CN115494758A - Data acquisition device and decoding method of rotary transformer - Google Patents

Abstract

The application provides a resolver's data acquisition device and decoding method, belongs to conversion motor control field, the device includes: the motor speed conversion circuit, the double-excitation sine and cosine differential output circuit and the double-sine and cosine differential signal input circuit. The method comprises the following steps: generating sine and cosine excitation signals; converting the sine and cosine excitation signals into sine and cosine differential signals, wherein the sine and cosine differential signals are used as the input of a rotary transformer; receiving sine and cosine differential signals generated by a rotary transformer; converting sine and cosine differential signals generated by a rotary transformer into sine and cosine response signals which can be identified by a motor speed conversion circuit; obtaining a motor angle according to the sine and cosine excitation signal and the sine and cosine response signal; and obtaining the motor speed according to the motor angle. The device replaces a special rotary transformer decoding chip, the hardware device is strong in universality, the hardware development period and cost are reduced, and the sampling precision and the calculation precision are improved.

Description

A data acquisition device and decoding method for a resolver

technical field

The application belongs to the field of variable current motor control, and in particular relates to a data acquisition device and a decoding method of a rotary transformer.

Background technique

A resolver, referred to as a resolver, is a sensor that collects the position and speed of a motor, also known as an encoder. Compared with encoders of photoelectric technology, resolvers have the ability to adapt to harsh environments such as heat resistance, vibration resistance, impact resistance, oil stain resistance and corrosion resistance, and are widely used in the field of frequency converter motor control in many large factories. At present, for resolver signal acquisition, foreign manufacturers' dedicated integrated chips or MCU interfaces with dedicated resolver decoding integration are used, and the register configuration of the dedicated resolver integrated chip is performed through software to read the speed and position data in the register. This dedicated integrated chip is often out of supply and the price is generally high; currently there are various types of resolvers on the market, there are one pair of single-excitation differential signal input, two pairs of sine-cosine differential signal output; there are also two pairs of dual-excitation sine-cosine differential input , two pairs of sine and cosine differential signal outputs; there are also two pairs of dual excitation sine and cosine differential inputs, and a pair of differential signal outputs. The use of different dedicated resolver decoding integrated chips will lead to large differences in the hardware acquisition devices, thereby increasing the development cycle and cost of the hardware, which is not conducive to the generality requirements of the hardware.

Contents of the invention

Based on the above technical problems, the present application proposes a data acquisition device and a decoding method for a resolver.

In the first aspect, the present application proposes a data acquisition device for a resolver, including: a motor speed conversion circuit, a dual excitation sine and cosine differential output circuit, and a dual sine and cosine differential signal input circuit;

The output end of the motor speed conversion circuit is connected to the input end of the dual-excitation sin-cosine differential output circuit, and the output end of the dual-excitation sin-cosine differential output circuit is connected to the input end of the resolver, and the resolver The output end of the double sine-cosine differential signal input circuit is connected to the input end, and the output end of the double sine-cosine differential signal input circuit is connected to the input end of the motor speed conversion circuit;

The motor speed conversion circuit is used to generate the sine-cosine excitation signal, and simultaneously receive the sine-cosine response signal output by the dual-sin-cosine differential signal input circuit, and obtain the motor angle according to the sine-cosine excitation signal and the sine-cosine response signal, obtain the motor speed according to the motor angle;

The dual-excitation sin-cosine differential output circuit is used to convert the sin-cosine excitation signal into a sin-cosine differential signal, and the sin-cosine differential signal is used as the input of the resolver;

The dual sine-cosine differential signal input circuit is used to convert the sine-cosine differential signal output by the rotary transformer into a sine-cosine response signal that can be recognized by the motor speed conversion circuit.

The data acquisition device of the resolver further includes a communication circuit for communication between the main controller and the motor speed conversion circuit.

The data acquisition device of the rotary transformer further includes a signal isolation circuit, which is used for performing signal isolation between the dual-excitation sin-cosine differential output circuit and the rotary transformer, and between the dual-sin-cosine differential signal input circuit and the rotary transformer. isolation.

