Leg device, active energy-adding lower extremity exoskeleton and control method

Abstract

The application provides a leg device, an active energy-assisted lower extremity exoskeleton and a control method. The active energy-assisted lower extremity exoskeleton comprises a first connecting piece, a first mounting seat and a second connecting piece. The first connecting piece can rotate around a coronal axis, and the first connecting piece is connected with the first mounting seat. The second connecting piece is rotationally connected with the first mounting seat and can rotate around a first rotation axis relative to the first mounting seat. The first rotation axis is perpendicular to the coronal axis, and the first rotation axis extends along the length direction of the leg device. The rotation of the second connecting piece around the first rotation axis relative to the first mounting seat is used for following the internal rotation and external rotation of the human thigh or the human lower leg around a vertical axis. The application can solve the problem of insufficient flexibility of natural movement of the user of the existing leg device, the active energy-assisted lower extremity exoskeleton and the control method.

Description

Technical Field

[0001] This invention relates to the field of rehabilitation and assistive robot technology, and in particular to a leg device, an active power-enhancing lower limb exoskeleton, and a control method. Background Technology

[0002] Lower limb exoskeletons, as wearable devices that assist human movement, are widely used in medical rehabilitation, physical training, and competitive sports assistance. Existing exoskeleton systems typically consist of a mechanical skeleton, drive unit, control system, and human-computer interaction module, aiming to provide driving torque to the joints of the lower limbs to achieve motion assistance or posture correction. However, existing lower limb exoskeletons still have the following technical shortcomings in practical applications: The current exoskeletons suffer from simplistic motion judgment and control methods, lacking sophisticated force feedback mechanisms. When assisting users in performing dynamic movements such as squats and lunges, most systems rely solely on preset trajectories for open-loop position control, making it difficult to determine in real-time whether the user has actually reached the correct movement position. Especially during movement execution, the system cannot effectively distinguish between changes in state caused by natural body swaying, momentary shaking, or movement deviations, easily leading to misjudgments. Furthermore, existing systems have insufficient monitoring capabilities for movement speed and rhythm, lacking multimodal force feedback methods combined with vibration cues, resulting in difficulty in providing precise guidance for users regarding movement accuracy and rhythm control.

[0003] The low degree of fusion of multi-source sensor information and the inflexible switching of control modes mean that existing systems mostly adopt a single position control mode, which cannot flexibly switch between position mode, speed mode, damping mode or torque mode according to the action stage (such as start-up, approach to target, reset), thus reducing the adaptability of control and motion safety.

[0004] Human-computer interaction methods are simple, and motion cues are scarce. Existing exoskeletons mainly rely on visual feedback or simple auditory cues for user motion guidance, lacking tactile feedback mechanisms that affect proprioception. Especially in coordinated movements requiring rapid response (such as footwork and rhythm control), single visual or auditory cues are easily affected by environmental interference, making it difficult for users to obtain intuitive and immediate motion correction signals. At the same time, existing systems lack effective physical cues for abnormal states such as excessive speed or movement deviations during movement, affecting training effectiveness and user experience.

[0005] Insufficient mechanical structure degree-of-freedom distribution and fit design: Some existing lower limb exoskeletons fail to adequately balance active drive and passive adaptation requirements in their joint degree-of-freedom distribution, resulting in ergonomic mismatch and limiting the user's natural movement flexibility. Furthermore, traditional rigid skeletons have poor fit with the human body and lack passive adaptation structures such as multi-degree-of-freedom sliding rails, making it difficult to achieve free internal / external rotation of the exoskeleton along the vertical axis of the lower limbs. This can easily lead to movement interference or localized pressure, reducing wearing comfort and movement flexibility.

[0006] Among these technical problems, the most significant is the insufficient distribution of degrees of freedom and fit design in the mechanical structure. Some existing lower limb exoskeletons fail to adequately balance the needs of active actuation and passive adaptation in the distribution of joint degrees of freedom, resulting in a mismatch between human and machine kinematics and limiting the user's flexibility in natural movement. For example, during squatting exercises, when the thigh rotates internally or externally, the mechanical structure does not fit snugly against the lower limb, leading to problems of pulling and compressing the lower limb. Summary of the Invention

[0007] The purpose of this invention is to provide a leg device, an active power-enhanced lower limb exoskeleton, and a control method to solve the problem of insufficient flexibility in natural movement of users in existing leg devices, active power-enhanced lower limb exoskeletons, and control methods.

[0008] To solve the above-mentioned technical problems, the present invention provides a leg device for an active power-enhancing lower limb exoskeleton, comprising a first connector, a first mounting base, and a second connector; The first connector is rotatable about the coronal axis and is connected to the first mounting base; The second connector is rotatably connected to the first mounting base and can rotate relative to the first mounting base about a first rotating shaft, the first rotating shaft being perpendicular to the coronal shaft and extending along the length direction of the leg device; The rotation of the second connector relative to the first mounting base around the first axis is used to follow the internal and external rotation movements of the human thigh or calf around the vertical axis.

[0009] Optionally, the first connector is slidably connected to the first mounting base, and the first mounting base can slide relative to the first connector in a direction parallel to the first axis of rotation.

[0010] Optionally, the first mounting base is provided with a first annular cavity, and the second connector is provided with a first annular fixing seat adapted to the first annular cavity and used for binding to the human body by a strap. A first slide rail structure is provided between the first annular fixing seat and the first annular cavity. The first annular fixing seat slides along the inner surface of the first annular cavity through the first slide rail structure, so that the second connector rotates relative to the first mounting base around the first rotating shaft.

[0011] Optionally, an electromagnetic friction clamping assembly is provided between the first mounting base and the second connecting member. The electromagnetic friction clamping assembly includes a compression spring, an electromagnetic coil, a first friction plate disposed on the first mounting base, and a second friction plate disposed on the second connecting member and opposite to the first friction plate. When the electromagnetic coil is de-energized, the compression spring drives the first friction plate and the second friction plate to press against each other, thereby locking the rotation of the second connecting member relative to the first mounting base around the first rotating shaft. When the electromagnetic coil is energized, the electromagnetic force generated by the electromagnetic coil overcomes the elastic force of the compression spring, causing the first friction plate and the second friction plate to separate from each other, thereby releasing the lock on the rotation.

[0012] Optionally, the electromagnetic friction clamping assembly further includes a clamping control unit and an angular velocity sensor. The angular velocity sensor is used to detect the rotational angular velocity of the second connector relative to the first mounting base. The clamping control unit is electrically connected to the electromagnetic coil and configured to keep the electromagnetic coil energized when the rotational angular velocity is less than or equal to a preset speed threshold, and to cut off the power supply to the electromagnetic coil when the rotational angular velocity is greater than the preset speed threshold.

[0013] Optionally, the first mounting base and the second connecting member are respectively provided with elastic buffer blocks. The elastic buffer blocks are arranged opposite to each other along the rotation direction of the second connecting member relative to the first mounting base, and abut against each other when the second connecting member rotates to the rotation limit position, so that the rotation angle of the second connecting member relative to the first mounting base in the inward rotation direction and the outward rotation direction does not exceed a predetermined angle, and prevents the second connecting member from detaching from the first mounting base.

[0014] The present invention also provides an active power-enhanced lower limb exoskeleton, comprising a mechanical skeleton, a drive module, a sensing module, a control module and a human-computer interaction module. The mechanical skeleton includes a lumbar support, a hip joint support, a thigh support, a calf support, an ankle joint support and a foot support, wherein the thigh support and / or the calf support are the aforementioned leg devices. The drive module includes multiple joint motors mounted on the mechanical frame. The joint motors are used to drive the hip joint support to rotate about the sagittal axis relative to the lumbar support, drive the thigh support to rotate about the coronal axis relative to the hip joint support, and drive the lower leg support to rotate about the coronal axis relative to the thigh support. The sensing module includes a position encoder, a speed sensor, and a torque sensor integrated within the joint motor; The control module is communicatively connected to the drive module and the sensing module, and is configured to automatically switch the working state of the drive module and generate corresponding joint control commands based on the actual joint position, actual joint speed and actual output torque transmitted by the sensing module, so as to drive the drive module to run. The human-computer interaction module includes multiple vibration motors mounted on the thigh support. The control module is also configured to control the vibration motors to output different vibration signals based on the safe speed deviation between the actual joint speed and the safe speed limit, so as to provide tactile feedback to the user's current movement.

[0015] Optionally, both the thigh support and the calf support are leg devices. The first connector of the thigh support is rotatably connected to the hip joint support about the coronal axis. The second connector of the thigh support is rotatably connected to the first connector of the calf support about the coronal axis. The second connector of the calf support is rotatably connected to the ankle joint support about a second axis perpendicular to the coronal axis.

[0016] Optionally, the first connecting member of the calf support is slidably connected to the first mounting seat of the calf support, and the first mounting seat of the calf support can slide relative to the first connecting member of the calf support in a direction parallel to the first axis of rotation. The ankle joint support includes a second annular fixing seat rotatably connected to the second connecting member of the calf support about a second axis of rotation. The second annular fixing seat is bound to the human body by a strap. The second connecting member of the calf support extends along the sliding direction of the first mounting seat relative to the first connecting member of the calf support and is tapered. A second slide rail structure is provided between the second connecting member of the calf support and the second annular fixing seat. The second annular fixing seat rotates relative to the second connecting member of the calf support through the second slide rail structure. The second axis of rotation is parallel to the first axis of rotation.

[0017] This invention also provides a control method for an active power-enhanced lower limb exoskeleton, applied to the aforementioned active power-enhanced lower limb exoskeleton, comprising the following steps: Step S1: Read the action node sequence from the preset action database. The action node sequence consists of multiple action nodes arranged in chronological order. Step S2: The actual joint position, the actual joint speed, and the actual output torque are collected in real time by the position encoder, the speed sensor, and the torque sensor integrated in the joint motor. Step S3: Identify the human-machine interaction load characteristics based on the actual output torque, and generate a feedforward torque compensation amount based on the human-machine interaction load characteristics; Step S4: Calculate the positional deviation between the actual joint position and the desired joint position in the action node sequence, and the velocity deviation between the actual joint velocity and the desired joint velocity; Step S5: Determine the user's action node status based on the position deviation, the speed deviation, and the action node sequence; Step S6: Automatically switch the working state of the drive module based on the user's current action node state, and generate the corresponding joint control command in combination with the feedforward torque compensation amount to drive the joint motor to run; Step S7: Based on the safe speed deviation between the actual joint speed and the safe speed limit, control the vibration motor to output different vibration signals to provide tactile feedback to the user's current movement.

