Dexterous hand based on shape memory alloy transmission and robot thereof

Abstract

The invention discloses a dexterous hand based on shape memory alloy transmission. The dexterous hand comprises an arm module, a wrist module and a palm module which are sequentially connected. A thumb module and a plurality of finger modules are arranged on the palm module; the device further comprises an SMA transmission module. The SMA transmission module comprises an SMA driver, a shape memory alloy and a transmission tendon rope; the finger module and the thumb module are provided with finger tendon rope fixing points, reset tension springs and reset tendon ropes. When the fingers need to be driven, the shape memory alloy is powered on through the SMA driver, the shape memory alloy is heated and shrunk after being powered on, and then the transmission tendon rope is driven to enable the fingers to be bent. When the fingers need to be reset and straightened, the SMA driver controls the shape memory alloy to stop heating, the shape memory alloy is cooled, and under the action of the reset tension spring, the reset tendon rope is pulled, so that the joints are reset.

Description

A dexterous hand and its robot based on shape memory alloy transmission Technical Field

[0001] This invention relates to the field of robotics, specifically to a dexterous hand based on shape memory alloy transmission and its robot. Background Technology

[0002] In fields such as industrial automation, service robots, and special operations, the dexterous hand, as the core execution component for robot interaction with the external environment, directly determines the robot's operational flexibility, job adaptability, size, weight, and operating costs through its drive method and transmission structure. Currently, the existing dexterous hand transmission drive structures are mainly divided into three categories: chord drive, direct motor drive, and linkage drive. Each type of structure has insurmountable technical defects, and the industry generally adopts a single drive method to adapt to all joints of the dexterous hand, which cannot simultaneously meet the comprehensive performance requirements of high degree of freedom, lightweight, high-output joint torque requirements, and precise control of low-output joints. This has become the core bottleneck restricting the development of miniaturized and integrated dexterous hands.

[0003] Tendon-driven dexterous hands are currently the most widely used type. They use a motor, reducer, coupling, and other transmission components to drive a winding wheel to pull tendon ropes, enabling finger joint movement. While they have advantages such as excellent heat dissipation and high output force, achieving multi-degree-of-freedom movement requires a large number of actuators and supporting transmission components, resulting in a large number of parts, complex structure, high overall size and weight, and significantly increased manufacturing costs and assembly difficulty, failing to meet the integration requirements of miniaturized dexterous hands. Motor-driven dexterous hands eliminate intermediate transmission components, resulting in a compact structure and a size close to that of a human hand. However, due to miniaturization design limitations, the supporting motor and reducer are extremely small, leading to defects such as difficult heat dissipation, fragile structure, and limited output torque. High-output joints are prone to performance degradation or even failure, while low-output joints have redundant drive power. Linkage-driven dexterous hands, while having high precision and rigidity, have complex structures, heavy weight, weak impact resistance, and limited degrees of freedom, making it difficult to achieve dexterity similar to that of a human hand.

[0004] Meanwhile, although there have been attempts to apply shape memory alloys to chord drives in existing technologies, these are merely simple "SMA + chord" splicing designs, without differentiated adaptation to the force output characteristics of different joints in dexterous hands. Furthermore, they suffer from several key technical pain points: First, the SMA relies on natural cooling after energizing and contracting, resulting in slow cooling and low joint reset efficiency, severely impacting dexterous hand work efficiency. Second, the reset and transmission structures are designed separately, leading to chord misalignment, joint jamming, and poor reset accuracy during reset. Third, the SMA drive is not integrated with direct motor drive, failing to simultaneously meet the torque requirements of high-output joints and the precise fine-tuning needs of low-output joints.

