Mechanical structure of a flexible powered exoskeleton system and control method thereof

Abstract

The application discloses a mechanical structure of a flexible power-assisted exoskeleton system and a control method thereof, and the mechanical structure comprises an actuating unit box, a driving device, a main controller, a power module, an intention detection component and a power-assisted unit; the body function of a user can be enhanced under different environments, including climbing, crawling, going upstairs and downstairs; the control method is characterized in that an inertial measurement unit is fixed on each main limb of the human body, and the real-time measured limb posture data are transmitted to the main controller; the main controller performs mean filtering and preprocessing on the data, so that the credibility of the data is enhanced; the main controller obtains the corresponding human motion phase according to the posture analysis of different human motions; finally, the main controller sends a driving signal to the driving device according to a preset power-assisted strategy, and the motor rotates according to the signal, so that power assistance is achieved. The application has the advantages of simple algorithm, high real-time performance, strong stability, low hardware cost, low hardware demand and easy engineering application implementation.

Description

Technical Field

[0001] This invention relates to the field of assistive exoskeleton systems, and in particular to the mechanical structure and control method of a flexible assistive exoskeleton system. Background Technology

[0002] An exoskeleton robot is a wearable mechatronic mechanical device composed of sensors, actuators, a control system, and an exoskeleton. It works in conjunction with the wearer through control algorithms and mechanical structures to enhance and assist the wearer's strength and endurance. Exoskeletons are classified into flexible and rigid exoskeletons based on differences in transmission materials and structural design. Rigid exoskeletons typically use rigid linkage structures connected in parallel to the wearer's limbs. Their heavy weight and highly tight human-machine coupling lead to instability in the human-machine system, causing discomfort or unnaturalness for the wearer. In contrast to rigid exoskeletons, flexible exoskeletons are usually driven by flexible materials, such as flexible rope actuation and pneumatic muscle actuation. These flexible exoskeleton systems better conform to the human biomechanical structure, providing tension parallel to human tendons, and are characterized by lighter overall weight and reduced limb end-effector inertia.

[0003] Accurate judgment and control of the user's movement intentions are the prerequisites and foundation for exoskeletons to improve the user's work efficiency and reduce the user's burden. However, currently, exoskeleton devices do not accurately recognize the user's intentions, and the control methods cannot meet the user's purpose, resulting in insignificant assistance effects. In measuring human posture, most exoskeleton devices obtain human posture information by measuring electromyographic signals, which is easily affected by electromagnetic interference, causing data anomalies. Furthermore, because electromyographic sensors need to be attached to the body surface for measurement, it significantly reduces user comfort and wearing experience. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the technical problem to be solved by this patent application is how to provide a mechanical structure and control method for a flexible assistive exoskeleton system with simple algorithm, high real-time performance, strong stability, low hardware cost, low hardware requirements, and easy engineering application.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A mechanical structure of a flexible assistive exoskeleton system includes an actuation unit box, a drive device, a main controller, a power module, an intention detection component, and an assistive unit;

[0007] The drive unit, main controller, and power module are installed inside the actuation unit box;

[0008] The drive device includes two upper limb drive components and two lower limb drive components, and the drive device receives control commands from the main controller.

[0009] The upper limb drive assembly includes two upper limb drive motors and an upper limb drive shaft driven by the upper limb drive motors;

[0010] The lower limb drive assembly includes two lower limb drive motors and a lower limb drive shaft driven by the lower limb drive motors;

[0011] The power module supplies power to the drive unit and the main controller;

[0012] The intent detection module includes an inertial measurement unit and a wireless Bluetooth module. The inertial measurement unit is installed on the two forearms, two thighs, and chest of the human body via straps. The wireless Bluetooth module is connected to the main controller via a serial port and is installed inside the actuation unit box.

[0013] The assist unit includes a limb restraint and a flexible rope, one end of which is connected to the limb restraint and the other end of which is connected to a drive device.

[0014] The main controller receives and converts data from the inertial measurement unit via a wireless Bluetooth module, runs a control algorithm to identify the motion phase, and issues drive commands to the drive device.

[0015] Specifically, the actuation unit box is equipped with a protective tube for guiding the flexible rope through the back anchor point.

