Inductance type multi-turn encoder

Abstract

The invention relates to the technical field of encoders, in particular to an inductance type multi-turn encoder. Comprising a main body, a power shaft, a single-circle angle measuring module, a multi-circle angle measuring module and a signal processing unit, the single-circle angle measuring module and the multi-circle angle measuring module are both arranged in a cylinder of the main body, and one end of the power shaft is used for being connected with an external driving source; the multi-turn angle measuring module comprises a central gear, a reduction gear set and a turn number sensing unit, the central gear is fixed on a power shaft, one end of the reduction gear set is meshed with the central gear, the other end of the reduction gear set is connected with the turn number sensing unit, and the reduction gear set is fixed on the power shaft. And the signal processing unit is electrically connected with the single-circle angle measuring module and the circle number sensing unit, and is used for receiving the single-circle angle electric signal and the multi-circle count value electric signal and integrating, correcting and outputting an absolute angle value based on a backlash compensation module in the signal processing unit.

Description

Technical Field

[0001] This invention belongs to the field of encoder technology, and specifically relates to an inductive multi-turn encoder. Background Technology

[0002] An encoder is a sensor used to accurately measure the angular displacement of a rotating object. With the increasing demands for position feedback in fields such as industrial automation, robotics, and precision instruments, it is necessary not only to measure the angle within a single revolution (0°~360°), but also to accurately record and output the total number of revolutions, i.e., the absolute multi-turn angle value, when the equipment rotates continuously. Therefore, multi-turn encoders have emerged, and their core technology lies in how to reliably and accurately detect and memorize the total number of revolutions.

[0003] Currently, there are two main technical approaches to multi-turn encoders on the market. The first is the photoelectric multi-turn encoder, which detects the number of turns by placing a photoelectric code disk at the end of a mechanical reduction gear set. This approach utilizes the mature photoelectric sensing principle and has the advantages of high resolution and good repeatability. However, it is sensitive to environmental vibrations, dust, oil, and changes in temperature and humidity, and its reliability is easily affected by long-term use. The second is the electronic storage multi-turn encoder, which typically consists of a single-turn absolute encoder (such as a magnetic encoder or capacitive encoder), an electronic counter, and a non-volatile memory (such as an EEPROM). Its advantage lies in eliminating the need for a sophisticated multi-turn detection mechanical structure, making the product more compact and lightweight. However, the lifespan of this approach largely depends on the number of times the memory can be erased and rewritten, resulting in a theoretical lifespan bottleneck. More importantly, if rotation occurs while the power is completely off, the number of turns generated during rotation will be lost upon power-on because a write operation is not possible, leading to incorrect position information and a risk of "lost turns."

[0004] To overcome the aforementioned problems, inductive (or rotary transformer) encoding technology, which offers stronger environmental adaptability and a longer theoretical lifespan, has been introduced into the multi-turn encoding field. Existing solutions attempt to combine an inductive single-turn angle measurement module with a multi-turn counting mechanism using mechanical gear reduction. However, this approach suffers from inherent backlash (return error) in the gear transmission system, leading to slight asynchrony or errors between the actual rotation of the drive shaft and the count reflected by the reduction gear set during small-angle reciprocating motion or start-stop. This error introduced by mechanical backlash is not effectively compensated for in existing solutions and is directly added to the final multi-turn angle output value. Especially in applications requiring high-precision positioning and repeated adjustments of small angles, this reduces the overall accuracy and stability of the system, limiting the application of inductive multi-turn encoders in high-performance applications. Summary of the Invention

[0005] To address the aforementioned problems in the prior art, this invention provides an inductive multi-turn encoder that effectively overcomes the inherent backlash error problem of mechanical gear transmission by combining inductive single-turn measurement with multi-turn measurement of reduction gears using an integrated real-time backlash compensation algorithm.

[0006] The objective of this invention can be achieved through the following technical solutions: An inductive multi-turn encoder includes a main body, a drive shaft, a single-turn angle measurement module, a multi-turn angle measurement module, and a signal processing unit. Both the single-turn and multi-turn angle measurement modules are housed inside the cylinder of the main body. One end of the drive shaft is connected to an external drive source, and the other end is connected to the single-turn rotor coil plate of the single-turn angle measurement module to obtain a single-turn angle electrical signal. The multi-turn angle measurement module includes a central gear, a reduction gear set, and a turn count sensing unit. The central gear is fixed to the drive shaft. One end of the reduction gear set meshes with the central gear, and the other end is connected to the turn count sensing unit, outputting a multi-turn count electrical signal. The signal processing unit is electrically connected to the single-turn angle measurement module and the turn count sensing unit, and receives the single-turn angle electrical signal and the multi-turn count electrical signal, integrating and correcting the output absolute angle value based on the backlash compensation module in the signal processing unit.