[0005] In summary, existing dexterous hands suffer from technical problems such as a single driving method, poor joint adaptability, low heat dissipation and reset efficiency of SMA drive, and low degree of structural integration. There is still no hybrid drive dexterous hand design based on joint output characteristics that can simultaneously solve the technical contradictions of high degree of freedom and lightweight, large output and precise control, and rapid cooling of SMA and precise joint reset. This has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] The present invention aims to overcome at least one of the defects of the prior art and provide a dexterous hand and robot based on shape memory alloy transmission, so as to solve the technical problems of poor joint adaptability and inability to balance high degree of freedom and lightweight in the prior art.

[0007] This invention provides a dexterous hand based on shape memory alloy (SMA) transmission, comprising an arm module, a wrist module, and a palm module connected in sequence; the palm module is equipped with a thumb module and multiple finger modules; it also includes an SMA transmission module; the SMA transmission module includes an SMA driver, a shape memory alloy, and a transmission tendon cord; the finger and thumb modules are provided with finger tendon cord fixing points, return springs, and return tendon cords; one end of the return tendon cord is connected to the return spring, and the other end moves in conjunction with the extension and contraction of the transmission tendon cord; one end of the transmission tendon cord is connected to the finger tendon cord fixing point, and the other end is connected to the SMA driver; when the finger needs to be driven, the SMA driver energizes the shape memory alloy, which is heated and contracts, thereby driving the transmission tendon cord to bend the finger; when the finger needs to be straightened, the SMA driver controls the shape memory alloy to stop heating, the shape memory alloy cools down, and under the action of the return spring, the return tendon cord is pulled, causing the joint to return to its original position. This structure constructs an integrated drive and reset system through the SMA transmission module, eliminating the need for complex transmission components such as reducers and couplings required by traditional motor tendon cable drives, greatly simplifying the overall structure. At the same time, it utilizes the deformation characteristics of shape memory alloys to achieve power transmission. Combined with the linkage design of the reset tension spring and reset tendon cable, it realizes automated cyclic control of finger joint flexion and extension. While ensuring driving torque, it effectively reduces the size and weight of the dexterous hand and improves the integration level of the structure.

[0008] Furthermore, each finger module includes three interphalangeal joint degrees of freedom; the thumb module includes two thumb interphalangeal joint degrees of freedom and one metacarpophalangeal joint degree of freedom. The interphalangeal joint degrees of freedom and the thumb interphalangeal joint degrees of freedom are driven by the SMA transmission module to achieve flexion or extension movements; the metacarpophalangeal joint degree of freedom is driven by the SMA transmission module to perform adduction or abduction. This design is based on the different functions and force characteristics of the joints of the dexterous hand, and makes differentiated degree of freedom configurations to conform to the natural movement characteristics of the human hand. At the same time, the SMA transmission module is precisely adapted to drive all joint degrees of freedom that require high force, so that the high-power-density SMA transmission module provides sufficient and stable torque for core force-generating movements such as flexion, extension, adduction, and abduction, ensuring the force requirements of the dexterous hand when performing grasping, pinching and other operations. At the same time, by adapting a single drive module to the same type of high-force joint, the number of drive components is reduced, further optimizing the structural layout of the hand module and improving the operational flexibility and movement coordination of the dexterous hand.

[0009] Furthermore, the SMA transmission module also includes a cooling fan. The shape memory alloy is integrated inside the arm module. The arm module is also provided with a cooling fan and a cooling air inlet for cooling the shape memory alloy. The cooling fan and the cooling air inlet cooperate to form a cooling air duct to cool the shape memory alloy. The cooling fan is electrically connected to the SMA driver. When the SMA driver controls the shape memory alloy to stop being powered, it simultaneously starts the cooling fan.

[0010] This invention adds an active heat dissipation system to the SMA transmission module, integrating the shape memory alloy into the arm module to achieve an integrated layout of the drive structure and heat dissipation structure, avoiding additional space occupation. At the same time, active heat dissipation is achieved through the air duct formed by the cooling fan and the heat dissipation air intake, replacing the traditional natural cooling method. Furthermore, the synchronous linkage control between the cooling fan and the SMA driver allows the shape memory alloy to immediately enter a high-efficiency heat dissipation state after power failure, significantly shortening the cooling time of the shape memory alloy, accelerating the joint reset speed, improving the working efficiency of the dexterous hand, and effectively avoiding the performance degradation of the shape memory alloy due to prolonged high temperature, thus extending its service life.