[0016] Specifically, the limb restraints employ a double-buckle structure on the lower limbs and a palm-sleeve structure on the upper limbs.

[0017] Specifically, the actuation unit box is installed on the back waist of the vest. The actuation unit box is fixedly connected to the vest by adjusting bolts. The adjusting bolts are fitted with a first adjusting nut and a second adjusting nut on the top and bottom surfaces of the actuation unit box, respectively.

[0018] Specifically, the inertial measurement unit has a wireless data transmission module with a specified wireless connection address and a real-time limb posture data measurement module. The wireless Bluetooth module transmits the limb posture data to the main controller in the form of Bluetooth transmission.

[0019] A method for controlling the mechanical structure of a flexible assistive exoskeleton system, specifically including the following steps:

[0020] S1: Self-check of the mechanical structure of the exoskeleton system;

[0021] S2: Connect five inertial measurement units; install the five inertial measurement units on the two forearms, two thighs and chest of the human body with straps, and connect the five inertial measurement units to the main controller via a wireless Bluetooth module;

[0022] S3: Determine whether the inertial measurement units are successfully connected; if yes, transmit the limb posture data measured in real time by the five inertial measurement units to the main controller; if no, return to step S2.

[0023] S4: Mechanical structure parameter settings for the exoskeleton system; The wearer stands in an upright posture, and the main controller records the limb posture data at this time as the initial state;

[0024] S5: Preprocessing of acquired limb posture data; the data wirelessly transmitted from the inertial measurement unit to the main controller is quaternions. These quaternions are first preprocessed and converted into rotation matrices. Given a quaternion with a modulus of length 1, it can be calculated using the basic elements mentioned above in the following way:

[0025]

[0026] R is a rotation matrix of quaternion q. Smoothing filtering of each element of the rotation matrix can reduce or eliminate unwanted high-frequency noise in the signal and increase the stability of phase judgment. In order to enable the exoskeleton device to assist in more complex environments, the sensor devices of the limbs use the inertial measurement unit in the chest as the reference coordinate system.

[0027] S6: Determine limb phase;

[0028] S7: The main controller sends a drive command to the drive device, drives the motor to rotate according to the phase, and after completing one assist, returns to step S5, obtains limb posture data for preprocessing, and then proceeds to step S8.

[0029] S8: Feedforward modeling obtains exoskeleton parameters; the wearer can move freely, and a simplified model of the wearer is obtained by analyzing the limb posture data in the inertial measurement unit. Combined with the wearer's posture analysis when performing various motion tasks, the upper limb phase switching threshold T is obtained. 11 T 12 and lower limb phase switching threshold T 21 T 22 T 23 The upper limb phase switching threshold T 11 T 12 and lower limb phase switching threshold T 21 T 22 T 23 Input into the main controller and return to step S4; repeat steps S4-S7 until the end.

[0030] Specifically, in step S6, when determining limb phase:

[0031] 1) Upper limb posture phase judgment:

[0032] Based on the analysis of human upper limb movement posture, three human upper limb posture phases are obtained, namely phase S11, phase S12, and phase S13. The human movement posture is correlated with the phase. Phase S11 is the preparation phase, in which the human body is naturally suspended on a thin bar with both arms naturally extended, at time A. Phase S12 is the rising phase, in which the human body's arms and back exert continuous force, the angle between the upper arm and forearm and the torso decreases, and the entire torso is continuously rising, at time A to time B. Phase S13 is the descending phase, in which the angle between the upper arm and forearm increases, the angle between the upper arm and the torso increases, and the entire torso is continuously descending to return to phase S11, at time B to time C.

[0033] The switching conditions for the three phases S11, S12, and S13 are as follows:

[0034] The S11 phase switching condition is:

[0035] c) The preceding phase is the S13 phase;

[0036] d) The upper arm sensor posture measurement value α is greater than the threshold T 11 ;

[0037] The S12 phase switching condition is:

[0038] c) Upper arm sensor speed direction Upward, where the current direction of gravity is defined as the positive direction;

[0039] d) The preceding phase is the S11 phase;

[0040] The S13 phase switching condition is:

[0041] c) The upper arm sensor measurement value α is less than the threshold T 12 ;

[0042] d) The previous phase is S12;

[0043] If the current human body posture is in a certain phase, then determine whether the switching condition for the next phase is met. If the condition is met, switch to the next phase; otherwise, maintain the original phase.

