Encoder device for joint actuator, robot joint actuator, and robot
By connecting the encoder rotor and stator of the joint actuator to different moving parts, the dimension and stability problems caused by traditional encoder topology are solved, and a high-integration and low-cost joint actuator design is achieved, which improves the robot's accuracy and safety performance.
Patent Information
- Application Number
- CN202422685646.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-04
- Publication Date
- 2025-08-29
- Estimated Expiration
- 2034-11-04
AI Technical Summary
The encoder topology of traditional joint actuators makes it longer axial direction, difficult to miniaturize the size, and poor structural stability, which cannot meet the needs of humanoid robots for high precision and high stability.
The encoder rotor using the first encoder is connected to the motor rotor, the encoder stator of the second encoder is connected to the reducer rotor, and the encoder rotor of the second encoder is connected to the reducer rotor or the motor rotor. The output position of the joint actuator is calculated by the reduction ratio, and the components of the second encoder are installed dispersed to reduce space occupation and installation pressure.
It improves the integration and structural stability of joint actuators, reduces costs, simplifies assembly processes, enhances design flexibility and adaptability, extends service life, and improves system reliability and user experience.
Smart Images
Figure CN223278022U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of robotics technology, and in particular to an encoder device for a joint actuator, a robot joint actuator, and a robot. Background Art
[0002] The robot's motion joints need to be equipped with integrated actuators to complete the motion commands of the master control unit. For joint actuators, in addition to providing sufficient torque, humanoid robots have higher requirements for the motion accuracy, size, structural stability, etc. of the joint actuators. The motion accuracy of humanoid robots depends on the accuracy of each actuator. On the basis of having the best precision mechanical parts, the control accuracy of each actuator must rely on the encoder's precise position feedback of the motion to obtain high-precision motion of the robot as a whole. The joint space of humanoid robots is small, and the encoder topology of traditional joint actuators makes them longer in axis and difficult to miniaturize. The joint stability requirements of humanoid robots are high, and the encoder topology of traditional joint actuators makes their routing complex and their stability poor.
[0003] The two encoders of a traditional joint actuator are located on the motor side and the actuator output end, respectively. The traditional dual-encoder topology has the following two main problems: (1) The space available for installing the encoder on the actuator output end is generally small, and the encoder cannot be directly connected to the actuator output end, making it impossible to directly measure the position of the actuator output side. (2) The problem of the position of the encoder and the output flange: To use the encoder to measure the change of the actuator rotor, the encoder stator generally needs to be fixed to the actuator stator, which means that the encoder must be installed on the side of the output flange close to the actuator stator. This results in a complex structure, an increase in the output shaft length, an increase in the bending moment, and relatively poor structural stability.
[0004] An existing dual-encoder solution, in order to solve the above problems, the existing technology provides a dual-encoder solution, the stator of the encoder at the output end of the actuator is fixed on the stator of the actuator, and the rotor of the encoder at the output end of the actuator is connected to the output end of the actuator through a transmission mechanism. Although this method solves the problem of small space at the output end of the actuator, it requires an additional transmission mechanism, the structural stability is poor, and the mechanical structure integration is low.
[0005] Further, if Figure 1 As shown, in order to solve the above problem, the prior art also provides another dual encoder solution. Through the hollow shaft design, the installation position of the encoder at the output end of the actuator is transferred to the stator side of the actuator, and the output shaft has an additional loop axis Z ( Figure 1 (as shown), providing rotation data to the encoder. However, this hollow shaft design makes the actuator mechanically complex, costly, and unstable. Utility Model Content
[0006] The present application provides an encoder device for a joint actuator, a robot joint actuator, and a robot.
[0007] According to one aspect of the present application, an encoder device for a joint actuator is provided, which is applied to the joint actuator. The joint actuator includes a joint actuator stator, a joint actuator rotor and an encoder device. The joint actuator rotor includes a motor rotor and a reducer rotor. The encoder device includes: a first encoder, the encoder rotor of the first encoder is connected to the motor rotor; a second encoder, the encoder rotor of the second encoder is connected to the motor rotor, the encoder stator of the second encoder is connected to the reducer rotor, and the encoder rotor of the second encoder and the encoder stator of the second encoder have a first positional relationship; or the encoder rotor of the second encoder is connected to the reducer rotor, the encoder stator of the second encoder is connected to the motor rotor, and the encoder rotor of the second encoder and the encoder stator of the second encoder have a second positional relationship.
