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CN-121973165-A - Forearm wearable device based on four-bar two-cable stretch-draw structure

CN121973165ACN 121973165 ACN121973165 ACN 121973165ACN-121973165-A

Abstract

The invention discloses a forearm wearable device based on a four-rod two-cable tension structure, and belongs to the technical field of upper limb wearable power assisting equipment. The wrist self-recovery device mainly comprises a forearm rotating mechanism and a wrist self-recovery mechanism which are coaxially arranged. The forearm rotating mechanism is composed of an upper fixing ring, a three-rod parallel mechanism and three four-rod two-cable stretching integral units which are distributed at equal intervals. The stretching integral unit and the three-rod parallel mechanism cooperate to realize multi-position steady-state switching and elastic power assistance in the rotation/outward rotation of the forearm. The wrist self-recovery mechanism comprises a hand support ring, four wrist support blocks, four branched chains and four elastic ropes, and forms a two-degree-of-freedom parallel tensioning structure to realize the auxiliary, buffering and automatic resetting of wrist flexion and extension and inward-extension movements. The device combines the stretching integral structure with the rigid parallel mechanism, has the characteristics of flexibility, stability and light weight, can be matched with the motion mechanism of a human body, and improves the wearing comfort and safety.

Inventors

  • SUN JIANWEI
  • SHI CHENYU
  • NI PENG
  • LV HAN
  • ZHANG MEILING
  • JIANG DAWEI

Assignees

  • 长春工业大学

Dates

Publication Date
20260505
Application Date
20260408

Claims (10)

  1. 1. A forearm wearable device based on a four-rod two-cable tensioning structure is characterized by comprising a forearm rotating mechanism (1) and a wrist self-restoring mechanism (2), wherein the wrist self-restoring mechanism (2) is coaxially arranged with the forearm rotating mechanism (1) and the wrist self-restoring mechanism (2) is positioned above the forearm rotating mechanism (1), the forearm rotating mechanism (1) comprises an upper fixing ring (101), an upper cover plate (102), a supporting ring (103), a bearing (109), a sleeve piece (104), a clamping piece (106), a three-rod parallel mechanism (108), a central shaft (107) and a four-rod two-cable tensioning integral unit (105), the three-rod parallel mechanism (108) is positioned below the upper fixing ring (101), the four-rod two-cable tensioning integral unit (105) is connected between the upper fixing ring (101) and the three-rod parallel mechanism (108), the lower fixing ring (101) and the lower end of the central shaft (107) can be rotatably fixed through a sleeve and the bearing (109), the upper fixing ring (101) and the lower end of the central shaft (107) can be fixedly inserted into the upper fixing ring (107) in a sliding way, the four-rod two-cable tensioning integral unit (105) comprises two rigid upper connecting rods (10501), two rigid lower connecting rods (10502) and two stretchable tension springs (10503), one ends of the two upper connecting rods (10501) are hinged to the upper fixed ring (101), the other ends of the two upper connecting rods are respectively hinged to one ends of the corresponding lower connecting rods (10502), the other ends of the two rigid lower connecting rods (10502) are hinged to the three-rod parallel mechanism (108), one tension spring (10503) is connected to the hinge point of the upper connecting rods (10501) and the hinge point of the lower connecting rods (10502) in a horizontal direction, the other tension springs are connected between the hinge point of the upper connecting rods and the upper fixed ring and the hinge point of the lower connecting rods and the upper surface of the parallel mechanism in a vertical direction, the wrist self-recovery mechanism (2) comprises a hand supporting ring (201), a plurality of supporting blocks (204), a plurality of branched chains (202) and a plurality of elastic ropes (203), one end of each supporting block is connected to the corresponding to one end of the corresponding wrist (201) of the corresponding to the corresponding supporting ring (201), and the other end of the corresponding wrist (201) is hinged to the corresponding to the wrist (201).
  2. 2. The forearm wearable device based on the four-bar two-cable tensioning structure according to claim 1, wherein the forearm rotating mechanism (1) comprises a sleeve piece (104) and a bearing (109), the upper end of the sleeve piece (104) is sleeved with an inner ring of the bearing (109), and an outer ring of the bearing (109) is sleeved on an inner ring of the upper fixing ring (101) so as to realize rotatable coaxial fixation of the upper fixing ring (101) and the bottom surface of the three-bar parallel mechanism (108).
  3. 3. The forearm wearable device based on a four-bar two-cable tension structure according to claim 1, wherein the upper cover plate (102), the upper cover plate (102) is fixedly connected to the top of the upper fixing ring (101) for assisting in fixing the outer ring of the bearing (109).
  4. 4. The forearm wearable device based on a four-bar two-cable tension structure according to claim 1, wherein the number of sleeve pieces (104) is three, the three sleeve pieces (104) are circumferentially distributed in the upper fixing ring (101) and the three-bar parallel mechanism (108) at equal intervals, and the three sleeve pieces (104) are connected into an integral sleeve structure through a supporting ring (103).
  5. 5. The forearm wearable device based on a four-bar two-cable tension structure according to claim 1, wherein the three-bar parallel mechanism (108) comprises an upper cover plate (10801), a bottom plate (10807) and three ball-head connecting rods (10804), spherical grooves are formed in the upper cover plate (10801) and the bottom plate (10807), and two ends of the three ball-head connecting rods (10804) form revolute pairs with the spherical grooves in the upper cover plate (10801) and the bottom plate (10807) respectively.
  6. 6. The forearm wearable device based on a four-bar two-cable tensioning structure according to claim 1, wherein the number of four-bar two-cable tensioning integral units (105) is three, and three four-bar two-cable tensioning integral units (105) are uniformly distributed between the upper fixing ring (101) and the three-bar parallel mechanism (108) at equal intervals.
  7. 7. The forearm wearable device based on a four-bar two-cable tensioning structure according to claim 1, wherein in the four-bar two-cable tensioning integral unit (105), two upper links (10501) and two lower links (10502) are mounted in a bilaterally symmetrical manner, and four links are rectangular in distribution.
  8. 8. The forearm wearable device based on the four-bar two-cable tension structure according to claim 1, wherein the number of the wrist supporting blocks (204) is four, the wrist supporting blocks are fixedly connected to the upper surface of the upper fixing ring (101) in a circumferential equidistant mode, the number of the branched chains (202) is four, and the branched chains are uniformly distributed circumferentially around the hand supporting ring (201).
  9. 9. The forearm wearable device based on a four-bar two-cable tension structure according to claim 1, wherein the branched chain (202) comprises an upper arm (20201), a middle connection block (20202) and a lower arm (20203), one end of the upper arm (20201) is hinged with the hand support ring (201), the other end is hinged with one end of the middle connection block (20202), the other end of the middle connection block (20202) is hinged with one end of the lower arm (20203), and the other end of the lower arm (20203) is hinged with the wrist support block (204).
  10. 10. The forearm wearable device based on a four-bar two-cable tensioning structure according to claim 1, wherein the clip (106) is fixedly arranged inside a base plate (10807) of the three-bar parallel mechanism (108) for connecting the end of the arm of the wearer with the base plate (10807) to thereby fix the relative position of the whole wearable device and the forearm of the wearer.

