An encoder assembly and joint module

Abstract

The application relates to the technical field of robot joints, and provides an encoder assembly and a joint module. The encoder assembly comprises a substrate, a first encoder and a second encoder. The substrate has a central hole for a first rotating shaft and / or a second rotating shaft to pass through. A side surface of the substrate is divided into a first region and a second region along a radial direction. A first sensing stator of the first encoder is fixed to the first region. A first sensing rotor is connected with the first rotating shaft and is gap-fitted, so as to detect a rotating angle of the first rotating shaft based on a first sensing principle. A second sensing stator of the second encoder is fixed to the second region. A second sensing rotor is connected with the second rotating shaft and is gap-fitted, so as to detect a rotating angle of the second rotating shaft based on a second sensing principle different from the first sensing principle. The first sensing principle is a sensing principle not dependent on a permanent magnet, and the second sensing principle is a sensing principle dependent on a permanent magnet. Through the heterogeneous sensing principle and the radial partition layout, high-precision double-encoding detection can be realized in a compact space.

Description

Technical Field

[0001] This application relates to the field of robot joint technology, specifically to an encoder assembly and a joint module. Background Technology

[0002] To achieve high torque density and a compact design, robot joint modules generally adopt an integrated architecture of motor and reducer. To achieve high-precision closed-loop control of the joint, two sets of encoders are usually installed within the joint to acquire position information from the motor side and the reducer output side, respectively.

[0003] In related technologies, a common practice is to use two independent encoder modules, such as two sets of magnetic encoders, which are fixed to the motor output side and the reducer output side respectively by brackets or other structures. However, this installation method results in an excessively large axial dimension of the joint and a less compact structure, which is not conducive to the miniaturization and integration of the joint. Moreover, the magnetic rings of the two sets of magnetic encoders are close together in the narrow annular space of the joint, and the magnetic fields generated by the two magnetic rings will inevitably crosstalk and superimpose, reducing the encoder accuracy. Even if the axial spacing and radial concentricity of the two magnetic rings are strictly controlled during assembly, it is difficult to eliminate the impact of magnetic field coupling on detection accuracy from the root. Summary of the Invention

[0004] This application provides an encoder assembly and a joint module to enable reliable dual-encoder detection within a compact space.

[0005] To achieve one of the above objectives, some embodiments of this application provide an encoder assembly for detecting the rotational angular position of a coaxially arranged first and second rotating shaft, including: A substrate is fixed relative to the support structure of the first rotating shaft and the second rotating shaft. The substrate has a central hole for the first rotating shaft and / or the second rotating shaft to pass through. The substrate is radially divided into a first region and a second region. The first encoder includes a first sensing stator and a first sensing rotor. The first sensing stator is fixed to the first region. The first sensing rotor is used to connect to the first rotating shaft and rotate with the first rotating shaft. The first sensing rotor and the first sensing stator are axially clearance-fitted along the central hole to detect the rotation angle position of the first rotating shaft based on the first sensing principle. The second encoder includes a second sensing stator and a second sensing rotor. The second sensing stator is fixed to the second region, and the second sensing rotor is used to connect to and rotate with the second rotating shaft. The second sensing rotor and the second sensing stator are axially clearance-fitted along the central hole to detect the rotation angle position of the second rotating shaft based on a second sensing principle different from the first sensing principle. The first sensing principle is a sensing principle that does not rely on a permanent magnet to generate a working magnetic field, while the second sensing principle is a sensing principle that relies on a permanent magnet to generate a working magnetic field.

[0006] The encoder assembly shown in the above embodiments, by dividing a first region and a second region radially on the same substrate, and respectively setting a first encoder based on a first sensing principle and a second encoder based on a second sensing principle different from the first sensing principle, forms radial physical isolation between the two encoders on the same substrate plane. This fundamentally avoids the problem of decreased detection accuracy caused by crosstalk between homogeneous dual encoders, while taking into account the performance advantages and cost characteristics of the two sensing principles, reducing system cost while ensuring overall detection performance. In addition, the substrate has a central hole through which a coaxially mounted first rotating shaft and / or second rotating shaft pass, forming a compact annular layout, significantly reducing the axial and radial space occupied by the encoder assembly. It can be understood that the division of the first and second regions is not limited to radial division on the same surface; it can also be divided on different surfaces of the substrate, as long as the two encoders are physically separated and use different sensing principles.

[0007] In some embodiments, the first sensing principle is electromagnetic induction, the first sensing stator includes an excitation part and a receiving part, the first sensing rotor includes a conductive structure, the excitation part is used to generate an alternating electromagnetic field, the conductive structure is used to modulate the alternating electromagnetic field, and the receiving part is used to pick up the induced signal modulated by the conductive structure.