[0044] 2) Lower limb posture phase judgment:

[0045] Based on the analysis of the human lower limb movement posture, three lower limb posture phases are obtained, namely phase S21, phase S22, and phase S23. The lower limb movement postures are correlated with the phases. Phase S21 is the ascending phase, in which the left or right foot naturally steps onto the step, and the angle between the thigh and the torso decreases, at time A1. Phase S22 is the assisting phase, in which the left or right leg begins to exert force, the angle between the thigh and the torso gradually increases, and the torso moves towards the step, at time B1. Phase S23 is the stationary phase, in which both legs are stationary on the step, at time C1.

[0046] The switching conditions for the three phases S21, S22, and S23 are as follows:

[0047] The S21 phase switching condition is:

[0048] c) The lower limb sensor posture measurement value θ is less than the threshold T 21 ;

[0049] d) The previous phase is S23;

[0050] The S22 phase switching condition is:

[0051] e) Lower limb sensor posture measurement value θ is greater than threshold T 22 ;

[0052] f) Lower limb sensor velocity direction Upward, where the direction of gravitational acceleration is defined as the positive direction;

[0053] g) Lower limb sensor acceleration direction and velocity direction Consistent;

[0054] h) The preceding phase is S21;

[0055] The S23 phase switching condition is:

[0056] c) The lower limb sensor posture measurement value θ is less than the threshold T 23 ;

[0057] d) The previous phase is S22;

[0058] If the human body is in a certain phase at the current moment, it is determined whether the switching conditions for the next phase are met. If the conditions are met, the body switches to the next phase; otherwise, the body maintains the original phase.

[0059] Specifically, in step S7, the main controller sends a drive command to the drive device, which drives the motor to rotate according to the phase, and the drive device assists in the control.

[0060] 1) Upper limb phase-assisted control:

[0061] When in phase S11, the drive unit remains stationary;

[0062] When in phase S12, the body moves upward and the drive device drives the upper limb drive motor to rotate at a certain speed to assist the upper limb. The assistance stops after the phase switches to the next phase.

[0063] When in phase S13, the body has completed the pull-up task, and the drive device rotates in the opposite direction at a certain speed and time, so that the upper limbs have enough space to perform only activities.

[0064] 2) Lower limb phase-assisted control:

[0065] When in phase S21, the drive unit remains stationary;

[0066] When in phase S22, the left or right leg moves upward, and the drive device drives the lower limb drive motor to rotate at a certain speed to assist the lower limb. The assistance stops after the phase switches to the next phase.

[0067] When in phase S23, the body has already climbed the steps, and the drive device rotates in the opposite direction at a certain speed and time, giving the lower limbs enough space to move freely.

[0068] In summary, the mechanical structure and control method of this flexible assistive exoskeleton system utilize feedforward modeling and state transition algorithms, combined with human posture data measured by sensors, to analyze the human posture phase and thus provide assistance. Furthermore, the feedforward modeling algorithm can pre-obtain suitable exoskeleton parameters for the user and make personalized adjustments, thereby improving the user experience and enhancing the assistive effect of the exoskeleton. The state transition algorithm enhances the safety of system operation and ensures system controllability. This invention features a simple algorithm, high real-time performance, strong stability, low hardware cost, low hardware requirements, and ease of engineering application implementation. Attached Figure Description

[0069] Figure 1 This is a schematic diagram of the wearable structure of the present invention;

[0070] Figure 2 This is a schematic diagram of the actuation unit box of the present invention;

[0071] Figure 3 This is a flowchart of the algorithm of the present invention;

[0072] Figure 4 This is a schematic diagram of the sensor installation of the present invention;

[0073] Figure 5 It is a diagram of upper limb assisted posture;

[0074] Figure 6 It is a diagram of lower limb assisted posture;

[0075] Figure 7 It is a phase state transition diagram of the upper limbs;

[0076] Figure 8 This is a diagram showing the phase transition of lower limb movement. Detailed Implementation

[0077] The present invention will now be described in further detail with reference to the accompanying drawings. In the description of the present invention, it should be understood that directional terms such as "upper," "lower," "top," and "bottom" indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. These terms are used only for the convenience of describing the present invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the scope of protection of the present invention. The directional terms "inner" and "outer" refer to the inner or outer contours relative to the outline of each component itself.