Description

Forearm wearable device based on four-bar two-cable stretch-draw structure Technical Field The invention relates to the technical field of upper limb wearable power assisting equipment, in particular to a forearm wearable device based on a four-rod two-cable tensioning structure. Background In recent years, with the development of man-machine cooperation and auxiliary assistance technology, wearable devices for enhancing or assisting the movement ability of a human body are attracting attention in the engineering field, and in particular, the development of upper limb wearable devices is rapid. The upper limb of the human body has wide movement space range and various movement forms, such as grabbing, carrying, dragging and other operations, and has higher requirements on the flexibility and stability of the movement. Among them, the forearm serves as an important part connecting the hand and the forearm, and plays a key role in force transmission and fine manipulation. Therefore, the forearm wearable device is an important type of upper limb wearable device, and has important significance in improving work efficiency, reducing muscle burden and enhancing continuous work capacity. However, although the existing forearm wearable device can assist the human body to complete part of the operation to a certain extent, a plurality of defects still exist in practical application. Firstly, the existing device adopts a rigid structure, and has the defects of large overall volume, heavy weight, and influence on wearing comfort and long-time use experience. For example, patent CN202610013844.2 discloses an exoskeleton with an adjustable back plate, the driving unit and the supporting frame are made of metal, which results in heavy overall quality, limited freedom of joint movement, and difficulty in adapting to forearm shapes and exercise habits of different users. Secondly, partial forearm exoskeleton has insufficient matching degree with biomechanical characteristics of human forearms in structural design, is easy to generate constraint incompatibility or additional stress, and reduces naturalness and flexibility of movement. For example, patent CN202512052958.6 discloses an exoskeleton device and a robot with the exoskeleton device, which uses an adjusting motor at each joint as a power source with a power assisting function, ignoring that the instant center of the human joint changes along with the movement angle of the joint in the rotation process, so that an additional moment can be applied to the joint of the wearer, and the joint movement of the wearer is difficult or uncomfortable. Disclosure of Invention The invention provides a forearm wearable device based on a four-bar two-cable tensioning structure, which aims to overcome the defects in the prior art, and the four-bar two-cable tensioning structure formed by two flexible stretching units and four rigid compression units is utilized to realize the rigid-flexible coupling characteristic of the forearm wearable device by combining the tensioning integral structure with a rigid parallel mechanism, so that the forearm wearable device has certain rigidity and bearing capacity while realizing flexibility, stability and light weight, and solves the problems of excessively complex structure, large integral weight of equipment, mismatching of the movement track of the equipment and the movement track of a human body and the like in the traditional forearm wearable mechanism. According to the invention, the multi-position steady state of the forearm wearable device is realized through the innovative four-rod two-cable stretch-draw integral structure, and three steady states in the four-rod two-cable stretch-draw integral structure correspond to specific rotation angles in the three-rod parallel mechanism, so that the forearm wearable device can be kept stable at the external rotation limit position, the neutral position and the internal rotation limit position of the arm, and can be matched with the human body movement mechanism. And by utilizing the unique mechanical property of the four-rod two-cable tensioning structure during steady-state switching, elastic thrust can be applied in the rotating process of the three-rod parallel mechanism, so that the boosting effect of the forearm wearable device in the internal rotation and external rotation processes of a human body is realized. It should be noted that the naming of the related components in the present invention is only for descriptive purposes, and is used for illustrating the technical solution, and should not be construed as limiting the present invention. The invention provides a forearm wearable device based on a four-bar two-cable tension structure, which mainly comprises a forearm rotating mechanism and a wrist self-recovery mechanism. The wrist self-recovery mechanism is coaxially arranged with the forearm rotating mechanism, the wrist self-recovery mechanism is arranged above the forearm rotating