Dexterous hand based on speed reducer and difference mechanism

Abstract

The embodiment of the invention relates to the technical field of robots, and discloses a dexterous hand based on a speed reducer and a difference mechanism. A plurality of motor-speed reducer combinations are reasonably distributed, two motor-speed reducer combinations are combined with a difference mechanism to achieve the pitching degree of freedom and the yawing degree of freedom of the finger root joint, one motor-speed reducer combination is used for driving the bending and stretching degree of freedom of the middle-end joint, and therefore the degree of freedom is high while the degree of freedom is achieved. And the number of driving devices is obviously reduced. And moreover, the fingers are driven by a motor-speed reducer combination, the speed reducer of a duplex planetary gear structure is adopted, and the design of specific tooth number is combined, so that torque output is effectively optimized, and the compact structure is realized on the premise of ensuring high gripping power of the dexterous hand.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of robotics, and in particular to a dexterous hand based on a reducer and a differential mechanism. Background Art

[0002] With the rapid development of robotics technology, dexterous hands, as robot end effectors, are widely used in industrial automation, medical assistance, service robots and other fields. The core function of dexterous hands is to simulate the fine manipulation ability of human hands, including flexible movement in multiple degrees of freedom, stable gripping force and high-precision sensory feedback. At present, the design of mechanical dexterous hands is usually optimized around indicators such as degrees of freedom, gripping force, weight, volume and sensing accuracy to achieve flexibility and manipulation capabilities similar to those of human hands.

[0003] However, the dexterous hands in the prior art still have many deficiencies in performance, especially the inability to achieve high degrees of freedom and high gripping force in a small size and weight. Summary of the invention

[0004] The purpose of the embodiment of the present invention is to provide a dexterous hand based on a reducer, which can achieve high degrees of freedom and high gripping force while ensuring small size and weight.

[0005] To solve the above technical problems, an embodiment of the present invention provides a dexterous hand based on a reducer and a differential mechanism, comprising: a palm part, and fingers connected to the palm part; wherein the palm part comprises a shell structure and a drive module; the drive module comprises a plurality of motor-reducer combinations, and every three motor-reducer combinations are used to drive one finger, wherein two motor-reducer combinations are connected to the differential mechanism of the finger base joint, and one motor-reducer combination is connected to the mid-end joint to form the flexion and extension degrees of freedom of the mid-end joint, and the differential mechanism is used to realize the pitch degree of freedom and yaw degree of freedom of the finger base joint through differential transmission; the reducer is a double planetary gear structure, comprising: a first planetary gear and a second planetary gear, wherein the number of teeth of the first planetary gear is more than the number of teeth of the second planetary gear; a two-stage internal gear, wherein the number of teeth of the first internal gear is more than the number of teeth of the second internal gear.

[0006] In addition, in another embodiment of the present invention, the two motor-reducer combinations connected to the differential mechanism of the finger base joint include a left motor-reducer combination and a right motor-reducer combination, wherein: the two motor-reducer combinations are parallel to the finger direction and are located on the same vertical line of the finger direction; when the two motor-reducer combinations transmit the same torque and direction to the synchronous belt, they drive the left and right drive wheels to rotate synchronously in the same direction; when the two motor-reducer combinations transmit different torque directions to the synchronous belt, they drive the left and right drive wheels to rotate in opposite directions. This design not only realizes the flexible control of the two degrees of freedom of the finger base joint, but also significantly improves the efficiency of power transmission and the stability of the transmission system.

[0007] In an embodiment of the present invention, a dexterous hand based on a reducer and a differential mechanism is provided. By reasonably distributing multiple motor-reducer combinations, two motor-reducer combinations are used in combination with differential mechanisms to realize the pitch and yaw degrees of freedom of the finger base joints, and one motor-reducer combination is used to drive the flexion and extension degrees of freedom of the mid-end joints. While achieving high degrees of freedom, the number of driving devices is significantly reduced. The use of a reducer with a double planetary gear structure and a specific number of teeth design effectively optimizes the torque output and realizes a compact structure while ensuring high gripping force of the dexterous hand. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings represent similar elements, and unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0009] Figure 1 is an external structural diagram of a dexterous hand provided in one embodiment of the present application;

[0010] Figure 2 is an overall structural diagram of a dexterous hand provided in one embodiment of the present application;

[0011] Figure 3 is a structural diagram of a single finger in a dexterous hand provided in an embodiment of the present application;

[0012] Figure 4 This is a structural diagram of a dexterous hand reducer provided in an embodiment of the present application;

[0013] Figure 5 It is a structural diagram of a difference mechanism in a dexterous hand provided in an embodiment of the present application;

[0014] Figure 6 is a structural diagram of a torque sensor in a dexterous hand provided in an embodiment of the present application;

[0015] Figure 7This is a control logic diagram of the dexterous hand provided in one embodiment of the present application.

