Data acquisition device and decoding method for a resolver

Abstract

The application provides a data acquisition device and decoding method of a resolver, and belongs to the field of variable flow motor control. The device comprises a motor speed conversion circuit, a double-excitation sine-cosine differential output circuit and a double-sine-cosine differential signal input circuit. The method comprises the following steps: generating a sine-cosine excitation signal; converting the sine-cosine excitation signal into a sine-cosine differential signal, which is used as the input of the resolver; receiving the sine-cosine differential signal generated by the resolver; 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; obtaining the motor angle according to the sine-cosine excitation signal and the sine-cosine response signal; and obtaining the motor speed according to the motor angle. The device of the application replaces the special resolver decoding chip, has high universality, reduces the hardware development cycle and cost, and improves the sampling precision and calculation precision.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of variable flow motor control, and particularly relates to a data acquisition device of a rotary transformer and a decoding method. BACKGROUND

[0002] The rotary transformer, abbreviated as rotary transformer, is a sensor for collecting motor position and speed, also known as an encoder. Compared with the optical technology encoder, the rotary transformer has the adaptability to harsh environments such as heat resistance, vibration resistance, impact resistance, oil stain resistance and corrosion resistance, and is widely used in many large factory frequency converter motor control fields. At present, the signal acquisition of the rotary transformer is all carried out by using special integrated chips of foreign manufacturers or MCUs with special rotary transformer decoding integrated interfaces. The speed and position data in the register are read by configuring the register of the special rotary transformer integrated chip through software. Such special integrated chips are often out of supply and generally have high prices; there are various types of rotary transformers on the market, including one pair of single excitation differential signal input, two pairs of sine and cosine differential signal output; two pairs of double excitation sine and cosine differential input, two pairs of sine and cosine differential signal output; and two pairs of double excitation sine and cosine differential input and one pair of differential signal output. Using different special rotary transformer decoding integrated chips will result in great difference in the hardware acquisition device, thereby increasing the development cycle and cost of the hardware and being not conducive to the universality requirement of the hardware. SUMMARY

[0003] Based on the above technical problems, the application provides a data acquisition device of a rotary transformer and a decoding method.

[0004] In a first aspect, the application provides a data acquisition device of a rotary transformer, comprising: a motor speed conversion circuit, a double excitation sine and cosine differential output circuit, and a double sine and cosine differential signal input circuit.

[0005] The output end of the motor speed conversion circuit is connected with the input end of the double excitation sine and cosine differential output circuit, the output end of the double excitation sine and 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 and cosine differential signal input circuit, and the output end of the double sine and cosine differential signal input circuit is connected with the input end of the motor speed conversion circuit.

[0006] The motor speed conversion circuit is used for generating a sine and cosine excitation signal, receiving a sine and cosine response signal output by the double sine and cosine differential signal input circuit at the same time, and obtaining a motor angle according to the sine and cosine excitation signal and the sine and cosine response signal, and obtaining a motor speed according to the motor angle.

[0007] The double-excitation positive and negative sine differential output circuit is used for converting the positive and negative sine excitation signals into positive and negative sine differential signals as inputs of the rotary transformer.

[0008] The double-positive and negative sine differential signal input circuit is used for converting the positive and negative sine differential signals output by the rotary transformer into positive and negative sine response signals recognizable by the motor speed conversion circuit.

[0009] The data acquisition device of the rotary transformer further comprises a communication circuit used for communication between the main controller and the motor speed conversion circuit.

[0010] The data acquisition device of the rotary transformer further comprises a signal isolation circuit used for signal isolation between the double-excitation positive and negative sine differential output circuit and the rotary transformer and between the double-positive and negative sine differential signal input circuit and the rotary transformer.

[0011] The double-excitation positive and negative sine differential output circuit comprises a digital-to-analog conversion circuit, a push-pull driving circuit and a single-end-to-differential circuit.

[0012] 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-end-to-differential 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-end-to-differential circuit, and the first output end, the second output end, the third output end and the fourth output end of the single-end-to-differential 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.

[0013] The digital-to-analog conversion circuit is used for converting the positive and negative sine excitation signals into analog signals.

