WO2018165399A1

WO2018165399A1 - Devices for the support and balance of human exoskeletons

Info

Publication number: WO2018165399A1
Application number: PCT/US2018/021498
Authority: WO
Inventors: Kurt Amundson; Adam Preuss; Matt SWEENEY
Original assignee: Ekso Bionics, Inc.
Priority date: 2017-03-08
Filing date: 2018-03-08
Publication date: 2018-09-13

Abstract

An exoskeleton (501, 701) includes a body harness (505, 703, 704) to attach the exoskeleton (501, 701) to a person (500, 700). In one embodiment, the exoskeleton (501, 701) also includes a tool-holding arm (502) to support a tool (519) and a leg (509) to transfer the weight of the tool (519) and the tool-holding arm (502) to a support surface (518). The leg (509) is non-anthropomorphic. In another embodiment, the exoskeleton (501, 701) further includes an overhead gantry (712), which slides along an overhead guide and support (713), and an elastic support (708) connected to the overhead gantry (712). The elastic support (708) partially suspends the person (500, 700) from the overhead gantry (712) through the exoskeleton (501, 701).

Description

DEVICES FOR THE SUPPORT AND BALANCE OF HUMAN EXOSKELETONS

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No.

62/468,492, which was filed on March 8, 2017 and titled "Devices for the Support and Balance of Human Exoskeletons". The entire content of this application is incorporated herein by reference.

FIELD OF THE INVENTION

[0002] The present invention relates to a device and method that augment a wearer's carrying capacity and strength, increasing performance and aiding in the prevention of injury during the execution of certain load-bearing or strength-requiring tasks. More particularly, the present invention relates to a device suitable for use by a person engaging in heavy tool use or weight-bearing tasks, incorporating a set of artificial limbs, joints, and related control systems that potentiate improved function of the person's appendages for activities including, but not limited to, greater strength and endurance in the wearers legs, allowing for more weight to be carried by the wearer while walking.

BACKGROUND OF THE INVENTION

[0003] Wearable exoskeletons have been designed for medical, commercial, and military applications. Medical exoskeletons are designed to help restore a user's mobility. Commercial and military exoskeletons help prevent injury and augment the user's strength. Commercial and military exoskeletons are used to alleviate loads supported by workers or soldiers during strenuous activities, thereby preventing injuries and increasing their stamina and strength.

[0004] Exoskeletons designed for use by able-bodied wearers often act to improve the wearer's stamina by transferring the weight of a tool or load through the exoskeleton structure and into the ground, thereby decreasing the weight borne by the wearer. In some cases, tool- holding exoskeletons are outfitted with a non-anthropomorphic tool-holding arm that supports the weight of the tool, reducing user fatigue by providing tool-holding assistance. The tool- holding arm transfers the vertical force required to hold the tool through the exoskeleton- supported tool-holding arm rather than through the user's arms and body. In other cases, the exoskeleton structure is generally anthropomorphic and acts in tandem with the user's body to support some or all of the tool weight by supporting the positioning of the wearer's arms, and then transferring that tool weight around the body of the wearer and into the ground. Weight- bearing exoskeletons transfer the weight of the exoskeleton load through the legs of the exoskeleton rather than through the user's legs. In some cases, weight-bearing exoskeletons are designed to carry a specific load, such as a heavy backpack. In other cases, military weight- bearing exoskeletons support the weight of armor. Commercial and military exoskeletons may have actuated joints that augment the strength of the exoskeleton user, with these actuated joints being controlled by the exoskeleton control system, and with the exoskeleton user using any of a plurality of possible input means to command an exoskeleton control system.

[0005] In powered exoskeletons, exoskeleton control systems prescribe and control trajectories in the joints of an exoskeleton, resulting in the movement of the structure of the exoskeleton and, in some cases, the positioning of a tool supported by the exoskeleton. These control trajectories can be prescribed as position-based, force-based, or a combination of both methodologies, such as those seen in impedance controllers. Position-based control systems can be modified directly through modification of the prescribed positions. Force-based control systems can also be modified directly through modification of the prescribed force profiles. As exoskeleton users and exoskeleton tools may vary in proportion, variously adjusted or customized powered exoskeletons will fit each user somewhat differently. The exoskeleton control system should take into account these differences in exoskeleton user proportion, exoskeleton configuration/customization, exoskeleton user fit, and tool support, resulting in changes to prescribed exoskeleton trajectories. The exoskeleton user may control changes in exoskeleton trajectories through communication with the exoskeleton control system through a variety of means, including but not limited to body pressure sensors, joysticks, touchpads, gestural sensors, voice sensors, or sensors that directly detect nervous system activity.