The dual-excitation sin-cosine differential output circuit includes: a digital-to-analog conversion circuit, a push-pull drive circuit, and a single-ended to differential circuit;

The first output end of the digital-to-analog conversion circuit is connected to the first input end of the push-pull drive circuit, and the first output end of the push-pull drive circuit is connected to the first input end of the single-ended to differential circuit, The second output end of the digital-to-analog conversion circuit is connected to the second input end of the push-pull drive circuit, and the second output end of the push-pull drive circuit is connected to the second input end of the single-ended to differential circuit, The first output terminal, the second output terminal, the third output terminal and the fourth output terminal of the single-ended to differential circuit are respectively connected to the first input terminal, the second input terminal, the third input terminal and the first input terminal of the signal isolation circuit. The four input terminals are connected;

The digital-to-analog conversion circuit is used to convert the sine-cosine excitation signal into an analog signal;

The push-pull drive circuit is used to amplify the analog signal to a predetermined multiple according to the requirements of the resolver to obtain an analog amplified signal;

The single-ended-to-differential conversion circuit is used to convert the analog amplified signal into a sine-cosine differential signal.

The dual-sine-cosine differential signal input circuit includes: a differential-to-single-ended circuit, an operational amplifier conditioning circuit, and an analog-to-digital conversion circuit;

The first input terminal, the second input terminal, the third input terminal and the fourth input terminal of the differential-to-single-ended circuit are respectively connected to the first output terminal, the second output terminal, the third output terminal and the signal isolation circuit. The fourth output terminal is connected, the first output terminal of the differential to single-ended circuit is connected to the first input terminal of the operational amplifier conditioning circuit, the first output terminal of the operational amplifier conditioning circuit is connected to the analog-to-digital conversion The first input end of the circuit is connected, the second output end of the differential to single-ended circuit is connected to the second input end of the operational amplifier conditioning circuit, the second output end of the operational amplifier conditioning circuit is connected to the analog The second input terminal of the digital conversion circuit is connected;

The differential-to-single-ended circuit is used to convert the sine-cosine differential signal output by the resolver into a sine-cosine single-ended signal;

The operational amplifier conditioning circuit is used to reduce the sine-cosine single-ended signal to a predetermined multiple according to the requirements of the analog-to-digital conversion circuit, so as to obtain the reduced sine-cosine single-ended signal;

The analog-to-digital conversion circuit is used to convert the reduced sin-cos single-ended signal into the sin-cos response signal.

The motor speed conversion circuit is implemented by a programmable logic array or a programmable chip.

The motor angle is calculated according to the following formula:

Among them, E _{E_F} is the sine differential signal output by the resolver. According to the principle of the double sine and cosine differential signal input circuit, the sine differential signal is deduced from the sine response signal. E _{G_H} is the cosine differential signal output by the resolver. According to the double sine and cosine differential signal input The circuit principle is to deduce the cosine differential signal from the cosine response signal. E _{A_B} is the sine differential signal input by the resolver. According to the principle of the dual-excitation sine-cosine differential output circuit, the sine differential signal is deduced from the sine excitation signal. E _{C_D} is the cosine input from the resolver. Differential signal, according to the principle of dual excitation sine and cosine differential output circuit, the cosine differential signal is deduced from the cosine excitation signal, and θ is the motor angle.

The motor speed is calculated according to the following formula:

Among them, θ ₂ is the motor angle at T ₂ time, θ ₁ is the motor angle at T ₁ time.

In the second aspect, the present application proposes a data decoding method of a resolver, which is realized by the data acquisition device of the resolver, and includes the following steps:

Generate a sine-cosine excitation signal;

converting the sine-cosine excitation signal into a sine-cosine differential signal, and the sine-cosine differential signal is used as an input of a resolver;

Receive the sine-cosine differential signal generated by the resolver;

Convert the sine-cosine differential signal generated by the resolver into a sine-cosine response signal that can be recognized by the motor speed conversion circuit;

Obtaining the motor angle according to the sine-cosine excitation signal and the sine-cosine response signal;

The motor speed is obtained according to the motor angle.

