A flexible exoskeleton actuation device and a flexible exoskeleton system for upper limb training

Abstract

The application relates to a flexible exoskeleton execution device and a flexible exoskeleton system for upper limb training, and relates to the field of robot technology. In order to solve the problem that the exoskeleton robot at the present stage adopts rigid driving to realize joint flexion and extension or expansion and contraction, etc., resulting in the problems of complex mechanical structure, large volume, heavy weight and large inertia. The application comprises a bandage, a forward wire wheel, a reverse wire wheel, a wire wheel driving mechanism and Bowden wires, the bandage is fixed on a limb, one end of one of the Bowden wires is wound on the forward wire wheel, the other end is fixed on the bandage, one end of the other Bowden wire is reversely wound on the reverse wire wheel, and the other end is fixed on the bandage; the wire wheel driving mechanism is arranged on the trunk and can drive the reverse rotation of the forward wire wheel and the reverse wire wheel in the pre-tightening stage to realize wire winding pre-tightening, and can drive the synchronous and same-direction rotation of the forward wire wheel and the reverse wire wheel in the working stage, and can apply a correction force to the force-generating muscle group through the two Bowden wires which are alternately wound and unwound, so as to correct the action of the wearer.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of robot technology, in particular to a flexible exoskeleton execution device and a flexible exoskeleton system for upper limb training. BACKGROUND

[0002] The exoskeleton robot is also called wearable robot, which is worn on the human body and acts on the joint of the human body, so that the wearer's limbs can achieve standardized action in the movement process. It is mainly used to correct the action posture of the wearer in the training process, which can be sports training of sports players or rehabilitation training of patients. Taking sports players as an example, the current teaching method of sports players is limited by the experience and communication ability of the coach, and it is impossible to accurately correct the specific action of the players 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 mechanism, and usually only after the action is completed, technical analysis is carried out, requiring the athlete to pause after executing a series of actions, waiting for video playback or data analysis, in order to identify and correct the problems in the execution of the technology. This "after-diagnosis" mode causes time delay, so that the athlete cannot obtain feedback and adjust the action immediately, thereby affecting the continuity of learning and the immediacy of action correction. However, the exoskeleton robot can correct the joint angle in real time, which can fully solve the demand of players for accurate, efficient and personalized training in the process of learning new sports skills.

[0003] However, the joint of the exoskeleton robot and the wearer at the present stage usually adopts rigid drive to realize the flexion or extension of the joint, which leads to the problems of complex mechanical structure, large volume, heavy weight and large inertia. In addition, rigid drive will affect the degree of freedom of limb movement and is not convenient to wear and take off, and cannot achieve the compatibility of man-machine. Moreover, rigid drive does not conform to the natural muscle coordination and force distribution mode of the human body, so that the wearer's muscles cannot form memory after training, and thus the incorrect posture and force mode in the process of sports training or rehabilitation training cannot be corrected scientifically and effectively. SUMMARY

[0004] Therefore, the present application provides a flexible exoskeleton execution device and a flexible exoskeleton system for upper limb training, which can correct the incorrect posture and force mode of the wearer's limbs in the movement process.

[0005] The technical scheme adopted by the present application to solve the above technical problems is:

[0006] The flexible exoskeleton execution device comprises a bandage and a joint driving unit, at least one bandage is provided, each bandage corresponds to at least one joint driving unit, the bandage is fixed on the limb and arranged at the end away from the trained joint; each joint driving unit comprises a positive line wheel, a reverse line wheel, a line wheel driving mechanism and a Bowden cable mechanism, each Bowden cable mechanism comprises a Bowden cable, the Bowden cable mechanism is provided with two, one of the Bowden cable mechanism corresponds to the positive line wheel, one end of the Bowden cable in the Bowden cable mechanism is wound on the positive line wheel, the other end extends along the stretching direction of the muscle and is fixed on the corresponding bandage, the other Bowden cable mechanism corresponds to the reverse line wheel, one end of the Bowden cable in the Bowden cable mechanism is reversely wound on the reverse line wheel, the other end extends along the stretching direction of the muscle and is fixed on the corresponding bandage, the two Bowden cables are respectively on the front and back sides of the trained limb to simulate the antagonistic muscles of the limb; the line wheel driving mechanism is arranged on the torso and can drive the reverse rotation of the positive line wheel and the reverse line wheel in the pre-tightening stage to realize the pre-tightening of the line, and drive the synchronous and same direction rotation of the positive line wheel and the reverse line wheel in the working stage, and apply the correction force to the force muscle group through the two Bowden cables which are alternately collected and released to correct the action of the wearer.

[0007] On the basis of technical scheme 1, the line wheel driving mechanism comprises a driving motor, a damping rotating shaft, a support disc and a planetary gear train, the planetary gear train comprises a sun gear, a planet gear, an inner ring gear and a planet carrier, the driving motor can drive the support disc to rotate, the sun gear is coaxially connected with the support disc and can rotate synchronously with the support disc, the reverse line wheel and the planet carrier are coaxially arranged opposite to each other and are rotatably installed on the disc surface of the side of the support disc provided with the sun gear, the positive line wheel is coaxially connected with the inner ring gear and can rotate synchronously with the inner ring gear, the planet gear is provided with three, the three planet gears are circumferentially and uniformly installed between the planet carrier and the reverse line wheel and can rotate, and each planet gear is meshingly connected with the sun gear and the inner ring gear; the support disc is connected with the positive line wheel through the damping rotating shaft, and in the Bowden cable pre-tightening stage, the support disc drives the reverse line wheel and the positive line wheel to rotate in sequence through the planetary gear train to pre-tighten the lines; in the Bowden cable working stage, the support disc drives the reverse line wheel and the positive line wheel to rotate synchronously through the damping rotating shaft to alternately collect or release the lines.