[0008] In some embodiments, the second sensing principle is the magnetic induction principle, the second sensing stator includes at least one magnetic field sensing element, and the second sensing rotor is a permanent magnet rotor.

[0009] In some embodiments, the magnetic field sensing element includes at least one of anisotropic magnetoresistive elements, giant magnetoresistive elements, tunneling magnetoresistive elements, or Hall elements.

[0010] In some embodiments, the first sensing principle is electromagnetic induction, the first sensing stator includes an excitation part and a receiving part, the first sensing rotor includes a conductive structure, the excitation part is used to generate an alternating electromagnetic field, the conductive structure is used to modulate the alternating electromagnetic field, and the receiving part is used to pick up the sensing signal modulated by the conductive structure. The second sensing principle is the magnetic induction principle, the second sensing stator includes at least one magnetic field sensing element, and the second sensing rotor is a permanent magnet rotor.

[0011] It should be noted that the sensing principles described in this application, which are based on electromagnetic induction and do not rely on permanent magnets to generate a working magnetic field, include, but are not limited to, inductive sensing principles and eddy current sensing principles; while the sensing principles based on magnetic induction and relying on permanent magnets to generate a working magnetic field include, but are not limited to, magnetoresistive effects and Hall effects. The core difference between the two sensing principles lies in whether or not they rely on permanent magnets to generate a working magnetic field. This difference makes the working mechanisms of the two encoders physically independent, fundamentally avoiding crosstalk between working magnetic fields.

[0012] In some embodiments, the first region and the second region are arranged radially apart along the substrate.

[0013] In some embodiments, the first sensing rotor and the second sensing rotor are located on the same side of the substrate.

[0014] In some embodiments, the first sensing rotor and the second sensing rotor at least partially overlap in the axial direction of the central hole.

[0015] In some embodiments, a processing unit is further included, which is fixed on the substrate and electrically connected to the first sensing stator and the second sensing stator, respectively. The processing unit is configured to acquire first position data output by the first encoder and second position data output by the second encoder.

[0016] In some embodiments, the processing unit is further configured to integrate the first location data and the second location data into the same communication protocol frame and output them uniformly through a communication interface.

[0017] To achieve one of the above objectives, some embodiments of this application provide a joint module, including: case; The motor shaft is at least partially rotatably disposed within the housing; The reducer output shaft is at least partially rotatably disposed within the housing, and is coaxially arranged and connected to the motor shaft for transmission. As described in any of the above embodiments, the encoder assembly has its base plate fixed to the housing, one of the first rotating shaft and the second rotating shaft corresponding to the motor shaft and the other corresponding to the reducer output shaft, the first sensing rotor being connected to the first rotating shaft and the second sensing rotor being connected to the second rotating shaft.

[0018] According to the joint module of the above embodiment, by fixing the base plate of the encoder assembly to the housing and connecting the first sensing rotor to the first rotating shaft and the second sensing rotor to the second rotating shaft, the inductive encoder and the magnetic induction encoder are integrated into the joint, eliminating the need for separate encoder modules. This effectively reduces the axial size and structural complexity of the joint module while achieving dual-axis position detection, providing a structural basis for the miniaturization and high integration design of the joint. Attached Figure Description

[0019] Figure 1 This is a cross-sectional structural diagram of an encoder assembly in one embodiment of this application; Figure 2 This is a front view of an encoder component in one embodiment of this application.

[0020] Label Explanation: 10. Motor shaft; 10a. First rotating shaft; 20. Reducer output shaft; 20a. Second rotating shaft; 30. Substrate; 31. Center hole; 32. First region; 33. Second region; 40. Inductive encoder; 40a. First encoder; 41. First sensing stator; 42. First sensing rotor; 50. Magnetic induction encoder; 50a. Second encoder; 51. Second sensing stator; 511. Magnetic field sensing element; 52. Second sensing rotor; 60. Processing unit; 70. Communication interface. Detailed Implementation

[0021] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments. Similar elements in different embodiments are referred to by related similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of the present application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to the present application are not shown or described in the specification. This is to avoid obscuring the core parts of the present application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0022] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can be rearranged or adjusted in a manner obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for the clear description of a particular embodiment and do not imply a necessary order, unless otherwise stated that a particular order must be followed.

[0023] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages).

[0024] For dual-encoder detection schemes in robot joint modules, when both encoders rely on permanent magnets to generate magnetic fields—for example, two sets of magnetic encoders used on the motor and reducer sides respectively—the two magnetic rings are close together within the narrow annular space of the joint, inevitably causing crosstalk and superposition of their magnetic fields. Even with strict control over the axial spacing and radial concentricity of the two magnetic rings during assembly, it is difficult to eliminate the impact of magnetic field coupling on detection accuracy at its source. Furthermore, if both encoders use inductive sensing, while magnetic field interference can be avoided, inductive encoders suffer from performance overkill and cost inefficiency when the joint output speed on the reducer side is low. Using a dedicated vernier magnetic encoder chip solution results in high costs for the dedicated chip and dual-track magnetic rings, and limited system flexibility. Moreover, the independent, separate installation of the two encoders in the above schemes leads to excessively large axial dimensions of the joint, hindering miniaturization and integration.

