Apparatus and method for recovering a carrier signal

Abstract

This application relates to the field of resolver technology and discloses an apparatus for recovering a carrier signal. A phase detector compares the phase error between the carrier signal and the first feedback signal output by a numerically controlled oscillator in the carrier signal to be recovered, obtaining a phase difference signal corresponding to the phase error. Then, a loop filter is used to filter the phase difference signal. The numerically controlled oscillator obtains the first feedback signal corresponding to the oscillation frequency. With the phase error between the first feedback signal and the carrier signal within a set range, the recovered carrier signal is determined based on the first feedback signal at the carrier signal output terminal, and this carrier signal is output. This avoids phase delay in the recovered carrier signal, improving the subsequent tracking effect of the envelope signal, thereby improving the accuracy of obtaining the position and speed information of the motor rotor. This application also discloses a method for recovering a carrier signal.

Description

Technical Field

[0001] This application relates to the field of resolver technology, and for example to an apparatus and method for recovering carrier signals. Background Technology

[0002] Currently, to achieve high-performance control of motors, accurate position and speed information of the motor rotor is required. In fields such as electric vehicles, resolvers are typically used as position and speed sensors for the motor rotor to acquire this information. A resolver has three ports: the input port receives an external excitation carrier signal, and the two output ports output two orthogonal envelope signals, which contain the position and speed information of the motor rotor. Therefore, an RDC (Resolver-to-Digital Converter) is needed to extract the carrier signal from the envelope signal output by the resolver to recover the carrier signal. This allows for tracking of the envelope signal based on the recovered carrier signal to obtain the motor rotor's position and speed information. Recovering the carrier signal from the envelope signal is the most crucial step in extracting the position and speed information. Phase-locked loops (PLLs) are commonly used in related technologies for carrier recovery.

[0003] In the process of implementing the embodiments of this disclosure, it has been found that at least the following problems exist in the related technology: the phase-locked loop in the related technology uses a low-pass filter for filtering, which will cause a phase delay in the recovered carrier signal, resulting in poor tracking effect of the envelope signal, and thus the accuracy of the obtained motor rotor position information and speed information is low. Summary of the Invention

[0004] To provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended as a general commentary, nor is it intended to identify key / important components or describe the scope of protection of these embodiments, but rather as a prelude to the detailed description that follows.

[0005] This disclosure provides an apparatus and method for recovering carrier signals, so as to improve the accuracy of obtaining the position and speed information of the motor rotor.

[0006] In some embodiments, the apparatus for recovering a carrier signal includes: a phase detector connected to a numerically controlled oscillator and a loop filter; the phase detector is used to receive a carrier signal to be recovered output from a resolver and a first feedback signal output from the numerically controlled oscillator; compare the phase error between the carrier signal and the first feedback signal in the carrier signal to be recovered to obtain a phase difference signal corresponding to the phase error; the loop filter is used to receive the phase difference signal output from the phase detector and filter the phase difference signal to obtain a phase error signal; the numerically controlled oscillator is connected to the loop filter; the numerically controlled oscillator is used to receive the phase error signal output from the loop filter and control the oscillation frequency according to the phase error signal; then obtain a first feedback signal corresponding to the oscillation frequency; the first feedback signal includes a second feedback signal and a third feedback signal; a carrier signal output terminal is connected to the numerically controlled oscillator; the carrier signal output terminal is used to output the recovered carrier signal; the recovered carrier signal is obtained according to the first feedback signal.

[0007] In some embodiments, the method for recovering a carrier signal includes: acquiring a carrier signal to be recovered output by an output resolver; inputting the carrier signal to be recovered into the aforementioned carrier signal recovery device for carrier signal recovery processing to obtain a recovered carrier signal.

