Flexible exoskeleton execution device and flexible exoskeleton system for upper limb training

Abstract

The invention discloses a flexible exoskeleton execution device and a flexible exoskeleton system for upper limb training, and relates to the technical field of robots. The problems that an existing exoskeleton robot is complex in mechanical structure, large in size, heavy in weight and large in inertia due to the fact that rigid driving is adopted for achieving actions such as joint bending and stretching or unfolding and folding are solved. The device comprises a bandage, a forward line wheel, a reverse line wheel, a line wheel driving mechanism and Bowden lines, the bandage is fixed to a limb, one end of one Bowden line is wound around the forward line wheel, the other end of the Bowden line is fixed to the bandage, one end of the other Bowden line is reversely wound around the reverse line wheel, and the other end of the other Bowden line is fixed to the bandage; the line wheel driving mechanism is arranged on the trunk and can drive the forward line wheel and the reverse line wheel to rotate reversely in the pre-tightening stage so as to achieve line winding and pre-tightening, the forward line wheel and the reverse line wheel are driven to rotate synchronously in the same direction in the working stage, and correction force is applied to the force exerting muscle group through the two Bowden lines which are wound and unwound alternately so as to correct the action of a wearer.

Description

Technical Field

[0001] The present invention relates to the field of robotics technology, and in particular to a flexible exoskeleton actuator and a flexible exoskeleton system for upper limb training. Background Art

[0002] Exoskeleton robots, also known as wearable robots, are worn outside the human body and act on the joints of the human body, so that the wearer's limbs can achieve standardized movements during exercise. They are mainly used to correct the wearer's posture during training, which can be sports training for athletes or rehabilitation training for patients. Taking athletes as an example, the current teaching methods for athletes are limited by the experience and communication skills of coaches, and it is impossible to accurately correct the specific movements of athletes in a short time. Although modern technical means such as optical motion capture and IMU can efficiently collect motion data, they often lack intelligent real-time feedback mechanisms. Technical analysis is usually performed after the action is completed, requiring athletes to pause after performing a series of actions and wait for video playback or data analysis to identify and correct problems in technical execution. This "post-diagnosis" mode causes time delays, making it impossible for athletes to get feedback and adjust their movements in real time, thereby affecting the continuity of learning and the immediacy of movement correction. However, the use of this exoskeleton robot can correct joint angles in real time, which can fully solve the needs of athletes for accurate, efficient and personalized training in the process of learning new sports skills.

[0003] However, the current exoskeleton robot and the wearer's joints usually use rigid drive to achieve joint flexion and extension or expansion and contraction and other movements, which leads to problems such as complex mechanical structure, large size, heavy weight and large inertia. In addition, rigid drive affects the freedom of limb movement and is inconvenient to put on and take off, and cannot achieve human-machine compatibility. Moreover, rigid drive does not conform to the natural muscle coordination and force distribution pattern of the human body, making it impossible for the wearer's muscles to form memory after training, and thus unable to scientifically and effectively correct incorrect postures and force patterns during sports training or rehabilitation training. Summary of the invention

[0004] In view of this, the present invention provides a flexible exoskeleton actuator and a flexible exoskeleton system for upper limb training, which can correct incorrect postures and force patterns of the wearer's limbs during exercise.

[0005] The technical solution adopted by the present invention to solve the above technical problems is:

[0006] A flexible exoskeleton actuator comprises a strap and a joint drive unit, wherein the strap is provided with at least one, each strap corresponds to at least one joint drive unit, the strap is fixed on a limb and arranged at one end away from a trained joint; each joint drive unit comprises a forward wire wheel, a reverse wire wheel, a wire wheel drive mechanism and a Bowden wire mechanism, each Bowden wire mechanism comprises a Bowden wire, two Bowden wire mechanisms are provided, one of which corresponds to the forward wire wheel, one end of the Bowden wire in the Bowden wire mechanism is wound around the forward wire wheel, the other end extends along the stretching direction of the muscle and is fixed to the corresponding strap, and the other end A Bowden cable mechanism is provided corresponding to a reverse wire wheel, one end of the Bowden cable in the Bowden cable mechanism is reversely wound around the reverse wire wheel, and the other end extends along the stretching direction of the muscle and is fixed to the corresponding strap, and the two Bowden cables are respectively located at the front and back sides of the trained limb to imitate the antagonist muscles of the limb; the wire wheel driving mechanism is arranged on the trunk and can drive the forward wire wheel and the reverse wire wheel to rotate in the reverse direction during the pre-tightening stage to realize the wire reel pre-tightening, and drive the forward wire wheel and the reverse wire wheel to rotate synchronously in the same direction during the working stage, and apply a corrective force to the force-generating muscle group through the two alternately retracted and released Bowden cables to correct the wearer's movements.

[0007] On the basis of technical solution 1, the wire wheel driving mechanism includes a driving motor, a damping shaft, a support disc and a planetary gear train, the planetary gear train includes a sun gear, a planetary gear, an inner gear ring and a planet carrier, the driving motor can drive the support disc to rotate, the sun gear is coaxially connected to the support disc and can rotate synchronously with the support disc, the reverse wire wheel and the planet carrier are coaxially arranged relative to each other, and are rotatably installed on a side of the disc surface of the support disc provided with the sun gear, the forward wire wheel is coaxially connected to the inner gear ring and can rotate synchronously with the inner gear ring, there are three planetary wheels, the three planetary wheels are evenly installed circumferentially between the planet carrier and the reverse wire wheel and can rotate by themselves, and each planetary wheel is meshed and connected with the sun gear and the inner gear ring; the support disc is connected to the forward wire wheel via the damping shaft, and in the pre-tightening stage of the Bowden line, the support disc drives the reverse wire wheel and the forward wire wheel to rotate successively via the planetary gear train to pre-tighten the wire respectively; in the working stage of the Bowden line, the support disc drives the reverse wire wheel and the forward wire wheel to rotate synchronously via the damping shaft to alternately reel or release the wire.

[0008] Based on technical solution 1, the radii of the forward wire wheel and the reverse wire wheel are different.