[0025] The encoder assembly provided in this application divides the same side surface of the same substrate 30 into two radially regions, each equipped with an encoder based on a different sensing principle. The motor side uses an inductive encoder 40, which operates based on the principle of electromagnetic induction and does not rely on a permanent magnet to generate a working magnetic field, fundamentally avoiding magnetic field interference to the magnetic induction encoder on the reducer side. The reducer side uses a magnetic induction encoder 50, which utilizes a permanent magnet rotor in conjunction with a magnetic field sensing element 511 to achieve absolute position detection, resulting in a simple structure and low cost. The two encoders are physically isolated radially, eliminating signal crosstalk while balancing detection performance and cost. Furthermore, through coplanar integration and the design of a central hole 31 through which the motor shaft 10 and / or the reducer output shaft pass, a compact annular layout is achieved, significantly reducing the axial and radial space occupied by the joints and enabling reliable dual-encoder detection within a compact space.

[0026] The technical solutions of this application will be described in detail below with reference to specific embodiments. It should be noted that the specific implementation methods described in the following embodiments are only used to explain this application, and the technical features disclosed in each embodiment can be freely combined provided that there is no technical contradiction.

[0027] Please refer to Figure 1 A robot's joint module typically includes a coaxially arranged motor shaft 10 and a reducer output shaft 20. To achieve high-precision closed-loop control, the rotational angular positions of the two axes need to be detected separately. Some embodiments of this application provide an encoder assembly for this joint module. Please refer to... Figure 1 and Figure 2 The encoder assembly includes a base plate 30, an inductive encoder 40, and a magnetic encoder 50.

[0028] Please refer to the following: Figure 1 and Figure 2 The base plate 30 is configured to be fixed relative to the housing (not shown) of the joint module, with the housing serving as a stationary reference to provide a mounting base for the base plate 30. The base plate 30 can be positioned close to the end of the reducer output shaft 20. The base plate 30 has a central hole 31 through which the motor shaft 10 and / or the reducer output shaft 20 pass, allowing the entire encoder assembly to be mounted around the motor shaft 10 and / or the reducer output shaft 20, making full use of the radial space of the joint and avoiding additional axial length occupation. It should be noted that in practical applications, depending on the specific structural design of the joint module, the arrangement can be either a spatial arrangement where only the reducer output shaft 20 passes through the central hole 31, and the motor shaft 10 does not pass through the central hole 31 but is located outside the base plate 30, or a spatial arrangement where only the motor shaft 10 passes through the central hole 31, and the reducer output shaft 20 does not pass through the central hole 31 but is located outside the base plate 30, or an arrangement where both the motor shaft 10 and the reducer output shaft 20 pass through the central hole 31. The central hole 31, "for the motor shaft 10 and / or the reducer output shaft 20 to pass through," encompasses the various combinations described above, allowing the encoder assembly to be flexibly configured according to the actual constraints of the joint's internal space. One side surface of the substrate 30 is radially divided into a first region 32 and a second region 33. It is understood that the first region 32 and the second region 33 can be located on the same surface of the substrate 30, such as two regions arranged side-by-side on the same surface of the substrate 30; or they can be located on different surfaces of the substrate 30, such as two surfaces on the substrate 30 with an axial height difference, or two surfaces radially spaced apart. In short, two physically separate regions can be formed on one side surface of the substrate 30 for encoders employing different sensing principles to be installed.

[0029] Please refer to Figure 1 and Figure 2An inductive encoder 40 is disposed in the first region 32 and includes a first sensing stator 41 and a first sensing rotor 42. The first sensing stator 41 is fixedly disposed in the first region 32 and remains relatively stationary with respect to the substrate 30. The first sensing rotor 42 is used to connect to the motor shaft 10 and rotates with the motor shaft 10. The first sensing rotor 42 and the first sensing stator 41 maintain a clearance fit along the axial direction of the central hole 31, with a preset axial clearance between them, and do not come into contact. When the motor shaft 10 rotates, the first sensing rotor 42 rotates relative to the first sensing stator 41. The first sensing stator 41 detects the rotational position of the first sensing rotor 42 through the principle of electromagnetic induction, thereby detecting the rotational angle position of the motor shaft 10 and obtaining the incremental angular position information of the motor shaft 10. The inductive encoder 40 does not rely on permanent magnets to generate a magnetic field during operation, so it will not cause magnetic field interference to other magnetic components in the joint space, fundamentally avoiding the problem of crosstalk between the magnetic fields of the two magnetic rings in the dual magnetic encoder scheme. Compared to the two sets of magnetic encoders that require strict control over the axial spacing and radial concentricity of the two magnetic rings, the inductive encoder 40 and the magnetic induction encoder 50 in this embodiment can work stably without additional magnetic field shielding measures.

