A rope-driven hip exoskeleton for ease of force transmission

Abstract

The present application relates to the field of robot technology, and more particularly to a rope-driven hip joint exoskeleton facilitating force transmission, comprising a back frame, a waist frame, a shaft connecting frame, a leg frame and a Bowden cable, the waist frame comprising a waist frame double-layer carbon plate, a tension sensor, a Bowden tube seat, a Bowden tube seat pulley and an adapter pulley, the shaft connecting frame comprising a shaft connecting piece, a carbon fiber cantilever beam and a carbon fiber cantilever beam pulley, the shaft connecting piece comprising an upper shaft connecting piece, a middle shaft connecting piece and a lower shaft connecting piece, the free end of the carbon fiber cantilever beam being provided with the carbon fiber cantilever beam pulley, and the Bowden cable being connected with the tension sensor after sequentially passing through the Bowden tube seat pulley, the carbon fiber cantilever beam pulley and the adapter pulley. The exoskeleton provided by the present application is light in weight, easy to assemble, high in interactive compliance, and can double the applied force.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of robots, and in particular to a rope-driven hip exoskeleton facilitating force transmission. BACKGROUND

[0002] Hip exoskeletons, as an assistive device to enhance human mobility, have broad potential in clinical rehabilitation and industrial applications. These systems can reduce metabolic energy consumption during walking, improve the musculoskeletal function of the elderly or impaired people, and play an important role in improving physical performance and conducting therapeutic interventions.

[0003] However, existing hip exoskeletons generally have some problems. First, the exoskeleton actuators are generally rigidly connected to the human body, lacking elastic elements for buffering, which can cause control oscillation and damage to the human joints. Second, rope-driven exoskeletons generally set the pulley terminal at the joint, which has a similar effect to placing the motor at the joint, and have not yet completely abandoned the exoskeleton mechanical structure in the form of joint motors.

[0004] Third, existing exoskeletons cannot simultaneously satisfy lightweight and high torque output performance. Existing rope-driven hip exoskeletons generally weigh more than 4 kg, and if greater torque output is required, the weight of the exoskeleton will increase accordingly.

[0005] How to provide a flexible force transmission path through a rope, effectively decouple the actuator from the joint, enhance the comfort of the human body, and improve the compliance of the system, is still a difficult problem that needs to be broken through. SUMMARY

[0006] The technical problem to be solved by the present application is to provide a rope-driven hip exoskeleton facilitating force transmission, which is lightweight, easy to assemble, and can double the applied force, reduce the overall transverse size of the exoskeleton, and increase the compliance, reliability, and comfort when the human body interacts with the exoskeleton.

[0007] A kind of convenient force transmission's rope-driven hip exoskeleton, including back frame, waist frame, shaft connecting frame, leg frame and Bowden cable, the waist frame is fixedly connected to the both ends of back frame by waist back connector, the waist frame includes waist frame double-layer carbon plate, tension sensor, Bowden tube seat, Bowden tube seat pulley and adapter pulley, the tension sensor and Bowden tube seat are fixedly installed between waist frame double-layer carbon plate and tension sensor is opposite with Bowden tube seat, Bowden tube seat pulley and adapter pulley are all installed on Bowden tube seat, the shaft connecting frame includes shaft connecting piece, carbon fiber cantilever beam and carbon fiber cantilever beam pulley, the shaft connecting piece includes upper shaft connecting piece, middle shaft connecting piece and lower shaft connecting piece, the upper shaft connecting piece is rotatably connected between middle shaft connecting piece, the lower shaft connecting piece is connected between middle shaft connecting piece, the upper shaft connecting piece is fixedly connected with waist frame double-layer carbon plate, the lower shaft connecting piece is fixedly connected with leg frame, one end of the carbon fiber cantilever beam is fixedly connected with middle shaft connecting piece, the carbon fiber cantilever beam pulley is installed on the free end of carbon fiber cantilever beam, the Bowden cable is connected with tension sensor after being sequentially wound around Bowden tube seat pulley, carbon fiber cantilever beam pulley, adapter pulley.

