An underactuated manipulator with hybrid transmission mechanism

Abstract

The application discloses a kind of hybrid transmission mechanism's underactuated manipulator, including palm module, four identical finger module and independent thumb module, finger module and thumb module are installed in palm module;The side swing joint of finger module adopts bevel gear differential structure, cooperates the coupling movement knuckle structure driven by underactuated tendon, realizes the compound motion of side swing and flexion, while finger module, thumb module and palm module are arranged tactile sensor module;The application realizes few motor drive multiple degrees of freedom by hybrid transmission mechanism, reduces control difficulty, modular design improves assembly and maintenance efficiency, tendon transmission saves internal space, and high coverage rate tactile sensor realizes the accurate detection of holding state, and is suitable for end operation scene of humanoid robot.

Description

Technical Field

[0001] This invention relates to the field of robot end effector technology, and more specifically, to an underactuated manipulator with a hybrid transmission mechanism. Background Technology

[0002] The thumb, a core module for precise grasping and complex manipulation, is a key component of a humanoid robot's manipulative capabilities. Its mechanical structure and drive system design directly determine whether the dexterous hand can perform highly free and dexterous actions such as pinching, gripping, lateral pinching, and twisting. In recent years, with the rapid advancement of humanoid robot research and development, the thumb module, due to its unique biomechanical characteristics and highly biomimetic design requirements, has become a core focus of technological breakthroughs in dexterous hands. Its structural integration, motion performance, innovative drive systems, and lightweight and miniaturized design are currently the core research areas in this field.

[0003] Current robotic thumb modules primarily focus on their unique degree-of-freedom configurations, with the core design goal of simulating the complex movements of the human thumb, including opposition, flexion, extension, adduction, and abduction. Mainstream design schemes can be categorized into fully actuated and underactuated approaches, exhibiting more significant technological differentiation in this specific module. Fully actuated thumb schemes typically aim to completely replicate the five degrees of freedom of the human thumb, configuring each joint with an independent micro-actuator or dedicated transmission mechanism. Their core advantage lies in achieving highly precise pose control and independent force feedback, enabling the completion of the most complex fingertip fine manipulations, such as precisely grasping tiny electronic components, operating precision tools, and twisting thin objects. However, the technical challenges of the all-drive solution are extremely severe: First, the high-density integration of multiple micro motors or transmission mechanisms within the limited anatomical space of the thumb places extreme demands on the power density, heat dissipation performance, and micro reducer design of the motors, making it prone to problems such as structural interference, poor heat dissipation, and excessive weight. Second, the multi-degree-of-freedom cooperative control algorithm is exceptionally complex, requiring a large amount of sensor data fusion and high-precision motion calculation, which significantly increases the R&D cost and computational load of the control system. Third, the all-drive structure has a large number of parts and extremely high assembly precision requirements, resulting in low product yield, high maintenance difficulty, and difficulty in achieving industrial application.

[0004] Therefore, to balance motion performance with structural complexity and R&D costs, many research institutions and companies have adopted underactuated or hybrid actuation schemes, achieving a balance between performance and complexity through mechanics optimization design. Common design strategies for existing underactuated thumbs include: using coupled actuation, mechanically coupling some degrees of freedom of the thumb, and using fewer actuators to achieve adaptive envelope grasping. While these solutions significantly simplify the control system and improve structural reliability, they also have several inherent drawbacks: First, they often sacrifice some independent motion capabilities (such as pure lateral motion or independent twisting motion), resulting in a significant reduction in motion flexibility. Second, they rely on ultra-precise mechanical design to preset the grasping trajectory, leading to poor adaptability to irregularly shaped objects and inadequate coverage. Third, existing underactuated solutions mostly use a full steel wire rope drive structure, with the steel wire rope running outside the fingers and densely arranged, requiring repeated tension adjustments during assembly, resulting in long assembly times and high difficulty. Furthermore, subsequent maintenance and upgrades require complete disassembly, making the operation cumbersome. Fourth, existing solutions have low sensor integration, often using only a single position sensor, lacking accurate detection of fingertip contact force, making it difficult to achieve precise force-controlled grasping, and prone to problems such as objects slipping or crushing fragile objects.

[0005] Furthermore, high-density integration of multi-dimensional force / torque sensors, tactile arrays, and joint position sensors at the thumb tip, fingertip, and joints is fundamental for achieving stable pinching, sliding detection, and precise force control. However, existing solutions suffer from low integration between the sensing modules and mechanical structures. Sensor installation can easily compromise the overall structural strength of the finger, and the incompatibility of sensor data makes it difficult to achieve closed-loop feedback for motion and force control. Meanwhile, although modular design concepts have permeated thumb development, aiming to unify the driving and communication interfaces between the thumb and other finger modules for easier maintenance and upgrades, existing modular designs only reach the interface level. Their internal structures lack versatility, and core transmission components cannot be standardized for replacement, failing to fundamentally reduce maintenance costs.

[0006] In summary, the technological evolution of thumb modules is shifting from simply pursuing a higher number of degrees of freedom to optimizing the integrated performance of "drive-transmission-sensing-control" within limited space, weight, and power consumption constraints. Currently, there is an urgent need for an underactuated thumb structure that balances motion accuracy, structural simplification, strong grasping adaptability, and convenient assembly and maintenance. Its development level is not only a core benchmark for evaluating the quality of a dexterous hand's mechanical design but also a key enabling component for humanoid robots to perform delicate operational tasks in everyday unstructured environments, significantly contributing to the industrial application of humanoid robots. As the core end effector of humanoid robots, the dexterous hand is a crucial component for interaction between the robot and the real physical world. Its structural design and transmission method directly determine the humanoid robot's operational capabilities and application scenarios. Currently, dexterous hand structural solutions in the industry are mainly divided into two directions: fully actuated and underactuated. Simultaneously, specific implementation forms such as linear drive chords, all-motor direct drive, and linkage transmission have emerged. All these solutions have significant technical drawbacks, making it difficult to balance control difficulty, assembly and maintainability, space utilization, and motion stability.

[0007] All movable joints of the fully driven dexterous hand are directly or indirectly driven by motors. The number of joint degrees of freedom is equal to the number of motors. Although it can achieve precise independent control of each joint, reproduce most of the gestures of the human hand, and even complete the actions that the human hand cannot perform, the increase in the number of motors not only greatly increases the design difficulty of the control system, but also easily causes communication and control coordination obstacles with the humanoid robot body. At the same time, the humanoid hand shape structure provides little space for motor installation, which limits the upper limit of motor performance, resulting in insufficient output force at the fingertips, making it difficult to meet the needs of heavy-duty gripping and other operations.

[0008] Underactuated dexterous hands achieve overall hand control through the coupling motion of mechanical structures, using a design where the number of degrees of freedom exceeds the number of driving forces. The most widely used drive scheme is a combination of linear motors and chords. Chords possess high tensile strength and small size, and their force application is similar to human muscle tissue, making them suitable for the small size and high torque requirements of dexterous hands. However, purely chord-driven dexterous hands have significant technical drawbacks. In dexterous hands with more than 20 degrees of freedom, the overall arrangement and precise installation of the chords are extremely difficult and time-consuming. Furthermore, chords are prone to wear, aging, and plastic deformation during long-term use, directly affecting the stability and control accuracy of the dexterous hand's movements. The complex installation method also makes maintenance and replacement of the chords cumbersome, increasing operating costs.

[0009] Furthermore, while underactuated dexterous hands with linkage transmission offer good transmission stability, the linkage structure requires a significant amount of internal space in the fingers, increasing the overall size and weight of the hand. This does not meet the design requirements for lightweight and miniaturized humanoid robots. At the same time, most existing dexterous hands only have tactile sensors at the fingertips, or even no tactile detection structure at all. This makes it impossible to accurately provide feedback on the contact state and pressure distribution when holding an object, which can easily lead to slippage or damage to objects, thus limiting the application of dexterous hands in precision operation scenarios. Summary of the Invention

[0010] This invention addresses the aforementioned problems in the prior art by providing an underactuated manipulator with a hybrid transmission mechanism. It aims to solve the technical problems of high control difficulty of fully driven manipulators, difficult assembly and maintenance of purely tendon-driven manipulators, low space utilization of linkage-driven manipulators, and insufficient tactile detection capabilities of existing dexterous hands. The invention achieves the effects of fewer motors driving multiple degrees of freedom, improved assembly and maintenance efficiency, saved internal space, and accurate detection of grip status.

[0011] The core objective of this invention is: A hybrid transmission mechanism for an underactuated manipulator is proposed, comprising a palm module, four identical finger modules, and a thumb module, characterized in that the four finger modules and the thumb module are independently mounted on the palm module; The finger module is composed of a lateral swing joint, a proximal phalanx, a middle phalanx, and a distal phalanx connected sequentially from bottom to top. The lateral swing joint adopts a bevel gear differential structure. The proximal phalanx, middle phalanx, and distal phalanx form a coupled motion structure through the cooperation of tendon ropes and tension springs. Furthermore, the palm module includes a stand plate, a base, a palm shell, a tactile sensor module, a control circuit board, and an external plug. The stand plate is vertically connected and fixed to the base. The stand plate is used to install four finger modules and their corresponding control circuit boards, and the base is used to install a thumb module and its corresponding control circuit board. The palm shell covers part of the structure of the finger module and thumb module, and the palm shell is fixedly connected to the upright plate and the base. The tactile sensor module is fixed inside the palm shell.

[0012] Furthermore, the side swing joint includes a motor, a motor mounting base, a motor bevel gear, a double-layer bevel gear, a double-layer cylindrical tooth-bevel gear, a cross bushing, a differential crossarm, a magnet, and an angle sensor module; The two motors are mounted on the bottom of the motor mounting base. The motor bevel gear is fixedly connected to the motor output shaft. The upper part of the motor mounting base is provided with mounting holes. The differential crossbar is mounted on the upper part of the motor mounting base and can rotate at a fixed angle around the axis of the mounting hole on the upper part of the motor mounting base. Two double-layer bevel gears are symmetrically mounted on the two longer shafts of the cross bushing, and the double-layer cylindrical bevel gear is mounted on one shorter shaft of the cross bushing. The bevel teeth of the two double-layer bevel gears and the double-layer cylindrical bevel gear mesh with each other at the center of the cross bushing and can rotate around the shaft of the bushing. The other layer of bevel teeth of the double-layer bevel gear meshes with the motor bevel gear. The cross bushing is fixed to the differential cross frame through the shaft. The differential crossbar has a slot, and the magnet is fixedly installed in the slot on the differential crossbar. The magnet rotates coaxially, in the same direction and at the same speed as the double-layer bevel gear during the lateral swing. The angle sensor module is fixed to the back of the motor mounting base and corresponds to the position of the magnet. The angle sensor module detects the angle position of the current lateral swing of the joint by the change in the direction of the magnetic field of the magnet.

[0013] Furthermore, the proximal phalanx includes a proximal phalanx skeleton, a proximal phalanx shell, a proximal phalanx guide wheel, an internal hexagonal cylindrical gear, a variable guide wheel, a large angle measuring gear component, a small angle measuring gear, a magnet, a phalanx angle measuring sensor module, a steel wire rope, and a tension spring; The internal hexagonal hole cylindrical gear meshes with the double-layer cylindrical tooth-bevel gear; A rotating shaft is provided in the mounting hole at the upper part of the differential crossarm. The rotating shaft is provided with a hexagonal socket cylindrical gear, a proximal knuckle guide wheel, the lower end of the proximal knuckle skeleton, and a large angle measuring gear component in sequence. The proximal knuckle guide wheel is fixedly connected to the hexagonal socket cylindrical gear, and their center holes are coaxial with the lower hole of the proximal knuckle skeleton, the center hole of the large angle measuring gear component, and the mounting hole at the upper part of the differential crossarm, and are connected through the rotating shaft. The large angle measuring gear component is fixed to the differential crossarm by fasteners. The proximal knuckle guide wheel and the proximal knuckle skeleton can rotate relatively independently. The protractor pinion is mounted between the protractor phalanx shell and the protractor phalanx skeleton via a pin. The protractor pinion is also mounted on the protractor phalanx skeleton via a pin. The protractor pinion can rotate around the pin. The protractor pinion meshes with the protractor large gear component. The magnet is installed in the gear hole of the protractor pinion. The phalanx angle sensor module is fixed on the protractor phalanx skeleton and corresponds to the position of the magnet. The phalanx angle sensor module feeds back the relative rotation angle information of the big toe joint by measuring the change in the direction angle of the magnetic field of the magnet. The wire rope includes a first reversing rope segment, a second reversing rope segment, a first rope segment, and a second rope segment. The guide pulley near the finger joint is provided with a first rope groove, a first reversing rope groove, and a second reversing rope groove. The first reversing rope groove is located on the side near the finger joint skeleton, the second reversing rope groove is located on the side away from the finger joint skeleton, and the third reversing rope groove is located on the side near the finger joint skeleton. The first reversing rope groove is located between the first rope groove and the second reversing rope groove. The two guide wheels include guide wheel one and guide wheel two. The two guide wheels are installed on one side of the proximal phalanx and are located at the upper and lower ends of the proximal phalanx. Guide wheel one is located at the lower end of the proximal phalanx, and guide wheel two is located at the upper end of the proximal phalanx. Guide groove one, guide groove two, and groove one are located on the same side of the proximal phalanx as guide wheels one and guide wheel two. Guide groove one, guide groove two, and groove one are provided with rope end mounting holes. One end of the first rope segment is fixedly installed in the rope head mounting hole in the first rope groove, and the other end of the first rope segment extends to the middle finger joint. The middle of the first rope segment is connected by a tension spring. One end of the first reversing rope segment is set in the rope head mounting hole fixedly set in the first reversing rope groove. After the first reversing rope segment extends out of the first reversing rope groove, it wraps around the first reversing guide wheel and then wraps around the upper end of the near-knuckle skeleton to the second reversing guide wheel. One end of the second reversing rope segment is set in the rope head mounting hole fixedly set in the second reversing rope groove. After the second reversing rope segment extends out of the second reversing rope groove, it wraps around the first reversing guide wheel and then wraps around the upper end of the near-knuckle skeleton onto the second reversing guide wheel. One end of the first reversing rope segment is disposed in the rope head mounting hole fixedly disposed in the first reversing rope groove, and the first reversing rope segment extends to the middle finger joint after being wound out of the first reversing rope groove. The first directional rope segment is located on one side of the second directional rope segment, and the first directional rope segment passes through the same side of the first directional guide wheel and the second directional guide wheel. Both the first and second deflection rope segments bypass the first and second deflection guide wheels on the near-knuckle skeleton and extend from the side of the first and second deflection guide wheels near the back of the finger toward the middle knuckle. The angle measuring gear component includes a large gear and an angle measuring component. The angle measuring component is disposed on the outer shell near the finger joint, and the large gear is disposed on the rotating shaft. A second rope groove is provided on one side of the large gear, and the second rope groove is disposed on the side near the angle measuring gear component. One end of the second rope segment is connected to the second rope groove on one side of the angle measuring gear component. The second rope groove is set in the slot on the differential crossbar. The other end of the second rope segment extends upward and is connected to the middle finger joint. The middle of the second rope segment is connected by a tension spring. The proximal phalanx shell and the proximal phalanx skeleton are fixedly connected to the back of the finger. The proximal phalanx includes the proximal phalanx skeleton, the proximal phalanx shell, the proximal phalanx guide wheel, the internal hexagonal cylindrical gear, the variable guide wheel, the angle measuring large gear component, the angle measuring small gear, the magnet, the phalanx angle measuring sensor module, the steel wire rope, and the tension spring. All parts are enclosed in the proximal phalanx shell.

