Angle calibration solution method and system of an inclination sensor

Abstract

The application relates to an angle calibration solution method and system of a tilt sensor. Compared with the prior art, the method comprises the following steps: 1) collecting three-axis original acceleration data output by a three-axis accelerometer and performing filtering processing; 2) adopting a six-position calibration method to perform calibration; and 3) adopting a segmented combination angle solution method to calculate the included angle between the X axis and the Y axis of the tilt sensor relative to a horizontal plane. The application has the advantages of high accuracy and high precision in full-range measurement, smooth angle output, high calibration efficiency and the like.

Description

Technical Field

[0001] This invention relates to the field of tilt sensor angle calculation, and in particular to a tilt sensor angle calibration calculation method and system. Background Technology

[0002] Currently, in the field of tilt sensor angle calculation technology, the most commonly used calculation algorithms include single-axis sinusoidal dual-axis tilt angle calculation algorithms and triaxial tangent dual-axis tilt angle calculation algorithms. However, actual calculation verification has revealed that the accuracy of the single-axis sinusoidal dual-axis tilt angle calculation algorithm for dual-axis tilt sensors in the ±60°~±90° range is significantly worse than that in the 0°~±60° range. Furthermore, to ensure high accuracy, the single-axis sinusoidal dual-axis tilt angle calculation algorithm requires too many calibration points within the ±90° range, resulting in long calibration times. In addition, the triaxial tangent dual-axis tilt angle calculation algorithm is affected by Z-axis performance. If the Z-axis performance is poor, leading to poor long-term stability (drift due to aging), a significant decrease in measurement accuracy will occur after several years of use. Therefore, it is necessary to develop an angle calculation algorithm that maintains high accuracy across the entire ±90° range. Summary of the Invention

[0003] To address the technical problems in the background art, the present invention provides an angle calibration calculation method and system for tilt sensors, the method comprising the following steps:

[0004] 1) Acquire raw triaxial acceleration data output from the triaxial accelerometer and perform filtering processing;

[0005] 2) Calibration is performed using the six-position calibration method;

[0006] 3) The angle between the X-axis and Y-axis of the tilt sensor and the horizontal plane is calculated using a segmented combination angle calculation method.

[0007] Furthermore, step 2) specifically includes the following steps:

[0008] 21) Collect acceleration output data from the tilt sensor at six different locations;

[0009] 22) Construct an error model for tilt sensor calibration;

[0010] 23) Estimate the parameters in the error model using the least squares method and save them.

[0011] Furthermore, the error model for the tilt sensor calibration is specifically as follows:

[0012]

[0013]

[0014] In the formula, To output the acceleration data matrix, This is the coefficient matrix for sensitivity and cross axes. For the true acceleration matrix, The zero-point deviation matrix, These are the output data of the triaxial accelerometer along the X, Y, and Z axes, respectively. These represent the axis sensitivities of the triaxial accelerometer along the X, Y, and Z axes, respectively. These are the actual values ​​of the triaxial accelerometer on the X, Y, and Z axes, respectively. These represent the zero-point deviations of the triaxial accelerometer along the X, Y, and Z axes, respectively. , , , , , These represent the cross-axis errors.

[0015] Furthermore, step 3) specifically includes the following steps:

[0016] 31) Configure the algorithm segmentation angle nodes and segment the angle interval within the range;

[0017] 32) Configure different angle calculation algorithms for each type of angle interval;

[0018] 33) The final output angles of the tilt sensor's X and Y axes are calculated using the angle calculation algorithm corresponding to the angle interval where the initial angle is located.

[0019] Furthermore, in step 31), the range is divided into three types of angle intervals by the algorithm segmentation angle nodes: small angle interval, transition angle interval, and large angle interval.

[0020] Furthermore, in step 31), when the range of the tilt sensor is 0° to ±90°, the segmented angle nodes are configured as ±60° and ±70°.

[0021] Furthermore, in step 33), the initial angle is calculated using a single-axis sinusoidal dual-axis tilt angle calculation algorithm. Then we have:

[0022]

[0023] Where 'a' represents the output value of the triaxial accelerometer for the corresponding axis after six-position calibration. This is the intermediate acceleration value, and sensi is the default sensitivity of the triaxial accelerometer.

