A single-sided driving double-degree-of-freedom robot joint module and a control method thereof

Abstract

The present application relates to the technical field of robot joint driving, and particularly relates to a single-side driven two-degree-of-freedom robot joint module and a control method thereof, which comprises a base assembly, a first driving source and a second driving source fixed to a first side of the base assembly, a center transmission shaft, a rotating support and a terminal output shaft, a first end of the center transmission shaft being rotatably installed on a second side of the base assembly, the rotating support being sleeved on a second end of the center transmission shaft and being rotatably connected with the base assembly, and the terminal output shaft being installed on the rotating support and being spatially perpendicular to the center transmission shaft; the first driving source drives the terminal output shaft to rotate, and the second driving source drives the rotating support to drive the terminal output shaft to revolve around a circle. The driving sources are arranged at the proximal end of the joint, so that the problems of a bulky volume, a large terminal inertia and a poor dynamic response of a traditional series driving joint are solved; meanwhile, the wiring across the joint is avoided, the cable abrasion is eliminated, and the reliability and the motion flexibility are improved.

Description

Technical Field

[0001] This invention relates to the field of robot joint drive technology, specifically to a single-sided driven dual-degree-of-freedom robot joint module and its control method. Background Technology

[0002] With the continuous development of robotics technology, miniature robots and bionic robotic arms are increasingly widely used in precision operations, medical assistance, and service and entertainment fields. To simulate the flexible movement of biological limbs, these devices typically require multiple rotational degrees of freedom. Currently, the mainstream technical solution for achieving multi-degree-of-freedom joint motion is a direct-drive series structure using modular servo motors or servo motors. The basic principle of this solution is to treat each independent drive unit as a joint module, rigidly connecting the housing of the subsequent motor to the output shaft of the preceding motor, thereby achieving the stacking and orthogonal arrangement of degrees of freedom. This design has become a common technical approach in the industry due to its simple structure, easy control decoupling, and high degree of modularity.

[0003] However, as application scenarios place higher demands on the size, weight, and dynamic performance of robot end effectors, the aforementioned traditional serial drive method has the following significant limitations: 1) In terms of spatial layout, since the drive motor of each joint occupies a certain physical space and the degree of freedom is increased by stacking, the motor must be distributed on both sides of the joint node. This "heavy at both ends" layout makes the robot arm, especially the joints near the base (such as the shoulder), appear abnormally bulky, making it difficult to achieve a slender and compact biomimetic shape design.

[0004] 2) In terms of dynamic performance, the drive motors located at the distal joints significantly increase the equivalent mass and rotational inertia of the robotic arm's end effector. This requires the robot to overcome greater inertial forces when starting, stopping, or changing direction at high speeds, resulting in sluggish dynamic response, reduced energy utilization efficiency, and exacerbated oscillations and positioning overshoot during movement.

[0005] 3) In terms of cable management, the serial structure means that power and signal lines must pass through multiple rotating joints to connect to the remote motor. With the frequent rotation of the joints, the cables are prone to twisting, bending and wear when passing through the joint axis. After long-term operation, internal breakage or insulation layer damage is likely to occur. At the same time, the physical stress of the wire harness will also limit the theoretical maximum rotation angle of the joint, affecting the robot's movement flexibility.

[0006] The above reasons together lead to multiple technical bottlenecks in the miniaturized biomimetic design of existing serial drive solutions, such as bulky size, insufficient dynamic performance and limited reliability, making it difficult to meet the application requirements of the next generation of high-performance, highly integrated robots. Summary of the Invention

[0007] To address the above technical problems, this invention provides a technical solution for a single-sided driven dual-degree-of-freedom robot joint module and its control method.

[0008] The technical problem solved by this invention can be achieved by the following technical solutions: A single-sided driven dual-DOF robot joint module, comprising: A base assembly having a first side and a second side disposed opposite to each other; The driving unit includes a first driving source and a second driving source, both of which are fixedly installed on the first side of the base assembly. A coaxial composite transmission mechanism includes a central transmission shaft, a rotating bracket, and an end output shaft. The first end of the central transmission shaft is rotatably mounted on the second side of the base assembly. The rotating bracket is rotatably sleeved on the second end of the central transmission shaft and rotatably connected to the base assembly through a bearing. The end output shaft is rotatably mounted on the rotating bracket and is spatially perpendicular to the central transmission shaft. The first drive source is connected to the central drive shaft via a first transmission chain, and is used to drive the end output shaft to rotate around its own axis in a first degree of freedom. The second drive source is connected to the rotating bracket via a second transmission chain, and is used to drive the rotating bracket together with the end output shaft to rotate around the axis of the central transmission shaft in a second degree of freedom.

[0009] Preferably, a receiving cavity is provided on the second side of the base assembly, and a main bearing seat and a first drive source positioning bushing are provided in the receiving cavity extending away from the base assembly. The bottom of the receiving cavity is provided with a second drive source positioning shaft hole, a first mounting hole and a second mounting hole. The first end of the first drive source is provided with a first drive output shaft and a third mounting hole; The first end of the second drive source is provided with a second drive output shaft and a fourth mounting hole; During assembly, the first drive source passes through the first drive source positioning bushing via the first drive output shaft, and is then fixedly connected to the base assembly via a fastener that passes through the first mounting hole and the third mounting hole in sequence. The second drive source passes through the positioning shaft hole of the second drive source via the second drive output shaft, and then passes through the second mounting hole and the fourth mounting hole in sequence via a fastener to fix the second drive source to the base assembly. The first end of the central drive shaft is rotatably mounted on the main bearing housing.

[0010] Preferably, the first transmission chain includes: The first gear is fixedly connected to the first drive output shaft and located on the first drive source positioning sleeve; The second gear is fixedly connected to the central drive shaft and located on the main bearing seat; the second gear meshes with the first gear. The third gear is fixedly connected to the central drive shaft and located above the second gear; The fourth gear is fixedly connected to the end output shaft and is orthogonal to the third gear; The first transmission chain is a self-rotating drive chain.

[0011] Preferably, the second transmission chain includes: The fifth gear is fixedly connected to the second drive output shaft; The sixth gear is integrally formed on the inner circumferential surface of the rotating bracket and meshes with the fifth gear; The second transmission chain is a revolution drive chain.

[0012] Preferably, the bearing is disposed in the receiving cavity of the base assembly, the inner ring of the bearing is fixedly connected to the outer side of the rotating bracket, and the outer ring of the bearing is fixedly connected to the inner side of the receiving cavity.

[0013] Preferably, the first side of the base assembly is provided with a whole-machine mounting structure, which extends in a direction away from the base assembly and is used to mount the joint module onto the robot.

[0014] Preferably, it further includes: The first magnetic encoder module is fixedly installed at the second end of the first drive source and is used to detect the rotation angle of the first drive source. The second magnetic encoder module is fixedly installed at the second end of the second drive source and is used to detect the rotation angle of the second drive source.

[0015] A control method for a single-sided driven dual-DOF robot joint module, applied to a single-sided driven dual-DOF robot joint module as described above, includes: Step S1: Generate the target output angle sequence of the end output axis according to the task requirements; Step S2: Based on the preset kinematic coupling model, the target angle sequence is converted into the target rotation angle sequence of the first driving source and the second driving source in real time; Step S3: Using a closed-loop control algorithm, the first drive source and the second drive source are driven to rotate to the target position according to the target rotation angle sequence and the encoded feedback of the first drive source and the second drive source.