[0009] Based on Technical Solution 2, each Bowden cable mechanism also includes a Bowden cable sheath, a cable outlet anchor, a cable lock and a terminal anchor seat. The cable outlet anchor is configured on the limb, and the terminal anchor seat is installed on the strap. One end of the Bowden cable sheath is configured on the side close to the forward cable wheel or the reverse cable wheel, and the other end extends in the extension direction of the muscle and is connected to the cable outlet anchor. The Bowden cable runs through the Bowden cable sheath and extends from the cable outlet anchor, and is connected to the terminal anchor seat via the cable lock.

[0010] On the basis of technical solution 4, each Bowden cable mechanism also includes a micro tension sensor, which is installed between the cable locker and the end anchor seat to measure the tension transmitted from the end of the Bowden cable to the strap during human-computer interaction.

[0011] On the basis of technical solution 4, each Bowden cable mechanism also includes a guide pulley assembly, the Bowden cable sheath is provided with two sections, the guide pulley assembly is installed between the two sections of the Bowden cable sheath, and is arranged at the position where the inflection point of the Bowden cable appears, and the Bowden cable passes through the first section of the Bowden cable sheath, the guide pulley assembly and the second section of the Bowden cable sheath in sequence to reduce the friction force on the Bowden cable during the process of reeling and releasing the cable.

[0012] On the basis of technical solution 6, the guide pulley assembly includes a guide pulley housing and a Bowden cable steering wheel. The Bowden cable steering wheel is rotatably installed in the guide pulley housing. The guide pulley housing is provided with a wire inlet and a wire outlet. The Bowden cable enters from the wire inlet of the guide pulley housing, bypasses the Bowden cable steering wheel, and then passes out from the wire outlet of the guide pulley housing.

[0013] A flexible exoskeleton system for upper limb training comprises a flexible exoskeleton actuator, wherein two sets of the flexible exoskeleton actuator are provided, each set corresponds to one arm, and each set of the flexible exoskeleton actuator has two straps, namely a forearm strap and an upper arm strap, wherein the forearm strap is fixed on the forearm near the wrist joint, and the upper arm strap is fixed on the upper arm near the elbow joint; each set of the flexible exoskeleton actuator has three joint drive units, wherein one joint drive unit is connected to the forearm strap and used for adjusting the angle of the elbow joint, and the other two joint drive units are connected to the upper arm straps and used for adjusting the angle of the shoulder joint.

[0014] Based on technical solution 8, it also includes a wearable garment, which is worn on the torso of the wearer, the forearm straps and the upper arm straps are fixed on the forearms and upper arms of the wearable garment, and the joint drive unit is installed on the back of the wearable garment.

[0015] Based on technical solution 9, the wearable garment is made of neoprene material, and the forearm strap and the upper arm strap are made of linen fiber material.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The flexible exoskeleton actuator of the present invention adopts the Bowden wire drive mode, replacing the rigid connecting rod structure, which can simulate the natural muscle coordination of the wearer. During the sports training process, it promotes sports learning through repetitive training, forms the wearer's internal control mechanism through multi-joint sports stimulation, and the dynamic correction force provided by the exoskeleton robot can enhance sensory nerve input, thereby promoting the learning and internalization of complex sports skills. Compared with the existing traditional teaching method combining optical motion capture system and IMU inertial measurement unit and other equipment, the exoskeleton robot has real-time somatosensory feedback, which greatly enhances the continuity of learning and the immediacy of motion correction, and has higher human-machine compatibility.

[0018] 2. With the cooperation of the damping shaft and the planetary gear system, the wire wheel drive mechanism of the present invention realizes the sequential pre-tightening of the Bowden wires of the double wire wheels and the alternating reeling and releasing of the wires of the double wire wheels by a single power source, so as to realize the correction of the joint angle. Compared with the complex pre-tightening mechanism, the wire wheel drive mechanism of the present invention is smaller in size and lighter in weight, which simplifies the complexity of control and improves the efficiency of the drive system.

[0019] 3. The present invention controls the diameter ratio of the forward and reverse reels of the Bowden cable to eliminate the relaxation effect caused by the different length change rates of the Bowden cables on the inner and outer sides of the arm, thereby improving the force transmission efficiency of the upper limb flexible exoskeleton during sports training.

[0020] 4. The present invention reduces the friction force on the Bowden cable by configuring the Bowden cable sheath and the guide pulley assembly, thereby ensuring the accuracy of the correction force generated by the Bowden cable.

[0021] 5. The present invention fixes the position of the Bowden cable force point through the configured wearable clothing and straps. The wearable clothing is made of chloroprene rubber material with high tensile strength and high elongation. Neoprene is highly flexible and elastic. When the wearable clothing is worn on the wearer's torso, it can not only fit well with the wearer's skin to prevent the clothing from moving, but also increase comfort. The forearm straps and upper arm straps are both made of flax fiber material with low elongation. The flax fiber material with low elongation is relatively hard, which can prevent the position of the forearm straps, upper arm straps and wearable clothing from moving. In addition, the forearm straps, upper arm straps and wearable clothing are fixed by sewing, which can further reduce the relative displacement of the end anchor seat of the Bowden cable and the wearable clothing when transmitting tension, thereby improving the force transmission efficiency of the exoskeleton. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are incorporated as part of this application and are used to provide a further understanding of the present invention.

[0023] Figure 1 The figure is a schematic diagram of the overall structure of a flexible exoskeleton actuator of the present invention.

[0024] Figure 2 It is a structural schematic diagram of the joint drive unit.

[0025] Figure 3 Schematic diagram of the structure of the Bowden cable mechanism arranged on the arm.

[0026] Figure 4 Schematic diagram of the structure of the guide pulley assembly.

[0027] Figure 5 This is a schematic diagram of the reverse structure of the forward wire wheel.

[0028] Figure 6 This is a schematic diagram of the front structure of the forward wire wheel.

