Inductance type absolute position encoder and motor
By setting the excitation module and detection module of the inductive absolute position encoder independently from the MCU and using hardware design to generate and process signals, the problem of high chip performance requirements in the existing technology is solved, and the effect of reducing costs and improving stability is achieved.
Patent Information
- Application Number
- CN202422887358.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-25
- Publication Date
- 2025-09-23
- Estimated Expiration
- 2034-11-25
AI Technical Summary
Existing inductive position encoders have high requirements for MCU chip performance, which increases development and manufacturing costs. They also have poor stability in complex environments and are difficult to maintain.
The excitation module and detection module are set independently from the absolute position calculation unit, and hardware design is used to generate the excitation signal and perform envelope detection, which reduces the chip's calculation workload and lowers the performance requirements for the MCU.
It reduces system design and manufacturing costs, improves equipment stability and maintainability, simplifies fault diagnosis and repair, and enhances system cost-effectiveness and reliability.
Smart Images
Figure CN223376656U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of encoders, and in particular to an inductive absolute position encoder and a motor. Background Art
[0002] The inductive position encoder is a key device used to measure the rotational position of an object. It is widely used in industrial automation, intelligent manufacturing, robotics, and automotive fields. Compared with traditional incremental encoders that can only provide relative position information, absolute position encoders can improve measurement reliability.
[0003] Current inductive position encoders generally use chips to generate excitation signals, receive signals, process waveforms, and perform calculations. This highly integrated architecture places high demands on the performance of the MCU (Microcontroller Unit) chip, increasing encoder development and manufacturing costs. Furthermore, the chip's highly integrated design compromises stability in complex environments, making fault diagnosis and repair difficult and increasing maintenance costs.
[0004] With regard to the problem in the related art that existing inductive encoders have high requirements on chip performance, no effective solution has been proposed yet. Utility Model Content
[0005] Based on this, it is necessary to provide an inductive absolute position encoder and motor that can reduce chip performance requirements by reducing chip calculation load to address the above technical problems.
[0006] In a first aspect, an inductive absolute position encoder is provided in this embodiment, comprising an excitation module, an inductance module, a detection module, an analog-to-digital conversion module, and an absolute position calculation unit connected in sequence; the excitation module and the detection module are provided independently of the absolute position calculation unit;
[0007] The inductor module includes a stator and a rotor, the rotor includes inner and outer base coils, and the stator includes an excitation coil and inner and outer induction coils;
[0008] The excitation module is configured to generate an excitation signal and apply the excitation signal to the excitation coil to generate a magnetic field in the stator, and generate an induction signal through electromagnetic induction between the inner and outer base coils and the inner and outer induction coils;
[0009] The detection module is used to perform envelope detection on the induction signal generated by the inductance module;
[0010] The analog-to-digital conversion module is used to convert the signal processed by the detection module into a digital signal;
[0011] The absolute position calculation unit is used to output absolute position information according to the input digital signal.
[0012] In some embodiments, the excitation signal generated by the excitation module is a sinusoidal wave signal.
[0013] In some embodiments, the excitation module includes a crystal oscillator for providing a high-frequency sinusoidal wave signal.
[0014] In some of the embodiments, the detection module includes a diode.
[0015] In some embodiments, the number of periods of the outer group of induction coils and the number of periods of the inner group of induction coils of the inner and outer induction coils are not divisible evenly.
[0016] In some of the embodiments, a front-end filtering module and a back-end filtering module are further included;
[0017] The front-end filter module is connected after the inductor module and is used to filter the induction signal; the low-pass threshold of the front-end filter module is the frequency of the excitation signal;
[0018] The back-end filtering module is connected between the detection module and the analog-to-digital conversion module, and is used to filter the signal processed by the detection module; the low-pass threshold of the back-end filtering module is determined by the maximum rotation speed of the detection object and the number of cycles of the external induction coil.
[0019] In some of the embodiments, further comprising an amplification module;
[0020] The amplifying module is connected between the front-end filtering module and the detecting module, and is used to amplify the filtered sensing signal.
[0021] In some of the embodiments, further comprising a communication module;
[0022] The communication module is connected to the absolute position calculation unit and is used to transmit the absolute position information.
[0023] In some embodiments, when the encoder is powered on, each module is started in sequence according to the order in which it is connected.
[0024] In a second aspect, this embodiment provides a motor, comprising the inductive absolute position encoder described in the first aspect.