[0016] Reference numerals:

[0017] 1. Palm part; 2. Fingers; 3. Palm shell; 4. Back shell; 5. First motor and second motor; 6. First reducer and second reducer; 7. Synchronous belt; 8. Differential mechanism; 9. Motor-reducer combination; 10. Drive circuit; 11. Power supply circuit; 12. Differential mechanism; 13. Third motor; 14. Third reducer; 15. Middle end joint bevel gear; 16. Connecting rod mechanism; 17. Miniature camera; 18. Soft material; 19. First angle sensor; 20. Second angle sensor; 21. Torque sensor; 22. First internal gear of reducer; 23. First planetary gear of reducer ; 24. The second planetary gear of the reducer; 25. The second internal gear of the reducer; 26. The output shaft of the reducer; 27. The sun gear of the reducer; 28. The input shaft of the reducer; 29. ​​The left drive wheel of the differential mechanism; 30. The left bevel gear of the differential mechanism; 31. The first bevel gear of the differential mechanism; 32. The right drive wheel of the differential mechanism; 33. The right bevel gear of the differential mechanism; 34. The second bevel gear of the differential mechanism; 35. The differential frame of the differential mechanism; 36. The differential frame of the torque sensor; 37. The first strain gauge of the torque sensor; 38. The second strain gauge of the torque sensor; 39. The third strain gauge of the torque sensor; 40. The fourth strain gauge of the torque sensor. DETAILED DESCRIPTION

[0018] With the rapid development of robotics technology, dexterous hands, as robot end effectors, have been widely used in industrial automation, medical assistance, service robots and other fields. As the core component for the interaction between robots and the environment, the performance of dexterous hands largely determines the working efficiency and scope of application of robots. Dexterous hands not only need to have flexible movement with multiple degrees of freedom and high-precision perception capabilities, but also need to achieve comprehensive optimization in terms of volume, weight, gripping force and control accuracy to meet the needs of different application scenarios. At present, the design of mechanical dexterous hands is usually optimized around the following key performance indicators:

[0019] 1. Degrees of freedom: The higher the degrees of freedom of a dexterous hand, the more it can simulate the complex movements of a human hand. However, due to the limitations of mechanical structure, circuits, and drive systems, the degrees of freedom of most mechanical dexterous hands are usually less than 15, and the realization of high degrees of freedom often requires more complex designs and more drive devices, which will significantly increase the size and weight of the palm.

[0020] 2. Grip force to weight ratio: Dexterous hands need to have sufficient grip force to meet various operational requirements, but the improvement of grip force often relies on high-power motors and high reduction ratio transmission, which will lead to an increase in weight and volume. In real-world applications, dexterous hands are required to have slender and flexible fingers and strong grip force, so a high grip to weight ratio (grip force to weight ratio) is one of the key indicators in dexterous hand design.

[0021] 3. Sensing capability: Dexterous hands need to perceive the external environment and the state of the object in real time, including the position, angle, torque, shape, surface characteristics, etc. of the fingers. The sensing capability of current mechanical dexterous hands is generally limited by space, and the accuracy and types of sensors are also relatively limited. Usually, only some sensors are selected for installation.

[0022] 4. Size and weight: While achieving high degrees of freedom and large grasping force, the dexterous robotic hand needs to minimize size and weight to meet the space limitations of the robot's end effector and ensure flexibility and energy efficiency.

[0023] At present, existing dexterous hand technology solutions at home and abroad are mostly focused on increasing the degree of freedom and improving the gripping force, but there are still significant deficiencies in terms of volume, weight and grip-to-weight ratio. For example:

[0024] 1. Insufficient degrees of freedom: Due to the limitations of mechanical structure, circuit and drive system, the realization of high degrees of freedom often requires more complex design and more drive devices, which will significantly increase the size and weight of the palm. Most domestic dexterous hands have a maximum of 15 degrees of freedom, but this is usually at the expense of size and weight.

[0025] 2. Limited drive mode: Dexterous hands often use motor drive combined with gear, connecting rod or tendon transmission. Although tendon transmission can reduce the size of fingers and palms, it will lead to insufficient grip and poor finger rigidity; while gear and connecting rod transmission requires a larger space, increasing the overall size of the dexterous hand.

[0026] 3. Limitation of gripping force: In order to achieve greater gripping force, existing dexterous hands usually use high-power motors or high-ratio reducers, which will significantly increase their own weight. For example, the Zhiyuan dexterous hand uses a motor + screw transmission method. Although the gripping force is greater, the finger gripping speed is slow, which limits its application in dynamic scenes.

