Single-machine bidirectional driving device applied to flexible exoskeleton

Abstract

The invention provides a single-machine bidirectional driving device applied to a flexible exoskeleton. The single-machine bidirectional driving device comprises a cable, a driving module and a spring clutch module, the cable is connected to the driving module, the driving module is configured to drive the cable to be wound and unwound, the spring clutch module is connected with the cable, and the spring clutch module is configured to lock the cable in a driving state. And the spring clutch module is configured to provide elastic force for the cable in a non-driving state, so that the cable is tensioned. According to the device, the cable can be kept tensioned in a non-driving state, and power-assisted switching can be rapidly carried out in a driving state.

Description

Technical Field

[0001] This application belongs to the field of exoskeleton robot drive technology, specifically, it relates to a single-machine bidirectional drive device applied to a flexible exoskeleton. Background Technology

[0002] Existing flexible exoskeleton robots widely employ cable (Bonden cable) actuation, which offers advantages such as lightweight design and flexible wiring. Since flexible joints transmit power via Bowden cables, the ends of the Bowden cable conduit and the cable itself are typically connected to both ends of the body of the driven joint. For bidirectional actuation, Bowden cables must be connected to both the front and rear sides of the driven joint. Currently, rapid forward and backward movement of the joint can be achieved by using two motors to drive two Bowden cables. Current single-motor driven bidirectional movement of a single joint often employs passive spring mechanisms, which have the following drawbacks:

[0003] (1) Slack cables can cause delays, affecting the wearer's comfort and natural movement.

[0004] (2) The passive spring has a slow response speed and cannot meet the tension requirements at the moment of assist switching.

[0005] Therefore, a tensioning module with a compact structure, active control capabilities, and the ability to provide constant preload is needed to improve the user experience and control precision of exoskeleton robots. Summary of the Invention

[0006] The technical problem solved by this application is: how to provide a single-unit bidirectional drive device for flexible exoskeletons that can keep the cable taut and quickly switch the assist.

[0007] This application provides a single-unit bidirectional drive device for use in flexible exoskeletons, the single-unit bidirectional drive device comprising:

[0008] Cables;

[0009] A drive module, wherein the cable is connected to the drive module, and the drive module is configured to drive the cable to extend and retract;

[0010] A spring clutch module connected to the cable, the spring clutch module being configured to lock the cable in a driven state and to provide elasticity to the cable in a non-driven state to tension the cable.

[0011] Optionally, the drive module includes a drive motor and a bidirectional reel, the bidirectional reel being connected to the output shaft of the drive motor, and the cable being wound around the bidirectional reel.

[0012] Optionally, the spring clutch module includes:

[0013] An outer casing, the interior of which has a receiving space;

[0014] A cable pull shaft is rotatably mounted inside the housing, and a portion of the cable is wound around the cable pull shaft;

[0015] A spiral spring, wherein both ends of the spiral spring are fixed to the inside of the housing and the pull wire shaft, respectively;

[0016] A braking element, installed inside the housing, is configured to lock the cable pull shaft in a driven state to lock the cable, and to release the cable pull shaft in a non-driven state, wherein a spiral spring provides elastic force to the cable pull shaft to tension the cable.

[0017] Optionally, the braking element is an electromagnetic brake.

[0018] Optionally, the electromagnetic brake is connected to the pull wire shaft via a flange; the electromagnetic brake is configured to lock the pull wire shaft in the driving state, and the electromagnetic brake is configured to release the pull wire shaft in the non-driving state.

[0019] Optionally, both ends of the pull wire shaft are mounted inside the housing via bearings.

[0020] Optionally, the single-machine bidirectional drive device further includes:

[0021] A magnet, which is mounted on the end of the pull wire shaft;

[0022] A magnetic encoder, mounted on the housing, is configured to detect the angular displacement of the drawbar shaft.

[0023] Optionally, the outer casing is provided with drainage holes.

[0024] Optionally, the number of spring clutch modules is two, and the number of cables is two. One cable connects the bidirectional reel and one spring clutch module, and the other cable connects the bidirectional reel and another spring clutch module.

