A power-assisted dual-mode knee exoskeleton device and a control method thereof

Abstract

This invention relates to the field of assistive device technology, specifically to a dual-mode power-generating and assistive knee exoskeleton device and its control method. The dual-mode power-generating and assistive knee exoskeleton device includes a device housing. A first wear-fixing component is located on the side of the device housing. A servo motor and a control system are connected inside the housing. The servo motor is connected to a transmission component, which is connected to an energy storage device on one side and a rotating connection component on the other. The rotating connection component is connected to a second wear-fixing component. A charging device is also located on the top of the device housing, and the charging device is electrically connected to the servo motor control system. This invention enables mode switching, achieving rapid conversion between power generation and assistive function.

Description

Technical Field

[0001] This invention relates to the field of assistive device technology, specifically to a dual-mode power-generating assistive knee brace exoskeleton device and its control method. Background Technology

[0002] With the integration of modern biomechanics and robotics, lower limb-assisted exoskeletons have become important auxiliary equipment for enhancing human motor function. These devices work in tandem with the lower limbs through mechanical structures, effectively distributing joint load and enhancing muscle output power. Their core principle lies in real-time detection of the user's movement intentions, providing timely assistance via motors or hydraulic systems. In outdoor sports scenarios, exoskeletons need to cope with the dynamic challenges posed by complex terrain changes, placing higher demands on sensor response speed, the adaptive capabilities of control algorithms, and the continuous supply of energy.

[0003] Currently available lower limb assistive exoskeletons generally use lithium-ion batteries for electric drive. Limited by battery energy density, their continuous operating time is typically no more than 4 hours, making it difficult to cover all-weather outdoor activity needs. Regarding assist strategies, existing products are mostly based on preset fixed parameter models, such as constant torque compensation or timed triggering of assist, failing to automatically adjust output torque according to slope changes. This results in insufficient assistance uphill and excessive braking downhill. Structurally, traditional exoskeletons often use single-axis rotating mechanisms for their knee joint hinges, lacking adaptive adjustments to individual anatomical differences. Long-term wear can easily lead to problems such as patellar displacement or popliteal fossa compression. Furthermore, rigid linkage structures may cause abnormal shear forces in the knee joint under sudden lateral loads, posing a potential risk of sports injuries. Summary of the Invention

[0004] Based on the aforementioned technical problems encountered when relying on power banks and other energy storage devices during outdoor activities, such as limited power supply making it difficult to support prolonged use, inability to adapt to slope, single-axis hinges compressing the knee joint, and rigid structures being prone to injury, this invention provides a dual-mode exoskeleton device with power generation and assistance, along with its control method. This invention primarily utilizes a four-quadrant motor for power generation and a spring-loaded shaft for dual energy storage, a control system with dual control of the four-quadrant motor, and the buffering function of multiple hinges and spring-loaded shafts. This improves endurance, provides adaptive assistance, ensures structural comfort, and offers safe buffering protection. The innovative integrated design of the exoskeleton's power generation and assistance functions enables outdoor power generation. Building upon the optimized assistance effect of existing exoskeletons, the addition of a power generation function solves the core pain points of traditional exoskeletons—short endurance and difficulty in accessing power outdoors—providing a highly efficient solution.

[0005] The technical means employed in this invention are as follows:

[0006] A dual-mode power-assisted knee brace exoskeleton device includes a device housing. A first wear-fixing component is provided on the side of the device housing. A servo motor and a control system are connected inside the device housing. The servo motor is connected to a transmission component. The transmission component is connected to an energy storage device on one side and a rotating connection component on the other side. The rotating connection component is connected to a second wear-fixing component. A charging device is also provided on the top of the device housing. The charging device is electrically connected to the servo motor control system.

[0007] Furthermore, the transmission assembly includes a first gear, a double-layer gear, and a second gear. The first gear is connected to the servo motor. The double-layer gear includes a third gear and a fourth gear. The third gear meshes with the first gear and the third gear and the fourth gear are coaxially connected. The diameter of the fourth gear is smaller than the diameter of the third gear. The fourth gear meshes with the second gear. The second gear is a sector gear, which includes a sector surface and a sector end. The sector surface is connected to the energy storage device, and the sector end is connected to the rotating connection assembly. The energy storage device is a spring reel.