[0018] The leg device, active power-enhancing lower limb exoskeleton, and control method provided by this invention have the following beneficial effects: First, a rotational joint around a first axis is established between the first mounting base and the second connector. This first axis is perpendicular to the coronal axis and extends along the length of the leg device, its orientation essentially coinciding with the vertical axis of the user's thigh or calf. When the user's thigh or calf undergoes internal or external rotation, the second connector rotates along with the limb around the first axis. The exoskeleton automatically adapts to the user's posture through a composite motion structure formed by the flexion and extension of the first connector around the coronal axis and the rotation of the second connector around the first axis, achieving passive following without motor drive. This avoids the wear and discomfort caused by the forced twisting of muscles and bones in traditional rigid supports, eliminates repeated rubbing between the straps and skin, and significantly improves wearing comfort.

[0019] Second, the sliding connection between the first mounting base and the first connecting member is arranged parallel to the first axis of rotation, so that the sliding direction is parallel to the axis of rotation, and the two movements are spatially decoupled and do not interfere with each other. This sliding degree of freedom allows for adjustment of the position of the first mounting base on the first connecting member to accommodate the differences in limb length among different users. On the other hand, it provides axial micro-displacement buffering during movement, absorbing length changes caused by muscle contraction and joint displacement, and avoiding axial traction on the limb by the support.

[0020] Third, the annular mating surface formed by the first annular cavity and the first annular fixing seat expands the bearing area of ​​the rotating pair from the point contact or line contact of a traditional hinge to a surface contact that surrounds the limb. After the first annular fixing seat is bound to the human body by the straps, the clamping force of the straps is distributed across the entire annular contact surface, significantly reducing the local pressure.

[0021] Fourth, the electromagnetic friction clamping assembly adopts a power-off braking configuration where the clamping spring is normally engaged and the electromagnetic coil is energized to release the clamp. During normal wear and use, the electromagnetic coil remains energized, the friction plates are separated, and the internal and external rotation degrees of freedom are fully open. In the event of a power outage or system failure, the clamping spring immediately clamps the first and second friction plates together, locking the rotating joint in its current position, preventing the user from falling due to sudden loss of control during power failure. This configuration ensures that the default behavior in a fault state is biased towards safety.

[0022] Fifth, the clamping control unit, combined with the angular velocity sensor, forms a rotational speed closed loop. When the rotational angular velocity of the second connector relative to the first mounting base exceeds a preset rotational speed threshold, the power supply to the electromagnetic coil is cut off, causing the friction plate to press tightly and apply frictional resistance to the rotation. Thus, the internal and external rotational degrees of freedom remain fully open within the normal speed range, with constraints only applied when the rotational speed is abnormal. This retains passive adaptability while avoiding the swaying sensation and discomfort caused by the rapid rotation of the second connector due to external impact.

[0023] Sixth, two elastic buffer blocks arranged opposite each other on the first mounting base and the second connecting member abut against each other when rotated to their limit positions, limiting the rotation range within a predetermined angle and preventing the second connecting member from rotating out of the effective coverage area of ​​the first annular cavity and detaching from the first mounting base. The blocks are made of elastic material, and the impact kinetic energy at the moment of contact is absorbed by the elastic deformation of the material, making the limiting process smooth without hard impact. This protects the slide rail structure from wear due to repeated impacts and also avoids the hard limiting effect being transmitted to the human joint.

[0024] Seventh, the mechanical skeleton concentrates the active degrees of freedom on the sagittal hip joint, coronal hip joint, and knee joint, while the internal and external rotation degrees of freedom are passively handled by the thigh and lower leg supports, forming a degree of freedom distribution pattern with active drive as the main focus and passive adaptation as a supplement. This distribution ensures the effectiveness of motion assistance while avoiding the increase in weight and volume caused by adding extra motors to cover rotational degrees of freedom.

[0025] Eighth, the position encoder, speed sensor and torque sensor are integrated inside the joint motor to directly measure the state of the motor output shaft, eliminating the elastic deformation and clearance error caused by external transmission mechanisms such as reducers and connecting rods, and realizing high-precision and low-latency sensing of the joint motion state; at the same time, it simplifies the wiring complexity and improves the system integration and reliability.

[0026] Ninth, both the thigh and lower leg supports employ the same leg device configuration. A second rotating joint around a second axis is installed between the second connector of the lower leg support and the ankle joint support. This second axis is parallel to the first axis, thus creating a multi-level passive rotational capability along the limb axis in the lower leg and ankle sections. The second connector of the lower leg support extends along the sliding direction and is tapered, conforming to the anatomical contour of the human lower leg, which gradually narrows from the knee to the ankle, reducing the volume and weight of the exoskeleton at the ankle.

[0027] Tenth, the control module forms a closed-loop control link based on the actual joint position, actual joint speed, and actual output force, enabling real-time correction of motion deviations and overcoming the shortcomings of open-loop control relying on preset trajectories. The drive module automatically switches between position control mode, speed control mode, damping control mode, torque control mode, and zero torque mode according to the motion stage, ensuring that each mode performs its specific function: position mode ensures the accuracy of motion node arrival, damping mode suppresses motion overshoot, speed mode constrains the reset rhythm, torque mode provides assistance at the moment of start-up, and zero torque mode ensures that the support completely follows the human body during wearing and posture calibration.

[0028] Eleventh, the feedforward torque compensation is generated by the human-machine interaction load characteristics reflected by the actual output torque, and is superimposed on the position stiffness term and velocity damping term to form the total control torque. This ensures that the exoskeleton does not generate dead zone forces that hinder the user's movement at the moment of startup, but actively outputs auxiliary power to help the user overcome static friction and gravity components, thus achieving assisted start.

[0029] Twelfth, the real-time protection logic based on speed deviation and speed change rate operates independently of the action stage judgment. When the user's movement speed is too fast or changes abruptly, it forcibly switches to damping control mode or torque control mode, providing a safety net that does not depend on stage indicators for the entire action process.

[0030] Thirteenth, the vibration motor directly acts on the user's leg proprioception. When the speed exceeds the safe speed limit, it outputs continuous intermittent vibration signals; when the rhythm is normal but not yet in place, it outputs a single-point vibration signal. The two signal patterns are clearly different, allowing the user to distinguish the movement state by touch without having to look at the screen, forming a closed-loop training mode of movement, feedback, and correction. The vibration frequency increases with the increase in the speed exceeding the limit, further establishing an intuitive mapping relationship between speed and touch.

[0031] Fourteenth, the determination of the action in place adopts the dual conditions of the position deviation entering the allowable range and lasting for multiple consecutive sampling cycles. This is equivalent to applying a jitter-reducing filter to the position signal, effectively eliminating the instantaneous data fluctuations caused by the inertial overshoot and physiological tremors at the moment the human body is in place, and avoiding misjudging the instantaneous position during the overshoot process as being in place.

[0032] In addition to the aforementioned effects, this invention also achieves an effect not anticipated at the initial design stage: the annular fit configuration of the first annular cavity and the first annular fixing seat, designed to release the degrees of freedom of internal and external rotation, not only provides rotational guidance but also transforms the tightening pressure of the straps on the limbs from localized concentration to uniform circumferential distribution. The structure originally intended to address motion interference also solves the problems of localized ischemia and numbness caused by strap pressure during prolonged wear. These two comfort improvements are achieved cumulatively within the same structure, something that cannot be obtained by simply adding a rotating hinge. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the overall structure of an embodiment of an active power-enhanced lower limb exoskeleton according to the present invention; Figure 2 This is a schematic diagram of the overall structure of an embodiment of an active power-enhanced lower limb exoskeleton according to another angle of the present invention; Figure 3 This is a schematic diagram of the thigh support structure of an embodiment of an active power-enhanced lower limb exoskeleton according to the present invention; Figure 4 This is a schematic diagram of the first mounting base structure of an embodiment of an active power-enhanced lower limb exoskeleton according to the present invention; Figure 5 This is a schematic diagram of the structure of the first annular fixing seat of an embodiment of an active power-enhanced lower limb exoskeleton according to the present invention; Figure 6 This is a schematic diagram of the lower leg support structure of an embodiment of an active power-enhanced lower limb exoskeleton according to the present invention; Figure 7 This is a schematic diagram of the second annular fixing base structure of an embodiment of an active power-enhanced lower limb exoskeleton according to the present invention; Figure 8 This is a partial cross-sectional view of the leg device in an embodiment of the present invention; Figure 9 This is a schematic diagram of another partial cross-sectional structure of the leg device in an embodiment of the present invention.

[0034] Explanation of reference numerals in the attached figures: 100-Leg Device; 110 - First connector; 120 - First mounting base; 121 - First annular cavity; 122 - Outer sliding groove; 123 - Middle sliding groove; 124 - Roller; 130 - Second connector; 131 - First annular fixing seat; 1311 - Inner layer slider; 132 - Strap; 210 - First friction plate; 220 - Second friction plate; 230 - Compression spring; 240 - Electromagnetic coil; 300-Elastic Buffer Stop; 410-Lumbar support; 420-Hip joint support; 430-Thigh support; 440-Lower leg support; 450-Ankle joint support; 451-Second annular fixing seat; 452-Second slide rail structure; 460-Foot support; 470-Joint motor. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0036] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0037] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0038] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0039] Furthermore, terms such as "horizontal" and "vertical" do not imply that components must be absolutely horizontal or suspended, but rather that they 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 can be slightly tilted.