[0029] Description of reference numerals:

[0030] 1- Install the base;

[0031] 2- strap, 21- upper arm strap, 22- lower arm strap;

[0032] 3-joint drive unit, 31-forward line wheel, 32-reverse line wheel, 33-line wheel drive mechanism, 331-drive motor, 332-harmonic reducer, 333-damping shaft, 334-support plate, 335-sun gear, 336-planetary gear, 337-inner gear ring, 338-planet carrier, 34-Bowden cable mechanism, 341-Bowden cable, 342-Bowden cable fixed joint, 343-Bowden cable sheath, 344-outlet anchor, 345-wire lock, 346-micro tension sensor, 347-end anchor seat, 348-guide pulley assembly, 3481-guide pulley housing, 3482-Bowden cable steering wheel, 3483-deep groove ball bearing;

[0033] Wearable clothing4. DETAILED DESCRIPTION

[0034] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Figure 1 The schematic diagram of the structure of the flexible exoskeleton actuator of this embodiment is shown as follows: Figure 1As shown, a flexible exoskeleton actuator of this embodiment includes a mounting base 1, a strap 2 and a joint drive unit 3. The strap 2 is provided with at least one, and each strap 2 corresponds to at least one joint drive unit 3. The strap 2 is fixed on the limb and arranged at one end away from the trained joint. Each joint drive unit 3 includes a forward wire wheel 31, a reverse wire wheel 32, a wire wheel drive mechanism 33 and a Bowden wire mechanism 34. The forward wire wheel 31, the reverse wire wheel 32 and the wire wheel drive mechanism 33 are installed in the mounting base 1. The mounting base 1 is arranged on the back of the wearer. On the one hand, it can prevent the mounting base 1 from affecting the movement of the wearer's limbs. On the other hand, it forms a remote drive. Compared with being installed on the limb, it can reduce the load and inertia of the limb and ensure the movement accuracy of the limb. Each Bowden cable mechanism 34 includes a Bowden cable 341. Two Bowden cable mechanisms 34 are provided. One of the Bowden cable mechanisms 34 is provided corresponding to the forward wire wheel 31. One end of the Bowden cable 341 in the Bowden cable mechanism 34 is wound around the winding groove of the forward wire wheel 31. The other end extends along the stretching direction of the muscle and is fixed to the corresponding strap. The other Bowden cable mechanism 34 is provided corresponding to the reverse wire wheel 32. One end of the Bowden cable 341 in the Bowden cable mechanism 34 is wound around the winding groove of the reverse wire wheel 32. The winding direction of the Bowden cable 341 is the same as that of the Bowden cable wound on the forward wire wheel 31. The winding direction of 341 is opposite, and the other end of the Bowden cable 341 extends along the stretching direction of the muscle and is fixed on the corresponding strap. The two Bowden cables 341 are respectively located on the front and back sides of the trained limb to imitate the antagonist muscles of the limb; the wire wheel driving mechanism 33 is arranged on the torso and can drive the forward wire wheel 31 and the reverse wire wheel 32 to rotate in the opposite direction during the pre-tightening stage to achieve wire pre-tightening, and drive the forward wire wheel 31 and the reverse wire wheel 32 to rotate synchronously in the same direction during the working stage, and apply corrective force to the force-generating muscle group through the two alternately retracted and released Bowden cables 341 to correct the wearer's movements.

[0036] The flexible exoskeleton actuator of this embodiment adopts the Bowden cable 341 drive mode, replacing the rigid connecting rod structure, which can simulate the natural muscle coordination of the wearer. During the sports training process, it promotes sports learning through repetitive training, forms the wearer's internal control mechanism through multi-joint sports stimulation, and the dynamic correction force provided by the exoskeleton robot can enhance sensory nerve input, thereby promoting the learning and internalization of complex sports skills. Compared with the existing traditional teaching method combining optical motion capture system and IMU inertial measurement unit and other equipment, the exoskeleton robot has real-time somatosensory feedback, which greatly enhances the continuity of learning and the immediacy of motion correction, and has higher human-machine compatibility. Specifically, before using the flexible exoskeleton system to train the wearer's limbs in standardized movements, the flexible exoskeleton system needs to be trained in advance, that is, the instructor puts on the flexible exoskeleton system in advance to perform standardized movements, and the Bowden cable 341 in the flexible exoskeleton system follows the instructor's limb movements to retract and release the cable, and records the angular motion trajectory information of the limb joints during the entire teaching process through various sensors, that is, the angle, angular velocity, angular acceleration, etc. of the degrees of freedom of each joint, as well as the tension information of the Bowden cable 341 at the anchor point transmitted by the micro tension sensor 346 at the end of the Bowden cable 341 during human-computer interaction. When the wearer puts on the flexible exoskeleton system and performs actions according to the video, the flexible exoskeleton system actively controls the operation of the wire wheel driving mechanism 33 according to the standardized action process, that is, the wire wheel driving mechanism 33 actively drives the forward wire wheel 31 and the reverse wire wheel 32 to rotate, so as to realize the alternating winding and releasing of the two Bowden cables 341. The force generation mode of the two Bowden cables 341 imitates the form of the antagonistic muscles of the human body, so as to simulate the muscle coordination and force distribution mode of the limbs. When there is a difference between the wearer's action and the standardized action, the winding and releasing of the two Bowden cables 341 can effectively apply a corrective force to the corresponding force-generating muscle groups to correct the wearer's action and realize timely correction of the action, so that the wearer can obtain feedback and adjust the action in time, thereby ensuring the continuity of learning and the immediacy of action correction.

