CN-121973260-A - Variable-rigidity rope-driven manipulator

CN121973260ACN 121973260 ACN121973260 ACN 121973260ACN-121973260-A

Abstract

The invention relates to a variable-rigidity rope driven manipulator, which has the same structure as five mechanical fingers, and comprises a proximal phalanx, a middle phalanx and a distal phalanx which are sequentially connected in a rotating way, wherein the variable-rigidity mechanism comprises a mounting part and a variable-rigidity transmission part, the five mechanical fingers are distributed at the mounting part at intervals, the proximal phalanx is rotationally connected with the mounting part, the variable-rigidity transmission part is slidingly connected with the mounting part, a transmission component is connected with the variable-rigidity transmission part, a variable-rigidity steering engine is connected with the transmission component, each mechanical finger is provided with an extending tendon rope and a bending tendon rope, a first coupling rope is connected between the middle phalanx and the distal phalanx, and a second coupling rope is connected between the distal phalanx and the proximal phalanx. The variable-stiffness rope-driven manipulator has lower tendon rope tension when grabbing objects, can grab objects with easily broken surfaces through stiffness adjustment, has enough safety during man-machine interaction, and belongs to the technical field of variable-stiffness manipulators.

Inventors

HUANG YANJIANG
Qiao Zedun
ZHANG XIANMIN

Assignees

华南理工大学

Dates

Publication Date: 20260505
Application Date: 20260306

Claims (10)