[0011] Preferably, the heat dissipation air inlet is located at the position of the arm module corresponding to the shell of the shape memory alloy. The airflow direction of the heat dissipation duct is adapted to the extension direction of the shape memory alloy, allowing the airflow to fully cover the length of the shape memory alloy, achieving rapid and uniform cooling. By precisely matching the elongated structural features of the shape memory alloy, the air outlet position of the heat dissipation air inlet directly corresponds to the body of the shape memory alloy, ensuring that the heat dissipation airflow can directly act on the heat-generating parts. At the same time, the adapted airflow direction allows the airflow to fully cover the length of the shape memory alloy, ensuring that all parts of the shape memory alloy can be cooled evenly and rapidly, avoiding inconsistent deformation recovery caused by insufficient local cooling. This further improves the cooling efficiency and reset consistency of the shape memory alloy, thereby ensuring the accuracy of finger joint reset and making the movement of the dexterous hand smoother.

[0012] Furthermore, the palm module also includes a finger adduction / abduction module and a thumb rolling module. The finger adduction / abduction module works in conjunction with the finger module, and the thumb rolling module works in conjunction with the thumb module. Both the finger adduction / abduction module and the thumb rolling module are driven by direct motor drive, forming a hybrid drive layout of SMA transmission module and direct motor drive. By combining the SMA drive module and the direct drive motor, a differentiated hybrid drive layout is constructed. Based on the actual force conditions of each joint in the dexterous hand, the SMA drive module is applied to joints that require high output, while the direct drive motor is applied to fine-tuning joints that require only low output, such as finger adduction / abduction and thumb rolling. This achieves a precise match between the drive method and the force requirements of the joints. It leverages the high power density of the SMA drive module to ensure torque supply to joints with high output, while utilizing the precise control advantage of the direct drive motor to meet the fine-tuning needs of joints with low output. At the same time, the design of the low-power direct drive motor avoids resource redundancy of high-power drive components, effectively reducing the structural volume of the hand module. This allows the dexterous hand to have high degrees of freedom while also being lightweight and having high drive efficiency.

[0013] Furthermore, the finger adduction / abduction module includes a DC motor, a reducer assembly, a double gear, a motor drive gear, and a gear pin. The reducer assembly includes a reducer cover and a reducer housing. The DC motor is fixedly connected to the reducer housing. The motor drive gear is fixed on the motor shaft of the DC motor and located inside the reducer housing. The double gear is mounted inside the reducer housing via a gear pin. The motor drive gear meshes with the double gear, and the double gear meshes with a gear below the finger module. The reducer cover closes to the open end of the reducer housing, achieving closed protection and precise transmission of the transmission components.

[0014] The aforementioned structure is designed with a dedicated direct-drive transmission system for the finger adduction / abduction joints with low force output. The DC motor and reducer assembly are fixedly connected, and the reducer assembly improves the transmission accuracy of the low-power DC motor, adapting to the fine-tuning needs of finger adduction / abduction. At the same time, all gear transmission components are placed in the closed cavity of the reducer housing, which not only prevents dust and impurities from entering the transmission structure and affecting the meshing accuracy, but also effectively reduces noise during the transmission process. Furthermore, the multi-stage gear meshing design ensures the smoothness of power transmission, making the finger adduction / abduction movements more precise and smoother, further improving the operational precision of dexterous hands.

[0015] Furthermore, the thumb roll module includes a brushless motor, a worm gear, and a worm wheel. The worm gear is fixed on the motor shaft of the brushless motor, and the worm wheel is fixed on the bottom of the thumb module. The worm gear and the worm wheel mesh with each other, and the self-locking property of the worm gear and worm wheel is used to improve the positional accuracy of the roll motion.