[0025] Compared with related art, the inductive absolute position encoder and motor provided in this embodiment include an excitation module, an inductance module, a detection module, an analog-to-digital conversion module, and an absolute position calculation unit connected in sequence; the excitation module and the detection module are independently provided from the absolute position calculation unit; the inductance module includes a stator and a rotor, the rotor includes inner and outer base coils, and the stator includes an excitation coil and inner and outer induction coils; the excitation module is configured to generate an excitation signal and apply it to the excitation coil to generate a magnetic field in the stator, generating an induction signal through electromagnetic induction of the inner and outer base coils and the inner and outer induction coils; the detection module is configured to perform envelope detection on the induction signal generated by the inductance module; the analog-to-digital conversion module is configured to convert the signal processed by the detection module into a digital signal; and the absolute position calculation unit is configured to output absolute position information based on the input digital signal. Through this embodiment, the excitation module and the detection module are designed using hardware independent of the absolute position calculation unit, and envelope detection of the inductance signal is performed, which can reduce the chip's computational workload and thus lower the chip's performance requirements.
[0026] The details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:
[0028] Figure 1 FIG. 1 is a schematic structural diagram of an inductive absolute position encoder in an embodiment. DETAILED DESCRIPTION
[0029] In order to more clearly understand the purpose, technical solutions and advantages of the present application, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments.
[0030] Unless otherwise defined, the technical terms or scientific terms involved in this application should have the general meaning understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "an", "a", "the", "these" and the like in this application do not indicate quantitative restrictions, and they can be singular or plural. The terms "include", "comprise", "have" and any variants thereof involved in this application are intended to cover non-exclusive inclusions; for example, a process, method and system, product or device comprising a series of steps or modules (units) is not limited to the listed steps or modules (units), but may include unlisted steps or modules (units), or may include other steps or modules (units) inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "plurality" involved in this application refers to two or more. "And / or" describes the relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A exists alone, A and B exist simultaneously, and B exists alone. Generally, the character " / " indicates that the related objects are in an "or" relationship. The terms "first," "second," "third," etc. used in this application are only used to distinguish similar objects and do not represent a specific ordering of the objects.
[0031] The inductive position encoder is a key device used to measure the rotational position of an object. It is widely used in industrial automation, intelligent manufacturing, robotics, and automotive fields. Compared with traditional incremental encoders that can only provide relative position information, absolute position encoders can improve measurement reliability.
[0032] Current inductive position encoders generally use chips to generate excitation signals, receive signals, process waveforms, and perform calculations. This highly integrated architecture places high demands on the performance of the MCU (Microcontroller Unit) chip, increasing encoder development and manufacturing costs. Furthermore, the chip's highly integrated design compromises stability in complex environments, making fault diagnosis and repair difficult and increasing maintenance costs.
[0033] In this embodiment, an inductive absolute position encoder is provided. Figure 1 Schematic diagram of the structure of the inductive absolute position encoder in this embodiment. Figure 1 As shown, the encoder includes an excitation module, an inductance module, a detection module, an analog-to-digital conversion module and an absolute position calculation unit connected in sequence; the excitation module and the detection module are set independently of the absolute position calculation unit.
[0034] The inductance module includes a stator and a rotor, the rotor includes inner and outer base coils, and the stator includes an excitation coil and inner and outer induction coils; the excitation module is used to generate an excitation signal and apply it to the excitation coil to generate a magnetic field in the stator, and generate an induction signal through electromagnetic induction of the inner and outer base coils and the inner and outer induction coils; the detection module is used to perform envelope detection on the induction signal generated by the inductance module; the analog-to-digital conversion module is used to convert the signal processed by the detection module into a digital signal; the absolute position calculation unit is used to output absolute position information based on the input digital signal.
[0035] The inductor module consists of a stator and rotor, located on the same axis. The rotor includes inner and outer base coils, while the stator includes an excitation coil and inner and outer induction coils. A cyclic structure is constructed using a multi-layer printed circuit board (PCB). The excitation coil generates a rotating magnetic field in response to an excitation signal applied by the excitation module. The rotor generates an induction signal within this rotating magnetic field through the inner and outer base coils and the inner and outer induction coils.
