Modularized exoskeleton joint power system and parametric control method

Abstract

The invention discloses a modular exoskeleton joint power system and a parameterization control method, and belongs to the technical field of exoskeletons. According to the modularized exoskeleton joint power system provided by the invention, through the modularized detachable joint modules, quick disassembly and assembly of the power modules with different parameters are realized, and the modularized exoskeleton joint power system is suitable for multi-scene use requirements. According to the parameterized control method provided by the invention, a parameterized compliant control algorithm based on human-computer interaction is provided, an inertial constraint term is introduced to avoid angular acceleration calculation, corresponding control parameters are selected according to a human body joint load bearing scene, and high-reliability and compliant human-computer cooperative movement is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of exoskeletons and relates to a modular exoskeleton joint power system and a parameterized control method based on human-computer interaction. Background Art

[0002] With the continuous development of exoskeleton technology, rigid exoskeleton robots have broad application prospects in improving human power efficiency. They can be widely used in medical rehabilitation, logistics and other fields, bringing great convenience to people's lives and work.

[0003] However, rigid exoskeleton robots still have many limitations in practical applications. In terms of structure, the joint module, as the core component of power output, is particularly critical. On the one hand, due to the limitation of motor power density, the output performance of the joint module is fixed at the design stage; on the other hand, the structural characteristics of the embedded package limit the possibility of subsequent performance adjustment, making it difficult for the system to adapt to changing working conditions. Some scenarios require high sensitivity, such as running and climbing, while some scenarios require large load capacity, such as carrying. Secondly, due to the rigid connection characteristics of the exoskeleton system, in non-powered conditions, its rigid structure will interfere with the wearer's natural gait and reduce mobility. At the same time, it requires the wearer to consume additional energy so that the exoskeleton can move with the wearer, reducing energy efficiency.

[0004] Rigid exoskeleton control strategies also have significant limitations. On the one hand, researchers often focus on the dynamic characteristics of the exoskeleton system itself, or model it as a rigid connection to the human body, while ignoring the impact of physical human-machine interactions. There is a dynamic coupling between the exoskeleton and the wearer, and this interaction directly affects the control performance and stability of the system. On the other hand, traditional compliant control algorithms have the following problems due to their inherent design: First, due to the fixed selection of motors, the algorithm parameters are rigid, making it difficult to adapt to changing interaction scenarios and easily leading to motion lag or rigid conflicts; second, high-order filtering in the data processing process can cause noise amplification, reducing the system's robustness to external disturbances and affecting human-machine coordination.

[0005] There is an urgent need to develop a modular exoskeleton joint power system and its control method to ensure that the power module maintains efficient coordination with the natural movement of human joints while providing assistance; the power module can be quickly installed and disassembled in different usage scenarios while ensuring the stability of the connection mechanism; and how to select power modules and flexible control algorithms with different parameters according to the body shape, exercise habits and assistance needs of different users to achieve personalized assistance effects. Summary of the Invention

[0006] In order to overcome the limitations of the prior art, the present application proposes a modular detachable exoskeleton joint module and a parameterized control method based on human-computer interaction. The core of the module structure design is to realize the quick disassembly of different parameter power modules to meet the use requirements of multiple scenes. In the case of non-assistance, the wearer can quickly remove the power module, thereby reducing the body burden and ensuring the freedom of action is not limited. When encountering a situation that requires assistance, the corresponding parameter power module can be quickly installed at the corresponding joint part to ensure that the exoskeleton robot can provide appropriate assistance to the human body. This modular design not only improves the applicability of the exoskeleton robot, but also brings a more personalized and efficient use experience to the user. In terms of control method, a parameterized control method based on human-computer interaction is proposed, which effectively solves the above problems by introducing an inertia constraint term and a parameterized compliant control algorithm, and significantly improves the compliance, anti-interference ability and dynamic response rate of the system. The purpose of the present application is to overcome the shortcomings of the above background art and provide a modular exoskeleton joint power system and a parameterized control method based on human-computer interaction. The purpose of the present application is achieved through the following specific technical solutions.

[0007] A modular exoskeleton joint power system comprises: A motor drive system comprising a motor, a stator base and a rotor base; An end cap fixing part comprising a rotating ring, a motor fixing ring, an end cap shell, a handle push rod bolt and a cross roller bearing; A rotating shaft connecting part comprising a rotor fixing ring and a rotor shell; The motor drive system is fixed on the stator base and the rotor base by means of bolt connection; The end cap fixing part is axially connected and fixed with the end cap shell by means of spring, allowing axial translation movement, and is connected with the rotating shaft connecting part through the cross roller bearing; The rotating shaft connecting part is connected and fixed with the rotor shell by means of spring, allowing axial translation movement; The motor drive system is quickly disassembled by rotating the handle push rod bolt.