[0007] As a further technical solution of the present invention, the backlash compensation module is integrated into the signal processing unit and is used to perform the following backlash compensation steps: a) Based on the dynamic relationship between the single-turn angle electrical signal and the multi-turn count value electrical signal when the motion state of the power shaft changes, detect the backlash error value of the reduction gear set and obtain the number of turns encoding signal based on a preset calibration algorithm model; b) Based on the obtained revolution count encoding signal; the signal processing unit is further configured to: synthesize the corrected revolution count encoding signal and the single-revolution angle electrical signal into the absolute position data of the power shaft and output it.

[0008] As a further technical solution of the present invention, the main body is composed of a base, a cylindrical body and an end cover. The base, the cylindrical body and the end cover are coaxial and locked together from bottom to top by bolts. A bearing is provided between the cylindrical body and the end cover.

[0009] As a further technical solution of the present invention, the single-turn angle measurement module further includes a stator coil plate and a stator signal processing module; the stator coil plate is fixedly arranged, and an array of excitation coils and receiving coils distributed radially in multiple layers is printed on it; the single-turn rotor coil plate is a PCB printed inductor coil, which is coaxially mounted on the power shaft and maintains a non-contact electromagnetic induction gap with the stator coil plate.

[0010] As a further technical solution of the present invention, the signal processing unit is configured to output the absolute angle data through a preset communication interface; the communication interface includes a UART interface for internal signal fusion encoding and / or a CAN interface for communication with a host system, wherein the CAN interface supports the CANopen communication protocol.

[0011] As a further technical solution of the present invention, the multi-turn angle measurement module further includes a mounting shell, a multi-turn rotor coil plate, and a multi-turn signal processing module; the mounting shell is fixed to the inside of the cylinder, and the reduction gear set is disposed inside the mounting shell; at least one of the multi-turn rotor coil plates is coaxially connected to the output end of the reduction gear set, and forms a non-contact inductive coupling link with the multi-turn signal processing module to generate the multi-turn count value electrical signal.

[0012] As a further technical solution of the present invention, the reduction gear set includes a first reduction gear, a second reduction gear and a third reduction gear; the central gear meshes with at least one of the first reduction gears; the first reduction gear meshes with the second reduction gear and the third reduction gear in sequence through a double-tooth structure to realize multi-stage reduction transmission; wherein the output shaft of at least one reduction gear is connected to the revolution sensing unit.

[0013] As a further technical solution of the present invention, in step a), the detection of the backlash error value of the reduction gear set specifically involves: real-time monitoring of the changing trend of the single-turn angle electrical signal and the response delay of the multi-turn count value electrical signal, and by comparing the phase difference between the two at the moment of commutation of the power shaft, extracting the idle travel deviation caused by the backlash as a compensation parameter.

[0014] As a further technical solution of the present invention, in step b), the synthesis of the corrected revolution number encoding signal and the single revolution angle electrical signal is specifically performed in real time by a high-precision fusion algorithm, and temperature drift compensation and signal timing alignment technology are used to generate continuous and uninterrupted full-range absolute position data before output.

[0015] The beneficial effects of this invention are as follows: By combining inductive single-turn measurement with multi-turn measurement of reduction gears using an integrated real-time backlash compensation algorithm, high-precision, absolute position measurement over a range of up to 4096 turns has been successfully achieved. This solution demonstrates superior measurement performance, not only eliminating the weaknesses of traditional photoelectric or magnetoelectric methods through non-contact inductive and capacitive sensing, but also effectively overcoming the inherent backlash error of mechanical gear transmissions through an intelligent self-learning compensation algorithm, ensuring high resolution and zero cumulative error in the full-range angle output. Furthermore, its fully non-contact design provides strong environmental adaptability, resisting the effects of oil, dust, and temperature and humidity changes, and eliminating the need for batteries or easily damaged storage units for turn counting, fundamentally solving the problem of "turn loss" during power outages. Attached Figure Description