[0037] Since each limb has two joints, such as the shoulder joint and elbow joint of the arm, and the knee joint and hip joint of the leg, when the standardized action only involves one joint that needs to be trained and corrected, a strap can be fixed at the position corresponding to the corresponding joint, and then the corresponding joint drive unit 3 realizes the movement of the joint, that is, the number of straps set is the same as the number of trained joints. However, the number of degrees of freedom of each joint is different. For example, the elbow joint has only one degree of freedom of flexion and extension, so only one joint drive unit 3 is needed to realize the training and correction of elbow flexion and extension, while the shoulder joint has two degrees of freedom of extension and contraction and flexion and extension, so two joint drive units 3 are needed to work together to realize the two-degree-of-freedom movement of the shoulder joint, that is, the degree of freedom of each joint movement is related to the number of joint drive units 3. Then, when the moving limb and the standardized action are determined, the number of straps and the number and installation positions of the joint drive units 3 can be determined. Taking the arm as an example, if you need to train the shooting action of the arm, since the shooting action is more complicated, it generally requires the coordinated action of the elbow joint and the shoulder joint, and the flexion and extension of the elbow joint as well as the flexion and extension and contraction and extension of the shoulder joint are required to complete the standardized shooting action, then it is necessary to set two straps 2 and three joint drive units 3, the two straps 2 are respectively set as a forearm strap 22 and an upper arm strap 21, the forearm strap 22 is fixed on the forearm and close to the wrist joint, the upper arm strap 21 is fixed on the upper arm and close to the elbow joint, and the three joint drive units 3 are installed on the back of the torso, that is, the wearer carries these three joint drive units 3 on his back, compared with directly installing the joint drive unit 3 on the arm, the load and motion inertia of the arm can be reduced. One of the joint drive units 3 is connected to the forearm strap 22 to adjust the bending angle of the elbow joint so that the flexion and extension of the elbow joint can reach a standardized flexion and extension movement. The other two joint drive units 3 are connected to the upper arm strap 21 to adjust the bending angle and the extension and retraction angle of the shoulder joint so that the flexion and extension and retraction of the shoulder joint can reach a standardized flexion and extension and retraction movement.

[0038] In order for the flexible exoskeleton system to work, it is necessary to pre-tighten the Bowden cable 341 before work, so that the correction force can be transmitted to correct the angle of the joint when the Bowden cable 341 is retracted and released. Therefore, the flexible exoskeleton system has two operation stages, one is the Bowden cable 341 pre-tightening stage before work, in which the two Bowden cables 341 in each joint drive unit 3 need to be retracted to achieve pre-tightening. The other is the working stage for correcting the joint angle, in which one of the Bowden cables 341 in each joint drive unit 3 needs to be retracted, while the other Bowden cable 341 needs to be released, so that the angle of the joint can be adjusted to achieve the correction of the joint angle. It can be seen that the two Bowden cables 341 in each joint drive unit 3 must be able to simultaneously or successively wind up and pre-tighten the wires in these two operation stages, and must also be able to alternately wind up and release the wires, and the two Bowden cables 341 are respectively wound on the forward wire wheel 31 and the reverse wire wheel 32, which requires the wire wheel drive mechanism 33 to be able to drive the forward wire wheel 31 and the reverse wire wheel 32 to move in the same direction to achieve alternate winding and releasing of the wires, and to drive the forward wire wheel 31 and the reverse wire wheel 32 to move in the opposite direction to achieve winding and pre-tightening. One implementation method is that the wire wheel drive mechanism 33 uses two drive motors, and each wire wheel is correspondingly provided with a drive motor. Such a design will result in a large number of joint drive units 3 configured when there are more degrees of freedom of the joints, and then the number of drive motors will increase linearly, which not only increases the weight and volume of the entire exoskeleton system, but also increases the complexity of control. The wire wheel drive mechanism 33 of this embodiment adopts another implementation method.

[0039] Figure 2 The schematic diagram of the structure of the wire wheel driving mechanism 33 of this embodiment is shown. Figure 2As shown, the wire wheel driving mechanism 33 of this embodiment includes a driving motor 331, a harmonic reducer 332, a damping shaft 333, a support disk 334 and a planetary gear system, the planetary gear system includes a sun gear 335, a planetary gear 336, an inner gear ring 337 and a planet carrier 338, the driving motor 331 adopts a brushless motor, which is connected to the support disk 334 through the harmonic reducer 332 and can drive the support disk 334 to rotate slowly, the sun gear 335 is coaxially connected to the support disk 334 and can rotate synchronously with the support disk 334, the reverse wire wheel 32 and the planet carrier 338 are coaxially arranged relative to each other, and are rotatably installed on one side of the support disk 334 provided with the sun gear 335, and the forward wire wheel 31 is coaxially connected to the support disk 334. The inner gear ring 337 can rotate synchronously with the inner gear ring 337. There are three planetary wheels 336. The three planetary wheels 336 are evenly installed between the planet carrier 338 and the reverse line wheel 32 in the circumferential direction and can rotate on their own. Each planetary wheel 336 is meshed and connected with the sun gear 335 and the inner gear ring 337; the support plate 334 is connected with the forward line wheel 31 via the damping shaft 333. In the pre-tightening stage of the Bowden line 341, the support plate 334 drives the reverse line wheel 32 and the forward line wheel 31 to rotate successively via the planetary gear system to pre-tighten the line respectively; in the working stage of the Bowden line 341, the support plate 334 drives the reverse line wheel 32 and the forward line wheel 31 to rotate synchronously via the damping shaft 333 to alternately reel in or release the line.

[0040] It should be noted that the damping shaft 333 is provided with a threshold torque. When the working torque of the driving motor 331 is greater than the threshold torque of the damping shaft 333, the upper shaft section and the lower shaft section of the damping shaft 333 can rotate relative to each other. When the working torque of the driving motor 331 is less than the threshold torque of the damping shaft 333, the upper shaft section and the lower shaft section of the damping shaft 333 are relatively fixed. At this time, the damping shaft 333 can be regarded as an axis that cannot be twisted at both ends. The following describes the driving process of the forward wire wheel 31 and the reverse wire wheel 32 by the wire wheel driving mechanism 33 in the pre-tightening stage and the working stage of the Bowden wire 341 respectively:

[0041] Bowden cable pre-tightening stage: Before the Bowden cable 341 is pre-tightened, the two Bowden cables 341 of each joint drive unit 3 are in a relaxed state. At this time, the forward line wheel 31 can rotate freely, and no fixing force is applied to the upper shaft section of the damping shaft 333. If the upper shaft section and the lower shaft section of the damping shaft 333 want to rotate relative to each other, the upper shaft section must be in a fixed state, so that the lower shaft section will rotate only when driven by a larger torque. Therefore, even if the torque of the driving motor 331 is greater than the threshold torque of the damping shaft 333, the two ends of the damping shaft 333 will not rotate relative to each other. In this case, the driving motor 331 drives the support disk 334 to rotate, and the support disk 334 drives the forward line wheel 31 to rotate synchronously in the same direction via the damping shaft 333. Since the sun gear 335 also rotates synchronously in the same direction with the support disk 334, the three planetary gears 336 drive the planetary carrier 338 and the reverse line wheel 32 to rotate synchronously in the same direction under the action of the sun gear 335 and the inner ring gear 337. At this time, the reverse line wheel 32 rotates in the direction of line collection, so the forward line wheel 31 releases the line (the forward line wheel 31 and the reverse line wheel 32 are wound in opposite directions). When the Bowden line 341 on the reverse line wheel 32 is pre-tightened, the reverse line wheel 32 is reeled in. The planetary carrier 338 and the three planetary wheels 336 connected to the reverse pulley 32 no longer revolve; the working torque of the driving motor 331 is set to be greater than the threshold torque of the damping shaft 333, the output direction of the torque of the driving motor 331 remains unchanged, and the supporting plate 334 and the sun gear 335 are driven to rotate, the sun gear 335 drives the three planetary wheels 336 to rotate, and the three planetary wheels 336 drive the forward pulley 31 to rotate in the reverse direction via the inner gear ring 337, at this time the forward pulley 31 is pre-tightened for winding until the Bowden line 341 on the forward pulley 31 is pre-tightened, and the pre-tightening stage of the Bowden line 341 ends.

[0042] Working stage of the Bowden cable 341: the working torque of the driving motor 331 is set to be less than the threshold torque of the damping shaft 333. At this time, the damping shaft 333 can be regarded as an integrated shaft. The driving motor 331 drives the sun gear 335 to rotate via the support plate 334. The sun gear 335 drives the forward line wheel 31 to rotate via the damping shaft 333 on the one hand, and drives the reverse line wheel 32 to rotate via the three planetary gears 336 on the other hand. At this time, the forward line wheel 31 and the reverse line wheel 32 rotate in the same direction, then the Bowden cable 341 on the forward line wheel 31 is in the winding state or the releasing state, and the corresponding Bowden cable 341 on the reverse line wheel 32 is in the releasing state or the winding state. It can be seen that the wire wheel drive mechanism 33 of this embodiment, with the cooperation of the damping shaft 333 and the planetary gear system, realizes the control of the Bowden wire 341 of the double wire wheels by a single power source for the sequential pre-tightening and the control of the alternating reeling and releasing of the double wire wheels to achieve the correction of the joint angle. Compared with the complex pre-tightening mechanism, the wire wheel drive mechanism 33 of this embodiment is smaller in size and lighter in weight, which simplifies the complexity of control and improves the efficiency of the drive system.

[0043] Since the two Bowden cables 341 in each joint drive unit 3 have different routing positions, if the radii of the forward and reverse pulleys 32 are the same, the two Bowden cables 341 will have the same rate of change during the alternating winding and unwinding process. In this case, one of the Bowden cables 341 will become loose during the correction process, and the correction purpose cannot be achieved. Therefore, the radii of the forward pulley 31 and the reverse pulley 32 of this embodiment are set differently. To further illustrate, taking the elbow joint of the arm as an example, the Bowden cable 341 on the forward pulley 31 is arranged on the outside of the arm, and the Bowden cable 341 on the reverse pulley 32 is arranged on the inside of the arm. Figure 1 It can be seen that the Bowden cable 341 wound on the forward wheel 31 extends from the wearer's back to the back of the shoulder, and then from the back of the shoulder to the forearm, and the Bowden cable 341 wound on the reverse wheel 32 extends from the wearer's back to the front of the shoulder, and then from the front of the shoulder to the forearm. The length of the Bowden cable 341 wound on the forward wheel 31 is shorter than that of the Bowden cable 341 wound on the reverse wheel 32; when the arm gradually transitions from an extended state to a flexed state, the length of the forward wheel 31 that releases the line is required to be shorter than the length of the reverse wheel 32 that reels the line, so as to ensure that the two Bowden cables 341 are always in a pre-tightened state, that is, by controlling the wheel diameter ratio of the forward and reverse wheels 32 of the Bowden cable 341, the relaxation effect caused by the different length change rates of the Bowden cables 341 on the inner and outer sides of the arm is eliminated, thereby improving the force transmission efficiency of the upper limb flexible exoskeleton during sports training. The radius sizes of the forward and reverse wire wheels 32 can be customized according to the arrangement positions of the corresponding Bowden wires 341 and the requirements of the wire length change rate.