[0027] 4. Low sensor integration: Currently, most dexterous mechanical hands use pressure sensors or angle sensors, which can only perceive limited operating information and cannot achieve high-precision and all-round perception functions.

[0028] In summary, the following technical difficulties are common in the design of existing dexterous hands: in order to achieve a higher degree of freedom, it is necessary to add drive devices and transmission mechanisms, which leads to a significant increase in volume and weight; the improvement of gripping force often relies on high-power drive devices and high-transmission ratio reducers, which leads to a low grip-to-weight ratio; the reduction in the size of dexterous hands usually limits the performance of motors and transmission devices, affecting gripping force and flexibility; due to space and circuit design constraints, the types and layout of sensors are limited, and multi-dimensional, high-precision real-time perception cannot be achieved.

[0029] To make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. However, it will be appreciated by those skilled in the art that in the embodiments of the present invention, many technical details are proposed in order to enable the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical scheme claimed in the present application can be implemented. The division of the following embodiments is for the convenience of description, and should not constitute any limitation on the specific implementation of the present invention. The various embodiments can be combined and referenced with each other without contradiction.

[0030] One embodiment of the present invention relates to a dexterous hand based on a reducer and a differential mechanism, comprising: a palm part, and fingers connected to the palm part; wherein the palm part comprises an outer shell structure and a drive module; the drive module comprises a plurality of motor-reducer combinations, and every three motor-reducer combinations are used to drive one finger, wherein two motor-reducer combinations are connected to the differential mechanism of the finger base joint, and one motor-reducer combination is connected to the mid-end joint to form the flexion and extension degrees of freedom of the mid-end joint, and the differential mechanism is used to realize the pitch degree of freedom and yaw degree of freedom of the finger base joint through differential transmission; the reducer is a double planetary gear structure, comprising: a first planetary gear and a second planetary gear, wherein the number of teeth of the first planetary gear is greater than the number of teeth of the second planetary gear; a two-stage internal gear, wherein the number of teeth of the first internal gear is greater than the number of teeth of the second internal gear. By rationally distributing multiple motor-reducer combinations, two motor-reducer combinations are used in combination with differential mechanisms to achieve the pitch and yaw degrees of freedom of the finger joints, and one motor-reducer combination is used to drive the flexion and extension degrees of freedom of the mid-end joints. While achieving high degrees of freedom, the number of drive devices is significantly reduced. The use of a double-planetary gear structure reducer, combined with a specific number of teeth design, effectively optimizes the torque output and achieves a compact structure while ensuring high gripping force of the dexterous hand.

[0031] The following is a specific description of the device details of the dexterous hand based on the reducer and the differential mechanism according to the present invention in conjunction with the accompanying drawings and embodiments. The following content is only the implementation details provided for easy understanding and is not necessary for the implementation of this solution.

[0032] like Figures 1 to 5 As shown, the dexterous hand of the embodiment of the present invention comprises: a palm part 1 and five fingers 2 connected to the palm part. Specifically, the palm part comprises a shell structure and a drive module, wherein the shell structure not only serves as a bearing unit of the dexterous hand, but also plays a role in protecting internal components. The shell structure is divided into a palm shell 3 and a back shell 4 to ensure the stability and firmness of the dexterous hand. The drive module comprises at least 15 sets of motor-reducer combinations for driving the fingers.

[0033] Optionally, to achieve high efficiency and compactness of the structure, such as Figure 2 The drive circuit 10 that controls the corresponding drive module is integrated in an independent circuit module and fixed to the back and palm shell by screws, and arranged inside the palm. At the same time, the power supply circuit 11 is also fixed inside the palm to provide power support for the drive module. This design not only effectively improves the grasping and operation capabilities of the dexterous hand in complex environments, but also ensures the efficiency and maintainability of the drive system.

[0034] Optionally, in order to increase the grip of the dexterous hand, a customized brushless motor and 3K reducer are used in the motor-reducer combination. The motor provides high power density output, while the reducer increases the transmission ratio while reducing the volume, achieving the effect of high torque output. The 3K reducer has a higher reduction ratio (346:1 and 467:1). Compared with traditional reducers, it can output higher torque at the same volume. At the same time, it is 4-10 times lighter than traditional reducers, which can significantly improve the grip of the dexterous hand.