[0014] Furthermore, the middle finger joint includes a middle finger joint skeleton, a left outer shell of the middle finger joint, a right outer shell of the middle finger joint, a middle finger joint guide wheel, a middle finger joint deflector guide wheel, a steel wire rope, and a tension spring; The middle finger joint guide wheel includes guide wheel three and guide wheel four. The left and right outer shells of the middle finger joint are fixed to both sides of the middle finger joint frame. The inner side of the middle finger joint frame is provided with a mounting plate. The upper and lower parts of the side wall of the mounting plate are respectively provided with guide wheel four and guide wheel three. The holes on the guide wheels of the middle finger joint are coaxial with the holes near the upper end of the middle finger joint frame, the holes at the lower part of the left outer shell of the middle finger joint, and the holes at the lower part of the right outer shell of the middle finger joint, and are connected by a rotating shaft. They can rotate relatively independently from each other. The wire rope includes reversing rope segment three, reversing rope segment four, rope segment three, and rope segment four; A rope groove three is fixedly provided on the lower part of the inner wall of the left outer shell of the middle finger joint, and a rope groove four is fixedly provided on the lower part of the inner wall of the right outer shell of the middle finger joint. The lower parts of the left and right outer shells of the middle phalanx are provided with mounting holes, and a rotating shaft is provided in the mounting holes. Rope grooves three and four are provided on the rotating shaft. The upper end of the proximal phalanx skeleton is rotatably provided in the middle of the rotating shaft. A deflecting rope groove three and a deflecting rope groove four are provided between rope groove three and the upper end of the proximal phalanx skeleton. The deflecting rope groove three is located close to rope groove three, and the deflecting rope groove four is located close to the upper end of the proximal phalanx skeleton. The deflecting guide wheel three is located close to the deflecting rope groove four, and the deflecting guide wheel four is located directly above the deflecting guide wheel three. The lower end of the third rope segment is wound around the third rope groove, and the middle of the third rope segment is connected by a tension spring; The upper end of the third rope segment is positioned on the distal phalanx; The lower end of the fourth rope segment is wound around the fourth rope groove, and the middle of the fourth rope segment is connected by a tension spring; The upper end of the fourth rope segment is positioned on the distal phalanx; The lower end of the third directional rope segment is wound in the third directional rope groove. The lower end of the third directional rope segment extends out of the third directional rope groove and is wound around the third directional guide wheel. The lower end of the third directional rope segment comes out of the third directional guide wheel and is wound around the third directional guide wheel. The lower end of the third directional rope segment comes out of the third directional guide wheel and is connected to the distal phalanx.

[0015] The lower end of the fourth directional rope segment is wound in the fourth directional rope groove. The lower end of the fourth directional rope segment extends out of the fourth directional rope groove and is wound around the third directional guide wheel. The lower end of the fourth directional rope segment comes out of the third directional guide wheel and is wound around the fourth directional guide wheel. The lower end of the fourth directional rope segment comes out of the fourth directional guide wheel and is connected to the distal phalanx.

[0016] Furthermore, the distal phalanx includes a finger, a distal phalanx guide wheel, a finger tactile sensor module, and a steel wire rope; The central hole of the distal phalanx guide wheel, the hole at the bottom of the fingertip, the hole at the top of the left outer shell of the middle phalanx, and the hole at the top of the right outer shell of the middle phalanx are coaxial and connected by a rotating shaft, and each component can rotate relatively independently. A rope groove five is fixedly provided above the inner wall of the left outer shell of the middle finger joint, and a rope groove six is ​​fixedly provided above the inner wall of the right outer shell of the middle finger joint. The upper end of the third rope segment is wrapped around the fifth rope groove, extends out of the fifth rope groove, and is then fixed to the inner wall of the finger. The upper end of the fourth rope segment is wrapped around the sixth rope groove, extends out of the sixth rope groove, and is then fixed to the inner wall of the finger. The distal finger joint guide wheel is mounted on the rotating shaft. The distal finger joint guide wheel is disposed between the mounting plate and the rope groove five. The distal finger joint guide wheel is provided with a reversing rope groove five and a reversing rope groove six. The reversing rope groove five is disposed close to the reversing rope groove five. The reversing rope groove six is ​​disposed between the mounting plate and the reversing rope groove five. The upper end of the reversing rope segment three is wound around the reversing rope groove five and fixed, and the reversing rope segment four is wound around the reversing rope groove six after coming out of the reversing guide wheel four and fixed. The finger tactile sensor module is fixed to the inner plane of the finger, while the outer side of the finger has a shape and structure that mimics the shape of a human finger.

[0017] Furthermore, the thumb module is mounted on the upper plane of the base of the palm module, and the thumb module is at a preset angle to the plane of the palm module. A tactile sensor module is arranged at the fingertip of the middle phalanx of the thumb module, and tactile sensor modules are arranged at the fingertips of the proximal and middle phalanxes of the finger module.

[0018] Furthermore, the thumb module includes, from bottom to top, the thumb lateral joint, the thumb proximal phalanx, the thumb middle phalanx, and the thumb distal phalanx; The thumb module has a differential structure on the thumb side joint. The intersection of the two axes driven by the thumb differential coincides with the joint rotation plane of the middle and distal phalanges of the thumb. The line connecting the midpoint of the joint rotation axis of the middle phalange of the thumb and the intersection of the differential axis forms a fitting proximal phalanx. The fitting proximal phalanx is in the same plane as the middle and distal phalanges of the thumb.

[0019] Furthermore, the thumb lateral joint includes a thumb motor mounting base, a thumb drive motor, a thumb motor bevel gear, a thumb double-layer bevel gear, a thumb hexagonal shaft bevel gear, a T-shaped bushing, and a thumb differential crossarm. The thumb motor mounting base has two thumb drive motors at its bottom, which are installed in the motor housing cavity at the bottom of the mounting base. The output shafts of both thumb drive motors are coaxially fixed to the thumb motor bevel gears via fasteners. The thumb differential crossarm is rotatably mounted at the rotation mating hole on the upper part of the thumb motor mounting base. The T-shaped bushing is connected via a crossarm... The longitudinally intersecting positioning shaft is rigidly fixed to the differential crossbeam. The T-shaped bushing includes two longer thumb shafts and one shorter thumb shaft. The two thumb double-layer bevel gears are symmetrically and clearance-fitted onto the two longer thumb shafts of the T-shaped bushing. The thumb hexagonal bevel gear is clearance-fitted onto one of the shorter thumb shafts of the T-shaped bushing. The inner bevel teeth of the two thumb double-layer bevel gears and the thumb hexagonal bevel gear mesh with each other at the center position of the T-shaped bushing and can all rotate independently around the corresponding shaft of the bushing. The outer bevel teeth of the two thumb double-layer bevel gears mesh with the two thumb motor bevel gears without backlash.

[0020] Furthermore, the proximal phalanx of the thumb includes an upper outer shell of the proximal phalanx of the thumb, a lower outer shell of the proximal phalanx of the thumb, a thumb drive motor, a bevel gear of the thumb drive motor, and a thumb wire rope. The thumb drive motor is fixed in the motor mounting cavity inside the upper outer shell of the proximal phalanx of the thumb by a thumb motor bracket. The bevel gear of the thumb drive motor is coaxially fixed with the output shaft of the thumb drive motor by fasteners. The lower outer shell of the proximal phalanx of the thumb is fixedly connected to the upper outer shell of the proximal phalanx of the thumb. The lower part of the outer shell of the thumb proximal phalanx is connected and fixed to the thumb hexagonal bevel gear on the thumb's lateral joint by fasteners. The lower end of the first steel wire rope is fixed to the steel wire rope positioning groove on the outer side of the upper shell of the thumb proximal phalanx by a crimping member. The upper end of the first thumb steel wire rope extends to the middle phalanx of the thumb along a preset wiring channel.

[0021] Furthermore, the thumb middle phalanx includes a thumb middle phalanx skeleton, a left outer shell of the thumb middle phalanx, a right outer shell of the thumb middle phalanx, a thumb drive bevel gear, a thumb middle phalanx guide wheel, a thumb deflector guide wheel, a second thumb wire rope, a third thumb wire rope, a fourth thumb wire rope, and a lower thumb mounting shaft. The left and right outer shells of the thumb middle phalanx are fixedly mounted on both sides of the thumb middle phalanx skeleton via the lower thumb mounting shaft and the upper thumb mounting shaft. A thumb deflector guide wheel is fixed on the side wall of the thumb middle phalanx skeleton. The thumb deflector guide wheel includes an upper thumb deflector guide wheel and a lower thumb deflector guide wheel. The upper and lower thumb deflector guide wheels are fixedly mounted on the side wall of the thumb middle phalanx skeleton. The upper and lower thumb deflector guide wheels are mounted on the side of the thumb middle phalanx that is close to the outer shell of the thumb middle phalanx. The upper part of the upper shell of the proximal thumb joint is provided with a thumb guide wheel mating hole, the lower part of the left shell of the middle thumb joint is provided with a thumb mounting hole one, and the lower part of the right shell of the middle thumb joint is provided with a thumb mounting hole two. The thumb middle joint guide wheel is coaxially arranged with the thumb guide wheel mating hole on the upper part of the upper shell of the proximal thumb joint, the thumb mounting hole one on the lower part of the left shell of the middle thumb joint, and the thumb mounting hole two on the lower part of the right shell of the middle thumb joint. The lower thumb mounting shaft is installed in the thumb guide wheel mating hole on the upper part of the upper shell of the proximal thumb joint, the thumb mounting hole one on the lower part of the left shell of the middle thumb joint, and the thumb mounting hole two on the lower part of the right shell of the middle thumb joint. The thumb middle joint guide wheel is disposed on the lower thumb mounting shaft and rotates on the lower thumb mounting shaft. The lower part of the thumb middle phalanx skeleton is mounted on the thumb lower mounting shaft. The thumb drive bevel gear is mounted on the thumb lower mounting shaft and is mounted close to the left outer shell of the thumb middle phalanx. The thumb middle phalanx guide wheel is provided with wire rope groove one, wire rope groove two, wire rope groove three, and wire rope groove four respectively from the left outer shell of the thumb middle phalanx to the right outer shell of the thumb middle phalanx. Wire rope groove one, wire rope groove two, and wire rope groove three are mounted on the left side of the thumb middle phalanx skeleton and close to the left outer shell of the thumb middle phalanx. Wire rope groove four is mounted on the right side of the thumb middle phalanx skeleton and close to the right outer shell of the thumb middle phalanx. The thumb drive bevel gear is located between the lower end of wire rope one and wire rope groove two. The thumb drive motor bevel gear meshes with the thumb drive bevel gear; The top of the outer shell of the thumb proximal phalanx is located between the right side wall of the thumb middle phalanx skeleton and the wire rope groove four. The thumb-down guide wheel is positioned above the wire rope groove three; Furthermore, the distal phalanx of the thumb includes a thumb tip, a distal phalanx guide wheel, a thumb mounting shaft, and a thumb tip tactile sensor module. The distal phalanx guide wheel has a central hole, the lower part of the thumb tip has a mounting shaft mating hole, and the upper parts of the left and right outer shells of the middle phalanx of the thumb have mounting shaft mating holes. The central hole on the distal phalanx guide wheel, the mounting shaft mating hole at the lower part of the thumb tip, and the mounting shaft mating holes at the upper parts of the left and right outer shells of the middle phalanx are coaxial and connected by a through-hole connection of the thumb mounting shaft. The thumb distal phalanx guide wheel is provided with wire rope grooves five, six, seven, and eight respectively, from the left outer shell of the thumb middle phalanx to the right outer shell of the thumb middle phalanx. Wire rope grooves five, six, and seven are installed on the left side of the thumb middle phalanx skeleton and close to the left outer shell of the thumb middle phalanx. Wire rope groove eight is installed on the right side of the thumb middle phalanx skeleton and close to the right outer shell of the thumb middle phalanx. The upper guide wheel of the thumb is located below the wire rope groove seven. The upper part of the middle phalanx of the thumb is mounted on the upper mounting shaft of the thumb. Both the upper mounting shaft of the thumb and the lower mounting shaft of the thumb are fixedly mounted between the left outer shell of the middle phalanx of the thumb and the right outer shell of the middle phalanx of the thumb. The lower end of the first wire rope is fixed in the wire rope positioning groove on the outer side of the outer shell of the thumb proximal phalanx. After the lower part of the first wire rope wraps around the first wire rope groove once, it comes out from the right side of the first wire rope groove, that is, the wire rope groove near the inner side of the thumb phalanx, and starts to wrap around the fifth wire rope groove on the left side of the fifth wire rope groove near the outer side of the thumb phalanx. After wrapping around the fifth wire rope groove once, the upper end of the first wire rope is fixed in the first wire rope fixing hole provided on the outer side of the finger through a crimping member. The lower end of the second wire rope is fixed in the second wire rope groove. After the second wire rope is wrapped around the second wire rope groove once, the left side of the second wire rope groove, that is, starting from the outside of the thumb joint and moving upward towards the finger, is wrapped around the sixth wire rope groove once. The upper end of the second wire rope is then fixed in the second wire rope fixing hole provided on the outside of the finger by a crimping member. The lower end of the third wire rope is fixed in the third wire rope groove. After the third wire rope wraps around the third wire rope groove once, it starts from the right side of the third wire rope groove, that is, from the inside of the thumb knuckle, and moves upward toward the bottom of the thumb-down guide wheel, wrapping around it once. Then, it comes out from the left side of the thumb-down guide wheel, that is, from the outside of the thumb knuckle, and moves upward toward the fingertip. After the third wire rope starts from the left side of the thumb-up guide wheel, that is, from the outside of the thumb knuckle, and wraps around the thumb-down guide wheel once, it comes out from the left side of the thumb-up guide wheel and starts from the lower part of the seventh wire rope groove once. Finally, it comes out from the right side of the seventh wire rope groove, that is, from the inside of the thumb knuckle. The upper end of the third wire rope is fixed in the fixing hole of the third wire rope on the outside of the thumb tip by a crimping member. The lower end of the wire rope four is fixed in the wire rope groove four. After the lower part of the wire rope four is wrapped around the wire rope groove four once, it comes out from the left side of the wire rope groove four, that is, the wire rope groove one near the outside of the thumb joint, and then starts to wrap around the wire rope groove eight on the right side of the distal joint, that is, the wire rope groove eight near the inside of the thumb joint. After that, the upper end of the wire rope eight is fixed in the wire rope four fixing hole provided on the outside of the finger through a crimping member. The thumb tactile sensor module is connected and fixed to the inner plane of the finger.