[0014] The push-pull driving circuit is used for amplifying the analog signals to a predetermined multiple according to requirements of the rotary transformer to obtain analog amplified signals.

[0015] The single-end-to-differential circuit is used for converting the analog amplified signals into positive and negative sine differential signals.

[0016] The double-positive and negative sine differential signal input circuit comprises a differential-to-single-end circuit, an operational amplifier conditioning circuit and an analog-to-digital conversion circuit.

[0017] 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 connected with the first output end, the second output end, the third output end and the fourth output end of the signal isolation circuit respectively, 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;

[0018] The differential-to-single-ended circuit is used for converting the sine and cosine differential signals output by the resolver into sine and cosine single-ended signals.

[0019] The operational amplifier conditioning circuit is used for reducing the sine and cosine single-ended signals to a predetermined multiple according to the requirement of the analog-to-digital conversion circuit, so as to obtain reduced sine and cosine single-ended signals.

[0020] The analog-to-digital conversion circuit is used for converting the reduced sine and cosine single-ended signals into the sine and cosine response signals.

[0021] The motor speed conversion circuit is realized by a programmable logic array or a programmable chip.

[0022] The motor angle is calculated according to the following formula:

[0023]

[0024]

[0025] Wherein, E E_F is a sine differential signal output by the resolver, which is obtained by inversely deducing the sine response signal according to the original double-sine and cosine differential signal input circuit, E G_H is a cosine differential signal output by the resolver, which is obtained by inversely deducing the cosine response signal according to the original double-sine and cosine differential signal input circuit, E A_B is a sine differential signal input by the resolver, which is obtained by inversely deducing the sine excitation signal according to the original double-excitation sine and cosine differential output circuit, E C_D is a cosine differential signal input by the resolver, which is obtained by inversely deducing the cosine excitation signal according to the original double-excitation sine and cosine differential output circuit, and θ is the motor angle.

[0026] The motor speed is calculated according to the following formula:

[0027]

[0028] Wherein, θ2 is the motor angle at T2 time, θ1 is the motor angle at T1 time.

[0029] In a second aspect, the application provides a data decoding method of a rotary transformer, which is implemented by using the data acquisition device of the rotary transformer and includes the following steps:

[0030] generating a sine and cosine excitation signal;

[0031] converting the sine and cosine excitation signal into a sine and cosine differential signal, which is used as the input of the rotary transformer;

[0032] receiving the sine and cosine differential signal generated by the rotary transformer;

[0033] converting the sine and cosine differential signal generated by the rotary transformer into a sine and cosine response signal that can be recognized by a motor speed conversion circuit;

[0034] obtaining the motor angle according to the sine and cosine excitation signal and the sine and cosine response signal;

[0035] obtaining the motor speed according to the motor angle.

[0036] The data decoding method of the rotary transformer further includes signal isolation processing before the sine and cosine differential signal is input into the rotary transformer.

[0037] The conversion of the sine and cosine excitation signal into the sine and cosine differential signal includes the following steps:

[0038] converting the sine and cosine excitation signal into an analog signal;

[0039] amplifying the analog signal to a predetermined multiple according to the requirements of the rotary transformer to obtain an analog amplified signal;

[0040] converting the analog amplified signal into the sine and cosine differential signal.

[0041] The conversion of the sine and cosine differential signal into the sine and cosine response signal includes the following steps:

[0042] converting the sine and cosine differential signal output by the rotary transformer into a sine and cosine single-ended signal;

[0043] reducing the sine and cosine single-ended signal to a predetermined multiple to obtain a reduced sine and cosine single-ended signal;

[0044] converting the reduced sine and cosine single-ended signal into the sine and cosine response signal.

[0045] The obtaining of the motor speed according to the motor angle includes the following steps:

[0046] Calculate the motor angle difference between the previous time and the next time;

[0047] Calculate the time difference between the previous time and the next time;

[0048] Divide the motor angle difference by the time difference to obtain the motor speed.

