Patent Description:
<CIT> relates to a pneumatic exoskeleton system that is wearable on a user's legs.

It should be noted that the figures are not drawn to scale and that elements of similar structures or functions are generally represented by like reference numerals for illustrative purposes throughout the figures. It also should be noted that the figures are only intended to facilitate the description of the preferred embodiments. The figures do not illustrate every aspect of the described embodiments and do not limit the scope of the present disclosure.

The following disclosure includes example embodiments of the design of novel exoskeleton devices for use during skiing activities. Exoskeletons have been conceived and evaluated for a variety of applications, however, the use of exoskeleton devices for recreational activities such as skiing is yet unexplored. This disclosure describes various embodiments of an exoskeleton used for skiing activities and methods of operating an exoskeleton in conjunction with the operator.

The present invention provides an exoskeleton system in accordance with claim <NUM>.

In one aspect, this disclosure teaches the method for developing various embodiments of an exoskeleton for use during recreational skiing. Various preferred embodiments include: a leg brace with integrated actuation, a mobile power source, and a control unit that determines the output behavior of the device in real-time.

A component of an exoskeleton system that is present in various embodiments is a body-worn, lower-extremity brace that incorporates the ability to introduce torque to the user. One preferred embodiment of this component is a leg brace that is configured to support the knee of the user and includes actuation across the knee joint to provide assistance torques in the extension direction. This embodiment can connect to the user through a series of attachments including one on the boot, below the knee, and along the user's thigh. This preferred embodiment can include this type of leg brace on both legs of the user.

The present disclosure teaches example embodiments of a fluidic exoskeleton system that includes one or more adjustable fluidic actuator. Some preferred embodiments include a fluidic actuator that can be operated at various pressure levels with a large stroke length in a configuration that can be oriented with a joint on a human body.

As discussed herein, an exoskeleton system <NUM> can be configured for various suitable uses. For example, <FIG> and <FIG> illustrate an exoskeleton system <NUM> being used by a user <NUM> during skiing. As shown in <FIG> and <FIG> the user <NUM> can wear the exoskeleton system <NUM> and a skiing assembly <NUM> that includes a pair of ski boots <NUM> and pair of skis <NUM>. <FIG> and <FIG> illustrate a front and side view of an actuator unit <NUM> coupled to a leg <NUM> of a user <NUM> and <FIG> illustrates a side view of an actuator unit <NUM> not being worn by a user <NUM>.

As shown in the example of <FIG> and <FIG>, the exoskeleton system <NUM> can comprise a left and right leg actuator unit <NUM>, 110R that are respectively coupled to a left and right leg <NUM>, 102R of the user. In various embodiments, the left and right leg actuator units <NUM>, 110R can be substantially mirror images of each other.

As shown in <FIG>, leg actuator units <NUM> can include an upper arm <NUM> and a lower arm <NUM> that are rotatably coupled via a joint <NUM>. A bellows actuator <NUM> extends between the upper arm <NUM> and lower arm <NUM>. One or more sets of pneumatic lines <NUM> can be coupled to the bellows actuator <NUM> to introduce and/or remove fluid from the bellows actuator <NUM> to cause the bellows actuator <NUM> to expand and contract and to stiffen and soften, as discussed herein. A backpack <NUM> can be worn by the user <NUM> and can hold various components of the exoskeleton system <NUM> such as a fluid source, control system, a power source, and the like.

As shown in <FIG>, the leg actuator units <NUM>, 110R can be respectively coupled about the legs <NUM>, 102R of the user <NUM> with the joints <NUM> positioned at the knees <NUM>, 103R of the user <NUM> with the upper arms <NUM> of the leg actuator units <NUM>, 110R being coupled about the upper legs portions <NUM>, 104R of the user <NUM> via one or more couplers <NUM> (e.g., straps that surround the legs <NUM>). The lower arms <NUM> of the leg actuator units <NUM>, 110R can be coupled about the lower leg portions <NUM>, 105R of the user <NUM> via one or more couplers <NUM>.

The upper and lower arms <NUM>, <NUM> of a leg actuator unit <NUM> can be coupled about the leg <NUM> of a user <NUM> in various suitable ways. For example, <FIG> illustrates an example where the upper and lower arms <NUM>, <NUM> and joint <NUM> of the leg actuator unit <NUM> are coupled along lateral faces (sides) of the top and bottom portions <NUM>, <NUM> of the leg <NUM>. As shown in the example of <FIG>, the upper arm <NUM> can be coupled to the upper leg portion <NUM> of a leg <NUM> above the knee <NUM> via two couplers <NUM> and the lower arm <NUM> can be coupled to the lower leg portion <NUM> of a leg <NUM> below the knee <NUM> via two couplers <NUM>.

Specifically, upper arm <NUM> can be coupled to the upper leg portion <NUM> of the leg <NUM> above the knee <NUM> via a first set of couplers 250A that includes a first and second coupler 150A, 150B, which are respectively a first and second upper leg coupler. The first and second couplers 150A, 150B can be joined by a rigid plate assembly <NUM> disposed on a lateral side of the upper leg portion <NUM> of the leg <NUM>, with straps <NUM> of the first and second couplers 150A, 150B extending around the upper leg portion <NUM> of the leg <NUM>. The upper arm <NUM> can be coupled to the plate assembly <NUM> on a lateral side of the upper leg portion <NUM> of the leg <NUM>, which can transfer force generated by the upper arm <NUM> to the upper leg portion <NUM> of the leg <NUM>.

The lower arm <NUM> can be coupled to the lower leg portion <NUM> of a leg <NUM> below the knee <NUM> via second set of couplers 250B that includes a third and fourth coupler 150C, 150D, which are respectively a first and a second lower leg coupler. A coupling branch unit <NUM> can extend from a distal end of, or be defined by a distal end of the lower arm <NUM>. The coupling branch unit <NUM> can comprise a first branch <NUM> that extends from a lateral position on the lower leg portion <NUM> of the leg <NUM>, curving upward and toward the anterior (front) of the lower leg portion <NUM> to a first attachment <NUM> on the anterior of the lower leg portion <NUM> below the knee <NUM>, with the first attachment <NUM> joining the third coupler 150C and the first branch <NUM> of the coupling branch unit <NUM>. The coupling branch unit <NUM> can comprise a second branch <NUM> that extends from a lateral position on the lower leg portion <NUM> of the leg <NUM>, curving downward and toward the posterior (back) of the lower leg portion <NUM> to a second attachment <NUM> on the posterior of the lower leg portion <NUM> below the knee <NUM>, with the second attachment <NUM> joining the fourth coupler 150D and the second branch <NUM> of the coupling branch unit <NUM>.

As shown in the example of <FIG>, the fourth coupler 150D can be configured to surround and engage the ski boot <NUM> of a user. For example, the strap <NUM> of the fourth coupler 150D can be of a size that allows the fourth coupler 150D to surround the larger diameter of a ski boot <NUM> compared to the lower portion <NUM> of the leg <NUM> alone. Also, the length of the lower arm <NUM> and/or coupling branch unit <NUM> can be of a length sufficient for the fourth coupler to 150D to be positioned over a ski boot <NUM> instead of being of a shorter length such that the fourth coupler 150D would surround a section of the lower portion <NUM> of the leg <NUM> above the ski boot <NUM> when the leg actuator unit <NUM> is worn by a user.

Attaching to the ski boot <NUM> can vary across various embodiments. In one embodiment, this attachment can be accomplished through a flexible strap that wraps around the circumference of ski boot <NUM> to affix the leg actuator unit <NUM> to the ski boot <NUM> with the desired amount of relative motion between the leg actuator unit <NUM> and the strap. Other embodiments can work to restrict various degrees of freedom while allowing the desired amount of relative motion between the leg actuator unit <NUM> and the boot <NUM> in other degrees of freedom. One such embodiment can include the use of a mechanical clip that connects to the back of the ski boot <NUM> that can provide a specific mechanical connection between the device and the ski boot <NUM>. Various embodiments can include but are not limited to the designs listed previously, a mechanical bolted connection, a rigid strap, a magnetic connection, an electro-magnetic connection, an electromechanical connection, an insert into the user's boot, a rigid or flexible cable, or a connection directly to a ski <NUM>.

Another aspect of the exoskeleton system <NUM> can be fit components used to secure the exoskeleton system <NUM> to the user <NUM>. Since the function of the exoskeleton system <NUM> in various embodiments can rely heavily on the fit of the exoskeleton system <NUM> efficiently transmitting forces between the user <NUM> and the exoskeleton system <NUM> without the exoskeleton system <NUM> significantly drifting on the body <NUM> or creating discomfort, improving the fit of the exoskeleton system <NUM> and monitoring the fit of the exoskeleton system <NUM> to the user over time can be desirable for the overall function of the exoskeleton system <NUM> in some embodiments.

In various examples, different couplers <NUM> can be configured for different purposes, with some couplers <NUM> being primarily for the transmission of forces, with others being configured for secure attachment of the exoskeleton system <NUM> to the body <NUM>. In one preferred embodiment for a single knee system, a coupler <NUM> that sits on the lower leg <NUM> of the user <NUM> (e.g., one or both of couplers 150C, 150D) can be intended to target body fit, and as a result, can remain flexible and compliant to conform to the body of the user <NUM>. Alternatively, in this embodiment a coupler <NUM> that affixes to the front of the user's thigh on an upper portion <NUM> of the leg <NUM> (e.g., one or both of couplers 150A, 150B) can be intended to target power transmission needs and can have a stiffer attachment to the body than others couplers <NUM> (e.g., one or both of couplers 150C, 150D). Various embodiments can employ a variety of strapping or coupling configurations, and these embodiments can extend to include any variety of suitable straps, couplings, or the like, where two parallel sets of coupling configurations are meant to fill these different needs.

In some cases the design of the joint <NUM> can improve the fit of the exoskeleton system <NUM> on the user. In one embodiment, the joint <NUM> of a single knee leg actuator unit <NUM> can be designed to use a single pivot joint that has some deviations with the physiology of the knee joint. Another embodiment, uses a polycentric knee joint to better fit the motion of the human knee joint, which in some examples can be desirably paired with a very well fit leg actuator unit <NUM>. Various embodiments of a joint <NUM> can include but are not limited to the example elements listed above, a ball and socket joint, a four bar linkage, and the like.

Some embodiments can include fit adjustments for anatomical variations in varus or valgus angles in the lower leg <NUM>. One preferred embodiment includes an adjustment incorporated into a leg actuator unit <NUM> in the form of a cross strap that spans the joint of the knee <NUM> of the user <NUM>, which can be tightened to provide a moment across the knee joint in the frontal plane which varies the nominal resting angle. Various embodiments can include but are not limited to the following: a strap that spans the joint <NUM> to vary the operating angle of the joint <NUM>; a mechanical assembly including a screw that can be adjusted to vary the angle of the joint <NUM>; mechanical inserts that can be added to the leg actuator unit <NUM> to discreetly change default angle of the joint <NUM> for the user <NUM>, and the like.