[0022] Furthermore, the thumb lateral joint also includes a thumb magnet and a thumb angle sensor module. The thumb differential crossbeam is provided with a dedicated slot. The thumb magnet is interference-fitted and fixed in the dedicated slot on the thumb differential crossbeam. The thumb motor mounting base is provided with a sensor mounting position on the back. The thumb angle sensor module is fixed to the sensor mounting position on the back of the thumb motor mounting base by bolts. The thumb angle sensor module and the thumb magnet cooperate non-contactly to detect the real-time rotation angle of the lateral joint.

[0023] Furthermore, the wire rope is made of stainless steel.

[0024] Furthermore, the middle sections of wire rope one and wire rope four are connected by a tension spring, which is a precision tension spring made of stainless steel. Furthermore, the thumb angle sensor module is a magnetoelectric angle encoder with a detection accuracy of not less than 0.1°.

[0025] Furthermore, the thumb tactile sensor module is a flexible array pressure sensor, and the detection accuracy of the flexible array pressure sensor is not less than 0.2N.

[0026] Furthermore, the wire rope is a 7×19 multi-strand twisted stainless steel wire rope with a diameter of 0.3 to 0.8 mm. The surface of the wire rope is galvanized for rust prevention, and the wire rope's routing channels are all equipped with wear-resistant nylon bushings.

[0027] Furthermore, the motor mounting base of the thumb lateral joint, the thumb differential crossbeam, the upper and lower outer shells of the thumb proximal joint, the skeleton of the thumb middle joint and the left and right outer shells of the thumb middle joint, and the anthropomorphic finger of the thumb distal joint are all made of lightweight and high-strength aerospace-grade aluminum alloy.

[0028] Furthermore, a limiting baffle is provided at the top of the thumb hexagonal bevel gear, and the limiting baffle is adapted to the tail of the lower outer shell of the thumb proximal phalanx.

[0029] Furthermore, the outer side of the thumb tip has a biomimetic arc shape that mimics the human thumb tip.

[0030] Working principle: A hybrid transmission mechanism for underactuated manipulators consists of a side swing joint, proximal phalanx, middle phalanx, and distal phalanx rigidly connected from bottom to top, with a total of 4 movable joints corresponding to 4 degrees of freedom. It combines active precision drive of bevel gear differential with underactuated coupling adaptive transmission of wire rope-guide wheel-tension spring, and integrates angle sensing and tactile sensing modules to achieve an integrated design of "precise control + adaptive grasping + closed-loop feedback". The overall structure is compact, lightweight, and easy to assemble and maintain.

[0031] The lateral swing joint and thumb lateral swing joint are the basic drive joints of the entire finger and are the core of realizing the two orthogonal active degrees of freedom of lateral swing and flexion and extension. They include motor mounting base, two drive motors, two motor bevel gears, two double-layer bevel gears, one hexagonal shaft bevel gear, T-shaped bushing, differential crossbar, magnet and angle sensor module.

[0032] Two drive motors are symmetrically and coaxially mounted in a dedicated motor housing at the bottom of the motor mounting base, effectively avoiding structural interference. The motor output shafts are coaxially fixed to the motor bevel gears by fasteners to ensure the coaxiality of the transmission. In the thumb module: the thumb differential crossarm is rotatably mounted on the rotating mating hole on the upper part of the motor mounting base, and can rotate within ±75° around the axis of the hole on the upper part of the motor mounting base, covering the lateral movement range of the human thumb. The lateral movement range of the other four identical finger modules is ±15°. The four identical finger modules and the thumb module cooperate with each other to meet most grasping operation requirements. The T-shaped bushing is rigidly fixed to the thumb differential crossarm through the horizontal and vertical interlocking positioning shafts. The two thumb double-layer bevel gears are symmetrically and clearance-fitted onto the T-shaped bushing. The two longer shafts, the thumb hexagonal bevel gear, and the shorter shaft are fitted with a T-shaped bushing with clearance. The inner bevel teeth of the three gear components mesh with each other at the center of the T-shaped bushing, and the outer bevel teeth mesh with the thumb motor bevel gear without backlash, ensuring the accuracy and smoothness of the transmission and eliminating transmission backlash. The thumb magnet is interference-fitted and fixed to a special slot in the thumb differential crossbeam. The thumb angle sensor module is fixed to the back of the thumb motor mounting base, and it cooperates with the thumb magnet in a non-contact manner to detect the side swing angle, avoiding wear caused by mechanical contact and improving detection accuracy and service life. The core working principle of this joint (thumb lateral swing joint) is as follows: by precisely controlling the steering combination and speed difference of the two thumb drive motors, the lateral swing motion of the thumb differential crossbeam (corresponding to the lateral swing degree of freedom of the thumb) and the rotational motion of the thumb hexagonal shaft bevel gear (corresponding to the flexion and extension active degree of freedom of the thumb) are controlled synchronously, so as to achieve stepless speed regulation and precise posture control of the two orthogonal active degrees of freedom. There is no need to configure a separate driver for each joint, which greatly simplifies the structure and control.

[0033] The proximal phalanx of the thumb serves as a transitional joint connecting the lateral pivot joint of the thumb and the middle phalanx of the thumb. It also provides the power transmission foundation for the wire rope drive, including the upper shell of the proximal phalanx of the thumb, the lower shell of the proximal phalanx of the thumb, the thumb drive motor, the bevel gear of the thumb drive motor, and the multi-strand stainless steel wire rope.

[0034] The thumb drive motor is fixed to the motor mounting cavity inside the outer shell of the thumb proximal phalanx via a thumb motor bracket, achieving built-in installation of the motor and effectively reducing the external volume of the thumb. The bevel gear of the thumb drive motor is coaxially fixed with the motor output shaft to ensure power transmission efficiency. The lower outer shell of the thumb proximal phalanx is fixed to the upper outer shell by a combination of clips and bolts, which is a firm connection and easy to disassemble and assemble. The lower part of the lower outer shell of the thumb proximal phalanx is rigidly fixed coaxially with the thumb hexagonal shaft bevel gear, so that the thumb proximal phalanx can rotate synchronously with the thumb hexagonal shaft bevel gear to achieve active flexion and extension movements. The steel wire rope in the thumb module uses a 7×19 structure multi-strand twisted stainless steel wire rope as the transmission element, with a diameter of 0.3~0.8mm and a galvanized surface for rust prevention. One end of the wire rope is fixed to the positioning groove on both sides of the outer shell near the thumb joint through a crimping piece, and the other end extends along the internal preset wiring channel to the middle joint of the thumb to avoid the steel wire rope being exposed and improve the stability of the transmission.

[0035] The thumb and middle phalanx is the core joint of the underactuated coupling transmission, realizing the proportional relationship between driving force and rotational speed. It includes the thumb and middle phalanx skeleton, the left outer shell of the thumb and middle phalanx, the right outer shell of the thumb and middle phalanx, the thumb and middle phalanx guide wheel, the two upper and lower variable guide wheels of the thumb, the multi-strand stainless steel wire rope, and the thumb tension spring.

[0036] The thumb and middle phalanx skeleton is made of aerospace-grade aluminum alloy, providing core structural support for the thumb and middle phalanx. The left and right outer shells of the thumb are fixed to both sides of the skeleton with bolts, forming a closed accommodating space to protect the internal transmission components. Two upper and lower guide wheels for the thumb are arranged symmetrically in a figure-eight shape on the side wall of the thumb and middle phalanx skeleton, effectively optimizing the routing angle of the wire rope and reducing bending wear. The thumb and middle phalanx guide wheels are coaxial with the corresponding holes of the thumb proximal phalanx and the thumb and middle phalanx, and are connected by a clearance fit of the rotating shaft, allowing each component to rotate independently relative to each other; the two steel rods in the middle... The wire rope is fixed to the guide wheel of the thumb and middle joint, and after passing through the upper and lower guide wheels of the thumb, it extends to the end of the thumb along a preset arc-shaped cable channel. The two outer sections of the wire rope are elastically connected by the thumb tension spring. The two ends pass through the rope rail grooves at the upper and lower parts of the thumb and middle joint respectively, and then connect the proximal joint and distal joint of the thumb. The inner side of the rope rail groove is equipped with a wear-resistant nylon bushing to reduce the wear of the wire rope during movement. The core design point is that by designing the wheel diameter ratio of the wire rope around the guide wheel, the driving force of the middle joint and distal joint is related in a preset ratio of 1:(0.6~0.8). By precisely designing the diameter ratio of the arc-shaped rope rail enveloping the outer steel wire rope, the rotation speed of the two knuckles is correlated according to a preset ratio of 1:(0.7~0.9); the tension spring is a precision stainless steel tension spring with a stiffness of 0.5~2N / mm, which can be customized according to the grasping requirements to achieve flexible adaptive movement of the fingers.

[0037] The distal phalanx of the thumb is the actuating end of the thumb, enabling direct contact with the object being grasped. It includes a humanoid finger, a distal phalanx guide wheel, and a thumb tactile sensor module. The distal phalanx guide wheel is coaxial with the corresponding holes of the thumb tip and the middle phalanx of the thumb, and is connected by a positioning shaft with clearance fit to ensure the independence and smoothness of the rotation of each component. Self-lubricating oil-impregnated bearings are installed at each rotating joint to reduce frictional resistance. All wire ropes are secured using crimp connectors, replacing traditional knotting methods. This improves the stability of the fixation, prevents the wire ropes from loosening, and facilitates later replacement and adjustment. The integrated sensing and lightweight design of this invention combines a magnetoelectric angle encoder (thumb angle sensor module) and a flexible array pressure sensor (thumb fingertip tactile sensor module). The angle encoder has a detection accuracy of no less than 0.1° and outputs angle data via an SPI interface. The pressure sensor outputs tactile data via an I2C interface, achieving dual closed-loop feedback of motion position and contact force, providing data support for the precise control of the robot control system. The core structural components of the fingers are all made of lightweight, high-strength aerospace-grade aluminum alloy and undergo hard anodizing treatment. While ensuring structural strength (able to withstand axial pressure of no less than 100N), the overall weight is reduced to the minimum. The overall weight of the robotic hand does not exceed 1000g, meeting the lightweight requirements of humanoid robots. Each structural component adopts standardized design dimensions and installation interfaces, achieving unified drive and communication interfaces with other finger modules of the robot's dexterous hand. Core transmission components can be replaced in a standardized manner, greatly improving versatility and ease of maintenance.

[0038] Compared with the prior art, the present invention has the following beneficial effects: This invention achieves the following significant benefits through a hybrid transmission structure design using a bevel gear differential coupled with a wire rope, internalized wire rope routing, multi-parameter proportional correlation design, integrated sensor integration, and lightweight standardized design: It balances motion accuracy with structural simplification, and significantly reduces control difficulty. This invention employs a bevel gear differential structure for the lateral swing joint, which achieves coordinated and precise control of two orthogonal active degrees of freedom—lateral swing and flexion / extension—through two drive motors. This eliminates the need for an independent driver for each joint, effectively solving the problems of high integration difficulty and complex control in full-drive solutions. Meanwhile, the backlash-free gear meshing design ensures the accuracy of motion, with a position and posture control accuracy of no less than 0.1°, meeting the requirements for refined operation.

[0039] Convenient assembly and maintenance, significantly reducing time and cost: This invention arranges all steel wire ropes in a pre-designed wiring channel inside the finger, replacing the external steel wire rope arrangement method of the existing technology. This avoids mutual interference between steel wire ropes, and there is no need to repeatedly adjust the tension of the external steel wire ropes during assembly. The assembly time is shortened by more than 60% compared with the existing all-steel wire rope solution. At the same time, each component adopts a composite connection method of buckle + bolt, and the core transmission components can be replaced in a standardized manner. During later maintenance and upgrades, only the corresponding shell needs to be disassembled, without overall disassembly, which greatly reduces maintenance costs.

[0040] With strong gripping and enveloping adaptability and significant flexible adaptation effect: This invention achieves a preset proportional relationship between the driving force and rotation speed of the middle and distal phalanges by customizing the wheel diameter ratio of the steel wire rope surrounding the guide wheel and the diameter ratio of the arc-shaped rope rail. Combined with a precision tension spring with customizable stiffness, it enables flexible adaptive enveloping motion of the fingers within a contact force range of 0~25N. It can achieve good enveloping gripping of objects with regular and irregular shapes, and the gripping stability is improved by more than 50% compared with the existing underactuated solution.

[0041] High sensor integration enables dual closed-loop feedback control: This invention innovatively integrates a magnetoelectric angle encoder and a flexible array pressure sensor, which can collect the rotation angle of the side swing joint and the magnitude and distribution of the contact force of the fingertip in real time. The data is output to the robot control system through the SPI / I2C communication interface, realizing dual closed-loop feedback of motion position and contact force. This effectively solves the problem of low force control accuracy in existing solutions, enabling precise pinching and gripping operations and preventing objects from slipping or being pinched.

[0042] Lightweight and standardized design with broad prospects for industrial application: The core structural components of this invention are all made of aerospace-grade aluminum alloy, and the overall weight of the robotic hand does not exceed 1000g, meeting the lightweight requirements of humanoid robots. At the same time, each structural component adopts a standardized design, achieving unified drive and communication interfaces with other finger modules. Core transmission components can be replaced in a standardized manner, which greatly improves the versatility and yield rate of the product, reduces industrial production costs, and can be widely used in dexterous hand modules of humanoid robots and industrial collaborative robots, possessing extremely high engineering application value.

[0043] This invention employs a hybrid transmission method that combines a bevel gear differential structure for the lateral swing joint with an underactuated tendon-driven coupled motion finger joint structure. Two motors are used to control the two active degrees of freedom of the finger's lateral swing and flexion / extension. This achieves the same number of degrees of freedom and overall hand dexterity as a fully driven manipulator with fewer motors, significantly reducing the design difficulty of the control system and the communication and coordination difficulty of the humanoid robot. At the same time, the modular structural design makes the control system easier to package and improves the overall integration.

[0044] This invention arranges tendon cords only inside the fingers, abandoning the overall tendon cord arrangement scheme of pure tendon cord driven robotic arms. Combined with the independent modular design of the palm module, finger module, and thumb module, each module can be quickly installed and disassembled, greatly reducing assembly time. At the same time, the maintenance and replacement of tendon cords and the difficulty of upgrading and modifying robotic arms are also significantly reduced, improving the convenience and economy of use.

[0045] This invention uses tendon cord transmission to replace traditional linkage transmission. The tendon cord structure is small in size and light in weight, which can save a lot of internal space in the fingers and effectively reduce the weight of the entire hand, meeting the design requirements of lightweight and miniaturized humanoid robots. At the same time, the flexible transmission characteristics of the tendon cord also improve the flexibility of finger movement.

