Thumb mechanism of five-finger manipulator

Abstract

The invention discloses a thumb mechanism of a five-finger manipulator, and belongs to the field of robots. The device mainly comprises a finger bending assembly, a finger inward swinging assembly and a finger around-wrist rotating assembly. The finger bending gear set is composed of a plurality of straight gears meshed in sequence. According to the mechanical thumb, the finger bending assembly, the finger inward swinging assembly and the finger around-wrist rotating assembly are combined to one mechanical thumb, three-degree-of-freedom actions including the finger bending action, the finger inward swinging action and the finger around-wrist rotating action can be achieved on one mechanical thumb at the same time, and the size of the mechanical thumb is reduced. A connecting rod in a transmission mechanism of the finger bending assembly is a corrugated elastic connecting rod, so that a bending joint of a mechanical thumb has elasticity, energy generated by impact can be absorbed to protect a driving motor, the service life of the motor is prolonged, and meanwhile, a mechanical thumb grabbing structure has self-adaptability in the grabbing process; the action area of the manipulator and a grabbed object is increased, and the grabbing stability of the manipulator is improved.

Description

Technical Field

[0001] The invention relates to a thumb mechanism of a five-fingered manipulator applied to a humanoid robot, belonging to the field of robots. Background Art

[0002] One of the core functions of humanoid robots is to grasp and manipulate various objects and tools. The five-finger manipulator is an ideal solution to achieve this function by simulating the movement of human hands. Among the existing five-finger manipulator devices, the rope-driven manipulator is heavy and the transmission structure cannot be integrated into the hand. The motor-direct-driven manipulator has a high joint inertia and a weak load capacity. At the same time, the thumb plays an important role in tasks such as manipulating objects and needs to have the characteristics of high load and strong flexibility. Therefore, a highly integrated finger mechanical structure is needed to overcome the above defects. Summary of the invention

[0003] In order to improve the mobility of the robot manipulator and the degree of freedom of the manipulator, the present invention comprehensively considers factors such as volume, load, compliance interaction, and impact changes. The purpose of the present invention is to provide a thumb mechanism of a five-finger manipulator, which combines the three components of the finger bending component, the finger inward swing component, and the finger wrist rotation component into a mechanical thumb. The three degrees of freedom of finger bending, finger inward swing, and finger wrist rotation can be realized on the mechanical thumb at the same time, thereby reducing the overall size of the mechanical thumb. The connecting rod in the transmission mechanism of the finger bending component adopts a corrugated elastic connecting rod, so that the bending joint of the mechanical thumb is elastic, can absorb the energy generated by the impact, protect the drive motor, and increase the life of the motor. At the same time, the grasping configuration of the mechanical thumb is adaptive during the grasping process, increasing the interaction area between the manipulator and the grasped object, and improving the grasping stability of the manipulator.

[0004] The objective of the present invention is achieved through the following technical solutions:

[0005] The invention discloses a thumb mechanism of a five-finger manipulator, which is mainly composed of a finger bending component, a finger inner swing component and a finger wrist rotation component.

[0006] The finger bending component is mainly composed of a finger bending drive motor, a finger bending gear set, a finger bending ball screw nut pair, a finger bending elastic connecting rod and a finger joint. The finger bending gear set is a gear set composed of a plurality of spur gears meshing in sequence. When the finger bending component realizes the finger bending action, the driving motor provides the gear set with rotational power. The rotational power transmits the rotational motion to the shaft end of the ball screw through the mutually meshing gear set, and then the rotational motion is converted into linear motion by the motion characteristics of the ball screw nut pair. The ball nut drives the finger joint to perform the finger bending action under the constraint of the finger bending elastic connecting rod. The finger joint is mainly composed of a universal joint, an upper finger joint, a lower finger joint and a contact soft rubber.

[0007] Preferably, the finger bending elastic link adopts a corrugated elastic link, so that the bending joint of the mechanical thumb is elastic, which can absorb the energy generated by the impact to protect the drive motor and increase the life of the motor. At the same time, during the grasping process, the grasping configuration of the mechanical thumb is made adaptive, increasing the interaction area between the manipulator and the grasped object and improving the grasping stability of the manipulator.

