Intelligent power assisting device for assisting assembly of aircraft parts and control method

Abstract

The invention discloses an intelligent power assisting device for assisting assembly of aircraft parts and a control method. The intelligent power assisting device comprises a power assisting skeleton unit; the human body signal sensing unit comprises an electromyographic signal sensor for detecting electromyographic signals of calf muscles and an elastic bandage which is used for detecting change signals of thigh muscles and is embedded with a graphene sensor; the control unit is used for controlling the hip joint disc type motor, the knee joint disc type motor and the ankle joint disc type motor according to sensing signals of the hip joint unit, the knee joint unit, the ankle joint unit and the human body signal sensing unit. A fusion control method of various types of sensors such as a myoelectricity sensor, a graphene sensor, an RFID, a pressure sensor, a torque sensor and an angular acceleration sensor is applied to an intelligent power assisting device for assisting assembly of aircraft parts, the human body motion intention can be rapidly and accurately obtained, and misjudgment of the motion intention is avoided; the efficient and flexible power assisting function of various complex operation scenes such as single-leg kneeling posture operation, walking, squatting and standing, sitting and heavy object carrying in a narrow space is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of robots, and in particular relates to an intelligent power-assisting device for assisting in assembling aircraft components and a control method thereof. Background Art

[0002] With the development of exoskeleton robot technology, exoskeleton robots are currently widely used in various industrial technology fields.

[0003] Patent document CN109223456A discloses a lower-limb exoskeleton robot system based on end-user interaction. This robot system uses six-dimensional force sensors within the back frame to detect upper body tilt and squatting intentions. Because squatting posture is primarily controlled by lower limb muscles, the six-dimensional force sensors within the back frame detect squatting intentions with delays and misjudgments, making it impossible to quickly and effectively identify squatting intentions, and failing to achieve intelligent assistance for motion intention perception through multi-sensor fusion. The control system and sensors are integrated into the back frame. In complex industrial assembly scenarios, the back frame design seriously hinders workers' flexible movements such as bending, squatting, and half-kneeling.

[0004] Patent document CN209316409U discloses a wearable electric-powered exoskeleton lower limb mechanism, primarily used for assisted rehabilitation and assisting lower limb rehabilitation training. It is not suitable for complex industrial operations such as aircraft assembly, where it can control and assist in complex postures such as weight-bearing and single-leg kneeling. The wearer's movement intention is controlled by mechanical information collected by force sensors in the thigh and calf. However, the force sensors in the thigh and calf can only collect mechanical information when the legs produce corresponding movements, resulting in a lag in movement intention perception. This makes it impossible to quickly perceive movement intention and is prone to misjudgment. Furthermore, multi-sensor fusion of movement intention perception is not possible.

[0005] Patent document CN110695959A discloses an exoskeleton robot and its control system for assisting weight-bearing walking. However, the robot can only complete weight-bearing walking under a fixed walking gait and is not suitable for complex industrial operation scenarios such as aircraft assembly operations, such as controlling and assisting complex postures such as human weight-bearing carrying and single-leg kneeling operations. Motion control is achieved through pressure sensors, which cannot fully perceive the human muscle movement intention, easily leading to misjudgment of movement intention, and fails to achieve intelligent assistance for motion intention perception through multi-sensor fusion.

[0006] Patent document CN108161905A discloses a variable-stiffness lower-limb exoskeleton-assisted robot. This lower-limb exoskeleton achieves human-machine interaction through a crutch unit, a waist gyroscope, and a plantar pressure information acquisition unit. The robot uses crutch support to support the wearer and capture the wearer's movement intentions, thereby helping the wearer walk. The robot requires crutches to assist walking and capture the wearer's movement intentions, and the wearer must hold the crutches, making it impossible to complete any work. Furthermore, the wearer's mobility is limited and cannot meet the demands of any fast-paced production site. The hip joint and leg components are driven by two hydraulic cylinders, which increases the product's weight and size, making it impossible to use in any confined space.

[0007] Patent document CN 115531144A discloses a lower-limb exoskeleton robot that assists in standing up. This exoskeleton uses a hydraulic swing cylinder to rotate the thigh rod, meeting the required angle of hip joint rotation during standing up. The standing motion is controlled by electro-hydraulic servo control of the knee joint. The exoskeleton only provides walking assistance with a single, fixed gait, and cannot meet the flexibility requirements of workers in aircraft manufacturing sites who frequently switch between different work scenarios.

[0008] Patent document CN115531144A discloses a lower limb exoskeleton robot that assists in standing up. This exoskeleton uses a hydraulic swing cylinder to drive the thigh rod for rotational motion, meeting the angle requirements for hip joint rotation during standing up, and controls the standing motion by controlling the knee joint electro-hydraulic servo. This device can only provide assistance in a single fixed standing up scenario, and cannot accurately and effectively capture the human body's movement intention in a timely, accurate, and effective manner. It is also unable to achieve assistance scenarios such as maintaining assistance in squatting, switching squatting movements without a fixed time, and squatting to carry heavy objects. It lacks the motion intention perception function of multi-sensor fusion and can only work in a fixed single assistance scenario. It cannot meet the complex scenarios and flexible work requirements of aircraft assembly. In addition, the lack of intelligent sensors makes the wearer inconvenient to move when switching between work scenarios, affecting the normal work of workers. Summary of the Invention

[0009] The purpose of the present invention is to provide an intelligent power-assisting device and control method for assisting the assembly of aircraft components, so as to solve the problems existing in existing exoskeleton robots in actual assembly scenarios, such as the inability to flexibly switch movements and the large impact force during movement switching.

