CN115348851A - Parallel elastic driver of power-assisted exoskeleton and control method thereof - Google Patents

Abstract

The driver (12) comprises a driving mechanism, a wire pulling mechanism and an elastic mechanism used for providing recovery force for the wire pulling mechanism to tighten a pull wire (4) in the wire pulling mechanism when the driving mechanism stops providing assistance, wherein the elastic mechanism and the driving mechanism are arranged at the input end of the wire pulling mechanism in parallel. The assistance provided by the driving mechanism and the recovery force provided by the elastic mechanism are flexibly transmitted to each actuating mechanism through the wire pulling mechanism, so that the separation design of the exoskeleton driving and the actuating mechanisms is realized, and the mechanisms such as a driver with large mass and the like which can be separated from the actuating mechanisms can be arranged at the waist and above the waist of a wearer, so that the system dead weight of the assistance exoskeleton is reduced, and the negative influence of the dead weight of the exoskeleton on the walking of the wearer is further reduced.

Description

Parallel elastic driver of power-assisted exoskeleton and control method thereof

Priority application

Chinese patent application CN 2020102424530, "an exoskeleton driver and driving state monitoring method", filed on 31/3/2020 and chinese patent application CN2021103293593, filed on 28/3/2021, priority of "parallel elastic driving device, series and parallel elastic driving device and exoskeleton", both of which are incorporated by reference in their entirety.

Technical Field

The invention relates to the technical field of exoskeleton power assisting devices, in particular to a parallel elastic driver of a power assisting exoskeleton, a series-parallel elastic driver, a control method of the driver and the power assisting exoskeleton with the driver.

Background

The power-assisted exoskeleton is a novel modern wearable device, integrates various information, control systems and sensing systems, provides a corresponding control function for a wearer of the power-assisted exoskeleton, and can assist the wearer to finish various tasks (such as bearing, carrying and the like) more efficiently.

Currently, the driving methods of exoskeleton assistance include hydraulic assistance, motor assistance and the like. Wherein, the motor helping hand technique adopts the most commonly used drive mode at present. However, most of the existing motor driving methods are to directly install the driving motor at the actuator that needs power assistance, for example, when power assistance is performed on the lower limb joints of the wearer, the driving mechanism is often installed at the leg corresponding power assistance joint mechanism, which inevitably causes the exoskeleton device to increase the swing inertia of the legs of the wearer (even a micro motor), so that the wearer needs more power to overcome the increase of the leg inertia during walking, so as to generate the same movement acceleration as that generated when the exoskeleton is not worn. For such reasons, not only can such exoskeletons in the prior art not provide significant assistance to the wearer during walking, but they may also cause the wearer to feel that the device is heavy, limiting their freedom of movement, i.e., reducing the wearer's user experience.

On the other hand, in most application scenarios, it is necessary to assist a plurality of joints of a wearer, and therefore, if an existing motor driving manner is adopted, when assistance is required to be performed on a plurality of joints (for example, knee joints and ankle joints) of a lower limb, an individual motor is often required to be installed for each joint, which further increases the weight of the exoskeleton, and thus affects the walking gait of the wearer, that is, further reduces the user experience of the wearer.

Disclosure of Invention

The invention aims to provide a parallel elastic driver of an assistance exoskeleton and a control method thereof, which partially solve or alleviate the defects in the prior art, realize the separation of a driving mechanism and an executing mechanism, and simultaneously reduce the system self-weight of the assistance exoskeleton, thereby reducing the negative influence of the self-weight of the exoskeleton on the walking gait of a wearer.

In order to solve the above mentioned technical problems, the present invention specifically adopts the following technical solutions:

in a first aspect the present invention provides a parallel elastic drive for a powered exoskeleton comprising: the elastic mechanism and the driving mechanism are arranged at the input end of the wire pulling mechanism in parallel.

In some exemplary embodiments, the driving mechanism includes: an electric motor.

In some exemplary embodiments, the wire pulling mechanism comprises: the pull wire is used for transmitting the assistance force, and the winch is used for winding the pull wire, wherein the winch is synchronously connected with the motor in a rotating mode, the fixed end of the pull wire is fixed on the winch, and at least one force output end of the pull wire is connected with the at least one executing mechanism.

In some exemplary embodiments, the parallel spring driver further comprises: the clutch locking mechanism is arranged between two adjacent actuating mechanisms and is respectively connected with the two actuating mechanisms through pull wires in the wire pulling mechanism; when the assisted joint of the wearer is in a straightened state or a state close to the straightened state, the clutch locking mechanism is in a meshed state, so that the assistance output by the driving mechanism is transmitted to the two executing mechanisms connected with the clutch locking mechanism through the wire pulling mechanism; and when the assisted joint is in a bending state, the clutch locking mechanism is in an unengaged state, so that the assistance output by the driving mechanism is transmitted to the executing mechanism close to the driving mechanism through the wire pulling mechanism.

In some exemplary embodiments, the elastic mechanism includes: the elastic energy storage component is arranged on the wire pulling mechanism, and when the power mechanism provides assistance for the wire pulling mechanism, the elastic energy storage component stores energy; when the power mechanism stops providing the assisting force for the wire pulling mechanism, the elastic energy storage component releases energy to provide the recovery force for the wire pulling mechanism.

In some exemplary embodiments, the elastic energy storage component is a coil spring, an outer ear of the coil spring is fixed on the wire pulling mechanism, and an inner ear of the coil spring is fixed on a rotating shaft of the coil spring.

In some exemplary embodiments, the pull wires in the wire pulling mechanism are divided into three branches by three wire pulling channels in the power-assisted exoskeleton, wherein two branches are symmetrically arranged at the left side and the right side of the corresponding power-assisted joint mechanism in the power-assisted exoskeleton, and the other branch is arranged right in front of or right behind the power-assisted joint mechanism.

In some exemplary embodiments, the pull wires in the pull wire mechanism are divided into two branches by two pull wire channels in the power-assisted exoskeleton, and the two branches are symmetrically arranged at the left side and the right side of the corresponding power-assisted joint mechanism in the power-assisted exoskeleton.

In a second aspect, the present invention provides a parallel elastic drive without motion damping in a powered exoskeleton, comprising: the device comprises a driving mechanism for providing assistance, a wire pulling mechanism for transmitting the assistance to at least one executing mechanism in the assistance exoskeleton, an elastic mechanism for providing recovery force to the wire pulling mechanism to tighten a wire pulling mechanism when the driving mechanism stops providing the assistance, and a centrifugal clutch, wherein the driving mechanism and the elastic mechanism are connected in parallel at the input end of the wire pulling mechanism, the centrifugal clutch is arranged between the driving mechanism and the wire pulling mechanism, the centrifugal clutch connects the driving mechanism and the wire pulling mechanism when the driving mechanism provides the assistance, the centrifugal clutch disconnects the driving mechanism and the wire pulling mechanism when the driving mechanism stops providing the assistance, and the elastic mechanism provides the recovery force to the wire pulling mechanism. Wherein the drive mechanism comprises a motor.

In some exemplary embodiments, the centrifugal clutch includes: the wire pulling mechanism comprises at least one pawl, at least one elastic resetting piece, a pawl seat and a ratchet wheel, wherein the pawl seat is synchronously and rotationally connected with the motor, the ratchet wheel is synchronously and rotationally connected with a winch in the wire pulling mechanism, the at least one pawl is uniformly distributed on the pawl seat in a manner of rotating relative to the pawl seat, a first end of the elastic resetting piece is fixed on the pawl seat, and a second end of the elastic resetting piece is connected with the pawl; when the motor provides assistance, the motor drives the pawl seat to synchronously rotate, so that the pawl is expanded outwards along the direction away from the central shaft of the pawl seat under the action of centrifugal force and is gradually meshed with the ratchet wheel, and the motor is connected with the wire drawing mechanism; when the motor stops assisting power, the pawls are gathered along the direction close to the central shaft of the pawl seat under the action of the elastic resetting piece and gradually separated from the ratchet wheel, so that the connection between the motor and the wire drawing mechanism is disconnected.

In some exemplary embodiments, the centrifugal clutch further comprises: a synchronous gear arranged in the center of the pawl seat, and correspondingly, an incomplete gear which can be meshed with the synchronous gear is arranged on one side of each pawl corresponding to the synchronous gear; and when the pawls rotate around the rotating shaft, at least one pawl rotates synchronously.

In some exemplary embodiments, the centrifugal clutch further comprises: the pawl limiting block is arranged on the pawl seat and used for limiting the maximum angle of the pawl rotating in the direction far away from the center of the pawl seat.

In a third aspect of the present invention, there is provided a series-parallel elastic driver for a power-assisted exoskeleton, comprising: a drive mechanism for providing assistance; a cable pull mechanism for transmitting the assistance force to at least one actuator of the assistance exoskeleton; the elastic mechanism is used for providing recovery force for the wire pulling mechanism when the driving mechanism stops providing the assistance force; the driving mechanism and the elastic mechanism are connected in parallel at the input end of the wire pulling mechanism, a centrifugal clutch is arranged between the driving mechanism and the wire pulling mechanism, and the elastic buffer component is connected in series at the input end/output end of the wire pulling mechanism; when the driving mechanism provides boosting force, the centrifugal clutch is engaged to connect the driving mechanism with the wire pulling mechanism, and the elastic buffer component is used for relieving impact force caused by the engagement moment of the centrifugal clutch; when the driving mechanism stops providing the assisting force, the centrifugal clutch disconnects the driving mechanism from the wire pulling mechanism, and the elastic mechanism provides the recovery force for the wire pulling mechanism.

In a fourth aspect, the present invention provides a power assisted exoskeleton comprising at least one actuator, and a driver as described above, wherein an output of the driver is coupled to an input of the at least one actuator.

In a fifth aspect, the present invention provides a method for controlling a driver of a power-assisted exoskeleton, wherein the driver is any one of the drivers described above, and accordingly, the method specifically includes the steps of: acquiring and identifying the current working state of the driver, wherein the working state comprises the following steps: preparing and assisting power;

if the working state of the driver is identified as preparation, acquiring the current joint extension angular speed and joint bending angle of a power-assisted joint mechanism in the power-assisted exoskeleton;

judging whether the power-assisted joint mechanism needs power assistance according to the joint extension angular speed, the joint bending angle, a preset extension threshold angle and a failure threshold angle;

if the assistance is needed, the current working state of the driver is set to be the assistance state from the preparation state, and the output torque of the driver is set to be a preset threshold T _ref 。

In some exemplary embodiments, the control method further includes the steps of:

if the working state of the driver is recognized as assistance, acquiring the current knee joint bending angle, knee joint extension angular velocity or knee joint bending angular velocity of the assistance joint mechanism;

judging whether assistance needs to be cancelled currently or not according to the knee joint bending angle and a preset failure threshold angle, or the knee joint extension angular velocity and a preset maximum extension angular velocity, or the knee joint bending angular velocity and a preset bending threshold angular velocity, if so, setting the current working state of the driver from an assistance state to a follow-up state, and setting the output torque of the driver to 0.

In some exemplary embodiments, the operating state of the driver further comprises: carrying out follow-up; correspondingly, the control method further comprises the following steps:

if the working state of the driver is identified as follow-up, acquiring the current joint bending angle and joint bending angular speed of the power-assisted joint mechanism;

and judging whether assistance needs to be prepared currently or not according to the joint bending angle and the joint bending angular velocity as well as a preset assistance threshold angle and a preset bending threshold angular velocity, if so, setting the current working state of the driver from a follow-up state to a preparation state, and setting the output torque of the driver to 0.

