Jointed mechanical devices

Patent metadata

Field	Value
Publication number	US-2016166409-A1
Application number	US-201615049826-A
Country	US
Kind code	A1
Filing date	Feb 22, 2016
Priority date	Aug 20, 2009
Publication date	Jun 16, 2016
Grant date	—

Abstract

A jointed mechanical device is provided. The device includes at least one element having a fixed end and a deflectable end. The device also includes at least one actuating structure having a first end coupled to at least the deflectable end of the element, where the actuating structure includes at least one elastic element in series with at least one non-elastic element. The device further includes at least one force actuator configured to apply an actuator force to a second end of the actuating structure. Additionally, the device includes a control system for adjusting an operation of the force actuator based at least one actuation input, an amount of the actuator force, and an amount of displacement generated by the force actuator.

First claim

1 . A device, comprising:
at least one element having a fixed end and a deflectable end; at least one actuating structure having a first end coupled to at least said deflectable end of said element, said actuating structure comprising at least one elastic element in series with at least one non-elastic element; at least one force actuator configured to apply an actuator force to a second end of said actuating structure; and a control system for adjusting an operation of said force actuator based at least one actuation input, an amount of said actuator force, and an amount of displacement generated by said force actuator.

2 . The device of claim 1 , wherein said control system further comprises a computing device for detecting when said element is in contact with an object and for operating said force actuator using one of a motion control mode and a force control mode based on said detecting, said detecting based on said amount of said actuator force and said amount of displacement.

3 . The device of claim 1 , further comprising at least one restorative element coupled to said element, said restorative element applying a restoring force opposing said actuator force.

4 . The device of claim 1 , wherein said non-elastic element comprises at least one cable, and wherein said force actuator comprises an electric motor and a pulley for actuating said cable.

5 . The device of claim 4 , wherein said force actuator further comprises a roller clutch between said electric motor and said pulley.

6 . The device of claim 4 , wherein said control system is configured for adjusting a velocity of said electric motor based on an amplitude of said actuation input.

7 . The device of claim 4 , wherein said control system is configured for determining said amount of actuator force based on an input current of said electric motor.

8 . The device of claim 4 , wherein said control system is configured for determining said amount of displacement based on a position measurement of said electric motor.

9 . The device of claim 1 , further comprising at least one sensor for generating said actuation input.

10 . The device of claim 9 , wherein said sensor comprises an electromyogram sensor.

11 . The device of claim 1 , wherein said element comprises a digit of a hand prosthesis.

12 .- 21 . canceled

22 . The method of claim 21 , wherein the compliance characteristics of the device are automatically calibrated by having the hand slowly close and open without grasping an object, while the motor current and position are monitored to create a position/force map in the absence of an object.

23 .- 26 . canceled

27 . A prosthetic device, comprising:
At least one member; a hand device coupled to the member, said hand device comprising a base, at least one force actuator, at least one digit pivotably coupled to said base, said digit comprising a plurality of phalangeal portions connected by a plurality of flexible joint portions, at least one actuating structure having a first end coupled to a distal end of said digit and a second end coupled to the at least one force actuator, said actuating structure comprising at least one elastic element in series with at least one non-elastic element, and at least one force actuator configured to apply an actuator force to a second end of said at least one actuating structure; and a control system for operating said force actuator, the control system comprising a processor and a computer-readable medium having stored thereon a plurality of instructions for causing the processor to perform the method comprising: receiving at least one control signal associated with said at least one force actuator; and initiating an operation of the at least one force actuator according to the at least one control signal, the operation comprising: determining, based on at least actuator signal from the at least one force actuator, an amount of said actuator force applied by said at least one force actuator to said second end of said at least one actuating structure and an amount of displacement of said actuating structure generated by said at least one force actuator, determining a relationship between said amount of actuator force and said amount of displacement based on stiffness values associated with said at least one actuating structure, and adjusting a mode of said operation of said at least one force actuator to one of a force control mode or a motion control mode based on said relationship between said amount of said actuator force and said amount of displacement.

28 . The prosthetic device of claim 27 , wherein said member is attachable to at least one residual limb.

29 . The prosthetic device of claim 28 , further comprising a plurality of electromyogram (EMG) sensors for generating said at least one control signal based on EMG signals from said residual limb.

30 .- 32 . canceled

33 . A non-transitory computer-readable medium, having stored thereon a plurality of instructions for a control system of a jointed mechanical device comprising a base, at least one force actuator disposed in the base, at least one deflectable element comprising a plurality of joints and pivotably extending from the base and having a distal end, and at least one actuating structure having a first end coupled to at least said distal end of said deflectable element and a second end coupled to the at least one force actuator, where the at least one force actuator is configured to apply an actuator force to the second end of said at least one actuating structure, where said at least one actuating structure comprises at least one elastic element in series with at least one non-elastic element, the plurality of instructions comprising code sections for performing the method comprising:
receiving at least one control signal for said at least one force actuator; and initiating an operation of the at least one force actuator according to the at least one control signal, the operation comprising: determining, based on at least one output signal from the at least one force actuator, an amount of said actuator force applied by said at least one force actuator to said second end of said at least one actuating structure and an amount of displacement of said at least one non-elastic element of said actuating structure, from a resting position, generated by said at least one force actuator, determining a relationship between said amount of actuator force and said amount of displacement based on stiffness values associated with said at least one actuating structure, and adjusting a mode of said operation of said at least one force actuator to one of a force control mode or a motion control mode based on said relationship between said amount of said actuator force and said amount of displacement.

34 . The method of claim 33 , wherein said adjusting further comprises:
detecting that said relationship corresponds to a pre-defined relationship for said deflectable element being in contact with an object; and upon detecting that said deflectable element is in said pre-defined relationship for said deflectable element being in contact with said object, selecting said mode of operation to be said force control mode.

35 . The method of claim 34 , wherein said force control mode comprises operating said at least one force actuator at a first velocity, and wherein said motion control mode comprises operating said at least one force actuator at a second velocity greater than said first velocity.

36 . The

Assignees

• Univ Vanderbilt

Inventors

• Goldfarb Michael
• Dalley Skyler
• Varol Huseyin Atakan
• Wiste Tuomas

Classifications

• A61F2/586 Primary

  Fingers · CPC title

• Y10T74/20329

  Joint between elements · CPC title

• Y10T74/20317

  including electric motor · CPC title

• A61F2002/7615

  Measuring means · CPC title

• A61F2002/701

  operated by electrically controlled means, e.g. solenoids or torque motors · CPC title