[0010] The present invention is achieved through the following technical solutions:

[0011] Intelligent power assist devices for assisting in the assembly of aircraft components, including:

[0012] A power-assisted skeletal unit, comprising a hip joint connecting plate, a hip joint unit, a knee joint connecting plate, a knee joint unit, an ankle joint connecting plate, an ankle joint unit, and a foot connecting plate; the hip joint unit, the knee joint unit, and the ankle joint unit all comprise a disc motor, a torque sensor, and an angular acceleration sensor; the disc motors of the hip joint unit, the knee joint unit, and the ankle joint unit are respectively a hip joint disc motor, a knee joint disc motor, and an ankle joint disc motor; the torque sensors of the hip joint unit, the knee joint unit, and the ankle joint unit are respectively a hip joint torque sensor, a knee joint torque sensor, and an ankle joint torque sensor;

[0013] The human body signal sensing unit includes an electromyographic signal sensor for detecting calf muscle electromyographic signals and an elastic bandage embedded with a graphene sensor for detecting thigh muscle change signals;

[0014] A control unit controls the hip joint disc motor, the knee joint disc motor and the ankle joint disc motor according to sensing signals from the hip joint unit, the knee joint unit, the ankle joint unit and the human body signal sensing unit.

[0015] In some embodiments, the control unit recognizes the human body's intention to squat, maintain a single-leg kneeling position, maintain a double-leg sitting position, or walk while carrying heavy objects through the acquired sensor signals, and controls the hip joint disc motor, knee joint disc motor, and ankle joint disc motor.

[0016] In some embodiments, the control unit identifies the intention of maintaining a single-leg kneeling posture or a double-leg sitting posture through the torque values ​​of the ankle torque sensor, the knee torque sensor, the hip torque sensor, and the sensing signals of the electromyography signal sensor and the graphene sensor, and controls the disc motor to lock and not rotate or to provide a counter torque to support the joint according to the deformation of the elastic bandage and the threshold value calibrated by the torque sensor.

[0017] In some embodiments, the control unit releases the lock on each disc motor and puts the disc motor into a follow-up state when it determines that the human body has a tendency to squat, stand up, or walk based on changes in the output signals of the electromyographic signal sensor and the graphene sensor and changes in the torque values ​​of the ankle torque sensor, the knee torque sensor, and the hip torque sensor.

[0018] In some embodiments, the control unit obtains the acceleration changes of each joint of the lower limbs of the human body during squatting and standing up through an angular acceleration sensor, and controls the hip joint disc motor, knee joint disc motor, and ankle joint disc motor.

[0019] In some embodiments, the hip joint unit, the knee joint unit, and the ankle joint unit all include encoders, and the control unit obtains the rotation speed of the disc motor through the encoder and performs closed-loop control on the disc motor.

[0020] In some embodiments, pneumatic dampers are provided between the ankle joint unit and the knee joint connecting plate, and between the knee joint unit and the ankle joint connecting plate.

[0021] In some embodiments, a pressure sensor is provided on the foot connecting plate;

[0022] The control unit captures the change of the sole pressure through the pressure sensor and controls the hip joint disc motor, the knee joint disc motor and the ankle joint disc motor.

[0023] On the other hand, the present invention also provides an intelligent power-assistance control method for assisting the assembly of aircraft components, which uses the intelligent power-assistance device, including obtaining sensor signals from the hip joint unit, knee joint unit, ankle joint unit and human signal sensing unit, identifying the human body's squatting, single-leg kneeling work, double-leg sitting, and carrying heavy objects and walking movement intentions based on the sensor signals, and controlling the hip joint disc motor, knee joint disc motor, and ankle joint disc motor.

[0024] In some embodiments, the control logic for performing the squat action is:

[0025] When it is determined whether the human body intends to squat, the disc motors at the ankle joint, knee joint, and hip joint are controlled to generate torque to assist the human body in performing the squat action;

[0026] The human body is judged to have the intention to squat when the following conditions are met, including: the electromyographic signal exceeds the threshold, the elastic bandage on the thigh detects deformation, the pressure sensor installed on the foot connection plate detects the change of the human body's center of gravity, the ankle / hip joint torque sensor detects counterclockwise torque change, and the knee joint torque sensor detects clockwise torque change.

[0027] In some embodiments, when it is determined that the human body performs a squatting action to a movement position, the disc motors at the ankle joint, knee joint, and hip joint are automatically locked, and a single-leg kneeling position and a double-leg sitting position are performed;

[0028] The human body is judged to have performed a squatting action to the movement position when the following conditions are met, including: the deformation of the elastic bandage at the thigh is less than a threshold, the angular acceleration sensor detects that the angular acceleration is zero, and the torque value of the torque sensor does not change.

[0029] In some embodiments, the method further includes the steps of recognizing the human body's intention to stand up and controlling the hip joint disc motor, the knee joint disc motor, and the ankle joint disc motor, including:

[0030] When it is determined that the human body intends to stand, the disc motors at the ankle, knee and hip joints are unlocked and follow the human body to perform follow-up movements;

[0031] The human body is judged to have the intention to stand when the following conditions are met, including: the electromyographic signal exceeds the no-load threshold, the elastic bandage at the thigh detects deformation, the pressure sensor detects the change of the human body's center of gravity, the ankle / hip torque sensor detects a clockwise torque change, and the knee torque sensor detects a clockwise torque change.

[0032] In some embodiments, when the deformation of the elastic bandage at the thigh returns to its original value, the angular acceleration sensor detects that the angular acceleration is zero, and the torque value of the torque sensor returns to the size of the human body standing state and no longer changes, it is determined that the human body has completed standing.