[0040] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0041] The following description, in conjunction with the accompanying drawings, illustrates the leg device, the active power-enhancing lower limb exoskeleton, and the control method of this invention. The coronal axis, also known as the frontal axis, is a horizontal axis extending in the left-right direction, forming three mutually perpendicular axes in a three-dimensional coordinate system together with the sagittal axis and the vertical axis. In human anatomy, rotation about the coronal axis corresponds to flexion and extension movements of the human body (such as knee flexion and hip flexion). The vertical axis is vertical and perpendicular to the ground. The sagittal axis is anteroposterior and parallel to the ground.

[0042] Example 1 refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 and Figure 9 , Figure 1 This is a schematic diagram of the overall structure of an embodiment of an active power-enhanced lower limb exoskeleton according to the present invention. Figure 2 This is a schematic diagram of the overall structure of another embodiment of an active power-enhanced lower limb exoskeleton according to an embodiment of the present invention. Figure 3 This is a schematic diagram of the thigh support 430 structure of an embodiment of an active power-enhanced lower limb exoskeleton according to the present invention. Figure 4 This is a schematic diagram of the first mounting base 120 of an embodiment of an active power-enhanced lower limb exoskeleton according to the present invention. Figure 5 This is a schematic diagram of the structure of the first annular fixing base 131 of an embodiment of an active power-enhanced lower limb exoskeleton according to an embodiment of the present invention. Figure 6 This is a schematic diagram of the lower leg support 440 structure of an embodiment of an active power-enhanced lower limb exoskeleton according to the present invention. Figure 7 This is a schematic diagram of the second annular fixing base 451 of an embodiment of an active power-enhanced lower limb exoskeleton according to the present invention. Figure 8 This is a partial cross-sectional view of the leg device 100 in an embodiment of the present invention. Figure 9This is a partial cross-sectional view of the leg device 100 in another embodiment of the present invention. This embodiment provides an active power-enhanced lower limb exoskeleton, which includes a mechanical skeleton, a drive module, a sensing module, a control module, and a human-computer interaction module.

[0043] The mechanical skeleton includes a lumbar support 410, a hip joint support 420, a thigh support 430, a calf support 440, an ankle support 450, and a foot support 460. The lumbar support 410 is fixed to the user's waist and abdomen, serving as the reference load-bearing component for the entire lower limb exoskeleton; it has flexible padding inside to improve wearing comfort. One end of the hip joint support 420 connects to the lumbar support 410, and the other end extends downwards to connect to the thigh support 430, forming a kinematic pair connecting the torso and lower limbs. The thigh support 430 connects downwards to the calf support 440, the end of the calf support 440 connects to the ankle support 450, and the end of the ankle support 450 connects to the foot support 460, thus forming a complete lower limb kinematic chain. The connection points between the lumbar support 410 and the hip joint support 420 are at the sagittal hip joint, the connection points between the hip joint support 420 and the thigh support 430 are at the coronal hip joint, the connection points between the thigh support 430 and the lower leg support 440 are at the knee joint, and the connection points between the lower leg support 440 and the ankle joint support 450 are at the ankle joint. The mechanical frame can be made of high-strength, lightweight materials such as stainless steel, aluminum alloy, or carbon fiber to ensure support strength while reducing the user's load.

[0044] The drive module includes multiple joint motors 470 mounted on a mechanical skeleton. These motors drive the hip joint support 420 to rotate relative to the lumbar support 410 around the sagittal axis, drive the thigh support 430 to rotate relative to the hip joint support 420 around the coronal axis, and drive the lower leg support 440 to rotate relative to the thigh support 430 around the coronal axis. Rotation along the sagittal axis corresponds to the forward and backward swinging of the lower limbs, such as taking a step while walking; rotation along the coronal axis corresponds to the lateral swinging and flexion / extension of the lower limbs. In this embodiment, the joint motors 470 are permanent magnet synchronous motors, which have high torque density and precise control response characteristics, and include two symmetrically arranged first joint motors, two second joint motors, and two third joint motors. A first joint motor is located at the connection point between the hip joint support 420 and the lumbar support 410, and is used to drive the hip joint support 420 to rotate relative to the lumbar support 410 around the sagittal axis. A second joint motor is located at the connection point between the hip joint support 420 and the thigh support 430, and is used to drive the thigh support 430 to rotate relative to the hip joint support 420 around the coronal axis. A third joint motor is located at the connection point between the thigh support 430 and the calf support 440, and is used to drive the calf support 440 to rotate relative to the thigh support 430 around the coronal axis. In this embodiment, the rotation range of the hip joint support 420 relative to the lumbar support 410 around the sagittal axis is -10 degrees to 120 degrees, the rotation range of the thigh support 430 relative to the hip joint support 420 around the coronal axis is -30 degrees to 45 degrees, the rotation range of the calf support 440 relative to the thigh support 430 around the coronal axis is -125 degrees to 0 degrees, and the rotation range of the ankle joint support 450 relative to the calf support 440 is -20 degrees to 75 degrees.

[0045] The joint parameters of the mechanical skeleton are shown in Table 1: The sensing module includes a position encoder, a speed sensor, and a torque sensor integrated within the articulated motor 470. This embodiment employs a highly integrated drive unit, directly embedding these three types of sensors within the articulated motor 470. The position encoder provides real-time feedback of the accumulated position value of the motor rotor over multiple revolutions; the speed sensor calculates the real-time angular velocity using position differentiation or Hall effect signals; and the torque sensor calculates the real-time output torque through current loop feedback.

[0046] The control module is communicatively connected to both the drive module and the sensing module. It is configured to automatically switch the operating state of the drive module and generate corresponding joint control commands based on the actual joint position, actual joint speed, and actual output torque transmitted by the sensing module, thereby driving the drive module to operate. In this embodiment, the control module uses a microcontroller or industrial computer as its core processor, establishes a communication connection with each joint motor 470 via an RS485 bus or CAN bus, and is equipped with non-volatile memory to store a preset motion database.

[0047] The human-computer interaction module includes multiple vibration motors mounted on the thigh support 430. The control module is further configured to control the vibration motors to output different vibration signals based on the safe speed deviation between the actual joint speed and the upper limit of the safe speed, so as to provide tactile feedback to the user's current movement. In this embodiment, the vibration motors are installed on the front and outer sides of the thigh support 430. These two areas correspond to the main motor sensory nerve distribution areas of the human lower limb and are more sensitive to tactile stimulation.

[0048] First, by concentrating the active degrees of freedom on the sagittal hip joint, coronal hip joint, and knee joint, precise matching of the main degrees of freedom of the human lower limbs is achieved. This allows the exoskeleton to conform to the natural movement patterns of the human joints, avoiding movement interference and local skin compression caused by mismatch in degrees of freedom. Second, three types of sensors are integrated inside the motor to directly measure the state of the motor output shaft, eliminating elastic deformation and clearance errors caused by external transmission mechanisms such as reducers and connecting rods. This achieves high-precision, low-latency joint state perception while reducing the installation requirements and wiring complexity of external sensors. Third, the joint motor 470 uses a permanent magnet synchronous motor and is arranged symmetrically in pairs at the three joint positions, ensuring that the driving power of the left and right lower limbs is completely equal. This avoids trunk tilt caused by unilateral driving, and the high torque density characteristic allows the auxiliary torque required to complete squats and lunges to be obtained within the limited joint space. Fourth, a closed-loop link of perception, judgment, and execution is formed between the control module, drive module, and perception module, overcoming the defects of open-loop control that relies on preset trajectories.

[0049] Example 2 This embodiment provides a leg device 100 for an active power-enhanced lower limb exoskeleton. The leg device 100 includes a first connector 110, a first mounting base 120, and a second connector 130.

[0050] The first connector 110 serves as the main support rod of the leg device 100. One end of the first connector 110 is connected to the external bracket via a rotating joint, allowing it to rotate around the coronal axis and realize the flexion and extension of the leg device 100 in the sagittal plane. The other end of the first connector 110 is connected to the first mounting base 120.

[0051] The second connector 130 is rotatably connected to the first mounting base 120 and can rotate relative to the first mounting base 120 about a first axis. The first axis is perpendicular to the coronal axis and extends along the length of the leg device 100. Since the leg device 100 is arranged longitudinally along the thigh or calf of the human body when worn, the orientation of the first axis is substantially coincident with the vertical axis of the thigh or calf itself. Therefore, the rotation of the second connector 130 relative to the first mounting base 120 about the first axis is used to follow the internal and external rotation movements of the thigh or calf of the human body about the vertical axis.

[0052] In the worn state, the second connector 130 is bound to the human limb via the strap 132, while the first connector 110 is connected to the upstream support of the exoskeleton via a rotating joint at its upper end. When the user's thigh or calf rotates internally or externally during walking or squatting, the human limb causes the second connector 130 to rotate around the first axis, while the orientation of the first connector 110 and the first mounting base 120 remains unchanged. The rotational movement of the human limb is absorbed by the rotating joint and is no longer transmitted as the rubbing motion of the strap 132 on the skin, nor is it subject to torsional constraint by the support in the opposite direction.

[0053] Furthermore, the first connecting member 110 is slidably connected to the first mounting base 120, and the first mounting base 120 can slide relative to the first connecting member 110 in a direction parallel to the first rotating axis. In this embodiment, the first mounting base 120 is sleeved on the outer or inner side of the first connecting member 110, and linear sliding along the length direction of the first connecting member 110 is achieved through a slide rail or slide groove structure. Since the first rotating axis extends along the length direction of the leg device 100, the sliding direction of the first mounting base 120 is parallel to the first rotating axis, thereby decoupling the sliding motion and the rotational motion in space. In this embodiment, when the leg device 100 is used as a thigh support 430, the sliding stroke of the first mounting base 120 is 0mm to 60mm; when used as a calf support 440, the sliding stroke of the first mounting base 120 is 0mm to 90mm.

