Six-degree-of-freedom intelligent force control modular dexterous hand

Abstract

The invention belongs to the field of robots, and discloses a six-degree-of-freedom intelligent force control modular dexterous hand, a palm structure comprises a palm shell and a skeleton, and the skeleton is used for assembling fingers, a thumb and a motor control system; the motor system comprises a first motor and a second motor; the fingers are connected with a first motor through a connecting rod mechanism, and the first motor drives the bending action of each finger; the thumb has two degrees of freedom including the bending degree of freedom and the transverse swinging degree of freedom of the thumb, bending of the thumb is controlled by a first motor and a connecting rod mechanism, and transverse swinging of the thumb is controlled by a second motor; the thumb is controlled by the second motor to swing transversely, so that palm-to-palm movement is achieved, and complex grasping tasks are completed in cooperation with other fingers. The thumb is designed to have two independent degrees of freedom, one degree of freedom is used for controlling bending of the thumb, the other degree of freedom is used for achieving transverse swinging of the thumb, the thumb can work in cooperation with other fingers, and therefore the flexibility and accuracy during grabbing are improved.

Description

Technical Field

[0001] The invention belongs to the field of robots, and in particular to the design and application of a multi-freedom bionic dexterous hand used in an industrial automation environment. Background Art

[0002] In recent years, the rapid development of robotics has promoted the widespread application of dexterous hands in the fields of industry, medicine, etc. The design requirements of dexterous hands are not limited to simulating the appearance of human hands, but also to integrate mechanical and electrical components in a limited space to achieve efficient and flexible grasping functions. However, in a complex and changing working environment, dexterous hands need to have strong grasping force and dexterity, which puts high demands on the structural design of fingers. How to enhance the flexibility and diversified functions of fingers while improving the grasping force is still one of the key challenges in the current structural design of dexterous hands.

[0003] Most existing bionic hand designs rely on multiple motors to control the bending of fingers through tendons or linkage mechanisms. This design usually places five motors inside the palm or arm, and controls the bending of each finger through a connecting rod or rope. However, since this system can only achieve grasping movements in a single direction, the independence between fingers is poor and it is impossible to accurately simulate the complex operations of the human hand. In addition, the thumb of the existing dexterous hand lacks the function of lateral swing at the root (palm-to-palm movement), resulting in insufficient flexibility and limited operational ability when grasping irregular shapes or complex tools. Finger joints usually only have passive degrees of freedom, making it difficult to achieve independent and flexible movements, which makes the existing dexterous hands obviously insufficient in dexterity, grasping power and functional diversity.

[0004] In addition, most existing dexterous hands are not equipped with a force feedback system, which makes it impossible to monitor the gripping force in real time during the grasping process. Due to the lack of such a feedback mechanism, the reliability and safety of the dexterous hand when grasping objects are greatly reduced. Therefore, developing a dexterous hand with high degrees of freedom and flexibility, and improving its gripping force and safety through an integrated force feedback system, has become a key direction of current technological development.

[0005] In addition, the maintenance and subsequent upgrade process of existing dexterous hands is usually complicated. The motor and fingers are directly assembled with the palm in the structural design. When these parts need to be replaced, upgraded or maintained, disassembly and assembly will lead to unnecessary waste of materials. In order to solve this problem, further optimizing the structural design of the dexterous hand so that it can be maintained, upgraded and disassembled more conveniently has also become an important aspect of improving the industrial application capability of the dexterous hand. Summary of the invention

[0006] The present invention is to solve at least one of the above technical problems and provide a multi-degree-of-freedom bionic robot dexterous hand, which aims to solve the problems of insufficient flexibility, low grasping accuracy and complex maintenance in the prior art. The dexterous hand is suitable for industrial automation scenarios, can complete complex grasping and operation tasks, and improves the functionality and maintenance convenience of the dexterous hand through an innovative mechanical structure.