The data decoding method of the resolver further includes: performing signal isolation processing before the sine-cosine differential signal is input into the resolver.

Said converting said sin-cos excitation signal into a sin-cos differential signal comprises the following steps:

converting the sine-cosine excitation signal into an analog signal;

Amplifying the analog signal to a predetermined multiple according to the requirements of the resolver to obtain an analog amplified signal;

converting the analog amplified signal into a sine-cosine differential signal.

Said converting said sine-cosine differential signal into a sine-cosine response signal comprises the following steps:

converting the sine-cosine differential signal output by the resolver into a sine-cosine single-ended signal;

reducing the sine-cosine single-ended signal to a predetermined multiple to obtain the reduced sine-cosine single-ended signal;

converting the reduced sin-cos single-ended signal into the sin-cos response signal.

Described obtaining motor speed according to described motor angle, comprises the steps:

Calculate the motor angle difference between the previous moment and the next moment;

Calculate the time difference between the previous moment and the next moment;

The motor speed is obtained by dividing the motor angle difference by the time difference.

The motor angle is calculated according to the following formula:

Among them, E _{E_F} is the sine differential signal output by the resolver. According to the principle of converting the sine-cosine differential signal into a sine-cosine response signal, the sine differential signal is deduced from the sine response signal. E _{G_H} is the cosine differential signal output by the resolver. According to the sine-cosine differential signal The principle of signal conversion into sine and cosine response signals is to deduce the cosine differential signal from the cosine response signal, and E _{A_B} is the sine differential signal input by the resolver. , E _{C_D} is the cosine differential signal input by the resolver, and the cosine differential signal is derived from the cosine excitation signal according to the principle of converting the sine-cosine excitation signal into a sine-cosine differential signal, and θ is the motor angle.

The motor speed is calculated according to the following formula:

Among them, θ ₂ is the motor angle at T ₂ time, θ ₁ is the motor angle at T ₁ time.

Beneficial technical effects:

This application proposes a data acquisition device and decoding method for a resolver, cancels the dedicated resolver decoding chip, and uses soft decoding to realize the hard decoding function of the dedicated chip, so this application can be applied to most different types of resolver signal acquisition, hardware The device has strong versatility and reduces the hardware development cycle and cost.

Using FPGA to realize the soft decoding function of speed and position improves the sampling accuracy and calculation accuracy, and has the advantages of flexible and diverse programming.

Description of drawings

FIG. 1 is a schematic block diagram of a data acquisition device for a resolver according to an embodiment of the present application;

Fig. 2 is the internal functional block diagram of the dual-excitation sin-cosine differential output circuit and the dual-sin-cosine differential signal input circuit of the embodiment of the present application;

FIG. 3 is a flow chart of a data decoding method for a resolver according to an embodiment of the present application;

Fig. 4 is the flowchart of converting the sine and cosine excitation signal into a sine and cosine differential signal according to the embodiment of the present application;

FIG. 5 is a flowchart of converting a sine-cosine differential signal into a sine-cosine response signal according to an embodiment of the present application.

detailed description

The present disclosure will be further described below in conjunction with the embodiments shown in the accompanying drawings.

The motor speed conversion circuit described in this embodiment is realized by a programmable logic array FPGA (Field ProgramGate Way, field programmable gate array). The same method can also be realized by a programmable chip, but its data sampling accuracy and calculation accuracy Compared with FPGA, the effect will be much worse.

The motor speed conversion circuit (FPGA) is used to generate the sine-cosine excitation signal, and the sine-cosine excitation signal includes: da_data (FPGA internal digital quantity), da_cs_n (FPGA according to the DA (Digital to Analog, digital to analog) in the digital-to-analog conversion circuit turn analog) chip drive timing requirements, generate DA chip select signal) and da_wr_n (DA write enable signal), the digital-to-analog conversion circuit converts da_data, da_cs_n and da_wr_n into sina1 according to the received sine-cosine excitation signal (sine excitation analog quantity) and cosa1 (cosine excitation analog quantity).

