Encoder device for joint actuator, robot joint actuator, and robot

Abstract

The invention relates to the technical field of robots, in particular to an encoder device of a joint actuator, the robot joint actuator and a robot. The joint actuator specifically comprises a joint actuator stator, a joint actuator rotor and an encoder device, the joint actuator rotor comprises a motor rotor and a speed reducer rotor, the encoder device comprises a first encoder, an encoder rotor of the first encoder is connected with the motor rotor, and a first position relation exists between an encoder rotor of a second encoder and the stator; an encoder rotor of the second encoder is connected with the motor rotor, and an encoder stator of the second encoder is connected with the speed reducer rotor; or the encoder rotor of the second encoder is connected with the speed reducer rotor, the encoder stator of the second encoder is connected with the motor rotor, and a second position relation exists between the encoder rotor and the stator of the second encoder, so that the integration level of the joint actuator is improved, and the cost of the joint actuator is reduced.

Description

Technical Field

[0001] The present application relates to the field of robot 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 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 humanoid robot has a small joint space, and the encoder topology of traditional joint actuators makes it longer in axis and difficult to miniaturize. The humanoid robot joints have high requirements for stability, and the encoder topology of traditional joint actuators makes its routing complex and its stability poor.

[0003] The two encoders of the 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 for installing the encoder on the actuator output end is generally small, and the encoder cannot be directly connected to the actuator output end, which cannot achieve the purpose of directly measuring 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 stator of the encoder generally needs to be fixed on the stator of the actuator, resulting in the encoder having to be installed on the side of the output flange close to the actuator stator, which results in a complex structure. The increase in the length of the output shaft increases the bending moment, and the structural stability is relatively poor.

[0004] An existing dual encoder solution, in order to solve the above problem, the prior art 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] Furthermore, if Figure 1 As shown, in order to solve the above problems, 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 (Z) passing through the hollow shaft in the reverse direction. Figure 1 As shown in the figure, the encoder is provided with rotation data. However, with this hollow shaft design, the actuator mechanical structure is too complex, the cost is high, and the structural stability is poor. Summary of the invention

[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 of a joint actuator is provided, which is applied to the joint actuator, the joint actuator comprising a joint actuator stator, a joint actuator rotor and an encoder device, the joint actuator rotor comprising a motor rotor and a reducer rotor; the encoder device comprising: 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 has a first position relationship with the encoder stator of the second encoder; 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 has a second position relationship with the encoder stator of the second encoder.

[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 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.

[0011] Optionally, the encoder rotor of the first encoder and the encoder rotor of the second encoder are symmetrically arranged on an axis in the length 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 via 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 in the above technical solution.

[0018] The present application provides an encoder device for a joint actuator, a robot joint actuator, and a robot, and 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. It creatively proposes to connect the rotor and stator in the second encoder to different moving parts of the joint actuator respectively, and 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, and 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 parts 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; the encoder stator and encoder rotor of the second encoder are both installed at the output end of the actuator, without the need for additional connectors, which improves the integration of the joint actuator and reduces the cost of the joint actuator. By cleverly distributing different parts of the second encoder in different areas of the joint actuator, this layout not only makes the structure of the entire joint actuator more compact, but also reserves more space for the installation of other necessary components, improving the flexibility and adaptability of the design. The dispersed installation of the second encoder components significantly reduces the installation pressure in a single area, reduces the installation complexity and potential failure risks caused by the concentration of components in a single area. This design helps to extend the service life of the encoder and the entire joint actuator, and improves the stability and reliability of the system. The encoder stator and encoder rotor of the second encoder are directly installed at the output end of the actuator, eliminating additional connectors, which not only simplifies the assembly process, but also reduces the possibility of assembly errors. This integrated design makes the system more concise and efficient, and easy to maintain and upgrade. Reduce costs and improve market competitiveness: Through the above design optimization, the use of materials is reduced (such as omitting connectors), the production process is simplified, and the manufacturing cost of the joint actuator is effectively reduced. The decentralized installation design also makes it easier to locate the problem when a fault occurs, facilitating rapid fault diagnosis and repair. This can not only shorten the maintenance cycle and reduce downtime, but also further improve the 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 used to better understand the present solution 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 It is a structural schematic diagram of an embodiment of an encoder device of a joint actuator of the present application;

[0023] Figure 3 is a schematic 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 shown;

[0025] Figure 5 It 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 is a description of exemplary embodiments of the present application in conjunction with the accompanying drawings, including various details of the embodiments of the present application to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications can 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, the description of well-known functions and structures is omitted in the following description.

