Powered knee exoskeleton device

Abstract

The application discloses a power knee exoskeleton walking aid device which comprises a main control unit, a gear box reducer, a thigh brace, a shank brace, an exoskeleton thigh, an exoskeleton shank, an angle encoder, an exoskeleton knee joint, a joint motor, an output rocker arm and a series elastic unit. The device is a power knee exoskeleton based on a compression spring type series elastic driver, which is simple in structure, convenient to wear, good in safety, strong in adaptability and high in comfort. The device can improve the comfort of use and ensure the safety of users by moving the gravity center of the exoskeleton upwards under the premise of ensuring the aid effect. Meanwhile, the elastic element in the series elastic driver can also be used for measuring the human-machine interaction torque, avoiding the use of expensive torque sensors, thereby reducing the manufacturing cost.

Description

Technical Field

[0001] The present invention relates to the technical field of exoskeleton robots, in particular to a powered knee joint exoskeleton walking aid device. Background Art

[0002] Powered knee exoskeletons originally originated in military applications, used to enhance soldiers' walking and load-bearing abilities and improve combat capabilities. Research into rehabilitation exoskeletons began in 1960, but due to technological limitations at the time, they failed to achieve their intended goals. It wasn't until recent decades, particularly with the clinical application of the Lokomat weight-reducing gait training exoskeleton, that powered knee exoskeletons have been gradually adopted to reconstruct walking patterns in patients with central nervous system damage and assist those with lower limb motor dysfunction. In the military, powered knee exoskeletons help soldiers carry combat equipment, improving their endurance, mobility, and battlefield survivability. In medicine, powered knee exoskeletons can assist with reciprocating movements, stimulate the nervous system's compensatory response, and restore voluntary movement in patients with movement disorders. Consequently, they are widely used in rehabilitation treatment for neurological disorders such as stroke. Furthermore, in the civilian sector, powered knee exoskeletons, as power-assisted devices, can be used to assist the elderly with outdoor exercise and for other specialized applications, such as mountaineering, field search and rescue, and forest firefighting.

[0003] Existing powered knee exoskeletons are wearable mechanical devices designed to assist the wearer in performing knee joint movements based on the human limb movement and physiological structure. During use, the powered knee exoskeleton fits tightly against the human body. The motor's output torque is transmitted to the lower limb knee joint via the motor shaft, reducer, and exoskeleton hardware, thereby driving knee rotation. As a wearable device, the powered knee exoskeleton has a direct physical connection with the human body, making safety and comfort paramount. Current powered knee exoskeletons mostly use direct motor drive, which presents issues of poor safety and comfort. Due to the direct physical contact between the human body and the exoskeleton, the lack of flexible drive and mechanical structure reduces wearer comfort and may even cause personal injury. Furthermore, existing powered knee exoskeletons are bulky and heavy, have unfriendly actuators, lack flexibility to accommodate the user after sudden power-on or power-off, and are rigid. These shortcomings are the main obstacles to the widespread adoption of powered knee exoskeletons.

[0004] Chinese patent CN202310351850.5 discloses a power exoskeleton structure design and motion control method for the lower limbs of the human body, especially the knee joints. The patent discloses a lower limb knee joint power-assisted exoskeleton that can identify terrain and automatically switch between active and passive modes according to the human body's movement state, as well as a control method that matches it. The design uses a motor installed at the knee joint position to output auxiliary torque to assist the movement of the knee joint; and uses an airbag to adjust the tightness of the waist to improve the comfort of wearing the exoskeleton device. However, the exoskeleton disclosed in the patent uses a direct motor drive method, which makes the interaction between man and machine lack flexibility, thereby reducing the safety of the exoskeleton device and the comfort of motion assistance; and the exoskeleton device measures the interaction torque between man and machine by adding a pressure sensor, which is costly and not conducive to popularization and application.

[0005] Chen Shaocong's paper (Chen Shaocong. Research on the Design and Control System of a Knee-Assisted Exoskeleton [D]. Guilin University of Electronic Technology, 2023. DOI: 10.27049 / d.cnki.ggldc.2023.001247.) designs a rope-driven knee-assisted exoskeleton and a matching control method based on admittance control and iterative learning. The paper establishes the kinematic and dynamic models of the knee-assisted exoskeleton. The paper uses a Bowden cable to transmit power from the motor output shaft to the human knee joint. Regarding control, iterative learning is used to determine and track the desired knee-assisted power curve during walking. However, due to certain inherent disadvantages of rope-driven structures, the rope-driven exoskeleton presented in the paper suffers from low assist torque and delayed control response. Furthermore, the rope-driven approach is structurally complex. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a powered knee exoskeleton walking aid. This device features a simple structure, easy wear, excellent safety, and high comfort. It ensures user safety while maintaining effective assistance. Furthermore, the elastic element in the series elastic actuator can be used to measure torque during human-machine interaction, eliminating the need for expensive torque sensors and thus reducing manufacturing costs.

[0007] The technical solution of the present invention to solve the above technical problems is to design a powered knee joint exoskeleton walking aid device, characterized in that the powered knee joint exoskeleton walking aid device includes a main control unit, a gearbox reducer, a thigh brace, a calf brace, an exoskeleton thigh, an exoskeleton calf, an angle encoder, an exoskeleton knee joint, a joint motor, an output rocker arm, and a series elastic unit;

[0008] The exoskeleton thigh includes an exoskeleton thigh support plate, a No. 1 sheet metal fixing, and quick-press screws; the upper portion of the exoskeleton thigh support plate is a mounting plate with a plurality of screw holes arranged in the middle from top to bottom, and strip-shaped through holes arranged on the upper and lower sides of the left and right sides; the middle portion is a connecting plate with a plurality of screw holes, and the middle portion of the lower portion is provided with a concave step hole in the middle position of the outer side surface at the end thereof, and a plurality of screw holes are arranged inside and around the concave step hole, and the upper, middle, and lower portions are connected together;

[0009] One end of the No. 1 sheet metal fastener is fixed to the upper inner portion of the connecting plate of the exoskeleton thigh support plate, and the other end thereof is provided with a groove. One end of the quick-press screw is fixedly mounted on the thigh brace, and the other end thereof is disposed in the groove of the No. 1 sheet metal fastener, with the two ends connected to secure the thigh brace to the No. 1 sheet metal fastener.