[0035] Optionally, the shell structure design of the dexterous hand adopts lightweight and high-strength materials to meet the application needs of the dexterous hand under miniaturization and high-strength load-bearing requirements. In the selection of materials for the palm shell and the back of the hand shell, the present invention preferably uses high-strength aluminum alloy or high-performance plastic composite materials. Aluminum alloy has excellent corrosion resistance and mechanical strength, which can ensure reliability under long-term high-intensity loads; while composite materials provide higher impact resistance and help to reduce the overall weight, especially in reducing the weight of the transmission system. The palm shell and the back of the hand shell are connected by specially designed anti-loosening threaded connectors to ensure a firm connection and easy disassembly and maintenance. In addition, the shell design adopts a modular combination structure, and each module can be replaced or repaired separately. This design not only reduces the maintenance cost, but also improves the scalability of the dexterous hand.

[0036] The finger parts of the above-mentioned dexterous hand include the thumb, index finger, middle finger, ring finger and little finger, and each finger is composed of a base joint, a base knuckle, a middle joint, a middle knuckle, a knuckle joint and a fingertip knuckle part, as shown in the figure. Figure 2As shown. The finger knuckles are manufactured using precision casting and injection molding processes to ensure high-precision fit of each joint and stability during long-term use. In the design of the finger joints, in order to improve the flexibility and durability of the joints, self-lubricating ceramic bearings and high-strength polyurethane seals are used to ensure smooth movement of the joints under long-term and high-frequency use, reduce wear and improve operating accuracy. The materials for each part of the finger are selected taking into account mechanical properties, fatigue resistance and wear resistance, and aluminum alloy and reinforced nylon composite materials are used.

[0037] The dexterous hand based on the above five fingers realizes at least 20 degrees of freedom, including at least 15 active degrees of freedom and at least 5 passive degrees of freedom. Each finger provides at least 3 active degrees of freedom and at least 1 passive degree of freedom, and is designed to simulate the complex movement capabilities of the human hand, especially when performing complex operation tasks, it can provide sufficient flexibility and high-precision control.

[0038] In the embodiment of the present invention, Figure 2 As shown, at least three motor-reducer combinations drive one finger. Specifically, two motor-reducer combinations (5 and 6) are connected to the differential mechanism 12 of the finger base joint, and the differential mechanism realizes the pitch and yaw degrees of freedom of the finger base joint through differential transmission; the middle joint of each finger is connected to the bevel gear 15 of the middle joint through the third motor-reducer combination (13 and 14) to form the flexion and extension degrees of freedom of the middle joint; the fingertip joint of each finger is coupled to the middle joint through the connecting rod mechanism 16 to form a passive flexion and extension degree of freedom based on the middle joint. Each motor-reducer combination is connected to different parts of the dexterous hand to ensure that the dexterous hand has precise control capabilities when performing complex movements.

[0039] The differential mechanism at the finger joint connected by the synchronous belt and two sets of motor-reducer combinations is as follows: Figure 5 As shown, it includes a differential frame 35, a first bevel gear 31 fixed on the differential frame, a left bevel gear 30 and a right bevel gear 33 meshing with the first bevel gear, a second bevel gear 34 meshing with the first bevel gear and the left and right bevel gears at the same time, and a left drive wheel 29 and a right drive wheel 32 respectively fixed on the outside of the left and right bevel gears. The design of the differential mechanism is based on the precise meshing of the four gears, which ensures the efficient transmission of the finger joint when performing complex movements. The left and right drive wheels are respectively connected to a set of motor-reducer combination through a synchronous belt 7, wherein the first bevel gear 31 is used to carry the differential frame 35 to produce pitch motion when the left drive wheel 29 and the right drive wheel 32 rotate synchronously; the first bevel gear is used to carry the differential frame 35 to produce yaw motion when the left drive wheel 29 and the right drive wheel 32 rotate in the opposite direction.

[0040] Furthermore, the two motor-reducer combinations (such as Figure 2 and Figure 3 Numbers 5 and 6) include a lower motor-reducer combination near the palm and an upper motor-reducer combination near the base of the finger. In order to optimize the spatial layout and reduce the volume, the two sets of motor-reducer combinations are parallel to the vertical direction of the finger, and the reducers are in opposite directions. This arrangement not only effectively reduces the space occupied by the drive device, but also ensures the effective transmission of torque, so that the system can achieve higher power output under the condition of miniaturization. The layout angles of the two sets of motor-reducer combinations are parallel to the vertical direction of the finger, and the reducers are in opposite directions. When the drive module is running, when the two sets of motor-reducer combinations transmit the same torque and direction to the synchronous belt 7, the left drive wheel 29 and the right drive wheel 32 of the drive differential mechanism rotate synchronously in the same direction; when the two sets of motor-reducer combinations transmit different torque directions to the synchronous belt 7, the left drive wheel 29 and the right drive wheel 32 of the drive differential mechanism rotate in the opposite direction.