[0008] On the basis of technical scheme 1, the radii of the positive line wheel and the reverse line wheel are different.

[0009] On the basis of technical scheme 2, each Bowden cable mechanism further comprises a Bowden cable sheath, a line outlet anchor point device, a line locking device and a terminal anchor seat, the line outlet anchor point device is arranged on the limb, the terminal anchor seat is installed on the bandage, one end of the Bowden cable sheath is arranged on the side close to the positive line wheel or the reverse line wheel, the other end extends along the extension direction of the muscle and is connected to the line outlet anchor point device, the Bowden cable penetrates through the Bowden cable sheath and extends out from the line outlet anchor point device, and is connected to the terminal anchor seat through the line locking device.

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

[0011] On the basis of technical solution 4, each Bowden cable mechanism further comprises 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 configured at the position where the Bowden cable appears an inflection point, 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 suffered by the Bowden cable during winding and unwinding.

[0012] On the basis of technical solution 6, the guide pulley assembly comprises a guide pulley shell and a Bowden cable deflector, the Bowden cable deflector is rotatably installed in the guide pulley shell, the guide pulley shell is provided with an inlet and an outlet, the Bowden cable enters from the inlet of the guide pulley shell, and passes out from the outlet of the guide pulley shell after passing around the Bowden cable deflector.

[0013] A flexible exoskeleton system for upper limb training, comprising two sets of flexible exoskeleton execution devices, each set corresponding to an arm, each set of flexible exoskeleton execution devices having two bands, a small arm band and a large arm band, the small arm band being fixed to the small arm near the wrist joint, and the large arm band being fixed to the large arm near the elbow joint, each set of flexible exoskeleton execution devices having three joint driving units, one of which is connected to the small arm band and used to adjust the angle of the elbow joint, and the other two are connected to the large arm band and used to adjust the angle of the shoulder joint.

[0014] On the basis of technical solution 8, a wearable garment is further included, which is worn on the wearer's torso, the small arm band and the large arm band are fixed to the small arm and the large arm of the wearable garment, and the joint driving units are installed on the back of the wearable garment.

[0015] On the basis of technical solution 9, the wearable garment is made of neoprene material, and the small arm band and the large arm band are made of linen fiber material.

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

[0017] 1、The flexible exoskeleton execution device of the present application adopts the mode of Bowden wire driving, instead of rigid connecting rod structure, can simulate the natural muscle coordination of the wearer, in the process of movement training, promotes movement learning through repetitive training, stimulates the internal control mechanism of the wearer through multi-joint movement, the dynamic correction force provided by the exoskeleton robot can enhance the sensory nerve input, thereby promoting the learning and internalization of complex motor skills. Compared with the existing traditional teaching method combined with optical motion capture system and IMU inertial measurement unit and other devices, the exoskeleton robot has real-time somatosensory feedback, greatly enhances the coherence of learning and the immediacy of action correction, and has higher human-computer compatibility.

[0018] 2、The wire wheel driving mechanism of the present application realizes the pre-tightening of the Bowden wire of the double wire wheels in sequence and the control of the alternating take-up and pay-off of the double wire wheels under the cooperation of the damping rotating shaft and the planetary gear system, so as to realize the correction of the joint angle. Compared with the complex pre-tightening mechanism, the wire wheel driving mechanism of the present application is smaller in size, lower in weight, simplifies the complexity of control and improves the efficiency of the driving system.

[0019] 3、The present application eliminates the relaxation effect caused by the different line length change rates of the inner and outer Bowden wires of the arm by controlling the wire wheel diameter ratio of the forward and reverse wire wheels, thereby improving the force transmission efficiency of the upper limb flexible exoskeleton during movement training.

[0020] 4、The present application reduces the frictional force borne by the Bowden wire through the configured Bowden wire sheath and guide pulley assembly, thereby ensuring the accuracy of the correction force generated by the Bowden wire.

[0021] 5、The present application fixes the position of the force point of the Bowden wire through the configured wearable clothes and binding belts. The wearable clothes are made of neoprene material with high tensile strength and high elongation rate. The neoprene has high flexibility and large elasticity, and when the wearable clothes are worn on the wearer's torso, they can well fit the wearer's skin to prevent the clothes from moving, and also increase comfort. The small arm binding belt and the large arm binding belt are made of low-elongation-rate linen fiber material. The low-elongation-rate linen fiber material is relatively hard, which can prevent the position between the small arm binding belt, the large arm binding belt and the wearable clothes from moving. In addition, the small arm binding belt, the large arm binding belt and the wearable clothes are fixed by sewing, which can further reduce the relative displacement between the end anchor point seat and the wearable clothes when the Bowden wire transmits tension, thereby improving the force transmission efficiency of the exoskeleton. BRIEF DESCRIPTION OF DRAWINGS

[0022] The accompanying drawings are part of the present application and serve to provide a further understanding of the present application.

[0023] Figure 1 It is a whole structure schematic view of a flexible exoskeleton execution device of the present application.

[0024] Figure 2 Structure diagram of joint driving unit.

[0025] Figure 3 Structure diagram of Bowden wire mechanism arranged on arm.

[0026] Figure 4 Structure diagram of guide pulley assembly.

[0027] Figure 5 Structure diagram of reverse side of positive wire wheel.

[0028] Figure 6 Structure diagram of front side of positive wire wheel.

