CN110539289B - Three-degree-of-freedom centering hip joint mechanism of power-assisted exoskeleton - Google Patents

Abstract

The invention discloses a three-degree-of-freedom centering hip joint mechanism of an assistance exoskeleton, which comprises a waist adjustable part, a three-degree-of-freedom centering serial part and a thigh adjustable part. The waist adjustable component is provided with a waist sliding cross beam which can be adjusted left and right; the three-degree-of-freedom centering series component is provided with a left and a right two parallelogram mechanisms formed by four vertical shafts; the output end is connected with the upper and lower positions of a crown shaft motor in the thigh adjustable part through the free vertical shaft to form a revolute pair. In order to adapt to the difference of body sizes of different wearers, the output end of the three-free centering series part is connected with the thigh adjustable part through an adjustable locking mechanism. Thigh outer panel and thigh bandage support that thigh adjustable part included, thigh outer panel and coronal axis motor are connected, install thigh bandage support on the thigh outer panel, and thigh bandage support position is adjustable. The invention realizes the three-degree-of-freedom centering of the hip on the premise of meeting the requirement of a working space.

Description

A three-degree-of-freedom-aligned hip joint mechanism for assisting exoskeletons

technical field

The invention belongs to the technical field of machinery, and in particular relates to a three-degree-of-freedom centering hip joint mechanism for assisting an exoskeleton robot.

Background technique

The power-assisted exoskeleton robot is a wearable human-machine integrated device suitable for rescue and disaster relief, heavy-duty marching and dangerous operations in complex terrain environments. In the traditional mechanism design, a bionic structure is often used. This design usually simplifies the lower limbs of the human body into a multi-rigid body model, adopts a humanoid structure, and designs the hip and ankle joints with multi-degree-of-freedom serial structures and single-degree-of-freedom structures. knee joint. However, in order to simplify the mechanism design and improve the overall bearing performance of the mechanism, the hip joint usually chooses a non-aligned mechanism form, such as the BLEEX exoskeleton robot in the United States and the HUMA exoskeleton robot in South Korea. Because such a joint arrangement form does not align well with the actual hip joint center of the human body, the actual wearing experience of the human body is greatly reduced and the gait is deformed, thereby limiting the movement of the wearer to a certain extent.

In order to solve the centering problem of the hip joint mechanism in the power-assisted exoskeleton robot, many scholars and research institutions have given solutions. For example: Chinese Patent No. 201811377390.9 discloses "a power-assisted exoskeleton hip joint structure", which can realize a multi-degree-of-freedom rigid-flexible structure of the hip, knee-ankle joint, and can better fit the motion state of human joints , but in the two degrees of freedom of the hip, only the alignment of the degree of freedom of flexion and extension with the hip joint of the human body is realized, which will inevitably hinder the movement of the wearer. Chinese Patent No. 201810719712.7 discloses a "linear drive three-degree-of-freedom parallel hip joint mechanism", which adopts a parallel topology structure, and has high stiffness characteristics while achieving three-degree-of-freedom alignment, and the mechanism has the characteristics of semi-decoupling, However, the application of the parallel mechanism causes the overall structure of the hip to be too large and takes up a lot of space, which is not suitable for use in power-assisted exoskeleton robots that need to perform various complex tasks.

SUMMARY OF THE INVENTION

The purpose of the present invention is to propose a new hip joint series mechanism suitable for power-assisted exoskeletons, which can realize the three-degree-of-freedom alignment of the hip under the premise of meeting the requirements of the working space.

The three-degree-of-freedom centering hip joint mechanism of the assisting exoskeleton of the present invention includes an adjustable waist part, a three-degree-of-freedom centering series part and an adjustable thigh part.

The waist adjustable part has a waist beam and a waist sliding beam installed on both sides of the waist beam and can slide left and right along the waist beam.