[0025] This application provides a single-unit bidirectional drive device for flexible exoskeletons, which has the following technical advantages:

[0026] In drive mode, the cable is locked to facilitate a quick switching process; in non-drive mode, elasticity is provided to the cable to keep it taut. Attached Figure Description

[0027] Figure 1This is a front view of a single-unit bidirectional drive device applied to a flexible exoskeleton according to one or more embodiments.

[0028] Figure 2 This is a side view of a single-unit bidirectional drive device applied to a flexible exoskeleton according to one or more embodiments.

[0029] Figure 3 This is an exploded view of the spring clutch module of a single-unit bidirectional drive device applied to a flexible exoskeleton according to one or more embodiments.

[0030] Figure 4 This is an exploded view of the structure of a spring clutch module of a single-unit bidirectional drive device for a flexible exoskeleton according to one or more embodiments. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0032] Before describing the various embodiments of this application in detail, the technical concept of this application is first briefly described: Current single-unit bidirectional drive modules in exoskeleton robots employ passive spring mechanisms, resulting in slack cables and an inability to quickly switch between assist requirements. Therefore, this application provides a method for manufacturing a single-unit bidirectional drive device for flexible exoskeletons. The key improvement lies in using a spring clutch module to connect the cables. In the driving state, the cables are locked, allowing for rapid assist switching. In the non-driving state, elastic force is provided to the cables to keep them taut. The specific principle of the single-unit bidirectional drive device for flexible exoskeletons of this application will be described below with reference to more embodiments.

[0033] Specifically, such as Figure 1 and Figure 2 As shown, the single-unit bidirectional drive device for a flexible exoskeleton in this embodiment includes a cable 10, a drive module 20, and a spring clutch module 30. The cable 10 is connected to the drive module 20, which is configured to drive the cable 10 to extend and retract. The spring clutch module 30 is connected to the cable 10 and is configured to lock the cable 10 in the drive state and to provide elastic force to the cable 10 in the non-drive state to tension the cable 10. The drive state refers to the assisted state, and the non-drive state refers to the non-assisted state.

[0034] In one or more embodiments, the drive module 20 includes a drive motor 21 and a bidirectional reel 22. The bidirectional reel 22 is connected to the output shaft of the drive motor 21, and the cable 10 is wound around the bidirectional reel 22. The bidirectional reel 22 can wind two cables 10, and the same motor drives both cables 10 for winding and unwinding.

[0035] For example, there are two spring clutch modules 30 and two cables 10. One cable 10 connects the bidirectional pulley 22 and one spring clutch module 30, and the other cable 10 connects the bidirectional pulley 22 and another spring clutch module 30, so as to achieve a single motor bidirectional drive effect.

[0036] In one or more embodiments, such as Figure 3 and Figure 4 As shown, the spring clutch module 30 includes a housing 31, a cable spool 32, a spiral spring 33, and a brake 34. The housing 31 has an internal receiving space. The cable spool 32 is rotatably mounted inside the housing, and a portion of the cable 10 is wound around the cable spool 32. Both ends of the spiral spring 33 are fixed to the interior of the housing 31 and the cable spool 32, respectively. The brake 34 is mounted inside the housing 31 and is configured to lock the cable spool 32 to lock the cable 10 in the driven state, and to release the cable spool 32 in the non-driven state. The spiral spring 33 provides elastic force to the cable spool 32 to tension the cable 10. By automatically maintaining a slight cable tension, the wearer can move freely with extremely low resistance.

[0037] For example, the two ends of the pull wire shaft 32 are mounted inside the housing 31 via bearings 35. The bearings 35 are fixed inside the housing 31, and the two ends of the pull wire shaft 32 are fixedly connected to the inner ring of the bearings 35, so that the pull wire shaft 32 can be rotated.

