A personalized customizable rigid knee joint for an exoskeleton

Abstract

A personalized rigid knee exoskeleton consists of a thigh plate assembly, a first torque motor, a four-bar linkage transmission mechanism, a second torque motor, a two-bar linkage transmission mechanism, a planetary gear set, a calf plate assembly, a thigh strap, and a calf strap. The four-bar linkage transmission mechanism is used to transmit torque, avoiding the problem of overly concentrated installation of the first torque motor and the second torque motor at the two-bar linkage transmission mechanism. By controlling the first torque motor and the second torque motor to drive the two-bar linkage transmission mechanism, the calf plate assembly can fit the real human calf movement, thereby reducing the damage of the exoskeleton to the biological knee joint during the human-machine interaction process. By adjusting the cooperation relationship between the planetary gear set and the motor, the matching of different biological knee joints can be achieved, reducing the discomfort of the wearer when using the exoskeleton and shortening the adjustment time of the exoskeleton to adapt to different knee joints.

Description

Technical Field

[0001] The present invention relates to the field of rehabilitation devices and is a personalized customizable rigid knee joint for an exoskeleton. Background Art

[0002] With the aging of society, exoskeletons have great application prospects in aspects such as assisting the elderly and rehabilitation. The knee joint is one of the important joints participating in the movement of the lower limbs of the human body. As known from the available literature, currently, the knee joint in an exoskeleton often adopts a single-pin shaft structure. However, due to the influence of biological structures such as bones, ligaments, and muscles on the human knee joint, there is a problem that it is difficult to align the rotation axes between the single-pin shaft structure and the biological knee joint.

[0003] The biological characteristics of the knee joints of different patients are different. For different patients, it is necessary to adjust the knee joint structure in the exoskeleton to reduce the discomfort of patients when using the exoskeleton. Summary of the Invention

[0004] Aiming at the above problems and for the rehabilitation applications of different individuals, the present invention provides a personalized customizable rigid knee joint for an exoskeleton, which is characterized in that it includes a first torque motor 2, a four-bar linkage mechanism 3, a second torque motor 4, a two-bar linkage mechanism 5, a planetary gear set 6, a calf plate assembly 7, a calf strap 8, and a thigh strap 9.

[0005] The four-bar linkage mechanism 3 includes a rocker 301, a connecting rod 302, a first driving connecting rod 501, and a thigh plate assembly 1; the rocker 301 is installed on the thigh plate assembly 1 through a rolling bearing and forms a double rocker with the first driving connecting rod 501.

[0006] The thigh plate assembly 1 and the calf plate assembly 7 are connected by the two-bar linkage mechanism 5 to form the main mechanical structure; the planetary gear set 6 is coupled to the two-bar linkage mechanism 5 and the calf plate assembly 7; the thigh strap 9 and the calf strap 8 are installed on the thigh plate assembly 1 and the calf plate assembly 7 for connection with the human body; the first torque motor 2 drives the two-bar linkage mechanism 5 through the four-bar linkage mechanism 3; the second torque motor 4 drives the calf plate assembly 7 through the two-bar linkage mechanism 5 and the planetary gear set 6.

[0007] The two-bar linkage mechanism 5 includes a first driving connecting rod 501, an end cover 502, a rolling bearing 503, a slider 504, a second driving connecting rod 505, an axis positioning device 506, a first coupling 507, and a second coupling 508; the end of the first driving connecting rod 501 and the head of the second driving connecting rod 505 are connected through the end cover 502, the rolling bearing 503, and the first coupling 507; there is an arc-shaped guide rail at the end of the first driving connecting rod 501, and the slider 504 and the guide rail limit the movement range of the two-bar linkage mechanism 5.

[0008] Further, the planetary gear set 6 includes an internal sun gear 601, planet gears 602, and an external sun gear 603; the internal sun gear 601 is fixed to the end of the first driving link 501; the planet gears 602 are mounted on the second driving link 505 through an axis positioning device 506; the external sun gear 603 is fixed to the calf plate assembly 7; the module and number of teeth of each gear can be replaced to adapt to the movements of calves of different individuals.

