Robot joint transmission assembly based on tendon-imitating driving

Abstract

A robot joint transmission assembly based on tendon imitation driving comprises at least one rotary driving device and at least one support structure, the rotary driving device is arranged at one end of the support structure, and an output wire coil structure is rotationally installed at the other end of the support structure and used for being connected with a driven control piece. A transmission wheel disc structure is arranged at the output end of the rotary driving device, a transmission line driving structure is arranged between the output wire coil structure and the transmission wheel disc structure in a sleeving mode, and the transmission line driving structure forms a tightened loop structure between the output wire coil structure and the transmission wheel disc structure. The utility model has the advantages of extremely high flexibility and elaborate, high control stability and accuracy, and capability of avoiding fatigue fracture and prolonging the service life.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of humanoid robots, and particularly relates to a robot joint transmission assembly based on tendon simulation driving. BACKGROUND

[0002] In the field of humanoid robot research and development, the joint driving of robots has been a key technology restricting the development of robots. The current mainstream solution is to form a joint driving by a motor and a reducer (planetary reducer, cycloid reducer and harmonic reducer), which is also called a joint module. Then, joint modules of different sizes are connected in series according to needs to form a mechanical arm, a robot arm or a foot-type robot leg, etc. The biggest advantage of this technical solution is modular design and convenient maintenance, but it cannot achieve remote driving, resulting in large end rotation inertia.

[0003] One technology is to achieve remote driving through contraction and other bionics technologies. For example, a linear joint module, through the combination of a motor and a screw rod, achieves the swinging of a joint through a linkage mechanism, which can reduce the rotational inertia. The best way to reduce the rotational inertia at present is to place the motor and the reducer at the base, and then drive other rotating joints through a remote transmission scheme. The remote transmission scheme includes belt transmission, synchronous belt transmission, wire reel transmission and rope transmission. Due to the relatively large size of the belt and the transmission, the belt transmission has the disadvantages of low torque transmission and insufficient transmission stiffness. The wire reel transmission has the disadvantages of low transmission accuracy and complex wire reel system tensioning.

[0004] Rope driving (Cable-Driven) is similar to muscle and also known as tendon driving, which has the advantages of high stiffness, small space occupation, multi-stage coupling transmission, etc. The rope driving system also has significant advantages in remote driving. For example, the heavy and bulky driving device is installed in the base at the end of the robot hand or arm, rather than being dispersed on each movement joint, which greatly reduces the weight of each part of the movement joint, making the joint and the robot arm itself more flexible and agile, and the driving energy consumption is lower.

[0005] In the prior art, the patent document with the publication number CN 110420107 A discloses a rope-driven three-degree-of-freedom training robot, which comprises an active and passive hybrid driving system and a robot body. The robot body comprises a forearm outer ring, a forearm inner ring and a hand ring. The forearm outer ring is fixed to the support, and the forearm inner ring is nested in the forearm outer ring. A driving rope is arranged on the hand ring, and the other end of the driving rope is fixed to the extension arm of the forearm inner ring. Then, the driving rope is connected to the magnetorheological output module on the active and passive hybrid driving system along the Bowden wire. The active and passive hybrid driving system comprises a magnetorheological output module, a transmission module and a first DC motor. The first DC motor drives the magnetorheological output module to rotate through the transmission module. The rotation of the magnetorheological output module causes the driving rope connected thereto to generate tension. The tension of the driving rope is transmitted to the hand ring through the extension arm along the corresponding Bowden wire, thereby controlling the hand ring to make corresponding movements. The outer periphery of the forearm outer ring is also provided with a driving rope through the Bowden wire. The other end of the driving rope is connected to the winding shaft driven by the second DC motor. The rotation of the second DC motor driving the winding shaft causes the driving rope wound on the winding shaft to stretch and contract, thereby controlling the relative rotation between the forearm inner ring and the forearm outer ring. The above technical solution controls the arm joint by stretching and contracting the driving rope to generate tension. Although it has the flexibility and delicacy of tendon driving, the driving rope is frequently and suddenly stressed during driving, which can cause fatigue and low service life of the rope. Moreover, the control stability and precision are insufficient, and it is difficult to meet the requirements of robot motion control for delicate work. SUMMARY

[0006] The utility model makes up for the deficiency of prior art, proposes a kind of robot joint transmission assembly based on imitation tendon driving with very high flexibility and delicacy, control stability and precision are high, and fatigue fracture can be avoided, prolong the service life.