[0044] Figure 1 and Figure 3 The structure diagram of the Bowden cable mechanism 34 is shown. Figure 1 and Figure 3As shown, due to the friction between the Bowden cable 341 and the wearer's body during the process of retracting and releasing the cable, the friction will not only affect the tension test result at the end of the Bowden cable 341 of the flexible exoskeleton system during the teaching stage, but also affect the accurate value of the correction force when the correction force is applied through the Bowden cable 341 during the working stage, thereby failing to achieve the purpose of accurate correction of the joint angle. Therefore, each Bowden cable mechanism 34 of the present embodiment further includes a Bowden cable fixing joint 342, a Bowden cable sheath 343, a cable outlet anchor 344, a cable lock 345, a micro tension sensor 346 and a terminal anchor seat 347. The cable outlet anchor 344 is arranged on the limb, and the terminal anchor seat 347 is installed on the strap 2. One end of the Bowden cable sheath 343 is installed on the mounting base 1 via the Bowden cable fixing joint 342, and the other end extends in the extension direction of the muscle and is connected to the cable outlet anchor 344 via the Bowden cable fixing joint 342. The Bowden cable 341 passes through the Bowden cable sheath 343 and extends from the cable outlet anchor 344, and then is connected to the terminal anchor seat 347 via the cable lock 345. The micro tension sensor 346 is installed between the cable lock 345 and the terminal anchor seat 347 to measure the tension transmitted from the end of the Bowden cable 341 to the strap during human-computer interaction. It can be seen that the friction force on the Bowden cable 341 is reduced by configuring the Bowden cable sheath 343 in this embodiment. Since the Bowden cable 341 needs to generate a correction force by retracting and releasing the cable, the length of the Bowden cable sheath 343 is shorter than the length of the Bowden cable 341, which requires a section of the Bowden cable 341 to be exposed. In this embodiment, a section of the Bowden cable 341 near the strap is exposed, so that the force point of the Bowden cable 341 can be set at the strap, which is convenient for adjusting the corresponding joint angle. Let's take the elbow joint of the arm as an example to illustrate. Figure 3It can be seen that the force point of the Bowden cable 341 is the terminal end of the Bowden cable 341. The terminal end of the Bowden cable 341 is installed on the strap fixed to the forearm through the wire lock 345 and the terminal anchor seat 347. When the Bowden cable 341 is wound, the forearm is directly stressed and bends toward the upper arm or straightens away from the upper arm, so as to adjust the angle of the elbow joint. In addition, the friction between the Bowden cable 341 and the shoulder is the greatest when the Bowden cable 341 extends along the stretching direction of the muscle, so the Bowden cable sheath 343 is set at a position between the exit point of the Bowden cable 341 and the upper arm. Compared with setting the Bowden cable sheath 343 at a position close to the end of the Bowden cable 341, the friction on the Bowden cable 341 can be further reduced, thereby ensuring the accuracy of the tension measurement of the Bowden cable 341. When the instructor puts on the flexible exoskeleton system to perform standardized movements, since the Bowden cable 341 in the flexible exoskeleton system follows the instructor's limb movements to retract and release the cable, the instructor needs to use the micro-tension sensor 346 at the end of the Bowden cable 341 to measure and record the tension information of the Bowden cable 341 transmitted to the anchor point during the training of the flexible exoskeleton system. At the same time, the micro-tension sensor 346 can instantly feedback the axial tension of the Bowden cable 341 during the exercise training process, and based on this, the control system can adjust the tension and contraction and relaxation displacement of the Bowden cable 341 in real time, so as to correct the wearer's exercise posture and realize the exercise correction function.

[0045] Depend on Figure 1 It can be seen that when the flexible exoskeleton system is used to correct the wearer's arm joint angle, the two Bowden cables 341 in each joint drive unit 3 need to extend from the wearer's back to the shoulder, and then from the shoulder to the arm, which causes the Bowden cable 341 to have an inflection point. At the inflection point, the friction between the Bowden cable 341 and the Bowden cable sheath 343 is the largest. Therefore, each Bowden cable mechanism 34 also includes a guide pulley assembly 348 arranged at the inflection point. The guide pulley assembly 348 can convert the sliding friction between the Bowden cable 341 and the Bowden cable sheath 343 into rolling friction, so as to reduce the friction on the Bowden cable 341. Specifically, Figure 4As shown, the guide pulley assembly 348 of this embodiment includes a guide pulley housing 3481, a Bowden cable steering wheel 3482, a Bowden cable fixing joint 342 and two deep groove ball bearings 3483. The Bowden cable steering wheel 3482 is installed in the guide pulley housing 3481 via two deep groove ball bearings 3483. The guide pulley housing 3481 is provided with a line inlet and a line outlet. Two Bowden cable fixing joints 342 are provided and are respectively installed at the line inlet and the line outlet of the guide pulley housing 3481. The Bowden wire sheath 343 is provided with two sections, and the guide pulley assembly 348 is installed between the two sections of the Bowden wire sheath 343. The end of each section of the Bowden wire sheath 343 is connected to the Bowden wire fixing joint 342 on the guide pulley housing 3481. After the Bowden wire 341 passes through the first section of the Bowden wire sheath 343, it enters from the wire inlet of the guide pulley housing 3481, then bypasses the Bowden wire steering wheel 3482, and finally passes out from the wire outlet of the guide pulley housing 3481.

[0046] like Figure 1 As shown, this embodiment provides a flexible exoskeleton system for upper limb training, including a control module, a wearable garment 4 and a flexible exoskeleton actuator. The wearable garment 4 is made of a chloroprene rubber material with high tensile strength and high elongation. The chloroprene rubber has high flexibility and high elasticity. When the wearable garment 4 is worn on the wearer's torso, it can not only fit well with the wearer's skin to prevent the clothes from moving, but also increase comfort. Two sets of flexible exoskeleton actuators can be provided, each set corresponds to an arm, and each set of flexible exoskeleton actuators has two straps, namely a forearm strap 22 and an upper arm strap 21. The forearm strap 22 and the upper arm strap 21 are both made of flax fiber material with low stretch rate. The forearm strap 22 is sewn on the forearm of the wearable garment 4 and is close to the wrist joint, and the upper arm strap 21 is sewn on the upper arm of the wearable garment 4 and is close to the elbow joint. The flax fiber material with low stretch rate is relatively hard, which can prevent the position of the forearm strap 22, the upper arm strap 21 and the wearable garment 4 from moving. In addition, the forearm strap 22, the upper arm strap 21 and the wearable garment 4 are fixed by sewing, which can further reduce the relative displacement of the end anchor seat 347 of the Bowden cable 341 and the wearable garment 4 when transmitting tension, thereby improving the force transmission efficiency of the exoskeleton.