The technical scheme of the invention is that the exoskeleton rigid actuating mechanism is provided with the elastic drivers which are connected in parallel and combined with the steel wire pipe flexible transmission mechanism and the joint part. The wire reel fixing device comprises a motor, a wire reel, a wire pipe fixing seat and a steel wire, wherein the wire reel is fixedly installed at the output end of the motor, the wire pipe fixing seat is fixedly installed on a peripheral shell of the motor, the end of the steel wire is arranged in a wire end installing groove formed in the wire reel, a coil spring is installed inside the wire reel, the outer ear of the coil spring is arranged in the outer ear installing groove of the wire reel, and the central inner ear of the coil spring is fixed with the peripheral shell of the motor through a straight groove formed in a central shaft end cover.

As the preferred technical scheme, the spool fixing base includes the spool fixing body, set up the spool through-hole on the spool fixing body, the spool fixing body with the one side that the motor contacted sets up the spool fixed wall, the steel wire capstan winch passes through the spool through-hole is installed the output of motor, spool fixed wall downside is provided with the steel wire outlet groove, the central axis end cover with the cooperation of spool fixed wall is sealed, is used for the protection the steel wire capstan winch.

According to a preferable technical scheme, the steel wire winch comprises a steel wire winch body, wherein a mounting hole is formed in the middle of the steel wire winch body, the steel wire winch body is connected with the output end of the motor through the mounting hole, a steel wire winch wall is arranged on one surface of the steel wire winch body, and a steel wire end mounting groove for mounting a steel wire end and an external ear mounting groove for mounting external ears of the coil spring are formed in the steel wire winch wall;

the steel wire capstan is characterized by further comprising a coil spring end cover, wherein the coil spring end cover is matched and sealed with the wall of the steel wire capstan and used for protecting the coil spring.

According to the preferable technical scheme, the upper end of the steel wire winch wall is provided with a plurality of threaded holes, the end cover of the coil spring is correspondingly provided with a plurality of end cover mounting holes, and a plurality of bolts penetrate through the mounting holes to be matched with the threaded holes so as to fixedly mount the end cover of the coil spring on the steel wire winch wall.

As a preferred technical scheme, a plurality of central shaft end cover installation grooves are periodically arranged on the line pipe fixing wall, and the central shaft end cover is matched with the installation grooves through a plurality of installation blocks on the central shaft end cover to seal and protect the steel wire winch.

As the preferred technical scheme, a steel wire pipe is installed corresponding to the steel wire outlet groove.

As the preferred technical scheme, the steel wire appearance groove is internally provided with a tightness fine adjustment knob.

The invention also provides a driving state detection method of the parallel elastic driver, which judges the driving state according to the following modes:

if the knee joint angle is larger than the assistance threshold angle and the knee joint bending angular velocity is larger than the bending threshold angular velocity, judging that the driving state is ready and the motor moment =0;

angular velocity if knee joint extension>Extension threshold angular velocity and knee joint angle>Judging the driving state to be power assistance if the threshold angle is invalid, and judging the motor torque = T _ref ；

If the knee joint angle < failure threshold angle or knee joint extension angular velocity > maximum extension angular velocity or knee joint bending angular velocity > bending threshold angular velocity, the driving state is judged to be follow-up, and the motor moment =0.

Further, after the driving state is judged, whether the user modifies the Tref or each threshold parameter is judged;

if yes, judging whether the system is abnormal or not after adjusting the relevant threshold value;

if not, directly judging whether the system is abnormal or not;

if the system is abnormal, restarting or alarming;

and if the system is not abnormal, continuously judging the driving state according to the mode.

One technical scheme of the invention is that the exoskeleton driver is characterized by comprising a motor and an elastic mechanism, wherein the motor and the elastic mechanism are connected with a first end of a steel wire in a parallel manner and apply tension to the steel wire; the second end of the steel wire is connected with the knee power-assisted joint mechanism through a steel wire pipe mechanism; in use, the exoskeleton drivers are mounted at and above the waist of the wearer.

Preferably, the elastic mechanism is a coil spring.

As a preferable technical scheme, the third end of the steel wire is connected with the ankle power-assisted joint mechanism through the steel wire pipe mechanism.

As a preferable technical solution, a clutch locking mechanism is arranged between the second end and the third end of the steel wire, and when the knee joint of the wearer is in an upright state or close to the upright state in use, the clutch locking mechanism is in an engaged state, so that the pulling force applied by the exoskeleton driver is transmitted to the ankle power-assisted joint mechanism; when the knee joint of the wearer is in a bending state, the clutch locking mechanism is in a separation state, and the transmission of the pulling force applied by the exoskeleton driver to the ankle power-assisted joint mechanism is cut off.

Preferably, the second end of the steel wire passes through the knee joint power-assisted mechanism through at least three steel wire passages located in the knee joint power-assisted mechanism, and the at least three steel wire passages include a left rotating shaft located on the left side of the knee joint of the wearer, a right rotating shaft located on the right side of the knee joint of the wearer, and a front steel wire sliding groove located on the front side of the knee joint of the wearer.

According to the preferable technical scheme, the steel wire is wound on the power-assisted joint pulley of the knee power-assisted joint mechanism for multiple times through the movable pulley mechanism so as to change the transmission ratio of the steel wire from the exoskeleton driver to the knee power-assisted joint mechanism, and the power-assisted torque amplification of the knee power-assisted joint mechanism is realized.

The invention has the beneficial effects that:

according to the invention, the input end of the wire pulling mechanism is provided with the driving mechanism and the elastic mechanism in parallel, so that the assistance provided by the driving mechanism and/or the recovery force provided by the elastic mechanism can be transmitted to at least one executing mechanism through the wire pulling mechanism, and the separation of the driver and the executing mechanism in the assistance exoskeleton is realized, so that the driving mechanism with certain weight, such as a winch and a battery control system in the wire pulling mechanism, can be arranged at the waist of a wearer or above the waist, and the problems that in the prior art, the driving motor is directly arranged on the executing mechanism, so that the wearer feels heavy, and even the freedom of movement of the wearer is limited are avoided; in addition, the invention realizes that one driver drives a plurality of actuating mechanisms, and avoids the negative influence of the walking gait of a wearer caused by the increase of the dead weight of the power-assisted exoskeleton system due to the installation of one driving mechanism for each actuating mechanism in the prior art, namely the parallel elastic driver has simpler structure, reduces the system self of the power-assisted exoskeleton, lightens the negative influence of the dead weight of the exoskeleton device on the walking gait of the lower limbs of the wearer, and further improves the user experience of the wearer.

In another aspect, the present invention provides an elastic mechanism connected in parallel with the driving mechanism at the input end of the wire pulling mechanism, such that when the driving mechanism is operated (i.e. providing the assisting force), the driving mechanism (e.g. motor) and the elastic mechanism (e.g. coil spring) simultaneously pull the wire (e.g. steel wire or braided belt) of the wire pulling mechanism to transmit the assisting force to each actuator (e.g. knee assisting joint mechanism, ankle assisting joint mechanism) of the assisting exoskeleton; when the driving mechanism stops working (i.e. stopping providing the assisting power, such as the battery is exhausted or the motor is stopped intentionally), the elastic mechanism provides a recovery force to the pull wire to tighten the pull wire, i.e. under the action of the elastic mechanism, even if a wearer wears the assisting exoskeleton during movement, the pull wire in the pull wire mechanism is always in a tight state, so that the phenomenon that the pull wires at the winch (or the wire twisting disc) are mutually wound to cause mechanical failure and even the risk of safety accidents due to the fact that the pull wires are in a free and loose state is avoided.

In addition, the invention can transmit the assistance generated by the exoskeleton driver to a plurality of actuating mechanisms (such as a knee assistance joint mechanism and an ankle assistance joint mechanism) in the exoskeleton through the wire tube mechanism, thereby realizing that one driving mechanism can assist a plurality of positions: for example, when the curvature of the thigh and knee joint of the wearer is large (for example, when the wearer is on a step), the assisting force generated by the exoskeleton driver mainly acts on the knee assisting joint mechanism (at this time, the assisting force demand of the knee joint is large, and the assisting force demand of the ankle joint is small), but as the thigh and knee joint gradually return to be upright (the assisting force demand of the knee joint is reduced, and the assisting force demand of the ankle joint is increased), the assisting force generated by the exoskeleton driver gradually moves downwards from the knee joint to the ankle joint, and the assisting force provided for the ankle joint gradually increases.

Furthermore, the clutch locking mechanism is arranged between two adjacent actuating mechanisms and is connected with the two actuating mechanisms through the pull wire, so that the assisting force can be better distributed between the two actuating mechanisms, and the assisting force efficiency of the driver is improved. For example, a clutch locking mechanism is additionally arranged between the knee-assisted joint mechanism and the ankle-assisted joint mechanism, when the knee joint is bent to a large degree, the clutch locking mechanism can be enabled to enter a separation state (or an unlocking state or an unengaged state), the pull-wire mechanism is enabled to stop pulling force to transmit assistance force to the ankle-assisted joint mechanism (namely, an execution mechanism far away from a driver), and therefore assistance force generated by the exoskeleton driver is concentrated at the knee-assisted joint mechanism to help a wearer to go up steps and climb slopes; when the bending degree of the knee joint is reduced to a certain angle, the clutch locking mechanism enters a joint state (or a locking state or a meshing state) again, so that the wire pulling mechanism can not only transmit power to the knee power-assisted joint mechanism, but also transmit power to the ankle power-assisted joint mechanism, and the power of the knee joint and the ankle joint is realized. In other words, by adding the clutch mechanism, the assistance can be better distributed between the knee joint and the ankle joint, and the efficiency of the exoskeleton driver for providing assistance to the lower limbs is improved.

According to the parallel driver without motion damping, the centrifugal clutch is arranged between the driving mechanism and the wire pulling mechanism, when the driving mechanism provides power assistance, the driving mechanism is connected with the wire pulling mechanism through the centrifugal clutch, and when the driving mechanism stops providing the power assistance, the connection between the driving mechanism and the wire pulling mechanism is disconnected through the centrifugal clutch, so that the problem that when the driving mechanism stops providing the power assistance, the driving mechanism is converted into a damping piece, and a wearer feels continuous motion damping when wearing the power-assisted exoskeleton (and does not provide the power assistance) is solved, and the smoothness of free motion of the corresponding joint of the wearer is further ensured when the power assistance is not needed.

According to the series-parallel driver, the elastic buffer component is connected in series with the input end/output end of the pull wire mechanism to relieve the impact force caused by the centrifugal clutch engagement moment, so that the change trend of the assisting force strength of the limbs of a wearer is smoother, and the impact abrasion of a pawl when the centrifugal clutch is engaged is relieved.

Drawings

In order to more clearly illustrate the detailed description of the invention or the technical solutions in the prior art, the drawings that are needed in the detailed description of the invention or the prior art will be briefly described below. Throughout the drawings, like elements or portions are generally identified by like reference numerals. In the drawings, elements or portions are not necessarily drawn to scale.