[0024] Furthermore, in step 33), when the initial angle... When the angle is within a small range, the final output angle is calculated using a single-axis sinusoidal dual-axis tilt angle calculation algorithm, resulting in:

[0025]

[0026]

[0027] When the initial angle When the angle is within a large range, the final output angle is calculated using a three-axis tangent biaxial tilt angle calculation algorithm, resulting in:

[0028]

[0029]

[0030] When the initial angle When the angle is within the transition angle range, the complementary filtering algorithm is used to calculate the final output angle, resulting in:

[0031]

[0032]

[0033]

[0034]

[0035] in, , These are the final output angles for the X and Y axes, respectively. , , These are the X-axis, Y-axis, and Z-axis output values ​​of the triaxial accelerometer after six-position calibration. , These are the adaptive weights corresponding to the X-axis and Y-axis, respectively. , These are the first and second algorithm segmented angle nodes for the X-axis, respectively. , These are the first and second algorithm segment angle nodes for the Y-axis, respectively.

[0036] Furthermore, the method also includes the following steps:

[0037] 4) Before the tilt sensor leaves the factory, the X-axis and Y-axis are calibrated to absolute zero.

[0038] An angle calibration and calculation system for a tilt sensor, the system comprising:

[0039] Acquisition and Filtering Module: Used to acquire the raw triaxial acceleration data output by the triaxial accelerometer and perform filtering processing;

[0040] Six-position calibration module: used to estimate error model parameters based on acceleration output data at six different positions to complete calibration;

[0041] The segmented angle calculation module is used to calculate the final output angles of the tilt sensor along the X and Y axes using angle calculation algorithms corresponding to each angle interval.

[0042] Compared with the prior art, the present invention has the following advantages:

[0043] This invention provides an angle calibration calculation method and system for tilt sensors. It creatively proposes an angle calculation method that leverages the strengths of both algorithms while mitigating their weaknesses. Specifically, it employs a single-axis sinusoidal dual-axis tilt angle calculation algorithm within the 0°~±60° angle range, a three-axis tangent dual-axis tilt angle calculation algorithm within the ±70°~±90° angle range, and a complementary filtering algorithm within the ±60°~±70° angle range. The transition from the single-axis sinusoidal dual-axis tilt angle calculation algorithm to the three-axis tangent dual-axis tilt angle calculation algorithm is gradual to smooth the switching transitions between the two algorithms at segmented angle nodes. Furthermore, combined with a six-position calibration method, the calibration time is significantly reduced. Compared to existing algorithms, the debugging-verification time for each tilt sensor product can be reduced by approximately 90%. At room temperature, the angle accuracy of ±80°~±90° within 1.5 years is improved from a maximum of ±10° to a maximum of ±1°. In high-temperature aging simulations over a ten-year lifespan, the maximum accuracy across the entire temperature range of ±75°~±85° is improved from 5.83° to 2.79°. Attached Figure Description

[0044] Figure 1 A flowchart illustrating the steps of an angle calibration calculation method for a tilt sensor provided by the present invention;

[0045] Figure 2 Here is a flowchart of the six-position calibration method.

[0046] Figure 3 This is a flowchart illustrating the steps of the segmented combination angle calculation method.

[0047] Figure 4 A flowchart illustrating the steps of the algorithm for calculating the single-axis sinusoidal biaxial tilt angle.

[0048] Figure 5 A flowchart illustrating the steps of the algorithm for calculating the three-axis tangent bi-axis tilt angle.

[0049] Figure 6A comparison of the angle deviation (range 0°~±85°) of the tilt sensor in the HTOL (High Temperature Operating Life Test) experiment on October 29, 2025 and December 15, 2025.

[0050] Figure 7 This is a comparison chart of the angle deviation (range 0°~±85°) of the tilt sensor in the HTOL (High Temperature Operating Life Test) experiment on December 15, 2025.

[0051] Figure 8 This is a comparison chart of angle deviations (range 0°~±60°) of the tilt sensor in the HTOL (High Temperature Operating Life Test) experiment on December 15, 2025.