[0010] The main control unit is fixed to the upper part of the mounting plate of the exoskeleton thigh support plate by screws, and the gearbox reducer is fixed to the lower part of the mounting plate by screws; the gearbox reducer includes a primary gear body, a secondary gear body, a tertiary gear body, a carrier plate, and a cover plate; the carrier plate is provided with a plurality of connection holes at the top and bottom, a plurality of mounting holes in the middle from top to bottom, and a plurality of fixing holes on the left and right sides. The connection holes at the top and bottom are used to fix the mounting plate of the exoskeleton thigh support plate with screws, and the fixing holes on the left and right sides are used to fix the cover plate to the mounting plate; the mounting hole in the middle is used to install the joint motor, the primary gear body, the secondary gear body, and the tertiary gear body;

[0011] The joint motor is fixedly mounted on the upper middle portion of the carrier plate, with its output shaft arranged horizontally and facing outwards, and a transmission gear is fixedly mounted on the output shaft via a shaft key;

[0012] A first-stage gear body, a second-stage gear body, and a third-stage gear body are installed on the carrier plate below the joint motor in order from top to bottom; the first-stage gear body includes a gear shaft, a coaxially fixed large gear and a small gear of different sizes, and two sets of No. 1 flange bearings and a No. 1 gear shaft isolation sleeve; the second-stage gear body includes a gear shaft, a coaxially fixed large gear and a small gear of different sizes, and two sets of No. 2 flange bearings and a No. 2 gear shaft isolation sleeve; the third-stage gear body includes a gear shaft, a gear fixed on the gear shaft, two No. 3 flange bearings, a No. 3 gear shaft isolation sleeve, and an output flange plate;

[0013] A number of mounting holes are provided in the middle of the cover plate, and the first-stage gear body, the second-stage gear body, and the third-stage gear body are arranged between the cover plate and the carrier plate through corresponding flange bearings, and the gear shafts of the three gear bodies are parallel to the output shaft of the joint motor; wherein the first-stage gear body and the second-stage gear body realize their respective axial positioning through corresponding gear shaft isolation sleeves, and the third-stage gear body realizes its axial positioning through a third gear shaft isolation sleeve and an output flange; a threaded hole is provided on the end face of the shaft of the third-stage gear body facing outward, and the output flange is a connecting component with a connecting hole provided in the middle and a connecting hole also provided on the outer ring; the output flange is provided on the outside of the third flange bearing on the side of the threaded hole provided on the end face of the shaft of the third-stage gear body, and is fixedly connected to the end face of the shaft of the third-stage gear body facing outward by installing screws in the connecting hole in the middle thereof;

[0014] The large gear of the first-stage gear body is meshed with the transmission gear fixed on the output shaft of the joint motor, the small gear of the first-stage gear body is meshed with the large gear of the second-stage gear body, and the small gear of the second-stage gear body is meshed with the gear of the third-stage gear body;

[0015] One end of the output rocker arm is provided with a circle of connecting holes, and the other end thereof is provided with a connecting hole. The end provided with the circle of connecting holes is fixedly connected to the outer ring of the output flange by screws, and the end provided with the connecting hole is fixedly connected to the series elastic unit by bolts;

[0016] The series elastic unit includes an upper fisheye joint, a lower fisheye joint, a long connecting rod, a short connecting rod, a linear slide rail, an upper linear slider, a middle linear slider, a lower linear slider, an upper slide rail fixing part, a middle slide rail fixing part, a lower slide rail fixing part, an upper linear spring, a lower linear spring, and a displacement sensor; the upper fisheye joint is fixed to the top of the long connecting rod, the lower fisheye joint is fixed to the end of the short connecting rod, the long connecting rod is fixedly connected to the lower end of the output rocker arm through the upper fisheye joint by bolts, and the short connecting rod is fixedly connected to the exoskeleton shank through the lower fisheye joint by bolts;

[0017] Two straight line slide rails are symmetrically arranged on both sides of the short connecting rod, and an upper straight line slider, a middle straight line slider and a lower straight line slider are sequentially arranged on each straight line slide rail from top to bottom; the upper slide rail fixing part, the middle slide rail fixing part and the lower slide rail fixing part are all structures with a through hole in the middle and receiving openings on the left and right sides, wherein the middle through hole of the upper slide rail fixing part is a threaded hole, the middle through hole of the middle slide rail fixing part extends out spring guide columns on the upper and lower sides in the axial direction, and the inside of the lower spring guide column is a threaded hole, and the middle through hole of the lower slide rail fixing part is a smooth hole; two upper straight line sliders are symmetrically fixed in the two receiving openings of the upper slide rail fixing part by screws, two middle straight line sliders are symmetrically fixed in the two receiving openings of the middle slide rail fixing part by screws, and two lower straight line sliders are symmetrically fixed in the two receiving openings of the lower straight line slide rail fixing part by screws;