[0033] In some embodiments, the method further includes the steps of identifying the human body's intention to carry heavy objects and controlling the hip joint disc motor, the knee joint disc motor, and the ankle joint disc motor, including:

[0034] After determining that the human body has squatted to a predetermined position and identifying that the human body intends to lift a heavy object and stand up, the hip joint disc motor, the knee joint disc motor, and the ankle joint disc motor are controlled to generate torque;

[0035] When the following conditions are met, it is judged that the human body has the intention to lift heavy objects, including: the electromyographic signal exceeds the no-load threshold, the elastic bandage on the thigh detects deformation, the pressure sensor detects pressure changes that exceed the weight of the human body, the ankle torque sensor detects clockwise torque changes, the knee torque sensor detects counterclockwise torque changes, and the hip torque sensor detects clockwise torque changes.

[0036] In some embodiments, when the elastic bandage, electromyographic signal sensor and pressure sensor at the thigh detect regular changes in the center of gravity of the human body and the monitored deformation changes to the unloaded walking state value, it is determined that the human body is walking freely without weight, and the disc motor is controlled to follow the movement.

[0037] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0038] Aiming at the complex working scenarios in various confined spaces during aircraft production and assembly, the present invention applies the fusion control method of various types of sensors, such as electromyography sensors, graphene sensors, RFID, pressure sensors, torque sensors, and angular acceleration sensors, to an intelligent power-assisting device that assists in the assembly of aircraft components. This device can quickly and accurately obtain the human body's movement intentions and avoid misjudgment of movement intentions; it can achieve efficient and flexible power-assisting functions in various complex working scenarios in confined spaces, such as single-leg kneeling work, walking, squatting, sitting, and carrying heavy objects.

[0039] The present invention adopts a multi-stage elastic pneumatic damper as a flexible support skeleton, which can not only realize the gravity and torque transmission functions required by the auxiliary aircraft component assembly power assist device, but also provide cushioning for the lower limb joints of the human body in load-bearing scenarios, greatly improving the power assist effect and the comfort of the human-computer interaction system.

[0040] The power-assisting device of the present invention can be worn on one leg to maintain and assist a single-leg kneeling position, or it can be worn on both legs to provide assistance in various working conditions such as maintaining a squatting position and carrying heavy objects, thereby reducing the risk of aircraft assembly workers suffering from occupational diseases and effectively supporting the needs of rapid and precise aircraft development and high-quality and efficient mass production.

[0041] This invention utilizes an intelligent perception control strategy based on multi-sensor fusion, enabling automatic switching for specific work scenarios in the confined spaces of aircraft assembly. The design also implements logic for flexible switching of the power assist device during squatting, single-leg kneeling, sitting, heavy object handling, and walking, effectively addressing the technical difficulties associated with high-impact work scenarios such as squatting, single-leg kneeling, and ground contact during human-machine collaboration. Furthermore, the interactive use of multiple sensor fusions enables flexible switching of the power assist device during complex tasks, allowing for rapid and accurate perception and capture of human motion intent. This system offers advantages such as high control precision and rapid response. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings in the embodiments will be briefly introduced below. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0043] Figure 1 This is a schematic structural diagram of an intelligent power assist device according to an embodiment of the present invention.

[0044] Figure 2 Schematic diagram of the electromyographic signal of the tibialis anterior muscle.

[0045] Figure 3 This is a control flow chart of an implementation method of the intelligent power assistance control method according to an embodiment of the present invention.

[0046] Figure 4 This is a control flow chart of another implementation of the intelligent power assistance control method according to an embodiment of the present invention.

[0047] in:

[0048] 1. Hip joint connecting plate, 2. Hip joint unit, 3. Knee joint connecting plate, 4. Knee joint unit, 5. Ankle joint connecting plate, 6. Ankle joint unit, 7. Foot connecting plate, 8. Pressure sensor, 9. Pneumatic damper, 10. Elastic bandage. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0050] Existing exoskeleton robots lack intelligent perception and control strategies based on multi-sensor fusion, and are unable to automatically switch between specific operating scenarios in aircraft assembly. In addition, they are not designed with logic for flexible and free switching of power-assistance devices during squatting, kneeling on one leg, sitting, carrying heavy objects, and walking. This results in high impact in operating scenarios such as squatting, kneeling on one leg, and touching the ground during human-machine collaboration.

[0051] In addition, due to the lack of interactive utilization of multiple sensor fusions, the power assist device is unable to flexibly switch and quickly perceive the human body's movement intentions when performing complex tasks, and is unable to accurately judge and capture movement intentions. There are also problems such as low system control accuracy, slow response, and misjudgment of movement intentions.

[0052] To address the above problems, the intelligent power-assisting device of the present invention can be worn on one leg, enabling one-legged kneeling posture maintenance and work assistance, and can also be worn on both feet, enabling flexible assistance in various narrow spaces such as squatting and sitting posture maintenance and carrying heavy objects.

[0053] The intelligent power assist device for aircraft component assembly can assist in various specific aircraft assembly scenarios, such as squatting and sitting in confined spaces, single-leg kneeling, and heavy lifting, while ensuring that normal walking speed and flexibility are not affected by the device. The intelligent power assist device can be flexibly switched between work scenarios. It can be worn on one leg to maintain and assist single-leg kneeling positions, and can be worn on both legs to assist squatting and sitting and lifting heavy objects.