[0078] like Figure 1-2 As shown, the mechanical structure of a flexible assistive exoskeleton system includes an actuation unit box 1, a drive device, a main controller 5, a power module 6, an intention detection component, and an assistive unit.

[0079] The drive unit, main controller, and power module are installed inside the actuation unit box; the actuation unit box is a rectangular silicone box.

[0080] The drive device includes two upper limb drive components and two lower limb drive components, and the drive device receives control commands from the main controller.

[0081] The upper limb drive assembly includes two upper limb drive motors 2a and an upper limb drive shaft 2b driven by the upper limb drive motors;

[0082] The lower limb drive assembly includes two lower limb drive motors 4a and a lower limb drive shaft 4b driven by the lower limb drive motors;

[0083] Both the upper limb drive shaft and the lower limb drive shaft are connected to a drum; the upper limb drive assembly and the lower limb drive assembly are respectively located at the four corners of the actuation unit box; used to receive main control commands and contract and release the flexible rope;

[0084] The power module supplies power to the drive unit and the main controller, providing a stable voltage output to ensure stable operation of the exoskeleton.

[0085] The intent detection module includes an inertial measurement unit 9-13 and a wireless Bluetooth module 3. The inertial measurement unit is used to acquire human posture information during movement and transmit it to the main controller. It is installed on the two forearms, two thighs and chest of the human body through straps. The wireless Bluetooth module is connected to the main controller through a serial port and is installed in the actuation unit box.

[0086] The assist unit includes a limb restraint and a flexible rope 8. One end of the flexible rope is connected to the limb restraint, and the other end of the flexible rope 8 is connected to a drive device.

[0087] The main controller receives and converts data from the inertial measurement unit via a wireless Bluetooth module, runs a control algorithm to identify the motion phase, and issues drive commands to the drive device.

[0088] This system first completes the mechanical structure installation, then fixes the inertial measurement unit (IMU) to the forearm, thigh, and chest of the human body, allowing the IMU to move with the body and acquire posture information. A wireless Bluetooth module then connects to the IMU, enabling the real-time limb posture data measured by the IMU to be wirelessly transmitted to the main controller. The main controller processes the acquired data, converting it into limb state information and performing motion phase recognition. Then, the main controller sends data commands to the drive device based on the limb phase to drive the exoskeleton. Finally, the drive device rotates according to the data commands, driving a flexible rope fixed to a drum. The force generated by the contraction and release of the rope is transmitted to the corresponding limb, providing some motion assistance. Therefore, the mechanical structure and recognition algorithm of this system can effectively assist the upper and lower limbs in performing tasks, and it uses relatively few IMUs, featuring a simple structure, low cost, and easy operation.

[0089] Specifically, the inertial measurement unit uses wireless sensors.

[0090] During implementation, the actuation unit box is equipped with a protective tube 7 for guiding the flexible rope through the back anchor point. The protective tube prevents the flexible rope from swaying.

[0091] In practice, the limb restraints use a double-buckle structure 14 on the lower limbs and a palm-sleeve structure 15 on the upper limbs.

[0092] In practice, the actuation unit box is installed at the waist of the back of the vest. The actuation unit box is fixedly connected to the vest by adjusting bolts. A first adjusting nut and a second adjusting nut are respectively fitted onto the top and bottom surfaces of the actuation unit box by the adjusting bolts. The position of the box can be adjusted by the interaction between the adjusting bolts and the first and second adjusting nuts to achieve maximum user comfort.

[0093] In practice, the inertial measurement unit has a wireless data transmission module with a specified wireless connection address and a real-time limb posture data measurement module. The wireless Bluetooth module transmits the limb posture data to the main controller in the form of Bluetooth transmission.