According to the requirements of the resolver, the push-pull drive circuit amplifies the received sina1 (sine excitation analog quantity) and cosa1 (cosine excitation analog quantity) to a predetermined multiple to obtain an analog amplified signal, sina2 (sine analog amplified signal) and cosa2 (cosine analog amplified signal).

The single-ended to differential circuit converts the received sina2 (sine analog amplified signal) and cosa2 (cosine analog amplified signal) into sine-cosine differential signals that can be recognized by the resolver, respectively: differential sine signals: sina+ and sina -, differential cosine signal: cosa+ and cosa-.

In order to prevent the acquisition device from being damaged by external surges, etc., a signal isolation circuit is set to convert the differential sine signals: sina+ and sina-, and the differential cosine signals: cosa+ and cosa-, respectively into differential sine signals after signal isolation: Ex-sina+ and Ex-sina-, differential cosine signals: Ex-cosa+ and Ex-cosa-.

According to the output differential sine signal of the rotary transformer: sina+ and sina-, differential cosine signal: cosa+ and cosa-, through the signal isolation circuit, the differential sine signal: sina+ and sina-, differential cosine signal: cosa+ and cosa-, will sina+, sina-, cosa+ and cosa- are converted by the differential-to-single-ended circuit to obtain sine-cosine single-ended signals: sina4 (sine single-ended signal), cosa4 (cosine single-ended signal). According to the requirements of the analog-to-digital conversion circuit, the sine-cosine analog signal: sina4, cosa4 is reduced to a predetermined multiple by using the operational amplifier conditioning circuit, and the reduced sine-cosine single-ended signal sina5, cosa5 is obtained, and the analog-to-digital conversion circuit receives The reduced sine-cosine single-ended signals sina5 and cosa5 are generated through sina2 (sine excitation digital quantity) and cosa2 (cosine excitation digital quantity) according to the AD (Analog to Digital, analog to digital) chip manual drive timing in the analog-to-digital conversion circuit AD chip select signal (ad_cs_n), DA read enable signal (ad_rd_n), ad_data is obtained through analog-to-digital conversion, FPGA reads ad_data data, and the final motor speed is obtained through FPGA internal conversion.

In the first aspect, the present application proposes a data acquisition device for a resolver, as shown in Figure 1, including: a motor speed conversion circuit, a dual-excitation sin-cosine differential output circuit, and a dual-sin-cosine differential signal input circuit;

The output end of the motor speed conversion circuit is connected to the input end of the dual-excitation sin-cosine differential output circuit, and the output end of the dual-excitation sin-cosine differential output circuit is connected to the input end of the resolver, and the resolver The output end of the double sine-cosine differential signal input circuit is connected to the input end, and the output end of the double sine-cosine differential signal input circuit is connected to the input end of the motor speed conversion circuit;

The motor speed conversion circuit is used to generate the sine-cosine excitation signal, and simultaneously receive the sine-cosine response signal output by the dual-sin-cosine differential signal input circuit, and obtain the motor angle according to the sine-cosine excitation signal and the sine-cosine response signal, obtain the motor speed according to the motor angle;

The dual-excitation sin-cosine differential output circuit is used to convert the sin-cosine excitation signal into a sin-cosine differential signal, and the sin-cosine differential signal is used as the input of the resolver;

The dual sine-cosine differential signal input circuit is used to convert the sine-cosine differential signal output by the rotary transformer into a sine-cosine response signal that can be recognized by the motor speed conversion circuit.

