Motor position soft decoding method and system of self-adaptive eddy current sensor

Abstract

The invention discloses a motor position soft decoding method and system of a self-adaptive eddy current sensor. The method comprises the following steps: acquiring a differential processing sensor signal to obtain a preprocessed sine and cosine signal; acquiring eddy current magnetic field angular velocity according to the signal, and judging whether the eddy current magnetic field angular velocity is smaller than or equal to a preset threshold to distinguish low-speed and high-speed stages; at a low speed, calculating the angular speed and the electrical angle of the motor by using a preset default amplitude and a soft decoding formula; when the speed is high, the amplitude is updated based on the maximum value and the minimum value obtained through real-time statistics on the sine and cosine signals, and calculation is carried out by combining the updated amplitude with the same decoding formula; and repeating the judgment and calculation process to realize adaptive amplitude switching and continuous optimization. Through self-adaptive amplitude soft decoding of low-speed statistics and high-speed switching, the problem that the motor position decoding precision is reduced due to individual difference and signal drift in batch engineering application of the eddy current sensor is solved.

Description

Technical Field

[0001] This invention relates to the field of automotive motor control technology, specifically to a method and system for soft decoding of motor position using an adaptive eddy current sensor. Background Technology

[0002] Sensors, frequently integrated into automated products, play a vital role in our daily lives and production. They represent the cutting edge of modern technology, and their level is a key indicator of technological advancement. A wide variety of sensors are available on the market, offering numerous choices. High-performance sensors, such as eddy current sensors, are widely used across various industries, particularly in machine tools and automotive manufacturing.

[0003] Eddy current sensors can accurately measure the static and dynamic relative displacement changes between the measured object (which must be a metallic conductor) and the probe end face. In the condition analysis, vibration research, and measurement of high-speed rotating machinery and reciprocating motion machinery, they can continuously and accurately acquire various parameters of rotor vibration, such as radial vibration, amplitude, and axial position of the shaft, providing high-precision, non-contact vibration and displacement signals. Eddy current sensors are widely used in the online monitoring and fault diagnosis of large rotating machinery due to their advantages of high long-term reliability, wide measurement range, high sensitivity, and high resolution.

[0004] Currently, most methods use hardware chips to decode the motor position resolver, which is accurate but expensive and has complex peripheral circuits. Therefore, industries such as automotive use software to decode the motor position extensively.

[0005] In practical engineering applications, especially in the mass production and use in the automotive industry, the amplitude of the sine and cosine signals of a rotary transformer may vary due to a variety of factors. These factors include: individual manufacturing differences of the rotary transformer itself, electrical state reset caused by system power-on, and changes to the signal acquisition and control software.

[0006] Therefore, how to use eddy current sensors for soft decoding of motor position to maintain stable performance and achieve cost reduction in large-scale adjustments with individual differences is of great significance in industries such as automobiles. Summary of the Invention

[0007] To address the shortcomings of the existing technologies, this invention provides a method and system for soft decoding of motor position using an adaptive eddy current sensor. By employing adaptive amplitude soft decoding that switches between low-speed statistics and high-speed operation, the invention solves the problem of decreased motor position decoding accuracy caused by individual differences and signal drift in batch engineering applications of eddy current sensors.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0009] A soft decoding method for motor position using an adaptive eddy current sensor includes the following steps:

[0010] S1. Acquire the sine and cosine differential signals output by the eddy current sensor, and perform differential processing on the sine and cosine differential signals to obtain preprocessed sine and cosine signals;

[0011] S2. Obtain the angular velocity of the eddy current magnetic field based on the preprocessed sine and cosine signals, and determine whether the angular velocity of the eddy current magnetic field is less than or equal to a preset angular velocity threshold; if so, determine that the motor is in the low-speed stage and execute step S3; otherwise, determine that the motor is in the high-speed stage and execute step S4.

[0012] S3. Using the preset default sine and cosine amplitude values, and according to the software decoding calculation formula, the motor position is software decoded to calculate the angular velocity and electrical angle of the motor.

[0013] S4. During motor operation, the maximum and minimum values ​​of sine and cosine signals are counted in real time, and the sine and cosine amplitudes are updated based on the statistical results.

[0014] S5. Based on the updated sine and cosine amplitudes, and combined with the soft decoding calculation formula, the angular velocity and electrical angle of the motor are calculated.

[0015] S6. Repeat steps S2 to S5 to achieve adaptive amplitude switching and continuous optimization of motor position soft decoding.