[0029] Explanation of reference signs:

[0030] 1 - mounting base;

[0031] 2 - strap, 21 - large arm strap, 22 - small arm strap;

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

[0033] Wearable clothes 4. DETAILED DESCRIPTION

[0034] The present application will be described in detail below in conjunction with the drawings and specific examples.

[0035] Figure 1 The structure diagram of the flexible exoskeleton execution device of the embodiment is shown arranged on the upper limb. Specifically, as shown in Figure 1As shown, the flexible exoskeleton execution device of the embodiment includes a mounting base 1, a bandage 2 and a joint driving unit 3. The bandage 2 is provided at least one, each bandage 2 corresponds to at least one joint driving unit 3, and the bandage 2 is fixed on the limb and arranged at the end away from the trained joint. Each joint driving unit 3 includes a forward wire wheel 31, a reverse wire wheel 32, a wire wheel driving mechanism 33 and a Bowden wire mechanism 34. The forward wire wheel 31, the reverse wire wheel 32 and the wire wheel driving mechanism 33 are installed in the mounting base 1, which is configured on the back of the wearer. On the one hand, it can avoid the influence of the mounting base 1 on the movement of the wearer's limb, and on the other hand, it forms a remote driving, which can reduce the load and inertia of the limb compared to being installed on the limb, and ensure the movement accuracy of the limb. Each Bowden wire mechanism 34 includes a Bowden wire 341. The Bowden wire mechanism 34 is provided with two, one of which is arranged corresponding to the forward wire wheel 31. One end of the Bowden wire 341 in the Bowden wire mechanism 34 is wound on the winding groove of the forward wire wheel 31, and the other end extends along the stretching direction of the muscle and is fixed on the corresponding bandage. The other Bowden wire mechanism 34 is arranged corresponding to the reverse wire wheel 32. One end of the Bowden wire 341 in the Bowden wire mechanism 34 is wound on the winding groove of the reverse wire wheel 32. The winding direction of the Bowden wire 341 is opposite to that of the Bowden wire 341 wound on the forward wire wheel 31. The other end of the Bowden wire 341 extends along the stretching direction of the muscle and is fixed on the corresponding bandage. The two Bowden wires 341 are respectively on the front and rear sides of the trained limb to simulate the antagonistic muscles of the limb. The wire wheel driving mechanism 33 is configured on the torso and can drive the reverse rotation of the forward wire wheel 31 and the reverse wire wheel 32 in the pre-tightening stage to realize the pre-tightening of the wire, and drive the synchronous and same direction rotation of the forward wire wheel 31 and the reverse wire wheel 32 in the working stage, and apply the correction force to the force muscle group through the two Bowden wires 341 which are alternately collected and released, to correct the action of the wearer.

[0036] The flexible exoskeleton execution device of the embodiment adopts a Bowden wire 341 driving mode, instead of a rigid link structure, and can simulate natural muscle coordination of the wearer. In the process of movement training, the flexible exoskeleton execution device promotes movement learning through repetitive training, forms an internal control mechanism of the wearer through multi-joint movement stimulation, and enhances sensory nerve input through dynamic correction force provided by the exoskeleton robot, thereby promoting learning and internalization of complex movement skills. Compared with the existing traditional teaching method combined with an optical motion capture system and an IMU inertial measurement unit, the exoskeleton robot has real-time somatosensory feedback, greatly enhances the continuity of learning and the immediacy of movement correction, and has higher human-machine compatibility. Specifically, before training the standardized movement of the wearer's limbs by using the flexible exoskeleton system, the flexible exoskeleton system needs to be trained in advance, that is, the demonstrator wears the flexible exoskeleton system to perform the standardized movement, the Bowden wire 341 in the flexible exoskeleton system follows the movement of the demonstrator's limbs to wind and unwind, and the angular motion trajectory information of the joints of the limbs, that is, the angle, angular velocity, and angular acceleration of the degrees of freedom of each joint, and the tension information of the Bowden wire 341 at the anchor point transmitted by the micro-tension sensor 346 at the end of the Bowden wire 341 during human-computer interaction are recorded. When the wearer wears the flexible exoskeleton system and performs the movement according to the video, the flexible exoskeleton system actively controls the wire wheel driving mechanism 33 to operate according to the standardized movement 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 unwinding of the two Bowden wires 341. The power generation mode of the two Bowden wires 341 is to imitate the form of antagonistic muscles of the human body, so as to simulate the muscle coordination and force distribution mode of the limbs. When the movement of the wearer is different from the standardized movement, the winding and unwinding of the two Bowden wires 341 can effectively apply correction force to the corresponding muscle groups to correct the movement of the wearer, realize the timely correction of the movement, so that the wearer can obtain feedback and adjust the movement in real time, and ensure the continuity of learning and the immediacy of movement correction.

