Digital angle resolving system and method based on amplitude discrimination type rotary transformer

Abstract

The invention provides a digital angle resolving system and method based on an amplitude discrimination type rotary transformer. The system comprises an excitation generation module, the amplitude discrimination type rotary transformer and a phase discrimination module. The output end of the excitation generation module is connected to a secondary winding of the amplitude discrimination type rotary transformer, and a primary winding of the amplitude discrimination type rotary transformer is connected to the phase discrimination module; the output end of the excitation generation module is also connected to the input end of the phase discrimination module; the phase discrimination module is used for converting a signal output by a primary winding of the amplitude discrimination type rotary transformer into a square wave signal I and converting an excitation signal output by the excitation generation module into a square wave signal II; according to the system, on the premise that the structure of the amplitude discrimination type rotary transformer is not changed, low-cost angle calculation can be achieved, and the calculation precision can also be guaranteed.

Description

Technical Field

[0001] The invention relates to a measurement field, and in particular to a digital angle solution system and method based on an amplitude-detection rotary transformer. Background Art

[0002] A rotary transformer is a sensor used to measure the angle of rotation. It is widely used in aviation, aerospace, shipbuilding, weapons and equipment, automobiles and other fields because of its strong anti-interference and anti-impact vibration capabilities and high reliability. Based on the angle resolution principle, the rotary transformer can be divided into an amplitude-detection rotary transformer and a phase-detection rotary transformer. The rotary transformers available on the market are basically amplitude-detection rotary transformers, and phase-detection rotary transformers are rarely seen. The main reason is that the angle resolution technology of amplitude-detection rotary transformers has always followed the mature technology of foreign countries, and there is no good technical solution for the resolution method of phase-detection rotary transformers. In principle, the phase-detection resolution is easier to obtain higher resolution accuracy. This is because the amplitude-detection resolution has high requirements on the orthogonality and sinusoidality of the output sensing signal, which is generally difficult to achieve, while the phase-detection resolution measures the phase difference and has lower requirements on the quality of the output sensing signal.

[0003] In the prior art, the angle resolution of the amplitude-detection rotary transformer is generally achieved by using a complex phase-locked loop feedback tracking technology. In order to ensure the reliable operation of the circuit, a dedicated resolver chip RDC (Resolver Digital Converter) for the rotary transformer is generally used. The high-precision resolution technology is difficult, and it is difficult to find a high-precision angle resolution chip in China. Although imported chips can achieve high-precision resolution, they are expensive and difficult to use in civilian products.

[0004] Therefore, in order to solve the above technical problems, it is urgent to propose a new technical means. Summary of the invention

[0005] In view of this, in order to reduce the use cost of the amplitude-detection rotary transformer, the present invention proposes a digital angle resolution system and method based on the amplitude-detection rotary transformer.

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

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

[0008] The phase detection module is used to convert the signal output by the primary winding of the amplitude detection rotary transformer into a square wave signal I, and to convert the excitation signal output by the excitation generation module into a square wave signal II; and to determine the rotation angle value of the measured target 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 end of the zero-crossing comparator I is connected to the primary winding of the amplitude-detection rotary transformer, and is used to convert the signal output by the primary winding of the amplitude-detection rotary transformer into a square wave signal I;

[0011] The input end of the zero-crossing comparator II is connected to the output end 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 end of the phase comparison module is connected to the output end of the zero-crossing comparator I and the zero-crossing comparator II, and is used to determine the square wave signal III according to the phase difference between the square wave signal I and the square wave signal II, and insert high-frequency clock pulses into the square wave signal I and the square wave signal III and determine the number of inserted high-frequency clock pulses;

[0013] The input end of the rotation angle value calculation module is connected to the output end of the phase comparison module, and is used to calculate the rotation angle value of the measured target according to 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 end of the phase generator is connected to the output end of the zero-crossing comparator I and the zero-crossing comparator II, and is used to generate a square wave signal III according to 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;

[0016] The high-frequency clock generator is used to generate a high-frequency clock pulse, and insert it into a signal cycle of the square wave signal I, and insert it 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 the square wave signal III, and input the high-frequency clock pulse count value into 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 end of the filter is connected to the primary winding of the amplitude detection rotary transformer, the output end of the filter is connected to the input end of the amplifier, and the output end of the amplifier is connected to the input end of the phase detection module.

