the three-axis inertial sensor; constructing a comprehensive error model based on the non-orthogonal error sources; Measuring the actual output value of the three-axis inertial sensor; Calculating compensation parameters according to the actual output value and the comprehensive error model; The actual output value is corrected according to the compensation parameter.

2. The error correction method of the three-axis inertial sensor according to claim 1, characterized in that: The step of constructing a comprehensive error model according to the non-orthogonal error sources comprises: Obtaining the zero position output voltage of the three-axis inertial sensor; Applying a known standard input signal to the three-axis inertial sensor and calculating a scaling factor matrix; Determining a three-axis non-orthogonality error of the three-axis inertial sensor; The comprehensive error model is constructed according to the zero-position output voltage, the scale factor matrix and the three-axis non-orthogonality errors.

3. The error correction method of the three-axis inertial sensor according to claim 2, characterized in that: The step of obtaining the zero position output voltage of the three-axis inertial sensor comprises: Determining that the three-axis inertial sensor has no external input signal; Recording a plurality of voltage output values ​​on each axis of the three-axis inertial sensor within a preset time; The average value of the multiple voltage output values ​​on each axis is calculated respectively, and the average value on each axis is recorded as the zero-position output voltage.

4. The error correction method of the three-axis inertial sensor according to claim 2, characterized in that: The step of applying a known standard input signal to the three-axis inertial sensor and calculating a scaling factor matrix comprises: Applying the known standard input signal to the three-axis inertial sensor; Determine a standard output value for each axis according to the standard input signal; Measuring the measurement value of each axial direction of the three-axis inertial sensor; Calculating a voltage proportionality coefficient of each axis in the three-axis inertial sensor according to the standard output value and the measured value; The scaling factor matrix is ​​constructed based on the voltage proportionality coefficients.

5. The error correction method of the three-axis inertial sensor according to claim 4, characterized in that: The relationship between the standard output value and the measured value is expressed as: Among them, β x , β y , β z They represent the standard output values ​​of the X-axis, Y-axis, and Z-axis respectively, K represents the scale factor matrix, and U x , U y , U z Respectively represent the measurement values ​​of the X-axis, Y-axis, and Z-axis, k x , k y , k z Represents the voltage proportionality coefficients of the standard output values ​​and measured values ​​of the X-axis, Y-axis, and Z-axis respectively.

6. The error correction method of the three-axis inertial sensor according to claim 2, characterized in that: The step of determining the three-axis non-orthogonal error of the three-axis inertial sensor comprises: Establish an ideal orthogonal coordinate system; Performing Euler rotation on the ideal orthogonal coordinate system to obtain a virtual orthogonal coordinate system; Determining a transformation relationship between the ideal orthogonal coordinate system and the virtual orthogonal coordinate system; Calculating the three-axis non-orthogonality error according to the rotation angle of the Euler rotation and the conversion relationship; The ideal orthogonal coordinate system includes an X-axis, a Y-axis and a Z-axis.

7. The error correction method of the three-axis inertial sensor according to claim 6, characterized in that: The comprehensive error model is expressed as: Among them, R represents the transformation relationship between the ideal orthogonal coordinate system and the virtual orthogonal coordinate system, β x , β y , β z Respectively represent the standard output values ​​of the X-axis, Y-axis, and Z-axis, k x , k y , k z Respectively represents the voltage proportional coefficient of the standard output value and the measured value of the X-axis, Y-axis, and Z-axis, U x ′、U y ′、U z ′ represents the true value of the X-axis, Y-axis, and Z-axis respectively, U x0 , U y0 , U z0 Respectively represent the zero position output voltage of the X-axis, Y-axis, and Z-axis.

8. The error correction method for a three-axis inertial sensor according to any one of claims 1 to 7, characterized in that: The three-axis inertial sensor includes an accelerometer, a gyroscope, a magnetometer and an inertial device.

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