[0037] Since each limb has two joints, such as the shoulder joint and the elbow joint of the arm, the knee joint and the hip joint of the leg, when the standardized action only involves the training and correction of one joint, the upper strap can be fixed at the corresponding position of the corresponding joint, and the movement of the joint can be realized by the corresponding joint driving unit 3, that is, the number of straps is the same as the number of joints to be trained. The number of degrees of freedom of each joint is different, for example, the elbow joint only has one degree of freedom of flexion and extension, so only one joint driving unit 3 is needed to realize the training and correction of the elbow joint flexion and extension, and the shoulder joint has two degrees of freedom of extension and flexion, so two joint driving units 3 are needed to realize the movement of the shoulder joint with two degrees of freedom, that is, the degree of freedom of each joint movement is related to the number of joint driving units 3. Then in the case of moving limbs and standardized action, the number of straps and the number and installation position of joint driving units 3 can be determined. Still taking the arm as an example, if the training of the arm's shooting action is needed, since the shooting action is complex, the elbow joint and the shoulder joint need to work together, and the elbow joint flexion and the shoulder joint flexion and extension are needed to complete the standardized action of shooting, then two straps 2 and three joint driving units 3 are needed, two straps 2 are respectively small arm strap 22 and large arm strap 21, small arm strap 22 is fixed on the small arm and close to the wrist joint, large arm strap 21 is fixed on the large arm and close to the elbow joint, and three joint driving units 3 are installed on the back of the trunk, that is, the wearer carries the three joint driving units 3 on his back, which can reduce the load and movement inertia of the arm compared with directly installing the joint driving unit 3 on the arm. One of the joint driving units 3 is connected with the small arm strap 22 to adjust the angle of elbow joint flexion, so that the flexion and extension of the elbow joint reaches the standardized flexion and extension action, and the other two joint driving units 3 are connected with the large arm strap 21 to adjust the angle of shoulder joint flexion and extension, so that the flexion and extension of the shoulder joint reaches the standardized flexion and extension action.

[0038] To make the flexible exoskeleton system work, the Bowden cable 341 needs to be pre-tightened before work, so that the correction force can be transmitted to correct the angle of the joint when the Bowden cable 341 is wound and unwound. Therefore, the flexible exoskeleton system has two operation stages, one is the pre-tightening stage of the Bowden cable 341 before work, which requires both Bowden cables 341 in each joint driving unit 3 to be wound to achieve pre-tightening. The other is the working stage of correcting the angle of the joint, which requires one of the Bowden cables 341 in each joint driving unit 3 to be wound, while the other Bowden cable 341 to be unwound, so that the angle of the joint can be adjusted to correct the angle of the joint. As can be seen, the two Bowden cables 341 in each joint driving unit 3 need to be wound simultaneously or sequentially for pre-tightening, and alternately wound and unwound in the two operation stages, and the two Bowden cables 341 are wound on the forward wire wheel 31 and the reverse wire wheel 32 respectively, so the wire wheel driving mechanism 33 needs to be able to drive the forward wire wheel 31 and the reverse wire wheel 32 to move in the same direction to achieve alternating winding and unwinding, and to drive the forward wire wheel 31 and the reverse wire wheel 32 to move in opposite directions to achieve winding pre-tightening. One of the embodiments is that the wire wheel driving mechanism 33 uses two drive motors, and each wire wheel is provided with a drive motor, so the design will lead to the number of joint driving units 3 configured in the case of more joint degrees of freedom is also more, and then the number of drive motors will increase linearly, not only increases the weight and volume of the whole exoskeleton system, but also increases the complexity of control. The wire wheel driving mechanism 33 of the embodiment adopts another embodiment.

[0039] Figure 2 The structure diagram of the wire wheel driving mechanism 33 of the embodiment is shown, and the specific structure is as follows Figure 2As shown, the line wheel driving mechanism 33 of the embodiment comprises a driving motor 331, a harmonic reducer 332, a damping rotating shaft 333, a support disc 334 and a planetary gear train, the planetary gear train comprising a sun gear 335, a planet gear 336, an inner ring gear 337 and a planet carrier 338, the driving motor 331 is a brushless motor, which is connected to the support disc 334 through the harmonic reducer 332 and can drive the support disc 334 to rotate at a low speed, the sun gear 335 is coaxially connected to the support disc 334 and can rotate synchronously with the support disc 334, the reverse line wheel 32 and the planet carrier 338 are arranged coaxially opposite to each other and are rotatably installed on one side of the support disc 334 provided with the sun gear 335, the forward line wheel 31 is coaxially connected to the inner ring gear 337 and can rotate synchronously with the inner ring gear 337, the planet gear 336 is provided with three, the three planet gears 336 are circumferentially and uniformly installed between the planet carrier 338 and the reverse line wheel 32 and can rotate around their own axes, and each planet gear 336 is in meshing connection with the sun gear 335 and the inner ring gear 337; the support disc 334 is connected to the forward line wheel 31 through the damping rotating shaft 333, in the pre-tightening stage of the Bowden cable 341, the support disc 334 drives the reverse line wheel 32 and the forward line wheel 31 to rotate in sequence through the planetary gear train to collect the line and pre-tighten; in the working stage of the Bowden cable 341, the support disc 334 drives the reverse line wheel 32 and the forward line wheel 31 to rotate synchronously through the damping rotating shaft 333 to alternately collect the line or release the line.

[0040] It should be noted that the damping rotating 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 rotating shaft 333, the upper shaft section and the lower shaft section of the damping rotating shaft 333 can rotate relatively, when the working torque of the driving motor 331 is less than the threshold torque of the damping rotating shaft 333, the upper shaft section and the lower shaft section of the damping rotating shaft 333 are relatively fixed, at this time, the damping rotating shaft 333 can be regarded as a shaft with non-twistable ends. The driving process of the line wheel driving mechanism 33 to the forward line wheel 31 and the reverse line wheel 32 in the pre-tightening stage and the working stage of the Bowden cable 341 will be described below:

[0041] Pre-tightening stage of Bowden wire: Before the pre-tightening of the Bowden wire 341, the two Bowden wires 341 of each joint driving unit 3 are in a relaxed state, at this time the forward wire wheel 31 can rotate freely, and the upper shaft section of the damping shaft 333 will not provide a fixed force to the damping shaft 333, so that the upper shaft section of the damping shaft 333 is in a fixed state, and the lower shaft section will rotate only when a larger torque is applied, so 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 disc 334 to rotate, and the support disc 334 drives the forward wire wheel 31 to rotate synchronously and in the same direction through the damping shaft 333, and since the sun gear 335 also rotates synchronously and in the same direction with the support disc 334, the three planetary gears 336 drive the planet carrier 338 and the reverse wire wheel 32 to rotate synchronously and in the same direction through the sun gear 335 and the inner ring gear 337, at this time the reverse wire wheel 32 rotates in the direction of winding the wire, and the forward wire wheel 31 unwinds the wire (the winding directions of the forward wire wheel 31 and the reverse wire wheel 32 are opposite), and when the pre-tightening of the Bowden wire 341 on the reverse wire wheel 32 is completed, the reverse wire wheel 32 remains stationary due to the restriction of the Bowden wire 341, and the planet carrier 338 and the three planetary gears 336 connected with the reverse wire wheel 32 no longer perform a revolution; 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 driving motor 331 drives the support disc 334 and the sun gear 335 to rotate, the sun gear 335 drives the three planetary gears 336 to rotate, and the three planetary gears 336 drive the forward wire wheel 31 to rotate in the opposite direction through the inner ring gear 337, at this time the forward wire wheel 31 is pre-tightened until the pre-tightening of the Bowden wire 341 on the forward wire wheel 31 is completed, and the pre-tightening stage of the Bowden wire 341 is completed.

[0042] Working stage of Bowden wire 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 integral shaft, the driving motor 331 drives the sun gear 335 to rotate through the support disc 334, the sun gear 335 drives the forward wire wheel 31 to rotate through the damping shaft 333 on the one hand, and drives the reverse wire wheel 32 to rotate through the three planetary gears 336 on the other hand, at this time the forward wire wheel 31 and the reverse wire wheel 32 rotate in the same direction, and the Bowden wire 341 on the forward wire wheel 31 is in a winding state or an unwinding state, and the Bowden wire 341 on the corresponding reverse wire wheel 32 is in an unwinding state or a winding state. As can be seen, the wire wheel driving mechanism 33 of the embodiment realizes the pre-tightening of the Bowden wire 341 of the double wire wheels in sequence and the control of the alternating winding and unwinding of the double wire wheels through a single power source, so as to realize the correction of the joint angle, and compared with a complex pre-tightening mechanism, the wire wheel driving mechanism 33 has a smaller size, a lower weight, a simplified control complexity and an improved driving system efficiency.

[0043] Because the two Bowden wires 341 in each joint driving unit 3 are routed in different positions, if the radii of the forward and reverse wire wheels 32 are the same, the change rates of the two Bowden wires 341 will be the same in the process of alternating take-up and pay-off, so that in the correction process, a certain Bowden wire 341 will be relaxed, and the correction purpose cannot be achieved. Therefore, the radii of the forward wire wheel 31 and the reverse wire wheel 32 in the embodiment are set to be different. Taking the elbow joint of the arm as an example for further description, the Bowden wire 341 on the forward wire wheel 31 is arranged on the outer side of the arm, and the Bowden wire 341 on the reverse wire wheel 32 is arranged on the inner side of the arm, so that the radii of the forward wire wheel 31 and the reverse wire wheel 32 are set to be different. Figure 1 As can be seen, the Bowden wire 341 wound on the forward wire wheel 31 extends from the back of the wearer's back to the back of the shoulder, and then extends from the back of the shoulder to the forearm, and the Bowden wire 341 wound on the reverse wire wheel 32 extends from the back of the wearer's back to the front of the shoulder, and then extends from the front of the shoulder to the forearm, and the length of the Bowden wire 341 wound on the forward wire wheel 31 is relatively shorter than that of the Bowden wire 341 wound on the reverse wire wheel 32; when the arm gradually changes from the stretched state to the flexed state, the length of the pay-off of the forward wire wheel 31 is shorter than that of the take-up of the reverse wire wheel 32, so that the two Bowden wires 341 can always be in a pre-tightened state, that is, by controlling the diameter ratio of the forward and reverse wire wheels 32 of the Bowden wire 341, the relaxation effect caused by the different length change rates of the Bowden wires 341 on the inner and outer sides of the arm is eliminated, and the force transmission efficiency of the upper limb flexible exoskeleton during exercise training is improved. The radii of the forward and reverse wire wheels 32 can be customized according to the arrangement positions of the respective corresponding Bowden wires 341 and according to the length change rate requirements.