[0016] As a preferred embodiment, in step S1, the sine and cosine signals are respectively represented as:

[0017] ;

[0018] ;

[0019] In the formula, It is a sinusoidal signal; The acquired sinusoidal differential P signal; The acquired sinusoidal differential N-signal; It is a cosine signal; The acquired cosine differential P signal; The acquired cosine differential N signal.

[0020] As a preferred option, the judgment condition in step S2 during the decoding stage is expressed as follows:

[0021] ;

[0022] In the formula, ω represents the angular velocity of the eddy current magnetic field at the current moment; This is a preset angular velocity threshold.

[0023] As a preferred embodiment, step S3, specifically the process of calculating the angular velocity and electrical angle of the motor according to the soft decoding calculation formula, includes:

[0024] S301. Using the software's preset default sine and cosine amplitude values, and combining the following formulas, calculate the initial electrical angle value and decoding index of the motor position soft decoding layer of the eddy current sensor.

[0025] ;

[0026] ;

[0027] ;

[0028] In the formula, and These are the initial electrical angle sine and cosine values, respectively; and These are the software's preset default sine and cosine amplitudes, respectively. For decoding indicators;

[0029] S302. Based on the calculated initial electrical angle value and decoding index, combined with preset angle difference compensation and speed estimation, the real-time angular velocity and electrical angle of the motor are calculated.

[0030] As a preferred embodiment, in step S302, the calculation formula for the real-time angular velocity and electrical angle of the motor is expressed as follows:

[0031] ;

[0032] ;

[0033] ;

[0034] ;

[0035] ;

[0036] ;

[0037] In the formula, For the predicted electrical angle; The sampling period; The initial electrical angle acquired by the eddy current; This is the angle error value; It is an integral term; This is the integral gain coefficient; This is the proportional gain coefficient; This represents the number of pole pairs of the rotary transformer. This represents the number of pole pairs of the motor. The angular velocity of the motor at the current moment; The electric angle of the motor at the current moment.

[0038] As a preferred embodiment, in step S4, the calculation formula for updating the sine and cosine amplitudes is expressed as follows:

[0039] ;

[0040] ;

[0041] In the formula, This is the updated sine amplitude; and These represent the maximum and minimum amplitudes of the sinusoidal signal, respectively. This is the updated cosine amplitude; and These represent the maximum and minimum amplitudes of the cosine signal, respectively.

[0042] A motor position soft decoding system based on an adaptive eddy current sensor includes:

[0043] The signal acquisition module is used to acquire the sine and cosine differential signals output by the eddy current sensor, and to perform differential processing on the sine and cosine differential signals to obtain preprocessed sine and cosine signals.

[0044] The velocity determination module is used to obtain the angular velocity of the eddy current magnetic field based on the preprocessed sine and cosine signals, and to determine whether the angular velocity of the eddy current magnetic field is less than or equal to a preset angular velocity threshold.

[0045] The low-speed decoding module is used to perform soft decoding on the preprocessed sine and cosine signals using preset default sine and cosine amplitudes when the angular velocity of the eddy current magnetic field does not exceed the preset angular velocity threshold, so as to obtain the motor position information.

[0046] The amplitude update module is used to synchronously perform amplitude statistics on the preprocessed sine and cosine signals and update the sine and cosine amplitudes based on the statistical results.

[0047] The high-speed decoding module is used to call the updated sine and cosine amplitude values ​​when the angular velocity of the eddy current magnetic field exceeds the preset angular velocity threshold, and to perform soft decoding on the preprocessed sine and cosine signals to obtain the motor position information.

[0048] Compared with the prior art, the present invention has the following technical effects:

[0049] 1. This invention divides the motor operation process into two stages: low speed and high speed. In the low speed stage, the default amplitude is used for stable decoding to calculate the motor rotation position. At the same time, the actual amplitude range of the signal is statistically analyzed, thereby avoiding the strong dependence on amplitude accuracy at low speed. When entering the high speed stage, the system immediately switches to the maximum and minimum values ​​of the sine and cosine signals based on real-time statistics and updates the sine and cosine amplitudes for decoding. This significantly improves the position decoding accuracy and control performance of the motor under high speed and high dynamic conditions, thereby ensuring the overall efficiency and response speed of the motor system.

[0050] 2. This invention can solve the performance reduction or even failure caused by changes in individual amplitude through adaptive logic, ensure the robustness of motor control software, improve the rational utilization of eddy currents, and reduce costs. Based on the logic supervision of this invention, no hardware cost increase is required. The framework is simple, the logic is clear, and the applicability is strong. It can be quickly applied to the research and development of automotive power transmission technology with electric motors. Attached Figure Description

[0051] To make the objectives, technical solutions, and advantages of the invention clearer, the invention will now be described in further detail with reference to the accompanying drawings, wherein:

[0052] Figure 1 This is a flowchart of the motor position soft decoding method of the adaptive eddy current sensor in an embodiment of the present invention;

[0053] Figure 2 This is a sine curve of the electric motor eddy current processed by the software in this embodiment of the invention;

[0054] Figure 3 This is a graph of the cosine value processed by the motor eddy current software in an embodiment of the present invention.

