CN110353949A - A kind of active knee ankle-joint prosthetic device based on change born of the same parents' parallel institution - Google Patents

Abstract

An active knee-ankle joint prosthesis mechanism based on metamorphic parallel mechanism is mainly composed of a fixed platform, an active branch chain, a metamorphic branch chain, a moving platform and an active foot and ankle prosthesis, which realizes the multi-freedom of the knee and ankle joint. Rotation function. In the metamorphic parallel mechanism designed by the present invention, the driving moving pair of the active branch chain adopts a ball screw, which imitates the telescopic motion of the skeletal muscle group of the calf. Since the internal and external rotation of the human knee does not exist all the time, it is only activated when the knee is flexed. In addition, there is less dependence on internal and external rotation in life. When the metamorphic kinematic pair is fixed, under the coupling between the metamorphic branch chain and the two active branch chains, the moving platform can only realize the flexion and extension of the knee joint and the varus and varus motion of the ankle joint; when the metamorphic kinematic pair is the driving rotation pair , the moving platform can also realize the internal and external rotation of the knee joint. The prosthetic mechanism relates to a medical rehabilitation robot, and has the requirements of high bearing capacity, high rigidity, simple structure, easy processing and manufacturing, and low production cost.

Description

An active knee-ankle joint prosthesis mechanism based on metamorphic parallel mechanism

technical field

The invention belongs to the field of medical rehabilitation robot technology and artificial intelligence equipment, and in particular relates to an active knee-ankle joint prosthesis mechanism based on a metamorphic parallel mechanism, which can compensate knee-ankle amputee patients for losing the knee-ankle joint movement ability, and enable the patient to recover knee joints. Multi-degree-of-freedom kinematic characteristics of joints and ankles and activities of daily living.

Background technique

According to the second national census on the number of disabled persons published in 2006, the number of disabled persons has reached 82.42 million, accounting for 6.34% of the total population. trips. In recent years, with the increase of natural disasters, traffic accidents, diseases and other accidents, the number of patients with amputations of different degrees has increased year by year. increase the burden on society. At present, with the unscrupulous development of science and technology and industrial manufacturing, robot technology has been widely used in major engineering fields in China. In order to compensate for the lost limbs of amputee patients and restore their original daily life ability, prosthetic robots belonging to medical rehabilitation robots have become one of the hotspots in domestic research. However, due to the limitations of some technical research and development and manufacturing process levels, prosthetic robots still have great market prospects at home and abroad.

As amputees with knee-ankle damage account for the largest proportion of lower-extremity amputees, there are many knee-ankle prosthetic mechanism products on the market. Existing human joint prosthetic mechanisms can be divided into active prosthetic mechanisms, passive prosthetic mechanisms, and active-passive hybrid prosthetic mechanisms according to whether or not to provide a power source. Compared with foreign prosthetics institutions, domestic research started late, and the technology is relatively backward. The research and development of lower limb prosthesis institutions in the domestic market is still in its infancy. At present, the research and development of domestic knee-ankle prosthetic mechanisms has been improved from the traditional single-degree-of-freedom and single-support rod structure to the intelligent multi-degree-of-freedom multi-joint form. The overall size, weight, and carrying capacity of the mechanism are too large, and the complex mechanism leads to unstable control algorithms, and the cost of the prosthetic mechanism is high, so this type of intelligent prosthetic mechanism is still not the main product on the market.

Based on this, the present invention designs an active knee-ankle joint prosthesis mechanism based on a metamorphic parallel mechanism. It can realize the flexion and extension movement of the knee joint, the varus movement and flexion and extension movement of the ankle joint, and the internal and external rotation movement of the knee joint under the activation state of the metamorphic kinematic pair; the prosthetic mechanism based on the parallel mechanism can not only make the mechanism have high stiffness and strong bearing capacity. It can also simplify the overall structure, reduce the overall size of the mechanism and production costs. At the same time, the simplified mechanism also has the advantages of easy control and low energy consumption. The knee-ankle joint prosthesis mechanism has a high bionic effect and is suitable for human knee-ankle amputee patients.