In various embodiments, the leg actuator unit <NUM> can be configured to remain suspended vertically on the leg <NUM> and remain appropriately positioned with the joint of the knee <NUM>. In one embodiment, coupler <NUM> associated with a ski boot <NUM> (e.g., coupler 150D) can provide a vertical retention force for a leg actuator unit <NUM>. Another embodiment uses a coupler <NUM> positioned on the lower leg <NUM> of the user <NUM> (e.g., one or both of couplers 150C, 150D) that exerts a vertical force on the leg actuator unit <NUM> by reacting on the calf of the user <NUM>. Various embodiments can include but are not limited to the following: suspension forces transmitted through a coupler <NUM> on the ski boot (e.g., coupler 150D) or another embodiment of ski boot attachment discussed previously; suspension forces transmitted through an electronic and/or fluidic cable assembly; suspension forces transmitted through a connection to a waist belt; suspension forces transmitted through a mechanical connection to a backpack <NUM> or other housing for the exoskeleton device <NUM> and/or pneumatic system <NUM> (see <FIG>); suspension forces transmitted through straps or a harness to the shoulders of the user <NUM>, and the like.

In some embodiments, it can be desirable to verify that the fit of the leg actuator unit <NUM> on the leg <NUM> of the user <NUM> is within suitable operating parameters to enable ideal operation and performance of the exoskeleton system <NUM>. One embodiment can include the use of an external fit jig that can be held up to the leg <NUM> of the user <NUM> with the leg actuator unit <NUM> donned to determine whether the fit of the leg actuator unit <NUM> is outside of allowable tolerances. In some examples, such a mechanical jig can be used upon initial donning of one or more leg actuator units <NUM> or periodically throughout use of the one or more leg actuator unit <NUM> to determine whether the fit of the leg actuator unit <NUM> is outside of allowable tolerances. Various embodiments include but are not limited to the following: external mechanical jig; the exoskeleton device <NUM> tracking performance of the exoskeleton system <NUM> to identify proper or improper fit; visual inspection tools that analyze one or more images of the exoskeleton system <NUM> on the user <NUM> (e.g. an application on a smartphone); a laser-guided fit system, and the like.

In various embodiments, a leg actuator unit <NUM> can be spaced apart from the leg <NUM> of the user with a limited number of attachments to the leg <NUM>. For example, in some embodiments, the leg actuator unit <NUM> can consist or consist essentially of three attachments to the leg <NUM> of the user <NUM>, namely via the first and second attachments <NUM>, <NUM> and the <NUM>. In various embodiments, the couplings of the leg actuator unit <NUM> to the lower leg portion <NUM> can consist or consist essentially of a first and second attachment on the anterior and posterior of the lower leg portion <NUM>. In various embodiments, the coupling of the leg actuator unit <NUM> to the upper leg portion <NUM> can consist or consist essentially of a single lateral coupling, which can be associated with one or more couplers <NUM> (e.g., two couplers 150A, 150B as shown in <FIG>). In various embodiments, such a configuration can be desirable based on the specific force-transfer for use during skiing. Accordingly, the number and positions of attachments or coupling to the leg <NUM> of the user <NUM> in various embodiments is not a simple design choice and is specifically selected for the application of skiing.

While specific embodiments of couplers <NUM> are illustrated herein, in further embodiments, such components discussed herein can be operably replaced by an alternative structure to produce the same functionality. For example, while straps, buckles, padding and the like are shown in various examples, further embodiments can include couplers <NUM> of various suitable types and with various suitable elements. For example, some embodiments can include Velcro hook-and-loop straps, or the like.

Additionally, in various embodiments, it can be desirable for the exoskeleton system <NUM> to be configured for coupling over the clothing of a user <NUM> and without modification or addition of hardware to a skiing assembly <NUM> such as to ski boots <NUM>. For example, as shown in the embodiments of <FIG>, the fourth coupler can be configured to couple to the ski boot <NUM> of a user <NUM> without modification of the ski boot <NUM> or addition of hardware to the ski boot <NUM>. In other words, a user can don clothing and ski gear as they would normally and then don the exoskeleton system <NUM> over their normal clothing and ski gear. Such a configuration can be desirable so that users <NUM> can quickly and easily switch out or use different ski gear without need to modify or change hardware on the ski gear to use the exoskeleton system <NUM>. Additionally, such a configuration can allow multiple users <NUM> to easily use the same exoskeleton system <NUM> interchangeably.

<FIG> illustrate another example of an exoskeleton system <NUM> where the joint <NUM> is disposed laterally and adjacent to the knee <NUM> with a rotational axis of the joint <NUM> being disposed parallel to a rotational axis of the knee <NUM>. In some embodiments, the rotational axis of the joint <NUM> can be coincident with the rotational axis of the knee <NUM>. In some embodiments, a joint can be disposed on the anterior of the knee <NUM>, posterior of the knee <NUM>, inside of the knee <NUM>, or the like.

In various embodiments, the joint structure <NUM> can constrain the bellows actuator <NUM> such that force created by actuator fluid pressure within the bellows actuator <NUM> can be directed about an instantaneous center (which may or may not be fixed in space). In some cases of a revolute or rotary joint, or a body sliding on a curved surface, this instantaneous center can coincide with the instantaneous center of rotation of the joint <NUM> or a curved surface. Forces created by a leg actuator unit <NUM> about a rotary joint <NUM> can be used to apply a moment about an instantaneous center as well as still be used to apply a directed force. In some cases of a prismatic or linear joint (e.g., a slide on a rail, or the like), the instantaneous center can be kinematically considered to be located at infinity, in which case the force directed about this infinite instantaneous center can be considered as a force directed along the axis of motion of the prismatic joint. In various embodiments, it can be sufficient for a rotary joint <NUM> to be constructed from a mechanical pivot mechanism. In such an embodiment, the joint <NUM> can have a fixed center of rotation that can be easy to define, and the bellows actuator <NUM> can move relative to the joint <NUM>. In a further embodiment, it can be beneficial for the joint <NUM> to comprise a complex linkage that does not have a single fixed center of rotation. In yet another embodiment, the joint <NUM> can comprise a flexure design that does not have a fixed joint pivot. In still further embodiments, the joint <NUM> can comprise a structure, such as a human joint, robotic joint, or the like.

In various embodiments, leg actuator unit <NUM> (e.g., comprising bellows actuator <NUM>, joint structure <NUM>, and the like) can be integrated into a system to use the generated directed force of the leg actuator unit <NUM> to accomplish various tasks. In some examples, a leg actuator unit <NUM> can have one or more unique benefits when the leg actuator unit <NUM> is configured to assist the human body or is included into a powered exoskeleton system <NUM>. In an example embodiment, the leg actuator unit <NUM> can be configured to assist the motion of a human user about the user's knee joint <NUM>. To do so, in some examples, the instantaneous center of the leg actuator unit <NUM> can be designed to coincide or nearly coincide with the instantaneous center of rotation of the knee <NUM> of a user <NUM>. In one example configuration, the leg actuator unit <NUM> can be positioned lateral to the knee joint <NUM> as shown in <FIG>. In various examples, the human knee joint <NUM> can function as (e.g., in addition to or in place of) the joint <NUM> of the leg actuator unit <NUM>.

For clarity, example embodiments discussed herein should not be viewed as a limitation of the potential applications of the leg actuator unit <NUM> described within this disclosure. The leg actuator unit <NUM> can be used on other joints of the body including but not limited to one or more elbow, one or more hip, one or more finger, one or more ankle, spine, or neck. In some embodiments, the leg actuator unit <NUM> can be used in applications that are not on the human body such as in robotics, for general purpose actuation, animal exoskeletons, or the like.

Also, while example embodiments herein can relate to skiing, further embodiments can be used for or adapted for various other suitable applications such as tactical, medical, or labor applications, and the like. Examples of such applications can be found in <CIT> entitled "PNEUMATIC EXOMUSCLE SYSTEM AND METHOD" with attorney docket number <NUM>-002US1 and <CIT> entitled "LEG EXOSKELETON SYSTEM AND METHOD" with attorney docket number <NUM>-004US0.

Some embodiments can apply a configuration of a leg actuator unit <NUM> as described herein for linear actuation applications. In an example embodiment, the bellows <NUM> can comprise a two-layer impermeable/inextensible construction, and one end of one or more constraining ribs can be fixed to the bellows <NUM> at predetermined positions. The joint structure <NUM> in various embodiments can be configured as a series of slides on a pair of linear guide rails, where the remaining end of one or more constraining rib is connected to a slide. The motion and force of the fluidic actuator can therefore be constrained and directed along the linear rail.

<FIG> is a block diagram of an example embodiment of an exoskeleton system <NUM> that includes an exoskeleton device <NUM> that is operably connected to a pneumatic system <NUM>. While a pneumatic system <NUM> is used in the example of <FIG>, further embodiments can include any suitable fluidic system or a pneumatic system <NUM> can be absent in some embodiments, such as where an exoskeleton system <NUM> is actuated by electric motors, or the like.

The exoskeleton device <NUM> in this example comprises a processor <NUM>, a memory <NUM>, one or more sensors <NUM> a communication unit <NUM>, a user interface <NUM> and a power source <NUM>. A plurality of actuators <NUM> are operably coupled to the pneumatic system <NUM> via respective pneumatic lines <NUM>. The plurality of actuators <NUM> include a pair knee-actuators <NUM>, 130R that are positioned on the right and left side of a body <NUM>. For example, as discussed above, the example exoskeleton system <NUM> shown in <FIG> can comprise a left and right leg actuator unit <NUM>, 110R on respective sides of the body <NUM> as shown in <FIG> and <FIG> with one or both of the exoskeleton device <NUM> and pneumatic system <NUM>, or one or more components thereof, stored within or about a backpack <NUM> (see <FIG> and <FIG>) or otherwise mounted, worn or held by a user <NUM>.

Accordingly, in various embodiments, the exoskeleton system <NUM> can be a completely mobile and self-contained system that is configured to be powered and operate for an extended period of time without an external power source, such as during a skiing session, mountaineering, and the like. The size, weight and configuration of the actuator unit(s) <NUM>, exoskeleton device <NUM> and pneumatic system <NUM> can therefore be configured in various embodiments for such mobile and self-contained operation.

In various embodiments, the example system <NUM> can be configured to move and/or enhance movement of the user <NUM> wearing the exoskeleton system <NUM>. For example, the exoskeleton device <NUM> can provide instructions to the pneumatic system <NUM>, which can selectively inflate and/or deflate the bellows actuators <NUM> via pneumatic lines <NUM>. Such selective inflation and/or deflation of the bellows actuators <NUM> can move and/or support one or both legs <NUM> to generate and/or augment body motions such as walking, running, jumping, climbing, lifting, throwing, squatting, skiing or the like.

In some cases, the system <NUM> can be designed to support multiple configurations in a modular configuration. For example, one embodiment is a modular configuration that is designed to operate in either a single knee configuration or in a double knee configuration as a function of how many of the actuator units <NUM> are donned by the user <NUM>. For example, the exoskeleton device <NUM> can determine how many actuator units <NUM> are coupled to the pneumatic system <NUM> and/or exoskeleton device <NUM> (e.g., one or two actuator units <NUM>) and the exoskeleton device <NUM> can change operating capabilities based on the number of actuator units <NUM> detected.

In further embodiments, the pneumatic system <NUM> can be manually controlled, configured to apply a constant pressure, or operated in any other suitable manner. In some embodiments, such movements can be controlled and/or programmed by the user <NUM> that is wearing the exoskeleton system <NUM> or by another person. In some embodiments, the exoskeleton system <NUM> can be controlled by movement of the user <NUM>. For example, the exoskeleton device <NUM> can sense that the user is walking and carrying a load and can provide a powered assist to the user via the actuators <NUM> to reduce the exertion associated with the load and walking. Similarly, where a user <NUM> wears the exoskeleton system <NUM> while skiing, the exoskeleton system <NUM> can sense movements of the user <NUM> (e.g., made by the user <NUM>, in response to terrain, or the like) and can provide a powered assist to the user via the actuators <NUM> to enhance or provide an assist to the user while skiing.