[0020] Accordingly, the present invention also provides a method for the digital angle resolution system based on the amplitude detection rotary transformer, comprising the following steps:

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

[0022] S2. Convert the signal output by the primary winding and the excitation signal into square wave signal I and square wave signal II respectively;

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

[0024] 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;

[0025] S4. Obtaining the count value of the high-frequency clock pulse inserted in one cycle of the square wave signal Ⅰ, and the count value of the high-frequency clock pulse inserted in the high level of the square wave signal Ⅲ;

[0026] S5. Determine the rotation angle value of the measured target according to the count value.

[0027] Further, the rotation angle value of the measured target is calculated as follows:

[0028]

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

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

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

[0032] The beneficial effects of the present invention are as follows: the present invention converts the amplitude-detection rotary transformer into a phase-detection rotary transformer by connecting the secondary winding of the amplitude-detection rotary transformer with the excitation generation module and the primary winding with the phase-detection module, and the rotation angle of the measured target can be solved by the phase-detection module, thereby reducing the use cost of the amplitude-detection rotary transformer; and compared with the amplitude-detection rotary transformer, the output signal of the phase-detection rotary transformer is not easily affected by environmental factors, has stronger anti-interference ability, and the output phase information is easier to be parsed, which can improve the speed and accuracy of the solution. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0034] Figure 1 The invention discloses a digital angle calculation system based on an amplitude-detection rotary transformer.

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

[0036] Figure 3 It is a flow chart of the present invention. DETAILED DESCRIPTION

[0037] The present invention is further described below in conjunction with the accompanying drawings:

[0038] The present 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 detection rotary transformer and a phase detection module;

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

[0040] like Figure 2 As shown, in general, the primary winding of the amplitude detection rotary transformer is connected to the output end of the excitation generation module, and the secondary winding of the amplitude detection rotary transformer is connected to the induction signal resolution module; that is, the two wiring terminals R1 and R2 of the primary winding of the amplitude detection rotary transformer are connected to the output end of the excitation generation module, and the four wiring terminals S1-S4 of the secondary winding of the amplitude detection rotary transformer are connected to the induction signal resolution module; the induction signal resolution module refers to a module that resolves the rotation angle value of the measured target according to the output induction signal, and the structure of the induction signal resolution module is different according to the different rotary transformers set;

[0041] Since the working mode of the amplitude-detection type rotary transformer is to pass a sinusoidal excitation voltage through the primary winding, and to realize displacement detection by detecting the amplitude of the induced potential in the two secondary windings of the rotary transformer, and the amplitude of the induced potential is easily affected by factors such as temperature and power supply fluctuations, and is not easy to be analyzed; while the working mode of the phase-detection type rotary transformer is to pass an AC excitation voltage of the same amplitude and frequency but with a phase difference of π / 2 through the two secondary windings, respectively, and to determine the detection method of the measured displacement size according to the phase of the induced potential in the primary winding of the rotary transformer, the phase-detection type rotary transformer is not only insensitive to external interference, but also easy to be analyzed; therefore, the present application switches the amplitude-detection type rotary transformer to the phase-detection type rotary transformer by reversing the connection terminals;

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

[0043] Among them, R1 and R2, S1 and S3, and S2 and S4 correspond to the positive and negative ends of different phases respectively, R1 and R2 correspond to the positive and negative ends of the induction phase in the primary winding of the amplitude detection type rotary transformer respectively, S1 and S3 correspond to the positive and negative ends of the cosine excitation phase in the secondary winding of the amplitude detection type rotary transformer respectively, and S2 and S4 correspond to the positive and negative ends of the sine excitation phase in the secondary winding of the amplitude detection type rotary transformer respectively; J1 represents the positive output end of the cosine signal, J2 represents the positive output end of the sine signal, J3 represents the negative output end of the cosine signal, and J4 represents the negative output end of the sine signal; the positive output end and the negative output end correspond to the positive half cycle and the negative half cycle of the signal respectively, and the positive half cycle and the negative half cycle constitute a complete waveform;

[0044] The cosine excitation phase refers to a coil that receives a cosine excitation signal, and the sine excitation phase refers to a coil that receives a sine excitation signal; the phase detection module is used to convert the signal output by the primary winding of the amplitude detection rotary transformer into a square wave signal I, and to convert the excitation signal output by the excitation generation module into a square wave signal II; and the rotation angle value of the measured target is determined according to the square wave signal I and the square wave signal II. Through the above system, the measurement cost of the amplitude detection rotary transformer can be reduced.