SUMMARY OF THE INVENTION

The technical problem of the present invention is to design an active knee-ankle joint prosthesis mechanism based on a metamorphic parallel mechanism, which solves the problems of complex structure, large volume, heavy weight, high energy consumption, problems such as high stability and insufficient bearing capacity. The metamorphic parallel mechanism adopted by the mechanism can not only realize the multi-degree-of-freedom motion characteristics of the knee-ankle joint, but also have the characteristics of large bearing capacity and low energy consumption, which makes it highly bionic compared with the human knee-ankle joint.

The present invention adopts the following technical scheme to realize:

An active knee-ankle joint prosthesis mechanism based on a metamorphic parallel mechanism, characterized in that it comprises a fixed platform (1), an active branch chain (2.1, 2.2), a metamorphic branch chain (3), a moving platform (4) and Active ankle prosthesis (5).

The active branch chain (2.1, 2.2) includes: a lower foot seat (2-1), a lower U-shaped seat (2-2), a cylindrical cylinder (2-3) with a drive, a piston rod with a drive (2- 4), connector (2-5), upper U-shaped seat (2-6), upper foot seat (2-7);

The connection between the components constituting the active branch chain: the lower foot seat (2-1) and the fixed platform (1) are connected by screws to form a fixed pair; the lower foot seat (2-1) and the lower U-shaped seat (2-2) form a rotation pair, the lower U-shaped seat (2-2) and the cylinder (2-3) with drive form a rotating pair, and at the same time, the axes of the two rotating pairs are orthogonal and equivalent to a Hooke pair; the cylinder with drive (2-3) -3) and the drive-containing piston rod (2-4) form a driving moving pair, which can be an electric push rod or a ball screw; the drive-containing piston rod (2-4) and the joint (2-5) are formed by threaded connection Fixed pair; the joint (2-5) and the upper U-shaped seat (2-6) form a rotating pair, the upper U-shaped seat (2-6) and the upper foot seat (2-7) form a rotating pair, and at the same time, the two rotating The orthogonal axis of the secondary axis is equivalent to a Hooke pair; the upper foot seat (2-7) and the moving platform (4) are connected by screws to form a fixed pair; in this design, the active branch chain (2.1, 2.2) is imitated as the surface of the tibia and fibula The biomechanical characteristics of the skeletal muscle group, by driving the expansion and contraction of the mobile pair, realize the two rotations of the end in space and the movement along the branch chain direction;

The metamorphic branch chain (3) comprises: a lower foot seat (3-1), a large sleeve (3-2), a lower rod (3-3) with a limited rotation angle, a cover plate (3-4), a limited rotation angle Upper rod (3-5), joint (3-6), small sleeve (3-7), upper foot seat (3-8);

The connection between the components forming the metamorphic branch chain: the lower foot seat (3-1) and the fixed platform (1) are connected by screws to form a fixed pair; the lower foot seat (3-1) and the lower rod (3-3) with limited rotation angle A rotating pair is formed, and a large sleeve (3-2) is provided at the gap position; the lower rod (3-3) with limited rotation angle and the upper rod (3-5) with limited rotation angle form a metamorphic kinematic pair. The kinematic pair has an angle limit to avoid the bizarre phenomenon of the mechanism caused by its transitional rotation; because the internal and external rotation of the human knee joint does not exist all the time, it is only activated when the knee is flexed. In addition, the dependence on internal and external rotation in life Fewer, the introduction of metamorphic branch chain (3) In order to make the prosthetic mechanism better imitate the motion characteristics of the human knee joint, through the fixed or driven rotation mode switching of the metamorphic kinematic pair, the moving platform (4) is in the metamorphic branch. The coupling of the chain (3) and the two active branch chains (2.1, 2.2) can realize the motion characteristics of two-degree-of-freedom pure rotation and three-degree-of-freedom pure rotation in space; when the metamorphic kinematic pair is fixed, the moving platform (4) It can imitate the flexion motion of the knee joint of the human body and the inversion motion of the ankle joint; when the metamorphic kinematic pair is switched to the driving rotation pair limited by the rotation angle, the moving platform (4) can also imitate the internal and external rotation motion of the human knee joint; the cover plate ( 3-4) Pass through the upper rod (3-5) with limited rotation angle, and connect it with the lower rod with limited rotation angle (3-3) by screws, in order to restrict the movement of the upper rod (3-5) with limited rotation angle in the direction of the branch chain ;The upper rod (3-5) and the joint (3-6) are connected by thread to form a fixed pair; the joint (3-6) and the upper foot seat (3-8) form a rotating pair, and are equipped with Large sleeve (3-2), the use of the sleeve is to make the metamorphic branch chain have good centering and ensure the flexible rotation of the mechanism;