[0030] Please refer to Figure 1 and Figure 2 A magnetic induction encoder 50 is disposed in the second region 33, including a second sensing stator 51 and a second sensing rotor 52. The second sensing stator 51 is fixedly disposed in the second region 33 and includes at least one magnetic field sensing element 511. The second sensing rotor 52 is a permanent magnet rotor, used to connect to the reducer output shaft 20 and rotate with the reducer output shaft 20. The second sensing rotor 52 and the second sensing stator 51 maintain a clearance fit along the axial direction of the central hole 31. When the reducer output shaft 20 rotates, the permanent magnet rotor rotates accordingly, and the direction of the magnetic field it generates changes with the rotation angle. The magnetic field sensing element 511 senses the change in the direction of the magnetic field, thereby detecting the rotation angle position of the reducer output shaft 20. Compared with the scheme of using inductive encoders 40 on both sides, this embodiment uses a magnetic induction encoder 50 on the reducer output side, taking advantage of its simple structure and low cost, avoiding the cost waste caused by using a high-performance inductive encoder 40 when the joint output speed is low.

[0031] In different embodiments, the magnetic field sensing element 511 can be of various types, such as at least one of anisotropic magnetoresistive elements, giant magnetoresistive elements, tunneling magnetoresistive elements, or Hall elements. When an anisotropic magnetoresistive element is used, the anisotropic characteristic of its resistance changing with the direction of the magnetic field is utilized to calculate the direction of the magnetic field by detecting the change in resistance. When a Hall element is used, the relationship between the voltage generated by the Hall effect and the magnetic field strength is used to sense the change in the direction of the magnetic field. When a giant magnetoresistive element or a tunneling magnetoresistive element is used, the characteristic of its resistance changing with the direction of the magnetic field is also used to achieve the detection of the magnetic field direction. There can be two, four, or more magnetic field sensing elements 511, arranged at equal or non-equal intervals around the central hole 31.

[0032] In this embodiment, the inductive encoder 40 and the magnetic encoder 50 are located in the first region 32 and the second region 33 of the substrate 30, respectively, forming a physical isolation in the radial direction. The inductive encoder 40 operates based on the principle of electromagnetic induction and does not generate a permanent magnet magnetic field; although the magnetic encoder 50 has a permanent magnet rotor, its magnetic field distribution in the radial direction does not overlap with the effective working area of ​​the inductive encoder 40. The two encoders operate independently in space, fundamentally avoiding the problem of crosstalk between the magnetic fields of the two permanent magnets in a homogeneous dual-magnetic encoder. At the same time, the inductive encoder 40 is used on the motor side, which can meet the requirements of position detection accuracy and response speed at high motor speeds; the magnetic encoder 50 is used on the reducer output side, which uses a permanent magnet rotor and a magnetic field sensing element 511 to achieve absolute position detection. It has a simple structure and low cost, and can provide sufficient position detection accuracy even at low speeds at the joint output end. The two encoders are integrated on the same side surface of the same substrate 30, forming a compact annular layout with the central hole 31 through which the shaft passes, significantly reducing the axial and radial space occupied by the encoder assembly in the joint. Compared with the split dual encoder solution, this embodiment does not require the separate installation of two independent encoder modules, which reduces the number of parts and is conducive to the miniaturization design of the joint.

[0033] In some embodiments, please refer to Figure 2The first region 32 is the outer ring region near the outer edge of the substrate 30, and the second region 33 is the inner ring region near the central hole 31. The first sensing stator 41 of the inductive encoder 40 is fixedly disposed in the outer ring region, and its alternating electromagnetic field during operation is mainly distributed in the outer ring region. The magnetic field sensing element 511 of the magnetic induction encoder 50 is fixedly disposed in the inner ring region, and the permanent magnet rotor is near the central hole 31. There is sufficient radial spacing between the outer and inner rings. The attenuation of the electromagnetic field of the inductive encoder 40 in the radial direction beyond the outer ring region and the concentrated distribution of the magnetic field of the permanent magnet rotor in the inner ring region further separate the effective working areas of the two sensors in space. Of course, in an alternative embodiment, the inductive encoder 40 can also be disposed in the inner ring region, and the magnetic induction encoder 50 can be disposed in the outer ring region, as long as the two are radially separated.