[0008] Optionally, the joint actuator stator includes: a motor stator, and the encoder stator of the first encoder is connected to the motor stator.
[0009] Optionally, the motor rotor includes: a motor rotor shaft, and a first encoder and a second encoder are respectively located at two ends of the motor rotor shaft.
[0010] Optionally, when both the first encoder and the second encoder are single-turn absolute encoders, the output position of the joint actuator is obtained based on the output position of the first encoder and the output position of the second encoder.
[0011] Optionally, the encoder rotor of the first encoder and the encoder rotor of the second encoder are symmetrically arranged on the axis in the longitudinal direction of the motor rotor.
[0012] Optionally, the encoder rotor of the first encoder is fixed to an end of the motor rotor away from the reducer rotor, and the encoder rotor of the second encoder is fixed to the motor rotor and moves relative to the reducer rotor.
[0013] Optionally, the encoder stator of the second encoder is fixedly connected to the reducer rotor through a fixing member.
[0014] Optionally, the encoder stator of the second encoder is rotationally connected to the reducer rotor through a transmission member.
[0015] Optionally, the encoder rotor of the second encoder is a permanent magnet, and the encoder stator of the second encoder is an encoder chip.
[0016] According to a second aspect of the present application, a robot joint actuator is provided, comprising an encoder device according to any one of the above technical solutions.
[0017] According to a third aspect of the present application, a robot is provided, comprising at least one robot joint actuator according to the above technical solution.
[0018] The present application provides an encoder device for a joint actuator, a robot joint actuator, and a robot. The present application proposes an encoder device that supports a high-resolution joint actuator, including a first encoder on the motor side and a second encoder on the reducer side. The present application creatively proposes connecting the rotor and stator in the second encoder to different moving parts of the joint actuator, respectively. The encoder rotor of the second encoder moves with the movement of the motor rotor, and the encoder stator of the second encoder moves with the movement of the reducer rotor; or the encoder rotor of the second encoder moves with the movement of the reducer rotor, and the encoder stator of the second encoder moves with the movement of the motor rotor. According to the reduction ratio between the motor and the reducer, when the motor moves, the encoder rotor of the second encoder and the encoder stator of the second encoder move relative to each other. Based on the output value of the second encoder and the output of the first encoder, the absolute position of the reducer output can be effectively calculated. Different components of the second encoder are installed in different areas of the joint actuator, with some components mounted on the actuator stator side. This reduces the volume occupied by the second encoder in the same area and distributes the installation pressure. Both the encoder stator and encoder rotor of the second encoder are mounted at the actuator output, eliminating the need for additional connectors. This improves the integration and reduces the cost of the joint actuator. By strategically distributing the different components of the second encoder in different areas of the joint actuator, this layout not only makes the entire joint actuator more compact but also leaves more space for the installation of other necessary components, enhancing design flexibility and adaptability. The decentralized installation of the second encoder components significantly reduces installation pressure in a single area, minimizing installation complexity and potential failure risks associated with concentrating components in a single area. This design helps extend the lifespan of the encoder and the entire joint actuator, improving system stability and reliability. Mounting the encoder stator and encoder rotor directly at the actuator output eliminates additional connectors, simplifying the assembly process and reducing the possibility of assembly errors. This integrated design makes the system more streamlined and efficient, facilitating maintenance and upgrades. Reduced costs and improved market competitiveness: The aforementioned design optimizations reduce material usage (e.g., eliminating connectors) and streamline the production process, effectively lowering the manufacturing cost of the joint actuator. The decentralized installation design also makes it easier to locate the problem in the event of a fault, facilitating rapid troubleshooting and repair. This not only shortens maintenance cycles and reduces downtime, but also further enhances user experience and satisfaction.
[0019] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present application, nor is it intended to limit the scope of the present application. Other features of the present application will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The accompanying drawings are provided to facilitate a better understanding of the present invention and do not constitute a limitation of the present application.