The data acquisition device of the resolver, as shown in FIG. 1 , further includes a communication circuit for communication between the main controller and the motor speed conversion circuit. The resolver signal sampling device and the main control unit can use a variety of communication methods, such as optical fiber communication, 485 communication, Ethernet communication, direct EMIF (External Memory Interface, external memory interface) bus communication with the main controller, etc., and the FPGA calculation Good speed and position information uses reasonable communication methods to transmit position and speed data to the main controller. So that the master controller MCU (Master Control Unit, master controller) can perform motor algorithm control.

The data acquisition device of the rotary transformer, as shown in FIG. 1 , also includes a signal isolation circuit, which is used between the dual-excitation sin-cosine differential output circuit and the rotary transformer, and between the dual-sin-cosine differential signal input circuit and the rotary transformer. Signal isolation between resolvers.

The dual-excitation sin-cosine differential output circuit, as shown in Figure 2, includes: a digital-to-analog conversion circuit, a push-pull drive circuit, and a single-ended to differential circuit;

The first output end of the digital-to-analog conversion circuit is connected to the first input end of the push-pull drive circuit, and the first output end of the push-pull drive circuit is connected to the first input end of the single-ended to differential circuit, The second output end of the digital-to-analog conversion circuit is connected to the second input end of the push-pull drive circuit, and the second output end of the push-pull drive circuit is connected to the second input end of the single-ended to differential circuit, The first output terminal, the second output terminal, the third output terminal and the fourth output terminal of the single-ended to differential circuit are respectively connected to the first input terminal, the second input terminal, the third input terminal and the first input terminal of the signal isolation circuit. The four input terminals are connected;

The digital-to-analog conversion circuit is used to convert the sine-cosine excitation signal into an analog signal; the analog signal includes: sina1 (sine excitation analog quantity) and cosa1 (cosine excitation analog quantity).

The push-pull drive circuit is used to amplify the analog signal to a predetermined multiple according to the requirements of the resolver to obtain an analog amplified signal; the analog amplified signal includes: sina2 (sine analog amplified signal) and cosa2 (cosine analog amplified signal).

The single-ended-to-differential conversion circuit is used to convert the analog amplified signal into a sine-cosine differential signal. The sine-cosine differential signal includes: differential sine signals: sina+ and sina-, differential cosine signals: cosa+ and cosa-.

The dual sine and cosine differential signal input circuit, as shown in Figure 2, includes: a differential to single-ended circuit, an operational amplifier conditioning circuit and an analog-to-digital conversion circuit;

The first input terminal, the second input terminal, the third input terminal and the fourth input terminal of the differential-to-single-ended circuit are respectively connected to the first output terminal, the second output terminal, the third output terminal and the signal isolation circuit. The fourth output terminal is connected, the first output terminal of the differential to single-ended circuit is connected to the first input terminal of the operational amplifier conditioning circuit, the first output terminal of the operational amplifier conditioning circuit is connected to the analog-to-digital conversion The first input end of the circuit is connected, the second output end of the differential to single-ended circuit is connected to the second input end of the operational amplifier conditioning circuit, the second output end of the operational amplifier conditioning circuit is connected to the analog The second input terminal of the digital conversion circuit is connected;

The differential-to-single-ended circuit is used to convert the sine-cosine differential signal output by the resolver into a sine-cosine single-end signal; the sine-cosine differential signal output by the resolver includes: differential sine signals: sina+ and sina-, Differential cosine signals: cosa+ and cosa-, the sine-cosine single-ended signals include: sina4 (sine single-ended signal), cosa4 (cosine single-ended signal).

The operational amplifier conditioning circuit is used to reduce the sine-cosine single-ended signal to a predetermined multiple according to the requirements of the analog-to-digital conversion circuit to obtain a reduced sine-cosine single-ended signal, and the reduced sine-cosine single-ended signal includes : sina5, cosa5;

The analog-to-digital conversion circuit is used to convert the reduced sin-cos single-ended signal into the sin-cos response signal.

The motor speed conversion circuit is implemented by a programmable logic array or a programmable chip.