[0018] The lower part of the long connecting rod is fixed in the threaded hole of the upper slide rail fixing part by screwing; the upper straight line spring and the lower straight line spring are arranged on the spring guide columns on the upper and lower sides of the middle slide rail fixing part respectively, and the upper part of the short connecting rod is fixedly connected with the lower side spring guide column of the middle slide rail fixing part by screwing after passing through the middle through hole of the lower slide rail fixing part;

[0019] The compression directions of the upper straight line spring and the lower straight line spring are both parallel to the linear guide rail; the carbon fiber plate and the resin bottom plate fix the upper slide rail fixing part and the lower slide rail fixing part together by screws; a detection hole and a mounting hole are arranged on the carbon fiber plate opposite to the middle slide rail fixing part, a displacement sensor is fixed on the carbon fiber plate outside the middle slide rail fixing part by screwing and the sensing probe thereof faces the inside of the detection hole; the displacement sensor is used for measuring the displacement of the middle slide rail fixing part, i.e. the displacement of the middle straight line slider;

[0020] The exoskeleton knee joint comprises a cross roller bearing, an aluminum column, an angle encoder fixing plate, an encoder fixing flange and a knee joint angle limiting block, the lower part of the exoskeleton thigh support plate of the exoskeleton thigh and the top of the exoskeleton shank are connected through the cross roller bearing, the aluminum column is used for fixing the angle encoder fixing plate on the exoskeleton thigh support plate; the angle encoder is located at the exoskeleton knee joint, is fixed on the angle encoder fixing plate through the encoder fixing flange and screws, is coaxial with the cross roller bearing and is used for measuring the rotation angle of the knee joint; the knee joint angle limiting block is fixedly arranged on the lower part of the exoskeleton thigh support plate on the side of the cross roller bearing, and the lower edge plane of the knee joint angle limiting block is parallel to the lower end surface of the exoskeleton thigh support plate;

[0021] The exoskeleton calf includes an exoskeleton calf support plate, a calf brace relay printout, a calf brace relay plate, a No. 2 sheet metal fixing and quick-press screws. The top of the exoskeleton calf support plate is connected to the lower part of the exoskeleton thigh support plate through a cross-roller bearing; a calf brace relay printout is arranged between the lower part of the exoskeleton calf support plate and the upper part of a calf brace relay plate, and the three are fixed together by screws; a number of mounting holes are provided on the calf brace relay plate, one end of the No. 2 sheet metal fixing is fixedly connected to the calf brace relay plate, and the other end is provided with a groove, and the calf brace is fixed to the groove of the No. 2 sheet metal fixing by a quick-press screw.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The powered knee exoskeleton walking aid device designed by the present invention is a powered knee exoskeleton based on a compression spring series elastic driver. It has a simple structure, is easy to wear, has good safety, strong adaptability, and high comfort. It can ensure the safety of the user while ensuring the power-assisting effect. At the same time, the elastic elements in the series elastic driver can also be used to measure the torque of human-computer interaction, avoiding the use of expensive torque sensors, thereby reducing manufacturing costs.

[0024] 2. The present invention installs the series elastic unit between the motor reduction box and the calf rod unit, which facilitates the measurement of the output torque while ensuring power transmission. When in use, the interactive torque between the human and the machine can be obtained by measuring the deformation of the elastic element, without the need to install a torque sensor, which is convenient and quick. At the same time, the buffering and energy absorption characteristics of the elastic element are utilized to install the linear spring between the output end of the reduction gear box and the calf rod unit, which can improve the energy utilization efficiency while reducing impact, improving wearing comfort and equipment safety. At the same time, the elastic element has the effect of low-pass filtering the output torque, which can stabilize the output torque while ensuring the output torque and calf rod unit position tracking control input effect, thereby achieving precise torque control. The use of a gearbox reducer to amplify the output torque of the motor improves the compactness and load capacity of the equipment and reduces the power demand on the motor.

[0025] 3. The output portion of the motor-reduction box utilizes a connecting rod structure, utilizing an output rocker arm, connecting rod, and fisheye joint to convert rotational motion around the output shaft of the reduction box into linear motion, making the power transmission path clearer and more intuitive. Compared to traditional direct-drive knee exoskeletons, the structure elevates the position of modules such as the motor and reducer. This positions the majority of the weight of the knee-powered exoskeleton near the hip joint, which is close to the center of rotation of the torso and lower limb movements, rather than near the knee joint. This reduces the moment of inertia of the knee exoskeleton human-machine coupling system, facilitating the design of control algorithms and the achievement of control objectives. While the connecting rod structure transmits torque to the knee joint, assisting in its rotation, the component force along the calf can offset some of the weight of the calf, elevating the knee joint and improving the power assist effect.

[0026] 4. The elastic elements of this invention utilize high-stiffness linear springs. Compared to conventional knee powered exoskeletons that use structural springs and torsion springs, these linear springs offer greater durability, ease of processing, convenient installation, and reduced weight. Two linear springs are symmetrically positioned on either side of the slider. Sliding the slider in either direction compresses the corresponding spring, transmitting power to the output of the reduction gearbox or the calf rod unit. This achieves bidirectional power transmission through the elastic elements, enabling flexible actuation.

[0027] 5. Ensure flexible human-machine interaction, avoid personal injury accidents, guarantee safety of human-machine interaction at the hardware level, and enhance the comfort of the exoskeleton robot. Furthermore, the main body of the device is made of carbon fiber and photosensitive resin, ensuring structural strength that meets operational requirements while further reducing the weight of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the overall structure of an embodiment of a powered knee exoskeleton walking aid device of the present invention (view from the main perspective).

[0029] Figure 2 This is a schematic diagram of the three-dimensional structure of an embodiment of a powered knee exoskeleton walking aid device of the present invention (right side view).

[0030] Figure 3 This is a schematic structural diagram of a gearbox reducer in an embodiment of a powered knee exoskeleton walking aid device of the present invention.

