An ARM-based accelerometer nonlinear compensation circuit and compensation method

Abstract

The application provides an ARM-based accelerometer nonlinear compensation circuit and a compensation method. The compensation circuit comprises an ARM chip, a standard centrifugal output module, a carrier wave generating module, and a signal processing module, an A / D conversion module, a demodulation filtering module and a nonlinear compensation module connected in sequence. The carrier wave generating module is connected with the input end of the accelerometer, the signal processing module is connected with the output end of the accelerometer, the nonlinear compensation module is connected with the standard centrifugal output module, the ARM chip is connected with the carrier wave generating module, the A / D conversion module and the nonlinear compensation module, and the ARM chip contains multiple compensation algorithms. The technical scheme of the application solves the technical problems of single compensation algorithm, poor compensation effect and inability to compensate in real time in the prior art.

Description

Technical Field

[0001] This invention relates to the field of digital measurement and control technology for MEMS accelerometers, and in particular to an accelerometer nonlinear compensation circuit and compensation method based on ARM. Background Technology

[0002] The nonlinearity error of MEMS accelerometers mainly comprises two parts: the nonlinearity error of the accelerometer's sensing structure and the nonlinearity error of the measurement and control circuit. These two types of errors directly affect the accelerometer's output accuracy. The nonlinearity of the sensing structure is primarily caused by structural manufacturing errors and the inherent properties of the materials. This structural nonlinearity is mainly ensured through theoretical design and process parameter control during manufacturing. Similarly, the nonlinearity of the operational amplifier, demodulator, and ADC in the measurement and control circuit also causes nonlinearity in the final accelerometer output. This nonlinearity is mainly ensured through component selection or circuit molding processes during circuit design. Even with design safeguards against nonlinearity issues at each stage, nonlinearity errors are still unavoidable when the accelerometer is finally assembled.

[0003] Theoretically, for the same accelerometer, its sensing structure, bonding method, bonding wire method, packaging method, and circuit composition are all fixed. Therefore, as long as the accelerometer operates under its design conditions, the nonlinearity error of its acceleration output is already determined. Ideally, knowing the nonlinearity error at all output points within the accelerometer's range would eliminate any nonlinearity error in the accelerometer's output. However, since errors caused by nonlinearity are difficult to measure precisely, and it's impossible to measure nonlinearity errors across the entire range, the common practice is to use precise standard centrifugation equipment to obtain standard acceleration outputs, thereby obtaining the nonlinearity error at some fixed acceleration points. Then, a compensation algorithm is used to correct the nonlinearity error to ensure the final accuracy of the accelerometer output.

[0004] However, this approach has significant drawbacks, making it unable to meet current nonlinear compensation requirements. Specifically, the compensation algorithm is not integrated with the circuit, thus only offline compensation can be performed. Consequently, the meter output does not change in real time due to the compensation algorithm, serving only as a reference for the meter's nonlinear compensation capability. Furthermore, the algorithm is singular, requiring only one algorithm to compensate for the meter's nonlinear error, often failing to achieve optimal results, and even worsening the compensation effect at certain acceleration locations. Summary of the Invention

[0005] To address one of the problems existing in the prior art, this invention provides an accelerometer nonlinear compensation circuit and compensation method based on ARM.

[0006] According to one aspect of the present invention, an accelerometer nonlinear compensation circuit based on ARM is provided. The compensation circuit includes an ARM chip, a standard centrifugal output module, a carrier generation module, and a signal processing module, an A / D conversion module, a demodulation and filtering module, and a nonlinear compensation module connected in sequence. The carrier generation module is connected to the input terminal of the accelerometer, the signal processing module is connected to the output terminal of the accelerometer, and the nonlinear compensation module is connected to the standard centrifugal output module. The ARM chip is connected to the carrier generation module, the A / D conversion module, and the nonlinear compensation module respectively. The ARM chip contains multiple compensation algorithms.