[0055] Figure 4 This is a schematic diagram of the motor position soft decoding system of the adaptive eddy current sensor in an embodiment of the present invention. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but only to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0057] The present invention will now be described in further detail with reference to the accompanying drawings.

[0058] Example 1:

[0059] Currently, position sensors such as eddy current sensors and rotary transformers are widely used in motor control. However, traditional solutions relying on dedicated hardware decoding chips, while highly accurate, are expensive and have complex circuits, hindering large-scale commercial application. While purely software decoding solutions are inexpensive, their decoding accuracy and stability are often limited by the quality of the sensor's output signal. This is especially true in mass production in industries like automobiles, where manufacturing tolerances between individual sensors, minor variations in controller hardware parameters, and signal drift after long-term operation can all cause changes in the amplitude of the output sine and cosine signals. This amplitude inconsistency directly undermines the mathematical model upon which the software decoding algorithm relies, causing decoding angle errors. This can range from affecting motor efficiency to causing control instability, seriously threatening the reliability and robustness of software decoding solutions in practical applications.

[0060] To address the aforementioned problems and shortcomings, this invention proposes a soft decoding method and system for motor position using an adaptive eddy current sensor. This method no longer aims to operate under a single static model, but instead divides motor operation into two dynamic stages: low speed and high speed, and designs corresponding amplitude processing strategies. This fundamentally solves the problem of reduced decoding performance caused by individual differences and changes in operating conditions. Moreover, it achieves the accuracy and stability that were previously only guaranteed by hardware or complex calibration processes at the software level.

[0061] Specifically, the adaptive eddy current sensor motor position soft decoding method proposed in this invention, such as... Figure 1 As shown, it includes the following steps:

[0062] S1. Acquire the sine and cosine differential signals output by the eddy current sensor, and perform differential processing on the sine and cosine differential signals to obtain preprocessed sine and cosine signals;

[0063] In specific implementation, such as Figure 2 , Figure 3 As shown, these are the standardized sine and cosine signal curves obtained after preprocessing the original differential signal of the eddy current sensor in this embodiment. In this embodiment, the original signal containing angle information acquired by the eddy current sensor is preprocessed to obtain the sine and cosine differential signals SinP(n), SinN(n), CosP(n), and CosN(n) corresponding to the original signal containing angle information. Differential processing is performed on the sine and cosine differential signals to obtain: sine signal Cosine signal .

[0064] S2. Obtain the angular velocity of the eddy current magnetic field based on the preprocessed sine and cosine signals, and determine whether the angular velocity of the eddy current magnetic field is less than or equal to a preset angular velocity threshold; if so, determine that the motor is in the low-speed stage and execute step S3; otherwise, determine that the motor is in the high-speed stage and execute step S4.

[0065] In practical implementation, the judgment conditions during the decoding stage are expressed as follows:

[0066] ;

[0067] In the formula, ω represents the angular velocity of the eddy current magnetic field at the current moment; This is a preset angular velocity threshold.

[0068] S3. Using the preset default sine and cosine amplitude values, and according to the software decoding calculation formula, the motor position is software decoded to calculate the angular velocity and electrical angle of the motor.

[0069] In practice, considering that the accuracy of the amplitude has little impact on the motor control performance when the motor is at low speed, the position is decoded using the default sine and cosine amplitude preset by the software when the eddy current magnetic field angular velocity is reached.

[0070] Specifically, S301, using the software to preset the default sine and cosine amplitude values, and combining the following formulas, calculate the initial electrical angle value and decoding index of the motor position soft decoding layer of the eddy current sensor.

[0071] ;

[0072] ;

[0073] ;

[0074] In the formula, and These are the initial electrical angle sine and cosine values, respectively; and These are the software's preset default sine and cosine amplitudes, respectively. For decoding indicators;

[0075] S302. Based on the calculated initial electrical angle value and decoding index, combined with preset angle difference compensation and speed estimation, the real-time angular velocity and electrical angle of the motor are calculated using the following formula.