[0094] Specifically, the sensor has a wireless data transmission module with a specified wireless connection address and a module for real-time measurement of limb posture information. An additional Bluetooth module can transmit the limb posture information to the main controller via Bluetooth.

[0095] Specifically, the main controller has a wireless data receiving module for connecting sensors, a power supply and signal bus for driving the motor, and the computing power required by the intent recognition module and the assist control module.

[0096] Specifically, the drive motor has a reducer inside, which enables the motor to have greater torque and provide better pulling effect.

[0097] The beneficial effects of the mechanical structure of the exoskeleton system provided by this invention are:

[0098] 1. Using flexible ropes to provide assistance can reduce the overall mass of the exoskeleton, providing assistance without hindering normal human activities.

[0099] 2. Wireless transmission reduces the disturbance of the rope to the user's free movement, improves the user's wearing experience, and ensures the stability of the system operation;

[0100] 3. The added drive motor reducer, when used in conjunction with the drive motor, can increase the torque of the drive motor, thereby increasing its load capacity and improving the reliability and durability of the overall system.

[0101] 4. The drive unit is fixed on both sides of the waist of the exoskeleton device to improve the efficiency of upper limb assistance; fixed above the buttocks, the drive unit provides assistance to the lower limbs when performing tasks such as climbing and going up and down stairs, maximizing the assistance effect and thus enhancing the user's strength.

[0102] 5. By preprocessing the human posture information from the sensor, the human posture information can be used to the maximum extent, and the misjudgment of the phase judgment module can be avoided as much as possible.

[0103] A method for controlling the mechanical structure of a flexible assistive exoskeleton system, such as Figure 3-8 Specifically, it includes the following steps:

[0104] S1: Self-check of the mechanical structure of the exoskeleton system; ensures that external devices can work properly and that the system can operate stably;

[0105] S2: Connect five inertial measurement units (IMUs); install the five IMUs on the two forearms, two thighs, and chest of the wearer using straps, and connect them to the main controller via a wireless Bluetooth module; to eliminate random errors caused by position and orientation during manual installation, the sensors need to be zeroed before the exoskeleton device is used for actual assistance. The specific experimental method is: the assistant fixes the sensors to the wearer's limbs, such as... Figure 4 As shown. Subsequently, the sensor and the central processing unit are connected, and the data is transmitted to the central processing unit wirelessly.

[0106] S3: Determine if the inertial measurement units (IMUs) are successfully connected; if yes, transmit the limb posture data measured in real time by the five IMUs to the main controller; if not, return to step S2. When human limb posture data is acquired, preprocess the data, filter the posture data, and remove noise information generated by the sensors to ensure the accuracy of limb phase judgment. The algorithm judges the phase based on the posture data and finally selects an appropriate assist strategy based on the corresponding phase.

[0107] S4: Mechanical structure parameter settings for the exoskeleton system; The wearer stands in an upright posture, and the main controller records the limb posture data at this time as the initial state;

[0108] S5: Preprocessing of acquired limb posture data; the data wirelessly transmitted from the inertial measurement unit to the main controller is quaternions. These quaternions are first preprocessed and converted into rotation matrices. Given a quaternion with a modulus of length 1, it can be calculated using the basic elements mentioned above in the following way:

[0109]

[0110] R is a rotation matrix of quaternion q. Smoothing filtering of each element of the rotation matrix can reduce or eliminate unwanted high-frequency noise in the signal and increase the stability of phase judgment. In order to enable the exoskeleton device to assist in more complex environments, the sensor devices of the limbs use the inertial measurement unit in the chest as the reference coordinate system.

[0111] S6: Determine limb phase;

[0112] S7: The main controller sends a drive command to the drive device, drives the motor to rotate according to the phase, and after completing one assist, returns to step S5, obtains limb posture data for preprocessing, and then proceeds to step S8.

[0113] S8: Feedforward modeling obtains exoskeleton parameters; the wearer can move freely, and a simplified model of the wearer is obtained by analyzing the limb posture data in the inertial measurement unit. Combined with the wearer's posture analysis when performing various motion tasks, the upper limb phase switching threshold T is obtained.11 T 12 and lower limb phase switching threshold T 21 T 22 T 23 The upper limb phase switching threshold T 11 T 12 and lower limb phase switching threshold T 21 T 22 T 23 Input into the main controller and return to step S4; repeat steps S4-S7 until the end.

