Grasp assist system
Inventors
Rogers, Jonathan M. • Peters, Benjamin J. • Laske, Evan • McBryan, Emily R.
Assignees
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Publication Number
US-10888487-B1
Publication Date
2021-01-12
Expiration Date
2038-04-05
Abstract
A grasp assist system includes a glove having a glove palm and fingers, with the glove worn on a user's hand. A sensor measures flexion of the glove fingers, and thus a change of position and/or attitude of the fingers is determined. Finger saddles at least partially surround a phalange of a respective one of the user's fingers. The system uses one or more tendon actuators to pull on flexible tendons. Each tendon connects to a respective finger saddle. A controller is in communication with the actuators and sensor(s). The glove may use feedback from optional contact sensors to adjust tension, and may have a built-in restorative force. In executing a control method, the controller selectively applies tension to the tendons in response to finger flexion, via the tendon actuators, at a level sufficient for moving the user's fingers when the user executes a hand maneuver.
Core Innovation
The invention disclosed is a glove-based grasp assist system and a related control method designed to selectively assist the natural hand and finger motion of a human user. The system employs a tendon drive system connected to a glove worn on the user's hand, which includes a plurality of glove fingers and a glove palm. The system measures finger flexion using sensors and applies tension to flexible tendons connected to finger saddles that partially surround the phalanges of the user's fingers. This mechanism assists the user in moving their fingers when performing hand maneuvers such as grasping or flexing.
The system addresses the problem of overcoming bending stiffness associated with specialized gloves used in aerospace, recreational diving, industrial work, or for rehabilitation of users with limited finger strength or dexterity. The glove actuators are selectively energized in response to the user's intentional finger motion, measured by flexion sensors, and potentially adjusted by feedback from contact sensors detecting interaction with external objects. The design allows the user's fingers to move freely when actuators are unpowered to preserve tactile feedback and dexterity but provides mechanized assistance when needed to augment finger motion.
An embodiment includes multiple layers in the glove such as a bladder layer configured for pressurization to provide a restorative force, a restraint layer to maintain shape and attach components, a hardware layer containing tendon actuators and optionally the controller, and an outer protective layer. The system also integrates control electronics configured to interpret sensor data and command actuators to apply appropriate tendon tension for grasp assistance, with operational modes allowing whole glove or individual finger assistance.
Claims Coverage
The patent includes two independent claims covering a grasp assist system with specific structural and functional features. Each claim defines inventive aspects of the system components and their operation.
Glove-based grasp assist system with tendon actuators and sensor integration
A glove worn on a user's hand with a flexion sensor measuring finger flexion signals. Multiple finger saddles are positioned to at least partially surround the user's finger phalanges. One or more tendon actuators drive flexible tendons connected to the finger saddles. Contact sensors detect contact during hand maneuvers. A controller communicates with actuators, flexion sensors, and contact sensors to selectively apply tension to tendons sufficient to move the user's fingers. The controller supports operating modes where full glove closure is triggered by any finger flexion or individual finger closure is triggered by corresponding finger flexion.
Glove structure featuring a pressurizable bladder, restraint, palm bar, and Bowden cable tendon system
A glove with multiple layers including a pressurizable bladder layer, restraint layer with an attached palm bar spanning the palm width, a hardware layer containing tendon actuators, and an outer layer. The flexion sensor includes string potentiometers along the glove fingers' posterior side. Flexible finger saddles partially surround each user's finger phalange. Tendons driven by actuators connect to finger saddles and run through conduits arranged in a Bowden cable system within a conduit manifold adjacent to the palm bar. A ratchet mechanism connected on the opposite side of the restraint layer adjusts glove fit by mechanically coupling to the palm bar ends. Pressurization of the bladder layer provides a built-in restorative force assisting tendons' return to a relaxed position. A controller communicates with sensors and actuators to apply tendon tension responsive to the flexion signals.
The independent claims define innovative features of a multi-layer glove with tendon-driven grasp assistance controlled by flexion and contact sensors, including structural details such as a pressurizable bladder for restorative force, a palm bar with ratchet adjustment, and a Bowden cable tendon system. The system provides selective tensioning via actuators coordinated through a controller implementing different operating modes.
Stated Advantages
Assists users in overcoming finger bending stiffness caused by specialized gloves in aerospace, industrial, recreational, or rehabilitative contexts.
Allows free finger movement and tactile feedback when actuators are unpowered, preserving dexterity for ordinary tasks.
Automatically applies selective mechanical assistance to finger motion in response to user-initiated hand maneuvers detected by flexion sensors.
Provides a built-in restorative force to return the hand to a relaxed position, reducing user effort.
Enables intuitive operation with control modes that allow either whole glove or individual finger assistance based on sensed finger flexion.
Adjusts tendon tension responsively based on detected contact with external objects to enhance grasp stability and control.
Documented Applications
Use as part of pressurized space gloves in aerospace extravehicular activity suits.
Use in manufacturing and construction work requiring dexterous hand assistance.
Use in medical rehabilitation for users with limited finger strength and dexterity.
Use in recreational applications such as scuba diving gloves.
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