[0008] Optimized, adapter pulley is located in the side below Bowden tube seat pulley, the carbon fiber cantilever beam pulley is located directly below Bowden tube seat pulley, the tension sensor is horizontally opposite with adapter pulley.

[0009] Further, waist frame double-layer carbon plate is C-shaped structure, and one end of waist frame double-layer carbon plate connected with shaft connecting piece is lower than the opposite end of carbon fiber cantilever beam pulley, the upper shaft connecting piece includes waist connecting part, middle shaft connecting part connecting part and limiting plate fixedly arranged between waist connecting part and middle shaft connecting part connecting part, the upper shaft connecting piece is fixedly connected with waist frame double-layer carbon plate at waist connecting part by bolt, the middle shaft connecting piece and upper shaft connecting piece are connected at middle shaft connecting part connecting part by ball bearing and D-shaped shaft.

[0010] Further, the lower part of middle shaft connecting piece is provided with an opening, and the lower shaft connecting piece and the middle shaft connecting piece are connected by a locking screw at the opening.

[0011] Further, magnetic encoder is installed on shaft connecting piece, and the magnetic encoder includes magnetic encoder base, magnetic encoder main body, magnet and magnetic encoder upper cover, the magnetic encoder base is fixedly installed on the upper shaft connecting piece, the magnetic encoder main body is installed on the magnetic encoder base, the magnet is fixedly installed on the D-shaped shaft and opposite to the magnetic encoder main body, and the magnetic encoder upper cover is buckled with the magnetic encoder base.

[0012] The optimized back frame comprises a back carbon plate and a back protector, the back carbon plate is fixedly connected with the back protector, the back protector is located on the inner side of the back carbon plate, and two groups of back frame belt through slots are arranged on the back carbon plate and the back protector.

[0013] Further, the back carbon plate and the waist and back connecting piece are both provided with a plurality of rows of threaded holes, and the back carbon plate and the waist and back connecting piece are fixedly connected through bolts at the plurality of rows of threaded holes.

[0014] The optimized waist frame further comprises a waist protector, the waist protector is fixedly installed on the inner side of the waist frame double-layer carbon plate, and the waist protector is provided with a waist frame belt through slot.

[0015] The optimized leg frame comprises a leg double-layer carbon plate and a leg protector, the upper end of the leg double-layer carbon plate is fixedly connected with the upper side shaft connecting piece, and the leg protector is fixedly installed on the inner side of the lower end of the leg double-layer carbon plate.

[0016] Further, the upper side fixing piece and the lower side fixing piece are fixedly installed between the leg double-layer carbon plates.

[0017] The application has the following advantages:

[0018] The application provides a rope-driven hip joint exoskeleton facilitating force transmission, which has the following advantages.

[0019] 1. The use of a combination of Bowden cables and pulley sets reduces the transverse structure size, ensures the compactness of the exoskeleton, and increases the torque output of the exoskeleton.

[0020] 2. The design of the shaft connecting piece and the cantilever beam provides series elasticity for the exoskeleton, increases the compliance when a person interacts with the exoskeleton, and ensures the comfort of human-machine interaction.

[0021] 3. By designing the pulley set, the tension sensor is placed in the waist, which not only reduces the movement of the tension sensor, but also reduces the noise measured by the tension sensor.

[0022] 4. The double-layer carbon plate structure of the waist frame ensures the structural strength, allows the placement of the tension sensor and the routing of the Bowden cable and the transmission of force, and through the design of the double-layer carbon plate structure of the waist frame and the shaft connecting frame, reliable limiting is realized, so that the movement range of the exoskeleton is reliably limited within the normal human body activity range, preventing damage to the human body bones or joints.

[0023] 5. Through the structural design of the shaft connecting piece, the leg has a lateral passive degree of freedom, which can realize leg abduction and adduction, and is more suitable for the kinematic characteristics of the human body.

[0024] 6. The whole is made of lightweight and high-strength material, the whole system is lighter, and it is convenient to process. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a schematic diagram of the three-dimensional structure of the present application.