[0044] Figure 1 and Figure 3 The structure of the Bowden wire mechanism 34 is shown in the specific structure diagram of the Bowden wire mechanism 34. Figure 1 and Figure 3As shown, due to the friction between the Bowden cable 341 and the wearer's body during the winding and unwinding process, the friction will not only affect the tension test result of the end of the Bowden cable 341 in the demonstration stage of the flexible exoskeleton system, but also affect the accurate value of the correction force when the correction force is applied through the Bowden cable 341 in the working stage, and thus the purpose of accurate correction of the joint angle cannot be achieved. Therefore, each Bowden cable mechanism 34 of the embodiment further comprises a Bowden cable fixing joint 342, a Bowden cable sheath 343, a cable anchor point device 344, a cable locking device 345, a micro tension sensor 346 and an end anchor seat 347. The cable anchor point device 344 is configured on the limb, the end anchor seat 347 is installed on the bandage 2, one end of the Bowden cable sheath 343 is installed on the installation base 1 through the Bowden cable fixing joint 342, the other end extends in the direction of the muscle and is connected to the cable anchor point device 344 through the Bowden cable fixing joint 342, the Bowden cable 341 penetrates through the Bowden cable sheath 343 and extends out of the cable anchor point device 344, and then is connected to the end anchor seat 347 through the cable locking device 345. The micro tension sensor 346 is installed between the cable locking device 345 and the end anchor seat 347 to measure the tension of the end of the Bowden cable 341 transmitted to the bandage during human-computer interaction. As can be seen, the embodiment reduces the friction on the Bowden cable 341 by configuring the Bowden cable sheath 343. Since the Bowden cable 341 needs to generate a correction force through winding and unwinding, the length of the Bowden cable sheath 343 needs to be shorter than the length of the Bowden cable 341, which requires the Bowden cable 341 to be exposed. The embodiment exposes a section of the Bowden cable 341 near the bandage, so that the force point of the Bowden cable 341 can be set at the bandage, which is convenient for adjusting the corresponding joint angle. Still taking the elbow joint of the arm as an example for description, Figure 3It can be seen that the force point of the Bowden cable 341 is the end point of the Bowden cable 341, and the end of the Bowden cable 341 is installed on the strap fixed on the forearm through the lock cable device 345 and the end anchor seat 347. When the Bowden cable 341 is reeled in, the forearm is directly stressed and bent towards or away from the upper arm to straighten, thereby adjusting the elbow joint angle. In addition, the Bowden cable 341 has the maximum friction with the shoulder when extending along the stretching direction of the muscle, so the Bowden cable sheath 343 is arranged at the position between the outlet point of the Bowden cable 341 and the upper arm, which can further reduce the friction on the Bowden cable 341 compared to arranging the Bowden cable sheath 343 at the position close to the end of the Bowden cable 341, thereby ensuring the accuracy of the Bowden cable 341 tension measurement. When the demonstrator wears the flexible exoskeleton system to perform standardized movements, the Bowden cable 341 in the flexible exoskeleton system retracts and releases the line following the movement of the demonstrator's limbs, so the micro-tension sensor 346 at the end of the Bowden cable 341 is needed 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 instantaneously feedback the axial tension of the Bowden cable 341 during the movement training, and based on this, the tension and contraction and relaxation displacement of the Bowden cable 341 are adjusted in real time through the control system, so as to correct the movement posture of the wearer and realize the movement correction function.

[0045] By Figure 1 It can be seen that when the flexible exoskeleton system is used to correct the joint angle of the wearer's arm, the two Bowden cables 341 in each joint driving unit 3 need to extend from the wearer's back to the shoulder and then to the arm, which causes the Bowden cable 341 to have an inflection point. The friction between the Bowden cable 341 and the Bowden cable sheath 343 is the largest at the inflection point, so each Bowden cable mechanism 34 further includes a guide pulley assembly 348 arranged at the inflection point. The guide pulley assembly 348 can change the sliding friction between the Bowden cable 341 and the Bowden cable sheath 343 into rolling friction to reduce the friction on the Bowden cable 341. Specifically, as shown in FIG. 6, the guide pulley assembly 348 includes a guide pulley 348a and a guide pulley 348b arranged at the inflection point of the Bowden cable 341. The guide pulley 348a is arranged on the Bowden cable 341, and the guide pulley 348b is arranged on the Bowden cable sheath 343. The guide pulley 348a and the guide pulley 348b are arranged in the same direction and are connected by a connecting rod 348c. When the Bowden cable 341 is reeled in, the guide pulley 348a and the guide pulley 348b rotate in the same direction, and the connecting rod 348c is in a state of tension. When the Bowden cable 341 is released, the guide pulley 348a and the guide pulley 348b rotate in the opposite direction, and the connecting rod 348c is in a state of compression. The guide pulley assembly 348 can change the sliding friction between the Bowden cable 341 and the Bowden cable sheath 343 into rolling friction, thereby reducing the friction on the Bowden cable 341. Figure 4As shown, the guide pulley assembly 348 of this embodiment includes a guide pulley housing 3481, a Bowden wire steering wheel 3482, a Bowden wire fixing joint 342, and two deep groove ball bearings 3483. The Bowden wire steering wheel 3482 is installed inside the guide pulley housing 3481 via the two deep groove ball bearings 3483. The guide pulley housing 3481 is provided with an inlet and an outlet. There are two Bowden wire fixing joints 342, which are respectively installed at the inlet and outlet of the guide pulley housing 3481. The Bowden wire sheath 343 has 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 inlet of the guide pulley housing 3481, then goes around the Bowden wire steering wheel 3482, and finally exits from the 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 execution device. The wearable garment 4 is made of neoprene rubber material with high tensile strength and high elongation. Neoprene 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 shifting, but also increase comfort. Two sets of flexible exoskeleton actuators can be installed, each corresponding to one arm. Each set of flexible exoskeleton actuators has two straps: a forearm strap 22 and an upper arm strap 21. Both the forearm strap 22 and the upper arm strap 21 are made of low-elongation flax fiber material. The forearm strap 22 is sewn onto the forearm of the wearable garment 4 near the wrist joint, and the upper arm strap 21 is sewn onto the upper arm of the wearable garment 4 near the elbow joint. The low-elongation flax fiber material is relatively stiff, which can prevent the forearm strap 22, the upper arm strap 21 and the wearable garment 4 from shifting positions. 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 between the end anchor seat 347 and the wearable garment 4 when the Bowden line 341 transmits tension, thereby improving the force transmission efficiency of the exoskeleton.

