Control stay wire structure based on tendon driving robot

Abstract

A control wire pulling structure based on a tendon driving robot comprises a rotary driving device, a transmission wire driving structure, a first transmission wire coil and a second transmission wire coil, the rotary driving device is in transmission connection with the first transmission wire coil, and the transmission wire driving structure is arranged between the first transmission wire coil and the second transmission wire coil in a sleeving mode to form a tightened loop structure. And the transmission wire driving structure between the first transmission wire coil and the second transmission wire coil is arranged in a crossed wire drawing manner. The robot limb is exquisite in structure, the miniaturization of the robot limb is more thorough, installation is easy, control coupling interference can be avoided, and power transmission is stable enough.

Description

Technical Field

[0001] This utility model relates to the technical field of robots, specifically to a control cable structure for a tendon-driven robot. Background Technology

[0002] In the field of humanoid robot research and development and manufacturing, the joint drive of robots has always been a key technology that restricts the development of robots. The current mainstream solution is to form a joint drive by a motor and a reducer (planetary reducer, cycloidal reducer and harmonic reducer), also known as a joint module. Then, joint modules of different sizes are connected in series as needed to form a robotic arm, robot arm or leg of a legged robot, etc. The biggest advantage of this technical solution is modular design and convenient maintenance, but it cannot achieve remote drive, resulting in a large end rotational inertia.

[0003] One technology uses biomimetic techniques to achieve remote actuation through contraction, such as in linear joint modules. These modules utilize a combination of a motor and a lead screw, along with a linkage mechanism, to achieve joint oscillation, thus reducing rotational inertia. Currently, the best way to reduce rotational inertia is to place the motor and reducer at the base and then drive other rotary joints via a remote transmission scheme. Remote transmission schemes include belt drives, synchronous belt drives, reel drives, and rope drives. However, belt drives and reel drives suffer from drawbacks such as large size, low torque transmission, and insufficient rigidity. Reel drives have lower transmission accuracy and more complex tensioning systems.

[0004] Cable-driven systems, similar to muscles or tendons, offer advantages such as high rigidity, small footprint, and the ability to achieve multi-stage coupling transmission. Cable-driven systems also have significant advantages in distal actuation. For example, because the heavy and bulky drive components are concentrated in the base of the end of the robotic hand or arm, rather than being distributed across various joints, the weight of each part of the joint is greatly reduced, making the joints and robotic arm itself more flexible and agile, while also reducing drive energy consumption.

[0005] In the prior art, patent document CN 221391059 U discloses a robot joint transmission mechanism and a robot, including a first support, a first motor, a first input end, a first transmission belt, and a first transmission reel; the first motor is disposed at the upper end of the first support, the first transmission reel is disposed at the lower end of the first support, the first input end includes a first input reel, the power output end of the first motor is connected to the first input reel, the outer diameter of the first input reel is in the range of 10mm-45mm, the first transmission belt includes a first chain and a first pull cable, the first chain is connected to the first input reel, and the first pull cable is wound around the first transmission reel. The above technical solution solves the problem of short cable life in existing rope transmission while ensuring miniaturization. However, in order to achieve a sufficiently large transmission torque, the outer diameter of the cable reel is usually larger than the width of the support. Therefore, the direct cable pulling method will cause the cable to be exposed at a considerable distance outside the support, which makes the miniaturization of the robot limbs incomplete. Moreover, the exposed cable is easily interfered with, and the cable needs to be wound on the cable reel to achieve a sufficiently stable power transmission. However, the cable winding on the cable reel will cause serious coupling interference at the joints and make installation difficult. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies, this invention proposes a control cable structure for tendon-driven robots that is ingeniously designed, enabling more thorough miniaturization of robot limbs, easier installation, avoids control coupling interference, and provides sufficiently stable power transmission.