[0052] Figure 9 This represents the probability of different deviation threshold requirements within three angle ranges during zero-finding.

[0053] Figure 10 This represents the probability of different deviation threshold requirements within three angle ranges without seeking zero.

[0054] Figure 11 The present invention provides a functional principle block diagram of an angle calibration and calculation system for an tilt sensor. Detailed Implementation

[0055] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0056] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0057] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the product of the invention is usually placed in during use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0058] The terms “first”, “second”, etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0059] In the description of this embodiment, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set up," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this embodiment based on the specific circumstances.

[0060] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0061] Example

[0062] like Figure 1 As shown, this invention provides an angle calibration calculation method for tilt sensors. Based on the triaxial accelerometer data of the tilt sensor, it organically combines the single-axis sinusoidal dual-axis tilt angle calculation algorithm and the triaxial tangent dual-axis tilt angle calculation algorithm, while also considering the smooth transition requirements at the junction of the two algorithms. This achieves high-accuracy angle measurement calculation of the X-axis of a single-axis tilt sensor or the X-axis and Y-axis of a dual-axis tilt sensor within a range of ±90°. Specifically, it includes the following steps:

[0063] 1) Collect the raw triaxial acceleration data output by the triaxial accelerometer of the tilt sensor, and perform filtering and zero-point temperature compensation processing on the raw acceleration data;

[0064] 2) The processed acceleration values ​​were calibrated using the six-position calibration method to obtain the cross-axis error of the triaxial accelerometer, the zero-point deviation of the accelerometer itself, and the axis sensitivity.

[0065] The six-position calibration method is a common method for calibrating inertial measurement units (IMUs). IMUs typically include accelerometers and gyroscopes to measure the acceleration and angular velocity of an object, respectively. In this invention, a triaxial accelerometer is used inside the dual-axis tilt sensor to measure the acceleration along the X, Y, and Z axes. After conversion, the angle of the plane to be detected is measured. However, during the manufacturing process, the triaxial accelerometers are soldered onto the PCB board, resulting in alignment errors. Furthermore, alignment errors also occur when the PCB board is installed inside the tilt sensor housing. Additionally, each triaxial accelerometer carries a zero-point deviation after manufacturing, namely, cross-axis error and its own zero-point deviation. Therefore, these errors need to be calibrated.

[0066] Furthermore, such as Figure 2 As shown, step 2) specifically includes the following steps:

[0067] 21) Place the tilt sensor at six different known stationary positions (generally the +X, -X, +Y, -Y, +Z, and -Z directions of the triaxial accelerometer), keep it stationary at each position for a period of time, and automatically record the acceleration output data of the corresponding axis at the ±1g position after stabilization, thus completing the acquisition of acceleration output data at the six positions.

[0068] 22) Construct an error model for tilt sensor calibration, and estimate the parameters in the error model using the least squares method. In this example, the error model for tilt sensor calibration is as follows:

[0069]

[0070] Right now:

[0071]

[0072] In the above formula, To output the acceleration data matrix, This is the coefficient matrix for sensitivity and cross axes. For the true acceleration matrix, The zero-point deviation matrix, These are the output data of the triaxial accelerometer along the X, Y, and Z axes, respectively. These represent the axis sensitivities of the triaxial accelerometer along the X, Y, and Z axes, respectively. These are the actual values ​​of the triaxial accelerometer on the X, Y, and Z axes, respectively. These represent the zero-point deviations of the triaxial accelerometer along the X, Y, and Z axes, respectively. , , , , , These represent the cross-axis errors.

[0073] 23) Based on the output data of the triaxial accelerometer at six positions, the least squares method is used to estimate the parameters in the error model. The axis sensitivity, cross axis error and zero point deviation of the triaxial accelerometer in the X, Y and Z axes are obtained respectively, and saved to the EEPROM of the tilt sensor. Generally speaking, the axis sensitivity values ​​of the triaxial accelerometer in the X, Y and Z axes are normally within the range of 1±5%. If they exceed the normal range, recalibration or replacement with a new triaxial accelerometer is required.