[0008] The apparatus and method for recovering carrier signals provided in this disclosure can achieve the following technical effects: A phase detector compares the phase error between the carrier signal and the first feedback signal output by a numerically controlled oscillator in the carrier signal to be recovered, obtaining a phase difference signal corresponding to the phase error. Then, a loop filter is used to filter the phase difference signal. The numerically controlled oscillator controls the oscillation frequency according to the phase error signal; then, the first feedback signal corresponding to the oscillation frequency is obtained. The recovered carrier signal is output through the carrier signal output terminal. Thus, using a loop filter to filter the phase difference signal does not cause a phase delay in the recovered carrier signal, improving the subsequent tracking effect of the envelope signal, thereby improving the accuracy of obtaining the position and speed information of the motor rotor.

[0009] The above general description and the description below are exemplary and illustrative only and are not intended to limit this application. Attached Figure Description

[0010] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations and drawings do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are shown as similar elements. The drawings are not to be scaled. And wherein:

[0011] Figure 1This is a schematic diagram of an apparatus for recovering a carrier signal provided in an embodiment of this disclosure;

[0012] Figure 2 This is a schematic diagram of the structure of a phase detector provided in an embodiment of this disclosure;

[0013] Figure 3 This is a schematic diagram of the structure of a loop filter provided in an embodiment of this disclosure;

[0014] Figure 4 A schematic diagram of the structure of a numerically controlled oscillator provided in this embodiment of the present disclosure;

[0015] Figure 5 This is a schematic diagram of a method for recovering a carrier signal provided in an embodiment of this disclosure;

[0016] Figure 6 This is a schematic diagram of another method for recovering a carrier signal provided in an embodiment of this disclosure.

[0017] Figure label:

[0018] 1: Phase detector; 2: Loop filter; 3: Numerically controlled oscillator; 4: Carrier signal output; 5: First multiplier; 6: Second multiplier; 7: Third multiplier; 8: Fourth multiplier; 9: Fifth multiplier; 10: First accumulator; 11: First adder; 12: Second accumulator; 13: Third accumulator; 14: Second adder; 15: Feedback signal generator; 16: First input; 17: Second input; 18: Third input; 19: Fourth input; 20: Third output; 21: Seventh input; 22: Ninth input; 23: Eighth input; 24: Tenth input; 25: Seventh output; 26: Fourteenth input; 27: Fifteenth input; 28: Eleventh output; 29: Twelfth output. Detailed Implementation

[0019] To provide a more detailed understanding of the features and technical content of the embodiments of this disclosure, the implementation of the embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and are not intended to limit the embodiments of this disclosure. In the following technical description, for ease of explanation, several details are used to provide a full understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other cases, well-known structures and devices may be simplified in their depiction to simplify the drawings.

[0020] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this disclosure described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0021] In this disclosure, the terms "upper," "lower," "inner," "middle," "outer," "front," and "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for better description of the embodiments of this disclosure and their implementations, and are not intended to limit the indicated devices, elements, or components to having a specific orientation, or to require them to be constructed and operated in a specific orientation. Furthermore, some of the aforementioned terms may be used to indicate other meanings besides orientation or positional relationship; for example, the term "upper" may in some cases indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in the embodiments of this disclosure according to the specific circumstances.

[0022] Furthermore, the terms "set up," "connect," and "fix" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this disclosure according to the specific circumstances.

[0023] Unless otherwise stated, the term "multiple" means two or more.

[0024] In this embodiment of the disclosure, the character " / " indicates that the objects before and after it are in an "or" relationship. For example, A / B means: A or B.

[0025] The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0026] It should be noted that, unless otherwise specified, the embodiments and features described in the present disclosure can be combined with each other.

[0027] Combination Figure 1As shown in the figure, this disclosure provides an apparatus for recovering a carrier signal, including: a phase detector 1, a loop filter 2, a numerically controlled oscillator 3, and a carrier signal output terminal 4. The phase detector 1 is connected to both the numerically controlled oscillator 3 and the loop filter 2; the phase detector 1 receives the carrier signal to be recovered output from a resolver and a first feedback signal output from the numerically controlled oscillator; it compares the phase error between the carrier signal and the first feedback signal in the carrier signal to be recovered to obtain a phase difference signal corresponding to the phase error. The loop filter 2 receives the phase difference signal output from the phase detector and filters it to obtain a phase error signal. The numerically controlled oscillator 3 is connected to the loop filter 2. The numerically controlled oscillator receives the phase error signal output from the loop filter and controls the oscillation frequency according to the phase error signal. Then, it obtains a first feedback signal corresponding to the oscillation frequency. The first feedback signal includes a second feedback signal and a third feedback signal. The carrier signal output terminal 4 is connected to the numerically controlled oscillator 3; the carrier signal output terminal 4 is used to output the recovered carrier signal; the recovered carrier signal is obtained based on the first feedback signal.