[0054] Firstly, the first mounting base 120, as an intermediate component between the first connector 110 and the second connector 130, structurally separates the flexion and extension around the coronal axis from the internal and external rotation around the first rotation axis. This allows the exoskeleton frame to automatically adapt to the rotational posture of the human limbs through this composite motion structure, avoiding the wear and discomfort caused by the forced twisting of human muscles and bones by traditional rigid frames, and significantly improving wearing comfort. Secondly, the internal and external rotation degrees of freedom are passively achieved by the revolute joint, without the need to add a motor and reducer. While obtaining degrees of freedom, the weight, volume and response delay of the system are not increased. Third, the geometric constraint that the sliding direction of the first mounting base 120 relative to the first connecting member 110 is parallel to the first rotating axis ensures the decoupling of rotational and sliding motions. When the user performs internal or external rotational movements, they will not be subject to additional constraint forces in the sliding direction, and vice versa. The two movements are independent of each other and do not interfere with each other. Fourth, this sliding degree of freedom allows the leg device 100 to adapt to the differences in limb length of different users by adjusting the position of the first mounting base 120, and provides axial micro-displacement buffer during movement to absorb length changes caused by muscle contraction and joint displacement.

[0055] The first mounting base 120 is provided with a first annular cavity 121, and the second connector 130 is provided with a first annular fixing seat 131 that is adapted to the first annular cavity 121 and used for binding to the human body by a strap 132. A first slide rail structure is provided between the first annular fixing seat 131 and the first annular cavity 121. The first annular fixing seat 131 slides along the inner surface of the first annular cavity 121 through the first slide rail structure, so that the second connector 130 rotates relative to the first mounting base 120 around a first axis.

[0056] The first annular cavity 121 forms a rotational track, which is arranged around the human limb. The first annular fixing seat 131 directly or indirectly adheres to the skin or clothing of the human thigh or calf and is secured by straps 132. When the human limb undergoes internal or external rotation, the first annular fixing seat 131 slides along the annular track within the first annular cavity 121, thereby converting the human body's rotational motion into relative sliding within the exoskeleton frame.

[0057] In this embodiment, the first slide rail structure adopts a nested design with inner and outer layers. The upper and / or lower surfaces of the first annular cavity 121 are recessed inward to form an outer slide groove 122. The first annular fixing seat 131 is provided with an inner slider 1311 that matches the outer slide groove 122. The outer slide groove 122 and the inner slider 1311 are nested together to form the first slide rail structure. After the inner slider 1311 is embedded in the outer slide groove 122, the groove wall covers the inner slider 1311 from both the top and bottom sides, so that the first annular fixing seat 131 has the ability to rotate circumferentially while being subject to dual constraints in the axial and radial directions.

[0058] The outer groove 122 has a cross-sectional shape that can be C-shaped, O-shaped, or dovetail-shaped. When using a C-shaped cross-section, the groove opening is larger, making the assembly and disassembly of the inner slider 1311 most convenient, with the lowest processing cost, suitable for applications requiring high maintenance convenience. When using an O-shaped cross-section, the groove wall is completely closed in the circumferential direction, completely surrounding the inner slider 1311, significantly enhancing radial restraint compared to the C-shaped cross-section. When using a dovetail-shaped cross-section, the groove wall gradually narrows along the depth direction, and the corresponding side of the inner slider 1311 is also made into a bevel, forming a mechanical self-locking fit that will not disengage even under large axial pull-out forces, providing the strongest radial restraint among the three. Those skilled in the art can choose from these three options based on the target application scenario of the exoskeleton.

[0059] It should be understood that the first slide rail structure can also adopt other equivalent forms, such as an arc-shaped guide rail combined with a ball bearing, as long as it can achieve smooth sliding of the first annular fixed seat 131 relative to the first annular cavity 121.

[0060] Furthermore, the first annular cavity 121 also includes a central groove 123 arranged along the rotation direction of the first annular fixed seat 131. Multiple rollers 124 are disposed within the central groove 123, with the axes of the rollers 124 parallel to the first rotating shaft. The rollers 124 contact the first annular fixed seat 131. In this embodiment, the central groove 123 is located between the outer groove 122 on the upper surface and the outer groove 122 on the lower surface of the first annular cavity 121, extending circumferentially along the first annular cavity 121. Multiple rollers 124 are evenly distributed circumferentially along the central groove 123. Each roller 124 is supported by an axle on the groove wall of the central groove 123 and can rotate freely. Its outer circumferential surface extends out of the groove and abuts against the outer circumferential surface of the first annular fixed seat 131. When the first annular fixed seat 131 rotates relative to the first annular cavity 121, each roller 124 is driven by the first annular fixed seat 131 to roll around its own axle, and the original sliding friction between the two is converted into rolling friction.

[0061] Firstly, the annular mating surface formed by the first annular cavity 121 and the first annular fixing seat 131 expands the bearing area of ​​the rotating pair from the point contact or line contact of a traditional hinge to a surface contact around the limb. The clamping force of the strap 132 is distributed across the entire annular contact surface, significantly reducing local pressure. Simultaneously, the effects of releasing rotational freedom and reducing the pressure of the strap 132 are superimposed on the same structure. Secondly, the first slide rail structure, formed by the nested outer slide groove 122 and inner slider 1311, provides axial and radial constraints while ensuring smooth circumferential rotation, preventing the first annular fixing seat 131 from... 31 disengages from the first annular cavity 121 when subjected to lateral load; thirdly, the three optional cross-sectional shapes allow for an adjustable trade-off between radial constraint capability and processing and assembly costs, and the dovetail groove type mechanical self-locking fit can provide the highest anti-disengagement capability in violent motion situations; fourthly, the multiple rollers 124 in the central slide groove 123 convert sliding friction into rolling friction, which significantly reduces the starting torque of the internal and external rotation degrees of freedom, and the human limbs only need to exert a very small rotational force to drive the second connecting piece 130 to rotate, thereby improving the sensitivity of passive adaptation and reducing the wear of the slide rail mating surface during long-term use.

[0062] An electromagnetic friction clamping assembly is provided between the first mounting base 120 and the second connecting member 130. The electromagnetic friction clamping assembly includes a first friction plate 210 disposed on the first mounting base 120, a second friction plate 220 disposed on the second connecting member 130 and opposite to the first friction plate 210, a compression spring 230, and an electromagnetic coil 240.

[0063] In this embodiment, the first friction plate 210 is disposed on the end face of the first mounting base 120 (outer sliding groove) facing the second connecting member 130, and is annular and coaxially arranged with the first rotating shaft; the second friction plate 220 is fixed on the end face of the second connecting member 130 (inner sliding block) facing the first mounting base 120 (groove wall of the outer sliding groove), and is directly opposite the first friction plate 210. The compression spring 230 is a helical compression spring, one end of which abuts against the first mounting base 120, and the other end abuts against the back of the first friction plate 210, applying an axial preload force to the first friction plate 210 pointing towards the second friction plate 220. The electromagnetic coil 240 is wound inside the first mounting base 120, with an axial air gap between it and the first friction plate 210. The friction plates can be made of powder metallurgy friction materials or resin-based friction materials, and their friction coefficient and wear resistance can meet the requirements of repeated engagement and release.

[0064] The working process of the electromagnetic friction clamping assembly is as follows: When the electromagnetic coil 240 is de-energized, the electromagnetic force disappears, and the clamping spring 230 drives the first friction plate 210 and the second friction plate 220 to press against each other. The static friction torque generated between the contact surfaces of the two friction plates prevents the second connecting member 130 from rotating relative to the first mounting base 120 around the first axis, thereby locking the rotation. When the electromagnetic coil 240 is energized, the coil establishes a magnetic flux in the iron core, generating an axial attraction force on the first friction plate 210. This electromagnetic force overcomes the elastic force of the clamping spring 230, pulling the first friction plate 210 axially away from the second friction plate 220, causing the two friction plates to separate from each other, the friction torque disappears, and thus the locking of the rotation is released. It can be seen that this assembly adopts a de-energized braking configuration with the spring normally clamped and released when energized. Its default state is locked, and the rotational freedom is only opened when energized.

[0065] Furthermore, the electromagnetic friction clamping assembly also includes a clamping control unit and an angular velocity sensor. The angular velocity sensor is used to detect the rotational angular velocity of the second connector 130 relative to the first mounting base 120. In this embodiment, a microelectromechanical gyroscope or an incremental rotary encoder is used, and it is installed at the mating part between the first mounting base 120 and the second connector 130. The clamping control unit is electrically connected to the electromagnetic coil 240 and is configured to keep the electromagnetic coil 240 energized when the rotational angular velocity is less than or equal to a preset speed threshold, and to cut off the power supply to the electromagnetic coil 240 when the rotational angular velocity is greater than the preset speed threshold.

[0066] In this embodiment, the preset rotational speed threshold is set to 30 degrees per second to 90 degrees per second, and its value can be adjusted within this range according to the type of training action and the user's physical fitness level. During normal wear and training, the internal and external rotational angular velocities of the human thigh or calf are usually lower than this threshold. The clamping control unit continuously supplies power to the electromagnetic coil 240, the friction plates remain separated, the internal and external rotational degrees of freedom are fully open, and the passive adaptability of the leg device is not affected in any way. When the second connector 130 rotates rapidly due to external impact or loss of balance by the user, and the rotational angular velocity exceeds the preset rotational speed threshold, the clamping control unit immediately cuts off the power supply to the electromagnetic coil 240. The compression spring 230 drives the two friction plates to press together, the frictional torque rises rapidly and applies braking to the rotation, causing the rotational speed to drop. After the rotational speed drops back to within the threshold, the clamping control unit restores the power supply, and the friction plates separate again.

[0067] First, with the power-off braking configuration, the default behavior when power is interrupted or the system fails is to lock rather than release. The user will not lose support due to a sudden loss of freedom of freedom during power failure, and the system behavior in the fault state is biased towards safety. Second, the rotational closed loop formed by the clamping control unit and the angular velocity sensor keeps the internal and external rotational degrees of freedom fully open within the normal speed range, and only applies restraint when the rotational speed is abnormal. This not only fully preserves the passive adaptability of the leg device, but also avoids the swinging sensation and wearing discomfort caused by the second connecting piece 130 rotating too fast. Third, the braking force is generated by the contact surface of the friction plate, and its torque changes linearly with the preload of the compression spring 230. The braking strength can be adjusted by adjusting the spring preload without changing the structural layout. Fourth, the threshold can be adjusted according to the type of training movement and the user's physical fitness level, so that the same hardware can be adapted to different scenarios from the early stage of rehabilitation to high-intensity strength training.