[0016] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0017] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a schematic diagram of the disassembled structure of the present invention; Figure 3 This is a cross-sectional perspective view of the three-dimensional structure of the present invention; Figure 4 This is the first exploded view of the present invention; Figure 5 This is a second exploded view of the present invention; Figure 6 This is a schematic diagram of the deceleration mechanism of the present invention; Legend: 1. Base; 2. Cylinder; 21. Bearing; 3. End cover; 31. Power shaft; 22. Stator signal processing module; 23. Stator coil board; 24. Single-turn rotor coil board; 25. Multi-turn signal processing module; 26. Mounting shell; 261. Center gear; 262. Multi-turn rotor coil board; 263. First reduction gear; 264. Second reduction gear; 265. Third reduction gear. Detailed Implementation

[0018] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided.

[0019] Reference Figures 1 to 6As shown, this invention proposes an inductive multi-turn encoder, comprising a main body, a drive shaft 31, a single-turn angle measurement module, a multi-turn angle measurement module, and a signal processing unit. Both the single-turn and multi-turn angle measurement modules are housed inside the cylindrical body 2 of the main body. One end of the drive shaft 31 is connected to an external drive source, and the other end is connected to the single-turn rotor coil plate 24 of the single-turn angle measurement module. The multi-turn angle measurement module includes a central gear 261, a reduction gear set, and a turn count sensing unit. The central gear 261 is fixed to the drive shaft 31. One end of the reduction gear set meshes with the central gear 261, and the other end is connected to the turn count sensing unit, outputting a multi-turn count electrical signal. The signal processing unit… The processing unit is electrically connected to the single-turn angle measurement module and the number of turns sensing unit, and is used to receive the single-turn angle electrical signal and the multi-turn count value electrical signal and integrate and correct to output the absolute angle value; wherein, the main body is composed of a base 1, a cylinder 2, a bearing 21 and an end cover 3, wherein the base 1, the cylinder 2 and the end cover 3 are coaxially fixed from bottom to top by bolts, the base 1 is equipped with a communication parameter configuration module and a power module, the cylinder 2 is equipped with a single-turn angle measurement module, a multi-turn angle measurement module and a signal processing unit, forming a non-contact electromagnetic induction, the bearing 21 is provided between the cylinder 2 and the end cover 3, and the bearing 21 enables one end of the power shaft 31 to keep rotating and connect to the single-turn rotor coil plate 24.

[0020] With the above setup, one end of the power shaft 31 is connected to an external drive source to obtain continuous rotational power, while the other end drives the single-turn rotor coil plate 24 to rotate. Through the principle of inductance, a high-frequency alternating current is applied to the excitation coil on the single-turn angle measurement module, generating an alternating magnetic field. This magnetic field is coupled to the induction coil of the single-turn rotor coil plate 24 through an air gap, generating an induced voltage that is fed back to the signal processing unit, forming a high-resolution single-turn angle electrical signal. On the other hand, through the central gear 261 fixed on the shaft and the reduction gear set, multi-turn rotation information is transmitted to the number of turns sensing unit at a fixed reduction ratio. The signal processing unit simultaneously receives and integrates these two signals to calculate a continuous, error-free absolute angle value. This solution effectively solves the technical problems of traditional absolute encoders relying on battery memory (risk of loss upon power failure) and the difficulty in balancing high precision and high reliability in harsh industrial environments. Thus, it achieves a comprehensive effect of obtaining absolute position upon power-on, eliminating the need for batteries, being insensitive to environmental pollutants, and possessing both high measurement accuracy and long-term operational stability. Meanwhile, the backlash compensation module is integrated into the signal processing unit to detect and compensate for mechanical backlash errors in the reduction gear set, further improving the repeatability and accuracy of angle measurement. The revolution counting sensing unit adopts a capacitive sensing structure, which detects the relative displacement changes between capacitor plates, converting the mechanical rotation transmitted by the gear set into discrete capacitance change signals, and then converting them into digital pulse signals via a signal conditioning circuit before outputting them to the signal processing unit. This capacitive structure has high anti-interference capability and long-term stability, avoiding the performance degradation problems of magnetic or optical sensing methods in oily or dusty environments, ensuring the accuracy and reliability of multi-revolution counting.