[0076] ;

[0077] ;

[0078] ;

[0079] ;

[0080] ;

[0081] ;

[0082] In the formula, For the predicted electrical angle; The sampling period; The initial electrical angle acquired by the eddy current; This is the angle error value; It is an integral term; This is the integral gain coefficient; This is the proportional gain coefficient; This represents the number of pole pairs of the rotary transformer. This represents the number of pole pairs of the motor. The angular velocity of the motor at the current moment; The electric angle of the motor at the current moment.

[0083] S4. During motor operation, the maximum and minimum values ​​of sine and cosine signals are counted in real time, and the sine and cosine amplitudes are updated based on the statistical results.

[0084] In practice, while calculating the angular velocity and magnetic field angle of the eddy current magnetic field, the system continuously monitors the preprocessed signal generated in step S1. and And over a sufficiently long statistical period, the amplitude of the sinusoidal signal is recorded in real time and statistically analyzed to obtain the maximum amplitude. and minimum value The maximum amplitude is obtained by statistically analyzing the cosine signal. and minimum value Based on these statistical values, the updated amplitude, which better reflects the true level of the current signal, is calculated according to the following formula.

[0085] The formula for calculating the updated sine and cosine amplitudes is expressed as follows:

[0086] ;

[0087] ;

[0088] In the formula, This is the updated sine amplitude; and These represent the maximum and minimum amplitudes of the sinusoidal signal, respectively. This is the updated cosine amplitude; and These represent the maximum and minimum amplitudes of the cosine signal, respectively.

[0089] S5. Based on the updated sine and cosine amplitudes, and combined with the soft decoding calculation formula, the angular velocity and electrical angle of the motor are calculated.

[0090] In practical implementation, when the motor is at high speed, the accuracy of the amplitude has a significant impact on the motor control performance. This is especially true when the angular velocity of the eddy current magnetic field... At that time, use the amplitude updated in real time in step S4. , The next update amplitude and and Substituting into the same soft decoding calculation formula as in step S3, the angular velocity and electrical angle of the motor are calculated. This ensures that, under high-speed conditions with higher control precision requirements, the decoding result can adaptively compensate for signal attenuation or changes caused by factors such as individual sensor differences and temperature drift.

[0091] S6. Repeat steps S2 to S5 to achieve adaptive amplitude switching and continuous optimization of motor position soft decoding.

[0092] Example 2:

[0093] A soft decoding system for motor position using an adaptive eddy current sensor, such as Figure 4 As shown, it includes:

[0094] The signal acquisition module is used to acquire the sine and cosine differential signals output by the eddy current sensor, and to perform differential processing on the sine and cosine differential signals to obtain preprocessed sine and cosine signals.

[0095] The velocity determination module is used to obtain the angular velocity of the eddy current magnetic field based on the preprocessed sine and cosine signals, and to determine whether the angular velocity of the eddy current magnetic field is less than or equal to a preset angular velocity threshold.

[0096] The low-speed decoding module is used to perform soft decoding on the preprocessed sine and cosine signals using preset default sine and cosine amplitudes when the angular velocity of the eddy current magnetic field does not exceed the preset angular velocity threshold, so as to obtain the motor position information.

[0097] The amplitude update module is used to synchronously perform amplitude statistics on the preprocessed sine and cosine signals and update the sine and cosine amplitudes based on the statistical results.

[0098] The high-speed decoding module is used to call the updated sine and cosine amplitude values ​​when the angular velocity of the eddy current magnetic field exceeds the preset angular velocity threshold, and to perform soft decoding on the preprocessed sine and cosine signals to obtain the motor position information.

[0099] In summary, compared with the prior art, the adaptive eddy current sensor motor position soft decoding method and system proposed in this invention have the following technical advantages:

[0100] 1. This invention divides the motor operation process into two stages: low speed and high speed. In the low speed stage, the default amplitude is used for stable decoding to calculate the motor rotation position. At the same time, the actual amplitude range of the signal is statistically analyzed, thereby avoiding the strong dependence on amplitude accuracy at low speed. When entering the high speed stage, the system immediately switches to the maximum and minimum values ​​of the sine and cosine signals based on real-time statistics and updates the sine and cosine amplitudes for decoding. This significantly improves the position decoding accuracy and control performance of the motor under high speed and high dynamic conditions, thereby ensuring the overall efficiency and response speed of the motor system.