[0114] During implementation, in step S6, when determining the limb phase:

[0115] 1) Upper limb posture phase judgment:

[0116] Based on the analysis of human upper limb movement posture, three human upper limb posture phases are obtained, namely phase S11, phase S12, and phase S13. The human movement posture is correlated with the phase. Phase S11 is the preparation phase, in which the human body is naturally suspended on a thin bar with both arms naturally extended, at time A. Phase S12 is the rising phase, in which the human body's arms and back exert continuous force, the angle between the upper arm and forearm and the torso decreases, and the entire torso is continuously rising, at time A to time B. Phase S13 is the descending phase, in which the angle between the upper arm and forearm increases, the angle between the upper arm and the torso increases, and the entire torso is continuously descending to return to phase S11, at time B to time C.

[0117] The switching conditions for the three phases S11, S12, and S13 are as follows:

[0118] The S11 phase switching condition is:

[0119] e) The preceding phase is the S13 phase;

[0120] f) The upper arm sensor posture measurement value α is greater than the threshold T 11 ;

[0121] The S12 phase switching condition is:

[0122] e) Upper arm sensor speed direction Upward, where the current direction of gravity is defined as the positive direction;

[0123] f) The preceding phase is the S11 phase;

[0124] The S13 phase switching condition is:

[0125] e) The upper arm sensor measurement value α is less than the threshold T 12 ;

[0126] f) The previous phase is S12;

[0127] If the current human body posture is in a certain phase, then determine whether the switching condition for the next phase is met. If the condition is met, switch to the next phase; otherwise, maintain the original phase.

[0128] 2) Lower limb posture phase judgment:

[0129] Based on the analysis of the human lower limb movement posture, three lower limb posture phases are obtained, namely phase S21, phase S22, and phase S23. The lower limb movement postures are correlated with the phases. Phase S21 is the ascending phase, in which the left or right foot naturally steps onto the step, and the angle between the thigh and the torso decreases, at time A1. Phase S22 is the assisting phase, in which the left or right leg begins to exert force, the angle between the thigh and the torso gradually increases, and the torso moves towards the step, at time B1. Phase S23 is the stationary phase, in which both legs are stationary on the step, at time C1.

[0130] The switching conditions for the three phases S21, S22, and S23 are as follows:

[0131] The S21 phase switching condition is:

[0132] e) The lower limb sensor posture measurement value θ is less than the threshold T 21 ;

[0133] f) The preceding phase is S23;

[0134] The S22 phase switching condition is:

[0135] i) The lower limb sensor posture measurement value θ is greater than the threshold T 22 ;

[0136] j) Lower limb sensor velocity direction Upward, where the direction of gravitational acceleration is defined as the positive direction;

[0137] k) Lower limb sensor acceleration and velocity directions Consistent;

[0138] l) The previous phase is S21;

[0139] The S23 phase switching condition is:

[0140] e) The lower limb sensor posture measurement value θ is less than the threshold T 23 ;

[0141] f) The preceding phase is S22;

[0142] If the human body is in a certain phase at the current moment, it is determined whether the switching conditions for the next phase are met. If the conditions are met, the body switches to the next phase; otherwise, the body maintains the original phase.

[0143] During implementation, in step S7, the main controller sends a drive command to the drive device, which drives the motor to rotate according to the phase, and the drive device assists in control.

[0144] 1) Upper limb phase-assisted control:

[0145] When in phase S11, the drive unit remains stationary;

[0146] When in phase S12, the body moves upward and the drive device drives the upper limb drive motor to rotate at a certain speed to assist the upper limb. The assistance stops after the phase switches to the next phase.

[0147] When in phase S13, the body has completed the pull-up task, and the drive device rotates in the opposite direction at a certain speed and time, so that the upper limbs have enough space to perform only activities.

[0148] 2) Lower limb phase-assisted control:

[0149] When in phase S21, the drive unit remains stationary;

[0150] When in phase S22, the left or right leg moves upward, and the drive device drives the lower limb drive motor to rotate at a certain speed to assist the lower limb. The assistance stops after the phase switches to the next phase.