[0006] In unpowered tool-holding exoskeletons, the exoskeleton wearer provides the force to move the exoskeleton structure and any affixed tools, with the exoskeleton aiding the wearer by supporting the weight of tools in certain positions, aiding in certain tool or exoskeleton movements, and transferring the weight of tools around the body of the wearer, through the leg structures of the exoskeleton, and into the support surface.

[0007] In both powered and unpowered tool-holding exoskeletons, the design of the exoskeleton structure, and in particular the structure of the lower portion of the exoskeleton, plays an important role in transferring the weight of the exoskeleton load, including both tool weight and the tool-supporting arm weight, around the body of the wearer and into the support surface. In addition to simply supporting this weight, the design of the lower structure of an exoskeleton determines how well this weight can be balanced - with the balance affecting the usefulness of the exoskeleton and/or tool to the user. For example, consider an exoskeleton with a hip-mounted tool holding arm. As the tool and tool-holding arm are extended farther from the body of the exoskeleton wearer, the tool holding arm will act as a lever, and the weight of the tool will result in an increasing torque being exerted on the exoskeleton hip. To counteract this hip torque, the exoskeleton (and/or the wearer) must expend energy, and as the weight of the tool is extended away from the exoskeleton this results in a less-balanced exoskeleton that is more likely to fall over. Issues of balance and undesired joint torque can be addressed by making exoskeleton frames and joints heavier and more rigid, or adding weighted counterbalance arms that extend behind the exoskeleton (opposite the tool-holding arm they balance). However, these solutions come at the cost of making exoskeletons increasingly less mobile and/or less agile, and mobility and flexibility are key functions of tool-holding exoskeletons (relative to, for example, bench/floor mounted tools or tracked vehicles). Thus, the design of exoskeleton support structures, and in particular the lower structures including hip, leg, ankle, and foot structures, as well as the interconnecting joints, should take into account the tradeoff between load

support/balance with exoskeleton mobility/maneuverability. Depending on the application of the tool-holding exoskeleton, the relative importance of different exoskeleton characteristics may vary.

[0008] There exists a need to provide a range of devices for the support of tool-holding human exoskeletons. There further exists a need to provide devices for improving the balance of tool-holding exoskeletons. There further exists a need to provide devices for improving the mobility and maneuverability of tool-holding human exoskeletons. SUMMARY OF THE INVENTION

[0009] Disclosed herein are novel devices that allow for improvements in human exoskeleton balance, maneuverability, and tool/load capacity for both powered and unpowered exoskeletons. These enhancements to exoskeleton balance, maneuverability, and tool/load capacity will allow wearers of human exoskeletons to more effectively work with tools and move the exoskeleton and tool/load in complex environments.

[0010] It is an object of the present invention to provide a tool support device that bears the weight of an exoskeleton-affixed tool while the exoskeleton and wearer are in a stationary position.

[0011] It is an additional object of the present invention to provide a device that reduces the force required for an exoskeleton wearer to stand, or for an exoskeleton wearer to stand while lifting objects.

[0012] In accordance with certain aspects of the invention, a non-anthropomorphic support structure is affixed between the exoskeleton wearer and the tool-supporting arm, allowing the support structure to bear the weight of the tool-supporting arm and tool while the exoskeleton and wearer are stationary.

[0013] In accordance with another aspect of the invention, an exoskeleton is attached to an overhead structure with elastic members such that, as the exoskeleton wearer and the exoskeleton squat or bend, the elastic members are stretched, resulting in decreased energy requirements on the part of the exoskeleton and wearer upon rising.