[0046] This invention designs the diameter of the guide wheel around the two tendon cords inside the finger, so that the driving force of the three movable joints of the finger is correlated in a certain proportion; designs the diameter ratio of the arc-shaped rope rails wrapped by the four spring-loaded tendon cords on both sides, so that the rotation speed of the three phalanges of the finger is correlated in a certain proportion; and designs the stiffness of the springs to achieve a flexible adaptive effect of the finger within a certain range. The combination of these three features enables the robotic hand to achieve a good covering and gripping effect on objects of any shape, thus improving the stability of the grip.

[0047] This invention incorporates tactile sensor modules in the fingertips, the proximal and middle phalanges of the finger module, the middle phalange of the thumb module, and the palm, forming a high-coverage tactile detection network. Compared to most robotic hands on the market that lack tactile feedback or only have tactile feedback at the fingertips, this invention offers higher tactile sensor coverage, enabling richer and more accurate detection and feedback of the state of the object being held. This effectively prevents slippage and damage to objects, expanding the application range of robotic hands in precision operation scenarios. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 This is a three-dimensional structural diagram of the underactuated manipulator with the hybrid transmission mechanism described in this invention; Figure 2 This is a schematic diagram of the underactuated manipulator with the hybrid transmission mechanism described in this invention; Figure 3 This is a three-dimensional schematic diagram of the finger module described in this invention; Figure 4This is a schematic diagram of the structure of the finger module described in this invention; Figure 5 This is a three-dimensional structural diagram of the lateral swing joint described in this invention; Figure 6 This is a schematic cross-sectional view of the side swing joint described in this invention; Figure 7 This is a schematic cross-sectional view of the meshing structure between the cross bushing and each gear described in this invention; Figure 8 This is a cross-sectional schematic diagram of the finger module described in this invention; Figure 9 This is a schematic diagram of the internal structure of the finger module described in this invention; Figure 10 This is a schematic diagram of the external structure of the finger module described in this invention; Figure 11 This is a schematic diagram of the cross-sectional structure of the proximal and middle phalanges described in this invention; Figure 12 This is a schematic diagram of the internal structure of the proximal and middle phalanges of the present invention; Figure 13 This is a schematic diagram of the structure of the middle finger joint shell described in this invention; Figure 14 This is a schematic diagram of the internal three-dimensional structure of the distal phalanx described in this invention; Figure 15 This is a schematic diagram of the structure of the distal and middle phalanges described in this invention; Figure 16 This is a schematic diagram of the assembly structure of the lateral swing joint and the proximal phalanx skeleton described in this invention; Figure 17 This is a schematic cross-sectional view of the lateral swing joint and proximal phalanx skeleton described in this invention; Figure 18 This is a rear-view three-dimensional structural diagram of the finger module described in this invention; Figure 19 This is a rear view structural diagram of the finger module described in this invention; Figure 20 This is a schematic diagram of the assembly structure of the middle phalanx skeleton, the left outer shell of the middle phalanx, and the right outer shell of the middle phalanx according to the present invention; Figure 21 This is a schematic diagram of the structure of the middle finger joint skeleton described in this invention; Figure 22 This is a schematic diagram of the proximal phalanx skeleton described in this invention; Figure 23 This is a schematic diagram of the winding distribution of the steel wire rope segments described in this invention; Figure 24 This is a schematic diagram showing the winding of the various sections of wire rope described in this invention onto different guide wheels; Figure 25 For the present invention Figure 23 A three-dimensional structural diagram from another perspective; Figure 26 This is a three-dimensional structural diagram of the finger module described in this invention; Figure 27 This is a three-dimensional schematic diagram of the thumb lateral joint described in this invention; Figure 28 This is a cross-sectional schematic diagram of the thumb lateral joint described in this invention; Figure 29 This is a schematic diagram of the left side of the thumb module described in this invention; Figure 30 This is a front view of the thumb module described in this invention; Figure 31 This is a schematic diagram of the structure of the upper shell of the thumb proximal phalanx and the lower shell of the thumb proximal phalanx according to the present invention; Figure 32 This is a schematic diagram of the structure of the left outer shell of the thumb middle phalanx and the right outer shell of the thumb middle phalanx according to the present invention; Figure 33 This is a schematic diagram of the structure of the wire rope one surrounding the wire rope groove one and the wire rope groove five according to the present invention; Figure 34 This is a schematic diagram of the structure of the steel wire rope two surrounding the steel wire rope groove two and the steel wire rope groove six according to the present invention; Figure 35 This is a schematic diagram of the structure of the three-loop steel wire rope groove three and the steel wire rope groove seven described in this invention; Figure 36 This is a schematic diagram of the structure of the four-loop steel wire rope groove and the eight-loop steel wire rope groove described in this invention. Figure 37 This is a schematic diagram of the meshing structure of the modular motor bevel gear, the modular double-layer bevel gear, and the modular hexagonal shaft bevel gear described in this invention; In the attached diagram 1. Hand module, 2. Finger module, 3. Thumb module, 4. Stand plate, 5. Base, 6. Palm shell, 7. Tactile sensor module, 8. Control circuit board, 9. External plug; 100. Lateral joint, 200. Proximal phalanx, 300. Middle phalanx, 400. Distal phalanx; 101. Motor mounting bracket; 102. Motor; 103. Motor bevel gear; 104. Double-layer bevel gear; 105. Double-layer cylindrical-bevel gear; 106. Cross bushing; 107. Differential crossarm; 108. Longer shaft; 109. Shorter shaft; 110. Motor output shaft; 111. Magnet; 112. Angle sensor module; 113. Mounting hole; 114. Slot. 201. Proximal knuckle skeleton; 202. Proximal knuckle shell; 203. Proximal knuckle guide wheel; 204. Hexagonal socket cylindrical gear; 205. Guide wheel one; 206. Guide wheel two; 207. Angle measuring large gear component; 208. Angle measuring small gear; 209. Magnet; 210. Knuckle angle measuring sensor module; 211. Pin; 212. Tension spring; 213. Directional rope segment one; 214. Directional rope segment two; 215. Rope segment one; 216. Rope segment two; 217. Rope groove one; 218. Directional rope groove one; 219. Directional rope groove two; 220. Large gear; 221. Angle measuring component; 222. Rope groove two; 223. Rotating shaft; 301. Middle finger joint skeleton; 304. Middle finger joint left outer shell; 305. Middle finger joint right outer shell; 306. Middle finger joint guide wheel; 307. Middle finger joint deflector guide wheel; 308. Tension spring; 309. Deflector guide wheel three; 310. Deflector guide wheel four; 311. Mounting plate; 312. Deflector rope segment three; 313. Deflector rope segment four; 314. Rope segment three; 315. Rope segment four; 316. Rope groove three; 317. Rope groove four; 318. Rotating shaft; 319. Deflector rope groove three; 320. Deflector rope groove four; 401. Finger, 402. Distal knuckle guide wheel, 403. Rotating shaft, 404. Finger tactile sensor module, 405. Rope groove five, 406. Rope groove six, 407. Directional rope groove five, 408. Directional rope groove six; 500. Lateral joint of the thumb; 600. Proximal phalanx of the thumb; 700. Middle phalanx of the thumb; 800. Distal phalanx of the thumb; 501. Thumb motor mounting base; 502. Thumb drive motor; 503. Thumb motor bevel gear; 504. Thumb double-layer bevel gear; 505. Thumb hexagonal shaft bevel gear; 506. Thumb T-shaped bushing; 507. Thumb differential crossbar; 508. Thumb longer shaft; 509. Thumb shorter shaft; 510. Thumb limit baffle; 511. Thumb magnet; 512. Thumb angle sensor module; 601. Upper outer shell of the thumb proximal phalanx; 602. Lower outer shell of the thumb proximal phalanx; 603. Thumb drive motor; 604. Thumb drive motor bevel gear; 605. Steel wire rope one; 606. Steel wire rope positioning groove; 701. Thumb-middle phalanx skeleton; 704. Thumb-middle phalanx left outer shell; 705. Thumb-middle phalanx right outer shell; 706. Thumb drive bevel gear; 707. Thumb-middle phalanx guide wheel; 708. Thumb upper guide wheel; 709. Steel wire rope two; 710. Steel wire rope three; 711. Steel wire rope four; 712. Thumb lower guide wheel. 713. Thumb mounting hole one, 714. Thumb mounting hole two, 715. Thumb lower mounting shaft, 716. Wire rope groove one, 717. Wire rope groove two, 718. Wire rope groove three, 719. Wire rope groove four, 720. Thumb tension spring; 801. Thumb tip; 802. Thumb distal phalanx guide wheel; 803. Thumb mounting shaft; 804. Thumb tip tactile sensor module; 805. Steel wire rope groove five; 806. Steel wire rope groove six; 807. Steel wire rope groove seven; 808. Steel wire rope groove eight; 809. Outer side of thumb phalanx; 810. Inner side of thumb phalanx; Detailed Implementation To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to specific embodiments. Please note that the embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in the art or in accordance with the product manual.

[0050] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0051] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0052] The underactuated manipulator of the hybrid transmission mechanism of the present invention will be described in detail below through specific embodiments: like Figures 1-2 As shown, an underactuated manipulator with a hybrid transmission mechanism includes a palm module 1, four identical finger modules 2, and a thumb module 3. The four finger modules 2 and the thumb module 3 are independently mounted on the palm module 1. like Figures 3-26 As shown, the finger module 2 is composed of a lateral swing joint 100, a proximal phalanx 200, a middle phalanx 300, and a distal phalanx 400 connected sequentially from bottom to top. The lateral swing joint 100 adopts a bevel gear differential structure. The proximal phalanx 200, the middle phalanx 300, and the distal phalanx 400 form a coupled motion structure through tendon ropes and tension springs 212 and 308. As a further improvement to the above-mentioned method, the palm module 1 includes a stand plate 4, a base 5, a palm shell 6, a tactile sensor module 7, a control circuit board 8, and an external plug 9. The stand plate 4 is vertically connected and fixed to the base 5. The stand plate 4 is used to install four finger modules 2 and corresponding control circuit boards 8, and the base 5 is used to install thumb modules 3 and corresponding control circuit boards 8. The palm shell 6 covers part of the structure of the finger module 2 and the thumb module 3, and the palm shell 6 is fixedly connected to the upright plate 4 and the base 5. The tactile sensor module 7 is fixed inside the palm shell 6.

[0053] As a further improvement to the above-mentioned factual method, the side swing joint 100 includes a motor 102, a motor mounting base 101, a motor bevel gear 103, a double-layer bevel gear 104, a double-layer cylindrical tooth-bevel gear 105, a cross bushing 106, a differential crossbar 107, a magnet 111, and an angle sensor module 112. Two motors 102 are mounted on the bottom of the motor mounting base 101. The motor bevel gear 103 is fixedly connected to the motor output shaft 110. The upper part of the motor mounting base 101 is provided with mounting holes 113. The differential crossbar 107 is mounted on the upper part of the motor mounting base 101 and can rotate at a fixed angle around the axis of the mounting hole 113 on the upper part of the motor mounting base 101. Two double-layer bevel gears 104 are symmetrically mounted on the two longer shafts 108 of the cross bushing 106, and a double-layer cylindrical bevel gear 105 is mounted on a shorter shaft 109 of the cross bushing 106. The bevel teeth of the two double-layer bevel gears 104 and the double-layer cylindrical bevel gear 105 mesh with each other at the center of the cross bushing 106 and can rotate around the shaft of the bushing. The other layer of bevel teeth of the double-layer bevel gear 104 meshes with the motor bevel gear 103. The cross bushing 106 is fixed to the differential cross frame 107 by a shaft. The differential crossbar 107 is provided with a slot 114. The magnet 111 is fixedly installed in the slot 114 on the differential crossbar 107. The magnet 111 rotates coaxially, in the same direction and at the same speed as the lateral swing motion. The angle sensor module 112 is fixed to the back of the motor mounting base 101 and corresponds to the position of the magnet 111. The angle sensor module 112 detects the angle position of the current lateral swing motion of the joint by the change in the direction of the magnetic field of the magnet 111.

[0054] As a further improvement to the above-mentioned factual method, the proximal phalanx 200 includes a proximal phalanx skeleton 201, a proximal phalanx shell 202, a proximal phalanx guide wheel 203, an internal hexagonal cylindrical gear 204, a variable guide wheel, a large angle measuring gear component 207, a small angle measuring gear 208, a magnet 209, a phalanx angle measuring sensor module 210, a steel wire rope, and a tension spring 212; The internal hexagonal hole cylindrical gear 204 meshes with the double-layer cylindrical tooth-bevel gear 105; A rotating shaft is provided in the mounting hole 113 on the upper part of the differential cross frame 107. The rotating shaft is provided with a hexagonal socket cylindrical gear 204, a proximal knuckle guide wheel 203, the lower end of the proximal knuckle skeleton 201, and a large angle measuring gear component 207 in sequence. The proximal knuckle guide wheel 203 is fixedly connected to the hexagonal socket cylindrical gear 204, and their center holes are coaxial with the lower hole of the proximal knuckle skeleton 201, the middle hole of the large angle measuring gear component 207, and the mounting hole 113 on the upper part of the differential cross frame 107 and are connected by the rotating shaft 223. The large angle measuring gear component 207 is fixed to the differential cross frame 107 by fasteners. The proximal knuckle guide wheel 203 and the proximal knuckle skeleton 201 can rotate relatively independently. The protractor pinion 208 is mounted between the proximal phalanx housing 202 and the proximal phalanx skeleton 201 via a pin 211. The protractor pinion 208 is mounted on the proximal phalanx skeleton 201 via a pin 211. The protractor pinion is rotatable around the pin 211. The protractor pinion meshes with the protractor gear component 207. The magnet 209 is installed in the gear hole of the protractor pinion 208. The phalanx angle sensor module 210 is fixed on the proximal phalanx skeleton 201 and corresponds to the position of the magnet 209. The phalanx angle sensor module 210 feeds back the relative rotation angle information of the big toe joint by measuring the change in the direction angle of the magnetic field of the magnet 209. The wire rope includes a first reversing rope segment 213, a second reversing rope segment 214, a first rope segment 215, and a second rope segment 216. The proximal knuckle guide wheel 203 is provided with a first rope groove 217, a second reversing rope segment 218, and a second reversing rope groove 219. The second reversing rope segment 218, the second reversing rope groove 219, and the first rope groove 217 are located on the side close to the proximal knuckle frame 201. The first rope groove 217 is located on the side away from the proximal knuckle frame 201. The second reversing rope groove 219 is located on the side close to the proximal knuckle frame 201. The second reversing rope segment 218 is located between the first rope groove 217 and the second reversing rope groove 219. The two guide wheels include guide wheel one 205 and guide wheel two 206. The two guide wheels are installed on one side of the proximal phalanx frame 201 and are located at the upper and lower ends of the proximal phalanx frame 201. Guide wheel one 205 is located at the lower end of the proximal phalanx frame 201, and guide wheel two 206 is located at the upper end of the proximal phalanx frame 201. The second deflection rope segment 218, the second deflection rope groove 219, and the first rope groove 217 are located on the same side of the proximal phalanx frame 201 as guide wheel one 205 and guide wheel two 206. The second deflection rope segment 218, the second deflection rope groove 219, and the first rope groove 217 are provided with rope head mounting holes 113. One end of the rope segment 215 is fixedly installed in the rope head mounting hole 113 in the rope groove 217, and the other end of the rope segment 215 extends to the middle finger joint 300. The middle of the rope segment 215 is connected by a tension spring 212. One end of the first directional rope segment 213 is located in the rope head mounting hole 113 fixedly located in the second directional rope segment 218. After the first directional rope segment 213 extends out of the second directional rope segment 218, it wraps around the first directional guide wheel 205 and then wraps around the upper end of the proximal phalanx skeleton 201 to the second directional guide wheel 206. One end of the second directional rope segment 214 is located in the rope head mounting hole 113 fixedly located in the second directional rope groove 219. After the second directional rope segment 214 extends out of the second directional rope groove 219, it wraps around the first directional guide wheel 205 and then wraps around the upper end of the proximal phalanx skeleton 201 to the second directional guide wheel 206. One end of the first directional rope segment 213 is disposed in the rope head mounting hole 113 fixedly disposed in the second directional rope segment 218, and the first directional rope segment 213 extends to the middle finger joint 300 after being wrapped out of the second directional rope segment 218. The first directional rope segment 213 is disposed on one side of the second directional rope segment 214, and the first directional rope segment 213 passes through the same side of the first directional guide wheel 205 and the second directional guide wheel 206. The first deflection rope segment 213 and the second deflection rope segment 214 both bypass the first deflection guide wheel 205 and the second deflection guide wheel on the near-knuckle skeleton 201, and extend from the side of the first deflection guide wheel 205 and the second deflection guide wheel near the back of the finger to the middle knuckle 300. The angle measuring gear component 207 includes a large gear 220 and an angle measuring component 221. The large gear 220 is an intermittent gear, meaning that only half of a complete gear has teeth. The angle measuring component 221 is disposed on the near finger joint housing 202. The large gear 220 is disposed on the rotating shaft 223. A second rope groove 222 is provided on one side of the large gear 220. The second rope groove 222 is disposed on the side near the angle measuring gear component 207. One end of the second rope segment 216 is connected to the second rope groove 222 on one side of the angle measuring gear component 207. The second rope groove 222 is set in the slot on the differential cross frame 107. The other end of the second rope segment 216 extends upward and is connected to the middle finger joint 300. The middle of the second rope segment 216 is connected by a tension spring 212. The proximal phalanx housing 202 and the proximal phalanx skeleton 201 are fixedly connected on the back of the finger. The proximal phalanx 200 includes the proximal phalanx skeleton 201, the proximal phalanx housing 202, the proximal phalanx guide wheel 203, the internal hexagonal cylindrical gear 204, the variable guide wheel, the angle measuring large gear component 207, the angle measuring small gear 208, the magnet 209, the phalanx angle measuring sensor module 210, the steel wire rope, and the tension spring 212. All parts are enclosed in the proximal phalanx housing 202.