Compared with the prior art, the present invention has the following beneficial effects:

The invention is designed and applied to the metamorphic parallel mechanism in the knee-ankle joint prosthesis mechanism to perform pure rotation with two degrees of freedom or three degrees of freedom in space, so as to simulate the multi-degree-of-freedom rotation characteristics of the knee-ankle joint. Since the internal and external rotation of the human knee joint does not exist all the time, it is only activated when the knee is flexed. In addition, there is less dependence on internal and external rotation in life. Bionic design of the human knee joint. When the metamorphic motion pair of the metamorphic branch is fixed (bolt through connection), the moving platform (4) can imitate the human knee under the coupling of the metamorphic branch (3) and the two active branches (2.1, 2.2). Flexion and extension of the joint and inversion and inversion of the ankle. When the metamorphic motion pair of the metamorphic branch is the driving rotating pair (releasing the through-connected bolt), the moving platform (4) can also imitate the internal and external rotation motion of the human knee joint. The prosthetic mechanism has a simple structure, easy kinematics analysis, and easy processing and manufacturing. The design of the mechanism can provide an important reference for the design of other joint prosthetic mechanisms and even the design of precision mechanisms.

Description of drawings

Figure 1 is a structural model diagram of an active knee-ankle joint prosthesis mechanism based on a metamorphic parallel mechanism;

Figure 2 is a structural model diagram of a metamorphic parallel mechanism switching between two degrees of freedom and three degrees of freedom in pure rotation mode;

Figure 3 exploded view of the structural model of the active branch chain;

Figure 4 exploded view of the structural model of the metamorphic branch;

In the figure: fixed platform (1), active branch (2.1, 2.2), metamorphic branch (3), moving platform (4) and active ankle prosthesis (5). Active branch chain (2.1, 2.2) includes: lower foot seat (2-1), lower U-shaped seat (2-2), cylinder with drive (2-3), piston rod with drive (2-4), Joint (2-5), upper U-shaped seat (2-6), upper foot seat (2-7); metamorphic branch chain (3) includes: lower foot seat (3-1), large sleeve (3-2) ), lower rod with limited rotation angle (3-3), cover plate (3-4), upper rod with limited rotation angle (3-5), joint (3-6), small sleeve (3-7), upper foot Blocks (3-8).

Detailed ways

In order to further understand the active knee-ankle joint prosthesis mechanism based on the metamorphic parallel mechanism provided by the present invention, the present invention will be described in detail below with reference to the accompanying drawings and detailed embodiments.

1 is a structural model diagram of an active knee-ankle joint prosthesis mechanism based on a metamorphic parallel mechanism designed by the present invention, and its basic structure includes a fixed platform (1), an active branch (2.1, 2.2), and a metamorphic branch ( 3), a moving platform (4) and an active ankle joint prosthesis mechanism (5). The knee-ankle joint prosthesis mechanism is formed by a less-degree-of-freedom metamorphic parallel mechanism and a single-degree-of-freedom active foot and ankle prosthesis in series. The active foot and ankle prosthesis can make the prosthesis mechanism imitate the human body's ankle joint flexion and extension movement. The application of the metamorphic parallel mechanism can greatly simplify the complex structure of the prosthetic mechanism, reduce the design cost of the prosthetic mechanism, and also improve the overall stiffness characteristics and bearing capacity of the prosthetic mechanism.