[0007] In order to achieve the above-mentioned purpose, the technical solution of the present invention is to provide a six-degree-of-freedom intelligent force-controlled modular dexterous hand, including a palm structure, a thumb structure, a finger structure and a motor control system for driving the movement of the fingers and thumb. The palm structure includes a palm shell and a skeleton arranged in the palm shell, and the skeleton is used to assemble the fingers, thumb and motor control system;

[0008] The motor system includes a first motor for controlling the bending movement of the fingers and thumb and a second motor for controlling the lateral swinging movement of the thumb;

[0009] The fingers are all connected to the first motor via a connecting rod mechanism, and the first motor drives the bending action of each finger;

[0010] The thumb has two degrees of freedom, including a bending degree of freedom and a lateral swing degree of freedom. The bending of the thumb is controlled by a first motor and a connecting rod mechanism, and the lateral swing is controlled by a second motor.

[0011] The thumb is controlled to swing horizontally through a second motor to achieve palm-to-palm movement, and cooperates with other fingers to complete complex grasping tasks. The thumb is designed with two independent degrees of freedom, one for controlling the bending of the thumb and the other for achieving lateral swing (palm-to-palm movement) of the thumb. This design enables the thumb to work in coordination with other fingers, thereby improving flexibility and accuracy when grasping.

[0012] The present invention adopts a connecting rod drive system to replace the traditional wire rope drive method. The connecting rod drive system has the advantages of simple structure, stability and reliability, and is particularly suitable for high-frequency operation requirements in industrial scenarios. Compared with wire rope drive, the connecting rod drive system reduces friction and wear, and improves the durability and reliability of the system.

[0013] According to the present invention, further, the connecting rod mechanism is used to connect the fingertip joint and the knuckle joint of each finger, and the first motor drives the finger joints to bend synchronously through the connecting rod mechanism.

[0014] According to the present invention, further, the skeleton in the palm structure is detachably connected to the palm shell.

[0015] According to the present invention, further, the bending of the thumb is composed of three joints, including a first thumb joint, a second thumb joint and a third thumb joint, and the overall bending of the thumb is achieved through the synchronous movement of the first motor and the connecting rod mechanism.

[0016] According to the present invention, further, the first motor and the second motor are relatively independent, and each first motor corresponds to a finger, so that each finger moves relatively independently.

[0017] According to the present invention, further, the motor control system is integrated with a force feedback system, which detects the force and torque during grasping in real time and automatically adjusts the force according to the shape of the object and the grasping difficulty.

[0018] According to the present invention, further, the force feedback system includes a force sensor.

[0019] The motors used in the dexterous hand of the present invention are not completely fixed to the skeleton, and can slightly shake left and right during movement (the first degree of freedom of the motor). In addition, the push rod of the motor itself moves (the second degree of freedom of the motor). Therefore, in the two-dimensional mechanical principle structure sketch, the motor can be simplified into a rocker-connecting rod mechanism, which consists of two components, a rotating pair and a moving pair. The simplified motor mechanism provides two degrees of freedom.

[0020] Among them, one degree of freedom at the base of the thumb is used to realize the lateral swing of the base of the thumb, which is driven by a motor and a connecting rod. The connecting rod has two revolving pairs. The revolving pair at one end of the connecting rod is connected to the motor, and the other revolving pair is connected to the frame in the middle of the connecting rod. The other end of the connecting rod is connected to the thumb. When the motor is extended or retracted, it drives the rotation of the connecting rod, thereby driving the swing of the base of the thumb.

[0021] The bending movement of the thumb is completed by a motor and a connecting rod group. The thumb of the dexterous hand of the present invention includes three joints, namely the fingertip joint, the middle joint and the base joint. The fingertip joint (first knuckle) is used to achieve the end bending of the thumb; the middle joint (second knuckle) provides further flexibility, allowing the thumb to bend in a wider range; the base joint (third knuckle) is located at the root of the thumb and is connected to the connecting rod at the root of the palm, which is responsible for the overall movement of the thumb, including bending and lateral swinging.

[0022] The bending motion of the thumb is realized by the connecting rod group. After being simplified into a two-dimensional structural sketch of the mechanical principle, the thumb plus the motor consists of 7 components, and there are 10 low pairs. The connecting rod combination mechanism realizes one degree of freedom of the bending motion of the thumb. The motor is connected to the middle joint, and the motor stretches and contracts to drive the three joints of the thumb to bend synchronously.

[0023] The structures of the index finger, middle finger, ring finger and pinky finger are similar, and all use a connecting rod mechanism. Each finger contains two joints, namely the fingertip joint and the knuckle joint. The structure of the finger has a total of 5 components and 7 low pairs in the two-dimensional mechanical schematic diagram. The two joints are driven to bend synchronously by the extension and contraction of the motor to achieve the bending movement of the finger.