[0008] Furthermore, the servo motor is preferably a four-quadrant servo motor, which is connected to the transmission assembly.

[0009] Furthermore, the first wearable fixation assembly includes a first strap and a first guard plate, and the first wearable fixation assembly is used to fix the device to the thigh.

[0010] Furthermore, the second wearable fixing component includes a second strap and a second guard plate, the second wearable fixing component is used to fix the device to the lower leg, and the number of the second wearable fixing components is greater than or equal to 2.

[0011] Furthermore, the rotating connection assembly is a hinge device, and the rotating connection assembly is snapped together with the second wearable fixing assembly.

[0012] This invention also includes a control method for a power-assisted dual-mode knee exoskeleton device, implemented based on the aforementioned power-assisted dual-mode knee exoskeleton device, comprising the following steps: The first and second wearable fastening components are respectively fixed to the thigh and calf of the human body; Based on the exercise requirements, the control system selects a mode, which includes a power generation mode and an assist mode. In the power generation mode, when a person walks, the flexion and extension of the knee joint causes the rotating connection component to swing. The rotating connection component drives the transmission component, which in turn drives the servo motor to rotate and generate electricity. The generated electrical energy is stored through the charging device. At the same time, the flexion and extension of the knee joint drives the energy storage device to compress and release, thereby achieving knee extension buffering and knee flexion assistance. In the assisted mode, the control system outputs pulse signals in real time according to the speed of human movement, controls the servo motor to output torque, and the torque is transmitted to the transmission component. The transmission component assists the human lower leg in knee extension and flexion through the rotation connection component. At the same time, the energy storage device absorbs energy when the knee is extended and releases energy when the knee is flexed.

[0013] Furthermore, the servo motor is a four-quadrant servo motor. In the power generation mode, the motor operates in the second and fourth quadrants as a generator. In the assist mode, the motor operates in the first and third quadrants as a motor.

[0014] Furthermore, the control system switches between power generation mode and auxiliary mode by detecting the state of the mode selection switch: When the mode selection switch is in the assist mode, the control system controls the direction of the input voltage to be the same as the direction of rotation of the servo motor according to the real-time rotation direction of the servo motor, and the amplitude of the input voltage is greater than the amplitude of the back electromotive force generated by the servo motor, so that the current direction is consistent with the rotation direction, and the servo motor outputs driving torque and runs as a motor. When the mode selection switch is in the generator mode, the direction of the control input voltage is opposite to the rotation direction of the servo motor, and the amplitude of the input voltage is less than the amplitude of the back electromotive force generated by the servo motor, so that the current direction is opposite to the rotation direction. The servo motor generates braking torque and converts mechanical energy into electrical energy, thus operating as a generator.

[0015] Compared with the prior art, the present invention has the following advantages: 1. This invention achieves dual recovery of mechanical energy through the coordinated operation of a four-quadrant motor generating power and a spring coil energy storage system, thereby increasing the continuous working time and meeting the needs of all-weather outdoor activities.

[0016] 2. The triple-link hinge of the present invention simulates the multi-axis movement of the human knee joint. Combined with the 3D printed adjustable structure, it can adapt to different leg shapes and avoid patellar displacement and popliteal fossa compression caused by single-axis hinges.

[0017] 3. This invention uses a spring coil to achieve knee extension cushioning and knee flexion assistance, which plays a role in smoothing out peaks and valleys in knee joint movement and prolonging the force application time to reduce instantaneous load. At the same time, the servo motor provides real-time feedback of leg movement data, and the control system analyzes the data in real time and brakes in case of sudden abnormality, preventing the device from continuing to output assistance after the human body loses control, thus providing double protection for sports safety.

[0018] Based on the above reasons, this invention can be widely promoted in fields such as assistive devices. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the overall structure of the exoskeleton device of the present invention.

[0021] Figure 2 This is a schematic diagram of the spring coil structure of the energy storage device of the present invention.

[0022] Figure 3 This is a schematic diagram of the specific structure of the transmission component of the present invention.

