Lower extremity powered exoskeleton device for rehabilitation assistance

Abstract

The application discloses a lower limb power exoskeleton device for rehabilitation assistance, which comprises an ankle joint sagittal plane driving unit, a knee joint sagittal plane driving unit, a hip joint sagittal plane driving unit, a hip joint horizontal plane driving unit, a joint driver connecting frame, a lower limb fixing support, a sensor, a controller and a power supply; the hip joint sagittal plane adopts an antagonistic driving linear driving unit to realize the bending and stretching movement of the hip joint; the hip joint horizontal plane adopts a linear driving unit with a power-off self-locking function to realize the turning movement of the exoskeleton; and the knee joint sagittal plane adopts a linear driving unit matched with a magneto-rheological brake, so that the power consumption of the knee joint driver is obviously reduced and the control difficulty is simplified. The power exoskeleton device can help the lower limb movement function impaired patients to realize walking rehabilitation training.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of lower limb exoskeleton devices, and relates to a lower limb powered exoskeleton device for rehabilitation assistance. BACKGROUND

[0002] Due to stroke, brain injury, spinal cord injury, and physiological or pathological aging, patients with nervous system diseases or the elderly have varying degrees of motor dysfunction, and the quality of life is significantly reduced. Therefore, there is a large demand for motor rehabilitation for people with motor dysfunction.

[0003] In order to meet the needs of the above-mentioned population, researchers and rehabilitation medical companies have developed many lower limb rehabilitation exoskeleton devices to help people with impaired motor function, such as stroke patients and the elderly, to perform rehabilitation training. However, the existing lower limb rehabilitation exoskeleton devices have many problems, and there is a big difference between the engineering practicability and the wearer's expectations, which leads to the fact that the lower limb exoskeleton cannot be widely popularized and applied.

[0004] The existing lower limb exoskeleton is out of balance between flexibility and weight. For example, to increase flexibility, more driving devices are added, which makes the overall mass of the lower limb rehabilitation exoskeleton too large, and requires the help of professional personnel to wear, which makes the user unable to use the lower limb exoskeleton device independently, and affects the time and comfort of the wearer, and the motor rehabilitation effect is not ideal. Some lower limb exoskeleton rehabilitation robots cannot help users complete complex movements to reduce the flexibility of users using the lower limb exoskeleton. Most of the existing lower limb exoskeletons cannot actively realize the turning walking function, which will significantly reduce the user experience and practicability of the wearer in daily life, SUMMARY

[0005] Therefore, the present application provides a lower limb powered exoskeleton device for rehabilitation assistance, which adopts bionic design to propose an intelligent joint driver according to the movement characteristics of each joint of the lower limb, thereby greatly reducing the power consumption of the joint driver, simplifying the mass and control difficulty of the controller, and improving the engineering practicability of the device. At the same time, the present application improves the active turning of the lower limb exoskeleton, and realizes the turning movement of the exoskeleton by skillfully introducing degrees of freedom and corresponding drivers in the horizontal plane.

[0006] In order to solve the above problems, the embodiment of the present application provides a lower limb powered exoskeleton device for rehabilitation assistance, which is characterized in that it comprises:

[0007] The ankle joint sagittal plane driving unit is one of a main driving unit, a semi-passive driving unit, and a passive driving unit, and realizes joint driving of the ankle joint in the sagittal plane.

[0008] A sagittal plane driving unit of the knee joint, which is one of an active driving unit and a semi-passive driving unit, and realizes joint driving of the knee joint in the sagittal plane;

[0009] A sagittal plane driving unit of the hip joint, which is an active driving unit, and realizes joint driving of the hip joint in the sagittal plane;

[0010] A horizontal plane driving unit of the hip joint, which is one of an active driving unit and a passive driving unit, and realizes joint driving of the hip joint in the horizontal plane;

[0011] A joint driver connecting frame, which includes a waist connecting frame, a thigh connecting frame and a shank connecting frame, and connects and fixes the sagittal plane driving unit of the ankle joint, the sagittal plane driving unit of the knee joint, the sagittal plane driving unit of the hip joint and the horizontal plane driving unit of the hip joint;

[0012] A lower limb fixing support, which includes a waist fixing support, a thigh fixing support, a shank fixing support and a foot fixing support, and is used for fixing the waist, the lower limb thigh, the shank and the foot plate of a wearer of the exoskeleton device to the exoskeleton device;

[0013] A sensor, which is installed on the exoskeleton device and the wearer of the exoskeleton device, and is used for detecting the motion state of the exoskeleton and decoding the motion intention of the wearer of the exoskeleton;

[0014] A controller, which is used for controlling the motion angle, the angular velocity and the output torque of the sagittal plane driving unit of the ankle joint, the sagittal plane driving unit of the knee joint, the sagittal plane driving unit of the hip joint and the horizontal plane driving unit of the hip joint;

[0015] A power supply, which is used for supplying power to the driving unit, the sensor and the controller of the exoskeleton device.