[0016] Preferably, in step S1, the specific formula for the target output angle sequence is: , in, Output an angle sequence for the target. The first target output angle is the angle at which the end output shaft rotates about the axis of the central drive shaft. The second target output angle is the rotation of the end output shaft around its own axis. In step S2, the specific formula for the target turning angle sequence is as follows: , in, The target turning sequence, The first target turning angle of the first drive source. The second target rotation angle is the second driving source.

[0017] Preferably, step S2 includes: Step S21: Calculate the second target rotation angle of the second drive source based on the first target output angle. The specific calculation formula is as follows: , in, The transmission ratio from the second drive source to the rotating bracket; Step S22: Calculate the first target rotation angle of the first drive source based on the second target output angle and the second target rotation angle. The specific calculation formula is as follows: ,

[0018] in, As a self-rotating term, For decoupling compensation, The transmission ratio from the first drive source to the end output shaft is [value missing]. This represents the gear ratio between the fourth gear and the third gear.

[0019] Beneficial Effects: This invention effectively solves the problem of bulky joint size and inability to achieve a slim and compact structure design caused by the stacked distribution of motors in traditional series drive methods by centrally fixing the first and second drive sources on the first side of the base assembly and using a coaxial composite transmission mechanism consisting of a central drive shaft, a rotating bracket, and an end output shaft to transmit power to the execution end on the second side of the base assembly. At the same time, by using the layout of both drive sources located on the same side of the joint, the equivalent mass and moment of inertia of the execution end are significantly reduced, avoiding dynamic response lag, low energy efficiency, and motion oscillation overshoot caused by the mass of the far-end motor, thereby greatly improving the dynamic performance of the joint. In addition, since both drive sources are fixed on the first side of the base assembly, the cables connecting the two drive sources do not need to pass through any rotating joint for electrical connection, completely avoiding the problems of twisting, bending, and wear of the wiring harness caused by joint rotation, eliminating the physical limitation of the joint movement angle by cable stress, and greatly enhancing the reliability and motion flexibility of the system. Attached Figure Description

[0020] Figure 1 This is an exploded view of the structure of the dual-degree-of-freedom robot joint module of the present invention; Figure 2 This is a schematic diagram of the overall structure of the dual-degree-of-freedom robot joint module of the present invention; Figure 3 This is a schematic diagram of the joint module structure of the two-degree-of-freedom robot without a rotating support according to the present invention; Figure 4 This is a cross-sectional view of the dual-degree-of-freedom robot joint module of the present invention; Figure 5 This is a schematic diagram of the external structure of the rotating bracket of the present invention; Figure 6 This is a schematic diagram of the internal structure of the rotating bracket of the present invention; Figure 7 This is a schematic diagram of the first side structure of the base assembly of the present invention; Figure 8 This is a schematic diagram of the second side structure of the base assembly of the present invention; Figure 9 This is an exploded view of the first transmission chain structure of the present invention; Figure 10 This is an exploded view of the second transmission chain structure of the present invention; Figure 11 This is a flowchart of the method of the present invention.

[0021] Figure descriptions: 1. Base assembly; 101. Main bearing housing; 102. First drive source positioning bushing; 103. Second drive source positioning shaft hole; 104. Overall mounting structure; 105. First mounting hole; 106. Second mounting hole; 107. Receiving cavity; 2. First drive source; 201. First drive output shaft; 202. First magnetic positioning post; 203. Third mounting hole; 3. Second drive source; 301. Second drive output shaft; 302. Second magnetic positioning post. Positioning pin; 303, fourth mounting hole; 4, central drive shaft; 5, rotating bracket; 501, output shaft mounting hole; 502, central shaft through hole; 6, end output shaft; 7, bearing; 8, screw; 9, first gear; 10, second gear; 11, third gear; 12, fourth gear; 13, fifth gear; 14, sixth gear; 15, first magnetic braiding module; 151, first magnetic braiding positioning hole; 16, second magnetic braiding module; 161, second magnetic braiding positioning hole. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0024] The present invention will be further described below using two parallel drive motors as an example, in conjunction with the accompanying drawings and specific embodiments, but this is not intended to limit the present invention.

[0025] Reference Figure 1 This invention provides a single-sided driven dual-degree-of-freedom robot joint module, comprising: Base assembly 1, the base assembly 1 having a first side and a second side disposed opposite to each other; A drive unit, the drive unit includes a first drive source 2 and a second drive source 3, the first drive source 2 and the second drive source 3 are both fixedly installed on the first side of the base assembly 1; A coaxial composite transmission mechanism includes a central transmission shaft 4, a rotating bracket 5, and an end output shaft 6. The first end of the central transmission shaft 4 is rotatably mounted on the second side of the base assembly 1. The rotating bracket 5 is rotatably sleeved on the second end of the central transmission shaft 4 and rotatably connected to the base assembly 1 through a bearing 7. The end output shaft 6 is rotatably mounted on the rotating bracket 5 and is spatially perpendicular to the central transmission shaft 4. The first drive source 2 is connected to the central drive shaft 4 via a first transmission chain, and is used to drive the end output shaft 6 to rotate around its own axis in a first degree of freedom. The second drive source 3 is connected to the rotating bracket 5 via a second transmission chain, and is used to drive the rotating bracket 5 together with the end output shaft 6 to rotate around the axis of the central transmission shaft 4 in a second degree of freedom.

[0026] Specifically, in this embodiment of the invention, in order to address the problems of bulky joint size, sluggish dynamic response, and limited cable wear caused by the stacked distribution of motors in the traditional series drive method, the two drive sources are concentrated and fixed on the first side (i.e., the near end) of the base assembly 1, and the power is transmitted to the execution end (i.e., the far end) on the second side of the base assembly 2 using a coaxial composite transmission mechanism. This effectively avoids the structural limitations of the drive sources being distributed on both sides of the joint and achieves a compact layout of the drive unit on one side.

[0027] The first drive source 2 drives the end output shaft 6 to rotate around its own axis in the first degree of freedom through the central drive shaft 4, and the second drive source 3 drives the end output shaft 6 to rotate around the central drive shaft 4 in the second degree of freedom through the rotating bracket 5. In this way, while maintaining the compact structure of the joint module, the output of two degrees of freedom orthogonal motion is achieved.

[0028] Specifically, refer to Figure 1 The base assembly 1 is a circular disc structure with a first side being a flat mounting surface and a second side being a recessed cavity 107 formed away from the first side.

[0029] The first drive source 2 and the second drive source 3 are preferably drive motors. The first drive source 2 provides power input for the first degree of freedom (rotation), and the second drive source 3 provides power input for the second degree of freedom (revolution). The two drive sources are arranged in parallel to accommodate the tubular internal space of the arm or joint.

[0030] The central drive shaft 4 is a straight shaft structure. Its first end is rotatably fixed at the center of the receiving cavity 107, and its second end extends axially away from the receiving cavity 107.

[0031] The rotating bracket 5 has a cylindrical structure, with an open end near the base assembly 1 and a closed end away from the base assembly 1. Specifically: Reference Figure 1 The open end of the rotating bracket 5 is rotatably connected to the inner circumference of the receiving cavity 107 via the bearing 7, so that the rotating bracket 5 is suspended and sleeved on the central drive shaft 4. Reference Figure 5 The closed end of the rotating bracket 5 is provided with protruding structures on both sides, and each protruding structure is provided with an output shaft mounting hole 501. The two output shaft mounting holes 501 are coaxially opposite to each other. A central shaft through hole 502 is provided at the bottom of the closed end of the rotating bracket 5. The central shaft through hole 502 is located at the midpoint of the line connecting the centers of the two output shaft mounting holes 501. The second end of the central drive shaft 4 passes through the central shaft through hole 502 and extends to the outside of the closed end of the rotating bracket 5. Among them, the output shaft mounting hole 501 and the central shaft through hole 502 are both circular through holes that match the end output shaft 6 and the central drive shaft 4, and their diameters match the outer diameters of the end output shaft 6 and the central drive shaft 4, respectively.

