Modularized child knee-hip exoskeleton auxiliary device

Abstract

The invention discloses a modular child knee-hip exoskeleton auxiliary device, which belongs to the technical field of rehabilitation medical instruments, and comprises a waist support piece, a thigh support piece, a shank support piece and a central control module, and a hip joint driving module is mounted between the waist support piece and the thigh support piece; a knee joint driving module is mounted between the thigh supporting piece and the shank supporting piece; the hip joint driving module comprises a hip joint driving motor, the output end of the hip joint driving motor is connected with a hip joint driving substrate, and a waist restraining connecting rod with the other end connected to the waist supporting piece is fixed to a shell of the hip joint driving motor; the knee joint driving module comprises a knee joint driving motor, the output end of the knee joint driving motor is connected with a knee joint driving base plate, and a leg restraining connecting rod with the other end connected to the thigh supporting piece is fixed to a shell of the knee joint driving motor. The system has the characteristics of low cost, modularization and high adaptability, and can meet the use requirements of rapid growth and development of children.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of rehabilitation medical devices, in particular to a modularized knee-hip exoskeleton auxiliary device for children. BACKGROUND

[0002] Children with neuromuscular diseases (such as cerebral palsy, spinal cord injury, etc.) often have lower limb motor dysfunction, and need to use exoskeletons or orthoses for rehabilitation training or daily assistance. The active drive knee-hip exoskeletons specially designed for children on the market have the following defects: Firstly, the cost is extremely high: since the special body shape and needs of children need to be fully customized, especially the drive system, the unit price is expensive, which brings a heavy burden to the family.

[0003] Secondly, poor adaptability: children are in a rapid growth period, and their height and body shape change frequently. The traditional integrated design of active exoskeletons cannot adapt to such changes, and often needs to be replaced as a whole after a period of use, causing waste of resources.

[0004] And the widely used relatively low-cost children's hip-knee orthosis on the market, although it is solid and durable and easy to adjust, usually only provides static support or limited passive range of motion, lacks active assistance function, and cannot meet the rehabilitation or walking needs of power assistance. SUMMARY

[0005] The purpose of the present application is to provide a modularized knee-hip exoskeleton auxiliary device for children, which has the characteristics of low cost, modularity, high adaptability, and active driving capability, can significantly reduce the manufacturing and use cost, and can adapt to the use needs of the rapid growth and development of children.

[0006] To achieve the above purpose, the present application provides a modularized knee-hip exoskeleton auxiliary device for children, which comprises a waist support, a thigh support and a calf support; a hip joint driving module is installed between the waist support and the thigh support, and a knee joint driving module is installed between the thigh support and the calf support; a central control module is installed on one side of the waist support.

[0007] Preferably, the hip joint driving module comprises a hip joint driving motor, the shell of which serves as a first structure connection node, the output end of the hip joint driving motor is connected with a hip joint driving base plate, the other end of the hip joint driving base plate is connected to the thigh support; the shell of the hip joint driving motor is fixed with a waist restraint connecting rod, the other end of which is connected to the waist support.

[0008] Preferably, the knee joint driving module comprises a knee joint driving motor, the shell of the knee joint driving motor serves as a second structure connecting node, the output end of the knee joint driving motor is connected with a knee joint driving base plate, the other end of the knee joint driving base plate is connected on the shank support; the shell of the knee joint driving motor is fixed with a leg restraint connecting rod, the other end of the leg restraint connecting rod is connected on the thigh support.

[0009] Preferably, the hip joint driving base plate is fixed on the thigh support through the key groove and bolt cooperation mode; the knee joint driving base plate is fixed on the shank support through the key groove and bolt cooperation mode.

[0010] Preferably, the waist restraint connecting rod and the leg restraint connecting rod are rigid connecting rods, the two ends of the rigid connecting rods are fixedly connected with the corresponding support and the driving motor shell through screws respectively.

[0011] Preferably, the hip joint driving motor and the knee joint driving motor are both servo actuators integrated with motor controllers and encoders.

[0012] Preferably, the central control module comprises an electric control system, a torque system and a power supply system; the control core of the electric control system is a general controller Arduino Due, the general controller Arduino Due is connected with the motor controllers of the hip joint driving motor and the knee joint driving motor through a CAN bus, is connected with the encoders through I / O interfaces and is in communication connection with an IMU sensor fixed on the thigh support through a UART.