[0101] 2. This invention can solve the performance reduction or even failure caused by changes in individual amplitude through adaptive logic, ensure the robustness of motor control software, improve the rational utilization of eddy currents, and reduce costs. Based on the logic supervision of this invention, no hardware cost increase is required. The framework is simple, the logic is clear, and the applicability is strong. It can be quickly applied to the research and development of automotive power transmission technology with electric motors.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described with reference to preferred embodiments, those skilled in the art should understand that various changes in form and detail can be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A method of soft decoding of motor position of an adaptive eddy current sensor, characterized in that, Includes the following steps: S1. Acquire the sine and cosine differential signals output by the eddy current sensor, and perform differential processing on the sine and cosine differential signals to obtain preprocessed sine and cosine signals; S2. Obtain the angular velocity of the eddy current magnetic field based on the preprocessed sine and cosine signals, and determine whether the angular velocity of the eddy current magnetic field is less than or equal to a preset angular velocity threshold; if so, determine that the motor is in the low-speed stage and execute step S3; otherwise, determine that the motor is in the high-speed stage and execute step S4. S3. Using the preset default sine and cosine amplitude values, and according to the software decoding calculation formula, the motor position is software decoded to calculate the angular velocity and electrical angle of the motor. S4. During motor operation, the maximum and minimum values ​​of sine and cosine signals are counted in real time, and the sine and cosine amplitudes are updated based on the statistical results. S5. Based on the updated sine and cosine amplitudes, and combined with the soft decoding calculation formula, the angular velocity and electrical angle of the motor are calculated. S6. Repeat steps S2 to S5 to achieve adaptive amplitude switching and continuous optimization of motor position soft decoding.

2. The method of soft decoding of the motor position of an adaptive electrovortex sensor according to claim 1, characterized in that, In step S1, the sine and cosine signals are respectively represented as: ； ； wherein is a sine signal; is a sampled sine differential P signal; is a sampled sine differential N signal; is a cosine signal; is a sampled cosine differential P signal; is a sampled cosine differential N signal.

3. The method of claim 1, wherein, In step S2, the judgment condition for the decoding stage is expressed as follows: ； In the formula, is the current time eddy current magnetic field angular velocity; is a preset angular velocity threshold.

4. The method of claim 2, wherein, In step S3, the specific process of calculating the angular velocity and electrical angle of the motor according to the soft decoding calculation formula includes: S301. Using the software's preset default sine and cosine amplitude values, and combining the following formulas, calculate the initial electrical angle value and decoding index of the motor position soft decoding layer of the eddy current sensor. ； ； ； wherein, and are initial electrical angle sine and cosine values, respectively; and are software preset default sine and cosine amplitudes, respectively; is a decoding index; S302. Based on the calculated initial electrical angle value and decoding index, combined with preset angle difference compensation and speed estimation, the real-time angular velocity and electrical angle of the motor are calculated.

5. The motor position soft decoding method of the adaptive eddy current sensor according to claim 4, characterized in that, In step S302, the formula for calculating the real-time angular velocity and electrical angle of the motor is expressed as follows: ； ； ； ； ； ； In the formula, For the predicted electrical angle; The sampling period; The initial electrical angle acquired by the eddy current; This is the angle error value; It is an integral term; This is the integral gain coefficient; This is the proportional gain coefficient; This represents the number of pole pairs of the rotary transformer. This represents the number of pole pairs of the motor. The current angular velocity of the motor; The electric angle of the motor at the current moment.

6. The motor position soft decoding method of the adaptive eddy current sensor according to claim 1, characterized in that, In step S4, the formula for calculating the updated sine and cosine amplitudes is expressed as follows: ； ； In the formula, This is the updated sine amplitude; and These represent the maximum and minimum amplitudes of the sinusoidal signal, respectively. This is the updated cosine amplitude; and These represent the maximum and minimum amplitudes of the cosine signal, respectively.

7. A motor position soft decoding system based on an adaptive eddy current sensor, characterized in that, include: The signal acquisition module is used to acquire the sine and cosine differential signals output by the eddy current sensor, and to perform differential processing on the sine and cosine differential signals to obtain preprocessed sine and cosine signals. The velocity determination module is used to obtain the angular velocity of the eddy current magnetic field based on the preprocessed sine and cosine signals, and to determine whether the angular velocity of the eddy current magnetic field is less than or equal to a preset angular velocity threshold. The low-speed decoding module is used to perform soft decoding on the preprocessed sine and cosine signals using preset default sine and cosine amplitudes when the angular velocity of the eddy current magnetic field does not exceed the preset angular velocity threshold, so as to obtain the motor position information. The amplitude update module is used to synchronously perform amplitude statistics on the preprocessed sine and cosine signals and update the sine and cosine amplitudes based on the statistical results. The high-speed decoding module is used to call the updated sine and cosine amplitude values ​​when the angular velocity of the eddy current magnetic field exceeds the preset angular velocity threshold, and to perform soft decoding on the preprocessed sine and cosine signals to obtain the motor position information.

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