[0007] The specific technical scheme is as follows:

[0008] A robot joint transmission assembly based on imitation tendon driving, comprising at least one rotating drive device and at least one support structure. The rotating drive device is arranged at one end of the support structure. An output wire disc structure is rotatably installed at the other end of the support structure for connecting a driven control member. A transmission wheel disc structure is arranged at the output end of the rotating drive device. A transmission wire drive structure is sleeved between the output wire disc structure and the transmission wheel disc structure, and forms a taut loop structure between the output wire disc structure and the transmission wheel disc structure.

[0009] As preferred: the transmission line driving structure comprises a bending-resistant chain transmission structure or a flexible line driving structure, which is matched with the transmission wheel disc structure, and a cable structure is connected to both ends of the bending-resistant chain transmission structure or the flexible line driving structure, and the cable structure is matched with the output line disc structure.

[0010] As preferred: the transmission wheel disc structure is a chain wheel or a synchronous belt wheel, the transmission line driving structure comprises a chain or a synchronous belt and metal cables connected to both ends of the chain or the synchronous belt, the chain or the synchronous belt is matched with the chain wheel or the synchronous belt wheel, and the other ends of the two metal cables are fastened on the output line disc structure and / or the driven control member, wherein at least one metal cable is fastened on the output line disc structure and / or the driven control member through the tight adjustment structure.

[0011] As preferred: the rotary driving device is a motor module.

[0012] As preferred: the outer diameter of the transmission wheel disc structure ranges from 10 mm to 45 mm, the outer diameter of the output line disc structure ranges from 40 mm to 200 mm, and the diameter of the metal cable is less than or equal to 5 mm.

[0013] As preferred: the tight adjustment structure comprises an adjusting screw and a tight adjustment nut structure, the tight adjustment nut structure is sleeved on the adjusting screw, the front end of the adjusting screw is connected with the metal cable, a cable end cap seat is arranged on the output line disc structure and / or the driven control member, and the tight adjustment nut structure is clamped on the cable end cap seat.

[0014] As preferred: the rear end of the adjusting screw is further provided with a limiting and pressing cap structure, a through hole is arranged in the center of the adjusting screw, and the metal cable is pressed at the limiting and pressing cap structure through the through hole.

[0015] As preferred: the ends of the metal cable are fixedly connected to both ends of the chain structure through crimping joints.

[0016] The utility model discloses the beneficial effects are: through the transmission line driving structure between the output line disc structure and the transmission wheel disc structure forms the loop state of being tight, avoids the bearing impact transmission torque in the motion control process, does not have the vacuum distance of transmission slack, and avoids the steel cable cable structure of transmission line driving structure to appear the skidding phenomenon on the line disc, makes control stability and precision height, has very high flexibility and exquisite nature, can avoid producing fatigue fracture, prolongs the service life. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is the application schematic drawing of the whole utility model.

[0018] Figure 2 It is the installation structure schematic view of the first transmission line driving structure and the second transmission line driving structure in the utility model.

[0019] Figure 3 It is the transmission schematic view of the first transmission line driving structure and the second transmission line driving structure in the utility model.

[0020] Figure 4 It is the transmission schematic view of the second transmission line driving structure in the utility model.

[0021] Figure 5 It is the transmission schematic view of the first transmission line driving structure in the utility model.

[0022] Figure 6 It is the structure schematic view of the tightness adjusting structure in the utility model.