[0054] The intelligent power-assisting device and control method of the present invention adopt multi-sensor fusion perception, which can achieve precise control of the power-assisting device and rapid response to human movement intentions, avoiding misjudgment of movement intentions.

[0055] Reference Figure 1 The intelligent power-assisting device has three degrees of freedom, including rotational pairs arranged at the hip joint, knee joint and ankle joint respectively, and is driven by a disc motor. While providing the torque required for the operation, it can realize flexible rotation of each joint.

[0056] At the hip, knee and ankle joints, they are connected by a flexible skeleton composed of multi-stage elastic pneumatic dampers, and the weight and pressure of the human joints are transferred to the ground through the foot connection plate on the sole of the foot. This flexible skeleton can ensure the flexibility of the device while ensuring the adaptability of the disc motor to the joints of the human body.

[0057] In some embodiments of the present invention, the intelligent power-assisting device includes a power-assisting skeletal unit, including a hip joint connecting plate 1, a hip joint unit 2, a knee joint connecting plate 3, a knee joint unit 4, an ankle joint connecting plate 5, an ankle joint unit 6, and a foot connecting plate 7; the hip joint unit 2, the knee joint unit 4, and the ankle joint unit 6 each include a disc motor, a torque sensor, and an angular acceleration sensor, wherein the disc motors of the hip joint unit, the knee joint unit, and the ankle joint unit are respectively a hip joint disc motor, a knee joint disc motor, and an ankle joint disc motor, and the torque sensors of the hip joint unit, the knee joint unit, and the ankle joint unit are respectively a hip joint torque sensor, a knee joint torque sensor, and an ankle joint torque sensor;

[0058] The human body signal sensing unit includes an electromyographic signal sensor for detecting electromyographic signals of calf muscles and an elastic bandage 10 embedded with a graphene sensor for detecting change signals of thigh muscles;

[0059] The control unit controls the hip joint disc motor, the knee joint disc motor and the ankle joint disc motor according to the sensing signals of the hip joint unit, the knee joint unit, the ankle joint unit and the human body signal sensing unit.

[0060] like Figure 1 The intelligent power-assisting device shown includes an electromyographic signal sensor, a graphene sensor, a pressure sensor, a foot connecting plate 7, an ankle joint disc motor, an ankle joint torque sensor, an ankle joint angular acceleration sensor, an ankle joint encoder, an ankle joint reducer, an ankle joint connecting plate, a knee joint multi-stage elastic pneumatic damper 9, a knee joint disc motor, a knee joint torque sensor, a knee joint angular acceleration sensor, an ankle joint encoder, an ankle joint reducer, a knee joint connecting plate 3, a hip joint multi-stage elastic pneumatic damper 9, a hip joint disc motor, a hip joint torque sensor, a hip joint angular acceleration sensor, a hip joint encoder, a hip joint reducer, a hip joint connecting plate and an elastic bandage 10 embedded with a graphene sensor.

[0061] Among them, the disc motors of the ankle joint, knee joint and hip joint are used to provide rotational power at each joint.

[0062] Each torque sensor is used to detect the torque changes at each joint, and can determine the magnitude and direction of the torque at each joint of the human body.

[0063] The electromyographic signal sensor is fixed to the wearer's calf muscles. By real-time monitoring of the calf muscle force and changes in electromyographic signals under different movements, the corresponding movement intentions of the human body can be quickly identified.

[0064] The EMG sensor collects surface EMG (sEMG) signals from human muscles. Surface EMG signals can be used to reflect muscle activity and quantify muscle energy consumption and muscle status. By collecting sEMG signals and performing rectification, fourth-order Butterworth filtering, and normalization, a standardized EMG matrix is ​​obtained. The standardized EMG matrix is ​​subjected to non-negative matrix factorization and dimensionality reduction to obtain an EMG signal that can be used to assess muscle activity intensity.

[0065] The non-negative matrix expression is shown in formula (1):

[0066] Y0=Z0C+a

[0067]

[0068] Where Y0 is the collected electromyographic signal value; Z0 is the weight system between each muscle in the main component; C is the weight coefficient; a is the error; FRO is the Frobenius norm.

[0069] Among them, the main component is related to the cumulative contribution rate VAF, and its expression is:

[0070]

[0071] Where s is the duration and m is the number of muscles measured.

[0072] When the human body performs a certain action, the muscles first generate corresponding changes in myoelectric signals, and then generate corresponding actions. Therefore, the use of myoelectric signal sensors can quickly and efficiently identify the human body's movement intentions based on the changes in the myoelectric signals of the corresponding muscles. Taking the human body performing squatting as an example, when the human body intends to squat, the triceps surae, tibialis anterior, tibialis posterior, peroneus longus and peroneus brevis muscles will exert force. For example, in the initial stage of squatting, the tibialis anterior helps control the stability of the ankle to prevent excessive forward leaning, such as Figure 2 As shown in the figure, the tibialis anterior muscle EMG signal changes significantly during the initial squat compared to the normal standing phase, allowing for early prediction of movement intentions. Based on the changes in the calf muscle EMG signal during different movements, the corresponding movement intentions can be quickly identified.

[0073] The elastic bandage embedded with graphene sensors is extremely sensitive to environmental changes and can detect extremely small physical changes. The elastic bandage on the thigh is used as an RFID tag, and together with the RFID reader and antenna set up near the worker's working area, it forms a radio frequency communication to achieve real-time monitoring and identification of human movement intentions.

[0074] The two-dimensional structure of the graphene sensor makes it extremely sensitive to environmental changes and can detect extremely small physical changes. By embedding the graphene sensor in an elastic bandage, it can achieve highly sensitive, rapid and continuous response to the human body's movement status.