[0009] Further, the housing of the first torque motor 2 is mounted on the thigh plate assembly 1, and the housing of the second torque motor 4 is fixed to the first driving link 501; the first torque motor 2 drives the first driving link 501 through a four-bar linkage mechanism 3; the second torque motor 4 drives the second driving link 505 to make the mechanism move and generate traction force.

[0010] Further, the control input quantities of the first torque motor 2 and the second torque motor 4 are calculated by a computer software after analyzing the real calf trajectory.

[0011] Further, an angular velocity sensor is installed between the thigh plate assembly 1 and the first driving link 501; an angular velocity sensor is installed between the first driving link 501 and the second driving link 505. Description of the Drawings

[0012] Att Figure 1 is the overall structural schematic diagram of this mechanical device.

[0013] Att Figure 2 is the structural schematic diagram of the four-bar linkage mechanism.

[0014] Att Figure 3 is the structural schematic diagram of the two-bar linkage mechanism and the planetary gear set.

[0015] Att Figure 4 is the state diagram of this mechanical device after being driven by the motor at a certain angle.

[0016] The reference numerals of each component in the drawings are as follows: thigh plate assembly 1, first torque motor 2, four-bar linkage mechanism 3, second torque motor 4, two-bar linkage mechanism 5, planetary gear set 6, calf plate assembly 7, calf strap 8, thigh strap 9, rocker 301, connecting rod 302, first driving link 501, end cover 502, rolling bearing 503, slider 504, second driving link 505, axis positioning device 506, first coupling 507, second coupling 508, internal sun gear 601, planet gear 602, external sun gear 603. Detailed Embodiment

[0017] As Figure 1As shown, a customizable rigid knee joint for an exoskeleton comprises a thigh plate assembly 1, a first torque motor 2, a four-bar transmission mechanism 3, a second torque motor 4, a two-bar transmission mechanism 5, a planetary gear set 6, a calf plate assembly 7, a calf strap 8 and a thigh strap 9; the thigh plate assembly 1 and the calf plate assembly 7 are connected by the two-bar transmission mechanism 5 to form a main mechanical structure; the planetary gear set 6 couples the two-bar transmission mechanism 5 and the calf plate assembly 7; thigh straps 9 and calf straps 8 are installed on the thigh plate assembly 1 and the calf plate assembly 7 for connection with the human body; the first torque motor 2 drives the two-bar transmission mechanism 5 through the four-bar transmission mechanism 3; the second torque motor 4 drives the calf plate assembly 7 through the two-bar transmission mechanism 5 and the planetary gear set 6.

[0018] like Figure 2 As shown, the four-bar linkage 3 includes a rocker 301, a connecting rod 302, a first driving connecting rod 501 and a thigh plate assembly 1; the rocker 301 is mounted on the thigh plate assembly 1 through a rolling bearing and forms a double rocker with the first driving connecting rod 501.

[0019] like Figure 3 As shown, the two-link transmission mechanism includes a first drive link 501, an end cover 502, a rolling bearing 503, a slider 504, a second drive link 505, an axial positioning device 506, a first coupling 507 and a second coupling 508; the end of the first drive link 501 and the head end of the second drive link 505 are connected through the end cover 502, the rolling bearing 503 and the first coupling 507; there is an arc guide rail at the end of the first drive link 501, and the slider 504 and the guide rail are used to limit the movement range of the two-link transmission mechanism 5.

[0020] like Figure 3 As shown, the planetary gear set 6 includes an internal center wheel 601, a planetary wheel 602 and an external center wheel 603; the internal center wheel 601 is fixed at the end of the first driving link 501; the planetary wheel 602 is installed on the second driving link 505 through the axial positioning device 506; the external center wheel 603 is fixed on the calf plate assembly 7; the module and number of teeth of each gear can be replaced to adapt to the movement of different individual calves.