[0007] The ARM chip is used to control the carrier generation module to generate a carrier wave, and the acceleration information sensed by the accelerometer is modulated onto the carrier wave to generate an initial signal;

[0008] The signal processing module is used to process the initial signal to obtain a voltage signal;

[0009] The ARM chip is also used to control the A / D conversion module to convert voltage signals into digital signals;

[0010] The demodulation and filtering module is used to demodulate and output initial acceleration data based on the digital signal;

[0011] The standard centrifuge output module is used to output standard acceleration data;

[0012] The ARM chip is also used to control the nonlinear compensation module based on standard acceleration data using various compensation algorithms to perform nonlinear compensation on the initial acceleration data in an adaptive manner to generate compensated acceleration data.

[0013] Furthermore, the nonlinear compensation module includes a data acquisition module, a data normalization module, and an adaptive compensation module connected in sequence. The data acquisition module is connected to the demodulation and filtering module. The ARM chip controls the data acquisition module to acquire initial acceleration data, controls the data normalization module to normalize the initial acceleration data, and controls the adaptive compensation module to use multiple compensation algorithms to perform nonlinear compensation on the normalized initial acceleration data in an adaptive manner based on the standard acceleration data to generate compensated acceleration data.

[0014] Furthermore, the compensation circuit also includes a calibration factor adjustment module, which is connected to the adaptive compensation module and is used to adjust the calibration factor of the compensation acceleration data.

[0015] Furthermore, the signal processing module includes a charge amplification module and a preamplifier module connected in sequence. The charge amplification module is connected to the output terminal of the accelerometer, and the preamplifier module is connected to the A / D conversion module. The charge amplification module is used to convert the initial signal into a voltage signal, and the preamplifier module is used to amplify the voltage signal.

[0016] Furthermore, the carrier wave is a digitally synthesized sine wave.

[0017] According to another aspect of the present invention, an accelerometer nonlinearity compensation method is provided, the compensation method comprising:

[0018] The carrier wave is generated by controlling the carrier generation module through the ARM chip, and the acceleration information sensed by the accelerometer is modulated onto the carrier wave to generate the initial signal.

[0019] The initial signal is processed using a signal processing module to obtain a voltage signal;

[0020] The voltage signal is converted into a digital signal by controlling the A / D conversion module through the ARM chip;

[0021] The initial acceleration data is output by demodulating the digital signal using a demodulation and filtering module.

[0022] Standard acceleration data is output using a standard centrifugal output module;

[0023] The ARM chip utilizes various compensation algorithms to control the nonlinear compensation module based on standard acceleration data, performing nonlinear compensation on the initial acceleration data in an adaptive manner to generate compensated acceleration data.

[0024] Furthermore, the nonlinear compensation module includes a data acquisition module, a data normalization module, and an adaptive compensation module connected in sequence. Using an ARM chip and multiple compensation algorithms, the nonlinear compensation module adaptively performs nonlinear compensation on the initial acceleration data based on the standard acceleration data to generate compensated acceleration data, including:

[0025] The initial acceleration data is acquired by controlling the data acquisition module through an ARM chip.

[0026] The initial acceleration data is normalized by controlling the data normalization module through an ARM chip.

[0027] The ARM chip utilizes various compensation algorithms to control the adaptive compensation module based on standard acceleration data, performing nonlinear compensation on the normalized initial acceleration data in an adaptive manner to generate compensated acceleration data.

[0028] Furthermore, the ARM chip utilizes various compensation algorithms to control the adaptive compensation module based on standard acceleration data, performing nonlinear compensation on the normalized initial acceleration data in an adaptive manner to generate compensated acceleration data, including:

[0029] S131, Based on the standard acceleration data and the normalized initial acceleration data, each compensation algorithm is iteratively optimized to obtain the optimal weighting vector corresponding to each compensation algorithm;

[0030] S132, using the optimal weighting vector corresponding to each compensation algorithm to perform nonlinear compensation on the normalized initial acceleration data to obtain the theoretical compensated acceleration data corresponding to each compensation algorithm;

[0031] S133, calculate the maximum difference between the theoretical compensation acceleration data and the standard acceleration data corresponding to each compensation algorithm, and select the compensation algorithm corresponding to the smallest maximum difference as the selected compensation algorithm;

[0032] S134, using the optimal weighting vector corresponding to the selected compensation algorithm to perform nonlinear compensation on the normalized initial acceleration data to generate the final compensated acceleration data;

[0033] S135: After each initial acceleration data is collected, it is normalized and then compensated according to the process from S131 to S134 to achieve adaptive compensation across the entire range of the accelerometer.