[0021] Figure 1 It is the first dual encoder topology in the prior art;
[0022] Figure 2 1 is a schematic structural diagram of an embodiment of an encoder device for a joint actuator of the present application;
[0023] Figure 3 is a structural diagram of a joint actuator in an embodiment of the present application;
[0024] Figure 4 yes Figure 3 A cross-sectional view of the joint actuator is shown;
[0025] Figure 5 This is a schematic diagram of the output position signal of the first encoder, the output position signal of the second encoder, and the output position signal of the joint actuator. DETAILED DESCRIPTION
[0026] The following description of exemplary embodiments of the present application is made in conjunction with the accompanying drawings, including various details of the embodiments of the present application to facilitate understanding. These details should be considered as merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present application. Similarly, for the sake of clarity and conciseness, descriptions of well-known functions and structures are omitted in the following description.
[0027] All technical terms used in this document have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in this document are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.
[0028] In the description of the embodiments of the present application, the term "at least one" refers to one or more, and "a plurality of" refers to two or more (including two).
[0029] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.
[0030] With the rapid development of the robotics industry, robots are increasingly being used for collaborative work. To meet the various standards for collaboration, collaborative robots are facing higher requirements in terms of precision, size, safety, and other aspects. The movement of each joint in a robot requires motors, reducers, encoders, and drivers. Traditional large robots, however, require less space. To save costs, they are typically constructed by directly splicing together numerous modules with different functions. This results in a low level of integration, making them larger and more bulky.
[0031] In view of the above technical problems, the present application provides an encoder device for a joint actuator, which is applied to a joint actuator, such as Figure 2 As shown, it is a structural schematic diagram of an embodiment of the encoding device of the joint actuator of the present application, the above-mentioned joint actuator includes a joint actuator stator 1, a joint actuator rotor 2 and an encoder device, wherein the joint actuator rotor 2 includes a motor rotor 21 and a reducer rotor 22, and the above-mentioned encoder device includes: a first encoder 3 and a second encoder 4; the encoder rotor 31 of the first encoder 3 is connected to the motor rotor 21; the encoder rotor 41 of the second encoder 4 is connected to the motor rotor 21, and the encoder stator 42 of the second encoder 4 is connected to the reducer rotor 22, and there is a first positional relationship between the encoder rotor 41 of the second encoder 4 and the encoder stator 42 of the second encoder 4.
[0032] In this embodiment, the first position relationship means that the encoder rotor 41 and the encoder stator 42 are coaxial, and the distance between the encoder rotor 41 and the encoder stator 42 is within a first distance range value, wherein the first distance range value is a distance value that ensures that the encoder stator can capture the signal emitted by the encoder rotor.
[0033] In another embodiment of the present application, the encoder rotor of the second encoder is connected to the reducer rotor, and the encoder stator of the second encoder is connected to the motor rotor ( Figure 2 (not shown), the encoder rotor of the second encoder and the encoder stator of the second encoder have a second positional relationship.
[0034] In this embodiment, the second position relationship means that the encoder rotor and the encoder stator are coaxial, and the distance between the encoder rotor and the encoder stator is within a second distance range value, wherein the second distance range value is a distance value that ensures that the encoder stator can capture the signal emitted by the encoder rotor.
[0035] In this embodiment, the first encoder 3 is a mechanical position encoder. Its operating principle is based on reciprocating friction and is relevant for displacement and angle measurement. When the device to which the encoder is mounted moves, the encoder converts this motion into a more measurable form, generating signals. Position and velocity can be extracted from these signals by following signal capture rules.
[0036] In this embodiment, the first encoder 3 includes an encoder rotor 31 and an encoder stator 32. The encoder stator 32 of the first encoder 3 is a component of the first encoder 3 that collects the signal emitted by the encoder rotor 31. The encoder rotor 31 of the first encoder 3 is a component of the first encoder that collects the motion signal of the motor rotor. Through the mutual cooperation of the encoder rotor and the encoder stator, the rotation position and rotation speed of the motor rotor can be recorded when the motor rotor rotates.
[0037] In this embodiment, the second encoder 4 is an encoder for recording mechanical position. The second encoder 4 includes an encoder rotor 41 and an encoder stator 42. The encoder stator 42 of the second encoder 4 is a component in the second encoder 4 that collects the signal emitted by the encoder rotor 41 relative to its own movement. The encoder rotor 41 of the second encoder 4 is a component that collects the motion signal of the motor rotor. Through the mutual cooperation of the encoder rotor and the encoder stator, the relative rotation position and relative rotation speed of the motor rotor and the reducer can be recorded when the motor rotor rotates.