[0008] The modular exoskeleton joint power system provided by the present application can realize the quick disassembly of the exoskeleton joint power module, adapt to different use scenarios, and improve the flexibility and applicability of the exoskeleton robot.

[0009] Furthermore, the end cap fixing portion includes a first inertial measurement unit and a first strain gauge sensor for real-time detection of the motion state and interaction forces at the proximal end of the human joint. This design enables real-time monitoring of human motion and interaction forces, providing accurate data for control strategies and improving the precision of human-machine collaborative motion.

[0010] Furthermore, the shaft connection includes a second inertial measurement unit and a second strain gauge sensor for real-time monitoring of the motion state and interaction forces at the distal end of human joints. This design enables comprehensive monitoring of human joint motion and interaction forces, improving the system's ability to perceive human motion and enhancing the coordination of human-machine collaboration.

[0011] Furthermore, the motor drive system, the end cap fixing portion, and the rotating shaft connecting portion are fixed to the proximal and distal ends of the human joints via straps. This design ensures a secure connection between the exoskeleton joints and the human joints, improving wearing comfort and safety.

[0012] A parameterized control method is applied to the above modular exoskeleton joint power system, characterized in that the control method comprises the following steps: S1 establishes the dynamic equation of the system: set the moment of inertia to J , the joint rotation angle position is i , the torque acting on the joint is t , the external torque is t ext , the dynamic equation of the system is shown as follows: , S2 obtains the inertial constraint term as: , S3 design controls torque t , so that it is under external torque t ext and the system moves from the desired equilibrium position i 0 resulting in an angular deviation f g Create dynamic features between: , in, J d 、 B d and K d Mark the desired moment of inertia, damping coefficient and stiffness coefficient respectively; S4 collects human motion data in real time through the inertial measurement unit to calculate the joint rotation angle position i; At the same time, a strain gauge sensor is used to collect human-computer interaction force and obtain external torque t ext ; S5 adjusts the admittance model and admittance parameters according to different load-bearing scenarios of human joints, selects corresponding compliance control parameters, and achieves adaptive adjustment.

[0013] The parametric control method based on human-computer interaction provided by the present invention can improve the flexibility, anti-interference ability and dynamic response rate of the control strategy, adapt to different interaction scenarios, and achieve highly reliable and flexible human-computer collaborative motion.

[0014] Furthermore, when the human joints perform weightless motion, the admittance model prioritizes low stiffness and medium damping, ignoring inertial effects and prioritizing motion compliance. This ensures system compliance and safety in weightless scenarios like rehabilitation training, avoiding human-machine conflicts.

[0015] Furthermore, when the human joints are subjected to light load movements, the admittance parameters are adjusted to medium stiffness, high damping, and low inertia to suppress oscillations and compensate for load inertia. This provides balance assistance and stability in light load scenarios, such as everyday lifting, and improves the smoothness of system response.

[0016] Furthermore, when human joints undergo high-intensity weight-bearing exercise, the admittance parameters are adjusted to high stiffness, variable damping, and high inertia to suppress excessive joint movement and match the required acceleration. This ensures the continuity and safety of human joint movement in high-intensity weight-bearing scenarios such as weightlifting, providing effective assistance.

[0017] Furthermore, by describing the system's acceleration response through inertial constraints, the control algorithm eliminates the need to calculate the true angular acceleration, avoiding the amplification effect of second-order noise. This improves the smoothness of the control signal and the robustness of the algorithm, ensuring stable system operation.

[0018] Furthermore, the control strategy achieves complete closed-loop control from interactive force detection to motion compensation, enabling the exoskeleton system to adaptively coordinate with human joint movements, improving the robustness and adaptability of human-machine collaborative motion and achieving personalized assistance effects.

[0019] Compared to existing technologies, the present invention has the following beneficial technical effects: The modular exoskeleton joint power system provided by the present invention allows for the installation of power modules with different parameters and enables rapid assembly and disassembly of the power modules, adapting to the needs of multiple scenarios to improve the flexibility and applicability of the exoskeleton robot. The control method provided by the present invention proposes a parameterized compliant control algorithm for different interaction scenarios, introduces inertial constraints to reduce the impact of high-order noise, and improves the algorithm's smoothness and robustness. Combining the preset desired joint angle and the current joint motion state, the control command is output to adapt to different working environments, ultimately achieving highly reliable and compliant human-machine collaborative motion. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the knee joint module installation.