Accordingly, in various embodiments, the exoskeleton system <NUM> can react automatically without direct user interaction. In further embodiments, movements can be controlled in real-time by user interface <NUM> such as a controller, joystick, voice control or thought control. Additionally, some movements can be pre-preprogrammed and selectively triggered (e.g., walk forward, sit, crouch) instead of being completely controlled. In some embodiments, movements can be controlled by generalized instructions (e.g. walk from point A to point B, pick up box from shelf A and move to shelf B).

The user interface <NUM> can allow the user <NUM> to control various aspects of the exoskeleton system <NUM> including powering the exoskeleton system <NUM> on and off; controlling movements of the exoskeleton system <NUM>; configuring settings of the exoskeleton system <NUM>, and the like. The user interface <NUM> can include various suitable input elements such as a touch screen, one or more buttons, audio input, and the like. The user interface <NUM> can be located in various suitable locations about the exoskeleton system <NUM>. For example, in one embodiments, the user interface <NUM> can be disposed on a strap of a backpack <NUM> as shown in <FIG>. In some embodiments, the user interface can be defined by a user device such as smartphone, smart-watch, wearable device, or the like.

In various embodiments, the power source <NUM> can be a mobile power source that provides the operational power for the exoskeleton system <NUM>. In one preferred embodiment, the power pack unit contains some or all of the pneumatic system <NUM> (e.g., a compressor) and/or power source (e.g., batteries) required for the continued operation of pneumatic actuation of the leg actuator units <NUM>. The contents of such a power pack unit can be correlated to the specific actuation approach configured to be used in the specific embodiment. In some embodiments, the power pack unit will only contain batteries which can be the case in an electromechanically actuated system or a system where the pneumatic system <NUM> and power source <NUM> are separate. Various embodiments of a power pack unit can include but are not limited to a combination of the one or more of the following items: pneumatic compressor, batteries, stored high-pressure pneumatic chamber, hydraulic pump, pneumatic safety components, electric motor, electric motor drivers, microprocessor, and the like. Accordingly, various embodiments of a power pack unit can include one or more of elements of the exoskeleton device <NUM> and/or pneumatic system <NUM>.

Such components can be configured on the body of a user <NUM> in a variety of methods. One preferred embodiment is the inclusion of a power pack unit in a torso-worn pack that is not operably coupled to the leg actuator units <NUM> in any manner that transmits substantial mechanical forces to the leg actuator units <NUM>. Another embodiment includes the integration of the power pack unit, or components thereof, into the leg actuator units <NUM> themselves. Various embodiments can include but are not limited to the following configurations: torso-mounted in a backpack, torso-mounted in a messenger bag, hip-mounted bag, mounted to the leg, integrated into the brace component, and the like. Further embodiments can separate the components of the power pack unit and disperse them into various configurations on the user <NUM>. Such an embodiment may configure a pneumatic compressor on the torso of the user <NUM> and then integrate the batteries into the leg actuator units <NUM> of the exoskeleton system <NUM>.

One aspect of the power supply <NUM> in various embodiments is that it must be connected to the brace component in such a manner as to pass the operable system power to the brace for operation. One preferred embodiment is the use of electrical cables to connect the power supply <NUM> and the leg actuator units <NUM>. Other embodiments can use electrical cables and a pneumatic line <NUM> to deliver electrical power and pneumatic power to the leg actuator units <NUM>. Various embodiments can include but are not limited to any configuration of the following connections: pneumatic hosing, hydraulic hosing, electrical cables, wireless communication, wireless power transfer, and the like.

In some embodiments, it can be desirable to include secondary features that extend the capabilities of a cable connection (e.g., pneumatic lines <NUM> and/or power lines) between the leg actuator units <NUM> and the power supply <NUM> and/or pneumatic system <NUM>. One preferred embodiment includes retractable cables that are configured to have a small mechanical retention force to maintain cables that are pulled tight against the user with reduced slack remaining in the cable. Various embodiments can include, but are not limited to a combination of the following secondary features: retractable cables, a single cable including both fluidic and electrical power, magnetically-connected electrical cables, mechanical quick releases, breakaway connections designed to release at a specified pull force, integration into mechanical retention features on the users clothing, and the like. Yet another embodiment can include routing the cables in such a way as to minimize geometric differences between the user <NUM> and the cable lengths. One such embodiment in a dual knee configuration with a torso power supply can be routing the cables along the user's lower torso to connect the right side of a power supply bag with the left knee of the user. Such a routing can allow the geometric differences in length throughout the user's normal range of motion.

One specific additional feature that can be a concern in some embodiments is the need for proper heat management of the exoskeleton system <NUM>. As a result, there are a variety of features that can be integrated specifically for the benefit of controlling heat. One preferred embodiment integrates exposed heat sinks to the environment that allow elements of the exoskeleton device <NUM> and/or pneumatic system <NUM> to dispel heat directly to the environment through unforced cooling using ambient airflow. Another embodiment directs the ambient air through internal air channels in a backpack <NUM> or other housing to allow for internal cooling. Yet another embodiment can extend upon this capability by introducing scoops on a backpack <NUM> or other housing in an effort to allow air flow through the internal channels. Various embodiments can include but are not limited to the following: exposed heat sinks that are directly connected to a high heat component; a water-cooled or fluid-cooled heat management system; forced air cooling through the introduction of a powered fan or blower; external shielded heat sinks to protect them from direct contact by a user, and the like.

In some cases, it may be beneficial to integrate additional features into the structure of the backpack <NUM> or other housing to provide additional features to the exoskeleton system <NUM>. One preferred embodiment is the integration of mechanical attachments to support storage of the leg actuator units <NUM> along with the exoskeleton device <NUM> and/or pneumatic system <NUM> in a small package. Such an embodiment can include a deployable pouch that can secure the leg actuator units <NUM> against the backpack <NUM> along with mechanical clasps that hold the upper or lower arms <NUM>, <NUM> of the actuator units <NUM> to the backpack <NUM>. Another embodiment is the inclusion of storage capacity into the backpack <NUM> so the user <NUM> can hold additional items such as a water bottle, food, personal electronics, and other personal items. Various embodiments can include but are not limited to other additional features such as the following: a warming pocket which is heated by hot airflow from the exoskeleton device <NUM> and/or pneumatic system <NUM>; air scoops to encourage additional airflow internal to the backpack <NUM>; strapping to provide a closer fit of the backpack <NUM> on the user, waterproof storage, temperature-regulated storage, and the like.

In a modular configuration, it may be required in some embodiments that the exoskeleton device <NUM> and/or pneumatic system <NUM> be configured to support the power, fluidic, sensing and control requirements and capabilities of various potential configurations of the exoskeleton system. One preferred embodiment can include an exoskeleton device <NUM> and/or pneumatic system <NUM> that can be tasked with power a dual knee configuration or a single knee configuration (i.e., with one or two leg actuator units <NUM> on the user <NUM>). Such a system <NUM> can support the requirements of both configurations and then appropriately configured power, fluidic, sensing and control based on a determination or indication of a desired operating configuration. Various embodiments exist to support an array of potential modular system configurations, such as multiple batteries, and the like.

In various embodiments, the exoskeleton device <NUM> can be operable to perform methods or portions of methods described in more detail below. For example, the memory <NUM> can include non-transitory computer readable instructions (e.g., software), which if executed by the processor <NUM>, can cause the exoskeleton system <NUM> to perform methods or portions of methods described herein.

This software can embody various methods that interpret signals from the sensors <NUM> or other sources to determine how to best operate the system <NUM> to provide the desired benefit to the user. The specific embodiments described below should not be used to imply a limit on the sensors <NUM> that can be applied to such a system <NUM> or the source of sensor data. While some example embodiments can require specific information to guide decisions, it does not create an explicit set of sensors <NUM> that an exoskeleton system <NUM> for outdoor applications will require.

One aspect of control software can be the operational control of leg actuator units <NUM>, exoskeleton device <NUM> and pneumatic system <NUM> to provide the desired response. There can be various suitable responsibilities of the operational control software. For example, as discussed in more detail below, one can be low-level control which can be responsible for developing baseline feedback for operation of the leg actuator units <NUM>, exoskeleton device <NUM> and pneumatic system <NUM>. Another can be intent recognition which can be responsible for identifying the intended maneuvers of the user <NUM> based on data from the sensors <NUM> and causing the exoskeleton system <NUM> to operate based on one or more identified intended maneuvers. A further example can include reference generation, which can include selecting the desired torques the system <NUM> should generate to best assist the user <NUM>. It should be noted that this example architecture for delineating the responsibilities of the operational control software is merely for descriptive purposes and in no way limits the wide variety of software approaches that can be deployed on further embodiments of a system <NUM>.

One method implemented by control software can be for the low-level control and communication of the system <NUM>. This can be accomplished via a variety of methods as required by the specific joint and need of the user. In a preferred embodiment, the operational control is configured to provide a desired torque by the leg actuator unit <NUM> at the user's joint. In such a case, the system <NUM> can create low-level feedback to achieve a desired joint torque by the leg actuator units <NUM> as a function of feedback from the sensors <NUM> of the system <NUM>. For example, such a method can include obtaining sensor data from one or more sensors <NUM>, determining whether a change in torque by the leg actuator unit <NUM> is necessary, and if so, causing the pneumatic system <NUM> change the fluid state of the leg actuator unit <NUM> to achieve a target j oint torque by the leg actuator unit <NUM>. Various embodiments can include, but are not limited to, the following: current feedback; recorded behavior playback; position-based feedback; velocity-based feedback; feedforward responses; volume feedback which controls a fluidic system <NUM> to inject a desired volume of fluid into an actuator <NUM>, and the like.

Another method implemented by operational control software can be for intent recognition of the user's intended behaviors. This portion of the operational control software, in some embodiments, can indicate any array of allowable behaviors that the system <NUM> is configured to account for. In one preferred embodiment, the operational control software is configured to identify two specific states: Skiing, and Not Skiing. In such an embodiment, to complete intent recognition, the system <NUM> can use user input and/or sensor readings to identify when it is safe, desirable or appropriate to provide assistive actions for skiing. For example, in some embodiments, intent recognition can be based on input received via the user interface <NUM>, which can include an input for Skiing or Not Skiing. Accordingly, in some examples, the use interface can be configured for a binary input consisting of Skiing or Not Skiing.

In some embodiments, a method of skiing intent recognition can include the exoskeleton device <NUM> obtaining data from the sensors <NUM> and determining, based at least in part of the obtained data, whether the data corresponds to a user state of Skiing or Not Skiing. Where a change in state has been identified, the system <NUM> can be re-configured to operate in the current state. For example, the exoskeleton device <NUM> can determine that the user <NUM> is in a Not Skiing state such as walking, riding a chairlift or siting at a ski lodge and can configure the system <NUM> to operate in a Not Skiing configuration. For example, such a Not Skiing configuration can, compared to a Skiing configuration, provide for a wider range of motion; provide no torque or minimal torque to the leg actuation units <NUM>; save power and fluid by minimizing processing and fluidic operations; cause the system to be alert for supporting a wider variety of non-skiing motion, and the like.

