Digital angle calculation system and method based on amplitude-discriminating rotary transformer

Abstract

This invention provides a digital angle calculation system and method based on an amplitude-detecting rotary transformer. The system includes an excitation generation module, an amplitude-detecting rotary transformer, and a phase detection module. The output of the excitation generation module is connected to the secondary winding of the amplitude-detecting rotary transformer, and the primary winding of the amplitude-detecting rotary transformer is connected to the phase detection module. The output of the excitation generation module is also connected to the input of the phase detection module. The phase detection module converts the signal output from the primary winding of the amplitude-detecting rotary transformer into a square wave signal I, and converts the excitation signal output from the excitation generation module into a square wave signal II. The rotation angle value of the target under test is determined based on the square wave signal I and the square wave signal II. Through the aforementioned system, low-cost angle calculation can be achieved without changing the structure of the amplitude-detecting rotary transformer, while also ensuring the accuracy of the calculation.

Description

Technical Field

[0001] This invention relates to the field of measurement, and more particularly to a digital angle calculation system and method based on an amplitude-discriminating rotary transformer. Background Technology

[0002] A rotary transformer is a sensor used to measure rotation angles. Due to its advantages such as strong anti-interference and shock / vibration resistance, and high reliability, it is widely used in aviation, aerospace, shipbuilding, weaponry, and automotive industries. Rotary transformers can be divided into amplitude-detecting rotary transformers and phase-detecting rotary transformers based on their angle calculation principles. Most rotary transformers available on the market are amplitude-detecting, with phase-detecting rotary transformers being rare. This is mainly because the angle calculation technology for amplitude-detecting rotary transformers has followed mature foreign technologies, and there is no good technical solution for the calculation method of phase-detecting rotary transformers. In principle, phase-detecting calculation is easier to achieve higher calculation accuracy because amplitude-detecting calculation has very high requirements for the orthogonality and sinusoidality of the output induced signal, which is generally difficult to achieve. Phase-detecting calculation, on the other hand, measures the phase difference and has lower requirements for the quality of the output induced signal.

[0003] In existing technologies, the angle calculation of amplitude-discriminating rotary transformers is generally achieved using complex phase-locked loop feedback tracking technology. In order to ensure reliable circuit operation, it is generally made into a dedicated rotary transformer calculation chip RDC (Resolver Digital Converter). High-precision calculation technology is difficult to achieve, and it is difficult to find high-precision angle calculation chips in China. Although imported chips can achieve high-precision calculation, they are expensive and difficult to apply in civilian products.

[0004] Therefore, in order to solve the above-mentioned technical problems, it is urgent to propose a new technical approach. Summary of the Invention

[0005] In view of this, in order to reduce the cost of using amplitude-detecting rotary transformers, this invention proposes a digital angle calculation system and method based on amplitude-detecting rotary transformers.

[0006] The present invention provides a digital angle calculation system based on an amplitude-detecting rotary transformer, comprising an excitation generation module, an amplitude-detecting rotary transformer, and a phase detection module;

[0007] The output terminal of the excitation generation module is connected to the secondary winding of the amplitude-detecting rotary transformer, and the primary winding of the amplitude-detecting rotary transformer is connected to the phase detection module; the output terminal of the excitation generation module is also connected to the input terminal of the phase detection module.

[0008] The phase detection module is used to convert the signal output from the primary winding of the amplitude-detecting rotary transformer into a square wave signal I, and to convert the excitation signal output from the excitation generation module into a square wave signal II; and to determine the rotation angle value of the target under test based on the square wave signal I and the square wave signal II.

[0009] Furthermore, the phase detection module includes a zero-crossing comparator I, a zero-crossing comparator II, a phase comparison module, and a rotation angle value calculation module;

[0010] The input terminal of the zero-crossing comparator I is connected to the primary winding of the amplitude-discriminating rotary transformer, and is used to convert the signal output from the primary winding of the amplitude-discriminating rotary transformer into a square wave signal I.