[0068] like Figure 9 As shown, the first mounting base 120 and the second connecting member 130 are respectively provided with elastic buffer blocks 300. The elastic buffer blocks 300 are arranged opposite to each other along the rotation direction of the second connecting member 130 relative to the first mounting base 120, and abut against each other when the second connecting member 130 rotates to the rotation limit position, so that the rotation angle of the second connecting member 130 relative to the first mounting base 120 in the inward rotation direction and the outward rotation direction does not exceed a predetermined angle, and prevents the second connecting member 130 from disengaging from the first mounting base 120.

[0069] Specifically, two elastic buffer blocks 300 are provided on the top of the first mounting base 120, and one elastic buffer block 300 is provided at the middle position of the top of the second connector 130. When the elastic buffer block 300 on the second connector 130 rotates inward or outward around the first rotating shaft, it cooperates with the elastic buffer block 300 on the first mounting base 120 respectively, so that the rotation angle of the second connector 130 relative to the first mounting base 120 in the inward and outward rotation directions does not exceed a predetermined angle, and prevents the second connector 130 from disengaging from the first mounting base 120.

[0070] In this embodiment, the elastic buffer block 300 disposed on the first mounting base 120 is fixed to the inner wall of the first annular cavity 121, and the elastic buffer block 300 disposed on the second connecting member 130 is fixed to the outer circumferential surface of the first annular fixed base 131. Both are located on the same circumferential trajectory and are arranged facing each other along the rotation direction. When the first annular fixed base 131 is in the center position, there are circumferential gaps between the two elastic buffer blocks 300 corresponding to the inward and outward rotation directions, respectively. When the first annular fixed base 131 rotates inward until the gaps in that direction are exhausted, the two elastic buffer blocks 300 abut against each other, and the rotation is stopped; the limiting process in the outward rotation direction is the same. In this embodiment, the predetermined angle is 25 degrees, meaning that the rotation angle of the second connecting member 130 relative to the first mounting base 120 in both the inward and outward rotation directions does not exceed 25 degrees, consistent with the design range of the passive degrees of freedom of the mechanical skeleton.

[0071] The elastic buffer stop 300 is made of elastic materials such as polyurethane, nitrile rubber, or silicone rubber, and its Shore hardness can be selected in the range of 70A to 90A. The contact surface of the stop is made into a plane perpendicular to the rotation direction or an arc surface concentric with the first annular cavity 121 to maximize the contact area during contact. The circumferential thickness of the stop is its compressible buffer stroke, which is 3mm to 8mm in this embodiment.

[0072] First, the mechanical limiting formed by the mutual abutment of the two elastic buffer blocks 300 constrains the rotation range of the second connecting member 130 within a predetermined angle, ensuring that the first annular fixing seat 131 is always within the effective coverage area of ​​the first annular cavity 121, fundamentally preventing the second connecting member 130 from detaching from the first mounting seat 120 due to excessive rotation. Second, the blocks are made of elastic material and have a compressible buffer stroke; the impact kinetic energy at the moment of contact is absorbed by the elastic deformation of the material and gradually released, resulting in a smooth limiting process without hard impact. This design avoids both the plastic deformation and wear of the slide rail mating surface caused by repeated impacts from the rigid limit block, and the secondary injury caused by the impact torque being transmitted to the human joint through the strap 132. Thirdly, the limiting angle matches the physiological range of internal and external rotation of the human thigh and calf. Within the normal range of motion, the stop block does not participate in the work and will not interfere with the passive adaptive ability. It only intervenes when the physiological range is exceeded. Fourthly, the hardness and thickness of the stop block can be selected within a given range, and the trade-off between buffer stiffness and limiting accuracy can be adjusted according to the usage scenario.

[0073] Example 3 This embodiment provides an active power-enhanced lower limb exoskeleton, in which the thigh support 430 and the lower leg support 440 are both leg devices 100 as described in the previous embodiment. The first connector 110 of the thigh support 430 is rotatably connected to the hip joint support 420 about the coronal axis, the second connector 130 of the thigh support 430 is rotatably connected to the first connector 110 of the lower leg support 440 about the coronal axis, and the second connector 130 of the lower leg support 440 is rotatably connected to the ankle joint support 450 about a second axis perpendicular to the coronal axis.

[0074] Thus, the exoskeleton forms a sequence of degrees of freedom with alternating active and passive rotations along the lower limb kinetic chain: active rotation of the hip joint support 420 relative to the lumbar support 410 around the sagittal axis; active rotation of the thigh support 430 relative to the hip joint support 420 around the coronal axis; passive rotation of the second connecting member 130 inside the thigh support 430 around the first axis; active rotation of the lower leg support 440 relative to the thigh support 430 around the coronal axis; passive rotation of the second connecting member 130 inside the lower leg support 440 around the first axis; and passive rotation of the ankle joint support 450 relative to the lower leg support 440 around the second axis. The internal and external rotation components generated by the thigh and lower leg during movement are absorbed independently by the thigh support 430 and the lower leg support 440, respectively, without mutual interference.

[0075] Furthermore, such as Figure 7As shown, the first connector 110 of the calf support 440 is slidably connected to the first mounting base 120 of the calf support 440, and the first mounting base 120 of the calf support 440 can slide relative to the first connector 110 of the calf support 440 in a direction parallel to the first axis of rotation, for adjusting the length of the calf support 440 to accommodate different user body shapes. The ankle joint support 450 includes a second annular fixing seat 451 rotatably connected to the second connector 130 of the calf support 440 about a second axis of rotation, and the second annular fixing seat 451 is bound to the human body by a strap 132. The second connector 130 of the calf support 440 extends along the sliding direction of the first mounting base 120 relative to the first connector 110 of the calf support 440 and is gradually tapered. A second slide rail structure 452 is provided between the second connector 130 of the calf support 440 and the second annular fixing base 451. The second annular fixing base 451 rotates relative to the second connector 130 of the calf support 440 through the second slide rail structure 452. The second rotating shaft is parallel to the first rotating shaft.

[0076] In this embodiment, the second slide rail structure 452 is designed on the same principle as the first slide rail structure, achieving rotation through the relative sliding of the inner and outer sliders, which will not be elaborated further here. Considering that the human lower leg has a gradually tapering shape from the knee to the ankle, the second connector 130 of the lower leg support 440 is designed in a tapering shape, with its cross-section gradually narrowing from top to bottom along the sliding direction. The second annular fixing seat 451 is bound to the human ankle area by the strap 132, stably transmitting the driving force of the exoskeleton to the foot support 460.

[0077] In this embodiment, the mechanical skeleton structure parameters of the active power-enhanced lower limb exoskeleton are shown in Table 2: Firstly, the thigh support 430 and the calf support 440 adopt the same leg device 100 configuration, allowing the internal and external rotation degrees of freedom to be set independently in the thigh and calf segments respectively. The rotation of the human thigh will not be transmitted to the calf segment through the support, and vice versa, achieving passive adaptation capabilities of multiple joints in the lower limb. Secondly, the revolute joint around the second axis between the second connector 130 of the calf support 440 and the ankle joint support 450 is connected in series with the revolute joint around the first axis inside the calf support 440 along the limb axis, and the second axis is parallel to the first axis. This creates multi-level passive rotation capabilities in the calf and ankle segments, which is particularly important for large-amplitude movements such as lunges and high knees, effectively preventing the exoskeleton support from... During strenuous exercise, torsional torque is generated due to changes in human posture; thirdly, the sliding of the first mounting base 120 of the calf support 440 relative to the first connecting member 110 makes the length of the calf support 440 adjustable, and with the similar adjustment capability of the thigh support 430, the exoskeleton can cover a wide range of user heights; fourthly, the tapering design of the second connecting member 130 conforms to the natural contour of the human calf to the ankle, making the structure gradually narrow from top to bottom, reducing the volume and weight of the exoskeleton at the ankle, and reducing the burden on the user; fifthly, while the second annular fixing base 451 transmits the driving force to the foot through the strap 132, its own rotational freedom avoids restricting the rotational movement of the ankle.

[0078] Example 4 This embodiment provides a control method for an actively powered lower limb exoskeleton, applied to the actively powered lower limb exoskeleton described in the foregoing embodiment. The method includes the following steps.

[0079] Step S1: Read the action node sequence from the preset action database. The action node sequence consists of multiple action nodes arranged in chronological order. The preset action database is stored in the non-volatile memory of the control module and contains trajectory data of various standard training actions. Each training action is discretized into a sequence of action nodes arranged in chronological order. After power-on initialization, the control module calls the corresponding action node sequence into the running memory according to the training mode selected by the user, providing a benchmark reference for subsequent real-time control.

[0080] Step S2 involves real-time acquisition of the actual joint position, actual joint speed, and actual output torque using a position encoder, speed sensor, and torque sensor integrated within the joint motor 470. The position encoder provides real-time feedback of the accumulated position value of the motor rotor over multiple revolutions. The speed sensor calculates the real-time angular velocity using position differential or Hall effect signals, and the torque sensor calculates the real-time output torque using current loop feedback. This sensor data is transmitted to the control module in real-time via an RS485 bus or CAN bus. In this embodiment, the bus baud rate is set to 4.0 Mbps to ensure low latency and high synchronization of data acquisition.

[0081] Step S3: Identify the human-machine interaction load characteristics based on the actual output torque, and generate a feedforward torque compensation amount based on these characteristics. The actual output torque reflects the comprehensive load borne by the exoskeleton joint motor 470 during movement. This load consists of the exoskeleton's own weight, inertial force, and human-machine interaction force. The control module separates the steady-state component and the dynamic component from the total torque using a filtering algorithm, identifying the interaction force characteristics applied by the user's limbs: when the user's limbs are detected to be drooping, the interaction torque manifests as a resistive torque that hinders movement; when the user actively exerts force, the interaction torque manifests as a dynamic torque that assists movement. Based on this identification result, the control module generates a feedforward torque compensation amount to counteract inactive interferences such as gravity or friction, or to provide active assistance to the user.