[0032] The end output shaft 6 is also a straight shaft structure, which is transversely inserted into the two output shaft mounting holes 501 and rotatably connected to the rotating bracket 5 through the bearing 7. After assembly, the axis of the end output shaft 6 is perpendicular to and intersects the axis of the central drive shaft 4 in space.

[0033] Through the above structure, the power of the first drive source 2 is transmitted to the central drive shaft 4 via the first transmission chain, and then to the end output shaft 6 via the central drive shaft 4, driving the end output shaft 6 to rotate around its own axis; the power of the second drive source 3 is transmitted to the rotating bracket 5 via the second transmission chain, driving the rotating bracket 5 to rotate around the axis of the central drive shaft 4, thereby causing the end output shaft 6 to revolve together. The two degrees of freedom of motion are independent and orthogonal to each other, thus realizing the precise composite motion of the end output shaft 6.

[0034] In a preferred embodiment of the present invention, the second side of the base assembly 1 is a receiving cavity 107 recessed in the direction away from the first side. The receiving cavity 107 is provided with a main bearing seat 101 and a first drive source positioning bushing 102 extending in the direction away from the base assembly 1. The bottom of the receiving cavity 107 is provided with a second drive source positioning shaft hole 103, a first mounting hole 105 and a second mounting hole 106. The first end of the first drive source 2 is provided with a first drive output shaft 201 and a third mounting hole 203; The first end of the second drive source 3 is provided with a second drive output shaft 301 and a fourth mounting hole 303; During assembly, the first drive source 2 passes through the first drive output shaft 201 through the first drive source positioning bushing 102, and is then fixedly connected to the base assembly 1 by a fastener passing through the first mounting hole 105 and the third mounting hole 203 in sequence. The second drive source 3 passes through the second drive output shaft 301 through the second drive source positioning shaft hole 103, and then passes through the second mounting hole 106 and the fourth mounting hole 303 in sequence by a fastener to fix the second drive source 3 to the base assembly 1. The first end of the central drive shaft 4 is rotatably mounted on the main bearing housing 101.

[0035] Specifically, in order to ensure the precise positioning and stable fixation of the first driving source 2 and the second driving source 3 on the base assembly 1, and at the same time to ensure the rotational accuracy of the central transmission shaft 4, the internal structure of the accommodating cavity 107 of the base assembly 1 is further optimized in this embodiment of the invention.

[0036] Specifically, firstly, refer to Figure 8 Inside the receiving cavity 107 of the base assembly 1, a main bearing seat 101 is provided at the center of its bottom. The main bearing seat 101 is a hollow cylindrical structure that extends vertically out of the receiving cavity 107. Its axis coincides with the central axis of the receiving cavity 107 and is used to support the first end of the central drive shaft 4 to ensure that the central drive shaft 4 can rotate smoothly around its axis.

[0037] A first drive source positioning bushing 102 is coaxially arranged on one side of the main bearing housing 101. The first drive source positioning bushing 102 is also a hollow cylindrical structure that extends vertically out of the receiving cavity 107. Its inner diameter matches the outer diameter of the first drive output shaft 201 and is used to radially position and support the first drive output shaft 201. A second drive source positioning shaft hole 103 is coaxially provided on the other side of the main bearing housing 101. The second drive source positioning shaft hole 103 is a circular through hole, the diameter of which matches the outer diameter of the second drive output shaft 301, and is used to radially position the second drive output shaft 301.

[0038] Secondly, refer to Figure 7 and Figure 8 Along the direction perpendicular to the axis of the main bearing housing 101, the first drive source positioning bushing 102, and the second drive source positioning shaft hole 103, a first mounting hole 105 is provided on each side of the first drive source positioning bushing 102. The two first mounting holes 105 are symmetrically distributed with respect to the central axis of the first drive source positioning bushing 102. Both first mounting holes 105 are threaded through holes for mating with the third mounting hole 203 of the first drive source 2. Similarly, refer to Figure 7 and Figure 8Along a direction perpendicular to the axis of the main bearing housing 101, the first drive source positioning sleeve 102, and the second drive source positioning shaft hole 103, a second mounting hole 106 is provided on each side of the second drive source positioning shaft hole 103. The two second mounting holes 106 are symmetrically distributed with respect to the central axis of the second drive source positioning shaft hole 103. The two second mounting holes 106 are also threaded through holes, used to mate with the fourth mounting hole 303 of the second drive source 3. The symmetrical distribution design of the mounting holes ensures the uniformity of force during the installation of the two drive sources, thereby improving the stability and reliability of the connection.

[0039] Next, refer to Figure 1 Both the first drive source 2 and the second drive source 3 are cylindrical structures, arranged side by side on the first side of the base assembly 1, with their axes parallel to each other, to accommodate the tubular internal space of the arm or joint and achieve a compact layout. Wherein: A first drive output shaft 201 is provided at the center of the end of the first drive source 2 near the base assembly 1 (i.e., the first end). The first drive output shaft 201 is a cylindrical solid shaft used to provide power input for rotation. On both sides of the first drive output shaft 201, a third mounting hole 203 is provided. The positions of the two third mounting holes 203 correspond one-to-one with the positions of the two first mounting holes 105 on the base assembly 1. Both third mounting holes 203 are threaded blind holes used to cooperate with fasteners. Similarly, a second drive output shaft 301 is provided at the center of the end of the second drive source 3 near the base assembly 1 (i.e., the first end). The second drive output shaft 301 is also a cylindrical solid shaft, used to provide power input for revolution. On both sides of the second drive output shaft 301, a fourth mounting hole 303 is provided respectively. The positions of the two fourth mounting holes 303 correspond one-to-one with the positions of the two second mounting holes 106 on the base assembly 1. Both are threaded blind holes, used to cooperate with fasteners.

[0040] During assembly, refer to Figure 1 and Figure 4 First, insert the first drive output shaft 201 of the first drive source 2 into and out of the first drive source positioning sleeve 102 of the base assembly 1, and at the same time adjust the orientation of the first drive source 2 so that the two third mounting holes 203 are aligned with the two first mounting holes 105 respectively; then, preferably, two screws 8 are passed through the first mounting holes 105 and the third mounting holes 203 respectively and tightened, thereby fixing the first drive source 2 to the base assembly 1.

[0041] Similarly, the second drive output shaft 301 of the second drive source 3 is passed through the second drive source positioning shaft hole 103 of the base assembly 1, and the orientation of the second drive source 3 is adjusted so that the two fourth mounting holes 303 are aligned with the two second mounting holes 106 respectively; then, two other screws 8 are passed through the second mounting holes 106 and the fourth mounting holes 303 respectively and tightened, thereby fixing the second drive source 3 to the base assembly 1.

[0042] Through the above structural design and assembly method, the first drive source 2 and the second drive source 3 are precisely and firmly fixed to the first side of the base assembly 1, and the output shafts of the two drive sources extend through the corresponding positioning structure to the receiving cavity 107, providing a precise positioning and reliable power transmission basis for subsequent connection with the transmission chain; at the same time, this layout concentrates all drive sources at the proximal end of the joint, effectively solving the structural bulkiness problem caused by the distribution of drive sources on both sides of the joint in the traditional series drive method.