FIG. 1a is an exploded view of a parallel spring driver from a first perspective in an exemplary embodiment of the invention;

FIG. 1b is an exploded view of a parallel spring driver from a second perspective in an exemplary embodiment of the invention;

FIG. 2a is a perspective view of a parallel spring driver in an exemplary embodiment of the invention;

FIG. 2b is a schematic view of the installation of the spring mechanism and the wire pulling mechanism reflecting the parallel spring driver in an exemplary embodiment of the invention;

FIG. 3 is a perspective view of a conduit fixing base of the parallel elastic actuator according to an exemplary embodiment of the present invention;

FIG. 4 is a perspective view of a capstan in a parallel spring driver according to an exemplary embodiment of the present invention;

fig. 5a is a schematic diagram of the structural layout of an exoskeleton when worn, in an exemplary embodiment of the invention;

fig. 5b is a schematic diagram of the structural layout of the exoskeleton when worn, in an exemplary embodiment of the invention;

fig. 5c is a schematic diagram of the structural layout of an exoskeleton when worn in another exemplary embodiment of the invention;

fig. 5d is a schematic diagram of the exoskeleton when worn in yet another exemplary embodiment of the invention;

FIG. 5e is a schematic view of the outer skeletal knee joint structure of FIG. 5 d;

FIG. 5f is a schematic view of the outer skeletal knee joint structure of FIG. 5 d;

FIG. 5g is a schematic diagram of a clutch locking mechanism of a parallel spring driver in an unengaged state in accordance with an exemplary embodiment of the present invention;

FIG. 5h is a schematic diagram of a clutch locking mechanism of the parallel flexible driver in an engaged state according to an exemplary embodiment of the present invention;

FIG. 5i is an exploded view of the clutch locking mechanism in the parallel elastomeric drive in an exemplary embodiment of the invention;

FIG. 5j is a cross-sectional view of the clutch locking mechanism of the parallel spring actuator of FIG. 5 i;

FIG. 6 is a schematic diagram of the driving state detection method of the parallel elastic driver according to the present invention;

FIG. 7 is a flow chart of a method for detecting a driving state of a parallel elastic driver according to the present invention;

FIG. 8a is a driving schematic diagram reflecting the direct connection of the motor to the wire pulling mechanism;

FIG. 8b is a schematic view showing the driving of the series elastomeric dampers between the wire pulling mechanism and the actuator;

FIG. 8c is a schematic diagram of the actuation of a parallel spring driver in an exemplary embodiment reflecting the invention;

FIG. 8d is a driving schematic of a parallel spring driver reflecting no resistance to motion in an exemplary embodiment of the invention;

FIG. 8e is a driving schematic of a series-parallel elastic driver reflecting no resistance to motion in an exemplary embodiment of the invention;

FIG. 9a is a perspective view of a parallel spring driver without resistance to movement in accordance with an exemplary embodiment of the present invention;

FIG. 9b is a partial cross-sectional view of the parallel spring driver of FIG. 9 a;

FIG. 9c is a schematic diagram of the structure of the centrifugal clutch in the parallel spring driver without motion resistance in an unengaged state according to an exemplary embodiment of the present invention;

FIG. 9d is a schematic diagram of the configuration of the centrifugal clutch in the parallel spring driver without motion resistance in an engaged state according to an exemplary embodiment of the present invention;

FIG. 9e is a schematic diagram of an embodiment of a centrifugal clutch in a parallel spring actuator without kinetic resistance according to another exemplary embodiment of the present invention;

fig. 10 is a schematic structural diagram of a series-parallel elastic driver without motion resistance according to an exemplary embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without inventive step based on the embodiments of the present invention, are within the scope of protection of the present invention.

It should be noted that all the directional indicators (such as up, down, left, right, front, back, 8230; \8230;) in the embodiments of the present invention are only used to explain the relative position relationship between the components, the motion situation, etc. in a specific posture (as shown in the figure), and if the specific posture is changed, the directional indicator is changed accordingly.

In addition, the descriptions related to "first", "second", etc. in the present invention are only for descriptive purposes and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

The term is defined as:

"drive mechanism": in this context, a drive mechanism refers to a mechanism, such as an electric motor, capable of providing assistance to at least one actuator in an assisted exoskeleton.

The 'elastic power mechanism': in this context, an elastic power mechanism refers to a spring mechanism, such as a coil/spring, that provides a recovery force to a pull-wire mechanism that delivers an assist force to the assisted exoskeleton when the drive mechanism stops providing the assist force, to tighten the pull-wire in the pull-wire mechanism.

An "actuator": in this context, an actuator means a mechanism which performs a corresponding action or performs a corresponding function upon actuation of a drive mechanism, for example, a mechanism for assisting a wearer's joint and which moves upon actuation of a drive mechanism, in particular, such as a knee joint, an ankle joint, a hip joint, etc. in an assisted exoskeleton device.

"parallel": herein, parallel connection means that the force (e.g., boosting or recovering force) output ends of the driving mechanism and the elastic mechanism are connected with the input end of the wire pulling mechanism so as to provide certain acting force (e.g., boosting or recovering force) to the wire pulling mechanism. For example, a motor and a coil spring as an elastic mechanism are synchronously and rotationally connected with a winch for winding a stay wire, when the motor works, the motor and the coil spring simultaneously pull the stay wire to apply assistance to a knee-assisted joint mechanism and an ankle-assisted joint mechanism; when the motor stops working (such as the battery is exhausted or the motor stops working intentionally), the coil spring can still pull the pull wire, so that the pull wire is always in a tight state in the operation of the exoskeleton mechanism, the risk of mechanical failure caused by the mutual winding of the pull wires at the winch due to the fact that the pull wires are in a free loose state is prevented, and the occurrence probability of safety accidents is greatly reduced.

A stay wire: herein, a pull wire refers to various mechanisms for transmitting an assisting/pulling force, such as a wire or a tube-like steel wire, a rope, or a braided ribbon in a wire-like, or a belt-like or a strip-like shape, and the like.

The 'line pipe': in this context, a conduit means a pipe wrapped or sleeved outside a pulling wire, which is fixed at both ends and is incompressible, and which provides a moving path for the pulling wire, thereby realizing the transmission of power/pulling force.

The 'input end': in this context, the input end refers to the end of the component which receives the force, also referred to as the force input end. For example, the wire pulling mechanism receives the end of the assisting force output by the driving mechanism, or receives one end of the recovery force generated/output by the elastic mechanism; or the executing mechanism receives the tail end of the assisting force transmitted by the wire pulling mechanism.

An output end: in this context, the output end refers to the end of the component that outputs the force, also referred to as the force output end. For example, the end of the wire pulling mechanism that is connected to the actuator outputs the assist force provided by the drive mechanism to the input end of the actuator (i.e., the end that receives the assist force).

The "initial state": in this context, the initial state refers to the current natural state of each component without any external force or interference. For example, the initial state of the motor refers to a state when the motor is not energized or is not rotating. For another example, the initial state of the centrifugal clutch is a state where the motor does not drive the pawl seat to rotate, and (i) the pawl does not expand outward under the action of the centrifugal force, or (ii) the pawl approaches the center of the pawl seat due to the action of the elastic restoring member (at this time, the elastic restoring member is in a factory pre-tightening force state), as shown in fig. 9c and 9d. For another example, the initial state of the elastic mechanism refers to a state in which the coil spring is not tightened by the capstan or the pull wire, and is not loosened by other external forces.

In order to ensure that the wires in the wire pulling mechanism are in a tight state (i.e. in a tightened state) even when no assistance is provided to the actuator, thereby avoiding the risk of mechanical failure due to the wires winding around each other as a result of the wires being in a free, relaxed state, the invention provides a parallel elastic actuator 12 comprising:

a drive mechanism for providing an assistance force,

a wire pulling mechanism for transmitting the assistance force provided by the drive mechanism to at least one actuator, an

An elastic mechanism for providing a recovery force to the wire pulling mechanism to tighten the wire pulling in the wire pulling mechanism when the driving mechanism stops providing the assist force, wherein,

the elastic mechanism and the driving mechanism are connected in parallel and arranged at the input end of the wire pulling mechanism (namely, the force output end of the elastic mechanism and the force output end of the driving mechanism are both connected with the force input end of the wire pulling mechanism).

In some embodiments, the drive mechanism comprises: a motor 1; such as a pseudo-direct drive torque motor.

In some embodiments, referring to fig. 2a and 2b, the wire pulling mechanism comprises: a pulling wire 4 for transmitting the output assistance force of the driving mechanism, and a winch 2 for winding the pulling wire 4, wherein the winch 2 is synchronously connected with the motor 1 in a rotating way (for example, the winch 2 is fixed on the output end 6 of the torque motor, see fig. 1a and 1 b), the fixed end of the pulling wire 4 is fixed on the winch 2 (for example, the fixed end 41 of the pulling wire 4 is arranged in the end mounting groove 201 on the winch 2), and the tail end (or the force output end) of the pulling wire 4 is connected with the actuating mechanism.

In some embodiments, referring to fig. 2a and 2b, the resilient mechanism comprises: the elastic energy storage component is arranged on the wire pulling mechanism; when the driving mechanism (such as a torque motor) provides assistance for the wire pulling mechanism, the elastic energy storage part stores energy; when the driving mechanism (such as a torque motor) stops providing the assistance force for the wire pulling mechanism, the elastic energy storage part releases energy to provide the recovery force for the wire pulling mechanism. Specifically, the elastic energy storage component may be a coil spring 5, an outer ear 501 of which is fixed on the wire pulling mechanism (for example, the outer ear 501 of the coil spring 5 is fixed in the outer ear installation groove 202 on the winch 2), an inner ear 502 of which is fixed on a rotating shaft of the coil spring 5 (for example, by providing a coil spring cover 7, and the coil spring cover 7 may be fixed on the spool fixing seat 3 in the wire pulling mechanism by a fixing member such as a bolt, and a side of which corresponding to the coil spring 5 is provided with a central shaft, which is a rotating shaft when the coil spring 5 is tightened or loosened, and the central shaft is provided with a straight groove 701 for fixing the inner ear 502 of the coil spring 5, see fig. 1 b).

In specific implementation, the direction of the coil spring 5 and the selection of an outlet of the winch 2 need to be consistent with the winding direction of the stay wire 4, so that when the driving mechanism provides assistance for the stay wire mechanism, the stay wire 4 is pulled out of the winch 2, the coil spring 5 is tightened, namely, the coil spring 5 stores energy; when the driving mechanism stops providing the assistance force, the coil spring 5 releases energy to provide a recovery force for the winch 2 in the wire pulling mechanism, so that the wire 4 can be automatically wound back on the winch 2 under the action of the coil spring 5 after the corresponding joint (namely the actuating mechanism) bends and stretches and is always in a tightened state (namely a tightened state) even if the driving mechanism is in a non-working state.

Of course, the installation position of the elastic mechanism can be adjusted according to actual needs, and can also be installed on the motor, and only the elastic mechanism needs to be connected with the motor in parallel, and the elastic mechanism can realize the following technical functions: when the drive mechanism is deactivated (i.e., the assist force is stopped; e.g., the battery is depleted or the motor is intentionally stopped), it can still pull on the cable, placing the cable in the cable pulling mechanism in a taut state (i.e., a tightened state) during operation of the exoskeleton mechanism, thereby preventing the cable (e.g., a wire or webbing) from being in a free, slack state.

The invention will now be further described with reference to specific embodiments and drawings attached to the specification.

Example 1: parallel elastic driver

Referring to fig. 1a to 4, an embodiment of the present invention provides a parallel elastic driver, which includes a motor 1, a steel wire winch 2, a wire tube fixing seat 3, and a steel wire 4; the wire reel 2 is fixedly installed at the output end 6 of the motor 1, the wire tube fixing seat 3 is fixedly installed on the peripheral shell of the motor 1, the end of the wire 4 is arranged at the wire end installing groove 201 formed in the wire reel 2, the coil spring 5 is installed inside the wire reel 2, the outer ear 501 of the coil spring 5 is arranged in the outer ear installing groove 202 of the wire reel 2, and the central inner ear 502 of the coil spring 5 is fixed with the peripheral shell of the motor 1 through a straight groove 701 in the rotating shaft arranged at the center of the central shaft end cover 7.

When the embodiment of the invention is implemented specifically, the wire reel 2 is fixed at the output end 6 of the motor 1, the wire tube fixing seat 3 is fixed on the outer shell at the periphery of the motor 1, the aluminum end of the wire 4 is arranged at the wire end mounting groove 201 on the wire reel 2, the coil spring 5 is arranged in the wire reel 2, the outer ear 501 of the coil spring 5 is arranged in the outer ear mounting groove 202 of the wire reel 2, and the central inner ear 502 of the coil spring 5 is fixed with the outer shell of the motor 1 through the straight groove 701 on the central shaft end cover 7. The end cap of the coil spring 5 is assembled with the wire reel 2, both as an outer cover for the coil spring 5 and as an outer wall of the wire groove.