[0026] Figure 2 is a schematic diagram of the main view structure of the present application.

[0027] Figure 3 is a schematic diagram of the top view structure of the present application.

[0028] Figure 4 is a schematic diagram of the side view structure of the present application.

[0029] Figure 5 is a schematic diagram of the bowden cable connection of the present application.

[0030] Figure 6 is a schematic diagram of the waist frame explosion of the present application.

[0031] Figure 7 is a schematic diagram of the shaft connection frame explosion of the present application.

[0032] In the figure: 1, back frame; 1-1, back carbon plate; 1-2, back protector; 1-3, back frame belt slot; 2, waist frame; 2-1, waist inner carbon plate; 2-2, waist outer carbon plate; 2-3, tension sensor body; 2-4, tension sensor base; 2-5, tension sensor upper cover; 2-6, bowden tube seat; 2-7, bowden tube seat pulley; 2-8, adapter pulley; 2-9, waist protector; 2-10, waist frame belt slot; 3, shaft connection frame; 3-1, upper shaft connector; 3-1-1, waist connection part; 3-1-2, middle shaft connector connection part; 3-1-3, limiting plate; 3-2, middle shaft connector; 3-3, lower shaft connector; 3-4, carbon fiber cantilever beam; 3-5, cantilever beam connector; 3-6, carbon fiber cantilever beam pulley; 3-7, ball bearing; 3-8, D-shaped shaft; 4, leg frame; 4-1, waist inner carbon plate; 4-2, waist outer carbon plate; 4-3, upper fixing part; 4-4, lower fixing part; 4-5, leg protector; 5, waist back adapter; 6, magnetic encoder; 6-1, magnetic encoder base; 6-2, magnetic encoder body; 6-3, magnet; 6-4, magnetic encoder upper cover. DETAILED DESCRIPTION

[0033] A rope-driven hip joint exoskeleton convenient for force transmission, a schematic diagram of the structure is as Figures 1 to 4As shown, including back frame 1, waist frame 2, shaft connecting frame 3, leg frame 4 and Bowden cable (not shown), the waist frame is fixedly connected to both ends of the back frame through waist back adapter 5, and the three can be fixedly connected through bolts. The waist back adapter can be made of aluminum alloy material by CNC machining process. The design of the waist back adapter provides the connection between the back frame and the waist frame, forming a closed load-bearing structure.

[0034] The waist frame includes waist frame double-layer carbon plate, tension sensor, Bowden tube seat 2-6, Bowden tube seat pulley 2-7 and adapter pulley 2-8. The waist frame double-layer carbon plate includes waist inner carbon plate 2-1 and waist outer carbon plate 2-2, and the two plates can be fixedly connected through bolts.

[0035] The tension sensor and the Bowden tube seat are fixedly installed between the waist frame double-layer carbon plate, and the tension sensor is arranged opposite to the Bowden tube seat. The Bowden tube seat pulley and the adapter pulley are installed on the Bowden tube seat. Specifically, the tension sensor includes tension sensor base 2-4, tension sensor body 2-3 and tension sensor upper cover 2-5. The tension sensor base is fixedly installed between the waist frame double-layer carbon plate, one end of the tension sensor body is connected to the tension sensor base, and the other end is connected to the tension sensor upper cover. The tension sensor is used to measure the interaction force between the human body and the exoskeleton. By fixing the tension sensor and the Bowden tube seat between the waist frame double-layer carbon plate, the collision of the Bowden cable and the tension sensor caused by hand arm swing can be minimized, and at the same time, the force transmission can occur in the sagittal plane, without generating additional torsion.