[0016] Further, the waist fixing support is fixed on the waist connecting frame, the thigh fixing support is fixed on the thigh connecting frame, the shank fixing support is fixed on the shank connecting frame, and the foot fixing support is connected to the shank connecting frame through the sagittal plane driving unit of the ankle joint.

[0017] Further, the waist connecting frame and the thigh connecting frame are connected through one of a planar hinge and a spherical surface, and the thigh connecting frame and the shank connecting frame are connected through a planar hinge.

[0018] Further, the hip joint sagittal plane driving unit is driven by two antagonistically arranged linear drives, the linear drives contain DC motors, the DC motors cooperate with threaded rod transmission, while having displacement feedback and force feedback, the linear drives form a crank slider structure with the waist connecting frame and the thigh connecting frame, the rotation angle, angular velocity and joint torque of the hip joint in the sagittal plane can be actively controlled.

[0019] Further, the hip joint horizontal plane driving unit is an active driving unit, the driving unit is driven by two antagonistically arranged linear drives, the linear drives contain DC motors, the DC motors cooperate with threaded rod transmission, while having displacement feedback and force feedback, the linear drives form a crank slider structure with the waist connecting frame and the thigh connecting frame, the rotation angle, angular velocity and joint torque of the hip joint in the horizontal plane can be actively controlled, the turning motion is realized, the threaded rod transmission has the motor power-off self-locking function.

[0020] Further, the hip joint horizontal plane driving unit is a passive driving unit, the passive driving unit is driven by a return spring, the waist connecting frame and the thigh connecting frame can return to the initial relative position, the exoskeleton device can realize rotation in the horizontal plane under the active driving of the exoskeleton device wearer.

[0021] The return spring in the passive driving unit is one of a linear spring, a torsional spring and a pneumatic spring.

[0022] Further, the knee joint sagittal plane driving unit is an active driving unit, the driving unit is driven by two antagonistically arranged linear drives, the linear drives contain DC motors, the DC motors cooperate with threaded rod transmission, while having displacement feedback and force feedback, the linear drives form a crank slider structure with the thigh connecting frame and the shank connecting frame, the rotation angle, angular velocity and joint torque of the knee joint in the sagittal plane can be actively controlled.

[0023] Further, the knee joint sagittal plane driving unit is an active driving unit, the driving unit is driven by two antagonistically arranged linear drives, the linear drives contain DC motors, the DC motors cooperate with threaded rod transmission, while having displacement feedback and force feedback, the linear drives form a crank slider structure with the thigh connecting frame and the shank connecting frame, the rotation angle, angular velocity and joint torque of the knee joint in the sagittal plane can be actively controlled.

[0024] Further, the knee sagittal plane driving unit is a semi-passive driving unit, which is driven by a magnetic control damper cooperating with a return spring. The return spring can drive the knee to return to the initial position in the sagittal plane. The magnetic control damper and the thigh connecting frame and the lower leg connecting frame form a crank slider structure. By controlling the excitation current of the magnetic control damper, the rotation angle, angular velocity and joint torque of the knee in the sagittal plane bending and stretching can be passively controlled.

[0025] Further, the ankle sagittal plane driving unit is an active driving unit, which is composed of one of a DC motor, a gear reducer and a harmonic reducer. The active driving unit can actively control the rotation angle, angular velocity and output torque of the ankle in the sagittal plane.

[0026] Further, the ankle sagittal plane driving unit is a semi-passive unit, which is driven by a magnetic control damper cooperating with a return spring. The return spring can drive the knee to return to the initial position in the sagittal plane. The magnetic control damper and the thigh connecting frame and the lower leg connecting frame form a crank slider structure. By controlling the excitation current of the magnetic control damper, the rotation angle, angular velocity and joint torque of the knee in the sagittal plane bending and stretching can be passively controlled.

[0027] Further, the ankle sagittal plane driving unit is a passive driving unit, which is composed of a return spring. The return spring can help the relative angle of the lower leg connecting frame and the foot palm fixed support to return to the initial position. The lower leg connecting frame and the foot palm fixed support are connected through a planar hinge.

[0028] The return spring in the passive driving unit is one of a linear spring, a torsional spring and a pneumatic spring.

[0029] Further, the lower limb fixed support is used to fix the lower limb exoskeleton device and the lower limb exoskeleton device wearer. In order to improve the wearing comfort, the fixed support is firm, and the contact stress concentration is reduced. The lower limb fixed support is prepared by using a negative Poisson's ratio intelligent structure unit in part of the force bearing area.

[0030] Further, the inner surface of the lower limb fixed support is integrated with a curved surface pressure measuring unit. The pressure measuring unit measures the contact stress between the lower limb exoskeleton device and the lower limb exoskeleton device wearer. The measured contact stress can be used to quantify the wearing comfort of the lower limb fixed support, and can also be used to decode the motion intention of the lower limb exoskeleton wearer.

[0031] Further, the sensor comprises a lower limb electromyography sensor (EMG), a joint angle sensor, a pressure sensor distributed on the lower limb fixing support, a pressure measuring unit distributed on the lower limb fixing support, and an inertial measurement unit (IMU) installed on the lower limb sole, calf, thigh and waist.