[0043] In a preferred embodiment of the present invention, the first transmission chain includes: The first gear 9 is fixedly connected to the first drive output shaft 201 and located on the first drive source positioning sleeve 102; The second gear 10 is fixedly connected to the central drive shaft 4 and located on the main bearing seat 101. The second gear 10 meshes with the first gear 9. The third gear 11 is fixedly connected to the central drive shaft 4 and is located above the second gear 10; The fourth gear 12 is fixedly connected to the end output shaft 6 and is orthogonal to the third gear 11; The first transmission chain is a self-rotating drive chain.

[0044] Specifically, in order to achieve precise power transmission from the first drive source 2 to the end output shaft 6, and to ensure that the end output shaft 6 can rotate around its own axis (i.e., as shown in the figure), Figure 9 The Y-axis (as shown) rotates smoothly. In this embodiment of the invention, the gear arrangement and connection method of the first transmission chain are further optimized.

[0045] Specifically, refer to Figure 3 and Figure 4 First, after the first drive output shaft 201 passes through the first drive source positioning sleeve 102, a first gear 9 is fixedly sleeved on its protruding part. The first gear 9 is preferably a spur gear, whose axis coincides with the axis of the first drive output shaft 201. It is fixed to the first drive output shaft 201 by key connection or interference fit to ensure the reliability of power transmission.

[0046] Next, after the first end of the central drive shaft 4 is rotatably installed in the main bearing housing 101, a second gear 10 is fixedly sleeved on the part of the shaft that protrudes from the main bearing housing 101. The second gear 10 is preferably a spur gear, whose axis coincides with the axis of the central drive shaft 4, and is fixed to the central drive shaft 4 by key connection or interference fit. After assembly, the second gear 10 meshes with the first gear 9, and the axes of the two gears are parallel to each other, forming the first stage of reduction transmission.

[0047] Furthermore, after the second end of the central drive shaft 4 extends away from the base assembly 1 and passes through the central shaft through hole 502 of the rotating bracket 5, a third gear 11 is fixedly sleeved on its protruding part. The third gear 11 is preferably a bevel gear, whose axis coincides with the axis of the central drive shaft 4, and is fixed to the central drive shaft 4 by key connection or interference fit. At the same time, the third gear 11 is located outside the bottom of the closed end of the rotating bracket 5, that is, outside the rotating bracket 5, so as to facilitate orthogonal meshing with the fourth gear 12.

[0048] Then, a fourth gear 12 is fixedly sleeved on the inner side of the protrusion structure of the end output shaft 6 and the closed end of the rotating bracket 5. The fourth gear 12 is also preferably a bevel gear, and its axis coincides with the axis of the end output shaft 6. It is fixed to the end output shaft 6 by key connection or interference fit. After assembly, the fourth gear 12 and the third gear 11 are orthogonally meshed in space, that is, the axes of the two gears are perpendicular to each other, forming a bevel gear pair transmission.

[0049] It is worth mentioning that the third gear 11 and the fourth gear 12 are not limited to bevel gears; other gear combinations can also be used to achieve power transmission during rotation. For example, a combination of a spur gear and a crown gear can be used. The third gear 11 can be a spur gear, and the fourth gear 12 can be a crown gear. Through the meshing of the internal teeth or end face teeth of the spur gear and the crown gear, power transmission between the two perpendicular axes can also be achieved. Any gear transmission combination that can achieve smooth transmission with perpendicularly intersecting axes and meets the rotational requirements of the end output shaft 6 can be replaced according to actual design needs.

[0050] Specifically, the first gear 9 and the second gear 10 are located inside the rotating bracket 5, specifically in the internal space enclosed by the receiving cavity 107 and the opening end of the rotating bracket 5, making full use of the internal space of the module and avoiding interference with the external structure.

[0051] Reference Figure 2 The third gear 11 is located outside the rotating bracket 5, near the bottom of the closed end, and the fourth gear 12 is located outside the rotating bracket 5, away from the bottom of the closed end. The meshing point of the third gear 11 and the fourth gear 12 is located outside the rotating bracket 5, which facilitates installation, debugging and lubrication maintenance.

[0052] Reference Figure 9 In this embodiment of the invention, the rotation principle of the first transmission chain is as follows: When the first drive source 2 is started, its first drive output shaft 201 drives the first gear 9 to rotate; the first gear 9 transmits power to the second gear 10 that meshes with it, driving the central drive shaft 4 to rotate around its own axis (i.e., the X-axis); the rotation of the central drive shaft 4 drives the third gear 11 at its second end to rotate synchronously; since the third gear 11 and the fourth gear 12 are orthogonally meshed, the rotation of the third gear 11 drives the fourth gear 12 to rotate around the end output shaft 6's own axis (i.e., the Y-axis), thereby driving the end output shaft 6 to achieve rotational motion.

[0053] Through the aforementioned first transmission chain, the power of the first drive source 2 is precisely transmitted to the end output shaft 6, realizing the self-rotation drive of the end output shaft 6; at the same time, since the meshing of the first gear 9 and the second gear 10 and the meshing of the third gear 11 and the fourth gear 12 constitute a two-stage reduction transmission, the output torque is effectively improved, meeting the joint module's requirements for driving torque.

[0054] In a preferred embodiment of the present invention, the second transmission chain includes: The fifth gear 13 is fixedly connected to the second drive output shaft 301; The sixth gear 14 is integrally formed on the inner circumferential surface of the rotating bracket 5 and meshes with the fifth gear 13; The second transmission chain is a revolution drive chain.

[0055] Specifically, in order to achieve precise power transmission from the second drive source 3 to the rotating bracket 5, and to ensure that the rotating bracket 5 can drive the end output shaft 6 around its own axis of the central drive shaft 4 (i.e., as shown in the figure), Figure 9 The X-axis (as shown) rotates smoothly. In this embodiment of the invention, the gear arrangement and connection method of the second transmission chain have been optimized.

[0056] Specifically, firstly, refer to Figure 3 and Figure 4 After the second drive output shaft 301 passes through the second drive source positioning shaft hole 103, a fifth gear 13 is fixedly sleeved on its protruding part. The fifth gear 13 is preferably a spur gear, whose axis coincides with the axis of the second drive output shaft 301. It is fixed to the second drive output shaft 301 by key connection or interference fit to ensure the reliability of power transmission.

[0057] The fifth gear 13 is located inside the housing cavity 107, near the bottom of the base assembly 1, and is arranged side by side with the first gear 9 in space without interfering with each other.

[0058] Next, refer to Figure 6 The open end of the rotating bracket 5 faces the base assembly 1, and the closed end is away from the base assembly 1. On the inner circumferential surface of the open end of the rotating bracket 5, a sixth gear 14 is integrally formed. The sixth gear 14 is an internal gear ring structure, and its tooth profile is evenly distributed along the inner circumferential surface of the rotating bracket 5. Its axis coincides with the axis of the rotating bracket 5.

[0059] The sixth gear 14 and the rotating bracket 5 are an integral structure, requiring no additional connecting parts, which can effectively improve the structural rigidity and transmission accuracy of the module.

[0060] After assembly, the fifth gear 13 and the sixth gear 14 mesh with each other. Specifically, refer to... Figure 4 The external teeth of the fifth gear 13 mesh with the internal teeth of the sixth gear 14, forming an internal meshing gear transmission. This internal meshing structure has the advantages of compact structure, smooth transmission, and high load-bearing capacity.