[0021] As a further technical solution of the present invention, the backlash compensation module is integrated into the signal processing unit and is used to perform the following backlash compensation steps: a) Based on the dynamic relationship between the single-turn angle electrical signal and the turn count encoding signal when the motion state of the power shaft 31 changes, the backlash error value of the reduction gear set is detected and the accurate turn count encoding signal is obtained based on the preset calibration algorithm model. Specifically, when the power shaft 31 switches from forward rotation to reverse rotation or vice versa, the signal processing unit monitors the changing trend of the single-turn angle electrical signal and the response delay of the multi-turn count value electrical signal in real time. By comparing the phase difference between the two at the moment of commutation, the instantaneous phase difference between the single-turn signal and the multi-turn count value electrical signal near the commutation point is calculated by zero-crossing detection or correlation function method, and the idle travel deviation caused by backlash is extracted. This deviation is dynamically written into the preset existing calibration algorithm model as a compensation parameter for real-time compensation calculation. The calibration algorithm model includes a displacement-compensation lookup table. By querying the historical data of the phase difference corresponding to the current backlash deviation, the instantaneous compensation value is output to correct the multi-turn count value. In addition, the compensation parameters are continuously updated and stored in non-volatile memory during the compensation process to achieve self-learning closed-loop compensation. This allows the compensation algorithm to automatically call the latest stored compensation parameters each time it is powered on and initialized, ensuring that high-precision operation can be maintained without manual intervention. Meanwhile, the signal processing unit has a built-in environment adaptive module that can dynamically adjust the excitation frequency and sampling gain according to changes in operating conditions such as temperature and vibration, further suppressing the influence of external interference on the measurement results and obtaining a turn-encoded signal that eliminates backlash and external interference.

[0022] b) Based on the obtained revolution count encoding signal, the signal processing unit is further configured to synthesize the revolution count value in the corrected revolution count encoding signal with the single-revolution angle electrical signal to form the absolute position data of the power shaft 31 and output it. Specifically, the corrected revolution count encoding signal and the single-revolution angle electrical signal are synthesized in real time using a high-precision fusion algorithm to generate continuous, uninterrupted, full-range absolute position data, which is then output using a standard communication protocol. This process fully considers the dynamic nonlinear characteristics of the mechanical transmission chain, and combines temperature drift compensation and signal timing alignment technology to ensure microsecond-level synchronization and precise angular matching under frequent start-stop, reverse, and speed change conditions, achieving seamless absolute positioning. The synthesized absolute position data is verified for its integrity and consistency through multiple verification mechanisms to ensure reliable transmission in complex electromagnetic environments. The signal processing unit supports multi-channel redundant output and can simultaneously send data to the single-revolution module via the UART interface for single-revolution and multi-revolution position signal fusion encoding. It can also output data via the CAN interface, supporting the CANopen communication protocol, to transmit data to a host computer or motion controller, meeting the integration needs of different industrial scenarios.

[0023] As a further technical solution of the present invention, the single-turn angle measurement module also includes a stator signal processing module 22 and a stator coil plate 23, wherein a single-turn rotor coil plate 24 is coaxially mounted on the power shaft 31. The single-turn rotor coil plate 24 is specifically a PCB printed inductor coil, which is horizontally mounted on the rotating shaft. The stator coil plate 23 has an excitation coil and a receiving coil array radially distributed in multiple layers, which are PCB printed inductors used to generate an alternating electromagnetic field and sense the magnetic coupling change when the single-turn rotor coil plate 24 rotates. It is mounted on the encoder base 1 by a bracket, with a gap of 0.5mm±0.1mm between its lower surface and the upper surface of the rotor coil. The stator signal processing module 22 is coupled to the coil array and is configured to perform differential amplification, bandpass filtering and demodulation processing on the sensed signal to extract two orthogonal signals that are sinusoidally related to the single-turn angle. The orthogonal signals are input to the angle calculation unit after analog-to-digital conversion. The high-resolution single-turn absolute angle value is calculated by arctangent interpolation algorithm, and the harmonic error introduced by winding asymmetry and installation eccentricity is corrected by digital compensation algorithm. When the rotor rotates, a mutual inductance coefficient that varies with the angle is formed between the stator coil plate 23 and the rotor coil plate. After being modulated by the excitation signal, the output induced electromotive force has an amplitude and phase related.