[0016] To address the need for low-power, high-precision fine-tuning of the thumb roll mechanism, a brushless motor with higher control accuracy is selected as the drive source to ensure the stability and precision of power output. At the same time, a worm gear transmission structure is adopted, utilizing the self-locking characteristics of the worm gear to effectively prevent the thumb module from shifting due to external forces in the non-drive state. This ensures the positional stability of the thumb after rolling, making the thumb position more reliable when performing delicate tasks such as pinching and finger alignment, thus improving the overall accuracy of the operation.

[0017] Furthermore, the thumb rolling module also includes a deep groove ball bearing, a thumb mounting bracket, and a thumb rotating bracket. The deep groove ball bearing is respectively located at the mating points of the thumb mounting bracket and the thumb rotating bracket. The thumb module is adapted to be installed within the installation space formed by the thumb mounting bracket and the thumb rotating bracket. The rotation of the worm gear drives the rotation of the worm wheel, thereby causing the thumb module to rotate within the thumb mounting bracket and the thumb rotating bracket. This structure provides a dedicated rotational support system for the thumb module. The stable installation space formed by the thumb mounting bracket and the thumb rotating bracket provides a precise motion trajectory for the rotation of the thumb module. At the same time, the deep groove ball bearing at the mating point effectively reduces the rotational friction between the mounting bracket and the rotating bracket, reduces energy loss during power transmission, and makes the thumb rolling motion smoother and less strenuous. In addition, the deep groove ball bearing can also distribute the force during rotation, improve the overall rigidity and service life of the structure, and ensure the long-term stability of the thumb rolling motion.

[0018] Furthermore, the wrist module includes a push rod module, a double-headed spherical hinge, a wrist support, a cross shaft, and a cross shaft mounting bracket. The push rod module is fixed to the arm module. The two ends of the double-headed spherical hinge are respectively hinged to the push rod module and the wrist support. The cross shaft is fixed to the cross shaft mounting bracket and hinged to the wrist support. The wrist module can achieve two degrees of freedom of movement relative to the arm module: pitch and lateral swing. The double-headed spherical hinge forms a flexible joint, compensating for deviations in the direction of movement and ensuring smooth force transmission. To achieve multi-degree-of-freedom wrist adjustment, the push rod module provides linear power. Utilizing the flexible joint characteristics of the double-headed spherical hinge, it compensates for the directional deviation between the linear extension and retraction of the push rod module and the rotational movement of the wrist support, avoiding transmission jamming and stress concentration problems caused by rigid connections. At the same time, the cross shaft provides a stable rotation center for the wrist support, ensuring the accuracy of the wrist support's pitch and lateral swing movements. The two-degree-of-freedom motion design allows the dexterous hand to flexibly adjust its working posture to adapt to different angles and positions, improving the dexterous hand's scene adaptability and operational flexibility.

[0019] Furthermore, this solution also protects a robot equipped with the aforementioned dexterous hand based on shape memory alloy transmission. The robot includes a body, and the aforementioned dexterous hand based on shape memory alloy transmission is mounted on both sides of the body, forming the robot's two-handed mechanical operation structure. This design integrates and adapts the dexterous hand based on shape memory alloy transmission with the robot body. Utilizing the advantages of the dexterous hand—lightweight, high degree of freedom, and high precision—it enables the robot to perform more complex grasping, pinching, and assembly operations. The mounting layout on both sides of the body conforms to the robot's conventional operational needs, enabling collaborative operation of both hands, improving the robot's work efficiency and operational capabilities. Simultaneously, the integrated design of the dexterous hand allows for assembly without significant modifications to the robot body, enhancing the dexterous hand's adaptability to different types of robots and expanding its application scenarios.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The hybrid drive dexterous hand and the robot equipped with the dexterous hand of the present invention achieve precise matching between the drive mode and the force output characteristics of each joint of the dexterous hand by constructing a hybrid drive layout that combines SMA transmission module and motor direct drive. While ensuring high degree of freedom and large output torque, it effectively reduces the overall volume and weight, and improves the integration and lightweight level of the structure.