[0038] In this embodiment, the encoder stator and the encoder rotor are interacting components, and the interaction between the encoder stator and the encoder rotor can achieve the purpose of the encoder recording position information. Specifically, the encoder rotors of the first encoder and the second encoder can both be magnetic field generating devices. The magnetic field generating device is usually composed of permanent magnets, which are arranged according to a specific pattern to form a specific magnetic field distribution. The encoder stators of the first encoder and the second encoder can both be magnetic sensitive elements, which are responsible for capturing changes in the magnetic field generated by the magnetic field generating device and converting them into electrical signals. When the encoder rotors of the first encoder and the second encoder move, they cut the magnetic field generated by the encoder stators of the first encoder and the second encoder, forming a specific magnetic field distribution. The magnetic sensitive element can capture the magnetic field changes and convert them into electrical signals.
[0039] In this embodiment, Figure 3As shown, the joint actuator includes: a motor D, a reducer Q, and a motor controller K; the joint actuator stator is the non-moving part of the joint actuator except the encoder device, for example, the joint actuator stator includes: a motor housing, a motor controller circuit board, and a reducer housing; the joint actuator rotor is the movable part of the joint actuator, for example, the joint actuator rotor includes: a motor rotor, a reducer output end (which is also the joint actuator output end); the encoder device is a device for measuring the position information of the joint actuator output end. In this embodiment, the encoder device includes: a first encoder and a second encoder.
[0040] In this embodiment, Figure 4 As shown, the motor rotor 21 is the rotating component in the motor D. It is connected to the stator 22 of the motor D and is the key device for the motor D to achieve the conversion between electrical energy and mechanical energy, and vice versa. The motor rotor 21 is typically made of high-strength, high-toughness alloy steel to withstand the torque and centrifugal force generated during motor operation.
[0041] In this embodiment, Figure 4 As shown, the motor rotor shaft 211 in the motor rotor 21 is the rotating shaft that runs through the motor D and the reducer in the joint actuator. In addition to being connected to the motor stator 22, the motor rotor 211 is also connected to the stator of the reducer Q. Figure 4 In the embodiment, the reducer rotor 22 has threaded holes that allow the joint actuator to be connected to other components. The encoder rotor 31 of the first encoder 3 is located at one end of the motor rotor shaft 211. The other end of the motor rotor shaft 211 has an encoder rotor 41 mounted on the second encoder 4. A controller circuit board for the motor controller is located at one end of the motor.
[0042] In this embodiment, the encoder rotor of the first encoder is connected to the motor rotor, and the rotational position of the motor can be measured by the first encoder. The encoder rotor of the second encoder is connected to the motor rotor, and the encoder stator of the second encoder is connected to the reducer rotor; or the encoder rotor of the second encoder is connected to the reducer rotor, and the encoder stator of the second encoder is connected to the motor rotor. When both the first encoder and the second encoder are absolute encoders, the output position of the joint actuator can be directly calculated using the output positions of the first encoder and the second encoder. Specifically, the output position of the joint actuator is equal to the output position of the first encoder plus or minus the output position of the second encoder.
[0043] In this embodiment, when both the first encoder and the second encoder are single-turn encoders, the calculated output position of the joint actuator is within the range of 0 to 360°. When both the first encoder and the second encoder are multi-turn encoders, the calculated output position of the joint actuator can be greater than 360°.
[0044] The encoder device of the joint actuator provided by the present application proposes an encoder device that supports high-resolution joint actuator, including a first encoder on the motor side and a second encoder on the reducer side, and creatively proposes to connect the rotor and stator in the second encoder to different moving parts of the joint actuator respectively, the encoder rotor of the second encoder moves with the movement of the motor rotor, and the encoder stator of the second encoder moves with the movement of the reducer rotor; or the encoder rotor of the second encoder moves with the movement of the reducer rotor, and the encoder stator of the second encoder moves with the movement of the motor rotor. In view of the reduction ratio between the motor and the reducer, when the motor moves, the encoder of the second encoder moves with the movement of the motor rotor. The encoder rotor and the encoder stator of the second encoder move relative to each other. Based on the output value of the second encoder and the output of the first encoder, the absolute position of the reducer output can be effectively calculated; different parts of the second encoder are installed in different areas of the joint actuator, and some components of the second encoder are installed on one side of the actuator stator, which reduces the volume occupied by the second encoder in the same area when it is installed and disperses the installation pressure of the second encoder in the same area; there are no special requirements for the structure and size of the first encoder and the second encoder, and some components of the second encoder can be wired with the encoder on the motor side, which improves the stability of the encoder topology and reduces the cost of the joint actuator.