[0007] The specific technical solution is as follows:

[0008] A control cable structure for a tendon-driven robot includes a rotary drive device, a transmission cable drive structure, a first transmission cable reel, and a second transmission cable reel. The rotary drive device is connected to the first transmission cable reel. The transmission cable drive structure is sleeved between the first and second transmission cable reels to form a taut loop structure, and the transmission cable drive structure between the first and second transmission cable reels is arranged with cross-cable cable pulls.

[0009] Preferably, the rotary drive device is a motor module.

[0010] Preferably, the output end of the rotary drive device is connected to a transmission wheel structure, and the transmission wire drive structure is sleeved between the transmission wheel structure, the first transmission wire, and the second transmission wire to form a taut loop structure. The second transmission wire is used to connect the driven control component.

[0011] Preferably, the transmission wheel structure is a sprocket or a synchronous belt pulley, and the transmission line drive structure includes a chain or synchronous belt and a first metal cable and a second metal cable connected to both ends of the chain or synchronous belt respectively. The chain or synchronous belt cooperates with the sprocket or synchronous belt pulley, and the first metal cable and the second metal cable are respectively driven by the first transmission line reel and then cross-tensioned and sleeved on the second transmission line reel.

[0012] Preferably, the outer diameter of the transmission wheel structure is in the range of 10mm-45mm, the outer diameter of the first transmission reel and the second transmission reel is in the range of 40mm-200mm, the outer diameter of the first transmission reel is larger than the outer diameter of the second transmission reel, and the diameter of the first metal cable and the second metal cable is not greater than 5mm.

[0013] Preferably, the system further includes a first support structure and a second support structure. The rotary drive device and the transmission wheel structure are mounted on the top of the first support structure. The bottom of the first support structure is rotatably connected to the top of the second support structure via a rotating shaft structure. The first transmission reel is rotatably mounted on the rotating shaft structure between the first support structure and the second support structure, and the second transmission reel is rotatably mounted on the bottom of the second support structure.

[0014] Preferably, the second support structure is provided with intersecting through holes at both ends for the first metal cable and the second metal cable to pass through.

[0015] Preferably, the first metal cable end is clamped to the transmission reel structure or the driven control component, and the second metal cable is fastened to the transmission reel structure or the driven control component by a tension adjustment structure.

[0016] Preferably, the tension adjustment structure includes an adjustment screw and a tightening adjustment nut structure. The tightening adjustment nut structure is sleeved on the adjustment screw, and the front end of the adjustment screw is connected to a second metal cable. A cable end holder is provided on the transmission cable reel structure or the driven control component, and the tightening adjustment nut structure is clamped on the cable end holder.

[0017] Preferably, the rear end of the adjusting screw is also provided with a limiting clamping cap structure, and a through hole is provided in the center of the adjusting screw. The lower end of the second metal cable passes through the through hole to the limiting clamping cap structure and is clamped. The upper end of the second metal cable is fixedly connected to the end of the chain structure through a crimp connector.

[0018] The beneficial effects of this utility model are as follows: the transmission line drive structure is provided with a first metal cable and a second metal cable that are respectively driven by the first transmission line reel and then cross-tightened and sleeved onto the second transmission line reel, which makes the robot's end effector more flexible and delicate, and can change the direction of the transmission torque between the first transmission line reel and the second transmission line reel, and the wrapping force of the first metal cable and the second metal cable crossing the line onto the second transmission line reel is more sufficient.

[0019] Furthermore, by forming a taut loop structure between the first and second drive wires through the drive wire structure, the robot avoids bearing impact transmission torque during motion control, eliminates the vacuum distance of transmission loosening, and prevents slippage of the steel cable pull structure on the drive wires. This results in high control stability and precision, extremely high flexibility and dexterity, avoids fatigue fracture, and extends service life. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0021] Figure 2 This is a schematic diagram of the transmission line drive structure in this utility model.

[0022] Figure 3 This is a schematic diagram of the tension adjustment structure in this utility model.

[0023] In the diagram: 1. Rotary drive device; 2. Transmission wire drive structure; 3. First transmission wire reel; 4. Second transmission wire reel; 5. Transmission wheel structure; 6. First support structure; 7. Second support structure; 8. Rotating shaft structure; 9. Tension adjustment structure.