[0032] Further, the lower limb electromyography sensor (EMG) is used to detect the electromyography signal of the muscle of the lower limb exoskeleton wearer, thereby decoding the motion intention of the wearer, quantifying the rehabilitation effect of the wearer, and detecting the muscle movement fatigue information of the lower limb.

[0033] The pressure measuring unit distributed on the lower limb fixing support is used to detect the interaction force and torque between the above-mentioned exoskeleton and the wearer's limb, including the interaction force and torque between the fixing support and the user's thigh and calf, and the interaction force and torque between the user's metatarsal bottom and the lower limb exoskeleton foot bottom support plate; the inertial measurement unit is used to feedback the motion information of the lower limb exoskeleton device, including the motion direction, motion speed, motion acceleration, angle and angular velocity.

[0034] The controller identifies the motion intention of the user based on the signals obtained by the angle sensor, pressure sensor and electromyography signal detection sensor, and further controls the output torque of each direct current motor and damper of the lower limb exoskeleton device, so as to control the motion trajectory and motion posture of the hip joint, knee joint, ankle joint, thigh structure and calf structure of the lower limb exoskeleton device.

[0035] The pressure sensor is installed on the inner side of the fixing support and the foot bottom support plate, and is used to measure the interaction force between the user and the fixing support and the interaction force between the user and the ground.

[0036] The controller is used to control the hip joint, knee joint and ankle joint of the lower limb exoskeleton device to rotate according to the set direction, angle, angular velocity and angular acceleration, control the thigh structure and calf structure to swing according to the set posture, and control the interaction force and torque between the fixing support and the wearer of the lower limb exoskeleton device.

[0037] Compared with the prior art, the lower limb power exoskeleton device for rehabilitation assistance has at least the following beneficial effects:

[0038] 1) The lower limb power exoskeleton device is used to help the lower limb movement function impaired patients, such as lower limb stroke patients, to realize walking rehabilitation training, so that each joint of the lower limb realizes corresponding movement function, provides assistance to the patients, and makes the patients more easily complete standing, walking, turning around, sitting down and other actions;

[0039] 2) The lower limb power exoskeleton device is directed to the movement characteristics of each joint of the lower limb, an intelligent joint driver is proposed by adopting bionic design, so that the power consumption of the joint driver is greatly reduced, the mass and control difficulty of the controller are simplified, and the engineering practical performance of the device is improved. Meanwhile, the active turning of the lower limb exoskeleton is improved, the turning movement of the exoskeleton is realized by introducing the freedom and the corresponding driver in the horizontal plane skillfully.

[0040] 3) The sagittal plane of the hip joint of the lower limb power exoskeleton device adopts an antagonistic driving linear driving unit to realize the flexion and extension movement of the hip joint, the horizontal plane of the hip joint adopts a linear driving unit with power-off self-locking function to realize the turning movement of the exoskeleton, the sagittal plane of the knee joint adopts a linear driving unit cooperating with a magneto-rheological brake, the driving mode can obviously reduce the power consumption of the knee joint driver and simplify the control difficulty. In addition, in order to improve the man-machine interaction performance of the exoskeleton device and the wearer, the lower limb fixing support of the exoskeleton is improved, and an intelligent structure unit and a curved surface stress detection are introduced. The power exoskeleton device is mainly used for helping patients with impaired lower limb movement function, such as lower limb stroke patients, to realize walking rehabilitation training.

[0041] The above description is only a summary of the technical scheme of the present application. In order to more clearly understand the technical means of the present application, and can be implemented according to the content of the specification, the following will be described in detail with the preferred embodiments of the present application and with the help of the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the technical scheme of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creating any creative labor.

[0043] Figure 1 It is a front overall structure schematic view of the present application;

[0044] Figure 2 It is a back overall structure schematic view of the present application;

[0045] Figure 3 It is a side overall structure schematic view of the present application;

[0046] Figure 4 It is a hip joint horizontal plane active driving unit structure schematic view of the present application;

[0047] Figure 5 It is a hip joint horizontal plane passive driving unit structure schematic view of the present application;

[0048] Figure 6Structure and movement schematic diagram of hip joint sagittal plane active driving unit in the application;

[0049] Figure 7 Structure schematic diagram of knee joint sagittal plane active driving unit in the application;

[0050] Figure 8 Structure schematic diagram of knee joint sagittal plane passive driving unit in the application;

[0051] Figure 9 Structure schematic diagram of ankle joint sagittal plane active driving unit in the application;

[0052] Figure 10 Structure schematic diagram of ankle joint sagittal plane semi-passive driving unit in the application;

[0053] Figure 11 Structure schematic diagram of ankle joint sagittal plane passive driving unit in the application;

[0054] Figure 12 Schematic diagram of lower leg fixing support in the application;

[0055] Figure 13 Structure schematic diagram of linear driver in the application;

[0056] Figure 14 Structure schematic diagram of magnetic control damping driver in the application;

[0057] Figure 15 Structure schematic diagram of return spring driver in the application;