The exoskeleton device <NUM> can monitor the activity of the user <NUM> can determine that the user is skiing or is about to ski (e.g., based on sensor data and/or user input), and can then configure the system <NUM> to operate in a Skiing configuration. For example, such a Skiing configuration, compared to a Not Skiing configuration, can allow for a more limited range of motion that would be present during skiing (as opposed to motions during non-skiing); provide for high or maximum performance by increasing the processing and fluidic response of the system <NUM> to support skiing; and the like. When the user <NUM> finishes a ski run, is identified as resting, or the like, the system <NUM> can determine that the user is no longer skiing (e.g., based on sensor data and/or user input) and can then configure the system <NUM> to operate in the Not Skiing configuration.

In some embodiments, there can be a plurality of Skiing states, or Skiing substates that can be determined by the system <NUM>, including hard skiing, moderate skiing, light skiing, downhill, moguls, jumping, powder, ice, trees, open-slope, racing, recreational, and the like (e.g., based on sensor data and/or user input). Such states can be based on the difficulty of the skiing, skill of the user, snow conditions, weather conditions, elevation, angle of the ski slope, desired performance level, power-saving, and the like. Accordingly, in various embodiments, the exoskeleton system <NUM> can adapt for various specific types of skiing based on a wide variety of factors.

Also, it should be clear that while various examples, discussed herein relate to downhill snow skiing, such examples should not be construed as limiting and various other sports or activities are within the scope and spirit of the present disclosure including snowboarding, telemark skiing, mono-skiing, cross-country skiing, ski-jumping, freestyle skiing, ski mountaineering, ice skating, and the like. Also, it should be clear that the present disclosure is intended to cover similar sports or activities that are not necessarily performed on snow or ice, such as sand, dirt or volcano skiing, skateboarding, surfing, mountain biking, BMX biking, roller blading, rock climbing, and the like.

In another embodiment, operational control software can be configured to identify a variety of states and their safe transitions: skiing, standing, turning, stopping, chairlift, and the like. Identifying a given skiing state and possible transitions from the state can be desirable because it can allow the system <NUM> to predict, anticipate and prepare for possible transitions to provide improved performance and support for the user. For example, where the user <NUM> is determined to be in a chairlift state, the system <NUM> can predict that the next state of the user <NUM> will be dismounting the chairlift given that dismounting the chair lift is essentially the only possible next state for the user <NUM>. Accordingly, the system <NUM> can anticipate and prepare for dismounting the chairlift. For example, the system can <NUM> focusing or weighting state detection to chairlift dismounting states since other states may be extremely unlikely or impossible. Also, the system <NUM> can physically prepare for supporting a chairlift dismounting state by preparing the pneumatic system <NUM> for supporting a chairlift dismounting state, or the like. Various embodiments can include any suitable combination of specific maneuver states and it is not to be assumed that the inclusion of any added states necessarily changes the behavior or responsibility of the operational control software to complete intent recognition.

Additionally, the system <NUM> can be configured to identify crash, danger or emergency states and respond accordingly. For example, sensor data can indicate that the user is crashing or may have already crashed while skiing and can change the configuration of the leg actuation units <NUM> accordingly, such as releasing all torque, performing a diagnostic, and the like. For example, when a crash event is identified, the system can generate a free reference where the actuation units <NUM> work to maintain zero torque on the knee joint of the user <NUM> throughout the crash.

Similarly, system <NUM> may identify a danger or emergency of the user, such as a hard fall, crash followed by lack of movement by the user, or the like. In some examples, in response to danger or an emergency detected, the system <NUM> can be configured to alert authorities, activate a location beacon, activate an audio or visual alarm on the system <NUM>, or the like.

In another embodiment, an intent recognition method can identify a jump behavior where a portion of one or both of the skis <NUM> have left the ground during a jump. For example, were the system <NUM> identifies a jump state, the systems <NUM> can produce references to provide zero additional torque to the legs during the flight phase, but prepares to provide a large impulse of torque to brace the user <NUM> upon landing when a landing state is observed. In some embodiments, an amount of impulse torque to brace the user <NUM> can be determined based on factors such as length of time of the jump event; speed, velocity or acceleration of the user; identified snow conditions; orientation of the user <NUM>, and the like. Additionally, the system <NUM> can be configured to differentiate between a jump event and an event when a user is simply lifting a ski <NUM> off the ground; for example, based on data from sensors <NUM>.

In another embodiment, an intent recognition method can identify a walking maneuver. For example, when a walking maneuver is identified, the exoskeleton system <NUM> can generate references to free the legs <NUM> in an effort to provide no assistance but also not get in the user's way. Other embodiments may be configured to identify more phases of a walking gate to provide assistance during stance but not swing, for example, or extend the assistance to provide a substantial benefit while hiking in the system <NUM>. In another embodiment, the software can identify a sustained standing behavior and provide extension assistance at the user's knees <NUM> to support the body during extended standing. Various embodiments can include any one of, none of, all of, or more than these maneuvers.

Another method implemented by operational control software can be the development of desired referenced behaviors for the specific joints providing assistance. This portion of the control software can tie together identified maneuvers with the level control. For example, when the system <NUM> identifies an intended user maneuver, the software can generate reference behaviors that define the torques, or positions desired by the actuators <NUM> in the leg actuation units <NUM>. In one embodiment, the operational control software generates references to make the leg actuation units <NUM> simulate a mechanical spring at the knee <NUM> via the configuration actuator <NUM>. The operational control software can generate torque references at the knee joints that are a linear function of the knee joint angle. In another embodiment, the operational control software generates a volume reference to provide a constant standard volume of air into a pneumatic actuator <NUM>. This can allow the pneumatic actuator <NUM> to operate like a mechanical spring by maintaining the constant volume of air in the actuator <NUM> regardless of the knee angle, which can be identified through feedback from one or more sensors <NUM>.

In another embodiment, a method implemented by the operational control software can generate torques in a dual leg actuation unit <NUM> configuration (e.g., where left and right leg actuation units <NUM>, 110R are worn by a user <NUM>) such that the behavior is coordinated across or between the leg actuation units <NUM>. In one embodiment, the operational control software coordinates the behavior of the leg actuation units <NUM> to direct system torque away from the most bent leg <NUM>. In this example case, the leg actuation units <NUM> can operate opposite of a spring where the leg <NUM> receives less torque as the knee <NUM> is bent more, but based on the relative angles of the two knees <NUM>, 103R of the two legs <NUM>, 102R. For example, if both legs <NUM>, 102R are bent the same amount, the legs <NUM>, 102R can receive the same torque reference via the left and right leg actuation units <NUM>, 110R respectively, but if only one leg <NUM> is bent (e.g., if the left leg <NUM> is bent), the torque applied by the actuation units <NUM> can skewed towards the leg <NUM> that is more straight (e.g., to the right leg 102R if the left leg <NUM> is bent).

Accordingly, a method of operating an exoskeleton system can include the exoskeleton device <NUM> obtaining sensor data from the sensors <NUM> indicating an amount of bend in the legs <NUM>, 102R of a user <NUM> based on the configuration of left and right leg actuation units <NUM>, 110R and determining a difference between the amount of bend in the legs <NUM>, 102R of a user <NUM>. Where one leg <NUM> is bent more than the other leg 102R, the less-bent leg 102R can receive less torque than the more-bent leg <NUM>, with the amount of less torque being applied based at least in part on the difference between the amount of bend in the legs <NUM>, 102R of the user <NUM>.

In another embodiment, a method implemented by the operational control software can include evaluating the balance of the user <NUM> while skiing and directing torque in such a way to encourage the user <NUM> to remain balanced by directing knee assistance to the leg <NUM> that is on the outside of the users current balance profile. Accordingly, a method of operating an exoskeleton system can include the exoskeleton device <NUM> obtaining sensor data from the sensors <NUM> indicating a balance profile of a user <NUM> based on the configuration of left and right leg actuation units <NUM>, 110R and/or environmental sensors such as position sensors, accelerometers, and the like. The method can further include determining a balance profile based on the obtained data, including outside and inside leg, and then increasing torque to the actuation unit <NUM> associated with the leg <NUM> identified as the outside leg.

Various embodiments can use but are not limited to kinematic estimates of posture, joint kinetic profile estimates, as well as observed estimates of body pose. Various other embodiments exist for methods of coordinating two legs <NUM> to generate torques including but not limited to guiding torque to the most bent leg; guiding torque based on the mean amount of knee angle across both legs; scaling the torque as a function of speed or acceleration; and the like. It should also be noted that yet another embodiment can include a combination of various individual reference generation methods in a variety of matters which include but are not limited to a linear combination, a maneuver specific combination, or a non-linear combination.

In some cases where a method includes operational control software coordinating control between various legs <NUM>, it can be helpful to incorporate user preference to account for a variety of factors such as self-selected skiing style or skill. In such a scenario, there can be factors used to combine or scale the parameters for operating the exoskeleton system <NUM> while skiing. In one embodiment, the user <NUM> can provide input (e.g., via user interface <NUM>) about the overall amount of torque desired which can be used in an operational control method to scale the output torque reference up or down based on the input from the user <NUM>.

In another embodiment, an operational control method can blend two primary reference generation techniques: one reference focused on static assistance and one reference focused on leading the user <NUM> into their upcoming behavior. In some examples, the user <NUM> can select how much predictive assistance is desired while using the exoskeleton system <NUM>. For example, by a user <NUM> indicating a large amount of predictive assistance, the system <NUM> can be configured to very responsive and may be well configured for a skilled skier on a challenging terrain. The user <NUM> could also indicate a desire for very low amount of predictive assistance, which can result in slower system performance, which may be better tailored towards a learning skier or less challenging terrain.

Various embodiments can incorporate user intent in a variety of manners and the examples embodiments presented above should not be interpreted as limiting in any way. For example, method of determining and operating an exoskeleton system <NUM> can include systems and method of <CIT> entitled "SYSTEM AND METHOD FOR USER INTENT RECOGNITION" having attorney docket number <NUM>-003US0. Also, various embodiments can use user intent in a variety of manners including as a continuous unit, or as a discrete setting with only a few indicated values.

At times it can be beneficial for operational control software to manipulate its control to account for a secondary or additional objective in order to maximize device performance or user experience. In one embodiment, the exoskeleton system <NUM> can provide an elevation-aware control over a central compressor or other components of a pneumatic system <NUM> to account for the changing density of air at different elevations. For example, operational control software can identify that the system is operating at a higher elevation based on data from sensors <NUM>, or the like, and provide more current to the compressor in order to maintain electrical power consumed by the compressor. Accordingly, a method of operating a pneumatic exoskeleton system <NUM> can include obtaining data indicating air density where the pneumatic exoskeleton system <NUM> is operating (e.g., elevation data), determining optimal operating parameters of the pneumatic system <NUM> based on the obtained data, and configuring operation based on the determined optimal operating parameters. In further embodiments, operation of a pneumatic exoskeleton system <NUM> can be tuned based on environmental temperature, which may affect air volumes.

In another embodiment, the system <NUM> can monitor the ambient audible noise levels and vary the control behavior of the system <NUM> to reduce the noise profile of the system. For example, when a user <NUM> is in a quiet public place or quietly enjoying the outdoors alone or with others, noise associated with actuation of the leg actuation units <NUM> can be undesirable (e.g., noise of running a compressor or inflating or deflating actuators <NUM>). Accordingly, in some embodiments, the sensors <NUM> can include a microphone that detects ambient noise levels and can configure the exoskeleton system <NUM> to operate in a quiet mode when ambient noise volume is below a certain threshold. Such a quiet mode can configure elements of a pneumatic system <NUM> or actuators <NUM> to operate more quietly, or can delay or reduce frequency of noise made by such elements.