[0034] Furthermore, the least squares estimation method is used to iteratively optimize each compensation algorithm based on the standard acceleration data and the normalized initial acceleration data.

[0035] Furthermore, each compensation algorithm is iteratively optimized using the least squares estimation method based on standard acceleration data and normalized initial acceleration data, using the following formula:

[0036]

[0037] In the above formula, J(n) represents the evaluation function, e(i) represents the error output value of the i-th iteration optimization, and e(n) represents the matrix composed of the cumulative error output values ​​of n optimizations. T (n) represents the transpose of e(n), W opt Let X(n) represent the weighted vector, X(n) represent the matrix composed of the compensated acceleration data obtained after n iterations of optimization, d(n) represent the desired signal, and λ represent the forgetting factor, where 0 < λ < 1.

[0038] The present invention provides an ARM-based accelerometer nonlinear compensation circuit and method. This circuit acquires standard acceleration data through a standard centrifugal output module, uses an ARM chip to control a carrier generation module to generate a carrier wave for modulating the accelerometer output, controls an A / D conversion module to perform digital-to-analog conversion on the signal, and utilizes multiple compensation algorithms integrated in the ARM chip to control the nonlinear compensation module to adaptively compensate the initial acceleration data of the demodulated output based on the standard acceleration data. This allows for automatic compensation of the accelerometer's nonlinear error across its entire range and real-time online output without saturation of the accelerometer structure or circuitry. This significantly reduces the impact of nonlinear error on the accelerometer and improves its environmental adaptability. Attached Figure Description

[0039] The accompanying drawings, which form part of this specification, are provided to further illustrate embodiments of the invention and, together with the textual description, explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0040] Figure 1 A schematic diagram of an ARM-based accelerometer nonlinear compensation circuit according to a specific embodiment of the present invention is shown.

[0041] Figure 2 A schematic diagram of a nonlinear compensation module according to a specific embodiment of the present invention is shown;

[0042] Figure 3 A schematic diagram of the compensation principle provided according to a specific embodiment of the present invention is shown. Detailed Implementation

[0043] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. 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 a part of the embodiments of the present invention, and not all of them. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. 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.

[0044] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0045] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0046] like Figure 1 As shown, according to a specific embodiment of the present invention, an accelerometer nonlinear compensation circuit based on ARM is provided. The compensation circuit includes an ARM chip, a standard centrifugal output module, a carrier generation module, and a signal processing module, an A / D conversion module, a demodulation and filtering module, and a nonlinear compensation module connected in sequence. The carrier generation module is connected to the input terminal of the accelerometer, the signal processing module is connected to the output terminal of the accelerometer, and the nonlinear compensation module is connected to the standard centrifugal output module. The ARM chip is connected to the carrier generation module, the A / D conversion module, and the nonlinear compensation module respectively. The ARM chip contains multiple compensation algorithms.

[0047] The ARM chip is used to control the carrier generation module to generate a carrier wave, and the acceleration information sensed by the accelerometer is modulated onto the carrier wave to generate an initial signal;

[0048] The signal processing module is used to process the initial signal to obtain a voltage signal;

[0049] The ARM chip is also used to control the A / D conversion module to convert voltage signals into digital signals;

[0050] The demodulation and filtering module is used to demodulate and output initial acceleration data based on the digital signal;

[0051] The standard centrifuge output module is used to output standard acceleration data;

[0052] The ARM chip is also used to control the nonlinear compensation module based on standard acceleration data using various compensation algorithms to perform nonlinear compensation on the initial acceleration data in an adaptive manner to generate compensated acceleration data.