[0024] Chain structure 21; First metal cable 22; Second metal cable 23; Crimp connector 24;

[0025] Adjusting screw 91; tightening adjusting nut structure 92; limiting clamping cap structure 93; pull wire end holder 94. Detailed Implementation

[0026] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the scope of protection of the present invention.

[0027] In the description of this utility model, it should be noted that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0028] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or a connection through an intermediate medium; or they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances. Example

[0029] like Figure 1 , Figure 2 and Figure 3 As shown: A control cable structure for a tendon-driven robot is provided, which includes a rotary drive device 1, a transmission cable drive structure 2, a first transmission cable reel 3 and a second transmission cable reel 4. The rotary drive device 1 is a motor module, and other rotary drive devices such as hydraulic motors or pneumatic motors can also be used.

[0030] The aforementioned rotary drive device 1 is connected to the first transmission reel 3. The transmission drive structure 2 is sleeved between the first transmission reel 3 and the second transmission reel 4 to form a taut loop structure, i.e., a closed loop. This closed loop is not a physical loop structure of the transmission drive structure 2, but a closed loop structure in terms of transmission relationship. That is, it includes the transmission drive structure 2 being a complete loop structure, and it also includes the two ends of the transmission drive structure 2 being connected to synchronously moving objects to form a closed loop of transmission relationship only. For example, the two ends of the transmission drive structure 2 are fixed to the first transmission reel 3 or the second transmission reel 4 or other synchronously moving bodies. The transmission drive structure 2 between the first transmission reel 3 and the second transmission reel 4 is arranged with cross-wires. This is used in the joint control part of the robot limb, making the miniaturization of the robot limb more thorough.

[0031] The output end of the aforementioned rotary drive device 1 is connected to a transmission wheel structure 5. The transmission wire drive structure 2 is sleeved between the transmission wheel structure 5, the first transmission wire 3 and the second transmission wire 4 to form a taut loop structure. The second transmission wire 4 is used to connect the driven control component.

[0032] The transmission wheel structure 5 is a sprocket, but it can also be other flexible and high-precision transmission structures such as a synchronous belt pulley. The transmission line drive structure 2 includes a chain structure 21 and a first metal cable 22 and a second metal cable 23 connected to both ends of the chain structure 21, or a synchronous belt and the first metal cable 22 and the second metal cable 23 connected to both ends of the synchronous belt. The chain structure 21 cooperates with the sprocket, or the synchronous belt cooperates with the synchronous belt pulley. The first metal cable 22 and the second metal cable 23 are respectively driven by the first transmission reel 3 and then cross-tensioned and sleeved on the second transmission reel 4, making the robot's end cap more flexible and delicate. It can also change the direction of the transmission torque between the first transmission reel 3 and the second transmission reel 4. Furthermore, the cross-tension of the first metal cable 22 and the second metal cable 23 on the second transmission reel 4 has a stronger wrapping force, so the cable does not need to be wrapped too much on the second output reel 6. Normal wrapping and covering are sufficient.

[0033] The outer diameter of the transmission wheel structure 5 ranges from 10mm to 45mm, the outer diameters of the first transmission reel 3 and the second transmission reel 4 range from 40mm to 200mm, and the outer diameter of the first transmission reel 3 is larger than the outer diameter of the second transmission reel 4. The diameters of the first metal cable 22 and the second metal cable 23 are not greater than 5mm. Because the ratio of the diameter of the reel to the diameter of the metal cable directly affects the service life of the metal cable, the diameter of the metal cable is optimally selected based on the outer diameter of the first transmission reel 3 and / or the second transmission reel 4 and the actual load-bearing requirements. Selecting steel wire (metal cable) less than 5mm in diameter can meet the load-bearing requirements of general robots, for example, a steel wire with a diameter of 2.5mm can withstand a tensile force of up to 3000 Newtons. Conversely, the lower limit of the outer diameter range of the transmission reel is indirectly determined based on the diameter of the metal cable with the lowest load-bearing capacity, and the upper limit of the outer diameter range of the transmission reel is determined based on the optimal overall appearance size range of the robot's leg. Therefore, the outer diameter of the transmission reel can be set to be larger than the sprocket of the transmission wheel structure 5. Under the condition that the load-bearing capacity of the metal cable is sufficient, the transmission reel with a larger outer diameter will not affect the service life of the metal cable. However, if the transmission wheel structure 5 with a smaller outer diameter also directly uses a reel and covers it with a metal cable, the service life of the metal cable will be greatly reduced.