[0036] The positions and periods of the rotor's inner and outer base coils correspond to those of the stator's inner and outer induction coils, inducing an envelope waveform in the inductor module with a peak value representing the position information. The excitation signal applied to the excitation coil by the excitation module generates a magnetic field and serves as the carrier frequency for the envelope waveform output by the inductor module. The induction coils in the stator use this carrier frequency to generate a corresponding modulation signal, the induction signal.
[0037] The excitation module adopts a hardware design independent of the absolute position calculation unit, generates an excitation signal and applies it to the excitation coil of the stator.
[0038] The detection module adopts a hardware design independent of the absolute position calculation unit. In the detection module, the induction signal generated by the inductor module is demodulated by envelope detection. The modulation information is recovered mainly by detecting the envelope of the signal. Envelope detection only requires basic signal rectification and filtering operations, and has a small amount of calculation. Compared with complex demodulation methods such as synchronous demodulation, it is suitable for implementation through hardware or a lower-performance MCU to complete the reception and preliminary processing of the waveform signal.
[0039] The analog-to-digital conversion module maps the induced voltage (analog signal) processed by the front-end circuit to the corresponding digital voltage value interval to convert it into voltage data (digital signal), and uses the obtained voltage data as the input of the absolute position calculation unit. The absolute position calculation unit can be set in the MCU, and the induced voltage is input to the MCU through the analog-to-digital conversion module. The absolute position calculation unit outputs the absolute position information through calculation. The calculation method belongs to the existing technology. For example, the inner and outer induction coils each include two coils with a phase shift of 90 degrees. After excitation, a sine wave signal is generated. The sine and cosine signals are obtained through the detection module. The absolute position calculation unit calculates the two sets of angle information of the inner and outer induction coils through the inverse tangent calculation, one set is the incremental angle, and the other set is the cycle number of the incremental angle. The two sets of data are combined to obtain the absolute angle, thereby mapping the mechanical absolute position information.
[0040] Through this embodiment, an excitation signal is generated in the excitation module, envelope detection is implemented in the detection module, and the excitation module and detection module are set independently from the absolute position calculation unit. Compared with the existing technology that uses a chip to generate the excitation signal and is responsible for signal reception, waveform processing and calculation, the MCU chip can focus on absolute position data calculation without having to bear the generation of the excitation signal and complex waveform processing. That is, the absolute position calculation unit of this application is equivalent to the absolute angle encoder chip in the existing technology, which strips away the excitation and detection functions and only performs absolute position calculation, thereby simplifying the system design and cost and reducing the requirements for MCU performance. This not only improves the cost-effectiveness of the system, but also makes the equipment easier to debug, diagnose faults and repair, shortens downtime, and improves the reliability and maintainability of the system.
[0041] In some embodiments, the excitation signal generated by the excitation module is a sinusoidal wave signal.
[0042] Specifically, the excitation module applies a sinusoidal excitation signal to the excitation coil, generating a magnetic field that induces a sinusoidal envelope waveform in the inductor module, with the peak representing the position information. The induction coils in the inductor module's stator each generate a corresponding modulation signal, or induced signal, at this carrier frequency. The excitation module can be implemented using any device capable of generating a sinusoidal wave, such as a sine wave generator, crystal oscillator, or voltage-controlled oscillator.
[0043] In some embodiments, the excitation module includes a crystal oscillator for providing a high-frequency sinusoidal wave signal.
[0044] The excitation module uses an independent hardware design, which allows it to be set up independently from the absolute position calculation unit. Specifically, the crystal oscillator includes a quartz crystal and an operational amplifier. The quartz crystal provides a high-frequency fixed oscillation frequency, and the operational amplifier amplifies the voltage signal to generate an excitation signal with a natural frequency. In this way, the sinusoidal excitation signal is applied to the stator excitation coil. The frequency F of the excitation signal is calculated as follows:
[0045] F≥2 R
[0046] Where R is the encoder resolution.
[0047] In this embodiment, the excitation module is separated from the MCU and transferred to a dedicated hardware module, which not only reduces development and manufacturing costs, but also improves the stability, reliability and maintainability of the encoder, providing an efficient and economical solution for high-precision position detection under complex working conditions.
[0048] In some of the embodiments, the detection module includes a diode.
[0049] Specifically, the unidirectional conductivity of the diode is used in the detection module to remove the negative cycle of the high-frequency modulated induction signal, retain the positive half-cycle, and extract the original signal that changes with the carrier amplitude. Signal demodulation is achieved through envelope detection with low computing requirements, which can be implemented through hardware or a low-performance MCU.