[0047] There are three joint drive units 3 in each flexible exoskeleton actuator, namely an elbow joint drive unit, a shoulder joint drive unit 1 and a shoulder joint drive unit 2. The three joint drive units 3 are installed side by side horizontally on a mounting base, and the mounting base is fixed to the back of the wearable garment 4. The elbow joint drive unit is connected to the forearm strap 22 and is used to adjust the angle of the elbow joint. The outlet anchor 344 in the joint drive unit 3 is installed on the upper arm strap 21, and the guide pulley assembly 348 is installed on the shoulder of the wearable garment 4. The Bowden cable 341 on the forward line wheel 31 in the elbow joint drive unit is arranged on the outside of the arm, and the Bowden cable 341 on the reverse line wheel 32 bypasses the shoulder and is arranged on the inside of the arm. The shoulder joint drive unit 1 and the shoulder joint drive unit 2 are both connected to the upper arm strap 21 and are used to adjust the pitch angle and the lateral swing angle of the shoulder joint. The line anchor 344 in the two shoulder joint drive units is installed on the wearable garment 4 and close to the shoulder. The Bowden cable 341 on the forward line wheel 31 in the shoulder joint drive unit 1 and the shoulder joint drive unit 2 is arranged on the outside of the arm, and the Bowden cable 341 on the reverse line wheel 32 is arranged on the inside of the arm. The two Bowden cables 341 arranged on the outside of the arm in the two shoulder joint drive units are arranged side by side, and the two Bowden cables 341 arranged on the inside of the arm are also arranged side by side. The two Bowden cables 341 in the shoulder joint drive unit 1 are arranged on the upper arm close to the shoulder joint side, and the two Bowden cables 341 in the shoulder joint drive unit 1 are arranged on the upper arm away from the shoulder joint side.

[0048] The control module connects the driving motor 331 and the micro-tension sensor 346 in each joint driving unit 3 to control the driving motor 331 to cooperate with the force position signal measured by the corresponding micro-tension sensor 346 to drive the corresponding two Bowden cables 341 to retract and release the cables to different degrees to apply corrective force, thereby correcting the wearer's movement posture according to different sports training stages.

[0049] The working principle of the flexible exoskeleton system for upper limb training in this embodiment is as follows:

[0050] After the wearer puts on the flexible exoskeleton system, the Bowden cable 341 in each joint drive unit 3 is in a relaxed state.

[0051] Bowden line pre-tightening stage: the driving motor 331 in each joint driving unit 3 drives the corresponding supporting disk 334 to rotate, and the supporting disk 334 drives the forward line wheel 31 to rotate synchronously in the same direction via the damping shaft 333. Since the sun gear 335 also rotates synchronously in the same direction with the supporting disk 334, the three planetary gears 336 drive the planetary carrier 338 and the reverse line wheel 32 to rotate synchronously in the same direction under the action of the sun gear 335 and the inner gear ring 337. At this time, the reverse line wheel 32 rotates in the direction of taking up the line, so the forward line wheel 31 releases the line (the forward line wheel 31 and the reverse line wheel 32 are wound in opposite directions). When the Bowden line 341 on the reverse line wheel 32 is pre-tightened, the reverse line The wheel 32 is constrained by the Bowden cable 341 and remains stationary, so the planetary carrier 338 and the three planetary wheels 336 connected to the reverse line wheel 32 no longer revolve; the working torque of the three driving motors 331 is set to be greater than the threshold torque of the corresponding damping shaft 333, the output direction of the torque of the driving motor 331 remains unchanged, and drives the support plate 334 and the sun gear 335 to rotate, the sun gear 335 drives the three planetary wheels 336 to rotate, and the three planetary wheels 336 drive the forward line wheel 31 to rotate in the opposite direction via the inner ring gear 337, at this time, the forward line wheel 31 is pre-tightened until the Bowden cable 341 on the forward line wheel 31 is pre-tightened, and the pre-tightening stage of the Bowden cable 341 ends.

[0052] Bowden cable working stage: When the arm is gradually extended from the flexed state, the drive motor 331 in the elbow joint drive unit drives the sun gear 335 to rotate via the support plate 334. The sun gear 335 drives the forward line wheel 31 to rotate via the damping shaft 333 on the one hand, and drives the reverse line wheel 32 to rotate via the three planetary gears 336 on the other hand. At this time, the forward line wheel 31 and the reverse line wheel 32 rotate in the same direction, the forward line wheel 31 reels the line, and the reverse line wheel 32 releases the line. The outer side of the forearm is subjected to tension and the angle of the elbow joint is corrected to adjust the posture of the arm extension. Conversely, when the arm is gradually flexed from the extended state, the drive motor 331 drives the reverse line wheel 32 to reel in the line and the forward line wheel 31 to release the line. The inner side of the forearm is subjected to tension and the angle of the elbow joint is corrected to adjust the posture of the arm flexion.

[0053] When the whole arm performs the side swing motion outward, the driving motor 331 in the shoulder joint driving unit 1 drives the sun gear 335 to rotate forward via the supporting plate 334. The sun gear 335 drives the forward line wheel 31 to rotate forward via the damping shaft 333 on the one hand, and drives the reverse line wheel 32 to rotate forward via the three planetary gears 336 on the other hand, so that the forward line wheel 31 takes up the line and the reverse line wheel 32 releases the line. The driving motor 331 in the shoulder joint driving unit 2 drives the sun gear 335 to rotate reversely via the supporting plate 334. The sun gear 335 drives the forward line wheel 31 to rotate reversely via the damping shaft 333 on the one hand, and drives the reverse line wheel 32 to rotate reversely via the three planetary gears 336 on the other hand, so that the forward line wheel 31 releases the line and the reverse line wheel 32 takes up the line. At this time, the outer side of the upper arm is subjected to the tension of the two front and rear Bowden cables 341 and the angle of the shoulder joint is corrected to adjust the side swing posture of the whole arm. When the whole arm performs the side swing motion inward, the above process is reversed.