[0028] The apparatus for recovering a carrier signal provided in this disclosure compares the phase error between the carrier signal and the first feedback signal output by the numerically controlled oscillator in the carrier signal to be recovered using a phase detector to obtain a phase difference signal corresponding to the phase error. Then, a loop filter is used to filter the phase difference signal. The numerically controlled oscillator controls the oscillation frequency based on the phase error signal; then, the first feedback signal corresponding to the oscillation frequency is obtained. With the phase error between the first feedback signal and the carrier signal within a set range, the recovered carrier signal is determined based on the first feedback signal at the carrier signal output terminal, and this recovered carrier signal is output. Thus, using a loop filter to filter the phase difference signal does not cause a phase delay in the recovered carrier signal, improving the subsequent tracking effect of the envelope signal, thereby improving the accuracy of obtaining the position and speed information of the motor rotor.

[0029] Optionally, the phase error between the first feedback signal and the carrier signal is equal to the phase error between the oscillation frequency and the frequency of the carrier signal.

[0030] Optionally, the second feedback signal is orthogonal to the third feedback signal.

[0031] Optionally, the second feedback signal is a sinusoidal signal.

[0032] Optionally, the third feedback signal is a cosine signal.

[0033] Since the sine and cosine signals are orthogonal, the second and third feedback signals are in phase. This allows the phase error between the carrier signal and the first feedback signal in the carrier signal to be recovered to be obtained by comparing the phase error between the carrier signal and the second feedback signal, or by comparing the phase error between the carrier signal and the third feedback signal, thus obtaining a phase difference signal including the phase error.

[0034] In some embodiments, the carrier signal output terminal is configured to obtain the recovered carrier signal based on the first feedback signal by means of the following method: if the phase error between the first feedback signal and the carrier signal is within a set range, the second feedback signal is determined as the recovered carrier signal; or, if the phase error between the first feedback signal and the carrier signal is within a set range, the third feedback signal is determined as the recovered carrier signal.

[0035] In some embodiments, the numerically controlled oscillator controls the oscillation frequency based on the phase error signal, such that the phase of the output first feedback signal is close to the phase of the carrier signal. Thus, after multiple oscillations, the phase error between the first feedback signal and the carrier signal can be equal to the phase error between the oscillation frequency and the frequency of the carrier signal. This allows the third feedback signal or the second feedback signal to be determined as the recovered carrier signal.

[0036] Combination Figure 2 As shown, Figure 2 This is a schematic diagram of a phase detector. The phase detector includes: a first multiplier 5, a second multiplier 6, and a third multiplier 7. The second input terminal 17 of the first multiplier 5 and the third input terminal 18 of the second multiplier 6 are both used to receive the carrier signal to be recovered from the resolver output. The first input terminal 16 of the first multiplier 5 is used to receive the second feedback signal from the numerically controlled oscillator output. The fourth input terminal 19 of the second multiplier 6 is used to receive the third feedback signal from the numerically controlled oscillator output. The first output terminal of the first multiplier 5 is connected to the fifth input terminal of the third multiplier 7. The second output terminal of the second multiplier 6 is connected to the sixth input terminal of the third multiplier 7. The third output terminal 20 of the third multiplier 7 is used to output the phase difference signal. Thus, the phase detector contains four input data channels, two from the resolver output and two from the numerically controlled oscillator output signals. The phase detector performs two stages of cubic multiplication operations to ultimately output a single phase difference signal.