[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 end of the zero-crossing comparator I is connected to the primary winding of the amplitude-detection rotary transformer, and is used to convert the signal output by the primary winding of the amplitude-detection rotary transformer into a square wave signal I;

[0047] The signal output by the primary winding of the amplitude-detection rotary transformer is expressed as 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 ratio of the resolver, U m represents the amplitude of the induced electromotive force, ω represents the angular frequency of the excitation signal, t represents the time, and θ represents the rotation angle of the target being measured;

[0050] The phase of the output induction signal contains angle information. The angle information in the phase is converted into a digital signal by the phase comparison method, which can not only improve the measurement accuracy and reliability, but also simplify the signal processing process and enhance the anti-interference ability.

[0051] The input end of the zero-crossing comparator II is connected to the output end 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 end of the phase comparison module is connected to the output end of the zero-crossing comparator I and the zero-crossing comparator II, and is used to determine the square wave signal III according to the phase difference between the square wave signal I and the square wave signal II, and insert high-frequency clock pulses into the square wave signal I and the square wave signal III and determine the number of inserted high-frequency clock pulses; the square wave signal III can intuitively reflect the phase difference between the square wave signal I and the square wave signal II, thereby displaying the angle change information;

[0053] The input end of the rotation angle value calculation module is connected to the output end of the phase comparison module, and is used to calculate the rotation angle value of the measured target according to 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 end of the phase generator is connected to the output end of the zero-crossing comparator I and the zero-crossing comparator II, and is used to generate a square wave signal III according to 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;

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

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

[0058] The above method can realize the calculation of angle value by using a counter counting method with a multiplier, and can realize the operation by using the counter and multiplier functions integrated in the general processor chip, without adding additional devices, greatly simplifying the hardware circuit and reducing the use cost. In this embodiment, a signal preprocessing module is also included, and the signal preprocessing module includes at least a filter and an amplifier; a denoising module can also be added;

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

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

[0061] S2. Convert the signal output by the primary winding and the excitation signal into square wave signal I and square wave signal II respectively;

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

[0063] 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;

[0064] S4. Obtaining the count value of the high-frequency clock pulse inserted in one cycle of the square wave signal Ⅰ, and the count value of the high-frequency clock pulse inserted in the high level of the square wave signal Ⅲ;

[0065] S5. Determine the rotation angle value of the measured object according to the count value. The above method can quickly and accurately determine the rotation angle value of the measured object.

[0066] In this embodiment, in step S1, a signal output by the primary winding of the amplitude detection rotary transformer and an excitation signal output by the excitation generation module are obtained.

[0067] Through the above steps, a signal containing the rotation angle of the target to be measured can be obtained.

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

[0069] In this embodiment, in step S3, 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 pulse inserted in one cycle of the square wave signal I and the count value of the high-frequency clock pulse inserted in the high level of the square wave signal III are obtained; this step can be achieved by a high-frequency clock pulse generator and a counter.

[0071] In this embodiment, in step S5, the rotation angle value of the measured target is determined according to the count value, and the rotation angle value of the measured target is calculated as follows:

[0072]

[0073] Among them, C θ Indicates the rotation angle value of the target being measured, C T Indicates the count value of the high-frequency clock pulse inserted into the square wave signal I in one cycle, C ΔP It represents the count value of the high-frequency clock pulse inserted into the high level of the square wave signal III, P represents the total number of pole pairs of the amplitude-discriminator rotary transformer, n represents the number of pole pairs passed by the amplitude-discriminator rotary transformer during measurement, and n is less than P. Through the above method, the rotation angle of the measured target can be quickly and simply calculated without using expensive chips or changing the design of the existing amplitude-discriminator rotary transformer, which not only significantly reduces the calculation cost of the amplitude-discriminator rotary transformer, but also ensures the calculation accuracy and efficiency.