[0058] Figure 16 Schematic diagram of one complete gait cycle movement of lower limb power exoskeleton device for rehabilitation assistance;

[0059] Figure 17 Schematic diagram of hip joint, knee joint and ankle joint sagittal plane angle change of human body complete gait cycle (walking on ground force plate);

[0060] Figure 18 Schematic diagram of hip joint, knee joint and ankle joint moment of force change of human body complete gait cycle (walking on ground force plate);

[0061] Figure 19 Schematic diagram of hip joint, knee joint and ankle joint power change of human body complete gait cycle (walking on ground force plate);

[0062] Figure 20 Schematic diagram of ground force plate reaction force change of human body gait cycle (normal person walking on ground force plate);

[0063] Wherein: 1, control backpack; 2, waist fixed support; 3, thigh fixed support; 4, third DC motor 4; 5, seventh DC motor; 6, calf fixed support; 7, ninth DC motor; 8, fifth DC motor; 9, eighth DC motor; 10, tenth DC motor; 11, first DC motor; 12, fourth DC motor; 13, first magnetic control damper; 14, second DC motor; 15, sixth DC motor; 16, second magnetic control damper; 17, stopper; 18, threaded screw; 19, force sensor; 20, magnetorheological fluid valve; 21, magnetorheological fluid guide pipe; 22, hydraulic cylinder; 23, return spring; 24, flexible pressure sensor; 25, negative Poisson's ratio intelligent structure unit. DETAILED DESCRIPTION

[0064] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application. The present application is intended to be more generally applied to rehabilitation exoskeleton robots, and thus the present application can be used in any practical application as required for specific applications.

[0065] The present application provides a lower limb powered exoskeleton device for rehabilitation assistance, and the hardware part of the lower limb exoskeleton device comprises: a hip joint horizontal plane driving unit, a hip joint sagittal plane driving unit, a knee joint sagittal plane driving unit, an ankle joint sagittal plane driving unit, a joint driver connecting frame, a lower limb fixed support, a sensor, a controller and a power supply.

[0066] The ankle joint sagittal plane driving unit is used to realize the joint driving of the ankle joint in the sagittal plane; the knee joint sagittal plane driving unit realizes the joint driving of the knee joint in the sagittal plane; the hip joint sagittal plane driving unit realizes the joint driving of the hip joint in the sagittal plane; and the hip joint horizontal plane driving unit realizes the joint driving of the hip joint in the horizontal plane.

[0067] The joint driver connecting frame comprises a waist connecting frame, a thigh connecting frame and a calf connecting frame, and the joint driver connecting frame connects and fixes the ankle joint sagittal plane driving unit, the knee joint sagittal plane driving unit, the hip joint sagittal plane driving unit and the hip joint horizontal plane driving unit.

[0068] The lower limb fixing support includes a waist fixing support, a thigh fixing support, a lower leg fixing support and a foot fixing support, which are used to fix the waist, the lower limbs, the thighs, the lower legs and the foot plates of the wearer of the exoskeleton device. The sensors are installed on the exoskeleton device and the wearer of the exoskeleton device, and are used to detect the motion state of the exoskeleton and decode the motion intention of the wearer of the exoskeleton; the controller is used to control the motion angle, the angular velocity and the output torque of the sagittal plane driving units of the ankle joint, the knee joint, the hip joint and the horizontal plane driving unit of the hip joint; and the power supply is used to supply power to the driving units, the sensors and the controller of the exoskeleton device.

[0069] Specifically, referring to Figure 1 , the control backpack 1 is installed at a fixed position of the back support plate through the connecting piece, and the control backpack is provided with a signal processing module, a controller, a driving module and a power supply. The back support plate is fixed on the waist fixing support 2.

[0070] As a preferred embodiment of the present application, the horizontal plane driving unit of the hip joint can be an active driving unit or a passive driving unit,

[0071] Specifically, referring to Figure 2 and Figure 4 , when the horizontal plane driving unit of the hip joint is an active driving unit, the horizontal plane active driving unit of the hip joint is composed of two antagonistically arranged linear drives, referring to Figure 13 , the two linear drives are respectively composed of a first DC motor 11 cooperating with a threaded screw rod 18 and a second DC motor 14 cooperating with a threaded screw rod 18, and the linear drives are respectively connected to the waist fixing support 2 and the waist connecting frame through joint bearings, forming a crank slider structure. The rotational torque or holding torque dynamically output by the first DC motor 11 and the second DC motor 14 is transmitted through the threaded screw rod 18, which is used to drive the internal rotation and external rotation of the horizontal plane of the lower limb exoskeleton device, or to maintain the standing lock state of the horizontal plane of the wearer's hip joint, actively controlling the rotation angle, angular velocity and joint torque of the above-mentioned horizontal plane of the hip joint. For example, when a stroke patient wears the above-mentioned lower limb exoskeleton device to turn right, the first DC motor 11 rotates forward to provide a rotational torque, which is linearly displaced forward through the threaded screw rod 18 to drive the hip joint on one side of the lower limb exoskeleton device to rotate outward in the horizontal plane, and the second DC motor 14 rotates reversely to provide a reverse rotational torque, which is linearly displaced reversely through the threaded screw rod 18 to drive the hip joint on the other side of the lower limb exoskeleton device to rotate inward in the horizontal plane, so as to control the exoskeleton hip joint to rotate to a predetermined position in the horizontal plane. During the rotation, the waist fixing support of the lower limb exoskeleton device transmits motion assistance to the user, helping the user to complete the turning action.