[0013] Preferably, the torque control system comprises a high-level torque control loop and a low-level current control loop; the high-level torque control loop is configured with a torque reference value input end, a torque feedback path and a torque PID controller; the low-level current control loop is configured with a current reference value input end, a current feedback path, a current PI controller, a low-pass filter, a saturation block and a motor driver.

[0014] Preferably, the inner side of the waist support is provided with a waist pad, the inner side of the thigh support is provided with a thigh pad and the inner side of the shank support is provided with a shank pad.

[0015] Preferably, the waist support, the thigh support and the shank support are all provided with fixing seats and are surrounded by force transmission bandages.

[0016] Therefore, the modular child knee-hip exoskeleton auxiliary device has the following beneficial effects: (1) The application realizes excellent flexibility and adaptability through modular and adjustable design. The driving modules of the hip joint and the knee joint can be independently selected and installed (supporting three driving modes), and any damaged module can be independently replaced, which is convenient and low in maintenance cost.

[0017] (2) Each connecting rod of the application is flexibly adjustable, which can effectively adapt to children of different heights and leg lengths and the rapid growth and development needs of children.

[0018] (3) The application integrates multiple safety protection mechanisms such as joint torque limitation, abnormal gait detection and fall emergency stop, and provides sufficient safety protection for children's activities.

[0019] The technical solutions of the application will be further described in detail below through the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a structural schematic view of an embodiment of a modular child knee-hip exoskeleton auxiliary device of the application; Figure 2 is a side view schematic view of an embodiment of a modular child knee-hip exoskeleton auxiliary device of the application; Figure 3 is a result schematic view of a hip joint driving module of an embodiment of a modular child knee-hip exoskeleton auxiliary device of the application; Figure 4 is a structural schematic view of a knee joint driving module of an embodiment of a modular child knee-hip exoskeleton auxiliary device of the application; Figure 5 is a schematic view of an electric control system of an embodiment of the application; Figure 6 is a schematic view of a torque control system of an embodiment of the application.

[0021] REFERENCE NUMERALS 1, calf pad; 2, calf support; 3, force transmission bandage; 4, knee joint driving base plate; 5, leg restraint connecting rod; 6, knee joint driving motor; 7, thigh support; 8, thigh pad; 9, hip joint driving base plate; 10, waist restraint connecting rod; 11, hip joint driving motor; 12, waist support; 13, waist pad; 14, central control module. DETAILED DESCRIPTION

[0022] The technical solutions of the application will be further described in detail below through the drawings and examples.

[0023] Unless otherwise defined, technical terms or scientific terms used in the present application shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Unless otherwise defined, the terms "first", "second", and the like, used in the present application do not necessarily have any sequential or chronological significance. The terms "comprises", "comprising", "includes", "including" and the like, are inclusive of the terms "consisting of" and "consisting essentially of". The terms "plurality" and "a plurality" include "multiple" or "two or more". The term "coupled" or "connected" or the like, unless otherwise specified, means an electrical coupling or connection, which can be direct or indirect, mechanical, or the like. The terms "upper", "lower", "left", "right", and the like, are used for description only and are not intended to be limiting.

[0024] Embodiment one: As shown in Figure 1 and Figure 2 , the present application provides a modular child knee-hip exoskeleton auxiliary device, which comprises a waist support 12, a thigh support 7 and a shank support 2, a hip joint driving module is installed between the waist support 12 and the thigh support 7, and a knee joint driving module is installed between the thigh support 7 and the shank support 2.

[0025] As shown in Figure 3 , the hip joint driving module comprises a hip joint driving motor 11, the shell of which serves as a first structure connection node, the output end of the hip joint driving motor 11 is connected with a hip joint driving base plate 9, and the other end of the hip joint driving base plate 9 is fixed on the thigh support 7 through a key groove and bolt cooperation mode. The shell of the hip joint driving motor 11 is fixed with a waist restraint connecting rod 10, the other end of which is connected on the waist support 12, and the waist restraint connecting rod 10 is a rigid connecting rod.

[0026] A standard threaded mounting hole is designed on the shell of the hip joint driving motor 11, the lower end of the waist restraint connecting rod 10 is directly fastened in the threaded hole on the upper end of the shell through an internal hexagonal cylindrical head screw, so as to realize rigid connection. The upper end of the waist restraint connecting rod 10 is fixed on the preset connection point of the waist support 12 through the same mode.