[0041] In the driving mechanism of the finger root joint, based on the above dual motor-reducer combination (such as Figure 2 and Figure 3 The motor is rotated by the reducer and the power is transmitted to the left drive wheel 29 and the right drive wheel 32 of the differential mechanism 8 through the synchronous belts 7 on both sides. When the driving direction and the torque are consistent, the left drive wheel 29 and the right drive wheel 32 drive the left bevel gear 30 and the right bevel gear 33 to rotate in the same direction, thereby realizing the pitch rotation of the base of the finger joint; when the driving direction is opposite, the left drive wheel 29 and the right drive wheel 32 drive the left bevel gear 30 and the right bevel gear 33 to rotate in the opposite direction, and the differential frame 35 follows the bevel gear 34 to produce a yaw motion, thereby realizing the yaw motion of the base of the finger joint. In addition, when the driving directions are consistent but the torque sizes are inconsistent, the left driving wheel 29 and the right driving wheel 32 in the differential mechanism drive the left bevel gear 30 and the right bevel gear 33 in the same direction, but at inconsistent speeds. At this time, the differential frame 35 still follows the left and right yaw motion of the bevel gear 34, and the middle gear 31 rotates in the opposite direction, thereby realizing the yaw motion of the finger base joint and carrying a certain pitch angle.

[0042] In terms of motion control of mid-range joints, such as Figure 3 The middle joint is connected to the third motor-reducer combination through the bevel gear 15 ( Figure 3 In terms of driving, when the third motor 13 drives the third reducer 14, the motor increases the torque through the reducer and transmits it to the bevel gear 15 of the middle joint, thereby realizing the flexion and extension freedom of the middle joint.

[0043] Based on the structure of the above-mentioned mid-end joint, the motion control of the fingertip joint is realized. Figure 3, the middle joint is coupled with the fingertip joint through a connecting rod mechanism 16, and the flexion and extension movement of the middle joint drives the fingertip joint to move synchronously through the connecting rod mechanism 16, forming the active degree of freedom of the middle joint and the passive degree of freedom of the fingertip joint. According to the setting of the above-mentioned connecting rod structure 16, when the third motor 13 drives the third reducer 14, the motor driving force is increased by the torque of the reducer and transmitted to the bevel gear 15 of the middle joint. At this time, the middle joint moves independently in pitch and pitch. At the same time, after the middle joint moves in pitch and pitch, a part of the force will be transmitted to the fingertip joint through the connecting rod mechanism 16. At this time, the force on the fingertip joint will achieve coupled movement with the middle joint, thereby realizing the passive degree of freedom of the passive fingertip joint. This design enables the fingertip joint to move synchronously with the pitch and pitch movement of the middle joint through the transmission of torque without the need for an additional drive system. The fingertip joint mainly bears a lower load during the movement, so that the system avoids the increase of redundant drive devices while maintaining high degrees of freedom and flexibility, reducing complexity and cost.

[0044] In the embodiment of the present invention, in the driving module of the dexterous hand, the reducer in the motor-reducer combination is a double planetary gear structure, specifically as follows Figure 4 , including: a first planetary gear 23 and a second planetary gear 24, wherein the number of teeth of the first planetary gear is greater than the number of teeth of the second planetary gear; a two-stage internal gear, wherein the number of teeth of the first internal gear is greater than the number of teeth of the second internal gear. This structure adopts 3K reducer technology, which can effectively improve the torque output of the motor through precise gear meshing, while ensuring the high efficiency of the system.

[0045] Optionally, the number of teeth of the first planetary gear 23 in the reducer is 1 or 2 more than the number of teeth of the second planetary gear 24, and the number of teeth of the first internal gear is 1 or 2 more than the number of teeth of the second internal gear. By adjusting the difference in the number of teeth of the planetary gear and the internal gear, the embodiment of the present invention can provide a reduction ratio of up to 346:1 and 467:1, which significantly improves the power transmission efficiency while ensuring a small volume.

[0046] At the same time, the transmission mode of the above reducer structure is 3K mode, and the meshing type of the gear is NGWN. Figure 4As shown, the motor torque is transmitted to the sun gear 27 through the input shaft 28, and the first internal gear 22 is fixed, so the first planetary gear 23 meshes with the sun gear 27 and the internal gear 22 at the same time, and the planetary gears rotate while revolving around the sun gear. Since the first planetary gear 23 and the second planetary gear 24 are double gears, the angular velocity of the two planetary gears is the same. Since the second planetary gear 24 has 1 to 2 fewer teeth than the first planetary gear 23, the outer linear speed of the second planetary gear 24 will be slower. The second planetary gear 24 meshes with the second internal gear 25, which also has 1 to 2 fewer teeth than the first internal gear 22 and is fixedly connected to the output shaft 26. The final reduction ratio i of this reducer can be calculated by the following formula:

[0047]

[0048] Among them, Z 22 , Z 23 , Z 24 , Z 25 and Z 27 The numbers of teeth of the first internal gear, the first planetary gear, the second planetary gear, the second internal gear and the sun gear are represented respectively. Finally, the enhanced power torque is transmitted through the output shaft 26.