Fig. 2 is a structural model diagram of a metamorphic parallel mechanism for switching between two degrees of freedom and three degrees of freedom pure rotation modes provided by the present invention, the fixed platform (1), the active branch (2.1, 2.2), the metamorphic branch (3) and the The moving platform (4); when the metamorphic motion pair of the metamorphic branch chain (3) is fixed (bolt through connection), when the output force of the linear drive motors in the two active branch chains (2.1, 2.2) is the same, it will By stretching the driving piston rod (2-4), the moving platform (4) is caused to imitate the knee joint flexion and extension movement of the human body; when the linear drive motors in the two active branches (2.1, 2.2) have opposite output forces, it will By stretching the driven piston rod (2-4), the moving platform (4) is caused to imitate the inversion movement of the ankle joint of the human body; at this time, the role of the two active branches is equivalent to the gastrocnemius muscle and the gastrocnemius muscle on the posterior surface of the human tibia and fibula. Soleus muscle. Since the internal and external rotation of the human knee joint does not exist all the time, it is only activated when the knee is flexed. In addition, there is less dependence on internal and external rotation in life. The introduction of the metamorphic branch (3) is to enable the prosthetic mechanism to function Better bionic design of the human knee joint. When the metamorphic motion pair of the metamorphic branch (3) is the driving rotating pair (releasing the bolt through the connection), the moving platform (4) of the mechanism is between the active branch (2.1, 2.2) and the metamorphic branch (3) It can simulate the flexion and extension movement, internal and external rotation movement of the human knee joint and the inversion movement of the ankle joint.

3 is an exploded view of the structural model of the active branch chain provided by the present invention, including: a lower foot seat (2-1), a lower U-shaped seat (2-2), a cylindrical cylinder (2-3) including a drive, Piston rod (2-4), joint (2-5), upper U-shaped seat (2-6), upper foot seat (2-7). The lower foot seat (2-1) and the fixed platform (1) are connected by screws to form a fixed pair; the lower foot seat (2-1) and the lower U-shaped seat (2-2) form a rotating pair, and the lower U-shaped seat (2-2) It forms a rotating pair with the cylinder (2-3) including the drive, and at the same time, the axes of the two rotating pairs are orthogonal and equivalent to a Hooke pair; the cylinder (2-3) including the drive and the piston rod (2-3) including the drive -4) To form a driving moving pair, an electric push rod or a ball screw can be used; the driving piston rod (2-4) and the joint (2-5) are threaded to form a fixed pair; the joint (2-5) is connected to the upper The U-shaped seat (2-6) forms a rotating pair, the upper U-shaped seat (2-6) and the upper foot seat (2-7) form a rotating pair, and at the same time, the orthogonal axes of the two rotating pairs are equivalent to a Hooke pair ; The upper foot (2-7) and the moving platform (4) are connected by screws to form a fixed pair; in this design, the active branches (2.1, 2.2) are imitated as the biomechanical properties of the skeletal muscle group on the surface of the tibia and fibula. The expansion and contraction of the moving pair realizes the two rotations of the end in space and the movement along the direction of the branch chain.