[0027] All technical terms used in this document have the same meanings as those generally understood by technicians in the technical field to which this application belongs; 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 "plurality" refers to more than two (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. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which 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 referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not 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 to collaborate with humans. In order to meet the various standards for collaboration with humans, higher requirements are placed on collaborative robots in terms of accuracy, volume, safety, and other aspects. For a robot, the movement of each joint is inseparable from the motor, reducer, encoder, and driver. For traditional large robots, the space requirements for robots are not high, so in order to save costs, traditional robots are basically directly spliced ​​together by many of the above-mentioned modules with different functions, with a low degree of integration, resulting in traditional robots being 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 an encoding device of a joint actuator of the present application, wherein the joint actuator comprises a joint actuator stator 1, a joint actuator rotor 2 and an encoder device, wherein the joint actuator rotor 2 comprises a motor rotor 21 and a reducer rotor 22, and the encoder device comprises: 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, the encoder stator 42 of the second encoder 4 is connected to the reducer rotor 22, and there is a first position 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 is coaxial with the encoder stator 42, 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), there is a second positional relationship between the encoder rotor of the second encoder and the encoder stator of the second encoder.

[0034] In this embodiment, the second position relationship means that the encoder rotor is coaxial with the encoder stator, 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 an encoder for recording mechanical position. The working principle of the encoder is based on the reciprocating motion of friction, which is related to the application of displacement and angle measurement. When the device on which the encoder is installed moves, the encoder converts this motion into a more measurable form and generates some signals. Under the condition of following the signal capture rules, the position and speed can be extracted from these signals.

[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 for collecting signals emitted by the encoder rotor 31. The encoder rotor 31 of the first encoder 3 is a component of the first encoder for collecting motion signals 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 of the second encoder 4 that collects the signal emitted by the encoder rotor 41 and moves relative to itself. The encoder rotor 41 of the second encoder 4 is a component that collects the motion signal of the motor rotor. Through the cooperation between 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 purpose of the encoder recording position information can be achieved through the interaction between the encoder stator and the encoder rotor. 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 rule 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 the 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, the magnetic field generated by the encoder stators of the first encoder and the second encoder is cut to form 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 (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 a rotating component in the motor D, which is connected to the stator 22 of the motor D and is a key device for the motor D to realize the conversion between electrical energy and mechanical energy and between mechanical energy and electrical energy. The motor rotor 21 is usually made of high-strength and high-toughness alloy steel material to withstand the torque and centrifugal force generated during the operation of the motor.

[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 a threaded hole, through which the joint actuator can 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, and the encoder rotor 41 on which the second encoder 4 is installed is provided at the other end of the motor rotor shaft 211, and a controller circuit board of the motor controller is provided 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 rotation 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 the first encoder and the second encoder are both absolute encoders, the output position of the joint actuator can be directly calculated by the output position 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 the first encoder and the second encoder are both single-turn encoders, the calculated output position of the joint actuator is within the range of 0 to 360°. When the first encoder and the second encoder are both 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 make relative movement, and 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 parts 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 parts 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 on 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 the encoder stator of the first encoder is connected to the motor stator to 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 purpose of the encoder recording the position information of the motor can be achieved.

[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, an encoder stator of a first encoder connected to the motor stator, an encoder stator of the first encoder connected to the motor housing, and a distance between a position of the encoder stator of the first encoder and an encoder rotor of the first encoder is within a 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 at the motor side; the second encoder is located at the second end of the motor rotor shaft, and the second end is located at the reducer side.

[0055] The encoder device provided by this optional implementation mode arranges the first encoder and the second encoder at both ends of the motor rotor shaft, providing a reliable fixing method for installing 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] The position information of the output end of the joint actuator can be obtained by the encoder. Encoders are divided into incremental encoders and absolute encoders based on the signal principle. Each position of the absolute encoder corresponds to a certain digital code, so its indication is only related to the starting and ending positions of the measurement, but not to the intermediate process of the measurement. The incremental encoder can output the incremental changes of the encoder from the predefined starting position. Therefore, the output end of the joint actuator usually needs to use an absolute encoder to obtain the position information. According to the test range, the absolute position encoder can be divided into a single-turn absolute position encoder and a multi-turn position encoder. For a single-turn absolute position encoder, when the rotation exceeds 360°, the encoding returns to the origin, which does not meet the principle of absolute encoding only. Therefore, such encoding can only be used for measurements within a rotation range of 360°. If you want to measure the rotation range exceeding 360°, you must use a multi-turn absolute encoder. Although the multi-turn absolute encoder can realize the measurement of position information within a multi-turn range, it will usually add additional power supply circuits and batteries, resulting in an increase in the size of the joint actuator, which is not conducive to the high integration design of the joint actuator. Since multi-turn absolute position encoders usually require continuous power supply to record the current absolute position, they will not work properly when the joint actuator is shut down for a long time and the battery in the multi-turn absolute encoder is exhausted, which cannot meet the increasingly diverse usage scenarios of robots. In addition, the price of multi-turn absolute position encoders is relatively high and cannot adapt to the low-cost commercialization trend of robots.