[0074] 3) such as Figure 3 As shown, the segmented combined angle calculation method is used to calculate the angle between the X-axis and Y-axis of the tilt sensor relative to the horizontal plane. The steps of the segmented combined angle calculation method are described in detail below.

[0075] 31) Configure the algorithm segmented angle nodes, and segment the angle interval according to the algorithm segmented angle nodes within the range of the tilt sensor;

[0076] Actual measurements have confirmed that the existing single-axis sinusoidal dual-axis tilt angle calculation algorithm has good detection accuracy and long-term stability within the range of 0° to ±60°. However, since the accelerometer measures the gravitational acceleration and the angle being measured as sinusoidal, the slope of the sinusoidal curve gradually approaches 0 within the range of ±60° to ±90°, resulting in a significant decrease in sensitivity. In contrast, the three-axis tangent dual-axis tilt angle calculation algorithm maintains constant sensitivity within the range of ±70° to ±90°, and has higher resolution and accuracy. Therefore, in a feasible embodiment, the segmented angle nodes of the algorithm are configured as ±60° and ±70°, respectively.

[0077] It is foreseeable that, within the measurement range of 0 to ±90°, the selection of ±60° and ±70° as the algorithm segmentation angle nodes in this invention is based on a comprehensive consideration of the accuracy and other indicators of the single-axis sinusoidal dual-axis tilt angle calculation algorithm and the triaxial tangent dual-axis tilt angle calculation algorithm within different angle ranges. Therefore, for the triaxial output data of triaxial accelerometers of different models and performance, the algorithm segmentation angle nodes can be adaptively adjusted, such as combinations of ±55° and ±75°, ±62° and ±73°, ±65° and ±75°, etc., as long as the measurement accuracy and sensitivity requirements can be met.

[0078] 32) Configure different angle calculation algorithms for each type of angle interval, and calculate the final output angles of the tilt sensor X-axis and Y-axis according to the angle calculation algorithm corresponding to the angle interval where the initial angle is located;

[0079] Taking a tilt sensor with an X / Y axis range of 0° to ±90°, and the algorithm's segmented angle nodes configured as ±60° and ±70° respectively, the X and Y axes are divided into three angle intervals within the 0° to 90° range (the -90° to 0° range is similar), namely [0°, 60°], [60°, 70°], and (70°, 90°]. Figure 4 As shown, the initial angle is first calculated using a single-axis sinusoidal dual-axis tilt angle calculation algorithm. 'a' represents the output value of the corresponding axis of the triaxial accelerometer after six-position calibration. Here, sensi represents the intermediate acceleration value, and sensi is the default sensitivity of the triaxial accelerometer, which is a fixed value. The final output angle is calculated by combining this value with the calculation algorithm corresponding to the angle range of the initial angle.

[0080] 2.1 For the small angle range of [0°, 60°), the final output angle is calculated using a single-axis sinusoidal dual-axis tilt angle calculation algorithm, resulting in:

[0081]

[0082]

[0083] 2.2 For the large angle range of (70°, 90°), a three-axis tangent biaxial tilt angle calculation algorithm is used to calculate the final output angle, such as... Figure 5 As shown, we have:

[0084]

[0085]

[0086] 2.3 For the transition angle range of [60°, 70°], in order to maintain the continuity and smoothness of the angle output curve at the segmented angle nodes of the algorithm, this invention transitions from a 100% single-axis sinusoidal dual-axis tilt angle calculation algorithm to a 100% three-axis tangent dual-axis tilt angle calculation algorithm within this angle range. The present invention uses a complementary filtering algorithm to fuse and calculate the final output angle, resulting in:

[0087]

[0088]

[0089]

[0090]

[0091] in, , These are the final output angles for the X and Y axes, respectively. , , These are the X-axis, Y-axis, and Z-axis output values ​​of the triaxial accelerometer after six-position calibration. , These are the adaptive weights corresponding to the X-axis and Y-axis, respectively. , These are the first and second algorithm segmented angle nodes for the X-axis, respectively. , These are the first and second algorithm segment angle nodes for the Y-axis, respectively. In this example... , ;

[0092] For the tilt sensor's X and Y axes within the range of -90° to 0°, the corresponding angle calculation method is the same as the angle calculation method for the range of 0° to 90° mentioned above.