There are two sets of the three-degree-of-freedom concentric series components, which are respectively installed on the waist sliding beams on both sides of the waist beam. The three-degree-of-freedom concentric series components include a sagittal axis seat, a vertical axis seat, a sagittal axis, a main horizontal rod, an auxiliary horizontal rod, four vertical axes, and a free vertical axis. Let the four vertical axes be the first main vertical axis, the first auxiliary vertical axis, the second main vertical axis and the second auxiliary vertical axis, respectively. Among them, the sagittal axis passes through the connecting hole at the end of the lumbar sliding beam and is connected with the sagittal axis seat to form a rotating pair; the sagittal axis seat is installed with the first main vertical axis and the first auxiliary vertical axis; the main horizontal rod and the auxiliary axis are installed on the sagittal axis seat. One end of the horizontal rod is respectively sleeved on the first main vertical shaft and the first auxiliary vertical shaft; the other ends of the main horizontal rod and the auxiliary horizontal rod are respectively sleeved on the second main vertical shaft and the second auxiliary vertical shaft. The second main vertical shaft and the second auxiliary vertical shaft are installed on the vertical shaft seat; the center lines of the above four vertical shafts form a parallelogram mechanism; the front end of the vertical shaft seat is designed with a semi-ring connecting piece, and the upper and lower ends pass through the free vertical shaft. Connect the crown shaft motor.

The thigh adjustable part includes a thigh outer plate and a thigh strap bracket; the upper part of the thigh outer plate is fixed on the output shaft of the coronal shaft motor; the thigh band bracket is fixed with the adjusting screw hole on the lower part of the thigh outer plate through bolts.

In the three-degree-of-freedom centering hip joint mechanism of the power-assisted exoskeleton of the above structure, the first degree of freedom is: the passive movement of hip adduction and abduction is realized through the rotation pair formed between the centering component and the waist sliding beam. The second degree of freedom is: through the parallelogram mechanism formed in the centering component, at the same time, the four vertical axes of the parallelogram cooperate with the free vertical axis to synthesize the vertical axis rotational motion of the distal end, and provide the passive motion of internal and external rotation of the hip to achieve The axis of rotation of the five-axis composite motion coincides with the axis of the internal and external rotation of the human hip joint. The third degree of freedom is: the active flexion and extension of the hip in the sagittal plane is provided by the coronal axis motor. The rotation center axes of the above three degrees of freedom meet at a point, which is the center of the human hip joint, which realizes the centering of the human-machine joint and ensures the wearing comfort of the human body. Rotation ensures the safety of human body wear.

The advantages of the present invention are:

(1) The present invention assists the exoskeleton three-degree-of-freedom centering hip joint mechanism, by utilizing the motion characteristics of the parallelogram mechanism, the total motion axis of the hip internal and external rotation is unchanged and just passes through the human hip joint motion center. Different from the common double parallelogram mechanism, in order to facilitate the installation of the coronal shaft motor, the present invention simplifies one of the parallelograms while increasing the degree of freedom of a vertical axis, ensuring that the total motion axis of internal and external rotation is related to the internal and external rotation of the human hip joint. The axes of motion coincide. Furthermore, the sagittal axis and the coronal axis are in the same horizontal plane, and the three axes of the distal total vertical axis meet at the same point, which is the center of the human hip joint. A spring buffer module is also set on the adduction and abduction degrees of freedom, which can reduce the impact of the load on the exoskeleton during the movement.

(2) The three-degree-of-freedom alignment hip joint mechanism of the assisting exoskeleton of the present invention adopts a three-axis series arrangement. Unlike the general parallel three-degree-of-freedom mechanism, the series connection can simplify the overall mechanical structure, thereby making the mechanism more It is compact, and on the other hand, it avoids the problem of mechanism singularity that may be caused by the parallel structure, and expands the motion range of three degrees of freedom.

(3) The three-degree-of-freedom alignment hip joint mechanism of the present invention assists the exoskeleton, in order to adapt to the individual differences of different wearers, such as height, shortness, fatness and thinness, etc., the present invention is provided with lengths at the waist, the vertical axis seat and the thigh. Adjustment parts, in which the waist beam is three-level adjustment, which is fixed by two pairs of bolts and nuts; the length adjustment at the vertical shaft seat is stepless adjustment, which is fixed by a simple locking module; the length of the thigh is multi-level adjustment, Secure with a pair of bolts and nuts. Through the mutual cooperation of three length adjustments, the matching of the exoskeleton and the comfort of the wearer are ensured to the greatest extent.