[0027] The output end (i.e. rotor) of the hip joint driving motor 11 is downwardly fixed with the central part of the hip joint driving base plate 9 through a flange and a screw. The profile of the hip joint driving base plate 9 is accurately matched with the mounting surface on the outside of the thigh support 7, and a positioning key groove and a plurality of bolt through holes are opened on it.

[0028] During installation, first, the key groove of the hip joint driving base plate 9 is aligned with the positioning key protruding on the thigh support 7 to achieve radial accurate positioning, and then a high-strength bolt is used to pass through the bolt through hole and is screwed into the steel wire threaded sleeve pre-buried in the thigh support 7, so as to firmly lock the entire hip joint driving module on the thigh support 7.

[0029] As shown in Figure 4 , the knee joint driving module includes a knee joint driving motor 6, the shell of which serves as a second structural connection node, the output end of the knee joint driving motor 6 is connected with a knee joint driving base plate 4, and the other end of the knee joint driving base plate 4 is fixed on the calf support 2 in a manner of key groove and bolt cooperation. The shell of the knee joint driving motor 6 is fixed with a leg restraint connecting rod 5, the other end of which is connected to the thigh support 7, and the leg restraint connecting rod 5 is also a rigid connecting rod.

[0030] The structure and connection mode of the knee joint driving motor 6 are the same as those of the hip joint driving motor 11, and the upper end of the leg restraint connecting rod 5 is directly fixed to the shell of the knee joint driving motor 6 through a screw, and the lower end is fixed to the connection point at the lower part of the thigh support 7.

[0031] The output end of the knee joint driving motor 6 is also downwardly connected with the knee joint driving base plate 4. The knee joint driving base plate 4 is fixed on the calf support 2 in the same key groove-positioning key cooperation and bolt connection mode as the hip joint driving base plate 9.

[0032] As can be seen, the main function of the waist restraint connecting rod 10 and the leg restraint connecting rod 5 is to provide tensile and compressive restraint to prevent the driving module from producing undesired displacement or swing relative to the support during the working process. The shells of the knee joint driving motor 6 and the hip joint driving motor 11 become the core hinge for connecting the upper and lower supports and transmitting the restraint force. This design greatly simplifies the structure, reduces the number of parts, and improves the rigidity of the system.

[0033] The knee joint driving base plate 4 and the hip joint driving base plate 9 are made of CNC-processed 7075-T6 aerospace aluminum alloy or carbon fiber composite material, with a thickness of 3-5 mm, and have the advantages of lightweight and high strength. The waist restraint connecting rod 10 and the leg restraint connecting rod 5 are made of glass fiber reinforced nylon (PA66+30% GF) by injection molding, which is light in weight and has sufficient rigidity.

[0034] The auxiliary device of the embodiment is carefully designed for the children group, and comprehensively uses hard support, flexible buffer and intelligent binding technology. The main body of the waist support 12, the thigh support 7 and the calf support 2 are all made of thermoplastic polyurethane (TPU) through 3D printing. The process allows to generate a personalized, topologically optimized structure that fits the bone morphology of each child patient according to the MRI / CT data of each child patient, to realize the ultimate lightweight on the premise of ensuring the support stiffness. The inner side of the support is designed with a distributed reinforcement rib grid, and the key bearing areas (such as the connection with the driving base plate) are embedded with stainless steel embedded parts to ensure the connection reliability.

[0035] The inner side of the waist support 12 is provided with a waist pad 13, the inner side of the thigh support 7 is provided with a thigh pad 8, and the inner side of the calf support 2 is provided with a calf pad 1. Each pad is adhered to the corresponding support by a magic tape and can be replaced to adapt to different hygiene requirements and size changes after the growth of children.

[0036] The waist pad 13, the thigh pad 8 and the calf pad 1 are all multi-layer functional pads with sandwich structure, including from inside to outside: a skin-friendly layer, which adopts high-performance quick-drying breathable fabric to reduce sweating and skin irritation; a buffer layer, which adopts slow-rebound memory sponge (density 50D-70D), and the thickness is gradient designed according to the pressure bearing capacity of different parts of the human body to optimize the pressure distribution; a support layer, which is a layer of high-elasticity polyester fiber mesh cloth for transmitting and dispersing local pressure to the whole pad.