[0023] In the drawing: first rotary drive device 1;Second rotary drive device 2;First support 3;Second support 4;First output line disc 5;Second output line disc 6;First transmission line driving structure 7;Second transmission line driving structure 8;Tightness adjusting structure 9;Idler line disc 10;

[0024] First transmission wheel disc 101;Second transmission wheel disc 201;

[0025] Chain structure 81;First steel cable tensioning structure 82;Second steel cable tensioning structure 83;

[0026] Adjusting screw rod 91;Tight pressing adjusting nut structure 92;Limiting pressing cap structure 93. DETAILED DESCRIPTION

[0027] The preferred embodiments of the utility model are described in detail below in combination with the drawings, so that the advantages and characteristics of the utility model can be more easily understood by the person skilled in the art, and the protection scope of the utility model is more clearly and explicitly defined.

[0028] In the description of the utility model, it should be explained that the orientation or position relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is the orientation or position relationship shown based on the drawings, and is only for the convenience of describing the utility model and simplifying the description, and is not indicative or suggestive of the device or element indicated must have a particular orientation, and is constructed and operated in a particular orientation, so it cannot be understood as a limitation on the utility model.

[0029] It should be noted that, unless otherwise specified and limited, the terms "arranged", "mounted", "connected", "linked" should be understood in a broad sense, for example, can be fixedly connected, can be detachably connected, or integrally connected, can be directly connected, or connected through an intermediate medium, or can be connected internally between two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances. Embodiments

[0030] As Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 : a kind of robot joint transmission assembly based on tendon-driven, is provided with two rotating drive devices, two support structures and two output line disc structures, respectively first rotating drive device 1, second rotating drive device 2, first support 3, second support 4, first output line disc 5 and second output line disc 6, it is also available to be provided with one or more rotating drive devices, support structure and output line disc structure, its quantity depends on how many degrees of freedom required to drive.

[0031] The above-mentioned first rotating drive device 1 and second rotating drive device 2 are installed at the top of the first support 3, and the first rotating drive device 1 and the second rotating drive device 2 are motor modules, and other rotating drive devices such as hydraulic motor or pneumatic motor can also be used, but the rotating drive device is the motor module at present. First output line disc 5 and the top of second support 4 are rotatably installed at the bottom of first support 3 through the same rotating shaft structure, and the top of first output line disc 5 is fixedly connected with the top of second support 4, and the second support 4 is the first driven control member, and the second output line disc 6 is rotatably installed at the bottom of the second support 4, for connecting the second driven control member, which is applied to the corresponding foot plate structure of the robot leg, the second support 4 corresponding to the first driven control member is the calf structure, and the first support 3 is the thigh structure. If applied to the robot arm, the second driven control member, the second support 4 and the first support 3 correspond to the palm structure / forearm structure and the forearm structure respectively.

[0032] The first transmission wheel disc 101 and the second transmission wheel disc 201 are respectively arranged at the output ends of the first rotary driving device 1 and the second rotary driving device 2, the first transmission line driving structure 7 is sleeved between the first transmission wheel disc 101 and the first output line disc 5, the second transmission line driving structure 8 is sleeved between the second transmission wheel disc 201 and the second output line disc 6, and the idler line disc 10 is rotatably arranged at the bottom of the first support 3 or the top of the second support 4. The idler line disc 10 can be independently arranged, but preferably, the idler line disc 10 and the first output line disc 5 are rotatably arranged at the bottom of the first support 3 or the top of the second support 4 through the same rotating shaft structure, and the second transmission line driving structure 8 is tightly wound around the idler line disc 10 and the second output line disc 6. Similarly, the first transmission line driving structure 7 is tightly wound on the first transmission wheel disc 101 and forms a tight loop structure between the first transmission line driving structure 7 and the first output line disc 5, that is, a closed loop. This closed loop is not a physical transmission line driving structure in a loop structure, but a closed loop structure on the transmission relationship of the transmission line driving structure, that is, the transmission line driving structure is a complete loop structure, and the two ends of the transmission line driving structure disconnected are connected to the synchronous moving objects to form a closed loop in the transmission relationship. For example, the two ends of the transmission line driving structure are fixed on the first transmission line disc or the second transmission line disc or other synchronous moving objects, and the above transmission line driving structure is wound on the output line disc structure, which is not necessarily wound one turn, because the more the transmission line driving structure is wound on the output line disc structure, the more serious the coupling interference of the transmission line driving structure on the output line disc structure.