[0045] In some optional implementations of the present application, the above-mentioned joint actuator stator includes: a motor stator, and the encoder stator of the first encoder is connected to the motor stator.
[0046] like Figure 2 As shown, the joint actuator stator 1 includes a motor stator 11 and a reducer stator 12 , and the encoder stator 32 of the first encoder 3 is connected to the motor stator 11 . The reducer stator 12 is connected to the reducer rotor 22 .
[0047] In this optional implementation, the motor stator 11 is an important component of the motor of the joint actuator, which is usually fixed to the bottom plate of the motor. Its main function is to generate a rotating magnetic field, thereby driving the motor rotor to rotate.
[0048] In this optional implementation, when the encoder stator of the first encoder is connected to the motor stator, the distance between the position of the encoder stator of the first encoder and the encoder rotor of the first encoder needs to be within the position range of the encoder type to which the first encoder belongs, thereby ensuring that the first encoder can effectively measure the position information of the motor.
[0049] In this optional implementation, the position of the motor stator in the joint actuator is fixed, and connecting the encoder stator of the first encoder to the motor stator can ensure that the position of the encoder stator of the first encoder is fixed.
[0050] In this optional implementation, the encoder stator of the first encoder is fixed, and the motor rotor shaft drives the encoder rotor of the first encoder to move. The encoder stator and the encoder rotor of the first encoder are interacting components. Through the interaction between the encoder stator and the encoder rotor of the first encoder, the encoder can achieve the purpose of recording the position information of the motor.
[0051] The joint actuator provided by this optional implementation connects the encoder stator of the first encoder to the motor stator. Based on the fixed position of the motor stator, the encoder stator of the first encoder can be fixed, thereby ensuring the reliability of the position measurement of the first encoder.
[0052] Optionally, the above-mentioned joint actuator stator includes: a motor housing, the encoder stator of the first encoder is connected to the motor stator, the encoder stator of the first encoder is connected to the motor housing, and the distance between the position of the encoder stator of the first encoder and the encoder rotor of the first encoder is within the position range of the encoder type to which the first encoder belongs.
[0053] In some optional implementations of the present application, the motor rotor includes: a motor rotor shaft, and the first encoder and the second encoder are respectively located at two ends of the motor rotor shaft.
[0054] like Figure 2 As shown, the first encoder is located at the first end of the motor rotor shaft, and the first end is located on the motor side; the second encoder is located at the second end of the motor rotor shaft, and the second end is located on the reducer side.
[0055] The encoder device provided by this optional implementation arranges the first encoder and the second encoder at both ends of the motor rotor shaft, providing a reliable fixing method for the installation of the encoder device.
[0056] Optionally, the first encoder and the second encoder are respectively located at the same end of the motor rotor shaft, and the same end is the reducer side, the distance between the position of the encoder stator of the first encoder and the encoder rotor of the first encoder is within the position range of the encoder type to which the first encoder belongs, and the distance between the position of the encoder stator of the first encoder and the encoder rotor of the second encoder is within the position range of the encoder type to which the second encoder belongs.
[0057] Position information at the output of a joint actuator can be obtained using an encoder. Encoders are categorized by their signal principle into incremental and absolute encoders. With an absolute encoder, each position corresponds to a specific digital code, so its indication is only related to the starting and ending positions of the measurement, independent of any intermediate steps. Incremental encoders output incremental changes from a predefined starting position. Therefore, an absolute encoder is typically used to obtain position information at the output of a joint actuator. Absolute position encoders are categorized by test range as single-turn or multi-turn. With a single-turn absolute encoder, the encoder returns to its origin when rotation exceeds 360°, violating the principle of unique absolute encoding. Therefore, such encoders can only be used for measurements within a 360° rotation range. For measurements exceeding 360°, a multi-turn absolute encoder is required. While multi-turn absolute encoders can measure position information over multiple rotations, they typically require additional power supply circuitry and batteries, increasing the size of the joint actuator and hindering its highly integrated design. Because multi-turn absolute position encoders typically require continuous power to record the current absolute position, they become inoperable if the joint actuator is idle for an extended period and the multi-turn absolute encoder's battery runs out of power, failing to meet the growing variety of robotics applications. Furthermore, multi-turn absolute position encoders are relatively expensive, making them incompatible with the commercialization trend toward lower-cost robotics.