[0031] Figure 4 This is a schematic diagram of the internal structure of a gearbox reducer of an embodiment of a powered knee exoskeleton walking aid device of the present invention.

[0032] Figure 5 This is a structural schematic diagram (exploded view) of the secondary gear body of a gearbox reducer of an embodiment of a powered knee exoskeleton walking aid device of the present invention.

[0033] Figure 6 Figure 1 is a schematic structural diagram (exploded view) of a three-stage gear body of a gear box reducer of an embodiment of the power knee exoskeleton walking aid device of the present application.

[0034] Figure 7 Figure 2 is a schematic structural diagram of a series elastic unit of an embodiment of the power knee exoskeleton walking aid device of the present application.

[0035] Figure 8 Figure 3 is an exploded schematic diagram. Figure 7

[0036] Figure 9 Figure 4 is a schematic structural and assembly diagram of an exoskeleton knee joint of an embodiment of the power knee exoskeleton walking aid device of the present application.

[0037] Figure 10 Figure 5 is a schematic structural and assembly diagram of a thigh brace of an embodiment of the power knee exoskeleton walking aid device of the present application.

[0038] Figure 11 Figure 6 is a schematic structural and assembly diagram of a lower leg brace of an embodiment of the power knee exoskeleton walking aid device of the present application. DETAILED DESCRIPTION

[0039] The specific embodiments of the present application are given below. The specific embodiments are only used to further illustrate the present application and do not limit the protection scope of the claims of the present application.

[0040] The present application provides a flexible driven knee joint power exoskeleton device based on a series elastic driver for human motion assistance and rehabilitation training, to solve the problems of existing knee joint power exoskeleton robots, such as being heavy, low motion efficiency, rigid driving mode, poor safety, and low comfort.

[0041] Specifically, the motor shaft of the exoskeleton is connected with the gear box reducer, power is driven to output a rocker arm motion after passing through multiple gears, the output rocker arm is connected with a series elastic unit composed of a connecting rod and a linear spring, and through compression of the spring, the power is finally transmitted to the lower leg fixing brace, to realize assistance for flexion and extension motion of the human knee joint.

[0042] The present application provides a power knee exoskeleton walking aid device (see Figures 1-11 ), which comprises a main control unit 1, a gear box reducer 2, a thigh brace 3, a lower leg brace 8, an exoskeleton thigh 4, an exoskeleton lower leg 7, an angle encoder 5, an exoskeleton knee joint 6, a joint motor 12, a protective shell 11, an output rocker arm 10, and a series elastic unit 9.

[0043] ​The exoskeleton thigh 4 comprises an exoskeleton thigh support plate, a No. 1 sheet metal fixing member 401 and a quick pressure screw 402. The upper part of the exoskeleton thigh support plate is an installation plate provided with a plurality of screw holes in the middle position from top to bottom, and a strip-shaped through hole on the upper and lower sides of the left and right sides. The middle part is a connecting plate provided with a plurality of screw holes, and the middle position of the outer side of the end of the lower part (the position of the outer side of the side where the joint motor 12 is installed is referred to as the outer side) is provided with an inner recessed step hole, and a plurality of screw holes are provided inside and around the inner recessed step hole, and the upper part, the middle part and the lower part are connected together. The inner recessed step hole is used to install the crossed roller bearing 602. Figure 1

[0044] One end of the No. 1 sheet metal fixing member 401 is fixed to the inner side of the upper part of the connecting plate of the exoskeleton thigh support plate, and the other end is provided with a groove 403; one end of the quick pressure screw 402 is fixedly installed on the thigh brace 3, and the other end is arranged on the groove 403 of the No. 1 sheet metal fixing member 401, and the two ends are connected to fix a thigh brace 3 made of a resin material on the No. 1 sheet metal fixing member 401;

[0045] The main control unit 1 is fixed by screws on the upper part of the installation plate of the exoskeleton thigh support plate, and the gear box reducer 2 is fixed by screws on the lower part of the installation plate; the gear box reducer 2 comprises a primary gear body 201, a secondary gear body 202, a tertiary gear body 203, a carrier plate 204 and a cover plate. The top and bottom of the carrier plate 204 are provided with a plurality of connecting holes, and a plurality of installation holes are provided from top to bottom in the middle, and a plurality of fixing holes are provided on the left and right sides. The connecting holes on the top and bottom are used to be fixedly connected with the installation plate of the exoskeleton thigh support plate by screws, and the fixing holes on the left and right sides are used to fixedly connect the cover plate therewith; the installation holes in the middle are used to install the joint motor 12, the primary gear body 201, the secondary gear body 202 and the tertiary gear body 203.

[0046] The joint motor 12 is fixedly installed on the upper part of the middle of the carrier plate 204, and the output shaft is horizontally arranged outward, and a transmission gear is fixedly installed on the output shaft by a shaft key; as an embodiment, the transmission gear comprises a motor shaft gear 1201, a motor shaft isolation sleeve 1202 and a shaft end cover 1203, wherein the inside of the motor shaft gear 1201 is provided with a key groove, the middle part of the motor shaft isolation sleeve 1202 and the shaft end cover 1203 is provided with a shaft hole, and the two are fixed on the two outer sides of the shaft hole of the motor shaft gear 1201 by a threaded structure, to realize the axial fixation of the motor shaft gear 1201.