1. A variable-rigidity rope-driven manipulator is characterized by comprising a palm frame, a variable-rigidity steering engine, a transmission assembly, a variable-rigidity mechanism, five mechanical fingers, an stretching tendon rope and a bending tendon rope; The five mechanical fingers have the same structure and comprise a proximal phalanx, a middle phalanx and a distal phalanx, wherein the proximal phalanx, the middle phalanx and the distal phalanx are sequentially connected in a rotating way; The proximal phalanges of the five mechanical fingers are rotatably arranged on the palm frame; the variable stiffness mechanism comprises a mounting part and a variable stiffness transmission part, the mounting part is mounted in the palm frame, the variable stiffness transmission part is connected with the mounting part in a sliding way, and the transmission assembly is connected with the variable stiffness transmission part to drive the variable stiffness transmission part to slide at the mounting part; The variable stiffness steering engine is connected with the transmission assembly to drive the transmission assembly; The number of the stretching tendon ropes and the bending tendon ropes is five, and each mechanical finger is provided with one stretching tendon rope and one bending tendon rope; One end of each bending tendon rope is connected with the variable-rigidity transmission part, the other end of each bending tendon rope is used for being connected with external driving, and each bending tendon rope is in wire-wound connection with the proximal phalanx and the middle phalanx of the corresponding mechanical finger; one end of each stretching tendon rope is connected with the variable-rigidity transmission part, the other end of each stretching tendon rope is used for being connected with an external drive, and each stretching tendon rope is in wire-wound connection with the proximal phalanx and the middle phalanx of the corresponding mechanical finger; a first coupling rope is connected between the middle phalanx and the far-end phalanx, and a second coupling rope is connected between the far-end phalanx and the near-end phalanx.
2. The variable stiffness rope drive manipulator of claim 1, wherein: the proximal phalanx comprises a proximal right plate and a proximal left plate, and the proximal right plate and the proximal left plate are fixedly connected; The middle phalanx comprises a middle right plate and a middle left plate, and the middle right plate is fixedly connected with the middle left plate; the distal phalanx comprises a distal right plate and a distal left plate, and the distal right plate and the distal left plate are fixedly connected; wherein the proximal phalanx and the middle phalanx are rotationally connected by a first joint; the first joint comprises a first left plate, a first right plate, a first connecting shaft and two first joint bearings; the two ends of the first connecting shaft are respectively connected with a first left plate and a first right plate, the inner rings of the two first joint bearings are respectively sleeved on the first left plate and the first right plate, the near-end left plate and the near-end right plate are respectively inserted into the inner rings of the two first joint bearings and are respectively connected with the first left plate and the first right plate, and one end of the middle-section right plate and one end of the middle-section left plate are respectively connected with the outer rings of the two first joint bearings; The middle phalanx and the distal phalanx are rotationally connected through a second joint; the second joint comprises a second left plate, a second right plate, a second connecting shaft and two second joint bearings; Two ends of the second connecting shaft are respectively connected with a second left plate and a second right plate, inner rings of the two second joint bearings are respectively sleeved on the second left plate and the second right plate, the other end of the middle section right plate and the other end of the middle section left plate are respectively inserted into the inner rings of the two second joint bearings and are respectively connected with the second left plate and the second right plate, and one end of the far-end right plate and one end of the far-end left plate are respectively connected with outer rings of the two second joint bearings; A third joint is connected between the other end of the proximal right plate and the other end of the proximal left plate; The third joint comprises a third left plate, a third right plate, a third connecting shaft and two third joint bearings; the both ends of third connecting axle connect third left side board and third right side board respectively, and the inner circle of two third joint bearings cup joints respectively in third left side board and third right side board, and the other end of near-end right side board and the other end of near-end left side board are connected with the outer lane of two third joint bearings respectively, and the inner circle of two third joint bearings is connected with first connecting seat and second connecting seat respectively, and first connecting seat and second connecting seat are connected with third left side board and third right side board respectively, and first connecting seat and second connecting seat are all fixed in the palm frame.
3. The variable stiffness rope drive manipulator of claim 2, wherein the axes of the first connecting shaft, the second connecting shaft and the third connecting shaft are offset relative to the rotational centers of the first joint bearing, the second joint bearing and the third joint bearing, respectively.
4. The variable stiffness rope driving manipulator of claim 2, wherein tendon rope pulleys are rotatably connected to the first connecting shaft, the second connecting shaft and the third connecting shaft, and the tendon rope pulleys are connected with corresponding bending tendon ropes and stretching tendon ropes.
5. The variable-rigidity rope driving manipulator according to claim 2, wherein the middle phalanx is provided with a coupling wheel, the distal phalanx is provided with a tendon rope tension adjusting plate in an adjustable mode, one ends of the two first coupling ropes are connected with the coupling wheel, the other ends of the two first coupling ropes are connected with the tendon rope tension adjusting plate, one ends of the two second coupling ropes are connected with the coupling wheel, and the other ends of the two second coupling ropes are connected with the proximal phalanx.
6. The variable stiffness rope drive manipulator of claim 2, wherein the winding path of the curved tendon rope between the middle phalanx and the second joint is 8-shaped, the winding path of the curved tendon rope between the second joint and the proximal phalanx is 8-shaped, and the winding path of the curved tendon rope between the proximal phalanx and the third joint is 8-shaped.
7. The variable stiffness rope driving manipulator of claim 2, wherein the middle phalanx is provided with a tendon turning hole, and the tendon stretching rope turns to the tendon turning Kong Raojie after the proximal phalanx and the middle phalanx are sequentially wound and extends to the outside after the proximal phalanx is wound.
8. The variable-rigidity rope-driven mechanical arm of claim 1, wherein the palm frame comprises a palm back plate and a palm front plate, the palm back plate and the palm front plate are respectively fixed at two ends of the installation part, the proximal phalanges of the five mechanical fingers are all rotatably installed at the top of the palm back plate, five first pulley shafts are installed at the top of the palm back plate, first guide pulleys are all installed on the five first pulley shafts, the five first guide pulleys respectively correspond to the five mechanical fingers, the bending tendon ropes and the stretching tendon ropes configured by each mechanical finger are connected with the corresponding first guide pulleys, and one end of the bending tendon ropes and one end of the stretching tendon ropes are guided to the variable-rigidity transmission part by the first guide pulleys; the bottom of the palm backboard is connected with a wire guide plate, and the wire guide plate is provided with five wire guide holes; Five second pulley shafts are arranged at the bottom of the palm backboard, second guide pulleys are arranged on the five second pulley shafts, the five second guide pulleys correspond to the five wire guide holes respectively, the bending tendon ropes and the stretching tendon ropes configured by each mechanical finger are connected with the corresponding second guide pulleys, the other ends of the bending tendon ropes and the other ends of the stretching tendon ropes are guided to the wire guide holes by the second guide pulleys, and the bending tendon ropes and the stretching tendon ropes configured by each mechanical finger are connected with external driving after extending out of the wire guide holes.
9. The variable-rigidity rope driven manipulator of claim 1, wherein the transmission assembly comprises a guide rod, a screw rod, a driven gear and a driving gear, the driving gear is connected with an output shaft of the variable-rigidity steering engine, the driven gear is connected with the screw rod, the driven gear and the driving gear are in meshed transmission, the screw rod is rotatably arranged at the installation part, the variable-rigidity transmission part is in threaded connection with the screw rod, and the variable-rigidity transmission part is in sliding connection with the guide rod.
10. The variable stiffness rope driving manipulator of claim 9, wherein the variable stiffness transmission part comprises a wiring board, a variable stiffness moving board and a compression spring, the variable stiffness moving board is in threaded connection with a screw rod, the screw rod passes through the wiring board, the wiring board and the variable stiffness moving board are distributed at intervals along the axial direction of the screw rod, the wiring board and the variable stiffness moving board are in sliding connection with a guide rod, the compression spring is sleeved outside the guide rod, and the compression spring is positioned between the wiring board and the variable stiffness moving board; wherein, the one end that crooked tendon rope and stretch tendon rope all is connected with the wiring board fixed.