(4) The present invention assists the exoskeleton three-degree-of-freedom alignment hip joint mechanism. According to the human body movement gait data, the movement range of the hip joint in the sagittal plane, the required torque and the movement power should be obvious in the process of human movement. It is larger than the data of the other two planes of the hip joint, so the present invention only selects the coronal axis as the active drive, and the other axes are passively moved and mechanically limited by the mechanism design. Such a design reduces the size and weight of the joint and makes the structure more compact.

(5) The present invention assists the exoskeleton three-degree-of-freedom alignment hip joint mechanism, as a modular design of the hip, the present invention can be easily assembled and unloaded with the back frame module, the knee joint module, etc. Corresponding interfaces are left on the lumbar sliding beam and the outer thigh plate to realize the further development of the exoskeleton as a whole.

Description of drawings

FIG. 1 is a schematic diagram of the overall structure of the three-degree-of-freedom alignment hip joint mechanism of the assisting exoskeleton of the present invention.

FIG. 2 is a schematic structural diagram of the adjustable waist part in the three-degree-of-freedom centering hip joint mechanism of the assisting exoskeleton of the present invention.

3 is a side view of the parallel four-link structure in the three-degree-of-freedom centering hip joint mechanism of the assist exoskeleton of the present invention.

FIG. 4 is a plan view of the parallel four-link structure in the three-degree-of-freedom alignment hip joint mechanism of the assisting exoskeleton of the present invention.

FIG. 5 is a schematic structural diagram of the adjustable part of the thigh in the three-degree-of-freedom centering hip joint mechanism of the power-assisted exoskeleton of the present invention.

6 is a schematic side view of the overall structure of the three-degree-of-freedom centering hip joint mechanism of the assisting exoskeleton of the present invention.

7 is a schematic structural diagram of the locking mechanism in the three-degree-of-freedom centering hip joint mechanism of the assist exoskeleton of the present invention.

In the picture:

1- Waist adjustable parts 2- Three degrees of freedom centering tandem parts 3- Thigh adjustable parts

4-Locking mechanism 101-Back plate 102-Sliding beam at waist

103-waist beam 104-inward and outward extension spring 105-spring end cap

106-Spring compression slider 107-Locating screw hole 108-Adjusting screw hole

201-Sagittal Axis 202-Vertical Axis 203-Sagittal Axis

204-Main horizontal rod 205-Auxiliary horizontal rod 206-Spring compression stop

207-Coronal shaft motor 208-Free vertical shaft 209-First main vertical shaft

210-First auxiliary vertical axis 211-Second main vertical axis 212-Second auxiliary vertical axis

213-Half-ring shaft seat 214-Locking mechanism connecting rod 301-Outer thigh plate

302-Thigh strap bracket 303-Thigh plate adjustment screw hole 401-Lock slider body

402-Locking block 403-Locking knob 404-Locking port

405-Chute 403a-Recess Block 403b-Lock Bolt

403c-knob 403d-ring boss

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings.

A three-degree-of-freedom centering hip joint mechanism of a power-assisted exoskeleton of the present invention includes a waist adjustable part 1, a three-degree-of-freedom centering series part 2 and a thigh adjustable part 3, as shown in FIG. 1 .

The waist adjustable parts include a back plate 101 , a waist sliding beam 102 , a waist beam 103 , an inward and outward spring 104 , a spring end cover 105 and a spring compression slider 106 , as shown in FIG. 2 . The waist beam 103 is arranged horizontally and is divided into the left part of the waist beam, the middle part of the waist beam and the right part of the waist beam. The middle part of the waist beam is fixed to the rear of the back plate 101 from the outside by four sets of bolts; the left part of the waist beam and the right part of the waist beam are provided with multiple sets of positioning screw holes 107 along the left and right directions. The waist sliding beam 102 is divided into a left sliding beam and a right sliding beam, which are respectively connected with the left part of the waist beam and the right part of the waist beam; Therefore, the adjustment screw holes at different positions are matched with the positioning screw holes and fixed by bolts, so that the position adjustment of the left sliding beam and the right sliding beam on the waist beam 103 is realized. The lower part of the left sliding beam and the right sliding beam are provided with cylindrical grooves, and the inner and outer cylindrical grooves are nested with an inward and outward extension spring 104 and a spring compression slider 106. At the same time, four sets of screws are passed through the slots of the cylindrical groove. The spring end cap 105 is fixedly installed to provide a limit for the retraction and extension spring 104 and the spring compression slider 106 . The spring end cover 105 is provided with a through hole, so that the contact end of the spring compression slider 106 extends out of the through hole.