[0021] Figure 2 This is a schematic diagram of the elbow joint module installation.

[0022] Figure 3 This is a disassembly diagram of the motor drive system.

[0023] Figure 4 This is a schematic diagram of the internal assembly of the module.

[0024] Figure 5 This is the parts diagram of the motor drive module.

[0025] Figure 6 This is the parts drawing of the end cover fixing module.

[0026] Figure 7 This is the parts drawing of the shaft connection module.

[0027] Figure 8 It is a schematic block diagram of the parametric control method based on human-computer interaction.

[0028] Figure numerals: 100-motor drive system, 101-motor, 102-stator base, 103-rotor base, 200-end cover fixing part, 201-rotating ring, 202-motor fixing ring, 203-end cover housing, 204-handle push rod screw, 205-cross roller bearing, 206-first inertial measurement unit, 207-first fixing bolt, 208-first guide rail, 209-first strain gauge sensor, 300-rotating shaft connecting part, 301-rotor fixing ring, 302-rotor housing, 303-second guide rail, 304-second strain gauge sensor, 305-second inertial measurement unit, 306-second fixing bolt. DETAILED DESCRIPTION

[0029] The following is a clear and complete description of the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0030] In the description of the present invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate description and simplify the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance, quantity, or position.

[0031] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances. Example 1

[0032] A modular exoskeleton joint power system, such as Figure 1-Figure 7 As shown, it includes three main parts: a motor drive system 100, an end cover fixing part 200 and a rotating shaft connecting part 300.

[0033] In the motor drive system 100, the housing of the motor 101 is bolted to the stator base 102, and the rotating shaft of the motor 101 is also bolted to the rotor base 103. In the end cap fixing portion 200, the right end face of the motor fixing ring 202 is axially connected to the end cap housing 203 via a set of springs, allowing only axial translational movement. The slope on the right end face of the rotating ring 201 corresponds one-to-one with the rotational slope on the left end face of the motor fixing ring 202. The long cylindrical connecting pin on the left side of the motor fixing ring 202 passes through the corresponding slot in the rotating ring 201. The handle push rod screw 204 passes through the slot in the end cap housing 203 and bolts to the corresponding hole above the rotating ring 201, limiting the rotating ring 201's movement relative to the entire module to rotational direction. A first inertial measurement unit 206 is mounted on the end cap housing 203 to monitor the motion state of the proximal end of the human joint in real time. The right side of the end cap housing 203 is fixed to the outer ring of the crossed roller bearing 205, while the left side of the rotor housing 302 is fixed to the inner ring of the crossed roller bearing 205. The end cap housing 203 is bolted to the first guide rail 208 via a first fixing bolt 207. A first strain gauge sensor 209 is mounted on the right side of the first guide rail 208 for real-time detection of the interaction forces between the proximal end of the human joint and the exoskeleton system. In the rotating shaft connection portion 300, the right end face of the rotor fixing ring 301 is connected to the rotor housing 302 via a set of springs, limiting its movement to axial translation only. A second inertial measurement unit 305 is mounted on the rotor housing 302 for real-time detection of the motion state of the proximal end of the human joint. The rotor housing 302 is bolted to the second guide rail 303 via a second fixing bolt 306. This structural design allows for adjustment of the distal support length of the exoskeleton joint. A second strain gauge sensor 304 is mounted on the right side of the second guide rail 303 for real-time detection of the interaction forces between the distal end of the human joint and the exoskeleton system.

[0034] In the exoskeleton of the present invention, the end cap fixing part 200 is fixed to an appropriate position at the proximal end of the joint by a strap, and is connected to the shaft connecting part 300 through a cross roller bearing 205, and is also fixed to an appropriate position at the distal end of the joint by a strap.

[0035] When installing the motor drive system 100, the rotor base 103 first contacts the rotor retaining ring 301. When the two are not aligned, the rotor base 103 squeezes the rotor retaining ring 301, causing it to translate along the axis. Once aligned, the rotor retaining ring 301 moves to the left under the action of the spring force on the right side, allowing the square groove in the rotor retaining ring 301 to fit and secure with the square boss on the rotor base 103. The stator base 102 contacts the long cylindrical connecting pin on the left side of the motor retaining ring 202. When the two are not aligned, the stator base 102 squeezes the motor retaining ring 202, causing it to translate along the axis. Once aligned, the motor retaining ring 202 moves to the left under the action of the spring force on the right side, allowing the long cylindrical connecting pin on the left side of the motor retaining ring 202 to be inserted into the corresponding hole on the stator base 102 and secure. When the motor drive system 100 is installed to the stator base 102 and contacts the end cover shell 203, it rotates clockwise along the axial direction until the special-shaped boss on the right side of the stator base 102 rotates and fits with the special-shaped boss inside the end cover shell 203. At this time, the rotor base 103 is fixed to the rotor fixing ring 301, and the stator base 102 is fixed to the motor fixing ring 202, so that the motor drive system 100 is completely fixed on the exoskeleton.