[0054] When the entire arm swings forward, the driving motors 331 in the shoulder joint driving unit 1 and the shoulder joint driving unit 2 drive the forward and reverse wire wheels to rotate synchronously in the same direction, the reverse wire wheel 32 reels in the wire and the forward wire wheel 31 pays out the wire. At this time, the front side of the upper arm is subjected to the pulling force of the two front Bowden cables 341 and corrects the forward swinging angle of the shoulder joint. Conversely, the driving motors 331 in the shoulder joint driving unit 1 and the shoulder joint driving unit 2 drive the forward and reverse wire wheels to rotate synchronously in the same direction, the forward wire wheel 31 reels in the wire and the reverse wire wheel 32 pays out the wire. At this time, the back side of the upper arm is subjected to the pulling force of the two rear Bowden cables 341 and corrects the backward swinging angle of the shoulder joint to adjust the pitch posture of the entire arm.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A flexible exoskeleton actuator, characterized in that: It includes a strap and a joint drive unit, wherein the strap is provided with at least one, and each strap corresponds to at least one joint drive unit, and the strap is fixed on the limb and arranged at one end away from the trained joint; each joint drive unit includes a forward wire wheel, a reverse wire wheel, a wire wheel driving mechanism and a Bowden wire mechanism, and each Bowden wire mechanism includes a Bowden wire, and two Bowden wire mechanisms are provided, one of which is arranged corresponding to the forward wire wheel, one end of the Bowden wire in the Bowden wire mechanism is wound around the forward wire wheel, and the other end extends along the stretching direction of the muscle and is fixed to the corresponding strap, and the other Bowden wire mechanism Corresponding to the reverse wire wheel setting, one end of the Bowden wire in the Bowden wire mechanism is reversely wound on the reverse wire wheel, and the other end extends along the stretching direction of the muscle and is fixed on the corresponding strap. The two Bowden wires are respectively located on the front and back sides of the trained limb to imitate the antagonist muscles of the limb; the wire wheel driving mechanism is configured on the trunk and can drive the forward wire wheel and the reverse wire wheel to rotate in the opposite direction during the pre-tightening stage to achieve wire reel pre-tightening, and drive the forward wire wheel and the reverse wire wheel to rotate synchronously in the same direction during the working stage, and apply corrective force to the force-generating muscle group through two alternately retracted and released Bowden wires to correct the wearer's movements.

2. A flexible exoskeleton actuator according to claim 1, characterized in that: The wire wheel driving mechanism comprises a driving motor, a damping shaft, a supporting disc and a planetary gear system, the planetary gear system comprises a sun wheel, a planetary gear, an inner gear ring and a planet carrier, the driving motor can drive the supporting disc to rotate, the sun wheel is coaxially connected to the supporting disc and can rotate synchronously with the supporting disc, the reverse wire wheel and the planet carrier are coaxially arranged relative to each other, and are rotatably installed on a side disk surface of the supporting disc provided with the sun wheel, the forward wire wheel is coaxially connected to the inner gear ring and can rotate synchronously with the inner gear ring, three planetary gears are provided, the three planetary gears are evenly installed circumferentially between the planet carrier and the reverse wire wheel and can rotate on their own, each planetary gear is meshed and connected with the sun wheel and the inner gear ring; the supporting disc is connected to the forward wire wheel via the damping shaft, and in the Bowden line pre-tightening stage, the supporting disc drives the reverse wire wheel and the forward wire wheel to rotate successively via the planetary gear system to pre-tighten the wire respectively; in the Bowden line working stage, the supporting disc drives the reverse wire wheel and the forward wire wheel to rotate synchronously via the damping shaft to alternately reel in or unreel.

3. A flexible exoskeleton actuator according to claim 1, characterized in that: The radii of the forward wire wheel and the reverse wire wheel are different.

4. A flexible exoskeleton actuator according to claim 2, characterized in that: Each Bowden cable mechanism also includes a Bowden cable sheath, a cable outlet anchor, a cable lock and a terminal anchor seat. The cable outlet anchor is configured on the limb, and the terminal anchor seat is installed on the strap. One end of the Bowden cable sheath is configured on the side close to the forward cable wheel or the reverse cable wheel, and the other end extends in the extension direction of the muscle and is connected to the cable outlet anchor. The Bowden cable runs through the Bowden cable sheath and extends from the cable outlet anchor, and is connected to the terminal anchor seat via the cable lock.

5. A flexible exoskeleton actuator according to claim 4, characterized in that: Each Bowden cable mechanism also includes a micro tension sensor, which is installed between the cable locker and the end anchor seat to measure the tension transmitted from the end of the Bowden cable to the strap during human-computer interaction.

6. A flexible exoskeleton actuator according to claim 4, characterized in that: Each Bowden cable mechanism also includes a guide pulley assembly. The Bowden cable sheath is provided with two sections. The guide pulley assembly is installed between the two sections of the Bowden cable sheath and is arranged at the position where the inflection point of the Bowden cable appears. The Bowden cable passes through the first section of the Bowden cable sheath, the guide pulley assembly and the second section of the Bowden cable sheath in sequence to reduce the friction force on the Bowden cable during the process of retracting and releasing the cable.

7. A flexible exoskeleton actuator according to claim 6, characterized in that: The guide pulley assembly includes a guide pulley housing and a Bowden cable steering wheel. The Bowden cable steering wheel is rotatably installed in the guide pulley housing. The guide pulley housing is provided with a wire inlet and a wire outlet. The Bowden cable enters from the wire inlet of the guide pulley housing, bypasses the Bowden cable steering wheel, and then passes out from the wire outlet of the guide pulley housing.

8. A flexible exoskeleton system for upper limb training, characterized in that: The invention comprises a flexible exoskeleton actuator as claimed in any one of claims 1 to 7, wherein the flexible exoskeleton actuator is provided with two sets, each set corresponding to one arm, and each set of the flexible exoskeleton actuator is provided with two straps, namely a forearm strap and an upper arm strap, the forearm strap is fixed on the forearm and close to the wrist joint, and the upper arm strap is fixed on the upper arm and close to the elbow joint; each set of the flexible exoskeleton actuator is provided with three joint drive units, one of which is connected to the forearm strap and is used to adjust the angle of the elbow joint, and the other two joint drive units are connected to the upper arm straps and are used to adjust the angle of the shoulder joint.

9. A flexible exoskeleton system for upper limb training according to claim 8, characterized in that: The invention also includes a wearable garment, which is worn on the torso of the wearer, the forearm strap and the upper arm strap are fixed on the forearm and upper arm of the wearable garment, and the joint driving unit is installed on the back of the wearable garment.

10. A flexible exoskeleton system for upper limb training according to claim 9, characterized in that: The wearable garment is made of neoprene material, and the forearm and upper arm straps are made of linen fiber material.

Images