[0021] This implementation method uses a motor to drive the mechanical structure, and uses straps to pull the wearer's limbs to move, thereby reducing muscle force and metabolic energy consumption during walking. The two-link transmission mechanism 5 and the planetary gear set 6 are used in the structure to fit the movement trajectory of the real human calf, so as to compensate for the joint misalignment between the mechanism and the human body and align the biological knee joint and the exoskeleton joint; the housing of the first torque motor is installed on the thigh plate assembly, and the housing of the second torque motor 4 is fixed on the first drive link 501; the first torque motor 2 drives the first drive link 501 through the four-link transmission mechanism 3; the second torque motor 4 drives the second drive link 505, so that the mechanism moves and generates traction.

[0022] Further, the control input quantities of the first torque motor 2 and the second torque motor 4 are calculated by a computer software after analyzing the real calf trajectory.

[0023] Further, an angular velocity sensor is installed between the thigh plate assembly 1 and the first driving rod 501; an angular velocity sensor is installed between the first driving rod 501 and the second driving rod 505 to feedback motion parameters and achieve closed-loop control.

[0024] The specific working process of this invention patent: The first torque motor 2 and the second torque motor 4 respectively output torques to drive the first driving link 501 and the second driving link 505; the second driving link 505 drives the calf plate assembly 7 to move through the planetary gear set 6; the angular velocity sensor measures the angular velocity and returns the signal to the motor controller to form a feedback.

[0025] Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A personalized customizable rigid knee joint for an exoskeleton, characterized in that: It includes a first torque motor (2), a four-bar linkage mechanism (3), a second torque motor (4), a two-bar linkage mechanism (5), a planetary gear set (6), a calf plate assembly (7), a calf strap (8), and a thigh strap (9); The four-bar linkage mechanism (3) includes a rocker (301), a connecting rod (302), a first driving link (501), and a thigh plate assembly (1); the rocker (301) is mounted on the thigh plate assembly (1) through a rolling bearing and forms a double rocker with the first driving link (501); The thigh plate assembly (1) and the calf plate assembly (7) are connected by a two-bar linkage mechanism (5) to form the main mechanical structure; the planetary gear set (6) is coupled to the two-bar linkage mechanism (5) and the calf plate assembly (7); thigh straps (9) and calf straps (8) are mounted on the thigh plate assembly (1) and the calf plate assembly (7) for connection to the human body; the first torque motor (2) drives the two-bar linkage mechanism (5) through the four-bar linkage mechanism (3); the second torque motor (4) drives the calf plate assembly (7) through the two-bar linkage mechanism (5) and the planetary gear set (6); The two-bar linkage mechanism (5) includes a first driving link (501), an end cover (502), a rolling bearing (503), a slider (504), a second driving link (505), an axis positioning device (506), a first coupling (507), and a second coupling (508); the end of the first driving link (501) and the head of the second driving link (505) are connected through the end cover (502), the rolling bearing (503), and the first coupling (507); there is an arc-shaped guide rail at the end of the first driving link (501), and the slider (504) and the guide rail limit the movement range of the two-bar linkage mechanism (5).

2. The personalized customizable rigid knee joint for an exoskeleton according to claim 1, characterized in that: The planetary gear set (6) includes an internal sun gear (601), planet gears (602), and an external sun gear (603); the internal sun gear (601) is fixed to the end of the first driving link (501); the planet gears (602) are mounted on the second driving link (505) through the axis positioning device (506); the external sun gear (603) is fixed to the calf plate assembly (7); the module and number of teeth of each gear can be replaced to adapt to the movements of the calves of different individuals.

3. The personalized customizable rigid knee joint for an exoskeleton according to claim 1, characterized in that: The housing of the first torque motor (2) is mounted on the thigh plate assembly (1), and the housing of the second torque motor (4) is fixed to the first driving link (501); the first torque motor (2) drives the first driving link (501) through the four-bar linkage mechanism (3); the second torque motor (4) drives the second driving link (505) to make the mechanism move and generate traction force.

4. The personalized customizable rigid knee joint for an exoskeleton according to claim 3, characterized in that: The control input quantities of the first torque motor (2) and the second torque motor (4) are calculated by a computer software after analyzing the real calf trajectory.

5. The personalized customizable rigid knee joint for an exoskeleton according to claim 4, characterized in that: An angular velocity sensor is installed between the thigh plate assembly (1) and the first driving link (501); an angular velocity sensor is installed between the first driving link (501) and the second driving link (505).

Images