[0011] The input terminal of the zero-crossing comparator II is connected to the output terminal of the excitation generation module, and is used to convert the excitation signal output by the excitation generation module into a square wave signal II.

[0012] The input terminal of the phase comparison module is connected to the output terminals of the zero-crossing comparator I and the zero-crossing comparator II. It is used to determine the square wave signal III based on the phase difference between the square wave signal I and the square wave signal II, and to insert high-frequency clock pulses into the square wave signal I and the square wave signal III and determine the number of high-frequency clock pulses inserted.

[0013] The input terminal of the rotation angle calculation module is connected to the output terminal of the phase comparison module, and is used to calculate the rotation angle value of the target under test based on the number of high-frequency clock pulses output by the phase comparison module.

[0014] Furthermore, the phase comparison module includes a phase generator, a high-frequency clock generator, and a counter;

[0015] The input terminal of the phase generator is connected to the output terminals of zero-crossing comparator I and zero-crossing comparator II, and is used to generate square wave signal III based on the phase difference between square wave signal I and square wave signal II; the high-level duration of square wave signal III is equal to the phase difference between square wave signal I and square wave signal II;

[0016] The high-frequency clock generator is used to generate high-frequency clock pulses and insert them into one signal cycle of the square wave signal I, and into the high level of the square wave signal III;

[0017] The counter is used to count the high-frequency clock pulses inserted into the square wave signal I and square wave signal III, and input the high-frequency clock pulse count value to the rotation angle value calculation module.

[0018] Furthermore, it also includes a signal preprocessing module, which includes at least a filter and an amplifier;

[0019] The input terminal of the filter is connected to the primary winding of the amplitude-detecting rotary transformer, the output terminal of the filter is connected to the input terminal of the amplifier, and the output terminal of the amplifier is connected to the input terminal of the phase-detecting module.

[0020] Accordingly, the present invention also provides a method for the above-mentioned digital angle calculation system based on an amplitude-discriminating rotary transformer, comprising the following steps:

[0021] S1. Obtain the signal output from the primary winding of the amplitude-discriminating rotary transformer and the excitation signal output from the excitation generation module;

[0022] S2. The signal output from the primary winding and the excitation signal are respectively converted into square wave signal I and square wave signal II;

[0023] S3. Generate square wave signal III based on the phase difference between square wave signal I and square wave signal II;

[0024] The high-level duration of square wave signal III is equal to the phase difference between square wave signal I and square wave signal II;

[0025] S4. Obtain the count value of the high-frequency clock pulses inserted into the square wave signal I within one cycle, and the count value of the high-frequency clock pulses inserted into the square wave signal III within the high level.

[0026] S5. Determine the rotation angle value of the target being measured based on the count value.

[0027] Furthermore, the rotation angle value of the target under test is calculated as follows:

[0028]

[0029] Among them, C θ C represents the rotation angle value of the target being measured. T C represents the count value of the high-frequency clock pulses inserted into the square wave signal I within one cycle. ΔP This represents the count value of the high-frequency clock pulses inserted within the high level of the square wave signal III. P represents the total number of pole pairs of the amplitude-discriminating rotary transformer, and n represents the number of pole pairs passed through during the measurement of the amplitude-discriminating rotary transformer. n is less than P.

[0030] Furthermore, before converting the signal output from the primary winding into square wave signal I, the method further includes: preprocessing the signal output from the primary winding, and converting the preprocessed signal into square wave signal I.

[0031] Furthermore, the preprocessing includes at least filtering and amplification.

[0032] The beneficial effects of this invention are as follows: By connecting the secondary winding of the amplitude-detecting rotary transformer to the excitation generation module and the primary winding to the phase-detection module, this invention converts the amplitude-detecting rotary transformer into a phase-detection rotary transformer. The rotation angle of the target under test can be calculated through the phase-detection module, reducing the cost of using the amplitude-detecting rotary transformer. Furthermore, compared with the amplitude-detecting rotary transformer, the phase-detection rotary transformer has a more stable output signal, is less susceptible to environmental factors, has stronger anti-interference capabilities, and its output phase information is easier to analyze, thus improving the speed and accuracy of the calculation. Attached Figure Description

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0034] Figure 1 This invention relates to a digital angle calculation system based on an amplitude-discriminating rotary transformer.