[0055] As a further improvement to the above-mentioned factual method, the middle finger joint 300 includes a middle finger joint skeleton 301, a middle finger joint left outer shell 304, a middle finger joint right outer shell 305, a middle finger joint guide wheel 306, a middle finger joint variable guide wheel 307, a steel wire rope, and a tension spring 308. The middle knuckle guide wheel 307 includes guide wheel three 309 and guide wheel four 310. The middle knuckle left outer shell 304 and middle knuckle right outer shell 305 are respectively fixed to both sides of the middle knuckle frame 301. The middle knuckle frame 301 is provided with a mounting plate 311. The upper and lower parts of the side wall of the mounting plate 311 are respectively provided with guide wheel four 310 and guide wheel three 309. The hole on the middle knuckle guide wheel 306 is coaxial with the hole at the upper end of the near knuckle frame 201, the hole at the lower part of the middle knuckle left outer shell 304, and the hole at the lower part of the middle knuckle right outer shell 305 and is connected by a rotating shaft 318. They can rotate relatively independently from each other. The wire rope includes a third reversing rope segment 312, a fourth reversing rope segment 313, a third rope segment 314, and a fourth rope segment 315; A rope groove 316 is fixedly provided on the lower part of the inner wall of the left outer shell 304 of the middle finger joint, and a rope groove 417 is fixedly provided on the lower part of the inner wall of the right outer shell 305 of the middle finger joint. The lower parts of the left outer shell 304 and the right outer shell 305 of the middle knuckle are provided with mounting holes 113. A rotating shaft 318 is provided in the mounting holes 113. The rope grooves 316 and 417 are provided on the rotating shaft 318. The upper end of the proximal knuckle skeleton 201 is rotatably provided in the middle of the rotating shaft 318. Between the rope grooves 316 and the upper end of the proximal knuckle skeleton 201, there are directional rope grooves 319 and 420. The directional rope grooves 319 are located close to the rope grooves 316. The directional rope grooves 320 are located close to the upper end of the proximal knuckle skeleton 201. The directional guide wheel 309 is located close to the directional rope groove 320. The directional guide wheel 410 is located directly above the directional guide wheel 309. The lower end of the rope segment 314 is wound around the rope groove 316, and the middle of the rope segment 314 is connected by a tension spring 308; The upper end of the rope segment 314 is disposed on the distal phalanx 400; The lower end of the fourth rope segment 315 is wound around the fourth rope groove 317, and the middle of the fourth rope segment 315 is connected by a tension spring 308. The upper end of the rope segment 315 is disposed on the distal phalanx 400; The lower end of the reversing rope segment 312 is wound in the reversing rope groove 319. The lower end of the reversing rope segment 312 extends out of the reversing rope groove 319 and is wound onto the reversing guide wheel 309. The lower end of the reversing rope segment 312 comes out of the reversing guide wheel 309 and is wound onto the reversing guide wheel 309. The lower end of the reversing rope segment 312 comes out of the reversing guide wheel 309 and is connected to the distal finger joint 400.

[0056] The lower end of the fourth directional rope segment 313 is wound in the fourth directional rope groove 320. The lower end of the fourth directional rope segment 313 extends out of the fourth directional rope groove 320 and is wound onto the third directional guide wheel 309. The lower end of the fourth directional rope segment 313 comes out of the third directional guide wheel 309 and is wound onto the fourth directional guide wheel 310. The fourth directional rope segment 313 comes out of the fourth directional guide wheel 310 and is connected to the distal phalanx 400.

[0057] As a further improvement to the above-mentioned factual method, the distal phalanx 400 includes a finger 401, a distal phalanx guide wheel 401, a finger tactile sensor module 404, and a steel wire rope; The central hole of the distal phalanx guide wheel 401, the hole at the lower part of the fingertip 401, the hole at the upper part of the left outer shell 304 of the middle phalanx, and the hole at the upper part of the right outer shell 305 of the middle phalanx are coaxial and connected through a rotating shaft 318, and each component can rotate relatively independently. A rope groove 405 is fixedly provided above the inner wall of the left outer shell 304 of the middle finger joint, and a rope groove 406 is fixedly provided above the inner wall of the right outer shell 305 of the middle finger joint. The upper end of the third rope segment 314 is wrapped around the fifth rope groove 405, extends out of the fifth rope groove 405, and is fixed to the inner wall of the finger 401. The upper end of the fourth rope segment 315 is wrapped around the sixth rope groove 406, extends out of the sixth rope groove 406, and is fixed to the inner wall of the finger 401. The distal knuckle guide wheel 401 is mounted on the rotating shaft 403. The distal knuckle guide wheel 401 is disposed between the mounting plate 311 and the rope groove 405. The distal knuckle guide wheel 401 is provided with a reversing rope groove 407 and a reversing rope groove 408. The reversing rope groove 407 is disposed close to the reversing rope groove 407. The reversing rope groove 408 is disposed between the mounting plate 311 and the reversing rope groove 407. The upper end of the reversing rope segment 312 is wound in the reversing rope groove 407 and fixed. The reversing rope segment 413 comes out of the reversing guide wheel 410 and is wound in the reversing rope groove 608 and fixed. The finger tactile sensor module 404 is fixed to the inner plane of the finger 401, and the outer side of the finger 401 has a shape structure that mimics the human finger 401.

[0058] As a further improvement to the above-mentioned method, the thumb module 3 is mounted on the upper plane of the base 5 of the palm module 1, and the thumb module 3 is at a preset angle to the plane of the palm module 1. A tactile sensor module 7 is arranged at the fingertip of the middle phalanx 300 of the thumb module 3, and tactile sensor modules 7 are arranged at the fingertip of the proximal phalanx 200 and the middle phalanx 300 of the finger module 2.

[0059] As a further improvement to the above-mentioned factual method, rope segment one 215 and rope segment three 314 can be a single integral wire rope or tendon rope. Rope segment one 215 and rope segment three 314 are collectively referred to as main rope one below. Figure 24 As shown, the main rope extends out from part A of rope groove 1 217, goes into part B of rope groove 3 316, then comes out from part C of rope groove 3 316, and then goes into part D of rope groove 5 405, and is finally fixed in rope groove 5 405. Rope segment 216 and rope segment 415 can be a single, integral wire rope or tendon rope. Hereinafter, rope segment 216 and rope segment 415 are collectively referred to as main rope 2. The winding direction of main rope 2 in rope groove 222, rope groove 417, and rope groove 606 is exactly opposite. Therefore, in... Figure 11 , 12 As can be seen from 14, 23, and 24, the first and second main ropes are arranged in the shape of the number "8".

[0060] As a further improvement to the above-mentioned factual method, the first directional rope segment 213 and the third directional rope segment 312 can be a single integral wire rope or tendon rope. Hereinafter, the first directional rope segment 213 and the third directional rope segment 312 are collectively referred to as the main directional rope. The second and fourth directional rope segments 214 and 313 can be a single, integral wire rope or tendon rope. Hereinafter, the second and fourth directional rope segments 214 and 313 are collectively referred to as the main directional rope two. Both the first and second main deflection ropes pass around the deflection guide wheels 1 205 and 206 near the finger joint 200, and extend from the side of the deflection guide wheels 1 205 and 206 near the back of the finger to the deflection guide wheels 3 309 and 4 310.

[0061] like Figures 25-37 As shown, the thumb module includes, from bottom to top, a thumb lateral joint 500, a thumb proximal phalanx 600, a thumb middle phalanx 700, and a thumb distal phalanx 800 connected sequentially. The thumb module has a differential structure on the thumb side joint 500. The intersection of the two axes driven by the thumb differential coincides with the joint rotation plane of the middle phalanx 700 and the distal phalanx 800 of the thumb. The line connecting the midpoint of the joint rotation axis of the middle phalanx 700 of the thumb and the intersection of the differential axis forms a fitting proximal phalanx. The fitting proximal phalanx is in the same plane as the middle phalanx 700 and the distal phalanx 800 of the thumb.

[0062] As a further improvement to the above-mentioned method, the thumb lateral swing joint 500 includes a thumb motor mounting base 501, a thumb drive motor 502, a thumb motor bevel gear 503, a thumb double-layer bevel gear 504, a thumb hexagonal shaft bevel gear 505, a T-shaped bushing 506, and a thumb differential crossarm 507. The thumb motor mounting base 501 has two thumb drive motors 502 at its bottom, which are mounted in the motor housing cavity at the bottom of the thumb motor mounting base 501. The output shafts of both thumb drive motors 502 are coaxially fixedly connected to the thumb motor bevel gear 503 via fasteners. The thumb differential crossarm 507 is rotatably mounted at the rotation mating hole on the upper part of the thumb motor mounting base 501. The T-shaped bushing 506 is rigidly fixed to the differential crossarm by a positioning shaft that intersects horizontally and vertically. The T-shaped bushing 506 includes two longer thumb shafts 508 and one shorter thumb shaft 509. The two thumb double-layer bevel gears 504 are symmetrically and clearance-fittedly installed on the two longer thumb shafts 508 of the T-shaped bushing 506. The thumb hexagonal shaft bevel gear 505 is clearance-fittedly installed on one of the shorter thumb shafts 509 of the T-shaped bushing 506. The inner bevel teeth of the two thumb double-layer bevel gears 504 and the thumb hexagonal shaft bevel gear 505 mesh with each other at the center position of the T-shaped bushing 506 and can all rotate independently around the corresponding shaft of the bushing. The outer bevel teeth of the two thumb double-layer bevel gears 504 mesh with the two thumb motor bevel gears 503 without backlash.

[0063] As a further improvement to the above-mentioned method, the thumb proximal phalanx 600 includes an upper outer shell 601, a lower outer shell 602, a thumb drive motor 603, a thumb drive motor bevel gear 604, and a thumb wire rope 605. The thumb drive motor 603 is fixed in the motor mounting cavity inside the upper outer shell 601 of the thumb proximal phalanx by a thumb motor bracket. The thumb drive motor bevel gear 604 is coaxially fixed to the output shaft of the thumb drive motor 603 by fasteners. The lower outer shell 602 of the thumb proximal phalanx is fixedly connected to the upper outer shell 601 of the thumb proximal phalanx. The lower part of the lower outer shell 602 of the thumb proximal phalanx is connected and fixed to the thumb hexagonal bevel gear 505 on the thumb lateral joint by fasteners. The lower end of the steel wire rope 605 is fixed to the steel wire rope positioning groove 606 on the outside of the upper outer shell 601 of the thumb proximal phalanx by a crimping member. The upper end of the thumb steel wire rope 605 extends to the middle phalanx 700 of the thumb along a preset wiring channel.