[0049] The motor angle is calculated according to the following formula:

[0050]

[0051]

[0052] Wherein, E E_F is the sine difference signal output by the resolver, which is converted into the sine response signal according to the sine difference signal, and the sine difference signal is deduced from the sine response signal, E G_H is the cosine difference signal output by the resolver, which is converted into the cosine response signal according to the sine difference signal, and the cosine difference signal is deduced from the cosine response signal, E A_B is the sine difference signal input by the resolver, which is converted into the sine difference signal according to the sine excitation signal, and the sine difference signal is deduced from the sine excitation signal, E C_D is the cosine difference signal input by the resolver, which is converted into the cosine difference signal according to the sine excitation signal, and the cosine difference signal is deduced from the cosine excitation signal, and θ is the motor angle.

[0053] The motor speed is calculated according to the following formula:

[0054]

[0055] Wherein, θ2 is the motor angle at T2, and θ1 is the motor angle at T1.

[0056] Beneficial technical effects:

[0057] The application proposes a data acquisition device and decoding method for resolver, which cancels the special resolver decoding chip and realizes the hard decoding function of special chip by soft decoding, so that the application can be applied to most different types of resolver signal acquisition, and the hardware device has strong versatility, reducing the hardware development cycle and cost.

[0058] The FPGA is used to realize the speed position soft decoding function, which improves the sampling accuracy and calculation accuracy, and has the advantages of flexible and diverse programming. BRIEF DESCRIPTION OF DRAWINGS

[0059] Figure 1 It is a principle block diagram of a data acquisition device for resolver of an embodiment of the application;

[0060] Figure 2 The internal principle block diagram of the double-excitation sine-cosine differential output circuit and the double-sine-cosine differential signal input circuit of the embodiment of the present application is shown in FIG. 1.

[0061] Figure 3 The flow chart of the data decoding method of the resolver of the embodiment of the present application is shown in FIG. 2.

[0062] Figure 4 The flow chart of the conversion of the sine-cosine excitation signal into the sine-cosine differential signal of the embodiment of the present application is shown in FIG. 3.

[0063] Figure 5 The flow chart of the conversion of the sine-cosine differential signal into the sine-cosine response signal of the embodiment of the present application is shown in FIG. 4. DETAILED DESCRIPTION

[0064] The present disclosure is further described below in conjunction with the embodiments shown in the accompanying drawings.

[0065] The motor speed conversion circuit in the embodiment is implemented by using a programmable logic array FPGA (Field Programmable Gate Way), and the same method can also be implemented by using a programmable chip, but the data sampling accuracy and calculation accuracy will be much worse than that of the FPGA.

[0066] The motor speed conversion circuit (FPGA) is used to generate a sine-cosine excitation signal, which includes da_data (internal digital quantity of the FPGA), da_cs_n (DA (Digital to Analog) chip driving timing requirement DA chip select signal generated by the FPGA according to the digital-to-analog conversion circuit), 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 (sine excitation analog quantity) and cosa1 (cosine excitation analog quantity) according to the received sine-cosine excitation signal.

[0067] The push-pull driving circuit amplifies the received sina1 (sine excitation analog quantity) and cosa1 (cosine excitation analog quantity) to a predetermined multiple according to the requirements of the resolver to obtain analog amplified signals sina2 (sine analog amplified signal) and cosa2 (cosine analog amplified signal).

[0068] 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 recognizable by the resolver, which are differential sine signals sina+ and sina-, and differential cosine signals cosa+ and cosa-.

[0069] In order to prevent the acquisition device from being damaged by external surges, a signal isolation circuit is set up to convert the differential sine signals: sina+ and sina-, and the differential cosine signals: cosa+ and cosa-, into differential sine signals after signal isolation: Ex-sina+ and Ex-sina-, and differential cosine signals: Ex-cosa+ and Ex-cosa-.