Before use, the steel wire 4 needs to be wound on the steel wire winch 2 for a plurality of circles, so that when the power-assisted joint mechanism (or the assisted joint of a wearer) bends, enough redundant steel wire of the driver can be pulled out. It should be noted that the direction of the coil spring 5 and the selection of the capstan outlet need to be consistent with the winding direction of the wire 4, and when the wire 4 is pulled out of the wire capstan 2, the coil spring 5 tightens the accumulated energy. Thus, even if the motor 1 is in a non-working state, the steel wire 4 can be automatically wound back on the steel wire winch 2 under the action of the coil spring 5 after the joint is bent and stretched, and is always in a tight state.

Referring to fig. 5a, in order to fully utilize the unidirectional power assistance requirement of the lower limb joint of the wearer (carrying the load 11), the exoskeleton actuator 12 can adopt a pseudo-direct-drive torque motor (a planetary gear reducer with a reduction ratio of 6. The driver, the winch, the battery, the control system and the like with large mass are arranged above the waist of a wearer, so that the system dead weight of the exoskeleton at the position of the limb is reduced. Specifically, the parallel elastic driver 12 is mounted on the waist and abdomen, and the wire is connected to the knee joint wire assist mechanism 15 (i.e., actuator) through the wire tube transmission mechanism.

In addition, the technical scheme can also efficiently transmit the torque of the exoskeleton driver to the exoskeleton joint with the rigid actuating mechanism through the steel wire tube flexible transmission mechanism. The spool pulleys and the binding devices of the rigid mechanism further convert the torque of the exoskeleton driver into the torque of the exoskeleton joint mechanism (such as a knee-assisted joint mechanism and an ankle-assisted joint mechanism) and efficiently act on the adjacent limb of the corresponding joint of the wearer, so that efficient assistance is realized. In addition, the power assisting of more than two exoskeleton joint mechanisms (for example, two knee power-assisted joint mechanisms and two ankle power-assisted joint mechanisms of two legs) driven by a single motor can be realized through the technical scheme.

In some embodiments, please continue to refer to fig. 3, the spool fixing base 3 includes a spool fixing body 301, a spool through hole 302 is formed in the spool fixing body 301, the spool body 301 and one surface of the motor 1 contacting with the spool fixing wall 303 are disposed, the wire capstan 2 is installed at the output end of the motor 1 through the spool through hole 302, a wire outlet groove 304 is disposed on the lower side of the spool fixing wall 303, and the central shaft end cover 7 is matched with the spool fixing wall 303 for sealing, so as to protect the wire capstan 2.

In some embodiments, with continued reference to fig. 4, the wire winch 2 includes a wire winch body 203, three mounting holes 204 are formed on the wire winch body 203 near the middle, the wire winch body 203 is connected to the output end 6 of the motor 1 through the mounting holes 204, a wire winch wall 205 is disposed on one surface of the wire winch body 203 (i.e., the wire winch wall 205 encloses a space for placing the coil spring 5), and a wire end mounting groove 201 for mounting the wire end and an external ear mounting groove 202 for mounting an external ear 501 of the coil spring 5 are mounted on the wire winch wall 205;

in some embodiments, a coil spring end cap 8 may also be included, the coil spring end cap 8 cooperating with the wire capstan wall 205 to close for protecting the coil spring 5.

In some embodiments, a plurality of threaded holes 206 are formed in the upper end of the wire winch wall 205, a plurality of end cover mounting holes 9 are correspondingly formed in the coil spring end cover 8, and a plurality of bolts penetrate through the plurality of end cover mounting holes 9 to be matched with the plurality of threaded holes 206 so as to fixedly mount the coil spring end cover 8 on the wire winch wall 205.

In some embodiments, a plurality of central shaft end cover installation grooves 307 are periodically arranged on the conduit fixing wall 303, and the central shaft end cover 7 is matched with the central shaft end cover installation grooves 307 through a plurality of installation feet 10 on the central shaft end cover 7 to close and protect the wire winch 2.

In some embodiments, a wire tube 305 is installed corresponding to the wire outlet groove 304.

In some embodiments, a slack adjustment knob 306 is disposed within the wire presentation groove 304.

Referring to fig. 5b and 5d, in some embodiments of the present invention, the exoskeleton lower limb assisting mechanism comprises a driving mechanism, a thigh support 31, a shank support 36 (including a shank upper support 3601 and a shank lower support 3602), the thigh support 31 and the shank support 36 are rotatably connected via a knee joint rotating shaft 21, the shank lower support is rotatably connected via an ankle joint rotating shaft 29 to the exoskeleton shoe cover 28, and the thigh support 31 and the shank support 36 can be fixed on the leg of the wearer via a thigh tie 20 and a shank tie 22, respectively.

The exoskeleton drive mechanism, batteries, control circuitry, etc. can be placed on the waist (back side) of the wearer by means of waist straps 30, with the shunt elastic drivers located in the exoskeleton drive mechanism. Thigh wire pipe 305a one end is connected on exoskeleton actuating mechanism (the first end of steel wire promptly), the other end is downward along the thigh, stabilize on thigh support 31 through mechanisms such as thigh pipe end fixing base 32, behind rethread knee joint pivot 21 (the second end of steel wire promptly, can press the steel wire on knee joint pivot 21 through knee joint steel wire top cap 34, avoid the steel wire to shift), it is downward along the shank, mechanism such as end fixing base 35 through shank pipe 305b stabilizes on shank upper bracket 3601, fix the steel wire end on shoe cover cantilever 27 downwards again (the third end of steel wire promptly). Of course, if the exoskeleton driver only needs to provide assistance to the knee assisted joint mechanism (or the wearer's knee joint), the wire can be fixed after passing through the knee joint hinge 21, for example, at the upper portion of the lower leg support 3601, i.e., the third end where the wire is not present in this embodiment.

In some embodiments, a lower leg length adjustment mechanism 23 is also included on the lower leg support 36, and the length of the lower leg support 36 can be adjusted to accommodate wearers of different heights.

Further, referring to fig. 5c, in some embodiments, since the pull wire 4 can transmit the assisting force provided by the driving mechanism to at least one of the actuators, that is, the pull wire 4 has a plurality of force output ends (i.e., a plurality of ends 42 connected to the actuators), in order to better distribute the assisting force between the actuators and thus improve the assisting force efficiency, a clutch locking mechanism 37 can be further disposed between two adjacent actuators (e.g., two assisting joint mechanisms), and the clutch locking mechanism is respectively connected to the two actuators through the pull wire, and when the corresponding assisting joint mechanism (or the assisted joint of the wearer) in the assisting exoskeleton is in a straight state or a state close to the straight state, the clutch locking mechanism 37 is in an engaged state, so that the assisting force output by the driving mechanism is transmitted to the two actuators connected to the clutch locking mechanism 37 through the pull wire mechanism; when the assisted joint (or the assisted joint mechanism) is in a bending state, the clutch locking mechanism 37 is in an unengaged state, so that the assistance force output by the driving mechanism is transmitted to one of the two actuators which is close to the driving mechanism through the wire pulling mechanism (wherein, the one of the two actuators which is close to the driving mechanism refers to the one of the two actuators which is the shortest in wire pulling between the two actuators and the driving mechanism, or the one which is the closest to the driving mechanism based on the positional relationship among the wearer).

For example, the clutch locking mechanism 37 may be provided between the knee joint and the ankle joint so that the knee joint and the ankle joint constitute a joint, and/or the clutch locking mechanism 37 may be provided between the hip joint and the knee joint so that the hip joint and the knee joint constitute a joint.

In some embodiments, referring to fig. 5g and 5i, the clutch locking mechanism 37 comprises: the clutch locking base 371 is connected with the pull wires of the two actuating mechanisms and is provided with a pull wire sliding block 372 of a ratchet 372-1; a slide pawl 374 engageable with ratchet teeth on the wire pulling slider 372; and a clutch push rod 373 for pushing the slide pawl 374 to slide to engage with the wire block 372, wherein the clutch push rod 373 and the wire block 372 are both slidably mounted in the clutch lock base 371 up and down along the height direction of the clutch lock base 371, the slide pawl 374 is slidably mounted in the clutch lock base 371 left and right along the width direction of the clutch lock base 371, and in an initial state (i.e. no external force is applied to the clutch push rod 373), the slide pawl 374 is not engaged with the wire block 372, so that the wire block 372 can slide up and down along the height direction of the clutch lock base 371, and the assisting force provided by the driver is transmitted to the corresponding two actuators, see fig. 5g; when an external force F is applied to the clutch push rod 373, so that the clutch push rod 373 drives the sliding pawl 374 to move toward the cable pulling slider 372 and gradually engage with the cable pulling slider 372, the clutch locking mechanism 37 is in a locked state, so that the assisting force provided by the driver is only transmitted to one of the two actuators close to the driver, as shown in fig. 5h.

In some embodiments, referring to fig. 5j, corresponding wire end mounting slots 3720 may be respectively formed on both ends of the wire pulling slider 372 to mount the wire ends of the wires connected to the two actuators (e.g., the wire end 41a of the upper wire 4a close to the actuator of the actuator and the wire end 41b of the lower wire 4b far from the actuator of the actuator), so as to connect the two actuators, i.e., to connect both ends of the wire pulling slider 372 to the respective ends of the wires connected to the two actuators.

In some embodiments, the wire pulling slider 372 is installed on one side, for example, the right side, of the clutch locking base 371 in a manner of being slidable up and down with respect to the height direction of the clutch locking base 371. Specifically, referring to fig. 5j, a sliding block chute 3711 may be formed on the right side of the clutch lock base 371 along the height direction, and corresponding sliding block end covers 3711-1 may be disposed at the upper and lower ends of the sliding block chute 3711, and the sliding block end cover 3711-1 may be formed with a wire through hole 3711-2 through which the wire 4 may pass, and a wire pipe installation groove 3711-3 in which the end of the wire pipe 305 is installed, where of course, the height dimension of the sliding block chute 3711 is greater than the height dimension of the wire block 372, so as to provide a space for the wire block 372 to slide up and down.

In some embodiments, the sliding pawl 374 is slidably mounted to the other side, e.g., the left side, of the clutch lock base 371 in a left-right direction with respect to the width direction of the clutch lock base 371. Specifically, referring to fig. 5i and 5j, a pawl chute 3712 may be formed on the left side of the clutch lock base 371 along the width direction, and the rightmost end of the pawl chute 3712 is connected to the slider chute 3711; meanwhile, at least one second elastic restoring element 376 is provided at a position near the left side of the sliding catch 374 (specifically, at least one elastic restoring element mounting groove 3741 for mounting the second elastic restoring element 376 is provided in the sliding catch 374 in the width direction, a first mounting end cap 376-1 for sealing the catch sliding groove 3712 is provided at the notch of the catch sliding groove 3712, and a first guide post 376-2 for mounting the second elastic restoring element 376 is provided at a position corresponding to the second elastic element 376 on the first mounting end cap 376-1), and at least one limit bump 3740 is provided on the sliding catch 374.

In some embodiments, the clutch push rod 373 is also installed on the clutch lock base 371 in a manner of being able to slide up and down along the height direction of the clutch lock base 371. Specifically, a push rod chute 3713 may be formed on the clutch lock base 371 near the slider chute 3711, the push rod chute 3713 penetrates through the right side of the pawl chute 3712, a first elastic return element 375 may be mounted at the bottom of the push rod chute 3713 (specifically, a second guiding column 375-1 may be fixedly mounted at the bottom of the push rod chute 3713 to seal the bottom of the push rod chute 3713 while the first elastic return element 375 is mounted), and at least one protrusion chute 3730 for providing a moving path to the limit protrusion 3740 is disposed on the clutch push rod 373, as shown in fig. 5i and 5j.