[0047] ​A first-stage gear body 201, a second-stage gear body 202, and a third-stage gear body 203 are sequentially mounted on the carrier plate 204 below the joint motor 12 from top to bottom. The first-stage gear body 201 includes a gear shaft, a coaxially fixed large gear and a small gear of different sizes, and two sets of first flange bearings 201-1 and a first gear shaft isolation sleeve 201-2. The second-stage gear body 202 includes a gear shaft, a coaxially fixed large gear and a small gear of different sizes, and two sets of second flange bearings 202-1 and a second gear shaft isolation sleeve 202-2. The third-stage gear body 203 includes a gear shaft, a gear fixed on the gear shaft, two third flange bearings 203-1, a third gear shaft isolation sleeve 203-2, and an output flange 203-3.

[0048] The central portion of the cover plate is provided with several mounting holes. The primary gear body 201, secondary gear body 202, and tertiary gear body 203 are mounted between the cover plate and the carrier plate 204 via corresponding flange bearings. The gear shafts of these three gear bodies are parallel to the output shaft of the joint motor 12. The primary gear body 201 and the secondary gear body 202 are axially positioned by corresponding gear shaft spacing sleeves, while the tertiary gear body 203 is axially positioned by a third gear shaft spacing sleeve 203-2 and an output flange 203-3. The shaft end face of the third-stage gear body 203 facing outward (with the side facing the thigh brace 3 as the inner side) is provided with a threaded hole. The output flange 203-3 is a connecting component having a connecting hole in the middle and a connecting hole in the outer ring. The output flange 203-3 is arranged on the outer side of the third flange bearing 203-1 on the side of the shaft end face of the third-stage gear body 203 with the threaded hole, and is fixedly connected to the shaft end face of the third-stage gear body 203 facing outward by installing screws in the connecting hole in the middle thereof.

[0049] The large gear of the first-stage gear body 201 meshes with the transmission gear fixed to the output shaft of the joint motor 12. The small gear of the first-stage gear body 201 meshes with the large gear of the second-stage gear body 202. The small gear of the second-stage gear body 202 meshes with the gear of the third-stage gear body 203. The above meshing can be achieved by setting the size and position.

[0050] One end of the output rocker arm 10 is provided with a circle of connecting holes, and the other end is provided with a connecting hole. The end provided with a circle of connecting holes is fixedly connected to the outer ring of the output flange 203-3 by screws, and the end provided with a connecting hole is fixedly connected to the series elastic unit 9 by bolts.

[0051] The series elastic unit 9 includes an upper fisheye joint 901, a lower fisheye joint 9014, a long connecting rod 902, a short connecting rod 908, a linear slide rail 903, an upper linear slider 909, a middle linear slider 9011, a lower linear slider 9012, an upper slide rail fixing member 9010, a middle slide rail fixing member 905, a lower slide rail fixing member 9013, an upper linear spring 904 and a lower linear spring 907, and a displacement sensor 906.

[0052] The upper fisheye joint 901 is fixed to the top of the long connecting rod 902, and the lower fisheye joint 9014 is fixed to the end of the short connecting rod 908. The long connecting rod 902 is fixedly connected to the lower end of the output rocker arm 10 through the upper fisheye joint 901 by bolts, and the short connecting rod 908 is fixedly connected to the exoskeleton shank 7 through the lower fisheye joint 9014 by bolts.

[0053] The two linear slide rails 903 are symmetrically arranged on both sides of the short connecting rod 908. On each linear slide rail 903, an upper linear slider 909, a middle linear slider 9011 and a lower linear slider 9012 are arranged in sequence from top to bottom; the upper slide rail fixing member 9010, the middle slide rail fixing member 905 and the lower slide rail fixing member 9013 are all structures with a through hole in the middle and accommodating openings on the left and right sides, wherein the middle through hole of the upper slide rail fixing member 9010 is a threaded hole, and the middle through hole of the middle slide rail fixing member 905 is a threaded hole. Spring guide columns extend axially from the upper and lower sides of the hole, and the inner side of the lower spring guide column is a threaded hole, and the middle through hole of the lower slide rail fixing piece 9013 is a smooth hole; the two upper linear sliders 909 are symmetrically fixed in the two accommodating openings of the upper slide rail fixing piece 9010 by screws, the two middle linear sliders 9011 are symmetrically fixed in the two accommodating openings of the middle slide rail fixing piece 905 by screws, and the two lower linear sliders 9012 are symmetrically fixed in the two accommodating openings of the lower slide rail fixing piece 9013 by screws.

[0054] The lower part of the long connecting rod 902 is fixed in the threaded hole of the upper slide rail fixing part 9010 by means of threads; the upper linear spring 904 and the lower linear spring 907 are respectively arranged on the spring guide columns on the upper and lower sides of the middle slide rail fixing part 905, and the upper part of the short connecting rod 908 passes through the middle through hole of the lower slide rail fixing part 9013 and is fixed with the spring guide column on the lower side of the middle slide rail fixing part 905 by means of threads.

[0055] The compression directions of the upper linear spring 904 and the lower linear spring 907 are both parallel to the linear guide rail 903 .

[0056] The carbon fiber plate 9015 and the resin base plate 9016 secure the upper rail fixture 9010 and the lower rail fixture 9013 together with screws. A detection hole and a mounting hole are provided on the carbon fiber plate 9015, directly opposite the middle rail fixture 905. A displacement sensor 906 is screwed to the carbon fiber plate 9015 outside the middle rail fixture 905, with its sensor facing inward of the detection hole (i.e., toward the middle rail fixture 905). Displacement sensor 906 measures the displacement of the middle rail fixture 905, specifically the displacement of the middle linear slider 9011.

[0057] The middle linear slider 9011 can slide axially on the linear slide rail 903 inside the series elastic unit 9. The middle linear slider 9011 compresses / stretches the spring during the sliding process, and the power output by the gearbox reducer 2 is transmitted to the short connecting rod 908 fixedly connected to the middle slider through the elastic force of the spring. The short connecting rod 908 pulls / pushes the exoskeleton calf 7, driving the rotation of the exoskeleton knee joint 6.