[0058] In response to the above technical defects, in some optional implementations of the present application, when the first encoder and the second encoder are both single-turn absolute encoders, the output position of the joint actuator is obtained based on the output position of the first encoder and the output position of the second encoder.
[0059] In this optional implementation, both the first encoder (motor-side encoder) and the second encoder (actuator output-side encoder) are single-turn absolute position encoders, specifically magnetic encoders. The motor rotor is connected to a reducer, and the encoder rotors of the first encoder and the second encoder are mounted at either end of the motor rotor shaft, rotating with the motor rotor. The encoder stator of the first encoder is fixed relative to the motor stator. Therefore, the encoder stator of the first encoder can convert the alternating magnetic field information generated by the encoder rotor of the first encoder into a motor rotor position signal F ranging from 0 to 360 degrees. The encoder stator of the second encoder is connected to the output of the reducer (for example, by means of screws or other structures). Due to the reduction ratio of the reducer, the motor rotor and the reducer output undergo relative rotational motion. Therefore, the encoder stator of the second encoder can convert the alternating magnetic field information generated by the encoder rotor of the second encoder into an actuator output-side position signal S ranging from 0 to 360 degrees.
[0060] In this optional implementation, if Figure 5 As shown, the absolute position signal J at the reducer output (i.e., the absolute position at the actuator output) is designed to align at only one position scale—zero—within the range of the absolute position signal J to be measured. In the arbitrary angle reading window of the absolute position signal J, only the measurement value at the current angle is visible. Comparing the two measured values, the motor rotor position signal F and the actuator output position signal S, reveals the phase difference between the motor rotor position signal F and the actuator output position signal S, from which the absolute distance between this angular position and zero is calculated. The specific calculation process for the absolute position of the actuator output can be as follows: calculating the sensor signal amplitude difference between the motor rotor position signal F and the actuator output position signal S; based on this sensor signal amplitude difference, calculating the sensor signal phase difference between the motor rotor position signal and the actuator output position signal; and, based on this sensor signal phase difference, determining the absolute position of the actuator output.
[0061] The encoder device provided by this optional implementation method, when the first encoder and the second encoder are both single-turn absolute encoders, uses a single-turn absolute position encoder to measure the position information of the joint actuator output end relative to the motor rotor, and at the same time combines the position information of the single-turn absolute position encoder on the motor side to infer the absolute position of the joint actuator output end, thereby reducing the complexity of calculating the position of the joint actuator output end. Two single-turn absolute encoders are used to obtain the joint actuator output position, and a multi-turn encoder is not used to record the output position of the joint actuator, thereby saving the cost of obtaining the joint actuator output position.
[0062] In some optional implementations of the present application, the encoder rotor of the second encoder is symmetrically arranged with respect to the encoder rotor of the second encoder on an axis in the length direction of the motor rotor.
[0063] In this optional implementation, the length direction of the motor rotor is the extension direction of the length of the motor rotor.
[0064] The encoder device provided by this optional implementation method symmetrically arranges the encoder rotor of the first encoder and the encoder rotor of the second encoder in the length direction of the motor rotor, which can make the position measurement of the first encoder and the second encoder equipotential, thereby improving the accuracy of the output position of the joint actuator.
[0065] In some optional implementations of the present application, the encoder rotor of the first encoder is fixed to one end of the motor rotor away from the reducer rotor, and the encoder rotor of the second encoder is fixed to the motor rotor and moves relative to the reducer rotor.
[0066] In this optional implementation, the encoder rotor of the first encoder is fixed to the end of the motor rotor away from the reducer rotor, so that the first encoder can be brought closer to the motor, thereby improving the accuracy of the motor position recording.