[0053] In this invention, the carrier waveform is determined based on actual conditions. In one specific embodiment, the carrier is a digitally synthesized sine wave. This eliminates the influence of higher harmonics in traditional square waves on the circuit, resulting in a single frequency component and facilitating subsequent circuit processing. Furthermore, to more accurately acquire the acceleration signal output by the accelerometer, the initial signal generated by carrier modulation is preprocessed, such as… Figure 1 As shown in the figure, in a specific embodiment of the present invention, the signal processing module includes a charge amplification module and a preamplifier module connected in sequence. The charge amplification module is connected to the output terminal of the accelerometer, and the preamplifier module is connected to the A / D conversion module. The charge amplification module is used to convert the initial signal into a voltage signal, and the preamplifier module is used to amplify the voltage signal to form a stronger signal. In addition, in this embodiment of the present invention, the demodulation filtering module uses an output demodulator, and the charge amplification module uses a charge amplifier. Based on the above embodiments, in this invention, the ARM chip controls the generation of a sinusoidal carrier wave to modulate the acceleration signal, controls the A / D conversion module to perform signal conversion, and controls the nonlinear compensation module to perform nonlinear compensation of the signal. Simultaneously, the charge amplifier and the output demodulator together constitute a complete accelerometer circuit with nonlinear compensation function.

[0054] This configuration provides an ARM-based accelerometer nonlinear compensation circuit. The circuit acquires standard acceleration data through a standard centrifugal output module, uses an ARM chip to control a carrier generation module to generate a carrier wave for modulating the accelerometer output, controls an A / D conversion module to perform digital-to-analog conversion, and utilizes multiple compensation algorithms integrated in the ARM chip to adaptively compensate the initial acceleration data of the demodulated output using the standard acceleration data. This allows for automatic compensation of nonlinear errors across the entire accelerometer range without saturation of the accelerometer structure and circuitry, providing real-time online compensation. This significantly reduces the impact of nonlinear errors on the accelerometer and improves its environmental adaptability. Compared to existing technologies, this invention solves the problems of limited compensation algorithms, poor compensation effects, and the inability to provide real-time online compensation.

[0055] Furthermore, such as Figure 2As shown in the embodiment of the present invention, the nonlinear compensation module includes a data acquisition module, a data normalization module, and an adaptive compensation module connected in sequence. The data acquisition module is connected to the demodulation and filtering module. The ARM chip controls the data acquisition module to acquire initial acceleration data, controls the data normalization module to normalize the initial acceleration data, and controls the adaptive compensation module to use multiple compensation algorithms to perform nonlinear compensation on the normalized initial acceleration data in an adaptive manner based on the standard acceleration data to generate compensated acceleration data.

[0056] In other words, the main function of the data acquisition module is to acquire the data output of the accelerometer chip, ensuring that as much original signal information as possible is retained during the acquisition process. After the data acquisition is completed, the data normalization module performs normalization processing on the data. The purpose of data normalization processing is mainly to perform data matching with the computer, thereby ensuring the compensation accuracy of the subsequent compensation algorithm, so that the obtained data is not too small and does not exceed the computer's computing limits. After the data normalization is completed, the data preprocessing work is completed. Then, the ARM chip controls the adaptive compensation module to perform adaptive compensation on the normalized data. Based on the output, an appropriate compensation algorithm is selected to obtain the normalized accelerometer nonlinear compensation output. This configuration approach considers the ease of communication with the ARM chip in the algorithm. By introducing a data normalization step, it ensures that the data calculations in the entire compensation process do not exceed the limits, and it can easily transmit data with the host computer. At the same time, it adopts an adaptive compensation algorithm, integrating multiple algorithms within the ARM chip. Based on the results of the standard centrifugal output, it can adjust the nonlinear compensation algorithm for different MEMS accelerometers, and perform segmented compensation for the output of the same MEMS accelerometer, maximizing the effect of nonlinear compensation and playing a key role in improving the overall performance of the accelerometer.