[0049] In an embodiment of the present invention, the dexterous hand further includes a sensor module and a circuit module that is communicatively connected to the sensor module; the circuit module is used to receive the original electrical signal detected by the sensor module, and resolve the original electrical signal into object surface features, joint torque values, and angle values. The circuit module includes a drive circuit 10 for controlling the drive module, a sensor signal processing circuit, a communication circuit, and a power supply circuit 11. Each circuit in the circuit module is designed with an integrated circuit board, and the size of each integrated circuit board does not exceed 4×2×3cm, which ensures high integration while effectively reducing the volume.

[0050] Specifically, the power circuit 11 uses efficient voltage regulation and power management technology to ensure that all modules can operate stably under different loads, thereby extending the service life of the system. At the same time, the communication circuit supports wired high-bandwidth communication or high-speed wireless communication to achieve data exchange with an external control system, further improving the response speed and operation accuracy of the dexterous hand.

[0051] Specifically, in order to improve the integration of the circuit and reduce the space occupied, a high-density circuit board design is adopted in the driving circuit, in which the size of each circuit module does not exceed 4×2×3cm. This design not only reduces the space occupied by the circuit, but also makes the maintenance and replacement of the circuit unit easier through modular design. All circuit boards use surface mount technology (SMT) for component installation, thereby improving the stability, anti-interference and thermal management capabilities of the circuit. The circuit board ensures a stable supply of power and efficient processing of signals through integrated chips and distributed power management systems, supporting the real-time operation and feedback mechanism of the dexterous hand. In addition, the power supply circuit 11 of the circuit module provides voltage stabilization and filtering functions to ensure that the motor, sensor and other control systems can work stably under different voltage conditions. The power supply circuit also adopts a low-power design to ensure long-term stable operation of the system.

[0052] In the embodiment of the present invention, the sensor module is a key part for the dexterous hand to achieve precise operation and high-degree-of-freedom control. The sensor module includes: a visual tactile sensor device (17 and 18) installed at the fingertips and knuckles; an angle sensor (19 and 20) installed at the mid-end joint and the base joint; and a torque sensor 21 installed at the base joint.

[0053] In the above-mentioned sensor module, the core components of the visual tactile sensing device are the soft material 18 covering the fingertips and knuckles and the micro camera 17 arranged in the fingertips and knuckles. The soft material is made of highly elastic silicone or other highly elastic materials, which can sense tiny deformations when in contact with an object and transmit the deformation information to the micro camera. The micro camera monitors the deformation of the soft material in real time and generates image or video data. It extracts features from the image or video through an image recognition algorithm to identify the features of the object surface, such as material, temperature, surface shape, etc. This design enables the dexterous hand to accurately sense the surface characteristics of the contacted object, such as the shape, surface roughness, hardness and temperature of the contacted object, thereby providing more sophisticated operational feedback. Based on the above-mentioned visual tactile sensing device, the following visual tactile recognition process can be implemented: first, the camera monitors the soft material in real time; when the deformation of the soft material is identified, the current soft material picture or video is obtained by taking a picture or recording a video; the picture or video is feature-recognized based on a pre-built image recognition algorithm, and the features of the contacted object are obtained based on the picture or video of the soft material;

[0054] In the sensor module, an angle sensor 19 is provided on the left and right sides of the base joint to detect the original electrical signal used to calculate the pitch angle and the yaw angle; an angle sensor 20 is provided at the middle joint to detect the original electrical signal used to calculate the flexion and extension angle. The angle sensor uses a high-precision photoelectric encoder that can maintain high-precision measurement under different loads and operating speeds to ensure that the movement of each joint can be accurately reflected to the control system.