[0058] The exoskeleton knee joint 6 comprises a cross-roller bearing 602, an aluminum column 601, an angle encoder fixing plate 603, an encoder fixing flange 604, and a knee joint angle stopper 605. The lower portion of the exoskeleton thigh support plate of the exoskeleton thigh 4 is connected to the top of the exoskeleton shank 7 via the cross-roller bearing 602. The aluminum column 601 is used to secure the angle encoder fixing plate 603 to the exoskeleton thigh support plate. The angle encoder 5 is located at the exoskeleton knee joint 6 and is fixed to the angle encoder fixing plate 603 via the encoder fixing flange 604 and screws. The angle encoder 5 is coaxial with the cross-roller bearing 602 and is used to measure the rotation angle of the knee joint. The knee joint angle stopper 605 is a special-shaped hollow cylindrical structure fixed to the lower portion of the exoskeleton thigh support plate on one side of the cross-roller bearing 602 to avoid interference with other screws at the exoskeleton knee joint 6. Its lower edge plane is parallel to the lower end surface of the exoskeleton thigh support plate and is coaxial with the cross-roller bearing 602.

[0059] The exoskeleton calf 7 includes an exoskeleton calf support plate, a calf brace relay printout 701, a calf brace relay plate 702, a No. 2 sheet metal fixing 704, and a quick-press screw 703. The top of the exoskeleton calf support plate is connected to the bottom of the exoskeleton thigh support plate via a cross roller bearing 602. A calf brace relay printout 701 is provided between the bottom of the exoskeleton calf support plate and the top of a calf brace relay plate 702, and the three are fixed together by screws. The calf brace relay printout 701 ensures that the exoskeleton calf support plate and the calf brace relay plate 702 are located on the same horizontal plane.

[0060] Several mounting holes are provided on the calf brace relay plate 702. One end of the No. 2 sheet metal fixing piece 704 is fixedly connected to the calf brace relay plate 702, and the other end thereof is provided with a groove. The calf brace 8 is fixed to the groove of the No. 2 sheet metal fixing piece 704 by the quick-press screw 703.

[0061] As an embodiment, the knee joint angle limiter 605 is semi-circular and made of carbon fiber material. This limiter can prevent the exoskeleton shank 7 from hyperextension forward along the sagittal plane, acting as a hardware limiter to protect the user's safety.

[0062] The thigh brace 3 and calf brace 8 are made of resin and feature an ergonomic design. They wrap around the front and back of the thigh and calf, respectively. Strap holes are provided on the front edges to allow for the insertion of straps for customized tightness. Mounting holes are provided on the back of the thigh and calf brace to allow screws to secure them to the sheet metal mountings of the exoskeleton thigh 4 or calf 7.

[0063] There is a groove on the No. 1 sheet metal fixing part 401 of the thigh part and the No. 2 sheet metal fixing part 704 of the calf part. The quick-press screw passes through this groove to fix the thigh brace 3 and the calf brace 8 to the sheet metal fixing parts of the exoskeleton thigh 4 or the exoskeleton calf 7. By adjusting the position of the quick-press screw in the groove, the height of the thigh brace 3 and the calf brace 8 can be adjusted to accommodate wearers of different leg lengths. The wearer can adjust the height of the brace to a comfortable position.

[0064] In the series elastic unit 9, the upper linear spring 904 and the lower linear spring 907 arranged on both sides of the middle linear slider 9011 are fixed between the middle linear slider 9011 and the upper slide rail fixing piece 9010, and between the middle linear slider 9011 and the lower slide rail fixing piece 9013 by a pressing and fixing method. There is a cylindrical guide shaft along the axial direction of the series elastic unit between the upper linear spring 904 and the lower linear spring 907, which is used to constrain the elastic force direction of the spring. The two linear springs are not fixed to any parts by bolts. When in use, the upper and lower linear springs will always be in a state of one stretching and the other compressing.

[0065] The working principle and working process of the power knee joint exoskeleton walking aid device are as follows: when the device is worn, the thigh support 3 and the lower leg support 8 are fixed at the appropriate positions of the corresponding metal fixing parts according to the physiological parameters of the user, and are fixed by using quick pressure screws, and the belts on the thigh support 3 and the lower leg support 8 are adjusted to the appropriate tightness. At this time, the joint motor 12 and the gear box reducer 2 mainly bear the load weight and are located near the hip joint, so that the center of gravity of the power knee joint exoskeleton is moved upwards, so that the comfort and stability during use are guaranteed. The strip-shaped through holes on both sides of the mounting plate of the exoskeleton thigh support plate are used for fixing the exoskeleton on the hip of the user by using the belt, so as to prevent the exoskeleton from moving downward during movement.

[0066] In the case of knee extension movement, the joint motor 12 drives the output rocker arm 10 to swing downward after amplifying the torque through the gear box reducer 2, and then converts it into downward linear motion through the long connecting rod 902, and transmits power to the series elastic unit 9 in the connecting rod direction, the elastic element in the series elastic unit 9 is compressed, and the middle linear slider 9011 is driven to move, at this time, the displacement sensor 906 measures the displacement, and then calculates the joint torque, and transmits the power downward, and transmits to the exoskeleton lower leg 7 in the direction of the short connecting rod 908, and drives the knee joint to extend.