[0037] The waist support 12, the thigh support 7 and the calf support 2 are all provided with a fixing seat and a force transmission belt 3 around the fixing seat. The force transmission belt 3 adopts high-strength low-ductility nylon webbing, and the inner surface is compounded with a micro-point glue anti-slip layer to prevent sliding between the belt and clothes.

[0038] The fixing seat is integrated with the male part of the Fidlock magnetic buckle, one end of the belt is connected to the webbing ring on the fixing seat through a day buckle, and the other end is sewn with a magic tape hook surface matched with the Fidlock female buckle. When wearing, first wrap the belt around the limb, preliminarily fix it with the magic tape, and finally align and lock the Fidlock buckle through magnetic attraction to realize quick, reliable and single-handed operation. This system ensures high transmission efficiency and greatly improves the convenience of wearing, which is very suitable for children.

[0039] In addition, the hip joint driving motor 11 and the knee joint driving motor 6 are both servo actuators integrated with motor controllers and encoders. The rear of the waist support 12 is provided with a central control module 14 responsible for coordinating the operation of the whole system. The central control module 14 includes an electric control system, a torque system and a power supply system, and the hardware core of the electric control system is a general controller Arduino Due based on a high-performance microprocessor.

[0040] System hardware of the device: Sensing unit: including high-precision encoders integrated inside the servo actuators (i.e. drive motors) for real-time measurement of hip and knee joint angles; and inertial measurement units (IMUs) fixed on the thigh support 7 for detecting limb posture and motion acceleration. The IMUs communicate with the master controller at high speed through SPI (Serial Peripheral Interface).

[0041] Execution unit: i.e. hip joint drive motor 11 and knee joint drive motor 6.

[0042] Power supply unit: the system adopts a dual power supply scheme, with one set of lithium batteries providing 3.3V low-voltage DC power for the master controller and sensors; and another set of high-voltage battery pack directly providing 42V DC operating power for the servo actuators.

[0043] The connection mode of the device is shown in Figure 5 The master controller Arduino Due can be connected to a PC host through an RS232 serial interface for parameter debugging, data monitoring and program updating. The master controller Arduino Due is connected to the motor controllers of the hip joint drive motor 11 and the knee joint drive motor 6 through a CAN bus, connected to the encoders through I / O interfaces, and connected to the IMU sensor fixed on the thigh support 7 through a UART.

[0044] The torque control system adopts a layered real-time torque control strategy, including a high-level torque control loop and a low-level current control loop.

[0045] The high-level torque control loop is configured with a torque reference input, a torque feedback path and a torque PID controller, and mainly functions as torque reference generation, torque feedback, torque reference generation and PID adjustment. Based on the data collected by the IMU and the encoder in real time, the master controller Arduino Due determines the current motion phase (such as the standing phase and the swing phase) through a gait cycle detection algorithm. Then, it queries the torque-gait cycle lookup table pre-stored in the controller to obtain the torque reference value that meets the requirements of the current phase. The torque sensor integrated inside the servo actuator directly measures the output torque, and this signal, after being filtered by a 100Hz low-pass filter to eliminate high-frequency noise, serves as the torque feedback signal. The PID controller receives the torque reference value and the torque feedback value, and through proportional-integral-derivative operation, outputs a current reference value, aiming to eliminate the error between the target torque and the actual torque.

[0046] As shown in Figure 6As shown, the low-level current control loop is configured with a current reference input, a current feedback path, a current PI controller, a low-pass filter, a saturation block, and a motor driver. The core of the low-level current control loop is the current PI (proportional-integral) controller. It receives the current reference value from the high-level loop and compares it with the actual current value of the motor fed back by the driver (current feedback). The current signal calculated by the current PI controller is first smoothed by a 400Hz low-pass filter, then passed through a saturation degree limiting module to ensure that the output value is within a safe range, and finally a drive signal is generated and sent to the servo driver. The servo driver accurately controls the current flowing into the motor according to this drive signal, thereby generating the desired auxiliary torque. The driver simultaneously feeds back the current saturation state to the controller, forming a closed loop.