[0037] In some embodiments, the input signal of the rotary transformer is The carrier signal to be recovered output by the rotary transformer is and .in, It is a sine function. It is a cosine function. When the carrier signal to be recovered is... The second feedback signal is The third feedback signal is .in, φ This is the phase error between the carrier signal and the first feedback signal. The phase detector then... and ,Will and Multiplying them and adding the products allows us to use the product-to-sum formula to extract the result containing the product. w The number of items and including φ The terms are separated to facilitate the use of a loop filter to remove terms including w, thus obtaining the result. φ The relevant phase difference signal. Because this phase difference signal only... φ It does not exist. w Therefore, the phase difference signal can characterize the phase error between the carrier signal and the first feedback signal.

[0038] Combination Figure 3 As shown, Figure 3 This is a schematic diagram of a loop filter. The loop filter includes: a fourth multiplier 8, a fifth multiplier 9, a first accumulator 10, and a first adder 11. The seventh input terminal 21 of the fourth multiplier 8 and the ninth input terminal 22 of the fifth multiplier 9 are both used to receive phase difference signals. The eighth input terminal 23 of the fourth multiplier 8 is used to receive proportional control parameter signals. The fourth output terminal of the fourth multiplier 8 is connected to the twelfth terminal of the first adder 11. The tenth input terminal 24 of the fifth multiplier 9 is used to receive integral control parameter signals. The fifth output terminal of the fifth multiplier 9 is connected to the eleventh input terminal of the first accumulator. The sixth output terminal of the first accumulator 10 is connected to the thirteenth input terminal of the first adder 11. The seventh output terminal 25 of the first adder 11 is used to output a phase error signal. The first accumulator includes an adder and an integrator module. The adder adds the signal output from the integrator module and the signal input to the input terminal, outputs the sum, and inputs the sum into the integrator module for integration. In this way, accumulation can be achieved through multiple calculations.

[0039] In some embodiments, the loop filter is a PI (Proportional-Integral) controller. The proportional control parameter signal is input to the proportional control circuit, and the integral control signal is input to the integral control circuit. The integral control circuit and the proportional control circuit together implement PI control, thereby improving circuit stability. Simultaneously, the loop filter can replace the low-pass filter to filter the phase difference signal output by the phase detector. This avoids phase delay in the recovered carrier signal, improving the tracking effect of the envelope signal and thus increasing the accuracy of obtaining the motor rotor's position and speed information.

[0040] Combination Figure 4 As shown, Figure 4 This is a schematic diagram of a numerically controlled oscillator. The numerically controlled oscillator includes a second accumulator 12, a third accumulator 13, a second adder 14, and a feedback signal generator 15. The fourteenth input terminal 26 of the second accumulator 12 is used to input a carrier reference signal; the eighth output terminal of the second accumulator 12 is connected to the sixteenth input terminal of the second adder 14; the fifteenth input terminal 27 of the third accumulator 13 is used to receive a phase error signal; the ninth output terminal of the third accumulator 13 is connected to the seventeenth input terminal of the second adder 14; the tenth output terminal of the second adder 14 is connected to the eighteenth output terminal of the feedback signal generator 15; the eleventh output terminal 28 of the feedback signal generator 15 is used to output a second feedback signal; and the twelfth output terminal 29 of the feedback signal generator 15 is used to output a third feedback signal. In this way, the numerically controlled oscillator can control the oscillation frequency according to the phase error signal, making the phase error between the first feedback signal and the carrier signal equal to the phase error between the oscillation frequency and the frequency of the carrier signal. Then, the sine and cosine signals corresponding to the oscillation frequency are obtained.

[0041] In some embodiments, the second and third accumulators are implemented in the same way as the first accumulator. The carrier reference signal and the carrier signal are in phase. The numerically controlled oscillator generates a sine wave and a cosine wave centered on the carrier reference signal using the carrier reference signal and the phase error signal. As the number of times the first feedback signal is fed back to the phase detector increases, the phase of the sine wave or cosine wave becomes closer and closer to the phase of the carrier reference signal, that is, closer and closer to the phase of the carrier signal. Therefore, if the phase error between the first feedback signal and the carrier signal is within a set range, the cosine wave is determined as the recovered carrier signal and output through the carrier signal output terminal. In this way, carrier recovery is achieved.