[0082] The feedforward torque compensation is calculated using the following formula: in, This is the feedforward torque compensation amount. To boost the coefficient, This is the gravity compensation coefficient. To actively contribute to the gain, This represents the exoskeleton's own gravitational torque. Human-computer interaction torque, This indicates that the user actively applies force to assist the movement. This indicates a passive force that hinders movement in the user's limbs. This is an indicator function that takes the value 1 if the condition is true, and 0 otherwise.

[0083] Step S4: Calculate the positional deviation between the actual joint position and the desired joint position in the motion node sequence, and the velocity deviation between the actual joint velocity and the desired joint velocity. The control module subtracts the actual joint position acquired in step S2 from the desired joint position of the current target motion node read in step S1 to obtain the positional deviation; simultaneously, it subtracts the actual joint velocity from the desired joint velocity of the motion node to obtain the velocity deviation.

[0084] Specifically, the control module will collect the actual joint position in step S2. The desired joint position of the current target action node read in step S1 Perform the difference calculation to obtain the positional deviation. At the same time, the actual joint speed With the desired joint velocity of this node Compare and calculate speed deviation These two deviations are key indicators for judging the user's action execution status (such as whether it is in place or too fast), and are also the basis for subsequent selection of control mode and adjustment of control parameters.

[0085] Step S5: Based on position deviation, velocity deviation, and action node sequence, determine the user's action node state. Action node state includes the action initiation stage, fixed action node execution stage, and reset stage. The control module reads the stage identifiers from the action node sequence and combines this with the real-time calculated position and velocity deviations to comprehensively determine the current action stage of the user.

[0086] Step S6: Based on the user's current action node state, the working state of the drive module is automatically switched, and corresponding joint control commands are generated by combining the feedforward torque compensation to drive the joint motor 470. The control module selects the most suitable control mode for the current state based on the judgment result of step S5, and generates joint control commands using a proportional-derivative control algorithm combined with feedforward compensation.

[0087] Step S7: Based on the safe speed deviation between the actual joint speed and the upper limit of the safe speed, the vibration motor is controlled to output different vibration signals to provide tactile feedback to the user's current movement. The control module compares the safe speed deviation with a preset threshold and outputs vibration signals of different frequencies or modes: when the speed is too fast, a continuous intermittent vibration signal is output to warn the user to slow down; when the speed is within the allowable range but has not yet reached the target position, a single-point vibration signal is output to prompt the user to maintain the current rhythm.

[0088] First, steps S1 to S7 constitute a complete closed-loop control logic encompassing data acquisition, feature recognition, deviation calculation, state judgment, mode switching, command generation, and tactile feedback. This overcomes the shortcomings of relying on preset trajectories for open-loop position control, enabling the exoskeleton to correct motion deviations in real time. Second, the three types of data acquired in step S2 are actually received in subsequent steps. The actual output torque is used to generate the feedforward torque compensation in step S3, while the actual joint position and actual joint velocity are used to calculate the two types of deviations in step S4. These two types of deviations are then used for state judgment in step S5 and haptic feedback in step S6. In the mode switching, the actual joint speed is used for tactile feedback judgment in step S7, and the multi-source sensor information is fully integrated rather than just collected and not used; third, step S3 separates the human-computer interaction force characteristics from the comprehensive load and generates feedforward compensation accordingly, so that the auxiliary torque of the exoskeleton can change with the user's active force intention, reflecting the core characteristic of active power enhancement; fourth, the amount of feedforward torque compensation can be adaptively adjusted according to the user's rehabilitation stage or physical condition. A larger compensation amount is set in the early stage of rehabilitation to provide strong assistance, and the compensation amount is reduced in the later stage of rehabilitation to encourage the user to actively participate.

[0089] The following section provides a further explanation of the data structure and stage division logic in the control method.

[0090] The preset action database stores action node sequences categorized by training action type, with each training action corresponding to a set of action node sequences. The data structure employs a hierarchical indexing approach: the first layer is the training action type index, and the second layer contains the specific action node sequences, each sequence being an array arranged chronologically. Each array element is an action node, a structure containing control parameters. Each action node includes at least the desired joint position, desired joint velocity, and safe speed limit. The desired joint position defines the standard angle of the action posture, providing a quantitative benchmark for position deviation calculation and stable arrival determination; the desired joint velocity defines the reference rhythm of action execution, providing a basis for setting target values ​​in speed control mode; and the safe speed limit serves as a protection threshold, providing a basis for speed monitoring and triggering vibration tactile feedback.

[0091] The specific implementation method is as follows: {Node_ID,Target_Position,Target_Velocity,Safety_Limit,Phase_tag} In this structured data storage, Node_ID is the node identifier; Target_Position is the desired joint position, defining the standard angle for the movement posture; Target_Velocity is the desired joint velocity, defining the reference rhythm for movement execution; Safety_Limit is the upper limit of safe speed, serving as a protection threshold to prevent muscle strain or joint injury caused by excessively rapid movement; and Phase_tag is a phase identifier for each movement node. This structured data storage method allows the control module to quickly retrieve and call standardized motion trajectories, ensuring the standardization and repeatability of training.

[0092] Furthermore, each action node is assigned a corresponding stage identifier, including an initial stage identifier, a working stage identifier, and a reset stage identifier. The initial stage identifier marks the node at the start of the action, the working stage identifier marks the node in the execution phase of the fixed action node, and the reset stage identifier marks the node in the reset phase. A complete training cycle is thus divided into three distinct stages: the initial stage corresponds to the moment the action begins, when the user starts exerting force from a stationary state, needing to overcome significant static friction and inertia; the working stage corresponds to the core execution process of the action, such as squatting to the lowest point or maintaining balance, where positional accuracy and stability are most critical; and the reset stage corresponds to the return process after the action ends, where speed, rhythm, and smoothness are the primary concerns.

[0093] Accordingly, step S5 specifically includes: reading the stage identifier of the current action node and determining the current action stage based on the stage identifier. If a reset stage identifier is read, the current action is determined to be in the reset stage, at which point the control module recognizes that the user is in the relaxed return state after the action has ended. If a working stage identifier is read, the current action is determined to be in the fixed action node execution stage, at which point the control module recognizes that the user is in the key posture maintenance or trajectory tracking state of the action. If a start stage identifier is read and the actual joint speed is detected to increase from zero, the current action is determined to be in the action start stage.

[0094] It should be understood that the determination of the initial phase uses a dual-condition logic combining flags and speed. Simply reading the initial phase flag is not enough, because the user may not have started moving after putting on the exoskeleton, and the system should be in standby mode at this time; only when the control module simultaneously detects that the actual joint speed increases from zero, that is, when the user has generated the intention to move and begins to perform the action, is the initial phase officially determined.

[0095] First, the categorization and storage of training movements by type allows the exoskeleton to adapt to various training scenarios such as lunges, squats, high knees, and footwork, meeting different training needs such as strength and coordination, and overcoming the shortcomings of lacking a standardized movement reference system and being unable to provide differentiated guidance for different training tasks. Second, the chronological sequence of movement nodes decomposes complex movements into multiple ordered nodes, providing a standard reference system for phased guidance control. Third, the three types of parameters contained in each movement node have clear roles in subsequent control: expected joint position serves position deviation and positioning determination, expected joint speed serves the target setting of the speed control mode, and the upper limit of safe speed serves the trigger judgment of tactile feedback, eliminating redundant parameters that are defined but not used. Fourth, stage identifiers enable the control module to quickly and accurately identify the user's current movement stage, providing a clear decision basis for automatic switching of control modes and achieving precise matching between movement stages and control modes. Fifth, the dual condition judgment in the initial stage effectively prevents false triggering caused by accidental touches or signal noise, ensuring the robustness of the control logic.

[0096] The following further explains the automatic switching logic of the drive module's operating state. The drive module's operating states include position control mode, speed control mode, damping control mode, torque control mode, and zero torque mode. The control module calculates the position and speed deviations in real time and combines them with the current stage indicator to flexibly switch between these five modes to match the physical characteristics and control requirements of different action stages.

[0097] This embodiment employs a hybrid control strategy combining proportional-derivative (PD) control algorithm with feedforward compensation. The total control torque corresponding to the joint control command is the sum of three terms: the product of the position stiffness coefficient and the position deviation, the product of the velocity damping coefficient and the velocity deviation, and the feedforward torque compensation. Specifically, the feedforward torque compensation is the product of the assist coefficient and the compensation component, while the compensation component is the sum of the product of the gravity compensation coefficient and the exoskeleton's own gravity torque, and the product of the active assist gain and the human-machine interaction torque. By dynamically adjusting the values ​​of the position stiffness coefficient and the velocity damping coefficient, equivalent switching and smooth transition between the five control modes can be achieved.

[0098] Specifically, when generating joint control commands, this embodiment uses a PD control algorithm combined with feedforward compensation, and the following calculation method is used to achieve this: in, This represents the total control torque of the joint motor 470. This is the position stiffness coefficient. This is the feedforward torque compensation amount. For positional deviation, The velocity damping coefficient, For speed deviation, This refers to the actual joint position. For the desired joint position, This represents the actual joint velocity. The desired joint velocity. Adjusted in real time. and The parameter values ​​can achieve smooth switching and hybrid control between different control modes, ensuring both the accuracy of action execution and the smoothness of human-computer interaction.

[0099] During the execution phase of a fixed action node, the primary goal of control is to guide the user to accurately reach the target position and maintain stability. If the positional deviation exceeds a first preset threshold... This indicates a significant difference between the user's current posture and the target posture. In this case, the control module switches the drive module to position control mode, guiding the user's limbs towards the target position by setting the desired joint position, position stiffness coefficient, and velocity damping coefficient. The restoring torque generated by the motor pulls the user's limbs towards the target position. If the position deviation is less than or equal to a first preset threshold... This indicates that the user is very close to the target position. If strong position control is continued at this point, the joint is prone to oscillation around the target position due to inertia. Therefore, the control module switches the drive module to a damping control mode, suppressing motion overshoot by increasing the speed damping coefficient. In this mode, the motor no longer provides a strong restoring force, but instead provides a damping force proportional to the motion speed, which is equivalent to adding a hydraulic buffer to the joint, effectively absorbing kinetic energy.