In the case of a modular system, it can be desirable in various embodiments for operational control software to operate differently based on the number of leg actuation units <NUM> operational within the exoskeleton system <NUM>. For example, in some embodiments, a modular dual-knee system <NUM> (see e.g., <FIG> and <FIG>) can also operate in a single knee configuration where only one of two leg actuation units <NUM> are being worn by a user <NUM> (see e.g., <FIG> and <FIG>) and the system <NUM> can generate references differently when in a two-leg configuration compared to a single leg configuration. Such an embodiment can use a coordinated control approach to generate references where the system <NUM> is using inputs from both leg actuation units <NUM> to determine the desired operation. However in a single-leg configuration, the available sensor information may have changed, so in various embodiments the system <NUM> can implement a different control method. In various embodiments this can be done to maximize the performance of the system <NUM> for the given configuration or account for differences in available sensor information based on there being one or two leg actuation units <NUM> operating in the system <NUM>.

Accordingly, a method of operating an exoskeleton system <NUM> can include a startup sequence where a determination is made by the exoskeleton device <NUM> whether one or two leg actuation units <NUM> are operating in the system <NUM>; determining a control method based on the number of actuation units <NUM> that are operating in the system <NUM>; and implementing and operating the system <NUM> with the selected control method. A further method operating an exoskeleton system <NUM> can include monitoring by the exoskeleton device <NUM> of actuation units <NUM> that are operating in the system <NUM>, determining a change in the number of actuation units <NUM> operating in the system <NUM>, and then determining and changing the control method based on the new number of actuation units <NUM> that are operating in the system <NUM>.

For example, the system <NUM> can be operating with two actuation units <NUM> and with a first control method. The user <NUM> can disengage one of the actuation units <NUM>, and the exoskeleton device <NUM> can identify the loss of one of the actuation units <NUM> and the exoskeleton device <NUM> can determine and implement a new second control method to accommodate loss of one of the actuation units <NUM>. In some examples, adapting to the number of active actuation units <NUM> can be beneficial where one of the actuation units <NUM> is damaged or disconnected during use and the system <NUM> is able to adapt automatically so the user <NUM> can still continue skiing uninterrupted despite the system <NUM> only having a single active actuation unit <NUM>.

In various embodiments, operational control software can adapt a control method where user needs are different between individual actuation units <NUM> or legs <NUM>. In such an embodiment, it can be beneficial for the exoskeleton system <NUM> to change the torque references generated in each actuation unit <NUM> to tailor the experience for the user <NUM>. One example is of a dual knee exoskeleton system <NUM> (see e.g., <FIG> and <FIG>) where a user <NUM> has significant weakness issues in a single leg <NUM>, but only minor weakness issues in the other leg <NUM>. In this example, the exoskeleton system <NUM> can be configured to scale down the output torques on the less-affected limb compared to the more-affected limb to best meet the needs of the user <NUM>.

Such a configuration based on differential limb strength can be done automatically by the system <NUM> and/or can be configured via a user interface <NUM>, or the like. For example, in some embodiments, the user <NUM> can perform a calibration test while using the system <NUM>, which can test relative strength or weakness in the legs <NUM> of the user <NUM> and configure the system <NUM> based on identified strength or weakness in the legs <NUM>. Such a test can identify general strength or weakness of legs <NUM> or can identify strength or weakness of specific muscles or muscle groups such as the quadriceps, calves, hamstrings, gluteus, gastrocnemius; femoris, sartorius, soleus, and the like.

Another aspect of a method for operating an exoskeleton system <NUM> can include control software that monitors the system <NUM>. A monitoring aspect of such software can, in some examples, focus on monitoring the state of the system <NUM> and the user <NUM> throughout normal operation in an effort to provide the system <NUM> with situational awareness and understanding of sensor information in order to drive user understanding and device performance. One aspect of such monitoring software can be to monitor the state of the system <NUM> in order to provide device understanding to achieve a desired performance capability. A portion of this can be the development of a system body pose estimate. In one embodiment, the exoskeleton device <NUM> uses the onboard sensors <NUM> to develop a real-time understanding of the user's pose. In other words, data from sensors <NUM> can be used to determine the configuration of the actuation units <NUM>, which along with other sensor data can in turn be used to infer a user pose or body configuration estimate of the user <NUM> wearing the actuation units <NUM>.

At times, and in some embodiments, it can be unrealistic or impossible for the system <NUM> to directly sense all important aspects of the system pose due to the sensing modalities not existing or their inability to be practically integrated into the hardware. As a result, the system <NUM> in some examples can rely on a fused understanding of the sensor information around an underlying model of the user's body and the system <NUM> the user is wearing. In one embodiment of a dual leg knee assistance system <NUM>, the exoskeleton device <NUM> can use an underlying model of the user's lower extremity and torso body segments to enforce a relational constraint between the otherwise disconnected sensors <NUM>. Such a model can allow the system <NUM> to understand the constrained motion of the two legs <NUM> in that they are mechanically connected through the user's kinematic chain created by the body. This approach can be used to ensure that the estimates for knee orientation are properly constrained and biomechanically valid. In various embodiments, the system <NUM> can includes sensors <NUM> embedded in the exoskeleton device <NUM> and/or pneumatic system <NUM> to provide a fuller picture of the system posture. In yet another embodiment, the system <NUM> can include logical constraints that are unique to the application in an effort to provide additional constraints on the operation of the pose estimation. This can be desirable, in some embodiments, in conditions where ground truth information is unavailable such as highly dynamic actions, where the system <NUM> is denied an external GPS signal, or the earth's magnetic field is distorted.

Another aspect of a method of controlling an exoskeleton system <NUM> can include monitoring software configured to identify geolocation based triggers for different device behavior. In one embodiment, the system <NUM> can determine a ski run the user <NUM> is about to go down and then switch to a pre-recorded or previously user-defined or system-defined set of parameters to appropriately fit the identified ski run. For example, if a user <NUM> is going down a low difficulty ski slope she may choose to specify a low amount of predictive assistance for the system <NUM>, whereas before she goes down a high difficulty ski run she may typically switch the predictive assistance to a much higher level. In future visits to the low difficulty ski run, the system can use the geolocation based monitoring to identify the upcoming run and suggest to the user or automatically switch to the lower predictive setting and do the inverse when the monitoring software identifies the user <NUM> is entering a high difficulty area. Various embodiments can use this capability in a variety of methods which can include but are not limited to the discrete identification of specific geolocated indicators, or the continuous monitoring of geolocated triggers with the ability to manipulate performance as the user <NUM> is using the device <NUM>.

Identifying location of the user <NUM> and/or exoskeleton system <NUM> can be done in various suitable way, including via GPS system of the exoskeleton device <NUM>; a user device such as a smartphone or wearable device; or location tags such as an RFID, wireless signal, or the like. Identifying a given location as being associated with the beginning of a ski run, a portion of a ski run, an end of a ski run, or non-ski run location can be done in various suitable ways. In one example, an administrator can define geographic boundaries or locations for different ski runs, non-ski run locations, beginning and/or end of a ski run, or the like, and the determined location of the user <NUM> and/or exoskeleton system <NUM> can be compared to these defined boundaries or locations. Additionally, locations of different items or attributes of a location can be defined such as terrain, hazards, points of interest, or routes, which can include as open slope, trees, rocks, jumps, cliffs, crevasses, avalanche zones, chair lifts, slope angles, moguls, difficulty rating, and the like.

In some embodiments, local tags such as gates, beacons, or the like can identify a location and/or attributes of a location. For example, the user passing through a gate or coming within proximity of a beacon (e.g., RFID, wireless signal, or the like) can identify a location and/or attributes of a location, which can be used to configure an exoskeleton device <NUM>. In some embodiments, such a gate or beacon can communicate information regarding location and/or attributes of a location or such a gate or beacon can communicate an identifier, which the exoskeleton system <NUM> can use to lookup information corresponding to a location and/or attributes of a location.

For example, a user <NUM> with an exoskeleton system <NUM> can come into proximity of a beacon, pass through a gate or be geo-located at a location that can indicate that the user <NUM> is at the start of a black diamond ski run and the exoskeleton system <NUM> can be configured accordingly. Similarly, changes to the configuration of the system <NUM> can be based on being at the beginning of a chairlift, at the end of a chairlift, at the end of a ski run, entering a portion of a ski run with a different difficulty, entering a ski lodge, and the like.

In some embodiments, changes in configuration of the system <NUM> based location and/or location attributes can be performed automatically and/or with input from the user <NUM>. For example, in some embodiments, the system <NUM> can provide one or more suggestions for a change in configuration based location and/or location attributes and the user <NUM> can choose to accept such suggestions. In further embodiments, some or all configuration of the system <NUM> based location and/or location attributes can occur automatically without user interaction.

In some embodiments, tagging locations and recording location information and attributes can be initiated by a user <NUM>. For example, before going down a new ski run, the user can tag the current location of user as being the start of a ski run, which may or may not include ski run attributes such as difficulty level, or the like. Additionally, in some examples, the user can record activity of the system <NUM> during a ski run, which can be associate with that ski run. Accordingly, some embodiments allow users to generate profiles for a plurality of ski runs, which can be used to identify when the user is at the start of a given ski run, how to configure the system <NUM> for the ski run, how to change the configuration of the system <NUM> during the ski run, and the like.

Various embodiments can include the collection and storage of data from the system <NUM> throughout operation. In one embodiment, this can include the live streaming of the data collected on the exoskeleton device <NUM> to a cloud storage location via the communication unit(s) <NUM> through an available wireless communication protocol or storage of such data on the memory <NUM> of the exoskeleton device <NUM>, which may then be uploaded to another location via the communication unit(s) <NUM>. For example, when the system <NUM> obtains a network connection, recorded data can be uploaded to the cloud at a communication rate that is supported by the available data connection. Various embodiments can include variations of this, but the use of monitoring software to collect and store data about the device <NUM> locally and/or remotely for retrieval at a later time for a device such as this can be included in various embodiments.

In some embodiments, once such data has been recorded, it can be desirable to use the data for a variety of different applications. One such application can be the use of the data to develop further oversight functions on the device <NUM> in an effort to identify device system issues that are of note. One embodiment can be the use of the data to identify a specific exoskeleton device <NUM> or leg actuator unit <NUM> among a plurality, whose performance has varied significantly over a variety of uses. Another use of the data can be to provide it back to the user <NUM> to gain a better understanding of how they ski. One embodiment of this can be providing the data back to the user <NUM> through a mobile application that can allow the user <NUM> to review their day skiing on a mobile device. Yet another use of such device data can be to synchronize playback of data with an external data stream to provide additional context. One embodiment is a system that incorporates the GPS data from a companion smartphone with the data stored natively on the device. Another embodiment can include the time synchronization of recorded video with the data stored that was obtained from the device <NUM>. Various embodiments can use these methods for immediate use of data by the user to evaluate their own performance, for later retrieval by the user to understand behavior from the past, for users to compare with other users in-person or through an online profile, by developers to further the development of the system, and the like.