[0050] Compared with the existing technology that uses an MCU chip to generate the excitation signal and is also responsible for signal reception, waveform processing and calculation, which places higher requirements on the MCU performance, in this embodiment, the detection module is separated from the MCU and transferred to a dedicated hardware module, which not only reduces the development and manufacturing costs, but also improves the stability, reliability and maintainability of the encoder, providing an efficient and economical solution for high-precision position detection under complex working conditions.
[0051] In some embodiments, the number of periods of the outer induction coil and the number of periods of the inner induction coil of the inner and outer induction coils are not divisible evenly.
[0052] Specifically, the inner and outer induction coils include an outer group of induction coils and an inner group of induction coils. The period numbers of the outer group of induction coils and the inner group of induction coils of the stator are not divisible by an integer, that is, the period number of the outer group of induction coils and the period number of the inner group of induction coils do not have an integer multiple relationship. The period number W of the outer group of induction coils and the period number N of the inner group of induction coils specifically satisfy the following relationship: and W, N, and Z are integer sets. In this way, the absolute position calculation unit can combine the angle information of the inner and outer induction coils to obtain unique angular position information within a single rotation cycle of the rotor, thereby achieving absolute position determination for a single turn.
[0053] In this embodiment, the period number of the outer group of induction coils is made non-divisible by the period number of the inner group of induction coils. In this way, the absolute position information within a single rotation period can be obtained based on the non-divisible period numbers of the inner and outer induction coils, thereby improving the accuracy and resolution of the encoder.
[0054] In some embodiments, a front-end filtering module and a back-end filtering module are further included; the front-end filtering module is connected after the inductance module and is used to filter the induction signal; the low-pass threshold of the front-end filtering module is the frequency of the excitation signal; the back-end filtering module is connected between the detection module and the analog-to-digital conversion module and is used to filter the signal processed by the detection module; the low-pass threshold of the back-end filtering module is determined by the maximum rotation speed of the detection object and the number of cycles of the external induction coil.
[0055] Specifically, if Figure 1 As shown in the figure, the front-end filter module is connected to the inductor module, and a low-pass filter is used to filter out high-frequency clutter in the induction signal, reduce the influence of noise and interference, obtain a smoother modulation waveform, and better retain the position information in the induction signal. The low-pass threshold of the front-end filter module can be set to the frequency of the excitation signal emitted by the excitation module. The back-end filter module is connected between the detection module and the analog-to-digital conversion module. The low-pass threshold of the back-end filter module is determined by the maximum rotation speed of the detection object and the number of cycles of the external induction coil. The low-pass threshold F of the back-end filter module is 100. out_filter The specific settings can be as follows:
[0056] F out_filter =Wω max
[0057] Where W represents the period of the outer induction coil, ω max Indicates the maximum rotation speed of the detection object.
[0058] By adopting front-end filtering and back-end filtering in this embodiment, high-frequency clutter in the sensing signal can be filtered out, the influence of noise and interference can be reduced, a smoother modulation waveform can be obtained, and the position information in the sensing signal can be better retained.
[0059] In some embodiments, an amplification module is further included; the amplification module is connected between the front-end filtering module and the detection module, and is used to amplify the filtered sensing signal.
[0060] Specifically, if Figure 1As shown, the amplification module is connected between the front-end filtering module and the detection module, and is used to amplify the weaker induction signal obtained by electromagnetic induction to a voltage range that is easy for the detection module and the analog-to-digital conversion module to process, so as to meet the needs of the subsequent detection module and the analog-to-digital conversion module.
[0061] In some embodiments, a communication module is further included; the communication module is connected to the absolute position calculation unit and is used to transmit absolute position information.
[0062] Specifically, if Figure 1 As shown, after connecting to the absolute position calculation unit, the communication module can be set up in the MCU to output the current absolute position information of the rotor. The encoder connects to external electronic devices through the communication module, providing real-time position information. Furthermore, the communication module supports a variety of standard industrial interfaces and can be customized according to different needs. It can be seamlessly integrated with various electronic devices such as control systems and automation equipment to achieve precise rotor position monitoring and control.
[0063] The communication module in this embodiment can provide real-time position information to various external electronic devices, thereby achieving accurate rotor position monitoring and control.
[0064] In some embodiments, when the encoder is powered on, the modules are started in sequence according to the order in which they are connected.