[0024] As a further embodiment of the present invention, the multi-turn angle measurement module further includes a multi-turn signal processing module 25, a mounting shell 26, a multi-turn rotor coil plate 262, and a reduction gear set. The mounting shell 26 is fixed to the upper inner side of the cylinder 2, and the bearing 21 is located at the top center of the mounting shell 26. The reduction gear set has three sets installed inside the mounting shell 26, and the three sets of reduction gear sets are arranged in a circular array on the central gear 261. The three sets of reduction gear sets mesh sequentially to achieve multi-stage reduction and transmission of rotation. Each set of reduction gear sets has a multi-turn rotor coil plate 262, and the three multi-turn rotor coil plates 262 are located on the outer bottom of the mounting shell 26. The signal processing module 25 is located inside the cylinder 2, above the single-turn rotor coil plate 24. A certain gap exists between the multi-turn signal processing module 25 and the three multi-turn rotor coil plates 262, maintaining an air gap of 0.3mm to 0.8mm, forming a non-contact inductive coupling link. One set of reduction gears meshes with the central gear 261. Through the sequential meshing and torque transmission of the reduction gears, the three multi-turn rotor coil plates 262 rotate at low speed with the reduction gears, achieving mechanical accumulation of multiple turns. Each full turn of the multi-turn rotor coil plate 262 corresponds to a certain change in the number of teeth, generating a discrete turn count encoded signal. After this signal is acquired by the multi-turn signal processing module 25, the actual number of rotations is restored through Gray code decoding and direction discrimination algorithms, and then sent to the backlash compensation module for reverse backlash error correction to eliminate counting deviations caused by loose gear meshing. To ensure stable energy and signal transmission under vibration and temperature changes, a multi-turn stator coil board 23 is integrated into the inner wall of the mounting housing 26 and electrically connected to the multi-turn signal processing module 25. This module receives the coded electromagnetic signal corresponding to the rotation angle after deceleration, and outputs it to the main control unit after shaping, filtering, and digitization. The backlash compensation module establishes a dynamic compensation model based on historical motion direction and current acceleration information, correcting in real-time misjudgments of the number of turns caused by gear backlash, thus improving the continuity and accuracy of multi-turn counting.

[0025] As a further technical solution of the present invention, the reduction gear set is composed of a first reduction gear 263, a second reduction gear 264 and a third reduction gear 265. There are four first reduction gears 263 arranged in a ring around the central gear 261. Three of the first reduction gears 263 are coaxially connected to the corresponding multi-turn rotor coil plate 262, and the remaining one meshes with the central gear 261 as the transmission source. There are three sets of second reduction gears 264 and third reduction gears 265 between the four first reduction gears 263. Only the last first reduction gear 263 with a multi-turn rotor coil plate 262 is not connected to the first reduction gear 263 without a multi-turn rotor coil plate 262. It should be explained in detail that both the first reduction gear 263 and the third reduction gear 265 are coaxially equipped with double teeth. The double tooth structure is divided into large and small teeth. The transmission ratio is adjusted by the module difference between the two teeth. First, the first reduction gear 263 engages with the center gear 261 through the large tooth to receive the power input, and its small tooth engages with the second reduction gear 264 to transmit torque. The large tooth of the third reduction gear 265 engages with the second reduction gear 264, and the small tooth then engages with the large tooth of the next first reduction gear 263 equipped with a multi-turn rotor coil plate 262, realizing continuous deceleration of the multi-stage transmission chain. Finally, the small tooth of the third reduction gear 265 engages with the large tooth of the last first reduction gear 263, completing the step-by-step transmission and subdivision of the multi-turn angle signal. Three multi-turn rotor coil plates 262 are sequentially installed at different levels of the reduction output end, with their rotational speed decreasing exponentially. Specifically, the reduction ratio between adjacent stages of the three-stage gear reduction mechanism is designed to be 16:1. Each gear group records 16 full-turn position information, and the three cascaded groups can record 16*16*16=4096 turns of position information, thus achieving high-resolution subdivision and accumulation of the number of rotation turns. The multi-turn rotor coil plates 262 corresponding to each level of reduction output end sense periodic electromagnetic signals at different speeds. After being synchronously acquired by the multi-turn signal processing module 25, the current number of turns is determined by combining phase comparison and pulse counting algorithms, and the position information before power failure is recorded through a non-volatile storage unit. This structure effectively reduces the error accumulation caused by the single-stage transmission ratio and improves the overall return accuracy and long-term operational stability of the system. The transmission of each stage of the reduction gear set achieves bidirectional backlash-free transmission through precision tooth profile design and clearance preload structure.