[0035] Figure 2 This is a comparison diagram of the amplitude-measuring rotary transformer before and after conversion according to the present invention.

[0036] Figure 3 This is a flowchart of the present invention. Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings:

[0038] This invention provides a digital angle calculation system based on an amplitude-discriminating rotary transformer, such as... Figure 1 , Figure 2 As shown, it includes an excitation generation module, an amplitude-detecting rotary transformer, and a phase-detection module;

[0039] The output terminal of the excitation generation module is connected to the secondary winding of the amplitude-detecting rotary transformer, and the primary winding of the amplitude-detecting rotary transformer is connected to the phase detection module; the output terminal of the excitation generation module is also connected to the input terminal of the phase detection module.

[0040] like Figure 2 As shown, under normal circumstances, the primary winding of the amplitude-measuring rotary transformer is connected to the output terminal of the excitation generation module, and the secondary winding of the amplitude-measuring rotary transformer is connected to the induction signal calculation module; that is, the two terminals R1 and R2 of the primary winding of the amplitude-measuring rotary transformer are connected to the output terminal of the excitation generation module, and the four terminals S1-S4 of the secondary winding of the amplitude-measuring rotary transformer are connected to the induction signal calculation module; the induction signal calculation module is the module that calculates the rotation angle value of the measured target based on the output induction signal. The structure of the induction signal calculation module varies depending on the rotary transformer used.

[0041] Because amplitude-detecting rotary transformers operate by applying a sinusoidal excitation voltage to the primary winding and detecting displacement by measuring the amplitude of the induced electromotive force (EMF) in the two secondary windings, and because the amplitude of the induced EMF is easily affected by factors such as temperature and power supply fluctuations and is difficult to analyze; while phase-detecting rotary transformers operate by applying AC excitation voltages of the same amplitude and frequency but with a phase difference of π / 2 to the two secondary windings respectively, and determining the magnitude of the measured displacement based on the phase of the induced EMF in the primary winding, phase-detecting rotary transformers are not only insensitive to external interference but are also easily analyzed; therefore, this application switches the amplitude-detecting rotary transformer to a phase-detecting rotary transformer by reversing the terminal connections.

[0042] Specifically, the secondary winding S1-S4 terminals of the amplitude-detecting rotary transformer are connected to the excitation generation module, and the primary winding R1 terminal of the amplitude-detecting rotary transformer is connected to the phase detection module (induction signal calculation module); the primary winding R2 terminal is grounded; the S1 and S2 terminals are connected to the J1 and J2 terminals of the excitation generation module respectively; the J3 and J4 terminals of the excitation generation module, and the S3 and S4 terminals are shorted together and then grounded. Figure 2 As shown;

[0043] In this diagram, R1 and R2, S1 and S3, and S2 and S4 correspond to the positive and negative terminals of different phases, respectively. R1 and R2 represent the positive and negative terminals of the induced phase in the primary winding of the amplitude-discriminating rotary transformer, respectively. S1 and S3 represent the positive and negative terminals of the cosine excitation phase in the secondary winding of the amplitude-discriminating rotary transformer, respectively. S2 and S4 represent the positive and negative terminals of the sine excitation phase in the secondary winding of the amplitude-discriminating rotary transformer, respectively. J1 represents the positive output terminal of the cosine signal, J2 represents the positive output terminal of the sine signal, J3 represents the negative output terminal of the cosine signal, and J4 represents the negative output terminal of the sine signal. The positive and negative output terminals represent the positive and negative half-cycles of the signal, respectively, and the positive and negative half-cycles together form a complete waveform.