[0024] In addition, the dexterous hand of the present invention also integrates a force feedback system. The motor of each finger has a built-in force sensor, which can monitor the gripping force in real time and adjust the force as needed to ensure the stability and safety of the grip. The force feedback system can provide higher safety when grasping delicate objects and prevent damage to the objects due to excessive force.

[0025] Another innovation lies in the modular design of the palm structure. The palm includes an outer shell and a frame. Existing dexterous hands on the market usually install the motor and fingers directly in the palm structure, which makes maintenance and subsequent upgrades difficult. The present invention adds an independent palm frame, installs the fingers and motor on the frame, and then combines them with the inner and outer shells of the palm. The palm shell only serves an aesthetic purpose, while all core components are integrated on the frame. This design greatly simplifies the maintenance and upgrade process of the dexterous hand, allowing it to be quickly disassembled and assembled when maintenance is needed, reducing material waste and improving the industrial application efficiency of the product.

[0026] In terms of motor design, the present invention also introduces an innovation - a force feedback system. This system is integrated into each control motor and can monitor the force and torque applied during the grasping process in real time. When the dexterous hand grasps objects with complex shapes or difficult to hold, the force feedback system can dynamically adjust the force to avoid damage to the object due to excessive force, while ensuring the stability and accuracy of the grasp. This design is particularly suitable for scenarios that require high stability and fine operation, greatly improving the level of intelligent operation of the dexterous hand.

[0027] The multi-degree-of-freedom bionic dexterous hand provided by the present invention not only achieves high precision and high flexibility in the motion control of the thumb and fingers, but also improves the intelligent level of operation through the force feedback system. In addition, its modular skeleton structure design significantly optimizes the convenience of maintenance and upgrade replacement, and is particularly suitable for efficient operation tasks in the field of industrial automation, such as precise grasping and assembly tasks of complex industrial tools. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings of the present invention are used to further illustrate the specific embodiments of the present invention so as to more clearly understand the structure and principle of the present invention.

[0029] Figure 1 It is a schematic diagram of the overall structure of the six-degree-of-freedom intelligent force-controlled modular dexterous hand of the present invention;

[0030] Figure 2It is a schematic diagram of the internal structure of the thumb of the six-degree-of-freedom intelligent force-controlled modular dexterous hand of the present invention;

[0031] Figure 3 It is a schematic diagram of the skeleton structure of the six-degree-of-freedom intelligent force-controlled modular dexterous hand of the present invention;

[0032] Figure 4 It is a schematic diagram of the finger structure of the six-degree-of-freedom intelligent force-controlled modular dexterous hand of the present invention;

[0033] Figure 5 It is a schematic diagram of the internal structure of the fingers of the six-degree-of-freedom intelligent force-controlled modular dexterous hand of the present invention;

[0034] Figure 6 It is a schematic diagram of the lateral swinging motion of the thumb of the six-degree-of-freedom intelligent force-controlled modular dexterous hand of the present invention.

[0035] In the figure:

[0036] 1. Fingertip joint; 2. Knuckle joint; 3. Palm shell; 4. Skeleton; 5. First motor; 6. Second motor; 7. First joint of thumb; 8. Second joint of thumb; 9. Third joint of thumb; 10. Thumb lateral swing connecting rod; 11. Thumb fingertip connecting rod; 12. Thumb knuckle connecting rod; 13. Thumb bending motion motor; 14. Finger connecting rod; 15. Finger fixing base; 16. Thumb base. DETAILED DESCRIPTION

[0037] In order to more clearly explain the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved, the technical solutions of the embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. It should be noted that the described embodiments are only part of the present invention, not all embodiments. Based on these embodiments, other implementation methods that can be obtained by those skilled in the art without performing creative work should also be deemed to belong to the scope of protection of the present invention.

[0038] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, they can be fixedly connected or detachably connected, or an integrated structure; they can be mechanically connected or electrically connected; they can be directly connected or indirectly connected through an intermediate medium, or they can be internally connected between two elements or an interactive relationship between the two. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] In the present invention, unless otherwise expressly provided, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or being in indirect contact through other features. In addition, the orientation relationships such as "above", "below", "left", and "right" are based on the relative positions of the drawings and are only used to facilitate description and simplify explanation, and cannot be regarded as limitations on the invention. In addition, the terms "first" and "second" are only used for distinction and do not have special meanings.