The three-degree-of-freedom centering series components 2 are two sets, which are respectively installed on the outer ends of the left sliding beam and the right sliding beam, and the installation methods are the same. The centering component 2 includes a sagittal shaft seat 201, a vertical shaft seat 202, a sagittal shaft 203, a main horizontal rod 204, an auxiliary horizontal rod 205, a spring compression stop 206, a coronal shaft motor 207, a free vertical shaft 208, and four Let the four vertical axes be the first main vertical axis 209 , the first auxiliary vertical axis 210 , the second main vertical axis 211 and the second auxiliary vertical axis 212 respectively, as shown in FIGS. 3 and 4 . The sagittal axis 203 passes through the connecting hole at the end of the waist sliding beam 102 and is connected with the sagittal axis seat 201 to form a rotating pair. A spring compression stopper 206 is installed at the bottom of the sagittal axis seat 201 , and the spring compression stopper 206 is in contact with the contact end of the aforementioned spring compression block 106 through an adduction and abduction spring 104 . A first main vertical shaft 209 and a first auxiliary vertical shaft 210 are installed on the sagittal shaft seat 201; one end of the main horizontal rod 204 and the auxiliary horizontal rod 205 are respectively sleeved on the first main vertical shaft 209 and the first auxiliary vertical shaft 210; The other ends of the main horizontal rod 204 and the auxiliary horizontal rod 205 are respectively sleeved on the second main vertical shaft 211 and the second auxiliary vertical shaft 212 . The second main vertical shaft 211 and the second auxiliary vertical shaft 212 are mounted on the vertical shaft seat 202 . As shown in Figures 1 and 5, the front end of the vertical shaft seat 202 is provided with a semi-annular shaft seat 213, the outer circumference of the crown shaft motor 207 is coaxially arranged with the semi-annular shaft seat 213, and both ends of the semi-annular shaft seat 213 pass through copper sleeves A free vertical shaft 208 is installed; the relative positions of the upper and lower body of the crown shaft motor 207 are respectively fixed with the free vertical shaft 208 . The crown axis motor 207 has a harmonic reducer to improve the output torque of the motor; the thigh adjustable part 3 is installed on the output shaft of the crown axis motor 207 . The center line of the above-mentioned four vertical axes forms a parallelogram mechanism; at the same time, between the sagittal axis 203 and the waist sliding beam, as well as the first main vertical axis 207, the first auxiliary vertical axis 208, the second main vertical axis 209, the second The auxiliary vertical shaft 210 is connected with the main horizontal rod 204 and the auxiliary horizontal rod 205 through a copper sleeve. Compared with the ordinary bearing, the copper sleeve has a smaller volume and a higher bearing strength.

The thigh adjustable part 3 includes an outer thigh plate 301 and a thigh strap support 302 , as shown in FIGS. 5 and 6 . The upper part of the outer thigh plate 301 is fixed on the output shaft of the coronal shaft motor. The thigh strap bracket 302 is fixed with the adjusting screw hole 303 in the lower part of the outer thigh plate 301 through bolts. Similarly, the adjustment holes on the outer thigh plate 301 are provided with multiple groups in the up-down direction, so that the upper and lower positions of the thigh bandage bracket 302 can be adjusted on the outer thigh plate 301 through the cooperation between the bolts and the adjustment screw holes 303 of each group of the thigh plate.