[0014] In accordance with preferred embodiments, the above objects are achieved by providing an exoskeleton including a body harness configured to attach the exoskeleton to a person. The exoskeleton also includes a vertical support directly connected to the body harness. The vertical support is configured to transfer a weight of at least a portion of the exoskeleton to a support surface. The vertical support is non-anthropomorphic. In one embodiment, the exoskeleton further includes a tool-holding arm configured to support a tool, and the vertical support is a leg configured to transfer a weight of the tool and the tool-holding arm to the support surface. In another embodiment, the exoskeleton further includes an overhead gantry configured to slide along an overhead guide and support, and the vertical support is an elastic support connected to the overhead gantry. The elastic support is configured to partially suspend the person from the overhead gantry through the exoskeleton.

[0015] Additional objects, features and advantages of the invention will become more readily apparent from the following detailed description of preferred embodiments thereof when taken in conjunction with the drawings wherein like reference numerals refer to common parts in the several views.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a side view of a worker wearing an exoskeleton equipped with a hip- mounted non-anthropomorphic tool-holding arm and tool.

[0017] Figure 2 is a side view of a worker standing and holding a tool while affixed to a non-anthropomorphic exoskeleton equipped with a non-anthropomorphic leg support device, representing the first embodiment of this invention.

[0018] Figure 3 is a side view of a worker standing and holding a tool while affixed to a non-anthropomorphic exoskeleton equipped with a non-anthropomorphic leg support device, representing a mechanical variant of the first embodiment of this invention.

[0019] Figure 4 is a side view of a worker walking while wearing an exoskeleton, with the exoskeleton and worker being partially suspended from a ceiling-mounted, movable gantry system, representing the second embodiment of this invention.

DETAILED DESCRIPTION OF THE INVENTION

[0020] Detailed embodiments of the present invention are disclosed herein. However, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale, and some features may be exaggerated or minimized to show details of particular components.

Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to employ the present invention. [0021] Figure 1 shows a person 100 wearing a tool-holding exoskeleton 101, with exoskeleton 101 being attached to person 100 by a body harness or strapping 102. A hip structure 108 of exoskeleton 101 is connected to a tool-holding arm 105 at a hip coupling 107, with tool-holding arm 105 connecting to and supporting the weight of a tool 103 at a tool coupling 106. Tool-holding arm 105 is comprised of an upper tool arm link 109 and lower tool arm link 1 10, with tool arm links 109 and 1 10 being flexibly connected such that they are movable relative to one another to allow person 100 to use his arms 104 to change the position of tool 103 relative to exoskeleton 101 and person 100. The weight of tool 103 is transferred through tool coupling 106 to upper tool arm link 109, then to lower tool arm link 1 10, then to hip coupling 107 and into hip structure 108 of exoskeleton 101. Hip structure 108 is rotatably connected to a thigh link 1 13 at a hip joint 1 12, with thigh link 113 being rotatably connected to a shank link 1 15 at a knee joint 114. Shank link 115 is rotatably connected to a foot structure 117 at an ankle joint 1 16. This connectivity allows the weight of exoskeleton 101, tool 103, and tool-holding arm 105 to be transferred around legs 1 1 1 of person 100, through hip structure 108, through thigh link 113 and shank link 1 15, into foot structure 1 17 and ultimately to a support surface 1 18. Person 100 can also walk while wearing exoskeleton 101, with exoskeleton 101 continuing to support the weight of tool 103 and tool-holding arm 105.

[0022] A first embodiment of the present invention is shown in Figure 2. A person 500 is wearing an exoskeleton 501, with exoskeleton 501 having a brace structure 503. Brace structure 503 is attached to person 501 by a body harness or strapping 505. A tool-holding arm 502 supports a tool 519, with tool-holding arm 502 being connected to an exoskeleton hip 508. Exoskeleton hip 508 is supported by a vertical support or exoskeleton leg 509, with exoskeleton leg 509 being in contact with a support surface 518 through a surface-interacting tip 517.

Exoskeleton leg 509 is directly connected to strapping 505. By "directly connected", it is meant that exoskeleton leg 509 is not connected to strapping 505 through person 500. Person 500 has legs 515 and feet 516 that are also in contact with support surface 518. The weight of tool 519 and tool-supporting arm 502 is transferred through exoskeleton leg 509 and surface-interacting tip 517 to support surface 518, with the resulting torque from the distance of tool 519 from exoskeleton leg 509 being counteracted by the mass and position of person 500 opposite exoskeleton leg 509 from tool 519. In some embodiments, leg 509 is telescoping or collapsible, allowing easier movement of person 500 and exoskeleton 501. In some embodiments, there is a lockable joint brace structure 503 and exoskeleton hip 508, allowing person 500 to lift and rotate exoskeleton 501 in the sagittal plane to facilitate walking.