[0040] In this specification, terms such as "an embodiment", "an example", etc. indicate that a particular feature, structure, material or characteristic described in conjunction with the embodiment or example may be included in at least one embodiment of the present invention. The use of such terms does not mean that every embodiment includes the same features.

[0041] The technical solution of the present invention is further illustrated by specific implementation modes in conjunction with the accompanying drawings.

[0042] like Figures 1 to 6 As shown, the present invention provides a six-degree-of-freedom intelligent force-controlled modular dexterous hand, including fingers and a thumb, which are all mounted on a skeleton 4, and the skeleton 4 is connected to a palm shell 3. Four finger mounting bases 15 are provided on the skeleton 4 for connecting four fingers. There are also five motor mounting positions on the skeleton 4, which are respectively used to install a second motor 6 for controlling the bending movement of the fingers and a first motor 5 for controlling the lateral swing of the thumb.

[0043] This modular design separates the skeleton and palm shell, simplifying the maintenance and upgrade process of the dexterous hand. The modularization of each structure facilitates subsequent repairs and updates.

[0044] like Figure 2 As shown, it is a schematic diagram of the internal structure of the thumb, including the first thumb joint 7 (i.e., fingertip joint), the thumb fingertip connecting rod 11, the second thumb joint 8, the third thumb joint 9, the thumb knuckle connecting rod 12, the thumb bending motion motor 13 and the thumb lateral swing connecting rod 10.

[0045] Specifically, the first joint 7 of the thumb is connected to the second joint 8 of the thumb through a cylindrical pin, one end of the second joint 8 of the thumb is provided with a circular groove, and the third joint 9 of the thumb is provided with a cylindrical protrusion structure matched with the circular groove. The two ends of the thumb fingertip connecting rod 11 are respectively connected to the first joint 7 of the thumb and the second joint 8 of the thumb through a cylindrical pin. The two ends of the thumb knuckle connecting rod 12 are respectively connected to the second joint 8 of the thumb and the thumb lateral swing connecting rod 10 through a cylindrical pin. The thumb lateral swing connecting rod 10 is connected to the third joint 9 of the thumb through a cylindrical pin. Among them, the third joint 9 of the thumb is a shell structure, and there is a space for installing a motor in the shell. The thumb bending movement motor 13 for controlling the bending movement of the thumb is installed in the shell, and the end of the thumb bending movement motor 13 is connected to the small hole on the second joint 8 of the thumb through a cylindrical pin.

[0046] When the thumb lateral swing link 10 is assumed to be fixed, the linear motion of the thumb bending motion motor 13 push rod will drive the thumb second joint 8 to rotate with the cylindrical structure matched with the thumb housing 9. At the same time, since the link 11 is matched with the cylinder on the thumb third joint, it will also rotate, thereby driving the thumb first joint 7 to rotate relative to the thumb lateral swing link 10. The rotation of the thumb second joint 8 also drives the thumb knuckle link 12 connected thereto to move together, thereby causing the thumb third joint 9 to rotate relative to the thumb lateral swing link 10.

[0047] This thumb structure only requires one motor degree of freedom to complete the continuous bending movement of three joints, converting the telescopic movement of the motor push rod into the bending movement of the thumb, thereby improving the flexibility of the thumb movement.

[0048] like Figure 4 and Figure 5 As shown, it is a structural diagram of the little finger. Since the index finger, middle finger, ring finger and little finger have similar internal structures in the dexterous hand of the present invention, only the implementation method of the little finger is explained here.

[0049] Each of the four fingers consists of a fingertip joint 1, a knuckle joint 2 and a finger connecting rod 14. After the three are assembled, they are installed on the finger fixing base 15. The fingertip joint 1 is connected to the knuckle joint 2 by a cylindrical pin, and the two ends of the finger connecting rod 14 are respectively connected to the fingertip joint 1 and the finger fixing base 15 by cylindrical pins. The first motor 6 is installed in the skeleton 4 to drive the bending movement of the finger, and the end of the first motor 6 is connected to the small hole on the knuckle joint 2 by a cylindrical pin.