Because FPGA has flexible programming, rich IP core (IP CORE), high-efficiency parallel data sampling and data processing and computing capabilities, and can guarantee the calculation accuracy of data and the real-time performance of sampling calculation, this application is implemented by software programming based on FPGA devices. The implementation steps are as follows:

(A) Generate sine and cosine excitation signals: discretize the sine and cosine signals according to the DA sampling period and the period of the sine and cosine excitation, and store the discretized digital quantities in the FPGA on-chip ROM (Read Only Memory) area ;Drive the DA chip and read the ROM data and transmit it to the DA, converting the digital quantity into an analog signal excited by sine and cosine;

(B) Reading from analog signal to digital quantity: read the sine-cosine excitation signal and the sine-cosine signal output by the resolver by driving the AD chip, and collect E _{E_F} , E _{G_H} , E _{A_B} , E _{C_D} analog signals;

(C) Digital operation: use the multiplication IP core in the FPGA compiling software to realize the multiplication operation to realize E _{E_F} E _{A_B} , E _{G_ H} E _{C_D} , E _{E_F} E _{C_D} , E _{G_H} E _{A_B} , and obtain Y and X by addition and subtraction;

(D) Calculation of the motor angle: use the FPGA compiler software arctangent IP core to realize the arctangent operation of Y/X to obtain the motor angle;

The motor angle is calculated according to the following formula:

Among them, E _{E_F} is the sine differential signal output by the resolver. According to the principle of the double sine and cosine differential signal input circuit, the sine differential signal is deduced from the sine response signal. E _{G_H} is the cosine differential signal output by the resolver. According to the double sine and cosine differential signal input The circuit principle is to deduce the cosine differential signal from the cosine response signal. E _{A_B} is the sine differential signal input by the resolver. According to the principle of the dual-excitation sine-cosine differential output circuit, the sine differential signal is deduced from the sine excitation signal. E _{C_D} is the cosine input from the resolver. Differential signal, according to the principle of dual excitation sine and cosine differential output circuit, the cosine differential signal is deduced from the cosine excitation signal, and θ is the motor angle.

(E) motor speed calculation: utilize the differential of motor angle to obtain motor speed, that is, the speed is the angle change dθ in the sampling period (time dT), and utilize FPGA compiler software division IP core to realize motor speed calculation; described motor speed is according to the following formula calculate:

Among them, θ ₂ is the motor angle at T ₂ time, θ ₁ is the motor angle at T ₁ time.

(F) FPGA communicates with the main control unit: FPGA transmits the calculated motor angle and position information to the main control unit through communication, providing the input source of the control algorithm.

In the second aspect, the present application proposes a data decoding method of a rotary transformer, which is realized by the data acquisition device of the rotary transformer, as shown in FIG. 3 , including the following steps:

Step S1: generating a sine-cosine excitation signal;

Step S2: converting the sine-cosine excitation signal into a sine-cosine differential signal, and the sine-cosine differential signal is used as an input of a resolver;

Step S3: receiving the sine-cosine differential signal generated by the resolver;

Step S4: converting the sine-cosine differential signal generated by the resolver into a sine-cosine response signal that can be recognized by the motor speed conversion circuit;

Step S5: Obtain the motor angle according to the sine-cosine excitation signal and the sine-cosine response signal;

Step S6: Obtain the motor speed according to the motor angle.

The data decoding method of the resolver further includes: performing signal isolation processing before the sine-cosine differential signal is input into the resolver.

The described sin-cosine excitation signal is converted into a sin-cosine differential signal, as shown in Figure 4, comprising the following steps:

Step S2.1: converting the sine-cosine excitation signal into an analog signal;

Step S2.2: According to the requirements of the resolver, amplify the analog signal to a predetermined multiple to obtain an analog amplified signal;

Step S2.3: converting the analog amplified signal into a sine-cosine differential signal.