[0033] The first transmission disc 101 and the second transmission disc 201 are transmission chain wheels, and the first transmission disc 101 and the second transmission disc 201 are independently arranged side by side, that is, coaxially side by side but independently rotating, and do not affect each other. The second transmission line driving structure 8 is composed of a chain structure 81, a first steel cable tensioning structure 82 and a second steel cable tensioning structure 83. The first steel cable tensioning structure 82 and the second steel cable tensioning structure 83 can be replaced by other metal cables or high-load ropes. Similarly, the chain structure 81 can be replaced by a synchronous belt or other bending-resistant chain transmission structure or a flexible line driving structure. The transmission disc structure adopts a synchronous belt pulley structure matched therewith, for example, a pulley can also be used as long as the pulley is designed not to slip. One end of the first steel cable tensioning structure 82 and the second steel cable tensioning structure 83 is fixedly connected to the chain structure 81 at both ends thereof through a crimping joint 83, and the chain structure 81 is engaged with the transmission chain wheel. The first steel cable tensioning structure 82 and the second steel cable tensioning structure 83 are tightly wound around the idler pulley 10 and the second output pulley 6. The other end of the first steel cable tensioning structure 82 is provided with a tensioning end, and the tensioning end is provided with a tensioning end clamping hole on the side of the second output pulley 6. The tensioning end is clamped in the tensioning end clamping hole. The tensioning end can be clamped and fixed or welded on the driven control member, but it is easy to cause interference or breakage and is not easy to repair. The other end of the second steel cable tensioning structure 83 is provided with a tightness adjusting structure 9. The second steel cable tensioning structure 83 is tightly installed on the output pulley structure or the driven control member through the tightness adjusting structure 9.

[0034] The tightness adjusting structure 9 includes an adjusting screw 91 and a tightness adjusting nut structure 92. The tightness adjusting nut structure 92 is sleeved on the adjusting screw 91, and the front end of the adjusting screw 91 is connected with the steel cable tensioning structure. A tensioning end clamping seat is arranged on the output pulley structure and / or the driven control member, and the tightness adjusting nut structure 92 is clamped in the tensioning end clamping seat. A limiting and pressing cap structure 93 is arranged at the rear end of the adjusting screw 91. A through hole is arranged in the center of the adjusting screw 91, and the steel cable tensioning structure passes through the through hole to the limiting and pressing cap structure 93 and is pressed tightly. That is, the limiting and pressing cap structure 93 serves as a terminal limiting and a crimping joint. The steel cable tensioning structure can be directly welded at the front end of the adjusting screw 91, but the tensioning force and the maintenance after breakage will be limited.

[0035] Similarly, the first transmission line driving structure 7 and the second transmission line driving structure 8 are the same in structure, but the first transmission line driving structure 7 is a straight line transmission between the first transmission wheel disc 101 and the first output line disc 5, without the need for an idler line disc in the middle. When the transmission line driving structure involves flexible change of transmission direction, an idler line disc needs to be set to assist stable transmission direction change. Multiple transmission direction changes can also set multiple idler line discs. Of course, in the scene where only straight line driving force is needed, there is no need for an idler line disc, and only the first transmission line driving structure 7 can be set, and the second rotary driving device 2 can also be set as a straight line driving force to drive different components at the bottom of the first support 3 or different degrees of freedom of the same component.