[0061] Specifically, the fifth gear 13 is located inside the receiving cavity 107, near the bottom of the base assembly 1, and its meshing point with the sixth gear 14 is located inside the opening end of the rotating bracket 5. This allows for full utilization of the internal space of the rotating bracket 5, effectively preventing gear exposure, and also facilitates gear lubrication and protection.

[0062] Reference Figure 10 In this embodiment of the invention, the revolution principle of the second transmission chain is as follows: When the second drive source 3 is started, its second drive output shaft 301 drives the fifth gear 13 to rotate. Since the fifth gear 13 and the sixth gear 14 mesh with each other, the rotation of the fifth gear 13 drives the sixth gear 14 to rotate. Since the sixth gear 14 is integrally formed on the inner circumferential surface of the rotating bracket 5, the rotation of the sixth gear 14 directly drives the rotating bracket 5 to rotate around the axis (i.e., the X-axis) of its central drive shaft 4. The rotation of the rotating bracket 5 drives the end output shaft 6 installed on it to revolve around the axis of the central drive shaft 4, thereby realizing the revolution movement of the end output shaft 6.

[0063] Through the aforementioned second transmission chain, the power of the second drive source 3 is precisely transmitted to the rotating bracket 5, thereby realizing the revolution drive of the rotating bracket 5 and the end output shaft 6. At the same time, due to the use of an internal meshing gear transmission structure, the entire transmission chain is extremely compact, making full use of the internal space of the rotating bracket 5 and avoiding additional occupation of the external volume of the joint module.

[0064] In addition, the integrated design of the sixth gear 14 and the rotating support 5 effectively reduces the number of parts and assembly errors, and improves the rigidity and reliability of the transmission.

[0065] In a preferred embodiment of the present invention, the bearing 7 is disposed in the receiving cavity 107 of the base assembly 1, the inner ring of the bearing 7 is fixedly connected to the outer side of the rotating bracket 5, and the outer ring of the bearing 7 is fixedly connected to the inner side of the receiving cavity 107.

[0066] Specifically, since the rotating bracket 5 needs to rotate smoothly relative to the base assembly 1 while bearing radial and axial loads, the selection, installation position and connection method of the bearing 7 are further optimized in this embodiment of the invention to ensure the rotation accuracy and load-bearing capacity of the rotating bracket 5.

[0067] Specifically, refer to Figure 1 The bearing 7 is preferably a crossed roller bearing or a deep groove ball bearing, which has an overall annular structure and has an inner ring, an outer ring, and rolling elements located between the inner and outer rings. The bearing 7 is coaxially disposed in the receiving cavity 107 of the base assembly 1, specifically located between the inner circumferential side of the receiving cavity 107 and the outer circumferential side of the opening end of the rotating support 5.

[0068] Reference Figure 4 The outer circumferential surface of the open end of the rotating bracket 5 is provided with a mounting groove that matches the inner ring of the bearing 7. The inner ring of the bearing 7 is engaged in the mounting groove. The mounting groove is an annular groove that is continuously distributed circumferentially, and its radial depth matches the thickness of the inner ring of the bearing 7. During assembly, the inner ring of the bearing 7 is engaged in the mounting groove, and a fixed connection is achieved through an interference fit or a transition fit, thereby ensuring that there is no relative movement between the rotating bracket 5 and the inner ring of the bearing 7, so that the rotating bracket 5 can rotate together with the inner ring of the bearing 7.

[0069] Reference Figure 4 The inner circumferential surface of the receiving cavity 107 is a precision-machined cylindrical surface, the diameter of which matches the outer diameter of the outer ring of the bearing 7. During assembly, the outer ring of the bearing 7 is pressed into the receiving cavity 107, so that the outer circumferential surface of the outer ring of the bearing 7 and the inner circumferential surface of the receiving cavity 107 form a tight arc-shaped fit. This fit relies on the frictional force generated by the interference fit between the outer ring of the bearing 7 and the inner circumferential surface of the receiving cavity 107, as well as the radial constraint of the inner circumferential surface of the receiving cavity 107 on the outer ring of the bearing 7, thereby achieving axial and circumferential positioning of the outer ring of the bearing 7 within the receiving cavity 107, ensuring no relative movement between the outer ring of the bearing 7 and the base assembly 1 without the need for additional fasteners.

[0070] In a preferred embodiment of the present invention, the first side of the base assembly 1 is a planar mounting surface, and a whole-machine mounting structure 104 is provided on the planar mounting surface. The whole-machine mounting structure 104 extends in a direction away from the base assembly 1 and is used to mount the joint module on the robot.

[0071] Specifically, in order to achieve reliable fixation between the joint module and the robot body (such as the internal skeleton of the thoracic cavity, shoulder base, etc.), in this embodiment of the invention, reference is made to... Figures 1 to 3 On the planar mounting surface of the base assembly 1, a whole-machine mounting structure 104 is provided extending away from the base assembly 1. The whole-machine mounting structure 104 is used to fix the entire joint module to the predetermined mounting position of the robot.

[0072] Specifically, refer to Figure 7 Two complete machine mounting structures 104 are provided on the planar mounting surface of the base assembly 1. The two complete machine mounting structures 104 are coaxially distributed on both sides of the axis where the main bearing seat 101, the first drive source positioning bushing 102, and the second drive source positioning shaft hole 103 are located, and the line connecting their centers intersects the axis perpendicularly.

[0073] The overall mounting structure 104 is a hollow cylindrical structure, with a hollow interior forming the mounting hole for the entire machine. The axis of this hollow cylindrical structure is perpendicular to the first side plane of the base assembly 1, and its inner hole is a threaded hole that mates with mounting screws.

[0074] During assembly, screws are passed through the inner hole of the whole machine mounting structure 104 and screwed into the corresponding threaded hole on the robot mounting base, thereby fixing the base assembly 1 to the robot.

[0075] As a preferred embodiment of the present invention, it further includes: The first magnetic encoder module 15 is fixedly installed at the second end of the first drive source 2 and is used to detect the rotation angle of the first drive source 2. The second magnetic encoder module 16 is fixedly installed at the second end of the second drive source 3 and is used to detect the rotation angle of the second drive source 3.

[0076] Specifically, in order to achieve real-time and accurate detection of the rotation angle of the first driving source 2 and the second driving source 3, in this embodiment of the invention, a first magnetic coding module 15 and a second magnetic coding module 16 corresponding to the first driving source 2 and the second driving source 3 are further designed.

[0077] Specifically, refer to Figure 1 Both the first magnetic encoder module 15 and the second magnetic encoder module 16 are cylindrical structures, with their outer diameters matching the outer diameters of the corresponding drive sources. Each magnetic encoder module integrates a magnetic encoder chip and signal processing circuitry to detect the rotation angle of the drive source output shaft.

[0078] In this embodiment, both the first magnetic encoder module 15 and the second magnetic encoder module 16 employ a multi-turn cumulative angle detection method. Specifically, since the first drive source 2 and the second drive source 3 may need to rotate continuously for more than 360° during movement (e.g., when a joint performs multiple revolutions or rotations), traditional single-turn absolute encoders cannot meet the detection requirements. Therefore, in this embodiment of the invention, a magnetic encoder supporting multi-turn cumulative detection is used, which can count and accumulate the number of rotations of the drive source.