When no external force is applied to the clutch push rod 373, the first elastic return element 375 (e.g., a spring) located at the bottom of the clutch push rod 373 and installed in the clutch lock base 371 tightly pushes the clutch push rod 373 upward, and at this time, the limit bump 3740 on the sliding pawl 374 is located at a first limit position (e.g., the leftmost side of the bump runner 3730, see fig. 5 g) of the moving path provided by the bump runner 3730 on the clutch push rod 373, so that the sliding pawl 374 is compressed at one side of the sliding pawl 374, and the second elastic return element 376 (e.g., a spring) installed in the clutch lock base 371 is located at an unlocking position in the clutch lock base 371, so that the sliding pawl 374 is separated from the wire slider 372, and the clutch lock device is in a release state. In this state, the wire pulling slider 372 can freely move up and down along the height direction of the clutch locking base 371, so that when the driver provides the assisting force, the wire pulling 4a at the upper end of the clutch locking base 371 transmits the assisting force provided by the driver to the wire pulling slider 372, and the wire pulling slider 372 transmits the assisting force to the wire pulling 4b at the lower end, thereby driving the wire pulling 4b at the lower end to move up and down, and further transmitting the assisting force to an actuating mechanism (such as an ankle assisting joint mechanism) connected with the wire pulling 4b at the lower end.

When an external force F is applied to the clutch push rod 373, so that the clutch push rod 373 compresses the first elastic reset element 375, the clutch push rod 373 slides down integrally, so that the bump sliding slot 3730 releases the limit bump 3740 on the sliding pawl 374 (for example, the limit bump 3740 slides rightward to a second limit position, such as the rightmost side, see fig. 5h, along the moving track of the bump sliding slot 3730), and at the same time, the sliding pawl 374 slides rightward to an engagement position under the action of the two second elastic reset elements 376, so that the pawl on the sliding pawl 374 is engaged with the ratchet teeth on the wire pulling slider 372, that is, the clutch locking mechanism is engaged/locked. When the clutch lock mechanism is engaged, the wire block 372 cannot move upward any more, i.e., the assisting force provided by the driving mechanism is transmitted only to the actuator to which the upper end wire 4a is connected (i.e., the actuator closer to the actuator), and is not transmitted to the actuator to which the lower end wire 4b is connected (i.e., the actuator farther from the actuator).

Further, referring to fig. 5h, the ratchet 372-1 of the wire pulling slider 372 is wedge-shaped, so that when the wire pulling slider 372 is pulled by the lower end wire 4b, the wedge surface of the ratchet 372-1 can still push and slide the sliding pawl 374 toward the first limit position, e.g., toward the left side, so that the wire pulling slider 372 can move toward the lower end wire 4 b.

Of course, in addition to applying the external force F to the clutch push rod 373, a solenoid valve may be used, for example, a battery valve is disposed above the clutch push rod 373, and at least one magnetic rod is embedded in the top of the clutch push rod 373, when the battery valve is powered on, the polarity of the battery valve is the same as that of the magnetic rod, so as to push the magnetic rod to move away from the lower end of the battery valve, and further push the clutch push rod 373 to slide downward, so that the sliding pawl moves to the locking position (or the second limiting position) and gradually engages with the wire pulling slider; when the battery valve is powered off, the clutch push rod moves upward under the action of the first elastic reset element, so that the sliding pawl 374 is driven to move to the unlocking position (or the first limit position), and the sliding pawl 374 is separated from the pawl on the wire pulling slide block 372, namely, the clutch locking mechanism 37 is in an unengaged state.

Specifically, referring to fig. 5c, in some embodiments of the present invention, the clutch locking mechanism is disposed on a pull wire between the knee joint assisting joint mechanism and the ankle joint assisting joint mechanism (hereinafter referred to as knee assisting joint mechanism and ankle assisting joint mechanism), specifically, a clutch locking mechanism 37 is further disposed between the second end (or the upper end pull wire 4 a) of the steel wire and the third end (or the lower end pull wire 4 b) of the steel wire, when the knee joint is bent to a large degree by the clutch locking mechanism, the clutch locking mechanism enters a disengaged state, and transmission of the pulling force to the ankle assisting joint mechanism is stopped, so that the assisting force generated by the exoskeleton driver is concentrated at the knee assisting joint mechanism, and the wearer is helped to go up steps and climb; and when the bending degree of the knee joint is reduced to a certain angle, the clutch locking mechanism enters a joint state again, the transmission of the pulling force to the ankle power-assisted joint mechanism is recovered, and the power assistance to the ankle joint is realized. In other words, by adding the clutch locking mechanism between the tail ends of the pull wires between two adjacent actuating mechanisms, the assistance can be better distributed between the knee joint and the ankle joint, and the efficiency of the exoskeleton driver for providing assistance to the lower limbs is improved.

Furthermore, in some embodiments, the pull wire of the pull wire mechanism can be divided into three branches by three pull wire channels of the power-assisted exoskeleton, wherein the two branches are symmetrically arranged at the left side and the right side of the corresponding power-assisted joint mechanism of the power-assisted exoskeleton, and the other branch is arranged right in front of or right behind the power-assisted joint mechanism. Of course, the pull line can be divided into two branches or more branches according to actual needs. Referring to fig. 5d to 5f, a knee joint assist mechanism will be described as an example.

Specifically, the knee joint assisting mechanism comprises at least three wire channels (i.e. stay wire channels), including a left rotating shaft 21a located on the left side of the knee joint of the wearer, a right rotating shaft 21b located on the right side of the knee joint of the wearer, and a knee joint wire sliding groove 38 located on the front side of the knee joint of the wearer. The steel wire (or the pull wire 4 such as a braided belt) is divided into three paths to pass through the three steel wires to pass through the knee joint, when the driver 12 pulls the steel wire, the steel wires passing through the left rotating shaft 21a and the right rotating shaft 21b can provide left-right balanced assistance for the knee joint of a wearer, and the steel wire passing through the front side of the knee joint can provide larger assistance for the rotation of the knee joint of the wearer. This is because the assisting force from the wires on the left and right rotation shafts is small in displacement generated when the knee joint rotates, and therefore can be small, and the assisting force can be large by the wire positioned in the knee joint wire sliding groove 38 on the front side of the wearer's knee joint because the displacement generated when the knee joint rotates is large. The size of helping hand (provided through the steel wire of knee joint front knee joint steel wire spout) and the equilibrium of helping hand (provided through knee joint left and right sides pivot steel wire) that such knee joint structure was synthesized and is considered can promote exoskeleton mechanism wearer's use and experience.

Referring to fig. 5e and 5f, in some embodiments of the present invention, the wire passage of the knee joint mechanism is disposed on the front surface of the knee joint (including the knee joint wire sliding groove 38), the left and right rotating shafts 21a and 21b of the knee joint mechanism adopt a gear mechanism, and the wire passage from the thigh support 31 to the knee joint wire sliding groove 38 to the shank support 36 can be covered by the cover 40 to prevent the wire from being displaced. The steel wire is coiled at the power-assisted joint pulley 39 of the knee power-assisted joint mechanism for multiple times through the movable pulley mechanism so as to change the transmission ratio of the steel wire from the exoskeleton driver to the knee power-assisted joint mechanism and realize power-assisted torque amplification at the knee power-assisted joint mechanism.

Example 2: driving state detection method of parallel elastic driver

Based on the parallel elastic driver, the invention further provides a driver control method of the power-assisted exoskeleton, wherein the driver is any one of the drivers, and specifically, the control method comprises the following steps:

acquiring and identifying the current working state of a driver; specifically, since the working state of the driver is controlled by the controller, the current working state type of the driver, specifically, the follow-up, or the preparation, or the assistance, can be directly acquired from the controller;

if the working state of the driver is identified as follow-up, acquiring the current joint bending angle and joint bending angular speed of the power-assisted joint mechanism; judging whether assistance needs to be prepared currently or not according to the joint bending angle and the joint bending angular speed as well as a preset assistance threshold angle and a preset bending threshold angular speed, and if so, setting the current working state of the driver from a follow-up state to a preparation state;

if the working state of the driver is identified as preparation, acquiring the current joint stretching angular speed and joint bending angle of the power-assisted joint mechanism, and judging whether the power-assisted joint mechanism needs power assistance according to the joint stretching angular speed, the joint bending angle, a preset stretching threshold angle and a failure threshold angle of the power-assisted joint mechanism; if the assistance is needed, the current working state of the driver is set to be the assistance state from the preparation state, and the output torque of the driver is set to be a preset threshold value Tref;

if the current working state of the driver is recognized as power assistance, acquiring the current knee joint bending angle, knee joint extension angular velocity or knee joint bending angular velocity of the power assistance joint mechanism; and judging whether assistance is required to be cancelled currently or not according to the knee joint bending angle and a preset failure threshold angle, or the knee joint extension angular velocity and a preset maximum extension angular velocity, or the knee joint bending angular velocity and a preset bending threshold angular velocity, if so, setting the current working state of the driver from the assistance state to a follow-up state, and setting the output torque of the driver to 0.

In some embodiments, the operating state of the motor in the drive is controlled by the controller, so that the current operating state can be retrieved directly from the controller's memory module and the specific type, e.g., follow-up, prime and boost, identified.

An embodiment of the present invention is a method for detecting a driving state of a parallel elastic driver, and please refer to fig. 6 and fig. 7, the driving state is determined in the following manner:

if the knee joint angle is larger than the assistance threshold angle and the knee joint bending angular velocity is larger than the bending threshold angular velocity, judging that the driving state is ready and the motor moment =0;

angular velocity if knee joint extension>Extension threshold angular velocity and knee joint angle>Judging the driving state to be power assistance if the threshold angle is invalid, and judging the motor torque = T _ref ；

If the knee joint angle < failure threshold angle or knee joint extension angular velocity > maximum extension angular velocity or knee joint bending angular velocity > bending threshold angular velocity, the driving state is judged to be follow-up, and the motor moment =0.

Further, after the driving state is judged, whether the user modifies the Tref or each threshold parameter is judged;

if yes, judging whether the system is abnormal or not after adjusting the relevant threshold value;

if not, directly judging whether the system is abnormal or not;

if the system is abnormal, restarting or alarming;

and if the system is not abnormal, continuously judging the driving state according to the mode.

When the detection method is specifically implemented, the detection method can be realized by installing a controller and monitoring the state of the motor. Referring to the flowchart, the motor is initialized before starting to make the motor state follow-up and the torque 0, the follow-up process gradually becomes preparation, then the power is assisted, and finally the follow-up process is returned.

More specifically, figure 7 is a simplified control scheme for a knee assisted exoskeleton mechanism, according to some embodiments of the present invention. The exoskeleton evaluates and judges the working state of the exoskeleton through an angle sensor (obtaining angular velocity and angular acceleration after difference) embedded in the torque motor and an armature current sensor (obtaining motor output torque after formula conversion). Simultaneously, the controller sets for the motor three kinds of operating condition, does respectively: follow-up, preparation and assistance.

The judgment variables of the control system include: knee joint angle (obtained by converting motor angle through system total transmission ratio), knee joint bending angular velocity (obtained by converting motor rotation angular velocity through system total transmission ratio, note that knee joint bending angular velocity and knee joint extension angular velocity are actually the same parameter, and the two are only opposite in movement direction, so in order to avoid the size comparison of plus and minus parameters when single parameter is represented in the flow chart of fig. 7, two values belonging to positive value and negative value representing motor rotation angular velocity are adopted). In addition, a power-assisted threshold angle, a failure threshold angle, a bending threshold angular velocity, an extension threshold angular velocity and a maximum extension angular velocity are set as judgment threshold parameters of the control system, T _ref Is the output torque set by the control system during the motor assistance.

The system working process is described as follows: after the system is started, advanced initialization operation is carried out, wherein the knee joint rotation angle is set to be 0 degree, the motor state is set to be follow-up, the motor torque is set to be 0Nm, and then the system enters a main cycle. The motor state is judged firstly in the main circulation:

in the 'follow-up' state, the motor moves arbitrarily along with the knee joint of the wearer, when the bending angle of the knee joint is larger than the set assistance threshold angle and the bending angular speed of the knee joint is larger than the set assistance threshold angular speed, the bending degree of the knee joint reaches the bending degree which is expected to be assisted by us, and the knee joint is still in the leg bending motion, therefore, the motor state is set as 'preparation', and the motor moment is set as 0Nm.