[0100] During the reset phase, the drive module switches to speed control mode, using set joint speed and speed damping coefficient to constrain rhythm. In this mode, the motor primarily performs closed-loop speed control, guiding the user to return to the starting position at a set rhythm, preventing accelerated descent or excessively rapid return due to gravity.

[0101] During the initial phase of movement, the user begins exerting force from a stationary state, primarily facing static friction and limb inertia. The control module switches the drive module to torque control mode, adjusting the feedforward torque compensation to achieve auxiliary drive output. In this mode, both the position stiffness coefficient and velocity damping coefficient are zero or close to zero. The motor mainly outputs feedforward torque generated based on the human-machine interface load characteristics. This zero-stiffness characteristic ensures that the exoskeleton does not generate dead zone forces that impede the user's movement at the moment of activation.

[0102] During the user's wearing of the active power-enhanced lower limb exoskeleton, the drive module's operating state is switched to zero-torque mode. In this mode, the position stiffness coefficient, velocity damping coefficient, and feedforward torque compensation are all set to zero. The motor does not output any active torque, the mechanical skeleton completely follows the human body's posture, and the thigh support 430 and lower leg support 440 are in a free state, able to rotate with the user's lower limbs' natural rotation, facilitating wear adjustment and posture calibration.

[0103] In this embodiment, as shown in Table 3, the control mode is dynamically switched. Furthermore, to address unforeseen circumstances during training, this embodiment also includes real-time protection logic independent of stage determination. During the execution of any action node, if the speed deviation exceeds a second preset threshold, indicating that the user's movement speed is too fast and exceeds the safe range, the control module will forcibly switch the drive module's operating state to damping control mode, regardless of the current stage. This instantaneously increases the damping force to restrain the user's limbs, preventing muscle strain due to loss of control. If the speed deviation is less than or equal to the second preset threshold and the actual joint speed change rate is greater than a third preset threshold, it indicates that the user is making an emergency stop or a rapid change in speed. In this case, the control module will switch the drive module's operating state to torque control mode, dynamically adjusting the output torque according to the speed change rate to adapt to the user's intention to stop abruptly, providing a smooth force interaction.

[0104] It should be understood that the aforementioned preset thresholds are not fixed, but rather stored in a preset action database and are related to the specific training action type and the user's fitness level. For high-intensity strength training, the thresholds can be set higher; for flexibility training in the early stages of rehabilitation, the thresholds are set lower. This parameterized threshold setting mechanism allows the control strategy of this invention to be widely adaptable to different user groups and training scenarios.

[0105] The technical advantages of this embodiment are as follows: First, the five control modes automatically switch according to the action stage, allowing each mode to perform its specific function. The position mode ensures the accuracy of the action node arrival, the damping mode suppresses motion overshoot, the speed mode constrains the reset rhythm, the torque mode provides assistance at the moment of start-up, and the zero torque mode facilitates wear and attitude calibration, overcoming the shortcomings of a single position control mode, such as abrupt start-up and easy overshoot when approaching the target. Second, all five modes are achieved by adjusting the values ​​of the position stiffness coefficient and speed damping coefficient in the same control law, eliminating the need for hard switching between different controllers, resulting in smooth mode transitions and avoiding... The system achieves several key improvements: First, it eliminates the momentary torque jump during switching. Second, the feedforward torque compensation in the total control torque is superimposed in parallel with the position stiffness and velocity damping terms, enabling the exoskeleton to maintain its ability to compensate for human-machine interaction loads in any mode, achieving assisted start and smooth assistance. Third, the real-time protection logic based on speed deviation and speed change rate operates independently of stage judgment, providing a safety net for the entire movement process that does not rely on stage markers, ensuring protection is not lost even if stage judgment deviates. Fourth, the parameterized setting of thresholds allows the same control strategy to cover a wide range of scenarios from the early stages of rehabilitation to high-intensity training.

[0106] The following provides further explanation of the specific feedback logic of the vibration motor and the mechanism for determining the position of the action.

[0107] Step S7 specifically includes comparing the actual joint velocity with the upper limit of the safe speed for the corresponding motion node. This comparison process is real-time, and the control module continuously monitors the movement rate of key joints such as the hip and knee joints.

[0108] If the actual joint speed of any joint exceeds the safe speed limit, the current movement is determined to be too fast, and the vibration motor is controlled to output a continuous intermittent vibration signal. In this embodiment, the continuous intermittent vibration signal is a square wave signal with a duty cycle of 50% and a frequency of 10Hz. This vibration mode produces a distinct intermittent tactile warning, which contrasts sharply with the numbness of continuous vibration, quickly attracting the user's subconscious attention and prompting them to reduce their movement speed. Furthermore, the greater the extent to which the actual joint speed exceeds the safe speed limit, the higher the frequency of the continuous intermittent vibration signal, thereby establishing an intuitive mapping relationship between speed and tactile sensation.

[0109] If the user has not reached the target motion node and the actual joint speed of each joint is less than or equal to the corresponding safe speed limit, the vibration motor is controlled to output a single-point vibration signal. In this embodiment, the single-point vibration signal is a single pulse signal with a duration of 200ms. This vibration mode serves as a positive rhythmic cue, informing the user that the current motion state is good and that they should continue to maintain the current rhythm until they reach the target position.

[0110] To determine whether a user has reached the target action node, this embodiment adopts a dual-condition fault-tolerance mechanism: if the positional deviation between the actual joint positions corresponding to the hip joint support 420, thigh support 430 and calf support 440 and the target action node is less than the allowable positional deviation range, and this state continues for multiple consecutive sampling cycles, then it is determined that the user has stably reached the target action node; otherwise, it is determined that the user has not reached the target action node.

[0111] The design consideration for this judgment logic is as follows: In actual training, the human limbs often experience inertial overshoot or physiological tremors upon reaching the target position, causing the data fed back by the position sensor to fluctuate around the target value. If the judgment is based solely on the position deviation of a single sampling period, it is highly susceptible to misjudgment due to instantaneous data fluctuations. For example, the instantaneous position during the overshoot process might be mistakenly judged as being in place, causing the exoskeleton to switch to hold mode prematurely. Therefore, this embodiment introduces a continuous judgment condition in the time dimension: after detecting that the position deviation has entered the allowable range, the control module does not immediately determine that the position is in place, but instead starts a counter. Only when the position deviation remains within the allowable range for multiple consecutive sampling periods is the user confirmed to have reached the target stably. In this embodiment, these multiple consecutive sampling periods are 5 consecutive sampling periods, corresponding to a duration of 50ms. In addition, the types of training movements include lunges, squats, and high knees.

[0112] The technical advantages of this embodiment are as follows: First, the vibration motor directly acts on the user's leg proprioception, allowing the user to perceive the quality of movement solely through tactile sensation without relying on visual observation of the screen or status indicator lights. This overcomes the shortcomings of visual and auditory feedback, which are easily affected by environmental interference and require additional attention. Second, the two signals, continuous intermittent vibration and single-point vibration, correspond to the states of excessively fast movement and normal rhythm but not in place, respectively. The two differ significantly in temporal form, allowing the user to intuitively distinguish them and obtain immediate and clear movement correction signals, forming a closed-loop training mode of movement, feedback, and correction. Third, the vibration frequency increases with the increase in the speed exceeding the limit, upgrading the tactile feedback from a binary prompt. Fourth, the dual conditions for determining the position are equivalent to applying a jitter-reducing filter to the position signal, effectively eliminating instantaneous data fluctuations caused by inertial overshoot and physiological tremors, ensuring the accuracy of the position determination and the robustness of the system; fifth, the 5 consecutive sampling cycles correspond to a duration of 50ms, which is sufficient to filter out instantaneous fluctuations and is much shorter than the human body's perception delay of action feedback, so as not to cause a judgment lag that can be perceived by the user; sixth, the training action types cover typical lower limb training actions such as lunges, squats and high knees, and with the action node sequences stored by type, the same set of control methods can be directly adapted to a variety of training scenarios.

[0113] This embodiment uses a user wearing an exoskeleton for lunge training as an example to provide a detailed explanation of the execution flow of the mechanical structure coordination and control method. It should be understood that lunge training is only one of the many application scenarios of this invention, and those skilled in the art can extend its application to other lower limb training scenarios such as squats, high knees, and lateral lunges.

[0114] Wearing Phase. The control module sets the drive module to zero-torque mode. At this time, the thigh support 430 and calf support 440 are in a free state, and the second connector 130 can rotate around the first axis with the natural rotation of the user's lower limbs. The electromagnetic coil 240 remains energized, and the first friction plate 210 and second friction plate 220 are separated, exerting no resistance to the rotation. A gap remains between the two elastic buffer blocks 300, which also do not participate in the operation. The user adjusts the sliding position of the first mounting base 120 relative to the first connector 110 to match the length of the thigh support 430 and calf support 440 to their own limbs, and then tightens the strap 132, so that the first annular fixing seat 131 and the second annular fixing seat 451 fit the thigh, calf, and ankle respectively. The user selects the lunge training mode through the control terminal, and the control module then reads the corresponding action node sequence from the preset action database. This sequence includes a start node, a working node, and a reset node. In this embodiment, the desired hip joint angle of the working node is set to 120 degrees, and the upper limit of the safe speed is set to 45 degrees per second.

[0115] In the initial stage of the movement, the user prepares to squat from a standing position. The control module reads the current movement node's stage identifier as the initial stage identifier and detects that the actual joint velocities of the hip and knee joints are increasing from zero. Based on this, it determines that the current movement is in the initial stage and automatically switches the drive module's working state to torque control mode. Based on the actual output torque feedback from the torque sensor, the control module identifies the gravitational and inertial load characteristics of the lower limbs during initiation and generates a feedforward torque compensation. At this time, the position stiffness coefficient and velocity damping coefficient are zero, and the motor mainly outputs feedforward torque, which is equivalent to providing the user with an invisible thrust to help overcome the static friction and gravitational components at the moment of limb initiation.