[0023] In the diagram: 100, charging device; 200, first strap; 300, first protective plate; 400, servo motor; 500, transmission assembly; 501, first gear; 502, double-layer gear; 503, second gear; 600, energy storage device; 601, spring coil; 700, rotating connection assembly; 800, second strap; 900, second protective plate. Detailed Implementation

[0024] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0025] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0026] Example 1 like Figure 1 As shown, the present invention provides a dual-mode power-assisted knee exoskeleton device, including a device shell, a first wearable fixing component on the side of the device shell, a servo motor 400 and a control system connected inside the shell, the servo motor 400 being connected to a transmission component 500, the transmission component 500 being connected to an energy storage device 600 on one side and a rotating connection component 700 on the other side, the rotating connection component 700 being connected to a second wearable fixing component, and a charging device 100 being provided on the top of the device shell, the charging device 100 being electrically connected to the servo motor 400 control system.

[0027] In a preferred embodiment of the present invention, after the servo motor 400 generates electricity, the current is input to the charging device 100 through a rectifier bridge and a step-down module. On the one hand, it can be output via USB to charge mobile phones and power banks, and on the other hand, it can charge the battery of the servo motor 400.

[0028] This device is worn on the thighs and legs. The outer shell is the base of the entire device, and the whole is made using 3D printing technology. While ensuring the hardness of the material, it effectively reduces the weight and production cost of the device, making it easy for outdoor athletes to carry when they go out.

[0029] like Figure 2 and Figure 3 As shown, the transmission assembly 500 includes a first gear 501, a double-layer gear 502, and a second gear 503. The first gear 501 is connected to the servo motor 400. The double-layer gear 502 includes a third gear and a fourth gear. The third gear meshes with the first gear 501 and the third gear and the fourth gear are coaxially connected. The diameter of the fourth gear is smaller than the diameter of the third gear. The fourth gear meshes with the second gear 503. The second gear 503 is a sector gear, which includes a sector face and a sector end. The sector face is connected to the energy storage device 600, and the sector end is connected to the rotating connection assembly 700.

[0030] In power generation mode, the bidirectional transmission gear set drives the sector gear to rotate at low speed during human walking. This rotation, through the gear set's speed-up and torque-reduction mechanism, drives the servo motor 400 to rotate at high speed, generating electricity. Both knee extension and flexion movements are converted via the bidirectional gear set, achieving bidirectional secondary power generation and significantly improving conversion efficiency. In exercise mode, the servo motor 400's high-speed, low-torque power is reversed and reduced in torque by the gear set, outputting appropriate torque to assist movement. The gear set ensures unidirectional power transmission to the legs.

[0031] The energy storage device 600 is a spring coil 601. The spring coil 601 can convert the gravitational potential energy of the lower leg falling during exercise into elastic potential energy, and then into electrical energy, thereby improving the energy recovery and utilization rate. In addition, the contraction of the spring can effectively prolong the force application time, achieve the purpose of cushioning, and play an important role in protecting the human knee.

[0032] The spring coil 601 transforms leg flexion and extension movements into the compression and release of the spring, smoothing out peaks and valleys while providing cushioning during knee extension and assisting with knee flexion. In power generation mode, when the body extends the knee, the thigh descends, causing the lower leg to straighten, compressing the spring to store elastic potential energy. Simultaneously, this energy is transmitted through a linkage mechanism to drive a gear set, converting some of the gravitational potential energy into electrical energy. When the knee flexes, the spring releases its elastic potential energy, driving power generation. By optimizing the spring stiffness and preload, the device's energy recovery efficiency can be improved at a walking frequency of 1.5-2.2Hz, enhancing the device's endurance while protecting the knee joint.

[0033] The servo motor 400 is preferably a four-quadrant servo motor 400, which is connected to the transmission assembly 500. The motor enables the device to provide leg assistance and also generate electricity. Utilizing the four-quadrant control technology of the servo motor 400, the motor can sense the speed of the user's leg movement, send pulse signals to the control system, and after analysis, receive feedback signals. The control system then outputs a corresponding current to drive the motor to rotate, providing torque assistance for leg movement.

[0034] The servo motor 400 control system consists of a motor and a control system. The servo motor achieves dynamic assistance adjustment through a closed-loop feedback mechanism: the control system detects the motor position in real time and controls the torque and speed through voltage signals, providing positive assistance to the user during the knee extension phase and reverse compensation during the knee flexion phase, effectively helping the user move and reducing muscle fatigue.