[0055] In the above sensor modules, Figure 6 The torque sensor includes: a torque sensor differential frame 36, and a first strain gauge 37, a second strain gauge 38, a third strain gauge 39 and a fourth strain gauge 40 arranged on the differential frame. The four strain gauges are arranged in the upper, lower, left and right directions of the cross beam of the differential frame, respectively, for detecting torque through resistance changes. Figure 6 As shown in the figure, when the differential rack is subjected to a moment in the X direction, the corresponding strain gauge in the vertical direction will be slightly bent and deformed, resulting in a change in the resistance on the strain gauge. The change in resistance has a corresponding functional relationship with the corresponding bending moment. The resistance value is detected by the peripheral circuit, and the corresponding moment value in the X direction is obtained by data solution. Similarly, the moment value in the Y direction can be detected.

[0056] In an embodiment of the present invention, the control logic of each finger implemented based on the above-mentioned dexterous hand is as follows: Figure 7 As shown, the details are as follows:

[0057] First, the power supply circuit 11 starts to provide a stable power supply to ensure that all modules of the entire dexterous hand system can operate normally. The control logic of the system is issued by the host computer through the communication circuit. The host computer is usually a central processing unit, which is responsible for the planning and allocation of the overall task and transmits the operation instructions to the lower computer through a high-bandwidth communication interface (such as wired or high-speed wireless communication).

[0058] After receiving the instruction from the upper computer, the lower computer first transmits the instruction to the palm circuit board 10 through the communication circuit. As the control center, the palm circuit board is responsible for parsing the instruction and distributing the instruction to the drive circuit of the corresponding finger according to the specific needs of different fingers. Each motor-reducer of each finger corresponds to an independent drive circuit module. These drive circuit modules are integrated in independent unit modules, fixed to the back of the hand and the palm shell by screws, and arranged inside the palm to achieve an efficient and compact structural design.

[0059] Once the command is assigned to the corresponding drive circuit module, the drive circuit transmits the control signal to the motor controller of the corresponding finger through the internal connection. The motor controller is responsible for adjusting the motion parameters of each motor, including speed, torque and direction, to achieve precise motion control. Specifically, after receiving the command from the drive circuit, the motor controller first monitors the current state of the motor through a closed-loop feedback mechanism, and then adjusts the output of the motor according to the preset control algorithm to ensure that the finger can complete the expected movement according to the command.

[0060] The power is transmitted to the actuator through the reducer and transmission mechanism, ensuring that the finger movement is both flexible and powerful. The reducer (such as the 3K reducer) can not only effectively increase the torque output of the motor, but also maintain an efficient transmission ratio while reducing the volume, thereby improving the grasping and operation capabilities of the dexterous hand in complex environments.

[0061] At the same time, the sensor module monitors various state parameters of the finger in real time, including position, speed and tactile information. Specifically, the visual tactile sensor device (17 and 18) senses the deformation of the finger when it touches the object through a micro camera and soft material; the angle sensor (19 and 20) accurately measures the angle change of each joint of the finger; the torque sensor 21 detects the torque applied to the finger through a strain gauge. All these sensor data are transmitted back to the circuit module in real time through the sensor signal processing circuit, and further transmitted to the host computer for analysis and processing.

[0062] Through this closed-loop control system, the dexterous hand can achieve precise control and real-time feedback of finger movements. The system can dynamically adjust the operating status of the motor according to the feedback information provided by the sensor, ensuring that the fingers have high flexibility and precision when performing complex operation tasks. In addition, the real-time monitoring and feedback mechanism of the sensor module also improves the response speed and operational safety of the system, and can detect and correct potential misoperations or abnormal situations in a timely manner.

[0063] In general, the control logic design of the present invention builds a highly integrated and powerful control system through the collaborative work of the host computer and the slave computer, the efficient cooperation of the drive circuit and the motor controller, and the real-time feedback of the sensor module. The system not only improves the operation ability of the dexterous hand in complex environments, but also ensures the stability and maintainability of the overall system, meeting the high-precision and high-degree-of-freedom requirements of various application scenarios such as industrial automation, medical surgery, and precision assembly.

[0064] In an embodiment of the present invention, a dexterous hand based on a reducer and a differential mechanism is provided. By reasonably distributing multiple motor-reducer combinations, two motor-reducer combinations are used in combination with differential mechanisms to realize the pitch and yaw degrees of freedom of the finger base joints, and one motor-reducer combination is used to drive the flexion and extension degrees of freedom of the mid-end joints. While achieving high degrees of freedom, the number of driving devices is significantly reduced. The use of a reducer with a double planetary gear structure and a specific number of teeth design effectively optimizes the torque output and realizes a compact structure while ensuring high gripping force of the dexterous hand.

[0065] In summary, specific embodiments of the subject matter have been described. Other embodiments are within the scope of the appended claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve the desired results. In addition, the processes depicted in the accompanying drawings do not necessarily require the specific order or sequential order shown to achieve the desired results.