[0042] In some embodiments, the feedback signal generator uses a lookup table algorithm or CORDIC (Coordinate Rotation Digital Computer) to generate sine and cosine signals corresponding to the oscillation frequency.

[0043] Combination Figure 5 As shown, this disclosure provides a method for recovering a carrier signal, including:

[0044] Step S101: The resolver-to-digital converter acquires the carrier signal to be recovered output by the output resolver.

[0045] In step S102, the resolver-to-digital converter inputs the carrier signal to be recovered into the carrier signal recovery device to perform carrier signal recovery processing and obtain the recovered carrier signal.

[0046] The method for recovering a carrier signal provided in this disclosure involves inputting the carrier signal to be recovered into a carrier signal recovery device for carrier signal recovery processing to obtain the recovered carrier signal. Since the carrier signal recovery device uses a loop filter for filtering, it does not cause phase delay in the recovered carrier signal, improving the tracking effect of the envelope signal and thus increasing the accuracy of obtaining the position and speed information of the motor rotor.

[0047] In some embodiments, the resolver-to-digital converter is called an RDC device.

[0048] Optionally, the carrier signal to be recovered is input into a carrier signal recovery device for carrier signal recovery processing, including: comparing the phase error between the carrier signal and the first feedback signal output by the numerically controlled oscillator in the carrier signal to be recovered using a phase detector to obtain a phase difference signal corresponding to the phase error; filtering the phase difference signal using a loop filter to obtain a phase error signal; controlling the oscillation frequency using the numerically controlled oscillator according to the phase error signal; and then obtaining the first feedback signal corresponding to the oscillation frequency; and using the carrier signal output terminal, when the phase error between the first feedback signal and the carrier signal is within a set range, acquiring the recovered carrier signal according to the first feedback signal and outputting the recovered carrier signal.

[0049] Combination Figure 6 As shown, this disclosure provides a method for recovering a carrier signal, including:

[0050] Step S201: The resolver-to-digital converter acquires the carrier signal to be recovered output by the resolver.

[0051] In step S202, the resolver-to-digital converter uses a phase detector to compare the phase error between the carrier signal in the carrier signal to be recovered and the first feedback signal output by the numerically controlled oscillator, and obtains the phase difference signal corresponding to the phase error.

[0052] In step S203, the resolver-to-digital converter uses a loop filter to filter the phase difference signal to obtain a phase error signal.

[0053] In step S204, the resolver-to-digital converter uses a numerically controlled oscillator to control the oscillation frequency based on the phase error signal; then, it obtains a first feedback signal corresponding to the oscillation frequency. The first feedback signal includes a second feedback signal and a third feedback signal.

[0054] In step S205, the resolver-to-digital converter uses the carrier signal output terminal to obtain the recovered carrier signal based on the first feedback signal, provided that the phase error between the first feedback signal and the carrier signal is within a set range, and outputs the recovered carrier signal.

[0055] The apparatus for recovering a carrier signal provided in this embodiment compares the phase error between the carrier signal and the first feedback signal output by the numerically controlled oscillator in the carrier signal to be recovered using a phase detector to obtain a phase difference signal corresponding to the phase error. Then, a loop filter is used to filter the phase difference signal. The numerically controlled oscillator controls the oscillation frequency according to the phase error signal; then, the first feedback signal corresponding to the oscillation frequency is obtained. With the phase error between the first feedback signal and the carrier signal within a set range, the recovered carrier signal is obtained based on the first feedback signal at the carrier signal output terminal, and the recovered carrier signal is output. Thus, using a loop filter to filter the phase difference signal does not cause a phase delay in the recovered carrier signal, improving the tracking effect of the envelope signal, thereby improving the accuracy of obtaining the position and speed information of the motor rotor.

[0056] Furthermore, the second feedback signal is orthogonal to the third feedback signal. The second feedback signal is a sine wave, and the third feedback signal is a cosine wave. The phase of the cosine wave is equal to the phase of the sine wave.

[0057] Furthermore, the phase error between the first feedback signal and the carrier signal is equal to the phase error between the oscillation frequency and the frequency of the carrier signal.