[0072] Specifically, referring to Figure 5 andFigure 15 , the hip joint horizontal plane driving unit is a passive driving unit driven by a return spring connected to the waist fixed support 2 and the waist connecting frame through a joint bearing, so as to return the waist connecting frame and the thigh connecting frame to the initial relative position, and the exoskeleton device can rotate in the horizontal plane under the active driving of the exoskeleton device wearer. The return spring in the passive driving unit can be any one of a linear spring, a torsional spring and a pneumatic spring.

[0073] As a preferred embodiment of the present application, the hip joint sagittal plane driving unit is an active driving unit.

[0074] Specifically, referring to Figures 1-3 and Figure 6 , the hip joint sagittal plane active driving unit is located on both sides of the device, each hip joint sagittal plane active driving unit is composed of two antagonistically arranged linear drives, one side hip joint sagittal plane driving unit is driven by the third DC motor 4 and the fourth DC motor 12 cooperating with the threaded screw rod 18, the other side hip joint sagittal plane driving unit is driven by the fifth DC motor 8 and the sixth DC motor 15 cooperating with the threaded screw rod 18, the linear drive connecting the waist connecting frame and the thigh connecting frame forms a crank slider structure, the third DC motor 4, the fourth DC motor 12, the fifth DC motor 8 and the sixth DC motor 15 dynamically output rotation torque or holding torque through the threaded screw rod 18, for driving the hip joint of the lower extremity exoskeleton device to rotate smoothly in the sagittal plane, or keeping the hip joint standing in the sagittal plane, actively controlling the rotation angle, angular velocity and joint torque of the above-mentioned hip joint sagittal plane. For example, referring to Figure 6 , when the stroke patient wears the above-mentioned lower extremity exoskeleton device to walk, the third DC motor 4 rotates in the forward direction to provide rotation torque, the fourth DC motor 12 rotates in the reverse direction to provide reverse rotation torque, driving the lower extremity exoskeleton device one side hip joint to swing forward in the sagittal plane to a predetermined position, the fifth DC motor 8 rotates in the forward direction to provide rotation torque, the sixth DC motor 15 rotates in the reverse direction to provide reverse rotation torque, driving the lower extremity exoskeleton device the other side hip joint to swing backward in the sagittal plane to a predetermined position, the two sides of the hip joint alternately enter the swing phase and the support phase in the sagittal plane.

[0075] Specifically, referring to Figure 4 and Figure 5 , the waist fixed support and the waist connecting frame are connected through a plane hinge.

[0076] As a preferred embodiment of the present application, the knee joint sagittal plane driving unit is an active driving unit or a semi-passive driving unit.

[0077] Specifically, referring to Figure 2 , Figure 3 ,Figure 7 、 Figure 13 and Figure 14 , the knee sagittal plane active driving unit is composed of antagonistically arranged linear driving units and magnetic control dampers, one side knee sagittal plane driving unit is composed of the seventh DC motor matched with threaded rod 18 transmission and the first magnetic control damper 13 driving, the other side knee sagittal plane driving unit is composed of the eighth DC motor matched with threaded rod 18 transmission and the second magnetic control damper 16 driving, the linear driver connects the thigh connecting frame and the shank connecting frame through the joint bearing to form a crank slider structure, the DC motor transmits the dynamic output holding torque or output torque through the threaded rod 18, which is used to keep the knee joint of the lower extremity exoskeleton device standing lock or smooth swing in the sagittal plane, and actively controls the rotation angle, angular velocity and joint torque of the above-mentioned knee sagittal plane. For example, when the stroke patient wears the above-mentioned lower extremity exoskeleton device to walk, the seventh DC motor rotates in the positive direction to provide a rotary torque, drives one side knee joint of the lower extremity exoskeleton device to swing in the sagittal plane to a predetermined position, the eighth DC motor rotates in the reverse direction to provide a reverse rotary torque, drives the other side knee joint of the lower extremity exoskeleton device to swing in the sagittal plane to a predetermined position, so that the two sides of the shank structure alternately swing in phase and support phase.

[0078] Referring to Figure 2 and Figure 7 , the first magnetic control damper 13 and the second magnetic control damper 16 are matched with the slide rod transmission to form a magnetic control damper driving unit, the magnetic control damper driving unit connects the thigh connecting frame and the shank connecting frame of the lower extremity exoskeleton device through the joint bearing to form a crank slider structure, the first magnetic control damper 13 driving unit and the seventh linear driver are arranged in opposition on one side, the second magnetic control damper 16 driving unit and the eighth linear driver are arranged in opposition on the other side, the magnetic control damper outputs static damping force or dynamic damping force, which is used to keep the knee joint of the lower extremity exoskeleton in the sagittal plane to lock or swing smoothly, and passively controls the rotation angle, angular velocity and joint torque of the hip joint in the sagittal plane by controlling the excitation current of the magnetic control damper.