[0057] To further optimize the compensation circuit, such as Figure 2 As shown in the embodiment of the invention, the compensation circuit further includes a calibration factor adjustment module, which is connected to the adaptive compensation module and is used to adjust the calibration factor of the compensation acceleration data. By reasonably adjusting the calibration factor according to the A / D conversion capability and the maximum digital output of the compensation circuit, the pressure on the preamplifier module in the circuit can be relieved. In this way, the amplification factor of the preamplifier module can be reasonably selected according to the actual circuit conditions, without having to make it work at a very high amplification factor.

[0058] According to another aspect of the present invention, an accelerometer nonlinearity compensation method is provided, the compensation method comprising:

[0059] The carrier wave is generated by controlling the carrier generation module through the ARM chip, and the acceleration information sensed by the accelerometer is modulated onto the carrier wave to generate the initial signal.

[0060] The initial signal is processed using a signal processing module to obtain a voltage signal;

[0061] The voltage signal is converted into a digital signal by controlling the A / D conversion module through the ARM chip;

[0062] The initial acceleration data is output by demodulating the digital signal using a demodulation and filtering module.

[0063] Standard acceleration data is output using a standard centrifugal output module;

[0064] The ARM chip utilizes various compensation algorithms to control the nonlinear compensation module based on standard acceleration data, performing nonlinear compensation on the initial acceleration data in an adaptive manner to generate compensated acceleration data.

[0065] This configuration provides an accelerometer nonlinearity compensation method. This method uses a standard centrifugal output module to acquire standard acceleration data, an ARM chip to control a carrier generation module to generate a carrier wave for modulating the accelerometer output, an A / D conversion module to perform digital-to-analog conversion on the signal, and multiple compensation algorithms integrated in the ARM chip to adaptively compensate the initial acceleration data of the demodulated output using the standard acceleration data. This allows for automatic compensation of the accelerometer's nonlinearity error across its entire range and real-time online output without saturation of the accelerometer's structure or circuitry. This significantly reduces the impact of nonlinearity error on the accelerometer and improves its environmental adaptability.

[0066] Furthermore, this invention employs a combination of hardware and software to achieve nonlinear compensation. First, an ARM chip is used for signal processing, and then a hardware chip is combined with a software program to design an adaptive compensation algorithm. On the hardware side, in this embodiment, the nonlinear compensation module includes a data acquisition module, a data normalization module, and an adaptive compensation module connected in sequence. The ARM chip utilizes various compensation algorithms to control the nonlinear compensation module to adaptively perform nonlinear compensation on the initial acceleration data based on standard acceleration data to generate compensated acceleration data, including:

[0067] The initial acceleration data is acquired by controlling the data acquisition module through an ARM chip.

[0068] The initial acceleration data is normalized by controlling the data normalization module through an ARM chip.

[0069] The ARM chip utilizes various compensation algorithms to control the adaptive compensation module based on standard acceleration data, performing nonlinear compensation on the normalized initial acceleration data in an adaptive manner to generate compensated acceleration data.

[0070] For software-related information, please refer to [link / reference]. Figure 3 The principle is as follows: First, standard acceleration data is obtained through a standard centrifugation output module. Then, raw measurement data is obtained by performing raw centrifugation across the entire range of the accelerometer. Next, nonlinear compensation is performed across the entire range according to the principle of minimizing the difference between the compensated data and the standard acceleration at the corresponding position. Multiple algorithms integrated within the chip are adaptively selected to compensate all subsequent acceleration outputs of the accelerometer. Specifically, in this embodiment of the invention, the ARM chip uses multiple compensation algorithms to control the adaptive compensation module to perform nonlinear compensation on the normalized initial acceleration data in an adaptive manner to generate compensated acceleration data, including:

[0071] S131, Based on the standard acceleration data and the normalized initial acceleration data, each compensation algorithm is iteratively optimized to obtain the optimal weighting vector corresponding to each compensation algorithm;

[0072] S132, using the optimal weighting vector corresponding to each compensation algorithm to perform nonlinear compensation on the normalized initial acceleration data to obtain the theoretical compensated acceleration data corresponding to each compensation algorithm;

[0073] S133, calculate the maximum difference between the theoretical compensation acceleration data and the standard acceleration data corresponding to each compensation algorithm, and select the compensation algorithm corresponding to the smallest maximum difference as the selected compensation algorithm;

[0074] S134, using the optimal weighting vector corresponding to the selected compensation algorithm to perform nonlinear compensation on the normalized initial acceleration data to generate the final compensated acceleration data;

[0075] S135: After each initial acceleration data is collected, it is normalized and then compensated according to the process from S131 to S134 to achieve adaptive compensation across the entire range of the accelerometer.