[0021] 2. This invention significantly shortens the cooling time of the shape memory alloy by using the active heat dissipation design and synchronous linkage control of the SMA transmission module, thereby improving the joint reset efficiency and motion accuracy, and extending the service life of the shape memory alloy.

[0022] 3. This invention improves the transmission accuracy and motion stability of low-output joints through a refined structural design of the motor direct-drive module. Combined with the multi-degree-of-freedom flexible transmission design of the wrist module, it makes the dexterous hand more flexible in operation and easier in posture adjustment, adapting to various work scenarios. The overall structure, through modular and integrated design, significantly simplifies transmission components, reduces manufacturing costs and assembly difficulty, while improving the dexterous hand's work efficiency, operational accuracy, and scenario adaptability. When assembled onto a robot body, it effectively enhances the robot's operational capabilities, providing core component support for the development of miniaturized and integrated robots, and has promising prospects for industrial application. Attached Figure Description

[0023] Figure 1 is a three-dimensional structural diagram of the dexterous hand of the present invention.

[0024] Figure 2 is a schematic diagram of the SMA transmission module of the shape memory alloy in its natural state according to the present invention.

[0025] Figure 3 is a schematic diagram of the SMA transmission module of the shape memory alloy in the contracted state of the present invention.

[0026] Figure 4 is a schematic diagram of the heat dissipation air duct of the present invention.

[0027] Figure 5 is a schematic diagram of the overall structure of the palm module of the dexterous hand of the present invention.

[0028] Figure 6 is a three-dimensional structural diagram of the finger adduction / abduction module of the present invention.

[0029] Figure 7 is a structural schematic diagram of the thumb rolling module of the present invention.

[0030] Figure 8 is a structural schematic diagram of the thumb rolling module of the present invention from another perspective.

[0031] Figure 9 is an enlarged structural schematic diagram of the wrist module of the present invention. Detailed Implementation

[0032] The accompanying drawings illustrate the technical solutions of the embodiments of the present invention in more detail. Throughout the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. The described embodiments are some, but not all, embodiments of the present invention. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0033] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0034] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0035] Example 1

[0036] This embodiment provides a dexterous hand based on shape memory alloy transmission, as shown in Figure 1, including an arm module 1, a wrist module 2, and a palm module 3 connected in sequence; the palm module 3 is also provided with a thumb module 4 and four finger modules 5; each finger module 5 includes three interphalangeal joint degrees of freedom; the thumb module 4 includes two thumb interphalangeal joint degrees of freedom and one metacarpophalangeal joint degree of freedom, the interphalangeal joint degrees of freedom and the thumb interphalangeal joint degrees of freedom are driven by the SMA transmission module to achieve flexion or extension movements; the metacarpophalangeal joint degrees of freedom are driven by the SMA transmission module to adduct or abduct.

[0037] As shown in Figures 1-3, the SMA transmission module includes an SMA driver 6, a shape memory alloy 7, a transmission tendon 8, and a cooling fan 9; the shape memory alloy 7 is integrated inside the arm module 1. The finger module 5 and thumb module 4 are provided with finger tendon fixing points 10, return springs 20, and return tendon 30; one end of the return tendon 30 is connected to the return spring 20, and the other end moves in conjunction with the extension and retraction of the transmission tendon 8; one end of the transmission tendon 8 is connected to the finger tendon fixing point 10, and the other end is connected to the SMA driver 6; as shown in Figure 4, the arm module 1 is also provided with a heat dissipation air inlet 40 for cooling the shape memory alloy 7. The heat dissipation air inlet 40 is located on the arm module 1 at the position corresponding to the shell of the shape memory alloy 7. The cooling fan 9 cooperates with the heat dissipation air inlet 40 to form a heat dissipation airflow to cool the shape memory alloy 7, and the airflow direction of the heat dissipation airflow is adapted to the extension direction of the shape memory alloy 7. The cooling fan 9 is electrically connected to the SMA driver 6. The SMA driver 6 controls the shape memory alloy 7 to stop being powered while simultaneously starting the cooling fan 9.