[0008] The finger inner swing assembly is mainly composed of a finger inner swing drive motor, a finger inner swing gear set, a finger inner swing ball screw nut pair and two rotatable slide block plates. The finger inner swing gear set is a gear set composed of a plurality of spur gears meshing in sequence. When the finger inner swing assembly realizes the finger inner swing action, the drive motor provides rotational power to the gear set. The rotational power transmits the rotational motion to the shaft end of the ball screw through the mutually meshing spur gear set, and then the rotational motion is converted into linear motion by the motion characteristics of the ball screw nut pair. The ball nut drives the slide block plate to rotate around the center of the slide block plate, thereby realizing the finger inner swing movement.

[0009] The mechanical thumb wrist rotating assembly mainly includes a finger connector, a palm base, a drive motor, and a bevel gear set. The bevel gear set is composed of an active bevel gear and a driven bevel gear. When the mechanical thumb wrist rotating assembly is implemented, the drive motor provides rotational power to the direction-changing bevel gear set. The rotational power is changed in direction through the mutually meshing bevel gear set, that is, the rotational direction output by the drive motor is a rotational motion around the "X" axis, and the rotational direction is changed to a rotational motion around the "Y" axis after passing through the direction-changing bevel gear set, thereby realizing the change in the direction of the rotational power. The finger connector is driven by the driven gear in the bevel gear set, so that the entire mechanical thumb rotates around the wrist with the rotation point of the wrist as the axis, thereby realizing the mechanical thumb rotation around the wrist.

[0010] The working method of the thumb mechanism of a five-finger manipulator disclosed in the present invention is as follows:

[0011] When the finger bending assembly realizes the finger bending action, the finger bending drive motor generates rotational motion in the working state, and this rotational motion is transmitted to the shaft end of the finger bending ball screw through the finger bending gear set. The finger bending ball screw and the finger bending ball nut together form the finger bending ball screw nut pair, which converts the rotational motion transmitted to the finger bending ball screw into linear motion through the motion characteristics of the finger bending ball screw nut pair, and then outputs it through the finger bending ball nut. The calculation formula of the finger bending ball nut output force is:

[0012]

[0013] Among them, F is the output force of the finger bending ball nut, T is the torque on the shaft end of the finger bending ball screw, I is the lead of the finger bending ball screw, and η is the mechanical transmission efficiency.

[0014] The finger bending ball nut then drives the lower knuckle to rotate around the universal joint, and the rotational power of the lower knuckle is transmitted to the upper knuckle through the finger bending elastic link, thereby realizing the bending action of the entire mechanical thumb. When the upper knuckle contacts the object, the finger bending elastic link undergoes elastic deformation under the action of the contact force, causing the bending angle of the mechanical thumb to change with the magnitude of the contact force, thereby allowing more areas of the mechanical thumb to contact the object, increasing the area of ​​action between the manipulator and the grasped object, and improving the gripping stability of the manipulator. When the upper knuckle is impacted by an external force, the finger bending elastic link undergoes elastic deformation under the action of the impact force, absorbing the energy generated by the impact, thereby protecting the drive motor and increasing the life of the motor.

[0015] When the finger inner swing assembly realizes the finger inner swing action, the finger inner swing drive motor generates a rotational motion in the working state, and this rotational motion is transmitted to the shaft end of the finger inner swing ball screw through the finger inner swing gear set. The finger inner swing ball screw and the finger inner swing ball nut together form a finger inner swing ball screw nut pair. The rotational motion transmitted to the finger inner swing ball screw is converted into a linear motion through the motion characteristics of the finger inner swing ball screw nut pair, and then output by the finger inner swing ball nut. The calculation formula of the finger inner swing ball nut output force is the same as formula (1). The finger inner swing ball nut drives the slide block to rotate with the center of the block as the axis, and then the entire mechanical thumb also performs an inner swing motion with the center of the slide block as the center.

[0016] When the mechanical thumb wrist rotation assembly performs the finger wrist rotation action, the finger wrist drive motor generates a rotation motion in the working state to drive the active bevel gear. This rotation motion is converted into a rotation motion around the "X" axis through the bevel gear set and is output by the driven bevel gear. The driven wheel drives the finger connector to realize the rotation motion around the "Y" axis, and because the finger connector is fixedly connected to the entire mechanical thumb, the entire mechanical thumb can rotate around the wrist.