[0075] When the graphene sensor is subjected to a small external force such as elastic force or pressure, its geometric dimensions (such as graphene length or cross-sectional area) change, resulting in the output value a of the graphene sensor. x The expression for the change is:

[0076]

[0077] Where η is the resistivity of graphene, C is the length of the graphene material, and M is the cross-sectional area of ​​the graphene material.

[0078] The sensitivity of the graphene sensor is: (Δa1 / a0) / ΔX;

[0079] Where a0 is the initial output resistance of the sensor, Δa1 is the resistance change, and ΔX is the strain of the sensor.

[0080] Based on the properties of the thigh elastic bandage with embedded graphene sensors when it is subjected to tiny stretching and compression deformation of human muscles, radio frequency identification technology (RFID) is used to automatically identify the target object and obtain relevant data through radio signals without direct or visual contact.

[0081] The elastic bandage on the thigh is used as an RFID tag, and RFID readers and antennas are set up near the working area to achieve real-time monitoring and identification of human movement intentions.

[0082] Through the torque sensors of the ankle, knee and hip joints, the electromyographic signal sensors at the calves and the graphene sensors embedded in the elastic bandages, the human body's intentions for single-leg kneeling, double-leg squatting, sitting and other work movements are identified. Based on the deformation of the elastic bandage at the thigh and the threshold calibrated by the torque sensor, the motor is controlled to lock and not rotate, or provide a counter-torque to support the change of joint torque, thereby achieving assistance for single-leg kneeling, double-leg squatting, sitting and other work at any angle.

[0083] In the squatting state, the electromyographic signal sensors fixed to the calf muscles first identify and judge the force exerted by each muscle. The graphene sensor in the elastic bandage outputs the signal change value. Then the torque sensor identifies the changes in torque of the ankle joint, knee joint, and hip joint. When the above information is used to jointly determine that the human body has a tendency to stand up, the lock of the disc motors at each joint is canceled, and the disc motors enter the follow-up state. At this time, the human body can complete the standing action according to its own intention.

[0084] Angular acceleration sensors are used to capture the changes in acceleration of the joints of the lower limbs during sitting and standing. They are also used to determine the human body's movement intentions and control the forward and reverse rotation or lock the disc motor through the signal from the angular acceleration sensor.

[0085] A reducer is connected to the output shaft of the disc motor at each joint to reduce the rotation speed of the disc motor at each joint, thereby increasing the torque.

[0086] An encoder is used to obtain feedback on the disc motor speed, thereby forming a closed-loop control, making the disc motor control more precise.

[0087] The multi-stage elastic pneumatic damper 9 is installed below the hip joint and knee joint, so that the power assist device has a certain flexibility and plays a buffering role. At the same time, it can ensure the adaptability of the disc motor and the joints of the human body during walking.

[0088] The hip joint connecting plate, knee joint connecting plate and ankle joint connecting plate in the connecting frame can be adjusted in height according to the height of the human body. They are made of carbon fiber, which ensures rigidity while being lighter in weight.

[0089] Several pressure sensors 8 are arranged on the foot connecting plate 7. When the human body kneels on one leg, carries heavy objects, bears weight, walks, or squats, the pressure on the sole of the foot will change with different characteristics. The pressure sensor arranged on the sole of the foot can capture the change in sole pressure, and cooperate with the graphene sensor, electromyographic signal sensor, torque sensor, and angular acceleration sensor in the elastic bandage on the thigh to identify the working mode and movement state, and then control the disc motor to switch the power assistance mode of the device in different working scenarios.

[0090] The foot connecting plate 7 is used to set the pressure sensor 8, and transmits the weight and pressure of the human body to the ground when the human body performs actions such as carrying heavy objects, carrying weights, walking, squatting, etc.

[0091] In some embodiments of the present invention, the intelligent power-assistance control method for assisting aircraft component assembly performs a control algorithm logic diagram for maintaining a single-leg kneeling posture, maintaining a double-leg sitting posture, and carrying heavy objects, as shown in FIG. Figure 3 and Figure 4 shown.

[0092] Specifically include:

[0093] a) During human walking, when the graphene sensor, electromyographic signal sensor, and sole pressure sensor detect that the center of gravity of the human body changes regularly and the muscles exerting force and deformation are in the state of unloaded walking, it is determined that the human body is performing unloaded free walking, and the control disc motor is in the follow-up state.

[0094] b) When the human body is performing a single-leg kneeling position or a double-leg sitting position, the following six conditions must be met simultaneously:

[0095] If the corresponding electromyographic signal of the calf exceeds the threshold, the elastic bandage on the thigh detects a slight deformation, the pressure sensor senses the change in the human body's center of gravity, the ankle / hip torque sensor detects a counterclockwise torque change, and the knee torque sensor detects a clockwise torque change, it is determined that the human body has the intention to squat.

[0096] At this time, the disc motors at the ankle, knee, and hip joints are controlled to generate adaptive torque to assist the human body in squatting. At the same time, the angular acceleration sensors at each joint are used to detect changes in angular acceleration at each joint. When the deformation of the elastic bandage at the thigh is less than the threshold, the angular acceleration sensor detects that the angular acceleration is zero, and the torque no longer changes, it is determined that the human body has squatted to the predetermined position. At this time, the disc motors at the ankle, knee, and hip joints are automatically locked to assist the human body in sitting work.

[0097] c) When a person needs to stand up, determine whether the following six conditions are met:

[0098] The corresponding electromyographic signal of the calf exceeds the no-load threshold, the elastic bandage at the thigh detects a slight deformation, the pressure sensor detects a change in the center of gravity of the human body, the ankle / hip torque sensor detects a trend of clockwise torque change, and the knee torque sensor detects a trend of clockwise torque change.