[0023] In one embodiment, shown in Figure 3, rigid exoskeleton leg 509 is replaced with a jammed leg 529, with jammed leg 529 being a flexible tube structure jammed with granular material such as sand or rice. This jamming of granular material is sufficiently tight to allow jammed leg 529 to support compressive loads in stance but not so tight as to prevent jammed leg 529 from being flexible while exoskeleton 501 and wearer 500 are moving. This jammed structure acts as an undefined joint (or rather acts as many/infinite joints).

[0024] As an example of the first embodiment of this invention, consider a worker using a tool-supporting exoskeleton to support a heavy hand-held spot welding gun in a manufacturing environment. The worker spends extended periods of time in one location using the spot welder, and only rarely needs to reposition the exoskeleton and spot welding gun. Through use of the device of this invention, the worker can support the weight of the spot welding gun in specific work stations, allowing greater stamina and reducing risk of injury, without requiring an expensive, heavy, or complicated exoskeleton to gain these benefits.

[0025] A second embodiment of the present invention is shown in Figure 4. A person

700 is wearing an exoskeleton 701 , with exoskeleton 701 being attached to person 700 by a body harness or strapping 703, 704. Strapping 703, 704 includes a back structure 707, with back structure 707 being connected to vertical elastic supports 708. Elastic supports 708 are directly connected to strapping 703, 704. Again, by "directly connected", it is meant that elastic supports 708 are not connected to strapping 703, 704 through person 700. Elastic supports 708 are connected to an overhead gantry 712, with overhead gantry 712 sliding along an overhead guide and support 713. One portion of the weight of person 700 and exoskeleton 701 is transferred through a leg 714 to a foot 710 and to support surface 718. A second portion of the weight of person 700 and exoskeleton 701 is transferred to overhead guide and support 713 through elastic supports 708 and then to the support surface to which overhead guide and support 713 is attached (not shown). The relative portion of weight transferred to elastic supports 708 and to overhead guide and support 713 depends on both the extent of stretch that elastic supports 708 are subject to, with this depending on the extent to which person 700 is standing or squatting, and the spring force of elastic supports 708. As person 700 is only partially suspended by overhead gantry 712, person 700 is able to walk, with overhead gantry 712 sliding along overhead guide and support 713. If person 700 squats, using the force of gravity to stretch elastic supports 708, it will be easier for person 700 to stand as the stretch of elastic support 708 is reduced, resulting in less energy usage for person 700 in repeated standing and squatting motions. If a person lifting objects from a surface stands, the force to stand up is shown in Equation 1. If this person were wearing the device of the second embodiment of this invention, the force required to stand is shown in Equation 2.

[0026] Equation 1 : Force to stand up = (Mass of person + Mass of load) * Gravity

[0027] Equation 2: Force to stand up = (Mass of person + Mass of load) * Gravity -

Lifting spring force

[0028] In some embodiments, elastic supports 708 are attached differently to exoskeleton

701 or wearer 700, such as one or more attachment points at the back, shoulder, or waist. In some embodiments, elastic supports 708 are quickly detachable from exoskeleton 701 by means of a mechanical device such a carabiner, hook, or quick link.

[0029] As an example of the second embodiment of this invention, consider a worker loading or unloading objects such as boxes, with the lifting of these objects requiring the worker to squat and lift the object, and the worker then moving these objects a short distance. Through use of the device of the second embodiment of this invention, the force required for the worker to lift each object would be reduced by the spring force from the elastic supports, allowing the worker to lift heavier objects, or allowing for improved worker stamina and a reduced risk of injury.

[0030] In some embodiments, the various embodiments of this invention can be combined. For example, exoskeleton 701 can include tool-holding arm 502, exoskeleton leg 509 and the other related structure from the first embodiment.

[0031] In all embodiments, the exoskeleton can provide power to a power tool - even if the exoskeleton itself is passive and has no power requirements. In powered (actuated) exoskeleton embodiments, the power systems of the tool and exoskeleton can be shared, eliminating the need for disparate energy storage devices.