[0017] Beneficial effects:

[0018] 1. The thumb mechanism of a five-finger manipulator disclosed in the present invention combines three components, namely a finger bending component, a finger inward swing component and a finger wrist rotation component, into a mechanical thumb. The mechanical thumb can simultaneously realize three degrees of freedom of movement, namely finger bending movement, finger inward swing movement and finger wrist rotation movement, thereby reducing the overall size of the mechanical thumb.

[0019] 2. The thumb mechanism of a five-finger manipulator disclosed in the present invention adopts a corrugated elastic connecting rod and a ball screw-slide baffle transmission structure to convert the rotational motion of the motor into linear motion and then into joint rotational motion. Compared with the direct drive solution, it can obtain a higher transmission ratio, improve load performance, and grasp objects more firmly.

[0020] 3. The thumb mechanism of a five-finger manipulator disclosed in the present invention adopts a corrugated elastic connecting rod. The corrugated elastic connecting rod will undergo elastic deformation when subjected to force. Compared with the rigid connecting rod, the corrugated elastic connecting rod can absorb the energy generated by the impact to protect the drive motor and increase the life of the motor. At the same time, during the grasping process, the grasping configuration of the mechanical thumb is made adaptive, the interaction area of ​​the manipulator and the grasped object is increased, and the grasping stability of the manipulator is improved.

[0021] 4. The thumb mechanism of a five-finger manipulator disclosed in the present invention integrates a motor direct drive, a ball screw-slideway baffle transmission structure and a corrugated elastic connecting rod, realizes three active degrees of freedom in a volume close to the size of a human thumb, and has flexibility, load capacity and compliance. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Schematic diagram of finger bending action, where: Figure 1 (a) The mechanical thumb is in the straight position. Figure 1 (b) shows the mechanical thumb in a bent state.

[0023] Figure 2 Schematic diagram of a corrugated elastic connecting rod.

[0024] Figure 3 This is a schematic diagram of the finger swinging action, where: Figure 3 (a) The mechanical thumb is in the straight position. Figure 3 (b) The mechanical thumb is in the inward swing state.

[0025] Figure 4 Schematic diagram of finger rotation around wrist: Figure 4 (a) is the initial state of the mechanical thumb. Figure 4 (b) shows the state of the mechanical thumb after it rotates around the wrist.

[0026] Figure 5 The schematic diagram of the finger structure of the present invention, Figure 5 (a) is the side view of the mechanical thumb. Figure 5 (b) is the front view of the mechanical thumb.

[0027] Among them: 1-finger bending component, 2-finger inward swing component, 3-mechanical thumb wrist rotation component.

[0028] 1.1—upper finger joint, 1.2—finger bending elastic connecting rod, 1.3—lower finger joint, 1.4—universal joint, 1.5—finger bending ball screw nut pair, 1.6—finger bending guide shaft, 1.7—finger bending driving motor, 1.8—finger bending gear set.

[0029] Among them: 1.5-finger bending ball screw nut pair includes 1.5.1-finger bending ball nut, 1.5.2-finger bending ball screw

[0030] 2.1—finger inner swing driving motor, 2.2—finger inner swing gear set, 2.3—finger inner swing ball screw nut pair, 2.4—slideway baffle, 2.5—finger inner swing guide shaft.

[0031] Among them: 2.3-finger inward swing ball screw nut pair includes 2.3.1-finger inward swing ball screw and 2.3.2-finger inward swing ball nut.

[0032] 3.1—frame, 3.2—finger connector, 3.3—palm base, 3.4—direction-changing bevel gear set, 3.5—finger-wrist drive motor.

[0033] Among them: 3.4-change direction bevel gear set includes 3.4.1-driving bevel gear and 3.4.2-driven bevel gear. DETAILED DESCRIPTION

[0034] In order to better illustrate the purpose and advantages of the present invention, the invention is further described below with reference to the accompanying drawings and examples.

[0035] Embodiment 1:

[0036] like Figure 5 As shown, the thumb mechanism of a five-finger manipulator disclosed in this embodiment is mainly composed of a finger bending component 1, a finger inner swing component 2 and a finger wrist rotation component 3.