[0038] For example, the pull wire shaft 32 and the spiral spring 33 are coaxially arranged. One outer end of the spiral spring 33 is fixed to the outer casing 31, and one inner end of the spiral spring 33 is fixed to the pull wire shaft 32. When the pull wire shaft 32 is not locked, the spiral spring 33 has an elastic restoring force on the pull wire shaft 32, thereby causing the pull wire shaft 32 to pull the cable 10 taut, and the cable 10 remains taut.

[0039] For example, the braking element 34 is an electromagnetic brake. The electromagnetic brake 34 is connected to the cable shaft 32 via a flange; the electromagnetic brake 34 is configured to lock the cable shaft 32 in the driving state, and the electromagnetic brake 34 is configured to release the cable shaft 32 in the non-driving state. Through the instantaneous locking of the electromagnetic brake, combined with the high-rigidity assist output of the drive motor, rapid reversing drive of the joint is achieved. The electromagnetic brake should have both released and locked states. Depending on the effect requirements, the electromagnetic brake 34 includes, but is not limited to, the following types:

[0040] (1) Fail-safe (spring-loaded / power-on release):

[0041] Electromagnetic power failure brake (friction plate type): The most commonly used "hold / stop" brake. Power on → release; power off → lock immediately. Suitable for vertical loads and scenarios where power failure self-locking is required.

[0042] Permanent magnet brake (PM brake): It uses permanent magnet attraction for braking and is released only when "reverse excitation" is applied by power. It is also a self-locking mechanism when power is lost, but it consumes less power and generates less heat.

[0043] Tooth-clutch / brake (power-off engagement): No slippage, high residual torque, allows positive positioning; can only engage at rest or low speed, cannot engage at high speed.

[0044] (2) Power-on braking:

[0045] Electromagnetic friction type: It is attracted by electricity and generates frictional torque, which can be used for dynamic deceleration, but it is released when the power is cut off and does not have self-locking.

[0046] Magnetic-powder braking: The torque is approximately linear with the excitation current, which can be used for steady-state torque / tension control (e.g., wire feeding), but it is not suitable for long-term complete static holding.

[0047] Eddy / hysteresis braking: non-contact, adjustable damping, suitable for high-speed slow-stop and long service life; the static holding torque is close to zero and it does not self-lock.

[0048] (3) Others:

[0049] Electromagnetic pin / wedge lock: The pin is released when powered on and locked when powered off, suitable for "position stop / zero rotation".

[0050] Wrap-spring clutch / brake: compact structure, good self-locking, can be used for one-way locking or rapid locking.

[0051] In the non-drive state, the electromagnetic brake 34 is energized and released, causing the spiral spring 33 to provide a constant contraction tension to the cable 10. When the electromagnetic brake is released, the cable pull shaft is disengaged from the housing. At this time, since one end of the spiral spring is connected to the cable pull shaft 32 and the other end is connected to the housing 31, and the spiral spring 33 is tightened, the release direction is the direction of tightening the cable. Therefore, after the cable pull shaft is disengaged from the housing, the cable 10 will automatically tighten under the action of elastic force. The cable 10 remains slightly contracted, and the human-machine interaction resistance is minimal. In the non-drive state, only the spring tension acts, and the resistance can be adjusted by replacing the spring to adapt to different working conditions.

[0052] The electromagnetic brake 34 is de-energized and closes before the drive state switch, achieving rigid locking of the cable pull shaft 32. Specifically, the first step is drive preparation: when the assist intention is detected, the control system de-energizes and closes the electromagnetic brake within 0.05 seconds, locking the cable pull shaft 32. Next is drive output: the motor starts, and the cable pull shaft 32 outputs high-rigidity tension in the locked state, achieving closed-loop tension control.

[0053] For example, the housing 31 is made of lightweight metal or high-strength engineering plastic, and the surface of the housing 31 is provided with drainage holes to be suitable for underwater environments. The housing 31 includes two detachably connected front and rear parts.