In the 'preparation' state, if the extension angular velocity of the knee joint is greater than the extension threshold angular velocity, the knee joint is converted from the bending motion to the extension motion at the moment, and the previous bending motion exceeds the set assistance threshold angle (so the 'preparation' state is entered), and as long as the bending angle of the knee joint is greater than the failure threshold angle at the moment, the state of the motor is set as the 'assistance', and the motor is enabled to output T _ref The assist torque of (2). The failure threshold angle is a set value which is larger than 0 degree and smaller than the assistance threshold angle, and the purpose is to cancel assistance in advance when the knee joint is close to the upright state, so that the situation that the knee joint of a wearer is not completely in the upright state (the knee joint angle is slightly larger than 0) in a walking gait, a motor is always in the assistance state, and the knee joint of the wearer is difficult to bend legs again to realize the next state is avoided.

Under the state of 'power assisting', the motor continuously outputs T to the knee joint _ref The torque of (c). At the moment, if the knee joint angle is smaller than the failure threshold angle, the knee joint of the wearer is close to be upright under the assistance effect, and the assistance of the motor is cancelled; if the knee joint extension angular velocity is greater than the maximum extension angular velocity, which indicates that the load of the knee joint may be light (or the exoskeleton is not properly worn on the knee joint of the wearer and is idle), the knee joint of the exoskeleton has rapidly reached the maximum extension angular velocity with the assistance of the motor. The condition indicates that the human-machine coupling system is likely to be inIn the light load state, no such large power assistance is required. And in order to avoid a state in which the knee joint is over-extended after reaching an upright state due to an excessively high extension speed, the "maximum extension angular speed" is set.

In addition, if the bending angular velocity of the knee joint is greater than the bending threshold angular velocity, it indicates that although the motor is assisting the wearer's knee joint to perform the stretching movement in this state, the knee joint is actually performing the bending movement, and the speed of the bending movement exceeds the bending threshold angular velocity, which indicates that it is likely that the wearer has changed the movement intention and wants to bend the leg further in this state. Under all three conditions, the motor state is reset to the "follow-up" state, and the motor torque is set to 0Nm. It should be noted that, if the motor state is reset to the "follow-up" state due to the knee joint bending motion occurring again in the power-assisted state, the system will determine whether the knee joint bending angle is still larger than the power-assisted threshold angle through the sentence in the follow-up state in the next cycle, and if so, the motor resets the non "ready" power-assisted state. Therefore, the wearer changes the movement intention after assistance again, continues to bend legs, and the motor can provide assistance for the knee joint when stretching for the next time from the assistance state to the follow-up state to the preparation state.

It should be noted that the "maximum extension angular velocity" is set to determine whether the system is in a light load state, and avoid the hyperextension motion caused by the too high extension velocity of the knee joint. However, the advanced control strategy can also obtain the load state of the system through the difference of angular velocity, namely the angular acceleration reaction, and dynamically adjust the T of the motor torque in each boosting process through the change of the load state _ref Size. Therefore, the maximum power-assisted torque of each gait can be dynamically changed by the system according to different load states, and the power-assisted strategy of the exoskeleton is more intelligent.

After the motor state is judged, the system can further judge whether the user changes the T through keyboard or remote control input _ref Or each threshold parameter, if yes, adjusting the corresponding value of each threshold parameter, otherwise, judging that the playing system is playingAfter working frequently, the next cycle is started.

If the system judges that the abnormality occurs, the system is restarted and then enters the working state again.

The technical scheme provided by the invention mainly aims to solve the technical problem that most of active power-assisted exoskeletons in the prior art are 'too rigid' or 'too flexible'. "too rigid" means that the hydraulic push rod or the speed reducing motor is directly placed at the joint. Although the layout can transmit the driving torque to the joints of the wearer efficiently, the swing inertia of the lower limbs of the wearer is increased seriously, the dynamic characteristics of the movement gait of the man-machine coupling system are deteriorated, and the exoskeleton can feel that the joints are helped when the exoskeleton is used, but the heaviness of the exoskeleton can cause more tiredness to the wearer. The 'too soft' means that the driver is completely placed above the waist, and the torque of the motor is converted into the steel wire tension to act on each joint of the wearer by adopting a flexible binding and steel wire driving mode on the lower limbs of the wearer in a large quantity. Although the swing inertia of the lower limbs of a wearer can be slightly influenced by the layout, the equivalent rigidity of the man-machine interaction interface is too low due to the over-soft binding, the output torque of the motor is converted into the binding deformation more, the sliding of the flexible binding on the limbs can be caused by the over-large pulling force, and the output peak value of the assisting force is further obviously limited. According to the technical scheme, the steel wire flexible transmission mechanism and the joint rigid actuating mechanism are combined, the knee joint assisting exoskeleton is rigid and flexible, and the advantages of reducing the swing inertia of limbs by the flexible exoskeleton and efficiently transmitting the rigid exoskeleton can be taken into consideration.

In addition, considering that the steel wire is a nonlinear element which can efficiently transmit the pulling force but cannot transmit the pushing force, the steel wire may be in a freely loosened state under the condition that the motor does not assist or work, and the state is not beneficial to the active exoskeleton to judge the current motion state of the joint, and the steel wire at the winding reel may be intertwined to cause mechanical failure. Therefore, the invention proposes a solution (i.e., "parallel elastic driver") proposed by the applicant to connect the drivers in parallel (fig. 8) with an elastic mechanism, and by adding an elastic element in the mechanism, the steel wire rope can be ensured to be tensioned by the elastic element at any time, thereby avoiding the problem of system uncertainty caused by the slackening of the steel wire. Compared with a driver without an elastic mechanism (when a motor does not work, the steel wires at the joint end and the winding reel end are in a loose state) or a driver series elastic mechanism scheme (when a series spring is added, the steel wires are divided into two independent wire segments, the system complexity is increased, a pressure spring is connected between the motor winding reel and a knee joint steel wire pulley in series, although the steel wires at the joint end can be always in a tensioned state, the steel wires at the winding reel end are still in a free loose state when the motor does not work), the driver parallel elastic mechanism scheme can enable the mechanism to always keep redundant steel wires tightly wound on the winding reel in a state that the motor does not assist or does not work, further avoid system uncertainty caused by flexible introduction of the steel wires, meanwhile, an executing mechanism of the exoskeleton is simplified as much as possible, further, the influence on swing inertia of lower limbs is reduced, the motion sensitivity of a man-machine system is improved, in addition, the steel wires are pulled after the torques of the elastic element and the motor are connected in parallel, and further the peak output torque of the driver is improved.

EXAMPLE 3 No motion damping parallel elastic drive based on centrifugal Clutch

As is well known, in the daily movement of a human body, except for the movement occasions that a small part of the joints are assisted by a large amount of assistance, the movement occasions that the assistance is not needed are also provided, for example, when the knee joints of the human body go up steps and squats deeply, the human body walks on a level road, the exoskeleton is not needed to perform obvious assistance, and the exoskeleton is not expected to bring large damping to the walking of a wearer. However, in the above embodiment, since the capstan 2 of the wire pulling mechanism is always connected to the output end 6 (e.g. the output disc of the torque motor) of the torque motor 1, i.e. the driving mechanism is directly connected to the capstan 2 of the wire pulling mechanism, when the assisting force is not needed, the wire will also carry the torque motor 1 to reciprocate, and at this time, since the torque motor 1 is not electrified, it is converted into a damping member. That is, the wearer's joints feel constant motion damping when not assisting in motion. While this motion damping may allow the drive mechanism, such as the motor, to reverse charging the battery, the wearer's motion experience while wearing the assistive exoskeleton is more negative, i.e., has a constant motion damping, thereby reducing the wearer's motion experience.

In view of the above, the present invention further provides a parallel elastic driver without motion damping in an assisted exoskeleton, which can avoid or alleviate the problem of motion damping caused by a driving mechanism (such as a torque motor) being driven by a winch in a cable pulling mechanism when the parallel elastic driver is not assisted by force.

The invention provides a parallel elastic driver without motion damping, which comprises: the connection relationship among the components in the parallel elastic driver, such as the driving mechanism, the wire pulling mechanism and the elastic mechanism, can refer to the connection relationship among the components in the parallel elastic driver, which is not described herein again, see fig. 9a and 9b; in a different way, the parallel elastic drive without motion damping further comprises: a centrifugal clutch 47 disposed between the wire drawing mechanism and the driving mechanism, and engaged when the driving mechanism (such as the torque motor 1) provides an assisting force, so as to connect the driving mechanism and the wire drawing mechanism (such as connecting the winch 2 of the wire drawing mechanism and the output end 6 of the torque motor 1 in a synchronous rotation manner); when the driving mechanism (such as the torque motor 1) stops providing the assistance, the centrifugal clutch 47 is released, so that the connection between the driving mechanism and the wire pulling mechanism is disconnected, and the motion damping caused by the fact that the driving mechanism is converted into a damping piece is avoided; meanwhile, the elastic mechanism provides recovery force for the wire pulling mechanism to tighten the pull wire 4 in the wire pulling mechanism, so that the risk of mechanical failure caused by mutual winding of the pull wires due to the fact that the pull wire 4 is in a free and loose state is avoided.

For example, when the torque motor 1 is not assisted (i.e. not powered and not rotating), the winch 2 in the wire pulling mechanism can freely pull out and retract the wire under the action of the coil spring 5 (i.e. elastic mechanism); moreover, since the centrifugal clutch 47 is not engaged (i.e. in a released state), i.e. the connection between the torque motor 1 and the winch 2 of the wire pulling mechanism is disconnected, the winch 2 is not affected by the damping of the motor, and accordingly, after the power-assisted exoskeleton is worn by a wearer, the wearer feels like wearing a passive power-assisted joint mechanism with an elastic energy storage element (e.g. a parallel spring), thereby greatly improving the user experience.

In some embodiments, the centrifugal clutch 47 includes: a ratchet seat 60, a ratchet wheel 208, at least one ratchet 59 and at least one elastic restoring member 58, wherein the ratchet wheel 208 is coaxially and rotationally connected with the winch 2 in the wire pulling mechanism (for example, the ratchet wheel 208 can be directly fixed on the winch 2, or a winch ratchet wheel can be obtained by directly providing a ratchet groove on the inner circumferential surface of the winch 2); the detent seat 60 is connected to the output end 6 of the torque motor 1 so as to rotate synchronously (for example, the detent seat 60 may be fixed to the output end of the torque motor 1 by a fixing member such as a screw); each resilient return member 58 is secured at a first end to the pawl holder 60 and at a second end to a pawl 59 (i.e., each resilient return member 58 corresponds to a pawl 59); the at least one pawl 59 is uniformly mounted on the pawl seat 60 in such a way as to be rotatable relative to the pawl seat 60, and the axis of rotation of each pawl 59 is not coaxial with the axis of rotation/central axis of the pawl seat 60.

In this embodiment, since the rotation axis of each pawl 59 is not coaxial with the central axis of the pawl seat 60, that is, the pawl 59 is installed in an eccentric structure, when the torque motor 1 provides assistance, that is, the torque motor 1 drives the pawl seat 60 to rotate synchronously, a certain centrifugal force is generated, and when the rotation speed of the torque motor 1 reaches a certain threshold, each pawl 59 expands outwards in the direction away from the central axis of the pawl seat 60 under the action of the centrifugal force and gradually engages with the ratchet 208, thereby connecting the motor with the wire pulling mechanism; in addition, in the process that the pawls 59 expand outwards, the pawls 59 stretch the elastic restoring member 59 (in an initial state, the elastic restoring member 59 has a certain pretightening force), so that the elastic restoring member 59 stores energy; when the torque motor 1 stops assisting power, that is, the motor stops rotating, due to the absence of centrifugal force, the pawls 59 will gather in the direction close to the central axis of the pawl seat 60 under the action of the elastic restoring member 59, so that the pawls 59 gradually disengage from the ratchet 208, thereby disconnecting the motor from the wire pulling mechanism.