[0047] The safety monitoring runs as an independent thread continuously. Once it detects that the joint output torque exceeds the preset safety threshold, the IMU detects a fall feature, or the joint motion state is abnormal, the system will cut off the motor power within milliseconds to ensure the safety of the child user.

[0048] Thanks to the independence of the above-mentioned core mechanical connection structure, the present embodiment supports three typical configurations, and the user can flexibly control according to his own needs: Configuration A (hip drive only): Only install the hip joint drive module. At this time, the leg restraint link 5 can not be installed, or a passive link can be installed to maintain the structural integrity.

[0049] Configuration B (knee drive only): Only install the knee joint drive module.

[0050] Configuration C (hip-knee joint drive): Install the hip and knee joint drive modules at the same time.

[0051] When changing the configuration, only a few main bolts connecting the drive base plate and the support need to be disassembled, and the electrical interface needs to be unplugged, which is extremely simple to operate.

[0052] Therefore, the present application adopts the above-mentioned modular child knee-hip exoskeleton auxiliary device, which has the characteristics of low cost, modularity, and high adaptability, and has active driving capability, which can significantly reduce manufacturing and use costs, and can meet the use needs of the rapid growth and development of children.

[0053] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application and not to limit them, although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that: it can still modify or equivalently replace the technical solutions of the present application, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present application.

Claims

1. A modularized child knee-hip exoskeleton assistive device, characterized in that: It comprises a waist support, a thigh support and a calf support; a hip joint driving module is installed between the waist support and the thigh support, and a knee joint driving module is installed between the thigh support and the calf support; a central control module is installed on one side of the waist support.

2. A modularized knee-ankle-foot exoskeleton for children as claimed in claim 1, wherein: The hip joint driving module comprises a hip joint driving motor, the shell of which serves as a first structural connection node; the output end of the hip joint driving motor is connected with a hip joint driving base plate, the other end of the hip joint driving base plate being connected to the thigh support; the shell of the hip joint driving motor is fixed with a waist restraint connecting rod, the other end of which is connected to the waist support.

3. A modularized knee-ankle-foot exoskeleton for children as claimed in claim 2, wherein: The knee joint driving module comprises a knee joint driving motor, the shell of which serves as a second structural connection node; the output end of the knee joint driving motor is connected with a knee joint driving base plate, the other end of the knee joint driving base plate being connected to the calf support; the shell of the knee joint driving motor is fixed with a leg restraint connecting rod, the other end of which is connected to the thigh support.

4. The modularized exoskeleton device for children's knee and hip according to claim 3, characterized in that: The hip joint driving base plate is fixed to the thigh support by means of key groove and bolt cooperation; the knee joint driving base plate is fixed to the calf support by means of key groove and bolt cooperation.

5. The modularized exoskeleton device for children's knee and hip according to claim 3, characterized in that: The waist restraint connecting rod and the leg restraint connecting rod are rigid connecting rods, the two ends of each being fixedly connected with the corresponding support and the driving motor shell respectively through screws.

6. The modularized exoskeleton device for children's knee and hip according to claim 3, characterized in that: The hip joint driving motor and the knee joint driving motor are both servo actuators integrated with motor controllers and encoders.

7. The modularized exoskeleton device for children's knee and hip according to claim 6, characterized in that: The central control module comprises an electric control system, a torque system and a power supply system; the control core of the electric control system is a general controller Arduino Due, which is connected with the motor controllers of the hip joint driving motor and the knee joint driving motor through a CAN bus, connected with the encoders through I / O interfaces and communicatively connected with an IMU sensor fixed to the thigh support through a UART.

8. The modularized exoskeleton device for children's knee and hip according to claim 7, characterized in that: The torque control system comprises a high-level torque control loop and a low-level current control loop; the high-level torque control loop is configured with a torque reference value input end, a torque feedback path and a torque PID controller; the low-level current control loop is configured with a current reference value input end, a current feedback path, a current PI controller, a low-pass filter, a saturation block and a motor driver.

9. The modularized exoskeleton device for children's knee and hip according to claim 1, characterized in that: The inner side of the waist support is provided with a waist pad, the inner side of the thigh support is provided with a thigh pad, and the inner side of the calf support is provided with a calf pad.

10. The modularized exoskeleton device for children's knee and hip according to claim 1, characterized in that: The waist support, the thigh support and the calf support are all provided with fixing seats and are surrounded by force transmission bands.

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