The described sine-cosine differential signal is converted into a sine-cosine response signal, as shown in Figure 5, comprising the following steps:

Step S4.1: converting the sine-cosine differential signal output by the resolver into a sine-cosine single-ended signal;

Step S4.2: reducing the sine-cosine single-ended signal to a predetermined multiple to obtain the reduced sine-cosine single-ended signal;

Step S4.3: converting the reduced sin-cos single-ended signal into the sin-cos response signal.

Described obtaining motor speed according to described motor angle, comprises the steps:

Calculate the motor angle difference between the previous moment and the next moment;

Calculate the time difference between the previous moment and the next moment;

The motor speed is obtained by dividing the motor angle difference by the time difference.

The motor angle is calculated according to the following formula:

Among them, E _{E_F} is the sine differential signal output by the resolver. According to the principle of converting the sine-cosine differential signal into a sine-cosine response signal, the sine differential signal is deduced from the sine response signal. E _{G_H} is the cosine differential signal output by the resolver. According to the sine-cosine differential signal The principle of signal conversion into sine and cosine response signals is to deduce the cosine differential signal from the cosine response signal, and E _{A_B} is the sine differential signal input by the resolver. , E _{C_D} is the cosine differential signal input by the resolver, and the cosine differential signal is derived from the cosine excitation signal according to the principle of converting the sine-cosine excitation signal into a sine-cosine differential signal, and θ is the motor angle.

The motor speed is calculated according to the following formula:

Among them, θ ₂ is the motor angle at T ₂ time, θ ₁ is the motor angle at T ₁ time.

Each embodiment in the present disclosure is described in a progressive manner, the same and similar parts of the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments.

The protection scope of the present disclosure is not limited to the above-mentioned embodiments, and it is obvious that those skilled in the art can make various changes and modifications to the present disclosure without departing from the scope and spirit of the present disclosure. If these changes and modifications belong to the scope of the claims of the present disclosure and their equivalent technologies, the intent of the present disclosure is to also include these changes and modifications.

Claims (11)

1. A resolver data acquisition apparatus, comprising: the motor speed conversion circuit, the double-excitation sine and cosine differential output circuit and the double-sine and cosine differential signal input circuit;

the output end of the motor speed conversion circuit is connected with the input end of the double-excitation sine-cosine differential output circuit, the output end of the double-excitation sine-cosine differential output circuit is connected with the input end of the rotary transformer, the output end of the rotary transformer is connected with the input end of the double-sine-cosine differential signal input circuit, and the output end of the double-sine-cosine differential signal input circuit is connected with the input end of the motor speed conversion circuit;

the motor speed conversion circuit is used for generating sine and cosine excitation signals, receiving sine and cosine response signals output by the double sine and cosine differential signal input circuit at the same time, obtaining a motor angle according to the sine and cosine excitation signals and the sine and cosine response signals, and obtaining a motor speed according to the motor angle;

the double-excitation sine and cosine differential output circuit is used for converting the sine and cosine excitation signals into sine and cosine differential signals, and the sine and cosine differential signals are used as the input of the rotary transformer;

the double sine and cosine differential signal input circuit is used for converting sine and cosine differential signals output by the rotary transformer into sine and cosine response signals which can be identified by the motor speed conversion circuit.

2. The resolver data acquisition device according to claim 1, further comprising a communication circuit for communication between a main controller and the motor speed conversion circuit.

3. The resolver data acquisition device according to claim 2, further comprising a signal isolation circuit for signal isolation between the double-excitation sine-cosine differential output circuit and the resolver and between the double-sine-cosine differential signal input circuit and the resolver.