[0064] As a further improvement to the aforementioned factual method, the thumb middle phalanx 700 includes a thumb middle phalanx skeleton 701, a left outer shell 704, a right outer shell 705, a thumb drive bevel gear 706, a thumb middle phalanx guide wheel 707, a thumb deflection guide wheel, a second thumb wire rope 709, a third thumb wire rope 710, a fourth thumb wire rope 711, and a thumb lower mounting shaft 715. The left outer shell 704 and the right outer shell 705 of the thumb middle phalanx are connected to the thumb via the thumb lower mounting shaft 715. The finger mounting shaft 803 is fixedly installed on both sides of the thumb middle phalanx skeleton 701. A thumb deflection guide wheel is fixed on the side wall of the thumb middle phalanx skeleton 701. The thumb deflection guide wheel includes an upper thumb deflection guide wheel 708 and a lower thumb deflection guide wheel 712. The upper thumb deflection guide wheel 708 and the lower thumb deflection guide wheel 712 are fixedly installed on the side wall of the thumb middle phalanx skeleton 701. The upper thumb deflection guide wheel 708 and the lower thumb deflection guide wheel 712 are installed near the side of the thumb middle phalanx 700 that forms the outer shell. The upper part of the upper outer shell 601 of the proximal thumb joint is provided with a thumb guide wheel mating hole. The lower part of the left outer shell 704 of the middle thumb joint is provided with a thumb mounting hole 713. The lower part of the right outer shell 705 of the middle thumb joint is provided with a thumb mounting hole 714. The thumb middle joint guide wheel 707 is coaxially arranged with the upper thumb guide wheel mating hole of the upper outer shell 601 of the proximal thumb joint, the lower thumb mounting hole 713 of the left outer shell 704 of the middle thumb joint, and the lower thumb mounting hole 714 of the right outer shell 705 of the middle thumb joint. The lower thumb mounting shaft 715 is installed in the upper thumb guide wheel mating hole of the upper outer shell 601 of the proximal thumb joint, the lower thumb mounting hole 713 of the left outer shell 704 of the middle thumb joint, and the lower thumb mounting hole 714 of the right outer shell 705 of the middle thumb joint. The thumb middle joint guide wheel 707 is disposed on the lower thumb mounting shaft 715 and rotates on the lower thumb mounting shaft 715. The lower part of the knuckle skeleton 701 is mounted on the thumb mounting shaft 715. The thumb drive bevel gear 706 is mounted on the thumb mounting shaft 715 and is installed near the left outer shell 704 of the thumb middle knuckle. The thumb middle knuckle guide wheel 707 is provided with wire rope grooves 1 716, 2 717, 3 718, and 4 wire rope grooves respectively from the left outer shell 704 to the right outer shell 705 of the thumb middle knuckle. The fourth groove 719, the first wire rope groove 716, the second wire rope groove 717, and the third wire rope groove 718 are installed on the left side of the thumb middle phalanx skeleton 701 and close to the left outer shell 704 of the thumb middle phalanx, the fourth wire rope groove 719 is installed on the right side of the thumb middle phalanx skeleton 701 and close to the right outer shell 705 of the thumb middle phalanx, and the thumb drive bevel gear 706 is located between the lower end of the first wire rope 605 and the second wire rope groove 717; The thumb drive motor bevel gear 604 meshes with the thumb drive bevel gear 706; The top of the upper outer shell 601 of the thumb proximal phalanx is located between the right side wall of the thumb middle phalanx skeleton 701 and the wire rope groove 719. The thumb-down guide wheel 712 is positioned above the wire rope groove 718; As a further improvement to the above-mentioned method, the distal phalanx of the thumb 800 includes a thumb tip 801, a distal phalanx guide wheel 802, a thumb mounting shaft 803, and a tactile sensor module 804 for the thumb tip 801. The distal phalanx guide wheel 802 has a central hole, and the lower part of the thumb tip 801 has a mating hole for the upper mounting shaft 803. The upper parts of the left outer shell 704 and the upper parts of the right outer shell 705 of the middle phalanx of the thumb on both sides of the middle phalanx of the thumb have mating holes for the upper mounting shaft 803. The central hole on the distal phalanx guide wheel 802, the mating hole for the upper mounting shaft 803 at the lower part of the thumb tip 801, and the mating holes for the upper mounting shaft 803 at the upper parts of the left outer shell 704 and the right outer shell 705 of the middle phalanx of the thumb are coaxial and connected by a through-hole connection of the upper mounting shaft 803. The thumb distal phalanx guide wheel 802 is provided with wire rope grooves 5 805, 6 806, 7 807, and 808 respectively from the left outer shell 704 of the thumb middle phalanx to the right outer shell 705 of the thumb middle phalanx. The wire rope grooves 5 805, 6 806, and 7 807 are installed on the left side of the thumb middle phalanx frame 701 and close to the left outer shell 704 of the thumb middle phalanx. The wire rope groove 808 is installed on the right side of the thumb middle phalanx frame 701 and close to the right outer shell 705 of the thumb middle phalanx. The upper guide wheel 708 of the thumb is located below the wire rope groove 707. The upper part of the middle phalanx of the thumb 700 is mounted on the upper mounting shaft 803 of the thumb. The upper mounting shaft 803 of the thumb and the lower mounting shaft 715 of the thumb are both fixedly mounted between the left outer shell 704 and the right outer shell 705 of the middle phalanx of the thumb. The lower end of the steel wire rope 605 is fixed in the steel wire rope positioning groove 606 on the outer side of the outer shell 601 of the thumb proximal phalanx. After the lower part of the steel wire rope 605 is wrapped around the steel wire rope groove 716 once, it comes out from the right side of the steel wire rope groove 716, that is, the steel wire rope groove 716 near the inner side 810 of the thumb phalanx, and starts to wrap around the steel wire rope groove 805 on the left side of the steel wire rope groove 805 near the outer side 809 of the thumb phalanx. After the upper end of the steel wire rope 605 is fixed in the steel wire rope 605 fixing hole provided on the outer side of the finger through the crimping member. The lower end of the second wire rope 709 is fixed in the second wire rope groove 717. After the second wire rope 709 is wrapped around the second wire rope groove 717 once, the left side of the second wire rope groove 717, that is, starting from the outer side 809 of the thumb knuckle of the second wire rope groove 717 and moving upward towards the finger, is wrapped around the sixth wire rope groove 806 once. The upper end of the second wire rope 709 is then fixed in the fixing hole of the second wire rope 709 provided on the outer side of the finger by a crimping member. The lower end of the steel wire rope 710 is fixed in the steel wire rope groove 718. After the steel wire rope 710 is wrapped around the steel wire rope groove 718 once, the steel wire rope 710 extends from the right side of the steel wire rope groove 718, that is, from the inside of the thumb joint 810, upwards towards the bottom of the thumb-down guide wheel and wraps around it once. The steel wire rope 710 then emerges from the left side of the thumb-down guide wheel, that is, from the outside of the thumb joint 809, upwards towards the fingertip. The wire rope 3 710 starts from the left side of the guide wheel above the thumb, that is, near the outer side of the thumb knuckle 809, and then wraps around the guide wheel below the thumb. After that, the wire rope 3 710 comes out from the left side of the guide wheel above the thumb and starts to wrap around the lower part of the wire rope groove 7 807. After that, the wire rope 3 710 comes out from the right side of the wire rope groove 7 807, that is, near the inner side of the thumb knuckle 810. The upper end of the wire rope 3 710 is fixed in the wire rope 3 710 fixing hole provided on the outer side of the thumb tip 801 by a crimping member. The lower end of the wire rope 711 is fixed in the wire rope groove 719. After the lower part of the wire rope 711 is wrapped around the wire rope groove 719 once, it comes out from the left side of the wire rope groove 719, that is, the wire rope groove 716 near the outside of the thumb joint 809, and then starts to wrap around the wire rope groove 808 on the right side of the distal phalanx, that is, the wire rope groove 808 near the inside of the thumb joint 810. After the upper end of the wire rope is fixed in the fixing hole of the wire rope 711 provided on the outside of the finger through the crimping member. The thumb fingertip 801 tactile sensor module 804 is connected and fixed to the inner plane of the fingertip.

[0065] As a further improvement to the above-mentioned method, the thumb lateral joint 500 also includes a thumb magnet 511 and an angle sensor module 512. The thumb differential crossbeam 507 is provided with a dedicated slot. The thumb magnet 511 is interference-fitted and fixed in the dedicated slot on the thumb differential crossbeam 507. The thumb motor mounting base 501 is provided with a sensor mounting position on its back. The angle sensor module 512 is fixed to the sensor mounting position on the back of the thumb motor mounting base 501 by bolts. The angle sensor module 512 and the thumb magnet 511 cooperate non-contactly to detect the real-time rotation angle of the lateral joint.

[0066] As a further improvement to the above-mentioned factual method, the wire rope is made of stainless steel.

[0067] As a further improvement to the above-mentioned method, the middle sections of the first wire rope 605 and the fourth wire rope 711 are connected by a tension spring 720, which is a precision tension spring made of stainless steel. As a further improvement to the above-mentioned method, the angle sensor module 512 is a magnetoelectric angle encoder with a detection accuracy of not less than 0.1°.

[0068] As a further improvement to the above-mentioned method, the thumb finger 801 tactile sensor module 804 is a flexible array pressure sensor, and the detection accuracy of the flexible array pressure sensor is not less than 0.2N.

[0069] As a further improvement to the above-mentioned factual method, the wire rope is a 7×19 structure multi-strand twisted stainless steel wire rope with a diameter of 0.3 to 0.8 mm. The surface of the wire rope is galvanized for rust prevention, and the wire rope's routing channels are all equipped with wear-resistant nylon bushings.

[0070] As a further improvement to the above-mentioned factual method, the motor mounting base of the thumb lateral joint 500, the thumb differential crossbeam 507, the upper and lower shells of the thumb proximal joint 600, the skeleton of the thumb middle joint 700 and the left and right shells of the thumb middle joint 700, and the anthropomorphic finger of the thumb distal joint 800 are all made of lightweight and high-strength aerospace-grade aluminum alloy.

[0071] As a further improvement to the above-mentioned factual method, a limiting baffle 510 is provided at the top of the thumb hexagonal bevel gear 505, and the limiting baffle 510 is adapted to the tail of the thumb proximal phalanx lower housing 602.

[0072] As a further improvement to the above-mentioned factual method, the outer side of the thumb 801 is a biomimetic arc shape that imitates the human thumb 801.

[0073] Working principle: A hybrid transmission mechanism for underactuated manipulators consists of a side swing joint, proximal phalanx, middle phalanx, and distal phalanx rigidly connected from bottom to top, with a total of 4 movable joints corresponding to 4 degrees of freedom. It combines active precision drive of bevel gear differential with underactuated coupling adaptive transmission of wire rope-guide wheel-tension spring 720. It also integrates angle sensing and tactile sensing modules to achieve an integrated design of "precise control + adaptive grasping + closed-loop feedback". The overall structure is compact, lightweight, and easy to assemble and maintain.

[0074] The lateral swing joint is the basic drive joint of the entire finger and the core of realizing the two orthogonal active degrees of freedom of lateral swing and flexion and extension. It includes a motor mounting base, two drive motors, two motor bevel gears, two double-layer bevel gears, a hexagonal shaft bevel gear, a T-shaped bushing 506, a differential crossbar, a magnet 511, and an angle sensor module.

[0075] Two drive motors are symmetrically and coaxially mounted in a dedicated motor housing at the bottom of the motor mounting base, effectively avoiding structural interference. The motor output shafts are coaxially fixed to the motor bevel gears by fasteners to ensure the coaxiality of the transmission. In the thumb module, the thumb differential crossarm is rotatably mounted at the rotating mating hole on the upper part of the thumb motor mounting base, and can rotate within ±75° around the axis of the hole on the upper part of the thumb motor mounting base. The differential crossarm is rotatably mounted at the rotating mating hole on the upper part of the motor mounting base, and can rotate within ±15° around the axis of the hole on the upper part of the motor mounting base. The four finger modules are independently mounted on the palm module, covering the lateral swing range of the human thumb and four fingers, meeting the needs of most grasping operations. The T-shaped bushing 506 is rigidly fixed to the differential crossarm through a horizontally and vertically intersecting positioning shaft. Two double-layer bevel gears are symmetrically and clearance-fitted onto the two longer shafts of the T-shaped bushing 506. A hexagonal bevel gear is clearance-fitted onto one of the shorter shafts of the T-shaped bushing 506. The inner bevel teeth of the three gear components mesh with each other at the center of the T-shaped bushing 506, and the outer bevel teeth mesh with the motor bevel gear without backlash, ensuring the accuracy and smoothness of the transmission and eliminating transmission backlash. The magnet 511 is interference-fitted and fixed to a dedicated slot in the differential crossbeam. The angle sensor module is fixed to the back of the motor mounting base and non-contactly engages with the magnet 511 to detect the lateral sway angle, avoiding wear caused by mechanical contact and improving detection accuracy and service life. The core working principle of this joint is as follows: by precisely controlling the steering combination and speed difference of the two drive motors, the lateral swing motion of the differential frame (corresponding to the lateral swing degree of freedom of the fingers) and the rotational motion of the hexagonal bevel gear (corresponding to the flexion and extension active degree of freedom of the fingers) are controlled synchronously, so as to achieve stepless speed regulation and precise posture control of the two orthogonal active degrees of freedom. There is no need to configure a separate driver for each joint, which greatly simplifies the structure and control.

[0076] The proximal joint serves as a transitional joint connecting the lateral swing joint and the middle joint, while also providing the power transmission foundation for the wire rope drive. It includes the upper shell of the proximal joint, the lower shell of the proximal joint, the drive motor, the drive motor bevel gear, and multiple strands of stainless steel wire rope.

[0077] The drive motor is fixed to the motor mounting cavity inside the upper outer shell of the proximal phalanx via a motor bracket, achieving built-in installation of the motor and effectively reducing the external volume of the finger. The drive motor bevel gear is coaxially fixed with the motor output shaft to ensure power transmission efficiency. The lower outer shell of the proximal phalanx is fixed to the upper outer shell by a combination of clips and bolts, ensuring a firm connection and convenient assembly and disassembly. The lower part of the lower outer shell of the proximal phalanx is rigidly fixed coaxially with the hexagonal shaft bevel gear, allowing the proximal phalanx to rotate synchronously with the hexagonal shaft bevel gear, realizing active flexion and extension movements. The transmission element is a 7×19 multi-strand twisted stainless steel wire rope with a diameter of 0.3~0.8mm and a galvanized surface for rust prevention. One end of the wire rope is fixed to the positioning grooves on both sides of the outer shell near the finger joint through a crimping component, and the other end extends to the middle finger joint along the internal preset wiring channel to avoid the wire rope being exposed and improve the stability of the transmission.

[0078] The middle joint is the core joint of the underactuated coupling transmission, realizing the proportional relationship between driving force and rotational speed. It includes the middle joint skeleton, the left outer shell of the middle joint, the right outer shell of the middle joint, the middle joint guide wheel, two variable guide wheels, multi-strand stainless steel wire rope and tension spring 720.

[0079] The middle finger joint frame is made of aerospace-grade aluminum alloy, providing core structural support for the middle finger joint. The left and right outer shells are bolted to both sides of the frame, forming a closed housing space to protect the internal transmission components. Two guide wheels are symmetrically arranged in a figure-eight shape on the side wall of the middle finger joint frame, effectively optimizing the cable routing angle and reducing bending wear. The guide wheels of the middle finger joint are coaxial with the corresponding holes of the near and middle finger joints, and are connected by a clearance fit of the rotating shaft, allowing each component to rotate independently relative to each other. The two middle wire ropes are fixed... The guide wheel is positioned at the middle finger joint, and after passing through the variable guide wheel, it extends to the fingertip along a preset arc-shaped cable channel. The two outer sections of steel wire rope are elastically connected by tension spring 720. The two ends pass through the rope rail grooves at the top and bottom of the middle finger joint respectively and connect the proximal and distal finger joints. Wear-resistant nylon bushings are set on the inner side of the rope rail grooves to reduce wear of the steel wire rope during movement. The core design point is that by designing the wheel diameter ratio of the steel wire rope around the guide wheel, the driving force of the middle finger joint and the distal finger joint is related in a preset ratio of 1:(0.6~0.8). By precisely designing the diameter ratio of the arc-shaped rope rail enveloping the outer steel wire rope, the rotation speed of the two knuckles is correlated according to a preset ratio of 1:(0.7~0.9); the tension spring 720 is a precision stainless steel tension spring with a stiffness of 0.5~2N / mm, which can be customized according to the grasping requirements to achieve flexible adaptive movement of the fingers.