Another aspect of a method of operating an exoskeleton system can include monitoring software identifying of user-specific traits. For example, the system <NUM> can provide an awareness of how a specific skier <NUM> operates in the system <NUM> and over time can develop a profile of the user's specific traits in an effort to maximize device performance for that user. One embodiment can include the device <NUM> identifying a user-specific skiing type in an effort to identify the skiing style or level of the specific user. Through an evaluation of the skier's form and stability during skiing actions (e.g., via analysis of data obtained from the sensors <NUM> or the like), the exoskeleton device <NUM> in some examples can identify if the skier is highly skilled, novice, or beginner. This understanding of skill level or style can allow the system <NUM> to better tailor control references to the specific user.

In further embodiments, the exoskeleton system <NUM> can also use individualized information about a given user to build a profile of the user's biomechanic response to the exoskeleton system <NUM>. One embodiment can include the system <NUM> collecting data regarding the user to develop an estimate of the individual user's knee strain in an effort to assist the user with understanding the burden the user has placed on his legs <NUM> throughout skiing. This can allow the system <NUM> to alert a user if the user has reached a historically significant amount of knee strain to alert the user that he may want to stop to spare himself potential pain or discomfort.

Another embodiment of individualized biomechanic response can be the system collecting data regarding the user to develop an individualized system model for the specific user. In such an embodiment the individualized model can be developed through a system ID (identification) method that evaluates the system performance with an underlying system model and can identify the best model parameters to fit the specific user. The system ID in such an embodiment can operate to estimate segment lengths and masses (e.g., of legs <NUM> or portions of the legs <NUM>) to better define a dynamic user model. In another embodiment, these individualized model parameters can be used to deliver user specific control responses as a function of the users specific masses and segment lengths. In some example of a dynamic model, this can help significantly with the devices ability to account for dynamic forces during highly challenging ski activities.

In various embodiments the device <NUM> can monitor itself in relation to a community of skiers around the user <NUM> and device <NUM> where the others skiers may or may not be wearing an exoskeleton device <NUM> of their own. In addition some embodiments being configured to evaluate user time or location in relation to other skiers, the device <NUM> in some examples can allow the user to compare and broadcast a much wider variety of information with friends and others in proximity of the user.

One embodiment of community monitoring can include playback or broadcast of posture data during a ski run. This can allow others to observe the body posture of another user correlated to specific locations on the ski run. In some embodiments, this information can be displayed in a strictly private mode where users can selectively share their data with selected friends, and in other embodiments the data can be broadcast with nearby users for comparison or observation. In some embodiments it can be beneficial to compare ski performance on a specific run to that of another selected user. This can be done through a comparison of a specific user to the performance of a friend, or to the performance of specified target user such as a ski professional. In another embodiment, community ski data can be aggregated to determine the specific snowy conditions of the run. In another embodiment, the system <NUM> can determine when a skier has had a serious crash and appears to be injured. The system <NUM> can then use this information to alert nearby skiers or safety personnel to check in on the user.

In various embodiments, the exoskeleton system <NUM> can provide for various types of user interaction. For example such interaction can include input from the user <NUM> as needed into the system <NUM> and the system <NUM> providing feedback to the user <NUM> to indicate changes in operation of the system <NUM>, status of the system <NUM>, and the like. As discussed herein, user input and/or output to the user can be provided via one or more user interface <NUM> of the exoskeleton device <NUM> or can include various other interfaces or devices such as a smartphone user device. Such one or more user interfaces <NUM> or devices can be located in various suitable locations such as on a backpack <NUM> (see e.g., <FIG>, <FIG> and <FIG>), the pneumatic system <NUM>, leg actuation units <NUM>, or the like.

The system <NUM> can be configured to obtain intent from the user <NUM>. For example, this can be accomplished through a variety of input devices that are either integrated directly with the other components of the system <NUM> (e.g., one or more user interface <NUM>), or external and operably connected with the system <NUM> (e.g., a smartphone, wearable device, remote server, or the like). In one embodiment, a user interface <NUM> can comprise a button that is integrated directly into one or both of the leg actuation units <NUM> of the system <NUM>. This single button can allow the user <NUM> to indicate a variety of inputs. In another embodiment, a user interface <NUM> can be configured to be provided through a torso-mounted lapel input device that is integrated with the exoskeleton device <NUM> and/or pneumatic system <NUM> of the exoskeleton system <NUM>. In one example, such a user interface <NUM> can comprise a button that has a dedicated enable and disable functionality; a selection indicator dedicated to the user's desired power level (e.g., an amount or range of force applied by the leg actuator units <NUM>); and a selector switch that can be dedicated to the amount of predictive intent to integrate into the control of the system <NUM>. Such an embodiment of a user interface <NUM> can use a series of functionally locked buttons to provide the user <NUM> with a set of understood indicators that may be required for normal operation in some examples. Yet another embodiment can include a mobile device that is connected to the exoskeleton system <NUM> via a Bluetooth connection or other suitable wired or wireless. Use of a mobile device or smartphone as a user interface <NUM> can allow the user a far greater amount of input to the device due to the flexibility of the input method. Various embodiments can use the options listed above or combinations and variants thereof, but are in no way limited to the explicitly stated combinations of input methods and items.

The one or more user interface <NUM> can provide information to the user <NUM> to allow the user to appropriately use and operate the device <NUM>. Such feedback can be in a variety of visual, haptic and/or audio methods including, but not limited to, feedback mechanisms integrated directly one or both of the actuation units <NUM>; feedback through operation of the actuation units <NUM>; feedback through external items not integrated with the system <NUM> (e.g., a mobile device); and the like. Some embodiments can include integration of feedback lights in the actuation units <NUM>, of the exoskeleton system <NUM>. In one such embodiment, five multi-color lights are integrated into the knee joint <NUM> or other suitable location such that the user <NUM> can see the lights. These lights can be used to provide feedback of system errors, device power, successful operation of the device, and the like. In another embodiment, the system <NUM> can provide controlled feedback to the user to indicate specific pieces of information. In such embodiments, the system <NUM> can pulse the joint torque on one or both of the leg actuation units <NUM> to the maximum allowed torque when the user changes the maximum allowable user-desired torque, which can provide a haptic indicator of the torque settings. Another embodiment can use an external device such as a mobile device where the system <NUM> can provide alert notifications for device information such as operational errors, setting status, power status, and the like. Types of feedback can include, but are not limited to, lights, sounds, vibrations, notifications, and operational forces integrated in a variety of locations that the user <NUM> may be expected to interact with including the actuation units <NUM>, pneumatic system <NUM>, backpack <NUM>, mobile devices, or other suitable methods of interactions such as a web interface, SMS text or email.

The communication unit <NUM> can include hardware and/or software that allows the exoskeleton system <NUM> to communicate with other devices, including a user device, a classification server, other exoskeleton systems <NUM>, or the like, directly or via a network. For example, the exoskeleton system <NUM> can be configured to connect with a user device, which can be used to control the exoskeleton system <NUM>, receive performance data from the exoskeleton system <NUM>, facilitate updates to the exoskeleton system, and the like. Such communication can be wired and/or wireless communication.

In some embodiments, the sensors <NUM> can include any suitable type of sensor, and the sensors <NUM> can be located at a central location or can be distributed about the exoskeleton system <NUM>. For example, in some embodiments, the exoskeleton system <NUM> can comprise a plurality of accelerometers, force sensors, position sensors, and the like, at various suitable positions, including at the arms <NUM>, <NUM>, joint <NUM>, actuators <NUM> or any other location. Accordingly, in some examples, sensor data can correspond to a physical state of one or more actuators <NUM>, a physical state of a portion of the exoskeleton system <NUM>, a physical state of the exoskeleton system <NUM> generally, and the like. In some embodiments, the exoskeleton system <NUM> can include a global positioning system (GPS), camera, range sensing system, environmental sensors, elevation sensor, microphone, thermometer, or the like. In some embodiments, the exoskeleton system <NUM> can obtain sensor data from a user device such as a smartphone, or the like.

The pneumatic system <NUM> can comprise any suitable device or system that is operable to inflate and/or deflate the actuators <NUM> individually or as a group. For example, in one embodiment, the pneumatic system can comprise a diaphragm compressor as disclosed in related patent application <CIT>.

As discussed herein, various suitable exoskeleton systems <NUM> can be used in various suitable ways and for various suitable applications. However, such examples should not be construed to be limiting on the wide variety of exoskeleton systems <NUM> or portions thereof that are within the scope and spirit of the present disclosure. Accordingly, exoskeleton systems <NUM> that are more or less complex than the examples of <FIG> are within the scope of the present disclosure.

Additionally, while various examples relate to an exoskeleton system <NUM> associated with the legs or lower body of a user, further examples can be related to any suitable portion of a user body including the torso, arms, head, legs, or the like. Also, while various examples relate to exoskeletons, it should be clear that the present disclosure can be applied to other similar types of technology, including prosthetics, body implants, robots, or the like. Further, while some examples can relate to human users, other examples can relate to animal users, robot users, various forms of machinery, or the like.

Turning to <FIG>, <FIG>, examples of a leg actuator unit <NUM> can include the joint <NUM>, bellows <NUM>, constraint ribs <NUM>, and base plates <NUM>. More specifically, <FIG> illustrates a side view of a leg actuator unit <NUM> in a compressed configuration and <FIG> illustrates a side view of the leg actuator unit <NUM> of <FIG> in an expanded configuration. <FIG> illustrates a cross-sectional side view of a leg actuator unit <NUM> in a compressed configuration and <FIG> illustrates a cross-sectional side view of the leg actuator unit <NUM> of <FIG> in an expanded configuration.

As shown in <FIG>, <FIG>, the joint <NUM> can have a plurality of constraint ribs <NUM> extending from and coupled to the joint <NUM>, which surround or abut a portion of the bellows <NUM>. For example, in some embodiments, constraint ribs <NUM> can abut the ends <NUM> of the bellows <NUM> and can define some or all of the base plates <NUM> that the ends <NUM> of the bellows <NUM> can push against. However, in some examples, the base plates <NUM> can be separate and/or different elements than the constraint ribs <NUM> (e.g., as shown in <FIG>). Additionally, one or more constraint ribs <NUM> can be disposed between ends <NUM> of the bellows <NUM>. For example, <FIG>, <FIG> illustrate one constraint rib <NUM> disposed between ends <NUM> of the bellows <NUM>; however, further embodiments can include any suitable number of constraint ribs <NUM> disposed between ends of the bellows <NUM>, including <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and the like. In some embodiments, constraint ribs can be absent.

As shown in cross sections of <FIG>, the bellows <NUM> can define a cavity <NUM> that can be filled with fluid (e.g., air), to expand the bellow <NUM>, which can cause the bellows to elongate along axis B as shown in <FIG> and <FIG>. For example, increasing a pressure and/or volume of fluid in the bellows <NUM> shown in <FIG> can cause the bellows <NUM> to expand to the configuration shown in <FIG>. Similarly, increasing a pressure and/or volume of fluid in the bellows <NUM> shown in <FIG> can cause the bellows <NUM> to expand to the configuration shown in <FIG>. For clarity, the use of the term 'bellows' is to describe a component in the described actuator unit <NUM> and is not intended to limit the geometry of the component. The bellows <NUM> can be constructed with a variety of geometries including but not limited to: a constant cylindrical tube, a cylinder of varying cross-sectional area, a <NUM>-D woven geometry that inflates to a defined arc shape, and the like. The term 'bellows' should not be construed to necessary include a structure having convolutions.