[0034] It is understood that the first region 32 and the second region 33 can be adjacent or spaced apart. Spaced-apart arrangement is more conducive to physical spatial isolation and avoids mutual interference between encoders. Furthermore, although the above embodiment uses an inductive encoder 40 located in the outer region and a magnetic encoder 50 located in the inner region as examples, this application is not limited to this. In alternative embodiments, the inductive encoder 40 can also be located in the inner region, and the magnetic encoder 50 can be located in the outer region.

[0035] To further reduce the axial dimension of the encoder assembly, in some embodiments, please refer to... Figure 1 The first sensing rotor 42 and the second sensing rotor 52 are located on the same side of the substrate 30. For example, the first sensing rotor 42 and the second sensing rotor 52 can both be disposed on the side of the substrate 30 away from the end of the reducer output shaft 20, that is, on the side of the substrate 30 divided into the first region 32 and the second region 33. This arrangement helps to reduce the additional axial space occupied by arranging rotors on both sides.

[0036] In some further embodiments, please refer to Figure 1 The first sensing rotor 42 and the second sensing rotor 52 can at least partially overlap in the axial direction of the central hole 31, that is, there is an overlapping area in the axial projection of the two rotors, which makes full use of the layering of the joint radial space and further reduces the overall axial dimension. For example, the first sensing rotor 42 can be designed as a ring code disk with a larger diameter, and the second sensing rotor 52 can be designed as a magnetic ring with a smaller diameter. The two are at the same height range in the axial direction and form a compact layout of inner and outer nesting in the radial direction.

[0037] In some embodiments, the first sensing stator 41 includes an excitation section and a receiving section. The excitation section can be an excitation coil, and the receiving section can be a receiving coil. The excitation section and the receiving section are disposed in a first region 32 of the substrate 30. When a high-frequency AC excitation signal is applied to the excitation section, an alternating electromagnetic field is generated in space. The first sensing rotor 42 is axially clearance-fitted with the first sensing stator 41. The surface of the first sensing rotor 42 is provided with a conductive structure. When the first sensing rotor 42 rotates with the motor shaft 10, the conductive structure generates eddy currents in the alternating electromagnetic field. The eddy currents, in turn, modulate the original alternating electromagnetic field. The receiving section picks up the sensing signal modulated by the first sensing rotor 42. This sensing signal contains the rotation angle information of the first sensing rotor 42. By demodulating the sensing signal output by the receiving section, the incremental angular position information of the motor shaft 10 can be obtained.

[0038] In some embodiments, a non-conductive isolation layer may be provided between the first sensing rotor 42 and the first sensing stator 41, enabling non-contact relative arrangement between them. In other embodiments, a small air gap is maintained between the first sensing rotor 42 and the first sensing stator 41, the size of which can be designed according to the detection accuracy and mechanical tolerance requirements.

[0039] In one or more embodiments, a ring-shaped circuit board serves as the substrate 30, and the excitation and receiving portions are directly etched onto the ring-shaped circuit board, for example, formed in the form of conductive patterns in the copper foil layer of the circuit board. Using etching allows for precise control of the coil's geometric parameters, ensuring consistency, while eliminating the need for separate coil mounting space and connection structures, thus facilitating further compact design.

[0040] In other embodiments, the excitation and receiving parts can also be pre-wound or printed independent coil assemblies, mounted and fixed to the first region 32 of the substrate 30 in the form of a flexible circuit board or sheet, which can also achieve the electromagnetic induction function. The specific pattern and number of turns of the coil can be designed according to the resolution requirements, as long as it meets the design and usage requirements.

[0041] It is understood that the conductive structure of the first sensing rotor 42 is not limited; for example, in some embodiments, the conductive structure is a specific regular conductive pattern etched on the surface of a metal code disk, which is fixed to the motor shaft 10 and rotates with it. In other embodiments, the conductive structure can be a ferrite core code disk, utilizing the high magnetic permeability of ferrite material to achieve modulation. In still other embodiments, the conductive structure can be a PCB code disk, where the conductive pattern is directly etched onto another independent circuit board, which serves as the first sensing rotor 42 fixed to the end face of the motor shaft 10. Regardless of the form used, as long as the alternating electromagnetic field generated by the excitation unit can be modulated through the principle of electromagnetic induction, it is acceptable.