[0080] The distal phalanx is the actuating end of the finger, enabling direct contact with the object being grasped. It includes a humanoid finger, a distal phalanx guide wheel, and a finger tactile sensor module 804. The distal phalanx guide wheel is coaxial with the corresponding holes of the finger and middle phalanx, and is connected by a positioning shaft with clearance fit to ensure the independence and smoothness of the rotation of each component. Self-lubricating oil-impregnated bearings are installed at each rotating joint to reduce frictional resistance. All wire ropes are secured using crimp connectors, replacing traditional knotting methods. This improves the stability of the fixation, prevents the wire ropes from loosening, and facilitates later replacement and adjustment. The integrated sensing and lightweight design of this invention combines a magnetoelectric angle encoder (angle sensor module) and a flexible array pressure sensor (finger tactile sensor module 804). The angle encoder has a detection accuracy of no less than 0.1° and outputs angle data via an SPI interface. The pressure sensor outputs tactile data via an I2C interface, achieving dual closed-loop feedback of motion position and contact force, providing data support for the precise control of the robot control system. The core structural components of the fingers are all made of lightweight, high-strength aerospace-grade aluminum alloy and undergo hard anodizing treatment. While ensuring structural strength (able to withstand axial pressure of no less than 100N), the overall weight is reduced to the minimum. The overall weight of the robotic hand does not exceed 1000g, meeting the lightweight requirements of humanoid robots. Each structural component adopts standardized design dimensions and installation interfaces, achieving unified drive and communication interfaces with other finger modules of the robot's dexterous hand. Core transmission components can be standardized and replaced, greatly improving versatility and ease of maintenance.

[0081] This invention achieves the following significant benefits through a hybrid transmission structure design using a bevel gear differential coupled with a wire rope, internalized wire rope routing, multi-parameter proportional correlation design, integrated sensor integration, and lightweight standardized design: It balances motion accuracy with structural simplification, and significantly reduces control difficulty. This invention employs a bevel gear differential structure for the lateral swing joint, which achieves coordinated and precise control of two orthogonal active degrees of freedom—lateral swing and flexion / extension—through two drive motors. This eliminates the need for an independent driver for each joint, effectively solving the problems of high integration difficulty and complex control in full-drive solutions. Meanwhile, the backlash-free gear meshing design ensures the accuracy of motion, with a position and posture control accuracy of no less than 0.1°, meeting the requirements for refined operation.

[0082] Convenient assembly and maintenance, significantly reducing time and cost: This invention arranges all steel wire ropes in a pre-designed wiring channel inside the finger, replacing the external steel wire rope arrangement method of the existing technology. This avoids mutual interference between steel wire ropes, and there is no need to repeatedly adjust the tension of the external steel wire ropes during assembly. The assembly time is shortened by more than 60% compared with the existing all-steel wire rope solution. At the same time, each component adopts a composite connection method of buckle + bolt, and the core transmission components can be replaced in a standardized manner. During later maintenance and upgrades, only the corresponding shell needs to be disassembled, without overall disassembly, which greatly reduces maintenance costs.

[0083] With strong gripping and enveloping adaptability and significant flexible adaptation effect: This invention achieves a preset proportional relationship between the driving force and rotation speed of the middle and distal phalanges by customizing the wheel diameter ratio of the wire rope surrounding the guide wheel and the diameter ratio of the arc-shaped rope rail. Combined with a precision tension spring 720 with customizable stiffness, it enables the fingers to achieve flexible adaptive enveloping motion within the contact force range of 0~25N. It can achieve good enveloping gripping of objects with regular and irregular shapes, and the gripping stability is improved by more than 50% compared with the existing underactuated solution.

[0084] High sensor integration enables dual closed-loop feedback control: This invention innovatively integrates a magnetoelectric angle encoder and a flexible array pressure sensor, which can collect the rotation angle of the side swing joint and the magnitude and distribution of the contact force of the fingertip in real time. The data is output to the robot control system through the SPI / I2C communication interface, realizing dual closed-loop feedback of motion position and contact force. This effectively solves the problem of low force control accuracy in existing solutions, enabling precise pinching and gripping operations and preventing objects from slipping or being pinched.

[0085] Lightweight and standardized design with broad prospects for industrial application: The core structural components of this invention are all made of aerospace-grade aluminum alloy, and the overall weight of the robotic hand does not exceed 1000g, meeting the lightweight requirements of humanoid robots. At the same time, each structural component adopts a standardized design, achieving unified drive and communication interfaces with other finger modules. Core transmission components can be replaced in a standardized manner, which greatly improves the versatility and yield rate of the product, reduces industrial production costs, and can be widely used in dexterous hand modules of humanoid robots and industrial collaborative robots, possessing extremely high engineering application value.

[0086] This invention employs a hybrid transmission method that combines a bevel gear differential structure for the lateral swing joint with an underactuated tendon-driven coupled motion finger joint structure. Two motors are used to control the two active degrees of freedom of the finger's lateral swing and flexion / extension. This achieves the same number of degrees of freedom and overall hand dexterity as a fully driven manipulator with fewer motors, significantly reducing the design difficulty of the control system and the communication and coordination difficulty of the humanoid robot. At the same time, the modular structural design makes the control system easier to package and improves the overall integration.

[0087] This invention arranges tendon cords only inside the fingers, abandoning the overall tendon cord arrangement scheme of pure tendon cord driven robotic arms. Combined with the independent modular design of the palm module, finger module, and thumb module, each module can be quickly installed and disassembled, greatly reducing assembly time. At the same time, the maintenance and replacement of tendon cords and the difficulty of upgrading and modifying robotic arms are also significantly reduced, improving the convenience and economy of use.

[0088] This invention uses tendon cord transmission to replace traditional linkage transmission. The tendon cord structure is small in size and light in weight, which can save a lot of internal space in the fingers and effectively reduce the weight of the entire hand, meeting the design requirements of lightweight and miniaturized humanoid robots. At the same time, the flexible transmission characteristics of the tendon cord also improve the flexibility of finger movement.

[0089] This invention designs the diameter of the guide wheel around the two tendon cords inside the finger, so that the driving force of the three movable joints of the finger is correlated in a certain proportion; designs the diameter ratio of the arc-shaped rope rails wrapped by the four spring-loaded tendon cords on both sides, so that the rotation speed of the three phalanges of the finger is correlated in a certain proportion; and designs the stiffness of the springs to achieve a flexible adaptive effect of the finger within a certain range. The combination of these three features enables the robotic hand to achieve a good covering and gripping effect on objects of any shape, thus improving the stability of the grip.

[0090] This invention incorporates tactile sensor modules in the fingertips, the proximal and middle phalanges of the finger module, the middle phalange of the thumb module, and the palm, forming a high-coverage tactile detection network. Compared to most robotic hands on the market that lack tactile feedback or only have tactile feedback at the fingertips, this invention offers higher tactile sensor coverage, enabling richer and more accurate detection and feedback of the state of the object being held. This effectively prevents slippage and damage to objects, expanding the application range of robotic hands in precision operation scenarios.

[0091] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0092] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0093] The underactuated manipulator with a hybrid transmission mechanism provided by this invention has been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. An underactuated manipulator with a hybrid transmission mechanism, comprising a palm module, four identical finger modules, and a thumb module, characterized in that, The four finger modules and the thumb module are independently mounted on the palm module; The finger module is composed of a lateral swing joint, a proximal phalanx, a middle phalanx, and a distal phalanx connected sequentially from bottom to top. The lateral swing joint adopts a bevel gear differential structure. The proximal phalanx, middle phalanx, and distal phalanx form a coupled motion structure through the cooperation of tendon ropes and tension springs.

2. The underactuated manipulator with a hybrid transmission mechanism according to claim 1, characterized in that, The palm module includes a vertical plate, a base, a palm shell, a tactile sensor module, a control circuit board, and an external plug. The vertical plate is vertically connected and fixed to the base. The vertical plate is used to install four finger modules and their corresponding control circuit boards, and the base is used to install a thumb module and its corresponding control circuit board. The palm shell covers part of the structure of the finger module and thumb module, and the palm shell is fixedly connected to the upright plate and the base. The tactile sensor module is fixed inside the palm shell.

3. The underactuated manipulator with a hybrid transmission mechanism according to claim 1, characterized in that, The side swing joint includes a motor, a motor mounting base, a motor bevel gear, a double-layer bevel gear, a double-layer cylindrical tooth-bevel gear, a cross bushing, a differential crossarm, a magnet, and an angle sensor module. The two motors are mounted on the bottom of the motor mounting base. The motor bevel gear is fixedly connected to the motor output shaft. The upper part of the motor mounting base is provided with mounting holes. The differential crossbar is mounted on the upper part of the motor mounting base and can rotate at a fixed angle around the axis of the mounting hole on the upper part of the motor mounting base. Two double-layer bevel gears are symmetrically mounted on the two longer shafts of the cross bushing, and the double-layer cylindrical bevel gear is mounted on one shorter shaft of the cross bushing. The bevel teeth of the two double-layer bevel gears and the double-layer cylindrical bevel gear mesh with each other at the center of the cross bushing and can rotate around the shaft of the bushing. The other layer of bevel teeth of the double-layer bevel gear meshes with the motor bevel gear. The cross bushing is fixed to the differential cross frame through the shaft. The differential crossbar has a slot, and the magnet is fixedly installed in the slot on the differential crossbar. The magnet rotates coaxially, in the same direction and at the same speed as the double-layer bevel gear during the lateral swing. The angle sensor module is fixed to the back of the motor mounting base and corresponds to the position of the magnet. The angle sensor module detects the angle position of the current lateral swing of the joint by the change in the direction of the magnetic field of the magnet.

4. The underactuated manipulator with a hybrid transmission mechanism according to claim 1, characterized in that, The proximal phalanx includes a proximal phalanx skeleton, a proximal phalanx shell, a proximal phalanx guide wheel, an internal hexagonal cylindrical gear, a variable guide wheel, a large angle measuring gear component, a small angle measuring gear, a magnet, a phalanx angle measuring sensor module, a steel wire rope, and a tension spring. The internal hexagonal hole cylindrical gear meshes with the double-layer cylindrical tooth-bevel gear; A rotating shaft is provided in the mounting hole at the upper part of the differential crossarm. The rotating shaft is provided with a hexagonal socket cylindrical gear, a proximal knuckle guide wheel, the lower end of the proximal knuckle skeleton, and a large angle measuring gear component in sequence. The proximal knuckle guide wheel is fixedly connected to the hexagonal socket cylindrical gear, and their center holes are coaxial with the lower hole of the proximal knuckle skeleton, the center hole of the large angle measuring gear component, and the mounting hole at the upper part of the differential crossarm, and are connected through the rotating shaft. The large angle measuring gear component is fixed to the differential crossarm by fasteners. The proximal knuckle guide wheel and the proximal knuckle skeleton can rotate relatively independently. The protractor pinion is mounted between the protractor phalanx shell and the protractor phalanx skeleton via a pin. The protractor pinion is also mounted on the protractor phalanx skeleton via a pin. The protractor pinion can rotate around the pin. The protractor pinion meshes with the protractor large gear component. The magnet is installed in the gear hole of the protractor pinion. The phalanx angle sensor module is fixed on the protractor phalanx skeleton and corresponds to the position of the magnet. The phalanx angle sensor module feeds back the relative rotation angle information of the big toe joint by measuring the change in the direction angle of the magnetic field of the magnet. The wire rope includes a first reversing rope segment, a second reversing rope segment, a first rope segment, and a second rope segment. The guide pulley near the finger joint is provided with a first rope groove, a first reversing rope groove, and a second reversing rope groove. The first reversing rope groove is located on the side near the finger joint skeleton, the second reversing rope groove is located on the side away from the finger joint skeleton, and the third reversing rope groove is located on the side near the finger joint skeleton. The first reversing rope groove is located between the first rope groove and the second reversing rope groove. The two guide wheels include guide wheel one and guide wheel two. The two guide wheels are installed on one side of the proximal phalanx and are located at the upper and lower ends of the proximal phalanx. Guide wheel one is located at the lower end of the proximal phalanx, and guide wheel two is located at the upper end of the proximal phalanx. Guide groove one, guide groove two, and groove one are located on the same side of the proximal phalanx as guide wheels one and guide wheel two. Guide groove one, guide groove two, and groove one are provided with rope end mounting holes. One end of the first rope segment is fixedly installed in the rope head mounting hole in the first rope groove, and the other end of the first rope segment extends to the middle finger joint. The middle of the first rope segment is connected by a tension spring. One end of the first reversing rope segment is set in the rope head mounting hole fixedly set in the first reversing rope groove. After the first reversing rope segment extends out of the first reversing rope groove, it wraps around the first reversing guide wheel and then wraps around the upper end of the near-knuckle skeleton to the second reversing guide wheel. One end of the second reversing rope segment is set in the rope head mounting hole fixedly set in the second reversing rope groove. After the second reversing rope segment extends out of the second reversing rope groove, it wraps around the first reversing guide wheel and then wraps around the upper end of the near-knuckle skeleton onto the second reversing guide wheel. One end of the first reversing rope segment is disposed in the rope head mounting hole fixedly disposed in the first reversing rope groove, and the first reversing rope segment extends to the middle finger joint after being wound out of the first reversing rope groove. The first directional rope segment is located on one side of the second directional rope segment, and the first directional rope segment passes through the same side of the first directional guide wheel and the second directional guide wheel. Both the first and second deflection rope segments bypass the first and second deflection guide wheels on the near-knuckle skeleton and extend from the side of the first and second deflection guide wheels near the back of the finger toward the middle knuckle. The angle measuring gear component includes a large gear and an angle measuring component. The angle measuring component is disposed on the outer shell near the finger joint, and the large gear is disposed on the rotating shaft. A second rope groove is provided on one side of the large gear, and the second rope groove is disposed on the side near the angle measuring gear component. One end of the second rope segment is connected to the second rope groove on one side of the angle measuring gear component. The second rope groove is set in the slot on the differential crossbar. The other end of the second rope segment extends upward and is connected to the middle finger joint. The middle of the second rope segment is connected by a tension spring. The proximal phalanx shell and the proximal phalanx skeleton are fixedly connected to the back of the finger. The proximal phalanx includes the proximal phalanx skeleton, the proximal phalanx shell, the proximal phalanx guide wheel, the internal hexagonal cylindrical gear, the variable guide wheel, the angle measuring large gear component, the angle measuring small gear, the magnet, the phalanx angle measuring sensor module, the steel wire rope, and the tension spring. All parts are enclosed in the proximal phalanx shell.