[0026] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. An inductive multi-turn encoder, characterized in that: The system includes a main body, a drive shaft, a single-turn angle measurement module, a multi-turn angle measurement module, and a signal processing unit. Both the single-turn and multi-turn angle measurement modules are located inside the cylindrical body of the main body. One end of the drive shaft connects to an external drive source, and the other end connects to the single-turn rotor coil plate of the single-turn angle measurement module to obtain a single-turn angle electrical signal. The multi-turn angle measurement module includes a central gear, a reduction gear set, and a revolution count sensing unit. The central gear is fixed to the drive shaft. One end of the reduction gear set meshes with the central gear, and the other end connects to the revolution count sensing unit, outputting a multi-turn count electrical signal. The signal processing unit is electrically connected to the single-turn angle measurement module and the revolution count sensing unit, and receives the single-turn angle electrical signal and the multi-turn count electrical signal, integrating and correcting the output absolute angle value based on the backlash compensation module within the signal processing unit.

2. The inductive multi-turn encoder according to claim 1, characterized in that: The backlash compensation module is integrated into the signal processing unit and is used to perform the following backlash compensation steps: a) Based on the dynamic relationship between the single-turn angle electrical signal and the multi-turn count value electrical signal when the motion state of the power shaft changes, detect the backlash error value of the reduction gear set and obtain the number of turns encoding signal based on a preset calibration algorithm model; b) Based on the obtained revolution count encoding signal; the signal processing unit is further configured to: synthesize the corrected revolution count encoding signal and the single-revolution angle electrical signal into the absolute position data of the power shaft and output it.

3. The inductive multi-turn encoder according to claim 1, characterized in that: The main body consists of a base, a cylindrical body, and an end cover. The base, cylindrical body, and end cover are coaxial and fixed together from bottom to top by bolts. A bearing is provided between the cylindrical body and the end cover.

4. The inductive multi-turn encoder according to claim 1, characterized in that: The single-turn angle measurement module also includes a stator coil board and a stator signal processing module; the stator coil board is fixedly installed and has an array of excitation coils and receiving coils distributed radially in multiple layers printed on it; the single-turn rotor coil board is a PCB printed inductor coil, which is coaxially mounted on the power shaft and maintains a non-contact electromagnetic induction gap with the stator coil board.

5. The inductive multi-turn encoder according to claim 1, characterized in that: The signal processing unit is configured to output the absolute angle data through a preset communication interface; the communication interface includes a UART interface for internal signal fusion encoding and / or a CAN interface for communication with a host system, wherein the CAN interface supports the CANopen communication protocol.

6. The inductive multi-turn encoder according to claim 1, characterized in that: The multi-turn angle measurement module also includes a mounting shell, a multi-turn rotor coil plate, and a multi-turn signal processing module; the mounting shell is fixed inside the cylinder, and the reduction gear set is disposed inside the mounting shell; at least one of the multi-turn rotor coil plates is coaxially connected to the output end of the reduction gear set, and forms a non-contact inductive coupling link with the multi-turn signal processing module to generate the multi-turn count value electrical signal.

7. The inductive multi-turn encoder according to claim 6, characterized in that: The reduction gear set includes a first reduction gear, a second reduction gear, and a third reduction gear; the central gear meshes with at least one of the first reduction gears; the first reduction gear meshes with the second reduction gear and the third reduction gear in sequence through a double-tooth structure to achieve multi-stage reduction transmission; wherein the output shaft of at least one reduction gear is connected to the revolution sensing unit.

8. The inductive multi-turn encoder according to claim 2, characterized in that: In step a), the detection of the backlash error value of the reduction gear set is specifically achieved by: real-time monitoring of the changing trend of the single-turn angle electrical signal and the response delay of the multi-turn count value electrical signal, and by comparing the phase difference between the two at the moment of commutation of the power shaft, extracting the idle travel deviation caused by the backlash as a compensation parameter.

9. The inductive multi-turn encoder according to claim 2, characterized in that: In step b), the modified revolution number encoding signal is synthesized with the single revolution angle electrical signal. Specifically, the synthesis is performed in real time using a high-precision fusion algorithm, and temperature drift compensation and signal timing alignment technology are used to generate continuous, uninterrupted full-range absolute position data before output.

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