[0042] In some embodiments, the second sensing rotor 52 is a permanent magnet rotor, fixed to the output shaft 20 of the reducer. In some examples, the permanent magnet rotor is a single-pole permanent magnet rotor with a pair of magnetic poles, generating a rotating magnetic field in space whose direction changes linearly with the rotation angle. The magnetic field sensing element 511 can directly obtain the absolute angular position of a single turn of the reducer output shaft 20 by detecting the direction of the magnetic field. In other examples, the permanent magnet rotor is a multi-pole permanent magnet rotor, generating multiple electrical cycles within a 360° range, which is beneficial for improving the subdivision resolution. In this case, it can be used in conjunction with vernier calculation methods or combined with other sensing data to determine the absolute position. Compared with the solution using a dedicated vernier magnetic encoder chip, the solution in this embodiment using a single-pole permanent magnet rotor in conjunction with the magnetic field sensing element 511 eliminates the need for a dual-track magnetic ring with precision magnetization technology, reducing the processing cost of the magnetic ring and the overall system cost.

[0043] In some embodiments, please refer to Figure 1 A processing unit 60 may also be fixedly disposed on the substrate 30. The processing unit 60 is electrically connected to the first sensing stator 41 and the second sensing stator 51 respectively, and is used to process the signal output by the first sensing stator 41 to obtain first position data, and to process the signal output by the second sensing stator 51 to obtain second position data. For example, the processing unit 60 may have two independent signal processing channels, one of which demodulates and subdivides the sensing signal output by the inductive encoder 40 to obtain the first position data, and the other performs angle calculation on the magnetic field sensing signal output by the magnetic induction encoder 50 to obtain the second position data. The processing unit 60 may be an MCU, DSP, FPGA or other programmable logic device, or may be a commercially available general-purpose microcontroller or a dedicated signal processing chip. The specific selection can be determined according to the processing capacity, power consumption and cost requirements. In one or more embodiments, the processing unit 60 uses a commercially available MCU chip, and utilizes its internally integrated analog-to-digital converter and arithmetic unit to realize the independent processing of the two signals.

[0044] In some further embodiments, the processing unit 60 is also configured to integrate the first position data and the second position data into the same communication protocol frame and output them uniformly through a communication interface 70. This communication interface 70 can be fixed to the base plate 30 and uses one of the following interfaces: RS-485, RS-422, CAN, UART, SSI, or BiSS-C. The external joint controller only needs one communication port to simultaneously acquire two channels of position data from the motor side and the reducer output side, simplifying system wiring and software interface design. Compared to a scheme where two encoders output signals independently and an external controller is required to receive and process the two signals separately, this embodiment significantly reduces wiring complexity and software development integration workload through a single interface for unified output.

[0045] The above embodiments are illustrated in conjunction with specific application scenarios of the joint module. The application scenarios of this application are not limited to these, and can also be extended to a general encoder component for detecting the rotational angular position of the coaxially arranged first rotating shaft 10a and second rotating shaft 20a. The following is a detailed description in conjunction with specific embodiments.

[0046] In some embodiments, the encoder assembly includes a substrate 30, a first encoder 40a, and a second encoder 50a. The substrate 30 is fixed relative to a support structure for the first rotating shaft 10a and the second rotating shaft 20a. The support structure can be a housing, a bracket, or any stationary component that can provide a stable mounting reference. The substrate 30 has a central hole 31 for the coaxially arranged first rotating shaft 10a and / or second rotating shaft 20a to pass through. One side surface of the substrate 30 is radially divided into a first region 32 near the outer edge and a second region 33 near the central hole 31. The first region 32 and the second region 33 can be adjacent to each other or spaced apart, and can be located on the same surface of the substrate 30 or on different surfaces of one side of the substrate 30. The first encoder 40a includes a first sensing stator 41 and a first sensing rotor 42. The first sensing stator 41 is fixed to a first region 32. The first sensing rotor 42 is connected to and rotates with a first rotating shaft 10a. The first sensing rotor 42 and the first sensing stator 41 are axially clearance-fitted along the central hole 31 to detect the rotational angle position of the first rotating shaft 10a based on a first sensing principle. The second encoder 50a includes a second sensing stator 51 and a second sensing rotor 52. The second sensing stator 51 is fixed to a second region 33. The second sensing rotor 52 is connected to and rotates with a second rotating shaft 20a. The second sensing rotor 52 and the second sensing stator 51 are axially clearance-fitted along the central hole 31 to detect the rotational angle position of the second rotating shaft 20a based on a second sensing principle different from the first sensing principle.

[0047] The first and second sensing principles in the above embodiments are not limited to the specific combinations of inductive and magnetic induction methods mentioned above. The first sensing principle is a sensing principle that does not rely on a permanent magnet to generate a working magnetic field, such as electromagnetic induction, photoelectric sensing, or capacitive sensing. The second sensing principle is a sensing principle that relies on a permanent magnet to generate a working magnetic field, such as magnetoresistive effect or Hall effect. The two encoder sensing mechanisms are physically independent and have no magnetic field crosstalk. Specific examples will be used to illustrate this below.