[0116] Working Phase. As the user begins to squat, the control module reads the phase indicator and switches to the working phase indicator. In the initial squatting phase, the difference between the actual joint position and the target position is large, and the position deviation is greater than the first preset threshold. The control module switches the working state of the drive module to the position control mode, and uses the restoring torque generated by the motor to pull the user's limbs to move towards the target position. During this process, the user's front leg externally rotates and the rear leg internally rotates. The second connecting member 130 in the thigh support 430 and the lower leg support 440 rotates around their respective first rotation axes. The first annular fixing seat 131 slides along the inner surface of the first annular cavity 121, and the roller 124 rolls accordingly. The exoskeleton support automatically adapts to the rotational posture of the lower limbs without applying torsional constraints to the muscles and bones. If the rotation of one side of the limb is too violent, causing the rotational angular velocity to exceed the preset speed threshold, the clamping control unit immediately cuts off the power supply to the electromagnetic coil 240, the friction plate presses and applies damping to the rotation, causing the speed to drop. If the rotation amplitude is close to the physiological limit, the two elastic buffer blocks 300 abut against each other, limiting the rotation angle to within 25 degrees. When the user squats down and approaches the target position, and the positional deviation decreases to less than or equal to the first preset threshold, the control module automatically switches to damping control mode. This maintains the positional stiffness coefficient while significantly increasing the velocity damping coefficient, absorbing squatting kinetic energy, suppressing overshoot, and allowing the user to smoothly stop in a standard lunge squat posture. If the velocity deviation exceeds the second preset threshold during this process, the control module forcibly switches to damping control mode. Simultaneously, the control module compares the actual joint velocity with the safe speed limit. If the speed exceeds the limit, the vibration motor outputs a square wave signal with a 50% duty cycle and a frequency of 10Hz. Upon receiving a tactile warning, the user actively reduces their squatting speed, and the vibration motor then switches to a single-point vibration signal with a duration of 200ms, indicating that the rhythm has returned to normal.

[0117] Position Holding and Reset Phase. When the user reaches the target action node, the control module detects that the actual joint positions corresponding to the hip joint support 420, thigh support 430, and lower leg support 440 are all within the allowable position deviation range, and this state continues for 5 consecutive sampling cycles, approximately 50ms. It is determined that the user has stably reached the target action node, and the exoskeleton maintains the user's posture using damping control mode. When the user completes the holding action and prepares to stand up and reset, the control module reads the reset phase indicator, switches the drive module's operating state to speed control mode, sets the desired joint speed and speed damping coefficient, and guides the user to return to the starting position at a set safe rhythm to prevent discomfort caused by standing up too quickly. If the user shows a tendency to lose speed control during the standing process, the control module will also switch to damping control mode in real time based on the speed deviation for protection.

[0118] Through the design of revolute and sliding joints in the mechanical structure, the exoskeleton adapts to the complex movement requirements of the human lower limbs in the sagittal, coronal, and vertical planes. The electromagnetic friction clamping assembly and elastic buffer stop 300 constrain passive degrees of freedom in both speed and stroke dimensions, balancing freedom of movement with safety. Multi-mode adaptive switching in the control method achieves precise assistance and protection throughout the entire lifecycle of movement initiation, execution, positioning, and reset. A tactile feedback mechanism establishes an intuitive human-computer interaction channel. The organic combination of these features significantly improves the standardization, safety, and comfort of lower limb training.

[0119] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A leg device for an actively powered lower limb exoskeleton, characterized in that, Includes a first connector, a first mounting base, and a second connector; The first connector is rotatable about the coronal axis and is connected to the first mounting base; The second connector is rotatably connected to the first mounting base and can rotate relative to the first mounting base about a first rotating shaft, the first rotating shaft being perpendicular to the coronal shaft and extending along the length direction of the leg device; The rotation of the second connector relative to the first mounting base around the first axis is used to follow the internal and external rotation movements of the human thigh or calf around the vertical axis.

2. The leg device according to claim 1, characterized in that, The first connector is slidably connected to the first mounting base, and the first mounting base can slide relative to the first connector in a direction parallel to the first axis of rotation.

3. The leg device according to claim 1, characterized in that, The first mounting base is provided with a first annular cavity, and the second connector is provided with a first annular fixing seat adapted to the first annular cavity and used for binding to the human body by a strap. A first slide rail structure is provided between the first annular fixing seat and the first annular cavity. The first annular fixing seat slides along the inner surface of the first annular cavity through the first slide rail structure, so that the second connector rotates relative to the first mounting base around the first rotating axis.

4. The leg device according to claim 1, characterized in that, An electromagnetic friction clamping assembly is provided between the first mounting base and the second connecting member. The electromagnetic friction clamping assembly includes a compression spring, an electromagnetic coil, a first friction plate disposed on the first mounting base, and a second friction plate disposed on the second connecting member and opposite to the first friction plate. When the electromagnetic coil is de-energized, the compression spring drives the first friction plate and the second friction plate to press against each other, thereby locking the rotation of the second connecting member relative to the first mounting base around the first rotating shaft. When the electromagnetic coil is energized, the electromagnetic force generated by the electromagnetic coil overcomes the elastic force of the compression spring, causing the first friction plate and the second friction plate to separate from each other, thereby releasing the lock on the rotation.

5. The leg device according to claim 4, characterized in that, The electromagnetic friction clamping assembly further includes a clamping control unit and an angular velocity sensor. The angular velocity sensor is used to detect the rotational angular velocity of the second connector relative to the first mounting base. The clamping control unit is electrically connected to the electromagnetic coil and is configured to keep the electromagnetic coil energized when the rotational angular velocity is less than or equal to a preset speed threshold, and to cut off the power supply to the electromagnetic coil when the rotational angular velocity is greater than the preset speed threshold.

6. The leg device according to claim 1, characterized in that, The first mounting base and the second connecting member are respectively provided with elastic buffer blocks. The elastic buffer blocks are arranged opposite to each other along the rotation direction of the second connecting member relative to the first mounting base, and abut against each other when the second connecting member rotates to the rotation limit position, so that the rotation angle of the second connecting member relative to the first mounting base in the inward rotation direction and the outward rotation direction does not exceed a predetermined angle, and prevents the second connecting member from detaching from the first mounting base.

7. An active power-enhanced lower limb exoskeleton, comprising a mechanical skeleton, a drive module, a sensing module, a control module, and a human-computer interaction module, wherein the mechanical skeleton includes a lumbar support, a hip joint support, a thigh support, a calf support, an ankle joint support, and a foot support, characterized in that, The thigh support and / or the calf support are the leg devices according to any one of claims 1 to 6; The drive module includes multiple joint motors mounted on the mechanical frame. The joint motors are used to drive the hip joint support to rotate about the sagittal axis relative to the lumbar support, drive the thigh support to rotate about the coronal axis relative to the hip joint support, and drive the lower leg support to rotate about the coronal axis relative to the thigh support. The sensing module includes a position encoder, a speed sensor, and a torque sensor integrated within the joint motor; The control module is communicatively connected to the drive module and the sensing module, and is configured to automatically switch the working state of the drive module and generate corresponding joint control commands based on the actual joint position, actual joint speed and actual output torque transmitted by the sensing module, so as to drive the drive module to run. The human-computer interaction module includes multiple vibration motors mounted on the thigh support. The control module is also configured to control the vibration motors to output different vibration signals based on the safe speed deviation between the actual joint speed and the safe speed limit, so as to provide tactile feedback to the user's current movement.

8. The active power-enhanced lower limb exoskeleton according to claim 7, characterized in that, Both the thigh support and the calf support are leg devices. The first connector of the thigh support is rotatably connected to the hip joint support about the coronal axis. The second connector of the thigh support is rotatably connected to the first connector of the calf support about the coronal axis. The second connector of the calf support is rotatably connected to the ankle joint support about a second axis perpendicular to the coronal axis.

9. The active power-enhanced lower limb exoskeleton according to claim 8, characterized in that, The first connecting member of the calf support is slidably connected to the first mounting base of the calf support, and the first mounting base of the calf support can slide relative to the first connecting member of the calf support in a direction parallel to the first axis of rotation. The ankle joint support includes a second annular fixing seat that is rotatably connected to the second connecting member of the calf support about a second axis of rotation. The second annular fixing seat is bound to the human body by a strap. The second connecting member of the calf support extends along the sliding direction of the first mounting base relative to the first connecting member of the calf support and is tapered. A second slide rail structure is provided between the second connecting member of the calf support and the second annular fixing seat. The second annular fixing seat rotates relative to the second connecting member of the calf support through the second slide rail structure. The second axis of rotation is parallel to the first axis of rotation.

10. A control method for an active power-enhanced lower limb exoskeleton, applied to the active power-enhanced lower limb exoskeleton as described in any one of claims 7 to 9, characterized in that, Includes the following steps: Step S1: Read the action node sequence from the preset action database. The action node sequence consists of multiple action nodes arranged in chronological order. Step S2: The actual joint position, the actual joint speed, and the actual output torque are collected in real time by the position encoder, the speed sensor, and the torque sensor integrated in the joint motor. Step S3: Identify the human-machine interaction load characteristics based on the actual output torque, and generate a feedforward torque compensation amount based on the human-machine interaction load characteristics; Step S4: Calculate the positional deviation between the actual joint position and the desired joint position in the action node sequence, and the velocity deviation between the actual joint velocity and the desired joint velocity; Step S5: Determine the user's action node status based on the position deviation, the speed deviation, and the action node sequence; Step S6: Automatically switch the working state of the drive module based on the user's current action node state, and generate the corresponding joint control command in combination with the feedforward torque compensation amount to drive the joint motor to run; Step S7: Based on the safe speed deviation between the actual joint speed and the safe speed limit, control the vibration motor to output different vibration signals to provide tactile feedback to the user's current movement.

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