In the embodiment, the centrifugal clutch 47 is arranged between the wire drawing mechanism and the driving mechanism, and the centrifugal clutch 47 is always in a clutch release (namely, not engaged) state in a normal state that the motor is not electrified, so that the forward and reverse rotation motions of the winch are not influenced by the damping of the motor, namely, the wire drawing mechanism is disconnected from the driving mechanism, the driving mechanism is prevented, if the motor is changed into a damping piece, a wearer can feel that the joint free motion is not limited, the working reliability of the centrifugal clutch is high, the structure is simple, and the system cost and the control complexity are also reduced; however, when the motor starts to be powered on/starts to assist, the motor can rotate at an accelerated speed under the condition of no load because the clutch is originally in a loose state, and the centrifugal clutch just utilizes the accelerated rotation motion to open the pawl under centrifugal force and lock the ratchet groove on the winch (namely the pawl is meshed with the ratchet wheel), so that the wire pulling mechanism is connected with the driving mechanism, the output torque of the driving mechanism is transmitted to the winch of the wire pulling mechanism to drive the execution mechanism to move, and the assistance is realized.

The parallel elastic driver without motion damping of the present embodiment not only inherits the advantages of the parallel elastic driver in the above embodiments, such as: on the first hand, the separation of the driver and the actuating mechanism is realized, so that the heavier drivers such as a driver controller and a battery can be integrated on the back of a wearer through a wire pulling mechanism such as a wire pulling spool or a braided belt, namely a soft transmission form, thereby reducing the weight of the actuating mechanism, further reducing the increase degree of the swinging inertia of limbs of the wearer, and ensuring that the limbs of the wearer feel lighter when wearing the wearer; in the second aspect, when assistance is needed, the torque of the motor can be quickly transmitted to the joint execution end, and the assistance delay is small; in the third aspect, the stay wire in the stay wire mechanism, such as a steel wire or a woven bag, is always kept in a tight state when the driving mechanism is used for assisting and when the driving mechanism is not used for assisting, so that the problems of mechanical faults and even safety accidents caused by winding of the stay wire are avoided; and when the driving mechanism does not assist, the problem that the driving mechanism (such as a motor) is converted into a damping piece to move along with a winch in the wire pulling mechanism to cause obvious damping force to the free movement of the joint of the wearer is solved, and therefore the smoothness of the free movement of the joint of the wearer is guaranteed when the assisting force is not needed.

In some embodiments, referring to fig. 9a to 9c, the pawl seat 60 is annular, and can be fixed on the output end 6 of the motor 1 by a fixing member such as a screw, which is attached to the back surface of the motor 1, so as to be connected with the motor 1 in a synchronous rotation manner; three pawl rotating shafts 6001 are circumferentially and uniformly distributed at positions far away from the central shaft on the front surface of the pawl seat 60 opposite to the back surface, and one pawl seat limiting block 6002 is arranged beside each pawl rotating shaft 6001. And a first end of each pawl 59 is provided with a corresponding rotation hole 5901 such that when the rotation hole 5901 is mated with the pawl rotation axis 6001, the pawl 59 is rotatable about the pawl rotation axis 6001 (i.e., the pawl 59 is rotatably mounted to the pawl holder 60 relative to the pawl holder 60); and a second end of the pawl 59 remote from the pawl rotational axis 6001 is provided with a ratchet end face (including a front end face 5903 of the pawl tip and a second arcuate outer end face 5905) that is engageable with a ratchet groove 208-1 on the ratchet 208. Further, the first end of the pawl 59 is further provided with a pawl limit projection 5902 capable of cooperating with a pawl seat limit block 6002 of the pawl seat 60 close to the pawl rotation axis 6001, so that when the pawl 59 expands outwards in a direction away from the central axis of the pawl seat 60 under the action of centrifugal force, the pawl limit projection 5902 of each pawl 59 cooperates with its corresponding pawl seat limit block 6002, and at this time, the end surface of the ratchet tooth of the second end of the pawl 59 also cooperates with the ratchet tooth groove 208-1 of the ratchet 208, that is, the pawl 59 meshes with the ratchet 208, as shown in fig. 9d.

In an initial state (i.e., when the pawls of the centrifugal clutch are not engaged with the ratchet teeth), three pawls 59 are circumferentially arranged along the pawl seat 60, and a pawl seat projection 6002 is spaced between adjacent pawls 59 (specifically, a front end surface 5903 of a second end of one pawl 59 is attached to a first side surface 6002-1 of the pawl seat stopper 6002 away from the pawl rotation shaft 6001 adjacent to the first end, a first end of the other pawl 59 is attached to an inner side surface 5904 of the pawl limit projection 5902 and is attached to a second side surface 6002-2 of the pawl seat stopper 6002 close to the pawl rotation shaft 6001 adjacent to the first end), and the envelope/boundary lines of the three pawls 59 are located in a range surrounded by the outer circle of the annular pawl seat 60 (preferentially, a second arc-shaped outer end surface 5905 of the second end of the pawl 59 away from the center of the pawl seat 60, and a first arc-shaped outer end surface 5906 of the pawl limit projection 5902 away from the center of the pawl seat 60 are inscribed in the outer circle of the pawl seat 60), see fig. 9b and fig. 9c;

when the pawl 59 is engaged with the ratchet wheel 208 (i.e. the pawl 59 rotates counterclockwise by a certain angle θ around the corresponding pawl rotation axis 6001 under the action of centrifugal force and then engages with the ratchet groove 208-1 of the ratchet wheel 208), the inner end surface 5907 of the pawl limit projection 5902 abuts against the pawl seat limit block 6002, see fig. 9d.

In this embodiment, by providing the pawl stop lug 5902 at the first end of the pawl 59 proximate to its pawl rotation axis 6001 and providing the pawl seat stop 6002 at a position adjacent to its pawl rotation axis 6001, the maximum angle at which the pawl 59 rotates (i.e., the maximum angle at which the pawl 59 rotates about the pawl rotation axis 6001 when the pawl 59 is engaged with the ratchet 208) is defined by the pawl stop lug 5902 and the pawl seat stop 6002.

In some embodiments, each resilient return member 58 is secured at one end to the pawl holder 60 adjacent to the pawl pivot axis 6001 and at the other end to the pawl 59.

In this embodiment, instead of directly connecting the winch 2 of the wire pulling mechanism to the output disc 6 of the motor 1, the centrifugal clutch 47 is connected to the output disc 6 (i.e., the output end) of the motor 1 and the input end of the wire pulling mechanism, respectively. Specifically, by providing a winch mount for mounting the winch 2, the winch mount is fixed to the main body of the motor 1, and then the winch 2 is rotatably mounted on the winch mount with respect to the winch mount. For example, the winch mounting seat may be a second bearing seat 51 fixed on the main body of the motor 1, and the second bearing seat 51 is provided with a second bearing 61 capable of being matched with the shoulder of the winch 2, and the second bearing seat 51 is provided with a through hole for placing a pawl seat 60 in a centrifugal clutch corresponding to the position of the output disc 6 of the motor 1, so that the pawl seat 60 can be mounted in the center of the second bearing seat 51 and directly connected with the output disc 6 of the motor 1 in a synchronous rotation manner; and the winch 2 of the wire drawing mechanism is mounted on the second bearing seat 51 by shaft shoulder fit (specifically, the winch 2 can be provided with the bearing shoulder 207 with the second bearing 61) and is positioned above the pawl seat 60.

Further, in order to protect the centrifugal clutch and the winch 2, a pawl cover 57 may be further provided on the pawl seat 60. Specifically, a plurality of mounting posts/holes for mounting the pawl cover 57 may be provided on the pawl base 60, so that the pawl cover 57 can be mounted on the pawl base 60 by fixing members such as screws; alternatively, the pawl end cap 57 can be fixed to the capstan 2 in the wire pulling mechanism.

In some embodiments, the side of the winch 2 remote from the centrifugal clutch (or above the winch 2) is equipped with the above-mentioned elastic mechanism, which in particular comprises: a coil spring mounting seat 50 and a coil spring 5 mounted at the center of the coil spring mounting seat 50, wherein the coil spring mounting seat 50 is fixed on the bobbin base 3, and the inner ear of the coil spring 5 is mounted in the inner ear mounting groove provided on the capstan 2, and the outer ear is fixed in the outer ear mounting groove on the coil spring mounting seat 50.

Further, the elastic mechanism further includes: a coil spring end cap 8 disposed on the coil spring mount 50 for protecting the coil spring 5. Specifically, the center of the end cover 8 of the coil spring is provided with a first bearing 55, i.e. the end cover 8 of the coil spring can be mounted on the capstan 2 by the first bearing 55, so that the capstan 2 can rotate relative to the end cover 8 of the coil spring.

Referring to fig. 9c, when the motor 1 rotates clockwise, due to the centrifugal force, the pawl 59 rotates counterclockwise around the pawl rotation shaft 6001, that is, the pawl 59 expands outward in the direction gradually away from the central axis of the pawl seat 60 and gradually engages with the pawl groove 208-1 of the ratchet 208 on the winch 2, so as to lock the motor 1 and the winch 2, and further, the winch 2 rotates clockwise under the driving of the motor 1, at this time, the pulling wire 4 is retracted and transmits the pulling force to the executing end, so as to achieve the assisting force;

when the motor 1 stops rotating, in the process of the movement of the actuator, under the action of the pulling wire 4, the winch 2 rotates clockwise by a certain small amount of angle, so that the pawl 59 retracts into the pawl seat 60 under the pulling force of the elastic restoring member 58, at this time, the centrifugal clutch is disengaged, i.e. the connection between the winch 2 and the motor 1 is disconnected, and further the winch 2 can freely rotate clockwise or counterclockwise along with the pulling wire 4, i.e. the centrifugal clutch 47 returns to the initial state.

Referring to fig. 9e, in order to avoid the situation that the gravity of the pawls 59 expands to different angles for each pawl 59 due to the different mechanical characteristics of each elastic restoring member, such as a tension spring, and the different high and low positions, so that some pawls are engaged, and the other pawls 59 are not successfully engaged, the present invention further provides another parallel elastic driver, which comprises the above-mentioned components of the above-mentioned embodiments, except that a synchronizing gear is disposed at the center of the pawl seat 60 in the centrifugal clutch of the parallel elastic driver of this embodiment, and a first incomplete gear 76 capable of being engaged with the non-gear is disposed on one side of each pawl 59 corresponding to the synchronizing gear, so that when the pawl 59 rotates around its rotation axis 6001, each pawl 59 is synchronized by the corresponding first incomplete gear 76 and the synchronizing gear, thereby ensuring that all the eccentric ratchets 59 can be engaged with the ratchet 208 at the same time.

In some embodiments, the synchronizing gear includes three second incomplete gears 75 evenly distributed along the circumferential direction, and each second incomplete gear 75 corresponds to the first incomplete gear 76 on one pawl 59.

Of course, in other embodiments, the centrifugal clutch may be a multi-plate friction clutch actively controlled by a solenoid valve, or may be a passive clutch that uses physical and mechanical principles to achieve engagement and disengagement.

As mentioned above, in the parallel elastic driver in each of the above embodiments, when the driving mechanism, such as the motor 1, does not work, since the centrifugal clutch 47 is not engaged, i.e. the connection between the wire pulling mechanism and the driving mechanism is disconnected, the wire 4 in the wire pulling mechanism only drives the capstan 2 to rotate, at this time, since the driving mechanism, such as the motor 1, is not converted into a damping member, the capstan 2 can rotate in the forward and reverse directions; and the elastic mechanism connected with the winch 2 in parallel, such as a coil spring 5, can withdraw the redundant pull wire at any time; when the driving mechanism, such as the motor 1, works, because the pawl 59 in the centrifugal clutch 47 will be engaged with the ratchet 208 on the winch 2 under the action of centrifugal force, that is, the driving mechanism is connected with the wire pulling mechanism, so that the torque of the driving mechanism, such as the motor 1, can be directly transmitted to the winch 2, and then the pulling wire is dragged to retract the driver, the transmission efficiency is high, and the corresponding time is short.