[0066] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0067] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0068] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0069] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0070] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0071] Those skilled in the art will appreciate that the above embodiments are specific embodiments for implementing the present invention, and that in actual applications, various changes may be made in form and detail without departing from the spirit and scope of the present invention.

Claims

1. A dexterous hand based on a speed reducer and a differential mechanism, characterized in that: include: A palm part and fingers connected to the palm part; wherein the palm part includes a shell structure and a drive module; The driving module includes multiple motor-reducer combinations, and every three motor-reducer combinations are used to drive one finger, wherein two motor-reducer combinations are connected to the differential mechanism of the finger base joint, and one motor-reducer combination is connected to the middle end joint to form the flexion and extension degrees of freedom of the middle end joint, and the differential mechanism is used to realize the pitch degree of freedom and the yaw degree of freedom of the finger base joint through differential transmission; The reducer is a double planetary gear structure, including: a first planetary gear and a second planetary gear, wherein the number of teeth of the first planetary gear is greater than that of the second planetary gear; and a two-stage internal gear, wherein the number of teeth of the first internal gear is greater than that of the second internal gear.

2. A dexterous hand based on a speed reducer and a differential mechanism according to claim 1, characterized in that: In the reducer, the number of teeth of the first planetary gear is 1 or 2 more than the number of teeth of the second planetary gear, and the number of teeth of the first internal gear is 1 or 2 more than the number of teeth of the second internal gear.

3. The dexterous hand based on a speed reducer and a differential mechanism according to claim 1, characterized in that: The differential mechanism includes a differential frame, a first bevel gear fixed on the differential frame, left and right bevel gears meshing with the first bevel gear, a second bevel gear meshing with the first bevel gear and the left and right bevel gears, and left and right driving wheels respectively fixed on the outsides of the left and right bevel gears; The left and right drive wheels are respectively connected to a set of motor-reducer combination through a synchronous belt, wherein: The first bevel gear is used to carry the differential frame to produce pitch motion when the left and right driving wheels rotate synchronously; The first bevel gear is used to carry the differential frame to generate yaw motion when the left and right driving wheels rotate in opposite directions.

4. A dexterous hand based on a speed reducer and a differential mechanism according to claim 3, characterized in that: The two sets of motor-reducer assemblies connected to the differential mechanism of the finger root joint include a lower motor-reducer assembly close to the palm and an upper motor-reducer assembly close to the finger root, wherein: The two motor-reducer combinations are parallel to the vertical direction of the finger, and the reducers are in opposite directions; When the two motor-reducer combinations transmit the same torque and direction to the synchronous belt, the left and right drive wheels are driven to rotate synchronously in the same direction; When the two motor-reducer combinations transmit torques in different directions to the synchronous belt, the left and right driving wheels are driven to rotate in opposite directions.

5. The dexterous hand based on a speed reducer and a differential mechanism according to claim 1, characterized in that: Also includes a sensor module and a circuit module communicatively connected to the sensor module; The circuit module is used to receive the original electrical signal detected by the sensor module, and to resolve the original electrical signal into object surface features, joint torque values ​​and angle values.

6. The dexterous hand based on a speed reducer and a differential mechanism according to claim 5, characterized in that: The sensor module comprises: Visual tactile sensing devices installed at the fingertips and knuckles; Angle sensors installed at the mid-joint and finger-base joints; Torque sensor installed at the base of the finger joint.

7. A dexterous hand based on a speed reducer and a differential mechanism according to claim 6, characterized in that: The visual tactile sensing device comprises: Soft material covering the fingertips and knuckles; The miniature camera arranged in the fingertip knuckle is used to capture the deformation state data of the soft material from inside the fingertip knuckle.

8. The dexterous hand based on a speed reducer and a differential mechanism according to claim 6, characterized in that: An angle sensor is provided on the left and right sides of the finger base joint respectively, for detecting the original electrical signal used to calculate the pitch angle and the yaw angle; An angle sensor is set at the middle joint to detect the original electrical signal used to calculate the flexion and extension angle.

9. The dexterous hand based on a speed reducer and a differential mechanism according to claim 1, characterized in that: The circuit module includes a driving circuit, a sensor signal processing circuit, a communication circuit and a power supply circuit. The circuit module is designed with an integrated circuit board, and the size of each integrated circuit board does not exceed 4×2×3 cm.

10. The dexterous hand based on a speed reducer and a differential mechanism according to claim 1, characterized in that: The middle joint is coupled to the fingertip joint through a connecting rod mechanism, and the flexion and extension movement of the middle joint drives the fingertip joint to move synchronously through the connecting rod mechanism, thereby forming the active degree of freedom of the middle joint and the passive degree of freedom of the fingertip joint.

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