[0034] Specifically, the transmission wheel connected to the power output end of a typical rotary drive device such as a motor module provides the source power for remote transmission. The target joint acts as the transmission reel, and the ratio of the diameter of the transmission wheel to the diameter of the transmission reel is the reduction ratio. The larger the reduction ratio, the greater the torque that can drive the target joint. However, due to the limitation that the diameter of the robot's transmission reel cannot be too large and the diameter of the transmission wheel cannot be too small, the reduction ratio of tendon-driven rope transmission is generally within 5, and its service life is also insufficient. In contrast, the reduction ratio of the aforementioned composite transmission drive structure can reach up to 20. The size of the transmission reel directly determines the shape and size of the rotary joint. Generally, in robotic applications, the length and width of this joint shape do not exceed 200mm. This ensures sufficient maneuverability while avoiding a bulky and unsightly joint.

[0035] Furthermore, the diameter of the transmission wheel is also limited by the lifespan of the wire rope. According to test and experimental data, the ratio of the spool diameter to the wire rope diameter must be greater than 25 to effectively guarantee the service life of the wire rope. Of course, the larger the ratio, the longer the service life of the wire rope will be. In the above scheme, the ratio of the spool diameter to the wire diameter is at least 30. Assuming a 2mm wire rope is used, the spool diameter must be at least 50mm. With a transmission wheel diameter of 50mm, based on the general maximum reduction ratio of 5, the transmission spool diameter would be 250mm. This is not conducive to the miniaturization and weight reduction of the robot, nor is it conducive to improving the robot's load-bearing capacity.

[0036] Therefore, the transmission wheel section uses a transmission sprocket or synchronous belt pulley and a corresponding chain or synchronous belt. The transmission sprocket or synchronous belt pulley can be made small enough to avoid fatigue fracture due to excessive bending at the transmission wheel, thus greatly improving the driving torque and significantly extending the overall service life of the drive wire drive structure. Compared to single chain drives and synchronous belt drives, this composite drive wire drive structure allows for easier and more precise transmission by simultaneously tightening both sides, avoiding slippage of the metal cable on the wheel and preventing impact-type transmission forces, thereby also improving service life.

[0037] Furthermore, it also includes a first support structure 6 and a second support structure 7. The rotary drive device 1 and the transmission wheel structure 5 are mounted on the top of the first support structure 6. The bottom of the first support structure 6 is rotatably connected to the top of the second support structure 7 via a rotating shaft structure 8. The first transmission reel 3 is rotatably mounted on the rotating shaft structure 8 between the first support structure 6 and the second support structure 7, and the second transmission reel 4 is rotatably mounted on the bottom of the second support structure 7. Intersecting through holes are also provided at both ends of the second support structure 7 for the first metal cable 22 and the second metal cable 23 to pass through.

[0038] The first metal cable 22 is clamped at the end of the transmission cable reel structure or the driven control component, and the second metal cable 23 is fastened to the transmission cable reel structure or the driven control component by the tension adjustment structure 9.