4 is an exploded view of the structural model of the metamorphic branched chain provided by the present invention, including a lower foot seat (3-1), a large sleeve (3-2), a lower rod (3-3) with a limited rotation angle, a cover plate (3-1) -4), upper rod (3-5) with limited rotation angle, joint (3-6), small sleeve (3-7), upper foot seat (3-8). The lower foot seat (3-1) and the fixed platform (1) are connected by screws to form a fixed pair; the lower foot seat (3-1) and the lower rod (3-3) with limited rotation angle form a rotating pair, and a large sleeve is provided at the gap position Tube (3-2); the lower rod (3-3) with limited rotation angle and the upper rod (3-5) with limited rotation angle form a metamorphic kinematic pair, and the metamorphic kinematic pair has an angle limit to prevent it from being caused by excessive rotation The bizarre phenomenon of the mechanism; since the internal and external rotation of the human knee joint does not exist all the time, it is only activated when the knee is flexed. In addition, there is less dependence on the internal and external rotation in life, and the introduction of the metamorphic branch (3) In order to make the prosthetic mechanism better imitate the motion characteristics of the human knee joint, the moving platform (4) is connected between the metamorphic branch chain (3) and the two active branch chains (2.1 , 2.2), the motion characteristics of pure rotation with two degrees of freedom and pure rotation with three degrees of freedom in space can be realized, which can be used to imitate the flexion and extension of the knee joint, the varus movement of the ankle joint and the internal and external rotation of the knee joint; When the cell kinematic pair is fixed (bolt through connection), the moving platform (4) can simulate the flexion and extension movement of the knee joint and the varus and varus movement of the ankle joint under the driving of the active branch chain (2.1, 2.2) and the constraint of the metamorphic branch chain . When the metamorphic kinematic pair is the driving rotating pair (releasing the through-connected bolts), the moving platform (4) can also simulate the inside and outside of the human knee joint driven by the active branch (2.1, 2.2) and the metamorphic branch (3). Spinning movement. The cover plate (3-4) passes through the upper rod (3-5) with limited rotation angle, and is connected with the lower rod with limited rotation angle (3-3) by screws. In order to constrain the upper rod (3-5) with limited rotation angle along the branch chain direction of movement; the upper rod (3-5) with limited rotation angle and the joint (3-6) are threaded to form a fixed pair; the joint (3-6) and the upper foot (3-8) form a rotating pair, and there is a gap between The position is equipped with a large sleeve (3-2). The use of the sleeve is to make the metamorphic branch chain have good centering and ensure the flexible rotation of the mechanism.

The active knee-ankle joint prosthesis mechanism based on the metamorphic parallel mechanism according to the present invention can imitate the flexion and extension movement of the knee joint and the varus and varus movement of the ankle joint through the mode switching of the fixed or driven rotation pair of the metamorphic kinematic pair. and the internal and external rotation of the knee joint under certain conditions; in addition, the active ankle prosthesis (5) realizes the flexion and extension of the human ankle joint through an independent rotating motor; the prosthetic mechanism has the characteristics of high structural rigidity and strong bearing capacity, etc. It can not only realize the multi-degree of freedom of the human knee and ankle joint, but also simplify the complexity of the overall design of the mechanism to a certain extent, which is conducive to the layout and optimization of subsequent control strategies.

Claims (5)

1. a kind of based on the active knee ankle-joint prosthetic device for becoming born of the same parents' parallel institution, basic system includes: fixed platform (1), master Dynamic branch (2.1,2.2), become born of the same parents' branch (3), moving platform (4) and active ankle prosthese (5), which is lacked certainly by one respectively Become born of the same parents' parallel institution and the active ankle prosthese of a single-degree-of-freedom by degree to connect the knee ankle-joint prosthetic device formed；Wherein, Become the driving prismatic pair of active branched chain in born of the same parents' parallel institution into ball-screw, to imitate the stretching motion of Leg bones muscle group； Since the interior outward turning campaign of human body knee joint is not existing for the moment, be only just activated when bending knee, in addition, in living for The dependence of interior outward turning campaign is less, when metamorphic kinematic pair is fixed, in the case where change born of the same parents' branch and two determine the coupling of branch, moves Platform (4) is only able to achieve the rotational motion of two, space, with fortune of turning up in imitating the curvature movement and ankle-joint of human body knee joint It is dynamic；When metamorphic kinematic pair is the driving revolute pair of corner limitation, in the case where change born of the same parents' branch and two determine the coupling of branch, moving platform (4) three pure rotations are able to achieve, with fortune of turning up in imitating the curvature movement and interior outward turning campaign and ankle-joint of human body knee joint It is dynamic；The prosthetic device can effectively compensate for the biological motion characteristic of patients with amputation impaired knee joint and ankle-joint.