[0036] The shaft connecting frame includes shaft connecting piece, carbon fiber cantilever beam 3-4 and carbon fiber cantilever beam pulley 3-6. The shaft connecting piece includes upper shaft connecting piece 3-1, middle shaft connecting piece 3-2 and lower shaft connecting piece 3-3. The upper shaft connecting piece is rotatably connected to the middle shaft connecting piece, and the lower shaft connecting piece is connected to the middle shaft connecting piece. The upper shaft connecting piece is fixedly connected to the waist frame double-layer carbon plate, and the lower shaft connecting piece is fixedly connected to the leg frame. One end of the carbon fiber cantilever beam is fixedly connected to the middle shaft connecting piece, and a carbon fiber cantilever beam pulley is installed on the free end of the carbon fiber cantilever beam through cantilever beam connecting piece 3-5. The Bowden cable passes through the Bowden tube seat pulley, the carbon fiber cantilever beam pulley and the adapter pulley in sequence, and is connected to the tension sensor. The specific Bowden cable connection diagram is shown in Figure 5

[0037] ​The application provides a rope-driven hip exoskeleton facilitating force transmission, through the design of a waist frame and an axle connecting frame, so that a pulley set effectively changes the force transmission direction of the Bowden cable, and through a mechanism similar to a movable pulley, the applied force can be doubled within an effective distance (force arm), thereby reducing the overall transverse size of the exoskeleton; meanwhile, the tension sensor is arranged at the waist where the movement is relatively smooth, thereby reducing the movement of the tension sensor and effectively reducing the noise when the tension sensor reads.

[0038] The design of the carbon fiber cantilever beam, although the tensile strength of the plane parallel to the carbon fiber layer is low, can provide a large amount of elastic deformation, and provides controlled series elasticity in the process of force transmission, thereby increasing the compliance of the overall force transmission, which is beneficial to the stability of the exoskeleton control and the human joints, and improves the compliance when the human body and the exoskeleton interact, thereby ensuring the comfort of human-computer interaction.

[0039] Since the main components of the application can be made of carbon fiber plates or 3D printing, the processing is convenient, the cost is low, the weight is light, and the assembly is convenient, and the components are connected by screws, nuts and the like.

[0040] The power element driving the movement of the Bowden cable can be fixedly installed on the exoskeleton, or can be placed separately, thereby reducing the weight when the user does rehabilitation.

[0041] Specifically, the adapter pulley can be arranged below the side of the Bowden pipe seat pulley, the carbon fiber cantilever beam pulley is arranged directly below the Bowden pipe seat pulley, and the tension sensor is arranged horizontally opposite to the adapter pulley. This design makes the two Bowden cables around the carbon fiber cantilever beam pulley substantially parallel, so as to ensure balanced force distribution and save labor and stabilize.

[0042] Further, the waist frame double-layer carbon plate is in a C-shaped structure, and one end of the waist frame double-layer carbon plate connected with the axle connecting piece is lower than the other end opposite to the carbon fiber cantilever beam pulley, the upper axle connecting piece comprises a waist connecting portion 3-1-1, a middle axle connecting piece connecting portion 3-1-2 and a limiting plate 3-1-3 fixedly arranged between the waist connecting portion and the middle axle connecting piece connecting portion, the upper axle connecting piece is fixedly connected with the waist frame double-layer carbon plate at the waist connecting portion through a bolt, the middle axle connecting piece is connected with the upper axle connecting piece at the middle axle connecting piece connecting portion through a ball bearing 3-7 and a D-shaped shaft 3-8, and specifically, the waist frame explosion schematic view is as shown in Figure 6 The axle connecting frame explosion schematic view is as shown in Figure 7 .

[0043] The design of this structure is that when the Bowden cable drives the carbon fiber cantilever beam to rotate clockwise, i.e. the leg moves backward, when the carbon fiber cantilever beam pulley touches the corresponding waist frame double-layer carbon plate, the carbon fiber cantilever beam cannot continue to move, thereby forming reliable limiting and over-movement does not occur. When the leg moves forward, the carbon fiber cantilever beam rotates counterclockwise, and when the carbon fiber cantilever beam moves to a certain position, the middle shaft connecting piece touches the limiting plate of the upper shaft connecting piece, and cannot continue to move, thereby forming reliable limiting. The setting of this limiting structure can reliably limit the exoskeleton to about 40° in extension and about 90° in flexion, which conforms to the normal movement range of the human body.