[0039] Specifically, the tension adjustment structure 9 includes an adjustment screw 91 and a tightening adjustment nut structure 92. The tightening adjustment nut structure 92 is sleeved on the adjustment screw 91, and the front end of the adjustment screw 91 is connected to the second metal cable 23. A cable end holder is provided on the transmission reel structure or the driven control component, and the tightening adjustment nut structure 92 is clamped on the cable end holder. A limit clamping cap structure 93 is also provided at the rear end of the adjustment screw 91. A through hole is provided in the center of the adjustment screw 91, and the lower end of the second metal cable 23 passes through the through hole to the limit clamping cap structure 93 and is clamped. The upper end of the second metal cable 23 is fixedly connected to the end of the chain structure 21 through a crimp connector 24, which makes it easier for later maintenance.

[0040] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims.

Claims

1. A control cable structure for a tendon-driven robot, characterized in that: It includes a rotary drive device, a transmission wire drive structure, a first transmission wire reel, and a second transmission wire reel. The rotary drive device is connected to the first transmission wire reel. The transmission wire drive structure is sleeved between the first transmission wire reel and the second transmission wire reel to form a taut loop structure. The transmission wire drive structure between the first transmission wire reel and the second transmission wire reel is arranged with cross-pull wires.

2. The control cable structure for a tendon-driven robot according to claim 1, characterized in that: The rotary drive device is a motor module.

3. The control cable structure for a tendon-driven robot according to claim 1 or 2, characterized in that: The output end of the rotary drive device is connected to a transmission wheel structure. The transmission wire drive structure is sleeved between the transmission wheel structure, the first transmission wire disc, and the second transmission wire disc to form a taut loop structure. The second transmission wire disc is used to connect the driven control component.

4. The control cable structure for a tendon-driven robot according to claim 3, characterized in that: The transmission wheel structure is a sprocket or a synchronous belt pulley. The transmission line drive structure includes a chain or a synchronous belt and a first metal cable and a second metal cable connected to both ends of the chain or synchronous belt. The chain or synchronous belt cooperates with the sprocket or synchronous belt pulley. The first metal cable and the second metal cable are respectively driven by the first transmission line reel and then cross-tensioned and sleeved onto the second transmission line reel.

5. The control cable structure for a tendon-driven robot according to claim 4, characterized in that: The outer diameter of the transmission wheel structure ranges from 10mm to 45mm, the outer diameter of the first transmission reel and the second transmission reel ranges from 40mm to 200mm, and the outer diameter of the first transmission reel is larger than that of the second transmission reel. The diameters of the first metal cable and the second metal cable are not greater than 5mm.

6. The control wire structure for a tendon-driven robot according to claim 4 or 5, characterized in that: It also includes a first support structure and a second support structure. The rotary drive device and the transmission wheel structure are installed on the top of the first support structure. The bottom of the first support structure is rotatably connected to the top of the second support structure through a rotating shaft structure. The first transmission wheel is rotatably installed on the rotating shaft structure between the first support structure and the second support structure. The second transmission wheel is rotatably installed on the bottom of the second support structure.

7. The control cable structure for a tendon-driven robot according to claim 6, characterized in that: The second support structure also has intersecting through holes at both ends for the first metal cable and the second metal cable to pass through.

8. The control cable structure for a tendon-driven robot according to any one of claims 4, 5, or 7, characterized in that: The first metal cable end is clamped onto the transmission reel structure or the driven control component, and the second metal cable is securely mounted onto the transmission reel structure or the driven control component via a tension adjustment structure.

9. The control cable structure for a tendon-driven robot according to claim 8, characterized in that: The tension adjustment structure includes an adjustment screw and a tightening adjustment nut structure. The tightening adjustment nut structure is sleeved on the adjustment screw, and the front end of the adjustment screw is connected to a second metal cable. A cable end holder is provided on the transmission cable reel structure or the driven control component, and the tightening adjustment nut structure is clamped on the cable end holder.

10. The control wire structure for a tendon-driven robot according to claim 9, characterized in that: The rear end of the adjusting screw is also provided with a limiting clamping cap structure. A through hole is provided in the center of the adjusting screw. The lower end of the second metal cable passes through the through hole to the limiting clamping cap structure and is clamped. The upper end of the second metal cable is fixedly connected to the end of the chain structure through a crimp connector.

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