2. according to claim 1 a kind of based on the active knee ankle-joint prosthetic device for becoming born of the same parents' parallel institution, feature Be: the active branched chain (2.1,2.2) includes: lower pedestal (2-1), under U-shaped seat (2-2), the cylindrical drum (2- containing driving 3), the piston rod containing driving (2-4), connector (2-5), upper U-shaped seat (2-6), upper pedestal (2-7).

3. the connection between the components of active branched chain according to claim 2: lower pedestal (2-1) passes through with fixed platform (1) Screw connects into fixed joint；Lower pedestal (2-1) U-shaped seat (2-2) under forms revolute pair, under U-shaped seat (2-2) and the circle containing driving Column casing (2-3) forms revolute pair, meanwhile, two revolute pair axis vertical take-offs are equivalent to a Hooke pair；Cylindrical drum (2- containing driving 3) and the piston rod containing driving (2-4) forms driving prismatic pair, and electric putter or ball-screw can be used；Piston rod containing driving (2-4) and connector (2-5) is connected through a screw thread to form fixed joint；Connector (2-5) and upper U-shaped seat (2-6) form revolute pair, upper U Type seat (2-6) and upper pedestal (2-7) form revolute pair, meanwhile, two revolute pair axis vertical take-offs are equivalent to a Hooke pair；Upper foot Seat (2-7) and moving platform (4) are connected by screw into fixed joint；Imitating active branched chain (2.1,2.2) in the design is shin calf The biomechanics characteristic of the skeleton muscle group of bone surface realizes branch terminals at two of space by the flexible of driving prismatic pair Rotation and moving along branch chain direction.

4. according to claim 1 a kind of based on the active knee ankle-joint prosthetic device for becoming born of the same parents' parallel institution, feature Be: the change born of the same parents branch (3) includes lower pedestal (3-1), and big sleeve (3-2) limits angle of rotation lower beam (3-3), cover board (3- 4) angle of rotation upper boom (3-5), is limited, connector (3-6), small sleeve (3-7), upper pedestal (3-8).

5. the connection between the components according to claim 4 for becoming born of the same parents' branch: lower pedestal (3-1) passes through with fixed platform (1) Screw connects into fixed joint；Lower pedestal (3-1) and limit angle of rotation lower beam (3-3) form revolute pair, and in interstitial site equipped with big Sleeve (3-2)；It limits angle of rotation lower beam (3-3) and limit angle of rotation upper boom (3-5) forms a metamorphic kinematic pair, the metamorphic kinematic pair It is limited with angle, avoids the unusual appearance of its transition rotation and generation mechanism；Due to human body knee joint interior outward turning campaign simultaneously It is not only just to be activated when bending knee existing for the moment, in addition, less for the dependence of interior outward turning campaign in life, change born of the same parents The introducing of branch (3) passes through consolidating for metamorphic kinematic pair to enable prosthetic device more preferably to imitate the kinetic characteristic of human body knee joint Fixed or driving rotation pattern switching, moving platform (4) is in the case where becoming the coupling of born of the same parents' branch (3) and two active branched chains (2.1,2.2) It is able to achieve the kinetic characteristic of space two degrees of freedom pure rotation and the pure rotation of Three Degree Of Freedom, bends and stretches fortune to imitate human body knee joint Dynamic, ankle-joint interior turn up movement and kneed interior outward turning campaign；Cover board (3-4) passes through limit angle of rotation upper boom (3-5), with limit Angle of rotation lower beam (3-3) is connected by screw to, in order to constrain limit angle of rotation upper boom (3-5) moving along branch chain direction；Limit rotation Angle upper boom (3-5) and connector (3-6) are connected through a screw thread to form fixed joint；Connector (3-6) and upper pedestal (3-8), which are formed, to be rotated Pair, and it is furnished with big sleeve (3-2) in interstitial site, the use of sleeve is good to neutrality in order to have change born of the same parents' branch, it is ensured that The rotation of mechanical flexibility.