[0079] Specifically, referring to Figure 8 , when the knee sagittal plane driving unit is a semi-passive driving unit, it is driven by a magnetic control damper matched with a return spring, the return spring can drive the knee joint to return to the initial position in the sagittal plane, the magnetic control damper forms a crank slider structure with the thigh connecting frame and the shank connecting frame, and the rotation angle, angular velocity and joint torque of the knee joint when bending and stretching in the sagittal plane can be passively controlled by controlling the excitation current of the magnetic control damper.

[0080] As a preferred embodiment of the present application, the sagittal plane driving unit of the ankle joint can be an active driving unit, which is composed of one of a DC motor, a gear reducer and a harmonic reducer, and can actively control the rotation angle, angular velocity and output torque of the ankle joint in the sagittal plane.

[0081] Specifically, referring to Figure 9 , the active driving unit is composed of the ninth DC motor 7 or the tenth DC motor 10 in combination with a gear reducer. The active driving unit of the ankle joint in the sagittal plane is fixed to the end of the lower limb exoskeleton device calf support plate, dynamically outputs a holding torque and a rotary torque, and is used for maintaining the standing lock of the lower limb exoskeleton ankle joint or for driving the rotation of the lower limb exoskeleton device ankle joint in the sagittal plane. The active driving unit actively controls the rotation angle, angular velocity and joint torque of the ankle joint in the sagittal plane.

[0082] As a preferred embodiment of the present application, referring to Figure 10 , the sagittal plane driving unit of the ankle joint can also be a semi-passive unit driven by a magnetic control damper in combination with a return spring 23. The magnetic control damper includes a magnetorheological fluid valve 20, a magnetorheological fluid guide pipe 21 and a hydraulic cylinder 22. The return spring 23 drives the knee joint to return to the initial position in the sagittal plane extension. The magnetic control damper forms a crank slider structure with the calf connecting frame and the foot sole fixed support, wherein the calf connecting frame is connected with the foot sole fixed support through a planar hinge. By controlling the excitation current of the magnetic control damper, the rotation angle, angular velocity and joint torque of the ankle joint during flexion and extension in the sagittal plane can be passively controlled.

[0083] As a preferred embodiment of the present application, referring to Figure 11 , the sagittal plane driving unit of the ankle joint can also be a passive driving unit, which includes two symmetrical return springs. The return springs can help the relative angle of the calf connecting frame and the foot sole fixed support to return to the initial position. The calf connecting frame is connected with the foot sole fixed support through a planar hinge. The return spring in the passive driving unit can be any one of a linear spring, a torsional spring and a pneumatic spring.

[0084] As a preferred embodiment of the present application, the inner surface of the lower limb fixed support is integrated with a curved surface pressure measuring unit. The pressure measuring unit measures the contact stress between the lower limb exoskeleton device and the wearer of the lower limb exoskeleton device. The measured contact stress can be used to quantify the wearing comfort of the lower limb fixed support, and can also be used to decode the motion intention of the wearer of the lower limb exoskeleton.

[0085] Specifically, the sensor includes lower limb electromyography sensor (EMG), individual joint angle sensor, pressure sensor distributed on the lower limb fixed support, pressure measuring unit distributed on the lower limb fixed support, and inertial measurement unit (IMU) installed on the sole of the lower limb, calf, thigh and waist, etc.

[0086] Further, the lower limb electromyography sensor (EMG) is used to detect the electromyography signal of the muscle of the lower limb exoskeleton wearer, so as to decode the motion intention of the wearer, quantify the rehabilitation effect of the wearer, and detect the muscle movement fatigue information of the lower limb.

[0087] The pressure measuring unit distributed on the lower limb fixed support is used to detect the interaction force and torque between the above-mentioned exoskeleton and the wearer's limbs, including the interaction force and torque between the fixed support and the user's thigh and calf, and the interaction force and torque between the user's metatarsal bottom and the foot bottom support plate of the lower limb exoskeleton; the inertial measurement unit is used to feedback the motion information of the lower limb exoskeleton device, including the motion direction, motion speed, motion acceleration, angle, angular velocity.

[0088] The controller identifies the motion intention of the user based on the signals obtained by the angle sensor, pressure sensor and electromyography signal detection sensor, further controls the output torque of each direct current motor and damper of the lower limb exoskeleton device, controls the hip joint, knee joint and ankle joint of the lower limb exoskeleton device to rotate according to the set direction, angle, angular velocity and angular acceleration, so as to control the motion trajectory and motion posture of the hip joint, knee joint, ankle joint, thigh and calf structure of the lower limb exoskeleton device.

[0089] The pressure sensor is installed to the inner side of the fixed support and the foot bottom support plate, and is used to measure the interaction force between the user and the fixed support and the interaction force between the user and the ground.