[0065] Specifically, the excitation module generates the signal carrier, which cannot achieve instantaneous stable operation upon power-up, so it must be started first. The subsequent startup of the remaining components is determined by the circuit connection sequence. A startup delay is set within the MCU to ensure that the external circuits are stable before commencing angle calculation, ensuring the stability and accuracy of the angle output.
[0066] The present embodiment is described and illustrated below through preferred embodiments.
[0067] This embodiment provides an inductive absolute position encoder, such as Figure 1 As shown in the figure, the encoder includes an excitation module, an inductor module, a front-end filter module, an amplifier module, a detector module, a back-end filter module, an analog-to-digital conversion module, an absolute position calculation unit, and a communication module, all connected in sequence. When the encoder is powered on, each module starts up in the order in which it is connected. The excitation module, which generates the signal carrier, cannot achieve instantaneous stable operation upon power-up, so it must be started first. The order in which the remaining components start up is determined by the circuit connection sequence. A startup delay is set within the MCU to ensure that the external circuits are stable before starting angle calculation, thus ensuring the stability and accuracy of the angle output.
[0068] Among them, the inductance module includes a stator and a rotor, the rotor includes inner and outer base coils, and the stator includes an excitation coil and inner and outer induction coils; the inner and outer base coils of the rotor correspond to the positions and period numbers of the inner and outer induction coils of the stator, so as to induce a high-frequency induction signal with a sinusoidal envelope waveform whose peak value is position information in the inductance module.
[0069] The period number W of the outer induction coil is not divisible by the period number N of the inner induction coil, and specifically meets the following requirements: and W, N, and Z are sets of integers.
[0070] The excitation module includes a quartz crystal and an operational amplifier. The quartz crystal provides a fixed oscillation frequency, which is then amplified by the operational amplifier to generate an excitation signal with a natural frequency. The excitation signal applied to the excitation coil by the excitation module generates a magnetic field and serves as the carrier frequency for the envelope waveform output by the inductor module. The induction coils in the stator use this carrier frequency to generate a corresponding modulation signal, the induction signal.
[0071] The front-end filtering module is used to filter the induction signal and use a low-pass filter to filter out high-frequency clutter, reduce the impact of noise and interference, and better retain the rotor position information. Its threshold is the frequency of the excitation signal.
[0072] The amplifier module is used to amplify the weaker induction signal obtained by electromagnetic induction to meet the needs of subsequent detection module and analog-to-digital conversion module operations.
[0073] The detection module uses the unidirectional conductivity of the diode to remove the negative cycle of the high-frequency modulated induction signal, retain the positive half-cycle, and extract the original signal that changes with the carrier amplitude. Signal demodulation is achieved through envelope detection with low computing requirements. It can be implemented through hardware or a low-performance MCU.
[0074] The back-end filtering module is used to filter the demodulated signal, and its threshold is determined by the maximum rotation speed of the detection object and the number of cycles of the external induction coil.
[0075] When the detection object is working and driving the rotor to rotate, the waveforms of the internal and external induction coils are generated into a sinusoidal wave demodulation waveform through the front-end filtering module, amplification module, detection module and back-end filtering module.
[0076] The analog-to-digital conversion module is used to map the induced voltage (analog signal) processed by the front-end circuit to the corresponding digital voltage value interval to convert it into voltage data (digital signal), and use the obtained voltage data as the input of the absolute position calculation unit.
[0077] The absolute position calculation unit, located within the MCU, calculates the angles of the inner and outer induction coils using arctan and inverse tangent calculations. Finally, the absolute position of the rotor within a single rotation cycle is calculated based on the angles of the inner and outer induction coils.
[0078] The communication module, integrated into the MCU, outputs the current absolute rotor position. The encoder connects to external electronic devices through the communication module, providing real-time position information. Furthermore, the communication module supports a variety of standard industrial interfaces (such as RS485) and can be customized to meet specific needs. It seamlessly integrates with various control systems, automation equipment, and other electronic devices to achieve precise rotor position monitoring and control.
[0079] Among them, the excitation module and the detection module adopt a dedicated hardware design and are set independently from the absolute position calculation unit of the MCU to reduce the performance requirements of the MCU.