[0038] As shown in Figure 5, the palm module 3 is also provided with a finger adduction / abduction module 31 and a thumb rolling module 32. The finger adduction / abduction module 31 cooperates with the finger module 5, and the thumb rolling module 32 cooperates with the thumb module 4. Both the finger adduction / abduction module 31 and the thumb rolling module 32 are driven by a direct motor drive.

[0039] As shown in Figure 6, the finger adduction / abduction module 31 includes a DC motor 311, a reducer cover 312, a reducer housing 313, a double gear 314, a motor drive gear 315, and a gear pin 316. The DC motor 311 is fixedly connected to the reducer housing 313. The motor drive gear 315 is fixed on the motor shaft of the DC motor 311 and located inside the reducer housing 313. The double gear 314 is installed inside the reducer housing 313 via the gear pin 316. The motor drive gear 315 meshes with the double gear 314. The double gear 314 meshes with the gear below the finger module 5. The reducer cover 312 covers the open end of the reducer housing 313. After the DC motor 311 is started, the motor shaft drives the motor drive gear 315 to rotate, which in turn drives the double gear 314 on the gear pin 316 to rotate synchronously. Then, the double gear 314 drives the gear below the finger module 5 to rotate, ultimately realizing the inward / outward movement of the finger module 5.

[0040] As shown in Figures 7-8, the thumb roll module 32 includes a brushless motor 321, a worm gear 322, a worm wheel 323, a deep groove ball bearing 324, a thumb mounting bracket 325, and a thumb rotation bracket 326. The worm gear 322 is fixed on the motor shaft of the brushless motor 321, and the worm wheel 323 is fixed to the bottom of the thumb module 4. The worm gear 322 and the worm wheel 323 mesh with each other. The deep groove ball bearings 324 are respectively located at the mating points of the thumb mounting bracket 325 and the thumb rotation bracket 326. The thumb module 4 is adapted to be installed within the installation space formed by the thumb mounting bracket 325 and the thumb rotation bracket 326. The rotation of the worm gear 322 drives the rotation of the worm wheel 323, thereby causing the thumb module 4 to rotate within the thumb mounting bracket 325 and the thumb rotation bracket 326. After the brushless motor 321 starts, the motor shaft drives the worm gear 322 to rotate, and the worm gear 322 drives the worm wheel 323 to rotate synchronously, thereby driving the thumb module 4 to complete the rolling motion within the thumb mounting bracket 325 and the thumb rotating bracket 326. The deep groove ball bearing 324 effectively reduces the frictional resistance during the rotation process and improves the smoothness of the movement.

[0041] The wrist module 2 includes a push rod module 21, a double-headed ball hinge 22, a wrist support 23, a cross shaft 24, and a cross shaft fixing frame 25. The push rod module 21 is fixed to the arm module 1. The two ends of the double-headed ball hinge 22 are respectively hinged to the push rod module 21 and the wrist support 23, forming two PSS transmission chains. The cross shaft 24 is fixed to the cross shaft fixing frame 25 and hinged to the wrist support 23. When the push rod module 21 performs telescopic movement, it transmits linear power to the wrist support 23 through the double-headed ball hinge 22, causing the wrist support 23 to rotate around the cross shaft 24, thereby realizing the pitch and lateral movement of the wrist support 23 relative to the arm module 1, meeting the multi-posture adjustment needs during dexterity work.