[0044] The cosine excitation phase refers to the coil that receives the cosine excitation signal, and the sine excitation phase refers to the coil that receives the sine excitation signal. The phase detection module is used to convert the signal output from the primary winding of the amplitude-detecting rotary transformer into a square wave signal I, and to convert the excitation signal output from the excitation generation module into a square wave signal II. The rotation angle value of the target under test is determined based on the square wave signal I and the square wave signal II. This system reduces the measurement cost of the amplitude-detecting rotary transformer.

[0045] In this embodiment, the phase detection module includes a zero-crossing comparator I, a zero-crossing comparator II, a phase comparison module, and a rotation angle value calculation module;

[0046] The input terminal of the zero-crossing comparator I is connected to the primary winding of the amplitude-discriminating rotary transformer, and is used to convert the signal output from the primary winding of the amplitude-discriminating rotary transformer into a square wave signal I.

[0047] The signal output from the primary winding of the amplitude-discriminating rotary transformer is represented by an induced electromotive force E. r The expression is as follows:

[0048] E r =KU m sin(ω t +θ)

[0049] Where K represents the turns ratio of the rotary transformer, U m ω represents the amplitude of the induced electromotive force, ω represents the angular frequency of the excitation signal, t represents time, and θ represents the rotation angle of the target being measured.

[0050] The phase of the output induced signal contains angular information. By converting the angular information in the phase into a digital signal through phase comparison, the measurement accuracy and reliability can be improved, the signal processing flow can be simplified, and the anti-interference capability can be enhanced.

[0051] The input terminal of the zero-crossing comparator II is connected to the output terminal of the excitation generation module, and is used to convert the excitation signal output by the excitation generation module into a square wave signal II.

[0052] The input terminal of the phase comparison module is connected to the output terminals of the zero-crossing comparator I and the zero-crossing comparator II. It is used to determine the square wave signal III based on the phase difference between the square wave signal I and the square wave signal II, and to insert high-frequency clock pulses into the square wave signal I and the square wave signal III and determine the number of high-frequency clock pulses inserted. The phase difference between the square wave signal I and the square wave signal II can be intuitively reflected through the square wave signal III, thereby displaying the angle change information.

[0053] The input terminal of the rotation angle calculation module is connected to the output terminal of the phase comparison module, and is used to calculate the rotation angle value of the target under test based on the number of high-frequency clock pulses output by the phase comparison module.

[0054] In this embodiment, the phase comparison module includes a phase generator, a high-frequency clock generator, and a counter;

[0055] The input terminal of the phase generator is connected to the output terminals of zero-crossing comparator I and zero-crossing comparator II, and is used to generate square wave signal III based on the phase difference between square wave signal I and square wave signal II; the high-level duration of square wave signal III is equal to the phase difference between square wave signal I and square wave signal II;

[0056] The high-frequency clock generator is used to generate high-frequency clock pulses and insert them into one signal cycle of the square wave signal I, and into the high level of the square wave signal III;

[0057] The counter is used to count the high-frequency clock pulses inserted into the square wave signal I and square wave signal III, and input the high-frequency clock pulse count value to the rotation angle value calculation module. Counter I is used to count the high-frequency clock pulses inserted into the square wave signal I, and counter II is used to count the high-frequency clock pulses inserted into the square wave signal III.

[0058] The above method calculates the angle value using a counter and a multiplier. This calculation leverages the integrated counter and multiplier functions of a general-purpose processor chip, eliminating the need for additional components, significantly simplifying the hardware circuitry and reducing costs. This embodiment also includes a signal preprocessing module, which at least includes a filter and an amplifier; a noise reduction module may also be added.