[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, the first encoder (motor side encoder) and the second encoder (actuator output side encoder) are both single-turn absolute position encoders, and in particular, a magnetic encoder is used as an example. The motor rotor is connected to a reducer, and the encoder rotor of the first encoder and the encoder rotor of the second encoder are respectively installed at both ends of the motor rotor shaft and rotate with the rotation of the motor rotor. The encoder stator of the first encoder is fixed relative to the motor stator, so 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 of 0 to 360°. The encoder stator of the second encoder is connected to the output end of the reducer (for example, fixedly connected by a screw or other structure). Due to the reduction ratio of the reducer, the motor rotor and the output end of the reducer will produce relative rotational motion, so 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 of 0 to 360°.

[0060] In this optional implementation, if Figure 5 As shown, the absolute position signal J at the output end of the reducer (i.e., the absolute position at the output side of the actuator), the motor rotor position signal F and the actuator output side position signal S, are designed to be aligned only at one position scale within the range of the absolute position signal J to be measured - zero position alignment. In the reading window of the absolute position signal J at any angle, only the measurement value at the current angle can be seen. By comparing the two measurement values ​​of the motor rotor position signal F and the actuator output side position signal S, the phase difference between the motor rotor position signal F and the actuator output side position signal S can be obtained, and the absolute value distance between this angle position and the zero position can be deduced. The specific calculation process of the absolute position of the actuator output side can be: calculating the sensor signal amplitude difference between the motor rotor position signal F and the actuator output side position signal S, and calculating the sensor signal phase difference between the motor rotor position signal and the actuator output side position signal based on the sensor signal amplitude difference; based on the sensor signal phase difference, the absolute value position of the actuator output side is obtained.

[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 the position calculation of the joint actuator output end, using two single-turn absolute encoders to obtain the joint actuator output position, and not using a multi-turn encoder to record the joint actuator output position, 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 the encoder rotor of the first encoder on the 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 move 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 one 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 with respect 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 structure such as a screw), thereby realizing that the encoder stator 42 of the second encoder 4 is fixedly connected to the reducer rotor 22 through the fixing member.

[0071] In this optional implementation, the fixing member 5 may be a fixing plate that matches the output end of the reducer, or the fixing member 5 may 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, and the original shape and volume of the encoder stator and the reducer rotor of the second encoder are maintained through the connected fixing member, thereby improving the convenience of installing 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 drives and gear drive rods. 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 transmission member can be used to assign a reasonable fixed position to the encoder of the second encoder in the limited space of the joint actuator, thereby improving the flexibility of installing 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, which uses magnetic field sensing technology to achieve high-precision measurement and contains a magnetic field generating device composed of magnetic sensitive elements and permanent magnets. Signal processing includes signal amplification, filtering, shaping, conversion, decoding, compensation and logical operations. Common types include incremental, absolute, single-turn and 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 member, or the encoder chip can be connected to the reducer rotor through a transmission member.

[0079] The encoder device provided by this optional implementation method, the encoder rotor of the second encoder is a permanent magnet, and the encoder stator of the second encoder is an encoder chip, which provides a reliable implementation method for the second encoder to perform position measurement and improves the reliability of the joint actuator output position measurement.

[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. The incremental encoder is an encoder that converts displacement into a periodic electrical signal, and then converts the electrical signal into counting pulses, and uses the number of pulses to represent the magnitude of the displacement.

[0081] The present application provides a robot joint actuator, including an encoder device of 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 change between the motor rotor and the reducer, thereby combining the position output of the first encoder to obtain the change 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 in 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, so that the second encoder can detect the relative change between the motor rotor and the reducer, thereby combining the position output of the first encoder to obtain the change 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 size 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 processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this application can be executed in parallel, sequentially or in different orders, as long as the expected results of the technical solution disclosed in this application can be achieved, and this document is not limited here.

[0084] The above specific implementations do not constitute a limitation on the protection scope of this application. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of this application should be included in the protection scope 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 there is a first positional relationship between the encoder rotor of the second encoder and the encoder stator of the second encoder; 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 there is a second positional relationship between the encoder rotor of the second encoder and the encoder stator of the second encoder.

2. The encoder device according to claim 1, characterized in that 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, characterized in that The motor rotor comprises: 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, characterized in that 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, characterized in that The encoder rotor of the first encoder and the encoder rotor of the second encoder are symmetrically arranged on an axis in the length direction of the motor rotor.

6. The encoder device according to claim 1, characterized in that The encoder rotor of the first encoder is fixed to an 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 via 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: An encoder device comprising any one of claims 1-9.

11. A robot, characterized in that: Comprising at least one robot joint actuator as claimed in claim 10.

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