[0079] For example, when the drive source rotates two revolutions, the magnetic encoder module detects an angle of 720°, and so on, achieving absolute angle detection for more than one revolution. This accumulation method ensures that the control system can accurately obtain the absolute position information of the drive source, without losing angle reference even in long-term continuous motion or complex trajectory planning.

[0080] To be more specific, refer to Figure 1 A first magnetic positioning post 202 is provided at the center of the second end (i.e., the end away from the base assembly 1) of the first driving source 2. The first magnetic positioning post 202 is a solid cylindrical structure extending away from the base assembly 1, and its axis coincides with the axis of the first driving source 2.

[0081] Similarly, refer to Figure 1 A second magnetic positioning post 302 is provided at the center of the second end (i.e., the end away from the base assembly 1) of the second drive source 3. The second magnetic positioning post 302 is also a solid cylindrical structure extending away from the base assembly 1, and its axis coincides with the axis of the second drive source 3.

[0082] Accordingly, refer to Figure 1 A first magnetic coding positioning hole 151 is provided at the center of the end face of the first magnetic coding module 15 near the first driving source 2; a second magnetic coding positioning hole 161 is provided at the center of the end face of the second magnetic coding module 16 near the second driving source 3.

[0083] Reference Figure 4 The first magnetic positioning hole 151 is a cylindrical blind hole, the diameter of which matches the outer diameter of the first magnetic positioning post 202, and is used to cooperate with the first magnetic positioning post 202 to achieve radial positioning; the second magnetic positioning hole 161 is also a cylindrical blind hole, the diameter of which matches the outer diameter of the second magnetic positioning post 302.

[0084] During assembly, refer to Figure 1 The first magnetic braid positioning post 202 is inserted into the first magnetic braid positioning hole 151, and the second magnetic braid positioning post 302 is inserted into the second magnetic braid positioning hole 161, thereby firmly connecting the drive source and the magnetic braid module.

[0085] Reference Figure 11The present invention also provides a control method for a single-sided driven dual-degree-of-freedom robot joint module, applied to a single-sided driven dual-degree-of-freedom robot joint module as described above, comprising: Step S1: Generate the target output angle sequence of the end output axis 6 according to the task requirements; Step S2: Based on the preset kinematic coupling model, the target angle sequence is converted into a target rotation angle sequence of the first drive source 2 and the second drive source 3 in real time; Step S3: Using a closed-loop control algorithm, the first drive source 2 and the second drive source 3 are driven to rotate to the target position according to the target rotation angle sequence and the encoded feedback of the first drive source 2 and the second drive source 3.

[0086] In step S1, the specific formula for the target output angle sequence is as follows: , in, Output an angle sequence for the target. The first target output angle (i.e., revolution angle) for the rotation of the end output shaft 6 around the axis of the central transmission shaft 4. The second target output angle (i.e., rotation angle) is the rotation angle of the end output shaft 6 around its own axis. In step S2, the specific formula for the target turning angle sequence is as follows: , in, The target turning sequence, The first target turning angle of the first drive source 2. The second target rotation angle is the second driving source 3.

[0087] Specifically, in order to eliminate the inherent mechanical coupling of the coaxial differential transmission structure and achieve precise independent control of the revolution and rotation of the end output shaft 6, this embodiment of the invention adopts a hierarchical control architecture, using a closed-loop control algorithm to achieve kinematic decoupling and servo tracking. This hierarchical control architecture specifically includes: The trajectory planning layer generates the target output angle sequence for the end effector axis 6 based on the robot's task requirements (such as humanoid actions like waving or raising its arm). .in, The target angle corresponding to the revolution motion is achieved by the second drive source 3. The target angle corresponding to the rotational motion is achieved by the first drive source 2. This target output angle sequence It can be dynamically updated based on preset motion trajectories or real-time commands.

[0088] A kinematic decoupling layer is used to convert the target output angle sequence into the target rotation angle sequence of the first drive source 2 and the second drive source 3 in real time using a preset kinematic coupling model. This coupled model is based on mechanical structure parameters and fully considers the coupling effect of revolution on rotation. The compensation and drive amount required for each drive source are calculated through a decoupling algorithm, thereby eliminating mechanical coupling and realizing independent control of two degrees of freedom.

[0089] The servo execution layer calculates the first target turning angle. Second target turning angle As a control command, it is input into the closed-loop control algorithm of the driver. The driver drives the first drive source 2 and the second drive source 3 to accurately track their respective target positions based on the angle signals fed back in real time by the first magnetic encoder module 15 and the second magnetic encoder module 16 connected to the first drive source 2 and the second drive source 3.

[0090] More specifically, in this embodiment of the invention, in the servo execution layer, FOC (field-oriented control) or PID (proportional-integral-derivative control) algorithms are preferably used for decoupling analysis.

[0091] Among them, the FOC algorithm is suitable for permanent magnet synchronous motors and can achieve high-precision torque and speed control; the PID algorithm has the advantages of simple structure and fast response, and is suitable for position control scenarios with high control accuracy requirements. Regardless of the algorithm used, the first drive source 2 and the second drive source 3 remain enabled during the motion process, thereby ensuring the continuity and stability of control.

[0092] In a preferred embodiment of the present invention, step S2 includes: Step S21: Calculate the second target rotation angle of the second drive source 3 based on the first target output angle. The specific calculation formula is as follows: , in, The transmission ratio from the second drive source 3 to the rotating bracket 5; Step S22: Calculate the first target rotation angle of the first drive source 2 based on the second target output angle and the second target rotation angle. The specific calculation formula is as follows: ,

[0093] in, As a self-rotating term, For decoupling compensation, The transmission ratio from the first drive source 2 to the end output shaft 6 is given. The ratio of the number of teeth of the fourth gear 12 to the number of teeth of the third gear 11.

[0094] Specifically, since the joint module in this invention adopts a coaxial differential transmission structure, the second drive source 3 drives the rotating bracket 5 to achieve revolution, and the first drive source 2 drives the third gear 11 (equivalent to the sun gear) through the central transmission shaft 4 to achieve rotation input. According to the kinematic principle of planetary gear systems, the actual rotation of the end output shaft 6 is not determined solely by the input of the first drive source 2, but is jointly determined by the input of the first drive source 2 and the revolution of the rotating bracket 5. When the rotating bracket 5 rotates around the axis of the central transmission shaft 4, even if the first drive source 2 remains stationary, the fourth gear 12 (equivalent to a planet gear) will generate additional rotation due to the revolution.

[0095] Therefore, in order to solve the inherent mechanical coupling problem of the coaxial differential transmission structure and achieve precise independent control of the revolution and rotation of the end output shaft 6, this embodiment of the invention employs a decoupling control method based on a kinematic model to calculate the target rotation angle of the drive source. This decoupling control method establishes a positive coupling relationship between the actual angle of the drive source and the actual angle of the end, and then calculates inversely the target rotation angles of each drive source required to achieve the target output angle. The specific derivation process is as follows: First, since the revolution motion is controlled independently by the second transmission chain and has no coupling terms, there is a definite proportional relationship between the revolution angle of the rotating support 5 and the rotation angle of the second drive source 3, i.e. .

[0096] Based on this, by transforming the above relationship, we can obtain the formula for calculating the target turning angle of the second driving source 3: ,in, , which represents the total reduction ratio from the second drive source 3 to the end rotating bracket 5 in the second transmission chain.

[0097] Next, according to the kinematic principle of planetary gear systems, the rotation angle of the end output shaft 6 is determined by the input of the first drive source 2 and the revolution motion of the rotating support 5, and its positive coupling relationship can be expressed as: .