[0093] The above algorithm balances single-axis response speed and triaxial anti-interference capability through segmented weighted fusion; it fully relies on the single-axis sinusoidal dual-axis tilt angle calculation algorithm within the 0° to ±60° range to ensure measurement accuracy; and it uses linearly varying weights within the ±60° to ±70° transition range. Achieve smooth switching and eliminate angle jumps; within the ±70°~±90° range, fully utilize the three-axis tangent dual-axis tilt angle calculation algorithm to improve measurement accuracy and sensitivity at large angles.

[0094] After completing the above angle calculation, the present invention further includes the following steps:

[0095] 4) Before the tilt sensor leaves the factory, perform absolute zero-point calibration on the X-axis and Y-axis respectively so that the output value of the X-axis and Y-axis is 0° when the tilt sensor is placed on a horizontal surface. Specifically, place the tilt sensor horizontally on the marble surface and record the output value of the X-axis and Y-axis at this time as the reference value. Subtract this reference value from all subsequent output angles to obtain the actual output angle.

[0096] like Figure 11 As shown, in order to implement the above-mentioned tilt sensor angle calibration calculation method, the present invention also provides a tilt sensor angle calibration calculation system, the system comprising:

[0097] Acquisition and Filtering Module: Used to acquire the raw triaxial acceleration data output by the triaxial accelerometer and perform filtering processing;

[0098] Six-position calibration module: used to estimate error model parameters based on acceleration output data at six different positions to complete calibration, and to store the error model parameters, including axis sensitivity, cross-axis error and zero-point deviation;

[0099] The segmented angle calculation module is used to calculate the final output angles of the tilt sensor's X and Y axes using angle calculation algorithms corresponding to each angle interval. In this module, the final output angles of the tilt sensor's X and Y axes are calculated using a single-axis sinusoidal dual-axis tilt angle calculation algorithm, a three-axis tangent dual-axis tilt angle calculation algorithm, and a complementary filtering algorithm, respectively, for the small angle interval, the large angle interval, and the transition angle interval.

[0100] The present invention verifies the advantages and disadvantages of the segmented combined angle calculation method of the present invention and the single-axis sinusoidal dual-axis tilt angle calculation algorithm by conducting HTOL (High Temperature Operating Life Test) experiments on tilt sensors (tested from October 2, 2025 to December 15, 2025 for approximately 46 days).

[0101] like Figure 6As shown in the figure, the angle deviation areas of the single-axis sinusoidal dual-axis tilt angle calculation algorithm (siny algorithm) and the segmented combined angle calculation method (alty algorithm) adopted in this invention compared with the standard angle in the ±85° angle range and the temperature range of -40℃ to +85℃ (October 29, 2025 and December 15, 2025). It can be seen from the figure that the alty algorithm has a smaller angle deviation than the siny algorithm in the ±75° to ±85° angle deviation range, and performs better. Since ±90° is the physical measurement limit, the angle accuracy in the ±85° to ±90° angle range is directly affected by the initial installation deviation, so this part of the data is not shown in the figure.

[0102] like Figure 7 As shown in the figure, the angle deviation area between the single-axis sinusoidal dual-axis tilt angle calculation algorithm (siny algorithm) and the segmented combined angle calculation method (alty algorithm) adopted in this invention and the standard angle within the ±85° angle range and the -40℃ to +85℃ temperature range (December 15, 2025) is illustrated. It can be seen from the figure that the angle deviation of the alty algorithm is smaller than that of the siny algorithm within the ±60° to ±85° and the -40℃ to +85℃ temperature range.

[0103] like Figure 8 As shown, within the angle range of 0° to ±60°, after adopting the segmented combined angle calculation method of the present invention, the accuracy of the tilt sensor is comparable to that of the siny algorithm within the temperature range of -40℃ to +85℃.