However, since the engagement of the centrifugal clutch 47 is achieved by centrifugal force, that is, the centrifugal clutch 47 has a certain rotation speed for a certain time (such as several seconds or several milliseconds) before the engagement (or clutch), and the winch 2 in the wire pulling mechanism is probably at rest or motionless, even in the process of reverse rotation, at the moment of the engagement of the centrifugal clutch 47, the motor 1 and the winch 2 will both receive a large impact force, the impact force of the winch 2 will be further transmitted to the actuating mechanism of the exoskeleton, causing the limb of the wearer to feel a sudden impact assisting force, and the pawl tip of the centrifugal clutch 47 and the edge of the ratchet groove 208-1 of the ratchet 208 will be easily worn by the impact, thereby reducing the service life of the device.

In view of the above, the present invention further provides a series-parallel elastic actuator, which includes the components of the parallel elastic actuator in the above embodiments, such as the centrifugal clutch 47, the wire pulling mechanism, the elastic mechanism and the driving mechanism; differently, the series-parallel elastic driver of the embodiment of the present invention further includes: an elastic buffer component which is connected in series with the input end (such as being connected in series between the conduit 305 and the conduit fixing seat 3 in the wire drawing mechanism) or the output end (such as being connected in series between the tail end of the wire drawing mechanism and the actuating mechanism) of the wire drawing mechanism;

when the driving mechanism provides power assistance, the centrifugal clutch is engaged to connect the driving mechanism with the wire pulling mechanism, and the elastic buffer component is used for relieving impact force caused by the engagement moment of the centrifugal clutch;

when the driving mechanism stops providing the assisting force, the centrifugal clutch is disconnected between the driving mechanism and the wire pulling mechanism, and the elastic mechanism provides the recovery force for the wire pulling mechanism.

In some embodiments, the resilient buffer member is a compression spring 48, and in particular, referring to fig. 10, the compression spring is disposed before the pull wire 4 enters the spool 305 (for example, by providing a compression spring receiving groove 81 on the spool holder 3), and the end 80 of the spool 305 is assembled on a perforated plug that can slide along the compression direction of the compression spring 48, so that when the centrifugal clutch is engaged and an increased pull wire retracting torque is suddenly applied to the winch 2, and the actuator is subjected to a large resistance force (for example, the gravitational potential energy of the wearer needs to be lifted), the pull wire 4 presses the spool 305 to compress the compression spring 48 in series, and as the compression stroke of the compression spring 48 increases, the counter pressure of the compression spring 48 on the spool 305 also increases gradually, thereby gradually increasing the assisting torque of the actuator.

In this embodiment, the end 80 of the spool 305 is serially connected with the pressure spring 48, so that impact force caused by instant meshing of the centrifugal clutch is reduced, a smoother assistance force variation trend of limbs of a wearer can be provided, and impact abrasion of the pawl 59 in the centrifugal clutch 47 can also be reduced.

The above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention, and they should be construed as being included in the following claims and description.

Claims (18)

1. A parallel elastic drive for a power assisted exoskeleton comprising:

   a drive mechanism for providing an assistance force,

   a cable pull mechanism for transmitting the assistance force to at least one actuator of the assisted exoskeleton, an

   An elastic mechanism for providing a recovery force to the wire pulling mechanism to tighten the wire in the wire pulling mechanism when the driving mechanism stops providing the assisting force, wherein,

   the elastic power mechanism and the driving mechanism are connected in parallel and arranged at the input end of the wire pulling mechanism.
2. The parallel spring driver of claim 1, wherein the drive mechanism comprises: an electric motor.
3. The shunt elastic driver of claim 2, wherein said wire pulling mechanism comprises:

   a wire for transmitting the assisting force, and a capstan for winding the wire, wherein,

   the winch is connected with the motor in a synchronous rotating mode, the fixed end of the pull wire is fixed on the winch, and at least one force output end of the pull wire is connected with the at least one executing mechanism.
4. The parallel spring driver of claim 3, further comprising: the clutch locking mechanism is arranged between two adjacent actuating mechanisms and is respectively connected with the two actuating mechanisms through the pull wires;

   when the assisted joint of the wearer is in a straightened state or a state close to the straightened state, the clutch locking mechanism is in a meshed state, so that the assistance output by the driving mechanism is transmitted to the two executing mechanisms connected with the clutch locking mechanism through the wire pulling mechanism;

   when the assisted joint is in a bending state, the clutch locking mechanism is in an unengaged state, so that the assistance output by the driving mechanism is transmitted to the executing mechanism close to the driving mechanism in the two executing mechanisms through the wire pulling mechanism.
5. The parallel spring driver of claim 1, wherein the spring mechanism comprises:

   an elastic energy storage part mounted on the wire drawing mechanism and

   when the power mechanism provides assistance for the wire pulling mechanism, the elastic energy storage part stores energy;

   when the power mechanism stops providing the assisting force for the wire pulling mechanism, the elastic energy storage component releases energy so as to provide the recovery force for the wire pulling mechanism.
6. The parallel spring driver of claim 5, wherein the spring energy storage component is a coil spring, an outer ear of the coil spring is fixed on the wire pulling mechanism, and an inner ear of the coil spring is fixed on a rotating shaft of the coil spring.
7. The parallel elastic driver of any one of claims 2 to 6, wherein the pull wires of the wire pulling mechanism are divided into three branches by three pull wire channels of the power-assisted exoskeleton, wherein the two branches are symmetrically disposed at the left and right sides of the corresponding power-assisted joint mechanism of the power-assisted exoskeleton, and the other branch is disposed right in front of or right behind the power-assisted joint mechanism.
8. The parallel elastic driver as claimed in any one of claims 2 to 6, wherein the pull wires of the pull wire mechanism are divided into two branches by two pull wire channels of the power-assisted exoskeleton, and the two branches are symmetrically arranged at the left and right sides of the corresponding power-assisted joint mechanism of the power-assisted exoskeleton.
9. A parallel elastic drive without motion damping in a powered exoskeleton, comprising:

   a drive mechanism for providing an assistance force,

   a cable pull mechanism for transmitting the assistance force to at least one actuator in the assisted exoskeleton,

   an elastic mechanism for providing a recovery force to the wire pulling mechanism to tighten the wire in the wire pulling mechanism when the driving mechanism stops providing the assist force, and a centrifugal clutch, wherein,

   the driving mechanism and the elastic mechanism are connected in parallel at the input end of the wire pulling mechanism, the centrifugal clutch is arranged between the driving mechanism and the wire pulling mechanism, and

   when the driving mechanism provides assistance, the centrifugal clutch connects the driving mechanism with the wire drawing mechanism,

   when the driving mechanism stops providing the assisting force, the centrifugal clutch disconnects the connection between the driving mechanism and the wire pulling mechanism, and the elastic mechanism provides the recovery force for the wire pulling mechanism.
10. The parallel spring driver of claim 9, wherein the drive mechanism comprises a motor.
11. The parallel spring driver of claim 10, wherein the centrifugal clutch comprises: at least one pawl, at least one elastic resetting piece, a pawl seat synchronously and rotationally connected with the motor, and a ratchet wheel synchronously and rotationally connected with a winch in the wire pulling mechanism, wherein,

    at least one pawl is uniformly distributed on the pawl seat in a manner of rotating relative to the pawl seat, a first end of the elastic reset piece is fixed on the pawl seat, and a second end of the elastic reset piece is connected with the pawl;

    when the motor provides assistance, the motor drives the pawl seat to synchronously rotate, so that the pawl outwards expands along the direction away from the central shaft of the pawl seat under the action of centrifugal force and is gradually meshed with the ratchet wheel, and the motor is connected with the wire pulling mechanism;

    when the motor stops assisting power, the pawls are gathered along the direction close to the central shaft of the pawl seat under the action of the elastic resetting piece and gradually separated from the ratchet wheel, so that the connection between the motor and the wire drawing mechanism is disconnected.
12. The parallel spring driver of claim 11, wherein the centrifugal clutch further comprises: a synchronous gear arranged in the center of the pawl seat, and correspondingly, an incomplete gear which can be meshed with the synchronous gear is arranged on one side of each pawl corresponding to the synchronous gear; and is

    The at least one pawl rotates synchronously as the pawl rotates about the axis of rotation.
13. The parallel spring driver of any of claims 10 to 12, wherein the centrifugal clutch further comprises: the pawl limiting block is arranged on the pawl seat and used for limiting the maximum angle of the pawl rotating in the direction far away from the center of the pawl seat.
14. A series-parallel elastic drive for a power-assisted exoskeleton, comprising:

    a drive mechanism for providing assistance;

    a cable pull mechanism for transmitting the assistance force to at least one actuator of the assistance exoskeleton;

    the elastic mechanism is used for providing recovery force for the wire pulling mechanism when the driving mechanism stops providing the assistance force; and

    an elastic buffer member for providing a buffer to the wire pulling mechanism, wherein,

    the driving mechanism and the elastic mechanism are connected in parallel at the input end of the wire pulling mechanism, a centrifugal clutch is arranged between the driving mechanism and the wire pulling mechanism, and the elastic buffer component is connected in series at the input end/output end of the wire pulling mechanism;

    when the driving mechanism provides boosting force, the centrifugal clutch is engaged to connect the driving mechanism and the wire drawing mechanism, and the impact force caused by the engagement moment of the centrifugal clutch is relieved by the elastic buffer component;

    when the driving mechanism stops providing the assisting force, the centrifugal clutch disconnects the driving mechanism from the wire pulling mechanism, and the elastic mechanism provides the recovery force for the wire pulling mechanism.
15. A powered exoskeleton comprising at least one actuator, further comprising: an actuator according to any of claims 1 to 14, wherein the force output of the wire pulling mechanism in the actuator is connected to the force input of the at least one actuator.
16. A method of controlling a drive for a power assisted exoskeleton, the drive being according to any one of claims 1 to 14, the method comprising the steps of:

    acquiring and identifying the current working state of the driver, wherein the working state comprises the following steps: preparing and assisting power;

    if the working state of the driver is identified as ready, acquiring the current joint extension angular speed and the current joint bending angle of a power-assisted joint mechanism in the power-assisted exoskeleton;

    judging whether the power-assisted joint mechanism needs power assistance according to the joint extension angular speed, the joint bending angle, a preset extension threshold angle and a failure threshold angle;

    if the assistance is needed, the current working state of the driver is set to be the assistance state from the preparation state, and the output torque of the driver is set to be a preset threshold T _ref 。
17. The control method according to claim 16, characterized by further comprising the step of:

    if the working state of the driver is recognized as assistance, acquiring the current knee joint bending angle, knee joint extension angular velocity or knee joint bending angular velocity of the assistance joint mechanism;

    judging whether assistance needs to be cancelled currently or not according to the knee joint bending angle and a preset failure threshold angle, or the knee joint extension angular velocity and a preset maximum extension angular velocity, or the knee joint bending angular velocity and a preset bending threshold angular velocity, if so, setting the current working state of the driver from an assistance state to a follow-up state, and setting the output torque of the driver to 0.
18. The control method of claim 17, wherein the operating state of the driver further comprises: carrying out follow-up; correspondingly, the control method further comprises the following steps:

    if the working state of the driver is identified as follow-up, acquiring the current joint bending angle and joint bending angular speed of the power-assisted joint mechanism;

    and judging whether assistance needs to be prepared currently or not according to the joint bending angle and the joint bending angular velocity as well as a preset assistance threshold angle and a preset bending threshold angular velocity, if so, setting the current working state of the driver from a follow-up state to a preparation state, and setting the output torque of the driver to 0.

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