[0048] In one example, the first sensing principle is electromagnetic induction. The first sensing stator 41 includes an excitation part and a receiving part, and the first sensing rotor 42 includes a conductive structure. The excitation part is used to generate an alternating electromagnetic field, the conductive structure is used to modulate the alternating electromagnetic field, and the receiving part is used to pick up the sensing signal modulated by the conductive structure, thereby realizing electromagnetic induction position sensing.

[0049] The first sensing principle can also be any other sensing principle that does not rely on a permanent magnet to generate a working magnetic field. In another example, the first sensing principle is a photoelectric sensing principle, in which the first sensing stator 41 includes a light source and a photodetector, and the first sensing rotor 42 includes an optical code disk. In yet another example, the first sensing principle is a capacitive sensing principle, in which the first sensing stator 41 includes a transmitting electrode and a receiving electrode, and the first sensing rotor 42 includes a dielectric modulation structure. The capacitive sensing principle also does not rely on a permanent magnet to generate a working magnetic field; therefore, it is physically independent of the magnetic induction sensing principle of the second encoder, which relies on a permanent magnet to generate a working magnetic field, and they will not interfere with each other.

[0050] In one example, the second sensing principle can be the magnetoresistive effect principle. The second sensing stator 51 includes at least one magnetoresistive sensing element, and the second sensing rotor 52 is a permanent magnet rotor. The magnetoresistive sensing element achieves position sensing by sensing the change in the direction of the magnetic field when the permanent magnet rotor rotates. In other examples, the second sensing principle can also be the Hall effect principle, and the second sensing stator 51 includes at least one Hall element. The first and second sensing principles are different to ensure that the sensing mechanisms of the two encoders are physically independent.

[0051] In some embodiments, the first sensing rotor 42 and the second sensing rotor 52 may be located on the same side of the substrate 30, and the first sensing rotor 42 and the second sensing rotor 52 at least partially overlap in the axial direction of the central hole 31. Specific arrangements can be found in the related embodiments of the encoder assembly of the aforementioned joint module, and will not be repeated here.

[0052] In some embodiments, the first sensing rotor 42 is indirectly connected to the motor shaft via a rotor bracket. One end of the rotor bracket is fixedly connected to the motor shaft, and the other end supports the first sensing rotor 42. The second sensing rotor 52 is indirectly connected to the reducer output shaft via a magnetic ring bracket. This indirect connection method can adapt to different axial spatial constraints, improving layout flexibility.

[0053] In some embodiments, a processing unit 60 may also be disposed on the substrate 30. The processing unit 60 is electrically connected to the first sensing stator 41 and the second sensing stator 51, respectively, and is used to acquire the first position data output by the first encoder 40a and the second position data output by the second encoder 50a. The processing unit 60 may internally be provided with two independent signal processing channels. One channel demodulates and subdivides the sensing signal output by the first encoder 40a to obtain the first position data, and the other channel performs angle calculation on the sensing signal output by the second encoder 50a to obtain the second position data. The processing unit 60 may employ a commercially available general-purpose microcontroller or a dedicated signal processing chip. Furthermore, the processing unit 60 may further integrate the first position data and the second position data into the same communication protocol frame and output them uniformly through a single communication interface 70. Detailed configuration of the processing unit 60 can also be found in the arrangement of the encoder components in the aforementioned joint module embodiments, and will not be repeated here.

[0054] Furthermore, this application also provides an embodiment of a joint module. The joint module includes a housing, a motor shaft 10, a reducer output shaft 20, and an encoder assembly as described in any of the foregoing embodiments. The housing, as a stationary component, provides a mounting base for the various components of the joint module. The motor shaft 10 is at least partially rotatably disposed within the housing, and the reducer output shaft 20 is at least partially rotatably disposed within the housing, coaxially arranged and drivingly connected to the motor shaft 10. A reducer, such as a harmonic reducer or a planetary reducer, can be disposed between the motor shaft 10 and the reducer output shaft 20, converting the high-speed rotation of the motor shaft 10 into a low-speed, high-torque output of the reducer output shaft 20 via the reducer.

[0055] The base plate 30 of the encoder assembly is fixed to the housing. In some examples, the motor shaft 10 is used as the first rotating shaft 10a, and the reducer output shaft 20 is used as the second rotating shaft 20a. The first sensing rotor 42 is connected to the motor shaft 10 and rotates synchronously with the motor shaft 10; the second sensing rotor 52 is connected to the reducer output shaft 20 and rotates synchronously with the reducer output shaft 20. In other examples, the reducer output shaft 20 is used as the first rotating shaft 10a, and the motor shaft 10 is used as the second rotating shaft 20a. The first sensing rotor 42 is connected to the reducer output shaft 20 and rotates synchronously with the reducer output shaft 20; the second sensing rotor 52 is connected to the motor shaft 10 and rotates synchronously with the motor shaft 10.