[0104] like Figure 9 As shown in the figure, the probability of finding zero within three angle ranges (0°~±30°, ±30°~±60°, ±60°~±85°) with different deviation threshold requirements is illustrated. It can be seen that within the 0°~±30° and ±30°~±60° angle ranges, the two algorithms have roughly equal probabilities of meeting the requirements at the same deviation threshold (i.e., accuracy requirement). Within the ±60°~±85° angle range, the Alty algorithm begins to outperform the Siny algorithm at a 2° accuracy requirement, and reaches 100% probability at a 3° accuracy requirement, while the Siny algorithm still does not reach 100% probability at a 5° accuracy requirement.

[0105] like Figure 10As shown in the figure, the probability of different deviation threshold requirements within three angle ranges (0°~±30°, ±30°~±60°, ±60°~±85°) without zero finding is as follows. It can be seen that within the 0°~±30° and ±30°~±60° angle ranges, the two algorithms have roughly the same probability of meeting the requirements among 30 tested products at the same deviation threshold (i.e., accuracy requirement). Within the ±60°~±85° angle range, the Alty algorithm begins to outperform the Siny algorithm at a 1° accuracy requirement, and reaches 100% at a 3° accuracy requirement, while the Siny algorithm still does not reach 100% probability at a 5° accuracy requirement.

[0106] For triaxial accelerometers, this HTOL experiment also revealed that the main influencing factor for Z-axis instability is the drift of the Z-axis zero point due to aging, while temperature drift has a relatively small impact. Therefore, temperature compensation for the Z-axis is unnecessary; only temperature compensation for the X and Y axes is required, without adding any new workload. The tilt sensor product originally used two-axis zero point calibration at four positions and 10° intervals, as well as a 0° angle calibration. The turntable needed to run a total of 42 calibration positions, which was quite time-consuming. With the method of this invention, although the original single angle calculation method has been changed to a switching and fusion of two angle calculation methods, actual testing showed that only six positions are needed to achieve the required accuracy, reducing the number of calibration points by approximately 85.7%. Furthermore, the original algorithm used segmented angle calibration, requiring segmented verification of the calibrated angle accuracy. Generally, the number of verification points was the same as the number of calibration points. This invention, however, uses calibration of the original acceleration value of the triaxial accelerometer, eliminating segmentation. Only data from at least two angle positions are needed to confirm the calibration's effectiveness, reducing the number of calibration points in the complete debugging and verification process by approximately 90.5%. It can save about 90% of the time; at room temperature, the angle accuracy of ±80°~±90° within 1.5 years is improved from a maximum of ±10° to a maximum of ±1°. In the high temperature aging simulation of a ten-year life cycle, the accuracy of 30 products in the full temperature range of ±75°~±85° is improved from a maximum of 5.83° to 2.79° (due to the initial installation deviation during the experiment, the limit angle of ±85°~±90° could not be measured).

[0107] In summary, this invention provides an angle calibration calculation method for tilt sensors. This method, developed after 46 days of HTOL testing on 30 tilt sensor samples based on triaxial accelerometers and thoroughly evaluating both the triaxial tangent dual-axis tilt angle calculation algorithm and the single-axis sinusoidal dual-axis tilt angle calculation algorithm, creatively proposes an angle calculation method that leverages the strengths of both algorithms while mitigating their weaknesses. Specifically, it employs the single-axis sinusoidal dual-axis tilt angle calculation algorithm within the 0° to ±60° angle range, the triaxial tangent dual-axis tilt angle calculation algorithm within the ±70° to ±90° angle range, and a complementary filtering algorithm within the ±60° to ±70° angle range. The angle calculation algorithm gradually transitions to a three-axis tangent dual-axis tilt angle calculation algorithm to smoothly switch between the two algorithms at segmented angle nodes. In addition, the six-position calibration method significantly reduces the calibration time. Compared with existing algorithms, the debugging-verification time for each tilt sensor product can be reduced by about 90%. Under normal temperature, the angle accuracy of ±80°~±90° within 1.5 years is improved from a maximum of ±10° to a maximum of ±1°. In high-temperature aging simulation of a ten-year life cycle, the full-temperature accuracy within the range of ±75°~±85° is improved from a maximum of 5.83° to 2.79°. It can be seen that the angle calculation method of the present invention has good performance and is worth promoting.