[0067] In this optional implementation, the encoder rotor of the second encoder is fixed on the motor rotor and moves relative to the reducer rotor. Since the encoder stator of the second encoder is connected to the reducer rotor, the encoder rotor of the second encoder and the encoder stator of the second encoder run relative to each other, thereby achieving the purpose of the second encoder measuring the relative movement of the motor rotor shaft and the reducer.
[0068] The encoder device provided by this optional implementation method has an encoder rotor of the first encoder fixed at the end of the motor rotor away from the reducer rotor, and an encoder rotor of the second encoder fixed on the motor rotor and moves relative to the reducer rotor. On the basis of the first encoder effectively recording the moving position of the motor, the second encoder can effectively record the relative position relationship of the motor relative to the reducer, so that the moving position and relative position relationship of the combined motor can be used to obtain the accurate output absolute position of the joint actuator, thereby improving the reliability of the joint actuator position calculation.
[0069] In some optional implementations of the present application, the encoder stator of the second encoder is fixedly connected to the reducer rotor via a fixing member.
[0070] like Figure 2 As shown, the encoder stator 42 of the second encoder 4 is installed on the fixing member 5, that is, the relative position with the fixing member 5 remains unchanged, and the fixing member 5 is connected to the output end of the reducer (for example, fixed by a screw or other structure), thereby achieving the fixed connection between the encoder stator 42 of the second encoder 4 and the reducer rotor 22 through the fixing member.
[0071] In this optional implementation, the fixing member 5 can be a fixing plate that matches the output end of the reducer, and the fixing member 5 can also be a fixing seat that matches the output end of the retriever.
[0072] In the encoder device provided by this optional implementation, the encoder stator of the second encoder is fixedly connected to the reducer rotor through a fixing member. The original shape and volume of the encoder stator and reducer rotor of the second encoder are maintained by the connected fixing member, thereby improving the convenience of installation of the second encoder.
[0073] In some optional implementations of the present application, the encoder stator of the second encoder is rotationally connected to the reducer rotor through a transmission member.
[0074] In this optional implementation, the transmission member is the component responsible for transmitting power from the driving source to the actuator. In this application, the driving source is the reducer rotor, and the actuator is the encoder stator of the second encoder. The movement and function of the mechanical equipment can be realized through the transmission member, and there are many types of transmission members, such as belt drive and gear drive rod. Each transmission member has its unique application and advantages.
[0075] The encoder device provided by this optional implementation method has an encoder stator of the second encoder that is rotatably connected to the reducer rotor through a transmission member. The encoder of the second encoder can be assigned a reasonable fixed position through the transmission member in the limited space of the joint actuator, thereby improving the flexibility of the installation of the second encoder.
[0076] In some optional implementations of the present application, the encoder rotor of the second encoder is a permanent magnet, and the encoder stator of the second encoder is an encoder chip.
[0077] In this optional implementation, the second encoder is a magnetic encoder. Magnetic encoders utilize magnetic field sensing technology to achieve high-precision measurement. They internally contain a magnetic field generator consisting of a magnetic sensor and a permanent magnet. Signal processing includes signal amplification, filtering, shaping, conversion, decoding, compensation, and logical operations. Common types include incremental, absolute, single-turn, multi-turn, and linear magnetic encoders.
[0078] In this optional implementation, the permanent magnet in the second encoder that acts as a magnetic field generating device is matched with the encoder chip that serves as a magnetic sensitive element to detect the relative position of the reducer output end and the motor rotation. The permanent magnet is connected to the motor rotor, and the encoder chip is connected to the reducer rotor. Specifically, the encoder chip can be fixedly connected to the reducer rotor through a fixing part, or the encoder chip can be connected to the reducer rotor through a transmission part.
[0079] The encoder device provided by this optional implementation method has an encoder rotor of the second encoder that is a permanent magnet and an encoder stator of the second encoder that is an encoder chip, which provides a reliable implementation method for position measurement of the second encoder and improves the reliability of the output position measurement of the joint actuator.
[0080] Optionally, in the encoder device provided in this embodiment, the first encoder may be an incremental encoder, and the second encoder may be a magnetic encoder. An incremental encoder converts displacement into a periodic electrical signal, which is then converted into counting pulses, with the number of pulses representing the magnitude of the displacement.