[0070] According to the output differential sine signal of the rotating transformer: sina+ and sina-, and the differential cosine signal: cosa+ and cosa-, a differential sine signal: sina+ and sina-, and a differential cosine signal: cosa+ and cosa- are obtained through a signal isolation circuit. Sina+, sina-, cosa+ and cosa- are converted through the differential to single-ended circuit to obtain sine and cosine single-ended signals: sina4 (sine single-ended signal) and cosa4 (cosine single-ended signal). According to the requirements of the analog-to-digital conversion circuit, the operational amplifier conditioning circuit is used to reduce the sine and cosine analog signals: sina4, cosa4, to a predetermined multiple to obtain the reduced sine and cosine single-ended signals sina5, cosa5. The analog-to-digital conversion circuit receives the reduced sine and cosine single-ended signals sina5, cosa5, and generates an AD chip select signal (ad_cs_n) and a DA read enable signal (ad_rd_n) through sina2 (sine excitation digital quantity) and cosa2 (cosine excitation digital quantity) according to the AD (Analog to Digital) chip manual drive timing in the analog-to-digital conversion circuit. After analog-to-digital conversion, ad_data is obtained. The FPGA reads the ad_data data and obtains the final motor speed through internal conversion within the FPGA.

[0071] In the first aspect, the present application proposes a data acquisition device for a rotary transformer, such as Figure 1 As shown, it includes: a motor speed conversion circuit, a dual-excitation sine-cosine differential output circuit, and a dual sine-cosine differential signal input circuit;

[0072] The output end of the motor speed conversion circuit is connected to the input end of the dual-excitation sine-cosine differential output circuit, the output end of the dual-excitation sine-cosine differential output circuit is connected to the input end of the rotary transformer, the output end of the rotary transformer is connected to the input end of the dual sine-cosine differential signal input circuit, and the output end of the dual sine-cosine differential signal input circuit is connected to the input end of the motor speed conversion circuit;

[0073] The motor speed conversion circuit is used to generate a sine-cosine excitation signal, and simultaneously receive a sine-cosine response signal output by the dual sine-cosine differential signal input circuit, and obtain a motor angle according to the sine-cosine excitation signal and the sine-cosine response signal, and obtain a motor speed according to the motor angle;

[0074] The dual-excitation sine-cosine differential output circuit is used to convert the sine-cosine excitation signal into a sine-cosine differential signal, and the sine-cosine differential signal serves as the input of the resolver;

[0075] The dual sine-cosine differential signal input circuit is used to convert the sine-cosine differential signal output by the resolver into a sine-cosine response signal that can be recognized by the motor speed conversion circuit.

[0076] The data acquisition device of the rotary transformer, such as Figure 1 As shown, a communication circuit is also included 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 fiber optic communication, 485 communication, Ethernet communication, direct EMIF (External Memory Interface) bus communication with the main controller, etc. The speed and position information calculated by the FPGA is transmitted to the main controller using a reasonable communication method. The position and speed data can then be used by the main controller MCU (Master Control Unit) to perform motor algorithm control.

[0077] The data acquisition device of the rotary transformer, such as Figure 1 As shown, a signal isolation circuit is also included for performing signal isolation between the dual-excitation sine-cosine differential output circuit and the rotary transformer, and between the dual-excitation sine-cosine differential signal input circuit and the rotary transformer.

[0078] The dual excitation sine and cosine differential output circuit is as follows: Figure 2 As shown, it includes: a digital-to-analog conversion circuit, a push-pull driving circuit, and a single-ended to differential circuit;

[0079] The first output end of the digital-to-analog conversion circuit is connected to the first input end of the push-pull drive circuit, 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, the second output end of the push-pull drive circuit is connected to the second input end of the single-ended to differential 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 circuit are respectively connected to the first input end, the second input end, the third input end and the fourth input end of the signal isolation circuit;

[0080] The digital-to-analog conversion circuit is used for converting the positive and sine excitation signals into analog signals; the analog signals include sina1 (sine excitation analog quantity) and cosa1 (cosine excitation analog quantity).

[0081] The push-pull drive circuit is used for amplifying the analog signals to a predetermined multiple according to requirements of the resolver, to obtain analog amplified signals; the analog amplified signals include sina2 (sine analog amplified signal) and cosa2 (cosine analog amplified signal).

[0082] The single-ended-to-differential circuit is used for converting the analog amplified signals into positive and sine differential signals; the positive and sine differential signals include differential sine signals sina+ and sina- and differential cosine signals cosa+ and cosa-.