[0108] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A method for calibrating and calculating the angle of a tilt sensor, characterized in that, The method includes the following steps: 1) Acquire raw triaxial acceleration data output from the triaxial accelerometer and perform filtering processing; 2) Calibration is performed using the six-position calibration method; 3) The angle between the X-axis and Y-axis of the tilt sensor and the horizontal plane is calculated using a segmented combination angle calculation method.

2. The angle calibration calculation method for a tilt sensor according to claim 1, characterized in that, Step 2) specifically includes the following steps: 21) Collect acceleration output data from the tilt sensor at six different locations; 22) Construct an error model for tilt sensor calibration; 23) Estimate the parameters in the error model using the least squares method and save them.

3. The angle calibration calculation method for a tilt sensor according to claim 2, characterized in that, The error model for the tilt sensor calibration is as follows: In the formula, To output the acceleration data matrix, This is the coefficient matrix for sensitivity and cross axes. This is the matrix of true acceleration values. The zero-point deviation matrix, These are the output data of the triaxial accelerometer along the X, Y, and Z axes, respectively. These represent the axis sensitivities of the triaxial accelerometer along the X, Y, and Z axes, respectively. These are the actual values ​​of the triaxial accelerometer along the X, Y, and Z axes, respectively. These represent the zero-point deviations of the triaxial accelerometer along the X, Y, and Z axes, respectively. , , , , , These represent the cross-axis errors.

4. The angle calibration calculation method for a tilt sensor according to claim 1, characterized in that, Step 3) specifically includes the following steps: 31) Configure the algorithm segmentation angle nodes and segment the angle interval within the range; 32) Configure different angle calculation algorithms for each type of angle interval; 33) The final output angles of the tilt sensor's X and Y axes are calculated using the angle calculation algorithm corresponding to the angle interval where the initial angle is located.

5. The angle calibration calculation method for a tilt sensor according to claim 4, characterized in that, In step 31), the range is divided into three types of angle intervals by the algorithm segmentation angle nodes: small angle interval, transition angle interval and large angle interval.

6. The angle calibration calculation method for a tilt sensor according to claim 5, characterized in that, In step 31), when the range of the tilt sensor is 0° to ±90°, the segmented angle nodes are configured as ±60° and ±70°.

7. The angle calibration calculation method for a tilt sensor according to claim 5, characterized in that, In step 33), the initial angle is calculated using a single-axis sinusoidal biaxial tilt angle calculation algorithm. Then we have: Where 'a' represents the output value of the triaxial accelerometer for the corresponding axis after six-position calibration. This is the intermediate acceleration value, and sensi is the default sensitivity of the triaxial accelerometer.

8. The angle calibration calculation method for a tilt sensor according to claim 7, characterized in that, In step 33), when the initial angle When the angle is within a small range, the final output angle is calculated using a single-axis sinusoidal dual-axis tilt angle calculation algorithm, resulting in: When the initial angle When the angle is within a large range, the final output angle is calculated using a three-axis tangent biaxial tilt angle calculation algorithm, resulting in: When the initial angle When the angle is within the transition angle range, the complementary filtering algorithm is used to calculate the final output angle, resulting in: in, , These are the final output angles for the X and Y axes, respectively. , , These are the X-axis, Y-axis, and Z-axis output values ​​of the triaxial accelerometer after six-position calibration. , These are the adaptive weights corresponding to the X-axis and Y-axis, respectively. , These are the first and second algorithm segmented angle nodes for the X-axis, respectively. , These are the first and second algorithm segment angle nodes for the Y-axis, respectively.

9. The angle calibration calculation method for a tilt sensor according to claim 1, characterized in that, The method also includes the following steps: 4) Before the tilt sensor leaves the factory, the X-axis and Y-axis are calibrated to absolute zero.

10. A system for implementing the angle calibration calculation method as described in any one of claims 1-9, characterized in that, The system includes: Acquisition and Filtering Module: Used to acquire the raw triaxial acceleration data output by the triaxial accelerometer and perform filtering processing; Six-position calibration module: used to estimate error model parameters based on acceleration output data at six different positions to complete calibration; The segmented angle calculation module is used to calculate the final output angles of the tilt sensor's X and Y axes using the angle calculation algorithms corresponding to each angle interval.

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