[0036] The outer diameter of the transmission sprocket is 10-45 mm, i.e. the outer diameter of the first transmission wheel disc 101 and the second transmission wheel disc 201 is 10-45 mm, the outer diameter of the output line disc structure is 40-200 mm, i.e. the outer diameter of the first output line disc 5 and the second output line disc 6 is 40-200 mm, and the diameter of the steel cable structure is less than or equal to 5 mm. Because the ratio of the diameter of the line disc to the wire diameter of the steel cable structure directly affects the service life of the steel cable structure, the diameter of the steel cable structure is optimally selected according to the outer diameter of the output line disc and / or idler line disc and the actual load bearing requirement. According to different tension requirements, a steel wire (cable) with a diameter less than 5 mm can meet the load bearing requirement of a general robot, for example, a steel wire with a diameter of 2.5 mm can withstand a tension of 3000 Newtons. Conversely, the lower limit of the outer diameter of the output line disc structure is indirectly determined according to the diameter of the minimum load bearing capacity of the steel cable structure, and the upper limit of the outer diameter of the output line disc structure is determined according to the best overall appearance size range of the robot leg. Therefore, the output line disc structure can be set to be larger in diameter relative to the transmission sprocket. Under the condition that the wire diameter of the steel cable structure is sufficient, the larger output line disc structure will not affect the service life of the steel cable structure, and the smaller transmission wheel disc directly uses a line disc and a steel cable structure, which greatly reduces the service life of the steel cable structure.

[0037] Specific performance: the power output end of the general motor module and other rotary drive devices is connected to the transmission disc, which provides the source power for the far-end transmission, and the target joint is used as the output disc. The diameter ratio of the transmission disc and the output disc is the reduction ratio. The larger the reduction ratio is, the greater the torque of the target joint can be driven. However, due to the limitation of the diameter of the robot output disc, which cannot be too large, and the diameter of the transmission disc cannot be too small, the reduction ratio of the tendon-driven rope transmission is generally less than 5, and the service life is also insufficient. The above-mentioned composite transmission line drive structure scheme can reduce the ratio to 20. The size of the output disc directly determines the shape and size of the rotary joint. In general, the joint shape in the field of robots is not more than 200mm in length and width, which can avoid the joint being bloated and not beautiful while having enough control space.

[0038] In addition, the diameter of the transmission disc is also limited by the service life of the steel wire rope. According to the test and experimental data, the diameter ratio of the wire disc and the steel wire rope should be greater than 25 to effectively ensure the service life of the steel wire rope. Of course, the larger the ratio is, the better the service life of the steel wire rope can be ensured. The diameter ratio of the wire disc and the steel wire rope in the above-mentioned scheme is at least 30. Assuming that a 2mm steel wire rope is used, the wire disc should be at least 50mm in diameter. According to the general maximum reduction ratio of 5, the output disc diameter is 250mm. This is not conducive to the miniaturization and light weight of the robot, and is also not conducive to improving the carrying capacity of the robot.

[0039] Therefore, the transmission disc part adopts a transmission chain wheel or a synchronous belt wheel and corresponding chain or synchronous belt. The transmission chain wheel or synchronous belt wheel can be made small enough to avoid fatigue fracture due to excessive bending at the transmission disc, thereby greatly improving the driving torque and the service life of the entire transmission line drive structure. Compared with single chain transmission and synchronous belt transmission, this composite transmission line drive structure scheme is beneficial to the transmission line drive structure to be tightened on both sides at the same time, thereby making the transmission more accurate and avoiding the phenomenon of slipping on the wire disc. It also avoids the impact of transmission force, thereby improving the service life.

[0040] The outer diameter of the second transmission wheel disc 201 and the outer diameter of the second output wire disc 6 are both smaller than the outer diameter of the idler wire disc 10, so as to facilitate the increase of the transmission ratio and the torque, and the end joint can be made more exquisite and light, the first steel cable tensioning structure 82 and the second steel cable tensioning structure 83 are crossed and tensioned between the idler wire disc 10 and the second output wire disc 6, and the wire holes are arranged at both ends of the second support 4, which are crossed and penetrated, and the first steel cable tensioning structure 82 and the second steel cable tensioning structure 83 are crossed and penetrated, so that the whole is more flexible and exquisite, and the wire disc transmission torque direction can be changed. Since the outer diameter of the second output wire disc 6 is smaller than the outer diameter of the idler wire disc 10, the normal tensioning mode will cause insufficient wrapping force of the second output wire disc 6, and additional winding of the tensioning wire on the output wire disc will be required. However, the additional winding will cause coupling interference in the control process, the wrapping force of the first steel cable tensioning structure 82 and the second steel cable tensioning structure 83 on the second output wire disc 6 is sufficient, so that the tensioning wire on the second output wire disc 6 does not need to be wound again, and normal wrapping and winding can be achieved.