[0036] When disassembling the motor drive system 100, first rotate the handle push rod screw 204 counterclockwise to rotate the right slope of the rotating ring 201 counterclockwise relative to the left slope of the motor fixing ring 202, so that the motor fixing ring 202 is squeezed to the right until the long cylindrical pin connecting it on the left is separated from the stator base 102. The motor drive system 100 can then be directly removed to the left for quick disassembly. Example 2

[0037] A parametric control method based on human-computer interaction provides the system of Example 1 with the current joint rotation angle position of the human body and the external torque during the human-computer interaction force process through an inertial measurement unit and a strain gauge sensor. In a given rotary joint system, the moment of inertia is set to J , the joint rotation angle position is i , the torque acting on the joint is t , the external torque is t ext , based on the principle of Lagrangian mechanics, the dynamic equation of the system is established as: (1), The inertia constraint term is obtained as: (2), For impedance and admittance control, the control objective is to design the control torque t , so that it is under external torque t ext and the system moves from the desired equilibrium position i0 generated angle deviation f g The dynamic characteristics between them are established. The second-order linear relationship is usually as follows: (3), (4), Wherein, J d , B d And K d Respectively mark the desired moment of inertia, damping coefficient and stiffness coefficient.

[0038] Substitute (3) into (4) to arrange: (5), Substitute the inertia constraint term (2) into (5) to obtain: (6), The analytical expression of the torque t can be obtained by arranging: (7), In the implementation process of the rotational joint admittance control, the joint rotation angle signal i needs to be measured by a sensor, and the acquisition value will inevitably be disturbed by noise. Although signal processing algorithms (such as low-pass filtering or state observer) can effectively suppress high-frequency noise, the influence of noise on the signal will still be significantly amplified with high-order differential operation. The first derivative i of the joint rotation angle (angle velocity) and the second derivative (angle acceleration) will significantly amplify high-frequency noise in numerical calculation, especially the angle acceleration term , whose error may far exceed the control range, and the calculation result will seriously affect the control effect, and even lead to system instability. The core design of the present application is to describe the system acceleration response with the inertia constraint term, eliminating the need for calculation of the true angle acceleration in the control algorithm. This method avoids the second-order noise amplification effect from the root, only retains the angle velocity term which is one order of magnitude less sensitive to noise, greatly improves the smoothness of the control signal and the robustness of the algorithm, and provides a reliable solution for stable operation of the system.

[0039] The motion characteristics of human joints vary significantly under different load-bearing scenarios. Traditional compliant control algorithms, with their fixed parameters, struggle to adapt to the demands of diverse interactive scenarios. Therefore, parameterization is required to achieve adaptive adjustment of the exoskeleton robot, thereby improving the system's adaptability. Human joint motion can be broadly categorized into three states: no weight-bearing, light weight-bearing, and high-intensity weight-bearing, each requiring three distinct sets of compliant control parameters. Here, using the elbow joint as an example, motion capture and analysis are performed based on daily usage scenarios divided into rehabilitation training, daily lifting, and weightlifting training.

[0040] When performing unweighted joint movements, such as during rehabilitation training, the exoskeleton system must be adjusted to low speed and low torque, emphasizing system compliance and safety. At this time, the interaction forces are low, and the admittance model, centered around low stiffness and medium damping, can ignore inertial effects, prioritizing motion compliance and avoiding human-machine interaction.

[0041] When the joints are subjected to light loads, such as those in everyday lifting, with loads of 5N-20N, the exoskeleton system needs to be adjusted to medium speed and medium torque, emphasizing balance assistance and stability. The admittance parameters are adjusted to medium stiffness, high damping, and low inertia to suppress oscillations and compensate for load inertia.

[0042] When joints are subjected to extreme loads, such as during weightlifting, with loads exceeding 20N, the exoskeleton system must adjust to low speed and high torque, emphasizing the system's load-bearing capacity and joint protection. High stiffness is employed to suppress excessive joint movement, while variable damping and high inertia are used to match acceleration requirements, ensuring the continuity and safety of joint movement.