[0083] The double positive and sine 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.

[0084] 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 connected with the first output end, the second output end, the third output end and the fourth output end of the signal isolation circuit respectively; 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; the second output end of the operational amplifier conditioning circuit is connected with the second input end of the analog-to-digital conversion circuit.

[0085] The differential-to-single-ended circuit is used for converting the positive and sine differential signals output by the resolver into positive and sine single-ended signals; the positive and sine differential signals output by the resolver include differential sine signals sina+ and sina- and differential cosine signals cosa+ and cosa-; the positive and sine single-ended signals include sina4 (sine single-ended signal) and cosa4 (cosine single-ended signal).

[0086] The operational amplifier conditioning circuit is used for reducing the positive and sine single-ended signals to a predetermined multiple according to requirements of the analog-to-digital conversion circuit, to obtain reduced positive and sine single-ended signals; the reduced positive and sine single-ended signals include sina5 and cosa5.

[0087] The analog-to-digital conversion circuit is used for converting the reduced positive and sine single-ended signals into the positive and sine response signals.

[0088] The motor speed conversion circuit is implemented by a programmable logic array or a programmable chip.

[0089] Because the FPGA has the programming flexibility, the rich IP core (IP CORE), the efficient parallel data sampling and the data processing operation ability, can guarantee the data calculation precision and the sampling calculation real-time performance, therefore, the application is realized based on the FPGA device in the software programming mode, and the implementation steps are as follows:

[0090] (A) Generating sine and cosine excitation signals: discretizing sine and cosine signals according to DA sampling period and sine and cosine excitation period, and storing the discretized digital quantity in the FPGA internal ROM (Read Only Memory) area; driving the DA chip and reading the ROM data transmission to the DA, and converting the digital quantity into the analog signal of the sine and cosine excitation;

[0091] (B) Analog signal to digital quantity reading: reading the sine and cosine excitation signals and the sine and cosine signals output by the resolver through driving the AD chip, collecting the E E_F , E G_H , E A_B , E C_D analog signal;

[0092] (C) Digital operation: using the multiplication IP core in the FPGA compilation software to realize the multiplication operation to obtain Y and X through E E_F E A_B , E G_ H E C_D , E E_F E C_D , E G_H E A_B addition and subtraction operation;

[0093] (D) Motor angle calculation: using the arctangent IP core in the FPGA compilation software to realize the arctangent operation of Y / X to obtain the motor angle;

[0094] The motor angle is calculated according to the following formula:

[0095]

[0096]

[0097] Wherein, E E_F is the sine differential signal output by the resolver, which is obtained by inversely deducing the sine differential signal from the sine response signal according to the double sine and cosine differential signal input circuit principle, E G_H is the cosine differential signal output by the resolver, which is obtained by inversely deducing the cosine differential signal from the cosine response signal according to the double sine and cosine differential signal input circuit principle, E A_BThe sine differential signal is input to 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. C_D The cosine differential signal is input to the resolver. The cosine differential signal is deduced from the cosine excitation signal according to the principle of the dual-excitation sine-cosine differential output circuit. θ is the motor angle.

[0098] (E) Motor Speed ​​Calculation: The motor speed is obtained by differentially calculating the motor angle. That is, the speed is the angle change dθ within the sampling period (time dT). The motor speed calculation is implemented using the FPGA compiler software division IP core. The motor speed is calculated according to the following formula:

[0099]

[0100] Among them, θ2 is the motor angle at time T2, and θ1 is the motor angle at time T1.

[0101] (F) FPGA communicates with the main control unit: The FPGA transmits the calculated motor angle and position information to the main control unit via communication, providing the input source for the control algorithm.

[0102] In the second aspect, the present application proposes a data decoding method for a rotary transformer, which is implemented using the data acquisition device of the rotary transformer, such as Figure 3 As shown, the following steps are included:

[0103] Step S1: Generate sine and cosine excitation signals;

[0104] Step S2: converting the sine-cosine excitation signal into a sine-cosine differential signal, and the sine-cosine differential signal serves as the input of the resolver;

[0105] Step S3: receiving the sine-cosine differential signal generated by the rotary transformer;

[0106] 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;

[0107] Step S5: obtaining the motor angle according to the sine-cosine excitation signal and the sine-cosine response signal;

[0108] Step S6: Obtaining the motor speed according to the motor angle.