[0080] The inductive absolute position encoder provided in this embodiment is compared with the current inductive position encoders that generally use chips to generate excitation signals and a highly integrated architecture responsible for signal reception, waveform processing and calculation. The excitation module and the detection module are designed independently of the chip, and a hardware detection module is used to complete signal reception and preliminary processing, which reduces the computing load on the MCU and allows the MCU to focus on absolute position data calculation and communication tasks, simplifies system design and cost, reduces performance requirements for the MCU, makes debugging, fault diagnosis and maintenance easier, shortens downtime, improves reliability and maintainability, and ensures real-time and flexibility of the equipment through the compatibility of independent excitation modules and detection modules with multiple industrial communication protocols.
[0081] This embodiment further provides a motor, comprising the inductive absolute position encoder in any of the above embodiments, that is, the motor is the detection object of the encoder.
[0082] The encoder is mounted on the motor to detect the rotation angle of the motor rotor. The motor is suitable for equipment such as traction machines, industrial automation equipment, robots, CNC machine tools, CT scanners, MRI scanners, and automated operating tables. The encoder in this application can provide absolute position information for precise control.
[0083] It should be understood that the specific embodiments described herein are only used to explain this application and are not used to limit it. Based on the embodiments provided in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.
[0084] Obviously, the accompanying drawings are merely examples or embodiments of the present application. A person skilled in the art can also apply the present application to other similar situations based on these drawings without inventive effort. Furthermore, it is understandable that, although the work involved in this development process may be complex and lengthy, certain design, manufacturing, or production changes based on the technical content disclosed in this application are merely routine technical means for a person skilled in the art and should not be considered to constitute a deficiency in the disclosure of the present application.
[0085] The term "embodiment" as used in this application refers to specific features, structures, or characteristics described in conjunction with the embodiment that can be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment, nor does it mean that it is mutually exclusive with other embodiments and is independent or optional. It is understood, either explicitly or implicitly, by those skilled in the art that the embodiments described in this application can be combined with other embodiments when there is no conflict.
[0086] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of patent protection. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.
Claims
1. An inductive absolute position encoder, characterized in that: It includes an excitation module, an inductance module, a detection module, an analog-to-digital conversion module and an absolute position calculation unit connected in sequence; the excitation module and the detection module are independently provided with the absolute position calculation unit; The inductor module includes a stator and a rotor, the rotor includes inner and outer base coils, and the stator includes an excitation coil and inner and outer induction coils; The excitation module is configured to generate an excitation signal and apply the excitation signal to the excitation coil to generate a magnetic field in the stator, and generate an induction signal through electromagnetic induction between the inner and outer base coils and the inner and outer induction coils; The detection module is used to perform envelope detection on the induction signal generated by the inductance module; The analog-to-digital conversion module is used to convert the signal processed by the detection module into a digital signal; The absolute position calculation unit is used to output absolute position information according to the input digital signal.
2. The inductive absolute position encoder according to claim 1, wherein: The excitation signal generated by the excitation module is a sine wave signal.
3. The inductive absolute position encoder according to claim 2, wherein: The excitation module includes a crystal oscillator for providing a high-frequency sine wave signal.
4. The inductive absolute position encoder according to claim 1, wherein: The detection module includes a diode.
5. The inductive absolute position encoder according to claim 1, wherein: The number of periods of the outer group of induction coils and the number of periods of the inner group of induction coils of the inner and outer induction coils are not divisible evenly.
6. The inductive absolute position encoder according to claim 1, wherein: It also includes a front-end filtering module and a back-end filtering module; The front-end filter module is connected after the inductor module and is used to filter the induction signal; the low-pass threshold of the front-end filter module is the frequency of the excitation signal; The back-end filtering module is connected between the detection module and the analog-to-digital conversion module, and is used to filter the signal processed by the detection module; The low-pass threshold of the back-end filtering module is determined by the maximum rotation speed of the detection object and the number of cycles of the external induction coil.
7. The inductive absolute position encoder according to claim 6, wherein: Also included is an amplification module; The amplifying module is connected between the front-end filtering module and the detecting module, and is used to amplify the filtered sensing signal.
8. The inductive absolute position encoder according to claim 1, wherein: Also included is a communication module; The communication module is connected to the absolute position calculation unit and is used to transmit the absolute position information.
9. The inductive absolute position encoder according to claim 1, wherein: When the encoder is powered on, each module starts in sequence according to the connection order.
10. A motor, characterized in that: The invention comprises the inductive absolute position encoder according to any one of claims 1 to 9.