4. The resolver data collecting device according to claim 3, wherein the double-excitation sine-cosine differential output circuit comprises: the device comprises a digital-to-analog conversion circuit, a push-pull driving circuit and a single-end to differential circuit;

the first output end of the digital-to-analog conversion circuit is connected with the first input end of the push-pull driving circuit, the first output end of the push-pull driving circuit is connected with the first input end of the single-ended to differential conversion circuit, the second output end of the digital-to-analog conversion circuit is connected with the second input end of the push-pull driving circuit, the second output end of the push-pull driving circuit is connected with the second input end of the single-ended to differential conversion circuit, and the first output end, the second output end, the third output end and the fourth output end of the single-ended to differential conversion circuit are respectively connected with the first input end, the second input end, the third input end and the fourth input end of the signal isolation circuit;

the digital-to-analog conversion circuit is used for converting the sine and cosine excitation signals into analog signals;

the push-pull driving circuit is used for amplifying the analog signal to a preset multiple according to the requirement of the rotary transformer to obtain an analog amplified signal;

the single-ended to differential circuit is used for converting the analog amplification signal into a sine and cosine differential signal.

5. The resolver data acquisition device according to claim 4, wherein the double sine and cosine differential signal input circuit comprises: the circuit comprises a differential-to-single-ended circuit, an operational amplifier conditioning circuit and an analog-to-digital conversion circuit;

the first input end, the second input end, the third input end and the fourth input end of the differential-to-single-ended circuit are respectively connected with the first output end, the second output end, the third output end and the fourth output end of the signal isolation circuit, the first output end of the differential-to-single-ended circuit is connected with the first input end of the operational amplifier conditioning circuit, the first output end of the operational amplifier conditioning circuit is connected with the first input end of the analog-to-digital conversion circuit, the second output end of the differential-to-single-ended circuit is connected with the second input end of the operational amplifier conditioning circuit, and the second output end of the operational amplifier conditioning circuit is connected with the second input end of the analog-to-digital conversion circuit;

the differential-to-single-ended circuit is used for converting sine and cosine differential signals output by the rotary transformer into sine and cosine single-ended signals;

the operational amplifier conditioning circuit is used for reducing the sine and cosine single-ended signal to a preset multiple according to the requirement of the analog-to-digital conversion circuit to obtain a reduced sine and cosine single-ended signal;

the analog-to-digital conversion circuit is used for converting the reduced sine-cosine single-ended signal into the sine-cosine response signal.

6. The resolver data acquisition device according to claim 5, wherein the motor speed conversion circuit is implemented using a programmable logic array or a programmable chip.

7. A data decoding method of a rotary transformer is realized by the data acquisition device of the rotary transformer of any one of claims 1 to 6, and is characterized by comprising the following steps:

generating sine and cosine excitation signals;

converting the sine and cosine excitation signals into sine and cosine differential signals, wherein the sine and cosine differential signals are used as the input of a rotary transformer;

receiving sine and cosine differential signals generated by a rotary transformer;

converting the sine and cosine differential signals generated by the rotary transformer into sine and cosine response signals which can be identified by the motor speed conversion circuit;

obtaining a motor angle according to the sine and cosine excitation signal and the sine and cosine response signal;

and obtaining the motor speed according to the motor angle.

8. The data decoding method of a resolver according to claim 7, further comprising: and signal isolation processing is required before the sine and cosine differential signals are input into the rotary transformer.

9. The resolver data decoding method according to claim 8, wherein the converting the sin-cos excitation signal into the sin-cos differential signal includes the steps of:

converting the sine and cosine excitation signals into analog signals;

amplifying the analog signal to a preset multiple according to the requirement of the rotary transformer to obtain an analog amplified signal;

and converting the analog amplification signal into a sine and cosine differential signal.

10. The resolver data decoding method according to claim 9, wherein the converting the sine-cosine differential signal into a sine-cosine response signal comprises:

converting the sine and cosine differential signals output by the rotary transformer into sine and cosine single-ended signals;

reducing the sine and cosine single-ended signal to a preset multiple to obtain a reduced sine and cosine single-ended signal;

and converting the reduced sine and cosine single-ended signal into the sine and cosine response signal.

11. The resolver data decoding method according to claim 10, wherein the obtaining of the motor speed from the motor angle comprises the steps of:

calculating the motor angle difference between the previous moment and the next moment;

calculating the time difference between the previous moment and the next moment;

and dividing the motor angle difference value by the time difference value to obtain the motor speed.

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