[0037] The finger bending component 1 is mainly composed of a finger bending drive motor 1.7, a finger bending gear set 1.8, a finger bending ball screw nut pair 1.5, a finger bending elastic connecting rod 1.2, an upper finger joint 1.1 and a lower finger joint 1.3. The finger bending gear set 1.8 is a gear set composed of a plurality of spur gears meshing in sequence. When the finger bending component 1 realizes the finger bending action, the finger bending 1.7 drive motor provides rotational power to the finger bending gear set 1.8. The rotational power transmits the rotational motion to the shaft end of the finger bending ball screw 1.5.2 through the meshing gear set, and then the motion characteristics of the ball screw nut pair convert the rotational motion into linear motion. The finger bending ball nut 1.5.1 drives the upper finger joint 1.1 and the lower finger joint 1.3 to perform the finger bending action under the constraints of the finger bending elastic connecting rod 1.2 and the universal joint 1.4.

[0038] The finger bending elastic link 1.2 adopts a corrugated elastic link to make the bending joint of the mechanical thumb elastic, which can absorb the energy generated by the impact to protect the drive motor and increase the life of the motor. At the same time, during the grasping process, the grasping configuration of the mechanical thumb is adaptive, which increases the interaction area between the manipulator and the grasped object and improves the grasping stability of the manipulator.

[0039] The finger inner swing assembly 2 is mainly composed of a finger inner swing drive motor 2.1, a finger inner swing gear set 2.2, a finger inner swing ball screw nut pair 2.3 and two rotatable slide block pieces 2.4. The finger inner swing gear set 2.2 is a gear set composed of a plurality of spur gears meshing in sequence. When the finger inner swing assembly 2 realizes the finger inner swing action, the finger inner swing drive motor 2.1 provides rotational power to the finger inner swing gear set 2.2. The rotational power transmits the rotational motion to the shaft end of the finger inner swing ball screw 2.3.1 through the mutually meshing spur gear set, and then the rotational motion is converted into linear motion by the motion characteristics of the ball screw nut pair. The finger inner swing ball nut 2.3.2 drives the slide block piece 2.4 to rotate around the center of the slide block piece 2.4, thereby realizing the finger inner swing motion.

[0040] The mechanical thumb wrist rotating assembly 3 mainly includes a finger connector 3.2, a palm base 3.3, a finger wrist driving motor 3.5, and a direction-changing bevel gear set 3.4. The direction-changing bevel gear set 3.4 is composed of a driving bevel gear 3.4.1 and a driven bevel gear 3.4.2. When the mechanical thumb wrist rotating assembly 3 is implemented, the finger wrist driving motor 3.5 provides the direction-changing bevel gear set 3.4 with a rotational power. The rotational power is transformed in a rotational direction through the mutually meshing bevel gear sets, that is, the rotational direction output by the finger wrist driving motor 3.5 is a rotational motion around the "X" axis, and after passing through the direction-changing bevel gear set 3.4, the rotational direction is changed to a rotational motion around the "Y" axis, thereby realizing the transformation of the direction of the rotational power. The driven bevel gear 3.4.2 in the direction-changing bevel gear set 3.4 drives the finger connector 3.2, so that the entire mechanical thumb rotates around the wrist with the rotation point of the wrist as the axis, thereby realizing the mechanical thumb wrist rotation action.

[0041] The working method of the thumb mechanism of a five-finger manipulator disclosed in this embodiment is as follows:

[0042] When the finger bending assembly 1 realizes the finger bending action, the finger bending drive motor 1.7 generates a rotational motion in the working state, and this rotational motion is transmitted to the shaft end of the finger bending ball screw 1.5.2 through the finger bending gear set 1.8. The finger bending ball screw 1.5.2 and the finger bending ball nut 1.5.1 together form the finger bending ball screw nut pair 1.5, which converts the rotational motion transmitted to the finger bending ball screw 1.5.2 into a linear motion through the motion characteristics of the finger bending ball screw nut pair 1.5, and then output by the finger bending ball nut 1.5.1. The calculation formula for the output force of the finger bending ball nut 1.5.1 is:

[0043]

[0044] Among them, F is the output force of the finger bending ball nut 1.5.1, T is the torque on the shaft end of the finger bending ball screw 1.5.2, I is the lead of the finger bending ball screw 1.5.2, and η is the mechanical transmission efficiency.