[0054] For example, the spring clutch module also includes a magnet 36 and a magnetic encoder 37. The magnet 36 is mounted on the end of the pull-wire shaft 32, and the magnetic encoder 37 is mounted on the housing 31. The magnetic encoder 37 is configured to detect the angular displacement of the pull-wire shaft 32. The magnetic encoder 37 is coaxial with the pull-wire shaft 32, and obtains the relative position information of the two by detecting the polarity of the axially magnetized magnet through an internal magnetic sensitive element. The angular displacement signal output by the magnetic encoder 37 is used for gait phased and assist scheduling in the exoskeleton control system. By reading the angular displacement of the magnet polarity, the magnetic encoder further obtains the release length of the pull-wire shaft. Combined with the aforementioned motor angular displacement, the displacement between the drive module 20 and the spring clutch module 30 can be obtained.

[0055] For example, the locking and releasing process of the electromagnetic brake 34 is as follows: the control system reads the magnetic encoder and motor feedback in real time to calculate the bus length, which is the sum of the motor output and the tension output. It determines whether the bus length has retracted. If so, the bus length retraction feature is extracted, the motor trajectory is corrected, the electromagnetic brake 34 is de-energized and locked, the drive motor 21 retracts along the trajectory, it is determined that the retraction assistance is completed, and the electromagnetic brake 34 is energized and released.

[0056] The specific embodiments of this application have been described in detail above. Although some embodiments have been shown and described, those skilled in the art should understand that modifications and improvements can be made to these embodiments without departing from the principles and spirit of this application as defined by the claims and their equivalents, and such modifications and improvements should also be within the protection scope of this application.

Claims

1. A single-unit bidirectional drive device for use in flexible exoskeletons, characterized in that, The single-machine bidirectional drive device includes: Cables; A drive module, wherein the cable is connected to the drive module, and the drive module is configured to drive the cable to extend and retract; A spring clutch module connected to the cable, the spring clutch module being configured to lock the cable in a driven state and to provide elasticity to the cable in a non-driven state to tension the cable.

2. The single-unit bidirectional drive device for a flexible exoskeleton according to claim 1, characterized in that, The drive module includes a drive motor and a bidirectional reel. The bidirectional reel is connected to the output shaft of the drive motor, and the cable is wound around the bidirectional reel.

3. The single-unit bidirectional drive device for flexible exoskeletons according to claim 1, characterized in that, The spring clutch module includes: An outer casing, the interior of which has a receiving space; A cable pull shaft is rotatably mounted inside the housing, and a portion of the cable is wound around the cable pull shaft; A spiral spring, wherein both ends of the spiral spring are fixed to the inside of the housing and the pull wire shaft, respectively; A braking element, installed inside the housing, is configured to lock the cable pull shaft in a driven state to lock the cable, and to release the cable pull shaft in a non-driven state, wherein a spiral spring provides elastic force to the cable pull shaft to tension the cable.

4. The single-unit bidirectional drive device for flexible exoskeletons according to claim 3, characterized in that, The braking component is an electromagnetic brake.

5. The single-unit bidirectional drive device for a flexible exoskeleton according to claim 4, characterized in that, The electromagnetic brake is connected to the pull wire shaft via a flange; the electromagnetic brake is configured to lock the pull wire shaft in the driving state, and the electromagnetic brake is configured to release the pull wire shaft in the non-driving state.

6. The single-unit bidirectional drive device for flexible exoskeletons according to claim 3, characterized in that, The two ends of the pull wire shaft are mounted inside the housing via bearings.

7. The single-unit bidirectional drive device for a flexible exoskeleton according to claim 1, characterized in that, The single-machine bidirectional drive device also includes: A magnet, which is mounted on the end of the pull wire shaft; A magnetic encoder is mounted on the housing and is coaxial with the draw wire shaft. The magnetic encoder is configured to detect the angular displacement of the draw wire shaft.

8. The single-unit bidirectional drive device for a flexible exoskeleton according to claim 3, characterized in that, The outer shell is provided with drainage holes.

9. The single-unit bidirectional drive device for a flexible exoskeleton according to claim 2, characterized in that, The number of spring clutch modules is two, and the number of cables is two. One cable connects the bidirectional reel and one spring clutch module, and the other cable connects the bidirectional reel and another spring clutch module.

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