[0098] Wherein, assuming the rotating bracket 5 is fixed, , This represents the total reduction ratio from the first drive source 2 to the end output shaft 6 in the first transmission chain.

[0099] , The number of teeth on the fourth gear, number 12. The number of teeth on the third gear 11. This indicates the ratio of the number of teeth of the fourth gear 12 to the number of teeth of the third gear 11.

[0100] Specifically, the sign in the formula depends on the installation and definition directions of the fourth gear 12 and the third gear 11. According to common differential structures, it is usually expressed as addition or subtraction.

[0101] In this model, taking cumulative coupling as an example, the revolution increases the positive rotation angle, so a positive sign is used.

[0102] Based on this, substituting the target rotation angle calculation formula of the first driving source 2 into the forward coupling equation and transforming it, we can obtain the target rotation angle calculation formula of the first driving source 2: ,

[0103] in, The rotation drive required to drive the end output shaft 6 to rotate. This is a decoupling compensation term used to counteract the coupling effect of the revolution on the rotation.

[0104] Then, using the above calculation formula, the desired end-effector output angle is calculated in real time. and Converted into the target turning angle of the first drive source 2 and the second drive source 3 and The data is then input to the servo execution layer for tracking and control.

[0105] Furthermore, in specific control strategies: When the command requires the joint to only perform revolution (i.e.) When (remaining unchanged), the second driving source 3 follows The rotating drive bracket 5 rotates; simultaneously, the first drive source 2 automatically rotates in the opposite direction by a specific compensation angle. This completely cancels out the rotation of the fourth gear 12 relative to the rotating support 5, thus achieving "electronic decoupling," which manifests as the "pure revolution" motion of the end output shaft 6.

[0106] When the command requires the joint to perform a compound movement, the first drive source 2 outputs the superimposed rotation drive term and decoupling compensation term, that is, according to... It rotates, thus achieving a precise combined motion of revolution and rotation.

[0107] As a preferred embodiment of the present invention, taking the application of the humanoid robot shoulder joint as an example, the single-sided driven dual-degree-of-freedom robot joint module of the present invention is installed in the internal structure of the robot's thoracic cavity to drive the robot arm to achieve a compound movement of "pitch" and "upper arm abduction / internal rotation", thereby simulating the flexible posture of the human shoulder joint.

[0108] Specifically, in this embodiment of the invention, the joint module is integrated inside the robot's thoracic cavity, and the installation process is as follows: The main body of the joint module (including the first drive source 2, the second drive source 3 and the base assembly 1) is fixed to the metal skeleton inside the robot's chest cavity through the whole machine mounting structure 104.

[0109] The overall installation structure 104 consists of two symmetrically arranged hollow cylindrical structures with threaded holes inside. Screws and other fasteners are passed through these threaded holes and screwed into the corresponding threaded holes of the thoracic skeleton, thereby achieving a rigid connection between the module and the robot.

[0110] This installation method concentrates all the drive sources inside the chest cavity, so that there is no need to accommodate the motor at the shoulder joint node, only the drive shaft and gear structure are retained, thereby greatly reducing the size of the shoulder.

[0111] More specifically, in this embodiment of the invention, the end output shaft 6 of the module is integrated with the shoulder joint ball head and upper arm structure or fixedly connected by means of flanges, etc., to ensure the reliability of power transmission and the integrity of the structure.

[0112] The end output shaft 6 serves as the power output end of the entire joint module. Its revolution around the central transmission shaft 4 drives the boom to swing back and forth, and its rotation around its own axis drives the boom to extend outward or rotate inward.

[0113] Through the above installation and connection method, this invention achieves a separate layout of the drive source and the execution end, placing all drive units inside the robot's chest cavity, while retaining only a lightweight transmission structure at the shoulder joint. Its working principle is explained below with specific actions: 1. Implementation of Pitch: When the robot needs to perform a lifting or swinging motion, the control system determines the desired revolution angle. Calculate the target rotation angle of the second drive source 3 After the second drive source 3 is started, its second drive output shaft 301 drives the fifth gear 13 to rotate, and the fifth gear 13 drives the sixth gear 14 that meshes with it to rotate, thereby causing the rotating bracket 5 to rotate around the axis (X-axis) of the central transmission shaft 4.

[0114] Since the end output shaft 6 is mounted on the rotating bracket 5 via the bearing 7, the rotation of the rotating bracket 5 directly drives the end output shaft 6 and the upper arm structure fixedly connected to it to revolve around the axis of the central drive shaft 4, thereby realizing the back-and-forth swing of the arm.

[0115] During this process, the control system simultaneously controls the first drive source 2 according to the decoupling compensation term. The arm rotates in the opposite direction to counteract the coupling effect of the revolution on the rotation of the end output shaft 6, ensuring that the boom does not rotate unexpectedly during the swinging process.

[0116] 2. Implementation of outward swing / rotation (Roll): When the robot needs to perform an arm abduction or internal rotation movement, the control system determines the desired rotation angle. Calculate the target rotation angle of the first drive source 2 After the first drive source 2 is started, its first drive output shaft 201 drives the first gear 9 to rotate. The first gear 9 drives the second gear 10 and the central drive shaft 4 to rotate. The central drive shaft 4 drives the third gear 11 at its end to rotate. The third gear 11 drives the fourth gear 12, which meshes with it orthogonally, to rotate. This causes the end output shaft 6 to rotate around its own axis (Y-axis), realizing the abduction or inward rotation of the arm. If there is a need for revolution at the same time, it is controlled according to the compound motion mode.

[0117] 3. Realization of complex actions: When the robot needs to perform a complex humanoid action such as waving and raising its hand simultaneously, the control system determines the desired revolution angle. and rotation angle Simultaneously, the target rotation angles of the first drive source 2 and the second drive source 3 are calculated. The second drive source 3 is calculated according to... The rotating support rotates 5 revolutions to achieve the arm-raising action; the first drive source 2, according to... The arm rotates. Through this decoupled control algorithm, the two drive sources work together, enabling the arm to simultaneously complete the waving motion while raising its hand, without interfering with each other, thus achieving a highly anthropomorphic composite motion.

[0118] In summary, the present invention provides a single-sided driven dual-degree-of-freedom robot joint module and its control method, which effectively solves the technical problems of bulky joint volume, large end-effector inertia, complex wiring and motion coupling in traditional serial drive methods by centrally arranging two drive motors at the proximal end of the joint and combining a coaxial composite transmission mechanism with an active decoupling control algorithm.

[0119] Compared with the prior art, the present invention has the following significant effects: Significantly reducing joint volume and achieving a compact structure, this invention breaks the limitation of traditional serial joints requiring motors to be placed on both sides of the joint. By moving both motors to the proximal end, the distal end of the joint retains only lightweight transmission components such as the central drive shaft 4, the rotating support 5, and the end output shaft 6. This design drastically reduces the size of the joint node, eliminating the motor structure at the distal end of the joint. It is perfectly suited for applications with extremely high aesthetic requirements, such as bionic robots and micro-robotic arms, achieving a truly "slim joint."

[0120] Reducing end-effector inertia and improving dynamic performance. This invention employs a "rear-mounted motor" design, concentrating all drive sources on one side of the base assembly 1, significantly reducing the rotational inertia of the moving limb. Under the same driving torque, the robot can achieve higher acceleration and faster start-stop response, significantly improving dynamic performance. Simultaneously, due to the reduced end-effector inertia, overshoot and jitter during high-speed movement are effectively reduced, lowering system energy consumption and enabling the robot to complete complex movements with higher precision and stability.