[0076] As a specific embodiment of the present invention, the least squares estimation method is used to iteratively optimize each compensation algorithm based on standard acceleration data and normalized initial acceleration data.

[0077] Specifically, each compensation algorithm is iteratively optimized using the least squares estimation method based on standard acceleration data and normalized initial acceleration data, using the following formula:

[0078]

[0079] In the above formula, J(n) represents the evaluation function, e(i) represents the error output value of the i-th iteration optimization, and e(n) represents the matrix composed of the cumulative error output values ​​of n optimizations. T (n) represents the transpose of e(n), W opt Let X(n) represent the weighted vector, X(n) represent the matrix composed of the compensated acceleration data obtained after n iterations of optimization, d(n) represent the desired signal, and λ represent the forgetting factor, where 0 < λ < 1.

[0080] In other words, each algorithm is an iterative optimization process, with the goal of making the individual algorithm optimal. Each iteration of the algorithm yields a weighted vector, and the value of the evaluation function can be calculated based on this weighted vector. When the evaluation function is minimized, the corresponding weighted vector is optimal. By using this weighted vector for compensation, the optimal compensation result of the algorithm can be obtained.

[0081] After each algorithm reaches its optimal state, a comparison is performed between the algorithms. Assuming there are m algorithms and j acceleration output points, the criterion is: min(max(|a jm -a 0j |)), where a jm a represents the acceleration compensation output of the m-th algorithm at the j-th acceleration output point. 0j This represents the standard acceleration output at the j-th acceleration output point. In other words, we find the point with the worst compensation effect among all algorithms—that is, the point with the largest difference between the compensated data and the standard data. Then, we select the point with the smallest difference from these worst points; this is the optimal algorithm. In this way, we can find the best compensation algorithm and perform the corresponding compensation through ARM chip control.

[0082] In summary, this invention provides an accelerometer nonlinearity compensation circuit and method based on ARM. This circuit acquires standard acceleration data through a standard centrifugal output module, uses an ARM chip to control a carrier generation module to generate a carrier wave for modulating the accelerometer output, controls an A / D conversion module to perform digital-to-analog conversion on the signal, and utilizes multiple compensation algorithms integrated in the ARM chip to adaptively compensate the initial acceleration data of the demodulated output using a nonlinearity compensation module based on the standard acceleration data. This allows for automatic compensation of the accelerometer's nonlinearity error across its entire range and real-time online output without saturation of the accelerometer structure and circuitry. This significantly reduces the impact of nonlinearity error on the accelerometer and improves its environmental adaptability. Compared with existing technologies, the technical solution of this invention solves the technical problems of existing technologies, such as single compensation algorithms, poor compensation effects, and the inability to provide real-time online compensation.