[0045] The finger bending ball nut 1.5.1 then drives the lower knuckle to rotate around the universal joint 1.4, and the rotational power of the lower knuckle 1.3 is transmitted to the upper knuckle 1.1 through the finger bending elastic link 1.2, thereby realizing the bending action of the entire mechanical thumb. When the upper knuckle 1.1 contacts the object, the finger bending elastic link 1.2 undergoes elastic deformation under the action of the contact force, so that the bending angle of the mechanical thumb changes with the magnitude of the contact force, so that more areas of the mechanical thumb contact the object, increasing the action area between the manipulator and the grasped object, and improving the gripping stability of the manipulator. When the upper knuckle is impacted by an external force, the finger bending elastic link undergoes elastic deformation under the action of the impact force, absorbing the energy generated by the impact, thereby protecting the drive motor and increasing the life of the motor.

[0046] When the finger inner swing assembly 2 realizes the finger inner swing action, the finger inner swing driving motor 2.1 generates a rotational motion in the working state, and this rotational motion is transmitted to the shaft end of the finger inner swing ball screw 2.3.1 through the finger inner swing gear set 2.2. The finger inner swing ball screw 2.3.1 and the finger inner swing ball nut 2.3.2 together form the finger inner swing ball screw nut pair 2.3, which converts the rotational motion transmitted to the finger inner swing ball screw 2.3.1 into a linear motion through the motion characteristics of the finger inner swing ball screw nut pair 2.3, and then outputs it by the finger inner swing ball nut 2.3.2. The calculation formula of the output force of the finger inner swing ball nut 2.3.2 is the same as formula (1). The finger inner swing ball nut 2.3.2 drives the slide block 2.4 to rotate with the center of the block as the axis, and then the entire mechanical thumb also performs an inner swing motion with the center of the slide block 2.4 as the center.

[0047] When the mechanical thumb wrist rotation group 3 performs the finger wrist rotation action, the finger wrist drive motor 3.5 generates a rotational motion in the working state to drive the active bevel gear 3.4.1. This rotational motion is converted into a rotational motion around the "X" axis through the bevel gear group 3.4, and is output by the driven bevel gear 3.4.2. The driven wheel drives the finger connector to realize the rotational motion around the "Y" axis, and because the finger connector 3.2 is fixedly connected to the entire mechanical thumb, the entire mechanical thumb can rotate around the wrist.

[0048] The specific description above further illustrates the purpose, technical solutions and beneficial effects of the invention in detail. It should be understood that the above is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A thumb mechanism of a five-finger manipulator, characterized in that: It is mainly composed of a finger bending component, a finger inner swing component and a finger wrist rotation component; The finger bending assembly is mainly composed of a finger bending drive motor, a finger bending gear set, a finger bending ball screw nut pair, a finger bending elastic connecting rod and a finger joint; the finger bending gear set is a gear set composed of a plurality of spur gears meshing in sequence; when the finger bending assembly realizes the finger bending action, the drive motor provides the gear set with rotational power; the rotational power transmits the rotational motion to the shaft end of the ball screw through the meshing gear set, and then the rotational motion is converted into linear motion by the motion characteristics of the ball screw nut pair; the ball nut drives the finger joint to perform the finger bending action under the constraint of the finger bending elastic connecting rod; the finger joint is mainly composed of a universal joint, an upper finger joint, a lower finger joint and a contact soft rubber; The finger inner swing assembly is mainly composed of a finger inner swing drive motor, a finger inner swing gear set, a finger inner swing ball screw nut pair and two rotatable slide block pieces; the finger inner swing gear set is a gear set composed of a plurality of sequentially meshed spur gears; when the finger inner swing assembly realizes the finger inner swing action, the drive motor provides the gear set with rotational power; the rotational power transmits the rotational motion to the shaft end of the ball screw through the mutually meshed spur gear set, and then the rotational motion is converted into linear motion by the motion characteristics of the ball screw nut pair; the ball nut drives the slide block piece to rotate around the center of the slide block piece, thereby realizing the finger inner swing action; The mechanical thumb wrist rotating assembly is mainly composed of a finger connector, a palm base, a driving motor, and a bevel gear set; the bevel gear set is composed of an active bevel gear and a driven bevel gear; when the mechanical thumb wrist rotating assembly is implemented, the driving motor provides rotational power to the direction-changing bevel gear set; the rotational power is converted into a rotational direction through the mutually meshing bevel gear sets, that is, the rotational direction output by the driving motor is a rotational motion around the "X" axis, and after passing through the direction-changing bevel gear set, the rotational direction is converted into a rotational motion around the "Y" axis, thereby realizing the conversion of the direction of the rotational power; the driven gear in the bevel gear set drives the finger connector, so that the entire mechanical thumb rotates around the wrist with the rotation point of the wrist as the axis, thereby realizing the mechanical thumb wrist rotation action.