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

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

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A digital angle calculation system based on an amplitude-detection rotary transformer, characterized in that: It includes an excitation generation module, an amplitude detection rotary transformer and a phase detection module; The output end of the excitation generation module is connected to the secondary winding of the amplitude detection rotary transformer, and the primary winding of the amplitude detection rotary transformer is connected to the phase detection module; the output end of the excitation generation module is also connected to the input end of the phase detection module; The phase detection module is used to convert the signal output by the primary winding of the amplitude detection rotary transformer into a square wave signal I, and to convert the excitation signal output by the excitation generation module into a square wave signal II; and to determine the rotation angle value of the measured target based on the square wave signal I and the square wave signal II.

2. According to claim 1, the digital angle calculation system based on the amplitude detection rotary transformer is characterized in that: 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 end of the zero-crossing comparator I is connected to the primary winding of the amplitude-detection rotary transformer, and is used to convert the signal output by the primary winding of the amplitude-detection rotary transformer into a square wave signal I; The input end of the zero-crossing comparator II is connected to the output end 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 end of the phase comparison module is connected to the output end of the zero-crossing comparator I and the zero-crossing comparator II, and is used to determine the square wave signal III according to the phase difference between the square wave signal I and the square wave signal II, and insert high-frequency clock pulses into the square wave signal I and the square wave signal III and determine the number of inserted high-frequency clock pulses; the input end of the rotation angle value calculation module is connected to the output end of the phase comparison module, and is used to calculate the rotation angle value of the target to be measured according to the number of high-frequency clock pulses output by the phase comparison module.

3. The digital angle calculation system based on the amplitude-detection rotary transformer according to claim 2 is characterized in that: The phase comparison module includes a phase generator, a high-frequency clock generator, and a counter; The input end of the phase generator is connected to the output end of the zero-crossing comparator I and the zero-crossing comparator II, and is used to generate a square wave signal III according to 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 high-frequency clock generator is used to generate a high-frequency clock pulse, and insert it into a signal cycle of the square wave signal I, and insert it 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 the square wave signal III, and input the high-frequency clock pulse count value into the rotation angle value calculation module.

4. The digital angle calculation system based on the amplitude-detection rotary transformer according to any one of claims 1 to 3, characterized in that: It also includes a signal preprocessing module, which includes at least a filter and an amplifier; The input end of the filter is connected to the primary winding of the amplitude detection rotary transformer, the output end of the filter is connected to the input end of the amplifier, and the output end of the amplifier is connected to the input end of the phase detection module.

5. A method for a digital angle resolution system based on an amplitude detector rotary transformer according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. Obtain the output signal of the primary winding of the amplitude-discriminating rotary transformer and the excitation signal output by the excitation generating module; S2. Convert the signal output by the primary winding and the excitation signal into square wave signal I and square wave signal II respectively; S3. Generate a square wave signal III 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; S4. Obtaining the count value of the high-frequency clock pulse inserted in one cycle of the square wave signal Ⅰ, and the count value of the high-frequency clock pulse inserted in the high level of the square wave signal Ⅲ; S5. Determine the rotation angle value of the measured target according to the count value.

6. The method according to claim 5, characterized in that: The rotation angle value of the measured target is calculated as follows: Among them, C θ Indicates the rotation angle value of the target being measured, C T Indicates the count value of the high-frequency clock pulse inserted into the square wave signal I in one cycle, C ΔP It represents the count value of the high-frequency clock pulse inserted into the high level of the square wave signal III, P represents the total number of pole pairs of the amplitude-discrimination rotary transformer, n represents the number of pole pairs passed during the measurement of the amplitude-discrimination rotary transformer, and n is less than P.

7. The method according to any one of claim 5 or claim 6, characterized in that: Before converting the signal output by the primary winding into the square wave signal I, the method further includes: preprocessing the signal output by the primary winding, and converting the preprocessed signal into the square wave signal I.

8. The method according to claim 7, characterized in that: The preprocessing includes at least filtering and amplification.

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