[0041] The above scheme forms a tight loop state between the output wire disc structure and the transmission wheel disc structure through the transmission wire driving structure, avoids bearing impact transmission torque in the motion control process, has no transmission slack vacuum distance, and avoids the sliding phenomenon of the steel cable tensioning structure of the transmission wire driving structure on the wire disc, so that the control stability and precision are high, and the flexibility and exquisite are very high, fatigue fracture can be avoided, and the service life is prolonged.

[0042] Although the embodiments of the utility model have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to these embodiments without departing from the principles and spirits of the utility model, and the scope of the utility model is limited by the appended claims.

Claims

1. A robot joint transmission assembly based on tendon-mimicking actuation, characterized by: The application relates to a rotary drive device, which comprises at least one rotary drive device arranged at one end of a support structure, an output wire disc structure rotatably arranged at the other end of the support structure and used for connecting a driven control member, a transmission wheel disc structure arranged at the output end of the rotary drive device, a transmission wire drive structure sleeved between the output wire disc structure and the transmission wheel disc structure and forming a taut loop structure between the output wire disc structure and the transmission wheel disc structure.

2. The tendon-mimicry based robotic joint transmission assembly according to claim 1, wherein: The transmission wire drive structure comprises a bending-resistant chain transmission structure or a flexible wire drive structure matched with the transmission wheel disc structure, and a cable structure connected to both ends of the bending-resistant chain transmission structure or the flexible wire drive structure and matched with the output wire disc structure.

3. The tendon-mimicking actuation based robotic joint transmission assembly according to claim 1 or 2, characterized in that: The transmission wheel disc structure is a chain wheel or a synchronous belt wheel, the transmission wire drive structure comprises a chain or a synchronous belt and metal cables respectively connected to both ends of the chain or the synchronous belt, the chain or the synchronous belt is matched with the chain wheel or the synchronous belt wheel, and the other ends of the two metal cables are fastened to the output wire disc structure and / or the driven control member, wherein at least one metal cable is fastened to the output wire disc structure and / or the driven control member through a tautness adjusting structure.

4. The tendon-mimicking actuation based robotic joint transmission assembly according to claim 3, wherein: The rotary drive device is a motor module.

5. The tendon-mimicry based robotic joint transmission assembly according to claim 3, wherein: The outer diameter of the transmission wheel disc structure ranges from 10 mm to 45 mm, the outer diameter of the output wire disc structure ranges from 40 mm to 200 mm, and the diameter of the metal cable is less than or equal to 5 mm.

6. The tendon-mimicking actuation based robotic joint transmission assembly according to claim 4 or 5, characterized in that: The tautness adjusting structure comprises an adjusting screw and a compression adjusting nut structure, the compression adjusting nut structure is sleeved on the adjusting screw, the front end of the adjusting screw is connected with the metal cable, a cable end head clamping base is arranged on the output wire disc structure and / or the driven control member, and the compression adjusting nut structure is clamped on the cable end head clamping base.

7. The tendon-mimicry based robotic joint transmission assembly according to claim 6, wherein: The rear end of the adjusting screw is further provided with a limiting compression cap structure, a through hole is arranged in the center of the adjusting screw, and the metal cable is compressed at the limiting compression cap structure through the through hole.

8. A tendon-mimicking driven robotic joint transmission assembly according to any one of claims 4, 5 or 7, characterized in that: The ends of the metal cables are respectively fixedly connected to both ends of the chain structure through compression joints.

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