[0035] Furthermore, the control system is responsible for analyzing the appropriate amount of assistance to provide in the assist mode. Using the closed-loop feedback from the servo motor 400 as input, and based on the corresponding program code in the encoder, it outputs pulse signals to control the motor's rotation.

[0036] The first wearable fixation assembly includes a first strap 200 and a first guard plate 300, and is used to fix the device to the thigh.

[0037] The second wearable fixation component includes a second strap 800 and a second guard plate 900. The second wearable fixation component is used to fix the device to the lower leg, and the number of the second wearable fixation components is greater than or equal to 2.

[0038] The rotating connecting component 700 is a hinge device, which is snapped together with the second wearable fixing component. The hinge device connects the thigh and lower leg of the human body and serves as the device's connecting mechanism. This design fully considers the physiological structure of the human body, employing a multi-hinge connection structure to connect the thigh and lower leg parts of the device, ensuring the device's flexibility. The hinge design allows the device to adapt to a wider range of leg shapes, improving its adaptability to different body types.

[0039] The hinge employs a triple-link linkage structure, composed of 3D-printed materials, carbon fiber connecting rods, and adjustable joint pins. This hinge adds an extra degree of freedom between the upper and lower legs, accommodating differences in leg shape. The entire device is fixed to the exoskeleton frame via three positioning holes, and with adjustable straps, multi-dimensional angle adjustments are possible, further enhancing the device's comfort and adaptability.

[0040] The device features an innovative design with two operating systems: a power generation mode and an auxiliary mode.

[0041] In power generation mode, when a person is hiking or mountaineering, their lower legs bend, driving the generator to rotate under the transmission of the bidirectional gear set and the action of the four-quadrant motor control system. This further increases the transmission ratio, generating electrical energy, which is then used to charge the battery through a transformer, achieving energy recovery. Furthermore, the device's power generation mode has different settings, allowing the user to freely control the resistance level according to actual conditions, thereby controlling the amount of power generated.

[0042] In exercise mode, the device is equipped with a four-quadrant motor control system and a feedback analysis system, which can control the motor to rotate according to the human body's movement. Under the transmission action of the bidirectional transmission gear set, it assists in driving the lower leg movement, thereby achieving the assist effect.

[0043] As a preferred embodiment of the present invention, the device has a safety protection measure in which, when a sudden torque change (such as a fall) is detected, the controller triggers an emergency brake, cutting off the motor power supply in milliseconds to further ensure user safety.

[0044] This device cleverly utilizes the periodic movement characteristics of the knee joint during human walking—a process during which the knee joint generates a significant amount of unused negative work. A specialized mechanical structure captures this negative work and converts it into electrical energy. This electricity can be used to charge the exoskeleton itself or various electronic devices, thus providing a continuous and stable power supply for outdoor activities. This design effectively solves the problem of limited power supply for extended use when relying on power banks and other energy storage devices during outdoor activities, successfully resolving the contradiction between the scarcity of outdoor and wilderness power resources and the high dependence on small power devices.

[0045] In a preferred embodiment of the present invention, when a person falls, the motion feedback parameters of the knee joint and leg will show significant abrupt changes. Upon detecting this abnormal state, the control system immediately stops the power assist output and performs emergency braking, cutting off the drive power and disabling the active power assist function. When the system malfunctions or the motor locks abnormally, the knee joint freely flexes and extends due to limb inertia, driving the sector gear to rotate. Since the effective meshing angle range of the sector gear is 60°–90°, beyond this range, the sector gear and the tooth surface of the double-layer gear 502 automatically disengage, mechanically decoupling the motor from the leg joint and preventing constraint on joint movement under abnormal motor conditions. This passive mode is achieved through a purely mechanical clutch structure, ensuring that the knee joint can still move freely in the event of power failure, loss of control, or abnormal locking, preventing limb strain or secondary injury caused by motor hard locking, significantly improving the safety of the device.

[0046] Example 2 The present invention also includes a control method for a power-assisted dual-mode knee exoskeleton device, implemented based on the power-assisted dual-mode knee exoskeleton device in Embodiment 1, comprising the following steps: S1. Fix the first wearable fixing component and the second wearable fixing component to the thigh and calf of the human body, respectively.

[0047] S2. Based on the motion requirements, the control system selects the mode, which includes power generation mode and assist mode.