[0044] Further, the middle shaft connecting piece is provided with an opening, and the lower shaft connecting piece is connected with the middle shaft connecting piece at the opening through a locking screw. In this way, the lower shaft connecting piece has a passive degree of freedom relative to the middle shaft connecting piece, and can realize abduction and adduction of the leg, thereby being more suitable for the movement characteristics of the human body.

[0045] Further, a magnetic encoder 6 is installed on the shaft connecting piece, the magnetic encoder comprising a magnetic encoder base 6-1, a magnetic encoder body 6-2, a magnet 6-3 and a magnetic encoder upper cover 6-4. The magnetic encoder base is fixedly installed on the upper shaft connecting piece, the magnetic encoder body is installed on the magnetic encoder base, the magnet is fixedly installed on the D-shaped shaft and faces the magnetic encoder body, and the magnetic encoder upper cover is buckled with the magnetic encoder base. The magnetic encoder can be used to measure the joint angle of the hip exoskeleton.

[0046] Optimally, the back frame comprises a back carbon plate 1-1 and a back protector 1-2, the back carbon plate is fixedly connected with the back protector, and the back protector is located on the inner side of the back carbon plate. Corresponding two groups of back frame belt through slots 1-3 are arranged on the back carbon plate and the back protector. The back protector can be made of 3D printing, simulates the curvature of the human back, and maximizes the contact area with the skin to optimize the distribution of pressure.

[0047] Further, the back carbon plate and the waist-back connecting piece are both provided with a plurality of threaded holes, and the back carbon plate and the waist-back connecting piece are fixedly connected through bolts at the plurality of threaded holes. In this way, the installation position can be adjusted according to individual differences of users.

[0048] Optimally, the waist frame further comprises a waist protector 2-9, the waist protector is fixedly installed on the inner side of the waist frame double-layer carbon plate, and the waist protector is provided with a waist frame belt through slot 2-10.

[0049] The waist protector can be supported by 3D printing, and simulates the waist curvature of the human body.

[0050] Overall, the connecting part of the human body can be sequentially threaded through the waist frame strap slot on one side, a group of back frame strap slots, and then sequentially and reversely through another group of back frame strap slots and the waist frame strap slot on the other side, forming a strong connection with the human body, providing stability while achieving personalized fitting, promoting uniform load transmission.

[0051] The optimized leg frame includes a leg double-layer carbon plate and a leg protector 4-5, the upper end of the leg double-layer carbon plate is fixedly connected with the lower side shaft connector, and the leg protector is fixedly installed on the inner side of the lower end of the leg double-layer carbon plate.

[0052] The leg double-layer carbon plate includes a leg inner side carbon plate 4-1 and a leg outer side carbon plate 4-2, can have the functions of weight reduction and torsion resistance during force transmission, and can be fixedly connected between the upper end and the lower side shaft connector through a bolt.

[0053] Further, the upper side fixing member 4-3 and the lower side fixing member 4-4 are fixedly installed between the leg double-layer carbon plates, and the upper side fixing member and the lower side fixing member can be fixedly connected with the leg double-layer carbon plates through a locking screw, thereby fixing the leg double-layer carbon plates.

[0054] In summary, the rope-driven hip joint exoskeleton provided by the application has the advantages of light weight, easy assembly, double force increase, reduced overall transverse size of the exoskeleton, and increased flexibility, reliability and comfort when a person interacts with the exoskeleton.

[0055] The above only describes the preferred embodiments of the application and is not intended to limit the application. For those skilled in the art, the application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the application shall be included in the protection scope of the application.