[0032] In all embodiments, various sensors, including but not limited to pressure sensors or toggle switches, can be in communication with the exoskeleton control system, allowing the exoskeleton to respond to the user. [0033] In all embodiments, the exoskeleton control system can be in communication with any tool electronics or tool control systems, such as power and time settings on a spot welding gun or the remaining consumables for a tool, such as nails for a nail gun.

[0034] Based on the above, it should be readily apparent that the present invention provides devices for supporting, improving the balance of, and improving the mobility and maneuverability of tool-holding human exoskeletons. While certain preferred embodiments of the present invention have been set forth, it should be understood that various changes or modifications could be made without departing from the spirit of the present invention. In general, the invention is only intended to be limited by the scope of the following claims.

Claims

1. An exoskeleton comprising:

a body harness configured to attach the exoskeleton to a person; and

a vertical support directly connected to the body harness and configured to transfer a weight of at least a portion of the exoskeleton to a support surface, wherein the vertical support is non-anthropomorphic .

2. The exoskeleton of claim 1, further comprising a tool-holding arm configured to support a tool, wherein the vertical support is a leg configured to transfer a weight of the tool and the tool-holding arm to the support surface.

3. The exoskeleton of claim 2, wherein the exoskeleton is configured such that, in use, the leg is positioned between the person and the tool.

4. The exoskeleton of claim 2, wherein the leg is configured to contact the support surface.

5. The exoskeleton of claim 2, wherein the leg includes a surface-interacting tip configured to contact the support surface.

6. The exoskeleton of claim 2, wherein the leg is rigid.

7. The exoskeleton of claim 2, wherein the leg includes a flexible tube structure jammed with a granular material.

8. The exoskeleton of claim 7, wherein the leg is configured to support a compressive load when the exoskeleton is in stance and to flex when the exoskeleton is moving.

9. The exoskeleton of claim 2, further comprising a hip, wherein the tool-holding arm is connected to the hip, and the leg is configured to support the hip.

10. The exoskeleton of claim 1 , further comprising an overhead gantry configured to slide along an overhead guide and support, wherein the vertical support is an elastic support connected to the overhead gantry, and the elastic support is configured to partially suspend the person from the overhead gantry through the exoskeleton.

11. The exoskeleton of claim 10, wherein the exoskeleton is configured such that a first portion of the weight of the person and exoskeleton is transferred to a second support surface through a leg of the person and a second portion of the weight of the person and exoskeleton is transferred to the overhead guide and support through the elastic support.

12. The exoskeleton of claim 10, wherein the elastic support is configured to stretch as the person moves from a standing position to a squatting position and retract as the person moves from the squatting position to the standing position, thereby reducing the energy required for the person to move from the squatting position to the standing position.

13. The exoskeleton of claim 10, wherein the body harness includes a back structure connected to the elastic support.

14. The exoskeleton of claim 10, further comprising a second elastic support connected to the overhead gantry, wherein the second elastic support is configured to partially suspend the person from the overhead gantry through the exoskeleton.

15. A method of supporting an exoskeleton including a body harness configured to attach the exoskeleton to a person, the method comprising:

transferring a weight of at least a portion of the exoskeleton to a support surface with a vertical support directly connected to the body harness, wherein the vertical support is non- anthropomorphic .

16. The method of claim 15, wherein the exoskeleton further includes a tool-holding arm configured to support a tool, and the vertical support is a leg, the method further comprising transferring a weight of the tool and the tool-holding arm to the support surface with the leg.

17. The method of claim 16, further comprising positioning the leg between the person and the tool during use of the exoskeleton.

18. The method of claim 15, wherein the exoskeleton further includes an overhead gantry configured to slide along an overhead guide and support, and the vertical support is an elastic support connected to the overhead gantry, the method further comprising partially suspending the person from the overhead gantry through the exoskeleton with the elastic support.

19. The method of claim 18, further comprising:

transferring a first portion of the weight of the person and exoskeleton to a second support surface through a leg of the person; and

transferring a second portion of the weight of the person and exoskeleton to the overhead guide and support through the elastic support.

20. The method of claim 18, further comprising causing the elastic support to stretch as the person moves from a standing position to a squatting position and retract as the person moves from the squatting position to the standing position, thereby reducing the energy required for the person to move from the squatting position to the standing position.