Alternatively, decreasing a pressure and/or volume of fluid in the bellows <NUM> shown in <FIG> can cause the bellows <NUM> to contract to the configuration shown in <FIG>. Similarly, decreasing a pressure and/or volume of fluid in the bellows <NUM> shown in <FIG> can cause the bellows <NUM> to contract to the configuration shown in <FIG>. Such increasing or decreasing of a pressure or volume of fluid in the bellows <NUM> can be performed by pneumatic system <NUM> and pneumatic lines <NUM> of the exoskeleton system <NUM>, which can be controlled by the exoskeleton device <NUM> (see <FIG>).

In one preferred embodiment, the bellows <NUM> can be inflated with air; however, in further embodiments, any suitable fluid can be used to inflate the bellows <NUM>. For example, gasses including oxygen, helium, nitrogen, and/or argon, or the like can be used to inflate and/or deflate the bellows <NUM>. In further embodiments, a liquid such as water, an oil, or the like can be used to inflate the bellows <NUM>. Additionally, while some examples discussed herein relate to introducing and removing fluid from a bellows <NUM> to change the pressure within the bellows <NUM>, further examples can include heating and/or cooling a fluid to modify a pressure within the bellows <NUM>.

As shown in <FIG>, <FIG>, the constraint ribs <NUM> can support and constrain the bellows <NUM>. For example, inflating the bellows <NUM> cause the bellows <NUM> expand along a length of the bellows <NUM> and also cause the bellows <NUM> to expand radially. The constraint ribs <NUM> can constrain radial expansion of a portion of the bellows <NUM>. Additionally, as discussed herein, the bellows <NUM> comprise a material that is flexible in one or more directions and the constraint ribs <NUM> can control the direction of linear expansion of the bellows <NUM>. For example, in some embodiments, without constraint ribs <NUM> or other constraint structures the bellows <NUM> would herniate or bend out of axis uncontrollably such that suitable force would not be applied to the base plates <NUM> such that the arms <NUM>, <NUM> would not be suitably or controllably actuated. Accordingly, in various embodiments, the constraint ribs <NUM> can be desirable to generate a consistent and controllable axis of expansion B for the bellows <NUM> as they are inflated and/or deflated.

In some examples, the bellows <NUM> in a deflated configuration can substantially extend past a radial edge of the constraint ribs <NUM> and can retract during inflation to extend less past the radial edge of the constraint ribs <NUM>, to extend to the radial edge of the constraint ribs <NUM>, or to not extend less past the radial edge of the constraint ribs <NUM>. For example, <FIG> illustrates a compressed configuration of the bellows <NUM> where the bellows <NUM> substantially extend past a radial edge of the constraint ribs <NUM> and <FIG> illustrates the bellows <NUM> retracting during inflation to extend less past the radial edge of the constraint ribs <NUM> in an inflated configuration of the bellows <NUM>.

Similarly, <FIG> illustrates a top view of a compressed configuration of bellows <NUM> where the bellows <NUM> substantially extend past a radial edge of constraint ribs <NUM> and <FIG> illustrates a top view where the bellows <NUM> retract during inflation to extend less past the radial edge of the constraint ribs <NUM> in an inflated configuration of the bellows <NUM>.

Constraint ribs <NUM> can be configured in various suitable ways. For example, <FIG> and <FIG> illustrate a top view of an example embodiment of a constraint rib <NUM> having a pair of rib arms <NUM> that extend from the joint <NUM> and couple with a circular rib ring <NUM> that defines a rib cavity <NUM> through which a portion of the bellows <NUM> can extend (e.g., as shown in <FIG>, <FIG>). In various examples, the one or more constraint ribs <NUM> can be a substantially planar element with the rib arms <NUM> and rib ring <NUM> being disposed within a common plane.

In further embodiments, the one or more constraint ribs <NUM> can have any other suitable configuration. For example, some embodiments can have any suitable number of rib arms <NUM>, including one, two, three, four, five, or the like. Additionally, the rib ring <NUM> can have various suitable shapes and need not be circular, including one or both of an inner edge that defines the rib cavity <NUM> or an outer edge of the rib ring <NUM>.

In various embodiments, the constraining ribs <NUM> can be configured to direct the motion of the bellows <NUM> through a swept path about some instantaneous center (which may or may not be fixed in space) and/or to prevent motion of the bellows <NUM> in undesired directions, such as out-of-plane buckling. As a result, the number of constraining ribs <NUM> included in some embodiments can vary depending on the specific geometry and loading of the leg actuator unit <NUM>. Examples can range from one constraining rib <NUM> up to any suitable number of constraining ribs <NUM>; according, the number of constraining ribs <NUM> should not be taken to limit the applicability of the invention. Additionally, constraining ribs <NUM> can be absent in some embodiments.

The one or more constraining ribs <NUM> can be constructed in a variety of ways. For example the one or more constraining ribs <NUM> can vary in construction on a given leg actuator unit <NUM>, and/or may or may not require attachment to the joint structure <NUM>. In various embodiments, the constraining ribs <NUM> can be constructed as an integral component of a central rotary joint structure <NUM>. An example embodiment of such a structure can include a mechanical rotary pin joint, where the constraining ribs <NUM> are connected to and can pivot about the joint <NUM> at one end of the joint <NUM>, and are attached to an inextensible outer layer of the bellows <NUM> at the other end. In another set of embodiments, the constraining ribs <NUM> can be constructed in the form of a single flexural structure that directs the motion of the bellows <NUM> throughout the range of motion for the leg actuator unit <NUM>. Another example embodiment uses a flexural constraining rib <NUM> that is not connected integrally to the joint structure <NUM> but is instead attached externally to a previously assembled joint structure <NUM>. Another example embodiment can comprise the constraint rib <NUM> being composed of pieces of fabric wrapped around the bellows <NUM> and attached to the joint structure <NUM>, acting like a hammock to restrict and/or guide the motion of the bellows <NUM>. There are additional methods available for constructing the constraining ribs <NUM> that can be used in additional embodiments that include but are not limited to a linkage, a rotational flexure connected around the joint <NUM>, and the like.

In some examples, a design consideration for constraining ribs <NUM> can be how the one or more constraining ribs <NUM> interact with the bellows <NUM> to guide the path of the bellows <NUM>. In various embodiments, the constraining ribs <NUM> can be fixed to the bellows <NUM> at predefined locations along the length of the bellows <NUM>. One or more constraining ribs <NUM> can be coupled to the bellows <NUM> in various suitable ways, including but not limited to sewing, mechanical clamps, geometric interference, direct integration, and the like. In other embodiments, the constraining ribs <NUM> can be configured such that the constraining ribs <NUM> float along the length of the bellows <NUM> and are not fixed to the bellows <NUM> at predetermined connection points. In some embodiments, the constraining ribs <NUM> can be configured to restrict a cross sectional area of the bellows <NUM>. An example embodiment can include a tubular bellows <NUM> attached to a constraining rib <NUM> that has an oval cross section, which in some examples can be a configuration to reduce the width of the bellows <NUM> at that location when the bellows <NUM> is inflated.

The bellows <NUM> can have various functions in some embodiments, including containing operating fluid of the leg actuator unit <NUM>, resisting forces associated with operating pressure of the leg actuator unit <NUM>, and the like. In various examples, the leg actuator unit <NUM> can operate at a fluid pressure above, below or at about ambient pressure. In various embodiments, bellows <NUM> can comprise one or more flexible, yet inextensible or practically inextensible materials in order to resist expansion (e.g., beyond what is desired in directions other than an intended direction of force application or motion) of the bellows <NUM> beyond what is desired when pressurized above ambient pressure. Additionally, the bellows <NUM> can comprise an impermeable or semi-impermeable material in order to contain the actuator fluid.

For example, in some embodiments, the bellows <NUM> can comprise a flexible sheet material such as woven nylon, rubber, polychloroprene, a plastic, latex, a fabric, or the like. Accordingly, in some embodiments, bellows <NUM> can be made of a planar material that is substantially inextensible along one or more plane axes of the planar material while being flexible in other directions. For example, <FIG> illustrates a side view of a planar material <NUM> (e.g., a fabric) that is substantially inextensible along axis X that is coincident with the plane of the material <NUM>, yet flexible in other directions, including axis Z. In the example of <FIG>, the material <NUM> is shown flexing upward and downward along axis Z while being inextensible along axis X. In various embodiments, the material <NUM> can also be inextensible along an axis Y (not shown) that is also coincident with the plane of the material <NUM> like axis X and perpendicular to axis X.

In some embodiments, the bellows <NUM> can be made of a non-planar woven material that is inextensible along one or more axes of the material. For example, in one embodiment the bellows <NUM> can comprise a woven fabric tube. Woven fabric material can provide inextensibility along the length of the bellows <NUM> and in the circumferential direction. Such embodiments can still able to be configured along the body of the user <NUM> to align with the axis of a desired joint on the body <NUM> (e.g., the knee <NUM>).

In various embodiments, the bellows <NUM> can develop its resulting force by using a constrained internal surface length and/or external surface length that are a constrained distance away from each other (e.g. due to an inextensible material as discussed above). In some examples, such a design can allow the actuator to contract on bellows <NUM>, but when pressurized to a certain threshold, the bellows <NUM> can direct the forces axially by pressing on the plates <NUM> of the leg actuator unit <NUM> because there is no ability for the bellows <NUM> to expand further in volume otherwise due to being unable to extend its length past a maximum length defined by the body of the bellows <NUM>.

In other words, the bellows <NUM> can comprise a substantially inextensible textile envelope that defines a chamber that is made fluid-impermeable by a fluid-impermeable bladder contained in the substantially inextensible textile envelope and/or a fluid-impermeable structure incorporated into the substantially inextensible textile envelope. The substantially inextensible textile envelope can have a predetermined geometry and a non-linear equilibrium state at a displacement that provides a mechanical stop upon pressurization of the chamber to prevent excessive displacement of the substantially inextensible textile actuator.

In some embodiments, the bellows <NUM> can include an envelope that consists or consists essentially of inextensible textiles (e.g., inextensible knits, woven, non-woven, etc.) that can prescribe various suitable movements as discussed herein. Inextensible textile bellows <NUM> can be designed with specific equilibrium states (e.g., end states or shapes where they are stable despite increasing pressure), pressure/stiffness ratios, and motion paths. Inextensible textile bellows <NUM> in some examples can be configured accurately delivering high forces because inextensible materials can allow greater control over directionality of the forces.

Accordingly, some embodiments of inextensible textile bellows <NUM> can have a pre-determined geometry that produces displacement mostly via a change in the geometry between the uninflated shape and the pre-determined geometry of its equilibrium state (e.g., fully inflated shape) due to displacement of the textile envelope rather than via stretching of the textile envelope during a relative increase in pressure inside the chamber; in various embodiments, this can be achieved by using inextensible materials in the construction of the envelope of the bellows <NUM>. As discussed herein, in some examples "inextensible" or "substantially inextensible" can be defined as expansion by no more than <NUM>%, no more than <NUM>%, or no more than <NUM>% in one or more direction.

<FIG> illustrates a cross-sectional view of a pneumatic actuator unit <NUM> including bellows <NUM> in accordance with another embodiment and <FIG> illustrates a side view of the pneumatic actuator unit <NUM> of <FIG> in an expanded configuration showing the cross section of <FIG>. As shown in <FIG>, the bellows <NUM> can comprise an internal first layer <NUM> that defines the bellows cavity <NUM> and can comprise an outer second layer <NUM> with a third layer <NUM> disposed between the first and second layers <NUM>, <NUM>. Throughout this description, the use of the term 'layer' to describe the construction of the bellows <NUM> should not be viewed as limiting to the design. The use of 'layer' can refer to a variety of designs including but not limited to: a planar material sheet, a wet film, a dry film, a rubberized coating, a co-molded structure, and the like.