[0067] In the case of knee extension movement, the joint motor 12 drives the output rocker arm 10 to swing downward after amplifying the torque through the gear box reducer 2, and then converts it into downward linear motion through the long connecting rod 902, and transmits power to the series elastic unit 9 in the connecting rod direction, the elastic element in the series elastic unit 9 is compressed, and the middle linear slider 9011 is driven to move, at this time, the displacement sensor 906 measures the displacement, and then calculates the joint torque, and transmits the power downward, and transmits to the exoskeleton lower leg 7 in the direction of the short connecting rod 908, and drives the knee joint to extend.

[0068] The present application only provides a basic structure of a power knee joint exoskeleton walking aid device, and the control method of the main control unit 1, the gear box reducer 2, the angle encoder 5 and the joint motor 12 is not within the protection scope of the present application.

[0069] The unmentioned part of the present application is applicable to the prior art.

Claims

1. A powered knee joint exoskeleton walking aid device, characterized in that: The powered knee exoskeleton walking aid device includes a main control unit, a gearbox reducer, a thigh brace, a calf brace, an exoskeleton thigh, an exoskeleton calf, an angle encoder, an exoskeleton knee joint, a joint motor, an output rocker arm, and a series elastic unit. The exoskeleton thigh includes an exoskeleton thigh support plate, a No. 1 sheet metal fixing, and quick-press screws. The upper portion of the exoskeleton thigh support plate is a mounting plate with several screw holes arranged in the middle from top to bottom, and strip-shaped through holes arranged on the upper and lower sides of the left and right sides. The middle portion is a connecting plate with several screw holes. The middle portion of the lower portion has a concave step hole arranged in the middle of the outer side surface at the end, and several screw holes are arranged inside and around the concave step hole. The upper, middle, and lower portions of the exoskeleton thigh support plate are connected together. One end of the No. 1 sheet metal fastener is fixed to the upper inner portion of the connecting plate of the exoskeleton thigh support plate, and the other end thereof is provided with a groove. One end of the quick-press screw is fixedly mounted on the thigh brace, and the other end thereof is disposed in the groove of the No. 1 sheet metal fastener, with the two ends connected to secure the thigh brace to the No. 1 sheet metal fastener. The main control unit is fixed to the upper portion of the mounting plate of the exoskeleton thigh support plate via screws, and the gearbox reducer is fixed to the lower portion of the mounting plate via screws. The gearbox reducer includes a primary gear body, a secondary gear body, a tertiary gear body, a carrier plate, and a cover plate. The carrier plate is provided with a plurality of connection holes at the top and bottom, a plurality of mounting holes in the middle thereof from top to bottom, and a plurality of fixing holes on the left and right sides thereof. The connection holes at the top and bottom are used for fixing the carrier plate to the mounting plate of the exoskeleton thigh support plate via screws, and the fixing holes on the left and right sides are used for fixing the cover plate to the carrier plate. The middle mounting hole is used to install the joint motor, first-stage gear body, second-stage gear body, and third-stage gear body; The joint motor is fixedly mounted on the upper middle portion of the carrier plate, with its output shaft arranged horizontally and facing outwards, and a transmission gear is fixedly mounted on the output shaft via a shaft key; A first-stage gear body, a second-stage gear body, and a third-stage gear body are installed on the carrier plate below the joint motor in order from top to bottom; the first-stage gear body includes a gear shaft, a coaxially fixed large gear and a small gear of different sizes, and two sets of No. 1 flange bearings and a No. 1 gear shaft isolation sleeve; the second-stage gear body includes a gear shaft, a coaxially fixed large gear and a small gear of different sizes, and two sets of No. 2 flange bearings and a No. 2 gear shaft isolation sleeve; the third-stage gear body includes a gear shaft, a gear fixed on the gear shaft, two No. 3 flange bearings, a No. 3 gear shaft isolation sleeve, and an output flange plate; A number of mounting holes are provided in the middle of the cover plate, and the first-stage gear body, the second-stage gear body, and the third-stage gear body are arranged between the cover plate and the carrier plate through corresponding flange bearings, and the gear shafts of the three gear bodies are parallel to the output shaft of the joint motor; wherein the first-stage gear body and the second-stage gear body realize their respective axial positioning through corresponding gear shaft isolation sleeves, and the third-stage gear body realizes its axial positioning through a third gear shaft isolation sleeve and an output flange; a threaded hole is provided on the end face of the shaft of the third-stage gear body facing outward, and the output flange is a connecting component with a connecting hole provided in the middle and a connecting hole also provided on the outer ring; the output flange is provided on the outside of the third flange bearing on the side of the threaded hole provided on the end face of the shaft of the third-stage gear body, and is fixedly connected to the end face of the shaft of the third-stage gear body facing outward by installing screws in the connecting hole in the middle thereof; The large gear of the first-stage gear body is meshed with the transmission gear fixed on the output shaft of the joint motor, the small gear of the first-stage gear body is meshed with the large gear of the second-stage gear body, and the small gear of the second-stage gear body is meshed with the gear of the third-stage gear body; One end of the output rocker arm is provided with a circle of connecting holes, and the other end thereof is provided with a connecting hole. The end provided with the circle of connecting holes is fixedly connected to the outer ring of the output flange by screws, and the end provided with the connecting hole is fixedly connected to the series elastic unit by bolts; The series elastic unit includes an upper fisheye joint, a lower fisheye joint, a long connecting rod, a short connecting rod, a linear slide rail, an upper linear slider, a middle linear slider, a lower linear slider, an upper slide rail fixing part, a middle slide rail fixing part, a lower slide rail fixing part, an upper linear spring, a lower linear spring, and a displacement sensor; the upper fisheye joint is fixed to the top of the long connecting rod, the lower fisheye joint is fixed to the end of the short connecting rod, the long connecting rod is fixedly connected to the lower end of the output rocker arm through the upper fisheye joint by bolts, and the short connecting rod is fixedly connected to the exoskeleton shank through the lower fisheye joint by bolts; The two linear slide rails are symmetrically arranged on both sides of the short connecting rod, and an upper linear slider, a middle linear slider and a lower linear slider are sequentially arranged on each linear slide rail from top to bottom; the upper slide rail fixing piece, the middle slide rail fixing piece and the lower slide rail fixing piece are all structures with a through hole in the middle and accommodating openings on the left and right sides, wherein the middle through hole of the upper slide rail fixing piece is a threaded hole, and spring guide columns extend axially from the upper and lower sides of the middle through hole of the middle slide rail fixing piece, and the inner side of the spring guide column on the lower side is a threaded hole, and the middle through hole of the lower slide rail fixing piece is a smooth hole; the two upper linear sliders are symmetrically fixed in the two accommodating openings of the upper slide rail fixing piece by screws, the two middle linear sliders are symmetrically fixed in the two accommodating openings of the middle slide rail fixing piece by screws, and the two lower linear sliders are symmetrically fixed in the two accommodating openings of the lower linear slide rail fixing piece by screws; The lower part of the long connecting rod is fixed in the threaded hole of the upper slide rail fixing piece by means of a thread; the upper linear spring and the lower linear spring are respectively arranged on the spring guide posts on the upper and lower sides of the middle slide rail fixing piece; the upper part of the short connecting rod passes through the middle through-hole of the lower slide rail fixing piece and is fixedly connected to the spring guide post on the lower side of the middle slide rail fixing piece by means of a thread; when in use, the upper and lower linear springs are always in a state of one being stretched and the other being compressed; The compression directions of the upper and lower linear springs are parallel to the linear guide rails. The carbon fiber plate and the resin base plate are fixed together with screws to the upper and lower slide rail fixings. A detection hole and a mounting hole are provided on the carbon fiber plate directly opposite the middle slide rail fixing. The displacement sensor is fixed to the carbon fiber plate outside the middle slide rail fixing by screws, with its sensing probe facing the inside of the detection hole. The displacement sensor is used to measure the displacement of the middle slide rail fixing, that is, the displacement of the middle linear slider. The exoskeleton knee joint includes a crossed roller bearing, an aluminum column, an angle encoder fixing plate, an encoder fixing flange, and a knee joint angle limit block. The lower part of the exoskeleton thigh support plate of the exoskeleton thigh and the top of the exoskeleton calf are connected via a crossed roller bearing. The aluminum column is used to fix the angle encoder fixing plate to the exoskeleton thigh support plate. The angle encoder is located at the exoskeleton knee joint and is fixed to the angle encoder fixing plate via an encoder fixing flange and screws. The angle encoder is coaxial with the crossed roller bearing and is used to measure the rotation angle of the knee joint. The knee joint angle limit block is fixedly arranged at the lower position of the exoskeleton thigh support plate on one side of the crossed roller bearing, and its lower edge plane is parallel to the lower end face of the exoskeleton thigh support plate. The exoskeleton calf includes an exoskeleton calf support plate, a calf brace relay printout, a calf brace relay plate, a No. 2 sheet metal fixing and quick-press screws. The top of the exoskeleton calf support plate is connected to the lower part of the exoskeleton thigh support plate through a cross roller bearing; a calf brace relay printout is provided between the lower part of the exoskeleton calf support plate and the upper part of a calf brace relay plate, and the three are fixed together by screws; a number of mounting holes are provided on the calf brace relay plate, one end of the No. 2 sheet metal fixing is fixedly connected to the calf brace relay plate, and the other end is provided with a groove, and the calf brace is fixed to the groove of the No. 2 sheet metal fixing by a quick-press screw; When wearing the powered knee exoskeleton walking aid, a strap is used to fix the mounting plate of the exoskeleton thigh support plate to the user's hip, so that the gearbox reducer on the mounting plate of the exoskeleton thigh support plate and the joint motor on the carrier plate of the gearbox reducer are located near the hip joint; compared with the traditional knee joint direct-drive exoskeleton, the powered knee exoskeleton walking aid raises the position of the gearbox reducer on the mounting plate of the exoskeleton thigh support plate and the joint motor on the carrier plate of the gearbox reducer, which account for the main load weight, so that most of the weight of the powered knee exoskeleton walking aid is located near the hip joint, which is the center of rotation of the trunk and lower limb movements, thereby reducing the rotational inertia of the knee exoskeleton human-machine coupling system.