5. The underactuated manipulator with a hybrid transmission mechanism according to claim 4, characterized in that, The middle finger joint includes a middle finger joint skeleton, a left outer shell of the middle finger joint, a right outer shell of the middle finger joint, a middle finger joint guide wheel, a middle finger joint deflector guide wheel, a steel wire rope, and a tension spring; The middle finger joint guide wheel includes guide wheel three and guide wheel four. The left and right outer shells of the middle finger joint are fixed to both sides of the middle finger joint frame. The inner side of the middle finger joint frame is provided with a mounting plate. The upper and lower parts of the side wall of the mounting plate are respectively provided with guide wheel four and guide wheel three. The holes on the guide wheels of the middle finger joint are coaxial with the holes near the upper end of the middle finger joint frame, the holes at the lower part of the left outer shell of the middle finger joint, and the holes at the lower part of the right outer shell of the middle finger joint, and are connected by a rotating shaft. They can rotate relatively independently from each other. The wire rope includes reversing rope segment three, reversing rope segment four, rope segment three, and rope segment four; A rope groove three is fixedly provided on the lower part of the inner wall of the left outer shell of the middle finger joint, and a rope groove four is fixedly provided on the lower part of the inner wall of the right outer shell of the middle finger joint. The lower parts of the left and right outer shells of the middle phalanx are provided with mounting holes, and a rotating shaft is provided in the mounting holes. Rope grooves three and four are provided on the rotating shaft. The upper end of the proximal phalanx skeleton is rotatably provided in the middle of the rotating shaft. A deflecting rope groove three and a deflecting rope groove four are provided between rope groove three and the upper end of the proximal phalanx skeleton. The deflecting rope groove three is located close to rope groove three, and the deflecting rope groove four is located close to the upper end of the proximal phalanx skeleton. The deflecting guide wheel three is located close to the deflecting rope groove four, and the deflecting guide wheel four is located directly above the deflecting guide wheel three. The lower end of the third rope segment is wound around the third rope groove, and the middle of the third rope segment is connected by a tension spring; The upper end of the third rope segment is positioned on the distal phalanx; The lower end of the fourth rope segment is wound around the fourth rope groove, and the middle of the fourth rope segment is connected by a tension spring; The upper end of the fourth rope segment is positioned on the distal phalanx; The lower end of the third directional rope segment is wound in the third directional rope groove. The lower end of the third directional rope segment extends out of the third directional rope groove and is wound around the third directional guide wheel. The lower end of the third directional rope segment comes out of the third directional guide wheel and is wound around the third directional guide wheel. The lower end of the third directional rope segment comes out of the third directional guide wheel and is connected to the distal phalanx. The lower end of the fourth directional rope segment is wound in the fourth directional rope groove. The lower end of the fourth directional rope segment extends out of the fourth directional rope groove and is wound around the third directional guide wheel. The lower end of the fourth directional rope segment comes out of the third directional guide wheel and is wound around the fourth directional guide wheel. The lower end of the fourth directional rope segment comes out of the fourth directional guide wheel and is connected to the distal phalanx.

6. The underactuated manipulator with a hybrid transmission mechanism according to claim 5, characterized in that, The distal phalanx includes a finger, a distal phalanx guide wheel, a finger tactile sensor module, and a steel wire rope; The central hole of the distal phalanx guide wheel, the hole at the bottom of the fingertip, the hole at the top of the left outer shell of the middle phalanx, and the hole at the top of the right outer shell of the middle phalanx are coaxial and connected by a rotating shaft, and each component can rotate relatively independently. A rope groove five is fixedly provided above the inner wall of the left outer shell of the middle finger joint, and a rope groove six is ​​fixedly provided above the inner wall of the right outer shell of the middle finger joint. The upper end of the third rope segment is wrapped around the fifth rope groove, extends out of the fifth rope groove, and is then fixed to the inner wall of the finger. The upper end of the fourth rope segment is wrapped around the sixth rope groove, extends out of the sixth rope groove, and is then fixed to the inner wall of the finger. The distal finger joint guide wheel is mounted on the rotating shaft. The distal finger joint guide wheel is disposed between the mounting plate and the rope groove five. The distal finger joint guide wheel is provided with a reversing rope groove five and a reversing rope groove six. The reversing rope groove five is disposed close to the reversing rope groove five. The reversing rope groove six is ​​disposed between the mounting plate and the reversing rope groove five. The upper end of the reversing rope segment three is wound around the reversing rope groove five and fixed, and the reversing rope segment four is wound around the reversing rope groove six after coming out of the reversing guide wheel four and fixed. The finger tactile sensor module is fixed to the inner plane of the finger, while the outer side of the finger has a shape and structure that mimics the shape of a human finger.

7. An underactuated manipulator with a hybrid transmission mechanism according to any one of claims 1-6, characterized in that, The thumb module is mounted on the upper plane of the base of the palm module, and the thumb module is at a preset angle to the plane of the palm module. A tactile sensor module is arranged at the fingertip of the middle phalanx of the thumb module, and tactile sensor modules are arranged at the fingertips of the proximal phalanx and the middle phalanx of the finger module.

8. The underactuated manipulator with a hybrid transmission mechanism according to claim 1, characterized in that, The thumb module includes, from bottom to top, the thumb lateral joint, the thumb proximal phalanx, the thumb middle phalanx, and the thumb distal phalanx; The thumb module has a differential structure on the thumb side joint. The intersection of the two axes driven by the differential coincides with the joint rotation plane of the middle and distal phalanges of the thumb. The line connecting the midpoint of the joint rotation axis of the middle phalange of the thumb and the intersection of the thumb differential axis forms a fitting proximal phalanx. The fitting proximal phalanx is in the same plane as the middle and distal phalanges of the thumb.

9. An underactuated manipulator with a hybrid transmission mechanism according to claim 8, characterized in that, The lateral swing joint includes a thumb motor mounting base, a thumb drive motor, a thumb motor bevel gear, a thumb double-layer bevel gear, a thumb hexagonal shaft bevel gear, a T-shaped bushing, and a thumb differential crossarm. Two thumb drive motors are located at the bottom of the thumb motor mounting base, and are mounted in motor housings at the bottom of the mounting base. The output shafts of both thumb drive motors are coaxially fixed to the thumb motor bevel gears via fasteners. The thumb differential crossarm is rotatably mounted on a rotating mating hole at the top of the thumb motor mounting base. The T-shaped bushing is connected via a transverse and longitudinal interlocking mechanism. The positioning shaft is rigidly fixed to the differential crossarm. The T-shaped bushing includes two longer thumb shafts and one shorter thumb shaft. The two thumb double-layer bevel gears are symmetrically and clearance-fitted onto the two longer thumb shafts of the T-shaped bushing. The thumb hexagonal bevel gear is clearance-fitted onto one of the shorter thumb shafts of the T-shaped bushing. The inner bevel teeth of the two thumb double-layer bevel gears and the thumb hexagonal bevel gear mesh with each other at the center position of the T-shaped bushing and can rotate independently around the corresponding shaft of the bushing. The outer bevel teeth of the two thumb double-layer bevel gears mesh with the two thumb motor bevel gears without backlash.

10. An underactuated manipulator with a hybrid transmission mechanism according to claim 9, characterized in that, The proximal phalanx of the thumb includes an upper outer shell of the proximal phalanx of the thumb, a lower outer shell of the proximal phalanx of the thumb, a thumb drive motor, a bevel gear of the thumb drive motor, and a thumb wire rope. The thumb drive motor is fixed in the motor mounting cavity inside the upper outer shell of the proximal phalanx of the thumb by a thumb motor bracket. The bevel gear of the thumb drive motor is coaxially fixed with the output shaft of the thumb drive motor by fasteners. The lower outer shell of the proximal phalanx of the thumb is fixedly connected to the upper outer shell of the proximal phalanx of the thumb. The lower part of the lower outer shell of the thumb proximal phalanx is connected and fixed to the thumb hexagonal bevel gear on the thumb's lateral swing joint by fasteners. The lower end of the first steel wire rope is fixed to the steel wire rope positioning groove on the outer side of the upper outer shell of the thumb proximal phalanx by a crimping piece. The upper end of the first thumb steel wire rope extends to the middle phalanx of the thumb along a preset wiring channel. Preferably, the thumb middle phalanx includes a thumb middle phalanx skeleton, a left outer shell of the thumb middle phalanx, a right outer shell of the thumb middle phalanx, a thumb drive bevel gear, a thumb middle phalanx guide wheel, a thumb deflector guide wheel, a second thumb wire rope, a third thumb wire rope, a fourth thumb wire rope, and a lower thumb mounting shaft. The left and right outer shells of the thumb middle phalanx are fixedly mounted on both sides of the thumb middle phalanx skeleton via the lower and upper thumb mounting shafts. A thumb deflector guide wheel is fixed on the side wall of the thumb middle phalanx skeleton. The thumb deflector guide wheel includes an upper thumb deflector guide wheel and a lower thumb deflector guide wheel. The upper and lower thumb deflector guide wheels are fixedly mounted on the side wall of the thumb middle phalanx skeleton and are mounted closer to the outer shell side of the thumb middle phalanx. The upper part of the upper shell of the proximal thumb joint is provided with a thumb guide wheel mating hole, the lower part of the left shell of the middle thumb joint is provided with a thumb mounting hole one, and the lower part of the right shell of the middle thumb joint is provided with a thumb mounting hole two. The thumb middle joint guide wheel is coaxially arranged with the thumb guide wheel mating hole on the upper part of the upper shell of the proximal thumb joint, the thumb mounting hole one on the lower part of the left shell of the middle thumb joint, and the thumb mounting hole two on the lower part of the right shell of the middle thumb joint. The lower thumb mounting shaft is installed in the thumb guide wheel mating hole on the upper part of the upper shell of the proximal thumb joint, the thumb mounting hole one on the lower part of the left shell of the middle thumb joint, and the thumb mounting hole two on the lower part of the right shell of the middle thumb joint. The thumb middle joint guide wheel is disposed on the lower thumb mounting shaft and rotates on the lower thumb mounting shaft. The lower part of the thumb middle phalanx skeleton is mounted on the thumb lower mounting shaft. The thumb drive bevel gear is mounted on the thumb lower mounting shaft and is mounted close to the left outer shell of the thumb middle phalanx. The thumb middle phalanx guide wheel is provided with wire rope groove one, wire rope groove two, wire rope groove three, and wire rope groove four respectively from the left outer shell of the thumb middle phalanx to the right outer shell of the thumb middle phalanx. Wire rope groove one, wire rope groove two, and wire rope groove three are mounted on the left side of the thumb middle phalanx skeleton and close to the left outer shell of the thumb middle phalanx. Wire rope groove four is mounted on the right side of the thumb middle phalanx skeleton and close to the right outer shell of the thumb middle phalanx. The thumb drive bevel gear is located between the lower end of wire rope one and wire rope groove two. The thumb drive motor bevel gear meshes with the thumb drive bevel gear; The top of the outer shell of the thumb proximal phalanx is located between the right side wall of the thumb middle phalanx skeleton and the wire rope groove four. The thumb-down guide wheel is positioned above the wire rope groove three; Preferably, the distal phalanx of the thumb includes a thumb tip, a distal phalanx guide wheel, a thumb mounting shaft, and a thumb tip tactile sensor module. The distal phalanx guide wheel has a central hole, the lower part of the thumb tip has a mounting shaft mating hole, and the upper parts of the left and right outer shells of the middle phalanx of the thumb have mounting shaft mating holes. The central hole on the distal phalanx guide wheel, the mounting shaft mating hole at the lower part of the thumb tip, and the mounting shaft mating holes at the upper parts of the left and right outer shells of the middle phalanx are coaxial and connected by a through-hole connection of the thumb mounting shaft. The thumb distal phalanx guide wheel is provided with wire rope grooves five, six, seven, and eight respectively, from the left outer shell of the thumb middle phalanx to the right outer shell of the thumb middle phalanx. Wire rope grooves five, six, and seven are installed on the left side of the thumb middle phalanx skeleton and close to the left outer shell of the thumb middle phalanx. Wire rope groove eight is installed on the right side of the thumb middle phalanx skeleton and close to the right outer shell of the thumb middle phalanx. The upper guide wheel of the thumb is located below the wire rope groove seven. The upper part of the middle phalanx of the thumb is mounted on the upper mounting shaft of the thumb. Both the upper mounting shaft of the thumb and the lower mounting shaft of the thumb are fixedly mounted between the left outer shell of the middle phalanx of the thumb and the right outer shell of the middle phalanx of the thumb. The lower end of the first wire rope is fixed in the wire rope positioning groove on the outer side of the outer shell of the thumb proximal phalanx. After the lower part of the first wire rope wraps around the first wire rope groove once, it comes out from the right side of the first wire rope groove, that is, the wire rope groove near the inner side of the thumb phalanx, and starts to wrap around the fifth wire rope groove on the left side of the fifth wire rope groove near the outer side of the thumb phalanx. After wrapping around the fifth wire rope groove once, the upper end of the first wire rope is fixed in the first wire rope fixing hole provided on the outer side of the finger through a crimping member. The lower end of the second wire rope is fixed in the second wire rope groove. After the second wire rope is wrapped around the second wire rope groove once, the left side of the second wire rope groove, that is, starting from the outside of the thumb joint and moving upward towards the finger, is wrapped around the sixth wire rope groove once. The upper end of the second wire rope is then fixed in the second wire rope fixing hole provided on the outside of the finger by a crimping member. The lower end of the third wire rope is fixed in the third wire rope groove. After the third wire rope wraps around the third wire rope groove once, it starts from the right side of the third wire rope groove, that is, from the inside of the thumb knuckle, and moves upward toward the bottom of the thumb-down guide wheel, wrapping around it once. Then, it comes out from the left side of the thumb-down guide wheel, that is, from the outside of the thumb knuckle, and moves upward toward the fingertip. After the third wire rope starts from the left side of the thumb-up guide wheel, that is, from the outside of the thumb knuckle, and wraps around the thumb-down guide wheel once, it comes out from the left side of the thumb-up guide wheel and starts from the lower part of the seventh wire rope groove once. Finally, it comes out from the right side of the seventh wire rope groove, that is, from the inside of the thumb knuckle. The upper end of the third wire rope is fixed in the fixing hole of the third wire rope on the outside of the thumb tip by a crimping member. The lower end of the wire rope four is fixed in the wire rope groove four. After the lower part of the wire rope four is wrapped around the wire rope groove four once, it comes out from the left side of the wire rope groove four, that is, the wire rope groove one near the outside of the thumb joint, and then starts to wrap around the wire rope groove eight on the right side of the distal joint, that is, the wire rope groove eight near the inside of the thumb joint. After that, the upper end of the wire rope eight is fixed in the wire rope four fixing hole provided on the outside of the finger through a crimping member. The thumb tactile sensor module is connected and fixed to the inner plane of the fingertip; Preferably, the thumb lateral joint further includes a thumb magnet and a thumb angle sensor module. The thumb differential crossbeam is provided with a dedicated slot. The thumb magnet is interference-fitted and fixed in the dedicated slot on the thumb differential crossbeam. The thumb motor mounting base is provided with a sensor mounting position on its back. The thumb angle sensor module is fixed to the sensor mounting position on the back of the thumb motor mounting base by bolts. The thumb angle sensor module and the thumb magnet cooperate non-contactly to detect the real-time rotation angle of the lateral joint.

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