[0109] The data decoding method for the rotary transformer further includes: performing signal isolation processing before the sine-cosine differential signal is input into the rotary transformer.

[0110] The sine-cosine excitation signal is converted into a sine-cosine difference signal, such as Figure 4 As shown, the following steps are included:

[0111] Step S2.1: converting the sine-cosine excitation signal into an analog signal;

[0112] Step S2.2: amplifying the analog signal to a predetermined multiple according to the requirement of the resolver, to obtain an analog amplified signal;

[0113] Step S2.3: converting the analog amplified signal into a sine-cosine differential signal.

[0114] The conversion of the sine-cosine differential signal into a sine-cosine response signal comprises the following steps: Figure 5

[0115] Step S4.1: converting the sine-cosine differential signal output by the resolver into a sine-cosine single-ended signal;

[0116] Step S4.2: reducing the sine-cosine single-ended signal to a predetermined multiple, to obtain a reduced sine-cosine single-ended signal;

[0117] Step S4.3: converting the reduced sine-cosine single-ended signal into the sine-cosine response signal.

[0118] The obtaining of the motor speed according to the motor angle comprises the following steps:

[0119] calculating the motor angle difference between the previous time and the next time;

[0120] calculating the time difference between the previous time and the next time;

[0121] dividing the motor angle difference by the time difference to obtain the motor speed.

[0122] The motor angle is calculated according to the following formula:

[0123]

[0124]

[0125] wherein, E E_F is the sine differential signal output by the resolver, the sine-cosine response signal is converted from the sine-cosine differential signal, the sine differential signal is derived from the sine response signal, E G_H is the cosine differential signal output by the resolver, the sine-cosine response signal is converted from the sine-cosine differential signal, the cosine differential signal is derived from the cosine response signal, E A_B is the sine differential signal input by the resolver, the sine-cosine differential signal is converted from the sine-cosine excitation signal, the sine differential signal is derived from the sine excitation signal, E C_D ​The cosine difference signal is converted into the positive cosine difference signal from the positive cosine excitation signal, the cosine difference signal is back calculated from the positive cosine excitation signal, and θ is the motor angle.

[0126] The motor speed is calculated according to the following formula:

[0127]

[0128] Wherein, θ2 is the motor angle at T2, and θ1 is the motor angle at T1.

[0129] Each of the embodiments in the present disclosure is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other. Each of the embodiments focuses on the difference from other embodiments.

[0130] The scope of protection of the present disclosure is not limited to the above-mentioned embodiments. Obviously, those skilled in the art can make various modifications and changes to the present disclosure without departing from the scope and spirit of the present disclosure. If these modifications and changes belong to the scope of the claims of the present disclosure and its equivalent technologies, the intention of the present disclosure also includes these modifications and changes.

Claims

1. A data acquisition device for a rotary transformer, characterized by The motor speed conversion circuit, the double-excitation sine-cosine differential output circuit, and the double-sine-cosine differential signal input circuit are connected in series. 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 a sine-cosine excitation signal, receiving a sine-cosine response signal output by the double-sine-cosine differential signal input circuit, and obtaining a motor angle according to the sine-cosine excitation signal and the sine-cosine response signal, and obtaining a motor speed according to the motor angle. The double-excitation sine-cosine differential output circuit is used for converting the sine-cosine excitation signal into a sine-cosine differential signal, and the sine-cosine differential signal is used as the input of the rotary transformer. The double-sine-cosine differential signal input circuit is used for converting a sine-cosine differential signal output by the rotary transformer into a sine-cosine response signal recognizable by the motor speed conversion circuit. 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: Wherein, E E_F is the sine differential signal output by the resolver, the sine differential signal is obtained by the double sine-cosine differential signal input circuit from the sine response signal, E G_H is the cosine differential signal output by the resolver, the cosine differential signal is obtained by the double sine-cosine differential signal input circuit from the cosine response signal, E A_B is the sine differential signal input by the resolver, the sine differential signal is obtained by the double excitation sine-cosine differential output circuit from the sine excitation signal, E C_D is the cosine differential signal input by the resolver, the cosine differential signal is obtained by the double excitation sine-cosine differential output circuit from the cosine excitation signal, and θ is the motor angle. The motor speed is calculated according to the following formula: Wherein, θ2 is the motor angle at T2, and θ1 is the motor angle at T1.