[0099] If the above six conditions are met at the same time, it is determined that the human body has the intention to stand. At this time, the disc motors at the ankle joint, knee joint, and hip joint are unlocked and follow the human body to restore the standing state.

[0100] d) When the human body performs the task of squatting and carrying heavy objects, its control process is mainly divided into three steps: squatting, carrying heavy objects and standing up.

[0101] In the squat process, the human body's movement intention is first determined when the following six conditions are met at the same time:

[0102] If the corresponding electromyographic signal of the calf exceeds the threshold, the elastic bandage on the thigh detects a slight deformation, the pressure sensor detects a change in the center of gravity of the human body, the ankle / hip torque sensor detects a counterclockwise torque change, and the knee torque sensor detects a clockwise torque change, it is determined that the human body has the intention to squat.

[0103] At this time, the disc motors at the ankle, knee, and hip joints are controlled to generate adaptive torque to assist the human body in squatting. At the same time, the angular acceleration sensors at each joint detect changes in angular acceleration at each joint. When the deformation of the elastic bandage at the thigh is less than the threshold, the encoder detects that the angular acceleration is zero, and the torque no longer changes, it is determined that the human body has squatted to the predetermined position. At this time, the disc motors at the ankle, knee, and hip joints are automatically locked, and heavy object lifting operations can be performed.

[0104] When the human body lifts a heavy object, the corresponding electromyographic signal of the calf exceeds the no-load threshold, the elastic bandage on the thigh detects a slight deformation, and the pressure sensor on the sole of the foot detects a pressure change that exceeds the weight of the human body. At the same time, the ankle joint torque sensor detects a clockwise torque change, the knee joint torque sensor detects a counterclockwise torque change, and the hip joint torque sensor detects a clockwise torque change. At this time, it is determined that the human body has the intention to stand up.

[0105] At this time, the disc motors at the ankle, knee, and hip joints are controlled to generate adaptive torque to assist the human body in standing. At the same time, the angular acceleration sensors at each joint detect changes in angular acceleration at each joint. When the deformation of the elastic bandage at the thigh returns to its original value, the angular acceleration sensor detects that the angular acceleration is zero, and the torque returns to the size of the human body's standing state and no longer changes, it is determined that the human body has completed standing. Subsequently, the disc motors at the knee and hip joints begin to provide adaptive torque to assist walking, so as to reduce the damage to each joint caused by carrying heavy objects.

[0106] The control process of the intelligent power-assisting device of the present invention to achieve power-assisting control will be described in detail below with reference to specific embodiments.

[0107] When a person walks, the elastic bandage, electromyographic signal sensor, and pressure sensor at the thigh detect regular changes in the center of gravity of the person, and the muscles exerting force and deformation change to the state value of unloaded walking. It is then determined that the person is walking freely without weight, and the disc motor is in a follow-up state.

[0108] Execute a controlled squat and hold, including:

[0109] Step 101: Determine whether the following six conditions are met simultaneously:

[0110] The corresponding electromyographic signal of the calf exceeds the threshold, the elastic bandage on the thigh detects a slight deformation, the pressure sensor on the sole of the foot detects the change in the center of gravity of the human body, the ankle and hip joint torque sensors detect counterclockwise torque changes, and the knee joint torque sensor detects clockwise torque changes;

[0111] (1) If the conditions are not met simultaneously, the disc motors at each joint are controlled to follow the human body;

[0112] (2) If both conditions are met, it is determined that the human body has the intention to squat, and step 102 is executed.

[0113] Step 102: Control the disc motors at the ankle joint, knee joint, and hip joint to generate adaptive torque to assist the human body in squatting and alleviate damage to the knee joints during the squatting process. The multi-stage elastic pneumatic dampers provided between the hip joint connecting plate, the knee joint connecting plate, and the ankle joint connecting plate act as a buffer to ensure the adaptability of the disc motors to the joints of the human body during the squatting process. At the same time, the angular acceleration sensor at each joint is used to detect the change in angular acceleration at each joint.

[0114] Step 103: Determine whether the human body has squatted to the predetermined position

[0115] When the deformation of the elastic bandage at the thigh is less than the threshold, the angular acceleration sensor detects that the angular acceleration is zero, and the torque of the torque sensor at each joint no longer changes, it is determined that the human body has squatted to the predetermined position; execute step 104; otherwise, continue to execute step 102.

[0116] Step 104: The disc motors at the ankle joint, knee joint, and hip joint are automatically locked, and the human body enters a sitting position and performs sitting work.

[0117] The control process of switching from a sitting position to a standing position includes:

[0118] Step 105: Determine whether the following six conditions are met simultaneously:

[0119] The corresponding electromyographic signal of the calf exceeds the no-load threshold, the elastic bandage on the thigh detects a slight deformation, the pressure sensor senses the change in the human body's center of gravity, the ankle / hip torque sensor detects a clockwise torque change, and the knee torque sensor detects a clockwise torque change;

[0120] (1) If not, proceed to step 104;

[0121] (2) If both conditions are met, it is determined that the human body has the intention to stand up, and step 106 is executed.

[0122] Step 106: The disc motors at the ankle joint, knee joint, and hip joint are unlocked and follow the human body to resume standing. The multi-stage elastic pneumatic damper acts as a buffer to ensure the adaptability of the disc motors to the joints of the human body during standing.