[0058] In some embodiments, the phase error between the first feedback signal and the carrier signal is the same as the phase error between the second feedback signal and the carrier signal, or the phase error between the first feedback signal and the carrier signal is the same as the phase error between the third feedback signal and the carrier signal. Since the second feedback signal and the third feedback signal are orthogonal, the phase error between the second feedback signal and the carrier signal is equal to the phase error between the third feedback signal and the carrier signal.

[0059] Since the sine and cosine signals are orthogonal, the second and third feedback signals are in phase. This allows the phase error between the carrier signal and the first feedback signal in the carrier signal to be recovered to be obtained by comparing the phase error between the carrier signal and the second feedback signal, or by comparing the phase error between the carrier signal and the third feedback signal, thus obtaining a phase difference signal including the phase error.

[0060] In some embodiments, the phase detector includes four input data channels, two of which are from the output of a resolver and the other two are output signals from a numerically controlled oscillator. The phase detector obtains the phase difference signal through two stages of cubic multiplication operations.

[0061] In some embodiments, the input signal of the rotary transformer is The carrier signal to be recovered output by the rotary transformer is and When the carrier signal to be recovered is In this case, the carrier signal is Where w is the angular frequency of the carrier signal. θ The angle of the electronic rotor is given. The phase of the carrier signal is wt. When the carrier signal is... In this case, the second feedback signal is The third feedback signal is .in, φ This is the phase error between the carrier signal and the first feedback signal. The phase detector then... and Resolver-to-digital converters use phase detectors to... and Multiplying them and adding the products allows us to use the product-to-sum formula to extract the result containing the product. w The number of items and including φ The terms are separated to facilitate the use of a loop filter to remove terms including w, thus obtaining the result. φ The relevant phase difference signal. Because this phase difference signal only... φ It does not exist. w Therefore, the phase difference signal can characterize the phase error between the carrier signal and the first feedback signal.

[0062] Furthermore, the resolver-to-digital converter determines the recovered carrier signal based on the first feedback signal, including: when the phase error between the first feedback signal and the carrier signal is within a set range, the resolver-to-digital converter determines the second feedback signal as the recovered carrier signal; or, when the phase error between the first feedback signal and the carrier signal is within a set range, the resolver-to-digital converter determines the third feedback signal as the recovered carrier signal.

[0063] Furthermore, after obtaining the first feedback signal corresponding to the oscillation frequency, the resolver-to-digital converter further includes: feeding the first feedback signal back to a phase detector to re-compare the phase error between the carrier signal in the carrier signal to be recovered and the first feedback signal output by the numerically controlled oscillator, thereby obtaining the phase difference signal corresponding to the phase error. Thus, as the number of times the first feedback signal is fed back to the phase detector increases, the phase of the sine or cosine signal becomes increasingly closer to the phase of the carrier reference signal, i.e., increasingly closer to the phase of the carrier signal. Therefore, if the phase error between the first feedback signal and the carrier signal is within a set range, the cosine signal is determined as the recovered carrier signal and output through the carrier signal output terminal. This achieves carrier recovery.

[0064] In some embodiments, the resolver-to-digital converter outputs an excitation signal, which is then input into an analog circuit for conditioning and conversion. The resolver transformer receives the conditioned excitation signal and outputs a signal containing reference excitation information and rotor information. An ADC (Analog-to-Digital Converter) then receives this signal and performs analog-to-digital conversion. The resolver-to-digital converter receives the converted signal and identifies it as the carrier signal to be recovered. It then uses a phase detector to compare the phase error between the carrier signal and the first feedback signal output by the numerically controlled oscillator to obtain the phase difference signal corresponding to the phase error. A loop filter is used to filter the phase difference signal to obtain the phase error signal. The numerically controlled oscillator controls the oscillation frequency based on the phase error signal. The first feedback signal corresponding to the oscillation frequency is then obtained. Using the carrier signal output terminal, if the phase error between the first feedback signal and the carrier signal is within a set range, the recovered carrier signal is obtained based on the first feedback signal and output. This achieves the recovery of the carrier signal, facilitating subsequent envelope signal tracking to obtain the position and angle information of the motor rotor.