[0151] When in phase S23, the body has already climbed the steps, and the drive device rotates in the opposite direction at a certain speed and time, giving the lower limbs enough space to move freely.

[0152] Finally, it should be noted that those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for controlling the mechanical structure of a flexible assistive exoskeleton system, characterized in that, Specifically, the following steps are included: S1: Self-check of the mechanical structure of the exoskeleton system; S2: Connect five inertial measurement units; install the five inertial measurement units on the two forearms, two thighs and chest of the human body with straps, and connect the five inertial measurement units to the main controller via a wireless Bluetooth module; S3: Determine whether the inertial measurement units are successfully connected; if yes, transmit the limb posture data measured in real time by the five inertial measurement units to the main controller; if no, return to step S2. S4: Mechanical structure parameter settings for the exoskeleton system; The wearer stands in an upright posture, and the main controller records the limb posture data at this time as the initial state; S5: Preprocessing of acquired limb posture data; the data wirelessly transmitted from the inertial measurement unit to the main controller is quaternions. These quaternions are first preprocessed and converted into rotation matrices. Given a quaternion with a modulus of length 1, it can be calculated using the above basic elements in the following way: R is a rotation matrix of quaternion q. Smoothing filtering of each element of the rotation matrix can reduce or eliminate unwanted high-frequency noise in the signal and increase the stability of phase judgment. In order to enable the exoskeleton device to assist in more complex environments, the sensor devices of the limbs use the inertial measurement unit in the chest as the reference coordinate system. S6: Determine limb phase; S7: The main controller sends a drive command to the drive device, drives the motor to rotate according to the phase, and after completing one assist, returns to step S5, obtains limb posture data for preprocessing, and then proceeds to step S8. S8: Feedforward modeling obtains exoskeleton parameters; the wearer can move freely, and a simplified model of the wearer is obtained by analyzing the limb posture data in the inertial measurement unit. Combined with the wearer's posture analysis when performing various motion tasks, the upper limb phase switching threshold T is obtained. 11 T 12 and lower limb phase switching threshold T 21 T 22 T 23 The upper limb phase switching threshold T 11 T 12 and lower limb phase switching threshold T 21 T 22 T 23 Input into the main controller and return to step S4; repeat steps S4-S7 until the end; In step S6, when determining limb phase: 1) Upper limb posture phase judgment: Based on the analysis of human upper limb movement posture, three human upper limb posture phases were obtained: S11, S12, and S13. These phases were then correlated with the human movement posture. Phase S11 represents the preparation phase, where the body is naturally suspended on a thin bar with arms naturally extended, at time A. Phase S12 represents the ascent phase, where the arms and back exert continuous force, the angle between the upper arm and forearm and the torso decreases, and the entire body continuously rises, from time A to time B. Phase S13 represents the descent phase, where the angle between the upper arm and forearm increases, the angle between the upper arm and torso increases, and the entire body continuously descends to return to phase S11, from time B to time C. The switching conditions for the three phases S11, S12, and S13 are as follows: The S11 phase switching condition is: a) The previous phase is phase S13; b) Upper arm sensor posture measurement values Greater than threshold T 11 ; The S12 phase switching condition is: a) Upper arm sensor speed direction Upward, where the current direction of gravity is defined as the positive direction; b) The preceding phase is the S11 phase; The S13 phase switching condition is: a) Upper arm sensor measurements Less than threshold T 12 ; b) The previous phase is S12; If the current human body posture is in a certain phase, then determine whether the switching condition for the next phase is met. If the condition is met, switch to the next phase; otherwise, maintain the original phase. 2) Lower limb posture phase judgment: Based on the analysis of the human lower limb movement posture, three lower limb posture phases are obtained, namely phase S21, phase S22, and phase S23. The lower limb movement postures are correlated with the phases. Phase S21 is the ascending phase, in which the left or right foot naturally steps onto the step, and the angle between the thigh and the torso decreases, at time A1. Phase S22 is the assisting phase, in which the left or right leg begins to exert force, the angle between the thigh and the torso gradually increases, and the torso moves towards the step, at time B1. Phase S23 is the stationary phase, in which both legs are stationary on the step, at time C1. The switching conditions for the three phases S21, S22, and S23 are as follows: The S21 phase switching condition is: a) Lower limb sensor posture measurement values Less than threshold T 21 ; b) The previous phase is S23; The S22 phase switching condition is: a) Lower limb sensor posture measurement values Greater than threshold T 22 ; b) Lower limb sensor velocity direction Upward, where the direction of gravitational acceleration is defined as the positive direction; c) Direction of acceleration and direction of velocity of lower limb sensor Consistent; d) The previous phase is S21; The S23 phase switching condition is: a) Lower limb sensor posture measurement values Less than threshold T 23 ; b) The preceding phase is S22; If the human body is in a certain phase at the current moment, it is determined whether the switching conditions for the next phase are met. If the conditions are met, the body switches to the next phase; otherwise, the body maintains the original phase.