[0090] Specifically, the foot bottom pressure sensor is fixed on the upper surface of the sole fixed support, and is used to feedback the interaction force between the foot bottom of the wearer and the sole fixed support of the lower limb exoskeleton device.

[0091] Specifically, the potentiometer is installed at the sagittal plane connection of the hip joint, the sagittal plane connection of the knee joint and the sagittal plane connection of the ankle joint, and is used to feedback the rotation angle of the sagittal plane of the hip joint, knee joint and ankle joint of the lower limb exoskeleton.

[0092] Specifically, the electromyography signal detection sensor is installed on the inner surface of the thigh fixed support 3 and the calf fixed support 6, and through signal processing and calculation, the electrical signal generated by the main muscle of the lower limb is fed back to the control backpack in real time, and the muscle strength and fatigue degree information of the wearer is obtained through decoding. Referring to Figure 12For real-time detection of the interaction force between the wearer's thigh and calf and the thigh fixing support 3 and calf fixing support 6 of the lower limb exoskeleton device, flexible pressure sensors 24 are fixed on the inner surfaces of the waist fixing support, thigh fixing support 3 and calf fixing support 6. See Figure 3 A force sensor 19 is fixed at the joint between the threaded screw rod 18 and the joint bearing, for measuring the axial force of the threaded screw rod 18 in the linear drive.

[0093] Specifically, see Figure 12 A negative Poisson ratio intelligent structure unit 25 is applied to the force sensitive area of the waist fixing support, thigh fixing support 3, calf fixing support 6 and foot fixing support, for improving the comfort of the wearer, while achieving firm fixation and reducing contact stress concentration. An inertial measurement unit is installed in the control backpack, for measuring the feedback of the movement direction, movement speed, movement acceleration, angle and angular velocity of the lower limb exoskeleton.

[0094] In summary, the lower limb dynamic exoskeleton device for rehabilitation assistance proposed in the present application improves the lower limb exoskeleton fixing support, introduces intelligent structure units and curved surface stress detection, improves the human-machine interaction performance of the exoskeleton device and the wearer, and is used to help lower limb movement function impaired patients, such as lower limb stroke patients, to achieve walking rehabilitation training. Figure 16 For a complete gait cycle motion state of the lower limb dynamic exoskeleton device for rehabilitation assistance proposed in the present application, Figures 17-19 The changes in the sagittal plane angles, joint torques and joint powers of the hip joint, knee joint and ankle joint in the complete gait cycle of the human body are shown when the device walks on the ground force plate; Figure 20 The ground force plate reaction force change graph for the human gait cycle (normal person walking on the ground force plate).

[0095] The above is only the preferred embodiment of the present application, and does not limit the present application in any form. Any simple modification, equivalent change and modification of the technical essence of the present application to the above embodiment still belongs to the scope of the technical solution of the present application.

Claims

1. A lower extremity powered exoskeleton device for rehabilitation assistance, characterized by, It comprises: Ankle sagittal plane driving unit, which is one of active driving unit, semi-passive driving unit and passive driving unit, to realize ankle joint driving in sagittal plane; Knee sagittal plane driving unit, which is one of active driving unit and semi-passive driving unit, to realize knee joint driving in sagittal plane; Hip sagittal plane driving unit, which is active driving unit, to realize hip joint driving in sagittal plane; Hip horizontal plane driving unit, which is active driving unit or passive driving unit, to realize hip joint driving in horizontal plane; the active driving unit is driven by two antagonistic linear actuators, which form a crank slider structure with the waist connecting frame and the thigh connecting frame, to actively control the rotation angle, angular velocity and joint torque of the hip joint in horizontal plane, realizing turning motion; Joint actuator connecting frame, which comprises waist connecting frame, thigh connecting frame and shank connecting frame, connecting and fixing the ankle sagittal plane driving unit, knee sagittal plane driving unit, hip sagittal plane driving unit and hip horizontal plane driving unit; Lower limb fixing support, which comprises waist fixing support, thigh fixing support, shank fixing support and foot sole fixing support, to fix the waist, thigh, shank and foot sole of the exoskeleton device wearer with the exoskeleton device; Sensor, which is installed on the exoskeleton device and exoskeleton device wearer, to detect the motion state of the exoskeleton device and decode the motion intention of the exoskeleton device wearer; Controller, to control the motion angle, angular velocity and output torque of the ankle sagittal plane driving unit, knee sagittal plane driving unit, hip sagittal plane driving unit and hip horizontal plane driving unit; Power supply, to power the driving units, sensor and controller of the exoskeleton device.

2. The lower limb powered exoskeleton device for rehabilitation assistance according to claim 1, wherein: The waist fixing support is fixed on the waist connecting frame, the thigh fixing support is fixed on the thigh connecting frame, the shank fixing support is fixed on the shank connecting frame, and the foot sole fixing support is connected with the shank connecting frame through the ankle sagittal plane driving unit.