[0123] The control process of squatting and carrying heavy objects includes:

[0124] Step 201: Determine whether the following six conditions are met simultaneously:

[0125] The corresponding electromyographic signal of the calf exceeds the threshold, the elastic bandage on the thigh detects a slight deformation, the pressure sensor detects the change in the center of gravity of the human body, the ankle and hip joint torque sensors detect counterclockwise torque changes, and the knee joint torque sensor detects clockwise torque changes;

[0126] (1) If the conditions are not met simultaneously, the disc motors at each joint are controlled to follow the human body;

[0127] (2) If both conditions are met, it is determined that the human body has the intention to squat, and step 202 is executed.

[0128] Step 202: Control the disc motors at the ankle joint, knee joint, and hip joint to generate adaptive torque to assist the human body in squatting and alleviate damage to the knee joints during the squatting process. The multi-stage elastic pneumatic damper acts as a buffer to ensure the adaptability of the disc motors to the human body's joints during the squatting process. At the same time, the angular acceleration sensors at the joints detect changes in angular acceleration at the joints.

[0129] Step 203: Determine whether the human body has squatted to the predetermined position

[0130] When the deformation of the elastic bandage at the thigh is less than the threshold, the angular acceleration sensor detects that the angular acceleration is zero, and the torque no longer changes, it is determined that the human body has squatted to the predetermined position and step 204 is executed; otherwise, step 202 is continued.

[0131] Step 204: The disc motors at the ankle joint, knee joint, and hip joint are automatically locked, allowing the human body to lift heavy objects or maintain a single-leg kneeling position or a double-leg sitting position;

[0132] Step 205: Determine whether the following six conditions are met simultaneously:

[0133] The corresponding electromyographic signal of the calf exceeds the no-load threshold, the elastic bandage on the thigh detects a slight deformation, the pressure sensor on the sole of the foot detects a pressure change that exceeds the body weight, the ankle torque sensor detects a clockwise torque change, the knee torque sensor detects a counterclockwise torque change, and the hip torque sensor detects a clockwise torque change;

[0134] (1) If the conditions are not met simultaneously, the disc motors at the ankle, knee, and hip joints are controlled to remain locked;

[0135] (2) If both conditions are met, it is determined that the person is lifting a heavy object and intends to stand up, and step 206 is executed.

[0136] Step 206: Control the disc motors at the ankle joint, knee joint, and hip joint to generate adaptive torque to assist the human body in performing standing movements and alleviate damage to the joints during the standing process. The multi-stage elastic pneumatic damper acts as a buffer to ensure the adaptability of the disc motors to the joints of the human body during the standing process. At the same time, the angular acceleration sensors at the joints detect changes in angular acceleration at the joints.

[0137] Step 207: Determine whether the human body has reached an upright state

[0138] When the deformation of the elastic bandage at the thigh returns to its original value, the angular acceleration detected by the angular acceleration sensor is zero, and the torque returns to the magnitude of the human body standing state and does not change any more, it is determined that the human body has completed standing, and step 208 is executed; otherwise, step 206 is executed;

[0139] Step 208: The disc motors at the knee and hip joints begin to provide adaptive torque to assist walking. At the same time, the multi-stage elastic pneumatic damper acts as a buffer to ensure the adaptability of the disc motors to the joints of the human body during walking, thereby reducing the damage to the joints caused by carrying heavy objects.

[0140] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. used to indicate the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, or are the orientation or position relationship in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limiting the present invention.

[0141] Furthermore, the use of terms such as "horizontal" and "vertical" in the description of the present invention does not necessarily imply that the component must be absolutely horizontal or suspended, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical" and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0142] It should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood broadly. 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.

[0143] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the scope of protection of the present invention.

Claims

1. An intelligent power assist device for assisting in the assembly of aircraft components, characterized in that: include: A power-assisted skeletal unit, comprising a hip joint connecting plate, a hip joint unit, a knee joint connecting plate, a knee joint unit, an ankle joint connecting plate, an ankle joint unit, and a foot connecting plate; the hip joint unit, the knee joint unit, and the ankle joint unit all comprise a disc motor, a torque sensor, and an angular acceleration sensor; the disc motors of the hip joint unit, the knee joint unit, and the ankle joint unit are respectively a hip joint disc motor, a knee joint disc motor, and an ankle joint disc motor; the torque sensors of the hip joint unit, the knee joint unit, and the ankle joint unit are respectively a hip joint torque sensor, a knee joint torque sensor, and an ankle joint torque sensor; The human body signal sensing unit includes an electromyographic signal sensor for detecting calf muscle electromyographic signals and an elastic bandage embedded with a graphene sensor for detecting thigh muscle change signals; A control unit controls the hip joint disc motor, the knee joint disc motor and the ankle joint disc motor according to sensing signals from the hip joint unit, the knee joint unit, the ankle joint unit and the human body signal sensing unit.

2. The intelligent power assist device for assisting aircraft component assembly according to claim 1, characterized in that: The control unit recognizes the human body's intention to squat, maintain a single-leg kneeling position, maintain a double-leg sitting position, or walk while carrying heavy objects through the acquired sensor signals, and controls the hip joint disc motor, knee joint disc motor, and ankle joint disc motor.

3. The intelligent power assist device for assisting aircraft component assembly according to claim 2, characterized in that: The control unit identifies the intention of maintaining a single-leg kneeling posture or a double-leg sitting posture through the torque values ​​of the ankle joint torque sensor, the knee joint torque sensor, the hip joint torque sensor, and the sensing signals of the electromyographic signal sensor and the graphene sensor, and controls the disc motor to lock and not rotate or to provide a counter torque to support the joint according to the deformation of the elastic bandage and the threshold value calibrated by the torque sensor.