[0042] Therefore, the thumb module 4 and the four finger modules 5 in this invention each have 4 degrees of freedom, the palm module 3 has a total of 20 degrees of freedom, and the wrist module 2 is configured with 2 degrees of freedom. The 20 degrees of freedom of the palm module 3 are realized by two methods: tendon cable transmission and motor direct drive transmission. The tendon cable transmission realizes 15 degrees of freedom, specifically the three degrees of freedom of the IP joint of the finger module 5, and the three degrees of freedom of the IP joint and the MCP adduction / abduction joint of the thumb module 4. The motor direct drive transmission realizes the five degrees of freedom corresponding to the finger adduction / abduction module 31 and the thumb rolling module 32.

[0043] The end of the transmission tendon cable 8 is fixed to the joint position corresponding to the degree of freedom of the palm module 3, while the driving end is fixed to the SMA actuator 6. The SMA actuator 6 contains a shape memory alloy 7, and this unit is integrated into the arm module 1. When it is necessary to drive the finger to complete the flexion action, the shape memory alloy 7 in the SMA tendon cable drive unit is energized and heated, causing it to contract, thereby pulling the transmission tendon cable 8 to drive the finger joint to bend. When it is necessary to drive the finger to return to its original position and straighten, the shape memory alloy 7 is de-energized, and the cooling fan 9 starts simultaneously to cool the shape memory alloy 7 quickly. Under the elastic tension of the return spring 20 built into the finger module 5, the return spring 20 pulls the return tendon cable 30, thereby driving the driven joint to complete the return action. The SMA driver 6 pulls the transmission tendon rope 8 to retract, achieving the corresponding degree of freedom of movement. This allows the dexterous hand to have a high degree of freedom of operation while outputting sufficient gripping force to the grasping target. The finger adduction / abduction module 31 and thumb rolling module 32 only need to output a small force during the operation of the dexterous hand. Therefore, a low-power motor direct drive structure is used to effectively reduce the overall size of the dexterous hand, balancing operational flexibility and structural compactness.

[0044] Example 2

[0045] This embodiment provides a robot with the dexterous hand of Embodiment 1, and also includes a body, with the dexterous hand mounted on both sides of the body.

[0046] The above embodiments are merely illustrative of the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the preferred embodiments above, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of the present invention should not depart from the spirit and scope of the present invention. Those skilled in the art can also make other changes within the spirit of the present invention and use them in the design of the present invention, as long as they do not deviate from the technical effects of the present invention. These changes made according to the spirit of the present invention should all be included within the scope of protection claimed by the present invention.

Claims

1. A dexterous hand based on shape memory alloy transmission, characterized in that, The system includes an arm module (1), a wrist module (2), and a palm module (3) connected in sequence; the palm module (3) is also provided with a thumb module (4) and multiple finger modules (5); it also includes an SMA transmission module; the SMA transmission module includes an SMA driver (6), a shape memory alloy (7), and a transmission tendon rope (8); the finger module (5) and the thumb module (4) are provided with a finger tendon rope fixing point (10), a reset spring (20), and a reset tendon rope (30); one end of the reset tendon rope (30) is connected to the reset spring (20), and the other end moves in conjunction with the extension and retraction of the transmission tendon rope (8). Movement; one end of the transmission tendon rope (8) is connected to the finger tendon rope fixing point (10), and the other end is connected to the SMA driver (6); when the finger needs to be driven, the SMA driver (6) energizes the shape memory alloy (7), and the shape memory alloy (7) is heated and contracted after being energized, thereby driving the transmission tendon rope (8) to bend the finger; when the finger needs to be straightened, the SMA driver (6) controls the shape memory alloy (7) to stop heating, the shape memory alloy (7) cools down, and under the action of the reset tension spring (20), pulls the reset tendon rope (30) to reset the joint.

2. The dexterous hand according to claim 1, characterized in that, Each of the finger modules (5) includes three interphalangeal joint degrees of freedom; the thumb module (4) includes two thumb interphalangeal joint degrees of freedom and one metacarpophalangeal joint degree of freedom, the interphalangeal joint degrees of freedom and the thumb interphalangeal joint degrees of freedom are driven by the SMA transmission module to achieve flexion or extension movements; the metacarpophalangeal joint degrees of freedom are driven by the SMA transmission module to adduct or abduct.