In the three-degree-of-freedom centering hip joint mechanism of the power-assisted exoskeleton with the above structure, the first degree of freedom is: the passive movement of hip adduction and abduction is realized through the rotation pair formed between the centering member 2 and the waist sliding beam 102 . The second degree of freedom is: through the parallelogram mechanism formed in the centering component 2, at the same time, the four vertical axes of the parallelogram cooperate with the free vertical axis 208 to synthesize the vertical axis of the distal end (the axis passes through the center of the hip joint of the human body) to rotate, providing the hip joint. The internal and external rotation passive motion of the hip joint is realized, and the rotation axis of the five-axis composite motion is coincident with the internal and external rotation motion axis of the human hip joint. The third degree of freedom is that active flexion and extension motion of the hip in the sagittal plane is provided by the coronal axis motor 207 . The rotation center axes of the above three degrees of freedom meet at a point, which is the center of the human hip joint, which realizes the centering of the human-machine joint and ensures the wearing comfort of the human body. Rotation ensures the safety of human body wear. The adduction and abduction degree of freedom is also through the cooperation between the adduction and abduction spring 104 and the spring compression slider 106 and the centering member 2, which can reduce the impact of the load on the exoskeleton during the movement. Both the backboard 101 and the thigh strap bracket 302 are provided with strap slots, wherein the backboard 101 is connected to the waist of the human body through straps, and the thigh strap bracket 302 is connected to the left and right thighs of the human body through straps. The mechanism is a modular design of the exoskeleton hip, and the complete function of the exoskeleton is realized by connecting the exoskeleton knee module and the ankle module.

In the present invention, in order to adapt to the difference in body size of different wearers, a locking mechanism is designed between the free vertical axis 208 and the parallel four-bar linkage mechanism formed by the remaining four vertical axes, and the locking mechanism 4 is connected in series, the specific method is as follows:

The front end of the vertical shaft seat 202 is designed with a horizontally arranged rectangular cross-section locking mechanism connecting rod 214 for connecting the locking mechanism 4 ; The port 404 is sleeved on the connecting rod 214 of the locking mechanism, and the front end of the main body 401 of the locking slider is designed with a semi-annular shaft seat 213 . A locking block 402 is installed inside the locking slider body 401, and one side of the locking block 402 is a locking surface; after the locking slider body 401 is inserted, the locking block 402 is in contact with the side surface of the locking mechanism link 214 . The other side of the locking block 402 is a locking mating surface, which is an inclined surface, which is used to cooperate with the locking knob 403 .

The locking knob 403 includes a retracting block 403a, a locking bolt 403b and a knob 403c. Wherein, the locking bolt 403b is sleeved with a retraction block 403a, and the retraction block 403a is placed in the chute 405 on the main body 401 of the locking slider, and the sliding table designed on both sides and the two sides of the chute 405 are designed The sliding connections are matched with each other to realize the positioning of the retracting block 403 a in the sliding groove 405 and can slide along the sliding groove 405 . The front end of the locking bolt 403b is threadedly connected with the threaded channel 406 opened on the main body 401 of the locking slider, and a knob 403c is installed at the end. The side surface of the indentation block 403 a is an inclined surface, which is matched with the locking mating surface on the aforementioned locking block 402 . The locking bolt 403b is designed with an annular boss 403d in the upper direction. The boss 403d is matched with the retraction block 403a, and the knob 403c is matched with the end of the retraction block 403a, so as to realize the positioning of the retraction block 403a on the locking bolt 403b . Therefore, by rotating the knob 403c, the locking bolt 403b is driven to rotate, and the knob can push the retracting block 403a to move along the chute 405, so that the retracting block 403a applies a thrust to the locking block 402 and pushes the locking block 402 to move, Finally, the locking mechanism connecting rod 214 is pressed by the locking block 402 to realize the fixation between the locking mechanism 4 and the locking mechanism connecting rod 214 . When the locking bolt 403b is reversely rotated, the retracting block 403a can be moved in the opposite direction through the boss 403d, and finally the unlocking between the locking knob 403 and the connecting rod 214 of the locking mechanism is realized.

Claims (7)

1. A three-degree-of-freedom force-assisting exoskeleton centering hip joint mechanism is characterized in that: the device comprises a waist adjustable part, a three-degree-of-freedom centering series part and a thigh adjustable part;

the waist adjustable part is provided with a waist cross beam and waist sliding cross beams arranged on two sides of the waist cross beam;