[0065] In some embodiments, this solution improves upon the orthogonal loop by replacing the low-pass filter in the orthogonal loop with the original loop filter, thereby achieving functional reuse on the filter and reducing hardware implementation resources without compromising performance.

[0066] In some embodiments, related technologies generate an envelope signal by shaping and integrating, and then shape it to obtain the phase information of the excitation signal. However, integrating one sampling point per carrier cycle results in a coarse envelope signal with low resolution, low accuracy, and poor noise performance. This solution, on the other hand, continuously compares the carrier signal to be recovered with the first feedback signal output by the numerically controlled oscillator, avoiding integrating one sampling point per carrier cycle. This improves the quality of the recovered carrier signal and enhances the accuracy of the subsequently obtained envelope signal.

[0067] In some embodiments, related technologies involve passing two orthogonal carrier signals to be recovered through a filter, performing zero-crossing detection on the filtered data, and finally obtaining the carrier signal through a selector. Because the carrier signals to be recovered contain the angle information of the motor rotor, they are not filtered when passing through the filter but are modulated, resulting in speed modulation errors in the recovered carrier signal. This solution, however, uses a phase detector to compare the phase error between the carrier signal in the carrier signal to be recovered and the first feedback signal output by the numerically controlled oscillator, obtaining the phase difference signal corresponding to the phase error. By filtering out the angular frequency of the carrier signal and avoiding modulation, the carrier signal recovered by this solution has no speed modulation errors, improving the subsequent tracking effect of the envelope signal and thus improving the accuracy of obtaining the position and speed information of the motor rotor.

[0068] The technical solutions of this disclosure can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes one or more instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in this disclosure. The aforementioned storage medium can be a non-transitory storage medium, including: a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and other media capable of storing program code; it can also be a transient storage medium.

[0069] The foregoing description and accompanying drawings fully illustrate embodiments of this disclosure to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, procedural, and other changes. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operation may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. Moreover, the terminology used in this application is for describing embodiments only and is not intended to limit the claims. As used in the description of embodiments and claims, the singular forms “a,” “an,” and “the” are intended to equally include the plural forms unless the context clearly indicates otherwise. Similarly, the term “and / or” as used in this application means including one or more of the associated listed items and all possible combinations thereof. Additionally, when used in this application, the term "comprise" and its variations "comprises" and / or "comprising" refer to the presence of stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof. Without further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the process, method, or apparatus that includes said element. In this document, each embodiment may focus on the differences from other embodiments, and similar or identical parts between embodiments can be referred to mutually. For methods, products, etc., disclosed in the embodiments, if they correspond to the method section disclosed in the embodiments, the relevant parts can be referred to the description of the method section.

[0070] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the embodiments of this disclosure. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0071] The methods disclosed in the embodiments herein can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of units may be merely a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the shown or discussed mutual couplings, direct couplings, or communication connections may be through some interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units, i.e., they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to implement this embodiment according to actual needs. Additionally, the functional units in the embodiments of this disclosure may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0072] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than that shown in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different blocks may also occur in a different order than disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. Each block in a block diagram and / or flowchart, and combinations of blocks in a block diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0073] The foregoing description and accompanying drawings fully illustrate embodiments of the present disclosure to enable those skilled in the art to practice them. Other embodiments may include structural and other changes. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operation may vary. Parts and features of some embodiments may be included or substituted for parts and features of other embodiments. Embodiments of the present disclosure are not limited to the structures described above and shown in the accompanying drawings, and various modifications and changes may be made without departing from its scope. The scope of the present disclosure is limited only by the appended claims.