Description

Variable-rigidity rope-driven manipulator Technical Field The invention relates to the technical field of variable-rigidity mechanical arms, in particular to a variable-rigidity rope-driven mechanical arm. Background The traditional finger joint movement structure mainly adopts a mechanical hinge rotating joint design, the high-rigidity transmission mode has poor interaction with the outside, can not be quickly adapted to an unstructured environment on the premise of not improving the complexity of a control algorithm, and can possibly damage objects with low rigidity and easy deformation when grabbing, the robustness of a manipulator is poor, and the application of the manipulator is limited. Based on the problem that traditional manipulator exists, current manipulator utilizes tendon rope to drive, runs through the finger of whole manipulator with a tendon rope, and the pulley of each joint is walked around to the tendon rope and drives. However, friction in pulleys or guide mechanisms affects the efficiency of force transfer, wear over long periods of use, and additional pre-tensioning mechanisms are required to maintain tension in the tendon rope. And when the object is grabbed, fingers of the manipulator bear load, tendon rope tension can be increased, and excessive tension of the tendon rope can be caused to cause creep deformation and fracture. In order to solve the problems of the existing rope driving manipulator, the prior art applies the variable stiffness mechanism to the rope driving manipulator, but the following problems exist in the prior art: The current variable stiffness mechanisms are: The rigidity is regulated by changing the length of a force arm based on a lever or a mechanism with a transmission ratio regulation, one main actuator is used for generating displacement, the other rigidity regulating actuator is used for regulating the fulcrum position of a spring, and the mechanism has a complex structure and friction and gaps. The rigidity-changing mechanism based on the antagonism principle uses two main actuators to simultaneously pull through elastic elements to jointly drive one joint, realizes rigidity adjustment by changing the movement of two drivers, such as serial elastic drivers, and realizes the adjustment by actively changing the equivalent rigidity of a spring, wherein the two main actuators move in the same direction to change the joint position, and the opposite movement changes the pretension of the spring, so as to adjust the joint rigidity. This solution highly couples the position and stiffness control, which is complex. Based on the novel intelligent material, the rigidity is changed, and the internal state of the material is changed through an external thermal field, a magnetic field and an electric field by using materials such as shape memory alloy, magnetorheological or electrorheological fluid, low-melting-point alloy, dielectric elastomer and the like, so that the change of macroscopic rigidity is realized. The method has the advantages of limited output displacement, nonlinear and hysteresis of materials, complex control, and difficult solution of response speed, energy consumption and strength. The rigidity-changing mode based on the interlayer sliding and friction principle adjusts friction by controlling the pressing force between the multi-layer laminates or fibers, thereby changing bending rigidity. Such mechanisms are typically discrete or finite state adjustments, with continuous adjustments being difficult. In conclusion, the existing rigidity-changing mechanism is difficult to directly apply to the rope-driven mechanical arm, and miniaturization can lead to complex structure and difficult assembly, so that the cost is increased greatly. Disclosure of Invention Aiming at the technical problems in the prior art, the invention aims to provide the variable-rigidity rope-driven manipulator which has lower tendon rope tension when grabbing objects and has enough safety when man-machine interaction when grabbing objects with easily broken surfaces through rigidity adjustment. In order to achieve the above purpose, the invention adopts the following technical scheme: A variable-rigidity rope-driven manipulator comprises a palm frame, a variable-rigidity steering engine, a transmission assembly, a variable-rigidity mechanism, five mechanical fingers, an stretching tendon rope and a bending tendon rope; The five mechanical fingers have the same structure and comprise a proximal phalanx, a middle phalanx and a distal phalanx, wherein the proximal phalanx, the middle phalanx and the distal phalanx are sequentially connected in a rotating way; The proximal phalanges of the five mechanical fingers are rotatably arranged on the palm frame; the variable stiffness mechanism comprises a mounting part and a variable stiffness transmission part, the mounting part is mounted in the palm frame, the variable stiffness transmission part is connected with the mounting part i