3. The dexterous hand according to claim 1, characterized in that, The SMA transmission module also includes a cooling fan (9). The shape memory alloy (7) is integrated inside the arm module (1). The arm module (1) is also provided with a heat dissipation air inlet (40) for heat dissipation of the shape memory alloy (7). The cooling fan (9) and the heat dissipation air inlet (40) cooperate to form a heat dissipation air duct to cool the shape memory alloy (7). The cooling fan (9) is electrically connected to the SMA driver (6). The SMA driver (6) controls the shape memory alloy (7) to stop being powered while simultaneously starting the cooling fan (9).

4. The dexterous hand according to claim 3, characterized in that, The heat dissipation air inlet (40) is opened at the position of the arm module (1) corresponding to the housing position of the shape memory alloy (7), and the airflow direction of the heat dissipation duct is adapted to the extension direction of the shape memory alloy (7).

5. The dexterous hand according to claim 1, characterized in that, The palm module (3) is also provided with a finger adduction / abduction module (31) and a thumb rolling module (32). The finger adduction / abduction module (31) cooperates with the finger module (5), and the thumb rolling module (32) cooperates with the thumb module (4). Both the finger adduction / abduction module (31) and the thumb rolling module (32) are driven by direct motor drive.

6. The dexterous hand according to claim 5, characterized in that, The finger adduction / extension module (31) includes a DC motor (311), a reducer assembly, a double gear (314), a motor drive gear (315), and a gear pin (316). The reducer assembly includes a reducer cover (312) and a reducer housing (313). The DC motor (311) is fixedly connected to the reducer housing (313). The motor drive gear (315) is fixed on the motor shaft of the DC motor (311) and located inside the reducer housing (313). The double gear (314) is installed inside the reducer housing (313) via the gear pin (316). The motor drive gear (315) meshes with the double gear (314). The double gear (314) meshes with the gear below the finger module (5). The reducer cover (312) covers the opening of the reducer housing (313).

7. The dexterous hand according to claim 5, characterized in that, The thumb roll module (32) includes a brushless motor (321), a worm (322), and a worm wheel (323). The worm (322) is fixed on the motor shaft of the brushless motor (321), and the worm wheel (323) is fixed on the bottom of the thumb module (4). The worm (322) and the worm wheel (323) mesh with each other.

8. The dexterous hand according to claim 7, characterized in that, The thumb rolling module (32) also includes a deep groove ball bearing (324), a thumb mounting bracket (325), and a thumb rotating bracket (326). The deep groove ball bearing (324) is respectively located at the mating point of the thumb mounting bracket (325) and the thumb rotating bracket (326). The thumb module (4) is adapted to be installed in the installation space formed by the thumb mounting bracket (325) and the thumb rotating bracket (326). The rotation of the worm (322) drives the rotation of the worm wheel (323), thereby driving the thumb module (4) to rotate within the thumb mounting bracket (325) and the thumb rotating bracket (326).

9. The dexterous hand according to claim 7, characterized in that, The wrist module (2) includes a push rod module (21), a double-headed ball hinge (22), a wrist support (23), a cross shaft (24), and a cross shaft fixing frame (25). The push rod module (21) is fixed on the arm module (1). The two ends of the double-headed ball hinge (22) are respectively hinged to the push rod module (21) and the wrist support (23). The cross shaft (24) is fixed on the cross shaft fixing frame (25) and hinged to the wrist support (23). The wrist module (2) can realize two degrees of freedom of movement relative to the arm module (1): pitch and lateral swing.

10. A robot having a dexterous hand as described in any one of claims 1 to 9, characterized in that, It also includes the body, with the dexterous hands mounted on both sides of the body.

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