Claims

1. An apparatus for recovering a carrier signal, characterized in that, include: A phase detector is connected to a numerically controlled oscillator and a loop filter, respectively. The phase detector is used to receive the carrier signal to be recovered output by the resolver and the first feedback signal output by the numerically controlled oscillator. It compares the phase error between the carrier signal and the first feedback signal in the carrier signal to be recovered to obtain the phase difference signal corresponding to the phase error. The loop filter is used to receive the phase difference signal output by the phase detector, filter the phase difference signal, and obtain a phase error signal. The numerically controlled oscillator is connected to the loop filter; the numerically controlled oscillator is used to receive the phase error signal output by the loop filter, control the oscillation frequency according to the phase error signal, and then obtain a first feedback signal corresponding to the oscillation frequency; the first feedback signal includes a second feedback signal and a third feedback signal; the second feedback signal and the third feedback signal are orthogonal. The carrier signal output terminal is connected to the numerically controlled oscillator. The carrier signal output terminal is used to output the recovered carrier signal; The recovered carrier signal is obtained based on the first feedback signal; The phase detector includes a first multiplier, a second multiplier, and a third multiplier; the second input terminal of the first multiplier and the third input terminal of the second multiplier are both used to receive the carrier signal to be recovered output by the resolver; the first input terminal of the first multiplier is used to receive the second feedback signal output by the numerically controlled oscillator; the fourth input terminal of the second multiplier is used to receive the third feedback signal output by the numerically controlled oscillator; the first output terminal of the first multiplier is connected to the fifth input terminal of the third multiplier; the second output terminal of the second multiplier is connected to the sixth input terminal of the third multiplier; and the third output terminal of the third multiplier is used to output the phase difference signal.

2. The apparatus according to claim 1, characterized in that, The phase error between the first feedback signal and the carrier signal is equal to the phase error between the oscillation frequency and the frequency of the carrier signal.

3. The apparatus according to claim 1, characterized in that, The second feedback signal is a sinusoidal signal.

4. The apparatus according to claim 1, characterized in that, The third feedback signal is a cosine signal.

5. The apparatus according to claim 1, characterized in that, The loop filter includes: a fourth multiplier, a fifth multiplier, a first accumulator, and a first adder; the seventh input terminal of the fourth multiplier and the ninth input terminal of the fifth multiplier are both used to receive phase difference signals; the eighth input terminal of the fourth multiplier is used to receive proportional control parameter signals; the fourth output terminal of the fourth multiplier is connected to the twelfth terminal of the first adder; the tenth input terminal of the fifth multiplier is used to receive integral control parameter signals; the fifth output terminal of the fifth multiplier is connected to the eleventh input terminal of the first accumulator; the sixth output terminal of the first accumulator is connected to the thirteenth input terminal of the first adder; and the seventh output terminal of the first adder is used to output phase error signals.

6. The apparatus according to claim 1, characterized in that, The numerically controlled oscillator includes: a second accumulator, a third accumulator, a second adder, and a feedback signal generator; the fourteenth input terminal of the second accumulator is used to input a carrier reference signal; the eighth output terminal of the second accumulator is connected to the sixteenth input terminal of the second adder; the fifteenth input terminal of the third accumulator is used to receive a phase error signal; the ninth output terminal of the third accumulator is connected to the seventeenth input terminal of the second adder; the tenth output terminal of the second adder is connected to the eighteenth output terminal of the feedback signal generator; the eleventh output terminal of the feedback signal generator is used to output a second feedback signal; and the twelfth output terminal of the feedback signal generator is used to output a third feedback signal.

7. A method for recovering a carrier signal, characterized in that, include: Obtain the carrier signal to be recovered from the output of the resolver; The carrier signal to be recovered is input into the device for recovering carrier signals as described in claim 1 to perform carrier signal recovery processing, thereby obtaining the recovered carrier signal.

8. The method according to claim 7, characterized in that, include: A phase detector is used to compare the phase error between the carrier signal in the carrier signal to be recovered and the first feedback signal output by the numerically controlled oscillator to obtain the phase difference signal corresponding to the phase error. The phase difference signal is filtered using a loop filter to obtain a phase error signal; A numerically controlled oscillator is used to control the oscillation frequency based on the phase error signal; then a first feedback signal corresponding to the oscillation frequency is obtained; the first feedback signal includes a second feedback signal and a third feedback signal. Using the carrier signal output terminal, when the phase error between the first feedback signal and the carrier signal is within a set range, the recovered carrier signal is determined based on the first feedback signal, and the recovered carrier signal is output.

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