[0047] The joint driving unit 3 in each set of flexible exoskeleton execution device is provided with three, which are elbow joint driving unit, shoulder joint driving unit one and shoulder joint driving unit two. The three joint driving units 3 are transversely and side by side installed on the installation base, which is fixed on the back of the wearable clothes 4. The elbow joint driving unit is connected with the lower arm strap 22 and used for adjusting the angle of the elbow joint. The wire anchor point device 344 in the joint driving unit 3 is installed on the upper arm strap 21. The guide pulley assembly 348 is installed on the shoulder of the wearable clothes 4. The Bowden cable 341 on the positive wire wheel 31 in the elbow joint driving unit is arranged on the outside of the arm. The Bowden cable 341 on the reverse wire wheel 32 bypasses the shoulder and is arranged on the inside of the arm. The shoulder joint driving unit one and the shoulder joint driving unit two are both connected with the upper arm strap 21 and used for adjusting the pitch angle and the roll angle of the shoulder joint. The wire anchor point device 344 in the two shoulder joint driving units is installed on the wearable clothes 4 and close to the position of the shoulder. The Bowden cable 341 on the positive wire wheel 31 in the shoulder joint driving unit one and the shoulder joint driving unit two is arranged on the outside of the arm. The Bowden cable 341 on the reverse wire 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 driving units are side by side arranged. The two Bowden cables 341 arranged on the inside of the arm are also side by side arranged. The two Bowden cables 341 in the shoulder joint driving unit one are arranged on the side of the upper arm close to the shoulder joint. The two Bowden cables 341 in the shoulder joint driving unit one are arranged on the side of the upper arm away from the shoulder joint.

[0048] The control module is connected with the driving motor 331 and the micro tension sensor 346 in each joint driving unit 3 to control the driving motor 331 to drive the corresponding two Bowden cables 341 to be wound or unwound in different degrees to exert the correction force according to the force signal measured by the corresponding micro tension sensor 346, so as to correct the movement posture of the wearer for different movement training stages.

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

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

[0051] The Bowden wire pre-tightening stage: the driving motor 331 in each joint driving unit 3 drives the corresponding support disc 334 to rotate, which drives the forward wire wheel 31 to rotate synchronously and in the same direction via the damping rotating shaft 333. Since the sun gear 335 also rotates synchronously and in the same direction with the support disc 334, the three planetary gears 336 drive the planet carrier 338 and the reverse wire wheel 32 to rotate synchronously and in the same direction under the action of the sun gear 335 and the inner ring gear 337. At this time, the reverse wire wheel 32 rotates in the direction of winding the wire, so that the forward wire wheel 31 unwinds the wire (the winding direction of the forward wire wheel 31 is opposite to that of the reverse wire wheel 32). When the pre-tightening of the Bowden wire 341 on the reverse wire wheel 32 is completed, the reverse wire wheel 32 remains stationary due to the restriction of the Bowden wire 341, so that the planet carrier 338 and the three planetary gears 336 connected with the reverse wire wheel 32 no longer perform the revolution motion. The working torque of the three driving motors 331 is set to be greater than the threshold torque of the corresponding damping rotating shaft 333, and the output direction of the driving motor 331 torque remains unchanged, which drives the support disc 334 and the sun gear 335 to rotate. The sun gear 335 drives the three planetary gears 336 to rotate, and the three planetary gears 336 drive the forward wire wheel 31 to rotate in the opposite direction via the inner ring gear 337. At this time, the forward wire wheel 31 is pre-tightened, and the pre-tightening stage of the Bowden wire 341 ends.

[0052] The Bowden wire working stage: when the arm is gradually stretched from the flexion state, the driving motor 331 in the elbow joint driving unit drives the sun gear 335 to rotate via the support disc 334. The sun gear 335 drives the forward wire wheel 31 to rotate via the damping rotating shaft 333, and drives the reverse wire wheel 32 to rotate via the three planetary gears 336. At this time, the forward wire wheel 31 and the reverse wire wheel 32 rotate in the same direction, the forward wire wheel 31 winds the wire, and the reverse wire wheel 32 unwinds the wire. The outside of the forearm is subjected to a pulling force and corrects the angle of the elbow joint to adjust the posture of the arm stretching. Conversely, when the arm is gradually flexed from the stretched state, the driving motor 331 drives the reverse wire wheel 32 to wind the wire and the forward wire wheel 31 to unwind the wire, so that the inside of the forearm is subjected to a pulling force and corrects the angle of the elbow joint to adjust the posture of the arm flexing.

[0053] When the whole arm makes outward side swing movement, the driving motor 331 in the shoulder joint driving unit one drives the sun gear 335 to rotate forward via the support disc 334, the sun gear 335 drives the forward wire wheel 31 to rotate forward via the damping rotating shaft 333 and drives the reverse wire wheel 32 to rotate forward via the three planetary gears 336, the forward wire wheel 31 winds up and the reverse wire wheel 32 winds out, the driving motor 331 in the shoulder joint driving unit two drives the sun gear 335 to rotate reversely via the support disc 334, the sun gear 335 drives the forward wire wheel 31 to rotate reversely via the damping rotating shaft 333 and drives the reverse wire wheel 32 to rotate reversely via the three planetary gears 336, the forward wire wheel 31 winds out and the reverse wire wheel 32 winds up, at this time, the outer side of the upper arm is pulled by the two front and rear Bowden wires 341 and the angle of the shoulder joint is corrected to adjust the side swing posture of the whole arm. When the whole arm makes inward side swing movement, the above process is reversed.

[0054] When the whole arm swings forward, the driving motors 331 in the shoulder joint driving unit one and the shoulder joint driving unit two drive the forward and reverse wire wheels to rotate synchronously and in the same direction, the reverse wire wheel 32 winds up and the forward wire wheel 31 winds out, at this time, the front side of the upper arm is pulled by the two front Bowden wires 341 and the angle of the forward swing of the shoulder joint is corrected, on the contrary, the driving motors 331 in the shoulder joint driving unit one and the shoulder joint driving unit two drive the forward and reverse wire wheels to rotate synchronously and in the same direction, the forward wire wheel 31 winds up and the reverse wire wheel 32 winds out, at this time, the rear side of the upper arm is pulled by the two rear Bowden wires 341 and the angle of the rear swing of the shoulder joint is corrected to adjust the pitch posture of the whole arm.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the scope of protection of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application.