2. The control method for the mechanical structure of a flexible assistive exoskeleton system according to claim 1, characterized in that, In step S7, the main controller sends a drive command to the drive unit, which drives the motor to rotate according to the phase, and the drive unit assists in the control. 1) Upper limb phase-assisted control: When in phase S11, the drive unit remains stationary; When in phase S12, the body moves upward and the drive device drives the upper limb drive motor to rotate at a certain speed to assist the upper limb. The assistance stops after the phase switches to the next phase. When in phase S13, the body has completed the pull-up task, and the drive device rotates in the opposite direction at a certain speed and time, so that the upper limbs have enough space to move freely. 2) Lower limb phase-assisted control: When in phase S21, the drive unit remains stationary; When in phase S22, the left or right leg moves upward, and the drive device drives the lower limb drive motor to rotate at a certain speed to assist the lower limb. The assistance stops after the phase switches to the next phase. When in phase S23, the body has already climbed the steps, and the drive device rotates in the opposite direction at a certain speed and time, giving the lower limbs enough space to move freely.

3. A mechanical structure for a flexible assistive exoskeleton system, used to implement the control method as described in claim 1 or 2, characterized in that, It includes an actuation unit box, a drive unit, a main controller, a power module, an intent detection component, and an assist unit; The drive unit, main controller, and power module are installed inside the actuation unit box; The drive device includes two upper limb drive components and two lower limb drive components, and the drive device receives control commands from the main controller. The upper limb drive assembly includes two upper limb drive motors and an upper limb drive shaft driven by the upper limb drive motors; The lower limb drive assembly includes two lower limb drive motors and a lower limb drive shaft driven by the lower limb drive motors; The power module supplies power to the drive unit and the main controller; The intent detection component includes an inertial measurement unit and a wireless Bluetooth module. The inertial measurement unit is installed on the two forearms, two thighs, and chest of the human body via straps. The wireless Bluetooth module is connected to the main controller via a serial port and is installed inside the actuation unit box. The assist unit includes a limb restraint and a flexible rope, one end of which is connected to the limb restraint and the other end of which is connected to a drive device. The main controller receives and converts data from the inertial measurement unit via a wireless Bluetooth module, runs a control algorithm to identify the motion phase, and issues drive commands to the drive device.

4. The mechanical structure of a flexible assistive exoskeleton system according to claim 3, characterized in that, The actuation unit box is equipped with a protective tube for guiding the flexible rope out through the back anchor point.

5. The mechanical structure of a flexible assistive exoskeleton system according to claim 4, characterized in that, The limb restraints use a double-buckle structure on the lower limbs and a palm-sleeve structure on the upper limbs.

6. The mechanical structure of a flexible assistive exoskeleton system according to claim 3, characterized in that, The actuation unit box is installed on the back waist of the vest. The actuation unit box is fixedly connected to the vest by adjusting bolts. The adjusting bolts are fitted with a first adjusting nut and a second adjusting nut on the top and bottom surfaces of the actuation unit box, respectively.

7. The mechanical structure of a flexible assistive exoskeleton system according to claim 3, characterized in that, The inertial measurement unit has a wireless data transmission module with a specified wireless connection address and a real-time limb posture data measurement module. The wireless Bluetooth module transmits the limb posture data to the main controller in the form of Bluetooth transmission.

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