[0059] The input terminal of the filter is connected to the primary winding of the amplitude-discriminating rotary transformer, and the output terminal of the filter is connected to the input terminal of the amplifier. The output terminal of the amplifier is connected to the input terminal of the phase-detection module. Through the preprocessing module, unwanted frequency components in the signal can be removed and the signal amplified, ensuring the accuracy and reliability of the signal. Accordingly, the present invention also provides a method for the above-mentioned digital angle calculation system based on an amplitude-discriminating rotary transformer, comprising the following steps:

[0060] S1. Obtain the signal output from the primary winding of the amplitude-discriminating rotary transformer and the excitation signal output from the excitation generation module;

[0061] S2. The signal output from the primary winding and the excitation signal are respectively converted into square wave signal I and square wave signal II;

[0062] S3. Generate square wave signal III based on the phase difference between square wave signal I and square wave signal II;

[0063] The high-level duration of square wave signal III is equal to the phase difference between square wave signal I and square wave signal II;

[0064] S4. Obtain the count value of the high-frequency clock pulses inserted into the square wave signal I within one cycle, and the count value of the high-frequency clock pulses inserted into the square wave signal III within the high level.

[0065] S5. Determine the rotation angle value of the target being measured based on the count value. Using the above method, the rotation angle value of the target being measured can be determined quickly and accurately.

[0066] In this embodiment, in step S1, the signal output from the primary winding of the amplitude-discriminating rotary transformer and the excitation signal output from the excitation generation module are obtained.

[0067] By following the steps above, a signal containing the rotation angle of the target being measured can be obtained.

[0068] In this embodiment, in step S2, the signal output from the primary winding and the excitation signal are respectively converted into square wave signal I and square wave signal II. The aforementioned method can improve signal processing efficiency and stability.

[0069] In this embodiment, in step S3, a square wave signal III is generated based on the phase difference between the square wave signal I and the square wave signal II; the high-level duration of the square wave signal III is equal to the phase difference between the square wave signal I and the square wave signal II; the square wave signal III can accurately reflect the phase difference between the square wave signal I and the square wave signal II, thereby reflecting the change in angle.

[0070] In this embodiment, in step S4, the count value of the high-frequency clock pulses inserted into the square wave signal I within one cycle and the count value of the high-frequency clock pulses inserted into the square wave signal III within the high level are obtained; this step can be implemented by a high-frequency clock pulse generator and a counter.

[0071] In this embodiment, in step S5, the rotation angle value of the target under test is determined based on the count value. The rotation angle value of the target under test is calculated as follows:

[0072]

[0073] Among them, C θ C represents the rotation angle value of the target being measured. T C represents the count value of the high-frequency clock pulses inserted into the square wave signal I within one cycle. ΔP This represents the count value of the high-frequency clock pulses inserted within the high level of the square wave signal III. P represents the total number of pole pairs of the amplitude-discriminating rotary transformer, and n represents the number of pole pairs traversed by the amplitude-discriminating rotary transformer during measurement, where n is less than P. Using the above method, the rotation angle of the measured target can be calculated quickly and easily without using expensive chips or changing the design of the existing amplitude-discriminating rotary transformer. This significantly reduces the computational cost of the amplitude-discriminating rotary transformer while ensuring computational accuracy and efficiency.

[0074] In this embodiment, before converting the signal output from the primary winding into square wave signal I, the method further includes: preprocessing the signal output from the primary winding, and converting the preprocessed signal into square wave signal I; the preprocessing includes at least filtering and amplification, and can also remove noise. Signal preprocessing can significantly improve the quality and reliability of the signal.

[0075] The number of pole pairs, frequency, and amplitude in this application are set based on experience or requirements.