[0056] The encoder assembly is located entirely within the housing and is integrated into the joint, eliminating the need for a separate encoder module on the outside of the joint. The connection between the first sensing rotor 42 and the motor shaft 10, and between the second sensing rotor 52 and the reducer output shaft 20, can be a direct connection or an indirect connection via intermediate connecting parts such as flanges, rotor supports, or couplings, as long as the synchronous rotation of the sensing rotor and the corresponding shaft can be ensured.

[0057] While the principles herein have been illustrated in various embodiments, numerous modifications to the structures, arrangements, proportions, elements, materials, and components, particularly suited to specific environments and operational requirements, may be used without departing from the principles and scope of this disclosure. These modifications and other alterations or alterations will be included within the scope of this document. Those skilled in the art will recognize that many changes can be made to the details of the above embodiments without departing from the fundamental principles of this application.

Claims

1. An encoder assembly for detecting the rotational angular position of a first rotating shaft and a second rotating shaft arranged coaxially, characterized in that, include: A substrate is fixed relative to the support structure of the first rotating shaft and the second rotating shaft. The substrate has a central hole for the first rotating shaft and / or the second rotating shaft to pass through. One side surface of the substrate is radially divided into a first region and a second region. The first encoder includes a first sensing stator and a first sensing rotor. The first sensing stator is fixed to the first region. The first sensing rotor is used to connect to the first rotating shaft and rotate with the first rotating shaft. The first sensing rotor and the first sensing stator are axially clearance-fitted along the central hole to detect the rotation angle position of the first rotating shaft based on the first sensing principle. The second encoder includes a second sensing stator and a second sensing rotor. The second sensing stator is fixed to the second region, and the second sensing rotor is used to connect to and rotate with the second rotating shaft. The second sensing rotor and the second sensing stator are axially clearance-fitted along the central hole to detect the rotation angle position of the second rotating shaft based on a second sensing principle different from the first sensing principle. The first sensing principle is a sensing principle that does not rely on a permanent magnet to generate a working magnetic field, while the second sensing principle is a sensing principle that relies on a permanent magnet to generate a working magnetic field.

2. The encoder assembly according to claim 1, characterized in that, The first sensing principle is electromagnetic induction. The first sensing stator includes an excitation part and a receiving part. The first sensing rotor includes a conductive structure. The excitation part is used to generate an alternating electromagnetic field. The conductive structure is used to modulate the alternating electromagnetic field. The receiving part is used to pick up the induction signal modulated by the conductive structure.

3. The encoder assembly according to claim 1, characterized in that, The second sensing principle is the magnetic induction principle, the second sensing stator includes at least one magnetic field sensing element, and the second sensing rotor is a permanent magnet rotor.

4. The encoder assembly according to claim 3, characterized in that, The magnetic field sensing element includes at least one of anisotropic magnetoresistive element, giant magnetoresistive element, tunneling magnetoresistive element, or Hall element.

5. The encoder assembly according to claim 1, characterized in that, The first sensing principle is electromagnetic induction. The first sensing stator includes an excitation part and a receiving part, and the first sensing rotor includes a conductive structure. The excitation part is used to generate an alternating electromagnetic field, and the conductive structure is used to modulate the alternating electromagnetic field. The receiving part is used to pick up the induction signal modulated by the conductive structure. The second sensing principle is the magnetic induction principle, the second sensing stator includes at least one magnetic field sensing element, and the second sensing rotor is a permanent magnet rotor.

6. The encoder assembly according to any one of claims 1 to 5, characterized in that, The first region and the second region are arranged radially apart along the substrate.

7. The encoder assembly according to any one of claims 1 to 5, characterized in that, The first sensing rotor and the second sensing rotor are located on the same side of the substrate and at least partially overlap in the axial direction of the central hole.

8. The encoder assembly according to any one of claims 1 to 5, characterized in that, It also includes a processing unit, which is fixed on the substrate and electrically connected to the first sensing stator and the second sensing stator respectively. The processing unit is configured to acquire first position data output by the first encoder and second position data output by the second encoder.

9. The encoder assembly according to claim 8, characterized in that, The processing unit is further configured to integrate the first location data and the second location data into the same communication protocol frame and output them uniformly through a communication interface.

10. A joint module, comprising: case; The motor shaft is at least partially rotatably disposed within the housing; The reducer output shaft is at least partially rotatably disposed within the housing, and is coaxially arranged and connected to the motor shaft for transmission. The encoder assembly according to any one of claims 1 to 9, wherein the base plate of the encoder assembly is fixed to the housing, one of the first rotating shaft and the second rotating shaft corresponds to the motor shaft and the other corresponds to the reducer output shaft, the first sensing rotor is connected to the first rotating shaft, and the second sensing rotor is connected to the second rotating shaft.

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