2. The thumb mechanism of a five-finger manipulator according to claim 1, characterized in that: The finger bending elastic link adopts a corrugated elastic link, which makes the bending joint of the mechanical thumb elastic, able to absorb the energy generated by the impact to protect the drive motor. At the same time, during the grasping process, the grasping configuration of the mechanical thumb is adaptive, increasing the interaction area between the manipulator and the grasped object and improving the grasping stability of the manipulator.

3. A thumb mechanism of a five-finger manipulator as claimed in claim 1 or 2, characterized in that: When the finger bending assembly realizes the finger bending action, the finger bending drive motor generates a rotational motion in the working state, and this rotational motion is transmitted to the shaft end of the finger bending ball screw through the finger bending gear set; the finger bending ball screw and the finger bending ball nut together form a finger bending ball screw nut pair, which converts the rotational motion transmitted to the finger bending ball screw into a linear motion through the motion characteristics of the finger bending ball screw nut pair, and then outputs it through the finger bending ball nut. The calculation formula of the finger bending ball nut output force is: Among them, F is the output force of the finger bending ball nut, T is the torque on the shaft end of the finger bending ball screw, I is the lead of the finger bending ball screw, and η is the mechanical transmission efficiency; The finger bending ball nut then drives the lower knuckle to rotate around the universal joint, and the rotational power of the lower knuckle is transmitted to the upper knuckle through the finger bending elastic link, thereby realizing the bending action of the entire mechanical thumb. When the upper knuckle contacts the object, the finger bending elastic link undergoes elastic deformation under the action of the contact force, so that the bending angle of the mechanical thumb changes with the magnitude of the contact force, thereby making more areas of the mechanical thumb contact the object, increasing the action area of ​​the manipulator and the grasped object, and improving the grasping stability of the manipulator; when the upper knuckle is impacted by an external force, the finger bending elastic link undergoes elastic deformation under the action of the impact force, absorbing the energy generated by the impact, thereby protecting the drive motor and increasing the life of the motor; When the finger inner swing assembly realizes the finger inner swing action, the finger inner swing driving motor generates a rotational motion in the working state, and the rotational motion is transmitted to the shaft end of the finger inner swing ball screw through the finger inner swing gear set; the finger inner swing ball screw and the finger inner swing ball nut together form a finger inner swing ball screw nut pair, and the rotational motion transmitted to the finger inner swing ball screw is converted into a linear motion through the motion characteristics of the finger inner swing ball screw nut pair, and then output by the finger inner swing ball nut. The calculation formula of the finger inner swing ball nut output force is the same as formula (1). The finger inner swing ball nut drives the slide block to rotate with the center of the block as the axis, and then the entire mechanical thumb also performs an inner swing motion with the center of the slide block as the center. When the mechanical thumb wrist rotation assembly performs the finger wrist rotation action, the finger wrist drive motor generates a rotational motion in the working state to drive the active bevel gear. This rotational motion is converted into a rotational motion around the "X" axis through the bevel gear set and is output by the driven bevel gear. The driven wheel drives the finger connector to realize the rotational motion around the "Y" axis. Because the finger connector is fixedly connected to the entire mechanical thumb, the wrist rotation action of the entire mechanical thumb is realized.

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