[0121] Eliminating cross-joint wiring improves reliability and lifespan. Since both motors are fixed to base assembly 1 and have no relative movement to stationary components, power and signal cables do not need to pass through the rotating bracket 5. This fundamentally eliminates the risk of fatigue fracture caused by repeated twisting of the cables with the joint, and also removes the physical limitations imposed by cable stress on the joint's rotation angle, allowing the joint to achieve a wider range of interference-free movement. Furthermore, with the motors located on the non-moving side, the operating environment is more stable, avoiding damage from movement shocks and vibrations, further extending the motors' lifespan.

[0122] Precise motion control. This invention eliminates the inherent motion coupling problem of coaxial differential structures by establishing a precise kinematic coupling model and implementing an active decoupling control algorithm. The control system can convert the target angle of the end-effector 6 into the target rotation angle of the motor in real time, and drive the motor to accurately track the target position through FOC or PID algorithms. Whether performing pure revolution, pure rotation, or compound motion, it can achieve independent control of two degrees of freedom, making joint control as simple and precise as independent joints, meeting the high-precision control requirements of biomimetic robots for complex humanoid movements.

[0123] The above description is merely a preferred embodiment of the present invention and does not limit the implementation and protection scope of the present invention. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. A single-sided driven dual-degree-of-freedom robot joint module, characterized in that, include: A base assembly (1) having a first side and a second side disposed opposite to each other; The driving unit includes a first driving source (2) and a second driving source (3), both of which are fixedly installed on the first side of the base assembly (1). A coaxial composite transmission mechanism, comprising a central transmission shaft (4), a rotating bracket (5), and an end output shaft (6), wherein the first end of the central transmission shaft (4) is rotatably mounted on the second side of the base assembly (1), the rotating bracket (5) is rotatably sleeved on the second end of the central transmission shaft (4) and rotatably connected to the base assembly (1) through a bearing (7), and the end output shaft (6) is rotatably mounted on the rotating bracket (5) and is spatially perpendicular to the central transmission shaft (4); The first drive source (2) is connected to the central drive shaft (4) via a first transmission chain, and is used to drive the end output shaft (6) to rotate around its own axis in the first degree of freedom; The second drive source (3) is connected to the rotating bracket (5) via the second transmission chain, and is used to drive the rotating bracket (5) together with the end output shaft (6) to rotate around the axis of the central transmission shaft (4) in the second degree of freedom.

2. The single-sided driven dual-degree-of-freedom robot joint module according to claim 1, characterized in that, The second side of the base assembly (1) is a recessed cavity (107) formed away from the first side. The cavity (107) is provided with a main bearing seat (101) and a first drive source positioning bushing (102) extending away from the base assembly (1). The bottom of the cavity (107) is provided with a second drive source positioning shaft hole (103), a first mounting hole (105) and a second mounting hole (106). The first end of the first drive source (2) is provided with a first drive output shaft (201) and a third mounting hole (203). The first end of the second drive source (3) is provided with a second drive output shaft (301) and a fourth mounting hole (303). During assembly, the first drive source (2) passes through the first drive source positioning bushing (102) via the first drive output shaft (201), and passes through the first mounting hole (105) and the third mounting hole (203) in sequence via a fastener, so as to fix the first drive source (2) to the base assembly (1); The second drive source (3) passes through the second drive output shaft (301) through the second drive source positioning shaft hole (103), and then passes through the second mounting hole (106) and the fourth mounting hole (303) in sequence by a fastener to fix the second drive source (3) to the base assembly (1); The first end of the central drive shaft (4) is rotatably mounted on the main bearing housing (101).

3. A single-sided driven dual-degree-of-freedom robot joint module according to claim 2, characterized in that, The first transmission chain includes: The first gear (9) is fixedly connected to the first drive output shaft (201) and located on the first drive source positioning bushing (102); The second gear (10) is fixedly connected to the central drive shaft (4) and located on the main bearing seat (101). The second gear (10) meshes with the first gear (9). The third gear (11) is fixedly connected to the central drive shaft (4) and located above the second gear (10); The fourth gear (12) is fixedly connected to the end output shaft (6) and is orthogonal to the third gear (11); The first transmission chain is a self-rotating drive chain.

4. A single-sided driven dual-degree-of-freedom robot joint module according to claim 2, characterized in that, The second transmission chain includes: The fifth gear (13) is fixedly connected to the second drive output shaft (301); The sixth gear (14) is integrally formed on the inner circumferential surface of the rotating bracket (5) and meshes with the fifth gear (13); The second transmission chain is a revolution drive chain.

5. A single-sided driven dual-degree-of-freedom robot joint module according to claim 2, characterized in that, The bearing (7) is disposed in the receiving cavity (107) of the base assembly (1), the inner ring of the bearing (7) is fixedly connected to the outer side of the rotating bracket (5), and the outer ring of the bearing (7) is fixedly connected to the inner side of the receiving cavity (107).

6. A single-sided driven dual-degree-of-freedom robot joint module according to claim 1, characterized in that, The first side of the base assembly (1) is a planar mounting surface, and a whole machine mounting structure (104) is provided on the planar mounting surface. The whole machine mounting structure (104) extends in a direction away from the base assembly (1) and is used to mount the joint module on the robot.

7. A single-sided driven dual-degree-of-freedom robot joint module according to claim 1, characterized in that, Also includes: The first magnetic encoder module (15) is fixedly installed at the second end of the first drive source (2) and is used to detect the rotation angle of the first drive source (2); The second magnetic encoder module (16) is fixedly installed at the second end of the second drive source (3) and is used to detect the rotation angle of the second drive source (3).

8. A method for controlling a joint module of a two-degree-of-freedom robot with single-sided drive, characterized in that, An application to a single-sided driven, two-degree-of-freedom robot joint module as described in any one of claims 1-7, comprising: Step S1: Generate the target output angle sequence of the end output axis (6) according to the task requirements; Step S2: Based on the preset kinematic coupling model, the target angle sequence is converted into the target rotation angle sequence of the first driving source (2) and the second driving source (3) in real time; Step S3: Using a closed-loop control algorithm, the first drive source (2) and the second drive source (3) are driven to rotate to the target position according to the target rotation angle sequence and the encoded feedback of the first drive source (2) and the second drive source (3).

9. A method for controlling a single-sided driven dual-degree-of-freedom robot joint module according to claim 8, characterized in that, In step S1, the specific formula for the target output angle sequence is as follows: ， in, Output an angle sequence for the target. The first target output angle is the rotation of the end output shaft (6) about the axis of the central drive shaft (4). The second target output angle is the rotation of the end output shaft (6) around its own axis; In step S2, the specific formula for the target turning angle sequence is as follows: ， in, The target turning sequence, The first target turning angle is the first driving source (2). The second target rotation angle is the second driving source (3).

10. A method for controlling a single-sided driven dual-degree-of-freedom robot joint module according to claim 9, characterized in that, Step S2 includes: Step S21: Calculate the second target rotation angle of the second drive source (3) based on the first target output angle. The specific calculation formula is as follows: ， in, The transmission ratio from the second drive source (3) to the rotating bracket (5); Step S22: Calculate the first target rotation angle of the first drive source (2) based on the second target output angle and the second target rotation angle. The specific calculation formula is as follows: ， ， in, As a self-rotating term, For decoupling compensation, The transmission ratio from the first drive source (2) to the end output shaft (6) is... The ratio of the number of teeth of the fourth gear (12) to the number of teeth of the third gear (11).

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