In some examples, the internal first layer <NUM> can comprise a material that is impermeable or semi-permeable to the actuator fluid (e.g., air) and the external second layer <NUM> can comprise an inextensible material as discussed herein. For example, as discussed herein, an impermeable layer can refer to an impermeable or semi-permeable layer and an inextensible layer can refer to an inextensible or a practically inextensible layer.

In some embodiments comprising two or more layers, the internal layer <NUM> can be slightly oversized compared to an inextensible outer second layer <NUM> such that the internal forces can be transferred to the high-strength inextensible outer second layer <NUM>. One embodiment comprises a bellows <NUM> with an impermeable polyurethane polymer film inner first layer <NUM> and a woven nylon braid as the outer second layer <NUM>.

The bellows <NUM> can be constructed in various suitable ways in further embodiments, which can include a single layer design that is constructed of a material that provides both fluid impermeability and that is sufficiently inextensible. Other examples can include a complex bellows assembly that comprises multiple laminated layers that are fixed together into a single structure. In some examples, it can be necessary to limit the deflated stack height of the bellows <NUM> to maximize the range of motion of the leg actuator unit <NUM>. In such an example, it can be desirable to select a low-thickness fabric that meets the other performance needs of the bellows <NUM>.

In yet another embodiment, it can be desirable to reduce friction between the various layers of the bellows <NUM>. In one embodiment, this can include the integration of a third layer <NUM> that acts as an anti-abrasive and/or low friction intermediate layer between the first and second layers <NUM>, <NUM>. Other embodiments can reduce the friction between the first and second layers <NUM>, <NUM> in alternative or additional ways, including but not limited to the use of a wet lubricant, a dry lubricant, or multiple layers of low friction material. Accordingly, while the example of <FIG> illustrates an example of a bellows <NUM> comprising three layers <NUM>, <NUM>, <NUM>, further embodiments can include a bellows <NUM> having any suitable number of layers, including one, two, three, four, five, ten, fifteen, twenty five, and the like. Such one or more layers can be coupled together along adjoining faces in part or in whole, with some examples defining one or more cavity between layers. In such examples, material such as lubricants or other suitable fluids can be disposed in such cavities or such cavities can be effectively empty. Additionally, as described herein, one or more layers (e.g., the third layer <NUM>) need not be a sheet or planar material layer as shown in some examples and can instead comprise a layer defined by a fluid. For example, in some embodiments, the third layer <NUM> can be defined by a wet lubricant, a dry lubricant, or the like.

The inflated shape of the bellows <NUM> can be important to the operation of the bellows <NUM> and/or leg actuator unit <NUM> in some embodiments. For example, the inflated shape of the bellows <NUM> can be affected through the design of both an impermeable and inextensible portion of the bellows <NUM> (e.g., the first and second layer <NUM>, <NUM>). In various embodiments, it can be desirable to construct one or more of the layers <NUM>, <NUM>, <NUM> of the bellows <NUM> out of various two-dimensional panels that may not be intuitive in a deflated configuration.

In some embodiments, one or more impermeable layers can be disposed within the bellows cavity <NUM> and/or the bellows <NUM> can comprise a material that is capable of holding a desired fluid (e.g., a fluid impermeable first internal layer <NUM> as discussed herein). The bellows <NUM> can comprise a flexible, elastic, or deformable material that is operable to expand and contract when the bellows <NUM> are inflated or deflated as described herein. In some embodiments, the bellows <NUM> can be biased toward a deflated configuration such that the bellows <NUM> is elastic and tends to return to the deflated configuration when not inflated. Additionally, although bellows <NUM> shown herein are configured to expand and/or extend when inflated with fluid, in some embodiments, bellows <NUM> can be configured to shorten and/or retract when inflated with fluid in some examples. Also, the term 'bellows' as used herein should not be construed to be limiting in any way. For example the term 'bellows' as used herein should not be construed to require elements such as convolutions or other such features (although convoluted bellows <NUM> can be present in some embodiments). As discussed herein, bellows <NUM> can take on various suitable shapes, sizes, proportions and the like.

The bellows <NUM> can vary significantly across various embodiments, so the present examples should not be construed to be limiting. One preferred embodiment of a bellows <NUM> includes fabric-based pneumatic actuator configured such that it provides knee extension torque as discussed herein. Variants of this embodiment can exist to tailor the actuator to provide the desired performance characteristics of the actuators such as a fabric actuator that is not of a uniform cross-section. Other embodiments of can use an electromechanical actuator configured to provide flexion and extension torques at the knee instead of or in addition to a fluidic bellows <NUM>. Various embodiments can include but are not limited to designs that incorporate combinations of electromechanical, hydraulic, pneumatic, electro-magnetic, or electro-static for positive power or negative power assistance of extension or flexion of a lower extremity joint.

The actuator bellows <NUM> can also be located in a variety of locations as required by the specific design. One embodiment places the bellows <NUM> of a powered knee brace component located in line with the axis of the knee joint and positioned parallel to the joint itself. Various embodiments include but are not limited to, actuators configured in series with the joint, actuators configured anterior to the joint, and actuators configured to rest around the joint.

Various embodiments of the bellows <NUM> can include secondary features that augment the operation of the actuation. One such embodiment is the inclusion of user-adjustable mechanical hard end stops to limit the allowable range of motion to the bellows <NUM>. Various embodiments can include but are not limited to the following extension features: the inclusion of flexible end stops, the inclusion of an electromechanical brake, the inclusion of an electro-magnetic brake, the inclusion of a magnetic brake, the inclusion of a mechanical disengage switch to mechanically decouple the joint from the actuator, or the inclusion of a quick release to allow for quick changing of actuator components.

In various embodiments, the bellows <NUM> can comprise a bellows and/or bellows system as described in related <CIT>, which issued as patent <CIT>; as described in <CIT>; as described in <CIT>; or as described in <CIT>.

In some applications, the design of the fluidic actuator unit <NUM> can be adjusted to expand its capabilities. One example of such a modification can be made to tailor the torque profile of a rotary configuration of the fluidic actuator unit <NUM> such that the torque changes as a function of the angle of the joint structure <NUM>. To accomplish this in some examples, the cross-section of the bellows <NUM> can be manipulated to enforce a desired torque profile of the overall fluidic actuator unit <NUM>. In one embodiment, the diameter of the bellows <NUM> can be reduced at a longitudinal center of the bellows <NUM> to reduce the overall force capabilities at the full extension of the bellows <NUM>. In yet another embodiment, the cross-sectional areas of the bellows <NUM> can be modified to induce a desired buckling behavior such that the bellows <NUM> does not get into an undesirable configuration. In an example embodiment, the end configurations of the bellows <NUM> of a rotary configuration can have the area of the ends reduced slightly from the nominal diameter to provide for the end portions of the bellows <NUM> to buckle under loading until the actuator unit <NUM> extends beyond a predetermined joint angle, at which point the smaller diameter end portion of the bellows <NUM> would begin to inflate.

In other embodiments, this same capability can be developed by modifying the behavior of the constraining ribs <NUM>. As an example embodiment, using the same example bellows <NUM> as discussed in the previous embodiment, two constraining ribs <NUM> can fixed to such bellows <NUM> at evenly distributed locations along the length of the bellows <NUM>. In some examples, a goal of resisting a partially inflated buckling can be combated by allowing the bellows <NUM> to close in a controlled manner as the actuator unit <NUM> closes. The constraining ribs <NUM> can be allowed to get closer to the joint structure <NUM> but not closer to each other until they have bottomed out against the joint structure <NUM>. This can allow the center portion of the bellows <NUM> to remain in a fully inflated state which can be the strongest configuration of the bellows <NUM> in some examples.

In further embodiments, it can be desirable to optimize the fiber angle of the individual braid or weave of the bellows <NUM> in order to tailor specific performance characteristics of the bellows <NUM> (e.g., in an example where a bellows <NUM> includes inextensibility provided by a braided or woven fabric). In other embodiments, the geometry of the bellows <NUM> of the actuator unit <NUM> can be manipulated to allow the robotic exoskeleton system <NUM> to operate with different characteristics. Example methods for such modification can include but are not limited to the following: the use of smart materials on the bellows <NUM> to manipulate the mechanical behavior of the bellows <NUM> on command; or the mechanical modification of the geometry of the bellows <NUM> through means such as shortening the operating length and/or reducing the cross sectional area of the bellows <NUM>.

In further examples, a fluidic actuator unit <NUM> can comprise a single bellows <NUM> or a combination of multiple bellows <NUM>, each with its own composition, structure, and geometry. For example, some embodiments can include multiple bellows <NUM> disposed in parallel or concentrically on the same joint assembly <NUM> that can be engaged as needed. In one example embodiment, a joint assembly <NUM> can be configured to have two bellows <NUM> disposed in parallel directly next to each other. The system <NUM> can selectively choose to engage each bellows <NUM> as needed to allow for various amounts of force to be output by the same fluidic actuator unit <NUM> in a desirable mechanical configuration.

In further embodiments, a fluidic actuator unit <NUM> can include various suitable sensors to measure mechanical properties of the bellows <NUM> or other portions of the fluidic actuator unit <NUM> that can be used to directly or indirectly estimate pressure, force, or strain in the bellows <NUM> or other portions of the fluidic actuator unit <NUM>. In some examples, sensors located at the fluidic actuator unit <NUM> can be desirable due to the difficulty in some embodiments associated with the integration of certain sensors into a desirable mechanical configuration while others may be more suitable. Such sensors at the fluidic actuator unit <NUM> can be operably connected to the exoskeleton device <NUM> (see <FIG>) and the exoskeleton device <NUM> can use data from such sensors at the fluidic actuator unit <NUM> to control the exoskeleton system <NUM>.

Claim 1:
An exoskeleton system (<NUM>) comprising:
an actuator unit (<NUM>) configured to be coupled to a leg (<NUM>) of a user, the actuator unit (<NUM>) including:
an upper arm (<NUM>) and a lower arm (<NUM>) that are rotatably coupled via a joint (<NUM>), the joint (<NUM>) positioned at a knee (<NUM>) of the user with the upper arm (<NUM>) coupled about an upper leg portion (<NUM>) of the user above the knee and with the lower arm (<NUM>) coupled about a lower leg portion (<NUM>) of the user below the knee;
a fluidic actuator (<NUM>) that extends between the upper arm (<NUM>) and lower arm (<NUM>); and one or more fluid lines (<NUM>) coupled to the fluidic actuator (<NUM>) to introduce fluid to the fluidic actuator (<NUM>) that causes force to be applied to the upper arm (<NUM>) and lower arm (<NUM>);
wherein the lower arm (<NUM>) is coupled to the lower leg portion (<NUM>) below the knee (<NUM>) via at least one lower leg coupler (150C, 150D), with a coupling branch unit (<NUM>) extending from a distal end of the lower arm (<NUM>); and
wherein the coupling branch unit (<NUM>) comprises a first branch (<NUM>) that extends from a lateral position on the lower leg portion (<NUM>), curving upward and toward the anterior of the lower leg portion (<NUM>) to a first attachment (<NUM>) on the anterior of the lower leg portion below the knee (<NUM>), with the first attachment (<NUM>) joining a first one of the at least one lower leg coupler (150C) and the first branch (<NUM>) of the coupling branch unit (<NUM>).