[0076] 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 in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A digital angle calculation system based on an amplitude-discriminating rotary transformer, characterized in that: This includes an excitation generation module, an amplitude-detecting rotary transformer, and a phase-detection module; The output terminal of the excitation generation module is connected to the secondary winding of the amplitude-detecting rotary transformer, and the primary winding of the amplitude-detecting rotary transformer is connected to the phase detection module; the output terminal of the excitation generation module is also connected to the input terminal of the phase detection module. The phase detection module is used to convert the signal output from the primary winding of the amplitude-detecting rotary transformer into a square wave signal I, and to convert the excitation signal output from the excitation generation module into a square wave signal II; and to determine the rotation angle value of the target under test based on the square wave signal I and the square wave signal II. The phase detection module includes a zero-crossing comparator I, a zero-crossing comparator II, a phase comparison module, and a rotation angle value calculation module; The input terminal of the zero-crossing comparator I is connected to the primary winding of the amplitude-discriminating rotary transformer, and is used to convert the signal output from the primary winding of the amplitude-discriminating rotary transformer into a square wave signal I. The input terminal of the zero-crossing comparator II is connected to the output terminal of the excitation generation module, and is used to convert the excitation signal output by the excitation generation module into a square wave signal II. The input terminal of the phase comparison module is connected to the output terminals of the zero-crossing comparator I and the zero-crossing comparator II. It is used to determine the square wave signal III based on the phase difference between the square wave signal I and the square wave signal II, and to insert high-frequency clock pulses into the square wave signal I and the square wave signal III and determine the number of high-frequency clock pulses inserted. The input terminal of the rotation angle calculation module is connected to the output terminal of the phase comparison module. It is used to calculate the rotation angle value of the target under test based on the number of high-frequency clock pulses output by the phase comparison module. The phase comparison module includes a phase generator, a high-frequency clock generator, and a counter; The input terminal of the phase generator is connected to the output terminals of zero-crossing comparator I and zero-crossing comparator II, and is used to generate square wave signal III based on the phase difference between square wave signal I and square wave signal II; the high-level duration of square wave signal III is equal to the phase difference between square wave signal I and square wave signal II; The high-frequency clock generator is used to generate high-frequency clock pulses and insert them into one signal cycle of the square wave signal I, and into the high level of the square wave signal III; The counter is used to count the high-frequency clock pulses inserted into the square wave signal I and square wave signal III, and input the high-frequency clock pulse count value to the rotation angle value calculation module.

2. The digital angle calculation system based on an amplitude-discriminating rotary transformer according to claim 1, characterized in that: It also includes a signal preprocessing module, which includes at least a filter and an amplifier; The input terminal of the filter is connected to the primary winding of the amplitude-detecting rotary transformer, the output terminal of the filter is connected to the input terminal of the amplifier, and the output terminal of the amplifier is connected to the input terminal of the phase-detecting module.

3. A method for calculating digital angles based on the amplitude-discriminating rotary transformer as described in any one of claims 1-2, characterized in that: Includes the following steps: S1. Obtain the signal output from the primary winding of the amplitude-discriminating rotary transformer and the excitation signal output from the excitation generation module; S2. The signal output from the primary winding and the excitation signal are respectively converted into square wave signal I and square wave signal II; S3. Generate square wave signal III based on the phase difference between square wave signal I and square wave signal II; The high-level duration of square wave signal III is equal to the phase difference between square wave signal I and square wave signal II; S4. Obtain the count value of the high-frequency clock pulses inserted into the square wave signal I within one cycle, and the count value of the high-frequency clock pulses inserted into the square wave signal III within the high level. S5. Determine the rotation angle value of the target being measured based on the count value.

4. The method according to claim 3, characterized in that: The rotation angle value of the target under test is calculated as follows: Among them, C θ C represents the rotation angle value of the target being measured. T C represents the count value of the high-frequency clock pulses inserted into the square wave signal I within one cycle. ΔP This represents the count value of the high-frequency clock pulses inserted within the high level of the square wave signal III. P represents the total number of pole pairs of the amplitude-discriminating rotary transformer, and n represents the number of pole pairs passed through during the measurement of the amplitude-discriminating rotary transformer. n is less than P.

5. The method according to claim 3 or claim 4, characterized in that: Before converting the signal output from the primary winding into square wave signal I, the method further includes: preprocessing the signal output from the primary winding, and converting the preprocessed signal into square wave signal I.

6. The method according to claim 5, characterized in that: The preprocessing includes at least filtering and amplification.

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