2. A powered knee joint exoskeleton walking aid device according to claim 1, characterized in that: The transmission gear includes a motor shaft gear, a motor shaft isolation sleeve and a shaft end cover, wherein a keyway is provided inside the motor shaft gear, and an axial hole is provided in the middle of the motor shaft isolation sleeve and the shaft end cover. The two are fixed on the two outer sides of the axial hole of the motor shaft gear through a threaded structure to realize axial fixation of the motor shaft gear.

3. The powered knee exoskeleton walking aid device according to claim 1, characterized in that: The knee joint angle limit block is semi-annular and coaxial with the cross roller bearing.

4. The powered knee exoskeleton walking aid device according to claim 3, characterized in that: The knee joint angle limiter is made of carbon fiber material.

5. The powered knee joint exoskeleton walking aid device according to claim 1, characterized in that: The thigh brace and calf brace are made of resin material and are ergonomically designed. Both are provided with strap holes on their front edges and assembly holes on their back sides.

6. The powered knee exoskeleton walking aid device according to claim 1, characterized in that: In the series elastic unit, the upper linear spring and the lower linear spring arranged on both sides of the middle linear slider are respectively installed between the middle linear slider and the upper slide rail fixing piece and between the middle linear slider and the lower slide rail fixing piece by a pressing and fixing method.

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