[0043] like Figure 8 As shown, the system has the desired torque and angle ( J 、 i 0), the interaction torque between the human body and the exoskeleton system is calculated in real time through sensors ( t ext ) and joint angle error compensation ( f g ), and selects corresponding parameterized compliant control systems and power modules based on different interaction scenarios. Ultimately, it outputs optimized control commands, enabling the exoskeleton system to adaptively coordinate with human joint movements. This control method achieves complete closed-loop control from interaction force detection to motion compensation, effectively improving the robustness and adaptability of human-machine collaborative motion.

[0044] Although the embodiments of the present invention have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art may make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention without departing from the principles and intent of the present invention. The scope of protection of the present invention is defined by the claims and their equivalents.

Claims

1. A modular exoskeleton joint power system, characterized in that: include: A motor drive system (100), comprising a motor (101), a stator base (102), and a rotor base (103); an end cover fixing portion (200), the end cover fixing portion (200) comprising a rotating ring (201), a motor fixing ring (202), an end cover housing (203), a handle push rod bolt (204), and a cross roller bearing (205); A rotating shaft connecting portion (300), the rotating shaft connecting portion (300) comprising a rotor fixing ring (301) and a rotor housing (302); Wherein, the motor drive system (100) is fixed to the stator base (102) and the rotor base (103) by bolting; The end cover fixing portion (200) is axially connected and fixed to the end cover housing (203) via a spring, allowing axial translational movement, and is connected to the rotating shaft connecting portion (300) via a cross roller bearing (205); The rotating shaft connecting portion (300) is connected and fixed to the rotor housing (302) via a spring, allowing axial translational movement; The motor drive system (100) is quickly assembled and disassembled by rotating the handle push rod bolt (204).

2. The modular exoskeleton joint power system according to claim 1, characterized in that: The end cap fixing portion (200) includes a first inertial measurement unit (206) and a first strain gauge sensor (209).

3. The modular exoskeleton joint power system according to claim 1, characterized in that: The rotating shaft connection portion (300) includes a second inertial measurement unit (305) and a second strain gauge sensor (304).

4. The modular exoskeleton joint power system according to any one of claims 1 to 3, characterized in that: The motor drive system (100), the end cover fixing portion (200), and the rotating shaft connecting portion (300) are fixed to the proximal end and the distal end of a human joint via binding straps.

5. A parameterized control method, applied to the modular exoskeleton joint power system according to any one of claims 1 to 4, characterized in that: The control method comprises the following steps: S1 establishes the dynamic equation of the system: set the moment of inertia to J , the joint rotation angle position is θ , the torque acting on the joint is τ , the external torque is τ ext , the dynamic equation of the system is shown as follows: ， S2 obtains the inertial constraint term as: ， S3 design controls torque τ , so that it is under external torque τ ext and the system moves from the desired equilibrium position θ Angular deviation resulting from 0 φ g Create dynamic features between: ， in, J d 、 B d and K d Mark the desired moment of inertia, damping coefficient and stiffness coefficient respectively; S4 collects human motion data in real time through the inertial measurement unit to calculate the joint rotation angle position θ ; At the same time, a strain gauge sensor is used to collect human-computer interaction force and obtain external torque τ ext ; S5 adjusts the admittance model and admittance parameters according to different load-bearing scenarios of human joints, selects corresponding compliance control parameters, and achieves adaptive adjustment.

6. The parameterized control method according to claim 5, characterized in that: When the human joints perform weightless motion, the admittance model in step S5 is centered on low stiffness and medium damping, ignoring the inertia effect and prioritizing motion compliance.

7. The parameterized control method according to claim 5, characterized in that: When the human joint performs a slight load-bearing motion, the admittance parameters in step S5 are adjusted to medium stiffness, high damping, and low inertia to suppress oscillation and compensate for load inertia.

8. The parameterized control method according to claim 5, characterized in that: When the human joints perform ultra-high-intensity weight-bearing exercise, the admittance parameters in step S5 are adjusted to high stiffness, variable damping, and large inertia to suppress the joints from overspeeding and match the acceleration requirements.

9. The parameterized control method according to claim 5, characterized in that: The system acceleration response is described by inertial constraint terms, eliminating the need to calculate the true angular acceleration in the control algorithm and avoiding the second-order noise amplification effect.

10. The parameterized control method according to any one of claims 5 to 9, characterized in that: The control method realizes complete closed-loop control from interaction force detection to motion compensation, so that the exoskeleton system can adaptively coordinate with the human body's joint movements.

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