Claims

1. A rope-driven hip exoskeleton that facilitates force transmission, characterized by: The application relates to a back frame, a waist frame, an axle connecting frame, a leg frame and a Bowden cable, wherein the waist frame is fixedly connected to the two ends of the back frame through a waist-back connector; the waist frame comprises a waist frame double-layer carbon plate, a tension sensor, a Bowden tube base, a Bowden tube base pulley and an adapter pulley; the tension sensor and the Bowden tube base are fixedly installed between the waist frame double-layer carbon plate and are oppositely arranged; the Bowden tube base pulley and the adapter pulley are installed on the Bowden tube base; the axle connecting frame comprises an axle connecting piece, a carbon fiber cantilever beam and a carbon fiber cantilever beam pulley; the axle connecting piece comprises an upper axle connecting piece, a middle axle connecting piece and a lower axle connecting piece; the upper axle connecting piece is rotationally connected to the middle axle connecting piece; the lower axle connecting piece is connected to the middle axle connecting piece; the upper axle connecting piece is fixedly connected to the waist frame double-layer carbon plate; the lower axle connecting piece is fixedly connected to the leg frame; one end of the carbon fiber cantilever beam is fixedly connected to the middle axle connecting piece; the carbon fiber cantilever beam pulley is installed on the free end of the carbon fiber cantilever beam; the Bowden cable is sequentially wound around the Bowden tube base pulley, the carbon fiber cantilever beam pulley, the adapter pulley and connected to the tension sensor; the adapter pulley is located below the side of the Bowden tube base pulley; the carbon fiber cantilever beam pulley is located directly below the Bowden tube base pulley; the tension sensor and the adapter pulley are horizontally arranged opposite to each other; the waist frame double-layer carbon plate is in a C-shaped structure; and one end of the waist frame double-layer carbon plate, which is connected to the axle connecting piece, is lower than the other end, which is opposite to the carbon fiber cantilever beam pulley; the upper axle connecting piece comprises a waist connecting part, a middle axle connecting piece connecting part and a limiting plate fixedly arranged between the waist connecting part and the middle axle connecting piece connecting part; the upper axle connecting piece is fixedly connected to the waist frame double-layer carbon plate at the waist connecting part through a bolt; the middle axle connecting piece and the upper axle connecting piece are connected at the middle axle connecting piece connecting part through a ball bearing and a D-shaped shaft.

2. The rope-driven hip exoskeleton for ease of force transmission according to claim 1, wherein: An opening is arranged on the lower part of the middle axle connecting piece; the lower axle connecting piece and the middle axle connecting piece are connected through a locking screw at the opening.

3. The rope-driven hip exoskeleton for ease of force transmission according to claim 1, wherein: A magnetic encoder is installed on the axle connecting piece; the magnetic encoder comprises a magnetic encoder base, a magnetic encoder main body, a magnet and a magnetic encoder upper cover; the magnetic encoder base is fixedly installed on the upper axle connecting piece; the magnetic encoder main body is installed on the magnetic encoder base; the magnet is fixedly installed on the D-shaped shaft and faces the magnetic encoder main body; and the magnetic encoder upper cover is buckled with the magnetic encoder base.

4. The rope-driven hip exoskeleton for ease of force transmission according to claim 1, wherein: The back frame comprises a back carbon plate and a back protector; the back carbon plate is fixedly connected to the back protector; the back protector is located on the inner side of the back carbon plate; and two groups of back frame belt through slots are arranged on the back carbon plate and the back protector.

5. The rope-driven hip exoskeleton facilitating force transmission of claim 4, wherein: A plurality of threaded holes are arranged on the back carbon plate and the waist-back connector; and the back carbon plate and the waist-back connector are fixedly connected through bolts at the plurality of threaded holes.

6. The rope-driven hip exoskeleton facilitating force transmission according to claim 4, characterized in that: The waist frame further comprises a waist protector; the waist protector is fixedly installed on the inner side of the waist frame double-layer carbon plate; and the waist protector is provided with a waist frame belt through slot.

7. The rope-driven hip exoskeleton facilitating force transmission according to claim 1, wherein: The leg frame comprises a leg double-layer carbon plate and a leg protector, the upper end of the leg double-layer carbon plate is fixedly connected with the lower side shaft connector, and the leg protector is fixedly installed on the inner side of the lower end of the leg double-layer carbon plate.

8. The rope-driven hip exoskeleton facilitating force transmission according to claim 7, characterized in that: The upper side fixing member and the lower side fixing member are fixedly installed between the leg double-layer carbon plates.

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