[0050] Since the finger fixing base 15 is fixedly connected to the skeleton 4, we assume that the skeleton 4 remains stationary. When the push rod of the first motor 6 moves linearly, it will drive the finger joint 2 to rotate, and the finger connecting rod 14 will move accordingly, thereby realizing the synchronous bending of the two joints of the finger.

[0051] In this embodiment, if Figure 6 As shown, it shows how the six-degree-of-freedom dexterous hand of the present invention realizes the lateral swinging movement of the thumb. A thumb base 16 is connected to the skeleton 4, and the thumb base 16 is connected to the thumb lateral swing connecting rod 10 through the hole and cylindrical pin thereon. The small hole on the thumb lateral swing connecting rod 10 is connected to the end on the second motor 5 through the cylindrical pin.

[0052] Assuming that the base is fixed, when the second motor 5 performs linear motion, the thumb lateral swing link 10 rotates relative to the thumb base 16, thereby realizing the lateral swing of the thumb.

[0053] In the specific implementation of the present invention, each motor has a built-in force sensor as a force feedback system, which can detect the applied force and torque in real time when grasping an object. When the dexterous hand starts to grasp an object, it can avoid the problem of excessive force or insufficient grasping force, thereby ensuring the stability of the grasp. This design is particularly suitable for operating objects with complex shapes, fragile materials or objects that require precise manipulation.

[0054] Another advantage of the force feedback system is that it improves the grasping accuracy of the dexterous hand. When the system detects that the grasping force is greater than the set value, it will reduce the torque output by the motor to prevent damage to the object or mechanical parts caused by excessive force; conversely, when the grasping force is insufficient, the system will increase the motor output to ensure the success rate of the grasping action. This intelligent control mechanism not only ensures the accuracy of the operation, but also extends the service life of the equipment and reduces maintenance costs.

[0055] Through the introduction of this force feedback system, the dexterous hand can achieve adaptive grasping in different operating environments, which not only improves the operating efficiency but also ensures the safety and accuracy during the grasping process.

Claims

1. A six-degree-of-freedom intelligent force-controlled modular dexterous hand, comprising a palm structure, fingers, a thumb, and a motor control system for driving the fingers and thumb to move, characterized in that: The palm structure includes a palm shell and a skeleton arranged in the palm shell, and the skeleton is used to assemble fingers, thumb and motor control system; The motor system includes a first motor for controlling the bending movement of the fingers and thumb and a second motor for controlling the lateral swinging movement of the thumb; The fingers are connected to the first motor through a connecting rod mechanism, and the first motor drives the bending action of each finger; the thumb has two degrees of freedom, including the bending degree of freedom and the lateral swing degree of freedom of the thumb, the bending of the thumb is controlled by the first motor and the connecting rod mechanism, and the lateral swing is controlled by the second motor; The thumb is controlled to swing laterally through the second motor to achieve palm-to-palm movement, and cooperates with other fingers to complete complex grasping tasks.

2. The six-degree-of-freedom intelligent force-controlled modular dexterous hand according to claim 1, characterized in that: The connecting rod mechanism is used to connect the fingertip joint and the knuckle joint of each finger, and the first motor drives the finger joints to bend synchronously through the connecting rod mechanism.

3. The six-degree-of-freedom intelligent force-controlled modular dexterous hand according to claim 1, characterized in that: The frame in the palm structure is detachably connected to the palm shell.

4. A six-degree-of-freedom intelligent force-controlled modular dexterous hand according to any one of claims 1 to 3, characterized in that: The bending of the thumb consists of three joints, including a first thumb joint, a second thumb joint and a third thumb joint, and the overall bending of the thumb is achieved through the synchronous movement of the first motor and the connecting rod mechanism.

5. A six-degree-of-freedom intelligent force-controlled modular dexterous hand according to any one of claims 1 to 3, characterized in that: The first motor and the second motor are relatively independent, and each first motor corresponds to a finger, so that each finger moves relatively independently.

6. The six-degree-of-freedom intelligent force-controlled modular dexterous hand according to claim 1, characterized in that: The motor control systems are all integrated with a force feedback system, which detects the force and torque applied during grasping in real time and automatically adjusts the force applied according to the shape of the object and the grasping difficulty.

7. The six-degree-of-freedom intelligent force-controlled modular dexterous hand according to claim 6, characterized in that: The force feedback system includes a force sensor.

Images