3. The lower limb powered exoskeleton device for rehabilitation assistance according to claim 1, wherein: The waist connecting frame and the thigh connecting frame are connected by one of planar hinge and spherical surface, and the thigh connecting frame and the shank connecting frame are connected by planar hinge.

4. The lower limb powered exoskeleton device for rehabilitation assistance according to claim 1, wherein: The hip sagittal plane driving unit is driven by two antagonistic linear actuators, which contain DC motors, and the DC motors are driven by threaded rods, while having displacement feedback and force feedback; the linear actuators form a crank slider structure with the waist connecting frame and the thigh connecting frame, to actively control the rotation angle, angular velocity and joint torque of the hip joint in sagittal plane.

5. The lower extremity powered exoskeleton device for rehabilitation assistance according to claim 1, wherein: The linear actuator comprises a DC motor, which cooperates with a threaded screw drive and is provided with displacement feedback and force feedback, and the threaded screw drive is provided with motor power-off self-locking function.

6. The lower extremity powered exoskeleton device for rehabilitation assistance according to claim 1, wherein: The hip joint horizontal plane driving unit is a passive driving unit, which is driven by a return spring to make the waist connecting frame and the thigh connecting frame return to the initial relative position, and the exoskeleton device can realize rotation in the horizontal plane under the active driving of the exoskeleton device wearer.

7. The lower extremity powered exoskeleton device for rehabilitation assistance according to claim 1, wherein: The knee joint sagittal plane driving unit is an active driving unit, which is driven by two antagonistically arranged linear actuators, the linear actuator comprises a DC motor, which cooperates with a threaded screw drive and is provided with displacement feedback and force feedback, and the linear actuator and the thigh connecting frame and the shank connecting frame form a crank slider structure, which can actively control the rotation angle, angular velocity and joint torque of the knee joint in the sagittal plane.

8. The lower extremity powered exoskeleton device for rehabilitation assistance according to claim 1, wherein: The knee joint sagittal plane driving unit is an active driving unit, which is driven by an antagonistically arranged linear actuator and a magnetic control damper, the linear actuator comprises a DC motor, which cooperates with a threaded screw drive and is provided with displacement feedback and force feedback, and the linear actuator and the thigh connecting frame and the shank connecting frame form a crank slider structure, which can actively control the rotation angle, angular velocity and joint torque of the knee joint in the sagittal plane, and the magnetic control damper and the thigh connecting frame and the shank connecting frame form a crank slider structure, which can passively control the rotation angle, angular velocity and joint torque of the knee joint in the sagittal plane by controlling the excitation current of the magnetic control damper.

9. The lower extremity powered exoskeleton device for rehabilitation assistance according to claim 1, wherein: The knee joint sagittal plane driving unit is a semi-passive driving unit, which is driven by a magnetic control damper in cooperation with a return spring, the return spring can drive the knee joint to return to the initial position in the sagittal plane, and the magnetic control damper and the thigh connecting frame and the shank connecting frame form a crank slider structure, which can passively control the rotation angle, angular velocity and joint torque of the knee joint in the sagittal plane bending and stretching by controlling the excitation current of the magnetic control damper.

10. The lower extremity powered exoskeleton device for rehabilitation assistance according to claim 1, wherein: The ankle joint sagittal plane driving unit is an active driving unit, which is composed of a DC motor cooperating with a gear reducer and a harmonic reducer, and can actively control the rotation angle, angular velocity and output torque of the ankle joint in the sagittal plane.

11. The lower extremity powered exoskeleton device for rehabilitation assistance according to claim 1, wherein: The sagittal plane driving unit of the ankle joint is a semi-passive driving unit driven by a magnetic control damper matched with a return spring, the return spring can drive the knee joint to return to the initial position in the sagittal plane, the magnetic control damper and the calf connecting frame and the instep fixed support form a crank slider structure, wherein the calf connecting frame and the instep fixed support are connected through a planar hinge, by controlling the excitation current of the magnetic control damper, the rotation angle, angular velocity and joint torque of the ankle joint during bending and stretching in the sagittal plane can be passively controlled.

12. The lower limb powered exoskeleton device for rehabilitation assistance according to claim 1, characterized in that: The sagittal plane driving unit of the ankle joint is a passive driving unit including a return spring group, the return spring can help the relative angle of the calf connecting frame and the instep fixed support to return to the initial position, and the calf connecting frame and the instep fixed support are connected through a planar hinge.

13. The lower limb powered exoskeleton device for rehabilitation assistance according to claim 1, characterized in that: The lower limb fixed support is used to fix the exoskeleton device and the exoskeleton device wearer, and the lower limb fixed support is provided with a negative Poisson's ratio intelligent structure unit in a partial force bearing area.

14. The lower limb powered exoskeleton device for rehabilitation assistance according to claim 1, characterized in that: The inner surface of the lower limb fixed support is integrated with a curved surface pressure measuring unit, the pressure measuring unit measures the contact stress between the exoskeleton device and the exoskeleton device wearer, and the measured contact stress can be used to quantify the wearing comfort of the lower limb fixed support and can be used to decode the motion intention of the exoskeleton device wearer.

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