4. The intelligent power assist device for assisting aircraft component assembly according to claim 2, characterized in that: The control unit releases the locks on each disc motor and puts the disc motor into a follow-up state when it determines that the human body has a tendency to squat, stand up, or walk based on changes in the output signals of the electromyographic signal sensor and the graphene sensor and changes in the torque values ​​of the ankle joint torque sensor, the knee joint torque sensor, and the hip joint torque sensor.

5. The intelligent power assist device for assisting aircraft component assembly according to claim 1, characterized in that: The control unit obtains the acceleration changes of the joints of the lower limbs of the human body during squatting and standing up through the angular acceleration sensor, and controls the hip joint disc motor, knee joint disc motor and ankle joint disc motor.

6. The intelligent power assist device for assisting aircraft component assembly according to claim 1, characterized in that: The hip joint unit, the knee joint unit, and the ankle joint unit all include encoders. The control unit obtains the rotation speed of the disc motor through the encoder and performs closed-loop control on the disc motor.

7. The intelligent power assist device for assisting aircraft component assembly according to claim 1, characterized in that: Pneumatic dampers are provided between the ankle joint unit and the knee joint connecting plate, and between the knee joint unit and the ankle joint connecting plate.

8. The intelligent power assist device for assisting aircraft component assembly according to claim 1, characterized in that: A pressure sensor is provided on the foot connecting plate; The control unit captures the change of the sole pressure through the pressure sensor and controls the hip joint disc motor, the knee joint disc motor and the ankle joint disc motor.

9. An intelligent power assist control method for assisting aircraft component assembly, characterized in that: The intelligent power assist device according to any one of claims 1 to 8 comprises: The sensor signals of the hip joint unit, knee joint unit, ankle joint unit and human signal sensing unit are obtained, and the human body's movement intentions of squatting, maintaining a single-leg kneeling position, maintaining a double-leg sitting position, and carrying heavy objects and walking are identified according to the sensor signals, and the hip joint disc motor, knee joint disc motor and ankle joint disc motor are controlled.

10. The intelligent power assist control method for assisting aircraft component assembly according to claim 9, characterized in that: The control logic for performing the squat action is: When it is determined whether the human body intends to squat, the disc motors at the ankle joint, knee joint, and hip joint are controlled to generate torque to assist the human body in performing the squat action; The human body is judged to have the intention to squat when the following conditions are met, including: the electromyographic signal exceeds the threshold, the elastic bandage on the thigh detects deformation, the pressure sensor installed on the foot connection plate detects the change of the human body's center of gravity, the ankle / hip joint torque sensor detects counterclockwise torque change, and the knee joint torque sensor detects clockwise torque change.

11. The intelligent power-assistance control method for assisting aircraft component assembly according to claim 10, characterized in that: When it is determined that the human body has performed a squatting action and has reached the exercise position, the disc motors at the ankle joint, knee joint, and hip joint are automatically locked, and the single-leg kneeling position and double-leg sitting position are maintained; The human body is judged to have performed a squatting action to the movement position when the following conditions are met, including: the deformation of the elastic bandage at the thigh is less than a threshold, the angular acceleration sensor detects that the angular acceleration is zero, and the torque value of the torque sensor does not change.

12. The intelligent power-assistance control method for assisting aircraft component assembly according to claim 10 or 11, characterized in that: The method also includes the steps of recognizing the human body's intention to stand up and controlling the hip joint disc motor, the knee joint disc motor, and the ankle joint disc motor, including: When it is determined that the human body intends to stand, the disc motors at the ankle, knee and hip joints are unlocked and follow the human body to perform follow-up movements; The human body is judged to have the intention to stand when the following conditions are met, including: the electromyographic signal exceeds the no-load threshold, the elastic bandage at the thigh detects deformation, the pressure sensor detects the change of the human body's center of gravity, the ankle / hip torque sensor detects a clockwise torque change, and the knee torque sensor detects a clockwise torque change.

13. The intelligent power-assistance control method for assisting aircraft component assembly according to claim 12, characterized in that: When the deformation of the elastic bandage at the thigh returns to its original value, the angular acceleration sensor detects that the angular acceleration is zero, and the torque value of the torque sensor returns to the size of the human body standing state and no longer changes, it is determined that the human body has completed standing.

14. The intelligent power-assistance control method for assisting aircraft component assembly according to claim 12, characterized in that: The method also includes the steps of identifying the human body's intention to carry heavy objects and controlling the hip joint disc motor, the knee joint disc motor, and the ankle joint disc motor, including: After determining that the human body has squatted to a predetermined position and identifying that the human body intends to lift a heavy object and stand up, the hip joint disc motor, the knee joint disc motor, and the ankle joint disc motor are controlled to generate torque; When the following conditions are met, it is judged that the human body has the intention to lift heavy objects, including: the electromyographic signal exceeds the no-load threshold, the elastic bandage on the thigh detects deformation, the pressure sensor detects pressure changes that exceed the weight of the human body, the ankle torque sensor detects clockwise torque changes, the knee torque sensor detects counterclockwise torque changes, and the hip torque sensor detects clockwise torque changes.

15. The intelligent power-assistance control method for assisting aircraft component assembly according to claim 9, characterized in that: When the elastic bandage, electromyographic signal sensor and pressure sensor at the thigh detect regular changes in the center of gravity of the human body and the monitored deformation changes to the state value of unloaded walking, it is determined that the human body is walking freely without weight, and the disc motor is controlled to move with it.

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