the two sets of three-degree-of-freedom centering series components are respectively arranged on the waist sliding cross beams at two sides of the waist cross beam; the three-degree-of-freedom centering series component comprises a sagittal shaft seat, a vertical shaft seat, a sagittal shaft, a main horizontal rod, an auxiliary horizontal rod, four vertical shafts and a free vertical shaft; the four vertical shafts are respectively a first main vertical shaft, a first auxiliary vertical shaft, a second main vertical shaft and a second auxiliary vertical shaft; wherein, the sagittal axis passes through the connecting hole at the end of the waist sliding beam and then is connected with the sagittal axis seat to form a revolute pair; a first main vertical shaft and a first auxiliary vertical shaft are arranged on the sagittal shaft seat; one end of the main horizontal rod and one end of the auxiliary horizontal rod are respectively sleeved on the first main vertical shaft and the first auxiliary vertical shaft; the other ends of the main horizontal rod and the auxiliary horizontal rod are respectively sleeved on the second main vertical shaft and the second auxiliary vertical shaft; the second main vertical shaft and the second auxiliary vertical shaft are arranged on the vertical shaft seat; the four vertical axis center connecting lines form a parallelogram mechanism; a semi-annular connecting piece is designed at the front end of the vertical shaft seat, and the upper end and the lower end of the vertical shaft seat are connected with a crown shaft motor through free vertical shafts;

the three-degree-of-freedom centering series component has three degrees of freedom, and the first degree of freedom is as follows: the hip adduction-abduction passive motion is realized through a revolute pair formed between the three-degree-of-freedom centering series component and the waist sliding beam; the second degree of freedom is: the rotation axis of the five-axis synthetic motion is coincided with the internal and external rotation motion axis of the hip joint of the human body; the third degree of freedom is: providing active flexion and extension movement of the hip in a sagittal plane by a coronal axis motor; the rotating central axes of the three degrees of freedom are converged at one point, namely the center of the hip joint of the human body;

the thigh adjustable part comprises a thigh outer side plate and a thigh bandage bracket; the upper part of the thigh outer side plate is fixed on the output shaft of the crown shaft motor; the thigh bandage bracket is fixed with the lower part of the thigh outer side plate through a bolt.

2. The three-degree-of-freedom power-assisted exoskeleton center to center hip joint mechanism as claimed in claim 1, wherein: the position of the waist sliding beam on the waist beam is adjustable; the distance between the vertical shaft seat and the thigh plate is adjustable; the upper and lower positions of the thigh outer side plate are adjustable.

3. The three-degree-of-freedom power-assisted exoskeleton center to center hip joint mechanism as claimed in claim 1, wherein: an inward-contraction outward-expansion spring and a spring compression sliding block are arranged in the waist sliding beam; meanwhile, a spring compression stop block is installed at the bottom of the sagittal shaft seat, and the contact end of the spring compression stop block and the spring compression block is contacted through the action of an inward-folded outward-unfolded spring.

4. The three-degree-of-freedom power-assisted exoskeleton center to center hip joint mechanism as claimed in claim 1, wherein: a locking mechanism is designed, and meanwhile, the semi-annular connecting piece is designed on the locking mechanism; the locking mechanism is sleeved on a locking mechanism connecting rod designed on the vertical shaft seat, and the position of the locking mechanism connecting rod is adjustable.

5. The power-assisted exoskeleton three-degree-of-freedom central hip joint mechanism as claimed in claim 4, wherein: the locking mechanism comprises a locking slide block main body, a locking block and a locking knob; the locking slide block main body is provided with a locking opening matched with the section of the locking mechanism connecting rod, and the locking opening is sleeved on the locking mechanism connecting rod; a locking block is arranged in the locking slide block main body, and one side of the locking block is a locking surface; after the locking slide block main body is inserted, the locking block is attached to the side face of the locking mechanism connecting rod; the other side of the locking block is a locking matching inclined plane which is used for matching with the locking knob; the locking knob is provided with a locking bolt and a retraction block; the retraction block is driven by the locking bolt to move in the sliding groove on the locking sliding block main body; the side surface of the indentation block is an inclined surface which is matched and attached to the locking matching surface on the locking block.

6. The three-degree-of-freedom power-assisted exoskeleton center to center hip joint mechanism as claimed in claim 1, wherein: the whole body adopts a modular design, and the assembly and the disassembly with the knee module and the back frame are convenient.

7. The three-degree-of-freedom power-assisted exoskeleton center to center hip joint mechanism as claimed in claim 1, wherein: the motor with the crown shaft is used for driving, and the other shafts are in passive motion and are provided with mechanical limit.

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