Claims

1. A flexible exoskeleton actuation device, characterized by, The device comprises a plurality of straps and joint driving units, each strap is fixed on the limb and arranged at the end away from the joint to be trained, and each strap corresponds to at least one joint driving unit; each joint driving unit comprises a forward wire wheel, a reverse wire wheel, a wire wheel driving mechanism and a Bowden cable mechanism, each Bowden cable mechanism comprises a Bowden cable, and the Bowden cable mechanism is provided with two Bowden cables, one of which is arranged corresponding to the forward wire wheel, one end of the Bowden cable in the Bowden cable mechanism is wound on the forward wire wheel, and the other end extends along the stretching direction of the muscle and is fixed on the corresponding strap, and the other Bowden cable mechanism is arranged corresponding to the reverse wire wheel, one end of the Bowden cable in the Bowden cable 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, and the two Bowden cables are respectively arranged on the front and back sides of the limb to be trained to simulate the antagonistic muscles of the limb; the wire wheel driving mechanism is arranged on the torso and can drive the reverse rotation of the forward wire wheel and the reverse wire wheel in the pre-tightening stage to realize the pre-tightening of the wire, and can drive the synchronous and same direction rotation of the forward wire wheel and the reverse wire wheel in the working stage, and can apply a correction force to the force muscle group through the two Bowden cables which are alternately wound and unwound to correct the action of the wearer. The wire wheel driving mechanism comprises a driving motor, a damping shaft, a support disc and a planetary gear train, the planetary gear train comprises a sun gear, a planet gear, an inner ring and a planet carrier, the driving motor can drive the rotation of the support disc, the sun gear is coaxially connected with the support disc and can rotate synchronously with the support disc, the reverse wire wheel and the planet carrier are coaxially arranged opposite to each other and are rotatably installed on one side of the support disc which is provided with the sun gear, the forward wire wheel is coaxially connected with the inner ring and can rotate synchronously with the inner ring, the planet gear is provided with three, the three planet gears are circumferentially and uniformly installed between the planet carrier and the reverse wire wheel and can rotate, and each planet gear is meshingly connected with the sun gear and the inner ring; the support disc is connected with the forward wire wheel through the damping shaft, and in the Bowden cable pre-tightening stage, the support disc drives the reverse wire wheel and the forward wire wheel to rotate in sequence through the planetary gear train to pre-tighten the wire; in the Bowden cable working stage, the support disc drives the reverse wire wheel and the forward wire wheel to rotate synchronously through the damping shaft to alternately wind or unwind the wire.

2. A flexible exoskeleton actuation device according to claim 1, wherein, The radii of the forward wire wheel and the reverse wire wheel are different.

3. The flexible exoskeleton actuation device of claim 1, wherein, Each Bowden cable mechanism further comprises a Bowden cable sheath, a wire outlet anchor point device, a wire locking device and a terminal anchor seat, the wire outlet anchor point device is arranged on the limb, the terminal anchor seat is installed on the strap, one end of the Bowden cable sheath is arranged on one side close to the forward wire wheel or the reverse wire wheel, the other end extends along the extension direction of the muscle and is connected to the wire outlet anchor point device, the Bowden cable penetrates through the Bowden cable sheath and extends out of the wire outlet anchor point device, and is connected to the terminal anchor seat through the wire locking device.

4. A flexible exoskeleton actuation device according to claim 3, wherein, Each Bowden cable mechanism further comprises a micro tension sensor, the micro tension sensor is installed between the wire locking device and the terminal anchor seat to measure the tension of the Bowden cable terminal transmitted to the strap in the human-computer interaction process.

5. The flexible exoskeleton actuation device of claim 3, wherein, Each Bowden cable mechanism further comprises 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 configured at a position where the Bowden cable has an inflection point, 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 suffered by the Bowden cable during winding and unwinding.

6. A flexible exoskeleton actuation device according to claim 5, wherein, The guide pulley assembly comprises a guide pulley housing and a Bowden cable deflector wheel, the Bowden cable deflector wheel is rotatably installed in the guide pulley housing, the guide pulley housing is provided with an inlet and an outlet, the Bowden cable enters the guide pulley housing from the inlet, and exits the guide pulley housing from the outlet after passing around the Bowden cable deflector wheel.

7. A flexible exoskeleton system for upper limb training, characterized by, The flexible exoskeleton execution device comprises two sets, each set corresponding to an arm, each set of flexible exoskeleton execution device is provided with two bands, which are respectively small arm bands and large arm bands, the small arm bands are fixed on the small arms and close to the wrist joints, and the large arm bands are fixed on the large arms and close to the elbow joints; each set of flexible exoskeleton execution device is provided with three joint driving units, one of which is connected with the small arm bands and used for adjusting the angle of the elbow joint, and the other two are connected with the large arm bands and used for adjusting the angle of the shoulder joint.

8. The flexible exoskeleton system for upper limb training according to claim 7, wherein, The wearable clothes are worn on the trunk of the wearer, the small arm bands and the large arm bands are fixed on the small arms and the large arms of the wearable clothes, and the joint driving units are installed on the back of the wearable clothes.

9. The flexible exoskeleton system for upper limb training according to claim 8, wherein, The wearable clothes are made of neoprene, and the small arm bands and the large arm bands are made of linen fiber material.

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