[0048] S3. In the power generation mode, when a person walks, the flexion and extension of the knee joint causes the rotating connection component 700 to swing. The rotating connection component 700 drives the transmission component 500, and the transmission component 500 drives the servo motor 400 to rotate and generate electricity. The generated electrical energy is stored in the charging device 100. At the same time, the flexion and extension of the knee joint drives the energy storage device 600 to compress and release, realizing knee extension buffering and knee flexion assistance.

[0049] S4. In the assist mode, the control system outputs pulse signals in real time according to the speed of human movement, controls the servo motor 400 to output torque, and the torque is transmitted to the transmission component 500. The transmission component 500 assists the human lower leg to perform knee extension and knee flexion movements through the rotating connection component 700. At the same time, the energy storage device 600 absorbs energy when extending the knee and releases energy when flexing the knee.

[0050] The control system integrates a sensing module, with core detection devices including the motor encoder and IMU (Inertial Measurement Unit) integrated into the servo motor 400. The motor encoder is used to detect the motor rotor position and speed signals in real time; the IMU, mounted on the first guard plate 300, is used to detect thigh acceleration and angular velocity signals. The control system processes the signals acquired by the motor encoder and IMU, and, combined with the human lower limb dynamics model, estimates the human-machine interaction force. The system employs an admittance control strategy, using the human-machine interaction force as input to generate the desired knee joint motion trajectory; it compares the desired trajectory with the actual motion position, calculates the desired assist torque through position closed-loop and impedance control laws, and finally outputs control commands to drive the servo motor 400 to output the corresponding assist torque, achieving an assist function that coordinates with the human motion state.

[0051] The control system integrates encoder and IMU data, calculates the force exerted by the human body on the device through dynamic modeling, obtains the expected position of the device by using admittance control with this force as input, obtains the error by comparing the expected position with the actual position, solves the differential equation to obtain the desired assist torque, and finally outputs the corresponding pulse signal to control the motor to output the assist torque.

[0052] Furthermore, the servo motor 400 is a four-quadrant servo motor 400. In generator mode, the servo motor 400 operates in the second and fourth quadrants as a generator. In assist mode, the servo motor 400 operates in the first and third quadrants as a motor.

[0053] Specifically, the four-quadrant servo motor 400 achieves power generation and assist functions through bidirectional energy flow control. In power generation mode, the servo motor 400 operates in the second and fourth quadrants, functioning as a generator. The high-speed rotation of the gear set drives the rotor to cut magnetic lines of force, generating alternating current in the stator windings, which is then rectified into direct current by the controller. In motion mode, the servo motor 400 operates in the first and third quadrants, functioning as a motor to drive the rotor and provide assist. The four-quadrant characteristic allows the servo motor 400 to provide forward and reverse assist, outputting positive torque when the knee is extended and reverse compensation when the knee is flexed. This, combined with the elastic potential energy of the coil spring, improves motion smoothness. Furthermore, the system can switch modes, achieving millisecond-level transitions between power generation and assist, resulting in a seamless "power generation → assist" transition, adapting to complex motion scenarios.

[0054] The control system switches between power generation and auxiliary modes by detecting the state of the mode selection switch. When the mode selection switch is in the assist mode, the control system controls the direction of the input voltage to be the same as the rotation direction of the servo motor 400 according to the real-time rotation direction of the servo motor 400, and the amplitude of the input voltage is greater than the amplitude of the back electromotive force generated by the servo motor 400, so that the current direction is consistent with the rotation direction, and the servo motor 400 outputs driving torque and runs as a motor.

[0055] When the mode selection switch is in generator mode, the direction of the control input voltage is opposite to the rotation direction of the servo motor 400, and the amplitude of the input voltage is less than the amplitude of the back electromotive force generated by the servo motor 400, so that the current direction is opposite to the rotation direction. The servo motor 400 generates braking torque and converts mechanical energy into electrical energy, thus operating as a generator.

[0056] Specifically, when the switch is in assist mode, the system controls the voltage to be greater than the back electromotive force generated by the servo motor by 400, so that the torque generated by the current is in the same direction as the speed, and the motor drives the load. At this time, the motor is used as a motor. When the switch is in generator mode, the system controls the voltage to be less than the back electromotive force generated by the motor, so that the reverse current and braking torque are generated, and the motor converts inertial kinetic energy into electrical energy. At this time, the motor is used as a generator.