2. The data acquisition device for a resolver as recited in claim 1, wherein, The data acquisition device of the rotary transformer further comprises a communication circuit for communication between the main controller and the motor speed conversion circuit.

3. The data acquisition device for a resolver as recited in claim 2, wherein, The data acquisition device of the rotary transformer further comprises a signal isolation circuit for signal isolation between the double-excitation sine-cosine differential output circuit and the rotary transformer and between the double-sine-cosine differential signal input circuit and the rotary transformer.

4. The data acquisition apparatus for a resolver as claimed in claim 3, wherein, The double-excitation sine-cosine differential output circuit 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-end-to-differential 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-end-to-differential circuit, and the first output end, the second output end, the third output end, and the fourth output end of the single-end-to-differential circuit are connected with the first input end, the second input end, the third input end, and the fourth input end of the signal isolation circuit, respectively. The digital-to-analog conversion circuit is used for converting the sine-cosine excitation signal into an analog signal. The push-pull driving circuit is used for amplifying the analog signal to a predetermined multiple according to the requirement of the rotary transformer to obtain an analog amplified signal. The single-end-to-differential circuit is used for converting the analog amplified signal into a sine-cosine differential signal.

5. The data acquisition apparatus for a resolver as claimed in claim 4, wherein, The double-sine-cosine differential signal input circuit comprises a differential-to-single-end 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 connected with the first output end, the second output end, the third output end and the fourth output end of the signal isolation circuit respectively, 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 the sine and cosine differential signals output by the resolver into sine and cosine single-ended signals; The operational amplifier conditioning circuit is used for reducing the sine and cosine single-ended signals to a predetermined multiple according to the requirement of the analog-to-digital conversion circuit, so as to obtain reduced sine and cosine single-ended signals; The analog-to-digital conversion circuit is used for converting the reduced sine and cosine single-ended signals into the sine and cosine response signals.

6. A data decoding method of a resolver, implemented by using the data acquisition device of the resolver according to any one of claims 1 to 5, characterized in that, The method comprises the following steps: generating a sine and cosine excitation signal; converting the sine and cosine excitation signal into a sine and cosine differential signal, which is used as an input of the resolver; receiving a sine and cosine differential signal generated by the resolver; converting the sine and cosine differential signal generated by the resolver into a sine and cosine response signal which can be recognized 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; obtaining a motor speed according to the motor angle.

7. The data decoding method of a resolver as claimed in claim 6, characterized in that, The data decoding method of the resolver further comprises a signal isolation process before the sine and cosine differential signal is input into the resolver.

8. The data decoding method of a resolver according to claim 7, characterized by, The conversion of the sine and cosine excitation signal into the sine and cosine differential signal comprises the following steps: converting the sine and cosine excitation signal into an analog signal; amplifying the analog signal to a predetermined multiple according to the requirement of the resolver, so as to obtain an amplified analog signal; converting the amplified analog signal into the sine and cosine differential signal.

9. The data decoding method of a resolver according to claim 8, characterized by, The conversion of the sine and cosine differential signal into the sine and cosine response signal comprises the following steps: converting the sine and cosine differential signal output by the resolver into a sine and cosine single-ended signal; reducing the sine and cosine single-ended signal to a predetermined multiple, so as to obtain a reduced sine and cosine single-ended signal; converting the reduced sine and cosine single-ended signal into the sine and cosine response signal.

10. The data decoding method of a resolver according to claim 9, characterized by, The obtaining of the motor speed according to the motor angle comprises the following steps: calculating a motor angle difference value between a previous time and a next time; calculating a time difference value between the previous time and the next time; dividing the motor angle difference value by the time difference value to obtain the motor speed.

Images