[0081] The present application provides a robot joint actuator, including an encoder device according to any one of the above embodiments. By connecting the encoder rotor of the first encoder to the motor rotor, and at the same time, the encoder stator and encoder rotor of the second encoder are fixed to the rotor side of the joint actuator, the second encoder can detect the relative changes between the motor rotor and the reducer, thereby combining the position output of the first encoder to obtain the changes on the output side of the joint actuator rotor. Through the above technical solution, the stability of the dual-encoder mechanical structure can be improved, the problem of the complex structure of the traditional dual-encoder can be solved, the axial length of the joint actuator can be shortened, the integration of the joint actuator can be improved, and the cost of the joint actuator can be reduced.
[0082] The present application also provides a robot comprising at least one robot joint actuator according to the above-mentioned embodiment. By connecting the encoder rotor of the first encoder to the motor rotor, and at the same time, the encoder stator and encoder rotor of the second encoder are fixed to the rotor side of the joint actuator, the second encoder can detect the relative changes between the motor rotor and the reducer, thereby combining the position output of the first encoder to obtain the changes on the output side of the joint actuator rotor. Through the above-mentioned technical solution, compared with the traditional dual-encoder topology structure, the stability of the dual-encoder mechanical structure can be improved, the problem of the complex structure of the traditional dual-encoder can be solved, the axial length of the joint actuator can be shortened, the integration of the joint actuator can be improved, and the cost of the joint actuator can be reduced. As the integration of the robot joint actuator is further improved, the volume of the robot can be further reduced, the execution accuracy and safety performance of the robot can be improved, and the overall manufacturing cost of the robot can be reduced.
[0083] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this application can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solutions disclosed in this application can be achieved. This is not a limitation herein.
[0084] The above specific embodiments do not constitute a limitation on the scope of protection of this application. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application shall be included within the scope of protection of this application.
Claims
1. An encoder device for a joint actuator, applied to a joint actuator, wherein the joint actuator comprises a joint actuator stator, a joint actuator rotor, and an encoder device, wherein the joint actuator rotor comprises a motor rotor and a reducer rotor, and wherein: The encoder device comprises: a first encoder, wherein an encoder rotor of the first encoder is connected to the motor rotor; A second encoder, the encoder rotor of the second encoder is connected to the motor rotor, the encoder stator of the second encoder is connected to the reducer rotor, and the encoder rotor of the second encoder and the encoder stator of the second encoder have a first positional relationship; or the encoder rotor of the second encoder is connected to the reducer rotor, the encoder stator of the second encoder is connected to the motor rotor, and the encoder rotor of the second encoder and the encoder stator of the second encoder have a second positional relationship.
2. The encoder device according to claim 1, wherein The joint actuator stator includes: a motor stator, and the encoder stator of the first encoder is connected to the motor stator.
3. The encoder device according to claim 1, wherein The motor rotor includes a motor rotor shaft, and the first encoder and the second encoder are respectively located at two ends of the motor rotor shaft.
4. The encoder device according to claim 1, wherein When both the first encoder and the second encoder are single-turn absolute encoders, the output position of the joint actuator is obtained based on the output position of the first encoder and the output position of the second encoder.
5. The encoder device according to claim 1, wherein The encoder rotor of the first encoder and the encoder rotor of the second encoder are symmetrically arranged on an axis in the longitudinal direction of the motor rotor.
6. The encoder device according to claim 1, wherein The encoder rotor of the first encoder is fixed to one end of the motor rotor away from the output end of the reducer, and the encoder rotor of the second encoder is fixed to the motor rotor and moves relative to the reducer rotor.
7. The encoder device according to any one of claims 1 to 6, characterized in that: The encoder stator of the second encoder is fixedly connected to the reducer rotor through a fixing member.
8. The encoder device according to any one of claims 1 to 6, characterized in that: The encoder stator of the second encoder is rotationally connected to the reducer rotor through a transmission member.
9. The encoder device according to any one of claims 1 to 6, characterized in that: The encoder rotor of the second encoder is a permanent magnet, and the encoder stator of the second encoder is an encoder chip.
10. A robot joint actuator, characterized in that: The encoder device comprises the encoder device according to any one of claims 1 to 9.
11. A robot, characterized in that: The robot comprises at least one robot joint actuator according to claim 10.