[0057] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dual-mode, power-assisted knee brace exoskeleton device, characterized in that, The device includes a housing, a first wearable fixing component on the side of the housing, a servo motor and a control system connected inside the housing, a transmission component connected to a transmission component, an energy storage device on one side and a rotating connection component on the other side, a rotating connection component connected to a second wearable fixing component, and a charging device on the top of the housing, which is electrically connected to the servo motor control system.

2. The power-generating dual-mode knee exoskeleton device according to claim 1, characterized in that, The transmission assembly includes a first gear, a double-layer gear, and a second gear. The first gear is connected to the servo motor. The double-layer gear includes a third gear and a fourth gear. The third gear meshes with the first gear and the third gear and the fourth gear are coaxially connected. The diameter of the fourth gear is smaller than the diameter of the third gear. The fourth gear meshes with the second gear. The second gear is a sector gear, which includes a sector face and a sector end. The sector face is connected to the energy storage device, and the sector end is connected to the rotating connection assembly. The energy storage device is a spring reel.

3. The power-generating dual-mode knee exoskeleton device according to claim 1, characterized in that, The servo motor is preferably a four-quadrant servo motor, and the four-quadrant servo motor is connected to the transmission assembly.

4. The power-generating dual-mode knee exoskeleton device according to claim 1, characterized in that, The first wearable fixation assembly includes a first strap and a first guard plate, and is used to fix the device to the thigh.

5. The power-assisted dual-mode knee exoskeleton device according to claim 1, characterized in that, The second wearable fixing component includes a second strap and a second guard plate. The second wearable fixing component is used to fix the device to the lower leg, and the number of the second wearable fixing components is greater than or equal to 2.

6. The power-generating dual-mode knee exoskeleton device according to claim 1, characterized in that, The rotating connection component is a hinge device, and the rotating connection component is snapped together with the second wearable fixing component.

7. A control method for a power-assisted dual-mode knee exoskeleton device, implemented based on the power-assisted dual-mode knee exoskeleton device according to any one of claims 1-6, characterized in that, Includes the following steps: The first and second wearable fastening components are respectively fixed to the thigh and calf of the human body; Based on the exercise requirements, the control system selects a mode, which includes a power generation mode and an assist mode. In the power generation mode, when a person walks, the flexion and extension of the knee joint causes the rotating connection component to swing. The rotating connection component drives the transmission component, which in turn drives the servo motor to rotate and generate electricity. The generated electrical energy is stored through the charging device. At the same time, the flexion and extension of the knee joint drives the energy storage device to compress and release, thereby achieving knee extension buffering and knee flexion assistance. In the assisted mode, the control system outputs pulse signals in real time according to the speed of human movement, controls the servo motor to output torque, and the torque is transmitted to the transmission component. The transmission component assists the human lower leg in knee extension and flexion through the rotation connection component. At the same time, the energy storage device absorbs energy when the knee is extended and releases energy when the knee is flexed.

8. The control method for the power-assisted dual-mode knee exoskeleton device according to claim 7, characterized in that, The servo motor is a four-quadrant servo motor. In the generator mode, the motor operates in the second and fourth quadrants as a generator. In the assist mode, the motor operates in the first and third quadrants as a motor.

9. The control method for the power-assisted dual-mode knee exoskeleton device according to claim 7, characterized in that, The control system switches between power generation mode and auxiliary mode by detecting the state of the mode selection switch. When the mode selection switch is in the assist mode, the control system controls the direction of the input voltage to be the same as the direction of rotation of the servo motor according to the real-time rotation direction of the servo motor, and the amplitude of the input voltage is greater than the amplitude of the back electromotive force generated by the servo motor, so that the current direction is consistent with the rotation direction, and the servo motor outputs driving torque and runs as a motor. When the mode selection switch is in the generator mode, the direction of the control input voltage is opposite to the rotation direction of the servo motor, and the amplitude of the input voltage is less than the amplitude of the back electromotive force generated by the servo motor, so that the current direction is opposite to the rotation direction. The servo motor generates braking torque and converts mechanical energy into electrical energy, thus operating as a generator.

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