[0083] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0084] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0085] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method of accelerometer non-linearity compensation, characterized by, The compensation method comprises: The carrier is generated by an ARM chip controlling a carrier generation module, and acceleration information sensed by the accelerometer is modulated onto the carrier to generate an initial signal; The initial signal is processed by a signal processing module to obtain a voltage signal; The voltage signal is converted into a digital signal by an A / D conversion module controlled by the ARM chip; Initial acceleration data is demodulated and output from the digital signal by a demodulation filtering module; Standard acceleration data is output by a standard centrifugal output module; The initial acceleration data is adaptively nonlinearly compensated by a data acquisition module, a data normalization module and an adaptive compensation module connected in sequence in an adaptive manner to generate compensated acceleration data by the ARM chip according to the standard acceleration data, specifically comprising: The initial acceleration data is acquired by the data acquisition module controlled by the ARM chip; The initial acceleration data is normalized by the data normalization module controlled by the ARM chip; The initial acceleration data after normalization is nonlinearly compensated in an adaptive manner by the adaptive compensation module controlled by the ARM chip according to the standard acceleration data by using the plurality of compensation algorithms to generate compensated acceleration data, specifically comprising: S131, the least square estimation method is used to iteratively optimize each compensation algorithm according to the standard acceleration data and the initial acceleration data after normalization to obtain a best weighting vector corresponding to each compensation algorithm; S132, the best weighting vector corresponding to each compensation algorithm is used to nonlinearly compensate the initial acceleration data after normalization to obtain theoretical compensation acceleration data corresponding to each compensation algorithm; S133, the maximum difference between the theoretical compensation acceleration data corresponding to each compensation algorithm and the standard acceleration data is calculated, and the compensation algorithm corresponding to the smallest maximum difference is selected as the selected compensation algorithm; S134, the best weighting vector corresponding to the selected compensation algorithm is used to nonlinearly compensate the initial acceleration data after normalization to generate final compensated acceleration data; S135, each initial acceleration data is compensated according to the process of S131 to S134 after normalization to realize adaptive compensation in the full range of the accelerometer; In S131, the iterative optimization is performed by the following formula: In the above formula, Represents the evaluation function, Indicates the first The error output value of the next iteration of optimization. Indicates cumulative The matrix formed by the error output values ​​of the second optimization. express transpose, Represents a weighted vector. express The matrix formed by the compensated acceleration data obtained after each iteration of optimization. Indicates the desired signal. Represents the forgetting factor, and .

2. An ARM-based accelerometer non-linearity compensation circuit, characterized by, The compensation circuit is applicable to the accelerometer nonlinear compensation method of claim 1, and the compensation circuit comprises an ARM chip, a standard centrifugal output module, a carrier generation module and a signal processing module, an A / D conversion module, a demodulation filtering module and a nonlinear compensation module connected in sequence, the carrier generation module is connected with the input end of the accelerometer, the signal processing module is connected with the output end of the accelerometer, the nonlinear compensation module is connected with the standard centrifugal output module, the ARM chip is connected with the carrier generation module, the A / D conversion module and the nonlinear compensation module respectively, and the ARM chip comprises a plurality of compensation algorithms. The ARM chip is configured to control the carrier generation module to generate a carrier wave, and the acceleration information sensed by the accelerometer is modulated onto the carrier wave to generate an initial signal. The signal processing module is configured to process the initial signal to obtain a voltage signal. The ARM chip is further configured to control the A / D conversion module to convert the voltage signal into a digital signal. The demodulation and filtering module is configured to demodulate and output initial acceleration data according to the digital signal. The standard centrifugal output module is configured to output standard acceleration data. The ARM chip is further configured to control the non-linear compensation module to adaptively perform non-linear compensation on the initial acceleration data according to the standard acceleration data to generate compensated acceleration data.

3. The compensation circuit of claim 2, wherein, The non-linear compensation module comprises a data acquisition module, a data normalization module and an adaptive compensation module connected in sequence, the data acquisition module is connected with the demodulation and filtering module, the ARM chip controls the data acquisition module to acquire the initial acceleration data, controls the data normalization module to perform normalization processing on the initial acceleration data, and controls the adaptive compensation module to adaptively perform non-linear compensation on the normalized initial acceleration data according to the standard acceleration data by using the multiple compensation algorithms to generate compensated acceleration data.

4. The compensation circuit of claim 3, wherein, The compensation circuit further comprises a calibration factor adjustment module connected with the adaptive compensation module, and configured to perform calibration factor adjustment on the compensated acceleration data.

5. The compensation circuit of claim 4, wherein, The signal processing module comprises a charge amplification module and a preamplification module connected in sequence, the charge amplification module is connected with the output end of the accelerometer, and the preamplification module is connected with the A / D conversion module, the charge amplification module is configured to convert the initial signal into a voltage signal, and the preamplification module is configured to amplify the voltage signal.

6. The compensation circuit of claim 5, wherein, The carrier wave is a digital synthesized sine wave.

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